From f8c02856d772ebf074e1ea3ecc117eaa15ae6598 Mon Sep 17 00:00:00 2001
From: Greg Farnum <gregf@hq.newdream.net>
Date: Fri, 18 Sep 2009 13:51:26 -0700
Subject: [PATCH] uclient: Functions to create Dentrys prior to gettin caps
 from mds.

---
 src/client/Client.cc | 25 +++++++++++++++++++++++++
 src/client/Client.h  | 19 ++++++++++++-------
 2 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/src/client/Client.cc b/src/client/Client.cc
index 4cc60f0e757a2..ef6f52c9774e6 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -2982,6 +2982,31 @@ int Client::_lookup(Inode *dir, const string& dname, Inode **target)
   return r;
 }
 
+int Client::get_or_create(Inode *dir, const string& name, Dentry **pdn)
+{
+  // lookup
+  if (dir->dir && dir->dir->dentries.count(name)) {
+    Dentry *dn = *pdn = dir->dir->dentries[name];
+    
+    // is dn lease valid?
+    utime_t now = g_clock.now();
+    if (dn->inode &&
+	dn->lease_mds >= 0 && 
+	dn->lease_ttl > now &&
+	mds_sessions.count(dn->lease_mds)) {
+      MDSSession &s = mds_sessions[dn->lease_mds];
+      if (s.cap_ttl > now &&
+	  s.cap_gen == dn->lease_gen) {
+	return -EEXIST;
+      }
+    }
+  } else {
+    // link up new one
+    *pdn = link(dir->dir, name.c_str(), NULL);
+  }
+  return 0;
+}
+
 int Client::path_walk(const filepath& origpath, Inode **final, bool followsym)
 {
   filepath path = origpath;
diff --git a/src/client/Client.h b/src/client/Client.h
index e190f835b80ef..75ad46f9689f5 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -946,6 +946,9 @@ protected:
   //int get_cache_size() { return lru.lru_get_size(); }
   //void set_cache_size(int m) { lru.lru_set_max(m); }
 
+  /**
+   * Don't call this with in==NULL, use get_or_create for that
+   */
   Dentry* link(Dir *dir, const string& name, Inode *in) {
     Dentry *dn = new Dentry;
     dn->name = name;
@@ -955,13 +958,14 @@ protected:
     //cout << "link dir " << dir->parent_inode->ino << " '" << name << "' -> inode " << in->ino << endl;
     dir->dentries[dn->name] = dn;
 
-    // link to inode
-    dn->inode = in;
-    assert(in->dn == 0);
-    in->dn = dn;
-    in->get();
-
-    if (in->dir) dn->get();  // dir -> dn pin
+    if (in) {    // link to inode
+      dn->inode = in;
+      assert(in->dn == 0);
+      in->dn = dn;
+      in->get();
+      
+      if (in->dir) dn->get();  // dir -> dn pin
+    }
 
     lru.lru_insert_mid(dn);    // mid or top?
     return dn;
@@ -1178,6 +1182,7 @@ private:
   int _sync_fs();
 
   MClientRequest* make_request_from_Meta(MetaRequest * request);
+  int get_or_create(Inode *dir, const string& name, Dentry **pdn);
 
 public:
   int mount();
-- 
2.39.5