ocfs2/cluster: Make fence method configurable - v2
By default, o2cb fences the box by calling emergency_restart(). While this
scheme works well in production, it comes in the way during testing as it
does not let the tester take stack/core dumps for analysis.
This patch allows user to dynamically change the fence method to panic() by:
# echo "panic" > /sys/kernel/config/cluster/<clustername>/fence_method
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index 7ee6188..c81142e 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -35,6 +35,10 @@
* cluster references throughout where nodes are looked up */
struct o2nm_cluster *o2nm_single_cluster = NULL;
+char *o2nm_fence_method_desc[O2NM_FENCE_METHODS] = {
+ "reset", /* O2NM_FENCE_RESET */
+ "panic", /* O2NM_FENCE_PANIC */
+};
struct o2nm_node *o2nm_get_node_by_num(u8 node_num)
{
@@ -579,6 +583,43 @@
return o2nm_cluster_attr_write(page, count,
&cluster->cl_reconnect_delay_ms);
}
+
+static ssize_t o2nm_cluster_attr_fence_method_read(
+ struct o2nm_cluster *cluster, char *page)
+{
+ ssize_t ret = 0;
+
+ if (cluster)
+ ret = sprintf(page, "%s\n",
+ o2nm_fence_method_desc[cluster->cl_fence_method]);
+ return ret;
+}
+
+static ssize_t o2nm_cluster_attr_fence_method_write(
+ struct o2nm_cluster *cluster, const char *page, size_t count)
+{
+ unsigned int i;
+
+ if (page[count - 1] != '\n')
+ goto bail;
+
+ for (i = 0; i < O2NM_FENCE_METHODS; ++i) {
+ if (count != strlen(o2nm_fence_method_desc[i]) + 1)
+ continue;
+ if (strncasecmp(page, o2nm_fence_method_desc[i], count - 1))
+ continue;
+ if (cluster->cl_fence_method != i) {
+ printk(KERN_INFO "ocfs2: Changing fence method to %s\n",
+ o2nm_fence_method_desc[i]);
+ cluster->cl_fence_method = i;
+ }
+ return count;
+ }
+
+bail:
+ return -EINVAL;
+}
+
static struct o2nm_cluster_attribute o2nm_cluster_attr_idle_timeout_ms = {
.attr = { .ca_owner = THIS_MODULE,
.ca_name = "idle_timeout_ms",
@@ -603,10 +644,19 @@
.store = o2nm_cluster_attr_reconnect_delay_ms_write,
};
+static struct o2nm_cluster_attribute o2nm_cluster_attr_fence_method = {
+ .attr = { .ca_owner = THIS_MODULE,
+ .ca_name = "fence_method",
+ .ca_mode = S_IRUGO | S_IWUSR },
+ .show = o2nm_cluster_attr_fence_method_read,
+ .store = o2nm_cluster_attr_fence_method_write,
+};
+
static struct configfs_attribute *o2nm_cluster_attrs[] = {
&o2nm_cluster_attr_idle_timeout_ms.attr,
&o2nm_cluster_attr_keepalive_delay_ms.attr,
&o2nm_cluster_attr_reconnect_delay_ms.attr,
+ &o2nm_cluster_attr_fence_method.attr,
NULL,
};
static ssize_t o2nm_cluster_show(struct config_item *item,
@@ -778,6 +828,7 @@
cluster->cl_reconnect_delay_ms = O2NET_RECONNECT_DELAY_MS_DEFAULT;
cluster->cl_idle_timeout_ms = O2NET_IDLE_TIMEOUT_MS_DEFAULT;
cluster->cl_keepalive_delay_ms = O2NET_KEEPALIVE_DELAY_MS_DEFAULT;
+ cluster->cl_fence_method = O2NM_FENCE_RESET;
ret = &cluster->cl_group;
o2nm_single_cluster = cluster;