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