From 244c17f7389fc4eb9e489e9b22ec4aac0ec1de09 Mon Sep 17 00:00:00 2001
From: Samuel Just <sjust@redhat.com>
Date: Fri, 11 Feb 2022 04:22:56 +0000
Subject: [PATCH] crimson/osd/osd: introduce start_pg_operation

We're going to unify responsibility for routing requests to requests
to start_pg_operation from the different osd operation types.  Later,
this will move into a new type responsible for dealing with the pg->core
mapping.

Signed-off-by: Samuel Just <sjust@redhat.com>
---
 src/crimson/osd/osd.cc          |  1 +
 src/crimson/osd/osd.h           | 61 +++++++++++++++++++++++++++++++++
 src/crimson/osd/osd_operation.h |  4 +++
 3 files changed, 66 insertions(+)

diff --git a/src/crimson/osd/osd.cc b/src/crimson/osd/osd.cc
index 2c88f5a5de0..17339eaddd8 100644
--- a/src/crimson/osd/osd.cc
+++ b/src/crimson/osd/osd.cc
@@ -52,6 +52,7 @@
 #include "crimson/osd/osd_operations/pg_advance_map.h"
 #include "crimson/osd/osd_operations/recovery_subrequest.h"
 #include "crimson/osd/osd_operations/replicated_request.h"
+#include "crimson/osd/osd_operation_external_tracking.h"
 
 namespace {
   seastar::logger& logger() {
diff --git a/src/crimson/osd/osd.h b/src/crimson/osd/osd.h
index ae0ac9bc0e5..a40670fe0f2 100644
--- a/src/crimson/osd/osd.h
+++ b/src/crimson/osd/osd.h
@@ -246,6 +246,67 @@ public:
   Ref<PG> get_pg(spg_t pgid);
   seastar::future<> send_beacon();
 
+  template <typename T, typename... Args>
+  auto start_pg_operation(Args&&... args) {
+    auto op = shard_services.registry.create_operation<T>(
+      std::forward<Args>(args)...);
+    auto &logger = crimson::get_logger(ceph_subsys_osd);
+    logger.debug("{}: starting {}", *op, __func__);
+    auto &opref = *op;
+
+    auto fut = opref.template enter_stage<>(
+      opref.get_connection_pipeline().await_active
+    ).then([this, &opref, &logger] {
+      logger.debug("{}: start_pg_operation in await_active stage", opref);
+      return state.when_active();
+    }).then([&logger, &opref] {
+      logger.debug("{}: start_pg_operation active, entering await_map", opref);
+      return opref.template enter_stage<>(
+	opref.get_connection_pipeline().await_map);
+    }).then([this, &logger, &opref] {
+      logger.debug("{}: start_pg_operation await_map stage", opref);
+      using OSDMapBlockingEvent =
+	OSD_OSDMapGate::OSDMapBlocker::BlockingEvent;
+      return opref.template with_blocking_event<OSDMapBlockingEvent>(
+	[this, &opref](auto &&trigger) {
+	  return osdmap_gate.wait_for_map(std::move(trigger),
+					  opref.get_epoch());
+	});
+    }).then([&logger, &opref](auto epoch) {
+      logger.debug("{}: got map {}, entering get_pg", opref, epoch);
+      return opref.template enter_stage<>(
+	opref.get_connection_pipeline().get_pg);
+    }).then([this, &logger, &opref] {
+      logger.debug("{}: in get_pg", opref);
+      if constexpr (T::can_create()) {
+	logger.debug("{}: can_create", opref);
+	return opref.template with_blocking_event<
+	  PGMap::PGCreationBlockingEvent
+	  >([this, &opref](auto &&trigger) {
+	    std::ignore = this; // avoid clang warning
+	    return get_or_create_pg(
+	      std::move(trigger),
+	      opref.get_pgid(), opref.get_epoch(),
+	      std::move(opref.get_create_info()));
+	  });
+      } else {
+	logger.debug("{}: !can_create", opref);
+	return opref.template with_blocking_event<
+	  PGMap::PGCreationBlockingEvent
+	  >([this, &opref](auto &&trigger) {
+	    std::ignore = this; // avoid clang warning
+	    return wait_for_pg(std::move(trigger), opref.get_pgid());
+	  });
+      }
+    }).then([this, &logger, &opref](Ref<PG> pgref) {
+      logger.debug("{}: have_pg", opref);
+      return opref.with_pg(shard_services, pgref);
+    }).then([op] { /* Retain refcount on op until completion */ });
+
+    return std::make_pair(std::move(op), std::move(fut));
+  }
+
+
 private:
   LogClient log_client;
   LogChannelRef clog;
diff --git a/src/crimson/osd/osd_operation.h b/src/crimson/osd/osd_operation.h
index bbc5600c59c..e768503c02b 100644
--- a/src/crimson/osd/osd_operation.h
+++ b/src/crimson/osd/osd_operation.h
@@ -155,6 +155,10 @@ protected:
 
   template <class OpT>
   friend class crimson::os::seastore::OperationProxyT;
+
+  // OSD::start_pg_operation needs access to enter_stage, we can make this
+  // more sophisticated later on
+  friend class OSD;
 };
 
 /**
-- 
2.39.5