MFC r273127:

Make automountd(8) inform autofs(4) whether directory being handled can
have wildcards.  This makes it possible for autofs(4) to avoid requesting
automountd(8) action on access to nonexistent nodes - unless wildcards
are actually used.

Note that this change breaks ABI for automountd(8).

MFC r278521:

Restore ABI compatibility, broken in r273127.  Note that while this fixes
ABI with 10.1, it breaks ABI for 11-CURRENT, so rebuild of automountd(8)
is neccessary.

Sponsored by:	The FreeBSD Foundation

3 files changed, 54 insertions, 10 deletions

diff --git a/usr.sbin/autofs/automountd.c b/usr.sbin/autofs/automountd.c
index 374e901..44143e5 100644
--- a/usr.sbin/autofs/automountd.c
+++ b/usr.sbin/autofs/automountd.c
@@ -68,13 +68,14 @@ static int autofs_fd;
 static int request_id;
 
 static void
-done(int request_error)
+done(int request_error, bool wildcards)
 {
 	struct autofs_daemon_done add;
 	int error;
 
 	memset(&add, 0, sizeof(add));
 	add.add_id = request_id;
+	add.add_wildcards = wildcards;
 	add.add_error = request_error;
 
 	log_debugx("completing request %d with error %d",
@@ -172,7 +173,7 @@ static void
 exit_callback(void)
 {
 
-	done(EIO);
+	done(EIO, true);
 }
 
 static void
@@ -184,6 +185,7 @@ handle_request(const struct autofs_daemon_request *adr, char *cmdline_options,
 	FILE *f;
 	char *options, *fstype, *nobrowse, *retrycnt, *tmp;
 	int error;
+	bool wildcards;
 
 	log_debugx("got request %d: from %s, path %s, prefix \"%s\", "
 	    "key \"%s\", options \"%s\"", adr->adr_id, adr->adr_from,
@@ -209,9 +211,26 @@ handle_request(const struct autofs_daemon_request *adr, char *cmdline_options,
 		    checked_strdup(adr->adr_options), checked_strdup(map),
 		    checked_strdup("[kernel request]"), lineno);
 	}
-	parse_map(parent, map, adr->adr_key[0] != '\0' ? adr->adr_key : NULL);
+
+	/*
+	 * "Wildcards" here actually means "make autofs(4) request
+	 * automountd(8) action if the node being looked up does not
+	 * exist, even though the parent is marked as cached".  This
+	 * needs to be done for maps with wildcard entries, but also
+	 * for special and executable maps.
+	 */
+	parse_map(parent, map, adr->adr_key[0] != '\0' ? adr->adr_key : NULL,
+	    &wildcards);
+	if (!wildcards)
+		wildcards = node_has_wildcards(parent);
+	if (wildcards)
+		log_debugx("map may contain wildcard entries");
+	else
+		log_debugx("map does not contain wildcard entries");
+
 	if (adr->adr_key[0] != '\0')
 		node_expand_wildcard(root, adr->adr_key);
+
 	node = node_find(root, adr->adr_path);
 	if (node == NULL) {
 		log_errx(1, "map %s does not contain key for \"%s\"; "
@@ -236,7 +255,7 @@ handle_request(const struct autofs_daemon_request *adr, char *cmdline_options,
 		if (nobrowse != NULL && adr->adr_key[0] == '\0') {
 			log_debugx("skipping map %s due to \"nobrowse\" "
 			    "option; exiting", map);
-			done(0);
+			done(0, true);
 
 			/*
 			 * Exit without calling exit_callback().
@@ -263,7 +282,7 @@ handle_request(const struct autofs_daemon_request *adr, char *cmdline_options,
 		}
 
 		log_debugx("nothing to mount; exiting");
-		done(0);
+		done(0, wildcards);
 
 		/*
 		 * Exit without calling exit_callback().
@@ -337,7 +356,7 @@ handle_request(const struct autofs_daemon_request *adr, char *cmdline_options,
 		log_errx(1, "mount failed");
 
 	log_debugx("mount done; exiting");
-	done(0);
+	done(0, wildcards);
 
 	/*
 	 * Exit without calling exit_callback().
diff --git a/usr.sbin/autofs/common.c b/usr.sbin/autofs/common.c
index e6db682..6fd8a05 100644
--- a/usr.sbin/autofs/common.c
+++ b/usr.sbin/autofs/common.c
@@ -498,6 +498,19 @@ node_is_direct_map(const struct node *n)
 	return (true);
 }
 
+bool
+node_has_wildcards(const struct node *n)
+{
+	const struct node *child;
+
+	TAILQ_FOREACH(child, &n->n_children, n_next) {
+		if (strcmp(child->n_key, "*") == 0)
+			return (true);
+	}
+
+	return (false);
+}
+
 static void
 node_expand_maps(struct node *n, bool indirect)
 {
@@ -526,7 +539,7 @@ node_expand_maps(struct node *n, bool indirect)
 			log_debugx("map \"%s\" is a direct map, parsing",
 			    child->n_map);
 		}
-		parse_map(child, child->n_map, NULL);
+		parse_map(child, child->n_map, NULL, NULL);
 	}
 }
 
@@ -996,7 +1009,8 @@ parse_included_map(struct node *parent, const char *map)
 }
 
 void
-parse_map(struct node *parent, const char *map, const char *key)
+parse_map(struct node *parent, const char *map, const char *key,
+    bool *wildcards)
 {
 	char *path = NULL;
 	int error, ret;
@@ -1007,8 +1021,14 @@ parse_map(struct node *parent, const char *map, const char *key)
 
 	log_debugx("parsing map \"%s\"", map);
 
-	if (map[0] == '-')
+	if (wildcards != NULL)
+		*wildcards = false;
+
+	if (map[0] == '-') {
+		if (wildcards != NULL)
+			*wildcards = true;
 		return (parse_special_map(parent, map, key));
+	}
 
 	if (map[0] == '/') {
 		path = checked_strdup(map);
@@ -1035,6 +1055,9 @@ parse_map(struct node *parent, const char *map, const char *key)
 	if (executable) {
 		log_debugx("map \"%s\" is executable", map);
 
+		if (wildcards != NULL)
+			*wildcards = true;
+
 		if (key != NULL) {
 			yyin = auto_popen(path, key, NULL);
 		} else {
diff --git a/usr.sbin/autofs/common.h b/usr.sbin/autofs/common.h
index bc0b6f6..16a8d73 100644
--- a/usr.sbin/autofs/common.h
+++ b/usr.sbin/autofs/common.h
@@ -80,6 +80,7 @@ struct node	*node_new_map(struct node *parent, char *key, char *options,
 		    char *map, const char *config_file, int config_line);
 struct node	*node_find(struct node *root, const char *mountpoint);
 bool		node_is_direct_map(const struct node *n);
+bool		node_has_wildcards(const struct node *n);
 char	*node_path(const struct node *n);
 char	*node_options(const struct node *n);
 void	node_expand_ampersand(struct node *root, const char *key);
@@ -88,7 +89,8 @@ int	node_expand_defined(struct node *root);
 void	node_expand_indirect_maps(struct node *n);
 void	node_print(const struct node *n);
 void	parse_master(struct node *root, const char *path);
-void	parse_map(struct node *parent, const char *map, const char *args);
+void	parse_map(struct node *parent, const char *map, const char *args,
+	    bool *wildcards);
 char	*defined_expand(const char *string);
 void	defined_init(void);
 void	defined_parse_and_add(char *def);