vhost-user-bridge: fix iov_restore_front() warning

CC      tests/vhost-user-bridge.o
/home/dgilbert/git/qemu-world3/tests/vhost-user-bridge.c:228:23: warning: variables 'front' and 'iov' used in loop condition not modified in loop body [-Wfor-loop-analysis]
    for (cur = front; front != iov; cur++) {
                      ^~~~~    ~~~
1 warning generated.

Fix the loop, document the function, and fix some related assert().

In practice, the loop bug was harmless because the front sg buffer is
enough to discard/restore the header size.

Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Jens Freimann <jfreiman@redhat.com>
This commit is contained in:
Marc-André Lureau 2017-06-02 12:15:19 +04:00 committed by Michael S. Tsirkin
parent 64175afc69
commit 277238f9f4

View File

@ -220,12 +220,18 @@ vubr_handle_tx(VuDev *dev, int qidx)
free(elem);
}
/* this function reverse the effect of iov_discard_front() it must be
* called with 'front' being the original struct iovec and 'bytes'
* being the number of bytes you shaved off
*/
static void
iov_restore_front(struct iovec *front, struct iovec *iov, size_t bytes)
{
struct iovec *cur;
for (cur = front; front != iov; cur++) {
for (cur = front; cur != iov; cur++) {
assert(bytes >= cur->iov_len);
bytes -= cur->iov_len;
}
@ -302,7 +308,8 @@ vubr_backend_recv_cb(int sock, void *ctx)
}
iov_from_buf(sg, elem->in_num, 0, &hdr, sizeof hdr);
total += hdrlen;
assert(iov_discard_front(&sg, &num, hdrlen) == hdrlen);
ret = iov_discard_front(&sg, &num, hdrlen);
assert(ret == hdrlen);
}
struct msghdr msg = {