From 15fa5885350129880e8db6ba312e850da0acd2bc Mon Sep 17 00:00:00 2001
From: Greg Farnum <gregf@hq.newdream.net>
Date: Thu, 14 Jan 2010 11:11:51 -0800
Subject: [PATCH] mds: use CompatSet in disk format

---
 src/mds/CInode.cc | 21 +++++++++++++++++----
 src/mds/CInode.h  |  5 +++++
 src/mds/MDS.cc    |  8 ++++++++
 src/mds/MDS.h     | 11 ++++++++++-
 4 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/src/mds/CInode.cc b/src/mds/CInode.cc
index e641b2bed4263..e9e049f5d1ff4 100644
--- a/src/mds/CInode.cc
+++ b/src/mds/CInode.cc
@@ -42,7 +42,6 @@
 #undef dout_prefix
 #define dout_prefix *_dout << dbeginl << "mds" << mdcache->mds->get_nodeid() << ".cache.ino(" << inode.ino << ") "
 
-
 boost::pool<> CInode::pool(sizeof(CInode));
 boost::pool<> Capability::pool(sizeof(Capability));
 
@@ -664,6 +663,9 @@ void CInode::store(Context *fin)
   bufferlist bl;
   nstring magic = CEPH_FS_ONDISK_MAGIC;
   ::encode(magic, bl);
+  //hack: in future will want to only write USED features
+  //since we currently only have one feature, though, this works
+  mdcache->mds->mds_features.encode(bl);
   encode_store(bl);
 
   // write it.
@@ -733,9 +735,20 @@ void CInode::_fetched(bufferlist& bl, Context *fin)
 	    << "'" << dendl;
     fin->finish(-EINVAL);
   } else {
-    decode_store(p);
-    dout(10) << "_fetched " << *this << dendl;
-    fin->finish(0);
+    ondisk_ino_features.decode(p);
+    CompatSet& mds_features = mdcache->mds->mds_features;
+    if ( !mds_features.writeable(ondisk_ino_features)) {
+      dout(0) << "mds data on-disk uses unknown features!" << dendl;
+      CompatSet diff = mds_features.unsupported(ondisk_ino_features);
+      dout(0) << "missing features:" << dendl;
+      for (CompatSet::iterator i = diff.begin(); i != diff.end(); ++i)
+	dout(0) << *i << dendl;
+      fin->finish(-EOPNOTSUPP);
+    } else {
+      decode_store(p);
+      dout(10) << "_fetched " << *this << dendl;
+      fin->finish(0);
+    }
   }
   delete fin;
 }
diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 17d45a463af9d..2b74308c15aae 100644
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -18,6 +18,7 @@
 #define __CINODE_H
 
 #include "config.h"
+#include "include/CompatSet.h"
 #include "include/types.h"
 #include "include/lru.h"
 
@@ -53,11 +54,13 @@ class ObjectOperation;
 ostream& operator<<(ostream& out, CInode& in);
 
 
+
 // cached inode wrapper
 class CInode : public MDSCacheObject {
 private:
   static boost::pool<> pool;
 public:
+  CompatSet ondisk_ino_features;
   static void *operator new(size_t num_bytes) { 
     return pool.malloc();
   }
@@ -919,4 +922,6 @@ public:
 
 };
 
+
+
 #endif
diff --git a/src/mds/MDS.cc b/src/mds/MDS.cc
index ce32957003b51..9ffe89ee43217 100644
--- a/src/mds/MDS.cc
+++ b/src/mds/MDS.cc
@@ -70,6 +70,11 @@
 #undef dout_prefix
 #define dout_prefix *_dout << dbeginl << "mds" << whoami << '.' << incarnation << ' '
 
+const char *ceph_mds_feature_compat[ceph_mds_feature_compat_size] = {};
+const char *ceph_mds_feature_ro_compat[ceph_mds_feature_ro_compat_size]=
+  {};
+const char *ceph_mds_feature_incompat[ceph_mds_feature_incompat_size] =
+  { CEPH_MDS_FEATURE_INCOMPAT_BASE };
 
 
 // cons/des
@@ -78,6 +83,9 @@ MDS::MDS(const char *n, Messenger *m, MonClient *mc) :
   timer(mds_lock),
   name(n),
   whoami(-1), incarnation(0),
+  mds_features(ceph_mds_feature_compat, ceph_mds_feature_compat_size,
+	       ceph_mds_feature_ro_compat, ceph_mds_feature_ro_compat_size,
+	       ceph_mds_feature_incompat, ceph_mds_feature_incompat_size),
   standby_for_rank(-1),
   standby_replay_for(-1),
   messenger(m),
diff --git a/src/mds/MDS.h b/src/mds/MDS.h
index cf77a34fde26c..0bce1daae40de 100644
--- a/src/mds/MDS.h
+++ b/src/mds/MDS.h
@@ -20,6 +20,7 @@
 #include "mdstypes.h"
 
 #include "msg/Dispatcher.h"
+#include "include/CompatSet.h"
 #include "include/types.h"
 #include "include/Context.h"
 #include "common/DecayCounter.h"
@@ -144,6 +145,8 @@ class MDS : public Dispatcher {
   string name;
   int whoami;
   int incarnation;
+
+  CompatSet mds_features;
   
   int standby_for_rank;
   string standby_for_name;
@@ -395,6 +398,12 @@ public:
   }
 };
 
-
+#define CEPH_MDS_FEATURE_INCOMPAT_BASE "initial feature set (~v.18)"
+static const int ceph_mds_feature_compat_size = 0;
+static const int ceph_mds_feature_ro_compat_size = 0;
+static const int ceph_mds_feature_incompat_size = 1;
+extern const char *ceph_mds_feature_compat[];
+extern const char *ceph_mds_feature_ro_compat[];
+extern const char *ceph_mds_feature_incompat[];
 
 #endif
-- 
2.39.5