From: Neha Ojha <nojha@redhat.com>
Date: Mon, 25 Mar 2019 21:48:04 +0000 (-0700)
Subject: osd/PGLog: preserve original_crt in merge_log()
X-Git-Tag: v15.0.0~61^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F27200%2Fhead;p=ceph.git

osd/PGLog: preserve original_crt in merge_log()

Fixes: https://tracker.ceph.com/issues/21174
Signed-off-by: Neha Ojha <nojha@redhat.com>
---

diff --git a/src/osd/PGLog.cc b/src/osd/PGLog.cc
index 295019dc556..bd9cbc1b71b 100644
--- a/src/osd/PGLog.cc
+++ b/src/osd/PGLog.cc
@@ -444,6 +444,11 @@ void PGLog::merge_log(pg_info_t &oinfo, pg_log_t &olog, pg_shard_t fromosd,
 	     << lower_bound << dendl;
     mark_dirty_from(lower_bound);
 
+    // We need to preserve the original crt before it gets updated in rewind_from_head().
+    // Later, in merge_object_divergent_entries(), we use it to check whether we can rollback
+    // a divergent entry or not.
+    eversion_t original_crt = log.get_can_rollback_to();
+    dout(20) << __func__ << " original_crt = " << original_crt << dendl;
     auto divergent = log.rewind_from_head(lower_bound);
     // move aside divergent items
     for (auto &&oe: divergent) {
@@ -468,7 +473,7 @@ void PGLog::merge_log(pg_info_t &oinfo, pg_log_t &olog, pg_shard_t fromosd,
       divergent,
       info,
       log.get_can_rollback_to(),
-      log.get_can_rollback_to(),
+      original_crt,
       missing,
       rollbacker,
       this);
diff --git a/src/osd/PGLog.h b/src/osd/PGLog.h
index 862ca5f4139..6b492785e9e 100644
--- a/src/osd/PGLog.h
+++ b/src/osd/PGLog.h
@@ -1031,6 +1031,9 @@ protected:
     ldpp_dout(dpp, 10) << __func__ << ": hoid " << hoid
                        << " olog_can_rollback_to: "
                        << olog_can_rollback_to << dendl;
+    ldpp_dout(dpp, 10) << __func__ << ": hoid " << hoid
+                       << " original_crt: "
+                       << original_can_rollback_to << dendl;
     /// Distinguish between 4) and 5)
     for (list<pg_log_entry_t>::const_reverse_iterator i = entries.rbegin();
 	 i != entries.rend();