From: Simon Kirby <sim@hostway.ca>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: linux-nfs@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [3.6-rc3] rdirplus broken? (EBUSY)
Date: Wed, 12 Sep 2012 14:20:35 -0700 [thread overview]
Message-ID: <20120912212035.GB28555@hostway.ca> (raw)
In-Reply-To: <20120912121613.GC3009@fieldses.org>
On Wed, Sep 12, 2012 at 08:16:13AM -0400, J. Bruce Fields wrote:
> On Tue, Sep 11, 2012 at 12:25:23PM -0700, Simon Kirby wrote:
> > On Mon, Aug 27, 2012 at 02:55:10PM -0700, Simon Kirby wrote:
> >
> > > Something seems broiken in 3.6-rc[123] which was fine in 3.5 and earlier.
> > > This is a 3.4.1 knfsd server with ext3 and XFS-based NFS exports:
> > >
> > > / 192.168.13.0/24(rw,no_root_squash,no_subtree_check,async)
> > > /pics 192.168.13.0/24(rw,no_root_squash,no_subtree_check,async)
> > > /raid 192.168.13.0/24(rw,no_root_squash,no_subtree_check,async)
> > >
> > > and a 3.6-rc3 client with this in fstab:
> > >
> > > flick:/ /flick nfs rw,vers=3
> > > flick:/raid /flick/raid nfs rw,vers=3
> > > flick:/pics /flick/pics nfs rw,vers=3
> > >
> > > This seems to fail now as follows:
> > >
> > > [sroot@oof:/]# mount flick
> > > [sroot@oof:/]# mount flick/raid
> > > [sroot@oof:/]# mount flick/pics
> > > [sroot@oof:/]# ls -l flick
> > > ls: cannot access flick/pics: Device or resource busy
> > > ls: cannot access flick/raid: Device or resource busy
> > > total 2180
> > > drwxr-xr-x 45 root root 4096 Jun 18 14:19 ./
> > > drwxr-xr-x 58 root root 4096 Jul 3 22:24 ../
> > > ...
> > > ?????????? ? ? ? ? ? pics
> > > ?????????? ? ? ? ? ? raid
> > > ...
> > > [sroot@oof:/]# cd flick/pics
> > > flick/pics: Device or resource busy.
> > >
> > > These mount points are now stuck and cannot be unmounted until
> > > I reboot (umount -l fails with EBUSY).
> > >
> > > If I mount with "nordirplus", I can't seem to get it to break. However,
> > > sometimes it will work regardless. I can bisect this if it would help..
> >
> > This is still the case with 3.6-rc5. I hadn't noticed any problem since
> > mounting with nordirplus, and it broke immediately after removing the
> > option again. I will bisect.
>
> The symptoms sound similar to
> http://marc.info/?l=linux-fsdevel&m=134738157303017&w=2
>
> Might be worth checking whether it's that patch?
Indeed! I tried this hack:
diff --git a/fs/dcache.c b/fs/dcache.c
index 8086636..649a112 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2404,6 +2404,10 @@ out_unalias:
if (likely(!d_mountpoint(alias))) {
__d_move(alias, dentry);
ret = alias;
+ } else {
+ printk(KERN_WARNING "VFS: __d_move()ing a d_mountpoint(), uh oh\n");
+ __d_move(alias, dentry);
+ ret = alias;
}
out_err:
spin_unlock(&inode->i_lock);
With this applied, "ls -l flick" prints:
[ 77.217420] VFS: __d_move()ing a d_mountpoint(), uh oh
[ 77.222390] VFS: __d_move()ing a d_mountpoint(), uh oh
...and "pics" and "raid" then work as they did before, or with "nordirplus"
set. So, is something broken with nordirplus or the NFS layer, or should
__d_unalias() really move a mountpoint? With nordirplus, it works without
complaining about moving a mountpoint.
Simon-
next prev parent reply other threads:[~2012-09-12 21:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-27 21:55 [3.6-rc3] rdirplus broken? (EBUSY) Simon Kirby
2012-09-11 19:25 ` Simon Kirby
2012-09-12 12:16 ` J. Bruce Fields
2012-09-12 21:20 ` Simon Kirby [this message]
2012-09-20 0:13 ` Simon Kirby
2012-10-03 1:17 ` Simon Kirby
2013-08-27 15:33 ` J. Bruce Fields
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