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 (bp_internal(btree)) {
  24                for (i = 0; i < btree->n_used_nodes; i++)
  25                        if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
  26                                a = le32_to_cpu(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 (le32_to_cpu(btree->u.external[i].file_secno) <= sec &&
  38                    le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > sec) {
  39                        a = le32_to_cpu(btree->u.external[i].disk_secno) + sec - le32_to_cpu(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 = le32_to_cpu(btree->u.external[i].file_secno);
  47                                hpfs_inode->i_disk_sec = le32_to_cpu(btree->u.external[i].disk_secno);
  48                                hpfs_inode->i_n_secs = le32_to_cpu(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 (bp_internal(btree)) {
  86                a = le32_to_cpu(btree->u.internal[n].down);
  87                btree->u.internal[n].file_secno = cpu_to_le32(-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 (le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length) != fsecno) {
  98                        hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
  99                                le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(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 = le32_to_cpu(btree->u.external[n].disk_secno) + le32_to_cpu(btree->u.external[n].length))) {
 105                        btree->u.external[n].length = cpu_to_le32(le32_to_cpu(btree->u.external[n].length) + 1);
 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))) {
 119                brelse(bh);
 120                return -1;
 121        }
 122        fs = n < 0 ? 0 : le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length);
 123        if (!btree->n_free_nodes) {
 124                up = a != node ? le32_to_cpu(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 = cpu_to_le32(node);
 132                        anode->btree.flags |= BP_fnode_parent;
 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->flags |= BP_internal;
 138                        btree->n_free_nodes = 11;
 139                        btree->n_used_nodes = 1;
 140                        btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
 141                        btree->u.internal[0].file_secno = cpu_to_le32(-1);
 142                        btree->u.internal[0].down = cpu_to_le32(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 = cpu_to_le16(le16_to_cpu(btree->first_free) + 12);
 157        btree->u.external[n].disk_secno = cpu_to_le32(se);
 158        btree->u.external[n].file_secno = cpu_to_le32(fs);
 159        btree->u.external[n].length = cpu_to_le32(1);
 160        mark_buffer_dirty(bh);
 161        brelse(bh);
 162        if ((a == node && fnod) || na == -1) return se;
 163        c2 = 0;
 164        while (up != (anode_secno)-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 = cpu_to_le16(le16_to_cpu(btree->first_free) + 8);
 178                        btree->u.internal[n].file_secno = cpu_to_le32(-1);
 179                        btree->u.internal[n].down = cpu_to_le32(na);
 180                        btree->u.internal[n-1].file_secno = cpu_to_le32(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 = cpu_to_le32(up);
 187                                if (up == node && fnod)
 188                                        anode->btree.flags |= BP_fnode_parent;
 189                                else
 190                                        anode->btree.flags &= ~BP_fnode_parent;
 191                                mark_buffer_dirty(bh);
 192                                brelse(bh);
 193                        }
 194                        return se;
 195                }
 196                up = up != node ? le32_to_cpu(anode->up) : -1;
 197                btree->u.internal[btree->n_used_nodes - 1].file_secno = cpu_to_le32(/*fs*/-1);
 198                mark_buffer_dirty(bh);
 199                brelse(bh);
 200                a = na;
 201                if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
 202                        anode = new_anode;
 203                        /*anode->up = cpu_to_le32(up != -1 ? up : ra);*/
 204                        anode->btree.flags |= BP_internal;
 205                        anode->btree.n_used_nodes = 1;
 206                        anode->btree.n_free_nodes = 59;
 207                        anode->btree.first_free = cpu_to_le16(16);
 208                        anode->btree.u.internal[0].down = cpu_to_le32(a);
 209                        anode->btree.u.internal[0].file_secno = cpu_to_le32(-1);
 210                        mark_buffer_dirty(bh);
 211                        brelse(bh);
 212                        if ((anode = hpfs_map_anode(s, a, &bh))) {
 213                                anode->up = cpu_to_le32(na);
 214                                mark_buffer_dirty(bh);
 215                                brelse(bh);
 216                        }
 217                } else na = a;
 218        }
 219        if ((anode = hpfs_map_anode(s, na, &bh))) {
 220                anode->up = cpu_to_le32(node);
 221                if (fnod)
 222                        anode->btree.flags |= BP_fnode_parent;
 223                mark_buffer_dirty(bh);
 224                brelse(bh);
 225        }
 226        if (!fnod) {
 227                if (!(anode = hpfs_map_anode(s, node, &bh))) {
 228                        brelse(bh2);
 229                        return -1;
 230                }
 231                btree = &anode->btree;
 232        } else {
 233                if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
 234                        brelse(bh2);
 235                        return -1;
 236                }
 237                btree = &fnode->btree;
 238        }
 239        ranode->up = cpu_to_le32(node);
 240        memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));
 241        if (fnod)
 242                ranode->btree.flags |= BP_fnode_parent;
 243        ranode->btree.n_free_nodes = (bp_internal(&ranode->btree) ? 60 : 40) - ranode->btree.n_used_nodes;
 244        if (bp_internal(&ranode->btree)) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
 245                struct anode *unode;
 246                if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
 247                        unode->up = cpu_to_le32(ra);
 248                        unode->btree.flags &= ~BP_fnode_parent;
 249                        mark_buffer_dirty(bh1);
 250                        brelse(bh1);
 251                }
 252        }
 253        btree->flags |= BP_internal;
 254        btree->n_free_nodes = fnod ? 10 : 58;
 255        btree->n_used_nodes = 2;
 256        btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
 257        btree->u.internal[0].file_secno = cpu_to_le32(fs);
 258        btree->u.internal[0].down = cpu_to_le32(ra);
 259        btree->u.internal[1].file_secno = cpu_to_le32(-1);
 260        btree->u.internal[1].down = cpu_to_le32(na);
 261        mark_buffer_dirty(bh);
 262        brelse(bh);
 263        mark_buffer_dirty(bh2);
 264        brelse(bh2);
 265        return se;
 266}
 267
 268/*
 269 * Remove allocation tree. Recursion would look much nicer but
 270 * I want to avoid it because it can cause stack overflow.
