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linux-stable/fs/bcachefs/subvolume.c

1065 lines
26 KiB
C
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// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "btree_key_cache.h"
#include "btree_update.h"
#include "errcode.h"
#include "error.h"
#include "fs.h"
#include "subvolume.h"
/* Snapshot tree: */
void bch2_snapshot_to_text(struct printbuf *out, struct bch_fs *c,
struct bkey_s_c k)
{
struct bkey_s_c_snapshot s = bkey_s_c_to_snapshot(k);
prt_printf(out, "is_subvol %llu deleted %llu parent %10u children %10u %10u subvol %u",
BCH_SNAPSHOT_SUBVOL(s.v),
BCH_SNAPSHOT_DELETED(s.v),
le32_to_cpu(s.v->parent),
le32_to_cpu(s.v->children[0]),
le32_to_cpu(s.v->children[1]),
le32_to_cpu(s.v->subvol));
}
int bch2_snapshot_invalid(const struct bch_fs *c, struct bkey_s_c k,
int rw, struct printbuf *err)
{
struct bkey_s_c_snapshot s;
u32 i, id;
if (bkey_gt(k.k->p, POS(0, U32_MAX)) ||
bkey_lt(k.k->p, POS(0, 1))) {
prt_printf(err, "bad pos");
return -BCH_ERR_invalid_bkey;
}
if (bkey_val_bytes(k.k) != sizeof(struct bch_snapshot)) {
prt_printf(err, "bad val size (%zu != %zu)",
bkey_val_bytes(k.k), sizeof(struct bch_snapshot));
return -BCH_ERR_invalid_bkey;
}
s = bkey_s_c_to_snapshot(k);
id = le32_to_cpu(s.v->parent);
if (id && id <= k.k->p.offset) {
prt_printf(err, "bad parent node (%u <= %llu)",
id, k.k->p.offset);
return -BCH_ERR_invalid_bkey;
}
if (le32_to_cpu(s.v->children[0]) < le32_to_cpu(s.v->children[1])) {
prt_printf(err, "children not normalized");
return -BCH_ERR_invalid_bkey;
}
if (s.v->children[0] &&
s.v->children[0] == s.v->children[1]) {
prt_printf(err, "duplicate child nodes");
return -BCH_ERR_invalid_bkey;
}
for (i = 0; i < 2; i++) {
id = le32_to_cpu(s.v->children[i]);
if (id >= k.k->p.offset) {
prt_printf(err, "bad child node (%u >= %llu)",
id, k.k->p.offset);
return -BCH_ERR_invalid_bkey;
}
}
return 0;
}
int bch2_mark_snapshot(struct btree_trans *trans,
struct bkey_s_c old, struct bkey_s_c new,
unsigned flags)
{
struct bch_fs *c = trans->c;
struct snapshot_t *t;
t = genradix_ptr_alloc(&c->snapshots,
U32_MAX - new.k->p.offset,
GFP_KERNEL);
if (!t)
return -ENOMEM;
if (new.k->type == KEY_TYPE_snapshot) {
struct bkey_s_c_snapshot s = bkey_s_c_to_snapshot(new);
t->parent = le32_to_cpu(s.v->parent);
t->children[0] = le32_to_cpu(s.v->children[0]);
t->children[1] = le32_to_cpu(s.v->children[1]);
t->subvol = BCH_SNAPSHOT_SUBVOL(s.v) ? le32_to_cpu(s.v->subvol) : 0;
} else {
t->parent = 0;
t->children[0] = 0;
t->children[1] = 0;
t->subvol = 0;
}
return 0;
}
static int snapshot_lookup(struct btree_trans *trans, u32 id,
struct bch_snapshot *s)
{
struct btree_iter iter;
struct bkey_s_c k;
int ret;
bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots, POS(0, id),
BTREE_ITER_WITH_UPDATES);
k = bch2_btree_iter_peek_slot(&iter);
ret = bkey_err(k) ?: k.k->type == KEY_TYPE_snapshot ? 0 : -ENOENT;
if (!ret)
*s = *bkey_s_c_to_snapshot(k).v;
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static int snapshot_live(struct btree_trans *trans, u32 id)
{
struct bch_snapshot v;
