git.oblomov.eu Git - linux-2.6/blob - 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 (hpfs_sb(s)->sb_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 (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
  41                                 brelse(bh);
  42                                 return -1;
  43                         }
  44                         if (inode) {
  45                                 struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
  46                                 hpfs_inode->i_file_sec = btree->u.external[i].file_secno;
  47                                 hpfs_inode->i_disk_sec = btree->u.external[i].disk_secno;
  48                                 hpfs_inode->i_n_secs = btree->u.external[i].length;
  49                         }
  50                         brelse(bh);
  51                         return a;
  52                 }
  53         hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
  54         brelse(bh);
  55         return -1;
  56 }
  57
  58 /* Add a sector to tree */
  59
  60 secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
  61 {
  62         struct bplus_header *btree;
  63         struct anode *anode = NULL, *ranode = NULL;
  64         struct fnode *fnode;
  65         anode_secno a, na = -1, ra, up = -1;
  66         secno se;
  67         struct buffer_head *bh, *bh1, *bh2;
  68         int n;
  69         unsigned fs;
  70         int c1, c2 = 0;
  71         if (fnod) {
  72                 if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
  73                 btree = &fnode->btree;
  74         } else {
  75                 if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
  76                 btree = &anode->btree;
  77         }
  78         a = node;
  79         go_down:
  80         if ((n = btree->n_used_nodes - 1) < -!!fnod) {
  81                 hpfs_error(s, "anode %08x has no entries", a);
  82                 brelse(bh);
  83                 return -1;
  84         }
  85         if (btree->internal) {
  86                 a = btree->u.internal[n].down;
  87                 btree->u.internal[n].file_secno = -1;
  88                 mark_buffer_dirty(bh);
  89                 brelse(bh);
  90                 if (hpfs_sb(s)->sb_chk)
  91                         if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
  92                 if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
  93                 btree = &anode->btree;
  94                 goto go_down;
  95         }
  96         if (n >= 0) {
  97                 if (btree->u.external[n].file_secno + btree->u.external[n].length != fsecno) {
  98                         hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
  99                                 btree->u.external[n].file_secno + btree->u.external[n].length, fsecno,
 100                                 fnod?'f':'a', node);
 101                         brelse(bh);
 102                         return -1;
 103                 }
 104                 if (hpfs_alloc_if_possible(s, se = btree->u.external[n].disk_secno + btree->u.external[n].length)) {
 105                         btree->u.external[n].length++;
 106                         mark_buffer_dirty(bh);
 107                         brelse(bh);
 108                         return se;
 109                 }
 110         } else {
 111                 if (fsecno) {
 112                         hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
 113                         brelse(bh);
 114                         return -1;
 115                 }
 116                 se = !fnod ? node : (node + 16384) & ~16383;
 117         }
 118         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))) {
 119                 brelse(bh);
 120                 return -1;
 121         }
 122         fs = n < 0 ? 0 : btree->u.external[n].file_secno + btree->u.external[n].length;
 123         if (!btree->n_free_nodes) {
 124                 up = a != node ? anode->up : -1;
 125                 if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
 126                         brelse(bh);
 127                         hpfs_free_sectors(s, se, 1);
 128                         return -1;
 129                 }
 130                 if (a == node && fnod) {
 131                         anode->up = node;
 132                         anode->btree.fnode_parent = 1;
 133                         anode->btree.n_used_nodes = btree->n_used_nodes;
 134                         anode->btree.first_free = btree->first_free;
 135                         anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
 136                         memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
 137                         btree->internal = 1;
 138                         btree->n_free_nodes = 11;
 139                         btree->n_used_nodes = 1;
 140                         btree->first_free = (char *)&(btree->u.internal[1]) - (char *)btree;
 141                         btree->u.internal[0].file_secno = -1;
 142                         btree->u.internal[0].down = na;
 143                         mark_buffer_dirty(bh);
 144                 } else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
 145                         brelse(bh);
 146                         brelse(bh1);
 147                         hpfs_free_sectors(s, se, 1);
 148                         hpfs_free_sectors(s, na, 1);
 149                         return -1;
