Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull iov_iter updates from Al Viro:
 "Cleanups that sat in -next + -stable fodder that has just missed 4.11.

  There's more iov_iter work in my local tree, but I'd prefer to push
  the stuff that had been in -next first"

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  iov_iter: don't revert iov buffer if csum error
  generic_file_read_iter(): make use of iov_iter_revert()
  generic_file_direct_write(): make use of iov_iter_revert()
  orangefs: use iov_iter_revert()
  sctp: switch to copy_from_iter_full()
  net/9p: switch to copy_from_iter_full()
  switch memcpy_from_msg() to copy_from_iter_full()
  rds: make use of iov_iter_revert()

5 files changed, 12 insertions, 16 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index 8e5c6a8d0a37..1218fb3b52da 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -592,9 +592,8 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
                 ename = &req->rc->sdata[req->rc->offset];
                 if (len > inline_len) {
                         /* We have error in external buffer */
-                        err = copy_from_iter(ename + inline_len,
-                                             len - inline_len, uidata);
-                        if (err != len - inline_len) {
+                        if (!copy_from_iter_full(ename + inline_len,
+                                             len - inline_len, uidata)) {
                                 err = -EFAULT;
                                 goto out_err;
                         }
diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index 16d287565987..16e10680518c 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -74,7 +74,7 @@ pdu_write_u(struct p9_fcall *pdu, struct iov_iter *from, size_t size)
 {
         size_t len = min(pdu->capacity - pdu->size, size);
         struct iov_iter i = *from;
-        if (copy_from_iter(&pdu->sdata[pdu->size], len, &i) != len)
+        if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, &i))
                 len = 0;
 
         pdu->size += len;
diff --git a/net/core/datagram.c b/net/core/datagram.c
index f4947e737f34..d797baa69e43 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -760,7 +760,7 @@ int skb_copy_and_csum_datagram_msg(struct sk_buff *skb,
 
         if (msg_data_left(msg) < chunk) {
                 if (__skb_checksum_complete(skb))
-                        goto csum_error;
+                        return -EINVAL;
                 if (skb_copy_datagram_msg(skb, hlen, msg, chunk))
                         goto fault;
         } else {
@@ -768,15 +768,16 @@ int skb_copy_and_csum_datagram_msg(struct sk_buff *skb,
                 if (skb_copy_and_csum_datagram(skb, hlen, &msg->msg_iter,
                                                chunk, &csum))
                         goto fault;
-                if (csum_fold(csum))
-                        goto csum_error;
+
+                if (csum_fold(csum)) {
+                        iov_iter_revert(&msg->msg_iter, chunk);
+                        return -EINVAL;
+                }
+
                 if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE))
                         netdev_rx_csum_fault(skb->dev);
         }
         return 0;
-csum_error:
-        iov_iter_revert(&msg->msg_iter, chunk);
-        return -EINVAL;
 fault:
         return -EFAULT;
 }
diff --git a/net/rds/recv.c b/net/rds/recv.c
index 8b7e7b7f2c2d..c70c32cb05f5 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -594,7 +594,6 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
                 goto out;
 
         while (1) {
-                struct iov_iter save;
                 /* If there are pending notifications, do those - and nothing else */
                 if (!list_empty(&rs->rs_notify_queue)) {
                         ret = rds_notify_queue_get(rs, msg);
@@ -630,7 +629,6 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
                 rdsdebug("copying inc %p from %pI4:%u to user\n", inc,
                          &inc->i_conn->c_faddr,
                          ntohs(inc->i_hdr.h_sport));
-                save = msg->msg_iter;
                 ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter);
                 if (ret < 0)
                         break;
@@ -644,7 +642,7 @@ int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
                         rds_inc_put(inc);
                         inc = NULL;
                         rds_stats_inc(s_recv_deliver_raced);
-                        msg->msg_iter = save;
+                        iov_iter_revert(&msg->msg_iter, ret);
                         continue;
                 }
 
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 118faff6a332..8a08f13469c4 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1512,14 +1512,12 @@ int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
                           struct iov_iter *from)
 {
         void *target;
-        ssize_t copied;
 
         /* Make room in chunk for data.  */
         target = skb_put(chunk->skb, len);
 
         /* Copy data (whole iovec) into chunk */
-        copied = copy_from_iter(target, len, from);
-        if (copied != len)
+        if (!copy_from_iter_full(target, len, from))
                 return -EFAULT;
 
         /* Adjust the chunk length field.  */