From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755114Ab1JSE2X (ORCPT ); Wed, 19 Oct 2011 00:28:23 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:44380 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754383Ab1JSE0e (ORCPT ); Wed, 19 Oct 2011 00:26:34 -0400 From: Tejun Heo To: axboe@kernel.dk, linux-kernel@vger.kernel.org, vgoyal@redhat.com Cc: ctalbott@google.com, ni@google.com, Tejun Heo Subject: [PATCH 02/10] block: fix genhd refcounting in blkio_policy_parse_and_set() Date: Tue, 18 Oct 2011 21:26:16 -0700 Message-Id: <1318998384-22525-3-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.3.1 In-Reply-To: <1318998384-22525-1-git-send-email-tj@kernel.org> References: <1318998384-22525-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Jens Axboe --- 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