 271 */
 272
 273void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
 274{
 275        struct bplus_header *btree1 = btree;
 276        struct anode *anode = NULL;
 277        anode_secno ano = 0, oano;
 278        struct buffer_head *bh;
 279        int level = 0;
 280        int pos = 0;
 281        int i;
 282        int c1, c2 = 0;
 283        int d1, d2;
 284        go_down:
 285        d2 = 0;
 286        while (bp_internal(btree1)) {
 287                ano = le32_to_cpu(btree1->u.internal[pos].down);
 288                if (level) brelse(bh);
 289                if (hpfs_sb(s)->sb_chk)
 290                        if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
 291                                return;
 292                if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
 293                btree1 = &anode->btree;
 294                level++;
 295                pos = 0;
 296        }
 297        for (i = 0; i < btree1->n_used_nodes; i++)
 298                hpfs_free_sectors(s, le32_to_cpu(btree1->u.external[i].disk_secno), le32_to_cpu(btree1->u.external[i].length));
 299        go_up:
 300        if (!level) return;
 301        brelse(bh);
 302        if (hpfs_sb(s)->sb_chk)
 303                if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
 304        hpfs_free_sectors(s, ano, 1);
 305        oano = ano;
 306        ano = le32_to_cpu(anode->up);
 307        if (--level) {
 308                if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
 309                btree1 = &anode->btree;
 310        } else btree1 = btree;
 311        for (i = 0; i < btree1->n_used_nodes; i++) {
 312                if (le32_to_cpu(btree1->u.internal[i].down) == oano) {
 313                        if ((pos = i + 1) < btree1->n_used_nodes)
 314                                goto go_down;
 315                        else
 316                                goto go_up;
 317                }
 318        }
 319        hpfs_error(s,
 320                   "reference to anode %08x not found in anode %08x "
 321                   "(probably bad up pointer)",
 322                   oano, level ? ano : -1);
 323        if (level)
 324                brelse(bh);
 325}
 326
 327/* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
 328
 329static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
 330{
 331        struct anode *anode;
 332        struct buffer_head *bh;
 333        if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
 334        return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
 335}
 336
 337int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
 338            unsigned len, char *buf)
 339{
 340        struct buffer_head *bh;
 341        char *data;
 342        secno sec;
 343        unsigned l;
 344        while (len) {
 345                if (ano) {
 346                        if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
 347                                return -1;
 348                } else sec = a + (pos >> 9);
 349                if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
 350                if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
 351                        return -1;
 352                l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
 353                memcpy(buf, data + (pos & 0x1ff), l);
 354                brelse(bh);
 355                buf += l; pos += l; len -= l;
 356        }
 357        return 0;
 358}
 359
 360int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
 361             unsigned len, const char *buf)
 362{
 363        struct buffer_head *bh;
 364        char *data;
 365        secno sec;
 366        unsigned l;
 367        while (len) {
 368                if (ano) {
 369                        if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
 370                                return -1;
 371                } else sec = a + (pos >> 9);
 372                if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
 373                if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
 374                        return -1;
 375                l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
 376                memcpy(data + (pos & 0x1ff), buf, l);
 377                mark_buffer_dirty(bh);
 378                brelse(bh);
 379                buf += l; pos += l; len -= l;
 380        }
 381        return 0;
 382}
 383
 384void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
 385{
 386        struct anode *anode;
 387        struct buffer_head *bh;
 388        if (ano) {
 389                if (!(anode = hpfs_map_anode(s, a, &bh))) return;
 390                hpfs_remove_btree(s, &anode->btree);
 391                brelse(bh);
 392                hpfs_free_sectors(s, a, 1);
 393        } else hpfs_free_sectors(s, a, (len + 511) >> 9);
 394}
 395
 396/* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
 397
