From: Christoph Hellwig <hch@infradead.org>
To: Kanchan Joshi <joshi.k@samsung.com>
Cc: Christoph Hellwig <hch@infradead.org>,
axboe@kernel.dk, viro@zeniv.linux.org.uk, bcrl@kvack.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-aio@kvack.org, io-uring@vger.kernel.org,
linux-block@vger.kernel.org, selvakuma.s1@samsung.com,
nj.shetty@samsung.com, javier.gonz@samsung.com
Subject: Re: [PATCH 0/3] zone-append support in aio and io-uring
Date: Fri, 19 Jun 2020 00:56:20 -0700 [thread overview]
Message-ID: <20200619075620.GA20581@infradead.org> (raw)
In-Reply-To: <20200618175258.GA4141152@test-zns>
On Thu, Jun 18, 2020 at 11:22:58PM +0530, Kanchan Joshi wrote:
> I was thinking of raw block-access to zone device rather than pristine file
> abstraction.
Why?
> And in that context, semantics, at this point, are unchanged
> (i.e. same as direct writes) while flexibility of async-interface gets
> added.
> Synchronous-writes on single-zone sound fine, but synchronous-appends on
> single-zone do not sound that fine.
Where does synchronous access come into play?
> > What could be a useful addition is a way for O_APPEND/RWF_APPEND writes
> > to report where they actually wrote, as that comes close to Zone Append
> > while still making sense at our usual abstraction level for file I/O.
>
> Thanks for suggesting this. O and RWF_APPEND may not go well with block
> access as end-of-file will be picked from dev inode.
No, but they go really well with zonefs.
> But perhaps a new
> flag like RWF_ZONE_APPEND can help to transform writes (aio or uring)
> into append without introducing new opcodes.
I don't think this is a good idea. Zones are a concept for a a very
specific class of zoned devices. Trying to shoe-horn this into the
byte address files / whole device abstraction not only is ugly
conceptually but also adds the overhead for it to the VFS.
And O_APPEND that returns the written position OTOH makes total sense
at the file level as well and not just for raw zoned devices.
next prev parent reply other threads:[~2020-06-19 7:56 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200617172653epcas5p488de50090415eb802e62acc0e23d8812@epcas5p4.samsung.com>
2020-06-17 17:23 ` [PATCH 0/3] zone-append support in aio and io-uring Kanchan Joshi
[not found] ` <CGME20200617172702epcas5p4dbf4729d31d9a85ab1d261d04f238e61@epcas5p4.samsung.com>
2020-06-17 17:23 ` [PATCH 1/3] fs,block: Introduce IOCB_ZONE_APPEND and direct-io handling Kanchan Joshi
2020-06-17 19:02 ` Pavel Begunkov
2020-06-18 7:16 ` Damien Le Moal
2020-06-18 18:35 ` Kanchan Joshi
[not found] ` <CGME20200617172706epcas5p4dcbc164063f58bad95b211b9d6dfbfa9@epcas5p4.samsung.com>
2020-06-17 17:23 ` [PATCH 2/3] aio: add support for zone-append Kanchan Joshi
2020-06-18 7:33 ` Damien Le Moal
[not found] ` <CGME20200617172713epcas5p352f2907a12bd4ee3c97be1c7d8e1569e@epcas5p3.samsung.com>
2020-06-17 17:23 ` [PATCH 3/3] io_uring: " Kanchan Joshi
2020-06-17 18:55 ` Pavel Begunkov
2020-06-18 7:39 ` Damien Le Moal
2020-06-18 8:35 ` javier.gonz@samsung.com
2020-06-18 8:47 ` Damien Le Moal
2020-06-18 9:11 ` javier.gonz@samsung.com
2020-06-19 9:41 ` javier.gonz@samsung.com
2020-06-19 11:15 ` Matias Bjørling
2020-06-19 14:18 ` Jens Axboe
2020-06-19 15:14 ` Matias Bjørling
2020-06-19 15:20 ` Jens Axboe
2020-06-19 15:40 ` Matias Bjørling
2020-06-19 15:44 ` Jens Axboe
2020-06-21 18:55 ` javier.gonz@samsung.com
2020-06-19 14:15 ` Jens Axboe
2020-06-19 14:59 ` Pavel Begunkov
2020-06-19 15:02 ` Jens Axboe
2020-06-21 18:52 ` javier.gonz@samsung.com
2020-06-17 17:42 ` [PATCH 0/3] zone-append support in aio and io-uring Matthew Wilcox
2020-06-18 6:56 ` Christoph Hellwig
2020-06-18 8:29 ` Javier González
2020-06-18 17:52 ` Kanchan Joshi
2020-06-19 3:08 ` Damien Le Moal
2020-06-19 7:56 ` Christoph Hellwig [this message]
2020-06-18 8:04 ` Matias Bjørling
2020-06-18 8:27 ` Javier González
2020-06-18 8:32 ` Matias Bjørling
2020-06-18 8:39 ` Javier González
2020-06-18 8:46 ` Matias Bjørling
2020-06-18 14:16 ` Christoph Hellwig
2020-06-18 19:21 ` Kanchan Joshi
2020-06-18 20:04 ` Matias Bjørling
2020-06-19 1:03 ` Damien Le Moal
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