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 <assert.h>
  11 #include "config.h"
  12 #include "e2fsck.h"
  13 #include <sys/stat.h>
  14 #include <fcntl.h>
  15 #include "uuid/uuid.h"
  16
  17 #include "ext2fs/ext2fs.h"
  18 #include <ext2fs/tdb.h>
  19
  20 struct dir_info_db {
  21         ext2_ino_t      count;
  22         ext2_ino_t      size;
  23         struct dir_info *array;
  24         struct dir_info *last_lookup;
  25 #ifdef CONFIG_TDB
  26         char            *tdb_fn;
  27         TDB_CONTEXT     *tdb;
  28 #endif
  29 };
  30
  31 struct dir_info_iter {
  32         ext2_ino_t      i;
  33 #ifdef CONFIG_TDB
  34         TDB_DATA        tdb_iter;
  35 #endif
  36 };
  37
  38 struct dir_info_ent {
  39         ext2_ino_t              dotdot; /* Parent according to '..' */
  40         ext2_ino_t              parent; /* Parent according to treewalk */
  41 };
  42
  43
  44 static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir);
  45
  46 #ifdef CONFIG_TDB
  47 static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
  48 {
  49         struct dir_info_db      *db = ctx->dir_info;
  50         ext2_ino_t              threshold;
  51         errcode_t               retval;
  52         mode_t                  save_umask;
  53         char                    *tdb_dir, uuid[40];
  54         int                     fd, enable;
  55
  56         profile_get_string(ctx->profile, "scratch_files", "directory", 0, 0,
  57                            &tdb_dir);
  58         profile_get_uint(ctx->profile, "scratch_files",
  59                          "numdirs_threshold", 0, 0, &threshold);
  60         profile_get_boolean(ctx->profile, "scratch_files",
  61                             "dirinfo", 0, 1, &enable);
  62
  63         if (!enable || !tdb_dir || access(tdb_dir, W_OK) ||
  64             (threshold && num_dirs <= threshold))
  65                 return;
  66
  67         retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
  68         if (retval)
  69                 return;
  70
  71         uuid_unparse(ctx->fs->super->s_uuid, uuid);
  72         sprintf(db->tdb_fn, "%s/%s-dirinfo-XXXXXX", tdb_dir, uuid);
  73         save_umask = umask(077);
  74         fd = mkstemp(db->tdb_fn);
  75         umask(save_umask);
  76         if (fd < 0) {
  77                 db->tdb = NULL;
  78                 return;
  79         }
  80
  81         if (num_dirs < 99991)
  82                 num_dirs = 99991; /* largest 5 digit prime */
  83
  84         db->tdb = tdb_open(db->tdb_fn, num_dirs, TDB_NOLOCK | TDB_NOSYNC,
  85                            O_RDWR | O_CREAT | O_TRUNC, 0600);
  86         close(fd);
  87 }
  88 #endif
  89
  90 static void setup_db(e2fsck_t ctx)
  91 {
  92         struct dir_info_db      *db;
  93         ext2_ino_t              num_dirs;
  94         errcode_t               retval;
  95
  96         db = (struct dir_info_db *)
  97                 e2fsck_allocate_memory(ctx, sizeof(struct dir_info_db),
  98                                        "directory map db");
  99         db->count = db->size = 0;
 100         db->array = 0;
 101
 102         ctx->dir_info = db;
 103
 104         retval = ext2fs_get_num_dirs(ctx->fs, &num_dirs);
 105         if (retval)
 106                 num_dirs = 1024;        /* Guess */
 107
 108 #ifdef CONFIG_TDB
 109         setup_tdb(ctx, num_dirs);
 110
 111         if (db->tdb) {
 112 #ifdef DIRINFO_DEBUG
 113                 printf("Note: using tdb!\n");
 114 #endif
 115                 return;
 116         }
 117 #endif
 118
 119         db->size = num_dirs + 10;
 120         db->array  = (struct dir_info *)
 121                 e2fsck_allocate_memory(ctx, db->size
 122                                        * sizeof (struct dir_info),
 123                                        "directory map");
 124 }
 125
 126 /*
 127  * Return the min index that has ino larger or equal to @ino
 128  * If not found, return -ENOENT
 129  */
 130 static int
 131 e2fsck_dir_info_min_larger_equal(struct dir_info_db *dir_info,
 132                                  ext2_ino_t ino, ext2_ino_t *index)
 133 {
 134         ext2_ino_t low = 0;
 135         ext2_ino_t mid, high;
 136         ext2_ino_t tmp_ino;
 137         int found = 0;
 138
 139         if (dir_info->count == 0)
 140                 return -ENOENT;
 141
 142         high = dir_info->count - 1;
 143         while (low <= high) {
 144                 /* sum may overflow, but result will fit into mid again */
 145                 mid = (unsigned long long)(low + high) / 2;
 146                 tmp_ino = dir_info->array[mid].ino;
 147                 if (ino == tmp_ino) {
 148                         *index = mid;
 149                         found = 1;
 150                         return 0;
 151                 } else if (ino < tmp_ino) {
 152                         /*
 153                          * The mid ino is larger than @ino, remember the index
 154                          * here so we won't miss this ino
 155                          */
 156                         *index = mid;
 157                         found = 1;
 158                         if (mid == 0)
 159                                 break;
 160                         high = mid - 1;
 161                 } else {
 162                         low = mid + 1;
 163                 }
 164         }
 165
 166         if (found)
 167                 return 0;
 168
 169         return -ENOENT;
 170 }
 171
 172 /*
 173  *
 174  * Insert an inode into the sorted array. The array should have at least one
 175  * free slot.
