From: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Nicholas Piggin <npiggin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Yumei Huang <yuhuang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Michal Hocko <mhocko-IBi9RG/b67k@public.gmane.org>,
Xiao Guangrong
<guangrong.xiao-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
KVM list <kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Dave Hansen <dave.hansen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Gleb Natapov <gleb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
"linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org"
<linux-nvdimm-y27Ovi1pjclAfugRpC6u6w@public.gmane.org>,
mtosatti-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
Linux MM <linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org>,
Stefan Hajnoczi
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linux-fsdevel
<linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Paolo Bonzini <pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Subject: Re: DAX mapping detection (was: Re: [PATCH] Fix region lost in /proc/self/smaps)
Date: Mon, 12 Sep 2016 08:01:48 -0700 [thread overview]
Message-ID: <20160912150148.GA10039@infradead.org> (raw)
In-Reply-To: <20160912180507.533b3549-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>
On Mon, Sep 12, 2016 at 06:05:07PM +1000, Nicholas Piggin wrote:
> It's not fundamentally broken, it just doesn't fit well existing
> filesystems.
Or the existing file system architecture for that matter. Which makes
it a fundamentally broken model.
> Dave's post of requirements is also wrong. A filesystem does not have
> to guarantee all that, it only has to guarantee that is the case for
> a given block after it has a mapping and page fault returns, other
> operations can be supported by invalidating mappings, etc.
Which doesn't really matter if your use case is manipulating
fully mapped files.
But back to the point: if you want to use a full blown Linux or Unix
filesystem you will always have to fsync (or variants of it like msync),
period.
If you want a volume manager on stereoids that hands out large chunks
of storage memory that can't ever be moved, truncated, shared, allocated
on demand, etc - implement it in your library on top of a device file.
next prev parent reply other threads:[~2016-09-12 15:01 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-08 4:32 DAX mapping detection (was: Re: [PATCH] Fix region lost in /proc/self/smaps) Dan Williams
[not found] ` <CAPcyv4iDra+mRqEejfGqapKEAFZmUtUcg0dsJ8nt7mOhcT-Qpw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-09-08 22:56 ` Ross Zwisler
2016-09-08 23:04 ` Dan Williams
2016-09-09 8:55 ` Xiao Guangrong
2016-09-09 15:40 ` Dan Williams
[not found] ` <CAPcyv4ibiZG3SkW0TZywn8Qovo3hpxBqs4wCfw1DFEbbE=1-Mg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-09-12 6:00 ` Xiao Guangrong
2016-09-12 3:44 ` Rudoff, Andy
2016-09-12 6:31 ` Xiao Guangrong
[not found] ` <20160908225636.GB15167-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2016-09-12 1:40 ` Dave Chinner
2016-09-15 5:55 ` Darrick J. Wong
2016-09-15 6:25 ` Dave Chinner
2016-09-12 5:27 ` Christoph Hellwig
2016-09-12 7:25 ` Oliver O'Halloran
2016-09-12 7:51 ` Christoph Hellwig
2016-09-12 8:05 ` Nicholas Piggin
[not found] ` <20160912180507.533b3549-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>
2016-09-12 15:01 ` Christoph Hellwig [this message]
[not found] ` <20160912150148.GA10039-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2016-09-13 1:31 ` Nicholas Piggin
2016-09-13 4:06 ` Dan Williams
2016-09-13 5:40 ` Nicholas Piggin
2016-09-12 21:34 ` Dave Chinner
2016-09-13 1:53 ` Nicholas Piggin
2016-09-13 7:17 ` Christoph Hellwig
[not found] ` <20160913071732.GA19433-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2016-09-13 9:06 ` Nicholas Piggin
[not found] ` <20160913115311.509101b0-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>
2016-09-14 7:39 ` Dave Chinner
2016-09-14 10:19 ` Nicholas Piggin
[not found] ` <20160914201936.08315277-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>
2016-09-15 2:31 ` Dave Chinner
2016-09-15 3:49 ` Nicholas Piggin
[not found] ` <20160915134945.0aaa4f5a-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>
2016-09-15 10:32 ` Dave Chinner
2016-09-15 11:42 ` Nicholas Piggin
[not found] ` <20160915214222.505f4888-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>
2016-09-15 22:33 ` Dave Chinner
2016-09-16 5:54 ` Nicholas Piggin
[not found] ` <20160916155405.6b634bbc-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>
2016-12-19 21:11 ` Ross Zwisler
[not found] ` <20161219211149.GA12822-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2016-12-20 1:09 ` Darrick J. Wong
2016-12-20 1:18 ` Dan Williams
[not found] ` <CAPcyv4g6LVTVrtGz+vdV2bLvskrYrCBss80qB-HtjAE+Sae=UA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-12-21 0:40 ` Darrick J. Wong
[not found] ` <20161221004031.GF9865-PTl6brltDGh4DFYR7WNSRA@public.gmane.org>
2016-12-21 16:53 ` Dan Williams
2016-12-21 21:24 ` Dave Chinner
2016-12-21 21:33 ` Dan Williams
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