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Commit ece84241 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

block: fix genhd refcounting in blkio_policy_parse_and_set() 



blkio_policy_parse_and_set() calls blkio_check_dev_num() to check
whether the given dev_t is valid.  blkio_check_dev_num() uses
get_gendisk() for verification but never puts the returned genhd
leaking the reference.

This patch collapses blkio_check_dev_num() into its caller and updates
it such that the genhd is put before returning.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 523e1d39

block/blk-cgroup.c

+23 −33
Original line number Diff line number Diff line
@@ -768,25 +768,14 @@ static uint64_t blkio_get_stat(struct blkio_group *blkg, 
	return disk_total;

}



static int blkio_check_dev_num(dev_t dev)

{

	int part = 0;

	struct gendisk *disk;



	disk = get_gendisk(dev, &part);

	if (!disk || part)

		return -ENODEV;



	return 0;

}



static int blkio_policy_parse_and_set(char *buf,

	struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid)

{

	struct gendisk *disk = NULL;

	char *s[4], *p, *major_s = NULL, *minor_s = NULL;

	int ret;

	unsigned long major, minor;

	int i = 0;

	int i = 0, ret = -EINVAL;

	int part;

	dev_t dev;

	u64 temp;
@@ -804,37 +793,36 @@ static int blkio_policy_parse_and_set(char *buf, 
	}



	if (i != 2)

		return -EINVAL;

		goto out;



	p = strsep(&s[0], ":");

	if (p != NULL)

		major_s = p;

	else

		return -EINVAL;

		goto out;



	minor_s = s[0];

	if (!minor_s)

		return -EINVAL;

		goto out;



	ret = strict_strtoul(major_s, 10, &major);

	if (ret)

		return -EINVAL;

	if (strict_strtoul(major_s, 10, &major))

		goto out;



	ret = strict_strtoul(minor_s, 10, &minor);

	if (ret)

		return -EINVAL;

	if (strict_strtoul(minor_s, 10, &minor))

		goto out;



	dev = MKDEV(major, minor);



	ret = strict_strtoull(s[1], 10, &temp);

	if (ret)

		return -EINVAL;

	if (strict_strtoull(s[1], 10, &temp))

		goto out;



	/* For rule removal, do not check for device presence. */

	if (temp) {

		ret = blkio_check_dev_num(dev);

		if (ret)

			return ret;

		disk = get_gendisk(dev, &part);

		if (!disk || part) {

			ret = -ENODEV;

			goto out;

		}

	}



	newpn->dev = dev;
@@ -843,7 +831,7 @@ static int blkio_policy_parse_and_set(char *buf, 
	case BLKIO_POLICY_PROP:

		if ((temp < BLKIO_WEIGHT_MIN && temp > 0) ||

		     temp > BLKIO_WEIGHT_MAX)

			return -EINVAL;

			goto out;



		newpn->plid = plid;

		newpn->fileid = fileid;
@@ -860,7 +848,7 @@ static int blkio_policy_parse_and_set(char *buf, 
		case BLKIO_THROTL_read_iops_device:

		case BLKIO_THROTL_write_iops_device:

			if (temp > THROTL_IOPS_MAX)

				return -EINVAL;

				goto out;



			newpn->plid = plid;

			newpn->fileid = fileid;
@@ -871,8 +859,10 @@ static int blkio_policy_parse_and_set(char *buf, 
	default:

		BUG();

	}



	return 0;

	ret = 0;

out:

	put_disk(disk);

	return ret;

}



unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,