autofs-5.1.6 - only add expire alarm for active mounts

From: Ian Kent <raven@themaw.net>

There's no need to add expire alarms for mount points that have no
expirable mounts.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 CHANGELOG           |    1 
 daemon/automount.c  |    9 +-------
 daemon/direct.c     |    3 ++
 daemon/indirect.c   |    3 ++
 daemon/state.c      |   25 +++++++++++-----------
 include/automount.h |    1 
 include/mounts.h    |    1 
 lib/alarm.c         |   57 ++++++++++++++++++++++++++++++++++++++++++++++++----
 lib/mounts.c        |   19 +++++++++++++++++
 9 files changed, 96 insertions(+), 23 deletions(-)

--- autofs-5.1.4.orig/CHANGELOG
+++ autofs-5.1.4/CHANGELOG
@@ -131,6 +131,7 @@ xx/xx/2018 autofs-5.1.5
 - use struct mnt_list to track mounted mounts.
 - use struct mnt_list mounted list for expire.
 - remove unused function tree_get_mnt_list().
+- only add expre alarm for active mounts.
 
 19/12/2017 autofs-5.1.4
 - fix spec file url.
--- autofs-5.1.4.orig/daemon/automount.c
+++ autofs-5.1.4/daemon/automount.c
@@ -1844,7 +1844,7 @@ int handle_mounts_exit(struct autofs_poi
 
 	if (ap->state != ST_SHUTDOWN) {
 		if (!ap->submount)
-			alarm_add(ap, ap->exp_runfreq);
+			conditional_alarm_add(ap, ap->exp_runfreq);
 		/* Return to ST_READY is done immediately */
 		st_add_task(ap, ST_READY);
 		if (ap->submount)
@@ -1889,7 +1889,7 @@ int handle_mounts_exit(struct autofs_poi
 	/* Failed shutdown returns to ready */
 	warn(ap->logopt, "can't shutdown: filesystem %s still busy", ap->path);
 	if (!ap->submount)
-		alarm_add(ap, ap->exp_runfreq);
+		conditional_alarm_add(ap, ap->exp_runfreq);
 	/* Return to ST_READY is done immediately */
 	st_add_task(ap, ST_READY);
 	if (ap->submount)
@@ -1952,11 +1952,6 @@ void *handle_mounts(void *arg)
 	suc->status = 0;
 	pthread_cleanup_pop(1);
 
-	/* We often start several automounters at the same time.  Add some
-	   randomness so we don't all expire at the same time. */
-	if (!ap->submount && ap->exp_runfreq)
-		alarm_add(ap, ap->exp_runfreq + rand() % ap->exp_runfreq);
-
 	pthread_setcancelstate(cancel_state, NULL);
 
 	while (1) {
--- autofs-5.1.4.orig/daemon/direct.c
+++ autofs-5.1.4/daemon/direct.c
@@ -1245,6 +1245,9 @@ static void *do_mount_direct(void *arg)
 		info(ap->logopt, "mounted %s", mt.name);
 
 		mnts_set_mounted_mount(ap, mt.name);
+
+		if (!ap->submount)
+			conditional_alarm_add(ap, ap->exp_runfreq);
 	} else {
 		/* TODO: get mount return status from lookup_nss_mount */
 		ops->send_fail(ap->logopt,
--- autofs-5.1.4.orig/daemon/indirect.c
+++ autofs-5.1.4/daemon/indirect.c
@@ -753,6 +753,9 @@ static void *do_mount_indirect(void *arg
 		info(ap->logopt, "mounted %s", buf);
 
 		mnts_set_mounted_mount(ap, mt.name);
+
+		if (!ap->submount)
+			conditional_alarm_add(ap, ap->exp_runfreq);
 	} else {
 		/* TODO: get mount return status from lookup_nss_mount */
 		ops->send_fail(ap->logopt,
--- autofs-5.1.4.orig/daemon/state.c
+++ autofs-5.1.4/daemon/state.c
@@ -155,7 +155,7 @@ void expire_cleanup(void *arg)
 				ap->submount = 1;
 
 			if (ap->state == ST_EXPIRE && !ap->submount)
-				alarm_add(ap, ap->exp_runfreq);
+				conditional_alarm_add(ap, ap->exp_runfreq);
 
