address hfs on-disk corruption robustness review comments

Address Roman's review comments for the previously sent on-disk
corruption hfs robustness patch.

- use 0 as a failure value, rather than making a new macro HFS_BAD_KEYLEN,
  and use a switch statement instead of if's.

- Add new fail: target to __hfs_brec_find to skip assignments using bad
  values when exiting with a failure.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 9 deletions

diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
index 110dd3515dc8..24cf6fc43021 100644
--- a/fs/hfs/btree.c
+++ b/fs/hfs/btree.c
@@ -81,15 +81,23 @@ struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp ke
                 goto fail_page;
         if (!tree->node_count)
                 goto fail_page;
-        if ((id == HFS_EXT_CNID) && (tree->max_key_len != HFS_MAX_EXT_KEYLEN)) {
-                printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
-                        tree->max_key_len);
-                goto fail_page;
-        }
-        if ((id == HFS_CAT_CNID) && (tree->max_key_len != HFS_MAX_CAT_KEYLEN)) {
-                printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
-                        tree->max_key_len);
-                goto fail_page;
+        switch (id) {
+        case HFS_EXT_CNID:
+                if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
+                        printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
+                                tree->max_key_len);
+                        goto fail_page;
+                }
+                break;
+        case HFS_CAT_CNID:
+                if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
+                        printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
+                                tree->max_key_len);
+                        goto fail_page;
+                }
+                break;
+        default:
+                BUG();
         }
 
         tree->node_size_shift = ffs(size) - 1;