lkml.org 
[lkml]   [2011]   [Oct]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 02/10] block: fix genhd refcounting in blkio_policy_parse_and_set()
Date
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: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
---
block/blk-cgroup.c | 56 +++++++++++++++++++++------------------------------
1 files changed, 23 insertions(+), 33 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b596e54..d61ec56 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -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,
--
1.7.3.1


\
 
 \ /
  Last update: 2011-10-19 06:31    [from the cache]
©2003-2011 Jasper Spaans