Re: [PATCH] quota: allow users to truncate group and project quota files

["Darrick J. Wong" <djwong@kernel.org>]

Eric asked me to resend all the pending patches for 5.13, so I might as
well NAK this and tell everyone to watch for the imminent patchbomb.

--D

On Wed, Jul 28, 2021 at 01:02:08PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> In commit 79ac1ae4, I /think/ xfsprogs gained the ability to deal with
> project or group quotas.  For some reason, the quota remove command was
> structured so that if the user passes both -g and -p, it will only ask
> the kernel truncate the group quota file.  This is a strange behavior
> since -ug results in truncation requests for both user and group quota
> files, and the kernel is smart enough to return 0 if asked to truncate a
> quota file that doesn't exist.
> 
> In other words, this is a seemingly arbitrary limitation of the command.
> It's an unexpected behavior since we don't do any sort of parameter
> validation to warn users when -p is silently ignored.  Modern V5
> filesystems support both group and project quotas, so it's all the more
> surprising that you can't do group and project all at once.  Remove this
> pointless restriction.
> 
> Found while triaging xfs/007 regressions.
> 
> Fixes: 79ac1ae4 ("Fix xfs_quota disable, enable, off and remove commands Merge of master-melb:xfs-cmds:29395a by kenmcd.")
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  quota/state.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/quota/state.c b/quota/state.c
> index 3ffb2c88..43fb700f 100644
> --- a/quota/state.c
> +++ b/quota/state.c
> @@ -463,7 +463,8 @@ remove_extents(
>  	if (type & XFS_GROUP_QUOTA) {
>  		if (remove_qtype_extents(dir, XFS_GROUP_QUOTA) < 0)
>  			return;
> -	} else if (type & XFS_PROJ_QUOTA) {
> +	}
> +	if (type & XFS_PROJ_QUOTA) {
>  		if (remove_qtype_extents(dir, XFS_PROJ_QUOTA) < 0)
>  			return;
>  	}