 150                 }
 151                 brelse(bh);
 152                 bh = bh1;
 153                 btree = &anode->btree;
 154         }
 155         btree->n_free_nodes--; n = btree->n_used_nodes++;
 156         btree->first_free += 12;
 157         btree->u.external[n].disk_secno = se;
 158         btree->u.external[n].file_secno = fs;
 159         btree->u.external[n].length = 1;
 160         mark_buffer_dirty(bh);
 161         brelse(bh);
 162         if ((a == node && fnod) || na == -1) return se;
 163         c2 = 0;
 164         while (up != -1) {
 165                 struct anode *new_anode;
 166                 if (hpfs_sb(s)->sb_chk)
 167                         if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
 168                 if (up != node || !fnod) {
 169                         if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
 170                         btree = &anode->btree;
 171                 } else {
 172                         if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
 173                         btree = &fnode->btree;
 174                 }
 175                 if (btree->n_free_nodes) {
 176                         btree->n_free_nodes--; n = btree->n_used_nodes++;
 177                         btree->first_free += 8;
 178                         btree->u.internal[n].file_secno = -1;
 179                         btree->u.internal[n].down = na;
 180                         btree->u.internal[n-1].file_secno = fs;
 181                         mark_buffer_dirty(bh);
 182                         brelse(bh);
 183                         brelse(bh2);
 184                         hpfs_free_sectors(s, ra, 1);
 185                         if ((anode = hpfs_map_anode(s, na, &bh))) {
 186                                 anode->up = up;
 187                                 anode->btree.fnode_parent = up == node && fnod;
 188                                 mark_buffer_dirty(bh);
 189                                 brelse(bh);
 190                         }
 191                         return se;
 192                 }
 193                 up = up != node ? anode->up : -1;
 194                 btree->u.internal[btree->n_used_nodes - 1].file_secno = /*fs*/-1;
 195                 mark_buffer_dirty(bh);
 196                 brelse(bh);
 197                 a = na;
 198                 if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
 199                         anode = new_anode;
 200                         /*anode->up = up != -1 ? up : ra;*/
 201                         anode->btree.internal = 1;
 202                         anode->btree.n_used_nodes = 1;
 203                         anode->btree.n_free_nodes = 59;
 204                         anode->btree.first_free = 16;
 205                         anode->btree.u.internal[0].down = a;
 206                         anode->btree.u.internal[0].file_secno = -1;
 207                         mark_buffer_dirty(bh);
 208                         brelse(bh);
 209                         if ((anode = hpfs_map_anode(s, a, &bh))) {
 210                                 anode->up = na;
 211                                 mark_buffer_dirty(bh);
 212                                 brelse(bh);
 213                         }
 214                 } else na = a;
 215         }
 216         if ((anode = hpfs_map_anode(s, na, &bh))) {
 217                 anode->up = node;
 218                 if (fnod) anode->btree.fnode_parent = 1;
 219                 mark_buffer_dirty(bh);
 220                 brelse(bh);
 221         }
 222         if (!fnod) {
 223                 if (!(anode = hpfs_map_anode(s, node, &bh))) {
 224                         brelse(bh2);
 225                         return -1;
 226                 }
 227                 btree = &anode->btree;
 228         } else {
 229                 if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
 230                         brelse(bh2);
 231                         return -1;
 232                 }
 233                 btree = &fnode->btree;
 234         }
 235         ranode->up = node;
 236         memcpy(&ranode->btree, btree, btree->first_free);
 237         if (fnod) ranode->btree.fnode_parent = 1;
 238         ranode->btree.n_free_nodes = (ranode->btree.internal ? 60 : 40) - ranode->btree.n_used_nodes;
 239         if (ranode->btree.internal) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
 240                 struct anode *unode;
 241                 if ((unode = hpfs_map_anode(s, ranode->u.internal[n].down, &bh1))) {
 242                         unode->up = ra;
 243                         unode->btree.fnode_parent = 0;
 244                         mark_buffer_dirty(bh1);
 245                         brelse(bh1);
 246                 }
 247         }
 248         btree->internal = 1;
 249         btree->n_free_nodes = fnod ? 10 : 58;
 250         btree->n_used_nodes = 2;
 251         btree->first_free = (char *)&btree->u.internal[2] - (char *)btree;
 252         btree->u.internal[0].file_secno = fs;
 253         btree->u.internal[0].down = ra;
 254         btree->u.internal[1].file_secno = -1;
 255         btree->u.internal[1].down = na;
 256         mark_buffer_dirty(bh);
 257         brelse(bh);
 258         mark_buffer_dirty(bh2);
 259         brelse(bh2);
 260         return se;
 261 }
 262
 263 /*
 264  * Remove allocation tree. Recursion would look much nicer but
 265  * I want to avoid it because it can cause stack overflow.
