fs/hpfs/anode.c

   1 /*
   2  *  linux/fs/hpfs/anode.c
   3  *
   4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
   5  *
   6  *  handling HPFS anode tree that contains file allocation info
   7  */
   8
   9 #include "hpfs_fn.h"
  10
  11 /* Find a sector in allocation tree */
  12
  13 secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
  14                    struct bplus_header *btree, unsigned sec,
  15                    struct buffer_head *bh)
  16 {
  17         anode_secno a = -1;
  18         struct anode *anode;
  19         int i;
  20         int c1, c2 = 0;
  21         go_down:
  22         if (s->s_hpfs_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
  23         if (btree->internal) {
  24                 for (i = 0; i < btree->n_used_nodes; i++)
  25                         if (btree->u.internal[i].file_secno > sec) {
  26                                 a = btree->u.internal[i].down;
  27                                 brelse(bh);
  28                                 if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
  29                                 btree = &anode->btree;
  30                                 goto go_down;
  31                         }
  32                 hpfs_error(s, "sector %08x not found in internal anode %08x", sec, a);
  33                 brelse(bh);
  34                 return -1;
  35         }
  36         for (i = 0; i < btree->n_used_nodes; i++)
  37                 if (btree->u.external[i].file_secno <= sec &&
  38                     btree->u.external[i].file_secno + btree->u.external[i].length > sec) {
  39                         a = btree->u.external[i].disk_secno + sec - btree->u.external[i].file_secno;
  40                         if (s->s_hpfs_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
  41                                 brelse(bh);
  42                                 return -1;
  43                         }
  44                         if (inode) {
  45                                 inode->i_hpfs_file_sec = btree->u.external[i].file_secno;
  46                                 inode->i_hpfs_disk_sec = btree->u.external[i].disk_secno;
  47                                 inode->i_hpfs_n_secs = btree->u.external[i].length;
  48                         }
  49                         brelse(bh);
  50                         return a;
  51                 }
  52         hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
  53         brelse(bh);
  54         return -1;
  55 }
  56
  57 /* Add a sector to tree */
  58
  59 secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
  60 {
  61         struct bplus_header *btree;
  62         struct anode *anode = NULL, *ranode = NULL;
  63         struct fnode *fnode;
  64         anode_secno a, na = -1, ra, up = -1;
  65         secno se;
  66         struct buffer_head *bh, *bh1, *bh2;
  67         int n;
  68         unsigned fs;
  69         int c1, c2 = 0;
  70         if (fnod) {
  71                 if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
  72                 btree = &fnode->btree;
  73         } else {
  74                 if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
  75                 btree = &anode->btree;
  76         }
  77         a = node;
  78         go_down:
  79         if ((n = btree->n_used_nodes - 1) < -!!fnod) {
  80                 hpfs_error(s, "anode %08x has no entries", a);
  81                 brelse(bh);
  82                 return -1;
  83         }
  84         if (btree->internal) {
  85                 a = btree->u.internal[n].down;
  86                 btree->u.internal[n].file_secno = -1;
  87                 mark_buffer_dirty(bh);
  88                 brelse(bh);
  89                 if (s->s_hpfs_chk)
  90                         if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
  91                 if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
  92                 btree = &anode->btree;
  93                 goto go_down;
  94         }
  95         if (n >= 0) {
  96                 if (btree->u.external[n].file_secno + btree->u.external[n].length != fsecno) {
  97                         hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
  98                                 btree->u.external[n].file_secno + btree->u.external[n].length, fsecno,
  99                                 fnod?'f':'a', node);
 100                         brelse(bh);
 101                         return -1;
 102                 }
 103                 if (hpfs_alloc_if_possible(s, se = btree->u.external[n].disk_secno + btree->u.external[n].length)) {
 104                         btree->u.external[n].length++;
 105                         mark_buffer_dirty(bh);
 106                         brelse(bh);
 107                         return se;
 108                 }
 109         } else {
 110                 if (fsecno) {
 111                         hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
 112                         brelse(bh);
 113                         return -1;
 114                 }
 115                 se = !fnod ? node : (node + 16384) & ~16383;
 116         }
 117         if (!(se = hpfs_alloc_sector(s, se, 1, fsecno*ALLOC_M>ALLOC_FWD_MAX ? ALLOC_FWD_MAX : fsecno*ALLOC_M<ALLOC_FWD_MIN ? ALLOC_FWD_MIN : fsecno*ALLOC_M, 1))) {
 118                 brelse(bh);
 119                 return -1;
 120         }
 121         fs = n < 0 ? 0 : btree->u.external[n].file_secno + btree->u.external[n].length;
 122         if (!btree->n_free_nodes) {
 123                 up = a != node ? anode->up : -1;
 124                 if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
 125                         brelse(bh);
 126                         hpfs_free_sectors(s, se, 1);
 127                         return -1;
 128                 }
 129                 if (a == node && fnod) {
 130                         anode->up = node;
 131                         anode->btree.fnode_parent = 1;
 132                         anode->btree.n_used_nodes = btree->n_used_nodes;
 133                         anode->btree.first_free = btree->first_free;
 134                         anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
 135                         memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
