crush: implement swap_bucket

Swap contents between buckets.

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/crush/CrushWrapper.cc b/src/crush/CrushWrapper.cc
index ee6db9bc629ab3211a4b7c62496062b7a1944e4c..b4319ce33e4e5028f5382c2705b017bce276d99e 100644 (file)
--- a/src/crush/CrushWrapper.cc
+++ b/src/crush/CrushWrapper.cc
@@ -790,6 +790,52 @@ int CrushWrapper::move_bucket(CephContext *cct, int id, const map<string,string>
   return insert_item(cct, id, bucket_weight / (float)0x10000, id_name, loc);
 }
 
+int CrushWrapper::swap_bucket(CephContext *cct, int src, int dst)
+{
+  if (src >= 0 || dst >= 0)
+    return -EINVAL;
+  if (!item_exists(src) || !item_exists(dst))
+    return -EINVAL;
+  crush_bucket *a = get_bucket(src);
+  crush_bucket *b = get_bucket(dst);
+  unsigned aw = a->weight;
+  unsigned bw = b->weight;
+
+  // swap weights
+  adjust_item_weight(cct, a->id, bw);
+  adjust_item_weight(cct, b->id, aw);
+
+  // swap items
+  map<int,unsigned> tmp;
+  unsigned as = a->size;
+  unsigned bs = b->size;
+  for (unsigned i = 0; i < as; ++i) {
+    int item = a->items[0];
+    int itemw = crush_get_bucket_item_weight(a, 0);
+    tmp[item] = itemw;
+    crush_bucket_remove_item(crush, a, item);
+  }
+  assert(a->size == 0);
+  assert(b->size == bs);
+  for (unsigned i = 0; i < bs; ++i) {
+    int item = b->items[0];
+    int itemw = crush_get_bucket_item_weight(b, 0);
+    crush_bucket_remove_item(crush, b, item);
+    crush_bucket_add_item(crush, a, item, itemw);
+  }
+  assert(a->size == bs);
+  assert(b->size == 0);
+  for (auto t : tmp) {
+    crush_bucket_add_item(crush, b, t.first, t.second);
+  }
+  assert(a->size == bs);
+  assert(b->size == as);
+
+  // swap names
+  swap_names(src, dst);
+  return 0;
+}
+
 int CrushWrapper::link_bucket(CephContext *cct, int id, const map<string,string>& loc)
 {
   if (choose_args.size() > 0) {

diff --git a/src/crush/CrushWrapper.h b/src/crush/CrushWrapper.h
index c47a5badc412854f13db0846505e0912c142f6f3..dde6d4c63c039aa20b61892299e0bca323937bab 100644 (file)
--- a/src/crush/CrushWrapper.h
+++ b/src/crush/CrushWrapper.h
@@ -402,6 +402,16 @@ public:
       name_rmap[name] = i;
     return 0;
   }
+  void swap_names(int a, int b) {
+    string an = name_map[a];
+    string bn = name_map[b];
+    name_map[a] = bn;
+    name_map[b] = an;
+    if (have_rmaps) {
+      name_rmap[an] = b;
+      name_rmap[bn] = a;
+    }
+  }
   bool id_has_class(int i) {
     int idout;
     int classout;
@@ -651,6 +661,16 @@ public:
    */
   int move_bucket(CephContext *cct, int id, const map<string,string>& loc);
 
+  /**
+   * swap bucket contents of two buckets without touching bucket ids
+   *
+   * @param cct cct
+   * @param src bucket a
+   * @param dst bucket b
+   * @return 0 for success, negative on error
+   */
+  int swap_bucket(CephContext *cct, int src, int dst);
+
   /**
    * add a link to an existing bucket in the hierarchy to the new location
    *

diff --git a/src/test/crush/CrushWrapper.cc b/src/test/crush/CrushWrapper.cc
index 6e6fb05e5e7c8ac38bd49934cba4ca982239bc12..d5a90b056b1822ad653f59bcc5c71adedc8713fa 100644 (file)
--- a/src/test/crush/CrushWrapper.cc
+++ b/src/test/crush/CrushWrapper.cc
@@ -128,6 +128,69 @@ TEST(CrushWrapper, move_bucket) {
   delete c;
 }
 
