NLM: Call nsm_reboot_lookup() instead of nsm_find()
[safe/jmp/linux-2.6] / fs / lockd / host.c
index a0d0b58..230de93 100644 (file)
  */
 
 #include <linux/types.h>
-#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/in.h>
+#include <linux/in6.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/svc.h>
 #include <linux/lockd/lockd.h>
 #include <linux/lockd/sm_inter.h>
 #include <linux/mutex.h>
 
+#include <net/ipv6.h>
 
 #define NLMDBG_FACILITY                NLMDBG_HOSTCACHE
-#define NLM_HOST_MAX           64
 #define NLM_HOST_NRHASH                32
-#define NLM_ADDRHASH(addr)     (ntohl(addr) & (NLM_HOST_NRHASH-1))
 #define NLM_HOST_REBIND                (60 * HZ)
-#define NLM_HOST_EXPIRE                ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
-#define NLM_HOST_COLLECT       ((nrhosts > NLM_HOST_MAX)? 120 * HZ :  60 * HZ)
+#define NLM_HOST_EXPIRE                (300 * HZ)
+#define NLM_HOST_COLLECT       (120 * HZ)
 
-static struct nlm_host *       nlm_hosts[NLM_HOST_NRHASH];
+static struct hlist_head       nlm_hosts[NLM_HOST_NRHASH];
 static unsigned long           next_gc;
 static int                     nrhosts;
 static DEFINE_MUTEX(nlm_host_mutex);
 
-
 static void                    nlm_gc_hosts(void);
 
+struct nlm_lookup_host_info {
+       const int               server;         /* search for server|client */
+       const struct sockaddr   *sap;           /* address to search for */
+       const size_t            salen;          /* it's length */
+       const unsigned short    protocol;       /* transport to search for*/
+       const u32               version;        /* NLM version to search for */
+       const char              *hostname;      /* remote's hostname */
+       const size_t            hostname_len;   /* it's length */
+       const struct sockaddr   *src_sap;       /* our address (optional) */
+       const size_t            src_len;        /* it's length */
+       const int               noresvport;     /* use non-priv port */
+};
+
 /*
- * Find an NLM server handle in the cache. If there is none, create it.
+ * Hash function must work well on big- and little-endian platforms
  */
-struct nlm_host *
-nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version)
+static unsigned int __nlm_hash32(const __be32 n)
 {
-       return nlm_lookup_host(0, sin, proto, version);
+       unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
+       return hash ^ (hash >> 8);
 }
 
-/*
- * Find an NLM client handle in the cache. If there is none, create it.
- */
-struct nlm_host *
-nlmsvc_lookup_host(struct svc_rqst *rqstp)
+static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
+{
+       const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+       return __nlm_hash32(sin->sin_addr.s_addr);
+}
+
+static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
+{
+       const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+       const struct in6_addr addr = sin6->sin6_addr;
+       return __nlm_hash32(addr.s6_addr32[0]) ^
+              __nlm_hash32(addr.s6_addr32[1]) ^
+              __nlm_hash32(addr.s6_addr32[2]) ^
+              __nlm_hash32(addr.s6_addr32[3]);
+}
+
+static unsigned int nlm_hash_address(const struct sockaddr *sap)
 {
-       return nlm_lookup_host(1, &rqstp->rq_addr,
-                              rqstp->rq_prot, rqstp->rq_vers);
+       unsigned int hash;
+
+       switch (sap->sa_family) {
+       case AF_INET:
+               hash = __nlm_hash_addr4(sap);
+               break;
+       case AF_INET6:
+               hash = __nlm_hash_addr6(sap);
+               break;
+       default:
+               hash = 0;
+       }
+       return hash & (NLM_HOST_NRHASH - 1);
+}
+
+static void nlm_clear_port(struct sockaddr *sap)
+{
+       switch (sap->sa_family) {
+       case AF_INET:
+               ((struct sockaddr_in *)sap)->sin_port = 0;
+               break;
+       case AF_INET6:
+               ((struct sockaddr_in6 *)sap)->sin6_port = 0;
+               break;
+       }
 }
 
 /*
  * Common host lookup routine for server & client
  */
-struct nlm_host *
-nlm_lookup_host(int server, struct sockaddr_in *sin,
-                                       int proto, int version)
+static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
 {
-       struct nlm_host *host, **hp;
-       u32             addr;
-       int             hash;
-
-       dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
-                       (unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);
-
-       hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
+       struct hlist_head *chain;
+       struct hlist_node *pos;
+       struct nlm_host *host;
+       struct nsm_handle *nsm = NULL;
 
