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-rw-r--r--fs/lockd/mon.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 81e1cc14246..8e68e799293 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -47,12 +47,51 @@ struct nsm_res {
static struct rpc_clnt * nsm_create(void);
static struct rpc_program nsm_program;
+static LIST_HEAD(nsm_handles);
+static DEFINE_SPINLOCK(nsm_lock);
/*
* Local NSM state
*/
int nsm_local_state;
+static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf,
+ const size_t len)
+{
+ const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+ snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
+}
+
+static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf,
+ const size_t len)
+{
+ const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+ snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
+ else if (sin6->sin6_scope_id != 0)
+ snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
+ sin6->sin6_scope_id);
+ else
+ snprintf(buf, len, "%pI6", &sin6->sin6_addr);
+}
+
+static void nsm_display_address(const struct sockaddr *sap,
+ char *buf, const size_t len)
+{
+ switch (sap->sa_family) {
+ case AF_INET:
+ nsm_display_ipv4_address(sap, buf, len);
+ break;
+ case AF_INET6:
+ nsm_display_ipv6_address(sap, buf, len);
+ break;
+ default:
+ snprintf(buf, len, "unsupported address family");
+ break;
+ }
+}
+
/*
* Common procedure for NSMPROC_MON/NSMPROC_UNMON calls
*/
@@ -162,6 +201,100 @@ void nsm_unmonitor(const struct nlm_host *host)
}
}
+/**
+ * nsm_find - 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
+ * @create: one means create new handle if not found in cache
+ *
+ * Behavior is modulated by the global nsm_use_hostnames variable
+ * and by the @create argument.
+ *
+ * Returns a cached nsm_handle after bumping its ref count, or if
+ * @create is set, 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_find(const struct sockaddr *sap, const size_t salen,
+ const char *hostname, const size_t hostname_len,
+ const int create)
+{
+ struct nsm_handle *nsm = NULL;
+ struct nsm_handle *pos;
+
+ if (!sap)
+ return 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);
+ list_for_each_entry(pos, &nsm_handles, sm_link) {
+
+ if (hostname && nsm_use_hostnames) {
+ if (strlen(pos->sm_name) != hostname_len
+ || memcmp(pos->sm_name, hostname, hostname_len))
+ continue;
+ } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
+ continue;
+ atomic_inc(&pos->sm_count);
+ kfree(nsm);
+ nsm = pos;
+ goto found;
+ }
+ if (nsm) {
+ list_add(&nsm->sm_link, &nsm_handles);
+ goto found;
+ }
+ spin_unlock(&nsm_lock);
+
+ if (!create)
+ return NULL;
+
+ nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
+ if (nsm == NULL)
+ return NULL;
+
+ memcpy(nsm_addr(nsm), sap, salen);
+ nsm->sm_addrlen = salen;
+ nsm->sm_name = (char *) (nsm + 1);
+ memcpy(nsm->sm_name, hostname, hostname_len);
+ nsm->sm_name[hostname_len] = '\0';
+ nsm_display_address((struct sockaddr *)&nsm->sm_addr,
+ nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
+ atomic_set(&nsm->sm_count, 1);
+ goto retry;
+
+found:
+ spin_unlock(&nsm_lock);
+ return nsm;
+}
+
+/**
+ * nsm_release - Release an NSM handle
+ * @nsm: pointer to handle to be released
+ *
+ */
+void nsm_release(struct nsm_handle *nsm)
+{
+ if (!nsm)
+ return;
+ if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
+ list_del(&nsm->sm_link);
+ spin_unlock(&nsm_lock);
+ kfree(nsm);
+ }
+}
+
/*
* Create NSM client for the local host
*/