autofs-5.1.7 - don't add offset mounts to mounted mounts table

From: Ian Kent <raven@themaw.net>

Multi-mount offset mounts are added to the mounted mounts table whether

they have a real mount or not. If there are a large number of offsets

this can add unnecessary overhead to the mounted mounts table processing.

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

---

 CHANGELOG         |    1 +

 daemon/direct.c   |   14 ++++----------

 daemon/indirect.c |    4 +++-

 include/mounts.h  |    2 +-

 lib/mounts.c      |   43 +++++++++++--------------------------------

 5 files changed, 20 insertions(+), 44 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index cb709773..b144f6aa 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -22,6 +22,7 @@

 - remove unused mount offset list lock functions.

 - eliminate count_mounts() from expire_proc_indirect().

 - eliminate some strlen calls in offset handling.

+- don't add offset mounts to mounted mounts table.

 25/01/2021 autofs-5.1.7

 - make bind mounts propagation slave by default.

diff --git a/daemon/direct.c b/daemon/direct.c

index 311a98ba..fbfebbdd 100644

--- a/daemon/direct.c

+++ b/daemon/direct.c

@@ -605,9 +605,6 @@ force_umount:

 	} else

 		info(ap->logopt, "umounted offset mount %s", me->key);

-	if (!rv)

-		mnts_remove_mount(me->key, MNTS_OFFSET);

-

 	return rv;

 }

@@ -761,12 +758,6 @@ int mount_autofs_offset(struct autofs_point *ap, struct mapent *me)

 		notify_mount_result(ap, me->key, timeout, str_offset);

 	ops->close(ap->logopt, ioctlfd);

-	mnt = mnts_add_mount(ap, me->key, MNTS_OFFSET);

-	if (!mnt)

-		error(ap->logopt,

-		      "failed to add offset mount %s to mounted list",

-		      me->key);

-

 	debug(ap->logopt, "mounted trigger %s", me->key);

 	return MOUNT_OFFSET_OK;

@@ -1214,6 +1205,7 @@ static void *do_mount_direct(void *arg)

 		struct mapent *me;

 		struct statfs fs;

 		unsigned int close_fd = 0;

+		unsigned int flags = MNTS_DIRECT|MNTS_MOUNTED;

 		sbmnt = mnts_find_submount(mt.name);

 		if (statfs(mt.name, &fs) == -1 ||

@@ -1232,6 +1224,8 @@ static void *do_mount_direct(void *arg)

 				close_fd = 0;

 			if (!close_fd)

 				me->ioctlfd = mt.ioctlfd;

+			if (me->multi && me->multi != me)

+				flags |= MNTS_OFFSET;

 		}

 		ops->send_ready(ap->logopt, mt.ioctlfd, mt.wait_queue_token);

 		cache_unlock(mt.mc);

@@ -1240,7 +1234,7 @@ static void *do_mount_direct(void *arg)

 		info(ap->logopt, "mounted %s", mt.name);

-		mnts_set_mounted_mount(ap, mt.name);

+		mnts_set_mounted_mount(ap, mt.name, flags);

 		conditional_alarm_add(ap, ap->exp_runfreq);

 	} else {

diff --git a/daemon/indirect.c b/daemon/indirect.c

index b259ebdc..eddcfff7 100644

--- a/daemon/indirect.c

+++ b/daemon/indirect.c

@@ -747,12 +747,14 @@ static void *do_mount_indirect(void *arg)

 	status = lookup_nss_mount(ap, NULL, mt.name, mt.len);

 	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &state);

 	if (status) {

+		unsigned int flags = MNTS_INDIRECT|MNTS_MOUNTED;

+

 		ops->send_ready(ap->logopt,

 				ap->ioctlfd, mt.wait_queue_token);

 		info(ap->logopt, "mounted %s", buf);

-		mnts_set_mounted_mount(ap, mt.name);

+		mnts_set_mounted_mount(ap, mt.name, flags);

 		conditional_alarm_add(ap, ap->exp_runfreq);

 	} else {

diff --git a/include/mounts.h b/include/mounts.h

index e3022b23..ac480c06 100644

--- a/include/mounts.h

+++ b/include/mounts.h

@@ -131,7 +131,7 @@ 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);

