[PATCH 5.6 40/73] block: remove the bd_openers checks in blk_drop_partitions

[Greg Kroah-Hartman]

From: Christoph Hellwig <hch@xxxxxx>

commit 10c70d95c0f2f9a6f52d0e33243d2877370cef51 upstream.

When replacing the bd_super check with a bd_openers I followed a logical
conclusion, which turns out to be utterly wrong.  When a block device has
bd_super sets it has a mount file system on it (although not every
mounted file system sets bd_super), but that also implies it doesn't even
have partitions to start with.

So instead of trying to come up with a logical check for all openers,
just remove the check entirely.

Fixes: d3ef5536274f ("block: fix busy device checking in blk_drop_partitions")
Fixes: cb6b771b05c3 ("block: fix busy device checking in blk_drop_partitions again")
Reported-by: Michal Koutnà <mkoutny@xxxxxxxx>
Reported-by: Yang Xu <xuyang2018.jy@xxxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 block/partition-generic.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -468,7 +468,7 @@ int blk_drop_partitions(struct gendisk *
 
 	if (!disk_part_scan_enabled(disk))
 		return 0;
-	if (bdev->bd_part_count || bdev->bd_openers > 1)
+	if (bdev->bd_part_count)
 		return -EBUSY;
 	res = invalidate_partition(disk, 0);
 	if (res)