-       /* Lock hash table */
        mutex_lock(&nlm_host_mutex);
 
        if (time_after_eq(jiffies, next_gc))
                nlm_gc_hosts();
 
-       for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
-               if (host->h_proto != proto)
+       /* We may keep several nlm_host objects for a peer, because each
+        * nlm_host is identified by
+        * (address, protocol, version, server/client)
+        * We could probably simplify this a little by putting all those
+        * different NLM rpc_clients into one single nlm_host object.
+        * This would allow us to have one nlm_host per address.
+        */
+       chain = &nlm_hosts[nlm_hash_address(ni->sap)];
+       hlist_for_each_entry(host, pos, chain, h_hash) {
+               if (!nlm_cmp_addr(nlm_addr(host), ni->sap))
+                       continue;
+
+               /* See if we have an NSM handle for this client */
+               if (!nsm)
+                       nsm = host->h_nsmhandle;
+
+               if (host->h_proto != ni->protocol)
+                       continue;
+               if (host->h_version != ni->version)
                        continue;
-               if (host->h_version != version)
+               if (host->h_server != ni->server)
                        continue;
-               if (host->h_server != server)
+               if (ni->server &&
+                   !nlm_cmp_addr(nlm_srcaddr(host), ni->src_sap))
                        continue;
 
-               if (nlm_cmp_addr(&host->h_addr, sin)) {
-                       if (hp != nlm_hosts + hash) {
-                               *hp = host->h_next;
-                               host->h_next = nlm_hosts[hash];
-                               nlm_hosts[hash] = host;
-                       }
-                       nlm_get_host(host);
-                       mutex_unlock(&nlm_host_mutex);
-                       return host;
-               }
+               /* Move to head of hash chain. */
+               hlist_del(&host->h_hash);
+               hlist_add_head(&host->h_hash, chain);
+
+               nlm_get_host(host);
+               dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
+                               host->h_name, host->h_addrbuf);
+               goto out;
        }
 
-       /* Ooops, no host found, create it */
-       dprintk("lockd: creating host entry\n");
+       /*
+        * The host wasn't in our hash table.  If we don't
+        * have an NSM handle for it yet, create one.
+        */
+       if (nsm)
+               atomic_inc(&nsm->sm_count);
+       else {
+               host = NULL;
+               nsm = nsm_find(ni->sap, ni->salen,
+                               ni->hostname, ni->hostname_len, 1);
+               if (!nsm) {
+                       dprintk("lockd: nlm_lookup_host failed; "
+                               "no nsm handle\n");
+                       goto out;
+               }
+       }
 
        host = kzalloc(sizeof(*host), GFP_KERNEL);
-       if (!host)
-               goto nohost;
-
-       addr = sin->sin_addr.s_addr;
-       sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
-
-       host->h_addr       = *sin;
-       host->h_addr.sin_port = 0;      /* ouch! */
-       host->h_version    = version;
-       host->h_proto      = proto;
+       if (!host) {
+               nsm_release(nsm);
+               dprintk("lockd: nlm_lookup_host failed; no memory\n");
+               goto out;
+       }
+       host->h_name       = nsm->sm_name;
+       host->h_addrbuf    = nsm->sm_addrbuf;
+       memcpy(nlm_addr(host), ni->sap, ni->salen);
+       host->h_addrlen = ni->salen;
+       nlm_clear_port(nlm_addr(host));
+       memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len);
+       host->h_version    = ni->version;
+       host->h_proto      = ni->protocol;
        host->h_rpcclnt    = NULL;
        mutex_init(&host->h_mutex);
        host->h_nextrebind = jiffies + NLM_HOST_REBIND;
@@ -119,46 +191,148 @@ nlm_lookup_host(int server, struct sockaddr_in *sin,
        init_rwsem(&host->h_rwsem);
        host->h_state      = 0;                 /* pseudo NSM state */
        host->h_nsmstate   = 0;                 /* real NSM state */
-       host->h_server     = server;
-       host->h_next       = nlm_hosts[hash];
-       nlm_hosts[hash]    = host;
+       host->h_nsmhandle  = nsm;
+       host->h_server     = ni->server;
+       host->h_noresvport = ni->noresvport;
+       hlist_add_head(&host->h_hash, chain);
        INIT_LIST_HEAD(&host->h_lockowners);
        spin_lock_init(&host->h_lock);
        INIT_LIST_HEAD(&host->h_granted);
        INIT_LIST_HEAD(&host->h_reclaim);
 
