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>

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 364d491..075377e 100644 (file)
--- 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;