 266  */
 267
 268 void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
 269 {
 270         struct bplus_header *btree1 = btree;
 271         struct anode *anode = NULL;
 272         anode_secno ano = 0, oano;
 273         struct buffer_head *bh;
 274         int level = 0;
 275         int pos = 0;
 276         int i;
 277         int c1, c2 = 0;
 278         int d1, d2;
 279         go_down:
 280         d2 = 0;
 281         while (btree1->internal) {
 282                 ano = btree1->u.internal[pos].down;
 283                 if (level) brelse(bh);
 284                 if (hpfs_sb(s)->sb_chk)
 285                         if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
 286                                 return;
 287                 if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
 288                 btree1 = &anode->btree;
 289                 level++;
 290                 pos = 0;
 291         }
 292         for (i = 0; i < btree1->n_used_nodes; i++)
 293                 hpfs_free_sectors(s, btree1->u.external[i].disk_secno, btree1->u.external[i].length);
 294         go_up:
 295         if (!level) return;
 296         brelse(bh);
 297         if (hpfs_sb(s)->sb_chk)
 298                 if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
 299         hpfs_free_sectors(s, ano, 1);
 300         oano = ano;
 301         ano = anode->up;
 302         if (--level) {
 303                 if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
 304                 btree1 = &anode->btree;
 305         } else btree1 = btree;
 306         for (i = 0; i < btree1->n_used_nodes; i++) {
 307                 if (btree1->u.internal[i].down == oano) {
 308                         if ((pos = i + 1) < btree1->n_used_nodes)
 309                                 goto go_down;
 310                         else
 311                                 goto go_up;
 312                 }
 313         }
 314         hpfs_error(s,
 315                    "reference to anode %08x not found in anode %08x "
 316                    "(probably bad up pointer)",
 317                    oano, level ? ano : -1);
 318         if (level)
 319                 brelse(bh);
 320 }
 321
 322 /* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
 323
 324 static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
 325 {
 326         struct anode *anode;
 327         struct buffer_head *bh;
 328         if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
 329         return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
 330 }
 331
 332 int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
 333             unsigned len, char *buf)
 334 {
 335         struct buffer_head *bh;
 336         char *data;
 337         secno sec;
 338         unsigned l;
 339         while (len) {
 340                 if (ano) {
 341                         if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
 342                                 return -1;
 343                 } else sec = a + (pos >> 9);
 344                 if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
 345                 if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
 346                         return -1;
 347                 l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
 348                 memcpy(buf, data + (pos & 0x1ff), l);
 349                 brelse(bh);
 350                 buf += l; pos += l; len -= l;
 351         }
 352         return 0;
 353 }
 354
 355 int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
 356              unsigned len, char *buf)
 357 {
 358         struct buffer_head *bh;
 359         char *data;
 360         secno sec;
 361         unsigned l;
 362         while (len) {
 363                 if (ano) {
 364                         if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
 365                                 return -1;
 366                 } else sec = a + (pos >> 9);
 367                 if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
 368                 if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
 369                         return -1;
 370                 l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
 371                 memcpy(data + (pos & 0x1ff), buf, l);
 372                 mark_buffer_dirty(bh);
 373                 brelse(bh);
 374                 buf += l; pos += l; len -= l;
 375         }
 376         return 0;
 377 }
 378
 379 void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
 380 {
 381         struct anode *anode;
 382         struct buffer_head *bh;
 383         if (ano) {
 384                 if (!(anode = hpfs_map_anode(s, a, &bh))) return;
 385                 hpfs_remove_btree(s, &anode->btree);
 386                 brelse(bh);
 387                 hpfs_free_sectors(s, a, 1);
 388         } else hpfs_free_sectors(s, a, (len + 511) >> 9);
