Re: Locking NFS files on kernels 2.4.19 and 2.4.20

[Trond Myklebust <trond.myklebust@fys.uio.no>]

>>>>> " " == Bob Vickers <bobv@cs.rhul.ac.uk> writes:

     > I have recently upgraded some machines and have found that it
     > is no longer possible to lock files on NFS file systems. It is
     > definitely a client-side problem: upgraded clients could no
     > longer lock files on *any* NFS server (including Tru64 as well
     > as a variety of Linux servers).

Two questions:

  Are you running statd on the client and server?

if no, then you should...

  Does SuSE compile statd with or without the RESTRICTED_STATD flag?

If the latter, then you'll need an extra kernel patch in order to
allow the kernel NSM to use a reserved port. Something like the
appended scheme...

Cheers,
  Trond

--- linux/fs/lockd/mon.c.orig	2002-02-04 23:49:27.000000000 -0800
+++ linux/fs/lockd/mon.c	2003-06-09 10:02:57.000000000 -0700
@@ -105,12 +105,19 @@
 	struct rpc_xprt		*xprt;
 	struct rpc_clnt		*clnt = NULL;
 	struct sockaddr_in	sin;
+	uid_t saved_fsuid = current->fsuid;
+	kernel_cap_t saved_cap = current->cap_effective;
 
 	sin.sin_family = AF_INET;
 	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 	sin.sin_port = 0;
 
+	/* Create RPC socket as root user so we get a priv port */
+	current->fsuid = 0;
+	cap_raise (current->cap_effective, CAP_NET_BIND_SERVICE);
 	xprt = xprt_create_proto(IPPROTO_UDP, &sin, NULL);
+	current->fsuid = saved_fsuid;
+	current->cap_effective = saved_cap;
 	if (!xprt)
 		goto out;