Re: OOM & [OT] util-linux-2.12e

Herbert Poetzl
2004-09-21T09:18:47Z

On Tue, Sep 21, 2004 at 09:20:04AM +0200, Helge Hafting wrote:
> Herbert Poetzl wrote:
>
> >On Mon, Sep 20, 2004 at 03:32:59PM +0200, Helge Hafting wrote:
> >
> >>Olaf Hering wrote:
> >>
> >>>On Mon, Sep 20, Helge Hafting wrote:
> >>>
> >>>>Using a mtab that is a link to /proc/mounts fails with quota too.
> >>>>Quta tools read /etc/mtab looking for "usrquota" and or "grpquota"
> >>>>mount options. These appear in a normal /etc/mtab but not in
> >>>>/proc/mounts,
> >>>>
> >>>I have never played with quota. But: does the kernel or a userland tool
> >>>if quota is active for a mount point? smells like a kernel bug.
> >
> >- to make the quota active (enable it), the mount option
> > is required
> >
> >- to display an enabled quota as mount option, the quota
> > on that 'mount point' has to be enabled
> >
> >chicken egg thing, eh?
> >
> Chicken egg by design perhaps, but I can't see
> why it have to be that way.
>
> >besides that, not every mountpoint can support quota
> >and quota should (must) not be enabled at mount time
> >because before the quota is enabled, the quota hash
> >has to be initialized to the current usage ...
> >
> >
> A better way:
> Enable the quota at mount time. If the system isn't ready
> for that, i.e. the quota files aren't created/updated - then
> refuse the mount. (Alternatively, mount without quota and
> log a complaint.) The administrator can then mount
> without quota, run checkquota, and mount /fs -o remount,usrquota
> to turn quota on.
>
> In other words:
> quotaon becomes mount -o remount,usrquota
> quotaoff becomes mount -o remount,nousrquota
> (And/or grpquota of course)
>
> Does it have to be any more complicated than that?

probably not, but I guess you have to discuss
this with the quota maintainer ... ;)

best,
Herbert

> >>Doing it at mount time instead, byt actually using those options,
> >>seems saner to me. But I guess they had their reasons. . .
> >
> >yes, quota calculation, see above ...
> >
> What I don't get is why we have to mount with quota options
> that aren't acutally used, and then turn quota on.
> Why not mount without quota, and then remount with
> quota options when enabling quota for the first time?
>
> The common case should be a fs that was shut down
> cleanly and was mounted with quota the last time it
> was used. So it should be able to mount directly
> with quota on, because all the on-disk quota information
> is valid and up to date.
>
> Helge Hafting
>