lib/ext2fs/dblist.c

   1 /*
   2  * dblist.c -- directory block list functions
   3  *
   4  * Copyright 1997 by Theodore Ts'o
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #include <string.h>
  18 #include <time.h>
  19
  20 #include "ext2_fs.h"
  21 #include "ext2fsP.h"
  22
  23 static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b);
  24 static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b);
  25 static EXT2_QSORT_TYPE (*sortfunc32)(const void *a, const void *b);
  26
  27 /*
  28  * Returns the number of directories in the filesystem as reported by
  29  * the group descriptors.  Of course, the group descriptors could be
  30  * wrong!
  31  */
  32 errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
  33 {
  34         dgrp_t  i;
  35         ext2_ino_t      num_dirs, max_dirs;
  36
  37         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  38
  39         num_dirs = 0;
  40         max_dirs = fs->super->s_inodes_per_group;
  41         for (i = 0; i < fs->group_desc_count; i++) {
  42                 if (ext2fs_bg_used_dirs_count(fs, i) > max_dirs)
  43                         num_dirs += max_dirs / 8;
  44                 else
  45                         num_dirs += ext2fs_bg_used_dirs_count(fs, i);
  46         }
  47         if (num_dirs > fs->super->s_inodes_count)
  48                 num_dirs = fs->super->s_inodes_count;
  49
  50         *ret_num_dirs = num_dirs;
  51
  52         return 0;
  53 }
  54
  55 /*
  56  * helper function for making a new directory block list (for
  57  * initialize and copy).
  58  */
  59 static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size,
  60                              ext2_ino_t count,
  61                              struct ext2_db_entry2 *list,
  62                              ext2_dblist *ret_dblist)
  63 {
  64         ext2_dblist     dblist;
  65         errcode_t       retval;
  66         ext2_ino_t      num_dirs;
  67         size_t          len;
  68
  69         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  70
  71         if ((ret_dblist == 0) && fs->dblist &&
  72             (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
  73                 return 0;
  74
  75         retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
  76         if (retval)
  77                 goto cleanup;
  78         memset(dblist, 0, sizeof(struct ext2_struct_dblist));
  79
  80         dblist->magic = EXT2_ET_MAGIC_DBLIST;
  81         dblist->fs = fs;
  82         if (size)
  83                 dblist->size = size;
  84         else {
  85                 retval = ext2fs_get_num_dirs(fs, &num_dirs);
  86                 if (retval)
  87                         goto cleanup;
  88                 dblist->size = (num_dirs * 2) + 12;
  89         }
  90         len = (size_t) sizeof(struct ext2_db_entry2) * dblist->size;
  91         dblist->count = count;
  92         retval = ext2fs_get_array(dblist->size, sizeof(struct ext2_db_entry2),
  93                 &dblist->list);
  94         if (retval)
  95                 goto cleanup;
  96
  97         if (list)
  98                 memcpy(dblist->list, list, len);
  99         else
 100                 memset(dblist->list, 0, len);
 101         if (ret_dblist)
 102                 *ret_dblist = dblist;
 103         else
 104                 fs->dblist = dblist;
 105         return 0;
 106 cleanup:
 107         if (dblist)
 108                 ext2fs_free_mem(&dblist);
 109         return retval;
 110 }
 111
 112 /*
 113  * Initialize a directory block list
 114  */
 115 errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
 116 {
 117         ext2_dblist     dblist;
 118         errcode_t       retval;
 119
 120         retval = make_dblist(fs, 0, 0, 0, &dblist);
 121         if (retval)
 122                 return retval;
 123
 124         dblist->sorted = 1;
 125         if (ret_dblist)
 126                 *ret_dblist = dblist;
 127         else
 128                 fs->dblist = dblist;
 129
 130         return 0;
 131 }
 132
 133 /*
 134  * Copy a directory block list
 135  */
 136 errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
 137 {
 138         ext2_dblist     dblist;
 139         errcode_t       retval;
 140
 141         retval = make_dblist(src->fs, src->size, src->count, src->list,
 142                              &dblist);
 143         if (retval)
 144                 return retval;
 145         dblist->sorted = src->sorted;
 146         *dest = dblist;
 147         return 0;
 148 }
 149
