Commit 58e46ed9 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: refactor bd_start_claiming 



Move the locking and assignment of bd_claiming from bd_start_claiming to
bd_prepare_to_claim.

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 c5638ab4

fs/block_dev.c

+13 −20
Original line number Diff line number Diff line
@@ -1015,19 +1015,14 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, 
}



/**

 * bd_prepare_to_claim - prepare to claim a block device

 * 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

 *

 * Prepare to claim @bdev.  This function fails if @bdev is already

 * claimed by another holder and waits if another claiming is in

 * progress.  This function doesn't actually claim.  On successful

 * return, the caller has ownership of bd_claiming and bd_holder[s].

 *

 * CONTEXT:

 * spin_lock(&bdev_lock).  Might release bdev_lock, sleep and regrab

 * it multiple times.

 * Claim @bdev.  This function fails if @bdev is already claimed by another

 * holder and waits if another claiming is in progress. return, the caller

 * has ownership of bd_claiming and bd_holder[s].

 *

 * RETURNS:

 * 0 if @bdev can be claimed, -EBUSY otherwise.
@@ -1036,9 +1031,12 @@ static int bd_prepare_to_claim(struct block_device *bdev, 
			       struct block_device *whole, void *holder)

{

retry:

	spin_lock(&bdev_lock);

	/* if someone else claimed, fail */

	if (!bd_may_claim(bdev, whole, holder))

	if (!bd_may_claim(bdev, whole, holder)) {

		spin_unlock(&bdev_lock);

		return -EBUSY;

	}



	/* if claiming is already in progress, wait for it to finish */

	if (whole->bd_claiming) {
@@ -1049,11 +1047,12 @@ static int bd_prepare_to_claim(struct block_device *bdev, 
		spin_unlock(&bdev_lock);

		schedule();

		finish_wait(wq, &wait);

		spin_lock(&bdev_lock);

		goto retry;

	}



	/* yay, all mine */

	whole->bd_claiming = holder;

	spin_unlock(&bdev_lock);

	return 0;

}
@@ -1134,19 +1133,13 @@ struct block_device *bd_start_claiming(struct block_device *bdev, void *holder) 
	if (!whole)

		return ERR_PTR(-ENOMEM);



	/* prepare to claim, if successful, mark claiming in progress */

	spin_lock(&bdev_lock);



	err = bd_prepare_to_claim(bdev, whole, holder);

	if (err == 0) {

		whole->bd_claiming = holder;

		spin_unlock(&bdev_lock);

		return whole;

	} else {

		spin_unlock(&bdev_lock);

	if (err) {

		bdput(whole);

		return ERR_PTR(err);

	}



	return whole;

}

EXPORT_SYMBOL(bd_start_claiming);