Unverified Commit 08d96aa4 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
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!3379 md: do not return existing mddevs from mddev_find_or_alloc 

Merge Pull Request from: @ci-robot 
 
PR sync from: Li Lingfeng <lilingfeng3@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/Y3S6BLLOQH7K5HXD762ADZB52A6D6VBO/ 
Do not return existing mddevs from mddev_find_or_alloc.

Christoph Hellwig (3):
  md: factor out a mddev_alloc_unit helper from mddev_find
  md: refactor mddev_find_or_alloc
  md: do not return existing mddevs from mddev_find_or_alloc


-- 
2.31.1
 
https://gitee.com/openeuler/kernel/issues/I8O6NL 
 
Link:https://gitee.com/openeuler/kernel/pulls/3379

 

Reviewed-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents ee181715 10b2c6ae

drivers/md/md.c

+67 −72
Original line number Diff line number Diff line
@@ -723,6 +723,27 @@ static struct mddev *mddev_find_locked(dev_t unit) 
	return NULL;

}



/* find an unused unit number */

static dev_t mddev_alloc_unit(void)

{

	static int next_minor = 512;

	int start = next_minor;

	bool is_free = 0;

	dev_t dev = 0;



	while (!is_free) {

		dev = MKDEV(MD_MAJOR, next_minor);

		next_minor++;

		if (next_minor > MINORMASK)

			next_minor = 0;

		if (next_minor == start)

			return 0;		/* Oh dear, all in use. */

		is_free = !mddev_find_locked(dev);

	}



	return dev;

}



static struct mddev *mddev_find(dev_t unit)

{

	struct mddev *mddev;
@@ -739,73 +760,46 @@ 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, *new = NULL;

	struct mddev *new;

	int error;



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

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



 retry:

	spin_lock(&all_mddevs_lock);



	if (unit) {

		mddev = mddev_find_locked(unit);

		if (mddev) {

			mddev_get(mddev);

			spin_unlock(&all_mddevs_lock);

			kfree(new);

			return mddev;

		}



		if (new) {

			list_add(&new->all_mddevs, &all_mddevs);

			spin_unlock(&all_mddevs_lock);

			new->hold_active = UNTIL_IOCTL;

			return new;

		}

	} else if (new) {

		/* find an unused unit number */

		static int next_minor = 512;

		int start = next_minor;

		int is_free = 0;

		int dev = 0;

		while (!is_free) {

			dev = MKDEV(MD_MAJOR, next_minor);

			next_minor++;

			if (next_minor > MINORMASK)

				next_minor = 0;

			if (next_minor == start) {

				/* Oh dear, all in use. */

				spin_unlock(&all_mddevs_lock);

				kfree(new);

				return NULL;

			}



			is_free = !mddev_find_locked(dev);

		}

		new->unit = dev;

		new->md_minor = MINOR(dev);

		new->hold_active = UNTIL_STOP;

		list_add(&new->all_mddevs, &all_mddevs);

		spin_unlock(&all_mddevs_lock);

		return new;

	}

	spin_unlock(&all_mddevs_lock);



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

	if (!new)

		return NULL;

		return ERR_PTR(-ENOMEM);

	mddev_init(new);



	spin_lock(&all_mddevs_lock);

	if (unit) {

		error = -EEXIST;

		if (mddev_find_locked(unit))

			goto out_free_new;

		new->unit = unit;

		if (MAJOR(unit) == MD_MAJOR)

			new->md_minor = MINOR(unit);

		else

			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;

		new->md_minor = MINOR(new->unit);

		new->hold_active = UNTIL_STOP;

	}



	mddev_init(new);



	goto retry;

	list_add(&new->all_mddevs, &all_mddevs);

	spin_unlock(&all_mddevs_lock);

	return new;

out_free_new:

	spin_unlock(&all_mddevs_lock);

	kfree(new);

	return ERR_PTR(error);

}



static struct attribute_group md_redundancy_group;
@@ -5739,30 +5733,30 @@ 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.
@@ -5774,6 +5768,7 @@ 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);