+static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
+ const size_t salen,
+ const char *hostname,
+ const size_t hostname_len)
+{
+ struct nsm_handle *new;
+
+ new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
+ if (unlikely(new == NULL))
+ return NULL;
+
+ atomic_set(&new->sm_count, 1);
+ new->sm_name = (char *)(new + 1);
+ memcpy(nsm_addr(new), sap, salen);
+ new->sm_addrlen = salen;
+ nsm_init_private(new);
+
+ if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
+ sizeof(new->sm_addrbuf)) == 0)
+ (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
+ "unsupported address family");
+ memcpy(new->sm_name, hostname, hostname_len);
+ new->sm_name[hostname_len] = '\0';
+
+ return new;
+}
+
+/**
+ * nsm_get_handle - Find or create a cached nsm_handle
+ * @sap: pointer to socket address of handle to find
+ * @salen: length of socket address
+ * @hostname: pointer to C string containing hostname to find
+ * @hostname_len: length of C string
+ *
+ * Behavior is modulated by the global nsm_use_hostnames variable.
+ *
+ * Returns a cached nsm_handle after bumping its ref count, or
+ * returns a fresh nsm_handle if a handle that matches @sap and/or
+ * @hostname cannot be found in the handle cache. Returns NULL if
+ * an error occurs.
+ */
+struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
+ const size_t salen, const char *hostname,
+ const size_t hostname_len)
+{
+ struct nsm_handle *cached, *new = NULL;
+
+ if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
+ if (printk_ratelimit()) {
+ printk(KERN_WARNING "Invalid hostname \"%.*s\" "
+ "in NFS lock request\n",
+ (int)hostname_len, hostname);
+ }
+ return NULL;
+ }
+
+retry:
+ spin_lock(&nsm_lock);
+
+ if (nsm_use_hostnames && hostname != NULL)
+ cached = nsm_lookup_hostname(hostname, hostname_len);
+ else
+ cached = nsm_lookup_addr(sap);
+
+ if (cached != NULL) {
+ atomic_inc(&cached->sm_count);
+ spin_unlock(&nsm_lock);
+ kfree(new);
+ dprintk("lockd: found nsm_handle for %s (%s), "
+ "cnt %d\n", cached->sm_name,
+ cached->sm_addrbuf,
+ atomic_read(&cached->sm_count));
+ return cached;
+ }
+
+ if (new != NULL) {
+ list_add(&new->sm_link, &nsm_handles);
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: created nsm_handle for %s (%s)\n",
+ new->sm_name, new->sm_addrbuf);
+ return new;
+ }
+
+ spin_unlock(&nsm_lock);
+
+ new = nsm_create_handle(sap, salen, hostname, hostname_len);
+ if (unlikely(new == NULL))
+ return NULL;
+ goto retry;
+}
+
+/**
+ * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
+ * @info: pointer to NLMPROC_SM_NOTIFY arguments
+ *
+ * Returns a matching nsm_handle if found in the nsm cache. The returned
+ * nsm_handle's reference count is bumped. Otherwise returns NULL if some
+ * error occurred.
+ */
+struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
+{
+ struct nsm_handle *cached;
+
+ spin_lock(&nsm_lock);
+
+ cached = nsm_lookup_priv(&info->priv);
+ if (unlikely(cached == NULL)) {
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: never saw rebooted peer '%.*s' before\n",
+ info->len, info->mon);
+ return cached;
+ }
+
+ atomic_inc(&cached->sm_count);
+ spin_unlock(&nsm_lock);
+
+ dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
+ cached->sm_name, cached->sm_addrbuf,
+ atomic_read(&cached->sm_count));
+ return cached;
+}
+
+/**
+ * nsm_release - Release an NSM handle
+ * @nsm: pointer to handle to be released
+ *
+ */
+void nsm_release(struct nsm_handle *nsm)
+{
+ if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
+ list_del(&nsm->sm_link);
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
+ nsm->sm_name, nsm->sm_addrbuf);
+ kfree(nsm);
+ }