1 /* $NetBSD: ffs_alloc.c,v 1.16 2005/08/19 02:09:50 christos Exp $ */ 2 /* From: NetBSD: ffs_alloc.c,v 1.50 2001/09/06 02:16:01 lukem Exp */ 3 4 /* 5 * Copyright (c) 2002 Networks Associates Technology, Inc. 6 * All rights reserved. 7 * 8 * This software was developed for the FreeBSD Project by Marshall 9 * Kirk McKusick and Network Associates Laboratories, the Security 10 * Research Division of Network Associates, Inc. under DARPA/SPAWAR 11 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS 12 * research program 13 * 14 * Copyright (c) 1982, 1986, 1989, 1993 15 * The Regents of the University of California. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 3. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)ffs_alloc.c 8.19 (Berkeley) 7/13/95 42 */ 43 44 #if HAVE_NBTOOL_CONFIG_H 45 #include "nbtool_config.h" 46 #endif 47 48 #include <sys/cdefs.h> 49 #if defined(__RCSID) && !defined(__lint) 50 __RCSID("$NetBSD: ffs_alloc.c,v 1.16 2005/08/19 02:09:50 christos Exp $"); 51 #endif /* !__lint */ 52 53 #include <sys/param.h> 54 #include <sys/time.h> 55 56 #include <errno.h> 57 58 #include "makefs.h" 59 60 #include <ufs/ufs/dinode.h> 61 #include <ufs/ufs/ufs_bswap.h> 62 #include <ufs/ffs/fs.h> 63 64 #include "ffs/buf.h" 65 #include "ffs/ufs_inode.h" 66 #include "ffs/ffs_extern.h" 67 68 69 static int scanc(u_int, const u_char *, const u_char *, int); 70 71 static daddr_t ffs_alloccg(struct inode *, int, daddr_t, int); 72 static daddr_t ffs_alloccgblk(struct inode *, struct buf *, daddr_t); 73 static daddr_t ffs_hashalloc(struct inode *, int, daddr_t, int, 74 daddr_t (*)(struct inode *, int, daddr_t, int)); 75 static int32_t ffs_mapsearch(struct fs *, struct cg *, daddr_t, int); 76 77 /* in ffs_tables.c */ 78 extern const int inside[], around[]; 79 extern const u_char * const fragtbl[]; 80 81 /* 82 * Allocate a block in the file system. 83 * 84 * The size of the requested block is given, which must be some 85 * multiple of fs_fsize and <= fs_bsize. 86 * A preference may be optionally specified. If a preference is given 87 * the following hierarchy is used to allocate a block: 88 * 1) allocate the requested block. 89 * 2) allocate a rotationally optimal block in the same cylinder. 90 * 3) allocate a block in the same cylinder group. 91 * 4) quadradically rehash into other cylinder groups, until an 92 * available block is located. 93 * If no block preference is given the following hierarchy is used 94 * to allocate a block: 95 * 1) allocate a block in the cylinder group that contains the 96 * inode for the file. 97 * 2) quadradically rehash into other cylinder groups, until an 98 * available block is located. 99 */ 100 int 101 ffs_alloc(struct inode *ip, daddr_t lbn, daddr_t bpref, int size, 102 daddr_t *bnp) 103 { 104 struct fs *fs = ip->i_fs; 105 daddr_t bno; 106 int cg; 107 108 *bnp = 0; 109 if ((u_int)size > fs->fs_bsize || fragoff(fs, size) != 0) { 110 errx(1, "ffs_alloc: bad size: bsize %d size %d", 111 fs->fs_bsize, size); 112 } 113 if (size == fs->fs_bsize && fs->fs_cstotal.cs_nbfree == 0) 114 goto nospace; 115 if (bpref >= fs->fs_size) 116 bpref = 0; 117 if (bpref == 0) 118 cg = ino_to_cg(fs, ip->i_number); 119 else 120 cg = dtog(fs, bpref); 121 bno = ffs_hashalloc(ip, cg, bpref, size, ffs_alloccg); 122 if (bno > 0) { 123 DIP_ADD(ip, blocks, size / DEV_BSIZE); 124 *bnp = bno; 125 return (0); 126 } 127 nospace: 128 return (ENOSPC); 129 } 130 131 /* 132 * Select the desired position for the next block in a file. The file is 133 * logically divided into sections. The first section is composed of the 134 * direct blocks. Each additional section contains fs_maxbpg blocks. 