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, *old_array;
 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                 old_array = ctx->dir_info->array;
 140                 retval = ext2fs_resize_mem(old_size, ctx->dir_info->size *
 141                                            sizeof(struct dir_info),
 142                                            &ctx->dir_info->array);
 143                 if (retval) {
 144                         fprintf(stderr, "Couldn't reallocate dir_info "
 145                                 "structure to %d entries\n",
 146                                 ctx->dir_info->size);
 147                         fatal_error(ctx, 0);
 148                         ctx->dir_info->size -= 10;
 149                         return;
 150                 }
 151                 if (old_array != ctx->dir_info->array)
 152                         ctx->dir_info->last_lookup = NULL;
 153         }
 154
 155         ent.ino = ino;
 156         ent.parent = parent;
 157         ent.dotdot = parent;
 158
 159         if (db->tdb) {
 160                 e2fsck_put_dir_info(ctx, &ent);
 161                 return;
 162         }
 163
 164         /*
 165          * Normally, add_dir_info is called with each inode in
 166          * sequential order; but once in a while (like when pass 3
 167          * needs to recreate the root directory or lost+found
 168          * directory) it is called out of order.  In those cases, we
 169          * need to move the dir_info entries down to make room, since
 170          * the dir_info array needs to be sorted by inode number for
 171          * get_dir_info()'s sake.
 172          */
 173         if (ctx->dir_info->count &&
 174             ctx->dir_info->array[ctx->dir_info->count-1].ino >= ino) {
 175                 for (i = ctx->dir_info->count-1; i > 0; i--)
 176                         if (ctx->dir_info->array[i-1].ino < ino)
 177                                 break;
 178                 dir = &ctx->dir_info->array[i];
 179                 if (dir->ino != ino)
 180                         for (j = ctx->dir_info->count++; j > i; j--)
 181                                 ctx->dir_info->array[j] = ctx->dir_info->array[j-1];
 182         } else
 183                 dir = &ctx->dir_info->array[ctx->dir_info->count++];
 184
 185         dir->ino = ino;
 186         dir->dotdot = parent;
 187         dir->parent = parent;
 188 }
 189
 190 /*
 191  * get_dir_info() --- given an inode number, try to find the directory
 192  * information entry for it.
 193  */
 194 static struct dir_info *e2fsck_get_dir_info(e2fsck_t ctx, ext2_ino_t ino)
 195 {
 196         struct dir_info_db      *db = ctx->dir_info;
 197         int                     low, high, mid;
 198         struct dir_info_ent     *buf;
 199         static struct dir_info  ret_dir_info;
 200
 201         if (!db)
 202                 return 0;
 203
 204 #ifdef DIRINFO_DEBUG
 205         printf("e2fsck_get_dir_info %d...", ino);
 206 #endif
 207
 208         if (db->tdb) {
 209                 TDB_DATA key, data;
 210
 211                 key.dptr = (unsigned char *) &ino;
 212                 key.dsize = sizeof(ext2_ino_t);
 213
 214                 data = tdb_fetch(db->tdb, key);
 215                 if (!data.dptr) {
 216                         if (tdb_error(db->tdb) != TDB_ERR_NOEXIST)
 217                                 printf("fetch failed: %s\n",
 218                                        tdb_errorstr(db->tdb));
 219                         return 0;
 220                 }
 221
 222                 buf = (struct dir_info_ent *) data.dptr;
 223                 ret_dir_info.ino = ino;
 224                 ret_dir_info.dotdot = buf->dotdot;
 225                 ret_dir_info.parent = buf->parent;
 226 #ifdef DIRINFO_DEBUG
 227                 printf("(%d,%d,%d)\n", ino, buf->dotdot, buf->parent);
 228 #endif
 229                 free(data.dptr);
 230                 return &ret_dir_info;
