[PATCH 5.6 044/167] block: fix busy device checking in blk_drop_partitions again

[Greg Kroah-Hartman]

From: Christoph Hellwig <hch@xxxxxx>

[ Upstream commit cb6b771b05c3026a85ed4817c1b87c5e6f41d136 ]

The previous fix had an off by one in the bd_openers checking, counting
the callers blkdev_get.

Fixes: d3ef5536274f ("block: fix busy device checking in blk_drop_partitions")
Reported-by: Qian Cai <cai@xxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Tested-by: Qian Cai <cai@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 5f3b2a959aa51..ebe4c2e9834bd 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_openers)
+	if (bdev->bd_part_count || bdev->bd_openers > 1)
 		return -EBUSY;
 	res = invalidate_partition(disk, 0);
 	if (res)
-- 
2.20.1