autofs-5.1.7 - eliminate count_mounts() from expire_proc_indirect()

From: Ian Kent <raven@themaw.net>

The count_mounts() function traverses the directory tree under a given

automount in order to count the number of mounts.

If there are many directories (such as when there is a very large

number of offset trigger mounts) this can take a long time.

Eliminate the call in expire_proc_indirect() by changing the expire

ioctl function to better use the expire return from the kernel.

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

---

 CHANGELOG           |    1 +

 daemon/direct.c     |    4 ++--

 daemon/indirect.c   |   10 +++++-----

 lib/dev-ioctl-lib.c |   21 +++++++++++++--------

 4 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index c5619d2e..0b78eb62 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -20,6 +20,7 @@

 - pass mapent_cache to update_offset_entry().

 - fix inconsistent locking in parse_mount().

 - remove unused mount offset list lock functions.

+- eliminate count_mounts() from expire_proc_indirect().

 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 c41c680f..311a98ba 100644

--- a/daemon/direct.c

+++ b/daemon/direct.c

@@ -884,7 +884,7 @@ cont:

 			ioctlfd = me->ioctlfd;

 			ret = ops->expire(ap->logopt, ioctlfd, mnt->mp, how);

-			if (ret) {

+			if (ret == 1) {

 				left++;

 				pthread_setcancelstate(cur_state, NULL);

 				continue;

@@ -910,7 +910,7 @@ cont:

 		pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cur_state);

 		ret = ops->expire(ap->logopt, ioctlfd, mnt->mp, how);

-		if (ret)

+		if (ret == 1)

 			left++;

 		pthread_setcancelstate(cur_state, NULL);

 	}

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

index 65cfe4e3..b259ebdc 100644

--- a/daemon/indirect.c

+++ b/daemon/indirect.c

@@ -358,7 +358,6 @@ void *expire_proc_indirect(void *arg)

 	struct expire_args ec;

 	unsigned int how;

 	int offsets, submnts, count;

-	int retries;

 	int ioctlfd, cur_state;

 	int status, ret, left;

@@ -496,7 +495,7 @@ void *expire_proc_indirect(void *arg)

 		pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cur_state);

 		ret = ops->expire(ap->logopt, ioctlfd, mnt->mp, how);

-		if (ret)

+		if (ret == 1)

 			left++;

 		pthread_setcancelstate(cur_state, NULL);

 	}

@@ -507,10 +506,11 @@ void *expire_proc_indirect(void *arg)

 	 * so we need to umount or unlink them here.

 	 */

 	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cur_state);

-	retries = (count_mounts(ap, ap->path, ap->dev) + 1);

-	while (retries--) {

+	while (1) {

 		ret = ops->expire(ap->logopt, ap->ioctlfd, ap->path, how);

-		if (ret)

+		if (ret != 0 && errno == EAGAIN)

+			break;

+		if (ret == 1)

 			left++;

 	}

 	pthread_setcancelstate(cur_state, NULL);

diff --git a/lib/dev-ioctl-lib.c b/lib/dev-ioctl-lib.c

index 7040c3da..e7a1b42a 100644

--- a/lib/dev-ioctl-lib.c

+++ b/lib/dev-ioctl-lib.c

@@ -650,6 +650,7 @@ static int expire(unsigned int logopt,

 {

 	int ret, retries = EXPIRE_RETRIES;

 	unsigned int may_umount;

+	int save_errno = 0;

 	while (retries--) {

 		struct timespec tm = {0, 100000000};

@@ -657,9 +658,11 @@ static int expire(unsigned int logopt,

 		/* Ggenerate expire message for the mount. */

 		ret = ioctl(fd, cmd, arg);

 		if (ret == -1) {

+			save_errno = errno;

+

 			/* Mount has gone away */

 			if (errno == EBADF || errno == EINVAL)

-				return 0;

+				break;

 			/*

 			 * Other than EAGAIN is an expire error so continue.

@@ -673,14 +676,16 @@ static int expire(unsigned int logopt,

 		nanosleep(&tm, NULL);

 	}

-	may_umount = 0;

-	if (ctl.ops->askumount(logopt, ioctlfd, &may_umount))

-		return -1;

-

-	if (!may_umount)

-		return 1;

+	if (!ret || save_errno == EAGAIN) {

+		may_umount = 0;

+		if (!ctl.ops->askumount(logopt, ioctlfd, &may_umount)) {

+			if (!may_umount)

+				ret = 1;

+		}

+	}

+	errno = save_errno;

-	return 0;

+	return ret;

 }

 static int dev_ioctl_expire(unsigned int logopt,