Re: what on earth is going on here? paths above mountpoints turn into "(unreachable)"

From: "J. Bruce Fields" <bfields@fieldses.org>
To: Nix <nix@esperi.org.uk>
Cc: NeilBrown <neilb@suse.de>, NFS list <linux-nfs@vger.kernel.org>
Subject: Re: what on earth is going on here? paths above mountpoints turn into "(unreachable)"
Date: Mon, 16 Feb 2015 10:43:24 -0500	[thread overview]
Message-ID: <20150216154324.GA15486@fieldses.org> (raw)
In-Reply-To: <87vbj4ljjn.fsf@spindle.srvr.nix>

On Sat, Feb 14, 2015 at 01:17:00PM +0000, Nix wrote:
> On 10 Feb 2015, J. Bruce Fields outgrape:
> 
> > It might be interesting to see output from
> >
> > 	rpc.debug -m rpc -s cache
> > 	cat /proc/net/rpc/nfsd.export/content
> > 	cat /proc/net/rpc/nfsd.fh/content
> >
> > especially after the problem manifests.
> 
> So the mount has vanished again. I couldn't make it happen with
> nordirplus in the mount options, so that might provide you with a clue.
> 
> Obviously, on the client, no useful output was seen (I learned to avoid
> NFS cross-exports long ago, so the client doesn't normally NFS-export
> anything).

Nothing looks obviously wrong to me here.

I'm not sure why you have nfsd.fh but but not nfsd.export entries for
your two exports.  Might be worth reviewing the code to work out in
which cases that happens.

Anyway Neil's probably right to suspect the client here....

--b.

> 
> On the server:
> 
> # cat /proc/net/rpc/nfsd.export/content
> #path domain(flags)
> # expiry=1423920264 refcnt=1 flags=1
> /usr/src        mutilate.wkstn.nix(rw,no_root_squash,async,wdelay,no_subtree_check,fsid=16,uuid=333950aa:8e3f440a:bc94d0cc:4adae198,sec=1)
> # expiry=1423920746 refcnt=1 flags=1
> /home/.spindle.srvr.nix mutilate.wkstn.nix(rw,no_root_squash,async,wdelay,no_subtree_check,fsid=1,uuid=95bd22c2:253c456f:8e36b6cf:b9ecd4ef,sec=1)
> # expiry=1423920907 refcnt=1 flags=1
> /usr/lib/X11/fonts      mutilate.wkstn.nix(ro,root_squash,async,wdelay,fsid=12,uuid=5cccc224:a92440ee:b4450447:3898c2ec,sec=1)
> # expiry=1423920721 refcnt=1 flags=1
> /home/.spindle.srvr.nix *.srvr.nix,fold.srvr.nix(rw,root_squash,async,wdelay,no_subtree_check,fsid=1,uuid=95bd22c2:253c456f:8e36b6cf:b9ecd4ef,sec=1)
> 
> # cat /proc/net/rpc/nfsd.fh/content
> #domain fsidtype fsid [path]
> # expiry=2147483647 refcnt=1 flags=1
> *.vm.nix,192.168.20.0/24,owork.vm.nix 1 0x00000010 /usr/src
> # expiry=2147483647 refcnt=1 flags=1
> *.vm.nix,192.168.20.0/24,owork.vm.nix 1 0x00000016 /home/oranix/o
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000018 /home/.spindle.srvr.nix/nix/Graphics/Private
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000003 /home/.spindle.srvr.nix/nix/Graphics/Photos
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000002 /home/.spindle.srvr.nix/nix/Mail/nnmh/spambox-verified
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000013 /usr/share/clamav
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000012 /usr/share/httpd/htdocs/munin
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000011 /var/state/munin
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x0000001d /usr/archive/series
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000010 /usr/src
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x0000000b /pkg/non-free
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000015 /usr/share/flightgear
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000007 /usr/share/texlive
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x0000000a /usr/share/nethack
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000009 /usr/share/xplanet
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000016 /usr/share/emacs/site-lisp
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000008 /usr/share/xemacs
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000005 /usr/doc
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000006 /usr/info
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x0000000f /etc/shai-hulud
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x0000000e /var/log.real
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x0000000c /usr/lib/X11/fonts
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000019 /usr/archive
> # expiry=2147483647 refcnt=1 flags=1
> mutilate.wkstn.nix 1 0x00000001 /home/.spindle.srvr.nix
> # expiry=2147483647 refcnt=1 flags=1
> *.vm.nix,192.168.20.0/24,linux-o.vm.nix 1 0x00000010 /usr/src
> # expiry=2147483647 refcnt=1 flags=1
> *.vm.nix,192.168.20.0/24,linux-o.vm.nix 1 0x00000016 /home/oranix/o
> # expiry=2147483647 refcnt=1 flags=1
> *.srvr.nix,fold.srvr.nix 1 0x00000001 /home/.spindle.srvr.nix
> 
> I remounted it, and nfsd.export/content gained a few lines:
> 
> # expiry=1423921406 refcnt=1 flags=1
> /usr/archive/series     mutilate.wkstn.nix(rw,insecure,root_squash,async,wdelay,no_subtree_check,fsid=29,uuid=543a1ca9:d17246ca:b6c53092:5896549d,sec=1)
> # expiry=1423921383 refcnt=1 flags=1
> /usr/archive    mutilate.wkstn.nix(rw,insecure,root_squash,async,wdelay,fsid=25,uuid=d20e3edd:06a54a9b:85dcfa19:62975969,sec=1)
> 
> nfsd.fh/content is unchanged.
> 
> To me, this all looks completely normal: unused mounts *do* expire away.
> The problem is that they're not coming back as they should (I guess
> they're coming back with a different inode number?)
> 
> This is all with nfs-utils 1.3.0, btw.
> 
> -- 
> NULL && (void)