-       if (++nrhosts > NLM_HOST_MAX)
-               next_gc = 0;
+       nrhosts++;
 
-nohost:
+       dprintk("lockd: nlm_lookup_host created host %s\n",
+                       host->h_name);
+
+out:
        mutex_unlock(&nlm_host_mutex);
        return host;
 }
 
-struct nlm_host *
-nlm_find_client(void)
+/*
+ * Destroy a host
+ */
+static void
+nlm_destroy_host(struct nlm_host *host)
 {
-       /* find a nlm_host for a client for which h_killed == 0.
-        * and return it
-        */
-       int hash;
-       mutex_lock(&nlm_host_mutex);
-       for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
-               struct nlm_host *host, **hp;
-               for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
-                       if (host->h_server &&
-                           host->h_killed == 0) {
-                               nlm_get_host(host);
-                               mutex_unlock(&nlm_host_mutex);
-                               return host;
-                       }
-               }
+       struct rpc_clnt *clnt;
+
+       BUG_ON(!list_empty(&host->h_lockowners));
+       BUG_ON(atomic_read(&host->h_count));
+
+       nsm_unmonitor(host);
+       nsm_release(host->h_nsmhandle);
+
+       clnt = host->h_rpcclnt;
+       if (clnt != NULL)
+               rpc_shutdown_client(clnt);
+       kfree(host);
+}
+
+/**
+ * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
+ * @sap: network address of server
+ * @salen: length of server address
+ * @protocol: transport protocol to use
+ * @version: NLM protocol version
+ * @hostname: '\0'-terminated hostname of server
+ * @noresvport: 1 if non-privileged port should be used
+ *
+ * Returns an nlm_host structure that matches the passed-in
+ * [server address, transport protocol, NLM version, server hostname].
+ * If one doesn't already exist in the host cache, a new handle is
+ * created and returned.
+ */
+struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
+                                    const size_t salen,
+                                    const unsigned short protocol,
+                                    const u32 version,
+                                    const char *hostname,
+                                    int noresvport)
+{
+       const struct sockaddr source = {
+               .sa_family      = AF_UNSPEC,
+       };
+       struct nlm_lookup_host_info ni = {
+               .server         = 0,
+               .sap            = sap,
+               .salen          = salen,
+               .protocol       = protocol,
+               .version        = version,
+               .hostname       = hostname,
+               .hostname_len   = strlen(hostname),
+               .src_sap        = &source,
+               .src_len        = sizeof(source),
+               .noresvport     = noresvport,
+       };
+
+       dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
+                       (hostname ? hostname : "<none>"), version,
+                       (protocol == IPPROTO_UDP ? "udp" : "tcp"));
+
+       return nlm_lookup_host(&ni);
+}
+
+/**
+ * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
+ * @rqstp: incoming NLM request
+ * @hostname: name of client host
+ * @hostname_len: length of client hostname
+ *
+ * Returns an nlm_host structure that matches the [client address,
+ * transport protocol, NLM version, client hostname] of the passed-in
+ * NLM request.  If one doesn't already exist in the host cache, a
+ * new handle is created and returned.
+ *
+ * Before possibly creating a new nlm_host, construct a sockaddr
+ * for a specific source address in case the local system has
+ * multiple network addresses.  The family of the address in
+ * rq_daddr is guaranteed to be the same as the family of the
+ * address in rq_addr, so it's safe to use the same family for
+ * the source address.
+ */
+struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
+                                   const char *hostname,
+                                   const size_t hostname_len)
+{
+       struct sockaddr_in sin = {
+               .sin_family     = AF_INET,
+       };
+       struct sockaddr_in6 sin6 = {
+               .sin6_family    = AF_INET6,
+       };
+       struct nlm_lookup_host_info ni = {
+               .server         = 1,
+               .sap            = svc_addr(rqstp),
+               .salen          = rqstp->rq_addrlen,
+               .protocol       = rqstp->rq_prot,
+               .version        = rqstp->rq_vers,
+               .hostname       = hostname,
+               .hostname_len   = hostname_len,
+               .src_len        = rqstp->rq_addrlen,
+       };
+
+       dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
+                       (int)hostname_len, hostname, rqstp->rq_vers,
+                       (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
+
+       switch (ni.sap->sa_family) {
+       case AF_INET:
+               sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
+               ni.src_sap = (struct sockaddr *)&sin;
+               break;
+       case AF_INET6:
+               ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
+               ni.src_sap = (struct sockaddr *)&sin6;
+               break;
+       default:
+               return NULL;
        }
-       mutex_unlock(&nlm_host_mutex);
-       return NULL;
+
+       return nlm_lookup_host(&ni);
 }
 
