linux-stable/fs/btrfs/qgroup.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2011 STRATO. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/rbtree.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/btrfs.h>
#include <linux/sizes.h>
#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "locking.h"
#include "ulist.h"
#include "backref.h"
#include "extent_io.h"
Btrfs: rework qgroup accounting Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-05-14 00:30:47 +00:00
#include "qgroup.h"
#include "block-group.h"
/* TODO XXX FIXME
* - subvol delete -> delete when ref goes to 0? delete limits also?
* - reorganize keys
* - compressed
* - sync
* - copy also limits on subvol creation
* - limit
* - caches for ulists
* - performance benchmarks
* - check all ioctl parameters
*/
/*
* Helpers to access qgroup reservation
*
* Callers should ensure the lock context and type are valid
*/
static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
{
u64 ret = 0;
int i;
for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
ret += qgroup->rsv.values[i];
return ret;
}
#ifdef CONFIG_BTRFS_DEBUG
static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
{
if (type == BTRFS_QGROUP_RSV_DATA)
return "data";
if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
return "meta_pertrans";
if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
return "meta_prealloc";
return NULL;
}
#endif
static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
struct btrfs_qgroup *qgroup, u64 num_bytes,
enum btrfs_qgroup_rsv_type type)
{
trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
qgroup->rsv.values[type] += num_bytes;
}
static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
struct btrfs_qgroup *qgroup, u64 num_bytes,
enum btrfs_qgroup_rsv_type type)
{
trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
if (qgroup->rsv.values[type] >= num_bytes) {
qgroup->rsv.values[type] -= num_bytes;
return;
}
#ifdef CONFIG_BTRFS_DEBUG
WARN_RATELIMIT(1,
"qgroup %llu %s reserved space underflow, have %llu to free %llu",
qgroup->qgroupid, qgroup_rsv_type_str(type),
qgroup->rsv.values[type], num_bytes);
#endif
qgroup->rsv.values[type] = 0;
}
static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
struct btrfs_qgroup *dest,
struct btrfs_qgroup *src)
{
int i;
for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
}
static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
struct btrfs_qgroup *dest,
struct btrfs_qgroup *src)
{
int i;
for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
}
static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
int mod)
{
if (qg->old_refcnt < seq)
qg->old_refcnt = seq;
qg->old_refcnt += mod;
}
static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
int mod)
{
if (qg->new_refcnt < seq)
qg->new_refcnt = seq;
qg->new_refcnt += mod;
}
static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
{
if (qg->old_refcnt < seq)
return 0;
return qg->old_refcnt - seq;
}
static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
{
if (qg->new_refcnt < seq)
return 0;
return qg->new_refcnt - seq;
}
/*
* glue structure to represent the relations between qgroups.
*/
struct btrfs_qgroup_list {
struct list_head next_group;
struct list_head next_member;
struct btrfs_qgroup *group;
struct btrfs_qgroup *member;
};
static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
{
return (u64)(uintptr_t)qg;
}
static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
{
return (struct btrfs_qgroup *)(uintptr_t)n->aux;
}
Btrfs: rework qgroup accounting Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-05-14 00:30:47 +00:00
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
static int
qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
int init_flags);
static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
/* must be called with qgroup_ioctl_lock held */
static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
u64 qgroupid)
{
struct rb_node *n = fs_info->qgroup_tree.rb_node;
struct btrfs_qgroup *qgroup;
while (n) {
qgroup = rb_entry(n, struct btrfs_qgroup, node);
if (qgroup->qgroupid < qgroupid)
n = n->rb_left;
else if (qgroup->qgroupid > qgroupid)
n = n->rb_right;
else
return qgroup;
}
return NULL;
}
/* must be called with qgroup_lock held */
static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
u64 qgroupid)
{
struct rb_node **p = &fs_info->qgroup_tree.rb_node;
struct rb_node *parent = NULL;
struct btrfs_qgroup *qgroup;
while (*p) {
parent = *p;
qgroup = rb_entry(parent, struct btrfs_qgroup, node);
if (qgroup->qgroupid < qgroupid)
p = &(*p)->rb_left;
else if (qgroup->qgroupid > qgroupid)
p = &(*p)->rb_right;
else
return qgroup;
}
qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
if (!qgroup)
return ERR_PTR(-ENOMEM);
qgroup->qgroupid = qgroupid;
INIT_LIST_HEAD(&qgroup->groups);
INIT_LIST_HEAD(&qgroup->members);
INIT_LIST_HEAD(&qgroup->dirty);
rb_link_node(&qgroup->node, parent, p);
rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
return qgroup;
}
static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
{
struct btrfs_qgroup_list *list;
list_del(&qgroup->dirty);
while (!list_empty(&qgroup->groups)) {
list = list_first_entry(&qgroup->groups,
struct btrfs_qgroup_list, next_group);
list_del(&list->next_group);
list_del(&list->next_member);
kfree(list);
}
while (!list_empty(&qgroup->members)) {
list = list_first_entry(&qgroup->members,
struct btrfs_qgroup_list, next_member);
list_del(&list->next_group);
list_del(&list->next_member);
kfree(list);
}
kfree(qgroup);
}
/* must be called with qgroup_lock held */
static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
{
struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
if (!qgroup)
return -ENOENT;
rb_erase(&qgroup->node, &fs_info->qgroup_tree);
__del_qgroup_rb(qgroup);
return 0;
}
/* must be called with qgroup_lock held */
static int add_relation_rb(struct btrfs_fs_info *fs_info,
u64 memberid, u64 parentid)
{
struct btrfs_qgroup *member;
struct btrfs_qgroup *parent;
struct btrfs_qgroup_list *list;
member = find_qgroup_rb(fs_info, memberid);
parent = find_qgroup_rb(fs_info, parentid);
if (!member || !parent)
return -ENOENT;
list = kzalloc(sizeof(*list), GFP_ATOMIC);
if (!list)
return -ENOMEM;
list->group = parent;
list->member = member;
list_add_tail(&list->next_group, &member->groups);
list_add_tail(&list->next_member, &parent->members);
return 0;
}
/* must be called with qgroup_lock held */
static int del_relation_rb(struct btrfs_fs_info *fs_info,
u64 memberid, u64 parentid)
{
struct btrfs_qgroup *member;
struct btrfs_qgroup *parent;
struct btrfs_qgroup_list *list;
member = find_qgroup_rb(fs_info, memberid);
parent = find_qgroup_rb(fs_info, parentid);
if (!member || !parent)
return -ENOENT;
list_for_each_entry(list, &member->groups, next_group) {
if (list->group == parent) {
list_del(&list->next_group);
list_del(&list->next_member);
kfree(list);
return 0;
}
}
return -ENOENT;
}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
u64 rfer, u64 excl)
{
struct btrfs_qgroup *qgroup;
qgroup = find_qgroup_rb(fs_info, qgroupid);
if (!qgroup)
return -EINVAL;
if (qgroup->rfer != rfer || qgroup->excl != excl)
return -EINVAL;
return 0;
}
#endif
/*
* The full config is read in one go, only called from open_ctree()
* It doesn't use any locking, as at this point we're still single-threaded
*/
int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
{
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_root *quota_root = fs_info->quota_root;
struct btrfs_path *path = NULL;
struct extent_buffer *l;
int slot;
int ret = 0;
u64 flags = 0;
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
u64 rescan_progress = 0;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
return 0;
fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
if (!fs_info->qgroup_ulist) {
ret = -ENOMEM;
goto out;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
/* default this to quota off, in case no status key is found */
fs_info->qgroup_flags = 0;
/*
* pass 1: read status, all qgroup infos and limits
*/
key.objectid = 0;
key.type = 0;
key.offset = 0;
ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
if (ret)
goto out;
while (1) {
struct btrfs_qgroup *qgroup;
slot = path->slots[0];
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
struct btrfs_qgroup_status_item *ptr;
ptr = btrfs_item_ptr(l, slot,
struct btrfs_qgroup_status_item);
if (btrfs_qgroup_status_version(l, ptr) !=
BTRFS_QGROUP_STATUS_VERSION) {
btrfs_err(fs_info,
"old qgroup version, quota disabled");
goto out;
}
if (btrfs_qgroup_status_generation(l, ptr) !=
fs_info->generation) {
flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
btrfs_err(fs_info,
"qgroup generation mismatch, marked as inconsistent");
}
fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
ptr);
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
goto next1;
}
if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
found_key.type != BTRFS_QGROUP_LIMIT_KEY)
goto next1;
qgroup = find_qgroup_rb(fs_info, found_key.offset);
if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
(!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
btrfs_err(fs_info, "inconsistent qgroup config");
flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
}
if (!qgroup) {
qgroup = add_qgroup_rb(fs_info, found_key.offset);
if (IS_ERR(qgroup)) {
ret = PTR_ERR(qgroup);
goto out;
}
}
switch (found_key.type) {
case BTRFS_QGROUP_INFO_KEY: {
struct btrfs_qgroup_info_item *ptr;
ptr = btrfs_item_ptr(l, slot,
struct btrfs_qgroup_info_item);
qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
/* generation currently unused */
break;
}
case BTRFS_QGROUP_LIMIT_KEY: {
struct btrfs_qgroup_limit_item *ptr;
ptr = btrfs_item_ptr(l, slot,
struct btrfs_qgroup_limit_item);
qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
break;
}
}
next1:
ret = btrfs_next_item(quota_root, path);
if (ret < 0)
goto out;
if (ret)
break;
}
btrfs_release_path(path);
/*
* pass 2: read all qgroup relations
*/
key.objectid = 0;
key.type = BTRFS_QGROUP_RELATION_KEY;
key.offset = 0;
ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
if (ret)
goto out;
while (1) {
slot = path->slots[0];
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
goto next2;
if (found_key.objectid > found_key.offset) {
/* parent <- member, not needed to build config */
/* FIXME should we omit the key completely? */
goto next2;
}
ret = add_relation_rb(fs_info, found_key.objectid,
found_key.offset);
if (ret == -ENOENT) {
btrfs_warn(fs_info,
"orphan qgroup relation 0x%llx->0x%llx",
found_key.objectid, found_key.offset);
ret = 0; /* ignore the error */
}
if (ret)
goto out;
next2:
ret = btrfs_next_item(quota_root, path);
if (ret < 0)
goto out;
if (ret)
break;
}
out:
fs_info->qgroup_flags |= flags;
if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
ret >= 0)
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
btrfs_free_path(path);
if (ret < 0) {
ulist_free(fs_info->qgroup_ulist);
fs_info->qgroup_ulist = NULL;
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
}
return ret < 0 ? ret : 0;
}
/*
* This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
* first two are in single-threaded paths.And for the third one, we have set
* quota_root to be null with qgroup_lock held before, so it is safe to clean
* up the in-memory structures without qgroup_lock held.
*/
void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
{
struct rb_node *n;
struct btrfs_qgroup *qgroup;
while ((n = rb_first(&fs_info->qgroup_tree))) {
qgroup = rb_entry(n, struct btrfs_qgroup, node);
rb_erase(n, &fs_info->qgroup_tree);
__del_qgroup_rb(qgroup);
}
/*
* We call btrfs_free_qgroup_config() when unmounting
* filesystem and disabling quota, so we set qgroup_ulist
* to be null here to avoid double free.
*/
ulist_free(fs_info->qgroup_ulist);
fs_info->qgroup_ulist = NULL;
}
static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
u64 dst)
{
int ret;
struct btrfs_root *quota_root = trans->fs_info->quota_root;
struct btrfs_path *path;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = src;
key.type = BTRFS_QGROUP_RELATION_KEY;
key.offset = dst;
ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
return ret;
}
static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
u64 dst)
{
int ret;
struct btrfs_root *quota_root = trans->fs_info->quota_root;
struct btrfs_path *path;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = src;
key.type = BTRFS_QGROUP_RELATION_KEY;
key.offset = dst;
ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, quota_root, path);
out:
btrfs_free_path(path);
return ret;
}
static int add_qgroup_item(struct btrfs_trans_handle *trans,
struct btrfs_root *quota_root, u64 qgroupid)
{
int ret;
struct btrfs_path *path;
struct btrfs_qgroup_info_item *qgroup_info;
struct btrfs_qgroup_limit_item *qgroup_limit;
struct extent_buffer *leaf;
struct btrfs_key key;
if (btrfs_is_testing(quota_root->fs_info))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = 0;
key.type = BTRFS_QGROUP_INFO_KEY;
key.offset = qgroupid;
/*
* Avoid a transaction abort by catching -EEXIST here. In that
* case, we proceed by re-initializing the existing structure
* on disk.
*/
ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
sizeof(*qgroup_info));
if (ret && ret != -EEXIST)
goto out;
leaf = path->nodes[0];
qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_qgroup_info_item);
btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
key.type = BTRFS_QGROUP_LIMIT_KEY;
ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
sizeof(*qgroup_limit));
if (ret && ret != -EEXIST)
goto out;
leaf = path->nodes[0];
qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_qgroup_limit_item);
btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
btrfs_mark_buffer_dirty(leaf);
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
{
int ret;
struct btrfs_root *quota_root = trans->fs_info->quota_root;
struct btrfs_path *path;
struct btrfs_key key;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = 0;
key.type = BTRFS_QGROUP_INFO_KEY;
key.offset = qgroupid;
ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, quota_root, path);
if (ret)
goto out;
btrfs_release_path(path);
key.type = BTRFS_QGROUP_LIMIT_KEY;
ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, quota_root, path);
out:
btrfs_free_path(path);
return ret;
}
static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
struct btrfs_qgroup *qgroup)
{
struct btrfs_root *quota_root = trans->fs_info->quota_root;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_qgroup_limit_item *qgroup_limit;
int ret;
int slot;
key.objectid = 0;
key.type = BTRFS_QGROUP_LIMIT_KEY;
key.offset = qgroup->qgroupid;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
if (ret > 0)
ret = -ENOENT;
if (ret)
goto out;
l = path->nodes[0];
slot = path->slots[0];
qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
btrfs_mark_buffer_dirty(l);
out:
btrfs_free_path(path);
return ret;
}
static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
struct btrfs_qgroup *qgroup)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *quota_root = fs_info->quota_root;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_qgroup_info_item *qgroup_info;
int ret;
int slot;
if (btrfs_is_testing(fs_info))
return 0;
key.objectid = 0;
key.type = BTRFS_QGROUP_INFO_KEY;
key.offset = qgroup->qgroupid;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
if (ret > 0)
ret = -ENOENT;
if (ret)
goto out;
l = path->nodes[0];
slot = path->slots[0];
qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
btrfs_mark_buffer_dirty(l);
out:
btrfs_free_path(path);
return ret;
}
static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *quota_root = fs_info->quota_root;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *l;
struct btrfs_qgroup_status_item *ptr;
int ret;
int slot;
key.objectid = 0;
key.type = BTRFS_QGROUP_STATUS_KEY;
key.offset = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
if (ret > 0)
ret = -ENOENT;
if (ret)
goto out;
l = path->nodes[0];
slot = path->slots[0];
ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
btrfs_set_qgroup_status_rescan(l, ptr,
fs_info->qgroup_rescan_progress.objectid);
btrfs_mark_buffer_dirty(l);
out:
btrfs_free_path(path);
return ret;
}
/*
* called with qgroup_lock held
*/
static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *leaf = NULL;
int ret;
int nr = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
key.objectid = 0;
key.offset = 0;
key.type = 0;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
leaf = path->nodes[0];
nr = btrfs_header_nritems(leaf);
if (!nr)
break;
/*
* delete the leaf one by one
* since the whole tree is going
* to be deleted.
*/
path->slots[0] = 0;
ret = btrfs_del_items(trans, root, path, 0, nr);
if (ret)
goto out;
btrfs_release_path(path);
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *quota_root;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_path *path = NULL;
struct btrfs_qgroup_status_item *ptr;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_qgroup *qgroup = NULL;
struct btrfs_trans_handle *trans = NULL;
int ret = 0;
int slot;
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (fs_info->quota_root)
goto out;
fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
if (!fs_info->qgroup_ulist) {
ret = -ENOMEM;
goto out;
}
/*
* 1 for quota root item
* 1 for BTRFS_QGROUP_STATUS item
*
* Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
* per subvolume. However those are not currently reserved since it
* would be a lot of overkill.
*/
trans = btrfs_start_transaction(tree_root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
/*
* initially create the quota tree
*/
quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
if (IS_ERR(quota_root)) {
ret = PTR_ERR(quota_root);
btrfs_abort_transaction(trans, ret);
goto out;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
btrfs_abort_transaction(trans, ret);
goto out_free_root;
}
key.objectid = 0;
key.type = BTRFS_QGROUP_STATUS_KEY;
key.offset = 0;
ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
sizeof(*ptr));
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_free_path;
}
leaf = path->nodes[0];
ptr = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_qgroup_status_item);
btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
btrfs_mark_buffer_dirty(leaf);
key.objectid = 0;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = 0;
btrfs_release_path(path);
ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
if (ret > 0)
goto out_add_root;
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out_free_path;
}
while (1) {
slot = path->slots[0];
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.type == BTRFS_ROOT_REF_KEY) {
ret = add_qgroup_item(trans, quota_root,
found_key.offset);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_free_path;
}
qgroup = add_qgroup_rb(fs_info, found_key.offset);
if (IS_ERR(qgroup)) {
ret = PTR_ERR(qgroup);
btrfs_abort_transaction(trans, ret);
goto out_free_path;
}
}
ret = btrfs_next_item(tree_root, path);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out_free_path;
}
if (ret)
break;
}
out_add_root:
btrfs_release_path(path);
ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_free_path;
}
qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
if (IS_ERR(qgroup)) {
ret = PTR_ERR(qgroup);
btrfs_abort_transaction(trans, ret);
goto out_free_path;
}
ret = btrfs_commit_transaction(trans);
trans = NULL;
if (ret)
goto out_free_path;
Btrfs: fix deadlock when enabling quotas due to concurrent snapshot creation If the quota enable and snapshot creation ioctls are called concurrently we can get into a deadlock where the task enabling quotas will deadlock on the fs_info->qgroup_ioctl_lock mutex because it attempts to lock it twice, or the task creating a snapshot tries to commit the transaction while the task enabling quota waits for the former task to commit the transaction while holding the mutex. The following time diagrams show how both cases happen. First scenario: CPU 0 CPU 1 btrfs_ioctl() btrfs_ioctl_quota_ctl() btrfs_quota_enable() mutex_lock(fs_info->qgroup_ioctl_lock) btrfs_start_transaction() btrfs_ioctl() btrfs_ioctl_snap_create_v2 create_snapshot() --> adds snapshot to the list pending_snapshots of the current transaction btrfs_commit_transaction() create_pending_snapshots() create_pending_snapshot() qgroup_account_snapshot() btrfs_qgroup_inherit() mutex_lock(fs_info->qgroup_ioctl_lock) --> deadlock, mutex already locked by this task at btrfs_quota_enable() Second scenario: CPU 0 CPU 1 btrfs_ioctl() btrfs_ioctl_quota_ctl() btrfs_quota_enable() mutex_lock(fs_info->qgroup_ioctl_lock) btrfs_start_transaction() btrfs_ioctl() btrfs_ioctl_snap_create_v2 create_snapshot() --> adds snapshot to the list pending_snapshots of the current transaction btrfs_commit_transaction() --> waits for task at CPU 0 to release its transaction handle btrfs_commit_transaction() --> sees another task started the transaction commit first --> releases its transaction handle --> waits for the transaction commit to be completed by the task at CPU 1 create_pending_snapshot() qgroup_account_snapshot() btrfs_qgroup_inherit() mutex_lock(fs_info->qgroup_ioctl_lock) --> deadlock, task at CPU 0 has the mutex locked but it is waiting for us to finish the transaction commit So fix this by setting the quota enabled flag in fs_info after committing the transaction at btrfs_quota_enable(). This ends up serializing quota enable and snapshot creation as if the snapshot creation happened just before the quota enable request. The quota rescan task, scheduled after committing the transaction in btrfs_quote_enable(), will do the accounting. Fixes: 6426c7ad697d ("btrfs: qgroup: Fix qgroup accounting when creating snapshot") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-19 14:15:36 +00:00
/*
* Set quota enabled flag after committing the transaction, to avoid
* deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
* creation.
*/
spin_lock(&fs_info->qgroup_lock);
fs_info->quota_root = quota_root;
set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
spin_unlock(&fs_info->qgroup_lock);
ret = qgroup_rescan_init(fs_info, 0, 1);
if (!ret) {
qgroup_rescan_zero_tracking(fs_info);
btrfs: qgroup: ensure qgroup_rescan_running is only set when the worker is at least queued [BUG] There are some reports about btrfs wait forever to unmount itself, with the following call trace: INFO: task umount:4631 blocked for more than 491 seconds. Tainted: G X 5.3.8-2-default #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. umount D 0 4631 3337 0x00000000 Call Trace: ([<00000000174adf7a>] __schedule+0x342/0x748) [<00000000174ae3ca>] schedule+0x4a/0xd8 [<00000000174b1f08>] schedule_timeout+0x218/0x420 [<00000000174af10c>] wait_for_common+0x104/0x1d8 [<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs] [<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs] [<0000000016fa3136>] generic_shutdown_super+0x8e/0x158 [<0000000016fa34d6>] kill_anon_super+0x26/0x40 [<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs] [<0000000016fa39f8>] deactivate_locked_super+0x68/0x98 [<0000000016fcb198>] cleanup_mnt+0xc0/0x140 [<0000000016d6a846>] task_work_run+0xc6/0x110 [<0000000016d04f76>] do_notify_resume+0xae/0xb8 [<00000000174b30ae>] system_call+0xe2/0x2c8 [CAUSE] The problem happens when we have called qgroup_rescan_init(), but not queued the worker. It can be caused mostly by error handling. Qgroup ioctl thread | Unmount thread ----------------------------------------+----------------------------------- | btrfs_qgroup_rescan() | |- qgroup_rescan_init() | | |- qgroup_rescan_running = true; | | | |- trans = btrfs_join_transaction() | | Some error happened | | | |- btrfs_qgroup_rescan() returns error | But qgroup_rescan_running == true; | | close_ctree() | |- btrfs_qgroup_wait_for_completion() | |- running == true; | |- wait_for_completion(); btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake up close_ctree() and we get a deadlock. All involved qgroup_rescan_init() callers are: - btrfs_qgroup_rescan() The example above. It's possible to trigger the deadlock when error happened. - btrfs_quota_enable() Not possible. Just after qgroup_rescan_init() we queue the work. - btrfs_read_qgroup_config() It's possible to trigger the deadlock. It only init the work, the work queueing happens in btrfs_qgroup_rescan_resume(). Thus if error happened in between, deadlock is possible. We shouldn't set fs_info->qgroup_rescan_running just in qgroup_rescan_init(), as at that stage we haven't yet queued qgroup rescan worker to run. [FIX] Set qgroup_rescan_running before queueing the work, so that we ensure the rescan work is queued when we wait for it. Fixes: 8d9eddad1946 ("Btrfs: fix qgroup rescan worker initialization") Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ Change subject and cause analyse, use a smaller fix ] Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-07 05:38:20 +00:00
fs_info->qgroup_rescan_running = true;
btrfs_queue_work(fs_info->qgroup_rescan_workers,
&fs_info->qgroup_rescan_work);
}
out_free_path:
btrfs_free_path(path);
out_free_root:
if (ret)
btrfs_put_root(quota_root);
out:
if (ret) {
ulist_free(fs_info->qgroup_ulist);
fs_info->qgroup_ulist = NULL;
if (trans)
btrfs_end_transaction(trans);
}
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *quota_root;
struct btrfs_trans_handle *trans = NULL;
int ret = 0;
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!fs_info->quota_root)
goto out;
/*
* 1 For the root item
*
* We should also reserve enough items for the quota tree deletion in
* btrfs_clean_quota_tree but this is not done.
*/
trans = btrfs_start_transaction(fs_info->tree_root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
btrfs_qgroup_wait_for_completion(fs_info, false);
spin_lock(&fs_info->qgroup_lock);
quota_root = fs_info->quota_root;
fs_info->quota_root = NULL;
fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
spin_unlock(&fs_info->qgroup_lock);
btrfs_free_qgroup_config(fs_info);
ret = btrfs_clean_quota_tree(trans, quota_root);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto end_trans;
}
ret = btrfs_del_root(trans, &quota_root->root_key);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto end_trans;
}
list_del(&quota_root->dirty_list);
btrfs_tree_lock(quota_root->node);
btrfs_clean_tree_block(quota_root->node);
btrfs_tree_unlock(quota_root->node);
btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
btrfs_put_root(quota_root);
end_trans:
ret = btrfs_end_transaction(trans);
out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
static void qgroup_dirty(struct btrfs_fs_info *fs_info,
struct btrfs_qgroup *qgroup)
{
if (list_empty(&qgroup->dirty))
list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
}
/*
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
* The easy accounting, we're updating qgroup relationship whose child qgroup
* only has exclusive extents.
