linux-kernel - [PATCH AUTOSEL 5.6 43/50] block: remove the bd_openers checks in blk_drop

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Date:   Thu,  7 May 2020 10:27:19 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Christoph Hellwig <hch@....de>,
        Michal Koutný <mkoutny@...e.com>,
        Yang Xu <xuyang2018.jy@...fujitsu.com>,
        Jens Axboe <axboe@...nel.dk>, Sasha Levin <sashal@...nel.org>,
        linux-block@...r.kernel.org
Subject: [PATCH AUTOSEL 5.6 43/50] block: remove the bd_openers checks in blk_drop_partitions

From: Christoph Hellwig <hch@....de>

[ Upstream commit 10c70d95c0f2f9a6f52d0e33243d2877370cef51 ]

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 Koutný <mkoutny@...e.com>
Reported-by: Yang Xu <xuyang2018.jy@...fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@....de>
Signed-off-by: Jens Axboe <axboe@...nel.dk>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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 ebe4c2e9834bd..8a7906fa96fd6 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 > 1)
+	if (bdev->bd_part_count)
 		return -EBUSY;
 	res = invalidate_partition(disk, 0);
 	if (res)
-- 
2.20.1