[DLM] add lock timeouts and warnings [2/6]

New features: lock timeouts and time warnings.  If the DLM_LKF_TIMEOUT
flag is set, then the request/conversion will be canceled after waiting
the specified number of centiseconds (specified per lock).  This feature
is only available for locks requested through libdlm (can be enabled for
kernel dlm users if there's a use for it.)

If the new DLM_LSFL_TIMEWARN flag is set when creating the lockspace, then
a warning message will be sent to userspace (using genetlink) after a
request/conversion has been waiting for a given number of centiseconds
(configurable per node).  The time warnings will be used in the future
to do deadlock detection in userspace.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index 5a3d390cc82..2909abf1bbc 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -90,6 +90,7 @@ struct cluster {
         unsigned int cl_scan_secs;
         unsigned int cl_log_debug;
         unsigned int cl_protocol;
+        unsigned int cl_timewarn_cs;
 };
 
 enum {
@@ -103,6 +104,7 @@ enum {
         CLUSTER_ATTR_SCAN_SECS,
         CLUSTER_ATTR_LOG_DEBUG,
         CLUSTER_ATTR_PROTOCOL,
+        CLUSTER_ATTR_TIMEWARN_CS,
 };
 
 struct cluster_attribute {
@@ -162,6 +164,7 @@ CLUSTER_ATTR(toss_secs, 1);
 CLUSTER_ATTR(scan_secs, 1);
 CLUSTER_ATTR(log_debug, 0);
 CLUSTER_ATTR(protocol, 0);
+CLUSTER_ATTR(timewarn_cs, 1);
 
 static struct configfs_attribute *cluster_attrs[] = {
         [CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port.attr,
@@ -174,6 +177,7 @@ static struct configfs_attribute *cluster_attrs[] = {
         [CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs.attr,
         [CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug.attr,
         [CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol.attr,
+        [CLUSTER_ATTR_TIMEWARN_CS] = &cluster_attr_timewarn_cs.attr,
         NULL,
 };
 
@@ -916,6 +920,7 @@ int dlm_our_addr(struct sockaddr_storage *addr, int num)
 #define DEFAULT_SCAN_SECS          5
 #define DEFAULT_LOG_DEBUG          0
 #define DEFAULT_PROTOCOL           0
+#define DEFAULT_TIMEWARN_CS      500 /* 5 sec = 500 centiseconds */
 
 struct dlm_config_info dlm_config = {
         .ci_tcp_port = DEFAULT_TCP_PORT,
@@ -927,6 +932,7 @@ struct dlm_config_info dlm_config = {
         .ci_toss_secs = DEFAULT_TOSS_SECS,
         .ci_scan_secs = DEFAULT_SCAN_SECS,
         .ci_log_debug = DEFAULT_LOG_DEBUG,
-        .ci_protocol = DEFAULT_PROTOCOL
+        .ci_protocol = DEFAULT_PROTOCOL,
+        .ci_timewarn_cs = DEFAULT_TIMEWARN_CS
 };