From: Evgeniy Polyakov <zbr@ioremap.net>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [WTF] ... is going on with current->fs->{root,mnt} accesses in pohmelfs
Date: Wed, 10 Feb 2010 16:30:07 +0300 [thread overview]
Message-ID: <20100210133007.GA17744@ioremap.net> (raw)
In-Reply-To: <20100210115938.GO30031@ZenIV.linux.org.uk>
On Wed, Feb 10, 2010 at 11:59:39AM +0000, Al Viro (viro@ZenIV.linux.org.uk) wrote:
> > Let me guess... Mmmm, it was in the yesterday newspaper, I remember.
> > Maybe when we chroot somewhere. I meant not mounted fs root, but
> > thread's root.
>
> Why would a filesystem give a damn about the chroot of syscall originator
> in the first place?
That's the point - it is not needed.
> > > Why not use the dentries you've been given by VFS?
> >
> > At writeback we do not have parents, so must find a path somehow.
>
> Most of the places do have those just fine and unlike the writeback,
> rename et.al. really care which pathname is being dealt with...
POHMELFS uses writeback cache also for metadata, so effectively most of
such operations are also postponed. Later I turned that off though.
> BTW, what prevents writeback vs. rename races?
There are proper locks for such operations.
--
Evgeniy Polyakov
next prev parent reply other threads:[~2010-02-10 13:30 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-10 10:04 [WTF] ... is going on with current->fs->{root,mnt} accesses in pohmelfs Al Viro
2010-02-10 10:12 ` Evgeniy Polyakov
2010-02-10 10:24 ` Al Viro
2010-02-10 10:45 ` Evgeniy Polyakov
2010-02-10 11:00 ` Al Viro
2010-02-10 11:11 ` Evgeniy Polyakov
2010-02-10 11:59 ` Al Viro
2010-02-10 13:30 ` Evgeniy Polyakov [this message]
2010-02-10 21:02 ` Al Viro
2010-02-10 21:29 ` Evgeniy Polyakov
2010-02-11 3:02 ` Al Viro
2010-02-11 15:08 ` Evgeniy Polyakov
2010-02-11 17:10 ` Al Viro
2010-02-11 19:13 ` Evgeniy Polyakov
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=20100210133007.GA17744@ioremap.net \
--to=zbr@ioremap.net \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@ZenIV.linux.org.uk \
/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).