 389 }
 390
 391 /* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
 392
 393 void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
 394 {
 395         struct fnode *fnode;
 396         struct anode *anode;
 397         struct buffer_head *bh;
 398         struct bplus_header *btree;
 399         anode_secno node = f;
 400         int i, j, nodes;
 401         int c1, c2 = 0;
 402         if (fno) {
 403                 if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
 404                 btree = &fnode->btree;
 405         } else {
 406                 if (!(anode = hpfs_map_anode(s, f, &bh))) return;
 407                 btree = &anode->btree;
 408         }
 409         if (!secs) {
 410                 hpfs_remove_btree(s, btree);
 411                 if (fno) {
 412                         btree->n_free_nodes = 8;
 413                         btree->n_used_nodes = 0;
 414                         btree->first_free = 8;
 415                         btree->internal = 0;
 416                         mark_buffer_dirty(bh);
 417                 } else hpfs_free_sectors(s, f, 1);
 418                 brelse(bh);
 419                 return;
 420         }
 421         while (btree->internal) {
 422                 nodes = btree->n_used_nodes + btree->n_free_nodes;
 423                 for (i = 0; i < btree->n_used_nodes; i++)
 424                         if (btree->u.internal[i].file_secno >= secs) goto f;
 425                 brelse(bh);
 426                 hpfs_error(s, "internal btree %08x doesn't end with -1", node);
 427                 return;
 428                 f:
 429                 for (j = i + 1; j < btree->n_used_nodes; j++)
 430                         hpfs_ea_remove(s, btree->u.internal[j].down, 1, 0);
 431                 btree->n_used_nodes = i + 1;
 432                 btree->n_free_nodes = nodes - btree->n_used_nodes;
 433                 btree->first_free = 8 + 8 * btree->n_used_nodes;
 434                 mark_buffer_dirty(bh);
 435                 if (btree->u.internal[i].file_secno == secs) {
 436                         brelse(bh);
 437                         return;
 438                 }
 439                 node = btree->u.internal[i].down;
 440                 brelse(bh);
 441                 if (hpfs_sb(s)->sb_chk)
 442                         if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
 443                                 return;
 444                 if (!(anode = hpfs_map_anode(s, node, &bh))) return;
 445                 btree = &anode->btree;
 446         }
 447         nodes = btree->n_used_nodes + btree->n_free_nodes;
 448         for (i = 0; i < btree->n_used_nodes; i++)
 449                 if (btree->u.external[i].file_secno + btree->u.external[i].length >= secs) goto ff;
 450         brelse(bh);
 451         return;
 452         ff:
 453         if (secs <= btree->u.external[i].file_secno) {
 454                 hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
 455                 if (i) i--;
 456         }
 457         else if (btree->u.external[i].file_secno + btree->u.external[i].length > secs) {
 458                 hpfs_free_sectors(s, btree->u.external[i].disk_secno + secs -
 459                         btree->u.external[i].file_secno, btree->u.external[i].length
 460                         - secs + btree->u.external[i].file_secno); /* I hope gcc optimizes this :-) */
 461                 btree->u.external[i].length = secs - btree->u.external[i].file_secno;
 462         }
 463         for (j = i + 1; j < btree->n_used_nodes; j++)
 464                 hpfs_free_sectors(s, btree->u.external[j].disk_secno, btree->u.external[j].length);
 465         btree->n_used_nodes = i + 1;
 466         btree->n_free_nodes = nodes - btree->n_used_nodes;
 467         btree->first_free = 8 + 12 * btree->n_used_nodes;
 468         mark_buffer_dirty(bh);
 469         brelse(bh);
 470 }
 471
 472 /* Remove file or directory and it's eas - note that directory must
 473    be empty when this is called. */
 474
 475 void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
 476 {
 477         struct buffer_head *bh;
 478         struct fnode *fnode;
 479         struct extended_attribute *ea;
 480         struct extended_attribute *ea_end;
 481         if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
 482         if (!fnode->dirflag) hpfs_remove_btree(s, &fnode->btree);
 483         else hpfs_remove_dtree(s, fnode->u.external[0].disk_secno);
 484         ea_end = fnode_end_ea(fnode);
 485         for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
 486                 if (ea->indirect)
 487                         hpfs_ea_remove(s, ea_sec(ea), ea->anode, ea_len(ea));
 488         hpfs_ea_ext_remove(s, fnode->ea_secno, fnode->ea_anode, fnode->ea_size_l);
 489         brelse(bh);
 490         hpfs_free_sectors(s, fno, 1);
 491 }