e2fsck/dirinfo.c

   1 /*
   2  * dirinfo.c --- maintains the directory information table for e2fsck.
   3  *
   4  * Copyright (C) 1993 Theodore Ts'o.  This file may be redistributed
   5  * under the terms of the GNU Public License.
   6  */
   7
   8 #undef DIRINFO_DEBUG
   9
  10 #include "config.h"
  11 #include "e2fsck.h"
  12 #include <sys/stat.h>
  13 #include <fcntl.h>
  14 #include "uuid/uuid.h"
  15
  16 #include "ext2fs/ext2fs.h"
  17 #include <ext2fs/tdb.h>
  18
  19 struct dir_info_db {
  20         ext2_ino_t      count;
  21         ext2_ino_t      size;
  22         struct dir_info *array;
  23         struct dir_info *last_lookup;
  24 #ifdef CONFIG_TDB
  25         char            *tdb_fn;
  26         TDB_CONTEXT     *tdb;
  27 #endif
  28 };
  29
  30 struct dir_info_iter {
  31         ext2_ino_t      i;
  32 #ifdef CONFIG_TDB
  33         TDB_DATA        tdb_iter;
  34 #endif
  35 };
  36
  37 struct dir_info_ent {
  38         ext2_ino_t              dotdot; /* Parent according to '..' */
  39         ext2_ino_t              parent; /* Parent according to treewalk */
  40 };
  41
  42
  43 static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir);
  44
  45 #ifdef CONFIG_TDB
  46 static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
  47 {
  48         struct dir_info_db      *db = ctx->dir_info;
  49         ext2_ino_t              threshold;
  50         errcode_t               retval;
  51         mode_t                  save_umask;
  52         char                    *tdb_dir, uuid[40];
  53         int                     fd, enable;
  54
  55         profile_get_string(ctx->profile, "scratch_files", "directory", 0, 0,
  56                            &tdb_dir);
  57         profile_get_uint(ctx->profile, "scratch_files",
  58                          "numdirs_threshold", 0, 0, &threshold);
  59         profile_get_boolean(ctx->profile, "scratch_files",
  60                             "dirinfo", 0, 1, &enable);
  61
  62         if (!enable || !tdb_dir || access(tdb_dir, W_OK) ||
  63             (threshold && num_dirs <= threshold))
  64                 return;
  65
  66         retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
  67         if (retval)
  68                 return;
  69
  70         uuid_unparse(ctx->fs->super->s_uuid, uuid);
  71         sprintf(db->tdb_fn, "%s/%s-dirinfo-XXXXXX", tdb_dir, uuid);
  72         save_umask = umask(077);
  73         fd = mkstemp(db->tdb_fn);
  74         umask(save_umask);
  75         if (fd < 0) {
  76                 db->tdb = NULL;
  77                 return;
  78         }
  79
  80         if (num_dirs < 99991)
  81                 num_dirs = 99991; /* largest 5 digit prime */
  82
  83         db->tdb = tdb_open(db->tdb_fn, num_dirs, TDB_NOLOCK | TDB_NOSYNC,
  84                            O_RDWR | O_CREAT | O_TRUNC, 0600);
  85         close(fd);
  86 }
  87 #endif
  88
  89 static void setup_db(e2fsck_t ctx)
  90 {
  91         struct dir_info_db      *db;
  92         ext2_ino_t              num_dirs;
  93         errcode_t               retval;
  94
  95         db = (struct dir_info_db *)
  96                 e2fsck_allocate_memory(ctx, sizeof(struct dir_info_db),
  97                                        "directory map db");
  98         db->count = db->size = 0;
  99         db->array = 0;
 100
 101         ctx->dir_info = db;
 102
 103         retval = ext2fs_get_num_dirs(ctx->fs, &num_dirs);
 104         if (retval)
 105                 num_dirs = 1024;        /* Guess */
 106
 107 #ifdef CONFIG_TDB
 108         setup_tdb(ctx, num_dirs);
 109
 110         if (db->tdb) {
 111 #ifdef DIRINFO_DEBUG
 112                 printf("Note: using tdb!\n");
 113 #endif
 114                 return;
 115         }
 116 #endif
 117
 118         db->size = num_dirs + 10;
 119         db->array  = (struct dir_info *)
 120                 e2fsck_allocate_memory(ctx, db->size
 121                                        * sizeof (struct dir_info),
 122                                        "directory map");
 123 }
 124
 125 /*
 126  * This subroutine is called during pass1 to create a directory info
 127  * entry.  During pass1, the passed-in parent is 0; it will get filled
 128  * in during pass2.
