[PATCH v2 06/17] switch macvtap to ->read_iter()

From: Al Viro
Date: Tue Nov 25 2014 - 09:08:28 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
drivers/net/macvtap.c | 61 ++++++++++++++++++++++---------------------------
1 file changed, 27 insertions(+), 34 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 42a80d3..8f80045 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -831,64 +831,55 @@ done:
}

static ssize_t macvtap_do_read(struct macvtap_queue *q,
- const struct iovec *iv, unsigned long segs,
- unsigned long len,
+ struct iov_iter *to,
int noblock)
{
DEFINE_WAIT(wait);
struct sk_buff *skb;
ssize_t ret = 0;
- struct iov_iter iter;

- while (len) {
+ if (!iov_iter_count(to))
+ return 0;
+
+ while (1) {
if (!noblock)
prepare_to_wait(sk_sleep(&q->sk), &wait,
TASK_INTERRUPTIBLE);

/* Read frames from the queue */
skb = skb_dequeue(&q->sk.sk_receive_queue);
- if (!skb) {
- if (noblock) {
- ret = -EAGAIN;
- break;
- }
- if (signal_pending(current)) {
- ret = -ERESTARTSYS;
- break;
- }
- /* Nothing to read, let's sleep */
- schedule();
- continue;
+ if (skb)
+ break;
+ if (noblock) {
+ ret = -EAGAIN;
+ break;
}
- iov_iter_init(&iter, READ, iv, segs, len);
- ret = macvtap_put_user(q, skb, &iter);
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+ /* Nothing to read, let's sleep */
+ schedule();
+ }
+ if (skb) {
+ ret = macvtap_put_user(q, skb, to);
kfree_skb(skb);
- break;
}
-
if (!noblock)
finish_wait(sk_sleep(&q->sk), &wait);
return ret;
}

-static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
- unsigned long count, loff_t pos)
+static ssize_t macvtap_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *file = iocb->ki_filp;
struct macvtap_queue *q = file->private_data;
- ssize_t len, ret = 0;
+ ssize_t len = iov_iter_count(to), ret;

- len = iov_length(iv, count);
- if (len < 0) {
- ret = -EINVAL;
- goto out;
- }
-
- ret = macvtap_do_read(q, iv, count, len, file->f_flags & O_NONBLOCK);
+ ret = macvtap_do_read(q, to, file->f_flags & O_NONBLOCK);
ret = min_t(ssize_t, ret, len);
if (ret > 0)
iocb->ki_pos = ret;
-out:
return ret;
}

@@ -1089,7 +1080,8 @@ static const struct file_operations macvtap_fops = {
.owner = THIS_MODULE,
.open = macvtap_open,
.release = macvtap_release,
- .aio_read = macvtap_aio_read,
+ .read = new_sync_read,
+ .read_iter = macvtap_read_iter,
.aio_write = macvtap_aio_write,
.poll = macvtap_poll,
.llseek = no_llseek,
@@ -1112,11 +1104,12 @@ static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,
int flags)
{
struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
+ struct iov_iter to;
int ret;
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
return -EINVAL;
- ret = macvtap_do_read(q, m->msg_iov, m->msg_iovlen, total_len,
- flags & MSG_DONTWAIT);
+ iov_iter_init(&to, READ, m->msg_iov, m->msg_iovlen, total_len);
+ ret = macvtap_do_read(q, &to, flags & MSG_DONTWAIT);
if (ret > total_len) {
m->msg_flags |= MSG_TRUNC;
ret = flags & MSG_TRUNC ? ret : total_len;
--
1.7.10.4

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