crush: remove 'class rm' command

The current version is broken. E.g., it should only remove a class
which is never referenced by any device.

Since we now create new classes automatically, we shall automatically
recycle dead classes too. So this command is definitely unuseful.
(Actually it is weird that we keep 'class rm' without keeping the
 corresponding 'class create' command).

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

qa/standalone/crush/crush-classes.sh

@@ -176,18 +176,6 @@ function TEST_mon_classes() {
     ceph osd crush rm-device-class all || return 1
     ceph osd tree | grep -q 'asdf' && return 1
 
-    # test 'class rm' automatically recycles shadow trees
-    ceph osd crush set-device-class asdf 0 1 2 || return 1
-    ceph osd tree | grep -q 'asdf' || return 1
-    ceph osd crush dump | grep -q '~asdf' || return 1
-    ceph osd crush tree --show-shadow | grep -q '~asdf' || return 1
-    ceph osd crush class ls | grep -q 'asdf' || return 1
-    ceph osd crush class rm asdf || return 1
-    ceph osd tree | grep -q 'asdf' && return 1
-    ceph osd crush dump | grep -q '~asdf' && return 1
-    ceph osd crush tree --show-shadow | grep -q '~asdf' && return 1
-    ceph osd crush class ls | grep -q 'asdf' && return 1
-
     ceph osd crush set-device-class abc osd.2 || return 1
     ceph osd crush move osd.2 root=foo rack=foo-rack host=foo-host || return 1
     out=`ceph osd tree |awk '$1 == 2 && $2 == "abc" {print $0}'`
@@ -208,24 +196,6 @@ function TEST_mon_classes() {
 
     ceph osd crush rule create-replicated foo-rule foo host abc || return 1
 
-    # test class_is_in_use
-    ceph osd crush set-device-class hdd osd.0 || return 1
-    ceph osd crush set-device-class ssd osd.1 || return 1
-    ceph osd crush rule create-replicated foo-hdd1 default host hdd || return 1
-    ceph osd crush rule create-replicated foo-hdd2 default host hdd || return 1
-    ceph osd crush rule create-replicated foo-ssd default host ssd || return 1
-    expect_failure $dir EBUSY ceph osd crush class rm hdd || return 1
-    expect_failure $dir EBUSY ceph osd crush class rm ssd || return 1
-    ceph osd crush rule rm foo-hdd1 || return 1
-    expect_failure $dir EBUSY ceph osd crush class rm hdd || return 1 # still referenced by foo-hdd2
-    ceph osd crush rule rm foo-hdd2 || return 1
-    ceph osd crush rule rm foo-ssd || return 1
-    ceph osd crush class rm hdd || return 1
-    ceph osd crush class rm ssd || return 1
-    expect_failure $dir EBUSY ceph osd crush class rm abc || return 1 # still referenced by foo-rule
-    ceph osd crush rule rm foo-rule || return 1
-    ceph osd crush class rm abc || return 1
-
     # 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

src/crush/CrushWrapper.cc

@@ -1364,41 +1364,6 @@ int CrushWrapper::get_parent_of_type(int item, int type) const
   return item;
 }
 
-
-bool CrushWrapper::class_is_in_use(int class_id, ostream *ss)
-{
-  list<unsigned> rules;
-  for (unsigned i = 0; i < crush->max_rules; ++i) {
-    crush_rule *r = crush->rules[i];
-    if (!r)
-      continue;
-    for (unsigned j = 0; j < r->len; ++j) {
-      if (r->steps[j].op == CRUSH_RULE_TAKE) {
-        int root = r->steps[j].arg1;
-        for (auto &p : class_bucket) {
-          auto& q = p.second;
-          if (q.count(class_id) && q[class_id] == root) {
-            rules.push_back(i);
-          }
-        }
-      }
-    }
-  }
-  if (rules.empty()) {
-    return false;
-  }
-  if (ss) {
-    ostringstream os;
-    for (auto &p: rules) {
-      os << "'" << get_rule_name(p) <<"',";
-    }
-    string out(os.str());
-    out.resize(out.size() - 1); // drop last ','
-    *ss << "still referenced by crush_rule(s): " << out;
-  }
-  return true;
-}
-
 int CrushWrapper::populate_classes(
   const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket)
 {

src/crush/CrushWrapper.h

@@ -1214,7 +1214,6 @@ public:
     const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket,
     const std::set<int32_t>& used_ids,
     int *clone);
-  bool class_is_in_use(int class_id, ostream *ss = nullptr);
   int populate_classes(
     const std::map<int32_t, map<int32_t, int32_t>>& old_class_bucket);
   int rebuild_roots_with_classes();

src/mon/MonCommands.h

@@ -647,10 +647,6 @@ COMMAND("osd crush tree "
         "name=shadow,type=CephChoices,strings=--show-shadow,req=false", \
 	"dump crush buckets and items in a tree view",
 	"osd", "r", "cli,rest")
-COMMAND("osd crush class rm " \
-	"name=class,type=CephString,goodchars=[A-Za-z0-9-_]", \
-	"remove crush device class <class>", \
-	"osd", "rw", "cli,rest")
 COMMAND("osd crush class ls", \
 	"list all crush device classes", \
 	"osd", "r", "cli,rest")

src/mon/OSDMonitor.cc

@@ -7479,63 +7479,6 @@ bool OSDMonitor::prepare_command_impl(MonOpRequestRef op,
       goto reply;
     else
       goto update;
-  } else if (prefix == "osd crush class rm") {
-    string device_class;
-    if (!cmd_getval(g_ceph_context, cmdmap, "class", device_class)) {
-      err = -EINVAL; // no value!
-      goto reply;
-    }
-    if (osdmap.require_osd_release < CEPH_RELEASE_LUMINOUS) {
-      ss << "you must complete the upgrade and 'ceph osd require-osd-release "
-	 << "luminous' before using crush device classes";
-      err = -EPERM;
-      goto reply;
-    }
-
-    CrushWrapper newcrush;
-    _get_pending_crush(newcrush);
-
-    if (!newcrush.class_exists(device_class)) {
-      err = -ENOENT;
-      ss << "class '" << device_class << "' does not exist";
-      goto reply;
-    }
-
-    int class_id = newcrush.get_class_id(device_class);
-
-    stringstream ts;
-    if (newcrush.class_is_in_use(class_id, &ts)) {
-      err = -EBUSY;
-      ss << "class '" << device_class << "' " << ts.str();
-      goto reply;
-    }
-
-    set<int> osds;
-    newcrush.get_devices_by_class(device_class, &osds);
-    for (auto& p: osds) {
-      err = newcrush.remove_device_class(g_ceph_context, p, &ss);
-      if (err < 0) {
-        // ss has reason for failure
-        goto reply;
-      }
-    }
-
-    if (osds.empty()) {
-      // empty class, remove directly
-      err = newcrush.remove_class_name(device_class);
-      if (err < 0) {
-        ss << "class '" << device_class << "' cannot be removed '"
-           << cpp_strerror(err) << "'";
-        goto reply;
-      }
-    }
-
-    pending_inc.crush.clear();
-    newcrush.encode(pending_inc.crush, mon->get_quorum_con_features());
-    ss << "removed class " << device_class << " with id " << class_id
-       << " from crush map";
-    goto update;
-
   } else if (prefix == "osd crush weight-set create" ||
 	     prefix == "osd crush weight-set create-compat") {
     CrushWrapper newcrush;