Re: [PATCH] lock_page() doesn't lock if __wait_on_bit_lock returns -EINTR

[Chris Mason <clm@fb.com>]

On Sat, Dec 12, 2015 at 11:41:26AM -0800, Linus Torvalds wrote:
> On Sat, Dec 12, 2015 at 10:33 AM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > Peter, did that patch also handle just plain "lock_page()" case?
> 
> Looking more at it, I think this all goes back to commit 743162013d40
> ("sched: Remove proliferation of wait_on_bit() action functions").
> 
> It looks like PeterZ's pending patch should fix this, by passing in
> the proper TASK_UNINTERRUPTIBLE to the bit_wait_io function, and going
> back to signal_pending_state(). PeterZ, did I follow the history of
> this correctly?

Looks right to me, I found Peter's patch and have it running now. After
about 6 hours my patch did eventually crash again under trinity.  Btrfs has a
very old (from 2011) bug in the error handling path that trinity is
banging on.

Doing another run with Peter's patch and btrfs fixed up.  The btrfs patch is
small, but not urgent enough to shove in on Sunday.  I'll send for rc6
along with a few others we've queued up.

-chris