Commit b9a785d2 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

dm: cleanup open_table_device 



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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarMike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20221115141054.1051801-4-yukuai1@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 992ec6a9

drivers/md/dm.c

+27 −29
Original line number Diff line number Diff line
@@ -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) {

		td = open_table_device(md, dev, mode);

		if (IS_ERR(td)) {

			mutex_unlock(&md->table_devices_lock);

			return -ENOMEM;

			return PTR_ERR(td);

		}



		td->dm_dev.mode = mode;

		td->dm_dev.bdev = NULL;



		if ((r = open_table_device(td, dev, md))) {

			mutex_unlock(&md->table_devices_lock);

			kfree(td);

			return r;

		}



		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);

	}