From: David Howells <dhowells@redhat.com>
To: miklos@szeredi.hu, Linus Torvalds <torvalds@linux-foundation.org>
Cc: dhowells@redhat.com, "Myklebust,
Trond" <Trond.Myklebust@netapp.com>,
Jeff Layton <jlayton@redhat.com>,
viro@zeniv.linux.org.uk, gregkh@suse.de,
linux-nfs@vger.kernel.org, leonardo.lists@gmail.com
Subject: Re: [PATCH] VFS: Suppress automount on [l]stat, [l]getxattr, etc.
Date: Fri, 23 Sep 2011 11:33:45 +0100 [thread overview]
Message-ID: <21772.1316774025@redhat.com> (raw)
In-Reply-To: <1316747758.3346.89.camel@perseus.themaw.net>
Ian Kent <raven@themaw.net> wrote:
> But the other users of the vfs-automount didn't behave this way before
> the vfs-automount changes.
That's a very good point. Prior to my d_automount() patches, NFS, AFS and, I
think, CIFS used strict symlink rules for when to automount because the
automounting was done by a directory with a ->follow_link() op. Therefore,
stat() automounted and lstat() didn't.
Autofs, on the other hand took care to suppress automounting on stat() too.
My d_automount() patches had two purposes, in order of importance:
(1) Simplify the automount procedure in the kernel by giving it formal VFS
support, and thus getting rid of directories with follow_link() ops.
(2) Make the automount semantics consistent.
So my original patches are somewhat at fault here. I broke autofs's handling
of stat(), getxattr() and kept that of NFS, AFS and CIFS. Miklos's patch
simply flips the regression the other way.
The only fault I've had reported against my original patches in this respect is
with ls, and that's fixed in userspace upstream now (libacl was using getxattr
when it should've been using lgetxattr). It has been mentioned that nautilus
(I think it was) may also broken - which makes sense as it's a file manager.
The only fault I've had reported against Miklos's patch is the NFS4 pathwalk
during mount.
Having thought it over some more, I'm leaning towards reverting Miklos's patch,
removing the do we/don't we logic from follow_automount() (or simplifying it)
and having the syscalls suppy the LOOKUP_NO_AUTOMOUNT flag as appropriate -
whatever is meant by 'appropriate'.
I'm also okay with requiring userspace to be fixed up, but I can also see the
arguments against that.
David
next prev parent reply other threads:[~2011-09-23 10:34 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-22 13:45 [PATCH] VFS: Suppress automount on [l]stat, [l]getxattr, etc David Howells
2011-09-22 14:33 ` Miklos Szeredi
2011-09-22 16:04 ` Ian Kent
2011-09-22 16:30 ` Linus Torvalds
2011-09-22 16:45 ` Ian Kent
2011-09-22 17:35 ` Jeff Layton
2011-09-22 18:44 ` Jeff Layton
2011-09-22 19:20 ` Trond Myklebust
2011-09-22 22:57 ` Linus Torvalds
2011-09-23 0:56 ` Myklebust, Trond
2011-09-23 1:04 ` Linus Torvalds
2011-09-23 1:21 ` Trond Myklebust
2011-09-23 7:25 ` Miklos Szeredi
2011-09-23 10:57 ` Ian Kent
2011-09-23 3:15 ` Ian Kent
2011-09-23 10:33 ` David Howells [this message]
2011-09-23 14:34 ` Trond Myklebust
2011-09-23 14:46 ` Linus Torvalds
2011-09-23 15:01 ` Trond Myklebust
2011-09-23 15:15 ` Linus Torvalds
2011-09-23 15:41 ` Ian Kent
2011-09-23 16:19 ` Miklos Szeredi
2011-09-23 16:21 ` Linus Torvalds
2011-09-23 16:26 ` Linus Torvalds
[not found] ` <13920.1316796007@redhat.com! >
2011-09-23 16:54 ` David Howells
2011-09-23 17:18 ` Linus Torvalds
2011-09-23 16:40 ` David Howells
2011-09-23 16:47 ` Linus Torvalds
2011-09-23 15:18 ` David Howells
2011-09-23 16:10 ` Miklos Szeredi
2011-09-24 1:30 ` Ian Kent
2011-09-24 1:44 ` Linus Torvalds
2011-09-24 2:31 ` Ian Kent
2011-09-24 11:36 ` Jeff Layton
2011-09-24 15:56 ` Linus Torvalds
2011-09-26 5:11 ` Ian Kent
2011-09-26 20:48 ` Linus Torvalds
2011-09-26 21:13 ` Trond Myklebust
2011-09-26 21:24 ` Linus Torvalds
2011-09-26 21:31 ` Trond Myklebust
2011-09-26 22:24 ` Linus Torvalds
2011-09-26 22:33 ` Trond Myklebust
2011-09-26 22:56 ` Linus Torvalds
2011-09-26 23:09 ` Trond Myklebust
2011-09-26 23:26 ` Linus Torvalds
2011-09-27 0:59 ` Trond Myklebust
2011-09-27 1:18 ` Linus Torvalds
2011-09-27 4:24 ` Ian Kent
2011-09-27 3:57 ` Linus Torvalds
2011-09-27 4:16 ` Ian Kent
2011-09-27 4:35 ` Linus Torvalds
2011-09-27 4:51 ` Ian Kent
2011-09-27 14:32 ` Linus Torvalds
2011-09-27 15:11 ` Myklebust, Trond
2011-09-29 9:32 ` Ian Kent
2011-09-27 15:22 ` Linus Torvalds
2011-09-27 17:38 ` Greg KH
2011-09-27 17:51 ` Linus Torvalds
2011-09-27 18:00 ` Greg KH
2011-09-27 20:18 ` Miklos Szeredi
2011-09-27 22:38 ` Greg KH
2011-09-27 13:34 ` [PATCH 1/2] VFS: Fix the remaining automounter semantics regressions Trond Myklebust
2011-09-27 13:34 ` [PATCH 2/2] VFS: Document automounter semantics Trond Myklebust
2011-09-23 15:23 ` [PATCH] VFS: Suppress automount on [l]stat, [l]getxattr, etc David Howells
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=21772.1316774025@redhat.com \
--to=dhowells@redhat.com \
--cc=Trond.Myklebust@netapp.com \
--cc=gregkh@suse.de \
--cc=jlayton@redhat.com \
--cc=leonardo.lists@gmail.com \
--cc=linux-nfs@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=torvalds@linux-foundation.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 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.