lib/ext2fs/irel_ma.c

   1 /*
   2  * irel_ma.c
   3  *
   4  * Copyright (C) 1996, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #include <fcntl.h>
  13 #include <stdio.h>
  14 #include <string.h>
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18 #if HAVE_ERRNO_H
  19 #include <errno.h>
  20 #endif
  21
  22 #include "ext2_fs.h"
  23 #include "ext2fs.h"
  24 #include "irel.h"
  25
  26 static errcode_t ima_put(ext2_irel irel, ext2_ino_t old,
  27                          struct ext2_inode_relocate_entry *ent);
  28 static errcode_t ima_get(ext2_irel irel, ext2_ino_t old,
  29                          struct ext2_inode_relocate_entry *ent);
  30 static errcode_t ima_get_by_orig(ext2_irel irel, ext2_ino_t orig, ext2_ino_t *old,
  31                                  struct ext2_inode_relocate_entry *ent);
  32 static errcode_t ima_start_iter(ext2_irel irel);
  33 static errcode_t ima_next(ext2_irel irel, ext2_ino_t *old,
  34                           struct ext2_inode_relocate_entry *ent);
  35 static errcode_t ima_add_ref(ext2_irel irel, ext2_ino_t ino,
  36                              struct ext2_inode_reference *ref);
  37 static errcode_t ima_start_iter_ref(ext2_irel irel, ext2_ino_t ino);
  38 static errcode_t ima_next_ref(ext2_irel irel, struct ext2_inode_reference *ref);
  39 static errcode_t ima_move(ext2_irel irel, ext2_ino_t old, ext2_ino_t new);
  40 static errcode_t ima_delete(ext2_irel irel, ext2_ino_t old);
  41 static errcode_t ima_free(ext2_irel irel);
  42
  43 /*
  44  * This data structure stores the array of inode references; there is
  45  * a structure for each inode.
  46  */
  47 struct inode_reference_entry {
  48         __u16 num;
  49         struct ext2_inode_reference *refs;
  50 };
  51
  52 struct irel_ma {
  53         __u32 magic;
  54         ext2_ino_t max_inode;
  55         ext2_ino_t ref_current;
  56         int   ref_iter;
  57         ext2_ino_t      *orig_map;
  58         struct ext2_inode_relocate_entry *entries;
  59         struct inode_reference_entry *ref_entries;
  60 };
  61
  62 errcode_t ext2fs_irel_memarray_create(char *name, ext2_ino_t max_inode,
  63                                       ext2_irel *new_irel)
  64 {
  65         ext2_irel               irel = 0;
  66         errcode_t       retval;
  67         struct irel_ma  *ma = 0;
  68         size_t          size;
  69
  70         *new_irel = 0;
  71
  72         /*
  73          * Allocate memory structures
  74          */
  75         retval = ext2fs_get_mem(sizeof(struct ext2_inode_relocation_table),
  76                   (void **) &irel);
  77         if (retval)
  78                 goto errout;
  79         memset(irel, 0, sizeof(struct ext2_inode_relocation_table));
  80
  81         retval = ext2fs_get_mem(strlen(name)+1, (void **) &irel->name);
  82         if (retval)
  83                 goto errout;
  84         strcpy(irel->name, name);
  85
  86         retval = ext2fs_get_mem(sizeof(struct irel_ma), (void **) &ma);
  87         if (retval)
  88                 goto errout;
  89         memset(ma, 0, sizeof(struct irel_ma));
  90         irel->priv_data = ma;
  91
  92         size = (size_t) (sizeof(ext2_ino_t) * (max_inode+1));
  93         retval = ext2fs_get_mem(size, (void **) &ma->orig_map);
  94         if (retval)
  95                 goto errout;
  96         memset(ma->orig_map, 0, size);
  97
  98         size = (size_t) (sizeof(struct ext2_inode_relocate_entry) *
  99                          (max_inode+1));
 100         retval = ext2fs_get_mem(size, (void **) &ma->entries);
 101         if (retval)
 102                 goto errout;
 103         memset(ma->entries, 0, size);
 104
 105         size = (size_t) (sizeof(struct inode_reference_entry) *
 106                          (max_inode+1));
 107         retval = ext2fs_get_mem(size, (void **) &ma->ref_entries);
 108         if (retval)
 109                 goto errout;
 110         memset(ma->ref_entries, 0, size);
 111         ma->max_inode = max_inode;
 112
 113         /*
 114          * Fill in the irel data structure
 115          */
 116         irel->put = ima_put;
 117         irel->get = ima_get;
 118         irel->get_by_orig = ima_get_by_orig;
 119         irel->start_iter = ima_start_iter;
 120         irel->next = ima_next;
 121         irel->add_ref = ima_add_ref;
 122         irel->start_iter_ref = ima_start_iter_ref;
 123         irel->next_ref = ima_next_ref;
 124         irel->move = ima_move;
 125         irel->delete = ima_delete;
 126         irel->free = ima_free;
 127
 128         *new_irel = irel;
 129         return 0;
 130
 131 errout:
 132         ima_free(irel);
 133         return retval;
 134 }
 135
 136 static errcode_t ima_put(ext2_irel irel, ext2_ino_t old,
 137                         struct ext2_inode_relocate_entry *ent)
 138 {
 139         struct inode_reference_entry    *ref_ent;
 140         struct irel_ma                  *ma;
 141         errcode_t                       retval;
 142         size_t                          size, old_size;
 143
 144         ma = irel->priv_data;
 145         if (old > ma->max_inode)
 146                 return EXT2_ET_INVALID_ARGUMENT;
 147
 148         /*
 149          * Force the orig field to the correct value; the application
 150          * program shouldn't be messing with this field.
