From: Xuehan Xu <xxhdx1985126@163.com>
Date: Thu, 12 Mar 2020 05:53:39 +0000 (+0800)
Subject: crimson: make sure pg meta is valid when loading pg
X-Git-Tag: v16.1.0~2758^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=adbdd753f1d16942b279e5ae0cea01c2efd633f6;p=ceph.git

crimson: make sure pg meta is valid when loading pg

currently, PGMeta instances are all local variables in method,
which would lead to daggling reference/pointer problems when using
seastar::futures.

Signed-off-by: Xuehan Xu <xxhdx1985126@163.com>
---

diff --git a/src/crimson/osd/osd.cc b/src/crimson/osd/osd.cc
index 01f938535774..8e6ae3ea8fbf 100644
--- a/src/crimson/osd/osd.cc
+++ b/src/crimson/osd/osd.cc
@@ -549,13 +549,15 @@ seastar::future<Ref<PG>> OSD::make_pg(cached_map_t create_map,
 
 seastar::future<Ref<PG>> OSD::load_pg(spg_t pgid)
 {
-  return PGMeta{store.get(), pgid}.get_epoch().then([this](epoch_t e) {
+  return seastar::do_with(PGMeta(store.get(), pgid), [this, pgid] (auto& pg_meta) {
+    return pg_meta.get_epoch();
+  }).then([this](epoch_t e) {
     return get_map(e);
   }).then([pgid, this] (auto&& create_map) {
     return make_pg(std::move(create_map), pgid, false);
-  }).then([this, pgid](Ref<PG> pg) {
+  }).then([this](Ref<PG> pg) {
     return pg->read_state(store.get()).then([pg] {
-      return seastar::make_ready_future<Ref<PG>>(std::move(pg));
+	return seastar::make_ready_future<Ref<PG>>(std::move(pg));
     });
   }).handle_exception([pgid](auto ep) {
     logger().info("pg {} saw exception on load {}", pgid, ep);
diff --git a/src/crimson/osd/pg.cc b/src/crimson/osd/pg.cc
index fcef9c45aa19..62d5adfd0ff1 100644
--- a/src/crimson/osd/pg.cc
+++ b/src/crimson/osd/pg.cc
@@ -364,8 +364,9 @@ void PG::init(
 
 seastar::future<> PG::read_state(crimson::os::FuturizedStore* store)
 {
-  return PGMeta{store, pgid}.load(
-  ).then([this, store](pg_info_t pg_info, PastIntervals past_intervals) {
+  return seastar::do_with(PGMeta(store, pgid), [this, store] (auto& pg_meta) {
+    return pg_meta.load();
+  }).then([this, store](pg_info_t pg_info, PastIntervals past_intervals) {
     return peering_state.init_from_disk_state(
 	std::move(pg_info),
 	std::move(past_intervals),