From 80bf2f345411b9952a984b6105cd860500b01228 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sun, 6 Feb 2022 19:20:36 -0500 Subject: [PATCH] bcachefs: Fix freeing in bch2_dev_buckets_resize() 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 --- fs/bcachefs/bcachefs.h | 2 +- fs/bcachefs/buckets.c | 10 ++++++---- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h index 3d1a6773393c..59c0963f785f 100644 --- a/fs/bcachefs/bcachefs.h +++ b/fs/bcachefs/bcachefs.h @@ -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; diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c index acdc95d8d4c7..ae5760315223 100644 --- a/fs/bcachefs/buckets.c +++ b/fs/bcachefs/buckets.c @@ -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));