 150 /*
 151  * Close a directory block list
 152  *
 153  * (moved to closefs.c)
 154  */
 155
 156
 157 /*
 158  * Add a directory block to the directory block list
 159  */
 160 errcode_t ext2fs_add_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
 161                                 blk64_t blk, e2_blkcnt_t blockcnt)
 162 {
 163         struct ext2_db_entry2   *new_entry;
 164         errcode_t               retval;
 165         unsigned long           old_size;
 166
 167         EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
 168
 169         if (dblist->count >= dblist->size) {
 170                 old_size = dblist->size * sizeof(struct ext2_db_entry2);
 171                 dblist->size += dblist->size > 200 ? dblist->size / 2 : 100;
 172                 retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
 173                                            sizeof(struct ext2_db_entry2),
 174                                            &dblist->list);
 175                 if (retval) {
 176                         dblist->size = old_size / sizeof(struct ext2_db_entry2);
 177                         return retval;
 178                 }
 179         }
 180         new_entry = dblist->list + ( dblist->count++);
 181         new_entry->blk = blk;
 182         new_entry->ino = ino;
 183         new_entry->blockcnt = blockcnt;
 184
 185         dblist->sorted = 0;
 186
 187         return 0;
 188 }
 189
 190 /*
 191  * Change the directory block to the directory block list
 192  */
 193 errcode_t ext2fs_set_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
 194                                 blk64_t blk, e2_blkcnt_t blockcnt)
 195 {
 196         dgrp_t                  i;
 197
 198         EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
 199
 200         for (i=0; i < dblist->count; i++) {
 201                 if ((dblist->list[i].ino != ino) ||
 202                     (dblist->list[i].blockcnt != blockcnt))
 203                         continue;
 204                 dblist->list[i].blk = blk;
 205                 dblist->sorted = 0;
 206                 return 0;
 207         }
 208         return EXT2_ET_DB_NOT_FOUND;
 209 }
 210
 211 void ext2fs_dblist_sort2(ext2_dblist dblist,
 212                          EXT2_QSORT_TYPE (*sortfunc)(const void *,
 213                                                      const void *))
 214 {
 215         if (!sortfunc)
 216                 sortfunc = dir_block_cmp2;
 217         qsort(dblist->list, (size_t) dblist->count,
 218               sizeof(struct ext2_db_entry2), sortfunc);
 219         dblist->sorted = 1;
 220 }
 221
 222 /*
 223  * This function iterates over the directory block list
 224  */
 225 errcode_t ext2fs_dblist_iterate2(ext2_dblist dblist,
 226                                  int (*func)(ext2_filsys fs,
 227                                              struct ext2_db_entry2 *db_info,
 228                                              void       *priv_data),
 229                                  void *priv_data)
 230 {
 231         unsigned long long      i;
 232         int             ret;
 233
 234         EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
 235
 236         if (!dblist->sorted)
 237                 ext2fs_dblist_sort2(dblist, 0);
 238         for (i=0; i < dblist->count; i++) {
 239                 ret = (*func)(dblist->fs, &dblist->list[i], priv_data);
 240                 if (ret & DBLIST_ABORT)
 241                         return 0;
 242         }
 243         return 0;
 244 }
 245
 246 static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b)
 247 {
 248         const struct ext2_db_entry2 *db_a =
 249                 (const struct ext2_db_entry2 *) a;
 250         const struct ext2_db_entry2 *db_b =
 251                 (const struct ext2_db_entry2 *) b;
 252
 253         if (db_a->blk != db_b->blk)
 254                 return (int) (db_a->blk - db_b->blk);
 255
 256         if (db_a->ino != db_b->ino)
 257                 return (int) (db_a->ino - db_b->ino);
 258
 259         return (db_a->blockcnt - db_b->blockcnt);
 260 }
 261
 262 blk64_t ext2fs_dblist_count2(ext2_dblist dblist)
 263 {
 264         return dblist->count;
 265 }
 266
 267 errcode_t ext2fs_dblist_get_last2(ext2_dblist dblist,
 268                                   struct ext2_db_entry2 **entry)
 269 {
 270         EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
 271
 272         if (dblist->count == 0)
 273                 return EXT2_ET_DBLIST_EMPTY;
 274
 275         if (entry)
