1// SPDX-License-Identifier: GPL-2.0 2/* 3 * linux/fs/hpfs/alloc.c 4 * 5 * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 6 * 7 * HPFS bitmap operations 8 */ 9 10#include "hpfs_fn.h" 11 12static void hpfs_claim_alloc(struct super_block *s, secno sec) 13{ 14 struct hpfs_sb_info *sbi = hpfs_sb(s); 15 if (sbi->sb_n_free != (unsigned)-1) { 16 if (unlikely(!sbi->sb_n_free)) { 17 hpfs_error(s, "free count underflow, allocating sector %08x", sec); 18 sbi->sb_n_free = -1; 19 return; 20 } 21 sbi->sb_n_free--; 22 } 23} 24 25static void hpfs_claim_free(struct super_block *s, secno sec) 26{ 27 struct hpfs_sb_info *sbi = hpfs_sb(s); 28 if (sbi->sb_n_free != (unsigned)-1) { 29 if (unlikely(sbi->sb_n_free >= sbi->sb_fs_size)) { 30 hpfs_error(s, "free count overflow, freeing sector %08x", sec); 31 sbi->sb_n_free = -1; 32 return; 33 } 34 sbi->sb_n_free++; 35 } 36} 37 38static void hpfs_claim_dirband_alloc(struct super_block *s, secno sec) 39{ 40 struct hpfs_sb_info *sbi = hpfs_sb(s); 41 if (sbi->sb_n_free_dnodes != (unsigned)-1) { 42 if (unlikely(!sbi->sb_n_free_dnodes)) { 43 hpfs_error(s, "dirband free count underflow, allocating sector %08x", sec); 44 sbi->sb_n_free_dnodes = -1; 45 return; 46 } 47 sbi->sb_n_free_dnodes--; 48 } 49} 50 51static void hpfs_claim_dirband_free(struct super_block *s, secno sec) 52{ 53 struct hpfs_sb_info *sbi = hpfs_sb(s); 54 if (sbi->sb_n_free_dnodes != (unsigned)-1) { 55 if (unlikely(sbi->sb_n_free_dnodes >= sbi->sb_dirband_size / 4)) { 56 hpfs_error(s, "dirband free count overflow, freeing sector %08x", sec); 57 sbi->sb_n_free_dnodes = -1; 58 return; 59 } 60 sbi->sb_n_free_dnodes++; 61 } 62} 63 64/* 65 * Check if a sector is allocated in bitmap 66 * This is really slow. Turned on only if chk==2 67 */ 68 69static int chk_if_allocated(struct super_block *s, secno sec, char *msg) 70{ 71 struct quad_buffer_head qbh; 72 __le32 *bmp; 73 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail; 74 if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f)) & 1) { 75 hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec); 76 goto fail1; 77 } 78 hpfs_brelse4(&qbh); 79 if (sec >= hpfs_sb(s)->sb_dirband_start && sec < hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) { 80 unsigned ssec = (sec - hpfs_sb(s)->sb_dirband_start) / 4; 81 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail; 82 if ((le32_to_cpu(bmp[ssec >> 5]) >> (ssec & 0x1f)) & 1) { 83 hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec); 84 goto fail1; 85 } 86 hpfs_brelse4(&qbh); 87 } 88 return 0; 89 fail1: 90 hpfs_brelse4(&qbh); 91 fail: 92 return 1; 93} 94 95/* 96 * Check if sector(s) have proper number and additionally check if they're 97 * allocated in bitmap. 98 */ 99 100int hpfs_chk_sectors(struct super_block *s, secno start, int len, char *msg) 101{ 102 if (start + len < start || start < 0x12 || 103 start + len > hpfs_sb(s)->sb_fs_size) { 104 hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start); 105 return 1; 106 } 107 if (hpfs_sb(s)->sb_chk>=2) { 108 int i; 109 for (i = 0; i < len; i++) 110 if (chk_if_allocated(s, start + i, msg)) return 1; 111 } 112 return 0; 113} 114 115static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward) 116{ 117 struct quad_buffer_head qbh; 118 __le32 *bmp; 119 unsigned bs = near & ~0x3fff; 120 unsigned nr = (near & 0x3fff) & ~(n - 1); 121 /*unsigned mnr;*/ 122 unsigned i, q; 123 int a, b; 124 secno ret = 0; 125 if (n != 1 && n != 4) { 126 hpfs_error(s, "Bad allocation size: %d", n); 127 return 0; 128 } 129 if (bs != ~0x3fff) { 130 if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls; 131 } else { 132 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls; 133 } 134 if (!tstbits(bmp, nr, n + forward)) { 135 ret = bs + nr; 136 goto rt; 137 } 138 q = nr + n; b = 0; 139 while ((a = tstbits(bmp, q, n + forward)) != 0) { 140 q += a; 141 if (n != 1) q = ((q-1)&~(n-1))+n; 142 if (!b) { 143 if (q>>5 != nr>>5) { 144 b = 1; 145 q = nr & 0x1f; 146 } 147 } else if (q > nr) break; 148 } 149 if (!a) { 150 ret = bs + q; 151 goto rt; 152 } 153 nr >>= 5; 154 /*for (i = nr + 1; i != nr; i++, i &= 0x1ff) */ 155 i = nr; 156 do { 157 if (!le32_to_cpu(bmp[i])) goto cont; 158 if (n + forward >= 0x3f && le32_to_cpu(bmp[i]) != 0xffffffff) goto cont; 159 q = i<<5; 160 if (i > 0) { 161 unsigned k = le32_to_cpu(bmp[i-1]); 162 while (k & 0x80000000) { 163 q--; k <<= 1; 164 } 165 } 166 if (n != 1) q = ((q-1)&~(n-1))+n; 167 while ((a = tstbits(bmp, q, n + forward)) != 0) { 168 q += a; 169 if (n != 1) q = ((q-1)&~(n-1))+n; 170 if (q>>5 > i) break; 171 } 172 if (!a) { 173 ret = bs + q; 174 goto rt; 175 } 176 cont: 177 i++, i &= 0x1ff; 178 } while (i != nr); 179 rt: 180 if (ret) { 181 if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (le32_to_cpu(bmp[(ret & 0x3fff) >> 5]) | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) { 182 hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret); 183 ret = 0; 184 goto b; 185 } 186 bmp[(ret & 0x3fff) >> 5] &= cpu_to_le32(~(((1 << n) - 1) << (ret & 0x1f))); 187 hpfs_mark_4buffers_dirty(&qbh); 188 } 189 b: 190 hpfs_brelse4(&qbh); 191 uls: 192 return ret; 193} 194 195/* 196 * Allocation strategy: 1) search place near the sector specified 197 * 2) search bitmap where free sectors last found 198 * 3) search all bitmaps 199 * 4) search all bitmaps ignoring number of pre-allocated 200 * sectors 201 */ 202 203secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward) 204{ 205 secno sec; 206 int i; 207 unsigned n_bmps; 208 struct hpfs_sb_info *sbi = hpfs_sb(s); 209 int f_p = 0; 210 int near_bmp; 211 if (forward < 0) { 212 forward = -forward; 213 f_p = 1; 214 } 215 n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14; 216 if (near && near < sbi->sb_fs_size) { 217 if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret; 218 near_bmp = near >> 14; 219 } else near_bmp = n_bmps / 2; 220 /* 221 if (b != -1) { 222 if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) { 223 b &= 0x0fffffff; 224 goto ret; 225 } 226 if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret; 227 */ 228 if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc; 229 less_fwd: 230 for (i = 0; i < n_bmps; i++) { 231 if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) { 232 sbi->sb_c_bitmap = near_bmp+i; 233 goto ret; 234 } 235 if (!forward) { 236 if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) { 237 sbi->sb_c_bitmap = near_bmp-i-1; 238 goto ret; 239 } 240 } else { 241 if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) { 242 sbi->sb_c_bitmap = near_bmp+i-n_bmps; 243 goto ret; 244 } 245 } 246 if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) { 247 goto ret; 248 } 249 } 250 if (!f_p) { 251 if (forward) { 252 sbi->sb_max_fwd_alloc = forward * 3 / 4; 253 forward /= 2; 254 goto less_fwd; 255 } 256 } 257 sec = 0; 258 ret: 259 if (sec) { 260 i = 0; 261 do 262 hpfs_claim_alloc(s, sec + i); 263 while (unlikely(++i < n)); 264 } 265 if (sec && f_p) { 266 for (i = 0; i < forward; i++) { 267 if (!hpfs_alloc_if_possible(s, sec + n + i)) { 268 hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i); 269 sec = 0; 270 break; 271 } 272 } 273 } 274 return sec; 275} 276 277static secno alloc_in_dirband(struct super_block *s, secno near) 278{ 279 unsigned nr = near; 280 secno sec; 281 struct hpfs_sb_info *sbi = hpfs_sb(s); 282 if (nr < sbi->sb_dirband_start) 283 nr = sbi->sb_dirband_start; 284 if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size) 285 nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4; 286 nr -= sbi->sb_dirband_start; 287 nr >>= 2; 288 sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0); 289 if (!sec) return 0; 290 hpfs_claim_dirband_alloc(s, sec); 291 return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start; 292} 293 294/* Alloc sector if it's free */ 295 296int hpfs_alloc_if_possible(struct