> On 2010-03-25, at 21:38,
tytso@mit.edu wrote:
>> On Fri, Mar 26, 2010 at 01:47:38AM +0100, Jan Kara wrote:
>>> This is definitely a move in the right direction. I'd be even
>>> happier
>>> if e2fsck would write quota file directly - then we could just make
>>> quota files hidden inodes, start doing quota accounting immediately
>>> on mount and always do quota journaling. That would save us quite
>>> some
>>> trouble in kernel. The only problem with this is that we'd need to
>>> pull
>>> knowledge about quota formats in e2fsck...
>
> I totally agree. Having to run quotacheck when the quota is journaled
> is a major time waster on a large filesystem. This is doubly true
> since the only time the journal should ever get inconsistent is when
> e2fsck changes it.
>
>> Yes, quite possibly. How quota is currently is set up is quite
>> kludgy, with magic options that do nothing but display magic options
>> in /proc/mounts, just in case that's a hard link to /etc/mtab. It
>> also looks like that some of the magic is in various distribution's
>> init.d scripts, and so while I very much want to clean things up, it
>> wasn't clear to me how much flexibility we would have without worrying
>> about breaking the init scripts for Debian, Ubuntu, RHEL, SLES,
>> Fedora, Open SuSE, etc.
>>
>> There may also be other programs that depend on the existence of
>> aquota.user, and may be reading and writing them in various random
>> ways, and there is the question of how do we provide compatibility
>> with these other programs, some of which may not be within quotatools,
>> but in various magic virtualization or container or cluster management
>> systems....
>
> If the quota file is already present as a regular file, I don't think
> it would be terrible to leave it in place, but to create new quota
> files as hidden files.
> It also would be nice to always enable quota journaing in ext4, since
> I don't think this does any harm, and if quotacheck isn't run then at
> least there a good chance the quotas are still correct.
>
>> So maintaining compatibility between older kernels, newer kernels,
>> older init scripts, new init scripts, etc. may make changing the quota
>> system quite difficult. I would like to do as much cleanup as we can,
>> though.
>>
>> One question I have --- do we really have to support the 2 or 3
>> different quota variants? How many people/distributions are still
>> using the original old quota system? One thing that worries me is
>> that it looks like the old (non-journaled) quota system may be the
>> primary system still being used by Canonical and Debian... I really
>> do hope I'm wrong, but there are a bunch of HOWTO's that still people
>> to use usrquota and grpquota in /etc/fstab, and not the newer
>> usrjquota and grpjquota mount options.
>
> If there isn't a reason to continue using unjournaled quota (i.e. it
> doesn't break to just move to journaled quota everywhere), then these
> could just become aliases for the journaled quota implementation. The
> other alternative is to deprecate these options in the next kernel and
> have it print out a warning on the console to tell the user to switch
> over to the journaled version.
