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 Public
  11  * License.
  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                                 (void **) &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, (void **) &brel->name);
  66         if (retval)
  67                 goto errout;
  68         strcpy(brel->name, name);
  69
  70         retval = ext2fs_get_mem(sizeof(struct brel_ma), (void **) &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_mem(size, (void **) &ma->entries);
  79         if (retval)
  80                 goto errout;
  81         memset(ma->entries, 0, size);
  82         ma->max_block = max_block;
  83
  84         /*
  85          * Fill in the brel data structure
  86          */
  87         brel->put = bma_put;
  88         brel->get = bma_get;
  89         brel->start_iter = bma_start_iter;
  90         brel->next = bma_next;
  91         brel->move = bma_move;
  92         brel->delete = bma_delete;
  93         brel->free = bma_free;
  94
  95         *new_brel = brel;
  96         return 0;
  97
  98 errout:
  99         bma_free(brel);
 100         return retval;
 101 }
 102
 103 static errcode_t bma_put(ext2_brel brel, blk_t old,
 104                         struct ext2_block_relocate_entry *ent)
 105 {
 106         struct brel_ma  *ma;
 107
 108         ma = brel->priv_data;
 109         if (old > ma->max_block)
 110                 return EXT2_ET_INVALID_ARGUMENT;
 111         ma->entries[(unsigned)old] = *ent;
 112         return 0;
 113 }
 114
 115 static errcode_t bma_get(ext2_brel brel, blk_t old,
 116                         struct ext2_block_relocate_entry *ent)
 117 {
 118         struct brel_ma  *ma;
 119
 120         ma = brel->priv_data;
 121         if (old > ma->max_block)
 122                 return EXT2_ET_INVALID_ARGUMENT;
 123         if (ma->entries[(unsigned)old].new == 0)
 124                 return ENOENT;
 125         *ent = ma->entries[old];
 126         return 0;
 127 }
 128
 129 static errcode_t bma_start_iter(ext2_brel brel)
 130 {
 131         brel->current = 0;
 132         return 0;
 133 }
 134
 135 static errcode_t bma_next(ext2_brel brel, blk_t *old,
 136                           struct ext2_block_relocate_entry *ent)
 137 {
 138         struct brel_ma  *ma;
 139
 140         ma = brel->priv_data;
 141         while (++brel->current < ma->max_block) {
 142                 if (ma->entries[(unsigned)brel->current].new == 0)
 143                         continue;
 144                 *old = brel->current;
 145                 *ent = ma->entries[(unsigned)brel->current];
 146                 return 0;
 147         }
 148         *old = 0;
 149         return 0;
 150 }
 151
 152 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new)
 153 {
 154         struct brel_ma  *ma;
 155
 156         ma = brel->priv_data;
 157         if ((old > ma->max_block) || (new > ma->max_block))
 158                 return EXT2_ET_INVALID_ARGUMENT;
 159         if (ma->entries[(unsigned)old].new == 0)
 160                 return ENOENT;
 161         ma->entries[(unsigned)new] = ma->entries[old];
 162         ma->entries[(unsigned)old].new = 0;
 163         return 0;
 164 }
 165
 166 static errcode_t bma_delete(ext2_brel brel, blk_t old)
 167 {
 168         struct brel_ma  *ma;
 169
 170         ma = brel->priv_data;
 171         if (old > ma->max_block)
 172                 return EXT2_ET_INVALID_ARGUMENT;
 173         if (ma->entries[(unsigned)old].new == 0)
 174                 return ENOENT;
 175         ma->entries[(unsigned)old].new = 0;
 176         return 0;
 177 }
 178
 179 static errcode_t bma_free(ext2_brel brel)
 180 {
 181         struct brel_ma  *ma;
 182
 183         if (!brel)
 184                 return 0;
 185
 186         ma = brel->priv_data;
 187
 188         if (ma) {
 189                 if (ma->entries)
 190                         ext2fs_free_mem((void **) &ma->entries);
 191                 ext2fs_free_mem((void **) &ma);
 192         }
 193         if (brel->name)
 194                 ext2fs_free_mem((void **) &brel->name);
 195         ext2fs_free_mem((void **) &brel);
 196         return 0;
 197 }