[PATCH] vhost: drop hard-coded num_buffers size

The 2 that we use for copy_to_iter comes from sizeof(u16),
it used to be that way before the iov iter update.
Fix it up, making it obvious the size of stack access
is right.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index ca70434..2bbfc25 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c

@@ -621,7 +621,8 @@ static void handle_rx(struct vhost_net *net)
 
 		num_buffers = cpu_to_vhost16(vq, headcount);
 		if (likely(mergeable) &&
-		    copy_to_iter(&num_buffers, 2, &fixup) != 2) {
+		    copy_to_iter(&num_buffers, sizeof num_buffers,
+				 &fixup) != sizeof num_buffers) {
 			vq_err(vq, "Failed num_buffers write");
 			vhost_discard_vq_desc(vq, headcount);
 			break;

-- 
MST

From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Tue, 24 Feb 2015 17:31:10 +0100

The 2 that we use for copy_to_iter comes from sizeof(u16),
it used to be that way before the iov iter update.
Fix it up, making it obvious the size of stack access
is right.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Michael, what tree do you want these two patches to go through?

On Wed, Feb 25, 2015 at 04:56:52PM -0500, David Miller wrote:

From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Tue, 24 Feb 2015 17:31:10 +0100

quoted

The 2 that we use for copy_to_iter comes from sizeof(u16),
it used to be that way before the iov iter update.
Fix it up, making it obvious the size of stack access
is right.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Michael, what tree do you want these two patches to go through?

Sorry about being unclear.
They are net specific so I'd like them merged for 4.0 through net tree.
If that's a problem, pls let me know.

Thanks,
-- 
MST

From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Tue, 24 Feb 2015 17:31:10 +0100

The 2 that we use for copy_to_iter comes from sizeof(u16),
it used to be that way before the iov iter update.
Fix it up, making it obvious the size of stack access
is right.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Applied.