 129  */
 130 void e2fsck_add_dir_info(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
 131 {
 132         struct dir_info         *dir, *old_array;
 133         ext2_ino_t              i, j;
 134         errcode_t               retval;
 135         unsigned long           old_size;
 136
 137 #ifdef DIRINFO_DEBUG
 138         printf("add_dir_info for inode (%u, %u)...\n", ino, parent);
 139 #endif
 140         if (!ctx->dir_info)
 141                 setup_db(ctx);
 142
 143         if (ctx->dir_info->count >= ctx->dir_info->size) {
 144                 old_size = ctx->dir_info->size * sizeof(struct dir_info);
 145                 ctx->dir_info->size += 10;
 146                 old_array = ctx->dir_info->array;
 147                 retval = ext2fs_resize_mem(old_size, ctx->dir_info->size *
 148                                            sizeof(struct dir_info),
 149                                            &ctx->dir_info->array);
 150                 if (retval) {
 151                         fprintf(stderr, "Couldn't reallocate dir_info "
 152                                 "structure to %u entries\n",
 153                                 ctx->dir_info->size);
 154                         fatal_error(ctx, 0);
 155                         ctx->dir_info->size -= 10;
 156                         return;
 157                 }
 158                 if (old_array != ctx->dir_info->array)
 159                         ctx->dir_info->last_lookup = NULL;
 160         }
 161
 162 #ifdef CONFIG_TDB
 163         if (ctx->dir_info->tdb) {
 164                 struct dir_info ent;
 165
 166                 ent.ino = ino;
 167                 ent.parent = parent;
 168                 ent.dotdot = parent;
 169                 e2fsck_put_dir_info(ctx, &ent);
 170                 return;
 171         }
 172 #endif
 173
 174         /*
 175          * Normally, add_dir_info is called with each inode in
 176          * sequential order; but once in a while (like when pass 3
 177          * needs to recreate the root directory or lost+found
 178          * directory) it is called out of order.  In those cases, we
 179          * need to move the dir_info entries down to make room, since
 180          * the dir_info array needs to be sorted by inode number for
 181          * get_dir_info()'s sake.
 182          */
 183         if (ctx->dir_info->count &&
 184             ctx->dir_info->array[ctx->dir_info->count-1].ino >= ino) {
 185                 for (i = ctx->dir_info->count-1; i > 0; i--)
 186                         if (ctx->dir_info->array[i-1].ino < ino)
 187                                 break;
 188                 dir = &ctx->dir_info->array[i];
 189                 if (dir->ino != ino)
 190                         for (j = ctx->dir_info->count++; j > i; j--)
 191                                 ctx->dir_info->array[j] = ctx->dir_info->array[j-1];
 192         } else
 193                 dir = &ctx->dir_info->array[ctx->dir_info->count++];
 194
 195         dir->ino = ino;
 196         dir->dotdot = parent;
 197         dir->parent = parent;
 198 }
 199
 200 /*
 201  * get_dir_info() --- given an inode number, try to find the directory
 202  * information entry for it.
 203  */
 204 static struct dir_info *e2fsck_get_dir_info(e2fsck_t ctx, ext2_ino_t ino)
 205 {
 206         struct dir_info_db      *db = ctx->dir_info;
 207         ext2_ino_t low, high, mid;
 208
 209         if (!db)
 210                 return 0;
 211
 212 #ifdef DIRINFO_DEBUG
 213         printf("e2fsck_get_dir_info %u...", ino);
 214 #endif
 215
 216 #ifdef CONFIG_TDB
 217         if (db->tdb) {
 218                 static struct dir_info  ret_dir_info;
 219                 TDB_DATA key, data;
 220                 struct dir_info_ent     *buf;
 221
