[dm-devel] [RFC PATCH 3/6] multipathd: allow shutdown during configure()

[Martin Wilck]

reconfigure() can be a long-running operation; both initial path
discovery and initial map setup can take a long time. Allow
the main program to indicate that the process should be
interrupted if a shutdown signal was received.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 libmultipath/configure.c |  5 +++++
 libmultipath/discovery.c |  4 ++++
 libmultipath/exit.h      |  5 +++++
 mpathpersist/main.c      |  5 +++++
 multipath/main.c         |  6 ++++++
 multipathd/main.c        | 18 ++++++++++++++++++
 6 files changed, 43 insertions(+)
 create mode 100644 libmultipath/exit.h

diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index 84ae5f56..2b062b35 100644
--- a/libmultipath/configure.c
+++ b/libmultipath/configure.c
@@ -43,6 +43,7 @@
 #include "wwids.h"
 #include "sysfs.h"
 #include "io_err_stat.h"
+#include "exit.h"
 
 /* group paths in pg by host adapter
  */
@@ -1021,6 +1022,10 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
 
 	vector_foreach_slot (pathvec, pp1, k) {
 		int invalid;
+
+		if (should_exit())
+			return CP_FAIL;
+
 		/* skip this path for some reason */
 
 		/* 1. if path has no unique id or wwid blacklisted */
diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index 7f983a63..3834685c 100644
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -33,6 +33,7 @@
 #include "unaligned.h"
 #include "prioritizers/alua_rtpg.h"
 #include "foreign.h"
+#include "exit.h"
 
 int
 alloc_path_with_pathinfo (struct config *conf, struct udev_device *udevice,
@@ -160,6 +161,9 @@ path_discovery (vector pathvec, int flag)
 	udev_list_entry_foreach(entry,
 				udev_enumerate_get_list_entry(udev_iter)) {
 		const char *devtype;
+
+		if (should_exit())
+			break;
 		devpath = udev_list_entry_get_name(entry);
 		condlog(4, "Discover device %s", devpath);
 		udevice = udev_device_new_from_syspath(udev, devpath);
diff --git a/libmultipath/exit.h b/libmultipath/exit.h
new file mode 100644
index 00000000..1954c5ce
--- /dev/null
+++ b/libmultipath/exit.h
@@ -0,0 +1,5 @@
+#ifndef _EXIT_H
+#define _EXIT_H
+
+extern int should_exit(void);
+#endif /* _EXIT_H */
diff --git a/mpathpersist/main.c b/mpathpersist/main.c
index 10cba452..fa831a07 100644
--- a/mpathpersist/main.c
+++ b/mpathpersist/main.c
@@ -7,6 +7,7 @@
 #include "vector.h"
 #include "config.h"
 #include "structs.h"
+#include "exit.h"
 #include <getopt.h>
 #include <libudev.h>
 #include "mpath_persist.h"
@@ -42,6 +43,10 @@ int construct_transportid(const char * inp, struct transportid transid[], int nu
 
 int logsink;
 struct config *multipath_conf;
+int should_exit(void)
+{
+	return 0;
+}
 
 struct config *get_multipath_config(void)
 {
diff --git a/multipath/main.c b/multipath/main.c
index f40c179b..a5ca10ca 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -63,8 +63,14 @@
 #include "propsel.h"
 #include "time-util.h"
 #include "file.h"
+#include "exit.h"
 
 int logsink;
+int should_exit(void)
+{
+	return 0;
+}
+
 struct udev *udev;
 struct config *multipath_conf;
 
diff --git a/multipathd/main.c b/multipathd/main.c
index 6fc6a3ac..413beee0 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -67,6 +67,7 @@ static int use_watchdog;
 #include "uevent.h"
 #include "log.h"
 #include "uxsock.h"
+#include "exit.h"
 
 #include "mpath_cmd.h"
 #include "mpath_persist.h"
@@ -141,6 +142,11 @@ static inline enum daemon_status get_running_state(void)
 	return st;
 }
 
+int should_exit(void)
+{
+	return get_running_state() == DAEMON_SHUTDOWN;
+}
+
 /*
  * global copy of vecs for use in sig handlers
  */
@@ -2355,6 +2361,9 @@ configure (struct vectors * vecs)
 		goto fail;
 	}
 
+	if (should_exit())
+		goto fail;
+
 	conf = get_multipath_config();
 	pthread_cleanup_push(put_multipath_config, conf);
 	vector_foreach_slot (vecs->pathvec, pp, i){
@@ -2371,6 +2380,9 @@ configure (struct vectors * vecs)
 		goto fail;
 	}
 
+	if (should_exit())
+		goto fail;
+
 	/*
 	 * create new set of maps & push changed ones into dm
 	 * In the first call, use FORCE_RELOAD_WEAK to avoid making
@@ -2385,6 +2397,9 @@ configure (struct vectors * vecs)
 		goto fail;
 	}
 
+	if (should_exit())
+		goto fail;
+
 	/*
 	 * may need to remove some maps which are no longer relevant
 	 * e.g., due to blacklist changes in conf file
@@ -2396,6 +2411,9 @@ configure (struct vectors * vecs)
 
 	dm_lib_release();
 
+	if (should_exit())
+		goto fail;
+
 	sync_maps_state(mpvec);
 	vector_foreach_slot(mpvec, mpp, i){
 		if (remember_wwid(mpp->wwid) == 1)
-- 
2.19.2