 276                 *entry = dblist->list + ( dblist->count-1);
 277         return 0;
 278 }
 279
 280 errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist)
 281 {
 282         EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
 283
 284         if (dblist->count == 0)
 285                 return EXT2_ET_DBLIST_EMPTY;
 286
 287         dblist->count--;
 288         return 0;
 289 }
 290
 291 /*
 292  * Legacy 32-bit versions
 293  */
 294
 295 /*
 296  * Add a directory block to the directory block list
 297  */
 298 errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
 299                                int blockcnt)
 300 {
 301         return ext2fs_add_dir_block2(dblist, ino, blk, blockcnt);
 302 }
 303
 304 /*
 305  * Change the directory block to the directory block list
 306  */
 307 errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
 308                                int blockcnt)
 309 {
 310         return ext2fs_set_dir_block2(dblist, ino, blk, blockcnt);
 311 }
 312
 313 void ext2fs_dblist_sort(ext2_dblist dblist,
 314                         EXT2_QSORT_TYPE (*sortfunc)(const void *,
 315                                                     const void *))
 316 {
 317         if (sortfunc) {
 318                 sortfunc32 = sortfunc;
 319                 sortfunc = dir_block_cmp;
 320         } else
 321                 sortfunc = dir_block_cmp2;
 322         qsort(dblist->list, (size_t) dblist->count,
 323               sizeof(struct ext2_db_entry2), sortfunc);
 324         dblist->sorted = 1;
 325 }
 326
 327 /*
 328  * This function iterates over the directory block list
 329  */
 330 struct iterate_passthrough {
 331         int (*func)(ext2_filsys fs,
 332                     struct ext2_db_entry *db_info,
 333                     void        *priv_data);
 334         void *priv_data;
 335 };
 336
 337 static int passthrough_func(ext2_filsys fs,
 338                             struct ext2_db_entry2 *db_info,
 339                             void        *priv_data)
 340 {
 341         struct iterate_passthrough *p = priv_data;
 342         struct ext2_db_entry db;
 343         int ret;
 344
 345         db.ino = db_info->ino;
 346         db.blk = (blk_t) db_info->blk;
 347         db.blockcnt = (int) db_info->blockcnt;
 348         ret = (p->func)(fs, &db, p->priv_data);
 349         db_info->ino = db.ino;
 350         db_info->blk = db.blk;
 351         db_info->blockcnt = db.blockcnt;
 352         return ret;
 353 }
 354
 355 errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
 356                                 int (*func)(ext2_filsys fs,
 357                                             struct ext2_db_entry *db_info,
 358                                             void        *priv_data),
 359                                 void *priv_data)
 360 {
 361         struct iterate_passthrough pass;
 362
 363         EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
 364         pass.func = func;
 365         pass.priv_data = priv_data;
 366
 367         return ext2fs_dblist_iterate2(dblist, passthrough_func, &pass);
 368 }
 369
 370 static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
 371 {
 372         const struct ext2_db_entry2 *db_a =
 373                 (const struct ext2_db_entry2 *) a;
 374         const struct ext2_db_entry2 *db_b =
 375                 (const struct ext2_db_entry2 *) b;
 376
 377         struct ext2_db_entry a32, b32;
 378
 379         a32.ino = db_a->ino;  a32.blk = db_a->blk;
 380         a32.blockcnt = db_a->blockcnt;
 381
 382         b32.ino = db_b->ino;  b32.blk = db_b->blk;
 383         b32.blockcnt = db_b->blockcnt;
 384
 385         return sortfunc32(&a32, &b32);
 386 }
 387
 388 int ext2fs_dblist_count(ext2_dblist dblist)
 389 {
 390         return dblist->count;
 391 }
 392
 393 errcode_t ext2fs_dblist_get_last(ext2_dblist dblist,
 394                                  struct ext2_db_entry **entry)
 395 {
 396         EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
 397         static struct ext2_db_entry ret_entry;
 398         struct ext2_db_entry2 *last;
 399
 400         if (dblist->count == 0)
 401                 return EXT2_ET_DBLIST_EMPTY;
 402
 403         if (!entry)
 404                 return 0;
 405
 406         last = dblist->list + dblist->count -1;
 407
 408         ret_entry.ino = last->ino;
 409         ret_entry.blk = last->blk;
 410         ret_entry.blockcnt = last->blockcnt;
 411         *entry = &ret_entry;
 412
 413         return 0;
 414 }
 415