crush: "osd crush class rename" support

In 076a6abd80cc90ebcb901f908f880ef030721b2a I killed the 'class rename' command
and thought it was totally useless but I was wrong.

Consider the following user case:
(1) randomly choose some OSDs(e.g., from different hosts) and try to make them for private use only,
    say, by grouping them into 'pool1'
(2) ceph osd crush set-device-class pool1 'OSDs from (1)'
(3) ceph osd crush rule create-replicated rule_for_pool1 default host pool1
(4) ceph osd pool rename pool1 pool2
(5) ceph osd crush class rename pool1 pool2

From the above user case, we need to safely change a pool name without worrying
any risk of data migration. That is why the 'osd crush class rename' command
is still needed here.

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>

diff --git a/qa/standalone/crush/crush-classes.sh b/qa/standalone/crush/crush-classes.sh
index 24696fcd3193592954266db660e3291850c5340e..160f9d8c1a12d8f1844b489b479a1e867c0b6471 100755 (executable)
--- a/qa/standalone/crush/crush-classes.sh
+++ b/qa/standalone/crush/crush-classes.sh
@@ -201,6 +201,18 @@ function TEST_mon_classes() {
     # test set-device-class implicitly change class
     ceph osd crush set-device-class hdd osd.0 || return 1
     expect_failure $dir EBUSY ceph osd crush set-device-class nvme osd.0 || return 1
+
+    # test class rename
+    ceph osd crush rm-device-class all || return 1
+    ceph osd crush set-device-class class_1 all || return 1
+    ceph osd crush class ls | grep 'class_1' || return 1
+    ceph osd crush tree --show-shadow | grep 'class_1' || return 1
+    ceph osd crush rule create-replicated class_1_rule default host class_1 || return 1
+    ceph osd crush class rename class_1 class_2
+    ceph osd crush class ls | grep 'class_1' && return 1
+    ceph osd crush tree --show-shadow | grep 'class_1' && return 1
+    ceph osd crush class ls | grep 'class_2' || return 1
+    ceph osd crush tree --show-shadow | grep 'class_2' || return 1
 }
 
 main crush-classes "$@"

diff --git a/src/crush/CrushWrapper.cc b/src/crush/CrushWrapper.cc
index 8f2d63e77c8cc3d637f8e481c3f3fd14386eb58a..26350e63975f805317afe8bab0994f20ebe11f1b 100644 (file)
--- a/src/crush/CrushWrapper.cc
+++ b/src/crush/CrushWrapper.cc
@@ -1364,6 +1364,42 @@ int CrushWrapper::get_parent_of_type(int item, int type) const
   return item;
 }
 
+int CrushWrapper::rename_class(const string& srcname, const string& dstname)
+{
+  auto i = class_rname.find(srcname);
+  if (i == class_rname.end())
+    return -ENOENT;
+  auto j = class_rname.find(dstname);
+  if (j != class_rname.end())
+    return -EEXIST;
+
+  int class_id = i->second;
+  assert(class_name.count(class_id));
+  // rename any shadow buckets of old class name
+  for (auto &it: class_map) {
+    if (it.first < 0 && it.second == class_id) {
+        string old_name = get_item_name(it.first);
+        size_t pos = old_name.find("~");
+        assert(pos != string::npos);
+        string name_no_class = old_name.substr(0, pos);
+        string old_class_name = old_name.substr(pos + 1);
+        assert(old_class_name == srcname);
+        string new_name = name_no_class + "~" + dstname;
+        // we do not use set_item_name
+        // because the name is intentionally invalid
+        name_map[it.first] = new_name;
+        have_rmaps = false;
+    }
+  }
+
+  // rename class
+  class_rname.erase(srcname);
+  class_name.erase(class_id);
+  class_rname[dstname] = class_id;
+  class_name[class_id] = dstname;
+  return 0;
+}
+
 int CrushWrapper::populate_classes(
   const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket)
 {

diff --git a/src/crush/CrushWrapper.h b/src/crush/CrushWrapper.h
index 737ba583ececebcd90dd8ae99ddfef6bd8423d43..3808db08062cac4c5f622b2abd3256b9eb827838 100644 (file)
--- a/src/crush/CrushWrapper.h
+++ b/src/crush/CrushWrapper.h
@@ -1214,6 +1214,7 @@ public:
     const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket,
     const std::set<int32_t>& used_ids,
     int *clone);
+  int rename_class(const string& srcname, const string& dstname);
   int populate_classes(
     const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket);
   bool _class_is_dead(int class_id);

diff --git a/src/mon/MonCommands.h b/src/mon/MonCommands.h
index ef3c094b2339e83749eccfcdb6d01d06a504e767..57845ab3d27f1a45bc10730db861826bd05f4a0f 100644 (file)
--- a/src/mon/MonCommands.h
+++ b/src/mon/MonCommands.h
@@ -555,6 +555,11 @@ COMMAND("osd crush rm-device-class " \
         "remove class of the osd(s) <id> [<id>...]," \
         "or use <all|any|*> to remove all.", \
         "osd", "rw", "cli,rest")
+COMMAND("osd crush class rename " \
+        "name=srcname,type=CephString,goodchars=[A-Za-z0-9-_] " \
+        "name=dstname,type=CephString,goodchars=[A-Za-z0-9-_]", \
+        "rename crush device class <srcname> to <dstname>", \
+        "osd", "rw", "cli,rest")
 COMMAND("osd crush create-or-move " \
        "name=id,type=CephOsdName " \
        "name=weight,type=CephFloat,range=0.0 " \

diff --git a/src/mon/OSDMonitor.cc b/src/mon/OSDMonitor.cc
index 1d71a2070add9ca1b03a67f1bc2383abb82e4ce8..b1d509b21fc7d20a840fa9a268d4192e57b42f41 100644 (file)
--- a/src/mon/OSDMonitor.cc
+++ b/src/mon/OSDMonitor.cc
@@ -7454,7 +7454,43 @@ bool OSDMonitor::prepare_command_impl(MonOpRequestRef op,
         new Monitor::C_Command(mon,op, 0, rs, get_last_committed() + 1));
       return true;
     }
+  } else if (prefix == "osd crush class rename") {
+    string srcname, dstname;
+    if (!cmd_getval(g_ceph_context, cmdmap, "srcname", srcname)) {
+      err = -EINVAL;
+      goto reply;
+    }
+    if (!cmd_getval(g_ceph_context, cmdmap, "dstname", dstname)) {
+      err = -EINVAL;
+      goto reply;
+    }
 
+    CrushWrapper newcrush;
+    _get_pending_crush(newcrush);
+
+    if (!newcrush.class_exists(srcname)) {
+      err = -ENOENT;
+      ss << "class '" << srcname << "' does not exist";
+      goto reply;
+    }
+
+    if (newcrush.class_exists(dstname)) {
+      err = -EEXIST;
+      ss << "class '" << dstname << "' already exists";
+      goto reply;
+    }
+
+    err = newcrush.rename_class(srcname, dstname);
+    if (err < 0) {
+      ss << "fail to rename '" << srcname << "' to '" << dstname << "' : "
+         << cpp_strerror(err);
+      goto reply;
+    }
+
+    pending_inc.crush.clear();
+    newcrush.encode(pending_inc.crush, mon->get_quorum_con_features());
+    ss << "rename class '" << srcname << "' to '" << dstname << "'";
+    goto update;
   } else if (prefix == "osd crush add-bucket") {
     // os crush add-bucket <name> <type>
     string name, typestr;