lib/ext2fs/expanddir.c

   1 /*
   2  * expand.c --- expand an ext2fs directory
   3  *
   4  * Copyright (C) 1993 Theodore Ts'o.  This file may be redistributed
   5  * under the terms of the GNU Public License.
   6  */
   7
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <stdlib.h>
  12 #include <linux/fs.h>
  13 #include <linux/ext2_fs.h>
  14
  15 #include "ext2fs.h"
  16
  17 struct expand_dir_struct {
  18         int     done;
  19         errcode_t       err;
  20 };
  21
  22 static int expand_dir_proc(ext2_filsys fs,
  23                            blk_t        *blocknr,
  24                            int  blockcnt,
  25                            void *private)
  26 {
  27         struct expand_dir_struct *es = (struct expand_dir_struct *) private;
  28         blk_t   new_blk;
  29         static blk_t    last_blk = 0;
  30         char            *block;
  31         errcode_t       retval;
  32         int             group;
  33
  34         if (*blocknr) {
  35                 last_blk = *blocknr;
  36                 return 0;
  37         }
  38         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
  39         if (retval) {
  40                 es->err = retval;
  41                 return BLOCK_ABORT;
  42         }
  43         if (blockcnt > 0) {
  44                 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
  45                 if (retval) {
  46                         es->err = retval;
  47                         return BLOCK_ABORT;
  48                 }
  49                 es->done = 1;
  50         } else {
  51                 block = malloc(fs->blocksize);
  52                 if (!block) {
  53                         es->err = ENOMEM;
  54                         return BLOCK_ABORT;
  55                 }
  56                 memset(block, 0, fs->blocksize);
  57         }
  58         retval = io_channel_write_blk(fs->io, new_blk, 1, block);
  59         if (retval) {
  60                 es->err = retval;
  61                 return BLOCK_ABORT;
  62         }
  63         free(block);
  64         *blocknr = new_blk;
  65         ext2fs_mark_block_bitmap(fs, fs->block_map, new_blk);
  66         ext2fs_mark_bb_dirty(fs);
  67         group = ext2fs_group_of_blk(fs, new_blk);
  68         fs->group_desc[group].bg_free_blocks_count--;
  69         fs->super->s_free_blocks_count--;
  70         ext2fs_mark_super_dirty(fs);
  71         if (es->done)
  72                 return (BLOCK_CHANGED | BLOCK_ABORT);
  73         else
  74                 return BLOCK_CHANGED;
  75 }
  76
  77 errcode_t ext2fs_expand_dir(ext2_filsys fs, ino_t dir)
  78 {
  79         errcode_t       retval;
  80         struct expand_dir_struct es;
  81         struct ext2_inode       inode;
  82
  83         if (!(fs->flags & EXT2_FLAG_RW))
  84                 return EXT2_ET_RO_FILSYS;
  85
  86         retval = ext2fs_check_directory(fs, dir);
  87         if (retval)
  88                 return retval;
  89
  90         es.done = 0;
  91         es.err = 0;
  92
  93         retval = ext2fs_block_iterate(fs, dir, BLOCK_FLAG_APPEND,
  94                                       0, expand_dir_proc, &es);
  95
  96         if (es.err)
  97                 return es.err;
  98         if (!es.done)
  99                 return EXT2_ET_EXPAND_DIR_ERR;
 100
 101         /*
 102          * Update the size and block count fields in the inode.
 103          */
 104         retval = ext2fs_read_inode(fs, dir, &inode);
 105         if (retval)
 106                 return retval;
 107
 108         inode.i_size += fs->blocksize;
 109         inode.i_blocks += fs->blocksize / 512;
 110
 111         retval = ext2fs_write_inode(fs, dir, &inode);
 112         if (retval)
 113                 return retval;
 114
 115         return 0;
 116 }