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bcachefs: Fix freeing in bch2_dev_buckets_resize()

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We were double-freeing old_buckets and not freeing old_buckets_gens:
also, the code was supposed to free buckets, not old_buckets;
old_buckets is only needed because we have to use rcu_assign_pointer()
instead of swap(), and won't be set if we hit the error path.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This commit is contained in:
Kent Overstreet 2022-02-06 19:20:36 -05:00 committed by Kent Overstreet
parent 35228ecb7e
commit 80bf2f3454
2 changed files with 7 additions and 5 deletions
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2
fs/bcachefs/bcachefs.h
View File

@ -451,7 +451,7 @@ struct bch_dev {
* Or rcu_read_lock(), but only for ptr_stale():
*/
struct bucket_array __rcu *buckets[2];
struct bucket_gens *bucket_gens;
struct bucket_gens __rcu *bucket_gens;
unsigned long *buckets_nouse;
struct rw_semaphore bucket_lock;

10
fs/bcachefs/buckets.c
View File

@ -2106,7 +2106,7 @@ static void buckets_free_rcu(struct rcu_head *rcu)
container_of(rcu, struct bucket_array, rcu);
kvpfree(buckets,
sizeof(struct bucket_array) +
sizeof(*buckets) +
buckets->nbuckets * sizeof(struct bucket));
}
@ -2115,7 +2115,7 @@ static void bucket_gens_free_rcu(struct rcu_head *rcu)
struct bucket_gens *buckets =
container_of(rcu, struct bucket_gens, rcu);
kvpfree(buckets, sizeof(struct bucket_array) + buckets->nbuckets);
kvpfree(buckets, sizeof(*buckets) + buckets->nbuckets);
}
int bch2_dev_buckets_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
@ -2225,9 +2225,9 @@ err:
kvpfree(buckets_nouse,
BITS_TO_LONGS(nbuckets) * sizeof(unsigned long));
if (bucket_gens)
call_rcu(&old_buckets->rcu, bucket_gens_free_rcu);
call_rcu(&bucket_gens->rcu, bucket_gens_free_rcu);
if (buckets)
call_rcu(&old_buckets->rcu, buckets_free_rcu);
call_rcu(&buckets->rcu, buckets_free_rcu);
return ret;
}
@ -2242,6 +2242,8 @@ void bch2_dev_buckets_free(struct bch_dev *ca)
free_fifo(&ca->free[i]);
kvpfree(ca->buckets_nouse,
BITS_TO_LONGS(ca->mi.nbuckets) * sizeof(unsigned long));
kvpfree(rcu_dereference_protected(ca->bucket_gens, 1),
sizeof(struct bucket_gens) + ca->mi.nbuckets);
kvpfree(rcu_dereference_protected(ca->buckets[0], 1),
sizeof(struct bucket_array) +
ca->mi.nbuckets * sizeof(struct bucket));