 136                         btree->internal = 1;
 137                         btree->n_free_nodes = 11;
 138                         btree->n_used_nodes = 1;
 139                         btree->first_free = (char *)&(btree->u.internal[1]) - (char *)btree;
 140                         btree->u.internal[0].file_secno = -1;
 141                         btree->u.internal[0].down = na;
 142                         mark_buffer_dirty(bh);
 143                 } else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
 144                         brelse(bh);
 145                         brelse(bh1);
 146                         hpfs_free_sectors(s, se, 1);
 147                         hpfs_free_sectors(s, na, 1);
 148                         return -1;
 149                 }
 150                 brelse(bh);
 151                 bh = bh1;
 152                 btree = &anode->btree;
 153         }
 154         btree->n_free_nodes--; n = btree->n_used_nodes++;
 155         btree->first_free += 12;
 156         btree->u.external[n].disk_secno = se;
 157         btree->u.external[n].file_secno = fs;
 158         btree->u.external[n].length = 1;
 159         mark_buffer_dirty(bh);
 160         brelse(bh);
 161         if ((a == node && fnod) || na == -1) return se;
 162         c2 = 0;
 163         while (up != -1) {
 164                 struct anode *new_anode;
 165                 if (s->s_hpfs_chk)
 166                         if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
 167                 if (up != node || !fnod) {
 168                         if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
 169                         btree = &anode->btree;
 170                 } else {
 171                         if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
 172                         btree = &fnode->btree;
 173                 }
 174                 if (btree->n_free_nodes) {
 175                         btree->n_free_nodes--; n = btree->n_used_nodes++;
 176                         btree->first_free += 8;
 177                         btree->u.internal[n].file_secno = -1;
 178                         btree->u.internal[n].down = na;
 179                         btree->u.internal[n-1].file_secno = fs;
 180                         mark_buffer_dirty(bh);
 181                         brelse(bh);
 182                         brelse(bh2);
 183                         hpfs_free_sectors(s, ra, 1);
 184                         if ((anode = hpfs_map_anode(s, na, &bh))) {
 185                                 anode->up = up;
 186                                 anode->btree.fnode_parent = up == node && fnod;
 187                                 mark_buffer_dirty(bh);
 188                                 brelse(bh);
 189                         }
 190                         return se;
 191                 }
 192                 up = up != node ? anode->up : -1;
 193                 btree->u.internal[btree->n_used_nodes - 1].file_secno = /*fs*/-1;
 194                 mark_buffer_dirty(bh);
 195                 brelse(bh);
 196                 a = na;
 197                 if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
 198                         anode = new_anode;
 199                         /*anode->up = up != -1 ? up : ra;*/
 200                         anode->btree.internal = 1;
 201                         anode->btree.n_used_nodes = 1;
 202                         anode->btree.n_free_nodes = 59;
 203                         anode->btree.first_free = 16;
 204                         anode->btree.u.internal[0].down = a;
 205                         anode->btree.u.internal[0].file_secno = -1;
 206                         mark_buffer_dirty(bh);
 207                         brelse(bh);
 208                         if ((anode = hpfs_map_anode(s, a, &bh))) {
 209                                 anode->up = na;
 210                                 mark_buffer_dirty(bh);
 211                                 brelse(bh);
 212                         }
 213                 } else na = a;
 214         }
 215         if ((anode = hpfs_map_anode(s, na, &bh))) {
 216                 anode->up = node;
 217                 if (fnod) anode->btree.fnode_parent = 1;
 218                 mark_buffer_dirty(bh);
 219                 brelse(bh);
 220         }
 221         if (!fnod) {
 222                 if (!(anode = hpfs_map_anode(s, node, &bh))) {
 223                         brelse(bh2);
 224                         return -1;
 225                 }
 226                 btree = &anode->btree;
 227         } else {
 228                 if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
 229                         brelse(bh2);
 230                         return -1;
 231                 }
 232                 btree = &fnode->btree;
 233         }
 234         ranode->up = node;
 235         memcpy(&ranode->btree, btree, btree->first_free);
 236         if (fnod) ranode->btree.fnode_parent = 1;
 237         ranode->btree.n_free_nodes = (ranode->btree.internal ? 60 : 40) - ranode->btree.n_used_nodes;
 238         if (ranode->btree.internal) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
 239                 struct anode *unode;
 240                 if ((unode = hpfs_map_anode(s, ranode->u.internal[n].down, &bh1))) {
 241                         unode->up = ra;
 242                         unode->btree.fnode_parent = 0;
 243                         mark_buffer_dirty(bh1);
 244                         brelse(bh1);
 245                 }
 246         }
 247         btree->internal = 1;
 248         btree->n_free_nodes = fnod ? 10 : 58;
 249         btree->n_used_nodes = 2;
 250         btree->first_free = (char *)&btree->u.internal[2] - (char *)btree;
 251         btree->u.internal[0].file_secno = fs;
 252         btree->u.internal[0].down = ra;
 253         btree->u.internal[1].file_secno = -1;
 254         btree->u.internal[1].down = na;
 255         mark_buffer_dirty(bh);
 256         brelse(bh);
 257         mark_buffer_dirty(bh2);
 258         brelse(bh2);
 259         return se;
 260 }
 261
 262 /*
 263  * Remove allocation tree. Recursion would look much nicer but
 264  * I want to avoid it because it can cause stack overflow.
