lib/ext2fs/expanddir.c

   1 /*
   2  * expand.c --- expand an ext2fs directory
   3  *
   4  * Copyright (C) 1993, 1994, 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 #include <string.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17
  18 #if EXT2_FLAT_INCLUDES
  19 #include "ext2_fs.h"
  20 #else
  21 #include <linux/ext2_fs.h>
  22 #endif
  23
  24 #include "ext2fs.h"
  25
  26 struct expand_dir_struct {
  27         int     done;
  28         errcode_t       err;
  29 };
  30
  31 static int expand_dir_proc(ext2_filsys          fs,
  32                            blk_t                *blocknr,
  33                            e2_blkcnt_t          blockcnt,
  34                            blk_t                ref_block,
  35                            int                  ref_offset,
  36                            void                 *priv_data)
  37 {
  38         struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
  39         blk_t   new_blk;
  40         static blk_t    last_blk = 0;
  41         char            *block;
  42         errcode_t       retval;
  43         int             group;
  44
  45         if (*blocknr) {
  46                 last_blk = *blocknr;
  47                 return 0;
  48         }
  49         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
  50         if (retval) {
  51                 es->err = retval;
  52                 return BLOCK_ABORT;
  53         }
  54         if (blockcnt > 0) {
  55                 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
  56                 if (retval) {
  57                         es->err = retval;
  58                         return BLOCK_ABORT;
  59                 }
  60                 es->done = 1;
  61                 retval = ext2fs_write_dir_block(fs, new_blk, block);
  62         } else {
  63                 retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
  64                 if (retval) {
  65                         es->err = retval;
  66                         return BLOCK_ABORT;
  67                 }
  68                 memset(block, 0, fs->blocksize);
  69                 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
  70         }
  71         if (retval) {
  72                 es->err = retval;
  73                 return BLOCK_ABORT;
  74         }
  75         ext2fs_free_mem((void **) &block);
  76         *blocknr = new_blk;
  77         ext2fs_mark_block_bitmap(fs->block_map, new_blk);
  78         ext2fs_mark_bb_dirty(fs);
  79         group = ext2fs_group_of_blk(fs, new_blk);
  80         fs->group_desc[group].bg_free_blocks_count--;
  81         fs->super->s_free_blocks_count--;
  82         ext2fs_mark_super_dirty(fs);
  83         if (es->done)
  84                 return (BLOCK_CHANGED | BLOCK_ABORT);
  85         else
  86                 return BLOCK_CHANGED;
  87 }
  88
  89 errcode_t ext2fs_expand_dir(ext2_filsys fs, ino_t dir)
  90 {
  91         errcode_t       retval;
  92         struct expand_dir_struct es;
  93         struct ext2_inode       inode;
  94
  95         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  96
  97         if (!(fs->flags & EXT2_FLAG_RW))
  98                 return EXT2_ET_RO_FILSYS;
  99
 100         if (!fs->block_map)
 101                 return EXT2_ET_NO_BLOCK_BITMAP;
 102
 103         retval = ext2fs_check_directory(fs, dir);
 104         if (retval)
 105                 return retval;
 106
 107         es.done = 0;
 108         es.err = 0;
 109
 110         retval = ext2fs_block_iterate2(fs, dir, BLOCK_FLAG_APPEND,
 111                                        0, expand_dir_proc, &es);
 112
 113         if (es.err)
 114                 return es.err;
 115         if (!es.done)
 116                 return EXT2_ET_EXPAND_DIR_ERR;
 117
 118         /*
 119          * Update the size and block count fields in the inode.
 120          */
 121         retval = ext2fs_read_inode(fs, dir, &inode);
 122         if (retval)
 123                 return retval;
 124
 125         inode.i_size += fs->blocksize;
 126         inode.i_blocks += fs->blocksize / 512;
 127
 128         retval = ext2fs_write_inode(fs, dir, &inode);
 129         if (retval)
 130                 return retval;
 131
 132         return 0;
 133 }