Commit ff917638 authored by Jens Axboe's avatar Jens Axboe
Browse files

Merge branch 'md-next' of... 

Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-5.13/drivers

Pull MD updates from Song:

"These patches fix a race condition with md_release() and md_open()."

* 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: split mddev_find
  md: factor out a mddev_find_locked helper from mddev_find
  md: md_open returns -EBUSY when entering racing area
parents 9c282c29 65aa97c4

drivers/md/md.c

+39 −20
Original line number Diff line number Diff line
@@ -734,7 +734,34 @@ void mddev_init(struct mddev *mddev) 
}

EXPORT_SYMBOL_GPL(mddev_init);



static struct mddev *mddev_find_locked(dev_t unit)

{

	struct mddev *mddev;



	list_for_each_entry(mddev, &all_mddevs, all_mddevs)

		if (mddev->unit == unit)

			return mddev;



	return NULL;

}



static struct mddev *mddev_find(dev_t unit)

{

	struct mddev *mddev;



	if (MAJOR(unit) != MD_MAJOR)

		unit &= ~((1 << MdpMinorShift) - 1);



	spin_lock(&all_mddevs_lock);

	mddev = mddev_find_locked(unit);

	if (mddev)

		mddev_get(mddev);

	spin_unlock(&all_mddevs_lock);



	return mddev;

}



static struct mddev *mddev_find_or_alloc(dev_t unit)

{

	struct mddev *mddev, *new = NULL;
@@ -745,8 +772,8 @@ static struct mddev *mddev_find(dev_t unit) 
	spin_lock(&all_mddevs_lock);



	if (unit) {

		list_for_each_entry(mddev, &all_mddevs, all_mddevs)

			if (mddev->unit == unit) {

		mddev = mddev_find_locked(unit);

		if (mddev) {

			mddev_get(mddev);

			spin_unlock(&all_mddevs_lock);

			kfree(new);
@@ -777,12 +804,7 @@ static struct mddev *mddev_find(dev_t unit) 
				return NULL;

			}



			is_free = 1;

			list_for_each_entry(mddev, &all_mddevs, all_mddevs)

				if (mddev->unit == dev) {

					is_free = 0;

					break;

				}

			is_free = !mddev_find_locked(dev);

		}

		new->unit = dev;

		new->md_minor = MINOR(dev);
@@ -5644,7 +5666,7 @@ static int md_alloc(dev_t dev, char *name) 
	 * writing to /sys/module/md_mod/parameters/new_array.

	 */

	static DEFINE_MUTEX(disks_mutex);

	struct mddev *mddev = mddev_find(dev);

	struct mddev *mddev = mddev_find_or_alloc(dev);

	struct gendisk *disk;

	int partitioned;

	int shift;
@@ -6524,11 +6546,9 @@ static void autorun_devices(int part) 


		md_probe(dev);

		mddev = mddev_find(dev);

		if (!mddev || !mddev->gendisk) {

			if (mddev)

				mddev_put(mddev);

		if (!mddev)

			break;

		}



		if (mddev_lock(mddev))

			pr_warn("md: %s locked, cannot run\n", mdname(mddev));

		else if (mddev->raid_disks || mddev->major_version
@@ -7821,8 +7841,7 @@ static int md_open(struct block_device *bdev, fmode_t mode) 
		/* Wait until bdev->bd_disk is definitely gone */

		if (work_pending(&mddev->del_work))

			flush_workqueue(md_misc_wq);

		/* Then retry the open from the top */

		return -ERESTARTSYS;

		return -EBUSY;

	}

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