135 * 136 * If no blocks have been allocated in the first section, the policy is to 137 * request a block in the same cylinder group as the inode that describes 138 * the file. If no blocks have been allocated in any other section, the 139 * policy is to place the section in a cylinder group with a greater than 140 * average number of free blocks. An appropriate cylinder group is found 141 * by using a rotor that sweeps the cylinder groups. When a new group of 142 * blocks is needed, the sweep begins in the cylinder group following the 143 * cylinder group from which the previous allocation was made. The sweep 144 * continues until a cylinder group with greater than the average number 145 * of free blocks is found. If the allocation is for the first block in an 146 * indirect block, the information on the previous allocation is unavailable; 147 * here a best guess is made based upon the logical block number being 148 * allocated. 149 * 150 * If a section is already partially allocated, the policy is to 151 * contiguously allocate fs_maxcontig blocks. The end of one of these 152 * contiguous blocks and the beginning of the next is physically separated 153 * so that the disk head will be in transit between them for at least 154 * fs_rotdelay milliseconds. This is to allow time for the processor to 155 * schedule another I/O transfer. 156 */ 157 /* XXX ondisk32 */ 158 daddr_t 159 ffs_blkpref_ufs1(struct inode *ip, daddr_t lbn, int indx, int32_t *bap) 160 { 161 struct fs *fs; 162 int cg; 163 int avgbfree, startcg; 164 165 fs = ip->i_fs; 166 if (indx % fs->fs_maxbpg == 0 || bap[indx - 1] == 0) { 167 if (lbn < NDADDR + NINDIR(fs)) { 168 cg = ino_to_cg(fs, ip->i_number); 169 return (fs->fs_fpg * cg + fs->fs_frag); 170 } 171 /* 172 * Find a cylinder with greater than average number of 173 * unused data blocks. 174 */ 175 if (indx == 0 || bap[indx - 1] == 0) 176 startcg = 177 ino_to_cg(fs, ip->i_number) + lbn / fs->fs_maxbpg; 178 else 179 startcg = dtog(fs, 180 ufs_rw32(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + 1); 181 startcg %= fs->fs_ncg; 182 avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg; 183 for (cg = startcg; cg < fs->fs_ncg; cg++) 184 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) 185 return (fs->fs_fpg * cg + fs->fs_frag); 186 for (cg = 0; cg <= startcg; cg++) 187 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) 188 return (fs->fs_fpg * cg + fs->fs_frag); 189 return (0); 190 } 191 /* 192 * We just always try to lay things out contiguously. 193 */ 194 return ufs_rw32(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + fs->fs_frag; 195 } 196 197 daddr_t 198 ffs_blkpref_ufs2(ip, lbn, indx, bap) 199 struct inode *ip; 200 daddr_t lbn; 201 int indx; 202 int64_t *bap; 203 { 204 struct fs *fs; 205 int cg; 206 int avgbfree, startcg; 207 208 fs = ip->i_fs; 209 if (indx % fs->fs_maxbpg == 0 || bap[indx - 1] == 0) { 210 if (lbn < NDADDR + NINDIR(fs)) { 211 cg = ino_to_cg(fs, ip->i_number); 212 return (fs->fs_fpg * cg + fs->fs_frag); 213 } 214 /* 215 * Find a cylinder with greater than average number of 216 * unused data blocks. 