*
* In this case, all exclusive extents will also be exclusive for parent, so
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
* excl/rfer just get added/removed.
*
* So is qgroup reservation space, which should also be added/removed to
* parent.
* Or when child tries to release reservation space, parent will underflow its
* reservation (for relationship adding case).
*
* Caller should hold fs_info->qgroup_lock.
*/
static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
struct ulist *tmp, u64 ref_root,
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
struct btrfs_qgroup *src, int sign)
{
struct btrfs_qgroup *qgroup;
struct btrfs_qgroup_list *glist;
struct ulist_node *unode;
struct ulist_iterator uiter;
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
u64 num_bytes = src->excl;
int ret = 0;
qgroup = find_qgroup_rb(fs_info, ref_root);
if (!qgroup)
goto out;
qgroup->rfer += sign * num_bytes;
qgroup->rfer_cmpr += sign * num_bytes;
WARN_ON(sign < 0 && qgroup->excl < num_bytes);
qgroup->excl += sign * num_bytes;
qgroup->excl_cmpr += sign * num_bytes;
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
if (sign > 0)
qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
else
qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
qgroup_dirty(fs_info, qgroup);
/* Get all of the parent groups that contain this qgroup */
list_for_each_entry(glist, &qgroup->groups, next_group) {
ret = ulist_add(tmp, glist->group->qgroupid,
qgroup_to_aux(glist->group), GFP_ATOMIC);
if (ret < 0)
goto out;
}
/* Iterate all of the parents and adjust their reference counts */
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(tmp, &uiter))) {
qgroup = unode_aux_to_qgroup(unode);
qgroup->rfer += sign * num_bytes;
qgroup->rfer_cmpr += sign * num_bytes;
WARN_ON(sign < 0 && qgroup->excl < num_bytes);
qgroup->excl += sign * num_bytes;
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
if (sign > 0)
qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
else
qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
qgroup->excl_cmpr += sign * num_bytes;
qgroup_dirty(fs_info, qgroup);
/* Add any parents of the parents */
list_for_each_entry(glist, &qgroup->groups, next_group) {
ret = ulist_add(tmp, glist->group->qgroupid,
qgroup_to_aux(glist->group), GFP_ATOMIC);
if (ret < 0)
goto out;
}
}
ret = 0;
out:
return ret;
}
/*
* Quick path for updating qgroup with only excl refs.
*
* In that case, just update all parent will be enough.
* Or we needs to do a full rescan.
* Caller should also hold fs_info->qgroup_lock.
*
* Return 0 for quick update, return >0 for need to full rescan
* and mark INCONSISTENT flag.
* Return < 0 for other error.
*/
static int quick_update_accounting(struct btrfs_fs_info *fs_info,
struct ulist *tmp, u64 src, u64 dst,
int sign)
{
struct btrfs_qgroup *qgroup;
int ret = 1;
int err = 0;
qgroup = find_qgroup_rb(fs_info, src);
if (!qgroup)
goto out;
if (qgroup->excl == qgroup->rfer) {
ret = 0;
err = __qgroup_excl_accounting(fs_info, tmp, dst,
btrfs: qgroup: Fix wrong qgroup reservation update for relationship modification When modifying qgroup relationship, for qgroup which only owns exclusive extents, we will go through quick update path. In this path, we will add/subtract exclusive and reference number for parent qgroup, since the source (child) qgroup only has exclusive extents, destination (parent) qgroup will also own or lose those extents exclusively. The same should be the same for reservation, since later reservation adding/releasing will also affect parent qgroup, without the reservation carried from child, parent will underflow reservation or have dead reservation which will never be freed. However original code doesn't do the same thing for reservation. It handles qgroup reservation quite differently: It removes qgroup reservation, as it's allocating space from the reserved qgroup for relationship adding. But does nothing for qgroup reservation if we're removing a qgroup relationship. According to the original code, it looks just like because we're adding qgroup->rfer, the code assumes we're writing new data, so it's follows the normal write routine, by reducing qgroup->reserved and adding qgroup->rfer/excl. This old behavior is wrong, and should be fixed to follow the same excl/rfer behavior. Just fix it by using the correct behavior described above. Fixes: 31193213f1f9 ("Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-12 07:34:26 +00:00
qgroup, sign);
if (err < 0) {
ret = err;
goto out;
}
}
out:
if (ret)
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
return ret;
}
int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
u64 dst)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_qgroup *parent;
struct btrfs_qgroup *member;
struct btrfs_qgroup_list *list;
struct ulist *tmp;
int ret = 0;
/* Check the level of src and dst first */
if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
return -EINVAL;
tmp = ulist_alloc(GFP_KERNEL);
if (!tmp)
return -ENOMEM;
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!fs_info->quota_root) {
ret = -ENOTCONN;
goto out;
}
member = find_qgroup_rb(fs_info, src);
parent = find_qgroup_rb(fs_info, dst);
if (!member || !parent) {
ret = -EINVAL;
goto out;
}
/* check if such qgroup relation exist firstly */
list_for_each_entry(list, &member->groups, next_group) {
if (list->group == parent) {
ret = -EEXIST;
goto out;
}
}
ret = add_qgroup_relation_item(trans, src, dst);
if (ret)
goto out;
ret = add_qgroup_relation_item(trans, dst, src);
if (ret) {
del_qgroup_relation_item(trans, src, dst);
goto out;
}
spin_lock(&fs_info->qgroup_lock);
ret = add_relation_rb(fs_info, src, dst);
if (ret < 0) {
spin_unlock(&fs_info->qgroup_lock);
goto out;
}
ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
spin_unlock(&fs_info->qgroup_lock);
out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
ulist_free(tmp);
return ret;
}
static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
u64 dst)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_qgroup *parent;
struct btrfs_qgroup *member;
struct btrfs_qgroup_list *list;
struct ulist *tmp;
bool found = false;
int ret = 0;
int ret2;
tmp = ulist_alloc(GFP_KERNEL);
if (!tmp)
return -ENOMEM;
if (!fs_info->quota_root) {
ret = -ENOTCONN;
goto out;
}
member = find_qgroup_rb(fs_info, src);
parent = find_qgroup_rb(fs_info, dst);
/*
* The parent/member pair doesn't exist, then try to delete the dead
* relation items only.
*/
if (!member || !parent)
goto delete_item;
/* check if such qgroup relation exist firstly */
list_for_each_entry(list, &member->groups, next_group) {
if (list->group == parent) {
found = true;
break;
}
}
delete_item:
ret = del_qgroup_relation_item(trans, src, dst);
if (ret < 0 && ret != -ENOENT)
goto out;
ret2 = del_qgroup_relation_item(trans, dst, src);
if (ret2 < 0 && ret2 != -ENOENT)
goto out;
/* At least one deletion succeeded, return 0 */
if (!ret || !ret2)
ret = 0;
if (found) {
spin_lock(&fs_info->qgroup_lock);
del_relation_rb(fs_info, src, dst);
ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
spin_unlock(&fs_info->qgroup_lock);
}
out:
ulist_free(tmp);
return ret;
}
int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
u64 dst)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
int ret = 0;
mutex_lock(&fs_info->qgroup_ioctl_lock);
ret = __del_qgroup_relation(trans, src, dst);
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *quota_root;
struct btrfs_qgroup *qgroup;
int ret = 0;
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!fs_info->quota_root) {
ret = -ENOTCONN;
goto out;
}
quota_root = fs_info->quota_root;
qgroup = find_qgroup_rb(fs_info, qgroupid);
if (qgroup) {
ret = -EEXIST;
goto out;
}
ret = add_qgroup_item(trans, quota_root, qgroupid);
if (ret)
goto out;
spin_lock(&fs_info->qgroup_lock);
qgroup = add_qgroup_rb(fs_info, qgroupid);
spin_unlock(&fs_info->qgroup_lock);
if (IS_ERR(qgroup))
ret = PTR_ERR(qgroup);
out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_qgroup *qgroup;
struct btrfs_qgroup_list *list;
int ret = 0;
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!fs_info->quota_root) {
ret = -ENOTCONN;
goto out;
}
qgroup = find_qgroup_rb(fs_info, qgroupid);
if (!qgroup) {
ret = -ENOENT;
goto out;
}
/* Check if there are no children of this qgroup */
if (!list_empty(&qgroup->members)) {
ret = -EBUSY;
goto out;
}
ret = del_qgroup_item(trans, qgroupid);
if (ret && ret != -ENOENT)
goto out;
while (!list_empty(&qgroup->groups)) {
list = list_first_entry(&qgroup->groups,
struct btrfs_qgroup_list, next_group);
ret = __del_qgroup_relation(trans, qgroupid,
list->group->qgroupid);
if (ret)
goto out;
}
spin_lock(&fs_info->qgroup_lock);
del_qgroup_rb(fs_info, qgroupid);
spin_unlock(&fs_info->qgroup_lock);
out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
struct btrfs_qgroup_limit *limit)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_qgroup *qgroup;
int ret = 0;
/* Sometimes we would want to clear the limit on this qgroup.
* To meet this requirement, we treat the -1 as a special value
* which tell kernel to clear the limit on this qgroup.
*/
const u64 CLEAR_VALUE = -1;
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!fs_info->quota_root) {
ret = -ENOTCONN;
goto out;
}
qgroup = find_qgroup_rb(fs_info, qgroupid);
if (!qgroup) {
ret = -ENOENT;
goto out;
}
spin_lock(&fs_info->qgroup_lock);
if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
if (limit->max_rfer == CLEAR_VALUE) {
qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
qgroup->max_rfer = 0;
} else {
qgroup->max_rfer = limit->max_rfer;
}
}
if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
if (limit->max_excl == CLEAR_VALUE) {
qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
qgroup->max_excl = 0;
} else {
qgroup->max_excl = limit->max_excl;
}
}
if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
if (limit->rsv_rfer == CLEAR_VALUE) {
qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
qgroup->rsv_rfer = 0;
} else {
qgroup->rsv_rfer = limit->rsv_rfer;
}
}
if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
if (limit->rsv_excl == CLEAR_VALUE) {
qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
qgroup->rsv_excl = 0;
} else {
qgroup->rsv_excl = limit->rsv_excl;
}
}
qgroup->lim_flags |= limit->flags;
spin_unlock(&fs_info->qgroup_lock);
ret = update_qgroup_limit_item(trans, qgroup);
if (ret) {
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
btrfs_info(fs_info, "unable to update quota limit for %llu",
qgroupid);
}
out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
struct btrfs_delayed_ref_root *delayed_refs,
struct btrfs_qgroup_extent_record *record)
{
struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
struct rb_node *parent_node = NULL;
struct btrfs_qgroup_extent_record *entry;
u64 bytenr = record->bytenr;
lockdep_assert_held(&delayed_refs->lock);
trace_btrfs_qgroup_trace_extent(fs_info, record);
while (*p) {
parent_node = *p;
entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
node);
btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record [BUG] Btrfs/139 will fail with a high probability if the testing machine (VM) has only 2G RAM. Resulting the final write success while it should fail due to EDQUOT, and the fs will have quota exceeding the limit by 16K. The simplified reproducer will be: (needs a 2G ram VM) $ mkfs.btrfs -f $dev $ mount $dev $mnt $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ for i in $(seq -w 1 8); do xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null echo "file $i written" > /dev/kmsg done $ sync $ btrfs qgroup show -pcre --raw $mnt The last pwrite will not trigger EDQUOT and final 'qgroup show' will show something like: qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 none none --- --- 0/256 1073758208 1073758208 none 1073741824 --- --- And 1073758208 is larger than > 1073741824. [CAUSE] It's a bug in btrfs qgroup data reserved space management. For quota limit, we must ensure that: reserved (data + metadata) + rfer/excl <= limit Since rfer/excl is only updated at transaction commmit time, reserved space needs to be taken special care. One important part of reserved space is data, and for a new data extent written to disk, we still need to take the reserved space until rfer/excl numbers get updated. Originally when an ordered extent finishes, we migrate the reserved qgroup data space from extent_io tree to delayed ref head of the data extent, expecting delayed ref will only be cleaned up at commit transaction time. However for small RAM machine, due to memory pressure dirty pages can be flushed back to disk without committing a transaction. The related events will be something like: file 1 written btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840 btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096 btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344 btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192 btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344 cleanup_ref_head: num_bytes=54947840 cleanup_ref_head: num_bytes=5636096 cleanup_ref_head: num_bytes=569344 cleanup_ref_head: num_bytes=57344 cleanup_ref_head: num_bytes=8192 ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space file 2 written ... file 8 written cleanup_ref_head: num_bytes=8192 ... btrfs_commit_transaction <<< the only transaction committed during the test When file 2 is written, we have already freed 128M reserved qgroup data space for ino 258. Thus later write won't trigger EDQUOT. This allows us to write more data beyond qgroup limit. In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT. [FIX] By moving reserved qgroup data space from btrfs_delayed_ref_head to btrfs_qgroup_extent_record, we can ensure that reserved qgroup data space won't be freed half way before commit transaction, thus fix the problem. Fixes: f64d5ca86821 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:12 +00:00
if (bytenr < entry->bytenr) {
p = &(*p)->rb_left;
btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record [BUG] Btrfs/139 will fail with a high probability if the testing machine (VM) has only 2G RAM. Resulting the final write success while it should fail due to EDQUOT, and the fs will have quota exceeding the limit by 16K. The simplified reproducer will be: (needs a 2G ram VM) $ mkfs.btrfs -f $dev $ mount $dev $mnt $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ for i in $(seq -w 1 8); do xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null echo "file $i written" > /dev/kmsg done $ sync $ btrfs qgroup show -pcre --raw $mnt The last pwrite will not trigger EDQUOT and final 'qgroup show' will show something like: qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 none none --- --- 0/256 1073758208 1073758208 none 1073741824 --- --- And 1073758208 is larger than > 1073741824. [CAUSE] It's a bug in btrfs qgroup data reserved space management. For quota limit, we must ensure that: reserved (data + metadata) + rfer/excl <= limit Since rfer/excl is only updated at transaction commmit time, reserved space needs to be taken special care. One important part of reserved space is data, and for a new data extent written to disk, we still need to take the reserved space until rfer/excl numbers get updated. Originally when an ordered extent finishes, we migrate the reserved qgroup data space from extent_io tree to delayed ref head of the data extent, expecting delayed ref will only be cleaned up at commit transaction time. However for small RAM machine, due to memory pressure dirty pages can be flushed back to disk without committing a transaction. The related events will be something like: file 1 written btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840 btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096 btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344 btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192 btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344 cleanup_ref_head: num_bytes=54947840 cleanup_ref_head: num_bytes=5636096 cleanup_ref_head: num_bytes=569344 cleanup_ref_head: num_bytes=57344 cleanup_ref_head: num_bytes=8192 ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space file 2 written ... file 8 written cleanup_ref_head: num_bytes=8192 ... btrfs_commit_transaction <<< the only transaction committed during the test When file 2 is written, we have already freed 128M reserved qgroup data space for ino 258. Thus later write won't trigger EDQUOT. This allows us to write more data beyond qgroup limit. In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT. [FIX] By moving reserved qgroup data space from btrfs_delayed_ref_head to btrfs_qgroup_extent_record, we can ensure that reserved qgroup data space won't be freed half way before commit transaction, thus fix the problem. Fixes: f64d5ca86821 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:12 +00:00
} else if (bytenr > entry->bytenr) {
p = &(*p)->rb_right;
btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record [BUG] Btrfs/139 will fail with a high probability if the testing machine (VM) has only 2G RAM. Resulting the final write success while it should fail due to EDQUOT, and the fs will have quota exceeding the limit by 16K. The simplified reproducer will be: (needs a 2G ram VM) $ mkfs.btrfs -f $dev $ mount $dev $mnt $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ for i in $(seq -w 1 8); do xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null echo "file $i written" > /dev/kmsg done $ sync $ btrfs qgroup show -pcre --raw $mnt The last pwrite will not trigger EDQUOT and final 'qgroup show' will show something like: qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 none none --- --- 0/256 1073758208 1073758208 none 1073741824 --- --- And 1073758208 is larger than > 1073741824. [CAUSE] It's a bug in btrfs qgroup data reserved space management. For quota limit, we must ensure that: reserved (data + metadata) + rfer/excl <= limit Since rfer/excl is only updated at transaction commmit time, reserved space needs to be taken special care. One important part of reserved space is data, and for a new data extent written to disk, we still need to take the reserved space until rfer/excl numbers get updated. Originally when an ordered extent finishes, we migrate the reserved qgroup data space from extent_io tree to delayed ref head of the data extent, expecting delayed ref will only be cleaned up at commit transaction time. However for small RAM machine, due to memory pressure dirty pages can be flushed back to disk without committing a transaction. The related events will be something like: file 1 written btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840 btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096 btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344 btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192 btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344 cleanup_ref_head: num_bytes=54947840 cleanup_ref_head: num_bytes=5636096 cleanup_ref_head: num_bytes=569344 cleanup_ref_head: num_bytes=57344 cleanup_ref_head: num_bytes=8192 ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space file 2 written ... file 8 written cleanup_ref_head: num_bytes=8192 ... btrfs_commit_transaction <<< the only transaction committed during the test When file 2 is written, we have already freed 128M reserved qgroup data space for ino 258. Thus later write won't trigger EDQUOT. This allows us to write more data beyond qgroup limit. In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT. [FIX] By moving reserved qgroup data space from btrfs_delayed_ref_head to btrfs_qgroup_extent_record, we can ensure that reserved qgroup data space won't be freed half way before commit transaction, thus fix the problem. Fixes: f64d5ca86821 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:12 +00:00
} else {
if (record->data_rsv && !entry->data_rsv) {
entry->data_rsv = record->data_rsv;
entry->data_rsv_refroot =
record->data_rsv_refroot;
}
return 1;
btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record [BUG] Btrfs/139 will fail with a high probability if the testing machine (VM) has only 2G RAM. Resulting the final write success while it should fail due to EDQUOT, and the fs will have quota exceeding the limit by 16K. The simplified reproducer will be: (needs a 2G ram VM) $ mkfs.btrfs -f $dev $ mount $dev $mnt $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ for i in $(seq -w 1 8); do xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null echo "file $i written" > /dev/kmsg done $ sync $ btrfs qgroup show -pcre --raw $mnt The last pwrite will not trigger EDQUOT and final 'qgroup show' will show something like: qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 none none --- --- 0/256 1073758208 1073758208 none 1073741824 --- --- And 1073758208 is larger than > 1073741824. [CAUSE] It's a bug in btrfs qgroup data reserved space management. For quota limit, we must ensure that: reserved (data + metadata) + rfer/excl <= limit Since rfer/excl is only updated at transaction commmit time, reserved space needs to be taken special care. One important part of reserved space is data, and for a new data extent written to disk, we still need to take the reserved space until rfer/excl numbers get updated. Originally when an ordered extent finishes, we migrate the reserved qgroup data space from extent_io tree to delayed ref head of the data extent, expecting delayed ref will only be cleaned up at commit transaction time. However for small RAM machine, due to memory pressure dirty pages can be flushed back to disk without committing a transaction. The related events will be something like: file 1 written btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840 btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096 btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344 btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192 btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344 cleanup_ref_head: num_bytes=54947840 cleanup_ref_head: num_bytes=5636096 cleanup_ref_head: num_bytes=569344 cleanup_ref_head: num_bytes=57344 cleanup_ref_head: num_bytes=8192 ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space file 2 written ... file 8 written cleanup_ref_head: num_bytes=8192 ... btrfs_commit_transaction <<< the only transaction committed during the test When file 2 is written, we have already freed 128M reserved qgroup data space for ino 258. Thus later write won't trigger EDQUOT. This allows us to write more data beyond qgroup limit. In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT. [FIX] By moving reserved qgroup data space from btrfs_delayed_ref_head to btrfs_qgroup_extent_record, we can ensure that reserved qgroup data space won't be freed half way before commit transaction, thus fix the problem. Fixes: f64d5ca86821 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:12 +00:00
}
}
rb_link_node(&record->node, parent_node, p);
rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
return 0;
}
int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
struct btrfs_qgroup_extent_record *qrecord)
{
struct ulist *old_root;
u64 bytenr = qrecord->bytenr;
int ret;
btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and offset (encoded as a single logical address) to a list of extent refs. LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping (extent ref -> extent bytenr and offset, or logical address). These are useful capabilities for programs that manipulate extents and extent references from userspace (e.g. dedup and defrag utilities). When the extents are uncompressed (and not encrypted and not other), check_extent_in_eb performs filtering of the extent refs to remove any extent refs which do not contain the same extent offset as the 'logical' parameter's extent offset. This prevents LOGICAL_INO from returning references to more than a single block. To find the set of extent references to an uncompressed extent from [a, b), userspace has to run a loop like this pseudocode: for (i = a; i < b; ++i) extent_ref_set += LOGICAL_INO(i); At each iteration of the loop (up to 32768 iterations for a 128M extent), data we are interested in is collected in the kernel, then deleted by the filter in check_extent_in_eb. When the extents are compressed (or encrypted or other), the 'logical' parameter must be an extent bytenr (the 'a' parameter in the loop). No filtering by extent offset is done (or possible?) so the result is the complete set of extent refs for the entire extent. This removes the need for the loop, since we get all the extent refs in one call. Add an 'ignore_offset' argument to iterate_inodes_from_logical, [...several levels of function call graph...], and check_extent_in_eb, so that we can disable the extent offset filtering for uncompressed extents. This flag can be set by an improved version of the LOGICAL_INO ioctl to get either behavior as desired. There is no functional change in this patch. The new flag is always false. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: David Sterba <dsterba@suse.com> [ minor coding style fixes ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-22 17:58:45 +00:00
ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
if (ret < 0) {
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
btrfs_warn(fs_info,
"error accounting new delayed refs extent (err code: %d), quota inconsistent",
ret);
return 0;
}
/*
* Here we don't need to get the lock of
* trans->transaction->delayed_refs, since inserted qrecord won't
* be deleted, only qrecord->node may be modified (new qrecord insert)
*
* So modifying qrecord->old_roots is safe here
*/
qrecord->old_roots = old_root;
return 0;
}
int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
u64 num_bytes, gfp_t gfp_flag)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_qgroup_extent_record *record;
struct btrfs_delayed_ref_root *delayed_refs;
int ret;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
|| bytenr == 0 || num_bytes == 0)
return 0;
btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record [BUG] Btrfs/139 will fail with a high probability if the testing machine (VM) has only 2G RAM. Resulting the final write success while it should fail due to EDQUOT, and the fs will have quota exceeding the limit by 16K. The simplified reproducer will be: (needs a 2G ram VM) $ mkfs.btrfs -f $dev $ mount $dev $mnt $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ for i in $(seq -w 1 8); do xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null echo "file $i written" > /dev/kmsg done $ sync $ btrfs qgroup show -pcre --raw $mnt The last pwrite will not trigger EDQUOT and final 'qgroup show' will show something like: qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 none none --- --- 0/256 1073758208 1073758208 none 1073741824 --- --- And 1073758208 is larger than > 1073741824. [CAUSE] It's a bug in btrfs qgroup data reserved space management. For quota limit, we must ensure that: reserved (data + metadata) + rfer/excl <= limit Since rfer/excl is only updated at transaction commmit time, reserved space needs to be taken special care. One important part of reserved space is data, and for a new data extent written to disk, we still need to take the reserved space until rfer/excl numbers get updated. Originally when an ordered extent finishes, we migrate the reserved qgroup data space from extent_io tree to delayed ref head of the data extent, expecting delayed ref will only be cleaned up at commit transaction time. However for small RAM machine, due to memory pressure dirty pages can be flushed back to disk without committing a transaction. The related events will be something like: file 1 written btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840 btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096 btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344 btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192 btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344 cleanup_ref_head: num_bytes=54947840 cleanup_ref_head: num_bytes=5636096 cleanup_ref_head: num_bytes=569344 cleanup_ref_head: num_bytes=57344 cleanup_ref_head: num_bytes=8192 ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space file 2 written ... file 8 written cleanup_ref_head: num_bytes=8192 ... btrfs_commit_transaction <<< the only transaction committed during the test When file 2 is written, we have already freed 128M reserved qgroup data space for ino 258. Thus later write won't trigger EDQUOT. This allows us to write more data beyond qgroup limit. In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT. [FIX] By moving reserved qgroup data space from btrfs_delayed_ref_head to btrfs_qgroup_extent_record, we can ensure that reserved qgroup data space won't be freed half way before commit transaction, thus fix the problem. Fixes: f64d5ca86821 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:12 +00:00
record = kzalloc(sizeof(*record), gfp_flag);
if (!record)
return -ENOMEM;
delayed_refs = &trans->transaction->delayed_refs;
record->bytenr = bytenr;
record->num_bytes = num_bytes;
record->old_roots = NULL;
spin_lock(&delayed_refs->lock);
ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
spin_unlock(&delayed_refs->lock);
if (ret > 0) {
kfree(record);
return 0;
}
return btrfs_qgroup_trace_extent_post(fs_info, record);
}
int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
struct extent_buffer *eb)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
int nr = btrfs_header_nritems(eb);
int i, extent_type, ret;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
u64 bytenr, num_bytes;
/* We can be called directly from walk_up_proc() */
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
return 0;
for (i = 0; i < nr; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
/* filter out non qgroup-accountable extents */
extent_type = btrfs_file_extent_type(eb, fi);
if (extent_type == BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
if (!bytenr)
continue;
num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes,
GFP_NOFS);
if (ret)
return ret;
}
cond_resched();
return 0;
}
/*
* Walk up the tree from the bottom, freeing leaves and any interior
* nodes which have had all slots visited. If a node (leaf or
* interior) is freed, the node above it will have it's slot
* incremented. The root node will never be freed.
