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 Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #include <string.h>
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18
  19 #include "ext2_fs.h"
  20 #include "ext2fs.h"
  21
  22 struct expand_dir_struct {
  23         int             done;
  24         int             newblocks;
  25         blk64_t         goal;
  26         errcode_t       err;
  27 };
  28
  29 static int expand_dir_proc(ext2_filsys  fs,
  30                            blk64_t      *blocknr,
  31                            e2_blkcnt_t  blockcnt,
  32                            blk64_t      ref_block EXT2FS_ATTR((unused)),
  33                            int          ref_offset EXT2FS_ATTR((unused)),
  34                            void         *priv_data)
  35 {
  36         struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
  37         blk64_t new_blk;
  38         char            *block;
  39         errcode_t       retval;
  40
  41         if (*blocknr) {
  42                 if (blockcnt >= 0)
  43                         es->goal = *blocknr;
  44                 return 0;
  45         }
  46         if (blockcnt &&
  47             (EXT2FS_B2C(fs, es->goal) == EXT2FS_B2C(fs, es->goal+1)))
  48                 new_blk = es->goal+1;
  49         else {
  50                 es->goal &= ~EXT2FS_CLUSTER_MASK(fs);
  51                 retval = ext2fs_new_block2(fs, es->goal, 0, &new_blk);
  52                 if (retval) {
  53                         es->err = retval;
  54                         return BLOCK_ABORT;
  55                 }
  56                 es->newblocks++;
  57         }
  58         if (blockcnt > 0) {
  59                 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
  60                 if (retval) {
  61                         es->err = retval;
  62                         return BLOCK_ABORT;
  63                 }
  64                 es->done = 1;
  65                 retval = ext2fs_write_dir_block(fs, new_blk, block);
  66         } else {
  67                 retval = ext2fs_get_mem(fs->blocksize, &block);
  68                 if (retval) {
  69                         es->err = retval;
  70                         return BLOCK_ABORT;
  71                 }
  72                 memset(block, 0, fs->blocksize);
  73                 retval = io_channel_write_blk64(fs->io, new_blk, 1, block);
  74         }
  75         if (blockcnt >= 0)
  76                 es->goal = new_blk;
  77         if (retval) {
  78                 es->err = retval;
  79                 return BLOCK_ABORT;
  80         }
  81         ext2fs_free_mem(&block);
  82         *blocknr = new_blk;
  83         ext2fs_block_alloc_stats2(fs, new_blk, +1);
  84
  85         if (es->done)
  86                 return (BLOCK_CHANGED | BLOCK_ABORT);
  87         else
  88                 return BLOCK_CHANGED;
  89 }
  90
  91 errcode_t ext2fs_expand_dir(ext2_filsys fs, ext2_ino_t dir)
  92 {
  93         errcode_t       retval;
  94         struct expand_dir_struct es;
  95         struct ext2_inode       inode;
  96
  97         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  98
  99         if (!(fs->flags & EXT2_FLAG_RW))
 100                 return EXT2_ET_RO_FILSYS;
 101
 102         if (!fs->block_map)
 103                 return EXT2_ET_NO_BLOCK_BITMAP;
 104
 105         retval = ext2fs_check_directory(fs, dir);
 106         if (retval)
 107                 return retval;
 108
 109         es.done = 0;
 110         es.err = 0;
 111         es.goal = 0;
 112         es.newblocks = 0;
 113
 114         retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_APPEND,
 115                                        0, expand_dir_proc, &es);
 116
 117         if (es.err)
 118                 return es.err;
 119         if (!es.done)
 120                 return EXT2_ET_EXPAND_DIR_ERR;
 121
 122         /*
 123          * Update the size and block count fields in the inode.
 124          */
 125         retval = ext2fs_read_inode(fs, dir, &inode);
 126         if (retval)
 127                 return retval;
 128
 129         inode.i_size += fs->blocksize;
 130         ext2fs_iblk_add_blocks(fs, &inode, es.newblocks);
 131
 132         retval = ext2fs_write_inode(fs, dir, &inode);
 133         if (retval)
 134                 return retval;
 135
 136         return 0;
 137 }