 176  *
 177  * Normally, add_dir_info is called with each inode in
 178  * sequential order; but once in a while (like when pass 3
 179  * needs to recreate the root directory or lost+found
 180  * directory) it is called out of order.  In those cases, we
 181  * need to move the dir_info entries down to make room, since
 182  * the dir_info array needs to be sorted by inode number for
 183  * get_dir_info()'s sake.
 184  */
 185 static void e2fsck_insert_dir_info(struct dir_info_db *dir_info, ext2_ino_t ino, ext2_ino_t parent)
 186 {
 187         ext2_ino_t              index;
 188         struct dir_info         *dir;
 189         size_t                  dir_size = sizeof(*dir);
 190         struct dir_info         *array = dir_info->array;
 191         ext2_ino_t              array_count = dir_info->count;
 192         int                     err;
 193
 194         /*
 195          * Removing this check won't break anything. But since seqential ino
 196          * inserting happens a lot, this check avoids binary search.
 197          */
 198         if (array_count == 0 || array[array_count - 1].ino < ino) {
 199                 dir = &array[array_count];
 200                 dir_info->count++;
 201                 goto out;
 202         }
 203
 204         err = e2fsck_dir_info_min_larger_equal(dir_info, ino, &index);
 205         if (err >= 0 && array[index].ino == ino) {
 206                 dir = &array[index];
 207                 goto out;
 208         }
 209         if (err < 0) {
 210                 dir = &array[array_count];
 211                 dir_info->count++;
 212                 goto out;
 213         }
 214
 215         dir = &array[index];
 216         memmove((char *)dir + dir_size, dir, dir_size * (array_count - index));
 217         dir_info->count++;
 218 out:
 219         dir->ino = ino;
 220         dir->dotdot = parent;
 221         dir->parent = parent;
 222 }
 223
 224 /*
 225  * This subroutine is called during pass1 to create a directory info
 226  * entry.  During pass1, the passed-in parent is 0; it will get filled
 227  * in during pass2.
 228  */
 229 void e2fsck_add_dir_info(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
 230 {
 231         struct dir_info         *dir, *old_array;
 232         ext2_ino_t              i, j;
 233         errcode_t               retval;
 234         unsigned long           old_size;
 235
 236 #ifdef DIRINFO_DEBUG
 237         printf("add_dir_info for inode (%u, %u)...\n", ino, parent);
 238 #endif
 239         if (!ctx->dir_info)
 240                 setup_db(ctx);
 241
 242         if (ctx->dir_info->count >= ctx->dir_info->size) {
 243                 old_size = ctx->dir_info->size * sizeof(struct dir_info);
 244                 ctx->dir_info->size += 10;
 245                 old_array = ctx->dir_info->array;
 246                 retval = ext2fs_resize_mem(old_size, ctx->dir_info->size *
 247                                            sizeof(struct dir_info),
 248                                            &ctx->dir_info->array);
 249                 if (retval) {
 250                         fprintf(stderr, "Couldn't reallocate dir_info "
 251                                 "structure to %u entries\n",
 252                                 ctx->dir_info->size);
 253                         fatal_error(ctx, 0);
 254                         ctx->dir_info->size -= 10;
 255                         return;
 256                 }
 257                 if (old_array != ctx->dir_info->array)
 258                         ctx->dir_info->last_lookup = NULL;
 259         }
 260
 261 #ifdef CONFIG_TDB
 262         if (ctx->dir_info->tdb) {
 263                 struct dir_info ent;
 264
 265                 ent.ino = ino;
 266                 ent.parent = parent;
 267                 ent.dotdot = parent;
 268                 e2fsck_put_dir_info(ctx, &ent);
 269                 return;
 270         }
 271 #endif
 272
 273         e2fsck_insert_dir_info(ctx->dir_info, ino, parent);
 274 }
 275
 276 /*
 277  * get_dir_info() --- given an inode number, try to find the directory
 278  * information entry for it.
