Re: [PATCH] 'unused' calculated with wrong sign.

[Josef Bacik <josef@redhat.com>]

On Sat, Nov 13, 2010 at 12:17:56AM +0100, Arne Jansen wrote:
> 'unused' calculated with wrong sign in reserve_metadata_bytes().
> This might have lead to unwanted over-reservations.
> 
> Signed-off-by: Arne Jansen <sensille@gmx.net>
> ---
>  fs/btrfs/extent-tree.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index a541bc8..ddaf634 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -3413,7 +3413,7 @@ again:
>  	 * our reservation.
>  	 */
>  	if (unused <= space_info->total_bytes) {
> -		unused -= space_info->total_bytes;
> +		unused = space_info->total_bytes - unused;
>  		if (unused >= num_bytes) {
>  			if (!reserved)
>  				space_info->bytes_reserved += orig_bytes;
> -- 
> 1.7.2.2
> 

Good catch

Reviewed-by: Josef Bacik <josef@redhat.com>

Thanks,

Josef