 222                 key.dptr = (unsigned char *) &ino;
 223                 key.dsize = sizeof(ext2_ino_t);
 224
 225                 data = tdb_fetch(db->tdb, key);
 226                 if (!data.dptr) {
 227                         if (tdb_error(db->tdb) != TDB_ERR_NOEXIST)
 228                                 printf("fetch failed: %s\n",
 229                                        tdb_errorstr(db->tdb));
 230                         return 0;
 231                 }
 232
 233                 buf = (struct dir_info_ent *) data.dptr;
 234                 ret_dir_info.ino = ino;
 235                 ret_dir_info.dotdot = buf->dotdot;
 236                 ret_dir_info.parent = buf->parent;
 237 #ifdef DIRINFO_DEBUG
 238                 printf("(%u,%u,%u)\n", ino, buf->dotdot, buf->parent);
 239 #endif
 240                 free(data.dptr);
 241                 return &ret_dir_info;
 242         }
 243 #endif
 244
 245         if (db->last_lookup && db->last_lookup->ino == ino)
 246                 return db->last_lookup;
 247
 248         low = 0;
 249         high = ctx->dir_info->count - 1;
 250         if (ino == ctx->dir_info->array[low].ino) {
 251 #ifdef DIRINFO_DEBUG
 252                 printf("(%u,%u,%u)\n", ino,
 253                        ctx->dir_info->array[low].dotdot,
 254                        ctx->dir_info->array[low].parent);
 255 #endif
 256                 return &ctx->dir_info->array[low];
 257         }
 258         if (ino == ctx->dir_info->array[high].ino) {
 259 #ifdef DIRINFO_DEBUG
 260                 printf("(%u,%u,%u)\n", ino,
 261                        ctx->dir_info->array[high].dotdot,
 262                        ctx->dir_info->array[high].parent);
 263 #endif
 264                 return &ctx->dir_info->array[high];
 265         }
 266
 267         while (low < high) {
 268                 /* sum may overflow, but result will fit into mid again */
 269                 mid = (unsigned long long)(low + high) / 2;
 270                 if (mid == low || mid == high)
 271                         break;
 272                 if (ino == ctx->dir_info->array[mid].ino) {
 273 #ifdef DIRINFO_DEBUG
 274                         printf("(%u,%u,%u)\n", ino,
 275                                ctx->dir_info->array[mid].dotdot,
 276                                ctx->dir_info->array[mid].parent);
 277 #endif
 278                         return &ctx->dir_info->array[mid];
 279                 }
 280                 if (ino < ctx->dir_info->array[mid].ino)
 281                         high = mid;
 282                 else
 283                         low = mid;
 284         }
 285         return 0;
 286 }
 287
 288 static void e2fsck_put_dir_info(e2fsck_t ctx EXT2FS_NO_TDB_UNUSED,
 289                                 struct dir_info *dir EXT2FS_NO_TDB_UNUSED)
 290 {
 291 #ifdef CONFIG_TDB
 292         struct dir_info_db      *db = ctx->dir_info;
 293         struct dir_info_ent     buf;
 294         TDB_DATA                key, data;
 295 #endif
 296
 297 #ifdef DIRINFO_DEBUG
 298         printf("e2fsck_put_dir_info (%u, %u, %u)...", dir->ino, dir->dotdot,
 299                dir->parent);
 300 #endif
 301
 302 #ifdef CONFIG_TDB
 303         if (!db->tdb)
 304                 return;
 305
 306         buf.parent = dir->parent;
 307         buf.dotdot = dir->dotdot;
 308
 309         key.dptr = (unsigned char *) &dir->ino;
 310         key.dsize = sizeof(ext2_ino_t);
 311         data.dptr = (unsigned char *) &buf;
 312         data.dsize = sizeof(buf);
 313
 314         if (tdb_store(db->tdb, key, data, TDB_REPLACE) == -1) {
 315                 printf("store failed: %s\n", tdb_errorstr(db->tdb));
 316         }
 317 #endif
 318 }
 319
 320 /*
 321  * Free the dir_info structure when it isn't needed any more.
