From bc273957af2224d028626a961fdb1bf3bc153f40 Mon Sep 17 00:00:00 2001
From: Greg Farnum <gregory.farnum@dreamhost.com>
Date: Mon, 20 Jun 2011 17:55:54 -0700
Subject: [PATCH] AnchorServer: overwrite old Anchor backpointers when proper.

Sometimes when we do an AnchorTable update, it's because the inode
in question got moved. However, if the inode had multiple references,
its Anchor wasn't removed by decrementing its count, and so the add
function simply noted that it already had the Anchor and returned.

This obviously wasn't the proper behavior in cases where the inode
was getting moved -- we want to update its back pointer! So do so.

Signed-off-by: Greg Farnum <gregory.farnum@dreamhost.com>
---
 src/mds/AnchorServer.cc | 12 +++++++++---
 src/mds/AnchorServer.h  |  2 +-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/mds/AnchorServer.cc b/src/mds/AnchorServer.cc
index 5cc63b3ab8adc..14b541cc9038b 100644
--- a/src/mds/AnchorServer.cc
+++ b/src/mds/AnchorServer.cc
@@ -47,7 +47,8 @@ void AnchorServer::dump()
  * basic updates
  */
 
-bool AnchorServer::add(inodeno_t ino, inodeno_t dirino, __u32 dn_hash) 
+bool AnchorServer::add(inodeno_t ino, inodeno_t dirino, __u32 dn_hash,
+                       bool replace)
 {
   //dout(17) << "add " << ino << " dirfrag " << dirfrag << dendl;
   
@@ -60,6 +61,11 @@ bool AnchorServer::add(inodeno_t ino, inodeno_t dirino, __u32 dn_hash)
     anchor_map[ino] = Anchor(ino, dirino, dn_hash, 0, version);
     dout(7) << "add added " << anchor_map[ino] << dendl;
     return true;
+  } else if (replace) {
+    anchor_map[ino].dirino = dirino;
+    anchor_map[ino].dn_hash = dn_hash;
+    dout(7) << "add had old Anchor, updated it to "
+            << anchor_map[ino] << dendl;
   } else {
     dout(7) << "add had " << anchor_map[ino] << dendl;
     return false;
@@ -130,7 +136,7 @@ void AnchorServer::_prepare(bufferlist &bl, uint64_t reqid, int bymds)
     // make sure trace is in table
     dout(25) << "trace.size=" << trace.size() << dendl;
     for (unsigned i=0; i<trace.size(); i++) {
-      add(trace[i].ino, trace[i].dirino, trace[i].dn_hash);
+      add(trace[i].ino, trace[i].dirino, trace[i].dn_hash, false);
       dout(25) << trace[i] << dendl;
     }
     inc(ino);
@@ -184,7 +190,7 @@ void AnchorServer::_commit(version_t tid)
       
       // add new
       for (unsigned i=0; i<trace.size(); i++) 
-	add(trace[i].ino, trace[i].dirino, trace[i].dn_hash);
+	add(trace[i].ino, trace[i].dirino, trace[i].dn_hash, true);
       inc(ino);
     } else {
       dout(7) << "commit " << tid << " update " << ino << " -- DNE" << dendl;
diff --git a/src/mds/AnchorServer.h b/src/mds/AnchorServer.h
index d594cba03296e..ca70aa24bf63e 100644
--- a/src/mds/AnchorServer.h
+++ b/src/mds/AnchorServer.h
@@ -49,7 +49,7 @@ class AnchorServer : public MDSTableServer {
     ::decode(pending_update, p);
   }
 
-  bool add(inodeno_t ino, inodeno_t dirino, __u32 dn_hash);
+  bool add(inodeno_t ino, inodeno_t dirino, __u32 dn_hash, bool replace);
   void inc(inodeno_t ino);
   void dec(inodeno_t ino);
 
-- 
2.39.5