+void mnts_set_mounted_mount(struct autofs_point *ap, const char *name, unsigned int flags);

 int unlink_mount_tree(struct autofs_point *ap, const char *mp);

 void free_mnt_list(struct mnt_list *list);

 int is_mounted(const char *mp, unsigned int type);

diff --git a/lib/mounts.c b/lib/mounts.c

index 04fe3d00..25ae2e1d 100644

--- a/lib/mounts.c

+++ b/lib/mounts.c

@@ -1172,7 +1172,7 @@ struct mnt_list *mnts_add_mount(struct autofs_point *ap,

 	this = mnts_get_mount(mp);

 	if (this) {

 		this->flags |= flags;

-		if (list_empty(&this->mount))

+		if ((this->flags & MNTS_MOUNTED) && list_empty(&this->mount))

 			list_add(&this->mount, &ap->mounts);

 	}

 	mnts_hash_mutex_unlock();

@@ -1193,42 +1193,23 @@ void mnts_remove_mount(const char *mp, unsigned int flags)

 	this = mnts_lookup(mp);

 	if (this && this->flags & flags) {

 		this->flags &= ~flags;

-		if (!(this->flags & (MNTS_OFFSET|MNTS_MOUNTED)))

+		if (!(this->flags & MNTS_MOUNTED))

 			list_del_init(&this->mount);

 		__mnts_put_mount(this);

 	}

 	mnts_hash_mutex_unlock();

 }

-void mnts_set_mounted_mount(struct autofs_point *ap, const char *name)

+void mnts_set_mounted_mount(struct autofs_point *ap, const char *name, unsigned int flags)

 {

 	struct mnt_list *mnt;

-	mnt = mnts_add_mount(ap, name, MNTS_MOUNTED);

+	mnt = mnts_add_mount(ap, name, flags);

 	if (!mnt) {

 		error(ap->logopt,

 		      "failed to add mount %s to mounted list", name);

 		return;

 	}

-

-	/* Offset mount failed but non-strict returns success */

-	if (mnt->flags & MNTS_OFFSET &&

-	    !is_mounted(mnt->mp, MNTS_REAL)) {

-		mnt->flags &= ~MNTS_MOUNTED;

-		mnts_put_mount(mnt);

-	}

-

-	/* Housekeeping.

-	 * Set the base type of the mounted mount.

-	 * MNTS_AUTOFS and MNTS_OFFSET are set at mount time and

-	 * are used during expire.

-	 */

-	if (!(mnt->flags & (MNTS_AUTOFS|MNTS_OFFSET))) {

-		if (ap->type == LKP_INDIRECT)

-			mnt->flags |= MNTS_INDIRECT;

-		else

-			mnt->flags |= MNTS_DIRECT;

-	}

 }

 unsigned int mnts_has_mounted_mounts(struct autofs_point *ap)

@@ -1947,17 +1928,13 @@ static int do_remount_direct(struct autofs_point *ap,

 	ret = lookup_nss_mount(ap, NULL, path, strlen(path));

 	if (ret) {

-		struct mnt_list *mnt;

+		unsigned int flags = MNTS_DIRECT|MNTS_MOUNTED;

 		/* If it's an offset mount add a mount reference */

-		if (type == t_offset) {

-			mnt = mnts_add_mount(ap, path, MNTS_OFFSET);

-			if (!mnt)

-				error(ap->logopt,

-				      "failed to add mount %s to mounted list", path);

-		}

+		if (type == t_offset)

+			flags |= MNTS_OFFSET;

-		mnts_set_mounted_mount(ap, path);

+		mnts_set_mounted_mount(ap, path, flags);

 		info(ap->logopt, "re-connected to %s", path);

@@ -2032,7 +2009,9 @@ static int do_remount_indirect(struct autofs_point *ap, const unsigned int type,

 		ret = lookup_nss_mount(ap, NULL, de[n]->d_name, len);

 		if (ret) {

-			mnts_set_mounted_mount(ap, buf);

+			unsigned int flags = MNTS_INDIRECT|MNTS_MOUNTED;

+

+			mnts_set_mounted_mount(ap, buf, flags);

 			info(ap->logopt, "re-connected to %s", buf);