btrfs-progs: fix improper return value check for is_existing_blk_or_reg_file

The function @is_existing_blk_or_reg_file has a return value of -errno,
which indicate the @stat call fails with non-ENOENT errors.
In this condition, we should not continue the following work.

But -errno evaluates to true and will let the following work go.
So we should judge more accurately whether the return value of
@is_existing_blk_or_reg_file is > 0 or not to decide our behavior.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/utils.c b/utils.c
index 481e061..4f17583 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -1563,22 +1563,29 @@ int get_label(const char *btrfs_dev, char *label)
 {
        int ret;
 
-       if (is_existing_blk_or_reg_file(btrfs_dev))
-               ret = get_label_unmounted(btrfs_dev, label);
-       else
+       ret = is_existing_blk_or_reg_file(btrfs_dev);
+       if (!ret)
                ret = get_label_mounted(btrfs_dev, label);
+       else if (ret > 0)
+               ret = get_label_unmounted(btrfs_dev, label);
 
        return ret;
 }
 
 int set_label(const char *btrfs_dev, const char *label)
 {
+       int ret;
+
        if (check_label(label))
                return -1;
 
-       return is_existing_blk_or_reg_file(btrfs_dev) ?
-               set_label_unmounted(btrfs_dev, label) :
-               set_label_mounted(btrfs_dev, label);
+       ret = is_existing_blk_or_reg_file(btrfs_dev);
+       if (!ret)
+               ret = set_label_mounted(btrfs_dev, label);
+       else if (ret > 0)
+               ret = set_label_unmounted(btrfs_dev, label);
+
+       return ret;
 }
 
 int btrfs_scan_block_devices(int run_ioctl)