Re: [PATCH] aio: Do not return ERESTARTSYS as a result of AIO (v2)

[Jeff Moyer <jmoyer@redhat.com>]

Jan Kara <jack@suse.cz> writes:

> OCFS2 can return ERESTARTSYS from its write function when the process is
> signalled while waiting for a cluster lock (and the filesystem is mounted with
> intr mount option). Generally, it seems reasonable to allow filesystems to
> return this error code from its IO functions. As we must not leak ERESTARTSYS
> (and similar error codes) to userspace as a result of an AIO operation, we
> have to properly convert it to EINTR inside AIO code (restarting the syscall
> isn't really an option because other AIO could have been already submitted by
> the same io_submit syscall).

I had responded to your last posting with:

  This is a confusing problem description.  First, I'm assuming you
  actually experienced this, is that right?  Care to share the details of
  that?

The above paragraph I think you addressed.  I'm still curious about
this, though.  The submission path should be as non-blocking as
possible.  I guess you can't really get around locking, though.  Was the
problem witnessed when doing O_DIRECT or buffered AIO?

  Next, assuming we can get ERSTARTSYS and friends, it will be the return
  code of a single iocb (reaped via io_getevents), not the return code of
  the io_submit system call.  I'm not saying this is right, I'm just
  saying that your description of the problem is misleading.

That objection stands, but just warrants correcting the problem description.

Anyway, the code itself looks fine.  ;-)

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>