*
* At the end of this function, we should have a path which has all
* slots incremented to the next position for a search. If we need to
* read a new node it will be NULL and the node above it will have the
* correct slot selected for a later read.
*
* If we increment the root nodes slot counter past the number of
* elements, 1 is returned to signal completion of the search.
*/
static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
{
int level = 0;
int nr, slot;
struct extent_buffer *eb;
if (root_level == 0)
return 1;
while (level <= root_level) {
eb = path->nodes[level];
nr = btrfs_header_nritems(eb);
path->slots[level]++;
slot = path->slots[level];
if (slot >= nr || level == 0) {
/*
* Don't free the root - we will detect this
* condition after our loop and return a
* positive value for caller to stop walking the tree.
*/
if (level != root_level) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
free_extent_buffer(eb);
path->nodes[level] = NULL;
path->slots[level] = 0;
}
} else {
/*
* We have a valid slot to walk back down
* from. Stop here so caller can process these
* new nodes.
*/
break;
}
level++;
}
eb = path->nodes[root_level];
if (path->slots[root_level] >= btrfs_header_nritems(eb))
return 1;
return 0;
}
btrfs: qgroup: Introduce function to trace two swaped extents Introduce a new function, qgroup_trace_extent_swap(), which will be used later for balance qgroup speedup. The basis idea of balance is swapping tree blocks between reloc tree and the real file tree. The swap will happen in highest tree block, but there may be a lot of tree blocks involved. For example: OO = Old tree blocks NN = New tree blocks allocated during balance File tree (257) Reloc tree for 257 L2 OO NN / \ / \ L1 OO OO (a) OO NN (a) / \ / \ / \ / \ L0 OO OO OO OO OO OO NN NN (b) (c) (b) (c) When calling qgroup_trace_extent_swap(), we will pass: @src_eb = OO(a) @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] @dst_level = 0 @root_level = 1 In that case, qgroup_trace_extent_swap() will search from OO(a) to reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. The main work of qgroup_trace_extent_swap() can be split into 3 parts: 1) Tree search from @src_eb It should acts as a simplified btrfs_search_slot(). The key for search can be extracted from @dst_path->nodes[dst_level] (first key). 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. They should be marked during preivous (@dst_level = 1) iteration. 3) Mark file extents in leaves dirty We don't have good way to pick out new file extents only. So we still follow the old method by scanning all file extents in the leave. This function can free us from keeping two pathes, thus later we only need to care about how to iterate all new tree blocks in reloc tree. Signed-off-by: Qu Wenruo <wqu@suse.com> [ copy changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:30 +00:00
/*
* Helper function to trace a subtree tree block swap.
*
* The swap will happen in highest tree block, but there may be a lot of
* tree blocks involved.
*
* For example:
* OO = Old tree blocks
* NN = New tree blocks allocated during balance
*
* File tree (257) Reloc tree for 257
* L2 OO NN
* / \ / \
* L1 OO OO (a) OO NN (a)
* / \ / \ / \ / \
* L0 OO OO OO OO OO OO NN NN
* (b) (c) (b) (c)
*
* When calling qgroup_trace_extent_swap(), we will pass:
* @src_eb = OO(a)
* @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
* @dst_level = 0
* @root_level = 1
*
* In that case, qgroup_trace_extent_swap() will search from OO(a) to
* reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
*
* The main work of qgroup_trace_extent_swap() can be split into 3 parts:
*
* 1) Tree search from @src_eb
* It should acts as a simplified btrfs_search_slot().
* The key for search can be extracted from @dst_path->nodes[dst_level]
* (first key).
*
* 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
* NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
* They should be marked during previous (@dst_level = 1) iteration.
btrfs: qgroup: Introduce function to trace two swaped extents Introduce a new function, qgroup_trace_extent_swap(), which will be used later for balance qgroup speedup. The basis idea of balance is swapping tree blocks between reloc tree and the real file tree. The swap will happen in highest tree block, but there may be a lot of tree blocks involved. For example: OO = Old tree blocks NN = New tree blocks allocated during balance File tree (257) Reloc tree for 257 L2 OO NN / \ / \ L1 OO OO (a) OO NN (a) / \ / \ / \ / \ L0 OO OO OO OO OO OO NN NN (b) (c) (b) (c) When calling qgroup_trace_extent_swap(), we will pass: @src_eb = OO(a) @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] @dst_level = 0 @root_level = 1 In that case, qgroup_trace_extent_swap() will search from OO(a) to reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. The main work of qgroup_trace_extent_swap() can be split into 3 parts: 1) Tree search from @src_eb It should acts as a simplified btrfs_search_slot(). The key for search can be extracted from @dst_path->nodes[dst_level] (first key). 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. They should be marked during preivous (@dst_level = 1) iteration. 3) Mark file extents in leaves dirty We don't have good way to pick out new file extents only. So we still follow the old method by scanning all file extents in the leave. This function can free us from keeping two pathes, thus later we only need to care about how to iterate all new tree blocks in reloc tree. Signed-off-by: Qu Wenruo <wqu@suse.com> [ copy changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:30 +00:00
*
* 3) Mark file extents in leaves dirty
* We don't have good way to pick out new file extents only.
* So we still follow the old method by scanning all file extents in
* the leave.
*
* This function can free us from keeping two paths, thus later we only need
btrfs: qgroup: Introduce function to trace two swaped extents Introduce a new function, qgroup_trace_extent_swap(), which will be used later for balance qgroup speedup. The basis idea of balance is swapping tree blocks between reloc tree and the real file tree. The swap will happen in highest tree block, but there may be a lot of tree blocks involved. For example: OO = Old tree blocks NN = New tree blocks allocated during balance File tree (257) Reloc tree for 257 L2 OO NN / \ / \ L1 OO OO (a) OO NN (a) / \ / \ / \ / \ L0 OO OO OO OO OO OO NN NN (b) (c) (b) (c) When calling qgroup_trace_extent_swap(), we will pass: @src_eb = OO(a) @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] @dst_level = 0 @root_level = 1 In that case, qgroup_trace_extent_swap() will search from OO(a) to reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. The main work of qgroup_trace_extent_swap() can be split into 3 parts: 1) Tree search from @src_eb It should acts as a simplified btrfs_search_slot(). The key for search can be extracted from @dst_path->nodes[dst_level] (first key). 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. They should be marked during preivous (@dst_level = 1) iteration. 3) Mark file extents in leaves dirty We don't have good way to pick out new file extents only. So we still follow the old method by scanning all file extents in the leave. This function can free us from keeping two pathes, thus later we only need to care about how to iterate all new tree blocks in reloc tree. Signed-off-by: Qu Wenruo <wqu@suse.com> [ copy changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:30 +00:00
* to care about how to iterate all new tree blocks in reloc tree.
*/
static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
struct extent_buffer *src_eb,
struct btrfs_path *dst_path,
btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group For qgroup_trace_extent_swap(), if we find one leaf that needs to be traced, we will also iterate all file extents and trace them. This is OK if we're relocating data block groups, but if we're relocating metadata block groups, balance code itself has ensured that both subtree of file tree and reloc tree contain the same contents. That's to say, if we're relocating metadata block groups, all file extents in reloc and file tree should match, thus no need to trace them. This should reduce the total number of dirty extents processed in metadata block group balance. [[Benchmark]] (with all previous enhancement) Hardware: VM 4G vRAM, 8 vCPUs, disk is using 'unsafe' cache mode, backing device is SAMSUNG 850 evo SSD. Host has 16G ram. Mkfs parameter: --nodesize 4K (To bump up tree size) Initial subvolume contents: 4G data copied from /usr and /lib. (With enough regular small files) Snapshots: 16 snapshots of the original subvolume. each snapshot has 3 random files modified. balance parameter: -m So the content should be pretty similar to a real world root fs layout. | v4.19-rc1 | w/ patchset | diff (*) --------------------------------------------------------------- relocated extents | 22929 | 22851 | -0.3% qgroup dirty extents | 227757 | 140886 | -38.1% time (sys) | 65.253s | 37.464s | -42.6% time (real) | 74.032s | 44.722s | -39.6% Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:35 +00:00
int dst_level, int root_level,
bool trace_leaf)
btrfs: qgroup: Introduce function to trace two swaped extents Introduce a new function, qgroup_trace_extent_swap(), which will be used later for balance qgroup speedup. The basis idea of balance is swapping tree blocks between reloc tree and the real file tree. The swap will happen in highest tree block, but there may be a lot of tree blocks involved. For example: OO = Old tree blocks NN = New tree blocks allocated during balance File tree (257) Reloc tree for 257 L2 OO NN / \ / \ L1 OO OO (a) OO NN (a) / \ / \ / \ / \ L0 OO OO OO OO OO OO NN NN (b) (c) (b) (c) When calling qgroup_trace_extent_swap(), we will pass: @src_eb = OO(a) @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] @dst_level = 0 @root_level = 1 In that case, qgroup_trace_extent_swap() will search from OO(a) to reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. The main work of qgroup_trace_extent_swap() can be split into 3 parts: 1) Tree search from @src_eb It should acts as a simplified btrfs_search_slot(). The key for search can be extracted from @dst_path->nodes[dst_level] (first key). 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. They should be marked during preivous (@dst_level = 1) iteration. 3) Mark file extents in leaves dirty We don't have good way to pick out new file extents only. So we still follow the old method by scanning all file extents in the leave. This function can free us from keeping two pathes, thus later we only need to care about how to iterate all new tree blocks in reloc tree. Signed-off-by: Qu Wenruo <wqu@suse.com> [ copy changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:30 +00:00
{
struct btrfs_key key;
struct btrfs_path *src_path;
struct btrfs_fs_info *fs_info = trans->fs_info;
u32 nodesize = fs_info->nodesize;
int cur_level = root_level;
int ret;
BUG_ON(dst_level > root_level);
/* Level mismatch */
if (btrfs_header_level(src_eb) != root_level)
return -EINVAL;
src_path = btrfs_alloc_path();
if (!src_path) {
ret = -ENOMEM;
goto out;
}
if (dst_level)
btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
else
btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
/* For src_path */
atomic_inc(&src_eb->refs);
btrfs: qgroup: Introduce function to trace two swaped extents Introduce a new function, qgroup_trace_extent_swap(), which will be used later for balance qgroup speedup. The basis idea of balance is swapping tree blocks between reloc tree and the real file tree. The swap will happen in highest tree block, but there may be a lot of tree blocks involved. For example: OO = Old tree blocks NN = New tree blocks allocated during balance File tree (257) Reloc tree for 257 L2 OO NN / \ / \ L1 OO OO (a) OO NN (a) / \ / \ / \ / \ L0 OO OO OO OO OO OO NN NN (b) (c) (b) (c) When calling qgroup_trace_extent_swap(), we will pass: @src_eb = OO(a) @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] @dst_level = 0 @root_level = 1 In that case, qgroup_trace_extent_swap() will search from OO(a) to reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. The main work of qgroup_trace_extent_swap() can be split into 3 parts: 1) Tree search from @src_eb It should acts as a simplified btrfs_search_slot(). The key for search can be extracted from @dst_path->nodes[dst_level] (first key). 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. They should be marked during preivous (@dst_level = 1) iteration. 3) Mark file extents in leaves dirty We don't have good way to pick out new file extents only. So we still follow the old method by scanning all file extents in the leave. This function can free us from keeping two pathes, thus later we only need to care about how to iterate all new tree blocks in reloc tree. Signed-off-by: Qu Wenruo <wqu@suse.com> [ copy changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:30 +00:00
src_path->nodes[root_level] = src_eb;
src_path->slots[root_level] = dst_path->slots[root_level];
src_path->locks[root_level] = 0;
/* A simplified version of btrfs_search_slot() */
while (cur_level >= dst_level) {
struct btrfs_key src_key;
struct btrfs_key dst_key;
if (src_path->nodes[cur_level] == NULL) {
struct btrfs_key first_key;
struct extent_buffer *eb;
int parent_slot;
u64 child_gen;
u64 child_bytenr;
eb = src_path->nodes[cur_level + 1];
parent_slot = src_path->slots[cur_level + 1];
child_bytenr = btrfs_node_blockptr(eb, parent_slot);
child_gen = btrfs_node_ptr_generation(eb, parent_slot);
btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
eb = read_tree_block(fs_info, child_bytenr, child_gen,
cur_level, &first_key);
if (IS_ERR(eb)) {
ret = PTR_ERR(eb);
goto out;
} else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
ret = -EIO;
goto out;
}
src_path->nodes[cur_level] = eb;
btrfs_tree_read_lock(eb);
btrfs_set_lock_blocking_read(eb);
btrfs: qgroup: Introduce function to trace two swaped extents Introduce a new function, qgroup_trace_extent_swap(), which will be used later for balance qgroup speedup. The basis idea of balance is swapping tree blocks between reloc tree and the real file tree. The swap will happen in highest tree block, but there may be a lot of tree blocks involved. For example: OO = Old tree blocks NN = New tree blocks allocated during balance File tree (257) Reloc tree for 257 L2 OO NN / \ / \ L1 OO OO (a) OO NN (a) / \ / \ / \ / \ L0 OO OO OO OO OO OO NN NN (b) (c) (b) (c) When calling qgroup_trace_extent_swap(), we will pass: @src_eb = OO(a) @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] @dst_level = 0 @root_level = 1 In that case, qgroup_trace_extent_swap() will search from OO(a) to reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. The main work of qgroup_trace_extent_swap() can be split into 3 parts: 1) Tree search from @src_eb It should acts as a simplified btrfs_search_slot(). The key for search can be extracted from @dst_path->nodes[dst_level] (first key). 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. They should be marked during preivous (@dst_level = 1) iteration. 3) Mark file extents in leaves dirty We don't have good way to pick out new file extents only. So we still follow the old method by scanning all file extents in the leave. This function can free us from keeping two pathes, thus later we only need to care about how to iterate all new tree blocks in reloc tree. Signed-off-by: Qu Wenruo <wqu@suse.com> [ copy changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:30 +00:00
src_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
}
src_path->slots[cur_level] = dst_path->slots[cur_level];
if (cur_level) {
btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
&dst_key, dst_path->slots[cur_level]);
btrfs_node_key_to_cpu(src_path->nodes[cur_level],
&src_key, src_path->slots[cur_level]);
} else {
btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
&dst_key, dst_path->slots[cur_level]);
btrfs_item_key_to_cpu(src_path->nodes[cur_level],
&src_key, src_path->slots[cur_level]);
}
/* Content mismatch, something went wrong */
if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
ret = -ENOENT;
goto out;
}
cur_level--;
}
/*
* Now both @dst_path and @src_path have been populated, record the tree
* blocks for qgroup accounting.
*/
ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
nodesize, GFP_NOFS);
if (ret < 0)
goto out;
ret = btrfs_qgroup_trace_extent(trans,
dst_path->nodes[dst_level]->start,
nodesize, GFP_NOFS);
if (ret < 0)
goto out;
/* Record leaf file extents */
btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group For qgroup_trace_extent_swap(), if we find one leaf that needs to be traced, we will also iterate all file extents and trace them. This is OK if we're relocating data block groups, but if we're relocating metadata block groups, balance code itself has ensured that both subtree of file tree and reloc tree contain the same contents. That's to say, if we're relocating metadata block groups, all file extents in reloc and file tree should match, thus no need to trace them. This should reduce the total number of dirty extents processed in metadata block group balance. [[Benchmark]] (with all previous enhancement) Hardware: VM 4G vRAM, 8 vCPUs, disk is using 'unsafe' cache mode, backing device is SAMSUNG 850 evo SSD. Host has 16G ram. Mkfs parameter: --nodesize 4K (To bump up tree size) Initial subvolume contents: 4G data copied from /usr and /lib. (With enough regular small files) Snapshots: 16 snapshots of the original subvolume. each snapshot has 3 random files modified. balance parameter: -m So the content should be pretty similar to a real world root fs layout. | v4.19-rc1 | w/ patchset | diff (*) --------------------------------------------------------------- relocated extents | 22929 | 22851 | -0.3% qgroup dirty extents | 227757 | 140886 | -38.1% time (sys) | 65.253s | 37.464s | -42.6% time (real) | 74.032s | 44.722s | -39.6% Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:35 +00:00
if (dst_level == 0 && trace_leaf) {
btrfs: qgroup: Introduce function to trace two swaped extents Introduce a new function, qgroup_trace_extent_swap(), which will be used later for balance qgroup speedup. The basis idea of balance is swapping tree blocks between reloc tree and the real file tree. The swap will happen in highest tree block, but there may be a lot of tree blocks involved. For example: OO = Old tree blocks NN = New tree blocks allocated during balance File tree (257) Reloc tree for 257 L2 OO NN / \ / \ L1 OO OO (a) OO NN (a) / \ / \ / \ / \ L0 OO OO OO OO OO OO NN NN (b) (c) (b) (c) When calling qgroup_trace_extent_swap(), we will pass: @src_eb = OO(a) @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] @dst_level = 0 @root_level = 1 In that case, qgroup_trace_extent_swap() will search from OO(a) to reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. The main work of qgroup_trace_extent_swap() can be split into 3 parts: 1) Tree search from @src_eb It should acts as a simplified btrfs_search_slot(). The key for search can be extracted from @dst_path->nodes[dst_level] (first key). 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. They should be marked during preivous (@dst_level = 1) iteration. 3) Mark file extents in leaves dirty We don't have good way to pick out new file extents only. So we still follow the old method by scanning all file extents in the leave. This function can free us from keeping two pathes, thus later we only need to care about how to iterate all new tree blocks in reloc tree. Signed-off-by: Qu Wenruo <wqu@suse.com> [ copy changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:30 +00:00
ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
if (ret < 0)
goto out;
ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
}
out:
btrfs_free_path(src_path);
return ret;
}
/*
* Helper function to do recursive generation-aware depth-first search, to
* locate all new tree blocks in a subtree of reloc tree.
*
* E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
* reloc tree
* L2 NN (a)
* / \
* L1 OO NN (b)
* / \ / \
* L0 OO OO OO NN
* (c) (d)
* If we pass:
* @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
* @cur_level = 1
* @root_level = 1
*
* We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
* above tree blocks along with their counter parts in file tree.
* While during search, old tree blocks OO(c) will be skipped as tree block swap
* won't affect OO(c).
*/
static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
struct extent_buffer *src_eb,
struct btrfs_path *dst_path,
int cur_level, int root_level,
btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group For qgroup_trace_extent_swap(), if we find one leaf that needs to be traced, we will also iterate all file extents and trace them. This is OK if we're relocating data block groups, but if we're relocating metadata block groups, balance code itself has ensured that both subtree of file tree and reloc tree contain the same contents. That's to say, if we're relocating metadata block groups, all file extents in reloc and file tree should match, thus no need to trace them. This should reduce the total number of dirty extents processed in metadata block group balance. [[Benchmark]] (with all previous enhancement) Hardware: VM 4G vRAM, 8 vCPUs, disk is using 'unsafe' cache mode, backing device is SAMSUNG 850 evo SSD. Host has 16G ram. Mkfs parameter: --nodesize 4K (To bump up tree size) Initial subvolume contents: 4G data copied from /usr and /lib. (With enough regular small files) Snapshots: 16 snapshots of the original subvolume. each snapshot has 3 random files modified. balance parameter: -m So the content should be pretty similar to a real world root fs layout. | v4.19-rc1 | w/ patchset | diff (*) --------------------------------------------------------------- relocated extents | 22929 | 22851 | -0.3% qgroup dirty extents | 227757 | 140886 | -38.1% time (sys) | 65.253s | 37.464s | -42.6% time (real) | 74.032s | 44.722s | -39.6% Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:35 +00:00
u64 last_snapshot, bool trace_leaf)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct extent_buffer *eb;
bool need_cleanup = false;
int ret = 0;
int i;
/* Level sanity check */
if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
root_level < cur_level) {
btrfs_err_rl(fs_info,
"%s: bad levels, cur_level=%d root_level=%d",
__func__, cur_level, root_level);
return -EUCLEAN;
}
/* Read the tree block if needed */
if (dst_path->nodes[cur_level] == NULL) {
struct btrfs_key first_key;
int parent_slot;
u64 child_gen;
u64 child_bytenr;
/*
* dst_path->nodes[root_level] must be initialized before
* calling this function.
*/
if (cur_level == root_level) {
btrfs_err_rl(fs_info,
"%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
__func__, root_level, root_level, cur_level);
return -EUCLEAN;
}
/*
* We need to get child blockptr/gen from parent before we can
* read it.
*/
eb = dst_path->nodes[cur_level + 1];
parent_slot = dst_path->slots[cur_level + 1];
child_bytenr = btrfs_node_blockptr(eb, parent_slot);
child_gen = btrfs_node_ptr_generation(eb, parent_slot);
btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
/* This node is old, no need to trace */
if (child_gen < last_snapshot)
goto out;
eb = read_tree_block(fs_info, child_bytenr, child_gen,
cur_level, &first_key);
if (IS_ERR(eb)) {
ret = PTR_ERR(eb);
goto out;
} else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
ret = -EIO;
goto out;
}
dst_path->nodes[cur_level] = eb;
dst_path->slots[cur_level] = 0;
btrfs_tree_read_lock(eb);
btrfs_set_lock_blocking_read(eb);
dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
need_cleanup = true;
}
/* Now record this tree block and its counter part for qgroups */
ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group For qgroup_trace_extent_swap(), if we find one leaf that needs to be traced, we will also iterate all file extents and trace them. This is OK if we're relocating data block groups, but if we're relocating metadata block groups, balance code itself has ensured that both subtree of file tree and reloc tree contain the same contents. That's to say, if we're relocating metadata block groups, all file extents in reloc and file tree should match, thus no need to trace them. This should reduce the total number of dirty extents processed in metadata block group balance. [[Benchmark]] (with all previous enhancement) Hardware: VM 4G vRAM, 8 vCPUs, disk is using 'unsafe' cache mode, backing device is SAMSUNG 850 evo SSD. Host has 16G ram. Mkfs parameter: --nodesize 4K (To bump up tree size) Initial subvolume contents: 4G data copied from /usr and /lib. (With enough regular small files) Snapshots: 16 snapshots of the original subvolume. each snapshot has 3 random files modified. balance parameter: -m So the content should be pretty similar to a real world root fs layout. | v4.19-rc1 | w/ patchset | diff (*) --------------------------------------------------------------- relocated extents | 22929 | 22851 | -0.3% qgroup dirty extents | 227757 | 140886 | -38.1% time (sys) | 65.253s | 37.464s | -42.6% time (real) | 74.032s | 44.722s | -39.6% Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:35 +00:00
root_level, trace_leaf);
if (ret < 0)
goto cleanup;
eb = dst_path->nodes[cur_level];
if (cur_level > 0) {
/* Iterate all child tree blocks */
for (i = 0; i < btrfs_header_nritems(eb); i++) {
/* Skip old tree blocks as they won't be swapped */
if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
continue;
dst_path->slots[cur_level] = i;
/* Recursive call (at most 7 times) */
ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
dst_path, cur_level - 1, root_level,
btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group For qgroup_trace_extent_swap(), if we find one leaf that needs to be traced, we will also iterate all file extents and trace them. This is OK if we're relocating data block groups, but if we're relocating metadata block groups, balance code itself has ensured that both subtree of file tree and reloc tree contain the same contents. That's to say, if we're relocating metadata block groups, all file extents in reloc and file tree should match, thus no need to trace them. This should reduce the total number of dirty extents processed in metadata block group balance. [[Benchmark]] (with all previous enhancement) Hardware: VM 4G vRAM, 8 vCPUs, disk is using 'unsafe' cache mode, backing device is SAMSUNG 850 evo SSD. Host has 16G ram. Mkfs parameter: --nodesize 4K (To bump up tree size) Initial subvolume contents: 4G data copied from /usr and /lib. (With enough regular small files) Snapshots: 16 snapshots of the original subvolume. each snapshot has 3 random files modified. balance parameter: -m So the content should be pretty similar to a real world root fs layout. | v4.19-rc1 | w/ patchset | diff (*) --------------------------------------------------------------- relocated extents | 22929 | 22851 | -0.3% qgroup dirty extents | 227757 | 140886 | -38.1% time (sys) | 65.253s | 37.464s | -42.6% time (real) | 74.032s | 44.722s | -39.6% Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-27 06:42:35 +00:00
last_snapshot, trace_leaf);
if (ret < 0)
goto cleanup;
}
}
cleanup:
if (need_cleanup) {
/* Clean up */
btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
dst_path->locks[cur_level]);
free_extent_buffer(dst_path->nodes[cur_level]);
dst_path->nodes[cur_level] = NULL;
dst_path->slots[cur_level] = 0;
dst_path->locks[cur_level] = 0;
}
out:
return ret;
}
static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
struct extent_buffer *src_eb,
struct extent_buffer *dst_eb,
u64 last_snapshot, bool trace_leaf)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_path *dst_path = NULL;
int level;
int ret;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
return 0;
/* Wrong parameter order */
if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
btrfs_err_rl(fs_info,
"%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
btrfs_header_generation(src_eb),
btrfs_header_generation(dst_eb));
return -EUCLEAN;
}
if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
ret = -EIO;
goto out;
}
level = btrfs_header_level(dst_eb);
dst_path = btrfs_alloc_path();
if (!dst_path) {
ret = -ENOMEM;
goto out;
}
/* For dst_path */
atomic_inc(&dst_eb->refs);
dst_path->nodes[level] = dst_eb;
dst_path->slots[level] = 0;
dst_path->locks[level] = 0;
/* Do the generation aware breadth-first search */
ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
level, last_snapshot, trace_leaf);
if (ret < 0)
goto out;
ret = 0;
out:
btrfs_free_path(dst_path);
if (ret < 0)
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
return ret;
}
int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
struct extent_buffer *root_eb,
u64 root_gen, int root_level)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
int ret = 0;
int level;
struct extent_buffer *eb = root_eb;
struct btrfs_path *path = NULL;
BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
BUG_ON(root_eb == NULL);
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
return 0;
if (!extent_buffer_uptodate(root_eb)) {
ret = btrfs_read_buffer(root_eb, root_gen, root_level, NULL);
if (ret)
goto out;
}
if (root_level == 0) {
ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
goto out;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* Walk down the tree. Missing extent blocks are filled in as
* we go. Metadata is accounted every time we read a new
* extent block.
