mds: fix transitions away from XSYN state

If we are in XSYN, we need to transition first to EXCL before moving on.
Simply going to the other unstable state isn't enough, because if gather
is zero at the end of the method we end up jumping directly to the wrong
state without passing EXCL.   Instead, call file_excl(), and continue only
if we got there immediately.

Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index 46ef55df23f1a45fe95a34406265a7b2d86838b6..0aa7e4e6fa25d230f567e23cbb8ceaf5323aa55e 100644 (file)
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -3125,8 +3125,12 @@ bool Locker::simple_sync(SimpleLock *lock, bool *need_issue)
     case LOCK_MIX: lock->set_state(LOCK_MIX_SYNC); break;
     case LOCK_SCAN:
     case LOCK_LOCK: lock->set_state(LOCK_LOCK_SYNC); break;
+    case LOCK_XSYN:
+      file_excl((ScatterLock*)lock, need_issue);
+      if (lock->get_state() != LOCK_EXCL)
+       return false;
+      // fall-thru
     case LOCK_EXCL: lock->set_state(LOCK_EXCL_SYNC); break;
-    case LOCK_XSYN: lock->set_state(LOCK_XSYN_EXCL); break; // FIXME (and below!)
     default: assert(0);
     }
 
@@ -3172,8 +3176,7 @@ bool Locker::simple_sync(SimpleLock *lock, bool *need_issue)
     }
   }
 
-  if (lock->get_parent()->is_replicated() &&
-      lock->get_state() != LOCK_XSYN_EXCL) {    // FIXME
+  if (lock->get_parent()->is_replicated()) {    // FIXME
     bufferlist data;
     lock->encode_locked_state(data);
     send_lock_message(lock, LOCK_AC_SYNC, data);
@@ -3261,8 +3264,12 @@ void Locker::simple_lock(SimpleLock *lock, bool *need_issue)
   switch (lock->get_state()) {
   case LOCK_SCAN: lock->set_state(LOCK_SCAN_LOCK); break;
   case LOCK_SYNC: lock->set_state(LOCK_SYNC_LOCK); break;
+  case LOCK_XSYN:
+    file_excl((ScatterLock*)lock, need_issue);
+    if (lock->get_state() != LOCK_EXCL)
+      return;
+    // fall-thru
   case LOCK_EXCL: lock->set_state(LOCK_EXCL_LOCK); break;
-  case LOCK_XSYN: lock->set_state(LOCK_XSYN_EXCL); break; // FIXME
   case LOCK_MIX: lock->set_state(LOCK_MIX_LOCK); break;
   case LOCK_TSYN: lock->set_state(LOCK_TSYN_LOCK); break;
   default: assert(0);
@@ -3904,8 +3911,12 @@ void Locker::scatter_mix(ScatterLock *lock, bool *need_issue)
     // gather?
     switch (lock->get_state()) {
     case LOCK_SYNC: lock->set_state(LOCK_SYNC_MIX); break;
+    case LOCK_XSYN:
+      file_excl(lock, need_issue);
+      if (lock->get_state() != LOCK_EXCL)
+       return;
+      // fall-thru
     case LOCK_EXCL: lock->set_state(LOCK_EXCL_MIX); break;
-    case LOCK_XSYN: lock->set_state(LOCK_XSYN_EXCL); break; // FIXME (and see below!)
     case LOCK_TSYN: lock->set_state(LOCK_TSYN_MIX); break;
     default: assert(0);
     }