Messages in this thread | | | Subject | Re: [PATCH 0/23] File descriptor hot-unplug support v2 | From | Miklos Szeredi <> | Date | Tue, 09 Jun 2009 07:50:38 +0200 |
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On Mon, 8 Jun 2009, Al Viro wrote: > On Mon, Jun 08, 2009 at 06:44:41PM +0200, Miklos Szeredi wrote: > > > I'm still not getting what the problem is. AFAICS file operations are > > either > > > > a) non-interruptible but finish within a short time or > > b) may block indefinitely but are interruptible (or at least killable). > > > > Anything else is already problematic, resulting in processes "stuck in > > D state". > > Welcome to reality... > > * bread() is non-interruptible > * so's copy_from_user()/copy_to_user()
And why should revoke(2) care? Just wait for the damn thing to finish. Why exactly do these need to be interruptible?
Okay, if we want revoke or umount -f to be instantaneous then all that needs to be taken care of. But does it *need* to be?
My idea of revoke is something like below:
- make sure no new operations are started on the file - check state of tasks for ongoing operations, if interruptible send signal - wait for all pending operations to finish - kill file
Thanks, Miklos
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