linux/fs/bcachefs/snapshot.h
Kent Overstreet 6d48e61364 bcachefs: Add missing guard in bch2_snapshot_has_children()
We additionally need to be going inconsistent if passed an invalid
snapshot ID; that patch will need more thorough testing.

Reported-by: syzbot+1c9fca23fe478633b305@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-05-20 05:37:26 -04:00

269 lines
6.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_SNAPSHOT_H
#define _BCACHEFS_SNAPSHOT_H
enum bch_validate_flags;
void bch2_snapshot_tree_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
int bch2_snapshot_tree_invalid(struct bch_fs *, struct bkey_s_c,
enum bch_validate_flags, struct printbuf *);
#define bch2_bkey_ops_snapshot_tree ((struct bkey_ops) { \
.key_invalid = bch2_snapshot_tree_invalid, \
.val_to_text = bch2_snapshot_tree_to_text, \
.min_val_size = 8, \
})
struct bkey_i_snapshot_tree *__bch2_snapshot_tree_create(struct btree_trans *);
int bch2_snapshot_tree_lookup(struct btree_trans *, u32, struct bch_snapshot_tree *);
void bch2_snapshot_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
int bch2_snapshot_invalid(struct bch_fs *, struct bkey_s_c,
enum bch_validate_flags, struct printbuf *);
int bch2_mark_snapshot(struct btree_trans *, enum btree_id, unsigned,
struct bkey_s_c, struct bkey_s,
enum btree_iter_update_trigger_flags);
#define bch2_bkey_ops_snapshot ((struct bkey_ops) { \
.key_invalid = bch2_snapshot_invalid, \
.val_to_text = bch2_snapshot_to_text, \
.trigger = bch2_mark_snapshot, \
.min_val_size = 24, \
})
static inline struct snapshot_t *__snapshot_t(struct snapshot_table *t, u32 id)
{
u32 idx = U32_MAX - id;
return likely(t && idx < t->nr)
? &t->s[idx]
: NULL;
}
static inline const struct snapshot_t *snapshot_t(struct bch_fs *c, u32 id)
{
return __snapshot_t(rcu_dereference(c->snapshots), id);
}
static inline u32 bch2_snapshot_tree(struct bch_fs *c, u32 id)
{
rcu_read_lock();
const struct snapshot_t *s = snapshot_t(c, id);
id = s ? s->tree : 0;
rcu_read_unlock();
return id;
}
static inline u32 __bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
{
const struct snapshot_t *s = snapshot_t(c, id);
return s ? s->parent : 0;
}
static inline u32 bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
{
rcu_read_lock();
id = __bch2_snapshot_parent_early(c, id);
rcu_read_unlock();
return id;
}
static inline u32 __bch2_snapshot_parent(struct bch_fs *c, u32 id)
{
const struct snapshot_t *s = snapshot_t(c, id);
if (!s)
return 0;
u32 parent = s->parent;
if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
parent &&
s->depth != snapshot_t(c, parent)->depth + 1)
panic("id %u depth=%u parent %u depth=%u\n",
id, snapshot_t(c, id)->depth,
parent, snapshot_t(c, parent)->depth);
return parent;
}
static inline u32 bch2_snapshot_parent(struct bch_fs *c, u32 id)
{
rcu_read_lock();
id = __bch2_snapshot_parent(c, id);
rcu_read_unlock();
return id;
}
static inline u32 bch2_snapshot_nth_parent(struct bch_fs *c, u32 id, u32 n)
{
rcu_read_lock();
while (n--)
id = __bch2_snapshot_parent(c, id);
rcu_read_unlock();
return id;
}
u32 bch2_snapshot_skiplist_get(struct bch_fs *, u32);
static inline u32 bch2_snapshot_root(struct bch_fs *c, u32 id)
{
u32 parent;
rcu_read_lock();
while ((parent = __bch2_snapshot_parent(c, id)))
id = parent;
rcu_read_unlock();
return id;
}
static inline u32 __bch2_snapshot_equiv(struct bch_fs *c, u32 id)
{
const struct snapshot_t *s = snapshot_t(c, id);
