LU-2227 build: fix 'memory illegal access' errors

[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_iam_lvar.c

diff --git a/lustre/osd-ldiskfs/osd_iam_lvar.c b/lustre/osd-ldiskfs/osd_iam_lvar.c
index 75068e5..ef53adf 100644 (file)
--- a/lustre/osd-ldiskfs/osd_iam_lvar.c
+++ b/lustre/osd-ldiskfs/osd_iam_lvar.c
@@ -27,7 +27,7 @@
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2012 Whamcloud, Inc.
+ * Copyright (c) 2012, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -765,6 +765,11 @@ static void lvar_split(struct iam_leaf *leaf, struct buffer_head **bh,
         assert_inv(n_invariant(leaf));
 }
 
+static int lvar_leaf_empty(struct iam_leaf *leaf)
+{
+       return h_used(n_head(leaf)) == sizeof(struct lvar_leaf_header);
+}
+
 static struct iam_leaf_operations lvar_leaf_ops = {
         .init           = lvar_init,
         .init_new       = lvar_init_new,
@@ -787,7 +792,8 @@ static struct iam_leaf_operations lvar_leaf_ops = {
         .rec_add        = lvar_rec_add,
         .rec_del        = lvar_rec_del,
         .can_add        = lvar_can_add,
-        .split          = lvar_split
+       .split          = lvar_split,
+       .leaf_empty     = lvar_leaf_empty,
 };
 
 /*
@@ -938,11 +944,22 @@ static void lvar_root(void *buf,
                                         sizeof (lvar_hash_t) + ptrsize)
         };
 
-        entry = root + 1;
-        /*
-         * Skip over @limit.
-         */
-        entry += isize;
+       /* To guarantee that the padding "keysize + ptrsize"
+        * covers the "dx_countlimit" and the "idle_blocks". */
+       LASSERT((keysize + ptrsize) >=
+               (sizeof(struct dx_countlimit) + sizeof(__u32)));
+
+       entry = (void *)(limit + 1);
+       /* Put "idle_blocks" just after the limit. There was padding after
+        * the limit, the "idle_blocks" re-uses part of the padding, so no
+        * compatibility issues with old layout.
+        */
+       *(__u32 *)entry = 0;
+
+       /*
+        * Skip over @limit.
+        */
+       entry = (void *)(root + 1) + isize;
 
         /*
          * Entry format is <key> followed by <ptr>. In the minimal tree
@@ -1054,11 +1071,14 @@ static int lvar_guess(struct iam_container *c)
                         descr->id_node_gap  = 0;
                         descr->id_ops       = &lvar_ops;
                         descr->id_leaf_ops  = &lvar_leaf_ops;
-                } else
-                        result = -EBADF;
-                brelse(bh);
-        }
-        return result;
+
+                       c->ic_root_bh = bh;
+               } else {
+                       result = -EBADF;
+                       brelse(bh);
+               }
+       }
+       return result;
 }
 
 static struct iam_format lvar_format = {