 322  */
 323 void e2fsck_free_dir_info(e2fsck_t ctx)
 324 {
 325         if (ctx->dir_info) {
 326 #ifdef CONFIG_TDB
 327                 if (ctx->dir_info->tdb)
 328                         tdb_close(ctx->dir_info->tdb);
 329                 if (ctx->dir_info->tdb_fn) {
 330                         if (unlink(ctx->dir_info->tdb_fn) < 0)
 331                                 com_err("e2fsck_free_dir_info", errno,
 332                                         _("while freeing dir_info tdb file"));
 333                         ext2fs_free_mem(&ctx->dir_info->tdb_fn);
 334                 }
 335 #endif
 336                 if (ctx->dir_info->array)
 337                         ext2fs_free_mem(&ctx->dir_info->array);
 338                 ctx->dir_info->array = 0;
 339                 ctx->dir_info->size = 0;
 340                 ctx->dir_info->count = 0;
 341                 ext2fs_free_mem(&ctx->dir_info);
 342                 ctx->dir_info = 0;
 343         }
 344 }
 345
 346 /*
 347  * Return the count of number of directories in the dir_info structure
 348  */
 349 int e2fsck_get_num_dirinfo(e2fsck_t ctx)
 350 {
 351         return ctx->dir_info ? ctx->dir_info->count : 0;
 352 }
 353
 354 struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
 355 {
 356         struct dir_info_iter *iter;
 357
 358         iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
 359                                       "dir_info iterator");
 360
 361 #ifdef CONFIG_TDB
 362         if (ctx->dir_info->tdb)
 363                 iter->tdb_iter = tdb_firstkey(ctx->dir_info->tdb);
 364 #endif
 365
 366         return iter;
 367 }
 368
 369 void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
 370                               struct dir_info_iter *iter)
 371 {
 372 #ifdef CONFIG_TDB
 373         free(iter->tdb_iter.dptr);
 374 #endif
 375         ext2fs_free_mem(&iter);
 376 }
 377
 378 /*
 379  * A simple iterator function
 380  */
 381 struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
 382 {
 383         if (!ctx->dir_info || !iter)
 384                 return 0;
 385
 386 #ifdef CONFIG_TDB
 387         if (ctx->dir_info->tdb) {
 388                 static struct dir_info ret_dir_info;
 389                 struct dir_info_ent *buf;
 390                 TDB_DATA data, key;
 391
 392                 if (iter->tdb_iter.dptr == 0)
 393                         return 0;
 394                 key = iter->tdb_iter;
 395                 data = tdb_fetch(ctx->dir_info->tdb, key);
 396                 if (!data.dptr) {
 397                         printf("iter fetch failed: %s\n",
 398                                tdb_errorstr(ctx->dir_info->tdb));
 399                         return 0;
 400                 }
 401                 buf = (struct dir_info_ent *) data.dptr;
 402                 ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
 403                 ret_dir_info.dotdot = buf->dotdot;
 404                 ret_dir_info.parent = buf->parent;
 405                 iter->tdb_iter = tdb_nextkey(ctx->dir_info->tdb, key);
 406                 free(key.dptr);
 407                 free(data.dptr);
 408                 return &ret_dir_info;
 409         }
 410 #endif
 411
 412         if (iter->i >= ctx->dir_info->count)
 413                 return 0;
 414
 415 #ifdef DIRINFO_DEBUG
 416         printf("iter(%u, %u, %u)...", ctx->dir_info->array[iter->i].ino,
 417                ctx->dir_info->array[iter->i].dotdot,
 418                ctx->dir_info->array[iter->i].parent);
 419 #endif
 420         ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
 421         return(ctx->dir_info->last_lookup);
 422 }
 423
 424 /*
 425  * This function only sets the parent pointer, and requires that
 426  * dirinfo structure has already been created.
 427  */
 428 int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
 429                                ext2_ino_t parent)
 430 {
 431         struct dir_info *p;
 432
 433         p = e2fsck_get_dir_info(ctx, ino);
 434         if (!p)
 435                 return 1;
 436         p->parent = parent;
 437         e2fsck_put_dir_info(ctx, p);
 438         return 0;
 439 }
 440
 441 /*
 442  * This function only sets the dot dot pointer, and requires that
 443  * dirinfo structure has already been created.
 444  */
 445 int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 446                                ext2_ino_t dotdot)
 447 {
 448         struct dir_info *p;
 449
 450         p = e2fsck_get_dir_info(ctx, ino);
 451         if (!p)
 452                 return 1;
 453         p->dotdot = dotdot;
 454         e2fsck_put_dir_info(ctx, p);
 455         return 0;
 456 }
 457
 458 /*
 459  * This function only sets the parent pointer, and requires that
 460  * dirinfo structure has already been created.
 461  */
 462 int e2fsck_dir_info_get_parent(e2fsck_t ctx, ext2_ino_t ino,
 463                                ext2_ino_t *parent)
 464 {
 465         struct dir_info *p;
 466
 467         p = e2fsck_get_dir_info(ctx, ino);
 468         if (!p)
 469                 return 1;
 470         *parent = p->parent;
 471         return 0;
 472 }
 473
 474 /*
 475  * This function only sets the dot dot pointer, and requires that
 476  * dirinfo structure has already been created.
 477  */
 478 int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 479                                ext2_ino_t *dotdot)
 480 {
 481         struct dir_info *p;
 482
 483         p = e2fsck_get_dir_info(ctx, ino);
 484         if (!p)
 485                 return 1;
 486         *dotdot = p->dotdot;
 487         return 0;
 488 }
 489