Re: [PATCH v3] btrfs-progs: fi resize: fix false 0.00B sized output

[Boris Burkov <boris@bur.io>]

On Tue, Apr 20, 2021 at 12:58:27PM +0800, Su Yue wrote:
> Resize to nums without sign prefix makes false output:
>  btrfs fi resize 1:150g /srv/extra
> Resize device id 1 (/dev/sdb1) from 298.09GiB to 0.00B
> 
> The resize operation would take effect though.
> 
> check_resize_args() does not handle the mod 0 case and new_size is 0.
> Simply assigning @diff to @new_size to fix this.
> 
> Issue: #307
> Reported-by: Chris Murphy <lists@colorremedies.com>
> Signed-off-by: Su Yue <l@damenly.su>

Reviewed-by: Boris Burkov <boris@bur.io>

> ---
> Changelog:
> v3:
>   Just assign @diff to @new_size. (Boris Burkov)
> v2:
>   Calculate u64 diff using max() and min().
>   Calculate mod by comparing new and old size.
> ---
>  cmds/filesystem.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/cmds/filesystem.c b/cmds/filesystem.c
> index 9e3cce687d6e..b4c09768235c 100644
> --- a/cmds/filesystem.c
> +++ b/cmds/filesystem.c
> @@ -1158,7 +1158,10 @@ static int check_resize_args(const char *amount, const char *path) {
>  		}
>  		old_size = di_args[dev_idx].total_bytes;
>  
> -		if (mod < 0) {
> +		/* For target sizes without '+'/'-' sign prefix(e.g. 1:150g) */
> +		if (mod == 0) {
> +			new_size = diff;
> +		} else if (mod < 0) {
>  			if (diff > old_size) {
>  				error("current size is %s which is smaller than %s",
>  				      pretty_size_mode(old_size, UNITS_DEFAULT),
> -- 
> 2.30.1
>