Re: [patch] dax: pass NOWAIT flag to iomap_apply

[Jeff Moyer <jmoyer@redhat.com>]

Jan Kara <jack@suse.cz> writes:

> On Thu 06-02-20 09:33:39, Jeff Moyer wrote:
>> Jan Kara <jack@suse.cz> writes:
>> 
>> > On Wed 05-02-20 14:15:58, Jeff Moyer wrote:
>> >> fstests generic/471 reports a failure when run with MOUNT_OPTIONS="-o
>> >> dax".  The reason is that the initial pwrite to an empty file with the
>> >> RWF_NOWAIT flag set does not return -EAGAIN.  It turns out that
>> >> dax_iomap_rw doesn't pass that flag through to iomap_apply.
>> >> 
>> >> With this patch applied, generic/471 passes for me.
>> >> 
>> >> Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
>> >
>> > The patch looks good to me. You can add:
>> >
>> > Reviewed-by: Jan Kara <jack@suse.cz>
>> >
>> > BTW, I've just noticed ext4 seems to be buggy in this regard and even this
>> > patch doesn't fix it. So I guess you've been using XFS for testing this?
>> 
>> That's right, sorry I didn't mention that.  Will you send a patch for
>> ext4, or do you want me to look into it?
>
> I've taken down a note in todo list to eventually look into that but if you
> can have a look, I'm more than happy to remove that entry :).

OK, I'll take a look.

-Jeff