int ret;
if (!id)
return 0;
ret = snapshot_lookup(trans, id, &v);
if (ret == -ENOENT)
bch_err(trans->c, "snapshot node %u not found", id);
if (ret)
return ret;
return !BCH_SNAPSHOT_DELETED(&v);
}
static int bch2_snapshot_set_equiv(struct btree_trans *trans, struct bkey_s_c k)
{
struct bch_fs *c = trans->c;
unsigned i, nr_live = 0, live_idx = 0;
struct bkey_s_c_snapshot snap;
u32 id = k.k->p.offset, child[2];
if (k.k->type != KEY_TYPE_snapshot)
return 0;
snap = bkey_s_c_to_snapshot(k);
child[0] = le32_to_cpu(snap.v->children[0]);
child[1] = le32_to_cpu(snap.v->children[1]);
for (i = 0; i < 2; i++) {
int ret = snapshot_live(trans, child[i]);
if (ret < 0)
return ret;
if (ret)
live_idx = i;
nr_live += ret;
}
snapshot_t(c, id)->equiv = nr_live == 1
? snapshot_t(c, child[live_idx])->equiv
: id;
return 0;
}
/* fsck: */
static int check_snapshot(struct btree_trans *trans,
struct btree_iter *iter,
struct bkey_s_c k)
{
struct bch_fs *c = trans->c;
struct bkey_s_c_snapshot s;
struct bch_subvolume subvol;
struct bch_snapshot v;
struct printbuf buf = PRINTBUF;
bool should_have_subvol;
u32 i, id;
int ret = 0;
if (k.k->type != KEY_TYPE_snapshot)
return 0;
s = bkey_s_c_to_snapshot(k);
id = le32_to_cpu(s.v->parent);
if (id) {
ret = snapshot_lookup(trans, id, &v);
if (ret == -ENOENT)
bch_err(c, "snapshot with nonexistent parent:\n %s",
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf));
if (ret)
goto err;
if (le32_to_cpu(v.children[0]) != s.k->p.offset &&
le32_to_cpu(v.children[1]) != s.k->p.offset) {
bch_err(c, "snapshot parent %u missing pointer to child %llu",
id, s.k->p.offset);
ret = -EINVAL;
goto err;
}
}
for (i = 0; i < 2 && s.v->children[i]; i++) {
id = le32_to_cpu(s.v->children[i]);
ret = snapshot_lookup(trans, id, &v);
if (ret == -ENOENT)
bch_err(c, "snapshot node %llu has nonexistent child %u",
s.k->p.offset, id);
if (ret)
goto err;
if (le32_to_cpu(v.parent) != s.k->p.offset) {
bch_err(c, "snapshot child %u has wrong parent (got %u should be %llu)",
id, le32_to_cpu(v.parent), s.k->p.offset);
ret = -EINVAL;
goto err;
}
}
should_have_subvol = BCH_SNAPSHOT_SUBVOL(s.v) &&
!BCH_SNAPSHOT_DELETED(s.v);
if (should_have_subvol) {
id = le32_to_cpu(s.v->subvol);
ret = bch2_subvolume_get(trans, id, 0, false, &subvol);
if (ret == -ENOENT)
bch_err(c, "snapshot points to nonexistent subvolume:\n %s",
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf));
if (ret)
goto err;
if (BCH_SNAPSHOT_SUBVOL(s.v) != (le32_to_cpu(subvol.snapshot) == s.k->p.offset)) {
bch_err(c, "snapshot node %llu has wrong BCH_SNAPSHOT_SUBVOL",
s.k->p.offset);
ret = -EINVAL;
goto err;
}
} else {
if (fsck_err_on(s.v->subvol, c, "snapshot should not point to subvol:\n %s",
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
struct bkey_i_snapshot *u = bch2_trans_kmalloc(trans, sizeof(*u));
ret = PTR_ERR_OR_ZERO(u);
if (ret)
goto err;
bkey_reassemble(&u->k_i, s.s_c);
u->v.subvol = 0;
ret = bch2_trans_update(trans, iter, &u->k_i, 0);
if (ret)
goto err;
}
}
if (BCH_SNAPSHOT_DELETED(s.v))
set_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags);
err:
fsck_err:
