From e307b9aefb4b0d8735db00b361e12f2d0eda95a2 Mon Sep 17 00:00:00 2001
From: Kefu Chai <kchai@redhat.com>
Date: Tue, 25 Aug 2020 17:30:00 +0800
Subject: [PATCH] crimson/osd: drop misdirected ops

see also `PrimaryLogPG::do_op()`, we should ignore the ops hitting us if
we are not supposed to serve them. this happens when the client is using
a stale osdmap.

Fixes: https://tracker.ceph.com/issues/47031
Signed-off-by: Kefu Chai <kchai@redhat.com>
---
 .../osd/osd_operations/client_request.cc      | 31 ++++++++++++++++++-
 .../osd/osd_operations/client_request.h       |  3 ++
 src/crimson/osd/pg.h                          |  3 ++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/crimson/osd/osd_operations/client_request.cc b/src/crimson/osd/osd_operations/client_request.cc
index 339d4c0935f78..c14a83a1c4737 100644
--- a/src/crimson/osd/osd_operations/client_request.cc
+++ b/src/crimson/osd/osd_operations/client_request.cc
@@ -137,8 +137,12 @@ seastar::future<> ClientRequest::process_op(
     return seastar::now();
   }).then([this, &pg] {
     return with_blocking_future(handle.enter(pp(pg).get_obc));
-  }).then([this, &pg]() {
+  }).then([this, &pg]() -> PG::load_obc_ertr::future<> {
     op_info.set_from_op(&*m, *pg.get_osdmap());
+    if (is_misdirected(pg)) {
+      logger().trace("process_op: dropping misdirected op");
+      return seastar::now();
+    }
     return pg.with_locked_obc(
       m,
       op_info,
@@ -159,4 +163,29 @@ seastar::future<> ClientRequest::process_op(
   }));
 }
 
+bool ClientRequest::is_misdirected(const PG& pg) const
+{
+  // primary can handle both normal ops and balanced reads
+  if (pg.is_primary()) {
+    return false;
+  }
+  // otherwise take a closer look
+  if (const int flags = m->get_flags();
+      flags & CEPH_OSD_FLAG_BALANCE_READS ||
+      flags & CEPH_OSD_FLAG_LOCALIZE_READS) {
+    if (!op_info.may_read()) {
+      // no read found, so it can't be balanced read
+      return true;
+    }
+    if (op_info.may_write() || op_info.may_cache()) {
+      // write op, but i am not primary
+      return true;
+    }
+    // balanced reads; any replica will do
+    return pg.is_nonprimary();
+  }
+  // neither balanced nor localize reads
+  return true;
+}
+
 }
diff --git a/src/crimson/osd/osd_operations/client_request.h b/src/crimson/osd/osd_operations/client_request.h
index d2fdbe926dfe2..ea3124a93e532 100644
--- a/src/crimson/osd/osd_operations/client_request.h
+++ b/src/crimson/osd/osd_operations/client_request.h
@@ -68,6 +68,9 @@ private:
 
   ConnectionPipeline &cp();
   PGPipeline &pp(PG &pg);
+
+private:
+  bool is_misdirected(const PG& pg) const;
 };
 
 }
diff --git a/src/crimson/osd/pg.h b/src/crimson/osd/pg.h
index 421ff418e4ef2..9335ca35fcca6 100644
--- a/src/crimson/osd/pg.h
+++ b/src/crimson/osd/pg.h
@@ -427,6 +427,9 @@ public:
   bool is_primary() const final {
     return peering_state.is_primary();
   }
+  bool is_nonprimary() const {
+    return peering_state.is_nonprimary();
+  }
   bool is_peered() const final {
     return peering_state.is_peered();
   }
-- 
2.39.5