*
* When we reach a leaf, we account for file extent items in it,
* walk back up the tree (adjusting slot pointers as we go)
* and restart the search process.
*/
atomic_inc(&root_eb->refs); /* For path */
path->nodes[root_level] = root_eb;
path->slots[root_level] = 0;
path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
walk_down:
level = root_level;
while (level >= 0) {
if (path->nodes[level] == NULL) {
struct btrfs_key first_key;
int parent_slot;
u64 child_gen;
u64 child_bytenr;
/*
* We need to get child blockptr/gen from parent before
* we can read it.
*/
eb = path->nodes[level + 1];
parent_slot = path->slots[level + 1];
child_bytenr = btrfs_node_blockptr(eb, parent_slot);
child_gen = btrfs_node_ptr_generation(eb, parent_slot);
btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
eb = read_tree_block(fs_info, child_bytenr, child_gen,
level, &first_key);
if (IS_ERR(eb)) {
ret = PTR_ERR(eb);
goto out;
} else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
ret = -EIO;
goto out;
}
path->nodes[level] = eb;
path->slots[level] = 0;
btrfs_tree_read_lock(eb);
btrfs_set_lock_blocking_read(eb);
path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
fs_info->nodesize,
GFP_NOFS);
if (ret)
goto out;
}
if (level == 0) {
ret = btrfs_qgroup_trace_leaf_items(trans,
path->nodes[level]);
if (ret)
goto out;
/* Nonzero return here means we completed our search */
ret = adjust_slots_upwards(path, root_level);
if (ret)
break;
/* Restart search with new slots */
goto walk_down;
}
level--;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
#define UPDATE_NEW 0
#define UPDATE_OLD 1
/*
* Walk all of the roots that points to the bytenr and adjust their refcnts.
*/
static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
struct ulist *roots, struct ulist *tmp,
struct ulist *qgroups, u64 seq, int update_old)
{
struct ulist_node *unode;
struct ulist_iterator uiter;
struct ulist_node *tmp_unode;
struct ulist_iterator tmp_uiter;
struct btrfs_qgroup *qg;
int ret = 0;
if (!roots)
return 0;
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(roots, &uiter))) {
qg = find_qgroup_rb(fs_info, unode->val);
if (!qg)
continue;
ulist_reinit(tmp);
ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
GFP_ATOMIC);
if (ret < 0)
return ret;
ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
if (ret < 0)
return ret;
ULIST_ITER_INIT(&tmp_uiter);
while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
struct btrfs_qgroup_list *glist;
qg = unode_aux_to_qgroup(tmp_unode);
if (update_old)
btrfs_qgroup_update_old_refcnt(qg, seq, 1);
else
btrfs_qgroup_update_new_refcnt(qg, seq, 1);
list_for_each_entry(glist, &qg->groups, next_group) {
ret = ulist_add(qgroups, glist->group->qgroupid,
qgroup_to_aux(glist->group),
GFP_ATOMIC);
if (ret < 0)
return ret;
ret = ulist_add(tmp, glist->group->qgroupid,
qgroup_to_aux(glist->group),
GFP_ATOMIC);
if (ret < 0)
return ret;
}
}
}
return 0;
}
/*
* Update qgroup rfer/excl counters.
* Rfer update is easy, codes can explain themselves.
*
* Excl update is tricky, the update is split into 2 part.
* Part 1: Possible exclusive <-> sharing detect:
* | A | !A |
* -------------------------------------
* B | * | - |
* -------------------------------------
* !B | + | ** |
* -------------------------------------
*
* Conditions:
* A: cur_old_roots < nr_old_roots (not exclusive before)
* !A: cur_old_roots == nr_old_roots (possible exclusive before)
* B: cur_new_roots < nr_new_roots (not exclusive now)
* !B: cur_new_roots == nr_new_roots (possible exclusive now)
*
* Results:
* +: Possible sharing -> exclusive -: Possible exclusive -> sharing
* *: Definitely not changed. **: Possible unchanged.
*
* For !A and !B condition, the exception is cur_old/new_roots == 0 case.
*
* To make the logic clear, we first use condition A and B to split
* combination into 4 results.
*
* Then, for result "+" and "-", check old/new_roots == 0 case, as in them
* only on variant maybe 0.
*
* Lastly, check result **, since there are 2 variants maybe 0, split them
* again(2x2).
* But this time we don't need to consider other things, the codes and logic
* is easy to understand now.
*/
static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
struct ulist *qgroups,
u64 nr_old_roots,
u64 nr_new_roots,
u64 num_bytes, u64 seq)
{
struct ulist_node *unode;
struct ulist_iterator uiter;
struct btrfs_qgroup *qg;
u64 cur_new_count, cur_old_count;
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(qgroups, &uiter))) {
bool dirty = false;
qg = unode_aux_to_qgroup(unode);
cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
trace_qgroup_update_counters(fs_info, qg, cur_old_count,
cur_new_count);
/* Rfer update part */
if (cur_old_count == 0 && cur_new_count > 0) {
qg->rfer += num_bytes;
qg->rfer_cmpr += num_bytes;
dirty = true;
}
if (cur_old_count > 0 && cur_new_count == 0) {
qg->rfer -= num_bytes;
qg->rfer_cmpr -= num_bytes;
dirty = true;
}
/* Excl update part */
/* Exclusive/none -> shared case */
if (cur_old_count == nr_old_roots &&
cur_new_count < nr_new_roots) {
/* Exclusive -> shared */
if (cur_old_count != 0) {
qg->excl -= num_bytes;
qg->excl_cmpr -= num_bytes;
dirty = true;
}
}
/* Shared -> exclusive/none case */
if (cur_old_count < nr_old_roots &&
cur_new_count == nr_new_roots) {
/* Shared->exclusive */
if (cur_new_count != 0) {
qg->excl += num_bytes;
qg->excl_cmpr += num_bytes;
dirty = true;
}
}
/* Exclusive/none -> exclusive/none case */
if (cur_old_count == nr_old_roots &&
cur_new_count == nr_new_roots) {
if (cur_old_count == 0) {
/* None -> exclusive/none */
if (cur_new_count != 0) {
/* None -> exclusive */
qg->excl += num_bytes;
qg->excl_cmpr += num_bytes;
dirty = true;
}
/* None -> none, nothing changed */
} else {
/* Exclusive -> exclusive/none */
if (cur_new_count == 0) {
/* Exclusive -> none */
qg->excl -= num_bytes;
qg->excl_cmpr -= num_bytes;
dirty = true;
}
/* Exclusive -> exclusive, nothing changed */
}
}
if (dirty)
qgroup_dirty(fs_info, qg);
}
return 0;
}
btrfs: qgroup: Add quick exit for non-fs extents Modify btrfs_qgroup_account_extent() to exit quicker for non-fs extents. The quick exit condition is: 1) The extent belongs to a non-fs tree Only fs-tree extents can affect qgroup numbers and is the only case where extent can be shared between different trees. Although strictly speaking extent in data-reloc or tree-reloc tree can be shared, data/tree-reloc root won't appear in the result of btrfs_find_all_roots(), so we can ignore such case. So we can check the first root in old_roots/new_roots ulist. - if we find the 1st root is a not a fs/subvol root, then we can skip the extent - if we find the 1st root is a fs/subvol root, then we must continue calculation OR 2) both 'nr_old_roots' and 'nr_new_roots' are 0 This means either such extent got allocated then freed in current transaction or it's a new reloc tree extent, whose nr_new_roots is 0. Either way it won't affect qgroup accounting and can be skipped safely. Such quick exit can make trace output more quite and less confusing: (example with fs uuid and time stamp removed) Before: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 btrfs_qgroup_account_extent: bytenr=29556736 num_bytes=16384 nr_old_roots=0 nr_new_roots=1 ------ Extent tree block will trigger btrfs_qgroup_account_extent() trace point while no qgroup number is changed, as extent tree won't affect qgroup accounting. After: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 ------ Now such unrelated extent won't trigger btrfs_qgroup_account_extent() trace point, making the trace less noisy. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog and comment adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:34 +00:00
/*
* Check if the @roots potentially is a list of fs tree roots
*
* Return 0 for definitely not a fs/subvol tree roots ulist
* Return 1 for possible fs/subvol tree roots in the list (considering an empty
* one as well)
*/
static int maybe_fs_roots(struct ulist *roots)
{
struct ulist_node *unode;
struct ulist_iterator uiter;
/* Empty one, still possible for fs roots */
if (!roots || roots->nnodes == 0)
return 1;
ULIST_ITER_INIT(&uiter);
unode = ulist_next(roots, &uiter);
if (!unode)
return 1;
/*
* If it contains fs tree roots, then it must belong to fs/subvol
* trees.
* If it contains a non-fs tree, it won't be shared with fs/subvol trees.
*/
return is_fstree(unode->val);
}
int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
u64 num_bytes, struct ulist *old_roots,
struct ulist *new_roots)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct ulist *qgroups = NULL;
struct ulist *tmp = NULL;
u64 seq;
u64 nr_new_roots = 0;
u64 nr_old_roots = 0;
int ret = 0;
btrfs: fix memory leak in qgroup accounting When running xfstests on the current btrfs I get the following splat from kmemleak: unreferenced object 0xffff88821b2404e0 (size 32): comm "kworker/u4:7", pid 26663, jiffies 4295283698 (age 8.776s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 10 ff fd 26 82 88 ff ff ...........&.... 10 ff fd 26 82 88 ff ff 20 ff fd 26 82 88 ff ff ...&.... ..&.... backtrace: [<00000000f94fd43f>] ulist_alloc+0x25/0x60 [btrfs] [<00000000fd023d99>] btrfs_find_all_roots_safe+0x41/0x100 [btrfs] [<000000008f17bd32>] btrfs_find_all_roots+0x52/0x70 [btrfs] [<00000000b7660afb>] btrfs_qgroup_rescan_worker+0x343/0x680 [btrfs] [<0000000058e66778>] btrfs_work_helper+0xac/0x1e0 [btrfs] [<00000000f0188930>] process_one_work+0x1cf/0x350 [<00000000af5f2f8e>] worker_thread+0x28/0x3c0 [<00000000b55a1add>] kthread+0x109/0x120 [<00000000f88cbd17>] ret_from_fork+0x35/0x40 This corresponds to: (gdb) l *(btrfs_find_all_roots_safe+0x41) 0x8d7e1 is in btrfs_find_all_roots_safe (fs/btrfs/backref.c:1413). 1408 1409 tmp = ulist_alloc(GFP_NOFS); 1410 if (!tmp) 1411 return -ENOMEM; 1412 *roots = ulist_alloc(GFP_NOFS); 1413 if (!*roots) { 1414 ulist_free(tmp); 1415 return -ENOMEM; 1416 } 1417 Following the lifetime of the allocated 'roots' ulist, it gets freed again in btrfs_qgroup_account_extent(). But this does not happen if the function is called with the 'BTRFS_FS_QUOTA_ENABLED' flag cleared, then btrfs_qgroup_account_extent() does a short leave and directly returns. Instead of directly returning we should jump to the 'out_free' in order to free all resources as expected. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-08 12:07:32 +00:00
/*
* If quotas get disabled meanwhile, the resouces need to be freed and
* we can't just exit here.
*/
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
btrfs: fix memory leak in qgroup accounting When running xfstests on the current btrfs I get the following splat from kmemleak: unreferenced object 0xffff88821b2404e0 (size 32): comm "kworker/u4:7", pid 26663, jiffies 4295283698 (age 8.776s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 10 ff fd 26 82 88 ff ff ...........&.... 10 ff fd 26 82 88 ff ff 20 ff fd 26 82 88 ff ff ...&.... ..&.... backtrace: [<00000000f94fd43f>] ulist_alloc+0x25/0x60 [btrfs] [<00000000fd023d99>] btrfs_find_all_roots_safe+0x41/0x100 [btrfs] [<000000008f17bd32>] btrfs_find_all_roots+0x52/0x70 [btrfs] [<00000000b7660afb>] btrfs_qgroup_rescan_worker+0x343/0x680 [btrfs] [<0000000058e66778>] btrfs_work_helper+0xac/0x1e0 [btrfs] [<00000000f0188930>] process_one_work+0x1cf/0x350 [<00000000af5f2f8e>] worker_thread+0x28/0x3c0 [<00000000b55a1add>] kthread+0x109/0x120 [<00000000f88cbd17>] ret_from_fork+0x35/0x40 This corresponds to: (gdb) l *(btrfs_find_all_roots_safe+0x41) 0x8d7e1 is in btrfs_find_all_roots_safe (fs/btrfs/backref.c:1413). 1408 1409 tmp = ulist_alloc(GFP_NOFS); 1410 if (!tmp) 1411 return -ENOMEM; 1412 *roots = ulist_alloc(GFP_NOFS); 1413 if (!*roots) { 1414 ulist_free(tmp); 1415 return -ENOMEM; 1416 } 1417 Following the lifetime of the allocated 'roots' ulist, it gets freed again in btrfs_qgroup_account_extent(). But this does not happen if the function is called with the 'BTRFS_FS_QUOTA_ENABLED' flag cleared, then btrfs_qgroup_account_extent() does a short leave and directly returns. Instead of directly returning we should jump to the 'out_free' in order to free all resources as expected. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-08 12:07:32 +00:00
goto out_free;
btrfs: qgroup: Add quick exit for non-fs extents Modify btrfs_qgroup_account_extent() to exit quicker for non-fs extents. The quick exit condition is: 1) The extent belongs to a non-fs tree Only fs-tree extents can affect qgroup numbers and is the only case where extent can be shared between different trees. Although strictly speaking extent in data-reloc or tree-reloc tree can be shared, data/tree-reloc root won't appear in the result of btrfs_find_all_roots(), so we can ignore such case. So we can check the first root in old_roots/new_roots ulist. - if we find the 1st root is a not a fs/subvol root, then we can skip the extent - if we find the 1st root is a fs/subvol root, then we must continue calculation OR 2) both 'nr_old_roots' and 'nr_new_roots' are 0 This means either such extent got allocated then freed in current transaction or it's a new reloc tree extent, whose nr_new_roots is 0. Either way it won't affect qgroup accounting and can be skipped safely. Such quick exit can make trace output more quite and less confusing: (example with fs uuid and time stamp removed) Before: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 btrfs_qgroup_account_extent: bytenr=29556736 num_bytes=16384 nr_old_roots=0 nr_new_roots=1 ------ Extent tree block will trigger btrfs_qgroup_account_extent() trace point while no qgroup number is changed, as extent tree won't affect qgroup accounting. After: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 ------ Now such unrelated extent won't trigger btrfs_qgroup_account_extent() trace point, making the trace less noisy. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog and comment adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:34 +00:00
if (new_roots) {
if (!maybe_fs_roots(new_roots))
goto out_free;
nr_new_roots = new_roots->nnodes;
btrfs: qgroup: Add quick exit for non-fs extents Modify btrfs_qgroup_account_extent() to exit quicker for non-fs extents. The quick exit condition is: 1) The extent belongs to a non-fs tree Only fs-tree extents can affect qgroup numbers and is the only case where extent can be shared between different trees. Although strictly speaking extent in data-reloc or tree-reloc tree can be shared, data/tree-reloc root won't appear in the result of btrfs_find_all_roots(), so we can ignore such case. So we can check the first root in old_roots/new_roots ulist. - if we find the 1st root is a not a fs/subvol root, then we can skip the extent - if we find the 1st root is a fs/subvol root, then we must continue calculation OR 2) both 'nr_old_roots' and 'nr_new_roots' are 0 This means either such extent got allocated then freed in current transaction or it's a new reloc tree extent, whose nr_new_roots is 0. Either way it won't affect qgroup accounting and can be skipped safely. Such quick exit can make trace output more quite and less confusing: (example with fs uuid and time stamp removed) Before: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 btrfs_qgroup_account_extent: bytenr=29556736 num_bytes=16384 nr_old_roots=0 nr_new_roots=1 ------ Extent tree block will trigger btrfs_qgroup_account_extent() trace point while no qgroup number is changed, as extent tree won't affect qgroup accounting. After: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 ------ Now such unrelated extent won't trigger btrfs_qgroup_account_extent() trace point, making the trace less noisy. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog and comment adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:34 +00:00
}
if (old_roots) {
if (!maybe_fs_roots(old_roots))
goto out_free;
nr_old_roots = old_roots->nnodes;
btrfs: qgroup: Add quick exit for non-fs extents Modify btrfs_qgroup_account_extent() to exit quicker for non-fs extents. The quick exit condition is: 1) The extent belongs to a non-fs tree Only fs-tree extents can affect qgroup numbers and is the only case where extent can be shared between different trees. Although strictly speaking extent in data-reloc or tree-reloc tree can be shared, data/tree-reloc root won't appear in the result of btrfs_find_all_roots(), so we can ignore such case. So we can check the first root in old_roots/new_roots ulist. - if we find the 1st root is a not a fs/subvol root, then we can skip the extent - if we find the 1st root is a fs/subvol root, then we must continue calculation OR 2) both 'nr_old_roots' and 'nr_new_roots' are 0 This means either such extent got allocated then freed in current transaction or it's a new reloc tree extent, whose nr_new_roots is 0. Either way it won't affect qgroup accounting and can be skipped safely. Such quick exit can make trace output more quite and less confusing: (example with fs uuid and time stamp removed) Before: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 btrfs_qgroup_account_extent: bytenr=29556736 num_bytes=16384 nr_old_roots=0 nr_new_roots=1 ------ Extent tree block will trigger btrfs_qgroup_account_extent() trace point while no qgroup number is changed, as extent tree won't affect qgroup accounting. After: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 ------ Now such unrelated extent won't trigger btrfs_qgroup_account_extent() trace point, making the trace less noisy. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog and comment adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:34 +00:00
}
/* Quick exit, either not fs tree roots, or won't affect any qgroup */
if (nr_old_roots == 0 && nr_new_roots == 0)
goto out_free;
BUG_ON(!fs_info->quota_root);
trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
num_bytes, nr_old_roots, nr_new_roots);
qgroups = ulist_alloc(GFP_NOFS);
if (!qgroups) {
ret = -ENOMEM;
goto out_free;
}
tmp = ulist_alloc(GFP_NOFS);
if (!tmp) {
ret = -ENOMEM;
goto out_free;
}
mutex_lock(&fs_info->qgroup_rescan_lock);
if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
mutex_unlock(&fs_info->qgroup_rescan_lock);
ret = 0;
goto out_free;
}
}
mutex_unlock(&fs_info->qgroup_rescan_lock);
spin_lock(&fs_info->qgroup_lock);
seq = fs_info->qgroup_seq;
/* Update old refcnts using old_roots */
ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
UPDATE_OLD);
if (ret < 0)
goto out;
/* Update new refcnts using new_roots */
ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
UPDATE_NEW);
if (ret < 0)
goto out;
qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
num_bytes, seq);
/*
* Bump qgroup_seq to avoid seq overlap
*/
fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
out:
spin_unlock(&fs_info->qgroup_lock);
out_free:
ulist_free(tmp);
ulist_free(qgroups);
ulist_free(old_roots);
ulist_free(new_roots);
return ret;
}
int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_qgroup_extent_record *record;
struct btrfs_delayed_ref_root *delayed_refs;
struct ulist *new_roots = NULL;
struct rb_node *node;
u64 num_dirty_extents = 0;
u64 qgroup_to_skip;
int ret = 0;
delayed_refs = &trans->transaction->delayed_refs;
qgroup_to_skip = delayed_refs->qgroup_to_skip;
while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
record = rb_entry(node, struct btrfs_qgroup_extent_record,
node);
num_dirty_extents++;
trace_btrfs_qgroup_account_extents(fs_info, record);
if (!ret) {
/*
* Old roots should be searched when inserting qgroup
* extent record
*/
if (WARN_ON(!record->old_roots)) {
/* Search commit root to find old_roots */
ret = btrfs_find_all_roots(NULL, fs_info,
record->bytenr, 0,
btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and offset (encoded as a single logical address) to a list of extent refs. LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping (extent ref -> extent bytenr and offset, or logical address). These are useful capabilities for programs that manipulate extents and extent references from userspace (e.g. dedup and defrag utilities). When the extents are uncompressed (and not encrypted and not other), check_extent_in_eb performs filtering of the extent refs to remove any extent refs which do not contain the same extent offset as the 'logical' parameter's extent offset. This prevents LOGICAL_INO from returning references to more than a single block. To find the set of extent references to an uncompressed extent from [a, b), userspace has to run a loop like this pseudocode: for (i = a; i < b; ++i) extent_ref_set += LOGICAL_INO(i); At each iteration of the loop (up to 32768 iterations for a 128M extent), data we are interested in is collected in the kernel, then deleted by the filter in check_extent_in_eb. When the extents are compressed (or encrypted or other), the 'logical' parameter must be an extent bytenr (the 'a' parameter in the loop). No filtering by extent offset is done (or possible?) so the result is the complete set of extent refs for the entire extent. This removes the need for the loop, since we get all the extent refs in one call. Add an 'ignore_offset' argument to iterate_inodes_from_logical, [...several levels of function call graph...], and check_extent_in_eb, so that we can disable the extent offset filtering for uncompressed extents. This flag can be set by an improved version of the LOGICAL_INO ioctl to get either behavior as desired. There is no functional change in this patch. The new flag is always false. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: David Sterba <dsterba@suse.com> [ minor coding style fixes ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-22 17:58:45 +00:00
&record->old_roots, false);
if (ret < 0)
goto cleanup;
}
btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record [BUG] Btrfs/139 will fail with a high probability if the testing machine (VM) has only 2G RAM. Resulting the final write success while it should fail due to EDQUOT, and the fs will have quota exceeding the limit by 16K. The simplified reproducer will be: (needs a 2G ram VM) $ mkfs.btrfs -f $dev $ mount $dev $mnt $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ for i in $(seq -w 1 8); do xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null echo "file $i written" > /dev/kmsg done $ sync $ btrfs qgroup show -pcre --raw $mnt The last pwrite will not trigger EDQUOT and final 'qgroup show' will show something like: qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 none none --- --- 0/256 1073758208 1073758208 none 1073741824 --- --- And 1073758208 is larger than > 1073741824. [CAUSE] It's a bug in btrfs qgroup data reserved space management. For quota limit, we must ensure that: reserved (data + metadata) + rfer/excl <= limit Since rfer/excl is only updated at transaction commmit time, reserved space needs to be taken special care. One important part of reserved space is data, and for a new data extent written to disk, we still need to take the reserved space until rfer/excl numbers get updated. Originally when an ordered extent finishes, we migrate the reserved qgroup data space from extent_io tree to delayed ref head of the data extent, expecting delayed ref will only be cleaned up at commit transaction time. However for small RAM machine, due to memory pressure dirty pages can be flushed back to disk without committing a transaction. The related events will be something like: file 1 written btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840 btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096 btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344 btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192 btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344 cleanup_ref_head: num_bytes=54947840 cleanup_ref_head: num_bytes=5636096 cleanup_ref_head: num_bytes=569344 cleanup_ref_head: num_bytes=57344 cleanup_ref_head: num_bytes=8192 ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space file 2 written ... file 8 written cleanup_ref_head: num_bytes=8192 ... btrfs_commit_transaction <<< the only transaction committed during the test When file 2 is written, we have already freed 128M reserved qgroup data space for ino 258. Thus later write won't trigger EDQUOT. This allows us to write more data beyond qgroup limit. In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT. [FIX] By moving reserved qgroup data space from btrfs_delayed_ref_head to btrfs_qgroup_extent_record, we can ensure that reserved qgroup data space won't be freed half way before commit transaction, thus fix the problem. Fixes: f64d5ca86821 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:12 +00:00
/* Free the reserved data space */
btrfs_qgroup_free_refroot(fs_info,
record->data_rsv_refroot,
record->data_rsv,
BTRFS_QGROUP_RSV_DATA);
/*
* Use SEQ_LAST as time_seq to do special search, which
* doesn't lock tree or delayed_refs and search current
* root. It's safe inside commit_transaction().
