From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fgwmail.fujitsu.co.jp ([164.71.1.133]:58293 "EHLO fgwmail.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750822AbaGAFXS (ORCPT ); Tue, 1 Jul 2014 01:23:18 -0400 Received: from kw-mxq.gw.nic.fujitsu.com (unknown [10.0.237.131]) by fgwmail.fujitsu.co.jp (Postfix) with ESMTP id 4E9693EE0C2 for ; Tue, 1 Jul 2014 14:23:16 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.nic.fujitsu.com [10.0.50.94]) by kw-mxq.gw.nic.fujitsu.com (Postfix) with ESMTP id 5551AAC074B for ; Tue, 1 Jul 2014 14:23:15 +0900 (JST) Received: from g01jpfmpwkw02.exch.g01.fujitsu.local (g01jpfmpwkw02.exch.g01.fujitsu.local [10.0.193.56]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id F09731DB803B for ; Tue, 1 Jul 2014 14:23:14 +0900 (JST) Message-ID: <53B245AA.6060209@jp.fujitsu.com> Date: Tue, 1 Jul 2014 14:22:50 +0900 From: Satoru Takeuchi MIME-Version: 1.0 To: Anand Jain , CC: , , , Subject: [PATCH v5] btrfs: label should not contain return char References: <1400519071-5580-1-git-send-email-anand.jain@oracle.com> <1400813402-27474-1-git-send-email-anand.jain@oracle.com> In-Reply-To: <1400813402-27474-1-git-send-email-anand.jain@oracle.com> Content-Type: text/plain; charset="ISO-2022-JP" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Although Anand once sent the following two patches, - [PATCH 1/2 v4] btrfs: label should not contain return char - [PATCH 2/2 v4] btrfs: usage error should not be logged into system log only the latter patch was merged to mason/for-linus and 3.16-rc3 as 402a0f4 (by accident?). It results in that the former patch can't be cleanly applied to 3.16-rc3. I fixed this problem, wrote a reproducer, and tested it. Test Result: 3.16-rc3 w/o this patch: fail 3.16-rc3 w/ this patch: pass Subject: [PATCH v5] btrfs: label should not contain return char From: Anand Jain generally if you use echo "test" > /sys/fs/btrfs//label it would introduce return char at the end and it can not be part of the label. The correct command is echo -n "test" > /sys/fs/btrfs//label This patch will check for this user error reproducer.sh: =============================================================================== #!/bin/bash TEST_DEV=/dev/vdb TEST_DIR=/home/sat/mnt umount /home/sat/mnt mkfs.btrfs -f $TEST_DEV UUID=$(btrfs fi show $TEST_DEV | head -1 | sed -e 's/.*uuid: \([-0-9a-z]*\)$/\1/') mount $TEST_DEV $TEST_DIR LABELFILE=/sys/fs/btrfs/$UUID/label echo testlabel >$LABELFILE LINES="$(cat $LABELFILE | wc -l | awk '{print $1}')" RET=1 if [ $LINES -eq 1 ] ; then echo '[PASS] Trailing \n is removed correctly.' >&2 RET=0 else echo '[FAIL] Trailing \n still exists.' >&2 fi exit $RET =============================================================================== Signed-off-by: Anand Jain Signed-off-by: Satoru Takeuchi Reviewed-by: Satoru Takeuchi Tested-by: Satoru Takeuchi --- v5: tweak to be able to apply on the top of 402a0f4. add test program. v4: used memcpy and memset. Thanks David again v3: accepts review comments. Thanks David and Eric again v2: accepts review comments. Thanks Eric and Roman --- fs/btrfs/sysfs.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index df39458..dcae61a 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -374,8 +374,15 @@ static ssize_t btrfs_label_store(struct kobject *kobj, struct btrfs_trans_handle *trans; struct btrfs_root *root = fs_info->fs_root; int ret; + size_t p_len; - if (len >= BTRFS_LABEL_SIZE) + /* + * p_len is the len until the first occurrence of either + * '\n' or '\0' + */ + p_len = strcspn(buf, "\n"); + + if (p_len >= BTRFS_LABEL_SIZE) return -EINVAL; trans = btrfs_start_transaction(root, 0); @@ -383,7 +390,8 @@ static ssize_t btrfs_label_store(struct kobject *kobj, return PTR_ERR(trans); spin_lock(&root->fs_info->super_lock); - strcpy(fs_info->super_copy->label, buf); + memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); + memcpy(fs_info->super_copy->label, buf, p_len); spin_unlock(&root->fs_info->super_lock); ret = btrfs_commit_transaction(trans, root); -- 1.9.3