From: Pavel Machek <pavel@suse.cz>
To: Jamie Lokier <jamie@shareable.org>
Cc: andersen@codepoet.org, "Jörn Engel" <joern@wohnheim.fh-wedel.de>,
mj@ucw.cz, jack@ucw.cz,
"Patrick J. LoPresti" <patl@users.sourceforge.net>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cowlinks v2
Date: Sat, 3 Apr 2004 11:09:20 +0200 [thread overview]
Message-ID: <20040403090917.GD1316@elf.ucw.cz> (raw)
In-Reply-To: <20040403015920.GA2857@mail.shareable.org>
Hi!
> Erik Andersen wrote:
> > > Here's a tricky situation:
> > >
> > > 1. A file is cowlinked. Then each cowlink is mmap()'d, one per process.
> > >
> > > 2. At this point both mappings share the same pages in RAM.
> > >
> > > 3. Then one of the cowlinks is written to...
> >
> > Using mmap with PROT_WRITE on a cowlink must preemptively
> > break the link.
>
> I forget to mention, they are PROT_READ shared mappings.
I'm not mm guru, but... with rmap, we should be able to find all the
users of that shared memory, and unmap their pages, right?
Until copy is done, we don't do anything, because write is not allowed
to progress until copy is done. When copy is done we should unmap all
the pages that still point to "old" copy, let write progress, and make
users fault in.
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
next prev parent reply other threads:[~2004-04-03 9:09 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-20 8:34 [PATCH] cowlinks v2 Jörn Engel
2004-03-20 8:49 ` Andrew Morton
2004-03-20 11:27 ` Jörn Engel
2004-03-20 19:28 ` Andrew Morton
2004-03-21 12:43 ` Jörn Engel
2004-03-21 18:53 ` Jörn Engel
[not found] ` <mit.lcs.mail.linux-kernel/20040320083411.GA25934@wohnheim.fh-wedel.de>
2004-03-20 15:03 ` Patrick J. LoPresti
2004-03-20 15:23 ` Jörn Engel
2004-03-29 17:12 ` Pavel Machek
2004-03-29 21:05 ` Patrick J. LoPresti
2004-03-29 23:16 ` Pavel Machek
2004-03-31 14:34 ` Jamie Lokier
2004-03-31 14:45 ` Pavel Machek
2004-03-31 15:20 ` Jamie Lokier
2004-04-02 11:44 ` Tim Connors
2004-04-02 16:54 ` Jörn Engel
2004-04-02 18:01 ` Pavel Machek
2004-04-02 18:17 ` Jörn Engel
2004-04-02 18:23 ` Pavel Machek
2004-04-02 19:28 ` Ross Biro
2004-04-02 21:35 ` Pavel Machek
2004-04-05 8:12 ` Jörn Engel
2004-04-05 8:19 ` Pavel Machek
2004-04-05 8:45 ` Jörn Engel
2004-04-02 20:09 ` Jamie Lokier
2004-04-02 21:39 ` Pavel Machek
2004-04-02 22:00 ` Chris Friesen
2004-04-03 0:49 ` Jamie Lokier
2004-04-03 8:23 ` Pavel Machek
2004-04-03 13:15 ` Jamie Lokier
2004-04-05 8:19 ` Jörn Engel
2004-04-05 8:22 ` Pavel Machek
2004-04-03 0:46 ` Jamie Lokier
2004-04-03 1:04 ` Jamie Lokier
2004-04-03 1:21 ` Erik Andersen
2004-04-03 1:59 ` Jamie Lokier
2004-04-03 3:55 ` Ross Biro
2004-04-03 9:09 ` Pavel Machek [this message]
2004-04-03 13:27 ` Jamie Lokier
2004-04-03 18:39 ` Eric W. Biederman
2004-04-03 19:43 ` Jamie Lokier
2004-04-03 20:30 ` Eric W. Biederman
2004-04-03 21:59 ` Jamie Lokier
2004-04-04 8:15 ` Eric W. Biederman
2004-04-05 8:35 ` Jörn Engel
2004-04-05 9:15 ` Eric W. Biederman
2004-04-05 9:18 ` Jörn Engel
2004-04-05 11:43 ` Pavel Machek
2004-04-05 12:17 ` Jamie Lokier
2004-04-05 12:39 ` Jamie Lokier
2004-04-05 12:41 ` Jamie Lokier
2004-04-05 18:03 ` Jörn Engel
2004-04-05 11:10 ` jlnance
2004-04-05 11:46 ` Pavel Machek
2004-04-05 12:35 ` Jamie Lokier
2004-04-05 8:43 ` Jörn Engel
2004-04-03 19:47 ` Eric W. Biederman
2004-04-05 8:54 ` Jörn Engel
2004-04-05 9:07 ` Eric W. Biederman
2004-03-20 16:48 ` Davide Libenzi
2004-03-21 12:57 ` Jörn Engel
2004-03-21 17:59 ` Davide Libenzi
2004-03-21 18:14 ` Jörn Engel
2004-03-21 20:26 ` Davide Libenzi
2004-03-21 20:35 ` Jörn Engel
2004-03-22 0:18 ` Eric W. Biederman
2004-03-22 0:25 ` Davide Libenzi
2004-03-22 5:07 ` Eric W. Biederman
2004-03-22 5:11 ` Davide Libenzi
2004-03-22 11:20 ` Eric W. Biederman
2004-03-22 16:02 ` Davide Libenzi
2004-03-25 17:49 ` Jamie Lokier
2004-03-25 18:06 ` Eric W. Biederman
2004-03-25 19:43 ` Jamie Lokier
2004-03-25 20:38 ` Linus Torvalds
2004-03-25 22:16 ` Eric W. Biederman
2004-04-01 14:53 ` Jörn Engel
2004-04-02 11:54 ` Tim Connors
2004-03-25 21:46 ` Eric W. Biederman
2004-03-27 10:28 ` Jamie Lokier
2004-03-27 21:00 ` Eric W. Biederman
2004-03-27 21:42 ` Jamie Lokier
2004-03-27 23:45 ` Eric W. Biederman
2004-03-28 0:43 ` Eric W. Biederman
2004-03-28 12:22 ` Jamie Lokier
2004-03-28 20:07 ` Eric W. Biederman
2004-03-28 23:55 ` Jamie Lokier
2004-03-29 1:31 ` Eric W. Biederman
2004-03-29 12:36 ` Jamie Lokier
2004-03-29 19:36 ` Eric W. Biederman
2004-03-29 23:05 ` Jamie Lokier
2004-03-29 23:58 ` Eric W. Biederman
2004-03-29 7:45 ` Denis Vlasenko
2004-03-29 9:28 ` Pavel Machek
2004-03-29 12:40 ` Jamie Lokier
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=20040403090917.GD1316@elf.ucw.cz \
--to=pavel@suse.cz \
--cc=andersen@codepoet.org \
--cc=jack@ucw.cz \
--cc=jamie@shareable.org \
--cc=joern@wohnheim.fh-wedel.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mj@ucw.cz \
--cc=patl@users.sourceforge.net \
/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