lib/ext2fs/dirblock.c

   1 /*
   2  * dirblock.c --- directory block routines.
   3  *
   4  * Copyright (C) 1995, 1996 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #include <stdio.h>
  13 #if HAVE_UNISTD_H
  14 #include <unistd.h>
  15 #endif
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <time.h>
  19 #ifdef HAVE_ERRNO_H
  20 #include <errno.h>
  21 #endif
  22
  23 #include <linux/ext2_fs.h>
  24
  25 #include "ext2fs.h"
  26
  27 errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block,
  28                                 void *buf)
  29 {
  30         errcode_t       retval;
  31         char            *p, *end;
  32         struct ext2_dir_entry *dirent;
  33
  34         retval = io_channel_read_blk(fs->io, block, 1, buf);
  35         if (retval)
  36                 return retval;
  37         if ((fs->flags & (EXT2_FLAG_SWAP_BYTES|
  38                           EXT2_FLAG_SWAP_BYTES_READ)) == 0)
  39                 return 0;
  40         p = buf;
  41         end = (char *) buf + fs->blocksize;
  42         while (p < end) {
  43                 dirent = (struct ext2_dir_entry *) p;
  44                 dirent->inode = ext2fs_swab32(dirent->inode);
  45                 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
  46                 dirent->name_len = ext2fs_swab16(dirent->name_len);
  47                 p += (dirent->rec_len < 8) ? 8 : dirent->rec_len;
  48         }
  49         return 0;
  50 }
  51
  52 errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block,
  53                                  void *inbuf)
  54 {
  55         errcode_t       retval;
  56         char            *p, *end, *write_buf;
  57         char            *buf = 0;
  58         struct ext2_dir_entry *dirent;
  59
  60         if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
  61             (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)) {
  62                 write_buf = buf = malloc(fs->blocksize);
  63                 if (!buf)
  64                         return ENOMEM;
  65                 memcpy(buf, inbuf, fs->blocksize);
  66                 p = buf;
  67                 end = buf + fs->blocksize;
  68                 while (p < end) {
  69                         dirent = (struct ext2_dir_entry *) p;
  70                         p += (dirent->rec_len < 8) ? 8 : dirent->rec_len;
  71                         dirent->inode = ext2fs_swab32(dirent->inode);
  72                         dirent->rec_len = ext2fs_swab16(dirent->rec_len);
  73                         dirent->name_len = ext2fs_swab16(dirent->name_len);
  74                 }
  75         } else
  76                 write_buf = inbuf;
  77         retval = io_channel_write_blk(fs->io, block, 1, write_buf);
  78         if (buf)
  79                 free(buf);
  80         return retval;
  81 }
  82
  83