[PATCH] knfsd: lockd: optionally use hostnames for identifying peers

This patch adds the nsm_use_hostnames sysctl and module param.  If set, lockd
will use the client's name (as given in the NLM arguments) to find the NSM
handle.  This makes recovery work when the NFS peer is multi-homed, and the
reboot notification arrives from a different IP than the original lock calls.

Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 1bf3843..a1423c6 100644 (file)
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -462,7 +462,11 @@ __nsm_find(const struct sockaddr_in *sin,
        list_for_each(pos, &nsm_handles) {
                nsm = list_entry(pos, struct nsm_handle, sm_link);
 
-               if (!nlm_cmp_addr(&nsm->sm_addr, sin))
+               if (hostname && nsm_use_hostnames) {
+                       if (strlen(nsm->sm_name) != hostname_len
+                        || memcmp(nsm->sm_name, hostname, hostname_len))
+                               continue;
+               } else if (!nlm_cmp_addr(&nsm->sm_addr, sin))
                        continue;
                atomic_inc(&nsm->sm_count);
                goto out;

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 626b6c1..709cf7c 100644 (file)
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -47,6 +47,7 @@ nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
        }
 
        memset(&args, 0, sizeof(args));
+       args.mon_name = nsm->sm_name;
        args.addr = nsm->sm_addr.sin_addr.s_addr;
        args.prog = NLM_PROGRAM;
        args.vers = 3;
@@ -150,7 +151,7 @@ nsm_create(void)
 static u32 *
 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 {
-       char    buffer[20];
+       char    buffer[20], *name;
 
        /*
         * Use the dotted-quad IP address of the remote host as
@@ -158,8 +159,13 @@ xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
         * hostname first for whatever remote hostname it receives,
         * so this works alright.
         */
-       sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
-       if (!(p = xdr_encode_string(p, buffer))
+       if (nsm_use_hostnames) {
+               name = argp->mon_name;
+       } else {
+               sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
+               name = buffer;
+       }
+       if (!(p = xdr_encode_string(p, name))
         || !(p = xdr_encode_string(p, utsname()->nodename)))
                return ERR_PTR(-EIO);
        *p++ = htonl(argp->prog);

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 3cc369e..a3b7602 100644 (file)
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -61,6 +61,7 @@ static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
 static unsigned long           nlm_grace_period;
 static unsigned long           nlm_timeout = LOCKD_DFLT_TIMEO;
 static int                     nlm_udpport, nlm_tcpport;
+int                            nsm_use_hostnames = 0;
 
 /*
  * Constants needed for the sysctl interface.
@@ -395,6 +396,14 @@ static ctl_table nlm_sysctls[] = {
                .extra1         = (int *) &nlm_port_min,
                .extra2         = (int *) &nlm_port_max,
        },
+       {
+               .ctl_name       = CTL_UNNUMBERED,
+               .procname       = "nsm_use_hostnames",
+               .data           = &nsm_use_hostnames,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec,
+       },
        { .ctl_name = 0 }
 };
 
@@ -483,6 +492,7 @@ module_param_call(nlm_udpport, param_set_port, param_get_int,
                  &nlm_udpport, 0644);
 module_param_call(nlm_tcpport, param_set_port, param_get_int,
                  &nlm_tcpport, 0644);
+module_param(nsm_use_hostnames, bool, 0644);
 
 /*
  * Initialising and terminating the module.

diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 1fcf936..7be7aea 100644 (file)
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -142,6 +142,7 @@ extern struct svc_procedure nlmsvc_procedures4[];
 #endif
 extern int                     nlmsvc_grace_period;
 extern unsigned long           nlmsvc_timeout;
+extern int                     nsm_use_hostnames;
 
 /*
  * Lockd client functions

diff --git a/include/linux/lockd/sm_inter.h b/include/linux/lockd/sm_inter.h
index d93b074..daef509 100644 (file)
--- a/include/linux/lockd/sm_inter.h
+++ b/include/linux/lockd/sm_inter.h
@@ -28,6 +28,8 @@ struct nsm_args {
        u32             prog;           /* RPC callback info */
        u32             vers;
        u32             proc;
+
+       char *          mon_name;
 };
 
 /*