return s ? s->equiv : 0;
}
static inline u32 bch2_snapshot_equiv(struct bch_fs *c, u32 id)
{
rcu_read_lock();
id = __bch2_snapshot_equiv(c, id);
rcu_read_unlock();
return id;
}
static inline int bch2_snapshot_is_internal_node(struct bch_fs *c, u32 id)
{
rcu_read_lock();
const struct snapshot_t *s = snapshot_t(c, id);
int ret = s ? s->children[0] : -BCH_ERR_invalid_snapshot_node;
rcu_read_unlock();
return ret;
}
static inline int bch2_snapshot_is_leaf(struct bch_fs *c, u32 id)
{
int ret = bch2_snapshot_is_internal_node(c, id);
if (ret < 0)
return ret;
return !ret;
}
static inline u32 bch2_snapshot_depth(struct bch_fs *c, u32 parent)
{
u32 depth;
rcu_read_lock();
depth = parent ? snapshot_t(c, parent)->depth + 1 : 0;
rcu_read_unlock();
return depth;
}
bool __bch2_snapshot_is_ancestor(struct bch_fs *, u32, u32);
static inline bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor)
{
return id == ancestor
? true
: __bch2_snapshot_is_ancestor(c, id, ancestor);
}
static inline bool bch2_snapshot_has_children(struct bch_fs *c, u32 id)
{
rcu_read_lock();
const struct snapshot_t *t = snapshot_t(c, id);
bool ret = t && (t->children[0]|t->children[1]) != 0;
rcu_read_unlock();
return ret;
}
static inline bool snapshot_list_has_id(snapshot_id_list *s, u32 id)
{
darray_for_each(*s, i)
if (*i == id)
return true;
return false;
}
static inline bool snapshot_list_has_ancestor(struct bch_fs *c, snapshot_id_list *s, u32 id)
{
darray_for_each(*s, i)
if (bch2_snapshot_is_ancestor(c, id, *i))
return true;
return false;
}
static inline int snapshot_list_add(struct bch_fs *c, snapshot_id_list *s, u32 id)
{
BUG_ON(snapshot_list_has_id(s, id));
int ret = darray_push(s, id);
if (ret)
bch_err(c, "error reallocating snapshot_id_list (size %zu)", s->size);
return ret;
}
static inline int snapshot_list_add_nodup(struct bch_fs *c, snapshot_id_list *s, u32 id)
{
int ret = snapshot_list_has_id(s, id)
? 0
: darray_push(s, id);
if (ret)
bch_err(c, "error reallocating snapshot_id_list (size %zu)", s->size);
return ret;
}
static inline int snapshot_list_merge(struct bch_fs *c, snapshot_id_list *dst, snapshot_id_list *src)
{
darray_for_each(*src, i) {
int ret = snapshot_list_add_nodup(c, dst, *i);
if (ret)
return ret;
}
return 0;
}
int bch2_snapshot_lookup(struct btree_trans *trans, u32 id,
struct bch_snapshot *s);
int bch2_snapshot_get_subvol(struct btree_trans *, u32,
struct bch_subvolume *);
/* only exported for tests: */
int bch2_snapshot_node_create(struct btree_trans *, u32,
u32 *, u32 *, unsigned);
int bch2_check_snapshot_trees(struct bch_fs *);
int bch2_check_snapshots(struct bch_fs *);
int bch2_reconstruct_snapshots(struct bch_fs *);
int bch2_snapshot_node_set_deleted(struct btree_trans *, u32);
void bch2_delete_dead_snapshots_work(struct work_struct *);
int __bch2_key_has_snapshot_overwrites(struct btree_trans *, enum btree_id, struct bpos);
static inline int bch2_key_has_snapshot_overwrites(struct btree_trans *trans,
enum btree_id id,
struct bpos pos)
{
if (!btree_type_has_snapshots(id) ||
bch2_snapshot_is_leaf(trans->c, pos.snapshot) > 0)
return 0;
return __bch2_key_has_snapshot_overwrites(trans, id, pos);
}
int bch2_propagate_key_to_snapshot_leaves(struct btree_trans *, enum btree_id,
struct bkey_s_c, struct bpos *);
int bch2_snapshots_read(struct bch_fs *);
void bch2_fs_snapshots_exit(struct bch_fs *);
#endif /* _BCACHEFS_SNAPSHOT_H */