Index: linux-2.6.27.21-0.1/fs/ext4/ext4_extents.h
===================================================================
--- linux-2.6.27.21-0.1.orig/fs/ext4/ext4_extents.h	2009-07-07 14:47:22.000000000 +0530
+++ linux-2.6.27.21-0.1/fs/ext4/ext4_extents.h	2009-07-07 14:49:31.000000000 +0530
@@ -203,6 +203,11 @@
 	return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
 }
 
+static inline void ext4_ext_tree_changed(struct inode *inode)
+{
+	EXT4_I(inode)->i_ext_generation++;
+}
+
 static inline void
 ext4_ext_invalidate_cache(struct inode *inode)
 {
Index: linux-2.6.27.21-0.1/fs/ext4/ext4.h
===================================================================
--- linux-2.6.27.21-0.1.orig/fs/ext4/ext4.h	2009-07-07 14:47:13.000000000 +0530
+++ linux-2.6.27.21-0.1/fs/ext4/ext4.h	2009-07-07 14:50:07.000000000 +0530
@@ -114,6 +114,7 @@
 	struct inode vfs_inode;
 	struct jbd2_inode jinode;
 
+	unsigned long i_ext_generation;
 	struct ext4_ext_cache i_cached_extent;
 	/*
 	 * File creation time. Its function is same as that of
Index: linux-2.6.27.21-0.1/fs/ext4/extents.c
===================================================================
--- linux-2.6.27.21-0.1.orig/fs/ext4/extents.c	2009-07-07 14:48:03.000000000 +0530
+++ linux-2.6.27.21-0.1/fs/ext4/extents.c	2009-07-07 14:48:58.000000000 +0530
@@ -1618,6 +1618,7 @@
 		ext4_ext_drop_refs(npath);
 		kfree(npath);
 	}
+	ext4_ext_tree_changed(inode);
 	ext4_ext_invalidate_cache(inode);
 	return err;
 }
@@ -2279,6 +2280,7 @@
 		}
 	}
 out:
+	ext4_ext_tree_changed(inode);
 	ext4_ext_drop_refs(path);
 	kfree(path);
 	ext4_journal_stop(handle);