 231         }
 232
 233         if (db->last_lookup && db->last_lookup->ino == ino)
 234                 return db->last_lookup;
 235
 236         low = 0;
 237         high = ctx->dir_info->count-1;
 238         if (ino == ctx->dir_info->array[low].ino) {
 239 #ifdef DIRINFO_DEBUG
 240                 printf("(%d,%d,%d)\n", ino,
 241                        ctx->dir_info->array[low].dotdot,
 242                        ctx->dir_info->array[low].parent);
 243 #endif
 244                 return &ctx->dir_info->array[low];
 245         }
 246         if (ino == ctx->dir_info->array[high].ino) {
 247 #ifdef DIRINFO_DEBUG
 248                 printf("(%d,%d,%d)\n", ino,
 249                        ctx->dir_info->array[high].dotdot,
 250                        ctx->dir_info->array[high].parent);
 251 #endif
 252                 return &ctx->dir_info->array[high];
 253         }
 254
 255         while (low < high) {
 256                 mid = (low+high)/2;
 257                 if (mid == low || mid == high)
 258                         break;
 259                 if (ino == ctx->dir_info->array[mid].ino) {
 260 #ifdef DIRINFO_DEBUG
 261                         printf("(%d,%d,%d)\n", ino,
 262                                ctx->dir_info->array[mid].dotdot,
 263                                ctx->dir_info->array[mid].parent);
 264 #endif
 265                         return &ctx->dir_info->array[mid];
 266                 }
 267                 if (ino < ctx->dir_info->array[mid].ino)
 268                         high = mid;
 269                 else
 270                         low = mid;
 271         }
 272         return 0;
 273 }
 274
 275 static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir)
 276 {
 277         struct dir_info_db      *db = ctx->dir_info;
 278         struct dir_info_ent     buf;
 279         TDB_DATA                key, data;
 280
 281 #ifdef DIRINFO_DEBUG
 282         printf("e2fsck_put_dir_info (%d, %d, %d)...", dir->ino, dir->dotdot,
 283                dir->parent);
 284 #endif
 285
 286         if (!db->tdb)
 287                 return;
 288
 289         buf.parent = dir->parent;
 290         buf.dotdot = dir->dotdot;
 291
 292         key.dptr = (unsigned char *) &dir->ino;
 293         key.dsize = sizeof(ext2_ino_t);
 294         data.dptr = (unsigned char *) &buf;
 295         data.dsize = sizeof(buf);
 296
 297         if (tdb_store(db->tdb, key, data, TDB_REPLACE) == -1) {
 298                 printf("store failed: %s\n", tdb_errorstr(db->tdb));
 299         }
 300         return;
 301 }
 302
 303 /*
 304  * Free the dir_info structure when it isn't needed any more.
 305  */
 306 void e2fsck_free_dir_info(e2fsck_t ctx)
 307 {
 308         if (ctx->dir_info) {
 309                 if (ctx->dir_info->tdb)
 310                         tdb_close(ctx->dir_info->tdb);
 311                 if (ctx->dir_info->tdb_fn) {
 312                         unlink(ctx->dir_info->tdb_fn);
 313                         free(ctx->dir_info->tdb_fn);
 314                 }
 315                 if (ctx->dir_info->array)
 316                         ext2fs_free_mem(&ctx->dir_info->array);
 317                 ctx->dir_info->array = 0;
 318                 ctx->dir_info->size = 0;
 319                 ctx->dir_info->count = 0;
 320                 ext2fs_free_mem(&ctx->dir_info);
 321                 ctx->dir_info = 0;
 322         }
 323 }
 324
 325 /*
 326  * Return the count of number of directories in the dir_info structure
 327  */
 328 int e2fsck_get_num_dirinfo(e2fsck_t ctx)
 329 {
 330         return ctx->dir_info ? ctx->dir_info->count : 0;
 331 }
 332
 333 struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
 334 {
 335         struct dir_info_iter *iter;
 336         struct dir_info_db *db = ctx->dir_info;
 337
 338         iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
 339                                       "dir_info iterator");
 340
 341         if (db->tdb)
