Re: [PATCH] btrfs-progs: Fix the return value of btrfs_scan_kernel()

[Anand Jain <anand.jain@oracle.com>]

  I expect btrfs_scan_kernel()  would go away in the long run,
  however below fix has a problem - when there is no search item
  you would return fail (1) always. Since btrfs_scan_kernel() has
  limited usage as you mention as well. So I will leave it to David
  to decide.

Thanks, Anand

On 08/04/2014 17:16, Qu Wenruo wrote:
> btrfs_scan_kernel() is only used in 'btrfs fi show' but returns wrong
> return value.
> When search parameter is passed, it will never return 0 even the search
> can be matched.
>
> This patch will change the whatever strange logic to a more easy to
> understand one using 'found' var.
>
> Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> Cc: Anand Jain <anand.jain@oracle.com>
> ---
>   cmds-filesystem.c | 9 +++------
>   1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/cmds-filesystem.c b/cmds-filesystem.c
> index b81768b..49d3aa7 100644
> --- a/cmds-filesystem.c
> +++ b/cmds-filesystem.c
> @@ -430,6 +430,7 @@ static int btrfs_scan_kernel_v2(void *search)
>   static int btrfs_scan_kernel(void *search)
>   {
>   	int ret = 0, fd;
> +	int found = 0;
>   	FILE *f;
>   	struct mntent *mnt;
>   	struct btrfs_ioctl_fs_info_args fs_info_arg;
> @@ -452,7 +453,6 @@ static int btrfs_scan_kernel(void *search)
>
>   		if (get_label_mounted(mnt->mnt_dir, label)) {
>   			kfree(dev_info_arg);
> -			ret = 1;
>   			goto out;
>   		}
>   		if (search && !match_search_item_kernel(fs_info_arg.fsid,
> @@ -467,19 +467,16 @@ static int btrfs_scan_kernel(void *search)
>   					space_info_arg, label, mnt->mnt_dir);
>   			kfree(space_info_arg);
>   			memset(label, 0, sizeof(label));
> +			found = 1;
>   		}
>   		if (fd != -1)
>   			close(fd);
>   		kfree(dev_info_arg);
> -		if (search)
> -			ret = 0;
>   	}
> -	if (search)
> -		ret = 1;
>
>   out:
>   	endmntent(f);
> -	return ret;
> +	return !found;
>   }
>
>   static int dev_to_fsid(char *dev, __u8 *fsid)
>