mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Anand Jain](/assets/img/avatar_default.png)
Originally root_times_lock was introduced as part of send/receive code however newly developed patch to label the subvol reused the same lock, so renaming it for a meaningful name. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
556 lines
14 KiB
C
556 lines
14 KiB
C
/*
|
|
* Copyright (C) 2007 Oracle. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public
|
|
* License v2 as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public
|
|
* License along with this program; if not, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 021110-1307, USA.
|
|
*/
|
|
|
|
#include <linux/uuid.h>
|
|
#include "ctree.h"
|
|
#include "transaction.h"
|
|
#include "disk-io.h"
|
|
#include "print-tree.h"
|
|
|
|
/*
|
|
* Read a root item from the tree. In case we detect a root item smaller then
|
|
* sizeof(root_item), we know it's an old version of the root structure and
|
|
* initialize all new fields to zero. The same happens if we detect mismatching
|
|
* generation numbers as then we know the root was once mounted with an older
|
|
* kernel that was not aware of the root item structure change.
|
|
*/
|
|
void btrfs_read_root_item(struct btrfs_root *root,
|
|
struct extent_buffer *eb, int slot,
|
|
struct btrfs_root_item *item)
|
|
{
|
|
uuid_le uuid;
|
|
int len;
|
|
int need_reset = 0;
|
|
|
|
len = btrfs_item_size_nr(eb, slot);
|
|
read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),
|
|
min_t(int, len, (int)sizeof(*item)));
|
|
if (len < sizeof(*item))
|
|
need_reset = 1;
|
|
if (!need_reset && btrfs_root_generation(item)
|
|
!= btrfs_root_generation_v2(item)) {
|
|
if (btrfs_root_generation_v2(item) != 0) {
|
|
printk(KERN_WARNING "btrfs: mismatching "
|
|
"generation and generation_v2 "
|
|
"found in root item. This root "
|
|
"was probably mounted with an "
|
|
"older kernel. Resetting all "
|
|
"new fields.\n");
|
|
}
|
|
need_reset = 1;
|
|
}
|
|
if (need_reset) {
|
|
memset(&item->generation_v2, 0,
|
|
sizeof(*item) - offsetof(struct btrfs_root_item,
|
|
generation_v2));
|
|
|
|
uuid_le_gen(&uuid);
|
|
memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* lookup the root with the highest offset for a given objectid. The key we do
|
|
* find is copied into 'key'. If we find something return 0, otherwise 1, < 0
|
|
* on error.
|
|
*/
|
|
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
|
|
struct btrfs_root_item *item, struct btrfs_key *key)
|
|
{
|
|
struct btrfs_path *path;
|
|
struct btrfs_key search_key;
|
|
struct btrfs_key found_key;
|
|
struct extent_buffer *l;
|
|
int ret;
|
|
int slot;
|
|
|
|
search_key.objectid = objectid;
|
|
search_key.type = BTRFS_ROOT_ITEM_KEY;
|
|
search_key.offset = (u64)-1;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
BUG_ON(ret == 0);
|
|
if (path->slots[0] == 0) {
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
l = path->nodes[0];
|
|
slot = path->slots[0] - 1;
|
|
btrfs_item_key_to_cpu(l, &found_key, slot);
|
|
if (found_key.objectid != objectid ||
|
|
found_key.type != BTRFS_ROOT_ITEM_KEY) {
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
if (item)
|
|
btrfs_read_root_item(root, l, slot, item);
|
|
if (key)
|
|
memcpy(key, &found_key, sizeof(found_key));
|
|
|
|
ret = 0;
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
void btrfs_set_root_node(struct btrfs_root_item *item,
|
|
struct extent_buffer *node)
|
|
{
|
|
btrfs_set_root_bytenr(item, node->start);
|
|
btrfs_set_root_level(item, btrfs_header_level(node));
|
|
btrfs_set_root_generation(item, btrfs_header_generation(node));
|
|
}
|
|
|
|
/*
|
|
* copy the data in 'item' into the btree
|
|
*/
|
|
int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
|
|
*root, struct btrfs_key *key, struct btrfs_root_item
|
|
*item)
|
|
{
|
|
struct btrfs_path *path;
|
|
struct extent_buffer *l;
|
|
int ret;
|
|
int slot;
|
|
unsigned long ptr;
|
|
int old_len;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
ret = btrfs_search_slot(trans, root, key, path, 0, 1);
|
|
if (ret < 0) {
|
|
btrfs_abort_transaction(trans, root, ret);
|
|
goto out;
|
|
}
|
|
|
|
if (ret != 0) {
|
|
btrfs_print_leaf(root, path->nodes[0]);
|
|
printk(KERN_CRIT "unable to update root key %llu %u %llu\n",
|
|
(unsigned long long)key->objectid, key->type,
|
|
(unsigned long long)key->offset);
|
|
BUG_ON(1);
|
|
}
|
|
|
|
l = path->nodes[0];
|
|
slot = path->slots[0];
|
|
ptr = btrfs_item_ptr_offset(l, slot);
|
|
old_len = btrfs_item_size_nr(l, slot);
|
|
|
|
/*
|
|
* If this is the first time we update the root item which originated
|
|
* from an older kernel, we need to enlarge the item size to make room
|
|
* for the added fields.
