Re: [PATCH 6/6] xfs: allow individual quota grace period extension

[Eric Sandeen <sandeen@sandeen.net>]

On 5/19/20 11:39 AM, Darrick J. Wong wrote:
> On Mon, May 18, 2020 at 01:52:16PM -0500, Eric Sandeen wrote:
>> The only grace period which can be set in the kernel today is for id 0,
>> i.e. the default grace period for all users.  However, setting an
>> individual grace period is useful; for example:
>>
>>  Alice has a soft quota of 100 inodes, and a hard quota of 200 inodes
>>  Alice uses 150 inodes, and enters a short grace period
>>  Alice really needs to use those 150 inodes past the grace period
>>  The administrator extends Alice's grace period until next Monday
>>
>> vfs quota users such as ext4 can do this today, with setquota -T
> 
> Does setquota -T work on an XFS filesystem? 

With 

[PATCH] quota-tools: Set FS_DQ_TIMER_MASK for individual xfs grace times

it does.

> If so, does that mean that
> xfs had a functionality gap where the admin could extend someone's grace
> period on ext4 but trying the exact same command on xfs would do
> nothing?  Or would it at least error out?

The former; no error.  quota-tools didn't set the timer mask, so quotactl
wasn't set up to change it.  In addition, we ignored the change for id !=0.
 
>> To enable this for XFS, we simply move the timelimit assignment out
>> from under the (id == 0) test.  Default setting remains under (id == 0).
>> Note that this now is consistent with how we set warnings.
>>
>> (Userspace requires updates to enable this as well; xfs_quota needs to
>> parse new options, and setquota needs to set appropriate field flags.)
> 
> So ... xfs_quota simply never had the ability to do this, but what does
> "setquota needs to set appropriate field flags" mean exactly?

It means:

[PATCH] quota-tools: Set FS_DQ_TIMER_MASK for individual xfs grace times

+		if (flags & COMMIT_TIMES) /* indiv grace period */
+			xdqblk.d_fieldmask |= FS_DQ_TIMER_MASK;

-Eric