3 files changed, 16 insertions, 22 deletions

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 9e5ae8a4f5c..84168c0dcc2 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -54,11 +54,10 @@ static int check_name(const char *name)
  * Check a string doesn't overrun the chunk of
  * memory we copied from user land.
  */
-static int invalid_str(char *str, void *end)
+static int invalid_str(char *str, size_t size)
 {
-	while ((void *) str <= end)
-		if (!*str++)
-			return 0;
+	if (memchr(str, 0, size))
+		return 0;
 	return -EINVAL;
 }
 
@@ -138,8 +137,7 @@ static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
 	}
 
 	if (param->size > sizeof(*param)) {
-		err = invalid_str(param->path,
-				 (void *) ((size_t) param + param->size));
+		err = invalid_str(param->path, param->size - sizeof(*param));
 		if (err) {
 			AUTOFS_WARN(
 			  "path string terminator missing for cmd(0x%08x)",
@@ -488,7 +486,7 @@ static int autofs_dev_ioctl_requester(struct file *fp,
 	}
 
 	path = param->path;
-	devid = sbi->sb->s_dev;
+	devid = new_encode_dev(sbi->sb->s_dev);
 
 	param->requester.uid = param->requester.gid = -1;
 
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 75f7ddacf7d..3077d8f1652 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -70,8 +70,10 @@ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
 		 * Otherwise it's an offset mount and we need to check
 		 * if we can umount its mount, if there is one.
 		 */
-		if (!d_mountpoint(dentry))
+		if (!d_mountpoint(dentry)) {
+			status = 0;
 			goto done;
+		}
 	}
 
 	/* Update the expiry counter if fs is busy */
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index eeb24684590..2341375386f 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -297,20 +297,14 @@ static int validate_request(struct autofs_wait_queue **wait,
 	 */
 	if (notify == NFY_MOUNT) {
 		/*
-		 * If the dentry isn't hashed just go ahead and try the
-		 * mount again with a new wait (not much else we can do).
-		*/
-		if (!d_unhashed(dentry)) {
-			/*
-			 * But if the dentry is hashed, that means that we
-			 * got here through the revalidate path.  Thus, we
-			 * need to check if the dentry has been mounted
-			 * while we waited on the wq_mutex. If it has,
-			 * simply return success.
-			 */
-			if (d_mountpoint(dentry))
-				return 0;
-		}
+		 * If the dentry was successfully mounted while we slept
+		 * on the wait queue mutex we can return success. If it
+		 * isn't mounted (doesn't have submounts for the case of
+		 * a multi-mount with no mount at it's base) we can
+		 * continue on and create a new request.
+		 */
+		if (have_submounts(dentry))
+			return 0;
 	}
 
 	return 1;