autofs-5.1.0 - fix hosts map update on reload

From: Ian Kent <ikent@redhat.com>

Commit aedfd5aa - "amd lookup fix host mount naming" introduced a

regression when updating sun format maps.

The amd host mount type assumes the lookup name is the host name for

the host mount but amd uses ${rhost} for this.

This introduces the possibility of multiple concurrent mount requests

since constructing a mount tree that isn't under the lookup name can't

take advantage of the kernel queuing of other concurrent lookups while

the mount tree is constructed.

Consequently multi-mount updates (currently only done for the internal

hosts map which the amd parser also uses for its hosts map) can't be

allowed for amd mounts.

---

 CHANGELOG           |    1 +

 modules/parse_sun.c |   37 ++++++++++++++++++++++++++++---------

 2 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index 645efe5..59f2906 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -36,6 +36,7 @@

 - fix fix master map type check.

 - init qdn before use in get_query_dn().

 - fix typo in update_hosts_mounts().

+- fix hosts map update on reload.

 04/06/2014 autofs-5.1.0

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

diff --git a/modules/parse_sun.c b/modules/parse_sun.c

index b881ee9..a3c736e 100644

--- a/modules/parse_sun.c

+++ b/modules/parse_sun.c

@@ -1356,16 +1356,35 @@ int parse_mount(struct autofs_point *ap, const char *name,

 		}

 		cache_multi_writelock(me);

-		/* Someone beat us to it, return success */

-		if (me->multi) {

-			free(options);

-			cache_multi_unlock(me);

-			cache_unlock(mc);

-			pthread_setcancelstate(cur_state, NULL);

-			return 0;

-		}

 		/* So we know we're the multi-mount root */

-		me->multi = me;

+		if (!me->multi)

+			me->multi = me;

+		else {

+			/*

+			 * The amd host mount type assumes the lookup name

+			 * is the host name for the host mount but amd uses

+			 * ${rhost} for this.

+			 *

+			 * This introduces the possibility of multiple

+			 * concurrent mount requests since constructing a

+			 * mount tree that isn't under the lookup name can't

+			 * take advantage of the kernel queuing of other

+			 * concurrent lookups while the mount tree is

+			 * constructed.

+			 *

+			 * Consequently multi-mount updates (currently only

+			 * done for the internal hosts map which the amd

+			 * parser also uses for its hosts map) can't be

+			 * allowed for amd mounts.

+			 */

+			if (source->flags & MAP_FLAG_FORMAT_AMD) {

+				free(options);

+				cache_multi_unlock(me);

+				cache_unlock(mc);

+				pthread_setcancelstate(cur_state, NULL);

+				return 0;

+			}

+		}

 		age = me->age;