lib/ext2fs/expanddir.c

   1 /*
   2  * expand.c --- expand an ext2fs directory
   3  *
   4  * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999  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 #include "ext2_fs.h"
  19 #include "ext2fs.h"
  20
  21 struct expand_dir_struct {
  22         int             done;
  23         int             newblocks;
  24         errcode_t       err;
  25 };
  26
  27 static int expand_dir_proc(ext2_filsys          fs,
  28                            blk_t                *blocknr,
  29                            e2_blkcnt_t          blockcnt,
  30                            blk_t                ref_block,
  31                            int                  ref_offset,
  32                            void                 *priv_data)
  33 {
  34         struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
  35         blk_t   new_blk;
  36         static blk_t    last_blk = 0;
  37         char            *block;
  38         errcode_t       retval;
  39         int             group;
  40
  41         if (*blocknr) {
  42                 last_blk = *blocknr;
  43                 return 0;
  44         }
  45         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
  46         if (retval) {
  47                 es->err = retval;
  48                 return BLOCK_ABORT;
  49         }
  50         if (blockcnt > 0) {
  51                 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
  52                 if (retval) {
  53                         es->err = retval;
  54                         return BLOCK_ABORT;
  55                 }
  56                 es->done = 1;
  57                 retval = ext2fs_write_dir_block(fs, new_blk, block);
  58         } else {
  59                 retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
  60                 if (retval) {
  61                         es->err = retval;
  62                         return BLOCK_ABORT;
  63                 }
  64                 memset(block, 0, fs->blocksize);
  65                 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
  66         }
  67         if (retval) {
  68                 es->err = retval;
  69                 return BLOCK_ABORT;
  70         }
  71         ext2fs_free_mem((void **) &block);
  72         *blocknr = new_blk;
  73         ext2fs_mark_block_bitmap(fs->block_map, new_blk);
  74         ext2fs_mark_bb_dirty(fs);
  75         group = ext2fs_group_of_blk(fs, new_blk);
  76         fs->group_desc[group].bg_free_blocks_count--;
  77         fs->super->s_free_blocks_count--;
  78         ext2fs_mark_super_dirty(fs);
  79         es->newblocks++;
  80
  81         if (es->done)
  82                 return (BLOCK_CHANGED | BLOCK_ABORT);
  83         else
  84                 return BLOCK_CHANGED;
  85 }
  86
  87 errcode_t ext2fs_expand_dir(ext2_filsys fs, ext2_ino_t dir)
  88 {
  89         errcode_t       retval;
  90         struct expand_dir_struct es;
  91         struct ext2_inode       inode;
  92
  93         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  94
  95         if (!(fs->flags & EXT2_FLAG_RW))
  96                 return EXT2_ET_RO_FILSYS;
  97
  98         if (!fs->block_map)
  99                 return EXT2_ET_NO_BLOCK_BITMAP;
 100
 101         retval = ext2fs_check_directory(fs, dir);
 102         if (retval)
 103                 return retval;
 104
 105         es.done = 0;
 106         es.err = 0;
 107         es.newblocks = 0;
 108
 109         retval = ext2fs_block_iterate2(fs, dir, BLOCK_FLAG_APPEND,
 110                                        0, expand_dir_proc, &es);
 111
 112         if (es.err)
 113                 return es.err;
 114         if (!es.done)
 115                 return EXT2_ET_EXPAND_DIR_ERR;
 116
 117         /*
 118          * Update the size and block count fields in the inode.
 119          */
 120         retval = ext2fs_read_inode(fs, dir, &inode);
 121         if (retval)
 122                 return retval;
 123
 124         inode.i_size += fs->blocksize;
 125         inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
 126
 127         retval = ext2fs_write_inode(fs, dir, &inode);
 128         if (retval)
 129                 return retval;
 130
 131         return 0;
 132 }