Re: Long running ioctl and pm, which should have higher priority?

[Askar Safin <safinaskar@gmail.com>]

Qu Wenruo <quwenruo.btrfs@gmx.com>:
> But there is a question concerning me, which should have the higher 
> priority? The long running ioctl or pm?

Of course, pm.

I have a huge btrfs fs on a laptop.

I don't want scrub to prevent suspend, even if that suspend is happening
automatically.

> Furthermore the interruption may be indistinguishable between pm and 
> real user signals (SIGINT etc).

If we interrupted because of signal, ioctl should return EINTR. This is
what all other syscalls do.

If we were cancelled, we should return ECANCELED.

If we interrupted because of process freeze or fs freeze, then... I
don't know what we should do in this case, but definitely not ECANCELED
(because we are not cancelled). EINTR will go, or maybe something else
(EAGAIN?).

Then, userspace program "btrfs scrub" can resume process if it
got EINTR. (But this is totally unimportant for me.)

Also, please CC me when sending any emails about this scrub/trim bug.

-- 
Askar Safin