-                               
 /*
  * Create the NLM RPC client for an NLM peer
  */
@@ -167,8 +341,8 @@ nlm_bind_host(struct nlm_host *host)
 {
        struct rpc_clnt *clnt;
 
-       dprintk("lockd: nlm_bind_host(%08x)\n",
-                       (unsigned)ntohl(host->h_addr.sin_addr.s_addr));
+       dprintk("lockd: nlm_bind_host %s (%s)\n",
+                       host->h_name, host->h_addrbuf);
 
        /* Lock host handle */
        mutex_lock(&host->h_mutex);
@@ -180,11 +354,11 @@ nlm_bind_host(struct nlm_host *host)
                if (time_after_eq(jiffies, host->h_nextrebind)) {
                        rpc_force_rebind(clnt);
                        host->h_nextrebind = jiffies + NLM_HOST_REBIND;
-                       dprintk("lockd: next rebind in %ld jiffies\n",
+                       dprintk("lockd: next rebind in %lu jiffies\n",
                                        host->h_nextrebind - jiffies);
                }
        } else {
-               unsigned long increment = nlmsvc_timeout * HZ;
+               unsigned long increment = nlmsvc_timeout;
                struct rpc_timeout timeparms = {
                        .to_initval     = increment,
                        .to_increment   = increment,
@@ -193,17 +367,28 @@ nlm_bind_host(struct nlm_host *host)
                };
                struct rpc_create_args args = {
                        .protocol       = host->h_proto,
-                       .address        = (struct sockaddr *)&host->h_addr,
-                       .addrsize       = sizeof(host->h_addr),
+                       .address        = nlm_addr(host),
+                       .addrsize       = host->h_addrlen,
+                       .saddress       = nlm_srcaddr(host),
                        .timeout        = &timeparms,
                        .servername     = host->h_name,
                        .program        = &nlm_program,
                        .version        = host->h_version,
                        .authflavor     = RPC_AUTH_UNIX,
-                       .flags          = (RPC_CLNT_CREATE_HARDRTRY |
+                       .flags          = (RPC_CLNT_CREATE_NOPING |
                                           RPC_CLNT_CREATE_AUTOBIND),
                };
 
+               /*
+                * lockd retries server side blocks automatically so we want
+                * those to be soft RPC calls. Client side calls need to be
+                * hard RPC tasks.
+                */
+               if (!host->h_server)
+                       args.flags |= RPC_CLNT_CREATE_HARDRTRY;
+               if (host->h_noresvport)
+                       args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+
                clnt = rpc_create(&args);
                if (!IS_ERR(clnt))
                        host->h_rpcclnt = clnt;
@@ -259,6 +444,58 @@ void nlm_release_host(struct nlm_host *host)
        }
 }
 
+/**
+ * nlm_host_rebooted - Release all resources held by rebooted host
+ * @info: pointer to decoded results of NLM_SM_NOTIFY call
+ *
+ * We were notified that the specified host has rebooted.  Release
+ * all resources held by that peer.
+ */
+void nlm_host_rebooted(const struct nlm_reboot *info)
+{
+       struct hlist_head *chain;
+       struct hlist_node *pos;
+       struct nsm_handle *nsm;
+       struct nlm_host *host;
+
+       nsm = nsm_reboot_lookup(info);
+       if (unlikely(nsm == NULL))
+               return;
+
+       /* Mark all hosts tied to this NSM state as having rebooted.
+        * We run the loop repeatedly, because we drop the host table
+        * lock for this.
+        * To avoid processing a host several times, we match the nsmstate.
+        */
+again: mutex_lock(&nlm_host_mutex);
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry(host, pos, chain, h_hash) {
+                       if (host->h_nsmhandle == nsm
+                        && host->h_nsmstate != info->state) {
+                               host->h_nsmstate = info->state;
+                               host->h_state++;
+
+                               nlm_get_host(host);
+                               mutex_unlock(&nlm_host_mutex);
+
+                               if (host->h_server) {
+                                       /* We're server for this guy, just ditch
+                                        * all the locks he held. */
+                                       nlmsvc_free_host_resources(host);
+                               } else {
+                                       /* He's the server, initiate lock recovery. */
+                                       nlmclnt_recovery(host);
+                               }
+
+                               nlm_release_host(host);
+                               goto again;
+                       }
+               }
+       }
+
+       mutex_unlock(&nlm_host_mutex);
+}
+
 /*
  * Shut down the hosts module.
  * Note that this routine is called only at server shutdown time.
@@ -266,17 +503,23 @@ void nlm_release_host(struct nlm_host *host)
 void
 nlm_shutdown_hosts(void)
 {
+       struct hlist_head *chain;
+       struct hlist_node *pos;
        struct nlm_host *host;
-       int             i;
 
