FileStore,DBObjectMap: remove ObjectMap link method

hobject_t's are now globally unique in filestore.  Essentially, there is
a 1-to-1 mapping from inodes to hobject_t's.  The entry in the
DBObjectMap is now tied to the inode/hobject_t.  Thus, links needn't be
tracked.  Rather, we delete the ObjectMap entry when nlink == 0.

Signed-off-by: Samuel Just <sam.just@inktank.com>

4 files changed, 11 insertions, 50 deletions

diff --git a/src/os/DBObjectMap.cc b/src/os/DBObjectMap.cc
index ecd9d0133e6..b116e6bcd9f 100644
--- a/src/os/DBObjectMap.cc
+++ b/src/os/DBObjectMap.cc
@@ -939,33 +939,6 @@ int DBObjectMap::clone(const hobject_t &hoid,
   return db->submit_transaction(t);
 }
 
-int DBObjectMap::link(const hobject_t &hoid,
-		      Index index,
-		      const hobject_t &target,
-		      Index target_index)
-{
-  assert(index->coll() != target_index->coll() ||
-	 hoid != target);
-  KeyValueDB::Transaction t = db->get_transaction();
-  {
-    Header destination = lookup_map_header(target_index->coll(), target);
-    if (destination) {
-      remove_map_header(target_index->coll(), target, destination, t);
-      destination->num_children--;
-      _clear(destination, t);
-    }
-  }
-  Header header = lookup_create_map_header(index->coll(), hoid, t);
-
-  assert(header->num_children > 0);
-  header->num_children++;
-  set_header(header, t);
-  _Header ldestination;
-  ldestination.parent = header->seq;
-  set_map_header(target_index->coll(), target, ldestination, t);
-  return db->submit_transaction(t);
-}
-
 int DBObjectMap::upgrade()
 {
   assert(0);
diff --git a/src/os/DBObjectMap.h b/src/os/DBObjectMap.h
index 6e48bb0e384..018785afdc8 100644
--- a/src/os/DBObjectMap.h
+++ b/src/os/DBObjectMap.h
@@ -168,13 +168,6 @@ public:
     Index target_index
     );
 
-  int link(
-    const hobject_t &hoid,
-    Index index,
-    const hobject_t &target,
-    Index target_index
-    );
-
   /// Read initial state from backing store
   int init(bool upgrade = false);
 
diff --git a/src/os/FileStore.cc b/src/os/FileStore.cc
index 91978e4af90..17ae06d3b4c 100644
--- a/src/os/FileStore.cc
+++ b/src/os/FileStore.cc
@@ -360,11 +360,6 @@ int FileStore::lfn_link(coll_t c, coll_t cid, const hobject_t& o)
   if (r < 0)
     return -errno;
 
-  r = object_map->link(o, path_old->get_index(),
-		       o, path_new->get_index());
-  if (r < 0 && r != -ENOENT)
-    return r;
-
   r = index_new->created(o, path_new->path());
   if (r < 0)
     return r;
@@ -383,9 +378,17 @@ int FileStore::lfn_unlink(coll_t cid, const hobject_t& o)
     r = index->lookup(o, &path, &exist);
     if (r < 0)
       return r;
-    object_map->clear(o, path->get_index());
-    if (r < 0 && r != -ENOENT)
-      return r;
+
+    struct stat st;
+    r = ::stat(path->path(), &st);
+    if (r < 0) {
+      return -errno;
+    }
+    if (st.st_nlink == 1) {
+      r = object_map->clear(o, path->get_index());
+      if (r < 0 && r != -ENOENT)
+	return r;
+    }
   }
   return index->unlink(o);
 }
diff --git a/src/os/ObjectMap.h b/src/os/ObjectMap.h
index 0f3088e641e..ea6c78ec9ea 100644
--- a/src/os/ObjectMap.h
+++ b/src/os/ObjectMap.h
@@ -131,14 +131,6 @@ public:
     Index target_index                 ///< [in] path to target
     ) { return 0; }
 
-  /// Efficiently tie <target, target_path> to same key space as <hoid, path>
-  virtual int link(
-    const hobject_t &hoid,             ///< [in] object containing map
-    Index index,                       ///< [in] Path to hoid
-    const hobject_t &target,           ///< [in] target of link
-    Index target_index                 ///< [in] path to target
-    ) { return 0; }
-
   /// Ensure all previous writes are durable
   virtual int sync() { return 0; }