[AIO] introduce async sendmsg and recvmsg

Introduce thread based async sendmsg and recvmsg functionality to allow 
socket using applications to pass flags like MSG_WAITALL into the network 
stack.

Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
diff -purN --exclude=description 862_net_vfsmsg/fs/aio.c 867_async_msg/fs/aio.c
--- 862_net_vfsmsg/fs/aio.c	2005-08-17 13:46:58.000000000 -0400
+++ 867_async_msg/fs/aio.c	2005-08-17 13:47:02.000000000 -0400
@@ -30,6 +30,8 @@
 #include <linux/workqueue.h>
 #include <linux/security.h>
 #include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/socket.h>
 
 #include <asm/kmap_types.h>
 #include <asm/uaccess.h>
@@ -1537,6 +1539,36 @@ static int aio_thread_write_fn(void *arg
 	return 0;
 }
 
+static int aio_thread_recvmsg_fn(void *arg)
+{
+	struct kiocb *iocb = arg;
+	long ret;
+
+	set_fs(USER_DS);
+	use_mm(iocb->ki_ctx->mm);
+	ret = vfs_recvmsg(iocb->ki_filp->private_data,
+			  (void __user *)iocb->ki_buf, iocb->ki_pos);
+	unuse_mm(iocb->ki_ctx->mm);
+	aio_complete(iocb, ret, 0);
+
+	return 0;
+}
+
+static int aio_thread_sendmsg_fn(void *arg)
+{
+	struct kiocb *iocb = arg;
+	long ret;
+
+	set_fs(USER_DS);
+	use_mm(iocb->ki_ctx->mm);
+	ret = vfs_sendmsg(iocb->ki_filp->private_data,
+			  (void __user *)iocb->ki_buf, iocb->ki_pos);
+	unuse_mm(iocb->ki_ctx->mm);
+	aio_complete(iocb, ret, 0);
+
+	return 0;
+}
+
 static int aio_thread_rw_v_fn(void *arg)
 {
 	struct kiocb *iocb = arg;
@@ -1627,6 +1659,16 @@ static ssize_t aio_thread_fdsync(struct 
 	return aio_kernel_thread(iocb, aio_thread_fdsync_fn);
 }
 
+static ssize_t aio_thread_sendmsg(struct kiocb *iocb)
+{
+	return aio_kernel_thread(iocb, aio_thread_sendmsg);
+}
+
+static ssize_t aio_thread_recvmsg(struct kiocb *iocb)
+{
+	return aio_kernel_thread(iocb, aio_thread_recvmsg);
+}
+
 static ssize_t aio_fdsync(struct kiocb *iocb)
 {
 	struct file *file = iocb->ki_filp;
@@ -1747,6 +1789,18 @@ static ssize_t aio_setup_iocb(struct kio
 		else if (file->f_op->fsync)
 			kiocb->ki_retry = aio_thread_fsync;
 		break;
+	case IOCB_CMD_SENDMSG:
+		ret = -EINVAL;
+		if (kiocb->ki_nbytes != sizeof(struct msghdr))
+			break;
+		kiocb->ki_retry = aio_thread_thread_sendmsg;
+		break;
+	case IOCB_CMD_RECVMSG:
+		ret = -EINVAL;
+		if (kiocb->ki_nbytes != sizeof(struct msghdr))
+			break;
+		kiocb->ki_retry = aio_thread_thread_recvmsg;
+		break;
 	default:
 		dprintk("EINVAL: io_submit: no operation provided\n");
 		ret = -EINVAL;
diff -purN --exclude=description 862_net_vfsmsg/include/linux/aio_abi.h 867_async_msg/include/linux/aio_abi.h
--- 862_net_vfsmsg/include/linux/aio_abi.h	2005-08-09 19:13:07.000000000 -0400
+++ 867_async_msg/include/linux/aio_abi.h	2005-08-16 15:56:32.000000000 -0400
@@ -43,6 +43,14 @@ enum {
 	IOCB_CMD_NOOP = 6,
 	IOCB_CMD_PREADV = 7,
 	IOCB_CMD_PWRITEV = 8,
+
+	/* For these network operations:
+	 *	aio_buf points to struct msghdr *,
+	 *	aio_nbytes is sizeof(struct msghdr)
+	 *	aio_offset is the flags value.
+	 */
+	IOCB_CMD_SENDMSG = 9,
+	IOCB_CMD_RECVMSG = 10,
 };
 
 /* read() from /dev/aio returns these structures. */