*/
ret = btrfs_find_all_roots(trans, fs_info,
btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and offset (encoded as a single logical address) to a list of extent refs. LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping (extent ref -> extent bytenr and offset, or logical address). These are useful capabilities for programs that manipulate extents and extent references from userspace (e.g. dedup and defrag utilities). When the extents are uncompressed (and not encrypted and not other), check_extent_in_eb performs filtering of the extent refs to remove any extent refs which do not contain the same extent offset as the 'logical' parameter's extent offset. This prevents LOGICAL_INO from returning references to more than a single block. To find the set of extent references to an uncompressed extent from [a, b), userspace has to run a loop like this pseudocode: for (i = a; i < b; ++i) extent_ref_set += LOGICAL_INO(i); At each iteration of the loop (up to 32768 iterations for a 128M extent), data we are interested in is collected in the kernel, then deleted by the filter in check_extent_in_eb. When the extents are compressed (or encrypted or other), the 'logical' parameter must be an extent bytenr (the 'a' parameter in the loop). No filtering by extent offset is done (or possible?) so the result is the complete set of extent refs for the entire extent. This removes the need for the loop, since we get all the extent refs in one call. Add an 'ignore_offset' argument to iterate_inodes_from_logical, [...several levels of function call graph...], and check_extent_in_eb, so that we can disable the extent offset filtering for uncompressed extents. This flag can be set by an improved version of the LOGICAL_INO ioctl to get either behavior as desired. There is no functional change in this patch. The new flag is always false. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: David Sterba <dsterba@suse.com> [ minor coding style fixes ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-22 17:58:45 +00:00
record->bytenr, SEQ_LAST, &new_roots, false);
if (ret < 0)
goto cleanup;
if (qgroup_to_skip) {
ulist_del(new_roots, qgroup_to_skip, 0);
ulist_del(record->old_roots, qgroup_to_skip,
0);
}
ret = btrfs_qgroup_account_extent(trans, record->bytenr,
record->num_bytes,
record->old_roots,
new_roots);
record->old_roots = NULL;
new_roots = NULL;
}
cleanup:
ulist_free(record->old_roots);
ulist_free(new_roots);
new_roots = NULL;
rb_erase(node, &delayed_refs->dirty_extent_root);
kfree(record);
}
trace_qgroup_num_dirty_extents(fs_info, trans->transid,
num_dirty_extents);
return ret;
}
/*
* called from commit_transaction. Writes all changed qgroups to disk.
*/
int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
int ret = 0;
if (!fs_info->quota_root)
return ret;
spin_lock(&fs_info->qgroup_lock);
while (!list_empty(&fs_info->dirty_qgroups)) {
struct btrfs_qgroup *qgroup;
qgroup = list_first_entry(&fs_info->dirty_qgroups,
struct btrfs_qgroup, dirty);
list_del_init(&qgroup->dirty);
spin_unlock(&fs_info->qgroup_lock);
ret = update_qgroup_info_item(trans, qgroup);
if (ret)
fs_info->qgroup_flags |=
BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
ret = update_qgroup_limit_item(trans, qgroup);
if (ret)
fs_info->qgroup_flags |=
BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
spin_lock(&fs_info->qgroup_lock);
}
if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
else
fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
spin_unlock(&fs_info->qgroup_lock);
ret = update_qgroup_status_item(trans);
if (ret)
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
return ret;
}
/*
* Copy the accounting information between qgroups. This is necessary
* when a snapshot or a subvolume is created. Throwing an error will
* cause a transaction abort so we take extra care here to only error
* when a readonly fs is a reasonable outcome.
*/
int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
u64 objectid, struct btrfs_qgroup_inherit *inherit)
{
int ret = 0;
int i;
u64 *i_qgroups;
btrfs: qgroup: Don't hold qgroup_ioctl_lock in btrfs_qgroup_inherit() [BUG] Lockdep will report the following circular locking dependency: WARNING: possible circular locking dependency detected 5.2.0-rc2-custom #24 Tainted: G O ------------------------------------------------------ btrfs/8631 is trying to acquire lock: 000000002536438c (&fs_info->qgroup_ioctl_lock#2){+.+.}, at: btrfs_qgroup_inherit+0x40/0x620 [btrfs] but task is already holding lock: 000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&fs_info->tree_log_mutex){+.+.}: __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_commit_transaction+0x475/0xa00 [btrfs] btrfs_commit_super+0x71/0x80 [btrfs] close_ctree+0x2bd/0x320 [btrfs] btrfs_put_super+0x15/0x20 [btrfs] generic_shutdown_super+0x72/0x110 kill_anon_super+0x18/0x30 btrfs_kill_super+0x16/0xa0 [btrfs] deactivate_locked_super+0x3a/0x80 deactivate_super+0x51/0x60 cleanup_mnt+0x3f/0x80 __cleanup_mnt+0x12/0x20 task_work_run+0x94/0xb0 exit_to_usermode_loop+0xd8/0xe0 do_syscall_64+0x210/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&fs_info->reloc_mutex){+.+.}: __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_commit_transaction+0x40d/0xa00 [btrfs] btrfs_quota_enable+0x2da/0x730 [btrfs] btrfs_ioctl+0x2691/0x2b40 [btrfs] do_vfs_ioctl+0xa9/0x6d0 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&fs_info->qgroup_ioctl_lock#2){+.+.}: lock_acquire+0xa7/0x190 __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_qgroup_inherit+0x40/0x620 [btrfs] create_pending_snapshot+0x9d7/0xe60 [btrfs] create_pending_snapshots+0x94/0xb0 [btrfs] btrfs_commit_transaction+0x415/0xa00 [btrfs] btrfs_mksubvol+0x496/0x4e0 [btrfs] btrfs_ioctl_snap_create_transid+0x174/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x11c/0x180 [btrfs] btrfs_ioctl+0xa90/0x2b40 [btrfs] do_vfs_ioctl+0xa9/0x6d0 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &fs_info->qgroup_ioctl_lock#2 --> &fs_info->reloc_mutex --> &fs_info->tree_log_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->tree_log_mutex); lock(&fs_info->reloc_mutex); lock(&fs_info->tree_log_mutex); lock(&fs_info->qgroup_ioctl_lock#2); *** DEADLOCK *** 6 locks held by btrfs/8631: #0: 00000000ed8f23f6 (sb_writers#12){.+.+}, at: mnt_want_write_file+0x28/0x60 #1: 000000009fb1597a (&type->i_mutex_dir_key#10/1){+.+.}, at: btrfs_mksubvol+0x70/0x4e0 [btrfs] #2: 0000000088c5ad88 (&fs_info->subvol_sem){++++}, at: btrfs_mksubvol+0x128/0x4e0 [btrfs] #3: 000000009606fc3e (sb_internal#2){.+.+}, at: start_transaction+0x37a/0x520 [btrfs] #4: 00000000f82bbdf5 (&fs_info->reloc_mutex){+.+.}, at: btrfs_commit_transaction+0x40d/0xa00 [btrfs] #5: 000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs] [CAUSE] Due to the delayed subvolume creation, we need to call btrfs_qgroup_inherit() inside commit transaction code, with a lot of other mutex hold. This hell of lock chain can lead to above problem. [FIX] On the other hand, we don't really need to hold qgroup_ioctl_lock if we're in the context of create_pending_snapshot(). As in that context, we're the only one being able to modify qgroup. All other qgroup functions which needs qgroup_ioctl_lock are either holding a transaction handle, or will start a new transaction: Functions will start a new transaction(): * btrfs_quota_enable() * btrfs_quota_disable() Functions hold a transaction handler: * btrfs_add_qgroup_relation() * btrfs_del_qgroup_relation() * btrfs_create_qgroup() * btrfs_remove_qgroup() * btrfs_limit_qgroup() * btrfs_qgroup_inherit() call inside create_subvol() So we have a higher level protection provided by transaction, thus we don't need to always hold qgroup_ioctl_lock in btrfs_qgroup_inherit(). Only the btrfs_qgroup_inherit() call in create_subvol() needs to hold qgroup_ioctl_lock, while the btrfs_qgroup_inherit() call in create_pending_snapshot() is already protected by transaction. So the fix is to detect the context by checking trans->transaction->state. If we're at TRANS_STATE_COMMIT_DOING, then we're in commit transaction context and no need to get the mutex. Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-13 09:31:24 +00:00
bool committing = false;
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *quota_root;
struct btrfs_qgroup *srcgroup;
struct btrfs_qgroup *dstgroup;
u32 level_size = 0;
u64 nums;
btrfs: qgroup: Don't hold qgroup_ioctl_lock in btrfs_qgroup_inherit() [BUG] Lockdep will report the following circular locking dependency: WARNING: possible circular locking dependency detected 5.2.0-rc2-custom #24 Tainted: G O ------------------------------------------------------ btrfs/8631 is trying to acquire lock: 000000002536438c (&fs_info->qgroup_ioctl_lock#2){+.+.}, at: btrfs_qgroup_inherit+0x40/0x620 [btrfs] but task is already holding lock: 000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&fs_info->tree_log_mutex){+.+.}: __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_commit_transaction+0x475/0xa00 [btrfs] btrfs_commit_super+0x71/0x80 [btrfs] close_ctree+0x2bd/0x320 [btrfs] btrfs_put_super+0x15/0x20 [btrfs] generic_shutdown_super+0x72/0x110 kill_anon_super+0x18/0x30 btrfs_kill_super+0x16/0xa0 [btrfs] deactivate_locked_super+0x3a/0x80 deactivate_super+0x51/0x60 cleanup_mnt+0x3f/0x80 __cleanup_mnt+0x12/0x20 task_work_run+0x94/0xb0 exit_to_usermode_loop+0xd8/0xe0 do_syscall_64+0x210/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&fs_info->reloc_mutex){+.+.}: __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_commit_transaction+0x40d/0xa00 [btrfs] btrfs_quota_enable+0x2da/0x730 [btrfs] btrfs_ioctl+0x2691/0x2b40 [btrfs] do_vfs_ioctl+0xa9/0x6d0 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&fs_info->qgroup_ioctl_lock#2){+.+.}: lock_acquire+0xa7/0x190 __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_qgroup_inherit+0x40/0x620 [btrfs] create_pending_snapshot+0x9d7/0xe60 [btrfs] create_pending_snapshots+0x94/0xb0 [btrfs] btrfs_commit_transaction+0x415/0xa00 [btrfs] btrfs_mksubvol+0x496/0x4e0 [btrfs] btrfs_ioctl_snap_create_transid+0x174/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x11c/0x180 [btrfs] btrfs_ioctl+0xa90/0x2b40 [btrfs] do_vfs_ioctl+0xa9/0x6d0 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &fs_info->qgroup_ioctl_lock#2 --> &fs_info->reloc_mutex --> &fs_info->tree_log_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->tree_log_mutex); lock(&fs_info->reloc_mutex); lock(&fs_info->tree_log_mutex); lock(&fs_info->qgroup_ioctl_lock#2); *** DEADLOCK *** 6 locks held by btrfs/8631: #0: 00000000ed8f23f6 (sb_writers#12){.+.+}, at: mnt_want_write_file+0x28/0x60 #1: 000000009fb1597a (&type->i_mutex_dir_key#10/1){+.+.}, at: btrfs_mksubvol+0x70/0x4e0 [btrfs] #2: 0000000088c5ad88 (&fs_info->subvol_sem){++++}, at: btrfs_mksubvol+0x128/0x4e0 [btrfs] #3: 000000009606fc3e (sb_internal#2){.+.+}, at: start_transaction+0x37a/0x520 [btrfs] #4: 00000000f82bbdf5 (&fs_info->reloc_mutex){+.+.}, at: btrfs_commit_transaction+0x40d/0xa00 [btrfs] #5: 000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs] [CAUSE] Due to the delayed subvolume creation, we need to call btrfs_qgroup_inherit() inside commit transaction code, with a lot of other mutex hold. This hell of lock chain can lead to above problem. [FIX] On the other hand, we don't really need to hold qgroup_ioctl_lock if we're in the context of create_pending_snapshot(). As in that context, we're the only one being able to modify qgroup. All other qgroup functions which needs qgroup_ioctl_lock are either holding a transaction handle, or will start a new transaction: Functions will start a new transaction(): * btrfs_quota_enable() * btrfs_quota_disable() Functions hold a transaction handler: * btrfs_add_qgroup_relation() * btrfs_del_qgroup_relation() * btrfs_create_qgroup() * btrfs_remove_qgroup() * btrfs_limit_qgroup() * btrfs_qgroup_inherit() call inside create_subvol() So we have a higher level protection provided by transaction, thus we don't need to always hold qgroup_ioctl_lock in btrfs_qgroup_inherit(). Only the btrfs_qgroup_inherit() call in create_subvol() needs to hold qgroup_ioctl_lock, while the btrfs_qgroup_inherit() call in create_pending_snapshot() is already protected by transaction. So the fix is to detect the context by checking trans->transaction->state. If we're at TRANS_STATE_COMMIT_DOING, then we're in commit transaction context and no need to get the mutex. Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-13 09:31:24 +00:00
/*
* There are only two callers of this function.
*
* One in create_subvol() in the ioctl context, which needs to hold
* the qgroup_ioctl_lock.
*
* The other one in create_pending_snapshot() where no other qgroup
* code can modify the fs as they all need to either start a new trans
* or hold a trans handler, thus we don't need to hold
* qgroup_ioctl_lock.
* This would avoid long and complex lock chain and make lockdep happy.
*/
spin_lock(&fs_info->trans_lock);
if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
committing = true;
spin_unlock(&fs_info->trans_lock);
if (!committing)
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
goto out;
quota_root = fs_info->quota_root;
if (!quota_root) {
ret = -EINVAL;
goto out;
}
if (inherit) {
i_qgroups = (u64 *)(inherit + 1);
nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2 * inherit->num_excl_copies;
for (i = 0; i < nums; ++i) {
srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
/*
* Zero out invalid groups so we can ignore
* them later.
*/
if (!srcgroup ||
((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
*i_qgroups = 0ULL;
++i_qgroups;
}
}
/*
* create a tracking group for the subvol itself
*/
ret = add_qgroup_item(trans, quota_root, objectid);
if (ret)
goto out;
/*
* add qgroup to all inherited groups
*/
if (inherit) {
i_qgroups = (u64 *)(inherit + 1);
for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
if (*i_qgroups == 0)
continue;
ret = add_qgroup_relation_item(trans, objectid,
*i_qgroups);
if (ret && ret != -EEXIST)
goto out;
ret = add_qgroup_relation_item(trans, *i_qgroups,
objectid);
if (ret && ret != -EEXIST)
goto out;
}
ret = 0;
}
spin_lock(&fs_info->qgroup_lock);
dstgroup = add_qgroup_rb(fs_info, objectid);
if (IS_ERR(dstgroup)) {
ret = PTR_ERR(dstgroup);
goto unlock;
}
if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
dstgroup->lim_flags = inherit->lim.flags;
dstgroup->max_rfer = inherit->lim.max_rfer;
dstgroup->max_excl = inherit->lim.max_excl;
dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
dstgroup->rsv_excl = inherit->lim.rsv_excl;
ret = update_qgroup_limit_item(trans, dstgroup);
if (ret) {
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
btrfs_info(fs_info,
"unable to update quota limit for %llu",
dstgroup->qgroupid);
goto unlock;
}
}
if (srcid) {
srcgroup = find_qgroup_rb(fs_info, srcid);
if (!srcgroup)
goto unlock;
Btrfs: rework qgroup accounting Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-05-14 00:30:47 +00:00
/*
* We call inherit after we clone the root in order to make sure
* our counts don't go crazy, so at this point the only
* difference between the two roots should be the root node.
*/
level_size = fs_info->nodesize;
Btrfs: rework qgroup accounting Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-05-14 00:30:47 +00:00
dstgroup->rfer = srcgroup->rfer;
dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
dstgroup->excl = level_size;
dstgroup->excl_cmpr = level_size;
srcgroup->excl = level_size;
srcgroup->excl_cmpr = level_size;
/* inherit the limit info */
dstgroup->lim_flags = srcgroup->lim_flags;
dstgroup->max_rfer = srcgroup->max_rfer;
dstgroup->max_excl = srcgroup->max_excl;
dstgroup->rsv_rfer = srcgroup->rsv_rfer;
dstgroup->rsv_excl = srcgroup->rsv_excl;
qgroup_dirty(fs_info, dstgroup);
qgroup_dirty(fs_info, srcgroup);
}
if (!inherit)
goto unlock;
i_qgroups = (u64 *)(inherit + 1);
for (i = 0; i < inherit->num_qgroups; ++i) {
if (*i_qgroups) {
ret = add_relation_rb(fs_info, objectid, *i_qgroups);
if (ret)
goto unlock;
}
++i_qgroups;
}
for (i = 0; i < inherit->num_ref_copies; ++i, i_qgroups += 2) {
struct btrfs_qgroup *src;
struct btrfs_qgroup *dst;
if (!i_qgroups[0] || !i_qgroups[1])
continue;
src = find_qgroup_rb(fs_info, i_qgroups[0]);
dst = find_qgroup_rb(fs_info, i_qgroups[1]);
if (!src || !dst) {
ret = -EINVAL;
goto unlock;
}
dst->rfer = src->rfer - level_size;
dst->rfer_cmpr = src->rfer_cmpr - level_size;
}
for (i = 0; i < inherit->num_excl_copies; ++i, i_qgroups += 2) {
struct btrfs_qgroup *src;
struct btrfs_qgroup *dst;
if (!i_qgroups[0] || !i_qgroups[1])
continue;
src = find_qgroup_rb(fs_info, i_qgroups[0]);
dst = find_qgroup_rb(fs_info, i_qgroups[1]);
if (!src || !dst) {
ret = -EINVAL;
goto unlock;
}
dst->excl = src->excl + level_size;
dst->excl_cmpr = src->excl_cmpr + level_size;
}
unlock:
spin_unlock(&fs_info->qgroup_lock);
out:
btrfs: qgroup: Don't hold qgroup_ioctl_lock in btrfs_qgroup_inherit() [BUG] Lockdep will report the following circular locking dependency: WARNING: possible circular locking dependency detected 5.2.0-rc2-custom #24 Tainted: G O ------------------------------------------------------ btrfs/8631 is trying to acquire lock: 000000002536438c (&fs_info->qgroup_ioctl_lock#2){+.+.}, at: btrfs_qgroup_inherit+0x40/0x620 [btrfs] but task is already holding lock: 000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&fs_info->tree_log_mutex){+.+.}: __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_commit_transaction+0x475/0xa00 [btrfs] btrfs_commit_super+0x71/0x80 [btrfs] close_ctree+0x2bd/0x320 [btrfs] btrfs_put_super+0x15/0x20 [btrfs] generic_shutdown_super+0x72/0x110 kill_anon_super+0x18/0x30 btrfs_kill_super+0x16/0xa0 [btrfs] deactivate_locked_super+0x3a/0x80 deactivate_super+0x51/0x60 cleanup_mnt+0x3f/0x80 __cleanup_mnt+0x12/0x20 task_work_run+0x94/0xb0 exit_to_usermode_loop+0xd8/0xe0 do_syscall_64+0x210/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&fs_info->reloc_mutex){+.+.}: __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_commit_transaction+0x40d/0xa00 [btrfs] btrfs_quota_enable+0x2da/0x730 [btrfs] btrfs_ioctl+0x2691/0x2b40 [btrfs] do_vfs_ioctl+0xa9/0x6d0 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&fs_info->qgroup_ioctl_lock#2){+.+.}: lock_acquire+0xa7/0x190 __mutex_lock+0x76/0x940 mutex_lock_nested+0x1b/0x20 btrfs_qgroup_inherit+0x40/0x620 [btrfs] create_pending_snapshot+0x9d7/0xe60 [btrfs] create_pending_snapshots+0x94/0xb0 [btrfs] btrfs_commit_transaction+0x415/0xa00 [btrfs] btrfs_mksubvol+0x496/0x4e0 [btrfs] btrfs_ioctl_snap_create_transid+0x174/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x11c/0x180 [btrfs] btrfs_ioctl+0xa90/0x2b40 [btrfs] do_vfs_ioctl+0xa9/0x6d0 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &fs_info->qgroup_ioctl_lock#2 --> &fs_info->reloc_mutex --> &fs_info->tree_log_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->tree_log_mutex); lock(&fs_info->reloc_mutex); lock(&fs_info->tree_log_mutex); lock(&fs_info->qgroup_ioctl_lock#2); *** DEADLOCK *** 6 locks held by btrfs/8631: #0: 00000000ed8f23f6 (sb_writers#12){.+.+}, at: mnt_want_write_file+0x28/0x60 #1: 000000009fb1597a (&type->i_mutex_dir_key#10/1){+.+.}, at: btrfs_mksubvol+0x70/0x4e0 [btrfs] #2: 0000000088c5ad88 (&fs_info->subvol_sem){++++}, at: btrfs_mksubvol+0x128/0x4e0 [btrfs] #3: 000000009606fc3e (sb_internal#2){.+.+}, at: start_transaction+0x37a/0x520 [btrfs] #4: 00000000f82bbdf5 (&fs_info->reloc_mutex){+.+.}, at: btrfs_commit_transaction+0x40d/0xa00 [btrfs] #5: 000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs] [CAUSE] Due to the delayed subvolume creation, we need to call btrfs_qgroup_inherit() inside commit transaction code, with a lot of other mutex hold. This hell of lock chain can lead to above problem. [FIX] On the other hand, we don't really need to hold qgroup_ioctl_lock if we're in the context of create_pending_snapshot(). As in that context, we're the only one being able to modify qgroup. All other qgroup functions which needs qgroup_ioctl_lock are either holding a transaction handle, or will start a new transaction: Functions will start a new transaction(): * btrfs_quota_enable() * btrfs_quota_disable() Functions hold a transaction handler: * btrfs_add_qgroup_relation() * btrfs_del_qgroup_relation() * btrfs_create_qgroup() * btrfs_remove_qgroup() * btrfs_limit_qgroup() * btrfs_qgroup_inherit() call inside create_subvol() So we have a higher level protection provided by transaction, thus we don't need to always hold qgroup_ioctl_lock in btrfs_qgroup_inherit(). Only the btrfs_qgroup_inherit() call in create_subvol() needs to hold qgroup_ioctl_lock, while the btrfs_qgroup_inherit() call in create_pending_snapshot() is already protected by transaction. So the fix is to detect the context by checking trans->transaction->state. If we're at TRANS_STATE_COMMIT_DOING, then we're in commit transaction context and no need to get the mutex. Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-13 09:31:24 +00:00
if (!committing)
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
/*
* Two limits to commit transaction in advance.
