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