From e2a299e803978550c607086f414dcc0e9a58e232 Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
Date: Thu, 4 Jan 2018 17:14:49 +0800
Subject: [PATCH] mds: add asok command that dumps cached snap infos

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
---
 src/mds/MDSDaemon.cc  |  6 ++++++
 src/mds/MDSRank.cc    | 17 +++++++++++++++++
 src/mds/SnapClient.cc | 39 +++++++++++++++++++++++++++++++++++++++
 src/mds/SnapClient.h  |  2 ++
 src/mds/SnapServer.cc |  4 +++-
 5 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/src/mds/MDSDaemon.cc b/src/mds/MDSDaemon.cc
index 4b3a6a2a34b3f..0717f455b237a 100644
--- a/src/mds/MDSDaemon.cc
+++ b/src/mds/MDSDaemon.cc
@@ -258,6 +258,11 @@ void MDSDaemon::set_up_admin_socket()
                                      asok_hook,
                                      "dump metadata loads");
   assert(r == 0);
+  r = admin_socket->register_command("dump snaps",
+                                     "dump snaps name=server,type=CephChoices,strings=--server,req=false",
+                                     asok_hook,
+                                     "dump snapshots");
+  assert(r == 0);
   r = admin_socket->register_command("session evict",
 				     "session evict name=client_id,type=CephString",
 				     asok_hook,
@@ -333,6 +338,7 @@ void MDSDaemon::clean_up_admin_socket()
   admin_socket->unregister_command("cache status");
   admin_socket->unregister_command("dump tree");
   admin_socket->unregister_command("dump loads");
+  admin_socket->unregister_command("dump snaps");
   admin_socket->unregister_command("session evict");
   admin_socket->unregister_command("osdmap barrier");
   admin_socket->unregister_command("session ls");
diff --git a/src/mds/MDSRank.cc b/src/mds/MDSRank.cc
index 2337c4e07e094..e32db61df1204 100644
--- a/src/mds/MDSRank.cc
+++ b/src/mds/MDSRank.cc
@@ -2020,6 +2020,23 @@ bool MDSRankDispatcher::handle_asok_command(
       ss << "Failed to dump loads: " << cpp_strerror(r);
       f->reset();
     }
+  } else if (command == "dump snaps") {
+    Mutex::Locker l(mds_lock);
+    string server;
+    cmd_getval(g_ceph_context, cmdmap, "server", server);
+    if (server == "--server") {
+      if (mdsmap->get_tableserver() == whoami) {
+	snapserver->dump(f);
+      } else {
+	ss << "Not snapserver";
+      }
+    } else {
+      int r = snapclient->dump_cache(f);
+      if (r != 0) {
+	ss << "Failed to dump snapclient: " << cpp_strerror(r);
+	f->reset();
+      }
+    }
   } else if (command == "force_readonly") {
     Mutex::Locker l(mds_lock);
     mdcache->force_readonly();
diff --git a/src/mds/SnapClient.cc b/src/mds/SnapClient.cc
index 103fd2c50b198..df667df3b807a 100644
--- a/src/mds/SnapClient.cc
+++ b/src/mds/SnapClient.cc
@@ -274,3 +274,42 @@ void SnapClient::get_snap_infos(map<snapid_t, const SnapInfo*>& infomap,
 
   infomap.insert(result.begin(), result.end());
 }
+
+int SnapClient::dump_cache(Formatter *f) const
+{
+  if (!is_synced()) {
+    dout(5) << "dump_cache: not synced" << dendl;
+    return -EINVAL;
+  }
+
+  map<snapid_t, const SnapInfo*> snaps;
+  for (auto& p : cached_snaps)
+    snaps[p.first] = &p.second;
+
+  for (auto tid : committing_tids) {
+    auto q = cached_pending_update.find(tid);
+    if (q != cached_pending_update.end())
+      snaps[q->second.snapid] = &q->second;
+
+    auto r = cached_pending_destroy.find(tid);
+    if (r != cached_pending_destroy.end())
+      snaps.erase(r->second.first);
+  }
+
+  f->open_object_section("snapclient");
+
+  f->dump_int("last_created", get_last_created());
+  f->dump_int("last_destroyed", get_last_destroyed());
+
+  f->open_array_section("snaps");
+  for (auto p : snaps) {
+    f->open_object_section("snap");
+    p.second->dump(f);
+    f->close_section();
+  }
+  f->close_section();
+
+  f->close_section();
+
+  return 0;
+}
diff --git a/src/mds/SnapClient.h b/src/mds/SnapClient.h
index cc98587788209..8c30b2cc338ec 100644
--- a/src/mds/SnapClient.h
+++ b/src/mds/SnapClient.h
@@ -107,6 +107,8 @@ public:
   set<snapid_t> filter(const set<snapid_t>& snaps) const;
   const SnapInfo* get_snap_info(snapid_t snapid) const;
   void get_snap_infos(map<snapid_t, const SnapInfo*>& infomap, const set<snapid_t>& snaps) const;
+
+  int dump_cache(Formatter *f) const;
 };
 
 #endif
diff --git a/src/mds/SnapServer.cc b/src/mds/SnapServer.cc
index e6eed75307a0f..4bdbfd8e8fb75 100644
--- a/src/mds/SnapServer.cc
+++ b/src/mds/SnapServer.cc
@@ -366,7 +366,9 @@ void SnapServer::dump(Formatter *f) const
 {
   f->open_object_section("snapserver");
 
-  f->dump_int("last_snap", last_snap.val);
+  f->dump_int("last_snap", last_snap);
+  f->dump_int("last_created", last_created);
+  f->dump_int("last_destroyed", last_destroyed);
 
   f->open_array_section("pending_noop");
   for(set<version_t>::const_iterator i = pending_noop.begin(); i != pending_noop.end(); ++i) {
-- 
2.39.5