*
* For RATIO, it will be 1/RATIO of the remaining limit as threshold.
* For SIZE, it will be in byte unit as threshold.
*/
#define QGROUP_FREE_RATIO 32
#define QGROUP_FREE_SIZE SZ_32M
static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
const struct btrfs_qgroup *qg, u64 num_bytes)
{
u64 free;
u64 threshold;
if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
return false;
if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
return false;
/*
* Even if we passed the check, it's better to check if reservation
* for meta_pertrans is pushing us near limit.
* If there is too much pertrans reservation or it's near the limit,
* let's try commit transaction to free some, using transaction_kthread
*/
if ((qg->lim_flags & (BTRFS_QGROUP_LIMIT_MAX_RFER |
BTRFS_QGROUP_LIMIT_MAX_EXCL))) {
if (qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
free = qg->max_excl - qgroup_rsv_total(qg) - qg->excl;
threshold = min_t(u64, qg->max_excl / QGROUP_FREE_RATIO,
QGROUP_FREE_SIZE);
} else {
free = qg->max_rfer - qgroup_rsv_total(qg) - qg->rfer;
threshold = min_t(u64, qg->max_rfer / QGROUP_FREE_RATIO,
QGROUP_FREE_SIZE);
}
/*
* Use transaction_kthread to commit transaction, so we no
* longer need to bother nested transaction nor lock context.
*/
if (free < threshold)
btrfs_commit_transaction_locksafe(fs_info);
}
return true;
}
static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
enum btrfs_qgroup_rsv_type type)
{
struct btrfs_qgroup *qgroup;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 ref_root = root->root_key.objectid;
int ret = 0;
struct ulist_node *unode;
struct ulist_iterator uiter;
if (!is_fstree(ref_root))
return 0;
if (num_bytes == 0)
return 0;
if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
capable(CAP_SYS_RESOURCE))
enforce = false;
spin_lock(&fs_info->qgroup_lock);
if (!fs_info->quota_root)
goto out;
qgroup = find_qgroup_rb(fs_info, ref_root);
if (!qgroup)
goto out;
/*
* in a first step, we check all affected qgroups if any limits would
* be exceeded
*/
ulist_reinit(fs_info->qgroup_ulist);
ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
qgroup_to_aux(qgroup), GFP_ATOMIC);
if (ret < 0)
goto out;
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
struct btrfs_qgroup *qg;
struct btrfs_qgroup_list *glist;
qg = unode_aux_to_qgroup(unode);
if (enforce && !qgroup_check_limits(fs_info, qg, num_bytes)) {
ret = -EDQUOT;
goto out;
}
list_for_each_entry(glist, &qg->groups, next_group) {
ret = ulist_add(fs_info->qgroup_ulist,
glist->group->qgroupid,
qgroup_to_aux(glist->group), GFP_ATOMIC);
if (ret < 0)
goto out;
}
}
ret = 0;
/*
* no limits exceeded, now record the reservation into all qgroups
*/
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
struct btrfs_qgroup *qg;
qg = unode_aux_to_qgroup(unode);
qgroup_rsv_add(fs_info, qg, num_bytes, type);
}
out:
spin_unlock(&fs_info->qgroup_lock);
return ret;
}
/*
* Free @num_bytes of reserved space with @type for qgroup. (Normally level 0
* qgroup).
*
* Will handle all higher level qgroup too.
*
* NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
* This special case is only used for META_PERTRANS type.
*/
void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
u64 ref_root, u64 num_bytes,
enum btrfs_qgroup_rsv_type type)
{
struct btrfs_qgroup *qgroup;
struct ulist_node *unode;
struct ulist_iterator uiter;
int ret = 0;
if (!is_fstree(ref_root))
return;
if (num_bytes == 0)
return;
if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
WARN(1, "%s: Invalid type to free", __func__);
return;
}
spin_lock(&fs_info->qgroup_lock);
if (!fs_info->quota_root)
goto out;
qgroup = find_qgroup_rb(fs_info, ref_root);
if (!qgroup)
goto out;
if (num_bytes == (u64)-1)
/*
* We're freeing all pertrans rsv, get reserved value from
* level 0 qgroup as real num_bytes to free.
*/
num_bytes = qgroup->rsv.values[type];
ulist_reinit(fs_info->qgroup_ulist);
ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
qgroup_to_aux(qgroup), GFP_ATOMIC);
if (ret < 0)
goto out;
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
struct btrfs_qgroup *qg;
struct btrfs_qgroup_list *glist;
qg = unode_aux_to_qgroup(unode);
qgroup_rsv_release(fs_info, qg, num_bytes, type);
list_for_each_entry(glist, &qg->groups, next_group) {
ret = ulist_add(fs_info->qgroup_ulist,
glist->group->qgroupid,
qgroup_to_aux(glist->group), GFP_ATOMIC);
if (ret < 0)
goto out;
}
}
out:
spin_unlock(&fs_info->qgroup_lock);
}
btrfs: qgroup: Finish rescan when hit the last leaf of extent tree Under the following case, qgroup rescan can double account cowed tree blocks: In this case, extent tree only has one tree block. - | transid=5 last committed=4 | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 4). | Scan it, set qgroup_rescan_progress to the last | EXTENT/META_ITEM + 1 | now qgroup_rescan_progress = A + 1. | | fs tree get CoWed, new tree block is at A + 16K | transid 5 get committed - | transid=6 last committed=5 | btrfs_qgroup_rescan_worker() | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 5). | scan it using qgroup_rescan_progress (A + 1). | found new tree block beyong A, and it's fs tree block, | account it to increase qgroup numbers. - In above case, tree block A, and tree block A + 16K get accounted twice, while qgroup rescan should stop when it already reach the last leaf, other than continue using its qgroup_rescan_progress. Such case could happen by just looping btrfs/017 and with some possibility it can hit such double qgroup accounting problem. Fix it by checking the path to determine if we should finish qgroup rescan, other than relying on next loop to exit. Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-14 01:38:13 +00:00
/*
* Check if the leaf is the last leaf. Which means all node pointers
* are at their last position.
*/
static bool is_last_leaf(struct btrfs_path *path)
{
int i;
for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
return false;
}
return true;
}
/*
* returns < 0 on error, 0 when more leafs are to be scanned.
* returns 1 when done.
*/
static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
struct btrfs_path *path)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_key found;
struct extent_buffer *scratch_leaf = NULL;
struct ulist *roots = NULL;
Btrfs: rework qgroup accounting Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-05-14 00:30:47 +00:00
u64 num_bytes;
btrfs: qgroup: Finish rescan when hit the last leaf of extent tree Under the following case, qgroup rescan can double account cowed tree blocks: In this case, extent tree only has one tree block. - | transid=5 last committed=4 | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 4). | Scan it, set qgroup_rescan_progress to the last | EXTENT/META_ITEM + 1 | now qgroup_rescan_progress = A + 1. | | fs tree get CoWed, new tree block is at A + 16K | transid 5 get committed - | transid=6 last committed=5 | btrfs_qgroup_rescan_worker() | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 5). | scan it using qgroup_rescan_progress (A + 1). | found new tree block beyong A, and it's fs tree block, | account it to increase qgroup numbers. - In above case, tree block A, and tree block A + 16K get accounted twice, while qgroup rescan should stop when it already reach the last leaf, other than continue using its qgroup_rescan_progress. Such case could happen by just looping btrfs/017 and with some possibility it can hit such double qgroup accounting problem. Fix it by checking the path to determine if we should finish qgroup rescan, other than relying on next loop to exit. Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-14 01:38:13 +00:00
bool done;
int slot;
int ret;
mutex_lock(&fs_info->qgroup_rescan_lock);
ret = btrfs_search_slot_for_read(fs_info->extent_root,
&fs_info->qgroup_rescan_progress,
path, 1, 0);
btrfs_debug(fs_info,
"current progress key (%llu %u %llu), search_slot ret %d",
fs_info->qgroup_rescan_progress.objectid,
fs_info->qgroup_rescan_progress.type,
fs_info->qgroup_rescan_progress.offset, ret);
if (ret) {
/*
* The rescan is about to end, we will not be scanning any
* further blocks. We cannot unset the RESCAN flag here, because
* we want to commit the transaction if everything went well.
* To make the live accounting work in this phase, we set our
* scan progress pointer such that every real extent objectid
* will be smaller.
*/
fs_info->qgroup_rescan_progress.objectid = (u64)-1;
btrfs_release_path(path);
mutex_unlock(&fs_info->qgroup_rescan_lock);
return ret;
}
btrfs: qgroup: Finish rescan when hit the last leaf of extent tree Under the following case, qgroup rescan can double account cowed tree blocks: In this case, extent tree only has one tree block. - | transid=5 last committed=4 | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 4). | Scan it, set qgroup_rescan_progress to the last | EXTENT/META_ITEM + 1 | now qgroup_rescan_progress = A + 1. | | fs tree get CoWed, new tree block is at A + 16K | transid 5 get committed - | transid=6 last committed=5 | btrfs_qgroup_rescan_worker() | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 5). | scan it using qgroup_rescan_progress (A + 1). | found new tree block beyong A, and it's fs tree block, | account it to increase qgroup numbers. - In above case, tree block A, and tree block A + 16K get accounted twice, while qgroup rescan should stop when it already reach the last leaf, other than continue using its qgroup_rescan_progress. Such case could happen by just looping btrfs/017 and with some possibility it can hit such double qgroup accounting problem. Fix it by checking the path to determine if we should finish qgroup rescan, other than relying on next loop to exit. Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-14 01:38:13 +00:00
done = is_last_leaf(path);
btrfs_item_key_to_cpu(path->nodes[0], &found,
btrfs_header_nritems(path->nodes[0]) - 1);
fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
if (!scratch_leaf) {
ret = -ENOMEM;
mutex_unlock(&fs_info->qgroup_rescan_lock);
goto out;
}
slot = path->slots[0];
btrfs_release_path(path);
mutex_unlock(&fs_info->qgroup_rescan_lock);
for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
if (found.type != BTRFS_EXTENT_ITEM_KEY &&
found.type != BTRFS_METADATA_ITEM_KEY)
continue;
if (found.type == BTRFS_METADATA_ITEM_KEY)
num_bytes = fs_info->nodesize;
else
num_bytes = found.offset;
Btrfs: rework qgroup accounting Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-05-14 00:30:47 +00:00
ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and offset (encoded as a single logical address) to a list of extent refs. LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping (extent ref -> extent bytenr and offset, or logical address). These are useful capabilities for programs that manipulate extents and extent references from userspace (e.g. dedup and defrag utilities). When the extents are uncompressed (and not encrypted and not other), check_extent_in_eb performs filtering of the extent refs to remove any extent refs which do not contain the same extent offset as the 'logical' parameter's extent offset. This prevents LOGICAL_INO from returning references to more than a single block. To find the set of extent references to an uncompressed extent from [a, b), userspace has to run a loop like this pseudocode: for (i = a; i < b; ++i) extent_ref_set += LOGICAL_INO(i); At each iteration of the loop (up to 32768 iterations for a 128M extent), data we are interested in is collected in the kernel, then deleted by the filter in check_extent_in_eb. When the extents are compressed (or encrypted or other), the 'logical' parameter must be an extent bytenr (the 'a' parameter in the loop). No filtering by extent offset is done (or possible?) so the result is the complete set of extent refs for the entire extent. This removes the need for the loop, since we get all the extent refs in one call. Add an 'ignore_offset' argument to iterate_inodes_from_logical, [...several levels of function call graph...], and check_extent_in_eb, so that we can disable the extent offset filtering for uncompressed extents. This flag can be set by an improved version of the LOGICAL_INO ioctl to get either behavior as desired. There is no functional change in this patch. The new flag is always false. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: David Sterba <dsterba@suse.com> [ minor coding style fixes ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-22 17:58:45 +00:00
&roots, false);
if (ret < 0)
goto out;
/* For rescan, just pass old_roots as NULL */
ret = btrfs_qgroup_account_extent(trans, found.objectid,
num_bytes, NULL, roots);
if (ret < 0)
Btrfs: rework qgroup accounting Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-05-14 00:30:47 +00:00
goto out;
}
out:
if (scratch_leaf)
free_extent_buffer(scratch_leaf);
if (done && !ret) {
btrfs: qgroup: Finish rescan when hit the last leaf of extent tree Under the following case, qgroup rescan can double account cowed tree blocks: In this case, extent tree only has one tree block. - | transid=5 last committed=4 | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 4). | Scan it, set qgroup_rescan_progress to the last | EXTENT/META_ITEM + 1 | now qgroup_rescan_progress = A + 1. | | fs tree get CoWed, new tree block is at A + 16K | transid 5 get committed - | transid=6 last committed=5 | btrfs_qgroup_rescan_worker() | btrfs_qgroup_rescan_worker() | |- btrfs_start_transaction() | | transid = 5 | |- qgroup_rescan_leaf() | |- btrfs_search_slot_for_read() on extent tree | Get the only extent tree block from commit root (transid = 5). | scan it using qgroup_rescan_progress (A + 1). | found new tree block beyong A, and it's fs tree block, | account it to increase qgroup numbers. - In above case, tree block A, and tree block A + 16K get accounted twice, while qgroup rescan should stop when it already reach the last leaf, other than continue using its qgroup_rescan_progress. Such case could happen by just looping btrfs/017 and with some possibility it can hit such double qgroup accounting problem. Fix it by checking the path to determine if we should finish qgroup rescan, other than relying on next loop to exit. Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-14 01:38:13 +00:00
ret = 1;
fs_info->qgroup_rescan_progress.objectid = (u64)-1;
}
return ret;
}
static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
{
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
qgroup_rescan_work);
struct btrfs_path *path;
struct btrfs_trans_handle *trans = NULL;
int err = -ENOMEM;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
goto out;
btrfs: qgroup: Search commit root for rescan to avoid missing extent When doing qgroup rescan using the following script (modified from btrfs/017 test case), we can sometimes hit qgroup corruption. ------ umount $dev &> /dev/null umount $mnt &> /dev/null mkfs.btrfs -f -n 64k $dev mount $dev $mnt extent_size=8192 xfs_io -f -d -c "pwrite 0 $extent_size" $mnt/foo > /dev/null btrfs subvolume snapshot $mnt $mnt/snap xfs_io -f -c "reflink $mnt/foo" $mnt/foo-reflink > /dev/null xfs_io -f -c "reflink $mnt/foo" $mnt/snap/foo-reflink > /dev/null xfs_io -f -c "reflink $mnt/foo" $mnt/snap/foo-reflink2 > /dev/unll btrfs quota enable $mnt # -W is the new option to only wait rescan while not starting new one btrfs quota rescan -W $mnt btrfs qgroup show -prce $mnt umount $mnt # Need to patch btrfs-progs to report qgroup mismatch as error btrfs check $dev || _fail ------ For fast machine, we can hit some corruption which missed accounting tree blocks: ------ qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 8.00KiB 0.00B none none --- --- 0/257 8.00KiB 0.00B none none --- --- ------ This is due to the fact that we're always searching commit root for btrfs_find_all_roots() at qgroup_rescan_leaf(), but the leaf we get is from current transaction, not commit root. And if our tree blocks get modified in current transaction, we won't find any owner in commit root, thus causing the corruption. Fix it by searching commit root for extent tree for qgroup_rescan_leaf(). Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-14 01:38:12 +00:00
/*
* Rescan should only search for commit root, and any later difference
* should be recorded by qgroup
*/
path->search_commit_root = 1;
path->skip_locking = 1;
err = 0;
while (!err && !btrfs_fs_closing(fs_info)) {
trans = btrfs_start_transaction(fs_info->fs_root, 0);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
break;
}
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
err = -EINTR;
} else {
err = qgroup_rescan_leaf(trans, path);
}
if (err > 0)
btrfs_commit_transaction(trans);
else
btrfs_end_transaction(trans);
}
out:
btrfs_free_path(path);
mutex_lock(&fs_info->qgroup_rescan_lock);
if (err > 0 &&
fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
} else if (err < 0) {
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
}
mutex_unlock(&fs_info->qgroup_rescan_lock);
/*
* only update status, since the previous part has already updated the
* qgroup info.
*/
trans = btrfs_start_transaction(fs_info->quota_root, 1);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
Btrfs: fix race setting up and completing qgroup rescan workers There is a race between setting up a qgroup rescan worker and completing a qgroup rescan worker that can lead to callers of the qgroup rescan wait ioctl to either not wait for the rescan worker to complete or to hang forever due to missing wake ups. The following diagram shows a sequence of steps that illustrates the race. CPU 1 CPU 2 CPU 3 btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts the worker btrfs_qgroup_rescan_worker() mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN mutex_unlock(&fs_info->qgroup_rescan_lock) starts transaction, updates qgroup status item, etc btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts another worker mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_rescan_running = false mutex_unlock(&fs_info->qgroup_rescan_lock) complete_all(&fs_info->qgroup_rescan_completion) Before the rescan worker started by the task at CPU 3 completes, if another task calls btrfs_ioctl_quota_rescan(), it will get -EINPROGRESS because the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN is set at fs_info->qgroup_flags, which is expected and correct behaviour. However if other task calls btrfs_ioctl_quota_rescan_wait() before the rescan worker started by the task at CPU 3 completes, it will return immediately without waiting for the new rescan worker to complete, because fs_info->qgroup_rescan_running is set to false by CPU 2. This race is making test case btrfs/171 (from fstests) to fail often: btrfs/171 9s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad) --- tests/btrfs/171.out 2018-09-16 21:30:48.505104287 +0100 +++ /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad 2019-09-19 02:01:36.938486039 +0100 @@ -1,2 +1,3 @@ QA output created by 171 +ERROR: quota rescan failed: Operation now in progress Silence is golden ... (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/171.out /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad' to see the entire diff) That is because the test calls the btrfs-progs commands "qgroup quota rescan -w", "qgroup assign" and "qgroup remove" in a sequence that makes calls to the rescan start ioctl fail with -EINPROGRESS (note the "btrfs" commands 'qgroup assign' and 'qgroup remove' often call the rescan start ioctl after calling the qgroup assign ioctl, btrfs_ioctl_qgroup_assign()), since previous waits didn't actually wait for a rescan worker to complete. Another problem the race can cause is missing wake ups for waiters, since the call to complete_all() happens outside a critical section and after clearing the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN. In the sequence diagram above, if we have a waiter for the first rescan task (executed by CPU 2), then fs_info->qgroup_rescan_completion.wait is not empty, and if after the rescan worker clears BTRFS_QGROUP_STATUS_FLAG_RESCAN and before it calls complete_all() against fs_info->qgroup_rescan_completion, the task at CPU 3 calls init_completion() against fs_info->qgroup_rescan_completion which re-initilizes its wait queue to an empty queue, therefore causing the rescan worker at CPU 2 to call complete_all() against an empty queue, never waking up the task waiting for that rescan worker. Fix this by clearing BTRFS_QGROUP_STATUS_FLAG_RESCAN and setting fs_info->qgroup_rescan_running to false in the same critical section, delimited by the mutex fs_info->qgroup_rescan_lock, as well as doing the call to complete_all() in that same critical section. This gives the protection needed to avoid rescan wait ioctl callers not waiting for a running rescan worker and the lost wake ups problem, since setting that rescan flag and boolean as well as initializing the wait queue is done already in a critical section delimited by that mutex (at qgroup_rescan_init()). Fixes: 57254b6ebce4ce ("Btrfs: add ioctl to wait for qgroup rescan completion") Fixes: d2c609b834d62f ("btrfs: properly track when rescan worker is running") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-24 09:49:54 +00:00
trans = NULL;
btrfs_err(fs_info,
"fail to start transaction for status update: %d",
err);
}
Btrfs: fix race setting up and completing qgroup rescan workers There is a race between setting up a qgroup rescan worker and completing a qgroup rescan worker that can lead to callers of the qgroup rescan wait ioctl to either not wait for the rescan worker to complete or to hang forever due to missing wake ups. The following diagram shows a sequence of steps that illustrates the race. CPU 1 CPU 2 CPU 3 btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts the worker btrfs_qgroup_rescan_worker() mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN mutex_unlock(&fs_info->qgroup_rescan_lock) starts transaction, updates qgroup status item, etc btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts another worker mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_rescan_running = false mutex_unlock(&fs_info->qgroup_rescan_lock) complete_all(&fs_info->qgroup_rescan_completion) Before the rescan worker started by the task at CPU 3 completes, if another task calls btrfs_ioctl_quota_rescan(), it will get -EINPROGRESS because the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN is set at fs_info->qgroup_flags, which is expected and correct behaviour. However if other task calls btrfs_ioctl_quota_rescan_wait() before the rescan worker started by the task at CPU 3 completes, it will return immediately without waiting for the new rescan worker to complete, because fs_info->qgroup_rescan_running is set to false by CPU 2. This race is making test case btrfs/171 (from fstests) to fail often: btrfs/171 9s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad) --- tests/btrfs/171.out 2018-09-16 21:30:48.505104287 +0100 +++ /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad 2019-09-19 02:01:36.938486039 +0100 @@ -1,2 +1,3 @@ QA output created by 171 +ERROR: quota rescan failed: Operation now in progress Silence is golden ... (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/171.out /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad' to see the entire diff) That is because the test calls the btrfs-progs commands "qgroup quota rescan -w", "qgroup assign" and "qgroup remove" in a sequence that makes calls to the rescan start ioctl fail with -EINPROGRESS (note the "btrfs" commands 'qgroup assign' and 'qgroup remove' often call the rescan start ioctl after calling the qgroup assign ioctl, btrfs_ioctl_qgroup_assign()), since previous waits didn't actually wait for a rescan worker to complete. Another problem the race can cause is missing wake ups for waiters, since the call to complete_all() happens outside a critical section and after clearing the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN. In the sequence diagram above, if we have a waiter for the first rescan task (executed by CPU 2), then fs_info->qgroup_rescan_completion.wait is not empty, and if after the rescan worker clears BTRFS_QGROUP_STATUS_FLAG_RESCAN and before it calls complete_all() against fs_info->qgroup_rescan_completion, the task at CPU 3 calls init_completion() against fs_info->qgroup_rescan_completion which re-initilizes its wait queue to an empty queue, therefore causing the rescan worker at CPU 2 to call complete_all() against an empty queue, never waking up the task waiting for that rescan worker. Fix this by clearing BTRFS_QGROUP_STATUS_FLAG_RESCAN and setting fs_info->qgroup_rescan_running to false in the same critical section, delimited by the mutex fs_info->qgroup_rescan_lock, as well as doing the call to complete_all() in that same critical section. This gives the protection needed to avoid rescan wait ioctl callers not waiting for a running rescan worker and the lost wake ups problem, since setting that rescan flag and boolean as well as initializing the wait queue is done already in a critical section delimited by that mutex (at qgroup_rescan_init()). Fixes: 57254b6ebce4ce ("Btrfs: add ioctl to wait for qgroup rescan completion") Fixes: d2c609b834d62f ("btrfs: properly track when rescan worker is running") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-24 09:49:54 +00:00
mutex_lock(&fs_info->qgroup_rescan_lock);
if (!btrfs_fs_closing(fs_info))
fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
if (trans) {
ret = update_qgroup_status_item(trans);
if (ret < 0) {
err = ret;
btrfs_err(fs_info, "fail to update qgroup status: %d",
err);
}
}
Btrfs: fix race setting up and completing qgroup rescan workers There is a race between setting up a qgroup rescan worker and completing a qgroup rescan worker that can lead to callers of the qgroup rescan wait ioctl to either not wait for the rescan worker to complete or to hang forever due to missing wake ups. The following diagram shows a sequence of steps that illustrates the race. CPU 1 CPU 2 CPU 3 btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts the worker btrfs_qgroup_rescan_worker() mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN mutex_unlock(&fs_info->qgroup_rescan_lock) starts transaction, updates qgroup status item, etc btrfs_ioctl_quota_rescan() btrfs_qgroup_rescan() qgroup_rescan_init() mutex_lock(&fs_info->qgroup_rescan_lock) spin_lock(&fs_info->qgroup_lock) fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN init_completion( &fs_info->qgroup_rescan_completion) fs_info->qgroup_rescan_running = true mutex_unlock(&fs_info->qgroup_rescan_lock) spin_unlock(&fs_info->qgroup_lock) btrfs_init_work() --> starts another worker mutex_lock(&fs_info->qgroup_rescan_lock) fs_info->qgroup_rescan_running = false mutex_unlock(&fs_info->qgroup_rescan_lock) complete_all(&fs_info->qgroup_rescan_completion) Before the rescan worker started by the task at CPU 3 completes, if another task calls btrfs_ioctl_quota_rescan(), it will get -EINPROGRESS because the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN is set at fs_info->qgroup_flags, which is expected and correct behaviour. However if other task calls btrfs_ioctl_quota_rescan_wait() before the rescan worker started by the task at CPU 3 completes, it will return immediately without waiting for the new rescan worker to complete, because fs_info->qgroup_rescan_running is set to false by CPU 2. This race is making test case btrfs/171 (from fstests) to fail often: btrfs/171 9s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad) --- tests/btrfs/171.out 2018-09-16 21:30:48.505104287 +0100 +++ /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad 2019-09-19 02:01:36.938486039 +0100 @@ -1,2 +1,3 @@ QA output created by 171 +ERROR: quota rescan failed: Operation now in progress Silence is golden ... (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/171.out /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad' to see the entire diff) That is because the test calls the btrfs-progs commands "qgroup quota rescan -w", "qgroup assign" and "qgroup remove" in a sequence that makes calls to the rescan start ioctl fail with -EINPROGRESS (note the "btrfs" commands 'qgroup assign' and 'qgroup remove' often call the rescan start ioctl after calling the qgroup assign ioctl, btrfs_ioctl_qgroup_assign()), since previous waits didn't actually wait for a rescan worker to complete. Another problem the race can cause is missing wake ups for waiters, since the call to complete_all() happens outside a critical section and after clearing the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN. In the sequence diagram above, if we have a waiter for the first rescan task (executed by CPU 2), then fs_info->qgroup_rescan_completion.wait is not empty, and if after the rescan worker clears BTRFS_QGROUP_STATUS_FLAG_RESCAN and before it calls complete_all() against fs_info->qgroup_rescan_completion, the task at CPU 3 calls init_completion() against fs_info->qgroup_rescan_completion which re-initilizes its wait queue to an empty queue, therefore causing the rescan worker at CPU 2 to call complete_all() against an empty queue, never waking up the task waiting for that rescan worker. Fix this by clearing BTRFS_QGROUP_STATUS_FLAG_RESCAN and setting fs_info->qgroup_rescan_running to false in the same critical section, delimited by the mutex fs_info->qgroup_rescan_lock, as well as doing the call to complete_all() in that same critical section. This gives the protection needed to avoid rescan wait ioctl callers not waiting for a running rescan worker and the lost wake ups problem, since setting that rescan flag and boolean as well as initializing the wait queue is done already in a critical section delimited by that mutex (at qgroup_rescan_init()). Fixes: 57254b6ebce4ce ("Btrfs: add ioctl to wait for qgroup rescan completion") Fixes: d2c609b834d62f ("btrfs: properly track when rescan worker is running") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-24 09:49:54 +00:00
fs_info->qgroup_rescan_running = false;
complete_all(&fs_info->qgroup_rescan_completion);
mutex_unlock(&fs_info->qgroup_rescan_lock);
if (!trans)
return;
btrfs_end_transaction(trans);
if (btrfs_fs_closing(fs_info)) {
btrfs_info(fs_info, "qgroup scan paused");
} else if (err >= 0) {
btrfs_info(fs_info, "qgroup scan completed%s",
err > 0 ? " (inconsistency flag cleared)" : "");
} else {
btrfs_err(fs_info, "qgroup scan failed with %d", err);
}
}
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
/*
* Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
* memory required for the rescan context.
