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 "e2fsck.h"
  11 #include <sys/stat.h>
  12 #include <fcntl.h>
  13 #include "uuid/uuid.h"
  14
  15 #include <ext2fs/tdb.h>
  16
  17 struct dir_info_db {
  18         int             count;
  19         int             size;
  20         struct dir_info *array;
  21         struct dir_info *last_lookup;
  22         char            *tdb_fn;
  23         TDB_CONTEXT     *tdb;
  24 };
  25
  26 struct dir_info_iter {
  27         int     i;
  28         TDB_DATA        tdb_iter;
  29 };
  30
  31 struct dir_info_ent {
  32         ext2_ino_t              dotdot; /* Parent according to '..' */
  33         ext2_ino_t              parent; /* Parent according to treewalk */
  34 };
  35
  36
  37 static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir);
  38
  39 static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
  40 {
  41         struct dir_info_db      *db = ctx->dir_info;
  42         unsigned int            threshold;
  43         errcode_t               retval;
  44         char                    *tdb_dir, uuid[40];
  45         int                     fd, enable;
  46
  47         profile_get_string(ctx->profile, "scratch_files", "directory", 0, 0,
  48                            &tdb_dir);
  49         profile_get_uint(ctx->profile, "scratch_files",
  50                          "numdirs_threshold", 0, 0, &threshold);
  51         profile_get_boolean(ctx->profile, "scratch_files",
  52                             "dirinfo", 0, 1, &enable);
  53
  54         if (!enable || !tdb_dir || access(tdb_dir, W_OK) ||
  55             (threshold && num_dirs <= threshold))
  56                 return;
  57
  58         retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
  59         if (retval)
  60                 return;
  61
  62         uuid_unparse(ctx->fs->super->s_uuid, uuid);
  63         sprintf(db->tdb_fn, "%s/%s-dirinfo-XXXXXX", tdb_dir, uuid);
  64         fd = mkstemp(db->tdb_fn);
  65         db->tdb = tdb_open(db->tdb_fn, 0, TDB_CLEAR_IF_FIRST,
  66                            O_RDWR | O_CREAT | O_TRUNC, 0600);
  67         close(fd);
  68 }
  69
  70 static void setup_db(e2fsck_t ctx)
  71 {
  72         struct dir_info_db      *db;
  73         ext2_ino_t              num_dirs;
  74         errcode_t               retval;
  75
  76         db = (struct dir_info_db *)
  77                 e2fsck_allocate_memory(ctx, sizeof(struct dir_info_db),
  78                                        "directory map db");
  79         db->count = db->size = 0;
  80         db->array = 0;
  81
  82         ctx->dir_info = db;
  83
  84         retval = ext2fs_get_num_dirs(ctx->fs, &num_dirs);
  85         if (retval)
  86                 num_dirs = 1024;        /* Guess */
  87
  88         setup_tdb(ctx, num_dirs);
  89
  90         if (db->tdb) {
  91 #ifdef DIRINFO_DEBUG
  92                 printf("Note: using tdb!\n");
  93 #endif
  94                 return;
  95         }
  96
  97         db->size = num_dirs + 10;
  98         db->array  = (struct dir_info *)
  99                 e2fsck_allocate_memory(ctx, db->size
 100                                        * sizeof (struct dir_info),
 101                                        "directory map");
 102 }
 103
 104 /*
 105  * This subroutine is called during pass1 to create a directory info
 106  * entry.  During pass1, the passed-in parent is 0; it will get filled
 107  * in during pass2.
