linux/fs/hpfs/anode.c
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   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
  13secno 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
  60secno 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
 268void 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
 324static 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
 332int 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
 355int 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
 379void 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
 393void 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
 475void 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}
 492