Re: [PATCH v3 4/4] io_uring: add support for zone-append

Kanchan Joshi
2020-07-10T13:30:14Z

On Fri, Jul 10, 2020 at 6:39 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Thu, Jul 09, 2020 at 12:50:27PM -0600, Jens Axboe wrote:
> > It might, if you have IRQ context for the completion. task_work isn't
> > expensive, however. It's not like a thread offload.
> >
> > > Using flags have not been liked here, but given the upheaval involved so
> > > far I have begun to feel - it was keeping things simple. Should it be
> > > reconsidered?
> >
> > It's definitely worth considering, especially since we can use cflags
> > like Pavel suggested upfront and not need any extra storage. But it
> > brings us back to the 32-bit vs 64-bit discussion, and then using blocks
> > instead of bytes. Which isn't exactly super pretty.
>
> block doesn't work for the case of writes to files that don't have
> to be aligned in any way. And that I think is the more broadly
> applicable use case than zone append on block devices.

But when can it happen that we do zone-append on a file (zonefs I
asssume), and device returns a location (write-pointer essentially)
which is not in multiple of 512b?

--
Joshi