217 */ 218 if (indx == 0 || bap[indx - 1] == 0) 219 startcg = 220 ino_to_cg(fs, ip->i_number) + lbn / fs->fs_maxbpg; 221 else 222 startcg = dtog(fs, 223 ufs_rw64(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + 1); 224 startcg %= fs->fs_ncg; 225 avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg; 226 for (cg = startcg; cg < fs->fs_ncg; cg++) 227 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) { 228 return (fs->fs_fpg * cg + fs->fs_frag); 229 } 230 for (cg = 0; cg < startcg; cg++) 231 if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) { 232 return (fs->fs_fpg * cg + fs->fs_frag); 233 } 234 return (0); 235 } 236 /* 237 * We just always try to lay things out contiguously. 238 */ 239 return ufs_rw64(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + fs->fs_frag; 240 } 241 242 /* 243 * Implement the cylinder overflow algorithm. 244 * 245 * The policy implemented by this algorithm is: 246 * 1) allocate the block in its requested cylinder group. 247 * 2) quadradically rehash on the cylinder group number. 248 * 3) brute force search for a free block. 249 * 250 * `size': size for data blocks, mode for inodes 251 */ 252 /*VARARGS5*/ 253 static daddr_t 254 ffs_hashalloc(struct inode *ip, int cg, daddr_t pref, int size, 255 daddr_t (*allocator)(struct inode *, int, daddr_t, int)) 256 { 257 struct fs *fs; 258 daddr_t result; 259 int i, icg = cg; 260 261 fs = ip->i_fs; 262 /* 263 * 1: preferred cylinder group 264 */ 265 result = (*allocator)(ip, cg, pref, size); 266 if (result) 267 return (result); 268 /* 269 * 2: quadratic rehash 270 */ 271 for (i = 1; i < fs->fs_ncg; i *= 2) { 272 cg += i; 273 if (cg >= fs->fs_ncg) 274 cg -= fs->fs_ncg; 275 result = (*allocator)(ip, cg, 0, size); 276 if (result) 277 return (result); 278 } 279 /* 280 * 3: brute force search 281 * Note that we start at i == 2, since 0 was checked initially, 282 * and 1 is always checked in the quadratic rehash. 283 */ 284 cg = (icg + 2) % fs->fs_ncg; 285 for (i = 2; i < fs->fs_ncg; i++) { 286 result = (*allocator)(ip, cg, 0, size); 287 if (result) 288 return (result); 289 cg++; 290 if (cg == fs->fs_ncg) 291 cg = 0; 292 } 293 return (0); 294 } 295 296 /* 297 * Determine whether a block can be allocated. 298 * 299 * Check to see if a block of the appropriate size is available, 300 * and if it is, allocate it. 301 */ 302 static daddr_t 303 ffs_alloccg(struct inode *ip, int cg, daddr_t bpref, int size) 304 { 305 struct cg *cgp; 306 struct buf *bp; 307 daddr_t bno, blkno; 308 int error, frags, allocsiz, i; 309 struct fs *fs = ip->i_fs; 310 const int needswap = UFS_FSNEEDSWAP(fs); 311 312 if (fs->fs_cs(fs, cg).cs_nbfree == 0 && size == fs->fs_bsize) 313 return (0); 314 error = bread(ip->i_fd, ip->i_fs, fsbtodb(fs, cgtod(fs, cg)), 315 (int)fs->fs_cgsize, &bp); 316 if (error) { 317 brelse(bp); 318 return (0); 319 } 320 cgp = (struct cg *)bp->b_data; 321 if (!cg_chkmagic(cgp, needswap) || 322 (cgp->cg_cs.cs_nbfree == 0 && size == fs->fs_bsize)) { 323 brelse(bp); 324 return (0); 325 } 326 if (size == fs->fs_bsize) { 327 bno = ffs_alloccgblk(ip, bp, bpref); 328 bdwrite(bp); 329 return (bno); 330 } 331 /* 332 * check to see if any fragments are already available 333 * allocsiz is the size which will be allocated, hacking 334 * it down to a smaller size if necessary 335 */ 336 frags = numfrags(fs, size); 337 for (allocsiz = frags; allocsiz < fs->fs_frag; allocsiz++) 338 if (cgp->cg_frsum[allocsiz] != 0) 339 break; 340 if (allocsiz == fs->fs_frag) { 341 /* 342 * no fragments were available, so a block will be 