From: Sage Weil <sage@redhat.com>
Date: Tue, 31 Jul 2018 21:54:26 +0000 (-0500)
Subject: osd: no osd_lock for finish_splits
X-Git-Tag: v14.0.1~371^2~11
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=45a556ad7dbf3fb8963b734de931cdb60ce09d0a;p=ceph-ci.git

osd: no osd_lock for finish_splits

This used to protect the pg registration probably?  There is no need for
it now.

More importantly, having it here can cause a deadlock when we are holding
osd_lock and blocking on wait_min_pg_epoch(), because a PG may need to
finish splitting to advance and then merge with a peer.  (The wait won't
block on *this* PG since it isn't registered in the shard yet, but it
will block on the merge peer.)

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

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 073c90c66e0..022e2c46d5b 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -8035,7 +8035,6 @@ struct C_FinishSplits : public Context {
 void OSD::_finish_splits(set<PGRef>& pgs)
 {
   dout(10) << __func__ << " " << pgs << dendl;
-  Mutex::Locker l(osd_lock);
   if (is_stopping())
     return;
   PG::RecoveryCtx rctx = create_context();