lib/ext2fs/brel_ma.c

   1 /*
   2  * brel_ma.c
   3  *
   4  * Copyright (C) 1996, 1997 Theodore Ts'o.
   5  *
   6  * TODO: rewrite to not use a direct array!!!  (Fortunately this
   7  * module isn't really used yet.)
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Library
  11  * General Public License, version 2.
  12  * %End-Header%
  13  */
  14
  15 #include <fcntl.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #if HAVE_UNISTD_H
  19 #include <unistd.h>
  20 #endif
  21 #if HAVE_ERRNO_H
  22 #include <errno.h>
  23 #endif
  24
  25 #include "ext2_fs.h"
  26 #include "ext2fs.h"
  27 #include "brel.h"
  28
  29 static errcode_t bma_put(ext2_brel brel, blk_t old,
  30                         struct ext2_block_relocate_entry *ent);
  31 static errcode_t bma_get(ext2_brel brel, blk_t old,
  32                         struct ext2_block_relocate_entry *ent);
  33 static errcode_t bma_start_iter(ext2_brel brel);
  34 static errcode_t bma_next(ext2_brel brel, blk_t *old,
  35                          struct ext2_block_relocate_entry *ent);
  36 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new);
  37 static errcode_t bma_delete(ext2_brel brel, blk_t old);
  38 static errcode_t bma_free(ext2_brel brel);
  39
  40 struct brel_ma {
  41         __u32 magic;
  42         blk_t max_block;
  43         struct ext2_block_relocate_entry *entries;
  44 };
  45
  46 errcode_t ext2fs_brel_memarray_create(char *name, blk_t max_block,
  47                                       ext2_brel *new_brel)
  48 {
  49         ext2_brel               brel = 0;
  50         errcode_t       retval;
  51         struct brel_ma  *ma = 0;
  52         size_t          size;
  53
  54         *new_brel = 0;
  55
  56         /*
  57          * Allocate memory structures
  58          */
  59         retval = ext2fs_get_mem(sizeof(struct ext2_block_relocation_table),
  60                                 &brel);
  61         if (retval)
  62                 goto errout;
  63         memset(brel, 0, sizeof(struct ext2_block_relocation_table));
  64
  65         retval = ext2fs_get_mem(strlen(name)+1, &brel->name);
  66         if (retval)
  67                 goto errout;
  68         strcpy(brel->name, name);
  69
  70         retval = ext2fs_get_mem(sizeof(struct brel_ma), &ma);
  71         if (retval)
  72                 goto errout;
  73         memset(ma, 0, sizeof(struct brel_ma));
  74         brel->priv_data = ma;
  75
  76         size = (size_t) (sizeof(struct ext2_block_relocate_entry) *
  77                          (max_block+1));
  78         retval = ext2fs_get_array(max_block+1,
  79                 sizeof(struct ext2_block_relocate_entry), &ma->entries);
  80         if (retval)
  81                 goto errout;
  82         memset(ma->entries, 0, size);
  83         ma->max_block = max_block;
  84
  85         /*
  86          * Fill in the brel data structure
  87          */
  88         brel->put = bma_put;
  89         brel->get = bma_get;
  90         brel->start_iter = bma_start_iter;
  91         brel->next = bma_next;
  92         brel->move = bma_move;
  93         brel->delete = bma_delete;
  94         brel->free = bma_free;
  95
  96         *new_brel = brel;
  97         return 0;
  98
  99 errout:
 100         bma_free(brel);
 101         return retval;
 102 }
 103
 104 static errcode_t bma_put(ext2_brel brel, blk_t old,
 105                         struct ext2_block_relocate_entry *ent)
 106 {
 107         struct brel_ma  *ma;
 108
 109         ma = brel->priv_data;
 110         if (old > ma->max_block)
 111                 return EXT2_ET_INVALID_ARGUMENT;
 112         ma->entries[(unsigned)old] = *ent;
 113         return 0;
 114 }
 115
 116 static errcode_t bma_get(ext2_brel brel, blk_t old,
 117                         struct ext2_block_relocate_entry *ent)
 118 {
 119         struct brel_ma  *ma;
 120
 121         ma = brel->priv_data;
 122         if (old > ma->max_block)
 123                 return EXT2_ET_INVALID_ARGUMENT;
 124         if (ma->entries[(unsigned)old].new == 0)
 125                 return ENOENT;
 126         *ent = ma->entries[old];
 127         return 0;
 128 }
 129
 130 static errcode_t bma_start_iter(ext2_brel brel)
 131 {
 132         brel->current = 0;
 133         return 0;
 134 }
 135
 136 static errcode_t bma_next(ext2_brel brel, blk_t *old,
 137                           struct ext2_block_relocate_entry *ent)
 138 {
 139         struct brel_ma  *ma;
 140
 141         ma = brel->priv_data;
 142         while (++brel->current < ma->max_block) {
 143                 if (ma->entries[(unsigned)brel->current].new == 0)
 144                         continue;
 145                 *old = brel->current;
 146                 *ent = ma->entries[(unsigned)brel->current];
 147                 return 0;
 148         }
 149         *old = 0;
 150         return 0;
 151 }
 152
 153 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new)
 154 {
 155         struct brel_ma  *ma;
 156
 157         ma = brel->priv_data;
 158         if ((old > ma->max_block) || (new > ma->max_block))
 159                 return EXT2_ET_INVALID_ARGUMENT;
 160         if (ma->entries[(unsigned)old].new == 0)
 161                 return ENOENT;
 162         ma->entries[(unsigned)new] = ma->entries[old];
 163         ma->entries[(unsigned)old].new = 0;
 164         return 0;
 165 }
 166
 167 static errcode_t bma_delete(ext2_brel brel, blk_t old)
 168 {
 169         struct brel_ma  *ma;
 170
 171         ma = brel->priv_data;
 172         if (old > ma->max_block)
 173                 return EXT2_ET_INVALID_ARGUMENT;
 174         if (ma->entries[(unsigned)old].new == 0)
 175                 return ENOENT;
 176         ma->entries[(unsigned)old].new = 0;
 177         return 0;
 178 }
 179
 180 static errcode_t bma_free(ext2_brel brel)
 181 {
 182         struct brel_ma  *ma;
 183
 184         if (!brel)
 185                 return 0;
 186
 187         ma = brel->priv_data;
 188
 189         if (ma) {
 190                 if (ma->entries)
 191                         ext2fs_free_mem(&ma->entries);
 192                 ext2fs_free_mem(&ma);
 193         }
 194         if (brel->name)
 195                 ext2fs_free_mem(&brel->name);
 196         ext2fs_free_mem(&brel);
 197         return 0;
 198 }