|
|
*/
|
|
if (old_len < sizeof(*item)) {
|
|
btrfs_release_path(path);
|
|
ret = btrfs_search_slot(trans, root, key, path,
|
|
-1, 1);
|
|
if (ret < 0) {
|
|
btrfs_abort_transaction(trans, root, ret);
|
|
goto out;
|
|
}
|
|
|
|
ret = btrfs_del_item(trans, root, path);
|
|
if (ret < 0) {
|
|
btrfs_abort_transaction(trans, root, ret);
|
|
goto out;
|
|
}
|
|
btrfs_release_path(path);
|
|
ret = btrfs_insert_empty_item(trans, root, path,
|
|
key, sizeof(*item));
|
|
if (ret < 0) {
|
|
btrfs_abort_transaction(trans, root, ret);
|
|
goto out;
|
|
}
|
|
l = path->nodes[0];
|
|
slot = path->slots[0];
|
|
ptr = btrfs_item_ptr_offset(l, slot);
|
|
}
|
|
|
|
/*
|
|
* Update generation_v2 so at the next mount we know the new root
|
|
* fields are valid.
|
|
*/
|
|
btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
|
|
|
|
write_extent_buffer(l, item, ptr, sizeof(*item));
|
|
btrfs_mark_buffer_dirty(path->nodes[0]);
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
|
|
struct btrfs_key *key, struct btrfs_root_item *item)
|
|
{
|
|
/*
|
|
* Make sure generation v1 and v2 match. See update_root for details.
|
|
*/
|
|
btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
|
|
return btrfs_insert_item(trans, root, key, item, sizeof(*item));
|
|
}
|
|
|
|
/*
|
|
* at mount time we want to find all the old transaction snapshots that were in
|
|
* the process of being deleted if we crashed. This is any root item with an
|
|
* offset lower than the latest root. They need to be queued for deletion to
|
|
* finish what was happening when we crashed.
|
|
*/
|
|
int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid)
|
|
{
|
|
struct btrfs_root *dead_root;
|
|
struct btrfs_root_item *ri;
|
|
struct btrfs_key key;
|
|
struct btrfs_key found_key;
|
|
struct btrfs_path *path;
|
|
int ret;
|
|
u32 nritems;
|
|
struct extent_buffer *leaf;
|
|
int slot;
|
|
|
|
key.objectid = objectid;
|
|
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
|
|
key.offset = 0;
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
again:
|
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
|
|
if (ret < 0)
|
|
goto err;
|
|
while (1) {
|
|
leaf = path->nodes[0];
|
|
nritems = btrfs_header_nritems(leaf);
|
|
slot = path->slots[0];
|
|
if (slot >= nritems) {
|
|
ret = btrfs_next_leaf(root, path);
|
|
if (ret)
|
|
break;
|
|
leaf = path->nodes[0];
|
|
nritems = btrfs_header_nritems(leaf);
|
|
slot = path->slots[0];
|
|
}
|
|
btrfs_item_key_to_cpu(leaf, &key, slot);
|
|
if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
|
|
goto next;
|
|
|
|
if (key.objectid < objectid)
|
|
goto next;
|
|
|
|
if (key.objectid > objectid)
|
|
break;
|
|
|
|
ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
|
|
if (btrfs_disk_root_refs(leaf, ri) != 0)
|
|
goto next;
|
|
|
|
memcpy(&found_key, &key, sizeof(key));
|
|
key.offset++;
|
|
btrfs_release_path(path);
|
|
dead_root =
|
|
btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
|
|
&found_key);
|
|
if (IS_ERR(dead_root)) {
|
|
ret = PTR_ERR(dead_root);
|
|
goto err;
|
|
}
|
|
|
|
ret = btrfs_add_dead_root(dead_root);
|
|
if (ret)
|
|
goto err;
|
|
goto again;
|
|
next:
|
|
slot++;
|
|
path->slots[0]++;
|
|
}
|
|
ret = 0;
|
|
err:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
|
|
{
|
|
struct extent_buffer *leaf;
|
|
struct btrfs_path *path;
|
|
struct btrfs_key key;
|
|
struct btrfs_key root_key;
|
|
struct btrfs_root *root;
|
|
int err = 0;
|
|
