From 56548b2eab18c66b4ab1d15e934cf0fe5ab6e155 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Mon, 7 Mar 2011 16:25:30 -0800
Subject: [PATCH] mds: use projected subtree in rename anchor check

We want to (try to) reanchor the directory on rename when our _projected_
subtree is not a leaf.  If we use the normal get_subtree_root() call,
we get NULL if we are unlinked, which makes is_leaf_subtree() crash.

Signed-off-by: Sage Weil <sage.weil@dreamhost.com>
---
 src/mds/CDir.cc    |  2 +-
 src/mds/CInode.cc  |  7 +++++++
 src/mds/CInode.h   |  1 +
 src/mds/MDCache.cc | 12 ++++++++++++
 src/mds/MDCache.h  |  1 +
 src/mds/Server.cc  |  2 +-
 6 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/mds/CDir.cc b/src/mds/CDir.cc
index e19f91d78895a..96fa8fad26da9 100644
--- a/src/mds/CDir.cc
+++ b/src/mds/CDir.cc
@@ -49,7 +49,7 @@ boost::pool<> CDir::pool(sizeof(CDir));
 ostream& operator<<(ostream& out, CDir& dir)
 {
   string path;
-  dir.get_inode()->make_path_string(path);
+  dir.get_inode()->make_path_string_projected(path);
   out << "[dir " << dir.dirfrag() << " " << path << "/"
       << " [" << dir.first << ",head]";
   if (dir.is_auth()) {
diff --git a/src/mds/CInode.cc b/src/mds/CInode.cc
index 311d1d64f53b3..49fe113762384 100644
--- a/src/mds/CInode.cc
+++ b/src/mds/CInode.cc
@@ -685,6 +685,13 @@ CDir *CInode::get_parent_dir()
     return parent->dir;
   return NULL;
 }
+CDir *CInode::get_projected_parent_dir()
+{
+  CDentry *p = get_projected_parent_dn();
+  if (p)
+    return p->dir;
+  return NULL;
+}
 CInode *CInode::get_parent_inode() 
 {
   if (parent) 
diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 3c79245320d20..acb67dd93d8f9 100644
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -525,6 +525,7 @@ private:
   CDentry* get_parent_dn() { return parent; }
   CDentry* get_projected_parent_dn() { return projected_parent.size() ? projected_parent.back():parent; }
   CDir *get_parent_dir();
+  CDir *get_projected_parent_dir();
   CInode *get_parent_inode();
   
   bool is_lt(const MDSCacheObject *r) const {
diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 6d4fa4d79f110..46d6d390a5bfd 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -1096,6 +1096,18 @@ CDir *MDCache::get_subtree_root(CDir *dir)
   }
 }
 
+CDir *MDCache::get_projected_subtree_root(CDir *dir)
+{
+  // find the underlying dir that delegates (or is about to delegate) auth
+  while (true) {
+    if (dir->is_subtree_root()) 
+      return dir;
+    dir = dir->get_inode()->get_projected_parent_dir();
+    if (!dir) 
+      return 0;             // none
+  }
+}
+
 void MDCache::remove_subtree(CDir *dir)
 {
   dout(10) << "remove_subtree " << *dir << dendl;
diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h
index b1d557a7d886a..2c198bc2ec2b7 100644
--- a/src/mds/MDCache.h
+++ b/src/mds/MDCache.h
@@ -550,6 +550,7 @@ public:
   void subtree_merge_writebehind_finish(CInode *in, Mutation *mut);
   void eval_subtree_root(CInode *diri);
   CDir *get_subtree_root(CDir *dir);
+  CDir *get_projected_subtree_root(CDir *dir);
   bool is_leaf_subtree(CDir *dir) {
     assert(subtrees.count(dir));
     return subtrees[dir].empty();
diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index d006fba1ccba4..38dca7e44c602 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -4718,7 +4718,7 @@ void Server::handle_client_rename(MDRequest *mdr)
       (srcdnl->get_inode()->is_anchored() || 
        (srcdnl->get_inode()->is_dir() && (srcdnl->get_inode()->inode.rstat.ranchors ||
 					  srcdnl->get_inode()->nested_anchors ||
-					  !mdcache->is_leaf_subtree(mdcache->get_subtree_root(srcdn->get_dir()))))) &&
+					  !mdcache->is_leaf_subtree(mdcache->get_projected_subtree_root(srcdn->get_dir()))))) &&
       !mdr->more()->src_reanchor_atid) {
     dout(10) << "reanchoring src->dst " << *srcdnl->get_inode() << dendl;
     vector<Anchor> trace;
-- 
2.39.5