From b0d0ea50e7827b1d71c8ea466ff8b4b358f9548d Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Fri, 20 Jul 2018 08:15:14 +0800 Subject: vhost_net: introduce helper to initialize tx iov iter Introduce init_iov_iter() in order to be reused by future patch. Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- drivers/vhost/net.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 1a8175ae2941..cac28fdc938d 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -466,6 +466,18 @@ static bool vhost_exceeds_maxpend(struct vhost_net *net) min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2); } +static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter, + size_t hdr_size, int out) +{ + /* Skip header. TODO: support TSO. */ + size_t len = iov_length(vq->iov, out); + + iov_iter_init(iter, WRITE, vq->iov, out, len); + iov_iter_advance(iter, hdr_size); + + return iov_iter_count(iter); +} + /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */ static void handle_tx(struct vhost_net *net) @@ -531,18 +543,14 @@ static void handle_tx(struct vhost_net *net) "out %d, int %d\n", out, in); break; } - /* Skip header. TODO: support TSO. */ - len = iov_length(vq->iov, out); - iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len); - iov_iter_advance(&msg.msg_iter, hdr_size); + /* Sanity check */ - if (!msg_data_left(&msg)) { - vq_err(vq, "Unexpected header len for TX: " - "%zd expected %zd\n", - len, hdr_size); + len = init_iov_iter(vq, &msg.msg_iter, hdr_size, out); + if (!len) { + vq_err(vq, "Unexpected header len for TX: %zd expected %zd\n", + len, hdr_size); break; } - len = msg_data_left(&msg); zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN && !vhost_exceeds_maxpend(net) -- cgit v1.2.3