[JFFS2][XATTR] using 'delete marker' for xdatum/xref deletion

- When xdatum is removed, a new xdatum with 'delete marker' is
  written. (version==0xffffffff means 'delete marker')
- When xref is removed, a new xref with 'delete marker' is written.
  (odd-numbered xseqno means 'delete marker')

- delete_xattr_(datum/xref)_delay() are new deletion functions
  are added. We can only use them if we can detect the target
  obsolete xdatum/xref as a orphan or errir one.
  (e.g when inode deletion, or detecting crc error)

[1/3] jffs2-xattr-v6-01-delete_marker.patch

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h
index 935fec1..b985949 100644
--- a/fs/jffs2/jffs2_fs_sb.h
+++ b/fs/jffs2/jffs2_fs_sb.h
@@ -119,8 +119,11 @@
 #ifdef CONFIG_JFFS2_FS_XATTR
 #define XATTRINDEX_HASHSIZE	(57)
 	uint32_t highest_xid;
+	uint32_t highest_xseqno;
 	struct list_head xattrindex[XATTRINDEX_HASHSIZE];
 	struct list_head xattr_unchecked;
+	struct list_head xattr_dead_list;
+	struct jffs2_xattr_ref *xref_dead_list;
 	struct jffs2_xattr_ref *xref_temp;
 	struct rw_semaphore xattr_sem;
 	uint32_t xdatum_mem_usage;