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