iov_iter: Separate type from direction and use accessor functions

In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/tipc/topsrv.c b/net/tipc/topsrv.c
index d8956f7daac4..afa02eeec403 100644
--- a/net/tipc/topsrv.c
+++ b/net/tipc/topsrv.c
@@ -394,7 +394,7 @@ static int tipc_conn_rcv_from_sock(struct tipc_conn *con)
         iov.iov_base = &s;
         iov.iov_len = sizeof(s);
         msg.msg_name = NULL;
-        iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, iov.iov_len);
+        iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, iov.iov_len);
         ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
         if (ret == -EWOULDBLOCK)
                 return -EWOULDBLOCK;