vlog: Add vlog/close command.

Requested-by: P R Dinesh
Requested-at: https://github.com/openvswitch/ovs/pull/94
Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Russell Bryant <russell@ovn.org>

2 files changed, 31 insertions, 2 deletions

diff --git a/lib/vlog-unixctl.man b/lib/vlog-unixctl.man
index 7c47634fa..7372a7ef4 100644
--- a/lib/vlog-unixctl.man
+++ b/lib/vlog-unixctl.man
@@ -54,9 +54,14 @@ Lists the supported logging modules and their current levels.
 .IP "\fBvlog/list-pattern\fR"
 Lists logging patterns used for each destination.
 .
+.IP "\fBvlog/close\fR"
+Causes \fB\*(PN\fR to close its log file, if it is open.  (Use
+\fBvlog/reopen\fR to reopen it later.)
+.
 .IP "\fBvlog/reopen\fR"
-Causes \fB\*(PN\fR to close and reopen its log file.  (This is useful
-after rotating log files, to cause a new log file to be used.)
+Causes \fB\*(PN\fR to close its log file, if it is open, and then
+reopen it.  (This is useful after rotating log files, to cause a new
+log file to be used.)
 .IP
 This has no effect unless \fB\*(PN\fR was invoked with the
 \fB\-\-log\-file\fR option.
diff --git a/lib/vlog.c b/lib/vlog.c
index f514d65b5..49260d803 100644
--- a/lib/vlog.c
+++ b/lib/vlog.c
@@ -678,6 +678,28 @@ vlog_unixctl_reopen(struct unixctl_conn *conn, int argc OVS_UNUSED,
 }
 
 static void
+vlog_unixctl_close(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                   const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
+{
+    ovs_mutex_lock(&log_file_mutex);
+    if (log_fd >= 0) {
+        close(log_fd);
+        log_fd = -1;
+
+        async_append_destroy(log_writer);
+        log_writer = NULL;
+
+        struct vlog_module *mp;
+        LIST_FOR_EACH (mp, list, &vlog_modules) {
+            update_min_level(mp);
+        }
+    }
+    ovs_mutex_unlock(&log_file_mutex);
+
+    unixctl_command_reply(conn, NULL);
+}
+
+static void
 set_all_rate_limits(bool enable)
 {
     struct vlog_module *mp;
@@ -771,6 +793,8 @@ vlog_init(void)
                                  0, INT_MAX, vlog_disable_rate_limit, NULL);
         unixctl_command_register("vlog/reopen", "", 0, 0,
                                  vlog_unixctl_reopen, NULL);
+        unixctl_command_register("vlog/close", "", 0, 0,
+                                 vlog_unixctl_close, NULL);
 
         ovs_rwlock_rdlock(&pattern_rwlock);
         print_syslog_target_deprecation = syslog_fd >= 0;