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