md: fail if mddev->bio_set can't be created

The current behaviour is to fall back to allocate
bio from 'fs_bio_set', that isn't a correct way
because it might cause deadlock.

So this patch simply return failure if mddev->bio_set
can't be created.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 13020e5c8cc0..137a1fe124e8 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5228,8 +5228,11 @@ int md_run(struct mddev *mddev)
                 sysfs_notify_dirent_safe(rdev->sysfs_state);
         }
 
-        if (mddev->bio_set == NULL)
+        if (mddev->bio_set == NULL) {
                 mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
+                if (!mddev->bio_set)
+                        return -ENOMEM;
+        }
 
         spin_lock(&pers_lock);
         pers = find_pers(mddev->level, mddev->clevel);