 265  */
 266
 267 void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
 268 {
 269         struct bplus_header *btree1 = btree;
 270         struct anode *anode = NULL;
 271         anode_secno ano = 0, oano;
 272         struct buffer_head *bh;
 273         int level = 0;
 274         int pos = 0;
 275         int i;
 276         int c1, c2 = 0;
 277         int d1, d2;
 278         go_down:
 279         d2 = 0;
 280         while (btree1->internal) {
 281                 ano = btree1->u.internal[pos].down;
 282                 if (level) brelse(bh);
 283                 if (s->s_hpfs_chk)
 284                         if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
 285                                 return;
 286                 if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
 287                 btree1 = &anode->btree;
 288                 level++;
 289                 pos = 0;
 290         }
 291         for (i = 0; i < btree1->n_used_nodes; i++)
 292                 hpfs_free_sectors(s, btree1->u.external[i].disk_secno, btree1->u.external[i].length);
 293         go_up:
 294         if (!level) return;
 295         brelse(bh);
 296         if (s->s_hpfs_chk)
 297                 if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
 298         hpfs_free_sectors(s, ano, 1);
 299         oano = ano;
 300         ano = anode->up;
 301         if (--level) {
 302                 if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
 303                 btree1 = &anode->btree;
 304         } else btree1 = btree;
 305         for (i = 0; i < btree1->n_used_nodes; i++) {
 306                 if (btree1->u.internal[i].down == oano) {
 307                         if ((pos = i + 1) < btree1->n_used_nodes)
 308                                 goto go_down;
 309                         else
 310                                 goto go_up;
 311                 }
 312         }
 313         hpfs_error(s,
 314                    "reference to anode %08x not found in anode %08x "
 315                    "(probably bad up pointer)",
 316                    oano, level ? ano : -1);
 317         if (level)
 318                 brelse(bh);
 319 }
 320
 321 /* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
 322
 323 static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
 324 {
 325         struct anode *anode;
 326         struct buffer_head *bh;
 327         if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
 328         return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
 329 }
 330
 331 int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
 332             unsigned len, char *buf)
 333 {
 334         struct buffer_head *bh;
 335         char *data;
 336         secno sec;
 337         unsigned l;
 338         while (len) {
 339                 if (ano) {
 340                         if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
 341                                 return -1;
 342                 } else sec = a + (pos >> 9);
 343                 if (s->s_hpfs_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
 344                 if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
 345                         return -1;
 346                 l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
 347                 memcpy(buf, data + (pos & 0x1ff), l);
 348                 brelse(bh);
 349                 buf += l; pos += l; len -= l;
 350         }
 351         return 0;
 352 }
 353
 354 int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
 355              unsigned len, char *buf)
 356 {
 357         struct buffer_head *bh;
 358         char *data;
 359         secno sec;
 360         unsigned l;
 361         while (len) {
 362                 if (ano) {
 363                         if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
 364                                 return -1;
 365                 } else sec = a + (pos >> 9);
 366                 if (s->s_hpfs_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
 367                 if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
 368                         return -1;
 369                 l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
 370                 memcpy(data + (pos & 0x1ff), buf, l);
 371                 mark_buffer_dirty(bh);
 372                 brelse(bh);
 373                 buf += l; pos += l; len -= l;
 374         }
 375         return 0;
 376 }
 377
 378 void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
 379 {
 380         struct anode *anode;
 381         struct buffer_head *bh;
 382         if (ano) {
 383                 if (!(anode = hpfs_map_anode(s, a, &bh))) return;
 384                 hpfs_remove_btree(s, &anode->btree);
 385                 brelse(bh);
 386                 hpfs_free_sectors(s, a, 1);
 387         } else hpfs_free_sectors(s, a, (len + 511) >> 9);
