fs/autofs4/autofs_i.h     |   11 +++++++++++
 fs/autofs4/dev-ioctl.c    |    2 +-
 fs/autofs4/inode.c        |    2 +-
 fs/autofs4/waitq.c        |   14 ++++++--------
 fs/pipe.c                 |    6 +++---
 include/linux/pipe_fs_i.h |    1 +
 6 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index eb1cc92cd67d..f8642b8a1779 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -34,6 +34,7 @@
 #include <linux/sched.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
+#include <linux/pipe_fs_i.h>
 #include <asm/current.h>
 #include <asm/uaccess.h>
 
@@ -270,6 +271,16 @@ int autofs4_fill_super(struct super_block *, void *, int);
 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 (!pipe->f_dentry->d_inode->i_pipe)
+		return -EINVAL;
+	pipe->f_dentry->d_inode->i_pipe->packetized = 1;
+	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 9dacb8586701..6259e7142032 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -376,7 +376,7 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp,
 			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 d8dc002e9cc3..c525b74deefd 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -292,7 +292,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
 		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;
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 9c098db43344..5ce5026200b9 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -97,16 +97,14 @@ static int autofs4_write(struct autofs_sb_info *sbi,
  *
  * The packets are identical on x86-32 and x86-64, but have different
  * alignment. Which means that 'sizeof()' will give different results.
- * Fix it up for the case of running 32-bit user mode on a 64-bit kernel.
+ * However, we packetize the pipe, so just use the bigger size, the
+ * pipe read will discard the rest.
+ *
+ * This adds on 8 bytes of garbage FOR DEBUGGING ONLY!
  */
-static noinline size_t autofs_v5_packet_size(struct autofs_sb_info *sbi)
+static inline size_t autofs_v5_packet_size(struct autofs_sb_info *sbi)
 {
-	size_t pktsz = sizeof(struct autofs_v5_packet);
-#if defined(CONFIG_X86_64) && defined(CONFIG_COMPAT)
-	if (sbi->compat_daemon > 0)
-		pktsz -= 4;
-#endif
-	return pktsz;
+	return sizeof(struct autofs_v5_packet)+8;
 }
 
 static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
diff --git a/fs/pipe.c b/fs/pipe.c
index 25feaa3faac0..76febdfafcc3 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -407,7 +407,7 @@ redo:
 			ret += chars;
 			buf->offset += chars;
 			buf->len -= chars;
-			if (!buf->len) {
+			if (!buf->len || pipe->packetized) {
 				buf->ops = NULL;
 				ops->release(pipe, buf);
 				curbuf = (curbuf + 1) & (pipe->buffers - 1);
@@ -416,7 +416,7 @@ redo:
 				do_wakeup = 1;
 			}
 			total_len -= chars;
-			if (!total_len)
+			if (!total_len || pipe->packetized)
 				break;	/* common path: read succeeded */
 		}
 		if (bufs)	/* More to do? */
@@ -490,7 +490,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
 
 	/* We try to merge small writes */
 	chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */
-	if (pipe->nrbufs && chars != 0) {
+	if (!pipe->packetized && pipe->nrbufs && chars != 0) {
 		int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &
 							(pipe->buffers - 1);
 		struct pipe_buffer *buf = pipe->bufs + lastbuf;
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 6d626ff0cfd0..49f034aaca5e 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -43,6 +43,7 @@ struct pipe_buffer {
  **/
 struct pipe_inode_info {
 	wait_queue_head_t wait;
+	unsigned int packetized:1;
 	unsigned int nrbufs, curbuf, buffers;
 	unsigned int readers;
 	unsigned int writers;