autofs-5.1.1 - fix handle_mounts() termination condition check

From: Ian Kent <raven@themaw.net>

In get_pkt(), if a kernel request is present on the kernel pipe and

the autofs mount point state changes to ST_SHUTDOWN after the poll(2)

check but before the request has been processed the handle_mounts()

thread will exit without shutting down the autofs mount point.

So change the handle_mounts() exit condition check to take account

of this case.

Signed-off-by: Ian Kent <raven@themaw.net>

---

 CHANGELOG          |    1 

 daemon/automount.c |  191 ++++++++++++++++++++++++++++-------------------------

 2 files changed, 105 insertions(+), 87 deletions(-)

--- autofs-5.0.7.orig/CHANGELOG

+++ autofs-5.0.7/CHANGELOG

@@ -189,6 +189,7 @@

 - always set direct mounts catatonic at exit.

 - log pipe read errors.

 - fix rwlock unlock crash.

+- fix handle_mounts() termination condition check.

 25/07/2012 autofs-5.0.7

 =======================

--- autofs-5.0.7.orig/daemon/automount.c

+++ autofs-5.0.7/daemon/automount.c

@@ -1659,6 +1659,99 @@ static void submount_source_unlock_neste

 	master_source_unlock(parent->entry);

 }

+int handle_mounts_exit(struct autofs_point *ap)

+{

+	int ret, cur_state;

+

+	/*

+	 * If we're a submount we need to ensure our parent

+	 * doesn't try to mount us again until our shutdown

+	 * is complete and that any outstanding mounts are

+	 * completed before we try to shutdown.

+	 */

+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cur_state);

+

+	master_mutex_lock();

+

+	if (!ap->submount)

+		master_source_writelock(ap->entry);

+	else {

+		/*

+		 * If a mount request arrives before the locks are

+		 * aquired just return to ready state.

+		 */

+		ret = submount_source_writelock_nested(ap);

+		if (ret) {

+			warn(ap->logopt,

+			     "can't shutdown submount: mount in progress");

+			/* Return to ST_READY is done immediately */

+			st_add_task(ap, ST_READY);

+			master_mutex_unlock();

+			pthread_setcancelstate(cur_state, NULL);

+			return 0;

+		}

+	}

+

+	if (ap->state != ST_SHUTDOWN) {

+		if (!ap->submount)

+			alarm_add(ap, ap->exp_runfreq);

+		/* Return to ST_READY is done immediately */

+		st_add_task(ap, ST_READY);

+		if (ap->submount)

+			submount_source_unlock_nested(ap);

+		else

+			master_source_unlock(ap->entry);

+		master_mutex_unlock();

+

+		pthread_setcancelstate(cur_state, NULL);

+		return 0;

+	}

+

+	alarm_delete(ap);

+	st_remove_tasks(ap);

+	st_wait_task(ap, ST_ANY, 0);

+

+	/*

+	 * For a direct mount map all mounts have already gone

+	 * by the time we get here and since we only ever

+	 * umount direct mounts at shutdown there is no need

+	 * to check for possible recovery.

+	 */

+	if (ap->type == LKP_DIRECT) {

+		umount_autofs(ap, NULL, 1);

+		handle_mounts_cleanup(ap);

+		return 1;

+	}

+

+	/*

+	 * If umount_autofs returns non-zero it wasn't able

+	 * to complete the umount and has left the mount intact

+	 * so we can continue. This can happen if a lookup

+	 * occurs while we're trying to umount.

+	 */

+	ret = umount_autofs(ap, NULL, 1);

+	if (!ret) {

+		handle_mounts_cleanup(ap);

+		return 1;

+	}

+

+	/* 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);

+	/* Return to ST_READY is done immediately */

+	st_add_task(ap, ST_READY);

+	if (ap->submount)

+		submount_source_unlock_nested(ap);

+	else

+		master_source_unlock(ap->entry);

+	master_mutex_unlock();

+

+	pthread_setcancelstate(cur_state, NULL);

+

+	return 0;

+}

+

 void *handle_mounts(void *arg)

 {

 	struct startup_cond *suc;

@@ -1714,97 +1807,21 @@ void *handle_mounts(void *arg)

 	pthread_setcancelstate(cancel_state, NULL);

-	while (ap->state != ST_SHUTDOWN) {

+	while (1) {

 		if (handle_packet(ap)) {

-			int ret, cur_state;

-

-			/*

-			 * If we're a submount we need to ensure our parent

-			 * doesn't try to mount us again until our shutdown

-			 * is complete and that any outstanding mounts are

-			 * completed before we try to shutdown.

-			 */

-			pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cur_state);

-

-			master_mutex_lock();

-

-			if (ap->submount) {

-				/*

-				 * If a mount request arrives before the locks are

-				 * aquired just return to ready state.

-				 */

-				ret = submount_source_writelock_nested(ap);

-				if (ret) {

-					warn(ap->logopt,

-					     "can't shutdown submount: mount in progress");

-					/* Return to ST_READY is done immediately */

-					st_add_task(ap, ST_READY);

-					master_mutex_unlock();

-					pthread_setcancelstate(cur_state, NULL);

-					continue;

-				}

-			} else

-				master_source_writelock(ap->entry);

-

-			if (ap->state != ST_SHUTDOWN) {

-				if (!ap->submount)

-					alarm_add(ap, ap->exp_runfreq);

-				/* Return to ST_READY is done immediately */

-				st_add_task(ap, ST_READY);

-				if (ap->submount)

-					submount_source_unlock_nested(ap);

-				else

-					master_source_unlock(ap->entry);

-				master_mutex_unlock();

-

-				pthread_setcancelstate(cur_state, NULL);

-				continue;

-			}

-

-			alarm_delete(ap);

-			st_remove_tasks(ap);

-			st_wait_task(ap, ST_ANY, 0);

-

-			/*

-			 * For a direct mount map all mounts have already gone

-			 * by the time we get here and since we only ever

-			 * umount direct mounts at shutdown there is no need

-			 * to check for possible recovery.

-			 */

-			if (ap->type == LKP_DIRECT) {

-				umount_autofs(ap, NULL, 1);

-				handle_mounts_cleanup(ap);

+			if (handle_mounts_exit(ap))

 				break;

-			}

+		}

-			/*

-			 * If umount_autofs returns non-zero it wasn't able

-			 * to complete the umount and has left the mount intact

-			 * so we can continue. This can happen if a lookup

-			 * occurs while we're trying to umount.

-			 */

-			ret = umount_autofs(ap, NULL, 1);

-			if (!ret) {

-				handle_mounts_cleanup(ap);

+		/* If we get here a packet has been received and handled

+		 * and the autofs mount point has not been shutdown. But

+		 * if the autofs mount point has been set to ST_SHUTDOWN

+		 * we should attempt to perform the shutdown cleanup and

+		 * exit if successful.

+		 */

+		if (ap->state == ST_SHUTDOWN) {

+			if (handle_mounts_exit(ap))

 				break;

-			}

-

-			/* 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);

-			/* Return to ST_READY is done immediately */

-			st_add_task(ap, ST_READY);

-			if (ap->submount)

-				submount_source_unlock_nested(ap);

-			else

-				master_source_unlock(ap->entry);

-			master_mutex_unlock();

-

-			pthread_setcancelstate(cur_state, NULL);

-

 		}

 	}