From b5b74d8da7b8c2447941ce1fa18cfaa29b6b2493 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Mon, 11 Jul 2011 14:20:57 +0100
Subject: [PATCH] --- yaml --- r: 262066 b: refs/heads/master c:
 5a30d8a2b8ddd5102c440c7e5a7c8e1fd729c818 h: refs/heads/master v: v3

---
 [refs]           |  2 +-
 trunk/fs/namei.c | 24 +++++++++++++++---------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/[refs] b/[refs]
index 4739a12d4c06..3034c1ac3d77 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b4aff1f874f679320c03e3d97b60fc7babfd4623
+refs/heads/master: 5a30d8a2b8ddd5102c440c7e5a7c8e1fd729c818
diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
index f8c69d373793..445fd5da11fa 100644
--- a/trunk/fs/namei.c
+++ b/trunk/fs/namei.c
@@ -716,19 +716,25 @@ static int follow_automount(struct path *path, unsigned flags,
 	if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_PARENT))
 		return -EISDIR; /* we actually want to stop here */
 
-	/* We want to mount if someone is trying to open/create a file of any
-	 * type under the mountpoint, wants to traverse through the mountpoint
-	 * or wants to open the mounted directory.
-	 *
+	/*
 	 * We don't want to mount if someone's just doing a stat and they've
 	 * set AT_SYMLINK_NOFOLLOW - unless they're stat'ing a directory and
 	 * appended a '/' to the name.
 	 */
-	if (!(flags & LOOKUP_FOLLOW) &&
-	    !(flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
-		       LOOKUP_OPEN | LOOKUP_CREATE)))
-		return -EISDIR;
-
+	if (!(flags & LOOKUP_FOLLOW)) {
+		/* We do, however, want to mount if someone wants to open or
+		 * create a file of any type under the mountpoint, wants to
+		 * traverse through the mountpoint or wants to open the mounted
+		 * directory.
+		 * Also, autofs may mark negative dentries as being automount
+		 * points.  These will need the attentions of the daemon to
+		 * instantiate them before they can be used.
+		 */
+		if (!(flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
+			     LOOKUP_OPEN | LOOKUP_CREATE)) &&
+		    path->dentry->d_inode)
+			return -EISDIR;
+	}
 	current->total_link_count++;
 	if (current->total_link_count >= 40)
 		return -ELOOP;