Commit ecbe6bc0 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: use bd_prepare_to_claim directly in the loop driver 



The arcane magic in bd_start_claiming is only needed to be able to claim
a block_device that hasn't been fully set up.  Switch the loop driver
that claims from the ioctl path with a fully set up struct block_device
to just use the much simpler bd_prepare_to_claim directly.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 58e46ed9

drivers/block/loop.c

+3 −4
Original line number Diff line number Diff line
@@ -1090,12 +1090,11 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, 
	 * here to avoid changing device under exclusive owner.

	 */

	if (!(mode & FMODE_EXCL)) {

		claimed_bdev = bd_start_claiming(bdev, loop_configure);

		if (IS_ERR(claimed_bdev)) {

			error = PTR_ERR(claimed_bdev);

		claimed_bdev = bdev->bd_contains;

		error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure);

		if (error)

			goto out_putf;

	}

	}



	error = mutex_lock_killable(&loop_ctl_mutex);

	if (error)

fs/block_dev.c

+5 −4
Original line number Diff line number Diff line
@@ -1027,8 +1027,8 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, 
 * RETURNS:

 * 0 if @bdev can be claimed, -EBUSY otherwise.

 */

static int bd_prepare_to_claim(struct block_device *bdev,

			       struct block_device *whole, void *holder)

int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,

		void *holder)

{

retry:

	spin_lock(&bdev_lock);
@@ -1055,6 +1055,7 @@ static int bd_prepare_to_claim(struct block_device *bdev, 
	spin_unlock(&bdev_lock);

	return 0;

}

EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */



static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno)

{
@@ -1100,7 +1101,8 @@ static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno) 
 * Pointer to the block device containing @bdev on success, ERR_PTR()

 * value on failure.

 */

struct block_device *bd_start_claiming(struct block_device *bdev, void *holder)

static struct block_device *bd_start_claiming(struct block_device *bdev,

		void *holder)

{

	struct gendisk *disk;

	struct block_device *whole;
@@ -1141,7 +1143,6 @@ struct block_device *bd_start_claiming(struct block_device *bdev, void *holder) 


	return whole;

}

EXPORT_SYMBOL(bd_start_claiming);



static void bd_clear_claiming(struct block_device *whole, void *holder)

{

include/linux/blkdev.h

+2 −1
Original line number Diff line number Diff line
@@ -1919,7 +1919,8 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder); 
struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,

		void *holder);

struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);

struct block_device *bd_start_claiming(struct block_device *bdev, void *holder);

int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,

		void *holder);

void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,

		void *holder);

void blkdev_put(struct block_device *bdev, fmode_t mode);