 			/* FALLTHROUGH */
 
@@ -173,7 +173,7 @@ void expire_cleanup(void *arg)
 			if (!rv && !idle && !ap->shutdown) {
 				next = ST_READY;
 				if (!ap->submount)
-					alarm_add(ap, ap->exp_runfreq);
+					conditional_alarm_add(ap, ap->exp_runfreq);
 				break;
 			}
 
@@ -187,7 +187,7 @@ void expire_cleanup(void *arg)
 			/* Failed shutdown returns to ready */
 			warn(ap->logopt, "filesystem %s still busy", ap->path);
 			if (!ap->submount)
-				alarm_add(ap, ap->exp_runfreq);
+				conditional_alarm_add(ap, ap->exp_runfreq);
 			next = ST_READY;
 			break;
 #endif
@@ -522,9 +522,10 @@ static void *do_readmap(void *arg)
 		 * alarm will have been added. So add it here if there are
 		 * now map entries.
 		 */
-		if (append_alarm && ap->exp_runfreq)
-			alarm_add(ap, ap->exp_runfreq +
-				  rand() % ap->exp_runfreq);
+		if (append_alarm && ap->exp_runfreq) {
+			time_t seconds = ap->exp_runfreq + rand() % ap->exp_runfreq;
+			conditional_alarm_add(ap, seconds);
+		}
 
 		pthread_cleanup_pop(1);
 		pthread_cleanup_pop(1);
@@ -577,7 +578,7 @@ static unsigned int st_readmap(struct au
 		/* It didn't work: return to ready */
 		st_ready(ap);
 		if (!ap->submount)
-			alarm_add(ap, ap->exp_runfreq);
+			conditional_alarm_add(ap, ap->exp_runfreq);
 		return 0;
 	}
 
@@ -604,7 +605,7 @@ static unsigned int st_readmap(struct au
 		/* It didn't work: return to ready */
 		st_ready(ap);
 		if (!ap->submount)
-			alarm_add(ap, ap->exp_runfreq);
+			conditional_alarm_add(ap, ap->exp_runfreq);
 		return 0;
 	}
 	ap->readmap_thread = thid;
@@ -640,7 +641,7 @@ static unsigned int st_prepare_shutdown(
 	case EXP_PARTIAL:
 		/* It didn't work: return to ready */
 		if (!ap->submount)
-			alarm_add(ap, ap->exp_runfreq);
+			conditional_alarm_add(ap, ap->exp_runfreq);
 		st_ready(ap);
 		return 0;
 
@@ -666,7 +667,7 @@ static unsigned int st_force_shutdown(st
 	case EXP_PARTIAL:
 		/* It didn't work: return to ready */
 		if (!ap->submount)
-			alarm_add(ap, ap->exp_runfreq);
+			conditional_alarm_add(ap, ap->exp_runfreq);
 		st_ready(ap);
 		return 0;
 
@@ -699,7 +700,7 @@ static unsigned int st_prune(struct auto
 	case EXP_ERROR:
 	case EXP_PARTIAL:
 		if (!ap->submount)
-			alarm_add(ap, ap->exp_runfreq);
+			conditional_alarm_add(ap, ap->exp_runfreq);
 		st_ready(ap);
 		return 0;
 
@@ -720,7 +721,7 @@ static unsigned int st_expire(struct aut
 	case EXP_ERROR:
 	case EXP_PARTIAL:
 		if (!ap->submount)
-			alarm_add(ap, ap->exp_runfreq);
+			conditional_alarm_add(ap, ap->exp_runfreq);
 		st_ready(ap);
 		return 0;
 
--- autofs-5.1.4.orig/include/automount.h
+++ autofs-5.1.4/include/automount.h
@@ -637,6 +637,7 @@ static inline time_t monotonic_time(time
 /* Expire alarm handling routines */
 int alarm_start_handler(void);
 int alarm_add(struct autofs_point *ap, time_t seconds);
+int conditional_alarm_add(struct autofs_point *ap, time_t seconds);
 void alarm_delete(struct autofs_point *ap);
 
