af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages()

... and adjust the callers
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

crypto/af_alg.c

@@ -404,7 +404,7 @@ int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
 	ssize_t n;
 	int npages, i;
 
-	n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
+	n = iov_iter_get_pages2(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
 	if (n < 0)
 		return n;
 
@@ -1191,7 +1191,6 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
 		len += err;
 		atomic_add(err, &ctx->rcvused);
 		rsgl->sg_num_bytes = err;
-		iov_iter_advance(&msg->msg_iter, err);
 	}
 
 	*outlen = len;

crypto/algif_hash.c

@@ -102,11 +102,12 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
 		err = crypto_wait_req(crypto_ahash_update(&ctx->req),
 				      &ctx->wait);
 		af_alg_free_sg(&ctx->sgl);
-		if (err)
+		if (err) {
+			iov_iter_revert(&msg->msg_iter, len);
 			goto unlock;
+		}
 
 		copied += len;
-		iov_iter_advance(&msg->msg_iter, len);
 	}
 
 	err = 0;