*/
static int
qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
int init_flags)
{
int ret = 0;
if (!init_flags) {
/* we're resuming qgroup rescan at mount time */
if (!(fs_info->qgroup_flags &
BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
btrfs_warn(fs_info,
"qgroup rescan init failed, qgroup rescan is not queued");
ret = -EINVAL;
} else if (!(fs_info->qgroup_flags &
BTRFS_QGROUP_STATUS_FLAG_ON)) {
btrfs_warn(fs_info,
"qgroup rescan init failed, qgroup is not enabled");
ret = -EINVAL;
}
if (ret)
return ret;
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
}
mutex_lock(&fs_info->qgroup_rescan_lock);
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
if (init_flags) {
if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
btrfs_warn(fs_info,
"qgroup rescan is already in progress");
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
ret = -EINPROGRESS;
} else if (!(fs_info->qgroup_flags &
BTRFS_QGROUP_STATUS_FLAG_ON)) {
btrfs_warn(fs_info,
"qgroup rescan init failed, qgroup is not enabled");
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
ret = -EINVAL;
}
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
if (ret) {
mutex_unlock(&fs_info->qgroup_rescan_lock);
return ret;
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
}
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
}
memset(&fs_info->qgroup_rescan_progress, 0,
sizeof(fs_info->qgroup_rescan_progress));
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
fs_info->qgroup_rescan_progress.objectid = progress_objectid;
init_completion(&fs_info->qgroup_rescan_completion);
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
mutex_unlock(&fs_info->qgroup_rescan_lock);
btrfs_init_work(&fs_info->qgroup_rescan_work,
btrfs_qgroup_rescan_worker, NULL, NULL);
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
return 0;
}
static void
qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
{
struct rb_node *n;
struct btrfs_qgroup *qgroup;
spin_lock(&fs_info->qgroup_lock);
/* clear all current qgroup tracking information */
for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
qgroup = rb_entry(n, struct btrfs_qgroup, node);
qgroup->rfer = 0;
qgroup->rfer_cmpr = 0;
qgroup->excl = 0;
qgroup->excl_cmpr = 0;
btrfs: qgroup: Dirty all qgroups before rescan [BUG] In the following case, rescan won't zero out the number of qgroup 1/0: $ mkfs.btrfs -fq $DEV $ mount $DEV /mnt $ btrfs quota enable /mnt $ btrfs qgroup create 1/0 /mnt $ btrfs sub create /mnt/sub $ btrfs qgroup assign 0/257 1/0 /mnt $ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000 $ btrfs sub snap /mnt/sub /mnt/snap $ btrfs quota rescan -w /mnt $ btrfs qgroup show -pcre /mnt qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16.00KiB 16.00KiB none none --- --- 0/257 1016.00KiB 16.00KiB none none 1/0 --- 0/258 1016.00KiB 16.00KiB none none --- --- 1/0 1016.00KiB 16.00KiB none none --- 0/257 So far so good, but: $ btrfs qgroup remove 0/257 1/0 /mnt WARNING: quotas may be inconsistent, rescan needed $ btrfs quota rescan -w /mnt $ btrfs qgroup show -pcre /mnt qgoupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16.00KiB 16.00KiB none none --- --- 0/257 1016.00KiB 16.00KiB none none --- --- 0/258 1016.00KiB 16.00KiB none none --- --- 1/0 1016.00KiB 16.00KiB none none --- --- ^^^^^^^^^^ ^^^^^^^^ not cleared [CAUSE] Before rescan we call qgroup_rescan_zero_tracking() to zero out all qgroups' accounting numbers. However we don't mark all qgroups dirty, but rely on rescan to do so. If we have any high level qgroup without children, it won't be marked dirty during rescan, since we cannot reach that qgroup. This will cause QGROUP_INFO items of childless qgroups never get updated in the quota tree, thus their numbers will stay the same in "btrfs qgroup show" output. [FIX] Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even if we have childless qgroups, their QGROUP_INFO items will still get updated during rescan. Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Tested-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-10 02:20:26 +00:00
qgroup_dirty(fs_info, qgroup);
}
spin_unlock(&fs_info->qgroup_lock);
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
}
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
int
btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
{
int ret = 0;
struct btrfs_trans_handle *trans;
ret = qgroup_rescan_init(fs_info, 0, 1);
if (ret)
return ret;
/*
* We have set the rescan_progress to 0, which means no more
* delayed refs will be accounted by btrfs_qgroup_account_ref.
* However, btrfs_qgroup_account_ref may be right after its call
* to btrfs_find_all_roots, in which case it would still do the
* accounting.
* To solve this, we're committing the transaction, which will
* ensure we run all delayed refs and only after that, we are
* going to clear all tracking information for a clean start.
*/
trans = btrfs_join_transaction(fs_info->fs_root);
if (IS_ERR(trans)) {
fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
return PTR_ERR(trans);
}
ret = btrfs_commit_transaction(trans);
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
if (ret) {
fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
return ret;
}
qgroup_rescan_zero_tracking(fs_info);
btrfs: qgroup: ensure qgroup_rescan_running is only set when the worker is at least queued [BUG] There are some reports about btrfs wait forever to unmount itself, with the following call trace: INFO: task umount:4631 blocked for more than 491 seconds. Tainted: G X 5.3.8-2-default #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. umount D 0 4631 3337 0x00000000 Call Trace: ([<00000000174adf7a>] __schedule+0x342/0x748) [<00000000174ae3ca>] schedule+0x4a/0xd8 [<00000000174b1f08>] schedule_timeout+0x218/0x420 [<00000000174af10c>] wait_for_common+0x104/0x1d8 [<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs] [<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs] [<0000000016fa3136>] generic_shutdown_super+0x8e/0x158 [<0000000016fa34d6>] kill_anon_super+0x26/0x40 [<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs] [<0000000016fa39f8>] deactivate_locked_super+0x68/0x98 [<0000000016fcb198>] cleanup_mnt+0xc0/0x140 [<0000000016d6a846>] task_work_run+0xc6/0x110 [<0000000016d04f76>] do_notify_resume+0xae/0xb8 [<00000000174b30ae>] system_call+0xe2/0x2c8 [CAUSE] The problem happens when we have called qgroup_rescan_init(), but not queued the worker. It can be caused mostly by error handling. Qgroup ioctl thread | Unmount thread ----------------------------------------+----------------------------------- | btrfs_qgroup_rescan() | |- qgroup_rescan_init() | | |- qgroup_rescan_running = true; | | | |- trans = btrfs_join_transaction() | | Some error happened | | | |- btrfs_qgroup_rescan() returns error | But qgroup_rescan_running == true; | | close_ctree() | |- btrfs_qgroup_wait_for_completion() | |- running == true; | |- wait_for_completion(); btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake up close_ctree() and we get a deadlock. All involved qgroup_rescan_init() callers are: - btrfs_qgroup_rescan() The example above. It's possible to trigger the deadlock when error happened. - btrfs_quota_enable() Not possible. Just after qgroup_rescan_init() we queue the work. - btrfs_read_qgroup_config() It's possible to trigger the deadlock. It only init the work, the work queueing happens in btrfs_qgroup_rescan_resume(). Thus if error happened in between, deadlock is possible. We shouldn't set fs_info->qgroup_rescan_running just in qgroup_rescan_init(), as at that stage we haven't yet queued qgroup rescan worker to run. [FIX] Set qgroup_rescan_running before queueing the work, so that we ensure the rescan work is queued when we wait for it. Fixes: 8d9eddad1946 ("Btrfs: fix qgroup rescan worker initialization") Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ Change subject and cause analyse, use a smaller fix ] Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-07 05:38:20 +00:00
mutex_lock(&fs_info->qgroup_rescan_lock);
fs_info->qgroup_rescan_running = true;
btrfs_queue_work(fs_info->qgroup_rescan_workers,
&fs_info->qgroup_rescan_work);
btrfs: qgroup: ensure qgroup_rescan_running is only set when the worker is at least queued [BUG] There are some reports about btrfs wait forever to unmount itself, with the following call trace: INFO: task umount:4631 blocked for more than 491 seconds. Tainted: G X 5.3.8-2-default #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. umount D 0 4631 3337 0x00000000 Call Trace: ([<00000000174adf7a>] __schedule+0x342/0x748) [<00000000174ae3ca>] schedule+0x4a/0xd8 [<00000000174b1f08>] schedule_timeout+0x218/0x420 [<00000000174af10c>] wait_for_common+0x104/0x1d8 [<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs] [<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs] [<0000000016fa3136>] generic_shutdown_super+0x8e/0x158 [<0000000016fa34d6>] kill_anon_super+0x26/0x40 [<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs] [<0000000016fa39f8>] deactivate_locked_super+0x68/0x98 [<0000000016fcb198>] cleanup_mnt+0xc0/0x140 [<0000000016d6a846>] task_work_run+0xc6/0x110 [<0000000016d04f76>] do_notify_resume+0xae/0xb8 [<00000000174b30ae>] system_call+0xe2/0x2c8 [CAUSE] The problem happens when we have called qgroup_rescan_init(), but not queued the worker. It can be caused mostly by error handling. Qgroup ioctl thread | Unmount thread ----------------------------------------+----------------------------------- | btrfs_qgroup_rescan() | |- qgroup_rescan_init() | | |- qgroup_rescan_running = true; | | | |- trans = btrfs_join_transaction() | | Some error happened | | | |- btrfs_qgroup_rescan() returns error | But qgroup_rescan_running == true; | | close_ctree() | |- btrfs_qgroup_wait_for_completion() | |- running == true; | |- wait_for_completion(); btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake up close_ctree() and we get a deadlock. All involved qgroup_rescan_init() callers are: - btrfs_qgroup_rescan() The example above. It's possible to trigger the deadlock when error happened. - btrfs_quota_enable() Not possible. Just after qgroup_rescan_init() we queue the work. - btrfs_read_qgroup_config() It's possible to trigger the deadlock. It only init the work, the work queueing happens in btrfs_qgroup_rescan_resume(). Thus if error happened in between, deadlock is possible. We shouldn't set fs_info->qgroup_rescan_running just in qgroup_rescan_init(), as at that stage we haven't yet queued qgroup rescan worker to run. [FIX] Set qgroup_rescan_running before queueing the work, so that we ensure the rescan work is queued when we wait for it. Fixes: 8d9eddad1946 ("Btrfs: fix qgroup rescan worker initialization") Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ Change subject and cause analyse, use a smaller fix ] Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-07 05:38:20 +00:00
mutex_unlock(&fs_info->qgroup_rescan_lock);
return 0;
}
int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
bool interruptible)
{
int running;
int ret = 0;
mutex_lock(&fs_info->qgroup_rescan_lock);
running = fs_info->qgroup_rescan_running;
mutex_unlock(&fs_info->qgroup_rescan_lock);
if (!running)
return 0;
if (interruptible)
ret = wait_for_completion_interruptible(
&fs_info->qgroup_rescan_completion);
else
wait_for_completion(&fs_info->qgroup_rescan_completion);
return ret;
}
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
/*
* this is only called from open_ctree where we're still single threaded, thus
* locking is omitted here.
*/
void
btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
{
btrfs: qgroup: ensure qgroup_rescan_running is only set when the worker is at least queued [BUG] There are some reports about btrfs wait forever to unmount itself, with the following call trace: INFO: task umount:4631 blocked for more than 491 seconds. Tainted: G X 5.3.8-2-default #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. umount D 0 4631 3337 0x00000000 Call Trace: ([<00000000174adf7a>] __schedule+0x342/0x748) [<00000000174ae3ca>] schedule+0x4a/0xd8 [<00000000174b1f08>] schedule_timeout+0x218/0x420 [<00000000174af10c>] wait_for_common+0x104/0x1d8 [<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs] [<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs] [<0000000016fa3136>] generic_shutdown_super+0x8e/0x158 [<0000000016fa34d6>] kill_anon_super+0x26/0x40 [<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs] [<0000000016fa39f8>] deactivate_locked_super+0x68/0x98 [<0000000016fcb198>] cleanup_mnt+0xc0/0x140 [<0000000016d6a846>] task_work_run+0xc6/0x110 [<0000000016d04f76>] do_notify_resume+0xae/0xb8 [<00000000174b30ae>] system_call+0xe2/0x2c8 [CAUSE] The problem happens when we have called qgroup_rescan_init(), but not queued the worker. It can be caused mostly by error handling. Qgroup ioctl thread | Unmount thread ----------------------------------------+----------------------------------- | btrfs_qgroup_rescan() | |- qgroup_rescan_init() | | |- qgroup_rescan_running = true; | | | |- trans = btrfs_join_transaction() | | Some error happened | | | |- btrfs_qgroup_rescan() returns error | But qgroup_rescan_running == true; | | close_ctree() | |- btrfs_qgroup_wait_for_completion() | |- running == true; | |- wait_for_completion(); btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake up close_ctree() and we get a deadlock. All involved qgroup_rescan_init() callers are: - btrfs_qgroup_rescan() The example above. It's possible to trigger the deadlock when error happened. - btrfs_quota_enable() Not possible. Just after qgroup_rescan_init() we queue the work. - btrfs_read_qgroup_config() It's possible to trigger the deadlock. It only init the work, the work queueing happens in btrfs_qgroup_rescan_resume(). Thus if error happened in between, deadlock is possible. We shouldn't set fs_info->qgroup_rescan_running just in qgroup_rescan_init(), as at that stage we haven't yet queued qgroup rescan worker to run. [FIX] Set qgroup_rescan_running before queueing the work, so that we ensure the rescan work is queued when we wait for it. Fixes: 8d9eddad1946 ("Btrfs: fix qgroup rescan worker initialization") Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ Change subject and cause analyse, use a smaller fix ] Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-07 05:38:20 +00:00
if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
mutex_lock(&fs_info->qgroup_rescan_lock);
fs_info->qgroup_rescan_running = true;
btrfs_queue_work(fs_info->qgroup_rescan_workers,
&fs_info->qgroup_rescan_work);
btrfs: qgroup: ensure qgroup_rescan_running is only set when the worker is at least queued [BUG] There are some reports about btrfs wait forever to unmount itself, with the following call trace: INFO: task umount:4631 blocked for more than 491 seconds. Tainted: G X 5.3.8-2-default #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. umount D 0 4631 3337 0x00000000 Call Trace: ([<00000000174adf7a>] __schedule+0x342/0x748) [<00000000174ae3ca>] schedule+0x4a/0xd8 [<00000000174b1f08>] schedule_timeout+0x218/0x420 [<00000000174af10c>] wait_for_common+0x104/0x1d8 [<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs] [<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs] [<0000000016fa3136>] generic_shutdown_super+0x8e/0x158 [<0000000016fa34d6>] kill_anon_super+0x26/0x40 [<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs] [<0000000016fa39f8>] deactivate_locked_super+0x68/0x98 [<0000000016fcb198>] cleanup_mnt+0xc0/0x140 [<0000000016d6a846>] task_work_run+0xc6/0x110 [<0000000016d04f76>] do_notify_resume+0xae/0xb8 [<00000000174b30ae>] system_call+0xe2/0x2c8 [CAUSE] The problem happens when we have called qgroup_rescan_init(), but not queued the worker. It can be caused mostly by error handling. Qgroup ioctl thread | Unmount thread ----------------------------------------+----------------------------------- | btrfs_qgroup_rescan() | |- qgroup_rescan_init() | | |- qgroup_rescan_running = true; | | | |- trans = btrfs_join_transaction() | | Some error happened | | | |- btrfs_qgroup_rescan() returns error | But qgroup_rescan_running == true; | | close_ctree() | |- btrfs_qgroup_wait_for_completion() | |- running == true; | |- wait_for_completion(); btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake up close_ctree() and we get a deadlock. All involved qgroup_rescan_init() callers are: - btrfs_qgroup_rescan() The example above. It's possible to trigger the deadlock when error happened. - btrfs_quota_enable() Not possible. Just after qgroup_rescan_init() we queue the work. - btrfs_read_qgroup_config() It's possible to trigger the deadlock. It only init the work, the work queueing happens in btrfs_qgroup_rescan_resume(). Thus if error happened in between, deadlock is possible. We shouldn't set fs_info->qgroup_rescan_running just in qgroup_rescan_init(), as at that stage we haven't yet queued qgroup rescan worker to run. [FIX] Set qgroup_rescan_running before queueing the work, so that we ensure the rescan work is queued when we wait for it. Fixes: 8d9eddad1946 ("Btrfs: fix qgroup rescan worker initialization") Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ Change subject and cause analyse, use a smaller fix ] Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-07 05:38:20 +00:00
mutex_unlock(&fs_info->qgroup_rescan_lock);
}
Btrfs: fix qgroup rescan resume on mount When called during mount, we cannot start the rescan worker thread until open_ctree is done. This commit restuctures the qgroup rescan internals to enable a clean deferral of the rescan resume operation. First of all, the struct qgroup_rescan is removed, saving us a malloc and some initialization synchronizations problems. Its only element (the worker struct) now lives within fs_info just as the rest of the rescan code. Then setting up a rescan worker is split into several reusable stages. Currently we have three different rescan startup scenarios: (A) rescan ioctl (B) rescan resume by mount (C) rescan by quota enable Each case needs its own combination of the four following steps: (1) set the progress [A, C: zero; B: state of umount] (2) commit the transaction [A] (3) set the counters [A, C: zero; B: state of umount] (4) start worker [A, B, C] qgroup_rescan_init does step (1). There's no extra function added to commit a transaction, we've got that already. qgroup_rescan_zero_tracking does step (3). Step (4) is nothing more than a call to the generic btrfs_queue_worker. We also get rid of a double check for the rescan progress during btrfs_qgroup_account_ref, which is no longer required due to having step 2 from the list above. As a side effect, this commit prepares to move the rescan start code from btrfs_run_qgroups (which is run during commit) to a less time critical section. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-28 15:47:24 +00:00
}
/*
* Reserve qgroup space for range [start, start + len).
*
* This function will either reserve space from related qgroups or doing
* nothing if the range is already reserved.
*
* Return 0 for successful reserve
* Return <0 for error (including -EQUOT)
*
* NOTE: this function may sleep for memory allocation.
* if btrfs_qgroup_reserve_data() is called multiple times with
* same @reserved, caller must ensure when error happens it's OK
* to free *ALL* reserved space.
*/
int btrfs_qgroup_reserve_data(struct inode *inode,
struct extent_changeset **reserved_ret, u64 start,
u64 len)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct ulist_node *unode;
struct ulist_iterator uiter;
struct extent_changeset *reserved;
u64 orig_reserved;
u64 to_reserve;
int ret;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
!is_fstree(root->root_key.objectid) || len == 0)
return 0;
/* @reserved parameter is mandatory for qgroup */
if (WARN_ON(!reserved_ret))
return -EINVAL;
if (!*reserved_ret) {
*reserved_ret = extent_changeset_alloc();
if (!*reserved_ret)
return -ENOMEM;
}
reserved = *reserved_ret;
/* Record already reserved space */
orig_reserved = reserved->bytes_changed;
ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
start + len -1, EXTENT_QGROUP_RESERVED, reserved);
/* Newly reserved space */
to_reserve = reserved->bytes_changed - orig_reserved;
trace_btrfs_qgroup_reserve_data(inode, start, len,
to_reserve, QGROUP_RESERVE);
if (ret < 0)
goto cleanup;
ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
if (ret < 0)
goto cleanup;
return ret;
cleanup:
/* cleanup *ALL* already reserved ranges */
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(&reserved->range_changed, &uiter)))
clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL);
btrfs: qgroup: Fix reserved data space leak if we have multiple reserve calls [BUG] The following script can cause btrfs qgroup data space leak: mkfs.btrfs -f $dev mount $dev -o nospace_cache $mnt btrfs subv create $mnt/subv btrfs quota en $mnt btrfs quota rescan -w $mnt btrfs qgroup limit 128m $mnt/subv for (( i = 0; i < 3; i++)); do # Create 3 64M holes for latter fallocate to fail truncate -s 192m $mnt/subv/file xfs_io -c "pwrite 64m 4k" $mnt/subv/file > /dev/null xfs_io -c "pwrite 128m 4k" $mnt/subv/file > /dev/null sync # it's supposed to fail, and each failure will leak at least 64M # data space xfs_io -f -c "falloc 0 192m" $mnt/subv/file &> /dev/null rm $mnt/subv/file sync done # Shouldn't fail after we removed the file xfs_io -f -c "falloc 0 64m" $mnt/subv/file [CAUSE] Btrfs qgroup data reserve code allow multiple reservations to happen on a single extent_changeset: E.g: btrfs_qgroup_reserve_data(inode, &data_reserved, 0, SZ_1M); btrfs_qgroup_reserve_data(inode, &data_reserved, SZ_1M, SZ_2M); btrfs_qgroup_reserve_data(inode, &data_reserved, 0, SZ_4M); Btrfs qgroup code has its internal tracking to make sure we don't double-reserve in above example. The only pattern utilizing this feature is in the main while loop of btrfs_fallocate() function. However btrfs_qgroup_reserve_data()'s error handling has a bug in that on error it clears all ranges in the io_tree with EXTENT_QGROUP_RESERVED flag but doesn't free previously reserved bytes. This bug has a two fold effect: - Clearing EXTENT_QGROUP_RESERVED ranges This is the correct behavior, but it prevents btrfs_qgroup_check_reserved_leak() to catch the leakage as the detector is purely EXTENT_QGROUP_RESERVED flag based. - Leak the previously reserved data bytes. The bug manifests when N calls to btrfs_qgroup_reserve_data are made and the last one fails, leaking space reserved in the previous ones. [FIX] Also free previously reserved data bytes when btrfs_qgroup_reserve_data fails. Fixes: 524725537023 ("btrfs: qgroup: Introduce btrfs_qgroup_reserve_data function") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-16 12:02:39 +00:00
/* Also free data bytes of already reserved one */
btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid,
orig_reserved, BTRFS_QGROUP_RSV_DATA);
extent_changeset_release(reserved);
return ret;
}
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
/* Free ranges specified by @reserved, normally in error path */
static int qgroup_free_reserved_data(struct inode *inode,
struct extent_changeset *reserved, u64 start, u64 len)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct ulist_node *unode;
struct ulist_iterator uiter;
struct extent_changeset changeset;
int freed = 0;
int ret;
extent_changeset_init(&changeset);
len = round_up(start + len, root->fs_info->sectorsize);
start = round_down(start, root->fs_info->sectorsize);
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
u64 range_start = unode->val;
/* unode->aux is the inclusive end */
u64 range_len = unode->aux - range_start + 1;
u64 free_start;
u64 free_len;
extent_changeset_release(&changeset);
/* Only free range in range [start, start + len) */
if (range_start >= start + len ||
range_start + range_len <= start)
continue;
free_start = max(range_start, start);
free_len = min(start + len, range_start + range_len) -
free_start;
/*
* TODO: To also modify reserved->ranges_reserved to reflect
* the modification.
