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- -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
