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, 73 insertions, 6 deletions

diff --git a/sys/fs/autofs/autofs.c b/sys/fs/autofs/autofs.c
index 09f3c62..0393d13 100644
--- a/sys/fs/autofs/autofs.c
+++ b/sys/fs/autofs/autofs.c
@@ -274,6 +274,7 @@ autofs_task(void *context, int pending)
 	 * XXX: EIO perhaps?
 	 */
 	ar->ar_error = ETIMEDOUT;
+	ar->ar_wildcards = true;
 	ar->ar_done = true;
 	ar->ar_in_progress = false;
 	cv_broadcast(&autofs_softc->sc_cv);
@@ -291,12 +292,13 @@ autofs_cached(struct autofs_node *anp, const char *component, int componentlen)
 	AUTOFS_ASSERT_UNLOCKED(amp);
 
 	/*
-	 * For top-level nodes we need to request automountd(8)
-	 * assistance even if the node is marked as cached,
-	 * but the requested subdirectory does not exist.  This
-	 * is necessary for wildcard indirect map keys to work.
+	 * For root node we need to request automountd(8) assistance even
+	 * if the node is marked as cached, but the requested top-level
+	 * directory does not exist.  This is necessary for wildcard indirect
+	 * map keys to work.  We don't do this if we know that there are
+	 * no wildcards.
 	 */
-	if (anp->an_parent == NULL && componentlen != 0) {
+	if (anp->an_parent == NULL && componentlen != 0 && anp->an_wildcards) {
 		AUTOFS_SLOCK(amp);
 		error = autofs_node_find(anp, component, componentlen, NULL);
 		AUTOFS_SUNLOCK(amp);
@@ -366,6 +368,7 @@ autofs_trigger_one(struct autofs_node *anp,
 	struct autofs_request *ar;
 	char *key, *path;
 	int error = 0, request_error, last;
+	bool wildcards;
 
 	amp = anp->an_mount;
 
@@ -455,6 +458,8 @@ autofs_trigger_one(struct autofs_node *anp,
 		    ar->ar_path, request_error);
 	}
 
+	wildcards = ar->ar_wildcards;
+
 	last = refcount_release(&ar->ar_refcount);
 	if (last) {
 		TAILQ_REMOVE(&autofs_softc->sc_requests, ar, ar_next);
@@ -475,6 +480,7 @@ autofs_trigger_one(struct autofs_node *anp,
 	 */
 	if (error == 0 && request_error == 0 && autofs_cache > 0) {
 		anp->an_cached = true;
+		anp->an_wildcards = wildcards;
 		callout_reset(&anp->an_callout, autofs_cache * hz,
 		    autofs_cache_callout, anp);
 	}
@@ -577,6 +583,34 @@ autofs_ioctl_request(struct autofs_daemon_request *adr)
 }
 
 static int
+autofs_ioctl_done_101(struct autofs_daemon_done_101 *add)
+{
+	struct autofs_request *ar;
+
+	sx_xlock(&autofs_softc->sc_lock);
+	TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
+		if (ar->ar_id == add->add_id)
+			break;
+	}
+
+	if (ar == NULL) {
+		sx_xunlock(&autofs_softc->sc_lock);
+		AUTOFS_DEBUG("id %d not found", add->add_id);
+		return (ESRCH);
+	}
+
+	ar->ar_error = add->add_error;
+	ar->ar_wildcards = true;
+	ar->ar_done = true;
+	ar->ar_in_progress = false;
+	cv_broadcast(&autofs_softc->sc_cv);
+
+	sx_xunlock(&autofs_softc->sc_lock);
+
+	return (0);
+}
+
+static int
 autofs_ioctl_done(struct autofs_daemon_done *add)
 {
 	struct autofs_request *ar;
@@ -594,6 +628,7 @@ autofs_ioctl_done(struct autofs_daemon_done *add)
 	}
 
 	ar->ar_error = add->add_error;
+	ar->ar_wildcards = add->add_wildcards;
 	ar->ar_done = true;
 	ar->ar_in_progress = false;
 	cv_broadcast(&autofs_softc->sc_cv);
@@ -650,6 +685,9 @@ autofs_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
 	case AUTOFSREQUEST:
 		return (autofs_ioctl_request(
 		    (struct autofs_daemon_request *)arg));
+	case AUTOFSDONE101:
+		return (autofs_ioctl_done_101(
+		    (struct autofs_daemon_done_101 *)arg));
 	case AUTOFSDONE:
 		return (autofs_ioctl_done(
 		    (struct autofs_daemon_done *)arg));
diff --git a/sys/fs/autofs/autofs.h b/sys/fs/autofs/autofs.h
index dc33eef..6ea198c 100644
--- a/sys/fs/autofs/autofs.h
+++ b/sys/fs/autofs/autofs.h
@@ -74,6 +74,7 @@ struct autofs_node {
 	struct vnode			*an_vnode;
 	struct sx			an_vnode_lock;
 	bool				an_cached;
+	bool				an_wildcards;
 	struct callout			an_callout;
 	int				an_retries;
 	struct timespec			an_ctime;
@@ -97,6 +98,7 @@ struct autofs_request {
 	int				ar_id;
 	bool				ar_done;
 	int				ar_error;
+	bool				ar_wildcards;
 	bool				ar_in_progress;
 	char				ar_from[MAXPATHLEN];
 	char				ar_path[MAXPATHLEN];
diff --git a/sys/fs/autofs/autofs_ioctl.h b/sys/fs/autofs/autofs_ioctl.h
index 8d03ef7..92d7314 100644
--- a/sys/fs/autofs/autofs_ioctl.h
+++ b/sys/fs/autofs/autofs_ioctl.h
@@ -71,6 +71,21 @@ struct autofs_daemon_request {
 	char		adr_options[MAXPATHLEN];
 };
 
+/*
+ * Compatibility with 10.1-RELEASE automountd(8).
+ */
+struct autofs_daemon_done_101 {
+	/*
+	 * Identifier, copied from adr_id.
+	 */
+	int		add_id;
+
+	/*
+	 * Error number, possibly returned to userland.
+	 */
+	int		add_error;
+};
+
 struct autofs_daemon_done {
 	/*
 	 * Identifier, copied from adr_id.
@@ -78,12 +93,24 @@ struct autofs_daemon_done {
 	int		add_id;
 
 	/*
+	 * Set to 1 if the map may contain wildcard entries;
+	 * otherwise autofs will do negative caching.
+	 */
+	int		add_wildcards;
+
+	/*
 	 * Error number, possibly returned to userland.
 	 */
 	int		add_error;
+
+	/*
+	 * Reserved for future use.
+	 */
+	int		add_spare[7];
 };
 
 #define	AUTOFSREQUEST	_IOR('I', 0x01, struct autofs_daemon_request)
-#define	AUTOFSDONE	_IOW('I', 0x02, struct autofs_daemon_done)
+#define	AUTOFSDONE101	_IOW('I', 0x02, struct autofs_daemon_done_101)
+#define	AUTOFSDONE	_IOW('I', 0x03, struct autofs_daemon_done)
 
 #endif /* !AUTOFS_IOCTL_H */