From d68370304e376f561f4de4591da327e806763cf4 Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Wed, 24 Jun 2020 01:31:48 +0300
Subject: [PATCH] Support iovecs in cluster_client_t

---
 cluster_client.cpp | 32 ++++++++++++++++++++++++++++----
 cluster_client.h   |  5 +++--
 fio_cluster.cpp    |  4 ++--
 3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/cluster_client.cpp b/cluster_client.cpp
index d9868c74..8cef24a8 100644
--- a/cluster_client.cpp
+++ b/cluster_client.cpp
@@ -312,6 +312,7 @@ void cluster_client_t::continue_rw(cluster_op_t *op)
         op_copy->offset = op->offset;
         op_copy->len = op->len;
         op_copy->buf = malloc(op->len);
+        op_copy->iov.push_back(op_copy->buf, op->len);
         op_copy->callback = [](cluster_op_t* op_copy)
         {
             if (op_copy->orig_op)
@@ -322,7 +323,12 @@ void cluster_client_t::continue_rw(cluster_op_t *op)
                 op_copy->orig_op = NULL;
             }
         };
-        memcpy(op_copy->buf, op->buf, op->len);
+        void *cur_buf = op_copy->buf;
+        for (int i = 0; i < op->iov.count; i++)
+        {
+            memcpy(cur_buf, op->iov.buf[i].iov_base, op->iov.buf[i].iov_len);
+            cur_buf += op->iov.buf[i].iov_len;
+        }
         unsynced_writes.push_back(op_copy);
         cur_ops.erase(op);
         cur_ops.insert(op_copy);
@@ -407,6 +413,8 @@ void cluster_client_t::slice_rw(cluster_op_t *op)
     uint64_t last_stripe = ((op->offset + op->len + pg_block_size - 1) / pg_block_size - 1) * pg_block_size;
     op->retval = 0;
     op->parts.resize((last_stripe - first_stripe) / pg_block_size + 1);
+    int iov_idx = 0;
+    size_t iov_pos = 0;
     int i = 0;
     for (uint64_t stripe = first_stripe; stripe <= last_stripe; stripe += pg_block_size)
     {
@@ -419,10 +427,27 @@ void cluster_client_t::slice_rw(cluster_op_t *op)
             .offset = begin,
             .len = (uint32_t)(end - begin),
             .pg_num = pg_num,
-            .buf = op->buf + begin - op->offset,
             .sent = false,
             .done = false,
         };
+        int left = end-begin;
+        while (left > 0 && iov_idx < op->iov.count)
+        {
+            if (op->iov.buf[iov_idx].iov_len - iov_pos > left)
+            {
+                op->parts[i].iov.push_back(op->iov.buf[iov_idx].iov_base + iov_pos, op->iov.buf[iov_idx].iov_len - iov_pos);
+                left -= (op->iov.buf[iov_idx].iov_len - iov_pos);
+                iov_pos = 0;
+                iov_idx++;
+            }
+            else
+            {
+                op->parts[i].iov.push_back(op->iov.buf[iov_idx].iov_base + iov_pos, left);
+                iov_pos += left;
+                left = 0;
+            }
+        }
+        assert(left == 0);
         i++;
     }
 }
@@ -459,7 +484,7 @@ bool cluster_client_t::try_send(cluster_op_t *op, cluster_op_part_t *part)
                     handle_op_part(part);
                 },
             };
-            part->op.iov.push_back(part->buf, part->len);
+            part->op.iov = part->iov;
             msgr.outbox_push(&part->op);
             return true;
         }
@@ -619,7 +644,6 @@ void cluster_client_t::handle_op_part(cluster_op_part_t *part)
     cluster_op_t *op = part->parent;
     part->sent = false;
     op->sent_count--;
-    part->op.buf = NULL;
     int expected = part->op.req.hdr.opcode == OSD_OP_SYNC ? 0 : part->op.req.rw.len;
     if (part->op.reply.hdr.retval != expected)
     {
diff --git a/cluster_client.h b/cluster_client.h
index 80b4d43a..07782161 100644
--- a/cluster_client.h
+++ b/cluster_client.h
@@ -20,7 +20,7 @@ struct cluster_op_part_t
     uint32_t len;
     pg_num_t pg_num;
     osd_num_t osd_num;
-    void *buf;
+    osd_op_buf_list_t iov;
     bool sent;
     bool done;
     osd_op_t op;
@@ -33,9 +33,10 @@ struct cluster_op_t
     uint64_t offset;
     uint64_t len;
     int retval;
-    void *buf;
+    osd_op_buf_list_t iov;
     std::function<void(cluster_op_t*)> callback;
 protected:
+    void *buf = NULL;
     cluster_op_t *orig_op = NULL;
     bool is_internal = false;
     bool needs_reslice = false;
diff --git a/fio_cluster.cpp b/fio_cluster.cpp
index eb106c9a..1c541e54 100644
--- a/fio_cluster.cpp
+++ b/fio_cluster.cpp
@@ -175,7 +175,7 @@ static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
         op->inode = opt->inode;
         op->offset = io->offset;
         op->len = io->xfer_buflen;
-        op->buf = io->xfer_buf;
+        op->iov.push_back(io->xfer_buf, io->xfer_buflen);
         bsd->last_sync = false;
         break;
     case DDIR_WRITE:
@@ -183,7 +183,7 @@ static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
         op->inode = opt->inode;
         op->offset = io->offset;
         op->len = io->xfer_buflen;
-        op->buf = io->xfer_buf;
+        op->iov.push_back(io->xfer_buf, io->xfer_buflen);
         bsd->last_sync = false;
         break;
     case DDIR_SYNC: