From: Matan Breizman <mbreizma@redhat.com>
Date: Wed, 7 Jun 2023 12:35:59 +0000 (+0000)
Subject: crimson/osd/osd: serialize MOSDMap message handling
X-Git-Tag: v19.0.0~986^2~8
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=63fa59cbd285da369755412d93022393aad5aa36;p=ceph-ci.git

crimson/osd/osd: serialize MOSDMap message handling

See included comment for rationale.

Fixes: https://tracker.ceph.com/issues/59165
Signed-off-by: Matan Breizman <mbreizma@redhat.com>
---

diff --git a/src/crimson/osd/osd.cc b/src/crimson/osd/osd.cc
index 735b6d777ca..2ec8fc48f6f 100644
--- a/src/crimson/osd/osd.cc
+++ b/src/crimson/osd/osd.cc
@@ -855,6 +855,25 @@ bool OSD::require_mon_peer(crimson::net::Connection *conn, Ref<Message> m)
 
 seastar::future<> OSD::handle_osd_map(crimson::net::ConnectionRef conn,
                                       Ref<MOSDMap> m)
+{
+  /* Ensure that only one MOSDMap is processed at a time.  Allowing concurrent
+  * processing may eventually be worthwhile, but such an implementation would
+  * need to ensure (among other things)
+  * 1. any particular map is only processed once
+  * 2. PGAdvanceMap operations are processed in order for each PG
+  * As map handling is not presently a bottleneck, we stick to this
+  * simpler invariant for now.
+  * See https://tracker.ceph.com/issues/59165
+  */
+  return handle_osd_map_lock.lock().then([=, this] {
+    return _handle_osd_map(conn, m);
+  }).finally([=, this] {
+    return handle_osd_map_lock.unlock();
+  });
+}
+
+seastar::future<> OSD::_handle_osd_map(crimson::net::ConnectionRef conn,
+                                      Ref<MOSDMap> m)
 {
   logger().info("handle_osd_map {}", *m);
   if (m->fsid != superblock.cluster_fsid) {
diff --git a/src/crimson/osd/osd.h b/src/crimson/osd/osd.h
index b3933e80c26..1069a4b2f2d 100644
--- a/src/crimson/osd/osd.h
+++ b/src/crimson/osd/osd.h
@@ -90,6 +90,8 @@ class OSD final : public crimson::net::Dispatcher,
 
   ceph::mono_time startup_time;
 
+  seastar::shared_mutex handle_osd_map_lock;
+
   OSDSuperblock superblock;
 
   // Dispatcher methods
@@ -168,6 +170,8 @@ private:
 
   seastar::future<> handle_osd_map(crimson::net::ConnectionRef conn,
                                    Ref<MOSDMap> m);
+  seastar::future<> _handle_osd_map(crimson::net::ConnectionRef conn,
+                                    Ref<MOSDMap> m);
   seastar::future<> handle_pg_create(crimson::net::ConnectionRef conn,
 				     Ref<MOSDPGCreate2> m);
   seastar::future<> handle_osd_op(crimson::net::ConnectionRef conn,