From 04502c29f6892a39adcacfd844f46667ef8e6e4b Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Tue, 19 Feb 2019 17:01:50 +0300
Subject: [PATCH] move rbd image while freeing old one

---
 Makefile   |   3 ++
 rbd-move.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+)
 create mode 100644 Makefile
 create mode 100644 rbd-move.c

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..8bf9623
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,3 @@
+all: rbd-move
+rbd-move: rbd-move.c
+	gcc -g -o rbd-move -lrbd -lrados rbd-move.c
diff --git a/rbd-move.c b/rbd-move.c
new file mode 100644
index 0000000..983537e
--- /dev/null
+++ b/rbd-move.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include "rados/librados.h"
+#include "rbd/librbd.h"
+
+struct rbd_move_data
+{
+    rbd_image_t src;
+    rbd_image_t dst;
+};
+
+int move_extent(uint64_t offset, size_t len, const char *buf, void* data_ptr)
+{
+    struct rbd_move_data* data = (struct rbd_move_data*)data_ptr;
+    if (buf != NULL)
+    {
+        int err;
+        err = rbd_write2(data->dst, offset, len, buf, LIBRADOS_OP_FLAG_FADVISE_SEQUENTIAL);
+        if (err < 0)
+            return err;
+        err = rbd_discard(data->src, offset, len);
+        if (err < 0)
+            return err;
+    }
+    return 0;
+}
+
+void rbd_move(rbd_image_t src, rbd_image_t dst, uint64_t size)
+{
+    struct rbd_move_data data = {
+        src,
+        dst,
+    };
+    rbd_read_iterate2(src, 0, size, move_extent, &data);
+}
+
+int main(int argc, char **argv)
+{
+    char *pool_name = "rpool";
+    char *src_img = "one-1-49-1";
+    char *dst_img = "one-1-49-1-ec";
+    int err;
+    int st;
+    rados_t cluster;
+    rados_ioctx_t io;
+    rbd_image_t src, dst;
+    uint64_t size;
+    err = rados_create(&cluster, NULL);
+    if (err < 0)
+    {
+        fprintf(stderr, "%s: cannot create a cluster handle: %s\n", argv[0], strerror(-err));
+        st = 1;
+    }
+    else
+    {
+        err = rados_conf_read_file(cluster, "/etc/ceph/ceph.conf");
+        if (err < 0)
+        {
+            fprintf(stderr, "%s: cannot read config file: %s\n", argv[0], strerror(-err));
+            st = 1;
+        }
+        else
+        {
+            err = rados_connect(cluster);
+            if (err < 0)
+            {
+                fprintf(stderr, "%s: cannot connect to cluster: %s\n", argv[0], strerror(-err));
+                st = 1;
+            }
+            else
+            {
+                err = rados_ioctx_create(cluster, pool_name, &io);
+                if (err < 0)
+                {
+                    fprintf(stderr, "%s: cannot open rados pool %s: %s\n", argv[0], pool_name, strerror(-err));
+                    st = 1;
+                }
+                else
+                {
+                    err = rbd_open(io, src_img, &src, NULL);
+                    if (err < 0)
+                    {
+                        fprintf(stderr, "%s: cannot open image %s/%s: %s\n", argv[0], pool_name, src_img, strerror(-err));
+                        st = 1;
+                    }
+                    else
+                    {
+                        err = rbd_open(io, dst_img, &dst, NULL);
+                        if (err < 0)
+                        {
+                            fprintf(stderr, "%s: cannot open image %s/%s: %s\n", argv[0], pool_name, dst_img, strerror(-err));
+                            st = 1;
+                        }
+                        else
+                        {
+                            err = rbd_get_size(src, &size);
+                            if (err < 0)
+                            {
+                                fprintf(stderr, "%s: cannot stat %s/%s: %s\n", argv[0], pool_name, src_img, strerror(-err));
+                                st = 1;
+                            }
+                            rbd_move(src, dst, size);
+                            rbd_close(dst);
+                        }
+                        rbd_close(src);
+                    }
+                    rados_ioctx_destroy(io);
+                }
+                rados_shutdown(cluster);
+            }
+        }
+    }
+    return st;
+}