From 24dd3ee903e521b65657c4c2d421bc59e19bc51e Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Tue, 9 Jun 2009 10:36:03 -0700
Subject: [PATCH] osd: repair out of order logs in read_log

Works around bug fixed in f1ff93.
---
 src/osd/PG.cc | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/src/osd/PG.cc b/src/osd/PG.cc
index 6178dac76b03b..1ca3a4f42d589 100644
--- a/src/osd/PG.cc
+++ b/src/osd/PG.cc
@@ -1800,12 +1800,24 @@ void PG::read_log(ObjectStore *store)
     PG::Log::Entry e;
     bufferlist::iterator p = bl.begin();
     assert(log.log.empty());
+    eversion_t last;
+    bool reorder = false;
     while (!p.end()) {
       loff_t opos = ondisklog.bottom + p.get_off();
       ::decode(e, p);
       loff_t pos = ondisklog.bottom + p.get_off();
       dout(10) << "read_log " << pos << " " << e << dendl;
 
+      // [repair] in order?
+      if (e.version < last) {
+	dout(0) << "read_log " << pos << " out of order entry " << e << " follows " << last << dendl;
+  	stringstream ss;
+	ss << info.pgid << " log has out of order entry " << e << " following " << last;
+	osd->get_logclient()->log(LOG_ERROR, ss);
+	reorder = true;
+      }
+      last = e.version;
+
       if (e.version > log.bottom || log.backlog) { // ignore items below log.bottom
         if (opos % 4096 < pos % 4096)
 	  ondisklog.block_map[opos] = e.version;
@@ -1813,8 +1825,30 @@ void PG::read_log(ObjectStore *store)
       } else {
 	dout(10) << "read_log  ignoring entry at " << pos << dendl;
       }
+
+      // [repair] at end of log?
+      if (!p.end() && e.version == info.last_update) {
+	stringstream ss;
+	ss << info.pgid << " log has extra data at " << pos << "~" << (ondisklog.top-pos)
+	   << " after " << info.last_update;
+	osd->get_logclient()->log(LOG_ERROR, ss);
+	dout(0) << "read_log " << pos << " *** extra gunk at end of log, adjusting ondisklog.top" << dendl;
+	ondisklog.top = opos;
+	break;
+      }
+    }
+  
+    if (reorder) {
+      dout(0) << "read_log reordering log" << dendl;
+      map<eversion_t, Log::Entry> m;
+      for (list<Log::Entry>::iterator p = log.log.begin(); p != log.log.end(); p++)
+	m[p->version] = *p;
+      log.log.clear();
+      for (map<eversion_t, Log::Entry>::iterator p = m.begin(); p != m.end(); p++)
+	log.log.push_back(p->second);
     }
   }
+
   log.top = info.last_update;
   log.index();
 
-- 
2.39.5