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 #if EXT2_FLAT_INCLUDES
  26 #include "ext2_fs.h"
  27 #else
  28 #include <linux/ext2_fs.h>
  29 #endif
  30
  31 #include "ext2fs.h"
  32 #include "brel.h"
  33
  34 static errcode_t bma_put(ext2_brel brel, blk_t old,
  35                         struct ext2_block_relocate_entry *ent);
  36 static errcode_t bma_get(ext2_brel brel, blk_t old,
  37                         struct ext2_block_relocate_entry *ent);
  38 static errcode_t bma_start_iter(ext2_brel brel);
  39 static errcode_t bma_next(ext2_brel brel, blk_t *old,
  40                          struct ext2_block_relocate_entry *ent);
  41 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new);
  42 static errcode_t bma_delete(ext2_brel brel, blk_t old);
  43 static errcode_t bma_free(ext2_brel brel);
  44
  45 struct brel_ma {
  46         __u32 magic;
  47         blk_t max_block;
  48         struct ext2_block_relocate_entry *entries;
  49 };
  50
  51 errcode_t ext2fs_brel_memarray_create(char *name, blk_t max_block,
  52                                       ext2_brel *new_brel)
  53 {
  54         ext2_brel               brel = 0;
  55         errcode_t       retval;
  56         struct brel_ma  *ma = 0;
  57         size_t          size;
  58
  59         *new_brel = 0;
  60
  61         /*
  62          * Allocate memory structures
  63          */
  64         retval = ext2fs_get_mem(sizeof(struct ext2_block_relocation_table),
  65                                 (void **) &brel);
  66         if (retval)
  67                 goto errout;
  68         memset(brel, 0, sizeof(struct ext2_block_relocation_table));
  69
  70         retval = ext2fs_get_mem(strlen(name)+1, (void **) &brel->name);
  71         if (retval)
  72                 goto errout;
  73         strcpy(brel->name, name);
  74
  75         retval = ext2fs_get_mem(sizeof(struct brel_ma), (void **) &ma);
  76         if (retval)
  77                 goto errout;
  78         memset(ma, 0, sizeof(struct brel_ma));
  79         brel->priv_data = ma;
  80
  81         size = (size_t) (sizeof(struct ext2_block_relocate_entry) *
  82                          (max_block+1));
  83         retval = ext2fs_get_mem(size, (void **) &ma->entries);
  84         if (retval)
  85                 goto errout;
  86         memset(ma->entries, 0, size);
  87         ma->max_block = max_block;
  88
  89         /*
  90          * Fill in the brel data structure
  91          */
  92         brel->put = bma_put;
  93         brel->get = bma_get;
  94         brel->start_iter = bma_start_iter;
  95         brel->next = bma_next;
  96         brel->move = bma_move;
  97         brel->delete = bma_delete;
  98         brel->free = bma_free;
  99
 100         *new_brel = brel;
 101         return 0;
 102
 103 errout:
 104         bma_free(brel);
 105         return retval;
 106 }
 107
 108 static errcode_t bma_put(ext2_brel brel, blk_t old,
 109                         struct ext2_block_relocate_entry *ent)
 110 {
 111         struct brel_ma  *ma;
 112
 113         ma = brel->priv_data;
 114         if (old > ma->max_block)
 115                 return EXT2_ET_INVALID_ARGUMENT;
 116         ma->entries[(unsigned)old] = *ent;
 117         return 0;
 118 }
 119
 120 static errcode_t bma_get(ext2_brel brel, blk_t old,
 121                         struct ext2_block_relocate_entry *ent)
 122 {
 123         struct brel_ma  *ma;
 124
 125         ma = brel->priv_data;
 126         if (old > ma->max_block)
 127                 return EXT2_ET_INVALID_ARGUMENT;
 128         if (ma->entries[(unsigned)old].new == 0)
 129                 return ENOENT;
 130         *ent = ma->entries[old];
 131         return 0;
 132 }
 133
 134 static errcode_t bma_start_iter(ext2_brel brel)
 135 {
 136         brel->current = 0;
 137         return 0;
 138 }
 139
 140 static errcode_t bma_next(ext2_brel brel, blk_t *old,
 141                           struct ext2_block_relocate_entry *ent)
 142 {
 143         struct brel_ma  *ma;
 144
 145         ma = brel->priv_data;
 146         while (++brel->current < ma->max_block) {
 147                 if (ma->entries[(unsigned)brel->current].new == 0)
 148                         continue;
 149                 *old = brel->current;
 150                 *ent = ma->entries[(unsigned)brel->current];
 151                 return 0;
 152         }
 153         *old = 0;
 154         return 0;
 155 }
 156
 157 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new)
 158 {
 159         struct brel_ma  *ma;
 160
 161         ma = brel->priv_data;
 162         if ((old > ma->max_block) || (new > ma->max_block))
 163                 return EXT2_ET_INVALID_ARGUMENT;
 164         if (ma->entries[(unsigned)old].new == 0)
 165                 return ENOENT;
 166         ma->entries[(unsigned)new] = ma->entries[old];
 167         ma->entries[(unsigned)old].new = 0;
 168         return 0;
 169 }
 170
 171 static errcode_t bma_delete(ext2_brel brel, blk_t old)
 172 {
 173         struct brel_ma  *ma;
 174
 175         ma = brel->priv_data;
 176         if (old > ma->max_block)
 177                 return EXT2_ET_INVALID_ARGUMENT;
 178         if (ma->entries[(unsigned)old].new == 0)
 179                 return ENOENT;
 180         ma->entries[(unsigned)old].new = 0;
 181         return 0;
 182 }
 183
 184 static errcode_t bma_free(ext2_brel brel)
 185 {
 186         struct brel_ma  *ma;
 187
 188         if (!brel)
 189                 return 0;
 190
 191         ma = brel->priv_data;
 192
 193         if (ma) {
 194                 if (ma->entries)
 195                         ext2fs_free_mem((void **) &ma->entries);
 196                 ext2fs_free_mem((void **) &ma);
 197         }
 198         if (brel->name)
 199                 ext2fs_free_mem((void **) &brel->name);
 200         ext2fs_free_mem((void **) &brel);
 201         return 0;
 202 }