Make xenstored reopen its trace file on SIGHUP. This allows one to rotate the

logs beneath the daemon.

Signed-off-by: Ewan Mellor <ewan@xensource.com>

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 4dcdb52ef4ca96fdad10758a3bb807d3edc50166..268e859108541bd1ed8bbfe67755489892d4ed4a 100644 (file)
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -56,6 +56,7 @@ extern int eventchn_fd; /* in xenstored_domain.c */
 static bool verbose;
 LIST_HEAD(connections);
 static int tracefd = -1;
+static char *tracefile = NULL;
 static TDB_CONTEXT *tdb_ctx;
 
 #ifdef TESTING
@@ -242,6 +243,21 @@ void trace(const char *fmt, ...)
        talloc_free(str);
 }
 
+void reopen_log()
+{
+       if (!tracefile)
+               return;
+
+       if (tracefd > 0)
+               close(tracefd);
+       tracefd = open(tracefile, O_WRONLY|O_CREAT|O_APPEND, 0600);
+       if (tracefd < 0) {
+               perror("Could not open tracefile");
+               return;
+       }
+       write(tracefd, "\n***\n", strlen("\n***\n"));
+}
+
 static bool write_messages(struct connection *conn)
 {
        int ret;
@@ -1498,11 +1514,7 @@ int main(int argc, char *argv[])
                        outputpid = true;
                        break;
                case 'T':
-                       tracefd = open(optarg, O_WRONLY|O_CREAT|O_APPEND, 0600);
-                       if (tracefd < 0)
-                               barf_perror("Could not open tracefile %s",
-                                           optarg);
-                        write(tracefd, "\n***\n", strlen("\n***\n"));
+                       tracefile = optarg;
                        break;
                case 'V':
                        verbose = true;
@@ -1512,6 +1524,8 @@ int main(int argc, char *argv[])
        if (optind != argc)
                barf("%s: No arguments desired", argv[0]);
 
+       reopen_log();
+
        if (dofork) {
                openlog("xenstored", 0, LOG_DAEMON);
                daemonize();
@@ -1578,6 +1592,8 @@ int main(int argc, char *argv[])
                close(STDERR_FILENO);
        }
 
+       signal(SIGHUP, reopen_log);
+
 #ifdef TESTING
        signal(SIGUSR1, stop_failtest);
 #endif