Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
To: "hch@infradead.org" <hch@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>,
	Damien Le Moal <Damien.LeMoal@wdc.com>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	Jens Axboe <axboe@kernel.dk>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Subject: Re: [PATCH 2/2] zonefs: use zone-append for AIO as well
Date: Wed, 22 Jul 2020 12:43:21 +0000	[thread overview]
Message-ID: <SN4PR0401MB3598536959BFAE08AA8DA8AD9B790@SN4PR0401MB3598.namprd04.prod.outlook.com> (raw)
In-Reply-To: <20200721055410.GA18032@infradead.org>

On 21/07/2020 07:54, Christoph Hellwig wrote:
> On Mon, Jul 20, 2020 at 04:48:50PM +0000, Johannes Thumshirn wrote:
>> On 20/07/2020 15:45, Christoph Hellwig wrote:
>>> On Mon, Jul 20, 2020 at 10:21:18PM +0900, Johannes Thumshirn wrote:
>>>> On a successful completion, the position the data is written to is
>>>> returned via AIO's res2 field to the calling application.
>>>
>>> That is a major, and except for this changelog, undocumented ABI
>>> change.  We had the whole discussion about reporting append results
>>> in a few threads and the issues with that in io_uring.  So let's
>>> have that discussion there and don't mix it up with how zonefs
>>> writes data.  Without that a lot of the boilerplate code should
>>> also go away.
>>>
>>
>> OK maybe I didn't remember correctly, but wasn't this all around 
>> io_uring and how we'd report the location back for raw block device
>> access?
> 
> Report the write offset.  The author seems to be hell bent on making
> it block device specific, but that is a horrible idea as it is just
> as useful for normal file systems (or zonefs).

After having looked into io_uring I don't this there is anything that
prevents io_uring from picking up the write offset from ki_complete's
res2 argument. As of now io_uring ignores the filed but that can be 
changed.

The reporting of the write offset to user-space still needs to be 
decided on from an io_uring PoV.

So the only thing that needs to be done from a zonefs perspective is 
documenting the use of res2 and CC linux-aio and linux-abi (including
an update of the io_getevents man page).

Or am I completely off track now?

Thanks,
	Johannes

  reply	other threads:[~2020-07-22 12:43 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-20 13:21 [PATCH 0/2] zonefs: use zone-append for aio with rwf append Johannes Thumshirn
2020-07-20 13:21 ` [PATCH 1/2] fs: fix kiocb ki_complete interface Johannes Thumshirn
2020-07-20 13:38   ` Christoph Hellwig
2020-07-20 13:43     ` Damien Le Moal
2020-07-20 13:47       ` Christoph Hellwig
2020-07-20 13:21 ` [PATCH 2/2] zonefs: use zone-append for AIO as well Johannes Thumshirn
2020-07-20 13:45   ` Christoph Hellwig
2020-07-20 16:48     ` Johannes Thumshirn
2020-07-21  5:54       ` Christoph Hellwig
2020-07-22 12:43         ` Johannes Thumshirn [this message]
2020-07-22 13:02           ` Damien Le Moal
2020-07-22 14:53             ` Christoph Hellwig
2020-07-22 14:51           ` Christoph Hellwig
2020-07-22 15:00             ` Johannes Thumshirn
2020-07-24 13:57             ` Kanchan Joshi
2020-07-27  3:12               ` Damien Le Moal
2020-07-21 12:43   ` Kanchan Joshi
2020-07-22 14:32     ` Johannes Thumshirn

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=SN4PR0401MB3598536959BFAE08AA8DA8AD9B790@SN4PR0401MB3598.namprd04.prod.outlook.com \
    --to=johannes.thumshirn@wdc.com \
    --cc=Damien.LeMoal@wdc.com \
    --cc=axboe@kernel.dk \
    --cc=hch@infradead.org \
    --cc=hch@lst.de \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --subject='Re: [PATCH 2/2] zonefs: use zone-append for AIO as well' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).