From: Christoph Hellwig <hch@infradead.org>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: linux-kernel@vger.kernel.org, chris.mason@oracle.com,
linux-fsdevel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH][RFC] fast file mapping for loop
Date: Wed, 9 Jan 2008 09:31:07 +0000 [thread overview]
Message-ID: <20080109093107.GA5023@infradead.org> (raw)
In-Reply-To: <20080109085231.GE6650@kernel.dk>
On Wed, Jan 09, 2008 at 09:52:32AM +0100, Jens Axboe wrote:
> - The file block mappings must not change while loop is using the file.
> This means that we have to ensure exclusive access to the file and
> this is the bit that is currently missing in the implementation. It
> would be nice if we could just do this via open(), ideas welcome...
And the way this is done is simply broken. It means you have to get
rid of things like delayed or unwritten hands beforehand, it'll be
a complete pain for COW or non-block backed filesystems.
The right way to do this is to allow direct I/O from kernel sources
where the filesystem is in-charge of submitting the actual I/O after
the pages are handed to it. I think Peter Zijlstra has been looking
into something like that for swap over nfs.
next prev parent reply other threads:[~2008-01-09 9:31 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-09 8:52 [PATCH][RFC] fast file mapping for loop Jens Axboe
2008-01-09 9:31 ` Christoph Hellwig [this message]
2008-01-09 9:43 ` Jens Axboe
2008-01-09 11:00 ` Chris Mason
2008-01-09 15:34 ` Andi Kleen
2008-01-10 8:43 ` Jens Axboe
2008-01-09 23:16 ` Alasdair G Kergon
2008-01-10 8:31 ` Jens Axboe
2008-01-10 8:42 ` Jens Axboe
2008-01-11 7:39 ` Mikulas Patocka
2008-01-11 7:58 ` Jens Axboe
2008-01-10 12:47 ` Chris Mason
2008-01-10 12:57 ` Jens Axboe
2008-01-10 23:01 ` Neil Brown
2008-01-11 14:21 ` Chris Mason
2008-01-10 1:42 ` Nick Piggin
2008-01-10 8:34 ` Jens Axboe
2008-01-10 8:37 ` Christoph Hellwig
2008-01-10 8:44 ` Jens Axboe
2008-01-10 8:54 ` Christoph Hellwig
2008-01-10 9:01 ` Jens Axboe
2008-01-10 12:53 ` Chris Mason
2008-01-10 13:03 ` Jens Axboe
2008-01-10 13:46 ` Chris Mason
2008-01-10 9:37 ` Peter Zijlstra
2008-01-10 9:49 ` Jens Axboe
2008-01-10 9:52 ` Peter Zijlstra
2008-01-10 10:02 ` Jens Axboe
2008-01-10 10:20 ` Peter Zijlstra
2008-01-11 1:25 ` Bill Davidsen
2008-01-11 18:17 ` Daniel Phillips
2008-01-11 18:23 ` Jens Axboe
2008-01-14 17:10 ` Chris Mason
2008-01-14 17:54 ` Jens Axboe
2008-01-15 9:25 ` Jens Axboe
2008-01-15 9:36 ` Jens Axboe
2008-01-15 10:07 ` Jens Axboe
2008-01-15 14:04 ` Chris Mason
[not found] <95637914@web.de>
2008-01-09 23:53 ` Alasdair G Kergon
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=20080109093107.GA5023@infradead.org \
--to=hch@infradead.org \
--cc=chris.mason@oracle.com \
--cc=jens.axboe@oracle.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).