mirrors/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-02 07:29:12 -04:00
Code Issues Packages Projects Releases Wiki Activity

bcachefs: Fix race in bch2_accounting_mem_insert()

Browse Source 
bch2_accounting_mem_insert() drops and retakes mark_lock; thus, we need
to check if the entry in question has already been inserted.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet
2024-06-05 12:35:48 -04:00
parent 49858d869b
commit f295920bc4
2 changed files with 17 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
fs/bcachefs/disk_accounting.c
View File

@@ -218,7 +218,7 @@ int bch2_accounting_update_sb(struct btree_trans *trans)
return 0;
}
static int __bch2_accounting_mem_mod_slowpath(struct bch_fs *c, struct bkey_s_c_accounting a, bool gc)
static int __bch2_accounting_mem_insert(struct bch_fs *c, struct bkey_s_c_accounting a, bool gc)
{
struct bch_replicas_padded r;
@@ -226,7 +226,12 @@ static int __bch2_accounting_mem_mod_slowpath(struct bch_fs *c, struct bkey_s_c_
!bch2_replicas_marked_locked(c, &r.e))
return -BCH_ERR_btree_insert_need_mark_replicas;
/* raced with another insert, already present: */
struct bch_accounting_mem *acc = &c->accounting[gc];
if (eytzinger0_find(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
accounting_pos_cmp, &a.k->p) < acc->k.nr)
return 0;
unsigned new_nr_counters = acc->nr_counters + bch2_accounting_counters(a.k);
u64 __percpu *new_counters = __alloc_percpu_gfp(new_nr_counters * sizeof(u64),
@@ -256,17 +261,14 @@ static int __bch2_accounting_mem_mod_slowpath(struct bch_fs *c, struct bkey_s_c_
free_percpu(acc->v);
acc->v = new_counters;
acc->nr_counters = new_nr_counters;
for (unsigned i = 0; i < n.nr_counters; i++)
this_cpu_add(acc->v[n.offset + i], a.v->d[i]);
return 0;
}
int bch2_accounting_mem_mod_slowpath(struct bch_fs *c, struct bkey_s_c_accounting a, bool gc)
int bch2_accounting_mem_insert(struct bch_fs *c, struct bkey_s_c_accounting a, bool gc)
{
percpu_up_read(&c->mark_lock);
percpu_down_write(&c->mark_lock);
int ret = __bch2_accounting_mem_mod_slowpath(c, a, gc);
int ret = __bch2_accounting_mem_insert(c, a, gc);
percpu_up_write(&c->mark_lock);
percpu_down_read(&c->mark_lock);
return ret;

14
fs/bcachefs/disk_accounting.h
View File

@@ -104,15 +104,19 @@ static inline int accounting_pos_cmp(const void *_l, const void *_r)
return bpos_cmp(*l, *r);
}
int bch2_accounting_mem_mod_slowpath(struct bch_fs *, struct bkey_s_c_accounting, bool);
int bch2_accounting_mem_insert(struct bch_fs *, struct bkey_s_c_accounting, bool);
static inline int __bch2_accounting_mem_mod(struct bch_fs *c, struct bkey_s_c_accounting a, bool gc)
{
struct bch_accounting_mem *acc = &c->accounting[gc];
unsigned idx = eytzinger0_find(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
accounting_pos_cmp, &a.k->p);
if (unlikely(idx >= acc->k.nr))
return bch2_accounting_mem_mod_slowpath(c, a, gc);
unsigned idx;
while ((idx = eytzinger0_find(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
accounting_pos_cmp, &a.k->p)) >= acc->k.nr) {
int ret = bch2_accounting_mem_insert(c, a, gc);
if (ret)
return ret;
}
unsigned offset = acc->k.data[idx].offset;