super_block *s, secno sec) 297{ 298 struct quad_buffer_head qbh; 299 __le32 *bmp; 300 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end; 301 if (le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) & (1 << (sec & 0x1f))) { 302 bmp[(sec & 0x3fff) >> 5] &= cpu_to_le32(~(1 << (sec & 0x1f))); 303 hpfs_mark_4buffers_dirty(&qbh); 304 hpfs_brelse4(&qbh); 305 hpfs_claim_alloc(s, sec); 306 return 1; 307 } 308 hpfs_brelse4(&qbh); 309 end: 310 return 0; 311} 312 313/* Free sectors in bitmaps */ 314 315void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n) 316{ 317 struct quad_buffer_head qbh; 318 __le32 *bmp; 319 struct hpfs_sb_info *sbi = hpfs_sb(s); 320 /*pr_info("2 - ");*/ 321 if (!n) return; 322 if (sec < 0x12) { 323 hpfs_error(s, "Trying to free reserved sector %08x", sec); 324 return; 325 } 326 sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n; 327 if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff; 328 new_map: 329 if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) { 330 return; 331 } 332 new_tst: 333 if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f) & 1)) { 334 hpfs_error(s, "sector %08x not allocated", sec); 335 hpfs_brelse4(&qbh); 336 return; 337 } 338 bmp[(sec & 0x3fff) >> 5] |= cpu_to_le32(1 << (sec & 0x1f)); 339 hpfs_claim_free(s, sec); 340 if (!--n) { 341 hpfs_mark_4buffers_dirty(&qbh); 342 hpfs_brelse4(&qbh); 343 return; 344 } 345 if (!(++sec & 0x3fff)) { 346 hpfs_mark_4buffers_dirty(&qbh); 347 hpfs_brelse4(&qbh); 348 goto new_map; 349 } 350 goto new_tst; 351} 352 353/* 354 * Check if there are at least n free dnodes on the filesystem. 355 * Called before adding to dnode. If we run out of space while 356 * splitting dnodes, it would corrupt dnode tree. 357 */ 358 359int hpfs_check_free_dnodes(struct super_block *s, int n) 360{ 361 int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14; 362 int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff; 363 int i, j; 364 __le32 *bmp; 365 struct quad_buffer_head qbh; 366 if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) { 367 for (j = 0; j < 512; j++) { 368 unsigned k; 369 if (!le32_to_cpu(bmp[j])) continue; 370 for (k = le32_to_cpu(bmp[j]); k; k >>= 1) if (k & 1) if (!--n) { 371 hpfs_brelse4(&qbh); 372 return 0; 373 } 374 } 375 } 376 hpfs_brelse4(&qbh); 377 i = 0; 378 if (hpfs_sb(s)->sb_c_bitmap != -1) { 379 bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1"); 380 goto chk_bmp; 381 } 382 chk_next: 383 if (i == b) i++; 384 if (i >= n_bmps) return 1; 385 bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2"); 386 chk_bmp: 387 if (bmp) { 388 for (j = 0; j < 512; j++) { 389 u32 k; 390 if (!le32_to_cpu(bmp[j])) continue; 391 for (k = 0xf; k; k <<= 4) 392 if ((le32_to_cpu(bmp[j]) & k) == k) { 393 if (!--n) { 394 hpfs_brelse4(&qbh); 395 return 0; 396 } 397 } 398 } 399 hpfs_brelse4(&qbh); 400 } 401 i++; 402 goto chk_next; 403} 404 405void hpfs_free_dnode(struct super_block *s, dnode_secno dno) 406{ 407 if (hpfs_sb(s)->sb_chk) if (dno & 3) { 408 hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno); 409 return; 410 } 411 if (dno < hpfs_sb(s)->sb_dirband_start || 412 dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) { 413 hpfs_free_sectors(s, dno, 4); 414 } else { 415 struct quad_buffer_head qbh; 416 __le32 *bmp; 417 unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4; 418 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) { 419 return; 420 } 421 bmp[ssec >> 5] |= cpu_to_le32(1 << (ssec & 0x1f)); 422 hpfs_mark_4buffers_dirty(&qbh); 423 hpfs_brelse4(&qbh); 424 hpfs_claim_dirband_free(s, dno); 425 } 426} 427 428struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near, 429 dnode_secno *dno, struct quad_buffer_head *qbh) 430{ 431 struct dnode *d; 432 if (hpfs_get_free_dnodes(s) > FREE_DNODES_ADD) { 433 if (!