From: Somnath Roy <somnath.roy@sandisk.com>
Date: Sat, 9 Jul 2016 02:41:46 +0000 (-0400)
Subject: Bluestore: Fixed a Bluestore crash
X-Git-Tag: ses5-milestone5~381
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=bf70bcb6c54e4d6404533bc91781a5ef77d62033;p=ceph.git

Bluestore: Fixed a Bluestore crash

A bluestore race condition is been fixed by protecting txc structures
within _txc_state_poc with collection lock.

Mark's comments:

This fixes segfaults during random write tests with bluestore.
This passes "ceph_test_objectstore --gtest_filter=*/2".
This may introduce a small performance regresion, though there is enough
noise in the results to make it inconclusive.

Closes #10220

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
---

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index cc91d89af6f2..cd2a9a12adca 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -4589,11 +4589,19 @@ void BlueStore::_txc_state_proc(TransContext *txc)
       txc->log_state_latency(logger, l_bluestore_state_io_done_lat);
       txc->state = TransContext::STATE_KV_QUEUED;
       // FIXME: use a per-txc dirty blob list?
+      
+      if (txc->first_collection) {
+        (txc->first_collection)->lock.get_read();
+      }
       for (auto& o : txc->onodes) {
-	for (auto& p : o->blob_map.blob_map) {
-	  p.bc.finish_write(txc->seq);
+        for (auto& p : o->blob_map.blob_map) {
+	    p.bc.finish_write(txc->seq);
 	}
       }
+      if (txc->first_collection) {
+        (txc->first_collection)->lock.put_read();
+      }
+      
       if (!g_conf->bluestore_sync_transaction) {
 	if (g_conf->bluestore_sync_submit_transaction) {
 	  _txc_finalize_kv(txc, txc->t);
@@ -5160,7 +5168,6 @@ int BlueStore::queue_transactions(
   }
 
   _txc_write_nodes(txc, txc->t);
-
   // journal wal items
   if (txc->wal_txn) {
     // move releases to after wal