address hfs on-disk corruption robustness review comments
Eric Sandeen [Wed, 6 Feb 2008 09:37:10 +0000 (01:37 -0800)]
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>

fs/hfs/bfind.c
fs/hfs/brec.c
fs/hfs/btree.c
fs/hfs/hfs.h

index f8452a0..4129cdb 100644 (file)
@@ -52,9 +52,9 @@ int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd)
                rec = (e + b) / 2;
                len = hfs_brec_lenoff(bnode, rec, &off);
                keylen = hfs_brec_keylen(bnode, rec);
-               if (keylen == HFS_BAD_KEYLEN) {
+               if (keylen == 0) {
                        res = -EINVAL;
-                       goto done;
+                       goto fail;
                }
                hfs_bnode_read(bnode, fd->key, off, keylen);
                cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
@@ -71,9 +71,9 @@ int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd)
        if (rec != e && e >= 0) {
                len = hfs_brec_lenoff(bnode, e, &off);
                keylen = hfs_brec_keylen(bnode, e);
-               if (keylen == HFS_BAD_KEYLEN) {
+               if (keylen == 0) {
                        res = -EINVAL;
-                       goto done;
+                       goto fail;
                }
                hfs_bnode_read(bnode, fd->key, off, keylen);
        }
@@ -83,6 +83,7 @@ done:
        fd->keylength = keylen;
        fd->entryoffset = off + keylen;
        fd->entrylength = len - keylen;
+fail:
        return res;
 }
 
@@ -206,7 +207,7 @@ int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
 
        len = hfs_brec_lenoff(bnode, fd->record, &off);
        keylen = hfs_brec_keylen(bnode, fd->record);
-       if (keylen == HFS_BAD_KEYLEN) {
+       if (keylen == 0) {
                res = -EINVAL;
                goto out;
        }
index 8626ee3..878bf25 100644 (file)
@@ -49,14 +49,14 @@ u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
                        if (retval > node->tree->max_key_len + 2) {
                                printk(KERN_ERR "hfs: keylen %d too large\n",
                                        retval);
-                               retval = HFS_BAD_KEYLEN;
+                               retval = 0;
                        }
                } else {
                        retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
                        if (retval > node->tree->max_key_len + 1) {
                                printk(KERN_ERR "hfs: keylen %d too large\n",
                                        retval);
-                               retval = HFS_BAD_KEYLEN;
+                               retval = 0;
                        }
                }
        }
index 110dd35..24cf6fc 100644 (file)
@@ -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;
index c6aae61..6f194d0 100644 (file)
@@ -28,8 +28,6 @@
 #define HFS_MAX_NAMELEN                128
 #define HFS_MAX_VALENCE                32767U
 
-#define HFS_BAD_KEYLEN         0xFF
-
 /* Meanings of the drAtrb field of the MDB,
  * Reference: _Inside Macintosh: Files_ p. 2-61
  */