Merge pull request #143 from gonzoleeman/use-sd_notify-for-systemd

Use sd notify for systemd

8 files changed, 140 insertions, 20 deletions

diff --git a/etc/systemd/iscsi.service b/etc/systemd/iscsi.service
new file mode 100644
index 0000000..0edcf51
--- /dev/null
+++ b/etc/systemd/iscsi.service
@@ -0,0 +1,17 @@
+[Unit]
+Description=Login and scanning of iSCSI devices
+Documentation=man:iscsiadm(8) man:iscsid(8)
+Before=remote-fs.target
+After=network.target network-online.target iscsid.service
+ConditionPathExists=/etc/iscsi/initiatorname.iscsi
+
+[Service]
+Type=oneshot
+ExecStart=-/sbin/iscsiadm -m node --loginall=automatic
+ExecStop=/sbin/iscsiadm -m node --logoutall=automatic
+ExecStop=/sbin/iscsiadm -m node --logoutall=manual
+SuccessExitStatus=21
+RemainAfterExit=true
+
+[Install]
+WantedBy=remote-fs.target
diff --git a/etc/systemd/iscsid.service b/etc/systemd/iscsid.service
index 028e0b3..f5e8979 100644
--- a/etc/systemd/iscsid.service
+++ b/etc/systemd/iscsid.service
@@ -1,13 +1,16 @@
 [Unit]
 Description=Open-iSCSI
 Documentation=man:iscsid(8) man:iscsiuio(8) man:iscsiadm(8)
-After=network.target NetworkManager-wait-online.service iscsiuio.service tgtd.service targetcli.service
+DefaultDependencies=no
+After=network.target iscsiuio.service
+Before=remote-fs-pre.target
 
 [Service]
-Type=forking
-PIDFile=/var/run/iscsid.pid
-ExecStart=/usr/sbin/iscsid
-ExecStop=/sbin/iscsiadm -k 0 2
+Type=notify
+NotifyAccess=main
+ExecStart=/sbin/iscsid -f
+KillMode=mixed
 
 [Install]
 WantedBy=multi-user.target
+Also=iscsid.socket
diff --git a/etc/systemd/iscsid.socket b/etc/systemd/iscsid.socket
index 832451d..58a8d12 100644
--- a/etc/systemd/iscsid.socket
+++ b/etc/systemd/iscsid.socket
@@ -1,6 +1,6 @@
 [Unit]
 Description=Open-iSCSI iscsid Socket
-Documentation=man:iscsid(8) man:iscsiuio(8) man:iscsiadm(8)
+Documentation=man:iscsid(8) man:iscsiadm(8)
 
 [Socket]
 ListenStream=@ISCSIADM_ABSTRACT_NAMESPACE
diff --git a/usr/event_poll.c b/usr/event_poll.c
index ac25044..4cf4ce2 100644
--- a/usr/event_poll.c
+++ b/usr/event_poll.c
@@ -41,6 +41,10 @@
 
 static unsigned int reap_count;
 
+/* track pid of reload fork, while running */
+static pid_t reload_pid = 0;
+static void (*reload_callback)(void);
+
 #define REAP_WAKEUP 1000 /* in millisecs */
 
 void reap_inc(void)
@@ -48,9 +52,18 @@ void reap_inc(void)
 	reap_count++;
 }
 
+/* track the reload process to be reaped, when done */
+void reap_track_reload_process(pid_t reload_proc_pid, void (*reload_done_callback)(void))
+{
+	reload_pid = reload_proc_pid;
+	reload_callback = reload_done_callback;
+	reap_inc();
+}
+
 void reap_proc(void)
 {
-	int rc, i, max_reaps;
+	int i, max_reaps;
+	pid_t rc;
 
 	/*
 	 * We don't really need reap_count, but calling wait() all the
@@ -60,9 +73,13 @@ void reap_proc(void)
 	for (i = 0; i < max_reaps; i++) {
 		rc = waitpid(0, NULL, WNOHANG);
 		if (rc > 0) {
+			if (rc == reload_pid) {
+				log_debug(6, "reaped reload process");
+				reload_callback();
+			}
 			reap_count--;
 			log_debug(6, "reaped pid %d, reap_count now %d",
-				  rc, reap_count);
+				  (int)rc, reap_count);
 		}
 	}
 }
diff --git a/usr/event_poll.h b/usr/event_poll.h
index c0eed5c..f23132b 100644
--- a/usr/event_poll.h
+++ b/usr/event_poll.h
@@ -25,6 +25,7 @@ struct queue_task;
 int shutdown_callback(pid_t pid);
 void reap_proc(void);
 void reap_inc(void);
+void reap_track_reload_process(pid_t realod_proc_pid, void (*reload_done_callback)(void));
 void event_loop(struct iscsi_ipc *ipc, int control_fd, int mgmt_ipc_fd);
 void event_loop_exit(struct queue_task *qtask);
 
diff --git a/usr/iscsi_sysfs.c b/usr/iscsi_sysfs.c
index 8e89b30..f79a1af 100644
--- a/usr/iscsi_sysfs.c
+++ b/usr/iscsi_sysfs.c
@@ -1514,6 +1514,51 @@ free_info:
 	return rc;
 }
 
