From: John Spray <john.spray@redhat.com>
Date: Thu, 20 Nov 2014 14:27:27 +0000 (+0000)
Subject: mds: fix MDLog I/O callback without finisher
X-Git-Tag: v0.90~29^2~2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=2ec67733ce10e5f89ac3ed4d88601a141163bb7b;p=ceph.git

mds: fix MDLog I/O callback without finisher

This could deadlock if another caller was waiting
on a write_head callback while holding mds_lock.

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

diff --git a/src/mds/MDLog.cc b/src/mds/MDLog.cc
index 0beb6d68f2069..836db4730d8de 100644
--- a/src/mds/MDLog.cc
+++ b/src/mds/MDLog.cc
@@ -101,9 +101,9 @@ class C_MDL_WriteError : public MDSIOContextBase {
 
 void MDLog::write_head(MDSInternalContextBase *c) 
 {
-  MDSIOContext *fin = NULL;
+  C_OnFinisher *fin = NULL;
   if (c != NULL) {
-    fin = new C_IO_Wrapper(mds, c);
+    fin = new C_OnFinisher(new C_IO_Wrapper(mds, c), &(mds->finisher));
   }
   journaler->write_head(fin);
 }