e2fsck: allow to fix some superblock corruptions

[tools/e2fsprogs.git] / lib / ext2fs / check_desc.c

diff --git a/lib/ext2fs/check_desc.c b/lib/ext2fs/check_desc.c
index 602753d..3e3fa94 100644 (file)
--- a/lib/ext2fs/check_desc.c
+++ b/lib/ext2fs/check_desc.c
@@ -1,20 +1,20 @@
 /*
  * check_desc.c --- Check the group descriptors of an ext2 filesystem
- * 
+ *
  * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
  *
  * %Begin-Header%
- * This file may be redistributed under the terms of the GNU Public
- * License.
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
  * %End-Header%
  */
 
+#include "config.h"
 #include <stdio.h>
 #include <string.h>
 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif
-#include <stdlib.h>
 #include <fcntl.h>
 #include <time.h>
 #if HAVE_SYS_STAT_H
@@ -24,8 +24,7 @@
 #include <sys/types.h>
 #endif
 
-#include <linux/ext2_fs.h>
-
+#include "ext2_fs.h"
 #include "ext2fs.h"
 
 /*
@@ -33,38 +32,73 @@
  */
 errcode_t ext2fs_check_desc(ext2_filsys fs)
 {
-       int i;
-       blk_t block = fs->super->s_first_data_block;
-       blk_t next;
+       ext2fs_block_bitmap bmap;
+       errcode_t retval;
+       dgrp_t i;
+       blk64_t first_block = fs->super->s_first_data_block;
+       blk64_t last_block = ext2fs_blocks_count(fs->super)-1;
+       blk64_t blk, b;
+       unsigned int j;
 
        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 
+       if (EXT2_DESC_SIZE(fs->super) & (EXT2_DESC_SIZE(fs->super) - 1))
+               return EXT2_ET_BAD_DESC_SIZE;
+
+       retval = ext2fs_allocate_subcluster_bitmap(fs, "check_desc map", &bmap);
+       if (retval)
+               return retval;
+
+       for (i = 0; i < fs->group_desc_count; i++)
+               ext2fs_reserve_super_and_bgd(fs, i, bmap);
+
        for (i = 0; i < fs->group_desc_count; i++) {
-               next = block + fs->super->s_blocks_per_group;
+               if (!ext2fs_has_feature_flex_bg(fs->super)) {
+                       first_block = ext2fs_group_first_block2(fs, i);
+                       last_block = ext2fs_group_last_block2(fs, i);
+               }
+
                /*
-                * Check to make sure block bitmap for group is
-                * located within the group.
+                * Check to make sure the block bitmap for group is sane
                 */
-               if (fs->group_desc[i].bg_block_bitmap < block ||
-                   fs->group_desc[i].bg_block_bitmap >= next)
-                       return EXT2_ET_GDESC_BAD_BLOCK_MAP;
+               blk = ext2fs_block_bitmap_loc(fs, i);
+               if (blk < first_block || blk > last_block ||
+                   ext2fs_test_block_bitmap2(bmap, blk)) {
+                       retval = EXT2_ET_GDESC_BAD_BLOCK_MAP;
+                       goto errout;
+               }
+               ext2fs_mark_block_bitmap2(bmap, blk);
+
                /*
-                * Check to make sure inode bitmap for group is
-                * located within the group
+                * Check to make sure the inode bitmap for group is sane
                 */
-               if (fs->group_desc[i].bg_inode_bitmap < block ||
-                   fs->group_desc[i].bg_inode_bitmap >= next)
-                       return EXT2_ET_GDESC_BAD_INODE_MAP;
+               blk = ext2fs_inode_bitmap_loc(fs, i);
+               if (blk < first_block || blk > last_block ||
+                   ext2fs_test_block_bitmap2(bmap, blk)) {
+                       retval = EXT2_ET_GDESC_BAD_INODE_MAP;
+                       goto errout;
+               }
+               ext2fs_mark_block_bitmap2(bmap, blk);
+
                /*
-                * Check to make sure inode table for group is located
-                * within the group
+                * Check to make sure the inode table for group is sane
                 */
-               if (fs->group_desc[i].bg_inode_table < block ||
-                   ((fs->group_desc[i].bg_inode_table +
-                     fs->inode_blocks_per_group) >= next))
-                       return EXT2_ET_GDESC_BAD_INODE_TABLE;
-               
-               block = next;
+               blk = ext2fs_inode_table_loc(fs, i);
+               if (blk < first_block ||
+                   ((blk + fs->inode_blocks_per_group - 1) > last_block)) {
+                       retval = EXT2_ET_GDESC_BAD_INODE_TABLE;
+                       goto errout;
+               }
+               for (j = 0, b = blk; j < fs->inode_blocks_per_group;
+                    j++, b++) {
+                       if (ext2fs_test_block_bitmap2(bmap, b)) {
+                               retval = EXT2_ET_GDESC_BAD_INODE_TABLE;
+                               goto errout;
+                       }
+                       ext2fs_mark_block_bitmap2(bmap, b);
+               }
        }
-       return 0;
+errout:
+       ext2fs_free_block_bitmap(bmap);
+       return retval;
 }