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