+TEST(CrushWrapper, swap_bucket) {
+  CrushWrapper *c = new CrushWrapper;
+
+  const int ROOT_TYPE = 2;
+  c->set_type_name(ROOT_TYPE, "root");
+  const int HOST_TYPE = 1;
+  c->set_type_name(HOST_TYPE, "host");
+  const int OSD_TYPE = 0;
+  c->set_type_name(OSD_TYPE, "osd");
+
+  int root;
+  EXPECT_EQ(0, c->add_bucket(0, CRUSH_BUCKET_STRAW2, CRUSH_HASH_RJENKINS1,
+                            ROOT_TYPE, 0, NULL, NULL, &root));
+  EXPECT_EQ(0, c->set_item_name(root, "root"));
+
+  int a, b;
+  EXPECT_EQ(0, c->add_bucket(0, CRUSH_BUCKET_STRAW2, CRUSH_HASH_RJENKINS1,
+                            HOST_TYPE, 0, NULL, NULL, &a));
+  EXPECT_EQ(0, c->set_item_name(a, "a"));
+  EXPECT_EQ(0, c->add_bucket(0, CRUSH_BUCKET_STRAW2, CRUSH_HASH_RJENKINS1,
+                            HOST_TYPE, 0, NULL, NULL, &b));
+  EXPECT_EQ(0, c->set_item_name(b, "b"));
+
+  {
+    map<string,string> loc;
+    loc["root"] = "root";
+    EXPECT_EQ(0, c->move_bucket(g_ceph_context, a, loc));
+  }
+  {
+    map<string,string> loc;
+    loc["root"] = "root";
+    loc["host"] = "a";
+    EXPECT_EQ(0, c->insert_item(g_ceph_context, 0, 1.0, "osd.0", loc));
+    EXPECT_EQ(0, c->insert_item(g_ceph_context, 1, 1.0, "osd.1", loc));
+    EXPECT_EQ(0, c->insert_item(g_ceph_context, 2, 1.0, "osd.2", loc));
+  }
+  {
+    map<string,string> loc;
+    loc["host"] = "b";
+    EXPECT_EQ(0, c->insert_item(g_ceph_context, 3, 1.0, "osd.3", loc));
+  }
+  ASSERT_EQ(0x30000, c->get_item_weight(a));
+  ASSERT_EQ(string("a"), c->get_item_name(a));
+  ASSERT_EQ(0x10000, c->get_item_weight(b));
+  ASSERT_EQ(string("b"), c->get_item_name(b));
+  ASSERT_EQ(a, c->get_bucket_item(root, 0));
+  ASSERT_EQ(0, c->get_bucket_item(a, 0));
+  ASSERT_EQ(1, c->get_bucket_item(a, 1));
+  ASSERT_EQ(2, c->get_bucket_item(a, 2));
+  ASSERT_EQ(3, c->get_bucket_item(b, 0));
+
+  c->swap_bucket(g_ceph_context, a, b);
+  ASSERT_EQ(0x30000, c->get_item_weight(b));
+  ASSERT_EQ(string("a"), c->get_item_name(b));
+  ASSERT_EQ(0x10000, c->get_item_weight(a));
+  ASSERT_EQ(string("b"), c->get_item_name(a));
+  ASSERT_EQ(a, c->get_bucket_item(root, 0));
+  ASSERT_EQ(0, c->get_bucket_item(b, 0));
+  ASSERT_EQ(1, c->get_bucket_item(b, 1));
+  ASSERT_EQ(2, c->get_bucket_item(b, 2));
+  ASSERT_EQ(3, c->get_bucket_item(a, 0));
+}
+
 TEST(CrushWrapper, rename_bucket_or_item) {
   CrushWrapper *c = new CrushWrapper;