printbuf_exit(&buf);
return ret;
}
int bch2_fs_check_snapshots(struct bch_fs *c)
{
struct btree_trans trans;
struct btree_iter iter;
struct bkey_s_c k;
int ret;
bch2_trans_init(&trans, c, 0, 0);
ret = for_each_btree_key_commit(&trans, iter,
BTREE_ID_snapshots, POS_MIN,
BTREE_ITER_PREFETCH, k,
NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL,
check_snapshot(&trans, &iter, k));
if (ret)
bch_err(c, "error %i checking snapshots", ret);
bch2_trans_exit(&trans);
return ret;
}
static int check_subvol(struct btree_trans *trans,
struct btree_iter *iter,
struct bkey_s_c k)
{
struct bkey_s_c_subvolume subvol;
struct bch_snapshot snapshot;
unsigned snapid;
int ret;
if (k.k->type != KEY_TYPE_subvolume)
return 0;
subvol = bkey_s_c_to_subvolume(k);
snapid = le32_to_cpu(subvol.v->snapshot);
ret = snapshot_lookup(trans, snapid, &snapshot);
if (ret == -ENOENT)
bch_err(trans->c, "subvolume %llu points to nonexistent snapshot %u",
k.k->p.offset, snapid);
if (ret)
return ret;
if (BCH_SUBVOLUME_UNLINKED(subvol.v)) {
ret = bch2_subvolume_delete(trans, iter->pos.offset);
if (ret && !bch2_err_matches(ret, BCH_ERR_transaction_restart))
bch_err(trans->c, "error deleting subvolume %llu: %s",
iter->pos.offset, bch2_err_str(ret));
if (ret)
return ret;
}
return 0;
}
int bch2_fs_check_subvols(struct bch_fs *c)
{
struct btree_trans trans;
struct btree_iter iter;
struct bkey_s_c k;
int ret;
bch2_trans_init(&trans, c, 0, 0);
ret = for_each_btree_key_commit(&trans, iter,
BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k,
NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL,
check_subvol(&trans, &iter, k));
bch2_trans_exit(&trans);
return ret;
}
void bch2_fs_snapshots_exit(struct bch_fs *c)
{
genradix_free(&c->snapshots);
}
int bch2_fs_snapshots_start(struct bch_fs *c)
{
struct btree_trans trans;
struct btree_iter iter;
struct bkey_s_c k;
int ret = 0;
bch2_trans_init(&trans, c, 0, 0);
for_each_btree_key2(&trans, iter, BTREE_ID_snapshots,
POS_MIN, 0, k,
bch2_mark_snapshot(&trans, bkey_s_c_null, k, 0) ?:
bch2_snapshot_set_equiv(&trans, k));
bch2_trans_exit(&trans);
if (ret)
bch_err(c, "error starting snapshots: %s", bch2_err_str(ret));
return ret;
}
/*
* Mark a snapshot as deleted, for future cleanup:
*/
static int bch2_snapshot_node_set_deleted(struct btree_trans *trans, u32 id)
{
struct btree_iter iter;
struct bkey_i_snapshot *s;
int ret = 0;
bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots, POS(0, id),
BTREE_ITER_INTENT);
s = bch2_bkey_get_mut_typed(trans, &iter, snapshot);
ret = PTR_ERR_OR_ZERO(s);
if (unlikely(ret)) {
bch2_fs_inconsistent_on(ret == -ENOENT, trans->c, "missing snapshot %u", id);
goto err;
}
/* already deleted? */
if (BCH_SNAPSHOT_DELETED(&s->v))
goto err;
SET_BCH_SNAPSHOT_DELETED(&s->v, true);
SET_BCH_SNAPSHOT_SUBVOL(&s->v, false);
s->v.subvol = 0;
ret = bch2_trans_update(trans, &iter, &s->k_i, 0);
if (ret)
goto err;
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static int bch2_snapshot_node_delete(struct btree_trans *trans, u32 id)
{
struct btree_iter iter, p_iter = (struct btree_iter) { NULL };
struct bkey_s_c k;
