osd: sync old purged_snaps on startup after upgrade or osd creation

This path only triggers after an upgrade or osd creation, when
purged_snaps_last < current_epoch.  When that happens, we slurp down the
old purged snaps so that we have a full history recorded locally.

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

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index e316c1fc2f46b8b4e37f2dc77bf433f917cf75fb..ce7b39768bfd35fb6322f1161bd7f105ef3a586e 100644 (file)
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -124,6 +124,9 @@
 #include "messages/MOSDPGPushReply.h"
 #include "messages/MOSDPGPull.h"
 
+#include "messages/MMonGetPurgedSnaps.h"
+#include "messages/MMonGetPurgedSnapsReply.h"
+
 #include "common/perf_counters.h"
 #include "common/Timer.h"
 #include "common/LogClient.h"
@@ -5420,6 +5423,8 @@ void OSD::_preboot(epoch_t oldest, epoch_t newest)
     heartbeat();
   }
 
+  const auto& monmap = monc->monmap;
+
   // if our map within recent history, try to add ourselves to the osdmap.
   if (osdmap->get_epoch() == 0) {
     derr << "waiting for initial osdmap" << dendl;
@@ -5441,6 +5446,11 @@ void OSD::_preboot(epoch_t oldest, epoch_t newest)
   } else if (service.need_fullness_update()) {
     derr << "osdmap fullness state needs update" << dendl;
     send_full_update();
+  } else if (monmap.min_mon_release >= ceph_release_t::octopus &&
+            superblock.purged_snaps_last < superblock.current_epoch) {
+    dout(10) << __func__ << " purged_snaps_last " << superblock.purged_snaps_last
+            << " < newest_map " << superblock.current_epoch << dendl;
+    _get_purged_snaps();
   } else if (osdmap->get_epoch() >= oldest - 1 &&
             osdmap->get_epoch() + cct->_conf->osd_map_message_max > newest) {
 
@@ -5474,6 +5484,45 @@ void OSD::_preboot(epoch_t oldest, epoch_t newest)
     osdmap_subscribe(oldest - 1, true);
 }
 
+void OSD::_get_purged_snaps()
+{
+  // NOTE: this is a naive, stateless implementaiton.  it may send multiple
+  // overlapping requests to the mon, which will be somewhat inefficient, but
+  // it should be reliable.
+  dout(10) << __func__ << " purged_snaps_last " << superblock.purged_snaps_last
+          << ", newest_map " << superblock.current_epoch << dendl;
+  MMonGetPurgedSnaps *m = new MMonGetPurgedSnaps(
+    superblock.purged_snaps_last + 1,
+    superblock.current_epoch + 1);
+  monc->send_mon_message(m);
+}
+
+void OSD::handle_get_purged_snaps_reply(MMonGetPurgedSnapsReply *m)
+{
+  dout(10) << __func__ << " " << *m << dendl;
+  ObjectStore::Transaction t;
+  if (!is_preboot() ||
+      m->last < superblock.purged_snaps_last) {
+    goto out;
+  }
+  SnapMapper::record_purged_snaps(cct, store, service.meta_ch,
+                                 make_snapmapper_oid(), &t,
+                                 m->purged_snaps);
+  superblock.purged_snaps_last = m->last;
+  write_superblock(t);
+  store->queue_transaction(
+    service.meta_ch,
+    std::move(t));
+  service.publish_superblock(superblock);
+  if (m->last < superblock.current_epoch) {
+    _get_purged_snaps();
+  } else {
+    start_boot();
+  }
+out:
+  m->put();
+}
+
 void OSD::send_full_update()
 {
   if (!service.need_fullness_update())
@@ -6894,6 +6943,9 @@ void OSD::_dispatch(Message *m)
   case CEPH_MSG_OSD_MAP:
     handle_osd_map(static_cast<MOSDMap*>(m));
     break;
+  case MSG_MON_GET_PURGED_SNAPS_REPLY:
+    handle_get_purged_snaps_reply(static_cast<MMonGetPurgedSnapsReply*>(m));
+    break;
 
     // osd
   case MSG_OSD_SCRUB:

diff --git a/src/osd/OSD.h b/src/osd/OSD.h
index 3045abea831fbd95e49873e5ecd5e01813f7895c..fdf5633ddbc831c7ba27756c3c249cc512c42623 100644 (file)
--- a/src/osd/OSD.h
+++ b/src/osd/OSD.h
@@ -101,6 +101,7 @@ class MOSDPGNotify;
 class MOSDPGInfo;
 class MOSDPGRemove;
 class MOSDForceRecovery;
+class MMonGetPurgedSnapsReply;
 
 class OSD;
 
@@ -1815,6 +1816,8 @@ protected:
   void _preboot(epoch_t oldest, epoch_t newest);
   void _send_boot();
   void _collect_metadata(map<string,string> *pmeta);
+  void _get_purged_snaps();
+  void handle_get_purged_snaps_reply(MMonGetPurgedSnapsReply *r);
 
   void start_waiting_for_healthy();
   bool _is_healthy();