Re: [PATCH] btrfs-progs: Fix btrfs fi show by uuid and label

[Gui Hecheng <guihc.fnst@cn.fujitsu.com>]

On Tue, 2014-12-23 at 11:34 -0800, Justin Maggard wrote:
> Commit 8be2fff (btrfs-progs: apply realpath for btrfs fi
> show when mount point is given) changed the behavior of
> btrfs fi show to return an error if the call to realpath()
> failed.  This broke the ability to specify a filesystem by
> uuid or label.

Oh, that's my fault, thanks for correcting this.

> So let's not consider a failed call to realpath() as an
> error.  If the user really specified a bad device, just
> return nothing like we did before.
> ---
>  cmds-filesystem.c |    9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/cmds-filesystem.c b/cmds-filesystem.c
> index 8f037dd..a654e6f 100644
> --- a/cmds-filesystem.c
> +++ b/cmds-filesystem.c
> @@ -901,13 +901,8 @@ static int cmd_show(int argc, char **argv)
>  		 *     realpath do  /mnt/btrfs/  => /mnt/btrfs
>  		 *     which shall be recognized by btrfs_scan_kernel()
>  		 */
> -		if (!realpath(search, path)) {
> -			fprintf(stderr, "ERROR: Could not show %s: %s\n",
> -					search, strerror(errno));
> -			return 1;
> -		}
> -
> -		search = path;
> +		if (realpath(search, path))
> +			search = path;

This looks nice and stay consistent with the behavior before my faulty
commit.

Reviewed-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>

Thanks,
Gui

>  		/*
>  		 * Needs special handling if input arg is block dev And if