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 #include "ext2fsP.h"
  22
  23 struct expand_dir_struct {
  24         int             done;
  25         int             newblocks;
  26         blk64_t         goal;
  27         errcode_t       err;
  28         ext2_ino_t      dir;
  29 };
  30
  31 static int expand_dir_proc(ext2_filsys  fs,
  32                            blk64_t      *blocknr,
  33                            e2_blkcnt_t  blockcnt,
  34                            blk64_t      ref_block EXT2FS_ATTR((unused)),
  35                            int          ref_offset EXT2FS_ATTR((unused)),
  36                            void         *priv_data)
  37 {
  38         struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
  39         blk64_t new_blk;
  40         char            *block;
  41         errcode_t       retval;
  42
  43         if (*blocknr) {
  44                 if (blockcnt >= 0)
  45                         es->goal = *blocknr;
  46                 return 0;
  47         }
  48         if (blockcnt &&
  49             (EXT2FS_B2C(fs, es->goal) == EXT2FS_B2C(fs, es->goal+1)))
  50                 new_blk = es->goal+1;
  51         else {
  52                 es->goal &= ~EXT2FS_CLUSTER_MASK(fs);
  53                 retval = ext2fs_new_block2(fs, es->goal, 0, &new_blk);
  54                 if (retval) {
  55                         es->err = retval;
  56                         return BLOCK_ABORT;
  57                 }
  58                 es->newblocks++;
  59                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
  60         }
  61         if (blockcnt > 0) {
  62                 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
  63                 if (retval) {
  64                         es->err = retval;
  65                         return BLOCK_ABORT;
  66                 }
  67                 es->done = 1;
  68                 retval = ext2fs_write_dir_block4(fs, new_blk, block, 0,
  69                                                  es->dir);
  70                 ext2fs_free_mem(&block);
  71         } else
  72                 retval = ext2fs_zero_blocks2(fs, new_blk, 1, NULL, NULL);
  73         if (blockcnt >= 0)
  74                 es->goal = new_blk;
  75         if (retval) {
  76                 es->err = retval;
  77                 return BLOCK_ABORT;
  78         }
  79         *blocknr = new_blk;
  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         retval = ext2fs_read_inode(fs, dir, &inode);
 106         if (retval)
 107                 return retval;
 108
 109         es.done = 0;
 110         es.err = 0;
 111         es.goal = ext2fs_find_inode_goal(fs, dir, &inode, 0);
 112         es.newblocks = 0;
 113         es.dir = dir;
 114
 115         retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_APPEND,
 116                                        0, expand_dir_proc, &es);
 117         if (retval == EXT2_ET_INLINE_DATA_CANT_ITERATE)
 118                 return ext2fs_inline_data_expand(fs, dir);
 119
 120         if (es.err)
 121                 return es.err;
 122         if (!es.done)
 123                 return EXT2_ET_EXPAND_DIR_ERR;
 124
 125         /*
 126          * Update the size and block count fields in the inode.
 127          */
 128         retval = ext2fs_read_inode(fs, dir, &inode);
 129         if (retval)
 130                 return retval;
 131
 132         inode.i_size += fs->blocksize;
 133         ext2fs_iblk_add_blocks(fs, &inode, es.newblocks);
 134
 135         retval = ext2fs_write_inode(fs, dir, &inode);
 136         if (retval)
 137                 return retval;
 138
 139         return 0;
 140 }