struct bkey_s_c_snapshot s;
u32 parent_id;
unsigned i;
int ret = 0;
bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots, POS(0, id),
BTREE_ITER_INTENT);
k = bch2_btree_iter_peek_slot(&iter);
ret = bkey_err(k);
if (ret)
goto err;
if (k.k->type != KEY_TYPE_snapshot) {
bch2_fs_inconsistent(trans->c, "missing snapshot %u", id);
ret = -ENOENT;
goto err;
}
s = bkey_s_c_to_snapshot(k);
BUG_ON(!BCH_SNAPSHOT_DELETED(s.v));
parent_id = le32_to_cpu(s.v->parent);
if (parent_id) {
struct bkey_i_snapshot *parent;
bch2_trans_iter_init(trans, &p_iter, BTREE_ID_snapshots,
POS(0, parent_id),
BTREE_ITER_INTENT);
parent = bch2_bkey_get_mut_typed(trans, &p_iter, snapshot);
ret = PTR_ERR_OR_ZERO(parent);
if (unlikely(ret)) {
bch2_fs_inconsistent_on(ret == -ENOENT, trans->c, "missing snapshot %u", parent_id);
goto err;
}
for (i = 0; i < 2; i++)
if (le32_to_cpu(parent->v.children[i]) == id)
break;
if (i == 2)
bch_err(trans->c, "snapshot %u missing child pointer to %u",
parent_id, id);
else
parent->v.children[i] = 0;
if (le32_to_cpu(parent->v.children[0]) <
le32_to_cpu(parent->v.children[1]))
swap(parent->v.children[0],
parent->v.children[1]);
ret = bch2_trans_update(trans, &p_iter, &parent->k_i, 0);
if (ret)
goto err;
}
ret = bch2_btree_delete_at(trans, &iter, 0);
err:
bch2_trans_iter_exit(trans, &p_iter);
bch2_trans_iter_exit(trans, &iter);
return ret;
}
int bch2_snapshot_node_create(struct btree_trans *trans, u32 parent,
u32 *new_snapids,
u32 *snapshot_subvols,
unsigned nr_snapids)
{
struct btree_iter iter;
struct bkey_i_snapshot *n;
struct bkey_s_c k;
unsigned i;
int ret = 0;
bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots,
POS_MIN, BTREE_ITER_INTENT);
k = bch2_btree_iter_peek(&iter);
ret = bkey_err(k);
if (ret)
goto err;
for (i = 0; i < nr_snapids; i++) {
k = bch2_btree_iter_prev_slot(&iter);
ret = bkey_err(k);
if (ret)
goto err;
if (!k.k || !k.k->p.offset) {
ret = -BCH_ERR_ENOSPC_snapshot_create;
goto err;
}
n = bch2_bkey_alloc(trans, &iter, snapshot);
ret = PTR_ERR_OR_ZERO(n);
if (ret)
goto err;
n->v.flags = 0;
n->v.parent = cpu_to_le32(parent);
n->v.subvol = cpu_to_le32(snapshot_subvols[i]);
n->v.pad = 0;
SET_BCH_SNAPSHOT_SUBVOL(&n->v, true);
ret = bch2_trans_update(trans, &iter, &n->k_i, 0) ?:
bch2_mark_snapshot(trans, bkey_s_c_null, bkey_i_to_s_c(&n->k_i), 0);
if (ret)
goto err;
new_snapids[i] = iter.pos.offset;
}
if (parent) {
bch2_btree_iter_set_pos(&iter, POS(0, parent));
n = bch2_bkey_get_mut_typed(trans, &iter, snapshot);
ret = PTR_ERR_OR_ZERO(n);
if (unlikely(ret)) {
if (ret == -ENOENT)
bch_err(trans->c, "snapshot %u not found", parent);
goto err;
}
if (n->v.children[0] || n->v.children[1]) {
bch_err(trans->c, "Trying to add child snapshot nodes to parent that already has children");
ret = -EINVAL;
goto err;
}
n->v.children[0] = cpu_to_le32(new_snapids[0]);
n->v.children[1] = cpu_to_le32(new_snapids[1]);
n->v.subvol = 0;
SET_BCH_SNAPSHOT_SUBVOL(&n->v, false);
ret = bch2_trans_update(trans, &iter, &n->k_i, 0);
if (ret)
goto err;
}
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static int snapshot_delete_key(struct btree_trans *trans,
