Commit d1c09ab0 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by openeuler-sync-bot
Browse files

md: do not return existing mddevs from mddev_find_or_alloc 

mainline inclusion
from mainline-v5.13-rc1
commit 0d809b38
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8O6NL
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0d809b3837a0bede8f58a67e303e339585777bf4



-------------------------------------------------

Instead of returning an existing mddev, just for it to be discarded
later directly return -EEXIST.  Rename the function to mddev_alloc now
that it doesn't find an existing mddev.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarSong Liu <song@kernel.org>

Conflicts:
  Commit 4ad5f208 ("md: Flush workqueue md_rdev_misc_wq in md_alloc()")
  add flushing md_rdev_misc_wq in md_alloc().
Signed-off-by: default avatarLi Lingfeng <lilingfeng3@huawei.com>
(cherry picked from commit 10b2c6ae)
parent 64b2cb66

drivers/md/md.c

+23 −23
Original line number Diff line number Diff line
@@ -760,26 +760,24 @@ static struct mddev *mddev_find(dev_t unit) 
	return mddev;

}



static struct mddev *mddev_find_or_alloc(dev_t unit)

static struct mddev *mddev_alloc(dev_t unit)

{

	struct mddev *mddev = NULL, *new;

	struct mddev *new;

	int error;



	if (unit && MAJOR(unit) != MD_MAJOR)

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



	new = kzalloc(sizeof(*new), GFP_KERNEL);

	if (!new)

		return NULL;

		return ERR_PTR(-ENOMEM);

	mddev_init(new);



	spin_lock(&all_mddevs_lock);

	if (unit) {

		mddev = mddev_find_locked(unit);

		if (mddev) {

			mddev_get(mddev);

		error = -EEXIST;

		if (mddev_find_locked(unit))

			goto out_free_new;

		}



		new->unit = unit;

		if (MAJOR(unit) == MD_MAJOR)

			new->md_minor = MINOR(unit);
@@ -787,6 +785,7 @@ static struct mddev *mddev_find_or_alloc(dev_t unit) 
			new->md_minor = MINOR(unit) >> MdpMinorShift;

		new->hold_active = UNTIL_IOCTL;

	} else {

		error = -ENODEV;

		new->unit = mddev_alloc_unit();

		if (!new->unit)

			goto out_free_new;
@@ -800,7 +799,7 @@ static struct mddev *mddev_find_or_alloc(dev_t unit) 
out_free_new:

	spin_unlock(&all_mddevs_lock);

	kfree(new);

	return mddev;

	return ERR_PTR(error);

}



static struct attribute_group md_redundancy_group;
@@ -5722,30 +5721,30 @@ 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_or_alloc(dev);

	struct mddev *mddev;

	struct gendisk *disk;

	int partitioned;

	int shift;

	int unit;

	int error ;



	if (!mddev)

		return -ENODEV;



	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);

	shift = partitioned ? MdpMinorShift : 0;

	unit = MINOR(mddev->unit) >> shift;



	/* wait for any previous instance of this device to be

	 * completely removed (mddev_delayed_delete).

	/*

	 * Wait for any previous instance of this device to be completely

	 * removed (mddev_delayed_delete).

	 */

	flush_workqueue(md_misc_wq);

	flush_workqueue(md_rdev_misc_wq);



	mutex_lock(&disks_mutex);

	error = -EEXIST;

	if (mddev->gendisk)

		goto abort;

	mddev = mddev_alloc(dev);

	if (IS_ERR(mddev)) {

		mutex_unlock(&disks_mutex);

		return PTR_ERR(mddev);

	}



	partitioned = (MAJOR(mddev->unit) != MD_MAJOR);

	shift = partitioned ? MdpMinorShift : 0;

	unit = MINOR(mddev->unit) >> shift;



	if (name && !dev) {

		/* Need to ensure that 'name' is not a duplicate.
@@ -5757,6 +5756,7 @@ static int md_alloc(dev_t dev, char *name) 
			if (mddev2->gendisk &&

			    strcmp(mddev2->gendisk->disk_name, name) == 0) {

				spin_unlock(&all_mddevs_lock);

				error = -EEXIST;

				goto abort;

			}

		spin_unlock(&all_mddevs_lock);