From: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
To: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>,
Anand Jain <anand.jain@oracle.com>, <linux-btrfs@vger.kernel.org>
Cc: <dsterba@suse.cz>, <sandeen@redhat.com>, <rm@romanrm.net>,
<koen@dominion.thruhere.net>
Subject: Re: [PATCH v5] btrfs: label should not contain return char
Date: Tue, 1 Jul 2014 14:46:09 +0800 [thread overview]
Message-ID: <53B25931.2030200@cn.fujitsu.com> (raw)
In-Reply-To: <53B245AA.6060209@jp.fujitsu.com>
Hi Satoru and all,
I think there maybe a leftover issue.
That is if we don't set label, in default it will output a blank line.
Steps to reproduce:
# mkfs.btrfs -f /dev/sdb
# mount /dev/sdb
# cat /sys/fs/btrfs/<uuid>/label -->an extra line will be outputed.
This is because in btrfs_label_show(), we did something like this directly:
return snprintf(buf, PAGE_SIZE, "%s\n", fs_info->super_copy->label);
Maybe we can have a check whether label is NULL before we output?
otherwise,the
extra blank line is outputed, IMO this is not so nice thing!
Thanks,
Wang
On 07/01/2014 01:22 PM, Satoru Takeuchi wrote:
> 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 <Anand.Jain@oracle.com>
>
> generally if you use
> echo "test" > /sys/fs/btrfs/<fsid>/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/<fsid>/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 <Anand.Jain@oracle.com>
> Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
> Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
> Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
> ---
> 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);
>
next prev parent reply other threads:[~2014-07-01 6:50 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-19 17:04 [PATCH 1/2] btrfs: label should not contain return char Anand Jain
2014-05-19 17:04 ` [PATCH 2/2] btrfs: usage error should not be logged into system log Anand Jain
2014-05-20 6:38 ` [PATCH 2/2 v2] " Anand Jain
2014-05-20 16:36 ` David Sterba
2014-05-19 17:16 ` [PATCH 1/2] btrfs: label should not contain return char Eric Sandeen
2014-05-20 6:40 ` Anand Jain
2014-05-19 17:19 ` Roman Mamedov
2014-05-20 6:42 ` Anand Jain
2014-05-20 6:36 ` [PATCH 1/2 v2] " Anand Jain
2014-05-20 16:32 ` Eric Sandeen
2014-05-22 2:05 ` Anand Jain
2014-05-22 2:14 ` Eric Sandeen
2014-05-22 4:14 ` Roman Mamedov
2014-05-22 16:06 ` Eric Sandeen
2014-05-20 16:33 ` David Sterba
2014-05-20 16:41 ` Eric Sandeen
2014-05-22 10:47 ` Anand Jain
2014-05-22 10:41 ` [PATCH 1/2 v3] " Anand Jain
2014-05-22 10:41 ` [PATCH 2/2 v3] btrfs: usage error should not be logged into system log Anand Jain
2014-05-22 11:21 ` Koen Kooi
2014-05-23 2:41 ` Anand Jain
2014-05-22 11:41 ` [PATCH 1/2 v3] btrfs: label should not contain return char David Sterba
2014-05-23 2:50 ` [PATCH 1/2 v4] " Anand Jain
2014-05-23 2:50 ` [PATCH 2/2 v4] btrfs: usage error should not be logged into system log Anand Jain
2014-05-26 17:41 ` [PATCH 1/2 v4] btrfs: label should not contain return char David Sterba
2014-07-01 5:22 ` [PATCH v5] " Satoru Takeuchi
2014-07-01 6:46 ` Wang Shilong [this message]
2014-07-01 8:00 ` [PATCH v6] " Satoru Takeuchi
2014-07-01 8:29 ` Wang Shilong
2014-07-01 15:05 ` David Sterba
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=53B25931.2030200@cn.fujitsu.com \
--to=wangsl.fnst@cn.fujitsu.com \
--cc=anand.jain@oracle.com \
--cc=dsterba@suse.cz \
--cc=koen@dominion.thruhere.net \
--cc=linux-btrfs@vger.kernel.org \
--cc=rm@romanrm.net \
--cc=sandeen@redhat.com \
--cc=takeuchi_satoru@jp.fujitsu.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).