struct btree_iter *iter,
struct bkey_s_c k,
snapshot_id_list *deleted,
snapshot_id_list *equiv_seen,
struct bpos *last_pos)
{
struct bch_fs *c = trans->c;
u32 equiv = snapshot_t(c, k.k->p.snapshot)->equiv;
if (!bkey_eq(k.k->p, *last_pos))
equiv_seen->nr = 0;
*last_pos = k.k->p;
if (snapshot_list_has_id(deleted, k.k->p.snapshot) ||
snapshot_list_has_id(equiv_seen, equiv)) {
return bch2_btree_delete_at(trans, iter,
BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
} else {
return snapshot_list_add(c, equiv_seen, equiv);
}
}
static int bch2_delete_redundant_snapshot(struct btree_trans *trans, struct btree_iter *iter,
struct bkey_s_c k)
{
struct bkey_s_c_snapshot snap;
u32 children[2];
int ret;
if (k.k->type != KEY_TYPE_snapshot)
return 0;
snap = bkey_s_c_to_snapshot(k);
if (BCH_SNAPSHOT_DELETED(snap.v) ||
BCH_SNAPSHOT_SUBVOL(snap.v))
return 0;
children[0] = le32_to_cpu(snap.v->children[0]);
children[1] = le32_to_cpu(snap.v->children[1]);
ret = snapshot_live(trans, children[0]) ?:
snapshot_live(trans, children[1]);
if (ret < 0)
return ret;
if (!ret)
return bch2_snapshot_node_set_deleted(trans, k.k->p.offset);
return 0;
}
int bch2_delete_dead_snapshots(struct bch_fs *c)
{
struct btree_trans trans;
struct btree_iter iter;
struct bkey_s_c k;
struct bkey_s_c_snapshot snap;
snapshot_id_list deleted = { 0 };
u32 i, id;
int ret = 0;
if (!test_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags))
return 0;
if (!test_bit(BCH_FS_STARTED, &c->flags)) {
ret = bch2_fs_read_write_early(c);
if (ret) {
bch_err(c, "error deleleting dead snapshots: error going rw: %s", bch2_err_str(ret));
return ret;
}
}
bch2_trans_init(&trans, c, 0, 0);
/*
* For every snapshot node: If we have no live children and it's not
* pointed to by a subvolume, delete it:
*/
ret = for_each_btree_key_commit(&trans, iter, BTREE_ID_snapshots,
POS_MIN, 0, k,
NULL, NULL, 0,
bch2_delete_redundant_snapshot(&trans, &iter, k));
if (ret) {
bch_err(c, "error deleting redundant snapshots: %s", bch2_err_str(ret));
goto err;
}
for_each_btree_key2(&trans, iter, BTREE_ID_snapshots,
POS_MIN, 0, k,
bch2_snapshot_set_equiv(&trans, k));
if (ret) {
bch_err(c, "error in bch2_snapshots_set_equiv: %s", bch2_err_str(ret));
goto err;
}
for_each_btree_key(&trans, iter, BTREE_ID_snapshots,
POS_MIN, 0, k, ret) {
if (k.k->type != KEY_TYPE_snapshot)
continue;
snap = bkey_s_c_to_snapshot(k);
if (BCH_SNAPSHOT_DELETED(snap.v)) {
ret = snapshot_list_add(c, &deleted, k.k->p.offset);
if (ret)
break;
}
}
bch2_trans_iter_exit(&trans, &iter);
if (ret) {
bch_err(c, "error walking snapshots: %s", bch2_err_str(ret));
goto err;
}
for (id = 0; id < BTREE_ID_NR; id++) {
struct bpos last_pos = POS_MIN;
snapshot_id_list equiv_seen = { 0 };
if (!btree_type_has_snapshots(id))
continue;
ret = for_each_btree_key_commit(&trans, iter,
id, POS_MIN,
BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
NULL, NULL, BTREE_INSERT_NOFAIL,
snapshot_delete_key(&trans, &iter, k, &deleted, &equiv_seen, &last_pos));
darray_exit(&equiv_seen);
if (ret) {
bch_err(c, "error deleting snapshot keys: %s", bch2_err_str(ret));