+/*
+ * count the number of sessions -- a much-simplified
+ * version of iscsi_sysfs_for_each_session
+ *
+ * TODO: return an array of the session info we find, for use
+ * by iscsi_sysfs_for_each_session(), so it doesn't have to
+ * do it all over again
+ */
+int iscsi_sysfs_count_sessions(void)
+{
+	struct dirent **namelist = NULL;
+	int n, i;
+	struct session_info *info;
+
+
+	info = calloc(1, sizeof(*info));
+	if (!info)
+		/* no sessions found */
+		return 0;
+	info->iscsid_req_tmo = -1;
+
+	n = scandir(ISCSI_SESSION_DIR, &namelist, trans_filter, alphasort);
+	if (n <= 0)
+		/* no sessions found */
+		goto free_info;
+
+	/*
+	 * try to get session info for each session found, but ignore
+	 * errors if any since it may be a race condition
+	 */
+	for (i = 0; i < n; i++)
+		if (iscsi_sysfs_get_sessioninfo_by_id(info,
+					namelist[i]->d_name) != 0)
+			log_warning("could not find session info for %s",
+					namelist[i]->d_name);
+
+	for (i = 0; i < n; i++)
+		free(namelist[i]);
+	free(namelist);
+
+free_info:
+	free(info);
+	return n;
+}
+
 int iscsi_sysfs_get_session_state(char *state, int sid)
 {
 	char id[NAME_SIZE];
diff --git a/usr/iscsi_sysfs.h b/usr/iscsi_sysfs.h
index cdcefa6..1d0377f 100644
--- a/usr/iscsi_sysfs.h
+++ b/usr/iscsi_sysfs.h
@@ -53,6 +53,7 @@ extern int iscsi_sysfs_for_each_iface_on_host(void *data, uint32_t host_no,
 extern int iscsi_sysfs_for_each_session(void *data, int *nr_found,
 					iscsi_sysfs_session_op_fn *fn,
 					int in_parallel);
+extern int iscsi_sysfs_count_sessions(void);
 extern int iscsi_sysfs_for_each_host(void *data, int *nr_found,
 				     iscsi_sysfs_host_op_fn *fn);
 extern uint32_t iscsi_sysfs_get_host_no_from_sid(uint32_t sid, int *err);
diff --git a/usr/iscsid.c b/usr/iscsid.c
index 35e95ba..0c98440 100644
--- a/usr/iscsid.c
+++ b/usr/iscsid.c
@@ -34,6 +34,7 @@
 #include <sys/wait.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <systemd/sd-daemon.h>
 
 #include "iscsid.h"
 #include "mgmt_ipc.h"
@@ -62,6 +63,7 @@ static pid_t log_pid;
 static gid_t gid;
 static int daemonize = 1;
 static int mgmt_ipc_fd;
+static int sessions_to_recover = 0;
 
 static struct option const long_options[] = {
 	{"config", required_argument, NULL, 'c'},
@@ -334,6 +336,26 @@ static void missing_iname_warn(char *initiatorname_file)
 		  "ignored.", initiatorname_file, initiatorname_file);
 }
 
+/* called right before we enter the event loop */
+static void set_state_to_ready(void)
+{
+	if (sessions_to_recover)
+		sd_notify(0, "READY=1\n"
+				"RELOADING=1\n"
+				"STATUS=Syncing existing session(s)\n");
+	else
+		sd_notify(0, "READY=1\n"
+				"STATUS=Ready to process requests\n");
+}
+
+/* called when recovery process has been reaped */
+static void set_state_done_reloading(void)
+{
+	sessions_to_recover = 0;
+	sd_notifyf(0, "READY=1\n"
+			"STATUS=Ready to process requests\n");
+}
+
 int main(int argc, char *argv[])
 {
 	struct utsname host_info; /* will use to compound initiator alias */
@@ -526,18 +548,31 @@ int main(int argc, char *argv[])
 		daemon_config.safe_logout = 1;
 	free(safe_logout);
 
-	pid = fork();
-	if (pid == 0) {
-		int nr_found = 0;
-		/* child */
-		/* TODO - test with async support enabled */
-		iscsi_sysfs_for_each_session(NULL, &nr_found, sync_session, 0);
-		exit(0);
-	} else if (pid < 0) {
-		log_error("Fork failed error %d: existing sessions"
-			  " will not be synced", errno);
-	} else
-		reap_inc();
+	/* see if we have any stale sessions to recover */
+	sessions_to_recover = iscsi_sysfs_count_sessions();
+	if (sessions_to_recover) {
+
+		/*
+		 * recover stale sessions in the background
+		 */
+
+		pid = fork();
+		if (pid == 0) {
+			int nr_found; /* not used */
+			/* child */
+			/* TODO - test with async support enabled */
+			iscsi_sysfs_for_each_session(NULL, &nr_found, sync_session, 0);
+			exit(0);
+		} else if (pid < 0) {
+			log_error("Fork failed error %d: existing sessions"
+				  " will not be synced", errno);
+		} else {
+			/* parent */
+			log_debug(8, "forked child (pid=%d) to recover %d session(s)",
+					(int)pid, sessions_to_recover);
+			reap_track_reload_process(pid, set_state_done_reloading);
+		}
+	}
 
 	iscsi_initiator_init();
 	increase_max_files();
@@ -554,6 +589,7 @@ int main(int argc, char *argv[])
 		exit(ISCSI_ERR);
 	}
 
+	set_state_to_ready();
 	event_loop(ipc, control_fd, mgmt_ipc_fd);
 
 	idbm_terminate();