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