 108  */
 109 void e2fsck_add_dir_info(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
 110 {
 111         struct dir_info_db      *db;
 112         struct dir_info         *dir, ent;
 113         int                     i, j;
 114         errcode_t               retval;
 115         unsigned long           old_size;
 116
 117 #ifdef DIRINFO_DEBUG
 118         printf("add_dir_info for inode (%lu, %lu)...\n", ino, parent);
 119 #endif
 120         if (!ctx->dir_info)
 121                 setup_db(ctx);
 122         db = ctx->dir_info;
 123
 124         if (ctx->dir_info->count >= ctx->dir_info->size) {
 125                 old_size = ctx->dir_info->size * sizeof(struct dir_info);
 126                 ctx->dir_info->size += 10;
 127                 retval = ext2fs_resize_mem(old_size, ctx->dir_info->size *
 128                                            sizeof(struct dir_info),
 129                                            &ctx->dir_info->array);
 130                 if (retval) {
 131                         ctx->dir_info->size -= 10;
 132                         return;
 133                 }
 134         }
 135
 136         ent.ino = ino;
 137         ent.parent = parent;
 138         ent.dotdot = parent;
 139
 140         if (db->tdb) {
 141                 e2fsck_put_dir_info(ctx, &ent);
 142                 return;
 143         }
 144
 145         /*
 146          * Normally, add_dir_info is called with each inode in
 147          * sequential order; but once in a while (like when pass 3
 148          * needs to recreate the root directory or lost+found
 149          * directory) it is called out of order.  In those cases, we
 150          * need to move the dir_info entries down to make room, since
 151          * the dir_info array needs to be sorted by inode number for
 152          * get_dir_info()'s sake.
 153          */
 154         if (ctx->dir_info->count &&
 155             ctx->dir_info->array[ctx->dir_info->count-1].ino >= ino) {
 156                 for (i = ctx->dir_info->count-1; i > 0; i--)
 157                         if (ctx->dir_info->array[i-1].ino < ino)
 158                                 break;
 159                 dir = &ctx->dir_info->array[i];
 160                 if (dir->ino != ino)
 161                         for (j = ctx->dir_info->count++; j > i; j--)
 162                                 ctx->dir_info->array[j] = ctx->dir_info->array[j-1];
 163         } else
 164                 dir = &ctx->dir_info->array[ctx->dir_info->count++];
 165
 166         dir->ino = ino;
 167         dir->dotdot = parent;
 168         dir->parent = parent;
 169 }
 170
 171 /*
 172  * get_dir_info() --- given an inode number, try to find the directory
 173  * information entry for it.
 174  */
 175 static struct dir_info *e2fsck_get_dir_info(e2fsck_t ctx, ext2_ino_t ino)
 176 {
 177         struct dir_info_db      *db = ctx->dir_info;
 178         int                     low, high, mid;
 179         struct dir_info_ent     *buf;
 180         static struct dir_info  ret_dir_info;
 181
 182         if (!db)
 183                 return 0;
 184
 185 #ifdef DIRINFO_DEBUG
 186         printf("e2fsck_get_dir_info %d...", ino);
 187 #endif
 188
 189         if (db->tdb) {
 190                 TDB_DATA key, data;
 191
 192                 key.dptr = (unsigned char *) &ino;
 193                 key.dsize = sizeof(ext2_ino_t);
 194
 195                 data = tdb_fetch(db->tdb, key);
 196                 if (!data.dptr) {
 197                         if (tdb_error(db->tdb) != TDB_ERR_NOEXIST)
 198                                 printf("fetch failed: %s\n",
 199                                        tdb_errorstr(db->tdb));
 200                         return 0;
 201                 }
 202
 203                 buf = (struct dir_info_ent *) data.dptr;
 204                 ret_dir_info.ino = ino;
 205                 ret_dir_info.dotdot = buf->dotdot;
 206                 ret_dir_info.parent = buf->parent;
 207 #ifdef DIRINFO_DEBUG
 208                 printf("(%d,%d,%d)\n", ino, buf->dotdot, buf->parent);