343 * allocated, and hacked up 344 */ 345 if (cgp->cg_cs.cs_nbfree == 0) { 346 brelse(bp); 347 return (0); 348 } 349 bno = ffs_alloccgblk(ip, bp, bpref); 350 bpref = dtogd(fs, bno); 351 for (i = frags; i < fs->fs_frag; i++) 352 setbit(cg_blksfree(cgp, needswap), bpref + i); 353 i = fs->fs_frag - frags; 354 ufs_add32(cgp->cg_cs.cs_nffree, i, needswap); 355 fs->fs_cstotal.cs_nffree += i; 356 fs->fs_cs(fs, cg).cs_nffree += i; 357 fs->fs_fmod = 1; 358 ufs_add32(cgp->cg_frsum[i], 1, needswap); 359 bdwrite(bp); 360 return (bno); 361 } 362 bno = ffs_mapsearch(fs, cgp, bpref, allocsiz); 363 for (i = 0; i < frags; i++) 364 clrbit(cg_blksfree(cgp, needswap), bno + i); 365 ufs_add32(cgp->cg_cs.cs_nffree, -frags, needswap); 366 fs->fs_cstotal.cs_nffree -= frags; 367 fs->fs_cs(fs, cg).cs_nffree -= frags; 368 fs->fs_fmod = 1; 369 ufs_add32(cgp->cg_frsum[allocsiz], -1, needswap); 370 if (frags != allocsiz) 371 ufs_add32(cgp->cg_frsum[allocsiz - frags], 1, needswap); 372 blkno = cg * fs->fs_fpg + bno; 373 bdwrite(bp); 374 return blkno; 375 } 376 377 /* 378 * Allocate a block in a cylinder group. 379 * 380 * This algorithm implements the following policy: 381 * 1) allocate the requested block. 382 * 2) allocate a rotationally optimal block in the same cylinder. 383 * 3) allocate the next available block on the block rotor for the 384 * specified cylinder group. 385 * Note that this routine only allocates fs_bsize blocks; these 386 * blocks may be fragmented by the routine that allocates them. 387 */ 388 static daddr_t 389 ffs_alloccgblk(struct inode *ip, struct buf *bp, daddr_t bpref) 390 { 391 struct cg *cgp; 392 daddr_t blkno; 393 int32_t bno; 394 struct fs *fs = ip->i_fs; 395 const int needswap = UFS_FSNEEDSWAP(fs); 396 u_int8_t *blksfree; 397 398 cgp = (struct cg *)bp->b_data; 399 blksfree = cg_blksfree(cgp, needswap); 400 if (bpref == 0 || dtog(fs, bpref) != ufs_rw32(cgp->cg_cgx, needswap)) { 401 bpref = ufs_rw32(cgp->cg_rotor, needswap); 402 } else { 403 bpref = blknum(fs, bpref); 404 bno = dtogd(fs, bpref); 405 /* 406 * if the requested block is available, use it 407 */ 408 if (ffs_isblock(fs, blksfree, fragstoblks(fs, bno))) 409 goto gotit; 410 } 411 /* 412 * Take the next available one in this cylinder group. 413 */ 414 bno = ffs_mapsearch(fs, cgp, bpref, (int)fs->fs_frag); 415 if (bno < 0) 416 return (0); 417 cgp->cg_rotor = ufs_rw32(bno, needswap); 418 gotit: 419 blkno = fragstoblks(fs, bno); 420 ffs_clrblock(fs, blksfree, (long)blkno); 421 ffs_clusteracct(fs, cgp, blkno, -1); 422 ufs_add32(cgp->cg_cs.cs_nbfree, -1, needswap); 423 fs->fs_cstotal.cs_nbfree--; 424 fs->fs_cs(fs, ufs_rw32(cgp->cg_cgx, needswap)).cs_nbfree--; 425 fs->fs_fmod = 1; 426 blkno = ufs_rw32(cgp->cg_cgx, needswap) * fs->fs_fpg + bno; 427 return (blkno); 428 } 429 430 /* 431 * Free a block or fragment. 432 * 433 * The specified block or fragment is placed back in the 434 * free map. If a fragment is deallocated, a possible 435 * block reassembly is checked. 