[PATCH] jffs2: fix invocations of dbg_xattr() for dead jffs2_xattr_ref

[Hou Tao]

When jffs2_xattr_ref is dead, xref->ic or xref->xd will be invalid
because these fields will be reused as xref->ino or xref->xid,
so access xref->ic->ino or xref->xd->xid will lead to Oops.

Fix the problem by checking whether or not it is a dead xref.

Signed-off-by: Hou Tao <hout...@huawei.com>
---
 fs/jffs2/xattr.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/jffs2/xattr.c b/fs/jffs2/xattr.c
index 3d40fe02b003..0c4c7891556d 100644
--- a/fs/jffs2/xattr.c
+++ b/fs/jffs2/xattr.c
@@ -550,7 +550,8 @@ static int save_xattr_ref(struct jffs2_sb_info *c, struct 
jffs2_xattr_ref *ref)
        ref->xseqno = xseqno;
        jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, 
PAD(sizeof(rr)), (void *)ref);
 
-       dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, 
ref->xd->xid);
+       dbg_xattr("success on saving xref (ino=%u, xid=%u)\n",
+                       je32_to_cpu(rr.ino), je32_to_cpu(rr.xid));
 
        return 0;
 }
@@ -1329,7 +1330,11 @@ int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info 
*c, struct jffs2_xattr_
        rc = save_xattr_ref(c, ref);
        if (!rc)
                dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
-                         ref->ic->ino, ref->xd->xid, old_ofs, 
ref_offset(ref->node));
+                               is_xattr_ref_dead(ref) ?
+                                       ref->ino : ref->ic->ino,
+                               is_xattr_ref_dead(ref) ?
+                                       ref->xid : ref->xd->xid,
+                               old_ofs, ref_offset(ref->node));
  out:
        if (!rc)
                jffs2_mark_node_obsolete(c, raw);
-- 
2.16.2.dirty