---

yaml
---
r: 299841
b: refs/heads/master
c: 9883035
h: refs/heads/master
i:
  299839: 33e819c
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: de9e24eda331bbefb9195a4d646c786bdcbba7d4
+refs/heads/master: 9883035ae7edef3ec62ad215611cb8e17d6a1a5d

trunk/fs/pipe.c

@@ -346,6 +346,16 @@ static const struct pipe_buf_operations anon_pipe_buf_ops = {
 	.get = generic_pipe_buf_get,
 };
 
+static const struct pipe_buf_operations packet_pipe_buf_ops = {
+	.can_merge = 0,
+	.map = generic_pipe_buf_map,
+	.unmap = generic_pipe_buf_unmap,
+	.confirm = generic_pipe_buf_confirm,
+	.release = anon_pipe_buf_release,
+	.steal = generic_pipe_buf_steal,
+	.get = generic_pipe_buf_get,
+};
+
 static ssize_t
 pipe_read(struct kiocb *iocb, const struct iovec *_iov,
 	   unsigned long nr_segs, loff_t pos)
@@ -407,6 +417,13 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov,
 			ret += chars;
 			buf->offset += chars;
 			buf->len -= chars;
+
+			/* Was it a packet buffer? Clean up and exit */
+			if (buf->flags & PIPE_BUF_FLAG_PACKET) {
+				total_len = chars;
+				buf->len = 0;
+			}
+
 			if (!buf->len) {
 				buf->ops = NULL;
 				ops->release(pipe, buf);
@@ -459,6 +476,11 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov,
 	return ret;
 }
 
+static inline int is_packetized(struct file *file)
+{
+	return (file->f_flags & O_DIRECT) != 0;
+}
+
 static ssize_t
 pipe_write(struct kiocb *iocb, const struct iovec *_iov,
 	    unsigned long nr_segs, loff_t ppos)
@@ -593,6 +615,11 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
 			buf->ops = &anon_pipe_buf_ops;
 			buf->offset = 0;
 			buf->len = chars;
+			buf->flags = 0;
+			if (is_packetized(filp)) {
+				buf->ops = &packet_pipe_buf_ops;
+				buf->flags = PIPE_BUF_FLAG_PACKET;
+			}
 			pipe->nrbufs = ++bufs;
 			pipe->tmp_page = NULL;
 
@@ -1013,7 +1040,7 @@ struct file *create_write_pipe(int flags)
 		goto err_dentry;
 	f->f_mapping = inode->i_mapping;
 
-	f->f_flags = O_WRONLY | (flags & O_NONBLOCK);
+	f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT));
 	f->f_version = 0;
 
 	return f;
@@ -1057,7 +1084,7 @@ int do_pipe_flags(int *fd, int flags)
 	int error;
 	int fdw, fdr;
 
-	if (flags & ~(O_CLOEXEC | O_NONBLOCK))
+	if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT))
 		return -EINVAL;
 
 	fw = create_write_pipe(flags);

trunk/include/linux/pipe_fs_i.h

@@ -6,6 +6,7 @@
 #define PIPE_BUF_FLAG_LRU	0x01	/* page is on the LRU */
 #define PIPE_BUF_FLAG_ATOMIC	0x02	/* was atomically mapped */
 #define PIPE_BUF_FLAG_GIFT	0x04	/* page is a gift */
+#define PIPE_BUF_FLAG_PACKET	0x08	/* read() as a packet */
 
 /**
  *	struct pipe_buffer - a linux kernel pipe buffer