From: Ian Kent <raven@themaw.net>
To: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: autofs@linux.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [RFC PATCH]autofs4: hang and proposed fix
Date: Wed, 30 Nov 2005 23:44:34 +0800 (WST) [thread overview]
Message-ID: <Pine.LNX.4.63.0511302334390.2069@donald.themaw.net> (raw)
In-Reply-To: <1133331286.8195.29.camel@lade.trondhjem.org>
On Wed, 30 Nov 2005, Trond Myklebust wrote:
> On Tue, 2005-11-29 at 23:15 -0500, Jeff Moyer wrote:
>
> > The patch only drops the semaphore if d_lookup finds the dentry and the
> > dentry has a revalidate routine. I don't follow how you can end up with
> > multiple dentries for the same file in this case.
> >
> > Sorry if I'm missing something obvious.
>
> The inode->i_sem is what ensures that nobody can insert a new dentry
> between the lookup of the cached dentry by d_lookup() and the call to
> ->lookup() (which instantiates a new dentry).
>
> Imagine you have two separate processes that are doing a __lookup_hash()
> of the same cached dentry. Now imagine that d_revalidate() of the dentry
> fails.
And that would be why lookup is only called if d_lookup fails in do_lookup
when called from the link_path_walk routine. Do you think it is possible
to do this safely in __lookup_hash with a similar re-ordering?
Ian
next prev parent reply other threads:[~2005-11-30 15:44 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-16 10:17 [RFC PATCH]autofs4: hang and proposed fix Ram Pai
2005-11-16 12:41 ` [autofs] " Ian Kent
2005-11-16 16:50 ` Ram Pai
2005-11-16 22:57 ` Ian Kent
2005-11-17 1:52 ` [autofs] " Ram Pai
2005-11-17 18:50 ` Ian Kent
2005-11-17 19:19 ` William H. Taber
2005-11-17 20:39 ` Ram Pai
2005-11-17 22:31 ` William H. Taber
2005-11-18 14:57 ` Ian Kent
2005-11-18 14:54 ` Ian Kent
2005-11-18 14:44 ` Ian Kent
2005-11-18 15:20 ` William H. Taber
2005-11-18 16:30 ` Ian Kent
2005-11-18 17:12 ` William H. Taber
2005-11-18 18:57 ` Ram Pai
2005-11-18 20:08 ` William H. Taber
2005-11-19 2:52 ` Ian Kent
2005-11-21 16:40 ` William H. Taber
2005-11-22 13:13 ` Ian Kent
2005-11-22 17:48 ` [autofs] " William H. Taber
2005-11-23 14:11 ` Ian Kent
2005-11-23 16:42 ` William H. Taber
2005-11-23 17:52 ` Ian Kent
2005-11-23 18:47 ` William H. Taber
2005-11-23 17:52 ` Ian Kent
2005-11-19 1:40 ` [autofs] " Ian Kent
2005-11-16 15:22 ` Jeff Moyer
2005-11-16 15:22 ` Jeff Moyer
2005-11-16 17:00 ` [autofs] " Ram Pai
2005-11-16 18:25 ` Jeff Moyer
2005-11-16 19:24 ` William H. Taber
2005-11-16 19:51 ` Ram Pai
2005-11-27 10:47 ` Ian Kent
2005-11-28 17:19 ` William H. Taber
2005-11-28 23:12 ` Badari Pulavarty
2005-11-29 14:19 ` Ian Kent
2005-11-29 16:34 ` William H. Taber
2005-11-30 14:02 ` Ian Kent
2005-11-30 16:49 ` Badari Pulavarty
2005-11-30 17:04 ` Trond Myklebust
2005-11-30 21:10 ` William H. Taber
2005-11-29 14:20 ` Ian Kent
2005-11-30 1:16 ` [autofs] " Jeff Moyer
2005-11-30 1:16 ` Jeff Moyer
2005-11-30 1:56 ` Trond Myklebust
2005-11-30 4:15 ` Jeff Moyer
2005-11-30 6:14 ` Trond Myklebust
2005-11-30 15:44 ` Ian Kent [this message]
2005-11-30 15:53 ` Trond Myklebust
2005-11-30 16:12 ` Ian Kent
2005-11-30 16:27 ` Ian Kent
2005-11-30 16:45 ` [autofs] " Trond Myklebust
2005-11-30 20:32 ` William H. Taber
2005-11-30 20:53 ` Trond Myklebust
2005-11-30 21:30 ` William H. Taber
2005-11-30 22:32 ` Trond Myklebust
2005-12-01 16:27 ` William H. Taber
2005-12-01 12:09 ` Ian Kent
2005-12-01 16:30 ` William H. Taber
2005-12-02 13:49 ` Ian Kent
2005-12-02 14:07 ` Jeff Moyer
2005-12-02 15:21 ` Ian Kent
2005-12-02 16:35 ` [autofs] " Will Taber
2005-12-02 17:11 ` Ian Kent
2005-12-02 15:34 ` Will Taber
2005-12-02 17:29 ` Ian Kent
2005-12-02 18:12 ` Trond Myklebust
2005-12-04 12:56 ` Christoph Hellwig
2005-12-04 12:57 ` Christoph Hellwig
2005-12-04 14:58 ` Ian Kent
2005-12-04 17:17 ` [autofs] " Christoph Hellwig
2005-12-05 14:02 ` Ian Kent
2005-12-06 21:20 ` Jeff Moyer
2005-12-06 21:40 ` Christoph Hellwig
2005-12-06 22:37 ` Jeff Moyer
2005-12-07 14:52 ` Will Taber
2005-12-07 15:18 ` Christoph Hellwig
2005-12-07 15:22 ` Brian Long
2005-12-07 15:25 ` Christoph Hellwig
2005-12-07 17:46 ` Will Taber
2005-12-08 14:16 ` Ian Kent
2005-12-09 12:12 ` Christoph Hellwig
2005-12-09 13:33 ` John T. Kohl
2005-12-13 18:39 ` Christoph Hellwig
2005-12-04 14:56 ` Ian Kent
2005-12-02 19:04 ` [autofs] " Will Taber
2005-12-04 9:39 ` Ian Kent
2005-12-02 16:04 ` [autofs] " Jeff Moyer
2005-12-02 17:36 ` Ian Kent
2005-12-02 18:33 ` [autofs] " Will Taber
2005-12-04 9:52 ` Ian Kent
2005-12-04 14:54 ` Ian Kent
2005-12-05 15:40 ` Ian Kent
2005-11-30 14:48 ` [autofs] " Ian Kent
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=Pine.LNX.4.63.0511302334390.2069@donald.themaw.net \
--to=raven@themaw.net \
--cc=autofs@linux.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=trond.myklebust@fys.uio.no \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.