        dprintk("lockd: shutting down host module\n");
        mutex_lock(&nlm_host_mutex);
 
        /* First, make all hosts eligible for gc */
        dprintk("lockd: nuking all hosts...\n");
-       for (i = 0; i < NLM_HOST_NRHASH; i++) {
-               for (host = nlm_hosts[i]; host; host = host->h_next)
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry(host, pos, chain, h_hash) {
                        host->h_expires = jiffies - 1;
+                       if (host->h_rpcclnt) {
+                               rpc_shutdown_client(host->h_rpcclnt);
+                               host->h_rpcclnt = NULL;
+                       }
+               }
        }
 
        /* Then, perform a garbage collection pass */
@@ -287,8 +530,8 @@ nlm_shutdown_hosts(void)
        if (nrhosts) {
                printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
                dprintk("lockd: %d hosts left:\n", nrhosts);
-               for (i = 0; i < NLM_HOST_NRHASH; i++) {
-                       for (host = nlm_hosts[i]; host; host = host->h_next) {
+               for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+                       hlist_for_each_entry(host, pos, chain, h_hash) {
                                dprintk("       %s (cnt %d use %d exp %ld)\n",
                                        host->h_name, atomic_read(&host->h_count),
                                        host->h_inuse, host->h_expires);
@@ -305,49 +548,35 @@ nlm_shutdown_hosts(void)
 static void
 nlm_gc_hosts(void)
 {
-       struct nlm_host **q, *host;
-       struct rpc_clnt *clnt;
-       int             i;
+       struct hlist_head *chain;
+       struct hlist_node *pos, *next;
+       struct nlm_host *host;
 
        dprintk("lockd: host garbage collection\n");
-       for (i = 0; i < NLM_HOST_NRHASH; i++) {
-               for (host = nlm_hosts[i]; host; host = host->h_next)
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry(host, pos, chain, h_hash)
                        host->h_inuse = 0;
        }
 
        /* Mark all hosts that hold locks, blocks or shares */
        nlmsvc_mark_resources();
 
-       for (i = 0; i < NLM_HOST_NRHASH; i++) {
-               q = &nlm_hosts[i];
-               while ((host = *q) != NULL) {
+       for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+               hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
                        if (atomic_read(&host->h_count) || host->h_inuse
                         || time_before(jiffies, host->h_expires)) {
                                dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
                                        host->h_name, atomic_read(&host->h_count),
                                        host->h_inuse, host->h_expires);
-                               q = &host->h_next;
                                continue;
                        }
                        dprintk("lockd: delete host %s\n", host->h_name);
-                       *q = host->h_next;
-                       /* Don't unmonitor hosts that have been invalidated */
-                       if (host->h_monitored && !host->h_killed)
-                               nsm_unmonitor(host);
-                       if ((clnt = host->h_rpcclnt) != NULL) {
-                               if (atomic_read(&clnt->cl_users)) {
-                                       printk(KERN_WARNING
-                                               "lockd: active RPC handle\n");
-                                       clnt->cl_dead = 1;
-                               } else {
-                                       rpc_destroy_client(host->h_rpcclnt);
-                               }
-                       }
-                       kfree(host);
+                       hlist_del_init(&host->h_hash);
+
+                       nlm_destroy_host(host);
                        nrhosts--;
                }
        }
 
        next_gc = jiffies + NLM_HOST_COLLECT;
 }
-