mon/PGMonitor: avoid useless pg gets when pool is deleted

If the .0 pg no longer exists, we know the entire pool was
deleted, and can avoid querying every other pg.  (This is a good
thing because leveldb and rocksdb can be very slow to query
missing keys.)

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

diff --git a/src/mon/PGMonitor.cc b/src/mon/PGMonitor.cc
index 0640b1a6e8c37d02403a2314b4ee73f91b21e5a3..e250f59ee218f38843f5442a1203cc00e375b8a0 100644 (file)
--- a/src/mon/PGMonitor.cc
+++ b/src/mon/PGMonitor.cc
@@ -432,16 +432,22 @@ void PGMonitor::apply_pgmap_delta(bufferlist& bl)
   while (!p.end()) {
     pg_t pgid;
     ::decode(pgid, p);
-    bufferlist bl;
-    int r = mon->store->get(pgmap_pg_prefix, stringify(pgid), bl);
-    dout(20) << " refreshing pg " << pgid << " got " << r << " len "
-            << bl.length() << dendl;
 
-    if (pg_pool_sum_old.count(pgid.pool()) == 0)
-      pg_pool_sum_old[pgid.pool()] = pg_map.pg_pool_sum[pgid.pool()];
+    int r;
+    bufferlist pgbl;
+    if (deleted_pools.count(pgid.pool())) {
+      r = -ENOENT;
+    } else {
+      r = mon->store->get(pgmap_pg_prefix, stringify(pgid), pgbl);
+      dout(20) << " refreshing pg " << pgid << " got " << r << " len "
+              << pgbl.length() << dendl;
+
+      if (pg_pool_sum_old.count(pgid.pool()) == 0)
+       pg_pool_sum_old[pgid.pool()] = pg_map.pg_pool_sum[pgid.pool()];
+    }
 
     if (r >= 0) {
-      pg_map.update_pg(pgid, bl);
+      pg_map.update_pg(pgid, pgbl);
     } else {
       pg_map.remove_pg(pgid);
       if (pgid.ps() == 0)