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bcachefs: BTREE_ID_subvolume_children

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Add a btree to record a parent -> child subvolume relationships,
according to the filesystem heirarchy.

The subvolume_children btree is a bitset btree: if a bit is set at pos
p, that means p.offset is a child of subvolume p.inode.

This will be used for efficiently listing subvolumes, as well as
recursive deletion.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2024-01-21 06:00:07 -05:00
parent b8628a2529
commit b26d79147f
7 changed files with 114 additions and 3 deletions
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1
fs/bcachefs/bcachefs.h
View File

@ -504,6 +504,7 @@ enum gc_phase {
GC_PHASE_BTREE_deleted_inodes,
GC_PHASE_BTREE_logged_ops,
GC_PHASE_BTREE_rebalance_work,
GC_PHASE_BTREE_subvolume_children,
GC_PHASE_PENDING_DELETE,
};

7
fs/bcachefs/bcachefs_format.h
View File

@ -841,7 +841,8 @@ struct bch_sb_field_downgrade {
x(deleted_inodes, BCH_VERSION(1, 2)) \
x(rebalance_work, BCH_VERSION(1, 3)) \
x(member_seq, BCH_VERSION(1, 4)) \
x(subvolume_fs_parent, BCH_VERSION(1, 5))
x(subvolume_fs_parent, BCH_VERSION(1, 5)) \
x(btree_subvolume_children, BCH_VERSION(1, 6))
enum bcachefs_metadata_version {
bcachefs_metadata_version_min = 9,
@ -1489,7 +1490,9 @@ enum btree_id_flags {
BIT_ULL(KEY_TYPE_logged_op_truncate)| \
BIT_ULL(KEY_TYPE_logged_op_finsert)) \
x(rebalance_work, 18, BTREE_ID_SNAPSHOT_FIELD, \
BIT_ULL(KEY_TYPE_set)|BIT_ULL(KEY_TYPE_cookie))
BIT_ULL(KEY_TYPE_set)|BIT_ULL(KEY_TYPE_cookie)) \
x(subvolume_children, 19, 0, \
BIT_ULL(KEY_TYPE_set))
enum btree_id {
#define x(name, nr, ...) BTREE_ID_##name = nr,

1
fs/bcachefs/btree_types.h
View File

@ -654,6 +654,7 @@ const char *bch2_btree_node_type_str(enum btree_node_type);
BIT_ULL(BKEY_TYPE_inodes)| \
BIT_ULL(BKEY_TYPE_stripes)| \
BIT_ULL(BKEY_TYPE_reflink)| \
BIT_ULL(BKEY_TYPE_subvolumes)| \
BIT_ULL(BKEY_TYPE_btree))
#define BTREE_NODE_TYPE_HAS_ATOMIC_TRIGGERS \

1
fs/bcachefs/recovery_types.h
View File

@ -34,6 +34,7 @@
x(check_snapshot_trees, 18, PASS_ONLINE|PASS_FSCK) \
x(check_snapshots, 19, PASS_ONLINE|PASS_FSCK) \
x(check_subvols, 20, PASS_ONLINE|PASS_FSCK) \
x(check_subvol_children, 35, PASS_ONLINE|PASS_FSCK) \
x(delete_dead_snapshots, 21, PASS_ONLINE|PASS_FSCK) \
x(fs_upgrade_for_subvolumes, 22, 0) \
x(resume_logged_ops, 23, PASS_ALWAYS) \

5
fs/bcachefs/sb-downgrade.c
View File

@ -48,7 +48,10 @@
BIT_ULL(BCH_RECOVERY_PASS_set_fs_needs_rebalance)) \
x(subvolume_fs_parent, \
BIT_ULL(BCH_RECOVERY_PASS_check_dirents), \
BCH_FSCK_ERR_subvol_fs_path_parent_wrong)
BCH_FSCK_ERR_subvol_fs_path_parent_wrong) \
x(btree_subvolume_children, \
BIT_ULL(BCH_RECOVERY_PASS_check_subvols), \
BCH_FSCK_ERR_subvol_children_not_set)
#define DOWNGRADE_TABLE()