*
* However as long as we free qgroup reserved according to
* EXTENT_QGROUP_RESERVED, we won't double free.
* So not need to rush.
*/
btrfs: qgroup: Fix the wrong target io_tree when freeing reserved data space [BUG] Under the following case with qgroup enabled, if some error happened after we have reserved delalloc space, then in error handling path, we could cause qgroup data space leakage: From btrfs_truncate_block() in inode.c: ret = btrfs_delalloc_reserve_space(inode, &data_reserved, block_start, blocksize); if (ret) goto out; again: page = find_or_create_page(mapping, index, mask); if (!page) { btrfs_delalloc_release_space(inode, data_reserved, block_start, blocksize, true); btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, true); ret = -ENOMEM; goto out; } [CAUSE] In the above case, btrfs_delalloc_reserve_space() will call btrfs_qgroup_reserve_data() and mark the io_tree range with EXTENT_QGROUP_RESERVED flag. In the error handling path, we have the following call stack: btrfs_delalloc_release_space() |- btrfs_free_reserved_data_space() |- btrsf_qgroup_free_data() |- __btrfs_qgroup_release_data(reserved=@reserved, free=1) |- qgroup_free_reserved_data(reserved=@reserved) |- clear_record_extent_bits(); |- freed += changeset.bytes_changed; However due to a completion bug, qgroup_free_reserved_data() will clear EXTENT_QGROUP_RESERVED flag in BTRFS_I(inode)->io_failure_tree, other than the correct BTRFS_I(inode)->io_tree. Since io_failure_tree is never marked with that flag, btrfs_qgroup_free_data() will not free any data reserved space at all, causing a leakage. This type of error handling can only be triggered by errors outside of qgroup code. So EDQUOT error from qgroup can't trigger it. [FIX] Fix the wrong target io_tree. Reported-by: Josef Bacik <josef@toxicpanda.com> Fixes: bc42bda22345 ("btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-16 12:02:38 +00:00
ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree,
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
free_start, free_start + free_len - 1,
EXTENT_QGROUP_RESERVED, &changeset);
if (ret < 0)
goto out;
freed += changeset.bytes_changed;
}
btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
BTRFS_QGROUP_RSV_DATA);
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
ret = freed;
out:
extent_changeset_release(&changeset);
return ret;
}
static int __btrfs_qgroup_release_data(struct inode *inode,
struct extent_changeset *reserved, u64 start, u64 len,
int free)
{
struct extent_changeset changeset;
int trace_op = QGROUP_RELEASE;
int ret;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED,
&BTRFS_I(inode)->root->fs_info->flags))
return 0;
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
/* In release case, we shouldn't have @reserved */
WARN_ON(!free && reserved);
if (free && reserved)
return qgroup_free_reserved_data(inode, reserved, start, len);
extent_changeset_init(&changeset);
ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
if (ret < 0)
goto out;
if (free)
trace_op = QGROUP_FREE;
trace_btrfs_qgroup_release_data(inode, start, len,
changeset.bytes_changed, trace_op);
if (free)
btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
BTRFS_I(inode)->root->root_key.objectid,
changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
ret = changeset.bytes_changed;
out:
extent_changeset_release(&changeset);
return ret;
}
/*
* Free a reserved space range from io_tree and related qgroups
*
* Should be called when a range of pages get invalidated before reaching disk.
* Or for error cleanup case.
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
* if @reserved is given, only reserved range in [@start, @start + @len) will
* be freed.
*
* For data written to disk, use btrfs_qgroup_release_data().
*
* NOTE: This function may sleep for memory allocation.
*/
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
int btrfs_qgroup_free_data(struct inode *inode,
struct extent_changeset *reserved, u64 start, u64 len)
{
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
}
/*
* Release a reserved space range from io_tree only.
*
* Should be called when a range of pages get written to disk and corresponding
* FILE_EXTENT is inserted into corresponding root.
*
* Since new qgroup accounting framework will only update qgroup numbers at
* commit_transaction() time, its reserved space shouldn't be freed from
* related qgroups.
*
* But we should release the range from io_tree, to allow further write to be
* COWed.
*
* NOTE: This function may sleep for memory allocation.
*/
int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
{
btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-27 07:10:39 +00:00
return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
}
static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
enum btrfs_qgroup_rsv_type type)
{
if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
type != BTRFS_QGROUP_RSV_META_PERTRANS)
return;
if (num_bytes == 0)
return;
spin_lock(&root->qgroup_meta_rsv_lock);
if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
root->qgroup_meta_rsv_prealloc += num_bytes;
else
root->qgroup_meta_rsv_pertrans += num_bytes;
spin_unlock(&root->qgroup_meta_rsv_lock);
}
static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
enum btrfs_qgroup_rsv_type type)
{
if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
type != BTRFS_QGROUP_RSV_META_PERTRANS)
return 0;
if (num_bytes == 0)
return 0;
spin_lock(&root->qgroup_meta_rsv_lock);
if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
num_bytes);
root->qgroup_meta_rsv_prealloc -= num_bytes;
} else {
num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
num_bytes);
root->qgroup_meta_rsv_pertrans -= num_bytes;
}
spin_unlock(&root->qgroup_meta_rsv_lock);
return num_bytes;
}
int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
enum btrfs_qgroup_rsv_type type, bool enforce)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
!is_fstree(root->root_key.objectid) || num_bytes == 0)
return 0;
BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
ret = qgroup_reserve(root, num_bytes, enforce, type);
if (ret < 0)
return ret;
/*
* Record what we have reserved into root.
*
* To avoid quota disabled->enabled underflow.
* In that case, we may try to free space we haven't reserved
* (since quota was disabled), so record what we reserved into root.
* And ensure later release won't underflow this number.
*/
add_root_meta_rsv(root, num_bytes, type);
return ret;
}
void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
!is_fstree(root->root_key.objectid))
return;
/* TODO: Update trace point to handle such free */
trace_qgroup_meta_free_all_pertrans(root);
/* Special value -1 means to free all reserved space */
btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
BTRFS_QGROUP_RSV_META_PERTRANS);
}
void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
enum btrfs_qgroup_rsv_type type)
{
struct btrfs_fs_info *fs_info = root->fs_info;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
!is_fstree(root->root_key.objectid))
return;
/*
* reservation for META_PREALLOC can happen before quota is enabled,
* which can lead to underflow.
* Here ensure we will only free what we really have reserved.
*/
num_bytes = sub_root_meta_rsv(root, num_bytes, type);
BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
num_bytes, type);
}
static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
int num_bytes)
{
struct btrfs_qgroup *qgroup;
struct ulist_node *unode;
struct ulist_iterator uiter;
int ret = 0;
if (num_bytes == 0)
return;
if (!fs_info->quota_root)
return;
spin_lock(&fs_info->qgroup_lock);
qgroup = find_qgroup_rb(fs_info, ref_root);
if (!qgroup)
goto out;
ulist_reinit(fs_info->qgroup_ulist);
ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
qgroup_to_aux(qgroup), GFP_ATOMIC);
if (ret < 0)
goto out;
ULIST_ITER_INIT(&uiter);
while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
struct btrfs_qgroup *qg;
struct btrfs_qgroup_list *glist;
qg = unode_aux_to_qgroup(unode);
qgroup_rsv_release(fs_info, qg, num_bytes,
BTRFS_QGROUP_RSV_META_PREALLOC);
qgroup_rsv_add(fs_info, qg, num_bytes,
BTRFS_QGROUP_RSV_META_PERTRANS);
list_for_each_entry(glist, &qg->groups, next_group) {
ret = ulist_add(fs_info->qgroup_ulist,
glist->group->qgroupid,
qgroup_to_aux(glist->group), GFP_ATOMIC);
if (ret < 0)
goto out;
}
}
out:
spin_unlock(&fs_info->qgroup_lock);
}
void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
{
struct btrfs_fs_info *fs_info = root->fs_info;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
!is_fstree(root->root_key.objectid))
return;
/* Same as btrfs_qgroup_free_meta_prealloc() */
num_bytes = sub_root_meta_rsv(root, num_bytes,
BTRFS_QGROUP_RSV_META_PREALLOC);
trace_qgroup_meta_convert(root, num_bytes);
qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
}
/*
* Check qgroup reserved space leaking, normally at destroy inode
* time
*/
void btrfs_qgroup_check_reserved_leak(struct inode *inode)
{
struct extent_changeset changeset;
struct ulist_node *unode;
struct ulist_iterator iter;
int ret;
extent_changeset_init(&changeset);
ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
EXTENT_QGROUP_RESERVED, &changeset);
WARN_ON(ret < 0);
if (WARN_ON(changeset.bytes_changed)) {
ULIST_ITER_INIT(&iter);
while ((unode = ulist_next(&changeset.range_changed, &iter))) {
btrfs_warn(BTRFS_I(inode)->root->fs_info,
"leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
inode->i_ino, unode->val, unode->aux);
}
btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
BTRFS_I(inode)->root->root_key.objectid,
changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
}
extent_changeset_release(&changeset);
}
btrfs: qgroup: Introduce per-root swapped blocks infrastructure To allow delayed subtree swap rescan, btrfs needs to record per-root information about which tree blocks get swapped. This patch introduces the required infrastructure. The designed workflow will be: 1) Record the subtree root block that gets swapped. During subtree swap: O = Old tree blocks N = New tree blocks reloc tree subvolume tree X Root Root / \ / \ NA OB OA OB / | | \ / | | \ NC ND OE OF OC OD OE OF In this case, NA and OA are going to be swapped, record (NA, OA) into subvolume tree X. 2) After subtree swap. reloc tree subvolume tree X Root Root / \ / \ OA OB NA OB / | | \ / | | \ OC OD OE OF NC ND OE OF 3a) COW happens for OB If we are going to COW tree block OB, we check OB's bytenr against tree X's swapped_blocks structure. If it doesn't fit any, nothing will happen. 3b) COW happens for NA Check NA's bytenr against tree X's swapped_blocks, and get a hit. Then we do subtree scan on both subtrees OA and NA. Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND). Then no matter what we do to subvolume tree X, qgroup numbers will still be correct. Then NA's record gets removed from X's swapped_blocks. 4) Transaction commit Any record in X's swapped_blocks gets removed, since there is no modification to swapped subtrees, no need to trigger heavy qgroup subtree rescan for them. This will introduce 128 bytes overhead for each btrfs_root even qgroup is not enabled. This is to reduce memory allocations and potential failures. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:16 +00:00
void btrfs_qgroup_init_swapped_blocks(
struct btrfs_qgroup_swapped_blocks *swapped_blocks)
{
int i;
spin_lock_init(&swapped_blocks->lock);
for (i = 0; i < BTRFS_MAX_LEVEL; i++)
swapped_blocks->blocks[i] = RB_ROOT;
swapped_blocks->swapped = false;
}
/*
* Delete all swapped blocks record of @root.
* Every record here means we skipped a full subtree scan for qgroup.
*
* Gets called when committing one transaction.
*/
void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
{
struct btrfs_qgroup_swapped_blocks *swapped_blocks;
int i;
swapped_blocks = &root->swapped_blocks;
spin_lock(&swapped_blocks->lock);
if (!swapped_blocks->swapped)
goto out;
for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
struct rb_root *cur_root = &swapped_blocks->blocks[i];
struct btrfs_qgroup_swapped_block *entry;
struct btrfs_qgroup_swapped_block *next;
rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
node)
kfree(entry);
swapped_blocks->blocks[i] = RB_ROOT;
}
swapped_blocks->swapped = false;
out:
spin_unlock(&swapped_blocks->lock);
}
/*
* Add subtree roots record into @subvol_root.
*
* @subvol_root: tree root of the subvolume tree get swapped
* @bg: block group under balance
* @subvol_parent/slot: pointer to the subtree root in subvolume tree
* @reloc_parent/slot: pointer to the subtree root in reloc tree
* BOTH POINTERS ARE BEFORE TREE SWAP
* @last_snapshot: last snapshot generation of the subvolume tree
*/
int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
struct btrfs_root *subvol_root,
struct btrfs_block_group *bg,
btrfs: qgroup: Introduce per-root swapped blocks infrastructure To allow delayed subtree swap rescan, btrfs needs to record per-root information about which tree blocks get swapped. This patch introduces the required infrastructure. The designed workflow will be: 1) Record the subtree root block that gets swapped. During subtree swap: O = Old tree blocks N = New tree blocks reloc tree subvolume tree X Root Root / \ / \ NA OB OA OB / | | \ / | | \ NC ND OE OF OC OD OE OF In this case, NA and OA are going to be swapped, record (NA, OA) into subvolume tree X. 2) After subtree swap. reloc tree subvolume tree X Root Root / \ / \ OA OB NA OB / | | \ / | | \ OC OD OE OF NC ND OE OF 3a) COW happens for OB If we are going to COW tree block OB, we check OB's bytenr against tree X's swapped_blocks structure. If it doesn't fit any, nothing will happen. 3b) COW happens for NA Check NA's bytenr against tree X's swapped_blocks, and get a hit. Then we do subtree scan on both subtrees OA and NA. Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND). Then no matter what we do to subvolume tree X, qgroup numbers will still be correct. Then NA's record gets removed from X's swapped_blocks. 4) Transaction commit Any record in X's swapped_blocks gets removed, since there is no modification to swapped subtrees, no need to trigger heavy qgroup subtree rescan for them. This will introduce 128 bytes overhead for each btrfs_root even qgroup is not enabled. This is to reduce memory allocations and potential failures. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:16 +00:00
struct extent_buffer *subvol_parent, int subvol_slot,
struct extent_buffer *reloc_parent, int reloc_slot,
u64 last_snapshot)
{
struct btrfs_fs_info *fs_info = subvol_root->fs_info;
struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
struct btrfs_qgroup_swapped_block *block;
struct rb_node **cur;
struct rb_node *parent = NULL;
int level = btrfs_header_level(subvol_parent) - 1;
int ret = 0;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
return 0;
if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
btrfs_err_rl(fs_info,
"%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
__func__,
btrfs_node_ptr_generation(subvol_parent, subvol_slot),
btrfs_node_ptr_generation(reloc_parent, reloc_slot));
return -EUCLEAN;
}
block = kmalloc(sizeof(*block), GFP_NOFS);
if (!block) {
ret = -ENOMEM;
goto out;
}
/*
* @reloc_parent/slot is still before swap, while @block is going to
* record the bytenr after swap, so we do the swap here.
*/
block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
reloc_slot);
block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
subvol_slot);
block->last_snapshot = last_snapshot;
block->level = level;
btrfs: qgroup: Check bg while resuming relocation to avoid NULL pointer dereference [BUG] When mounting a fs with reloc tree and has qgroup enabled, it can cause NULL pointer dereference at mount time: BUG: kernel NULL pointer dereference, address: 00000000000000a8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:btrfs_qgroup_add_swapped_blocks+0x186/0x300 [btrfs] Call Trace: replace_path.isra.23+0x685/0x900 [btrfs] merge_reloc_root+0x26e/0x5f0 [btrfs] merge_reloc_roots+0x10a/0x1a0 [btrfs] btrfs_recover_relocation+0x3cd/0x420 [btrfs] open_ctree+0x1bc8/0x1ed0 [btrfs] btrfs_mount_root+0x544/0x680 [btrfs] legacy_get_tree+0x34/0x60 vfs_get_tree+0x2d/0xf0 fc_mount+0x12/0x40 vfs_kern_mount.part.12+0x61/0xa0 vfs_kern_mount+0x13/0x20 btrfs_mount+0x16f/0x860 [btrfs] legacy_get_tree+0x34/0x60 vfs_get_tree+0x2d/0xf0 do_mount+0x81f/0xac0 ksys_mount+0xbf/0xe0 __x64_sys_mount+0x25/0x30 do_syscall_64+0x65/0x240 entry_SYSCALL_64_after_hwframe+0x49/0xbe [CAUSE] In btrfs_recover_relocation(), we don't have enough info to determine which block group we're relocating, but only to merge existing reloc trees. Thus in btrfs_recover_relocation(), rc->block_group is NULL. btrfs_qgroup_add_swapped_blocks() hasn't taken this into consideration, and causes a NULL pointer dereference. The bug is introduced by commit 3d0174f78e72 ("btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group"), and later qgroup refactoring still keeps this optimization. [FIX] Thankfully in the context of btrfs_recover_relocation(), there is no other progress can modify tree blocks, thus those swapped tree blocks pair will never affect qgroup numbers, no matter whatever we set for block->trace_leaf. So we only need to check if @bg is NULL before accessing @bg->flags. Reported-by: Juan Erbes <jerbes@gmail.com> Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1134806 Fixes: 3d0174f78e72 ("btrfs: qgroup: Only trace data extents in leaves if we're relocating data block group") CC: stable@vger.kernel.org # 4.20+ Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-21 11:28:08 +00:00
/*
* If we have bg == NULL, we're called from btrfs_recover_relocation(),
* no one else can modify tree blocks thus we qgroup will not change
* no matter the value of trace_leaf.
*/
if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
btrfs: qgroup: Introduce per-root swapped blocks infrastructure To allow delayed subtree swap rescan, btrfs needs to record per-root information about which tree blocks get swapped. This patch introduces the required infrastructure. The designed workflow will be: 1) Record the subtree root block that gets swapped. During subtree swap: O = Old tree blocks N = New tree blocks reloc tree subvolume tree X Root Root / \ / \ NA OB OA OB / | | \ / | | \ NC ND OE OF OC OD OE OF In this case, NA and OA are going to be swapped, record (NA, OA) into subvolume tree X. 2) After subtree swap. reloc tree subvolume tree X Root Root / \ / \ OA OB NA OB / | | \ / | | \ OC OD OE OF NC ND OE OF 3a) COW happens for OB If we are going to COW tree block OB, we check OB's bytenr against tree X's swapped_blocks structure. If it doesn't fit any, nothing will happen. 3b) COW happens for NA Check NA's bytenr against tree X's swapped_blocks, and get a hit. Then we do subtree scan on both subtrees OA and NA. Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND). Then no matter what we do to subvolume tree X, qgroup numbers will still be correct. Then NA's record gets removed from X's swapped_blocks. 4) Transaction commit Any record in X's swapped_blocks gets removed, since there is no modification to swapped subtrees, no need to trigger heavy qgroup subtree rescan for them. This will introduce 128 bytes overhead for each btrfs_root even qgroup is not enabled. This is to reduce memory allocations and potential failures. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:16 +00:00
block->trace_leaf = true;
else
block->trace_leaf = false;
btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
/* Insert @block into @blocks */
spin_lock(&blocks->lock);
cur = &blocks->blocks[level].rb_node;
while (*cur) {
struct btrfs_qgroup_swapped_block *entry;
parent = *cur;
entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
node);
if (entry->subvol_bytenr < block->subvol_bytenr) {
cur = &(*cur)->rb_left;
} else if (entry->subvol_bytenr > block->subvol_bytenr) {
cur = &(*cur)->rb_right;
} else {
if (entry->subvol_generation !=
block->subvol_generation ||
entry->reloc_bytenr != block->reloc_bytenr ||
entry->reloc_generation !=
block->reloc_generation) {
/*
* Duplicated but mismatch entry found.
* Shouldn't happen.
*
* Marking qgroup inconsistent should be enough
* for end users.
*/
WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
ret = -EEXIST;
}
kfree(block);
goto out_unlock;
}
}
rb_link_node(&block->node, parent, cur);
rb_insert_color(&block->node, &blocks->blocks[level]);
blocks->swapped = true;
out_unlock:
spin_unlock(&blocks->lock);
out:
if (ret < 0)
fs_info->qgroup_flags |=
BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
return ret;
}
btrfs: qgroup: Use delayed subtree rescan for balance Before this patch, qgroup code traces the whole subtree of subvolume and reloc trees unconditionally. This makes qgroup numbers consistent, but it could cause tons of unnecessary extent tracing, which causes a lot of overhead. However for subtree swap of balance, just swap both subtrees because they contain the same contents and tree structure, so qgroup numbers won't change. It's the race window between subtree swap and transaction commit could cause qgroup number change. This patch will delay the qgroup subtree scan until COW happens for the subtree root. So if there is no other operations for the fs, balance won't cause extra qgroup overhead. (best case scenario) Depending on the workload, most of the subtree scan can still be avoided. Only for worst case scenario, it will fall back to old subtree swap overhead. (scan all swapped subtrees) [[Benchmark]] Hardware: VM 4G vRAM, 8 vCPUs, disk is using 'unsafe' cache mode, backing device is SAMSUNG 850 evo SSD. Host has 16G ram. Mkfs parameter: --nodesize 4K (To bump up tree size) Initial subvolume contents: 4G data copied from /usr and /lib. (With enough regular small files) Snapshots: 16 snapshots of the original subvolume. each snapshot has 3 random files modified. balance parameter: -m So the content should be pretty similar to a real world root fs layout. And after file system population, there is no other activity, so it should be the best case scenario. | v4.20-rc1 | w/ patchset | diff ----------------------------------------------------------------------- relocated extents | 22615 | 22457 | -0.1% qgroup dirty extents | 163457 | 121606 | -25.6% time (sys) | 22.884s | 18.842s | -17.6% time (real) | 27.724s | 22.884s | -17.5% Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-23 07:15:17 +00:00
/*
* Check if the tree block is a subtree root, and if so do the needed
* delayed subtree trace for qgroup.
*
* This is called during btrfs_cow_block().
*/
int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *subvol_eb)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
struct btrfs_qgroup_swapped_block *block;
struct extent_buffer *reloc_eb = NULL;
struct rb_node *node;
bool found = false;
bool swapped = false;
int level = btrfs_header_level(subvol_eb);
int ret = 0;
int i;
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
return 0;
if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
return 0;
spin_lock(&blocks->lock);
if (!blocks->swapped) {
spin_unlock(&blocks->lock);
return 0;
}
node = blocks->blocks[level].rb_node;
while (node) {
block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
if (block->subvol_bytenr < subvol_eb->start) {
node = node->rb_left;
} else if (block->subvol_bytenr > subvol_eb->start) {
node = node->rb_right;
} else {
found = true;
break;
}
}
if (!found) {
spin_unlock(&blocks->lock);
goto out;
}
/* Found one, remove it from @blocks first and update blocks->swapped */
rb_erase(&block->node, &blocks->blocks[level]);
for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
swapped = true;
break;
}
}
blocks->swapped = swapped;
spin_unlock(&blocks->lock);
/* Read out reloc subtree root */
reloc_eb = read_tree_block(fs_info, block->reloc_bytenr,
block->reloc_generation, block->level,
&block->first_key);
if (IS_ERR(reloc_eb)) {
ret = PTR_ERR(reloc_eb);
reloc_eb = NULL;
goto free_out;
}
if (!extent_buffer_uptodate(reloc_eb)) {
ret = -EIO;
goto free_out;
}
ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
block->last_snapshot, block->trace_leaf);
free_out:
kfree(block);
free_extent_buffer(reloc_eb);
out:
if (ret < 0) {
btrfs_err_rl(fs_info,
"failed to account subtree at bytenr %llu: %d",
subvol_eb->start, ret);
fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
}
return ret;
}
void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans)
{
struct btrfs_qgroup_extent_record *entry;
struct btrfs_qgroup_extent_record *next;
struct rb_root *root;
root = &trans->delayed_refs.dirty_extent_root;
rbtree_postorder_for_each_entry_safe(entry, next, root, node) {
ulist_free(entry->old_roots);
kfree(entry);
}
}