 209 #endif
 210                 free(data.dptr);
 211                 return &ret_dir_info;
 212         }
 213
 214         if (db->last_lookup && db->last_lookup->ino == ino)
 215                 return db->last_lookup;
 216
 217         low = 0;
 218         high = ctx->dir_info->count-1;
 219         if (ino == ctx->dir_info->array[low].ino) {
 220 #ifdef DIRINFO_DEBUG
 221                 printf("(%d,%d,%d)\n", ino,
 222                        ctx->dir_info->array[low].dotdot,
 223                        ctx->dir_info->array[low].parent);
 224 #endif
 225                 return &ctx->dir_info->array[low];
 226         }
 227         if (ino == ctx->dir_info->array[high].ino) {
 228 #ifdef DIRINFO_DEBUG
 229                 printf("(%d,%d,%d)\n", ino,
 230                        ctx->dir_info->array[high].dotdot,
 231                        ctx->dir_info->array[high].parent);
 232 #endif
 233                 return &ctx->dir_info->array[high];
 234         }
 235
 236         while (low < high) {
 237                 mid = (low+high)/2;
 238                 if (mid == low || mid == high)
 239                         break;
 240                 if (ino == ctx->dir_info->array[mid].ino) {
 241 #ifdef DIRINFO_DEBUG
 242                         printf("(%d,%d,%d)\n", ino,
 243                                ctx->dir_info->array[mid].dotdot,
 244                                ctx->dir_info->array[mid].parent);
 245 #endif
 246                         return &ctx->dir_info->array[mid];
 247                 }
 248                 if (ino < ctx->dir_info->array[mid].ino)
 249                         high = mid;
 250                 else
 251                         low = mid;
 252         }
 253         return 0;
 254 }
 255
 256 static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir)
 257 {
 258         struct dir_info_db      *db = ctx->dir_info;
 259         struct dir_info_ent     buf;
 260         TDB_DATA                key, data;
 261
 262 #ifdef DIRINFO_DEBUG
 263         printf("e2fsck_put_dir_info (%d, %d, %d)...", dir->ino, dir->dotdot,
 264                dir->parent);
 265 #endif
 266
 267         if (!db->tdb)
 268                 return;
 269
 270         buf.parent = dir->parent;
 271         buf.dotdot = dir->dotdot;
 272
 273         key.dptr = (unsigned char *) &dir->ino;
 274         key.dsize = sizeof(ext2_ino_t);
 275         data.dptr = (unsigned char *) &buf;
 276         data.dsize = sizeof(buf);
 277
 278         if (tdb_store(db->tdb, key, data, TDB_REPLACE) == -1) {
 279                 printf("store failed: %s\n", tdb_errorstr(db->tdb));
 280         }
 281         return;
 282 }
 283
 284 /*
 285  * Free the dir_info structure when it isn't needed any more.
 286  */
 287 void e2fsck_free_dir_info(e2fsck_t ctx)
 288 {
 289         if (ctx->dir_info) {
 290                 if (ctx->dir_info->tdb)
 291                         tdb_close(ctx->dir_info->tdb);
 292                 if (ctx->dir_info->tdb_fn) {
 293                         unlink(ctx->dir_info->tdb_fn);
 294                         free(ctx->dir_info->tdb_fn);
 295                 }
 296                 if (ctx->dir_info->array)
 297                         ext2fs_free_mem(&ctx->dir_info->array);
 298                 ctx->dir_info->array = 0;
 299                 ctx->dir_info->size = 0;
 300                 ctx->dir_info->count = 0;
 301                 ext2fs_free_mem(&ctx->dir_info);
 302                 ctx->dir_info = 0;
 303         }
 304 }
 305
 306 /*
 307  * Return the count of number of directories in the dir_info structure
 308  */
 309 int e2fsck_get_num_dirinfo(e2fsck_t ctx)
 310 {
 311         return ctx->dir_info ? ctx->dir_info->count : 0;
 312 }
 313
 314 extern struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
 315 {
 316         struct dir_info_iter *iter;
 317         struct dir_info_db *db = ctx->dir_info;
 318
 319         iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
 320                                       "dir_info iterator");