 398void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
 399{
 400        struct fnode *fnode;
 401        struct anode *anode;
 402        struct buffer_head *bh;
 403        struct bplus_header *btree;
 404        anode_secno node = f;
 405        int i, j, nodes;
 406        int c1, c2 = 0;
 407        if (fno) {
 408                if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
 409                btree = &fnode->btree;
 410        } else {
 411                if (!(anode = hpfs_map_anode(s, f, &bh))) return;
 412                btree = &anode->btree;
 413        }
 414        if (!secs) {
 415                hpfs_remove_btree(s, btree);
 416                if (fno) {
 417                        btree->n_free_nodes = 8;
 418                        btree->n_used_nodes = 0;
 419                        btree->first_free = cpu_to_le16(8);
 420                        btree->flags &= ~BP_internal;
 421                        mark_buffer_dirty(bh);
 422                } else hpfs_free_sectors(s, f, 1);
 423                brelse(bh);
 424                return;
 425        }
 426        while (bp_internal(btree)) {
 427                nodes = btree->n_used_nodes + btree->n_free_nodes;
 428                for (i = 0; i < btree->n_used_nodes; i++)
 429                        if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;
 430                brelse(bh);
 431                hpfs_error(s, "internal btree %08x doesn't end with -1", node);
 432                return;
 433                f:
 434                for (j = i + 1; j < btree->n_used_nodes; j++)
 435                        hpfs_ea_remove(s, le32_to_cpu(btree->u.internal[j].down), 1, 0);
 436                btree->n_used_nodes = i + 1;
 437                btree->n_free_nodes = nodes - btree->n_used_nodes;
 438                btree->first_free = cpu_to_le16(8 + 8 * btree->n_used_nodes);
 439                mark_buffer_dirty(bh);
 440                if (btree->u.internal[i].file_secno == cpu_to_le32(secs)) {
 441                        brelse(bh);
 442                        return;
 443                }
 444                node = le32_to_cpu(btree->u.internal[i].down);
 445                brelse(bh);
 446                if (hpfs_sb(s)->sb_chk)
 447                        if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
 448                                return;
 449                if (!(anode = hpfs_map_anode(s, node, &bh))) return;
 450                btree = &anode->btree;
 451        }       
 452        nodes = btree->n_used_nodes + btree->n_free_nodes;
 453        for (i = 0; i < btree->n_used_nodes; i++)
 454                if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) >= secs) goto ff;
 455        brelse(bh);
 456        return;
 457        ff:
 458        if (secs <= le32_to_cpu(btree->u.external[i].file_secno)) {
 459                hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
 460                if (i) i--;
 461        }
 462        else if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > secs) {
 463                hpfs_free_sectors(s, le32_to_cpu(btree->u.external[i].disk_secno) + secs -
 464                        le32_to_cpu(btree->u.external[i].file_secno), le32_to_cpu(btree->u.external[i].length)
 465                        - secs + le32_to_cpu(btree->u.external[i].file_secno)); /* I hope gcc optimizes this :-) */
 466                btree->u.external[i].length = cpu_to_le32(secs - le32_to_cpu(btree->u.external[i].file_secno));
 467        }
 468        for (j = i + 1; j < btree->n_used_nodes; j++)
 469                hpfs_free_sectors(s, le32_to_cpu(btree->u.external[j].disk_secno), le32_to_cpu(btree->u.external[j].length));
 470        btree->n_used_nodes = i + 1;
 471        btree->n_free_nodes = nodes - btree->n_used_nodes;
 472        btree->first_free = cpu_to_le16(8 + 12 * btree->n_used_nodes);
 473        mark_buffer_dirty(bh);
 474        brelse(bh);
 475}
 476
 477/* Remove file or directory and it's eas - note that directory must
 478   be empty when this is called. */
 479
 480void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
 481{
 482        struct buffer_head *bh;
 483        struct fnode *fnode;
 484        struct extended_attribute *ea;
 485        struct extended_attribute *ea_end;
 486        if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
 487        if (!fnode_is_dir(fnode)) hpfs_remove_btree(s, &fnode->btree);
 488        else hpfs_remove_dtree(s, le32_to_cpu(fnode->u.external[0].disk_secno));
 489        ea_end = fnode_end_ea(fnode);
 490        for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
 491                if (ea_indirect(ea))
 492                        hpfs_ea_remove(s, ea_sec(ea), ea_in_anode(ea), ea_len(ea));
 493        hpfs_ea_ext_remove(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l));
 494        brelse(bh);
 495        hpfs_free_sectors(s, fno, 1);
 496}
 497
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