lib/ext2fs/newdir.c

   1 /*
   2  * newdir.c --- create a new directory block
   3  *
   4  * Copyright (C) 1994, 1995 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #include <string.h>
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18
  19 #include "ext2_fs.h"
  20 #include "ext2fs.h"
  21
  22 #ifndef EXT2_FT_DIR
  23 #define EXT2_FT_DIR             2
  24 #endif
  25
  26 /*
  27  * Create new directory block
  28  */
  29 errcode_t ext2fs_new_dir_block(ext2_filsys fs, ext2_ino_t dir_ino,
  30                                ext2_ino_t parent_ino, char **block)
  31 {
  32         struct ext2_dir_entry   *dir = NULL;
  33         errcode_t               retval;
  34         char                    *buf;
  35         int                     rec_len;
  36         int                     filetype = 0;
  37         struct ext2_dir_entry_tail      *t;
  38         int                     csum_size = 0;
  39
  40         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  41
  42         retval = ext2fs_get_mem(fs->blocksize, &buf);
  43         if (retval)
  44                 return retval;
  45         memset(buf, 0, fs->blocksize);
  46         dir = (struct ext2_dir_entry *) buf;
  47
  48         if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
  49                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
  50                 csum_size = sizeof(struct ext2_dir_entry_tail);
  51
  52         retval = ext2fs_set_rec_len(fs, fs->blocksize - csum_size, dir);
  53         if (retval)
  54                 return retval;
  55
  56         if (dir_ino) {
  57                 if (fs->super->s_feature_incompat &
  58                     EXT2_FEATURE_INCOMPAT_FILETYPE)
  59                         filetype = EXT2_FT_DIR << 8;
  60                 /*
  61                  * Set up entry for '.'
  62                  */
  63                 dir->inode = dir_ino;
  64                 dir->name_len = 1 | filetype;
  65                 dir->name[0] = '.';
  66                 rec_len = (fs->blocksize - csum_size) - EXT2_DIR_REC_LEN(1);
  67                 dir->rec_len = EXT2_DIR_REC_LEN(1);
  68
  69                 /*
  70                  * Set up entry for '..'
  71                  */
  72                 dir = (struct ext2_dir_entry *) (buf + dir->rec_len);
  73                 retval = ext2fs_set_rec_len(fs, rec_len, dir);
  74                 if (retval)
  75                         return retval;
  76                 dir->inode = parent_ino;
  77                 dir->name_len = 2 | filetype;
  78                 dir->name[0] = '.';
  79                 dir->name[1] = '.';
  80
  81         }
  82
  83         if (csum_size) {
  84                 t = EXT2_DIRENT_TAIL(buf, fs->blocksize);
  85                 ext2fs_initialize_dirent_tail(fs, t);
  86         }
  87         *block = buf;
  88         return 0;
  89 }