os/newstore: queue kv transactions in kv_sync_thread

It appears that db->submit_transaction() will block if there is a sync
commit that is in progress instead of simply queueing the new txn for
later.  To work around this, submit these to the backend in the
kv_sync_thread prior to the synchronous submit_transaction_sync().

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

diff --git a/src/os/newstore/NewStore.cc b/src/os/newstore/NewStore.cc
index 044f1ebe391765d4b24565df947fb689675e08c1..5a5f730ad86058ffe92086bddc339747fb4bb745 100644 (file)
--- a/src/os/newstore/NewStore.cc
+++ b/src/os/newstore/NewStore.cc
@@ -2084,7 +2084,6 @@ void NewStore::_txc_state_proc(TransContext *txc)
       txc->state = TransContext::STATE_KV_QUEUED;
       if (!g_conf->newstore_sync_transaction) {
        Mutex::Locker l(kv_lock);
-       db->submit_transaction(txc->t);
        kv_queue.push_back(txc);
        kv_cond.SignalOne();
        return;
@@ -2384,6 +2383,12 @@ void NewStore::_kv_sync_thread()
       utime_t start = ceph_clock_now(NULL);
       kv_lock.Unlock();
 
+      for (std::deque<TransContext *>::iterator it = kv_committing.begin();
+           it != kv_committing.end();
+           it++) {
+       db->submit_transaction((*it)->t);
+      }
+
       // one transaction to force a sync.  clean up wal keys while we
       // are at it.
       KeyValueDB::Transaction txc_cleanup_sync = db->get_transaction();