From e18001c11b8601d99b2356beb170b242823f7906 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Fri, 1 Oct 2010 12:43:20 -0700
Subject: [PATCH] mds: fix stray replica push on _rename_prepare_witness()

We need to push all parents of the straydn to the target.  This changed
a while back with the mdsdir stuff but this bit of code wasn't updated.
Updated to mirror send_dentry_unlink().

This fixes a crash like:
mds/MDCache.cc: In function 'void MDCache::adjust_subtree_auth(CDir*, std::pair<int, int>, bool)':
mds/MDCache.cc:644: FAILED assert(root)
 ceph version 0.22~rc (0e67718a365b42969e785f544ea3b4258bb2407f)
 1: (MDCache::add_replica_dir(ceph::buffer::list::iterator&, CInode*, int, std::list<Context*, std::allocator<Context*> >&)+0x1c1) [0x536a91]
 2: (MDCache::add_replica_stray(ceph::buffer::list&, int)+0xdb) [0x536fab]
 3: (Server::handle_slave_rename_prep(MDRequest*)+0x1113) [0x4d5c33]
 4: (Server::dispatch_slave_request(MDRequest*)+0x21b) [0x4de80b]
 5: (Server::handle_slave_request(MMDSSlaveRequest*)+0x145) [0x4e1955]
 6: (MDS::_dispatch(Message*)+0x2598) [0x49e038]
...

Signed-off-by: Sage Weil <sage@newdream.net>
---
 src/mds/MDCache.cc | 22 +++++++++++++---------
 src/mds/MDCache.h  |  2 ++
 src/mds/Server.cc  |  7 ++-----
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 176c150293806..0abe20e39c741 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -8142,7 +8142,17 @@ CInode *MDCache::add_replica_inode(bufferlist::iterator& p, CDentry *dn, list<Co
   return in;
 }
 
-    
+ 
+void MDCache::replicate_stray(CDentry *straydn, int who, bufferlist& bl)
+{
+  replicate_inode(get_myin(), who, bl);
+  replicate_dir(straydn->get_dir()->inode->get_parent_dn()->get_dir(), who, bl);
+  replicate_dentry(straydn->get_dir()->inode->get_parent_dn(), who, bl);
+  replicate_inode(straydn->get_dir()->inode, who, bl);
+  replicate_dir(straydn->get_dir(), who, bl);
+  replicate_dentry(straydn, who, bl);
+}
+   
 CDentry *MDCache::add_replica_stray(bufferlist &bl, int from)
 {
   list<Context*> finished;
@@ -8317,14 +8327,8 @@ void MDCache::send_dentry_unlink(CDentry *dn, CDentry *straydn)
        it != dn->replicas_end();
        it++) {
     MDentryUnlink *unlink = new MDentryUnlink(dn->get_dir()->dirfrag(), dn->name);
-    if (straydn) {
-      replicate_inode(get_myin(), it->first, unlink->straybl);
-      replicate_dir(straydn->get_dir()->inode->get_parent_dn()->get_dir(), it->first, unlink->straybl);
-      replicate_dentry(straydn->get_dir()->inode->get_parent_dn(), it->first, unlink->straybl);
-      replicate_inode(straydn->get_dir()->inode, it->first, unlink->straybl);
-      replicate_dir(straydn->get_dir(), it->first, unlink->straybl);
-      replicate_dentry(straydn, it->first, unlink->straybl);
-    }
+    if (straydn)
+      replicate_stray(straydn, it->first, unlink->straybl);
     mds->send_message_mds(unlink, it->first);
   }
 }
diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h
index 5d2b7e284a97d..086caa3df3431 100644
--- a/src/mds/MDCache.h
+++ b/src/mds/MDCache.h
@@ -1048,6 +1048,8 @@ public:
   CDir* forge_replica_dir(CInode *diri, frag_t fg, int from);
   CDentry *add_replica_dentry(bufferlist::iterator& p, CDir *dir, list<Context*>& finished);
   CInode *add_replica_inode(bufferlist::iterator& p, CDentry *dn, list<Context*>& finished);
+
+  void replicate_stray(CDentry *straydn, int who, bufferlist& bl);
   CDentry *add_replica_stray(bufferlist &bl, int from);
 
   // -- namespace --
diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 7466e1c08aed9..c2e83e8bcd0a0 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -4659,11 +4659,8 @@ void Server::_rename_prepare_witness(MDRequest *mdr, int who, CDentry *srcdn, CD
   destdn->make_path(req->destdnpath);
   req->now = mdr->now;
   
-  if (straydn) {
-    mdcache->replicate_inode(straydn->get_dir()->inode, who, req->stray);
-    mdcache->replicate_dir(straydn->get_dir(), who, req->stray);
-    mdcache->replicate_dentry(straydn, who, req->stray);
-  }
+  if (straydn)
+    mdcache->replicate_stray(straydn, who, req->stray);
   
   // srcdn auth will verify our current witness list is sufficient
   req->witnesses = mdr->more()->witnessed;
-- 
2.39.5