 151          */
 152         if (ma->entries[(unsigned) old].new == 0)
 153                 ent->orig = old;
 154         else
 155                 ent->orig = ma->entries[(unsigned) old].orig;
 156
 157         /*
 158          * If max_refs has changed, reallocate the refs array
 159          */
 160         ref_ent = ma->ref_entries + (unsigned) old;
 161         if (ref_ent->refs && ent->max_refs !=
 162             ma->entries[(unsigned) old].max_refs) {
 163                 size = (sizeof(struct ext2_inode_reference) * ent->max_refs);
 164                 old_size = (sizeof(struct ext2_inode_reference) *
 165                             ma->entries[(unsigned) old].max_refs);
 166                 retval = ext2fs_resize_mem(old_size, size,
 167                                            (void **) &ref_ent->refs);
 168                 if (retval)
 169                         return retval;
 170         }
 171
 172         ma->entries[(unsigned) old] = *ent;
 173         ma->orig_map[(unsigned) ent->orig] = old;
 174         return 0;
 175 }
 176
 177 static errcode_t ima_get(ext2_irel irel, ext2_ino_t old,
 178                         struct ext2_inode_relocate_entry *ent)
 179 {
 180         struct irel_ma  *ma;
 181
 182         ma = irel->priv_data;
 183         if (old > ma->max_inode)
 184                 return EXT2_ET_INVALID_ARGUMENT;
 185         if (ma->entries[(unsigned) old].new == 0)
 186                 return ENOENT;
 187         *ent = ma->entries[(unsigned) old];
 188         return 0;
 189 }
 190
 191 static errcode_t ima_get_by_orig(ext2_irel irel, ext2_ino_t orig, ext2_ino_t *old,
 192                         struct ext2_inode_relocate_entry *ent)
 193 {
 194         struct irel_ma  *ma;
 195         ext2_ino_t      ino;
 196
 197         ma = irel->priv_data;
 198         if (orig > ma->max_inode)
 199                 return EXT2_ET_INVALID_ARGUMENT;
 200         ino = ma->orig_map[(unsigned) orig];
 201         if (ino == 0)
 202                 return ENOENT;
 203         *old = ino;
 204         *ent = ma->entries[(unsigned) ino];
 205         return 0;
 206 }
 207
 208 static errcode_t ima_start_iter(ext2_irel irel)
 209 {
 210         irel->current = 0;
 211         return 0;
 212 }
 213
 214 static errcode_t ima_next(ext2_irel irel, ext2_ino_t *old,
 215                          struct ext2_inode_relocate_entry *ent)
 216 {
 217         struct irel_ma  *ma;
 218
 219         ma = irel->priv_data;
 220         while (++irel->current < ma->max_inode) {
 221                 if (ma->entries[(unsigned) irel->current].new == 0)
 222                         continue;
 223                 *old = irel->current;
 224                 *ent = ma->entries[(unsigned) irel->current];
 225                 return 0;
 226         }
 227         *old = 0;
 228         return 0;
 229 }
 230
 231 static errcode_t ima_add_ref(ext2_irel irel, ext2_ino_t ino,
 232                              struct ext2_inode_reference *ref)
 233 {
 234         struct irel_ma  *ma;
 235         size_t          size;
 236         struct inode_reference_entry *ref_ent;
 237         struct ext2_inode_relocate_entry *ent;
 238         errcode_t               retval;
 239
 240         ma = irel->priv_data;
 241         if (ino > ma->max_inode)
 242                 return EXT2_ET_INVALID_ARGUMENT;
 243
 244         ref_ent = ma->ref_entries + (unsigned) ino;
 245         ent = ma->entries + (unsigned) ino;
 246
 247         /*
 248          * If the inode reference array doesn't exist, create it.
