From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Mike Snitzer To: axboe@kernel.dk Cc: Ming Lei , hare@suse.de, Bart.VanAssche@wdc.com, dm-devel@redhat.com, linux-block@vger.kernel.org Subject: [for-4.16 PATCH v4 1/4] block: only bdi_unregister() in del_gendisk() if !GENHD_FL_HIDDEN Date: Thu, 11 Jan 2018 15:14:14 -0500 Message-Id: <20180111201417.2042-2-snitzer@redhat.com> In-Reply-To: <20180111201417.2042-1-snitzer@redhat.com> References: <20180111201417.2042-1-snitzer@redhat.com> List-ID: device_add_disk() will only call bdi_register_owner() if !GENHD_FL_HIDDEN, so it follows that del_gendisk() should only call bdi_unregister() if !GENHD_FL_HIDDEN. Found with code inspection. bdi_unregister() won't do any harm if bdi_register_owner() wasn't used but best to avoid the unnecessary call to bdi_unregister(). Fixes: 8ddcd65325 ("block: introduce GENHD_FL_HIDDEN") Signed-off-by: Mike Snitzer Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke --- block/genhd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/genhd.c b/block/genhd.c index 96a66f671720..00620e01e043 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -725,7 +725,8 @@ void del_gendisk(struct gendisk *disk) * Unregister bdi before releasing device numbers (as they can * get reused and we'd get clashes in sysfs). */ - bdi_unregister(disk->queue->backing_dev_info); + if (!(disk->flags & GENHD_FL_HIDDEN)) + bdi_unregister(disk->queue->backing_dev_info); blk_unregister_queue(disk); } else { WARN_ON(1); -- 2.15.0