osd/ReplicatedPG: respect RWORDERED rados flag

If this flag is set, we need to order reads as writes.  In particular, this
means that reads will wait for degraded object recovery even if there is a
local copy.  And subsequently will be ordered after a preceding write that
is waiting for the same thing.

Signed-off-by: Sage Weil <sage@inktank.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index a48372fe561..147b460c3e9 100644
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -660,13 +660,21 @@ void ReplicatedPG::do_op(OpRequestRef op)
     return do_pg_op(op);
   }
 
-  dout(10) << "do_op " << *m << (op->may_write() ? " may_write" : "") << dendl;
+  // order this op as a write?
+  bool write_ordered = op->may_write() || (m->get_flags() & CEPH_OSD_FLAG_RWORDERED);
+
+  dout(10) << "do_op " << *m
+	   << (op->may_write() ? " may_write" : "")
+	   << (op->may_read() ? " may_read" : "")
+	   << " -> " << (write_ordered ? "write-ordered" : "read-ordered")
+	   << dendl;
 
   hobject_t head(m->get_oid(), m->get_object_locator().key,
 		 CEPH_NOSNAP, m->get_pg().ps(),
 		 info.pgid.pool(), m->get_object_locator().nspace);
 
-  if (op->may_write() && scrubber.write_blocked_by_scrub(head)) {
+
+  if (write_ordered && scrubber.write_blocked_by_scrub(head)) {
     dout(20) << __func__ << ": waiting for scrub" << dendl;
     waiting_for_active.push_back(op);
     op->mark_delayed("waiting for scrub");
@@ -680,7 +688,7 @@ void ReplicatedPG::do_op(OpRequestRef op)
   }
 
   // degraded object?
-  if (op->may_write() && is_degraded_object(head)) {
+  if (write_ordered && is_degraded_object(head)) {
     wait_for_degraded_object(head, op);
     return;
   }
@@ -700,7 +708,7 @@ void ReplicatedPG::do_op(OpRequestRef op)
   }
 
   // degraded object?
-  if (op->may_write() && is_degraded_object(snapdir)) {
+  if (write_ordered && is_degraded_object(snapdir)) {
     wait_for_degraded_object(snapdir, op);
     return;
   }