From: Christoph Hellwig <hch@lst.de>
Date: Fri, 10 Apr 2020 12:31:47 +0000 (+0200)
Subject: block: fix busy device checking in blk_drop_partitions again
X-Git-Tag: v5.7-rc1~27^2
X-Git-Url: http://git.osdn.net/view?p=tomoyo%2Ftomoyo-test1.git;a=commitdiff_plain;h=cb6b771b05c3026a85ed4817c1b87c5e6f41d136

block: fix busy device checking in blk_drop_partitions again

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@lca.pw>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Qian Cai <cai@lca.pw>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 1a0a829d8416..bc1ded1331b1 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -496,7 +496,7 @@ 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)