From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>,
"Ober, Frank" <frank.ober@intel.com>,
"linux-xfs@vger.kernel.org" <linux-xfs@vger.kernel.org>
Subject: Re: write atomicity with xfs ... current status?
Date: Wed, 18 Mar 2020 00:54:24 -0700 [thread overview]
Message-ID: <20200318075424.GA24276@infradead.org> (raw)
In-Reply-To: <20200317225505.GU10776@dread.disaster.area>
On Wed, Mar 18, 2020 at 09:55:05AM +1100, Dave Chinner wrote:
> > That being said while I had a prototype to use the NVMe atomic write
> > size I will never submit that to mainline in that paticular form.
> >
> > NVMe does not have any flag to force atomic writes, thus a too large
> > or misaligned write will be executed by the device withour errors.
> > That kind of interface is way too fragile to be used in production.
>
> I didn't realise that the NVMe standard had such a glaring flaw.
> That basically makes atomic writes useless for anything that
> actually requires atomicity. Has the standard been fixed yet?
No.
> And
> does this means that hardware with usable atomic writes is still
> years away?
At least for the hardware I'm familiar with checking a flag and failing
it if the conditions are not met might be a relatively simple firmware
fix. It just needs a big enough customer to ask for, not just some
Linux developers.
prev parent reply other threads:[~2020-03-18 7:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-16 20:59 write atomicity with xfs ... current status? Ober, Frank
2020-03-16 21:59 ` Darrick J. Wong
2020-03-16 23:32 ` Dave Chinner
2020-03-17 22:56 ` Ober, Frank
2020-03-18 2:27 ` Dave Chinner
2020-03-18 8:00 ` Christoph Hellwig
2020-03-19 1:07 ` Ober, Frank
2020-03-17 19:19 ` Christoph Hellwig
2020-03-17 22:55 ` Dave Chinner
2020-03-18 7:54 ` Christoph Hellwig [this message]
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