 321
 322         if (db->tdb)
 323                 iter->tdb_iter = tdb_firstkey(db->tdb);
 324
 325         return iter;
 326 }
 327
 328 extern void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
 329                                      struct dir_info_iter *iter)
 330 {
 331         free(iter->tdb_iter.dptr);
 332         ext2fs_free_mem(&iter);
 333 }
 334
 335 /*
 336  * A simple interator function
 337  */
 338 struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
 339 {
 340         TDB_DATA data, key;
 341         struct dir_info_db *db = ctx->dir_info;
 342         struct dir_info_ent *buf;
 343         static struct dir_info ret_dir_info;
 344
 345         if (!ctx->dir_info || !iter)
 346                 return 0;
 347
 348         if (db->tdb) {
 349                 if (iter->tdb_iter.dptr == 0)
 350                         return 0;
 351                 key = iter->tdb_iter;
 352                 data = tdb_fetch(db->tdb, key);
 353                 if (!data.dptr) {
 354                         printf("iter fetch failed: %s\n",
 355                                tdb_errorstr(db->tdb));
 356                         return 0;
 357                 }
 358                 buf = (struct dir_info_ent *) data.dptr;
 359                 ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
 360                 ret_dir_info.dotdot = buf->dotdot;
 361                 ret_dir_info.parent = buf->parent;
 362                 iter->tdb_iter = tdb_nextkey(db->tdb, key);
 363                 free(key.dptr);
 364                 free(data.dptr);
 365                 return &ret_dir_info;
 366         }
 367
 368         if (iter->i >= ctx->dir_info->count)
 369                 return 0;
 370
 371 #ifdef DIRINFO_DEBUG
 372         printf("iter(%d, %d, %d)...", ctx->dir_info->array[iter->i].ino,
 373                ctx->dir_info->array[iter->i].dotdot,
 374                ctx->dir_info->array[iter->i].parent);
 375 #endif
 376         ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
 377         return(ctx->dir_info->last_lookup);
 378 }
 379
 380 /*
 381  * This function only sets the parent pointer, and requires that
 382  * dirinfo structure has already been created.
 383  */
 384 int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
 385                                ext2_ino_t parent)
 386 {
 387         struct dir_info *p;
 388
 389         p = e2fsck_get_dir_info(ctx, ino);
 390         if (!p)
 391                 return 1;
 392         p->parent = parent;
 393         e2fsck_put_dir_info(ctx, p);
 394         return 0;
 395 }
 396
 397 /*
 398  * This function only sets the dot dot pointer, and requires that
 399  * dirinfo structure has already been created.
 400  */
 401 int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 402                                ext2_ino_t dotdot)
 403 {
 404         struct dir_info *p;
 405
 406         p = e2fsck_get_dir_info(ctx, ino);
 407         if (!p)
 408                 return 1;
 409         p->dotdot = dotdot;
 410         e2fsck_put_dir_info(ctx, p);
 411         return 0;
 412 }
 413
 414 /*
 415  * This function only sets the parent pointer, and requires that
 416  * dirinfo structure has already been created.
 417  */
 418 int e2fsck_dir_info_get_parent(e2fsck_t ctx, ext2_ino_t ino,
 419                                ext2_ino_t *parent)
 420 {
 421         struct dir_info *p;
 422
 423         p = e2fsck_get_dir_info(ctx, ino);
 424         if (!p)
 425                 return 1;
 426         *parent = p->parent;
 427         return 0;
 428 }
 429
 430 /*
 431  * This function only sets the dot dot pointer, and requires that
 432  * dirinfo structure has already been created.
 433  */
 434 int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 435                                ext2_ino_t *dotdot)
 436 {
 437         struct dir_info *p;
 438
 439         p = e2fsck_get_dir_info(ctx, ino);
 440         if (!p)
 441                 return 1;
 442         *dotdot = p->dotdot;
 443         return 0;
 444 }
 445