mon: don't commit osdmap on no-op application ops

This enables callers to use "application set"... etc
freely without worrying about generating spurious
(and possibly slow) map updates in the cases where
the relevant app metadata was already set.

Signed-off-by: John Spray <john.spray@redhat.com>

diff --git a/src/mon/OSDMonitor.cc b/src/mon/OSDMonitor.cc
index fc22bae4fd765539792bea3c08f0fe6c3b73c8cc..7af03288d2a377d8a7ff5f95896902c113563954 100644 (file)
--- a/src/mon/OSDMonitor.cc
+++ b/src/mon/OSDMonitor.cc
@@ -5840,6 +5840,22 @@ bool OSDMonitor::preprocess_command(MonOpRequestRef op)
     rdata.append(ss.str());
     ss.str("");
     goto reply;
+  } else if (prefix == "osd pool application enable" ||
+             prefix == "osd pool application disable" ||
+             prefix == "osd pool application set" ||
+             prefix == "osd pool application rm") {
+    bool changed = false;
+    r = preprocess_command_pool_application(prefix, cmdmap, ss, &changed);
+    if (r != 0) {
+      // Error, reply.
+      goto reply;
+    } else if (changed) {
+      // Valid mutation, proceed to prepare phase
+      return false;
+    } else {
+      // Idempotent case, reply
+      goto reply;
+    }
   } else {
     // try prepare update
     return false;
@@ -7354,6 +7370,30 @@ int OSDMonitor::prepare_command_pool_set(const cmdmap_t& cmdmap,
 int OSDMonitor::prepare_command_pool_application(const string &prefix,
                                                  const cmdmap_t& cmdmap,
                                                  stringstream& ss)
+{
+  return _command_pool_application(prefix, cmdmap, ss, nullptr, true);
+}
+
+int OSDMonitor::preprocess_command_pool_application(const string &prefix,
+                                                    const cmdmap_t& cmdmap,
+                                                    stringstream& ss,
+                                                    bool *modified)
+{
+  return _command_pool_application(prefix, cmdmap, ss, modified, false);
+}
+
+
+/**
+ * Common logic for preprocess and prepare phases of pool application
+ * tag commands.  In preprocess mode we're only detecting invalid
+ * commands, and determining whether it was a modification or a no-op.
+ * In prepare mode we're actually updating the pending state.
+ */
+int OSDMonitor::_command_pool_application(const string &prefix,
+                                          const cmdmap_t& cmdmap,
+                                          stringstream& ss,
+                                          bool *modified,
+                                          bool preparing)
 {
   string pool_name;
   cmd_getval(cct, cmdmap, "pool", pool_name);
@@ -7364,8 +7404,10 @@ int OSDMonitor::prepare_command_pool_application(const string &prefix,
   }
 
   pg_pool_t p = *osdmap.get_pg_pool(pool);
-  if (pending_inc.new_pools.count(pool)) {
-    p = pending_inc.new_pools[pool];
+  if (preparing) {
+    if (pending_inc.new_pools.count(pool)) {
+      p = pending_inc.new_pools[pool];
+    }
   }
 
   string app;
@@ -7512,8 +7554,17 @@ int OSDMonitor::prepare_command_pool_application(const string &prefix,
     ceph_abort();
   }
 
-  p.last_change = pending_inc.epoch;
-  pending_inc.new_pools[pool] = p;
+  if (preparing) {
+    p.last_change = pending_inc.epoch;
+    pending_inc.new_pools[pool] = p;
+  }
+
+  // Because we fell through this far, we didn't hit no-op cases,
+  // so pool was definitely modified
+  if (modified != nullptr) {
+    *modified = true;
+  }
+
   return 0;
 }
 
@@ -12109,15 +12160,13 @@ bool OSDMonitor::prepare_command_impl(MonOpRequestRef op,
              prefix == "osd pool application set" ||
              prefix == "osd pool application rm") {
     err = prepare_command_pool_application(prefix, cmdmap, ss);
-    if (err == -EAGAIN)
+    if (err == -EAGAIN) {
       goto wait;
-    if (err < 0)
+    } else if (err < 0) {
       goto reply;
-
-    getline(ss, rs);
-    wait_for_finished_proposal(
-      op, new Monitor::C_Command(mon, op, 0, rs, get_last_committed() + 1));
-    return true;
+    } else {
+      goto update;
+    }
   } else if (prefix == "osd force-create-pg") {
     pg_t pgid;
     string pgidstr;

diff --git a/src/mon/OSDMonitor.h b/src/mon/OSDMonitor.h
index cb7ef1892ef1224e15a8bb3e5c93969704765434..03bfab807b159596e730afee12e06391c7975ecd 100644 (file)
--- a/src/mon/OSDMonitor.h
+++ b/src/mon/OSDMonitor.h
@@ -632,9 +632,19 @@ public:
 
   int prepare_command_pool_set(const cmdmap_t& cmdmap,
                                stringstream& ss);
+
   int prepare_command_pool_application(const string &prefix,
                                        const cmdmap_t& cmdmap,
                                        stringstream& ss);
+  int preprocess_command_pool_application(const string &prefix,
+                                          const cmdmap_t& cmdmap,
+                                          stringstream& ss,
+                                          bool *modified);
+  int _command_pool_application(const string &prefix,
+                                       const cmdmap_t& cmdmap,
+                                       stringstream& ss,
+                                       bool *modified,
+                                       bool preparing);
 
   bool handle_osd_timeouts(const utime_t &now,
                           std::map<int,utime_t> &last_osd_report);