1 files changed, 39 insertions, 0 deletions

diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 2c7974cccaf8..f7d19f4db897 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -2153,3 +2153,42 @@ out:
         brelse(ref_root_bh);
         return ret;
 }
+
+/*
+ * Mark the already-existing extent at cpos as refcounted for len clusters.
+ * This adds the refcount extent flag.
+ *
+ * If the existing extent is larger than the request, initiate a
+ * split. An attempt will be made at merging with adjacent extents.
+ *
+ * The caller is responsible for passing down meta_ac if we'll need it.
+ */
+static int ocfs2_mark_extent_refcounted(struct inode *inode,
+                                struct ocfs2_extent_tree *et,
+                                handle_t *handle, u32 cpos,
+                                u32 len, u32 phys,
+                                struct ocfs2_alloc_context *meta_ac,
+                                struct ocfs2_cached_dealloc_ctxt *dealloc)
+{
+        int ret;
+
+        mlog(0, "Inode %lu refcount tree cpos %u, len %u, phys cluster %u\n",
+             inode->i_ino, cpos, len, phys);
+
+        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
+                ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
+                            "tree, but the feature bit is not set in the "
+                            "super block.", inode->i_ino);
+                ret = -EROFS;
+                goto out;
+        }
+
+        ret = ocfs2_change_extent_flag(handle, et, cpos,
+                                       len, phys, meta_ac, dealloc,
+                                       OCFS2_EXT_REFCOUNTED, 0);
+        if (ret)
+                mlog_errno(ret);
+
+out:
+        return ret;
+}