 279  */
 280 static struct dir_info *e2fsck_get_dir_info(e2fsck_t ctx, ext2_ino_t ino)
 281 {
 282         struct dir_info_db      *db = ctx->dir_info;
 283         ext2_ino_t              index;
 284         int                     err;
 285
 286         if (!db)
 287                 return 0;
 288
 289 #ifdef DIRINFO_DEBUG
 290         printf("e2fsck_get_dir_info %u...", ino);
 291 #endif
 292
 293 #ifdef CONFIG_TDB
 294         if (db->tdb) {
 295                 static struct dir_info  ret_dir_info;
 296                 TDB_DATA key, data;
 297                 struct dir_info_ent     *buf;
 298
 299                 key.dptr = (unsigned char *) &ino;
 300                 key.dsize = sizeof(ext2_ino_t);
 301
 302                 data = tdb_fetch(db->tdb, key);
 303                 if (!data.dptr) {
 304                         if (tdb_error(db->tdb) != TDB_ERR_NOEXIST)
 305                                 printf("fetch failed: %s\n",
 306                                        tdb_errorstr(db->tdb));
 307                         return 0;
 308                 }
 309
 310                 buf = (struct dir_info_ent *) data.dptr;
 311                 ret_dir_info.ino = ino;
 312                 ret_dir_info.dotdot = buf->dotdot;
 313                 ret_dir_info.parent = buf->parent;
 314 #ifdef DIRINFO_DEBUG
 315                 printf("(%u,%u,%u)\n", ino, buf->dotdot, buf->parent);
 316 #endif
 317                 free(data.dptr);
 318                 return &ret_dir_info;
 319         }
 320 #endif
 321
 322         if (db->last_lookup && db->last_lookup->ino == ino)
 323                 return db->last_lookup;
 324
 325         err = e2fsck_dir_info_min_larger_equal(ctx->dir_info, ino, &index);
 326         if (err < 0)
 327                 return NULL;
 328         assert(ino <= ctx->dir_info->array[index].ino);
 329         if (ino == ctx->dir_info->array[index].ino) {
 330 #ifdef DIRINFO_DEBUG
 331                 printf("(%d,%d,%d)\n", ino,
 332                        ctx->dir_info->array[index].dotdot,
 333                        ctx->dir_info->array[index].parent);
 334 #endif
 335                 return &ctx->dir_info->array[index];
 336         }
 337         return NULL;
 338 }
 339
 340 static void e2fsck_put_dir_info(e2fsck_t ctx EXT2FS_NO_TDB_UNUSED,
 341                                 struct dir_info *dir EXT2FS_NO_TDB_UNUSED)
 342 {
 343 #ifdef CONFIG_TDB
 344         struct dir_info_db      *db = ctx->dir_info;
 345         struct dir_info_ent     buf;
 346         TDB_DATA                key, data;
 347 #endif
 348
 349 #ifdef DIRINFO_DEBUG
 350         printf("e2fsck_put_dir_info (%u, %u, %u)...", dir->ino, dir->dotdot,
 351                dir->parent);
 352 #endif
 353
 354 #ifdef CONFIG_TDB
 355         if (!db->tdb)
 356                 return;
 357
 358         buf.parent = dir->parent;
 359         buf.dotdot = dir->dotdot;
 360
 361         key.dptr = (unsigned char *) &dir->ino;
 362         key.dsize = sizeof(ext2_ino_t);
 363         data.dptr = (unsigned char *) &buf;
 364         data.dsize = sizeof(buf);
 365
 366         if (tdb_store(db->tdb, key, data, TDB_REPLACE) == -1) {
 367                 printf("store failed: %s\n", tdb_errorstr(db->tdb));
 368         }
 369 #endif
 370 }
 371
 372 /*
 373  * Free the dir_info structure when it isn't needed any more.