 249          */
 250         if (ref_ent->refs == 0) {
 251                 size = (size_t) ((sizeof(struct ext2_inode_reference) *
 252                                   ent->max_refs));
 253                 retval = ext2fs_get_mem(size, (void **) &ref_ent->refs);
 254                 if (retval)
 255                         return retval;
 256                 memset(ref_ent->refs, 0, size);
 257                 ref_ent->num = 0;
 258         }
 259
 260         if (ref_ent->num >= ent->max_refs)
 261                 return EXT2_ET_TOO_MANY_REFS;
 262
 263         ref_ent->refs[(unsigned) ref_ent->num++] = *ref;
 264         return 0;
 265 }
 266
 267 static errcode_t ima_start_iter_ref(ext2_irel irel, ext2_ino_t ino)
 268 {
 269         struct irel_ma  *ma;
 270
 271         ma = irel->priv_data;
 272         if (ino > ma->max_inode)
 273                 return EXT2_ET_INVALID_ARGUMENT;
 274         if (ma->entries[(unsigned) ino].new == 0)
 275                 return ENOENT;
 276         ma->ref_current = ino;
 277         ma->ref_iter = 0;
 278         return 0;
 279 }
 280
 281 static errcode_t ima_next_ref(ext2_irel irel,
 282                               struct ext2_inode_reference *ref)
 283 {
 284         struct irel_ma  *ma;
 285         struct inode_reference_entry *ref_ent;
 286
 287         ma = irel->priv_data;
 288
 289         ref_ent = ma->ref_entries + ma->ref_current;
 290
 291         if ((ref_ent->refs == NULL) ||
 292             (ma->ref_iter >= ref_ent->num)) {
 293                 ref->block = 0;
 294                 ref->offset = 0;
 295                 return 0;
 296         }
 297         *ref = ref_ent->refs[ma->ref_iter++];
 298         return 0;
 299 }
 300
 301
 302 static errcode_t ima_move(ext2_irel irel, ext2_ino_t old, ext2_ino_t new)
 303 {
 304         struct irel_ma  *ma;
 305
 306         ma = irel->priv_data;
 307         if ((old > ma->max_inode) || (new > ma->max_inode))
 308                 return EXT2_ET_INVALID_ARGUMENT;
 309         if (ma->entries[(unsigned) old].new == 0)
 310                 return ENOENT;
 311
 312         ma->entries[(unsigned) new] = ma->entries[(unsigned) old];
 313         if (ma->ref_entries[(unsigned) new].refs)
 314                 ext2fs_free_mem((void **) &ma->ref_entries[(unsigned) new].refs);
 315         ma->ref_entries[(unsigned) new] = ma->ref_entries[(unsigned) old];
 316
 317         ma->entries[(unsigned) old].new = 0;
 318         ma->ref_entries[(unsigned) old].num = 0;
 319         ma->ref_entries[(unsigned) old].refs = 0;
 320
 321         ma->orig_map[ma->entries[new].orig] = new;
 322         return 0;
 323 }
 324
 325 static errcode_t ima_delete(ext2_irel irel, ext2_ino_t old)
 326 {
 327         struct irel_ma  *ma;
 328
 329         ma = irel->priv_data;
 330         if (old > ma->max_inode)
 331                 return EXT2_ET_INVALID_ARGUMENT;
 332         if (ma->entries[(unsigned) old].new == 0)
 333                 return ENOENT;
 334
 335         ma->entries[old].new = 0;
 336         if (ma->ref_entries[(unsigned) old].refs)
 337                 ext2fs_free_mem((void **) &ma->ref_entries[(unsigned) old].refs);
 338         ma->orig_map[ma->entries[(unsigned) old].orig] = 0;
 339
 340         ma->ref_entries[(unsigned) old].num = 0;
 341         ma->ref_entries[(unsigned) old].refs = 0;
 342         return 0;
 343 }
 344
 345 static errcode_t ima_free(ext2_irel irel)
 346 {
 347         struct irel_ma  *ma;
 348         ext2_ino_t      ino;
 349
 350         if (!irel)
 351                 return 0;
 352
 353         ma = irel->priv_data;
 354
 355         if (ma) {
 356                 if (ma->orig_map)
 357                         ext2fs_free_mem((void **) &ma->orig_map);
 358                 if (ma->entries)
 359                         ext2fs_free_mem((void **) &ma->entries);
 360                 if (ma->ref_entries) {
 361                         for (ino = 0; ino <= ma->max_inode; ino++) {
 362                                 if (ma->ref_entries[(unsigned) ino].refs)
 363                                         ext2fs_free_mem((void **) &ma->ref_entries[(unsigned) ino].refs);
 364                         }
 365                         ext2fs_free_mem((void **) &ma->ref_entries);
 366                 }
 367                 ext2fs_free_mem((void **) &ma);
 368         }
 369         if (irel->name)
 370                 ext2fs_free_mem((void **) &irel->name);
 371         ext2fs_free_mem((void **) &irel);
 372         return 0;
 373 }