Linux 5.0 compat: Remove incorrect ASSERT

Not all block devices, notably scsi_debug, set a root_blkg on the
request queue.  Remove this assertion and allow the the existing
call to blkg_tryget() to gracefully handle the NULL (which it does).

Reviewed-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8678

diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
index c2312e6fa3bf8ec96bea7554b43d6d02aacad7dd..b329ef3c240fe7f0dee3d51f9419e1bf2033ef8e 100644 (file)
--- a/module/zfs/vdev_disk.c
+++ b/module/zfs/vdev_disk.c
@@ -543,7 +543,6 @@ vdev_bio_associate_blkg(struct bio *bio)
        struct request_queue *q = bio->bi_disk->queue;
 
        ASSERT3P(q, !=, NULL);
-       ASSERT3P(q->root_blkg, !=, NULL);
        ASSERT3P(bio->bi_blkg, ==, NULL);
 
        if (blkg_tryget(q->root_blkg))