 374  */
 375 void e2fsck_free_dir_info(e2fsck_t ctx)
 376 {
 377         if (ctx->dir_info) {
 378 #ifdef CONFIG_TDB
 379                 if (ctx->dir_info->tdb)
 380                         tdb_close(ctx->dir_info->tdb);
 381                 if (ctx->dir_info->tdb_fn) {
 382                         if (unlink(ctx->dir_info->tdb_fn) < 0)
 383                                 com_err("e2fsck_free_dir_info", errno,
 384                                         _("while freeing dir_info tdb file"));
 385                         ext2fs_free_mem(&ctx->dir_info->tdb_fn);
 386                 }
 387 #endif
 388                 if (ctx->dir_info->array)
 389                         ext2fs_free_mem(&ctx->dir_info->array);
 390                 ctx->dir_info->array = 0;
 391                 ctx->dir_info->size = 0;
 392                 ctx->dir_info->count = 0;
 393                 ext2fs_free_mem(&ctx->dir_info);
 394                 ctx->dir_info = 0;
 395         }
 396 }
 397
 398 /*
 399  * Return the count of number of directories in the dir_info structure
 400  */
 401 int e2fsck_get_num_dirinfo(e2fsck_t ctx)
 402 {
 403         return ctx->dir_info ? ctx->dir_info->count : 0;
 404 }
 405
 406 struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
 407 {
 408         struct dir_info_iter *iter;
 409
 410         iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
 411                                       "dir_info iterator");
 412
 413 #ifdef CONFIG_TDB
 414         if (ctx->dir_info->tdb)
 415                 iter->tdb_iter = tdb_firstkey(ctx->dir_info->tdb);
 416 #endif
 417
 418         return iter;
 419 }
 420
 421 void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
 422                               struct dir_info_iter *iter)
 423 {
 424 #ifdef CONFIG_TDB
 425         free(iter->tdb_iter.dptr);
 426 #endif
 427         ext2fs_free_mem(&iter);
 428 }
 429
 430 /*
 431  * A simple interator function
 432  */
 433 struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
 434 {
 435         if (!ctx->dir_info || !iter)
 436                 return 0;
 437
 438 #ifdef CONFIG_TDB
 439         if (ctx->dir_info->tdb) {
 440                 static struct dir_info ret_dir_info;
 441                 struct dir_info_ent *buf;
 442                 TDB_DATA data, key;
 443
 444                 if (iter->tdb_iter.dptr == 0)
 445                         return 0;
 446                 key = iter->tdb_iter;
 447                 data = tdb_fetch(ctx->dir_info->tdb, key);
 448                 if (!data.dptr) {
 449                         printf("iter fetch failed: %s\n",
 450                                tdb_errorstr(ctx->dir_info->tdb));
 451                         return 0;
 452                 }
 453                 buf = (struct dir_info_ent *) data.dptr;
 454                 ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
 455                 ret_dir_info.dotdot = buf->dotdot;
 456                 ret_dir_info.parent = buf->parent;
 457                 iter->tdb_iter = tdb_nextkey(ctx->dir_info->tdb, key);
 458                 free(key.dptr);
 459                 free(data.dptr);
 460                 return &ret_dir_info;
 461         }
 462 #endif
 463
 464         if (iter->i >= ctx->dir_info->count)
 465                 return 0;
 466
 467 #ifdef DIRINFO_DEBUG
 468         printf("iter(%u, %u, %u)...", ctx->dir_info->array[iter->i].ino,
 469                ctx->dir_info->array[iter->i].dotdot,
 470                ctx->dir_info->array[iter->i].parent);
 471 #endif
 472         ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
 473         return(ctx->dir_info->last_lookup);
 474 }
 475
 476 /*
 477  * This function only sets the parent pointer, and requires that
 478  * dirinfo structure has already been created.
 479  */
 480 int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
 481                                ext2_ino_t parent)
 482 {
 483         struct dir_info *p;
 484
 485         p = e2fsck_get_dir_info(ctx, ino);
 486         if (!p)
 487                 return 1;
 488         p->parent = parent;
 489         e2fsck_put_dir_info(ctx, p);
 490         return 0;
 491 }
 492
 493 /*
 494  * This function only sets the dot dot pointer, and requires that
 495  * dirinfo structure has already been created.
 496  */
 497 int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 498                                ext2_ino_t dotdot)
 499 {
 500         struct dir_info *p;
 501
 502         p = e2fsck_get_dir_info(ctx, ino);
 503         if (!p)
 504                 return 1;
 505         p->dotdot = dotdot;
 506         e2fsck_put_dir_info(ctx, p);
 507         return 0;
 508 }
 509
 510 /*
 511  * This function only sets the parent pointer, and requires that
 512  * dirinfo structure has already been created.
 513  */
 514 int e2fsck_dir_info_get_parent(e2fsck_t ctx, ext2_ino_t ino,
 515                                ext2_ino_t *parent)
 516 {
 517         struct dir_info *p;
 518
 519         p = e2fsck_get_dir_info(ctx, ino);
 520         if (!p)
 521                 return 1;
 522         *parent = p->parent;
 523         return 0;
 524 }
 525
 526 /*
 527  * This function only sets the dot dot pointer, and requires that
 528  * dirinfo structure has already been created.
 529  */
 530 int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 531                                ext2_ino_t *dotdot)
 532 {
 533         struct dir_info *p;
 534
 535         p = e2fsck_get_dir_info(ctx, ino);
 536         if (!p)
 537                 return 1;
 538         *dotdot = p->dotdot;
 539         return 0;
 540 }
 541