[PATCH 6.0 0332/1073] dm: cleanup close_table_device

Greg Kroah-Hartman
2022-12-28T15:37:16Z

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit 7b5865831c1003122f737df5e16adaa583f1a595 ]

Take the list unlink and free into close_table_device so that no half
torn down table_devices exist. Also remove the check for a NULL bdev
as that can't happen - open_table_device never adds a table_device to
the list that does not have a valid block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20221115141054.1051801-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 1a581b721699 ("dm: track per-add_disk holder relations in DM")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/dm.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 1903afa4618a..620abcef2df5 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -774,14 +774,11 @@ static struct table_device *open_table_device(struct mapped_device *md,
*/
static void close_table_device(struct table_device *td, struct mapped_device *md)
{
- if (!td->dm_dev.bdev)
- return;
-
bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
put_dax(td->dm_dev.dax_dev);
- td->dm_dev.bdev = NULL;
- td->dm_dev.dax_dev = NULL;
+ list_del(&td->list);
+ kfree(td);
}

static struct table_device *find_table_device(struct list_head *l, dev_t dev,
@@ -823,11 +820,8 @@ void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
struct table_device *td = container_of(d, struct table_device, dm_dev);

mutex_lock(&md->table_devices_lock);
- if (refcount_dec_and_test(&td->count)) {
+ if (refcount_dec_and_test(&td->count))
close_table_device(td, md);
- list_del(&td->list);
- kfree(td);
- }
mutex_unlock(&md->table_devices_lock);
}

--
2.35.1