 342                 iter->tdb_iter = tdb_firstkey(db->tdb);
 343
 344         return iter;
 345 }
 346
 347 void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
 348                               struct dir_info_iter *iter)
 349 {
 350         free(iter->tdb_iter.dptr);
 351         ext2fs_free_mem(&iter);
 352 }
 353
 354 /*
 355  * A simple interator function
 356  */
 357 struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
 358 {
 359         TDB_DATA data, key;
 360         struct dir_info_db *db = ctx->dir_info;
 361         struct dir_info_ent *buf;
 362         static struct dir_info ret_dir_info;
 363
 364         if (!ctx->dir_info || !iter)
 365                 return 0;
 366
 367         if (db->tdb) {
 368                 if (iter->tdb_iter.dptr == 0)
 369                         return 0;
 370                 key = iter->tdb_iter;
 371                 data = tdb_fetch(db->tdb, key);
 372                 if (!data.dptr) {
 373                         printf("iter fetch failed: %s\n",
 374                                tdb_errorstr(db->tdb));
 375                         return 0;
 376                 }
 377                 buf = (struct dir_info_ent *) data.dptr;
 378                 ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
 379                 ret_dir_info.dotdot = buf->dotdot;
 380                 ret_dir_info.parent = buf->parent;
 381                 iter->tdb_iter = tdb_nextkey(db->tdb, key);
 382                 free(key.dptr);
 383                 free(data.dptr);
 384                 return &ret_dir_info;
 385         }
 386
 387         if (iter->i >= ctx->dir_info->count)
 388                 return 0;
 389
 390 #ifdef DIRINFO_DEBUG
 391         printf("iter(%d, %d, %d)...", ctx->dir_info->array[iter->i].ino,
 392                ctx->dir_info->array[iter->i].dotdot,
 393                ctx->dir_info->array[iter->i].parent);
 394 #endif
 395         ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
 396         return(ctx->dir_info->last_lookup);
 397 }
 398
 399 /*
 400  * This function only sets the parent pointer, and requires that
 401  * dirinfo structure has already been created.
 402  */
 403 int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
 404                                ext2_ino_t parent)
 405 {
 406         struct dir_info *p;
 407
 408         p = e2fsck_get_dir_info(ctx, ino);
 409         if (!p)
 410                 return 1;
 411         p->parent = parent;
 412         e2fsck_put_dir_info(ctx, p);
 413         return 0;
 414 }
 415
 416 /*
 417  * This function only sets the dot dot pointer, and requires that
 418  * dirinfo structure has already been created.
 419  */
 420 int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 421                                ext2_ino_t dotdot)
 422 {
 423         struct dir_info *p;
 424
 425         p = e2fsck_get_dir_info(ctx, ino);
 426         if (!p)
 427                 return 1;
 428         p->dotdot = dotdot;
 429         e2fsck_put_dir_info(ctx, p);
 430         return 0;
 431 }
 432
 433 /*
 434  * This function only sets the parent pointer, and requires that
 435  * dirinfo structure has already been created.
 436  */
 437 int e2fsck_dir_info_get_parent(e2fsck_t ctx, ext2_ino_t ino,
 438                                ext2_ino_t *parent)
 439 {
 440         struct dir_info *p;
 441
 442         p = e2fsck_get_dir_info(ctx, ino);
 443         if (!p)
 444                 return 1;
 445         *parent = p->parent;
 446         return 0;
 447 }
 448
 449 /*
 450  * This function only sets the dot dot pointer, and requires that
 451  * dirinfo structure has already been created.
 452  */
 453 int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 454                                ext2_ino_t *dotdot)
 455 {
 456         struct dir_info *p;
 457
 458         p = e2fsck_get_dir_info(ctx, ino);
 459         if (!p)
 460                 return 1;
 461         *dotdot = p->dotdot;
 462         return 0;
 463 }
 464