1 files changed, 246 insertions, 79 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index a0d0b58ce7a4..fb24a9730345 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -27,46 +27,60 @@
 #define NLM_HOST_EXPIRE         ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
 #define NLM_HOST_COLLECT        ((nrhosts > NLM_HOST_MAX)? 120 * HZ :  60 * 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);
+static struct nsm_handle *      __nsm_find(const struct sockaddr_in *,
+                                        const char *, int, int);
 
 /*
  * Find an NLM server handle in the cache. If there is none, create it.
  */
 struct nlm_host *
-nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version)
+nlmclnt_lookup_host(const struct sockaddr_in *sin, int proto, int version,
+                        const char *hostname, int hostname_len)
 {
-        return nlm_lookup_host(0, sin, proto, version);
+        return nlm_lookup_host(0, sin, proto, version,
+                               hostname, hostname_len);
 }
 
 /*
  * Find an NLM client handle in the cache. If there is none, create it.
  */
 struct nlm_host *
-nlmsvc_lookup_host(struct svc_rqst *rqstp)
+nlmsvc_lookup_host(struct svc_rqst *rqstp,
+                        const char *hostname, int hostname_len)
 {
         return nlm_lookup_host(1, &rqstp->rq_addr,
-                               rqstp->rq_prot, rqstp->rq_vers);
+                               rqstp->rq_prot, rqstp->rq_vers,
+                               hostname, hostname_len);
 }
 
 /*
  * Common host lookup routine for server & client
  */
 struct nlm_host *
-nlm_lookup_host(int server, struct sockaddr_in *sin,
-                                        int proto, int version)
+nlm_lookup_host(int server, const struct sockaddr_in *sin,
+                                        int proto, int version,
+                                        const char *hostname,
+                                        int hostname_len)
 {
-        struct nlm_host *host, **hp;
-        u32             addr;
+        struct hlist_head *chain;
+        struct hlist_node *pos;
+        struct nlm_host *host;
+        struct nsm_handle *nsm = NULL;
         int             hash;
 
-        dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
-                        (unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);
+        dprintk("lockd: nlm_lookup_host(%u.%u.%u.%u, p=%d, v=%d, my role=%s, name=%.*s)\n",
+                        NIPQUAD(sin->sin_addr.s_addr), proto, version,
+                        server? "server" : "client",
+                        hostname_len,
+                        hostname? hostname : "<none>");
+
 
         hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
 
@@ -76,7 +90,22 @@ nlm_lookup_host(int server, struct sockaddr_in *sin,
         if (time_after_eq(jiffies, next_gc))
                 nlm_gc_hosts();
 
-        for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
+        /* 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[hash];
+        hlist_for_each_entry(host, pos, chain, h_hash) {
+                if (!nlm_cmp_addr(&host->h_addr, sin))
+                        continue;
+
+                /* See if we have an NSM handle for this client */
+                if (!nsm)
+                        nsm = host->h_nsmhandle;
+
                 if (host->h_proto != proto)
                         continue;
                 if (host->h_version != version)
@@ -84,28 +113,30 @@ nlm_lookup_host(int server, struct sockaddr_in *sin,
                 if (host->h_server != server)
                         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);
 
-        /* Ooops, no host found, create it */
-        dprintk("lockd: creating host entry\n");
+                nlm_get_host(host);
+                goto out;
+        }
+        if (nsm)
+                atomic_inc(&nsm->sm_count);
 
-        host = kzalloc(sizeof(*host), GFP_KERNEL);
-        if (!host)
-                goto nohost;
+        host = NULL;
 
-        addr = sin->sin_addr.s_addr;
-        sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
+        /* Sadly, the host isn't in our hash table yet. See if
+         * we have an NSM handle for it. If not, create one.
+         */
+        if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
+                goto out;
 
+        host = kzalloc(sizeof(*host), GFP_KERNEL);
+        if (!host) {
+                nsm_release(nsm);
+                goto out;
+        }
+        host->h_name       = nsm->sm_name;
         host->h_addr       = *sin;
         host->h_addr.sin_port = 0;      /* ouch! */
         host->h_version    = version;
@@ -119,9 +150,9 @@ 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_nsmhandle  = nsm;
         host->h_server     = server;
-        host->h_next       = nlm_hosts[hash];
-        nlm_hosts[hash]    = host;
+        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);
@@ -130,35 +161,39 @@ nlm_lookup_host(int server, struct sockaddr_in *sin,
         if (++nrhosts > NLM_HOST_MAX)
                 next_gc = 0;
 