int ret;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = BTRFS_ORPHAN_OBJECTID;
|
|
key.type = BTRFS_ORPHAN_ITEM_KEY;
|
|
key.offset = 0;
|
|
|
|
root_key.type = BTRFS_ROOT_ITEM_KEY;
|
|
root_key.offset = (u64)-1;
|
|
|
|
while (1) {
|
|
ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
|
|
if (ret < 0) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
|
|
leaf = path->nodes[0];
|
|
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
|
|
ret = btrfs_next_leaf(tree_root, path);
|
|
if (ret < 0)
|
|
err = ret;
|
|
if (ret != 0)
|
|
break;
|
|
leaf = path->nodes[0];
|
|
}
|
|
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
|
|
btrfs_release_path(path);
|
|
|
|
if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
|
|
key.type != BTRFS_ORPHAN_ITEM_KEY)
|
|
break;
|
|
|
|
root_key.objectid = key.offset;
|
|
key.offset++;
|
|
|
|
root = btrfs_read_fs_root_no_name(tree_root->fs_info,
|
|
&root_key);
|
|
if (!IS_ERR(root))
|
|
continue;
|
|
|
|
ret = PTR_ERR(root);
|
|
if (ret != -ENOENT) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
|
|
ret = btrfs_find_dead_roots(tree_root, root_key.objectid);
|
|
if (ret) {
|
|
err = ret;
|
|
break;
|
|
}
|
|
}
|
|
|
|
btrfs_free_path(path);
|
|
return err;
|
|
}
|
|
|
|
/* drop the root item for 'key' from 'root' */
|
|
int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
|
|
struct btrfs_key *key)
|
|
{
|
|
struct btrfs_path *path;
|
|
int ret;
|
|
struct btrfs_root_item *ri;
|
|
struct extent_buffer *leaf;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
ret = btrfs_search_slot(trans, root, key, path, -1, 1);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
BUG_ON(ret != 0);
|
|
leaf = path->nodes[0];
|
|
ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
|
|
|
|
ret = btrfs_del_item(trans, root, path);
|
|
out:
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *tree_root,
|
|
u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
|
|
const char *name, int name_len)
|
|
|
|
{
|
|
struct btrfs_path *path;
|
|
struct btrfs_root_ref *ref;
|
|
struct extent_buffer *leaf;
|
|
struct btrfs_key key;
|
|
unsigned long ptr;
|
|
int err = 0;
|
|
int ret;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = root_id;
|
|
key.type = BTRFS_ROOT_BACKREF_KEY;
|
|
key.offset = ref_id;
|
|
again:
|
|
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
|
|
BUG_ON(ret < 0);
|
|
if (ret == 0) {
|
|
leaf = path->nodes[0];
|
|
ref = btrfs_item_ptr(leaf, path->slots[0],
|
|
struct btrfs_root_ref);
|
|
|
|
WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
|
|
WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
|
|
ptr = (unsigned long)(ref + 1);
|
|
WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
|
|
*sequence = btrfs_root_ref_sequence(leaf, ref);
|
|
|
|
ret = btrfs_del_item(trans, tree_root, path);
|
|
if (ret) {
|
|
err = ret;
|
|
goto out;
|
|
}
|
|
} else
|
|
err = -ENOENT;
|
|
|
|
if (key.type == BTRFS_ROOT_BACKREF_KEY) {
|
|
btrfs_release_path(path);
|
|
key.objectid = ref_id;
|
|
key.type = BTRFS_ROOT_REF_KEY;
|
|
key.offset = root_id;
|
|
goto again;
|
|
}
|
|
|
|
out:
|
|
btrfs_free_path(path);
|
|
return err;
|
|
}
|
|
|
|
int btrfs_find_root_ref(struct btrfs_root *tree_root,
|
|
struct btrfs_path *path,
|
|
u64 root_id, u64 ref_id)
|
|
{
|
|
struct btrfs_key key;
|
|
int ret;
|
|
|
|
key.objectid = root_id;
|
|
key.type = BTRFS_ROOT_REF_KEY;
|
|
key.offset = ref_id;
|
|
|
|
ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
|
|
* or BTRFS_ROOT_BACKREF_KEY.
