From 7eac7b6d55822f01dbe41e7364653dfdd28bafc8 Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Mon, 2 Mar 2020 21:17:17 +0300
Subject: [PATCH] Use writev in libfio_sec_osd

---
 fio_sec_osd.cpp | 17 ++++++++++-------
 rw_blocking.cpp | 34 ++++++++++++++++++++++++++++++++++
 rw_blocking.h   |  2 ++
 3 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/fio_sec_osd.cpp b/fio_sec_osd.cpp
index 45404dd5..8038e824 100644
--- a/fio_sec_osd.cpp
+++ b/fio_sec_osd.cpp
@@ -261,15 +261,18 @@ static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
     bsd->op_n++;
     bsd->queue[n] = io;
 
-    if (write(bsd->connect_fd, op.buf, OSD_PACKET_SIZE) != OSD_PACKET_SIZE)
-    {
-        perror("write");
-        exit(1);
-    }
+    iovec iov[2] = { { .iov_base = op.buf, .iov_len = OSD_PACKET_SIZE } };
+    int iovcnt = 1, wtotal = OSD_PACKET_SIZE;
     if (io->ddir == DDIR_WRITE)
     {
-        // Send data
-        write_blocking(bsd->connect_fd, io->xfer_buf, io->xfer_buflen);
+        iov[1] = { .iov_base = io->xfer_buf, .iov_len = io->xfer_buflen };
+        wtotal += io->xfer_buflen;
+        iovcnt++;
+    }
+    if (writev_blocking(bsd->connect_fd, iov, iovcnt) != wtotal)
+    {
+        perror("writev");
+        exit(1);
     }
 
     if (io->error != 0)
diff --git a/rw_blocking.cpp b/rw_blocking.cpp
index 6e735681..7f5bd22e 100644
--- a/rw_blocking.cpp
+++ b/rw_blocking.cpp
@@ -50,3 +50,37 @@ int write_blocking(int fd, void *write_buf, size_t remaining)
     }
     return done;
 }
+
+int writev_blocking(int fd, iovec *iov, int iovcnt)
+{
+    int v = 0;
+    int done = 0;
+    while (v < iovcnt)
+    {
+        ssize_t r = writev(fd, iov, iovcnt);
+        if (r < 0)
+        {
+            if (errno != EAGAIN && errno != EPIPE)
+            {
+                perror("writev");
+                exit(1);
+            }
+            continue;
+        }
+        while (v < iovcnt)
+        {
+            if (iov[v].iov_len > r)
+            {
+                iov[v].iov_len -= r;
+                iov[v].iov_base += r;
+                break;
+            }
+            else
+            {
+                v++;
+            }
+        }
+        done += r;
+    }
+    return done;
+}
diff --git a/rw_blocking.h b/rw_blocking.h
index 015595f3..cb8387fe 100644
--- a/rw_blocking.h
+++ b/rw_blocking.h
@@ -1,6 +1,8 @@
 #pragma once
 
 #include <unistd.h>
+#include <sys/uio.h>
 
 int read_blocking(int fd, void *read_buf, size_t remaining);
 int write_blocking(int fd, void *write_buf, size_t remaining);
+int writev_blocking(int fd, iovec *iov, int iovcnt);