436 */ 437 void 438 ffs_blkfree(struct inode *ip, daddr_t bno, long size) 439 { 440 struct cg *cgp; 441 struct buf *bp; 442 int32_t fragno, cgbno; 443 int i, error, cg, blk, frags, bbase; 444 struct fs *fs = ip->i_fs; 445 const int needswap = UFS_FSNEEDSWAP(fs); 446 447 if ((u_int)size > fs->fs_bsize || fragoff(fs, size) != 0 || 448 fragnum(fs, bno) + numfrags(fs, size) > fs->fs_frag) { 449 errx(1, "blkfree: bad size: bno %lld bsize %d size %ld", 450 (long long)bno, fs->fs_bsize, size); 451 } 452 cg = dtog(fs, bno); 453 if (bno >= fs->fs_size) { 454 warnx("bad block %lld, ino %llu", (long long)bno, 455 (unsigned long long)ip->i_number); 456 return; 457 } 458 error = bread(ip->i_fd, ip->i_fs, fsbtodb(fs, cgtod(fs, cg)), 459 (int)fs->fs_cgsize, &bp); 460 if (error) { 461 brelse(bp); 462 return; 463 } 464 cgp = (struct cg *)bp->b_data; 465 if (!cg_chkmagic(cgp, needswap)) { 466 brelse(bp); 467 return; 468 } 469 cgbno = dtogd(fs, bno); 470 if (size == fs->fs_bsize) { 471 fragno = fragstoblks(fs, cgbno); 472 if (!ffs_isfreeblock(fs, cg_blksfree(cgp, needswap), fragno)) { 473 errx(1, "blkfree: freeing free block %lld", 474 (long long)bno); 475 } 476 ffs_setblock(fs, cg_blksfree(cgp, needswap), fragno); 477 ffs_clusteracct(fs, cgp, fragno, 1); 478 ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap); 479 fs->fs_cstotal.cs_nbfree++; 480 fs->fs_cs(fs, cg).cs_nbfree++; 481 } else { 482 bbase = cgbno - fragnum(fs, cgbno); 483 /* 484 * decrement the counts associated with the old frags 485 */ 486 blk = blkmap(fs, cg_blksfree(cgp, needswap), bbase); 487 ffs_fragacct(fs, blk, cgp->cg_frsum, -1, needswap); 488 /* 489 * deallocate the fragment 490 */ 491 frags = numfrags(fs, size); 492 for (i = 0; i < frags; i++) { 493 if (isset(cg_blksfree(cgp, needswap), cgbno + i)) { 494 errx(1, "blkfree: freeing free frag: block %lld", 495 (long long)(cgbno + i)); 496 } 497 setbit(cg_blksfree(cgp, needswap), cgbno + i); 498 } 499 ufs_add32(cgp->cg_cs.cs_nffree, i, needswap); 500 fs->fs_cstotal.cs_nffree += i; 501 fs->fs_cs(fs, cg).cs_nffree += i; 502 /* 503 * add back in counts associated with the new frags 504 */ 505 blk = blkmap(fs, cg_blksfree(cgp, needswap), bbase); 506 ffs_fragacct(fs, blk, cgp->cg_frsum, 1, needswap); 507 /* 508 * if a complete block has been reassembled, account for it 509 */ 510 fragno = fragstoblks(fs, bbase); 511 if (ffs_isblock(fs, cg_blksfree(cgp, needswap), fragno)) { 512 ufs_add32(cgp->cg_cs.cs_nffree, -fs->fs_frag, needswap); 513 fs->fs_cstotal.cs_nffree -= fs->fs_frag; 514 fs->fs_cs(fs, cg).cs_nffree -= fs->fs_frag; 515 ffs_clusteracct(fs, cgp, fragno, 1); 516 ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap); 517 fs->fs_cstotal.cs_nbfree++; 518 fs->fs_cs(fs, cg).cs_nbfree++; 519 } 520 } 521 fs->fs_fmod = 1; 522 bdwrite(bp); 523 } 524 525 526 static int 527 scanc(u_int size, const u_char *cp, const u_char table[], int mask) 528 { 529 const u_char *end = &cp[size]; 530 531 while (cp < end && (table[*cp] & mask) == 0) 532 cp++; 533 return (end - cp); 534 } 535 536 /* 537 * Find a block of the specified size in the specified cylinder group. 538 * 539 * It is a panic if a request is made to find a block if none are 540 * available. 541 */ 542 static int32_t 543 ffs_mapsearch(struct fs *fs, struct cg *cgp, daddr_t bpref, int allocsiz) 544 { 545 int32_t bno; 546 int start, len, loc, i; 547 int blk, field, subfield, pos; 548 int ostart, olen; 549 const int needswap = UFS_FSNEEDSWAP(fs); 550 551 /* 552 * find the fragment by searching through the free block 553 * map for an appropriate bit pattern 554 */ 555 if (bpref) 556 start = dtogd(fs, bpref) / NBBY; 557 else 558 start = ufs_rw32(cgp->cg_frotor, needswap) / NBBY; 559 len = howmany(fs->fs_fpg, NBBY) - start; 560 ostart = start; 561 olen = len; 562 loc = scanc((u_int)len, 563 (const u_char *)&cg_blksfree(cgp, needswap)[start], 564 (const u_char *)fragtbl[fs->fs_frag], 