|
|
*
|
|
* The dirid, sequence, name and name_len refer to the directory entry
|
|
* that is referencing the root.
|
|
*
|
|
* For a forward ref, the root_id is the id of the tree referencing
|
|
* the root and ref_id is the id of the subvol or snapshot.
|
|
*
|
|
* For a back ref the root_id is the id of the subvol or snapshot and
|
|
* ref_id is the id of the tree referencing it.
|
|
*
|
|
* Will return 0, -ENOMEM, or anything from the CoW path
|
|
*/
|
|
int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *tree_root,
|
|
u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
|
|
const char *name, int name_len)
|
|
{
|
|
struct btrfs_key key;
|
|
int ret;
|
|
struct btrfs_path *path;
|
|
struct btrfs_root_ref *ref;
|
|
struct extent_buffer *leaf;
|
|
unsigned long ptr;
|
|
|
|
path = btrfs_alloc_path();
|
|
if (!path)
|
|
return -ENOMEM;
|
|
|
|
key.objectid = root_id;
|
|
key.type = BTRFS_ROOT_BACKREF_KEY;
|
|
key.offset = ref_id;
|
|
again:
|
|
ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
|
|
sizeof(*ref) + name_len);
|
|
if (ret) {
|
|
btrfs_abort_transaction(trans, tree_root, ret);
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
leaf = path->nodes[0];
|
|
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
|
|
btrfs_set_root_ref_dirid(leaf, ref, dirid);
|
|
btrfs_set_root_ref_sequence(leaf, ref, sequence);
|
|
btrfs_set_root_ref_name_len(leaf, ref, name_len);
|
|
ptr = (unsigned long)(ref + 1);
|
|
write_extent_buffer(leaf, name, ptr, name_len);
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
|
|
if (key.type == BTRFS_ROOT_BACKREF_KEY) {
|
|
btrfs_release_path(path);
|
|
key.objectid = ref_id;
|
|
key.type = BTRFS_ROOT_REF_KEY;
|
|
key.offset = root_id;
|
|
goto again;
|
|
}
|
|
|
|
btrfs_free_path(path);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Old btrfs forgets to init root_item->flags and root_item->byte_limit
|
|
* for subvolumes. To work around this problem, we steal a bit from
|
|
* root_item->inode_item->flags, and use it to indicate if those fields
|
|
* have been properly initialized.
|
|
*/
|
|
void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
|
|
{
|
|
u64 inode_flags = le64_to_cpu(root_item->inode.flags);
|
|
|
|
if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
|
|
inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
|
|
root_item->inode.flags = cpu_to_le64(inode_flags);
|
|
root_item->flags = 0;
|
|
root_item->byte_limit = 0;
|
|
}
|
|
}
|
|
|
|
void btrfs_update_root_times(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root)
|
|
{
|
|
struct btrfs_root_item *item = &root->root_item;
|
|
struct timespec ct = CURRENT_TIME;
|
|
|
|
spin_lock(&root->root_item_lock);
|
|
item->ctransid = cpu_to_le64(trans->transid);
|
|
item->ctime.sec = cpu_to_le64(ct.tv_sec);
|
|
item->ctime.nsec = cpu_to_le32(ct.tv_nsec);
|
|
spin_unlock(&root->root_item_lock);
|
|
}
|