 388 }
 389
 390 /* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
 391
 392 void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
 393 {
 394         struct fnode *fnode;
 395         struct anode *anode;
 396         struct buffer_head *bh;
 397         struct bplus_header *btree;
 398         anode_secno node = f;
 399         int i, j, nodes;
 400         int c1, c2 = 0;
 401         if (fno) {
 402                 if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
 403                 btree = &fnode->btree;
 404         } else {
 405                 if (!(anode = hpfs_map_anode(s, f, &bh))) return;
 406                 btree = &anode->btree;
 407         }
 408         if (!secs) {
 409                 hpfs_remove_btree(s, btree);
 410                 if (fno) {
 411                         btree->n_free_nodes = 8;
 412                         btree->n_used_nodes = 0;
 413                         btree->first_free = 8;
 414                         btree->internal = 0;
 415                         mark_buffer_dirty(bh);
 416                 } else hpfs_free_sectors(s, f, 1);
 417                 brelse(bh);
 418                 return;
 419         }
 420         while (btree->internal) {
 421                 nodes = btree->n_used_nodes + btree->n_free_nodes;
 422                 for (i = 0; i < btree->n_used_nodes; i++)
 423                         if (btree->u.internal[i].file_secno >= secs) goto f;
 424                 brelse(bh);
 425                 hpfs_error(s, "internal btree %08x doesn't end with -1", node);
 426                 return;
 427                 f:
 428                 for (j = i + 1; j < btree->n_used_nodes; j++)
 429                         hpfs_ea_remove(s, btree->u.internal[j].down, 1, 0);
 430                 btree->n_used_nodes = i + 1;
 431                 btree->n_free_nodes = nodes - btree->n_used_nodes;
 432                 btree->first_free = 8 + 8 * btree->n_used_nodes;
 433                 mark_buffer_dirty(bh);
 434                 if (btree->u.internal[i].file_secno == secs) {
 435                         brelse(bh);
 436                         return;
 437                 }
 438                 node = btree->u.internal[i].down;
 439                 brelse(bh);
 440                 if (s->s_hpfs_chk)
 441                         if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
 442                                 return;
 443                 if (!(anode = hpfs_map_anode(s, node, &bh))) return;
 444                 btree = &anode->btree;
 445         }
 446         nodes = btree->n_used_nodes + btree->n_free_nodes;
 447         for (i = 0; i < btree->n_used_nodes; i++)
 448                 if (btree->u.external[i].file_secno + btree->u.external[i].length >= secs) goto ff;
 449         brelse(bh);
 450         return;
 451         ff:
 452         if (secs <= btree->u.external[i].file_secno) {
 453                 hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
 454                 if (i) i--;
 455         }
 456         else if (btree->u.external[i].file_secno + btree->u.external[i].length > secs) {
 457                 hpfs_free_sectors(s, btree->u.external[i].disk_secno + secs -
 458                         btree->u.external[i].file_secno, btree->u.external[i].length
 459                         - secs + btree->u.external[i].file_secno); /* I hope gcc optimizes this :-) */
 460                 btree->u.external[i].length = secs - btree->u.external[i].file_secno;
 461         }
 462         for (j = i + 1; j < btree->n_used_nodes; j++)
 463                 hpfs_free_sectors(s, btree->u.external[j].disk_secno, btree->u.external[j].length);
 464         btree->n_used_nodes = i + 1;
 465         btree->n_free_nodes = nodes - btree->n_used_nodes;
 466         btree->first_free = 8 + 12 * btree->n_used_nodes;
 467         mark_buffer_dirty(bh);
 468         brelse(bh);
 469 }
 470
 471 /* Remove file or directory and it's eas - note that directory must
 472    be empty when this is called. */
 473
 474 void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
 475 {
 476         struct buffer_head *bh;
 477         struct fnode *fnode;
 478         struct extended_attribute *ea;
 479         struct extended_attribute *ea_end;
 480         if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
 481         if (!fnode->dirflag) hpfs_remove_btree(s, &fnode->btree);
 482         else hpfs_remove_dtree(s, fnode->u.external[0].disk_secno);
 483         ea_end = fnode_end_ea(fnode);
 484         for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
 485                 if (ea->indirect)
 486                         hpfs_ea_remove(s, ea_sec(ea), ea->anode, ea_len(ea));
 487         hpfs_ea_ext_remove(s, fnode->ea_secno, fnode->ea_anode, fnode->ea_size_l);
 488         brelse(bh);
 489         hpfs_free_sectors(s, fno, 1);
 490 }