autofs-5.0.9 - amd lookup fix host mount naming
From: Ian Kent <raven@themaw.net>
Currently 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 other
concurrent lookups while the mount tree is constructed.
---
daemon/lookup.c | 20 +++++++++++++----
modules/parse_amd.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++--
modules/parse_sun.c | 22 +++++++++++-------
3 files changed, 89 insertions(+), 14 deletions(-)
--- autofs-5.0.7.orig/daemon/lookup.c
+++ autofs-5.0.7/daemon/lookup.c
@@ -815,7 +815,8 @@ static int lookup_amd_instance(struct au
m_key = malloc(strlen(ap->path) + strlen(me->multi->key) + 1);
if (!m_key) {
- error(ap->logopt, "failed to allocate storage for search key");
+ error(ap->logopt,
+ "failed to allocate storage for search key");
return NSS_STATUS_UNKNOWN;
}
@@ -823,12 +824,12 @@ static int lookup_amd_instance(struct au
strcat(m_key, "/");
strcat(m_key, me->multi->key);
entry = master_find_amdmount(ap, m_key);
+ free(m_key);
+
if (!entry) {
error(ap->logopt, "expected amd mount entry not found");
- free(m_key);
return NSS_STATUS_UNKNOWN;
}
- free(m_key);
if (strcmp(entry->type, "host")) {
error(ap->logopt, "unexpected map type %s", entry->type);
@@ -843,6 +844,17 @@ static int lookup_amd_instance(struct au
}
instance = master_find_source_instance(map, "hosts", "sun", argc, pargv);
+ /* If this is an nss map instance it may have an amd host map sub instance */
+ if (!instance && map->instance) {
+ struct map_source *next = map->instance;
+ while (next) {
+ instance = master_find_source_instance(next,
+ "hosts", "sun", argc, pargv);
+ if (instance)
+ break;
+ next = next->next;
+ }
+ }
if (!instance) {
error(ap->logopt, "expected hosts map instance not found");
return NSS_STATUS_UNKNOWN;
@@ -1174,7 +1186,6 @@ int lookup_nss_mount(struct autofs_point
}
if (ap->state != ST_INIT)
send_map_update_request(ap);
- pthread_cleanup_pop(1);
/*
* The last source lookup will return NSS_STATUS_NOTFOUND if the
@@ -1183,6 +1194,7 @@ int lookup_nss_mount(struct autofs_point
*/
if (result == NSS_STATUS_NOTFOUND || result == NSS_STATUS_UNAVAIL)
update_negative_cache(ap, source, name);
+ pthread_cleanup_pop(1);
return !result;
}
--- autofs-5.0.7.orig/modules/parse_amd.c
+++ autofs-5.0.7/modules/parse_amd.c
@@ -1068,6 +1068,23 @@ static int do_nfsl_mount(struct autofs_p
return do_link_mount(ap, name, entry, flags);
}
+static int wait_for_expire(struct autofs_point *ap)
+{
+ int ret = 1;
+
+ st_wait_task(ap, ST_EXPIRE, 0);
+
+ st_mutex_lock();
+ if (ap->state != ST_SHUTDOWN &&
+ ap->state != ST_SHUTDOWN_PENDING &&
+ ap->state != ST_SHUTDOWN_FORCE) {
+ ret = 0;
+ }
+ st_mutex_unlock();
+
+ return ret;
+}
+
static int do_host_mount(struct autofs_point *ap, const char *name,
struct amd_entry *entry, struct map_source *source,
unsigned int flags)
@@ -1080,6 +1097,36 @@ static int do_host_mount(struct autofs_p
int argc = 0;
int ret = 1;
+ /*
+ * If the mount point name isn't the same as the host name
+ * then we need to symlink to it after the mount. Attempt
+ * the allocation and set entry->path to the base location
+ * of the hosts mount tree so we can find it in
+ * lookup_nss_mount() later.
+ */
+ if (strcmp(name, entry->rhost)) {
+ char *target;
+ size_t len = strlen(ap->path) + strlen(entry->rhost) + 2;
+ target = malloc(len);
+ if (!target) {
+ warn(ap->logopt, MODPREFIX
+ "failed to alloc target to hosts mount base");
+ goto out;
+ }
+ strcpy(target, ap->path);
+ strcat(target, "/");
+ strcat(target, entry->rhost);
+ if (entry->path)
+ free(entry->path);
+ entry->path = target;
+ /*
+ * Wait for any expire before racing to mount the
+ * export tree or bail out if we're shutting down.
+ */
+ if (!wait_for_expire(ap))
+ goto out;
+ }
+
if (entry->opts) {
argv[0] = entry->opts;
argv[1] = NULL;
@@ -1095,7 +1142,8 @@ static int do_host_mount(struct autofs_p
goto out;
}
- instance = master_find_source_instance(source, "hosts", "sun", argc, pargv);
+ instance = master_find_source_instance(source,
+ "hosts", "sun", argc, pargv);
if (!instance) {
instance = master_add_source_instance(source,
"hosts", "sun", time(NULL), argc, pargv);
@@ -1119,7 +1167,16 @@ static int do_host_mount(struct autofs_p
master_source_current_wait(ap->entry);
ap->entry->current = source;
- ret = lookup->lookup_mount(ap, name, strlen(name), lookup->context);
+ ret = lookup->lookup_mount(ap, entry->rhost,
+ strlen(entry->rhost), lookup->context);
+
+ if (!strcmp(name, entry->rhost))
+ goto out;
+
+ if (do_mount(ap, ap->path,
+ name, strlen(name), entry->path, "bind", "symlink"))
+ warn(ap->logopt, MODPREFIX
+ "failed to create symlink to hosts mount base");
out:
return ret;
}
--- autofs-5.0.7.orig/modules/parse_sun.c
+++ autofs-5.0.7/modules/parse_sun.c
@@ -1343,26 +1343,32 @@ int parse_mount(struct autofs_point *ap,
strcat(m_root, name);
}
+ pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cur_state);
cache_readlock(mc);
me = cache_lookup_distinct(mc, name);
- if (me) {
- /* So we know we're the multi-mount root */
- if (!me->multi)
- me->multi = me;
- }
-
if (!me) {
free(options);
cache_unlock(mc);
+ pthread_setcancelstate(cur_state, NULL);
error(ap->logopt,
MODPREFIX "can't find multi root %s", name);
return 1;
}
+ 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;
+
age = me->age;
- pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cur_state);
- cache_multi_writelock(me);
/* It's a multi-mount; deal with it */
do {
char *path, *myoptions, *loc;