osdc/Journaler: fix C_RetryRead locking

Not sure this was ever actually getting used, but
it would have had a problem if it was.

Signed-off-by: John Spray <john.spray@redhat.com>

diff --git a/src/osdc/Journaler.cc b/src/osdc/Journaler.cc
index 0585e73bb246735affdbcf594e3c9a447796247c..579e49b3ca09ef863080ef0bd8f819bf6c752966 100644 (file)
--- a/src/osdc/Journaler.cc
+++ b/src/osdc/Journaler.cc
@@ -795,7 +795,8 @@ class Journaler::C_RetryRead : public Context {
 public:
   C_RetryRead(Journaler *l) : ls(l) {}
   void finish(int r) {
-    Mutex::Locker l(ls->lock);
+    // Should only be called from waitfor_safe i.e. already inside lock
+    assert(ls->lock.is_locked_by_me());
     ls->_prefetch();
   }  
 };

diff --git a/src/osdc/Journaler.h b/src/osdc/Journaler.h
index 375c5f9ffb9fe2ba23fa6b242f324a700edb5bbb..6d24c646e122128a372936dd6adbbd15baca69cf 100644 (file)
--- a/src/osdc/Journaler.h
+++ b/src/osdc/Journaler.h
@@ -297,8 +297,6 @@ private:
   bool waiting_for_zero;
   interval_set<uint64_t> pending_zero;  // non-contig bits we've zeroed
   std::set<uint64_t> pending_safe;
-  // XXX this would be C_OnFinisher reather than Context if it weren't for use of C_RetryRead here
-  // FIXME but oh dear, these are called back inside lock and RetryRead takes the lock!!!
   std::map<uint64_t, std::list<Context*> > waitfor_safe; // when safe through given offset
 
   void _flush(C_OnFinisher *onsafe);