shmem: put_super must percpu_counter_destroy
list_add() corruption messages reported from shmem_fill_super()'s recently
introduced percpu_counter_init(): shmem_put_super() needs to remember to
percpu_counter_destroy(). And also check error from percpu_counter_init().
Reported-bisected-and-tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/shmem.c b/mm/shmem.c
index dfaa0f4..080b09a 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2325,7 +2325,10 @@
static void shmem_put_super(struct super_block *sb)
{
- kfree(sb->s_fs_info);
+ struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+
+ percpu_counter_destroy(&sbinfo->used_blocks);
+ kfree(sbinfo);
sb->s_fs_info = NULL;
}
@@ -2367,7 +2370,8 @@
#endif
spin_lock_init(&sbinfo->stat_lock);
- percpu_counter_init(&sbinfo->used_blocks, 0);
+ if (percpu_counter_init(&sbinfo->used_blocks, 0))
+ goto failed;
sbinfo->free_inodes = sbinfo->max_inodes;
sb->s_maxbytes = SHMEM_MAX_BYTES;