loop: Make user notify for adding loop device failed

There is no error number returned if loop driver fails in function
alloc_disk to add new loop device. Add a correct error number to make
user notify in this case.

Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 364d491d4bdd..075377eee0c0 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1765,6 +1765,7 @@ static int loop_add(struct loop_device **l, int i)
          */
         queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, lo->lo_queue);
 
+        err = -ENOMEM;
         disk = lo->lo_disk = alloc_disk(1 << part_shift);
         if (!disk)
                 goto out_free_queue;