From 7ae075f24707dcc5877acf70198293f3ef948296 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Wed, 18 Mar 2009 13:46:04 -0700
Subject: [PATCH] mds: remember scatter requests

We want to make sure a REQSCATTER is remembered the next time we
reconsider the lock state, even if it arrives when the lock is
unstable (say, during EXCL->LOCK or some other transition that
won't affect the replica state and elicit a new REQSCATTER).
---
 src/mds/Locker.cc     | 8 ++++++--
 src/mds/ScatterLock.h | 7 ++++++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index 1e0b382671fd1..dd05e09f33284 100644
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -490,6 +490,7 @@ void Locker::eval_gather(SimpleLock *lock, bool first)
 	  lock->encode_locked_state(softdata);
 	  send_lock_message(lock, LOCK_AC_MIX, softdata);
 	}
+	((ScatterLock*)lock)->clear_scatter_wanted();
 	break;
 
 	// to sync
@@ -2861,8 +2862,8 @@ void Locker::file_eval(ScatterLock *lock)
   else if (lock->get_state() != LOCK_MIX &&
 	   //!lock->is_rdlocked() &&
 	   //!lock->is_waiter_for(SimpleLock::WAIT_WR) &&
-	   (wanted & CEPH_CAP_GRD) &&
-	   (wanted & CEPH_CAP_GWR)) {
+	   (lock->get_scatter_wanted() ||
+	    (wanted & (CEPH_CAP_GRD|CEPH_CAP_GWR)))) {
     dout(7) << "file_eval stable, bump to mixed " << *lock
 	    << " on " << *lock->get_parent() << dendl;
     file_mixed(lock);
@@ -2910,6 +2911,7 @@ void Locker::file_mixed(ScatterLock *lock)
 
     // change lock
     lock->set_state(LOCK_MIX);
+    lock->clear_scatter_wanted();
     issue_caps(in);
   } else {
     // gather?
@@ -2952,6 +2954,7 @@ void Locker::file_mixed(ScatterLock *lock)
     else {
       in->try_drop_loner();
       lock->set_state(LOCK_MIX);
+      lock->clear_scatter_wanted();
       if (in->is_replicated()) {
 	bufferlist softdata;
 	lock->encode_locked_state(softdata);
@@ -3167,6 +3170,7 @@ void Locker::handle_file_lock(ScatterLock *lock, MLock *m)
     } else {
       dout(7) << "handle_file_lock ignoring scatter request on " << *lock
 	      << " on " << *lock->get_parent() << dendl;
+      lock->set_scatter_wanted();
     }
     break;
 
diff --git a/src/mds/ScatterLock.h b/src/mds/ScatterLock.h
index fa07b3f97310f..3fa61ae30e112 100644
--- a/src/mds/ScatterLock.h
+++ b/src/mds/ScatterLock.h
@@ -20,6 +20,7 @@
 
 class ScatterLock : public SimpleLock {
   bool dirty, flushing;
+  bool scatter_wanted;
   utime_t last_scatter;
 
 public:
@@ -28,12 +29,16 @@ public:
 
   ScatterLock(MDSCacheObject *o, int t, int ws) : 
     SimpleLock(o, t, ws),
-    dirty(false), flushing(false),
+    dirty(false), flushing(false), scatter_wanted(false),
     xlistitem_updated(this) {}
   ~ScatterLock() {
     xlistitem_updated.remove_myself();   // FIXME this should happen sooner, i think...
   }
 
+  void set_scatter_wanted() { scatter_wanted = true; }
+  void clear_scatter_wanted() { scatter_wanted = false; }
+  bool get_scatter_wanted() { return scatter_wanted; }
+
   void mark_dirty() { 
     if (!dirty) {
       if (!flushing) 
-- 
2.39.5