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 EXT2FS_ATTR((unused)),
  31                            int          ref_offset EXT2FS_ATTR((unused)),
  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
  40         if (*blocknr) {
  41                 last_blk = *blocknr;
  42                 return 0;
  43         }
  44         retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
  45         if (retval) {
  46                 es->err = retval;
  47                 return BLOCK_ABORT;
  48         }
  49         if (blockcnt > 0) {
  50                 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
  51                 if (retval) {
  52                         es->err = retval;
  53                         return BLOCK_ABORT;
  54                 }
  55                 es->done = 1;
  56                 retval = ext2fs_write_dir_block(fs, new_blk, block);
  57         } else {
  58                 retval = ext2fs_get_mem(fs->blocksize, &block);
  59                 if (retval) {
  60                         es->err = retval;
  61                         return BLOCK_ABORT;
  62                 }
  63                 memset(block, 0, fs->blocksize);
  64                 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
  65         }
  66         if (retval) {
  67                 es->err = retval;
  68                 return BLOCK_ABORT;
  69         }
  70         ext2fs_free_mem(&block);
  71         *blocknr = new_blk;
  72         ext2fs_block_alloc_stats(fs, new_blk, +1);
  73         es->newblocks++;
  74
  75         if (es->done)
  76                 return (BLOCK_CHANGED | BLOCK_ABORT);
  77         else
  78                 return BLOCK_CHANGED;
  79 }
  80
  81 errcode_t ext2fs_expand_dir(ext2_filsys fs, ext2_ino_t dir)
  82 {
  83         errcode_t       retval;
  84         struct expand_dir_struct es;
  85         struct ext2_inode       inode;
  86
  87         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  88
  89         if (!(fs->flags & EXT2_FLAG_RW))
  90                 return EXT2_ET_RO_FILSYS;
  91
  92         if (!fs->block_map)
  93                 return EXT2_ET_NO_BLOCK_BITMAP;
  94
  95         retval = ext2fs_check_directory(fs, dir);
  96         if (retval)
  97                 return retval;
  98
  99         es.done = 0;
 100         es.err = 0;
 101         es.newblocks = 0;
 102
 103         retval = ext2fs_block_iterate2(fs, dir, BLOCK_FLAG_APPEND,
 104                                        0, expand_dir_proc, &es);
 105
 106         if (es.err)
 107                 return es.err;
 108         if (!es.done)
 109                 return EXT2_ET_EXPAND_DIR_ERR;
 110
 111         /*
 112          * Update the size and block count fields in the inode.
 113          */
 114         retval = ext2fs_read_inode(fs, dir, &inode);
 115         if (retval)
 116                 return retval;
 117
 118         inode.i_size += fs->blocksize;
 119         inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
 120
 121         retval = ext2fs_write_inode(fs, dir, &inode);
 122         if (retval)
 123                 return retval;
 124
 125         return 0;
 126 }