[PATCH 6.1 0341/1146] dm: cleanup open_table_device

Greg Kroah-Hartman
2022-12-28T15:43:32Z

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit b9a785d2dc6567b2fd9fc60057a6a945a276927a ]

Move all the logic for allocation the table_device and linking it into
the list into the open_table_device. This keeps the code tidy and
ensures that the table_devices only exist in fully initialized state.

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/20221115141054.1051801-4-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 | 56 ++++++++++++++++++++++++-------------------------
1 file changed, 27 insertions(+), 29 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 95a1ee3d314e..739996499f4d 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -732,28 +732,41 @@ static char *_dm_claim_ptr = "I belong to device-mapper";
/*
* Open a table device so we can use it as a map destination.
*/
-static int open_table_device(struct table_device *td, dev_t dev,
- struct mapped_device *md)
+static struct table_device *open_table_device(struct mapped_device *md,
+ dev_t dev, fmode_t mode)
{
+ struct table_device *td;
struct block_device *bdev;
u64 part_off;
int r;

- BUG_ON(td->dm_dev.bdev);
+ td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
+ if (!td)
+ return ERR_PTR(-ENOMEM);
+ refcount_set(&td->count, 1);

- bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr);
- if (IS_ERR(bdev))
- return PTR_ERR(bdev);
+ bdev = blkdev_get_by_dev(dev, mode | FMODE_EXCL, _dm_claim_ptr);
+ if (IS_ERR(bdev)) {
+ r = PTR_ERR(bdev);
+ goto out_free_td;
+ }

r = bd_link_disk_holder(bdev, dm_disk(md));
- if (r) {
- blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
- return r;
- }
+ if (r)
+ goto out_blkdev_put;

+ td->dm_dev.mode = mode;
td->dm_dev.bdev = bdev;
td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off, NULL, NULL);
- return 0;
+ format_dev_t(td->dm_dev.name, dev);
+ list_add(&td->list, &md->table_devices);
+ return td;
+
+out_blkdev_put:
+ blkdev_put(bdev, mode | FMODE_EXCL);
+out_free_td:
+ kfree(td);
+ return ERR_PTR(r);
}

/*
@@ -786,31 +799,16 @@ static struct table_device *find_table_device(struct list_head *l, dev_t dev,
int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
struct dm_dev **result)
{
- int r;
struct table_device *td;

mutex_lock(&md->table_devices_lock);
td = find_table_device(&md->table_devices, dev, mode);
if (!td) {
- td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
- if (!td) {
- mutex_unlock(&md->table_devices_lock);
- return -ENOMEM;
- }
-
- td->dm_dev.mode = mode;
- td->dm_dev.bdev = NULL;
-
- if ((r = open_table_device(td, dev, md))) {
+ td = open_table_device(md, dev, mode);
+ if (IS_ERR(td)) {
mutex_unlock(&md->table_devices_lock);
- kfree(td);
- return r;
+ return PTR_ERR(td);
}
-
- format_dev_t(td->dm_dev.name, dev);
-
- refcount_set(&td->count, 1);
- list_add(&td->list, &md->table_devices);
} else {
refcount_inc(&td->count);
}
--
2.35.1