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 <stdlib.h>
  18 #include <string.h>
  19 #if HAVE_UNISTD_H
  20 #include <unistd.h>
  21 #endif
  22 #if HAVE_ERRNO_H
  23 #include <errno.h>
  24 #endif
  25
  26 #include <linux/ext2_fs.h>
  27
  28 #include "ext2fs.h"
  29 #include "brel.h"
  30
  31 static errcode_t bma_put(ext2_brel brel, blk_t old,
  32                         struct ext2_block_relocate_entry *ent);
  33 static errcode_t bma_get(ext2_brel brel, blk_t old,
  34                         struct ext2_block_relocate_entry *ent);
  35 static errcode_t bma_start_iter(ext2_brel brel);
  36 static errcode_t bma_next(ext2_brel brel, blk_t *old,
  37                          struct ext2_block_relocate_entry *ent);
  38 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new);
  39 static errcode_t bma_delete(ext2_brel brel, blk_t old);
  40 static errcode_t bma_free(ext2_brel brel);
  41
  42 struct brel_ma {
  43         __u32 magic;
  44         blk_t max_block;
  45         struct ext2_block_relocate_entry *entries;
  46 };
  47
  48 errcode_t ext2fs_brel_memarray_create(char *name, blk_t max_block,
  49                                       ext2_brel *new_brel)
  50 {
  51         ext2_brel               brel = 0;
  52         errcode_t       retval;
  53         struct brel_ma  *ma = 0;
  54         size_t          size;
  55
  56         *new_brel = 0;
  57
  58         /*
  59          * Allocate memory structures
  60          */
  61         retval = ext2fs_get_mem(sizeof(struct ext2_block_relocation_table),
  62                                 (void **) &brel);
  63         if (retval)
  64                 goto errout;
  65         memset(brel, 0, sizeof(struct ext2_block_relocation_table));
  66
  67         retval = ext2fs_get_mem(strlen(name)+1, (void **) &brel->name);
  68         if (retval)
  69                 goto errout;
  70         strcpy(brel->name, name);
  71
  72         retval = ext2fs_get_mem(sizeof(struct brel_ma), (void **) &ma);
  73         if (retval)
  74                 goto errout;
  75         memset(ma, 0, sizeof(struct brel_ma));
  76         brel->private = ma;
  77
  78         size = (size_t) (sizeof(struct ext2_block_relocate_entry) *
  79                          (max_block+1));
  80         retval = ext2fs_get_mem(size, (void **) &ma->entries);
  81         if (retval)
  82                 goto errout;
  83         memset(ma->entries, 0, size);
  84         ma->max_block = max_block;
  85
  86         /*
  87          * Fill in the brel data structure
  88          */
  89         brel->put = bma_put;
  90         brel->get = bma_get;
  91         brel->start_iter = bma_start_iter;
  92         brel->next = bma_next;
  93         brel->move = bma_move;
  94         brel->delete = bma_delete;
  95         brel->free = bma_free;
  96
  97         *new_brel = brel;
  98         return 0;
  99
 100 errout:
 101         bma_free(brel);
 102         return retval;
 103 }
 104
 105 static errcode_t bma_put(ext2_brel brel, blk_t old,
 106                         struct ext2_block_relocate_entry *ent)
 107 {
 108         struct brel_ma  *ma;
 109
 110         ma = brel->private;
 111         if (old > ma->max_block)
 112                 return EXT2_ET_INVALID_ARGUMENT;
 113         ma->entries[(unsigned)old] = *ent;
 114         return 0;
 115 }
 116
 117 static errcode_t bma_get(ext2_brel brel, blk_t old,
 118                         struct ext2_block_relocate_entry *ent)
 119 {
 120         struct brel_ma  *ma;
 121
 122         ma = brel->private;
 123         if (old > ma->max_block)
 124                 return EXT2_ET_INVALID_ARGUMENT;
 125         if (ma->entries[(unsigned)old].new == 0)
 126                 return ENOENT;
 127         *ent = ma->entries[old];
 128         return 0;
 129 }
 130
 131 static errcode_t bma_start_iter(ext2_brel brel)
 132 {
 133         brel->current = 0;
 134         return 0;
 135 }
 136
 137 static errcode_t bma_next(ext2_brel brel, blk_t *old,
 138                           struct ext2_block_relocate_entry *ent)
 139 {
 140         struct brel_ma  *ma;
 141
 142         ma = brel->private;
 143         while (++brel->current < ma->max_block) {
 144                 if (ma->entries[(unsigned)brel->current].new == 0)
 145                         continue;
 146                 *old = brel->current;
 147                 *ent = ma->entries[(unsigned)brel->current];
 148                 return 0;
 149         }
 150         *old = 0;
 151         return 0;
 152 }
 153
 154 static errcode_t bma_move(ext2_brel brel, blk_t old, blk_t new)
 155 {
 156         struct brel_ma  *ma;
 157
 158         ma = brel->private;
 159         if ((old > ma->max_block) || (new > ma->max_block))
 160                 return EXT2_ET_INVALID_ARGUMENT;
 161         if (ma->entries[(unsigned)old].new == 0)
 162                 return ENOENT;
 163         ma->entries[(unsigned)new] = ma->entries[old];
 164         ma->entries[(unsigned)old].new = 0;
 165         return 0;
 166 }
 167
 168 static errcode_t bma_delete(ext2_brel brel, blk_t old)
 169 {
 170         struct brel_ma  *ma;
 171
 172         ma = brel->private;
 173         if (old > ma->max_block)
 174                 return EXT2_ET_INVALID_ARGUMENT;
 175         if (ma->entries[(unsigned)old].new == 0)
 176                 return ENOENT;
 177         ma->entries[(unsigned)old].new = 0;
 178         return 0;
 179 }
 180
 181 static errcode_t bma_free(ext2_brel brel)
 182 {
 183         struct brel_ma  *ma;
 184
 185         if (!brel)
 186                 return 0;
 187
 188         ma = brel->private;
 189
 190         if (ma) {
 191                 if (ma->entries)
 192                         ext2fs_free_mem((void **) &ma->entries);
 193                 ext2fs_free_mem((void **) &ma);
 194         }
 195         if (brel->name)
 196                 ext2fs_free_mem((void **) &brel->name);
 197         ext2fs_free_mem((void **) &brel);
 198         return 0;
 199 }