-nohost:
+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
+        struct rpc_clnt *clnt;
+
+        BUG_ON(!list_empty(&host->h_lockowners));
+        BUG_ON(atomic_read(&host->h_count));
+
+        /*
+         * Release NSM handle and unmonitor host.
          */
-        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;
-                        }
+        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);
                 }
         }
-        mutex_unlock(&nlm_host_mutex);
-        return NULL;
+        kfree(host);
 }
 
-                                
 /*
  * Create the NLM RPC client for an NLM peer
  */
@@ -260,22 +295,82 @@ void nlm_release_host(struct nlm_host *host)
 }
 
 /*
+ * We were notified that the host indicated by address &sin
+ * has rebooted.
+ * Release all resources held by that peer.
+ */
+void nlm_host_rebooted(const struct sockaddr_in *sin,
+                                const char *hostname, int hostname_len,
+                                u32 new_state)
+{
+        struct hlist_head *chain;
+        struct hlist_node *pos;
+        struct nsm_handle *nsm;
+        struct nlm_host *host;
+
+        dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
+                        hostname, NIPQUAD(sin->sin_addr));
+
+        /* Find the NSM handle for this peer */
+        if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
+                return;
+
+        /* When reclaiming locks on this peer, make sure that
+         * we set up a new notification */
+        nsm->sm_monitored = 0;
+
+        /* 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 != new_state) {
+                                host->h_nsmstate = new_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.
  */
 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;
         }
 
@@ -287,8 +382,8 @@ 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);
@@ -305,45 +400,32 @@ 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--;
                 }
         }
@@ -351,3 +433,88 @@ nlm_gc_hosts(void)
         next_gc = jiffies + NLM_HOST_COLLECT;
 }
 
+
+/*
+ * Manage NSM handles
+ */
+static LIST_HEAD(nsm_handles);
+static DEFINE_MUTEX(nsm_mutex);
+
+static struct nsm_handle *
+__nsm_find(const struct sockaddr_in *sin,
+                const char *hostname, int hostname_len,
+                int create)
+{
+        struct nsm_handle *nsm = NULL;
+        struct list_head *pos;
+
+        if (!sin)
+                return NULL;
+
+        if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
+                if (printk_ratelimit()) {
+                        printk(KERN_WARNING "Invalid hostname \"%.*s\" "
+                                            "in NFS lock request\n",
+                                hostname_len, hostname);
+                }
+                return NULL;
+        }
+
+        mutex_lock(&nsm_mutex);
+        list_for_each(pos, &nsm_handles) {
+                nsm = list_entry(pos, struct nsm_handle, sm_link);
+
+                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;
+        }
+
+        if (!create) {
+                nsm = NULL;
+                goto out;
+        }
+
+        nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
+        if (nsm != NULL) {
+                nsm->sm_addr = *sin;
+                nsm->sm_name = (char *) (nsm + 1);
+                memcpy(nsm->sm_name, hostname, hostname_len);
+                nsm->sm_name[hostname_len] = '\0';
+                atomic_set(&nsm->sm_count, 1);
+
+                list_add(&nsm->sm_link, &nsm_handles);
+        }
+
+out:
+        mutex_unlock(&nsm_mutex);
+        return nsm;
+}
+
+struct nsm_handle *
+nsm_find(const struct sockaddr_in *sin, const char *hostname, int hostname_len)
+{
+        return __nsm_find(sin, hostname, hostname_len, 1);
+}
+
+/*
+ * Release an NSM handle
+ */
+void
+nsm_release(struct nsm_handle *nsm)
+{
+        if (!nsm)
+                return;
+        if (atomic_dec_and_test(&nsm->sm_count)) {
+                mutex_lock(&nsm_mutex);
+                if (atomic_read(&nsm->sm_count) == 0) {
+                        list_del(&nsm->sm_link);
+                        kfree(nsm);
+                }
+                mutex_unlock(&nsm_mutex);
+        }
+}