[PATCH AUTOSEL 5.5 30/75] block: fix busy device checking in blk_drop_partitions

[Sasha Levin]

From: Christoph Hellwig <hch@xxxxxx>

[ Upstream commit d3ef5536274faf89e626276b833be122a16bdb81 ]

bd_super is only set by get_tree_bdev and mount_bdev, and thus not by
other openers like btrfs or the XFS realtime and log devices, as well as
block devices directly opened from user space.  Check bd_openers
instead.

Fixes: 77032ca66f86 ("Return EBUSY from BLKRRPART for mounted whole-dev fs")
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 block/partition-generic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/partition-generic.c b/block/partition-generic.c
index 564fae77711df..5f3b2a959aa51 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -468,7 +468,7 @@ int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev)
 
 	if (!disk_part_scan_enabled(disk))
 		return 0;
-	if (bdev->bd_part_count || bdev->bd_super)
+	if (bdev->bd_part_count || bdev->bd_openers)
 		return -EBUSY;
 	res = invalidate_partition(disk, 0);
 	if (res)
-- 
2.20.1