Commit 48fcc3ff authored Jul 01, 2014 by Satoru Takeuchi Committed by Chris Mason Sep 17, 2014

btrfs: label should not contain return char



Rediffed remaining parts of original patch from Anand Jain.  This makes
sure to avoid trailing newlines in the btrfs label output

reproducer.sh:

===============================================================================

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 "Test for empty label..." >&2
LINES="$(cat $LABELFILE | wc -l | awk '{print $1}')"
RET=0

if [ $LINES -eq 0 ] ; then
    echo '[PASS] Trailing \n is removed correctly.' >&2
else
    echo '[FAIL] Trailing \n still exists.' >&2
    RET=1
fi

echo "Test for non-empty label..." >&2

echo testlabel >$LABELFILE
LINES="$(cat $LABELFILE | wc -l | awk '{print $1}')"

if [ $LINES -eq 1 ] ; then
    echo '[PASS] Trailing \n is removed correctly.' >&2
else
    echo '[FAIL] Trailing \n still exists.' >&2
    RET=1
fi

exit $RET
===============================================================================

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

parent ec95d491

fs/btrfs/sysfs.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -363,7 +363,8 @@ static ssize_t btrfs_label_show(struct kobject *kobj,
		struct kobj_attribute a, char buf)
		{
		struct btrfs_fs_info *fs_info = to_fs_info(kobj);
		return snprintf(buf, PAGE_SIZE, "%s\n", fs_info->super_copy->label);
		char *label = fs_info->super_copy->label;
		return snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
		}

		static ssize_t btrfs_label_store(struct kobject *kobj,
		@@ -374,8 +375,15 @@ 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 +391,8 @@ 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);

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