fs: dlm: add check if dlm is currently running

This patch adds checks for dlm config attributes regarding to protocol
parameters as it makes only sense to change them when dlm is not running.
It also adds a check for valid protocol specifiers and return invalid
argument if they are not supported.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index 8439610..88d95d9 100644 (file)
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -164,6 +164,36 @@ static ssize_t cluster_##name##_show(struct config_item *item, char *buf)     \
 }                                                                             \
 CONFIGFS_ATTR(cluster_, name);
 
+static int dlm_check_protocol_and_dlm_running(unsigned int x)
+{
+       switch (x) {
+       case 0:
+               /* TCP */
+               break;
+       case 1:
+               /* SCTP */
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if (dlm_allow_conn)
+               return -EBUSY;
+
+       return 0;
+}
+
+static int dlm_check_zero_and_dlm_running(unsigned int x)
+{
+       if (!x)
+               return -EINVAL;
+
+       if (dlm_allow_conn)
+               return -EBUSY;
+
+       return 0;
+}
+
 static int dlm_check_zero(unsigned int x)
 {
        if (!x)
@@ -180,7 +210,7 @@ static int dlm_check_buffer_size(unsigned int x)
        return 0;
 }
 
-CLUSTER_ATTR(tcp_port, dlm_check_zero);
+CLUSTER_ATTR(tcp_port, dlm_check_zero_and_dlm_running);
 CLUSTER_ATTR(buffer_size, dlm_check_buffer_size);
 CLUSTER_ATTR(rsbtbl_size, dlm_check_zero);
 CLUSTER_ATTR(recover_timer, dlm_check_zero);
@@ -188,7 +218,7 @@ CLUSTER_ATTR(toss_secs, dlm_check_zero);
 CLUSTER_ATTR(scan_secs, dlm_check_zero);
 CLUSTER_ATTR(log_debug, NULL);
 CLUSTER_ATTR(log_info, NULL);
-CLUSTER_ATTR(protocol, NULL);
+CLUSTER_ATTR(protocol, dlm_check_protocol_and_dlm_running);
 CLUSTER_ATTR(mark, NULL);
 CLUSTER_ATTR(timewarn_cs, dlm_check_zero);
 CLUSTER_ATTR(waitwarn_us, NULL);

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index ca9bf54..4f2245e 100644 (file)
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -135,7 +135,7 @@ static DEFINE_SPINLOCK(dlm_node_addrs_spin);
 static struct listen_connection listen_con;
 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
 static int dlm_local_count;
-static int dlm_allow_conn;
+int dlm_allow_conn;
 
 /* Work queues */
 static struct workqueue_struct *recv_workqueue;

diff --git a/fs/dlm/lowcomms.h b/fs/dlm/lowcomms.h
index 790d670..bcd4dbd 100644 (file)
--- a/fs/dlm/lowcomms.h
+++ b/fs/dlm/lowcomms.h
@@ -14,6 +14,9 @@
 
 #define LOWCOMMS_MAX_TX_BUFFER_LEN     4096
 
+/* switch to check if dlm is running */
+extern int dlm_allow_conn;
+
 int dlm_lowcomms_start(void);
 void dlm_lowcomms_stop(void);
 void dlm_lowcomms_exit(void);