Commit 37c3fc9a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: simplify the block device claiming interface 



Stop passing the whole device as a separate argument given that it
can be trivially deducted and cleanup the !holder debug check.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a954ea81

drivers/block/loop.c

+5 −7
Original line number Diff line number Diff line
@@ -1069,7 +1069,6 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, 
	struct file	*file;

	struct inode	*inode;

	struct address_space *mapping;

	struct block_device *claimed_bdev = NULL;

	int		error;

	loff_t		size;

	bool		partscan;
@@ -1088,8 +1087,7 @@ 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 = bdev_whole(bdev);

		error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure);

		error = bd_prepare_to_claim(bdev, loop_configure);

		if (error)

			goto out_putf;

	}
@@ -1176,15 +1174,15 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, 
	mutex_unlock(&loop_ctl_mutex);

	if (partscan)

		loop_reread_partitions(lo, bdev);

	if (claimed_bdev)

		bd_abort_claiming(bdev, claimed_bdev, loop_configure);

	if (!(mode & FMODE_EXCL))

		bd_abort_claiming(bdev, loop_configure);

	return 0;



out_unlock:

	mutex_unlock(&loop_ctl_mutex);

out_bdev:

	if (claimed_bdev)

		bd_abort_claiming(bdev, claimed_bdev, loop_configure);

	if (!(mode & FMODE_EXCL))

		bd_abort_claiming(bdev, loop_configure);

out_putf:

	fput(file);

out:

fs/block_dev.c

+18 −33
Original line number Diff line number Diff line
@@ -110,24 +110,20 @@ EXPORT_SYMBOL(invalidate_bdev); 
int truncate_bdev_range(struct block_device *bdev, fmode_t mode,

			loff_t lstart, loff_t lend)

{

	struct block_device *claimed_bdev = NULL;

	int err;



	/*

	 * If we don't hold exclusive handle for the device, upgrade to it

	 * while we discard the buffer cache to avoid discarding buffers

	 * under live filesystem.

	 */

	if (!(mode & FMODE_EXCL)) {

		claimed_bdev = bdev_whole(bdev);

		err = bd_prepare_to_claim(bdev, claimed_bdev,

					  truncate_bdev_range);

		int err = bd_prepare_to_claim(bdev, truncate_bdev_range);

		if (err)

			return err;

	}



	truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend);

	if (claimed_bdev)

		bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range);

	if (!(mode & FMODE_EXCL))

		bd_abort_claiming(bdev, truncate_bdev_range);

	return 0;

}

EXPORT_SYMBOL(truncate_bdev_range);
@@ -978,7 +974,6 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, 
/**

 * bd_prepare_to_claim - claim a block device

 * @bdev: block device of interest

 * @whole: the whole device containing @bdev, may equal @bdev

 * @holder: holder trying to claim @bdev

 *

 * Claim @bdev.  This function fails if @bdev is already claimed by another
@@ -988,9 +983,12 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, 
 * RETURNS:

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

 */

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

		void *holder)

int bd_prepare_to_claim(struct block_device *bdev, void *holder)

{

	struct block_device *whole = bdev_whole(bdev);



	if (WARN_ON_ONCE(!holder))

		return -EINVAL;

retry:

	spin_lock(&bdev_lock);

	/* if someone else claimed, fail */
@@ -1030,15 +1028,15 @@ static void bd_clear_claiming(struct block_device *whole, void *holder) 
/**

 * bd_finish_claiming - finish claiming of a block device

 * @bdev: block device of interest

 * @whole: whole block device

 * @holder: holder that has claimed @bdev

 *

 * Finish exclusive open of a block device. Mark the device as exlusively

 * open by the holder and wake up all waiters for exclusive open to finish.

 */

static void bd_finish_claiming(struct block_device *bdev,

		struct block_device *whole, void *holder)

static void bd_finish_claiming(struct block_device *bdev, void *holder)

{

	struct block_device *whole = bdev_whole(bdev);



	spin_lock(&bdev_lock);

	BUG_ON(!bd_may_claim(bdev, whole, holder));

	/*
@@ -1063,11 +1061,10 @@ static void bd_finish_claiming(struct block_device *bdev, 
 * also used when exclusive open is not actually desired and we just needed

 * to block other exclusive openers for a while.

 */

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

		       void *holder)

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

{

	spin_lock(&bdev_lock);

	bd_clear_claiming(whole, holder);

	bd_clear_claiming(bdev_whole(bdev), holder);

	spin_unlock(&bdev_lock);

}

EXPORT_SYMBOL(bd_abort_claiming);
@@ -1487,7 +1484,6 @@ void blkdev_put_no_open(struct block_device *bdev) 
 */

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

{

	struct block_device *claiming;

	bool unblock_events = true;

	struct block_device *bdev;

	struct gendisk *disk;
@@ -1510,15 +1506,9 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) 
	disk = bdev->bd_disk;



	if (mode & FMODE_EXCL) {

		WARN_ON_ONCE(!holder);

	

		ret = -ENOMEM;

		claiming = bdget_disk(disk, 0);

		if (!claiming)

			goto put_blkdev;

		ret = bd_prepare_to_claim(bdev, claiming, holder);

		ret = bd_prepare_to_claim(bdev, holder);

		if (ret)

			goto put_claiming;

			goto put_blkdev;

	}



	disk_block_events(disk);
@@ -1528,7 +1518,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) 
	if (ret)

		goto abort_claiming;

	if (mode & FMODE_EXCL) {

		bd_finish_claiming(bdev, claiming, holder);

		bd_finish_claiming(bdev, holder);



		/*

		 * Block event polling for write claims if requested.  Any write
@@ -1547,18 +1537,13 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) 


	if (unblock_events)

		disk_unblock_events(disk);

	if (mode & FMODE_EXCL)

		bdput(claiming);

	return bdev;



abort_claiming:

	if (mode & FMODE_EXCL)

		bd_abort_claiming(bdev, claiming, holder);

		bd_abort_claiming(bdev, holder);

	mutex_unlock(&bdev->bd_mutex);

	disk_unblock_events(disk);

put_claiming:

	if (mode & FMODE_EXCL)

		bdput(claiming);

put_blkdev:

	blkdev_put_no_open(bdev);

	if (ret == -ERESTARTSYS)

include/linux/blkdev.h

+2 −4
Original line number Diff line number Diff line
@@ -1988,10 +1988,8 @@ void blkdev_show(struct seq_file *seqf, off_t offset); 
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);

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);

int bd_prepare_to_claim(struct block_device *bdev, void *holder);

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

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



/* just for blk-cgroup, don't use elsewhere */