Re: [PATCH] xfs: check if reserved free disk blocks is needed

[Brian Foster <bfoster@redhat.com>]

On Sun, Apr 05, 2020 at 05:17:19PM +0800, xiakaixu1987@gmail.com wrote:
> From: Kaixu Xia <kaixuxia@tencent.com>
> 
> We don't need to create the new quota inodes from disk when
> they exist already, so add check if reserved free disk blocks
> is needed in xfs_trans_alloc().
> 

I find the commit log to be a bit misleading. We don't actually get into
this code if the inodes exist already. The need_alloc == false case
looks like it has more to do with the scenario with the project/group
inode is shared on older superblocks (explained in the comment near the
top of the alloc function).

That aside, the code looks fine to me, so with an improved commit log:

Reviewed-by: Brian Foster <bfoster@redhat.com>

> Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
> ---
>  fs/xfs/xfs_qm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index 6678baa..b684b04 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -780,7 +780,8 @@ struct xfs_qm_isolate {
>  	}
>  
>  	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_create,
> -			XFS_QM_QINOCREATE_SPACE_RES(mp), 0, 0, &tp);
> +			need_alloc ? XFS_QM_QINOCREATE_SPACE_RES(mp) : 0,
> +			0, 0, &tp);
>  	if (error)
>  		return error;
>  
> -- 
> 1.8.3.1
>