dlm: show addresses in configfs
Masatake YAMATO [Thu, 30 Jun 2011 12:37:10 +0000 (21:37 +0900)]
Display all addresses the dlm is using for the local node
from the configfs file config/dlm/<cluster>/comms/<comm>/addr_list
Also make the addr file write only.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/config.c

index 9b026ea..ad3b5a8 100644 (file)
@@ -28,7 +28,8 @@
  * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/weight
  * /config/dlm/<cluster>/comms/<comm>/nodeid
  * /config/dlm/<cluster>/comms/<comm>/local
- * /config/dlm/<cluster>/comms/<comm>/addr
+ * /config/dlm/<cluster>/comms/<comm>/addr      (write only)
+ * /config/dlm/<cluster>/comms/<comm>/addr_list (read only)
  * The <cluster> level is useless, but I haven't figured out how to avoid it.
  */
 
@@ -80,6 +81,7 @@ static ssize_t comm_local_write(struct dlm_comm *cm, const char *buf,
                                size_t len);
 static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf,
                                size_t len);
+static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf);
 static ssize_t node_nodeid_read(struct dlm_node *nd, char *buf);
 static ssize_t node_nodeid_write(struct dlm_node *nd, const char *buf,
                                size_t len);
@@ -190,6 +192,7 @@ enum {
        COMM_ATTR_NODEID = 0,
        COMM_ATTR_LOCAL,
        COMM_ATTR_ADDR,
+       COMM_ATTR_ADDR_LIST,
 };
 
 struct comm_attribute {
@@ -217,14 +220,22 @@ static struct comm_attribute comm_attr_local = {
 static struct comm_attribute comm_attr_addr = {
        .attr   = { .ca_owner = THIS_MODULE,
                     .ca_name = "addr",
-                    .ca_mode = S_IRUGO | S_IWUSR },
+                    .ca_mode = S_IWUSR },
        .store  = comm_addr_write,
 };
 
+static struct comm_attribute comm_attr_addr_list = {
+       .attr   = { .ca_owner = THIS_MODULE,
+                    .ca_name = "addr_list",
+                    .ca_mode = S_IRUGO },
+       .show   = comm_addr_list_read,
+};
+
 static struct configfs_attribute *comm_attrs[] = {
        [COMM_ATTR_NODEID] = &comm_attr_nodeid.attr,
        [COMM_ATTR_LOCAL] = &comm_attr_local.attr,
        [COMM_ATTR_ADDR] = &comm_attr_addr.attr,
+       [COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list.attr,
        NULL,
 };
 
@@ -720,6 +731,50 @@ static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf, size_t len)
        return len;
 }
 
+static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf)
+{
+       ssize_t s;
+       ssize_t allowance;
+       int i;
+       struct sockaddr_storage *addr;
+       struct sockaddr_in *addr_in;
+       struct sockaddr_in6 *addr_in6;
+       
+       /* Taken from ip6_addr_string() defined in lib/vsprintf.c */
+       char buf0[sizeof("AF_INET6      xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255\n")];
+       
+
+       /* Derived from SIMPLE_ATTR_SIZE of fs/configfs/file.c */
+       allowance = 4096;
+       buf[0] = '\0';
+
+       for (i = 0; i < cm->addr_count; i++) {
+               addr = cm->addr[i];
+
+               switch(addr->ss_family) {
+               case AF_INET:
+                       addr_in = (struct sockaddr_in *)addr;
+                       s = sprintf(buf0, "AF_INET      %pI4\n", &addr_in->sin_addr.s_addr);
+                       break;
+               case AF_INET6:
+                       addr_in6 = (struct sockaddr_in6 *)addr;
+                       s = sprintf(buf0, "AF_INET6     %pI6\n", &addr_in6->sin6_addr);
+                       break;
+               default:
+                       s = sprintf(buf0, "%s\n", "<UNKNOWN>");
+                       break;
+               }
+               allowance -= s;
+               if (allowance >= 0)
+                       strcat(buf, buf0);
+               else {
+                       allowance += s;
+                       break;
+               }
+       }
+       return 4096 - allowance;
+}
+
 static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
                         char *buf)
 {