98
fs/bcachefs/subvolume.c
View File

@ -13,12 +13,24 @@
static int bch2_subvolume_delete(struct btree_trans *, u32);
static struct bpos subvolume_children_pos(struct bkey_s_c k)
{
if (k.k->type != KEY_TYPE_subvolume)
return POS_MIN;
struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
if (!s.v->fs_path_parent)
return POS_MIN;
return POS(le32_to_cpu(s.v->fs_path_parent), s.k->p.offset);
}
static int check_subvol(struct btree_trans *trans,
struct btree_iter *iter,
struct bkey_s_c k)
{
struct bch_fs *c = trans->c;
struct bkey_s_c_subvolume subvol;
struct btree_iter subvol_children_iter = {};
struct bch_snapshot snapshot;
struct printbuf buf = PRINTBUF;
unsigned snapid;
@ -57,6 +69,28 @@ static int check_subvol(struct btree_trans *trans,
n->v.fs_path_parent = 0;
}
if (subvol.v->fs_path_parent) {
struct bpos pos = subvolume_children_pos(k);
struct bkey_s_c subvol_children_k =
bch2_bkey_get_iter(trans, &subvol_children_iter,
BTREE_ID_subvolume_children, pos, 0);
ret = bkey_err(subvol_children_k);
if (ret)
goto err;
if (fsck_err_on(subvol_children_k.k->type != KEY_TYPE_set,
c, subvol_children_not_set,
"subvolume not set in subvolume_children btree at %llu:%llu\n%s",
pos.inode, pos.offset,
(printbuf_reset(&buf),
bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
ret = bch2_btree_bit_mod(trans, BTREE_ID_subvolume_children, pos, true);
if (ret)
goto err;
}
}
struct bch_inode_unpacked inode;
struct btree_iter inode_iter = {};
ret = bch2_inode_peek_nowarn(trans, &inode_iter, &inode,
@ -119,6 +153,7 @@ static int check_subvol(struct btree_trans *trans,
}
err:
fsck_err:
bch2_trans_iter_exit(trans, &subvol_children_iter);
printbuf_exit(&buf);
return ret;
}
@ -134,6 +169,42 @@ int bch2_check_subvols(struct bch_fs *c)
return ret;
}
static int check_subvol_child(struct btree_trans *trans,
struct btree_iter *child_iter,
struct bkey_s_c child_k)
{
struct bch_fs *c = trans->c;
struct bch_subvolume s;
int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, child_k.k->p.offset),
0, subvolume, &s);
if (ret && !bch2_err_matches(ret, ENOENT))
return ret;
if (fsck_err_on(ret ||
le32_to_cpu(s.fs_path_parent) != child_k.k->p.inode,
c, subvol_children_bad,
"incorrect entry in subvolume_children btree %llu:%llu",
child_k.k->p.inode, child_k.k->p.offset)) {
ret = bch2_btree_delete_at(trans, child_iter, 0);
if (ret)
goto err;
}
err:
fsck_err:
return ret;
}
int bch2_check_subvol_children(struct bch_fs *c)
{
int ret = bch2_trans_run(c,
for_each_btree_key_commit(trans, iter,
BTREE_ID_subvolume_children, POS_MIN, BTREE_ITER_PREFETCH, k,
NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
check_subvol_child(trans, &iter, k)));
bch_err_fn(c, ret);
return 0;
}
/* Subvolumes: */
int bch2_subvolume_invalid(struct bch_fs *c, struct bkey_s_c k,
@ -164,6 +235,33 @@ void bch2_subvolume_to_text(struct printbuf *out, struct bch_fs *c,
}
}
static int subvolume_children_mod(struct btree_trans *trans, struct bpos pos, bool set)
{
return !bpos_eq(pos, POS_MIN)
? bch2_btree_bit_mod(trans, BTREE_ID_subvolume_children, pos, set)
: 0;
}
int bch2_subvolume_trigger(struct btree_trans *trans,
enum btree_id btree_id, unsigned level,
struct bkey_s_c old, struct bkey_s new,
unsigned flags)
{
if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
struct bpos children_pos_old = subvolume_children_pos(old);
struct bpos children_pos_new = subvolume_children_pos(new.s_c);
if (!bpos_eq(children_pos_old, children_pos_new)) {
int ret = subvolume_children_mod(trans, children_pos_old, false) ?:
subvolume_children_mod(trans, children_pos_new, true);
if (ret)
return ret;
}
}
return 0;
}
static __always_inline int
bch2_subvolume_get_inlined(struct btree_trans *trans, unsigned subvol,
bool inconsistent_if_not_found,

4
fs/bcachefs/subvolume.h
View File

@ -8,14 +8,18 @@
enum bkey_invalid_flags;
int bch2_check_subvols(struct bch_fs *);
int bch2_check_subvol_children(struct bch_fs *);
int bch2_subvolume_invalid(struct bch_fs *, struct bkey_s_c,
enum bkey_invalid_flags, struct printbuf *);
void bch2_subvolume_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
int bch2_subvolume_trigger(struct btree_trans *, enum btree_id, unsigned,
struct bkey_s_c, struct bkey_s, unsigned);
#define bch2_bkey_ops_subvolume ((struct bkey_ops) { \
.key_invalid = bch2_subvolume_invalid, \
.val_to_text = bch2_subvolume_to_text, \
.trigger = bch2_subvolume_trigger, \
.min_val_size = 16, \
})