goto err;
}
}
for (i = 0; i < deleted.nr; i++) {
ret = commit_do(&trans, NULL, NULL, 0,
bch2_snapshot_node_delete(&trans, deleted.data[i]));
if (ret) {
bch_err(c, "error deleting snapshot %u: %s",
deleted.data[i], bch2_err_str(ret));
goto err;
}
}
clear_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags);
err:
darray_exit(&deleted);
bch2_trans_exit(&trans);
return ret;
}
static void bch2_delete_dead_snapshots_work(struct work_struct *work)
{
struct bch_fs *c = container_of(work, struct bch_fs, snapshot_delete_work);
bch2_delete_dead_snapshots(c);
bch2_write_ref_put(c, BCH_WRITE_REF_delete_dead_snapshots);
}
void bch2_delete_dead_snapshots_async(struct bch_fs *c)
{
if (bch2_write_ref_tryget(c, BCH_WRITE_REF_delete_dead_snapshots) &&
!queue_work(system_long_wq, &c->snapshot_delete_work))
bch2_write_ref_put(c, BCH_WRITE_REF_delete_dead_snapshots);
}
static int bch2_delete_dead_snapshots_hook(struct btree_trans *trans,
struct btree_trans_commit_hook *h)
{
struct bch_fs *c = trans->c;
set_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags);
if (!test_bit(BCH_FS_FSCK_DONE, &c->flags))
return 0;
bch2_delete_dead_snapshots_async(c);
return 0;
}
/* Subvolumes: */
int bch2_subvolume_invalid(const struct bch_fs *c, struct bkey_s_c k,
int rw, struct printbuf *err)
{
if (bkey_lt(k.k->p, SUBVOL_POS_MIN) ||
bkey_gt(k.k->p, SUBVOL_POS_MAX)) {
prt_printf(err, "invalid pos");
return -BCH_ERR_invalid_bkey;
}
if (bkey_val_bytes(k.k) != sizeof(struct bch_subvolume)) {
prt_printf(err, "incorrect value size (%zu != %zu)",
bkey_val_bytes(k.k), sizeof(struct bch_subvolume));
return -BCH_ERR_invalid_bkey;
}
return 0;
}
void bch2_subvolume_to_text(struct printbuf *out, struct bch_fs *c,
struct bkey_s_c k)
{
struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
prt_printf(out, "root %llu snapshot id %u",
le64_to_cpu(s.v->inode),
le32_to_cpu(s.v->snapshot));
}
static __always_inline int
bch2_subvolume_get_inlined(struct btree_trans *trans, unsigned subvol,
bool inconsistent_if_not_found,
int iter_flags,
struct bch_subvolume *s)
{
struct btree_iter iter;
struct bkey_s_c k;
int ret;
bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes, POS(0, subvol),
iter_flags);
k = bch2_btree_iter_peek_slot(&iter);
ret = bkey_err(k) ?: k.k->type == KEY_TYPE_subvolume ? 0 : -ENOENT;
if (ret == -ENOENT && inconsistent_if_not_found)
bch2_fs_inconsistent(trans->c, "missing subvolume %u", subvol);
if (!ret)
*s = *bkey_s_c_to_subvolume(k).v;
bch2_trans_iter_exit(trans, &iter);
return ret;
}
int bch2_subvolume_get(struct btree_trans *trans, unsigned subvol,
bool inconsistent_if_not_found,
int iter_flags,
struct bch_subvolume *s)
{
return bch2_subvolume_get_inlined(trans, subvol, inconsistent_if_not_found, iter_flags, s);
}
int bch2_snapshot_get_subvol(struct btree_trans *trans, u32 snapshot,
struct bch_subvolume *subvol)
{
struct bch_snapshot snap;
return snapshot_lookup(trans, snapshot, &snap) ?:
bch2_subvolume_get(trans, le32_to_cpu(snap.subvol), true, 0, subvol);
}
int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvol,
