From: Samuel Just <sjust@redhat.com>
Date: Tue, 13 Oct 2015 01:09:58 +0000 (-0700)
Subject: ReplicatedPG::_rollback_to: handle block on full correctly
X-Git-Tag: v9.2.0~16^2~1
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=da4803ecd2598198847b5dfa86f654d75eea0844;p=ceph.git

ReplicatedPG::_rollback_to: handle block on full correctly

If we fail to promote the clone due to a full cache tier, we need
to block writes on the head just as if we were waiting on the
promote.  Generally therefore, we block writes on head if we block
an op on a full cache tier.  Add a new blocked set to support this.

Fixes: 13434
Signed-off-by: Samuel Just <sjust@redhat.com>
---

diff --git a/src/osd/PG.h b/src/osd/PG.h
index 4f8ef48e21db..3860ad885423 100644
--- a/src/osd/PG.h
+++ b/src/osd/PG.h
@@ -764,6 +764,9 @@ protected:
 			     waiting_for_degraded_object,
 			     waiting_for_blocked_object;
 
+  set<
+    hobject_t,
+    hobject_t::BitwiseComparator> objects_blocked_on_cache_full;
   map<
     hobject_t,
     snapid_t,
diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index 0554d549e616..6a0e633a8413 100644
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -453,6 +453,16 @@ void ReplicatedPG::wait_for_degraded_object(const hobject_t& soid, OpRequestRef
   op->mark_delayed("waiting for degraded object");
 }
 
+void ReplicatedPG::block_write_on_full_cache(
+  const hobject_t& _oid, OpRequestRef op)
+{
+  const hobject_t oid = _oid.get_head();
+  dout(20) << __func__ << ": blocking object " << oid
+	   << " on full cache" << dendl;
+  objects_blocked_on_cache_full.insert(oid);
+  waiting_for_cache_not_full.push_back(op);
+}
+
 void ReplicatedPG::block_write_on_snap_rollback(
   const hobject_t& oid, ObjectContextRef obc, OpRequestRef op)
 {
@@ -1568,6 +1578,10 @@ void ReplicatedPG::do_op(OpRequestRef& op)
       op);
     return;
   }
+  if (write_ordered && objects_blocked_on_cache_full.count(head)) {
+    block_write_on_full_cache(head, op);
+    return;
+  }
 
   // missing snapdir?
   hobject_t snapdir = head.get_snapdir();
@@ -5745,16 +5759,33 @@ int ReplicatedPG::_rollback_to(OpContext *ctx, ceph_osd_op& op)
     block_write_on_degraded_snap(missing_oid, ctx->op);
     return ret;
   }
-  if (maybe_handle_cache(ctx->op, true, rollback_to, ret, missing_oid, true)) {
-    // promoting the rollback src, presumably
-    if (!rollback_to) {
-      // the obc must be cached now for the promotion to be happening
-      rollback_to = get_object_context(missing_oid, false);
-      assert(rollback_to);
+  {
+    ObjectContextRef promote_obc;
+    switch (
+      maybe_handle_cache_detail(
+	ctx->op,
+	true,
+	rollback_to,
+	ret,
+	missing_oid,
+	true,
+	false,
+	&promote_obc)) {
+    case cache_result_t::NOOP:
+      break;
+    case cache_result_t::BLOCKED_PROMOTE:
+      assert(promote_obc);
+      block_write_on_snap_rollback(soid, promote_obc, ctx->op);
+      return -EAGAIN;
+    case cache_result_t::BLOCKED_FULL:
+      block_write_on_full_cache(soid, ctx->op);
+      return -EAGAIN;
+    default:
+      assert(0 == "must promote was set, other values are not valid");
+      return -EAGAIN;
     }
-    block_write_on_snap_rollback(soid, rollback_to, ctx->op);
-    return -EAGAIN;
   }
+
   if (ret == -ENOENT || (rollback_to && rollback_to->obs.oi.is_whiteout())) {
     // there's no snapshot here, or there's no object.
     // if there's no snapshot, we delete the object; otherwise, do nothing.
@@ -9530,6 +9561,7 @@ void ReplicatedPG::on_change(ObjectStore::Transaction *t)
     waiting_for_cache_not_full.clear();
     waiting_for_all_missing.clear();
   }
+  objects_blocked_on_cache_full.clear();
 
 
   for (list<pair<OpRequestRef, OpContext*> >::iterator i =
@@ -9585,6 +9617,7 @@ void ReplicatedPG::on_pool_change()
     dout(10) << __func__ << " requeuing full waiters (not in writeback) "
 	     << dendl;
     requeue_ops(waiting_for_cache_not_full);
+    objects_blocked_on_cache_full.clear();
   }
   hit_set_setup();
   agent_setup();
@@ -11820,6 +11853,7 @@ bool ReplicatedPG::agent_choose_mode(bool restart, OpRequestRef op)
 	requeue_op(op);
       requeue_ops(waiting_for_active);
       requeue_ops(waiting_for_cache_not_full);
+      objects_blocked_on_cache_full.clear();
       requeued = true;
     }
     if (evict_mode == TierAgentState::EVICT_MODE_SOME) {
diff --git a/src/osd/ReplicatedPG.h b/src/osd/ReplicatedPG.h
index 1fcb9ba2fe90..e339e6a8d968 100644
--- a/src/osd/ReplicatedPG.h
+++ b/src/osd/ReplicatedPG.h
@@ -1582,6 +1582,8 @@ public:
   bool is_degraded_or_backfilling_object(const hobject_t& oid);
   void wait_for_degraded_object(const hobject_t& oid, OpRequestRef op);
 
+  void block_write_on_full_cache(
+    const hobject_t& oid, OpRequestRef op);
   void block_write_on_snap_rollback(
     const hobject_t& oid, ObjectContextRef obc, OpRequestRef op);
   void block_write_on_degraded_snap(const hobject_t& oid, OpRequestRef op);