565 (1 << (allocsiz - 1 + (fs->fs_frag % NBBY)))); 566 if (loc == 0) { 567 len = start + 1; 568 start = 0; 569 loc = scanc((u_int)len, 570 (const u_char *)&cg_blksfree(cgp, needswap)[0], 571 (const u_char *)fragtbl[fs->fs_frag], 572 (1 << (allocsiz - 1 + (fs->fs_frag % NBBY)))); 573 if (loc == 0) { 574 errx(1, 575 "ffs_alloccg: map corrupted: start %d len %d offset %d %ld", 576 ostart, olen, 577 ufs_rw32(cgp->cg_freeoff, needswap), 578 (long)cg_blksfree(cgp, needswap) - (long)cgp); 579 /* NOTREACHED */ 580 } 581 } 582 bno = (start + len - loc) * NBBY; 583 cgp->cg_frotor = ufs_rw32(bno, needswap); 584 /* 585 * found the byte in the map 586 * sift through the bits to find the selected frag 587 */ 588 for (i = bno + NBBY; bno < i; bno += fs->fs_frag) { 589 blk = blkmap(fs, cg_blksfree(cgp, needswap), bno); 590 blk <<= 1; 591 field = around[allocsiz]; 592 subfield = inside[allocsiz]; 593 for (pos = 0; pos <= fs->fs_frag - allocsiz; pos++) { 594 if ((blk & field) == subfield) 595 return (bno + pos); 596 field <<= 1; 597 subfield <<= 1; 598 } 599 } 600 errx(1, "ffs_alloccg: block not in map: bno %lld", (long long)bno); 601 return (-1); 602 } 603 604 /* 605 * Update the cluster map because of an allocation or free. 606 * 607 * Cnt == 1 means free; cnt == -1 means allocating. 608 */ 609 void 610 ffs_clusteracct(struct fs *fs, struct cg *cgp, int32_t blkno, int cnt) 611 { 612 int32_t *sump; 613 int32_t *lp; 614 u_char *freemapp, *mapp; 615 int i, start, end, forw, back, map, bit; 616 const int needswap = UFS_FSNEEDSWAP(fs); 617 618 if (fs->fs_contigsumsize <= 0) 619 return; 620 freemapp = cg_clustersfree(cgp, needswap); 621 sump = cg_clustersum(cgp, needswap); 622 /* 623 * Allocate or clear the actual block. 624 */ 625 if (cnt > 0) 626 setbit(freemapp, blkno); 627 else 628 clrbit(freemapp, blkno); 629 /* 630 * Find the size of the cluster going forward. 631 */ 632 start = blkno + 1; 633 end = start + fs->fs_contigsumsize; 634 if (end >= ufs_rw32(cgp->cg_nclusterblks, needswap)) 635 end = ufs_rw32(cgp->cg_nclusterblks, needswap); 636 mapp = &freemapp[start / NBBY]; 637 map = *mapp++; 638 bit = 1 << (start % NBBY); 639 for (i = start; i < end; i++) { 640 if ((map & bit) == 0) 641 break; 642 if ((i & (NBBY - 1)) != (NBBY - 1)) { 643 bit <<= 1; 644 } else { 645 map = *mapp++; 646 bit = 1; 647 } 648 } 649 forw = i - start; 650 /* 651 * Find the size of the cluster going backward. 652 */ 653 start = blkno - 1; 654 end = start - fs->fs_contigsumsize; 655 if (end < 0) 656 end = -1; 657 mapp = &freemapp[start / NBBY]; 658 map = *mapp--; 659 bit = 1 << (start % NBBY); 660 for (i = start; i > end; i--) { 661 if ((map & bit) == 0) 662 break; 663 if ((i & (NBBY - 1)) != 0) { 664 bit >>= 1; 665 } else { 666 map = *mapp--; 667 bit = 1 << (NBBY - 1); 668 } 669 } 670 back = start - i; 671 /* 672 * Account for old cluster and the possibly new forward and 673 * back clusters. 674 */ 675 i = back + forw + 1; 676 if (i > fs->fs_contigsumsize) 677 i = fs->fs_contigsumsize; 678 ufs_add32(sump[i], cnt, needswap); 679 if (back > 0) 680 ufs_add32(sump[back], -cnt, needswap); 681 if (forw > 0) 682 ufs_add32(sump[forw], -cnt, needswap); 683 684 /* 685 * Update cluster summary information. 686 */ 687 lp = &sump[fs->fs_contigsumsize]; 688 for (i = fs->fs_contigsumsize; i > 0; i--) 689 if (ufs_rw32(*lp--, needswap) > 0) 690 break; 691 fs->fs_maxcluster[ufs_rw32(cgp->cg_cgx, needswap)] = i; 692 } 693