u32 *snapid)
{
struct bch_subvolume s;
int ret;
ret = bch2_subvolume_get_inlined(trans, subvol, true,
BTREE_ITER_CACHED|
BTREE_ITER_WITH_UPDATES,
&s);
if (!ret)
*snapid = le32_to_cpu(s.snapshot);
return ret;
}
/*
* Delete subvolume, mark snapshot ID as deleted, queue up snapshot
* deletion/cleanup:
*/
int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
{
struct btree_iter iter;
struct bkey_s_c k;
struct bkey_s_c_subvolume subvol;
struct btree_trans_commit_hook *h;
u32 snapid;
int ret = 0;
bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes,
POS(0, subvolid),
BTREE_ITER_CACHED|
BTREE_ITER_INTENT);
k = bch2_btree_iter_peek_slot(&iter);
ret = bkey_err(k);
if (ret)
goto err;
if (k.k->type != KEY_TYPE_subvolume) {
bch2_fs_inconsistent(trans->c, "missing subvolume %u", subvolid);
ret = -EIO;
goto err;
}
subvol = bkey_s_c_to_subvolume(k);
snapid = le32_to_cpu(subvol.v->snapshot);
ret = bch2_btree_delete_at(trans, &iter, 0);
if (ret)
goto err;
ret = bch2_snapshot_node_set_deleted(trans, snapid);
if (ret)
goto err;
h = bch2_trans_kmalloc(trans, sizeof(*h));
ret = PTR_ERR_OR_ZERO(h);
if (ret)
goto err;
h->fn = bch2_delete_dead_snapshots_hook;
bch2_trans_commit_hook(trans, h);
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
void bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct *work)
{
struct bch_fs *c = container_of(work, struct bch_fs,
snapshot_wait_for_pagecache_and_delete_work);
snapshot_id_list s;
u32 *id;
int ret = 0;
while (!ret) {
mutex_lock(&c->snapshots_unlinked_lock);
s = c->snapshots_unlinked;
darray_init(&c->snapshots_unlinked);
mutex_unlock(&c->snapshots_unlinked_lock);
if (!s.nr)
break;
bch2_evict_subvolume_inodes(c, &s);
for (id = s.data; id < s.data + s.nr; id++) {
ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_NOFAIL,
bch2_subvolume_delete(&trans, *id));
if (ret) {
bch_err(c, "error deleting subvolume %u: %s", *id, bch2_err_str(ret));
break;
}
}
darray_exit(&s);
}
bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache);
}
struct subvolume_unlink_hook {
struct btree_trans_commit_hook h;
u32 subvol;
};
int bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans *trans,
struct btree_trans_commit_hook *_h)
{
struct subvolume_unlink_hook *h = container_of(_h, struct subvolume_unlink_hook, h);
struct bch_fs *c = trans->c;
int ret = 0;
mutex_lock(&c->snapshots_unlinked_lock);
if (!snapshot_list_has_id(&c->snapshots_unlinked, h->subvol))
ret = snapshot_list_add(c, &c->snapshots_unlinked, h->subvol);
mutex_unlock(&c->snapshots_unlinked_lock);
if (ret)
return ret;
if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_snapshot_delete_pagecache))
return -EROFS;
if (!queue_work(system_long_wq, &c->snapshot_wait_for_pagecache_and_delete_work))
bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache);
return 0;
}
int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
{
struct btree_iter iter;
struct bkey_i_subvolume *n;
struct subvolume_unlink_hook *h;
int ret = 0;
bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes,
POS(0, subvolid),
BTREE_ITER_CACHED|
BTREE_ITER_INTENT);
