vfs: fix: don't increase bio_slab_max if krealloc() fails

Without the patch, bio_slab_max, representing bio_slabs capacity, is increased before krealloc() of bio_slabs. If krealloc() fails, bio_slab_max is too high. Fix that by only updating bio_slab_max if krealloc() is successful.

Signed-off-by: Anna Leuschner <anna.m.leuschner@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 9298c65ad9c7..b96fc6ce4855 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -75,6 +75,7 @@ static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
         unsigned int sz = sizeof(struct bio) + extra_size;
         struct kmem_cache *slab = NULL;
         struct bio_slab *bslab, *new_bio_slabs;
+        unsigned int new_bio_slab_max;
         unsigned int i, entry = -1;
 
         mutex_lock(&bio_slab_lock);
@@ -97,12 +98,13 @@ static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
                 goto out_unlock;
 
         if (bio_slab_nr == bio_slab_max && entry == -1) {
-                bio_slab_max <<= 1;
+                new_bio_slab_max = bio_slab_max << 1;
                 new_bio_slabs = krealloc(bio_slabs,
-                                         bio_slab_max * sizeof(struct bio_slab),
+                                         new_bio_slab_max * sizeof(struct bio_slab),
                                          GFP_KERNEL);
                 if (!new_bio_slabs)
                         goto out_unlock;
+                bio_slab_max = new_bio_slab_max;
                 bio_slabs = new_bio_slabs;
         }
         if (entry == -1)