Followup to 1.4.2 write stall fix - sadly, the previous version was not working correctly :)

src/blockstore_impl.cpp

@@ -195,6 +195,10 @@ void blockstore_impl_t::loop()
                     // ring is full, stop submission
                     break;
                 }
+                else if (PRIV(op)->wait_for == WAIT_JOURNAL)
+                {
+                    PRIV(op)->wait_detail2 = (unstable_writes.size()+unstable_unsynced);
+                }
             }
         }
         if (op_idx != new_idx)
@@ -273,7 +277,8 @@ void blockstore_impl_t::check_wait(blockstore_op_t *op)
     }
     else if (PRIV(op)->wait_for == WAIT_JOURNAL)
     {
-        if (journal.used_start == PRIV(op)->wait_detail && !unstable_count_changed)
+        if (journal.used_start == PRIV(op)->wait_detail &&
+            (unstable_writes.size()+unstable_unsynced) == PRIV(op)->wait_detail2)
         {
             // do not submit
 #ifdef BLOCKSTORE_DEBUG
@@ -281,7 +286,6 @@ void blockstore_impl_t::check_wait(blockstore_op_t *op)
 #endif
             return;
         }
-        unstable_count_changed = false;
         flusher->release_trim();
         PRIV(op)->wait_for = 0;
     }
@@ -353,7 +357,6 @@ void blockstore_impl_t::enqueue_op(blockstore_op_t *op)
                     };
                 }
                 unstable_writes.clear();
-                unstable_count_changed = true;
                 op->callback = [old_callback](blockstore_op_t *op)
                 {
                     obj_ver_id *vers = (obj_ver_id*)op->buf;

src/blockstore_impl.h

@@ -202,7 +202,7 @@ struct blockstore_op_private_t
 {
     // Wait status
     int wait_for;
-    uint64_t wait_detail;
+    uint64_t wait_detail, wait_detail2;
     int pending_ops;
     int op_state;
 
@@ -276,7 +276,6 @@ class blockstore_impl_t
     std::vector<blockstore_op_t*> submit_queue;
     std::vector<obj_ver_id> unsynced_big_writes, unsynced_small_writes;
     int unsynced_big_write_count = 0, unstable_unsynced = 0;
-    bool unstable_count_changed = false;
     int unsynced_queued_ops = 0;
     allocator *data_alloc = NULL;
     uint64_t used_blocks = 0;

src/blockstore_rollback.cpp

@@ -162,7 +162,6 @@ void blockstore_impl_t::mark_rolled_back(const obj_ver_id & ov)
                     unstable_writes.erase(unstab_it);
                 else
                     unstab_it->second = max_unstable;
-                unstable_count_changed = true;
             }
         }
     }

src/blockstore_stable.cpp

@@ -537,6 +537,5 @@ void blockstore_impl_t::mark_stable(obj_ver_id v, bool forget_dirty)
         unstab_it->second <= v.version)
     {
         unstable_writes.erase(unstab_it);
-        unstable_count_changed = true;
     }
 }