n = bch2_bkey_get_mut_typed(trans, &iter, subvolume);
ret = PTR_ERR_OR_ZERO(n);
if (unlikely(ret)) {
bch2_fs_inconsistent_on(ret == -ENOENT, trans->c, "missing subvolume %u", subvolid);
goto err;
}
SET_BCH_SUBVOLUME_UNLINKED(&n->v, true);
ret = bch2_trans_update(trans, &iter, &n->k_i, 0);
if (ret)
goto err;
h = bch2_trans_kmalloc(trans, sizeof(*h));
ret = PTR_ERR_OR_ZERO(h);
if (ret)
goto err;
h->h.fn = bch2_subvolume_wait_for_pagecache_and_delete_hook;
h->subvol = subvolid;
bch2_trans_commit_hook(trans, &h->h);
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
u32 src_subvolid,
u32 *new_subvolid,
u32 *new_snapshotid,
bool ro)
{
struct bch_fs *c = trans->c;
struct btree_iter dst_iter, src_iter = (struct btree_iter) { NULL };
struct bkey_i_subvolume *new_subvol = NULL;
struct bkey_i_subvolume *src_subvol = NULL;
struct bkey_s_c k;
u32 parent = 0, new_nodes[2], snapshot_subvols[2];
int ret = 0;
for_each_btree_key(trans, dst_iter, BTREE_ID_subvolumes, SUBVOL_POS_MIN,
BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
if (bkey_gt(k.k->p, SUBVOL_POS_MAX))
break;
/*
* bch2_subvolume_delete() doesn't flush the btree key cache -
* ideally it would but that's tricky
*/
if (bkey_deleted(k.k) &&
!bch2_btree_key_cache_find(c, BTREE_ID_subvolumes, dst_iter.pos))
goto found_slot;
}
if (!ret)
ret = -BCH_ERR_ENOSPC_subvolume_create;
goto err;
found_slot:
snapshot_subvols[0] = dst_iter.pos.offset;
snapshot_subvols[1] = src_subvolid;
if (src_subvolid) {
/* Creating a snapshot: */
bch2_trans_iter_init(trans, &src_iter, BTREE_ID_subvolumes,
POS(0, src_subvolid),
BTREE_ITER_CACHED|
BTREE_ITER_INTENT);
src_subvol = bch2_bkey_get_mut_typed(trans, &src_iter, subvolume);
ret = PTR_ERR_OR_ZERO(src_subvol);
if (unlikely(ret)) {
bch2_fs_inconsistent_on(ret == -ENOENT, trans->c,
"subvolume %u not found", src_subvolid);
goto err;
}
parent = le32_to_cpu(src_subvol->v.snapshot);
}
ret = bch2_snapshot_node_create(trans, parent, new_nodes,
snapshot_subvols,
src_subvolid ? 2 : 1);
if (ret)
goto err;
if (src_subvolid) {
src_subvol->v.snapshot = cpu_to_le32(new_nodes[1]);
ret = bch2_trans_update(trans, &src_iter, &src_subvol->k_i, 0);
if (ret)
goto err;
}
new_subvol = bch2_bkey_alloc(trans, &dst_iter, subvolume);
ret = PTR_ERR_OR_ZERO(new_subvol);
if (ret)
goto err;
new_subvol->v.flags = 0;
new_subvol->v.snapshot = cpu_to_le32(new_nodes[0]);
new_subvol->v.inode = cpu_to_le64(inode);
SET_BCH_SUBVOLUME_RO(&new_subvol->v, ro);
SET_BCH_SUBVOLUME_SNAP(&new_subvol->v, src_subvolid != 0);
ret = bch2_trans_update(trans, &dst_iter, &new_subvol->k_i, 0);
if (ret)
goto err;
*new_subvolid = new_subvol->k.p.offset;
*new_snapshotid = new_nodes[0];
err:
bch2_trans_iter_exit(trans, &src_iter);
bch2_trans_iter_exit(trans, &dst_iter);
return ret;
}
int bch2_fs_subvolumes_init(struct bch_fs *c)
{
INIT_WORK(&c->snapshot_delete_work, bch2_delete_dead_snapshots_work);
INIT_WORK(&c->snapshot_wait_for_pagecache_and_delete_work,
bch2_subvolume_wait_for_pagecache_and_delete);
mutex_init(&c->snapshots_unlinked_lock);
return 0;
}
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