Commit 5b26804b authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

md: simplify md_open 



Now that devices are on the all_mddevs list until the gendisk is freed,
there can't be any duplicates.  Remove the global list lookup and just
grab a reference.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 12a6caf2

drivers/md/md.c

+15 −27
Original line number Diff line number Diff line
@@ -7783,44 +7783,32 @@ static int md_set_read_only(struct block_device *bdev, bool ro) 


static int md_open(struct block_device *bdev, fmode_t mode)

{

	/*

	 * Succeed if we can lock the mddev, which confirms that

	 * it isn't being stopped right now.

	 */

	struct mddev *mddev = mddev_find(bdev->bd_dev);

	struct mddev *mddev;

	int err;



	spin_lock(&all_mddevs_lock);

	mddev = mddev_get(bdev->bd_disk->private_data);

	spin_unlock(&all_mddevs_lock);

	if (!mddev)

		return -ENODEV;



	if (mddev->gendisk != bdev->bd_disk) {

		/* we are racing with mddev_put which is discarding this

		 * bd_disk.

		 */

		mddev_put(mddev);

		/* Wait until bdev->bd_disk is definitely gone */

		if (work_pending(&mddev->del_work))

			flush_workqueue(md_misc_wq);

		return -EBUSY;

	}

	BUG_ON(mddev != bdev->bd_disk->private_data);



	if ((err = mutex_lock_interruptible(&mddev->open_mutex)))

	err = mutex_lock_interruptible(&mddev->open_mutex);

	if (err)

		goto out;



	if (test_bit(MD_CLOSING, &mddev->flags)) {

		mutex_unlock(&mddev->open_mutex);

	err = -ENODEV;

		goto out;

	}

	if (test_bit(MD_CLOSING, &mddev->flags))

		goto out_unlock;



	err = 0;

	atomic_inc(&mddev->openers);

	mutex_unlock(&mddev->open_mutex);



	bdev_check_media_change(bdev);

	return 0;



out_unlock:

	mutex_unlock(&mddev->open_mutex);

out:

	if (err)

	mddev_put(mddev);

	return err;

}