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                            int  blockcnt,
  34                            void *priv_data)
  35 {
  36         struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
  37         blk_t   new_blk;
  38         static blk_t    last_blk = 0;
  39         char            *block;
  40         errcode_t       retval;
  41         int             group;
  42
  43         if (*blocknr) {
  44                 last_blk = *blocknr;
  45                 return 0;
  46         }
  47         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
  48         if (retval) {
  49                 es->err = retval;
  50                 return BLOCK_ABORT;
  51         }
  52         if (blockcnt > 0) {
  53                 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
  54                 if (retval) {
  55                         es->err = retval;
  56                         return BLOCK_ABORT;
  57                 }
  58                 es->done = 1;
  59                 retval = ext2fs_write_dir_block(fs, new_blk, block);
  60         } else {
  61                 retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
  62                 if (retval) {
  63                         es->err = retval;
  64                         return BLOCK_ABORT;
  65                 }
  66                 memset(block, 0, fs->blocksize);
  67                 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
  68         }
  69         if (retval) {
  70                 es->err = retval;
  71                 return BLOCK_ABORT;
  72         }
  73         ext2fs_free_mem((void **) &block);
  74         *blocknr = new_blk;
  75         ext2fs_mark_block_bitmap(fs->block_map, new_blk);
  76         ext2fs_mark_bb_dirty(fs);
  77         group = ext2fs_group_of_blk(fs, new_blk);
  78         fs->group_desc[group].bg_free_blocks_count--;
  79         fs->super->s_free_blocks_count--;
  80         ext2fs_mark_super_dirty(fs);
  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, 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
 108         retval = ext2fs_block_iterate(fs, dir, BLOCK_FLAG_APPEND,
 109                                       0, expand_dir_proc, &es);
 110
 111         if (es.err)
 112                 return es.err;
 113         if (!es.done)
 114                 return EXT2_ET_EXPAND_DIR_ERR;
 115
 116         /*
 117          * Update the size and block count fields in the inode.
 118          */
 119         retval = ext2fs_read_inode(fs, dir, &inode);
 120         if (retval)
 121                 return retval;
 122
 123         inode.i_size += fs->blocksize;
 124         inode.i_blocks += fs->blocksize / 512;
 125
 126         retval = ext2fs_write_inode(fs, dir, &inode);
 127         if (retval)
 128                 return retval;
 129
 130         return 0;
 131 }