mdmon: wait after trying to kill

Now that mdmon handles sigterm if another monitor wants to take over it
should wait until all managed arrays are clean.  So make WaitClean()
available to mdmon and teach try_kill_monitor() to wait on each subarray
in the container.

...since we may be communicating with a dieing process, we need to
block SIGPIPE earlier.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 47 insertions, 22 deletions

diff --git a/mdmon.c b/mdmon.c
index 7ef0c80f..d40adb26 100644
--- a/mdmon.c
+++ b/mdmon.c
@@ -105,11 +105,25 @@ int make_pidfile(char *devname, int o_excl)
 	return 0;
 }
 
+int is_container_member(struct mdstat_ent *mdstat, char *container)
+{
+	if (mdstat->metadata_version == NULL ||
+	    strncmp(mdstat->metadata_version, "external:", 9) != 0 ||
+	    !is_subarray(mdstat->metadata_version+9) ||
+	    strncmp(mdstat->metadata_version+10, container, strlen(container)) != 0 ||
+	    mdstat->metadata_version[10+strlen(container)] != '/')
+		return 0;
+
+	return 1;
+}
+
+void remove_pidfile(char *devname);
 static void try_kill_monitor(char *devname)
 {
 	char buf[100];
 	int fd;
 	pid_t pid;
+	struct mdstat_ent *mdstat;
 
 	sprintf(buf, "/var/run/mdadm/%s.pid", devname);
 	fd = open(buf, O_RDONLY);
@@ -135,8 +149,19 @@ static void try_kill_monitor(char *devname)
 		return;
 	}
 
-	if (strstr(buf, "mdmon") != NULL)
-		kill(pid, SIGTERM);
+	if (!strstr(buf, "mdmon"))
+		return;
+
+	kill(pid, SIGTERM);
+
+	mdstat = mdstat_read(0, 0);
+	for ( ; mdstat; mdstat = mdstat->next)
+		if (is_container_member(mdstat, devname)) {
+			sprintf(buf, "/dev/%s", mdstat->dev);
+			WaitClean(buf);
+		}
+	free_mdstat(mdstat);
+	remove_pidfile(devname);
 }
 
 void remove_pidfile(char *devname)
@@ -268,6 +293,26 @@ int main(int argc, char *argv[])
 	container->devname = devnum2devname(container->devnum);
 	container->device_name = argv[1];
 
+	/* SIGUSR is sent between parent and child.  So both block it
+	 * and enable it only with pselect.
+	 */
+	sigemptyset(&set);
+	sigaddset(&set, SIGUSR1);
+	sigaddset(&set, SIGHUP);
+	sigaddset(&set, SIGALRM);
+	sigaddset(&set, SIGTERM);
+	sigprocmask(SIG_BLOCK, &set, NULL);
+	act.sa_handler = wake_me;
+	act.sa_flags = 0;
+	sigaction(SIGUSR1, &act, NULL);
+	sigaction(SIGALRM, &act, NULL);
+	act.sa_handler = hup;
+	sigaction(SIGHUP, &act, NULL);
+	act.sa_handler = term;
+	sigaction(SIGTERM, &act, NULL);
+	act.sa_handler = SIG_IGN;
+	sigaction(SIGPIPE, &act, NULL);
+
 	/* If this fails, we hope it already exists */
 	mkdir("/var/run/mdadm", 0600);
 	/* pid file lives in /var/run/mdadm/mdXX.pid */
@@ -364,26 +409,6 @@ int main(int argc, char *argv[])
 
 	mlockall(MCL_FUTURE);
 
-	/* SIGUSR is sent between parent and child.  So both block it
-	 * and enable it only with pselect.
-	 */
-	sigemptyset(&set);
-	sigaddset(&set, SIGUSR1);
-	sigaddset(&set, SIGHUP);
-	sigaddset(&set, SIGALRM);
-	sigaddset(&set, SIGTERM);
-	sigprocmask(SIG_BLOCK, &set, NULL);
-	act.sa_handler = wake_me;
-	act.sa_flags = 0;
-	sigaction(SIGUSR1, &act, NULL);
-	sigaction(SIGALRM, &act, NULL);
-	act.sa_handler = hup;
-	sigaction(SIGHUP, &act, NULL);
-	act.sa_handler = term;
-	sigaction(SIGTERM, &act, NULL);
-	act.sa_handler = SIG_IGN;
-	sigaction(SIGPIPE, &act, NULL);
-
 	if (clone_monitor(container) < 0) {
 		fprintf(stderr, "mdmon: failed to start monitor process: %s\n",
 			strerror(errno));