From: Zengran Zhang <zhangzengran@sangfor.com.cn>
Date: Fri, 7 Dec 2018 08:37:32 +0000 (+0800)
Subject: objecter: avoid race when reset down osd's session
X-Git-Tag: v14.1.0~537^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=a67141528cd3560e7df28c82d2cf0fae8dac388e;p=ceph.git

objecter: avoid race when reset down osd's session

consider the sequence step of follow:
thread A: objecter handle new osdmap which says osd.X down
thread B: objecter reset session of osd.X,then reopen session
thread A: close seesion of osd.X because he is down

in such circumstance, we will hit failure on assert(is_up(osd))
the backtrace is:
1. ceph::__ceph_assert_fail(char const*, char const*, int, char const*) ()
2. OSDMap::get_inst(int) const [clone .part.224] ()
3. Objecter::_reopen_session(Objecter::OSDSession*) ()
4. Objecter::ms_handle_reset(Connection*) ()

Fixes: https://tracker.ceph.com/issues/24601

Signed-off-by: Zengran Zhang <zhangzengran@sangfor.com.cn>
---

diff --git a/src/osdc/Objecter.cc b/src/osdc/Objecter.cc
index 9f5610770cf7..fb0eea8759e2 100644
--- a/src/osdc/Objecter.cc
+++ b/src/osdc/Objecter.cc
@@ -4384,7 +4384,10 @@ bool Objecter::ms_handle_reset(Connection *con)
     if (session) {
       ldout(cct, 1) << "ms_handle_reset " << con << " session " << session
 		    << " osd." << session->osd << dendl;
-      if (!initialized) {
+      // the session maybe had been closed if new osdmap just handled
+      // says the osd down
+      if (!(initialized && osdmap->is_up(session->osd))) {
+	ldout(cct, 1) << "ms_handle_reset aborted,initialized=" << initialized << dendl;
 	wl.unlock();
 	return false;
       }