diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index d8d8e7b..908e184 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -269,6 +269,17 @@
 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
 void autofs4_clean_ino(struct autofs_info *);
 
+static inline int autofs_prepare_pipe(struct file *pipe)
+{
+	if (!pipe->f_op || !pipe->f_op->write)
+		return -EINVAL;
+	if (!S_ISFIFO(pipe->f_dentry->d_inode->i_mode))
+		return -EINVAL;
+	/* We want a packet pipe */
+	pipe->f_flags |= O_DIRECT;
+	return 0;
+}
+
 /* Queue management functions */
 
 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 3dfd615..aa9103f 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -376,7 +376,7 @@
 			err = -EBADF;
 			goto out;
 		}
-		if (!pipe->f_op || !pipe->f_op->write) {
+		if (autofs_prepare_pipe(pipe) < 0) {
 			err = -EPIPE;
 			fput(pipe);
 			goto out;
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index 14c7bc0..6e488eb 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -290,7 +290,7 @@
 		printk("autofs: could not open pipe file descriptor\n");
 		goto fail_dput;
 	}
-	if (!pipe->f_op || !pipe->f_op->write)
+	if (autofs_prepare_pipe(pipe) < 0)
 		goto fail_fput;
 	sbi->pipe = pipe;
 	sbi->pipefd = pipefd;