(*dno = alloc_in_dirband(s, near))) 434 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) return NULL; 435 } else { 436 if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) 437 if (!(*dno = alloc_in_dirband(s, near))) return NULL; 438 } 439 if (!(d = hpfs_get_4sectors(s, *dno, qbh))) { 440 hpfs_free_dnode(s, *dno); 441 return NULL; 442 } 443 memset(d, 0, 2048); 444 d->magic = cpu_to_le32(DNODE_MAGIC); 445 d->first_free = cpu_to_le32(52); 446 d->dirent[0] = 32; 447 d->dirent[2] = 8; 448 d->dirent[30] = 1; 449 d->dirent[31] = 255; 450 d->self = cpu_to_le32(*dno); 451 return d; 452} 453 454struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno, 455 struct buffer_head **bh) 456{ 457 struct fnode *f; 458 if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD))) return NULL; 459 if (!(f = hpfs_get_sector(s, *fno, bh))) { 460 hpfs_free_sectors(s, *fno, 1); 461 return NULL; 462 } 463 memset(f, 0, 512); 464 f->magic = cpu_to_le32(FNODE_MAGIC); 465 f->ea_offs = cpu_to_le16(0xc4); 466 f->btree.n_free_nodes = 8; 467 f->btree.first_free = cpu_to_le16(8); 468 return f; 469} 470 471struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano, 472 struct buffer_head **bh) 473{ 474 struct anode *a; 475 if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD))) return NULL; 476 if (!(a = hpfs_get_sector(s, *ano, bh))) { 477 hpfs_free_sectors(s, *ano, 1); 478 return NULL; 479 } 480 memset(a, 0, 512); 481 a->magic = cpu_to_le32(ANODE_MAGIC); 482 a->self = cpu_to_le32(*ano); 483 a->btree.n_free_nodes = 40; 484 a->btree.n_used_nodes = 0; 485 a->btree.first_free = cpu_to_le16(8); 486 return a; 487} 488 489static unsigned find_run(__le32 *bmp, unsigned *idx) 490{ 491 unsigned len; 492 while (tstbits(bmp, *idx, 1)) { 493 (*idx)++; 494 if (unlikely(*idx >= 0x4000)) 495 return 0; 496 } 497 len = 1; 498 while (!tstbits(bmp, *idx + len, 1)) 499 len++; 500 return len; 501} 502 503static int do_trim(struct super_block *s, secno start, unsigned len, secno limit_start, secno limit_end, unsigned minlen, unsigned *result) 504{ 505 int err; 506 secno end; 507 if (fatal_signal_pending(current)) 508 return -EINTR; 509 end = start + len; 510 if (start < limit_start) 511 start = limit_start; 512 if (end > limit_end) 513 end = limit_end; 514 if (start >= end) 515 return 0; 516 if (end - start < minlen) 517 return 0; 518 err = sb_issue_discard(s, start, end - start, GFP_NOFS, 0); 519 if (err) 520 return err; 521 *result += end - start; 522 return 0; 523} 524 525int hpfs_trim_fs(struct super_block *s, u64 start, u64 end, u64 minlen, unsigned *result) 526{ 527 int err = 0; 528 struct hpfs_sb_info *sbi = hpfs_sb(s); 529 unsigned idx, len, start_bmp, end_bmp; 530 __le32 *bmp; 531 struct quad_buffer_head qbh; 532 533 *result = 0; 534 if (!end || end > sbi->sb_fs_size) 535 end = sbi->sb_fs_size; 536 if (start >= sbi->sb_fs_size) 537 return 0; 538 if (minlen > 0x4000) 539 return 0; 540 if (start < sbi->sb_dirband_start + sbi->sb_dirband_size && end > sbi->sb_dirband_start) { 541 hpfs_lock(s); 542 if (sb_rdonly(s)) { 543 err = -EROFS; 544 goto unlock_1; 545 } 546 if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) { 547 err = -EIO; 548 goto unlock_1; 549 } 550 idx = 0; 551 while ((len = find_run(bmp, &idx)) && !err) { 552 err = do_trim(s, sbi->sb_dirband_start + idx * 4, len * 4, start, end, minlen, result); 553 idx += len; 554 } 555 hpfs_brelse4(&qbh); 556unlock_1: 557 hpfs_unlock(s); 558 } 559 start_bmp = start >> 14; 560 end_bmp = (end + 0x3fff) >> 14; 561 while (start_bmp < end_bmp && !err) { 562 hpfs_lock(s); 563 if (sb_rdonly(s)) { 564 err = -EROFS; 565 goto unlock_2; 566 } 567 if (!(bmp = hpfs_map_bitmap(s, start_bmp, &qbh, "trim"))) { 568 err = -EIO; 569 goto unlock_2; 570 } 571 idx = 0; 572 while ((len = find_run(bmp, &idx)) && !err) { 573 err = do_trim(s, (start_bmp << 14) + idx, len, start, end, minlen, result); 574 idx += len; 575 } 576 hpfs_brelse4(&qbh); 577unlock_2: 578 hpfs_unlock(s); 579 start_bmp++; 580 } 581 return err; 582} 583