 #endif
--- autofs-5.1.4.orig/include/mounts.h
+++ autofs-5.1.4/include/mounts.h
@@ -125,6 +125,7 @@ void mnts_remove_amdmount(const char *mp
 struct mnt_list *mnts_add_mount(struct autofs_point *ap, const char *name, unsigned int flags);
 void mnts_remove_mount(const char *mp, unsigned int flags);
 struct mnt_list *get_mnt_list(const char *path, int include);
+unsigned int mnts_has_mounted_mounts(struct autofs_point *ap);
 void mnts_get_expire_list(struct list_head *mnts, struct autofs_point *ap);
 void mnts_put_expire_list(struct list_head *mnts);
 void mnts_set_mounted_mount(struct autofs_point *ap, const char *name);
--- autofs-5.1.4.orig/lib/alarm.c
+++ autofs-5.1.4/lib/alarm.c
@@ -41,7 +41,7 @@ do { \
 } while (0)
 
 /* Insert alarm entry on ordered list. */
-int alarm_add(struct autofs_point *ap, time_t seconds)
+int __alarm_add(struct autofs_point *ap, time_t seconds)
 {
 	struct list_head *head;
 	struct list_head *p;
@@ -62,8 +62,6 @@ int alarm_add(struct autofs_point *ap, t
 	new->cancel = 0;
 	new->time = now + seconds;
 
-	alarm_lock();
-
 	head = &alarms;
 
 	/* Check if we have a pending alarm */
@@ -97,9 +95,42 @@ int alarm_add(struct autofs_point *ap, t
 			fatal(status);
 	}
 
+	return 1;
+}
+
+int alarm_add(struct autofs_point *ap, time_t seconds)
+{
+	int status;
+
+	alarm_lock();
+	status = __alarm_add(ap, seconds);
 	alarm_unlock();
 
-	return 1;
+	return status;
+}
+
+static int __alarm_exists(struct autofs_point *ap)
+{
+	struct list_head *head;
+	struct list_head *p;
+
+	head = &alarms;
+
+	if (list_empty(head))
+		return 0;
+
+	p = head->next;
+	while (p != head) {
+		struct alarm *this;
+
+		this = list_entry(p, struct alarm, list);
+		p = p->next;
+
+		if (ap == this->ap)
+			return 1;
+	}
+
+	return 0;
 }
 
 void alarm_delete(struct autofs_point *ap)
@@ -152,6 +183,24 @@ void alarm_delete(struct autofs_point *a
 	return;
 }
 
+int conditional_alarm_add(struct autofs_point *ap, time_t seconds)
+{
+	int status;
+
+	if (!mnts_has_mounted_mounts(ap))
+		return 1;
+
+	alarm_lock();
+	if (__alarm_exists(ap)) {
+		alarm_unlock();
+		return 1;
+	}
+	status = __alarm_add(ap, seconds);
+	alarm_unlock();
+
+	return status;
+}
+
 static void *alarm_handler(void *arg)
 {
 	struct list_head *head;
--- autofs-5.1.4.orig/lib/mounts.c
+++ autofs-5.1.4/lib/mounts.c
@@ -1208,6 +1208,19 @@ void mnts_set_mounted_mount(struct autof
 	}
 }
 
+unsigned int mnts_has_mounted_mounts(struct autofs_point *ap)
+{
+	unsigned int has_mounted_mounts = 0;
+
+	mnts_hash_mutex_lock();
+	if (list_empty(&ap->mounts))
+		goto done;
+	has_mounted_mounts = 1;
+done:
+	mnts_hash_mutex_unlock();
+	return has_mounted_mounts;
+}
+
 struct node {
 	struct mnt_list *mnt;
 	struct node *left;
@@ -1907,6 +1920,9 @@ static int do_remount_direct(struct auto
 		mnts_set_mounted_mount(ap, path);
 
 		info(ap->logopt, "re-connected to %s", path);
+
+		if (!ap->submount)
+			conditional_alarm_add(ap, ap->exp_runfreq);
 	} else {
 		status = REMOUNT_FAIL;
 		info(ap->logopt, "failed to re-connect %s", path);
@@ -1980,6 +1996,9 @@ static int do_remount_indirect(struct au
 			mnts_set_mounted_mount(ap, buf);
 
 			info(ap->logopt, "re-connected to %s", buf);
+
+			if (!ap->submount)
+				conditional_alarm_add(ap, ap->exp_runfreq);
 		} else {
 			status = REMOUNT_FAIL;
 			info(ap->logopt, "failed to re-connect %s", buf);