ffs_balloc.c revision 1.21
1 /* $NetBSD: ffs_balloc.c,v 1.21 2015/03/29 05:52:59 agc Exp $ */ 2 /* From NetBSD: ffs_balloc.c,v 1.25 2001/08/08 08:36:36 lukem Exp */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)ffs_balloc.c 8.8 (Berkeley) 6/16/95 33 */ 34 35 #if HAVE_NBTOOL_CONFIG_H 36 #include "nbtool_config.h" 37 #endif 38 39 #include <sys/cdefs.h> 40 #if defined(__RCSID) && !defined(__lint) 41 __RCSID("$NetBSD: ffs_balloc.c,v 1.21 2015/03/29 05:52:59 agc Exp $"); 42 #endif /* !__lint */ 43 44 #include <sys/param.h> 45 #include <sys/time.h> 46 47 #include <assert.h> 48 #include <errno.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 53 #include "makefs.h" 54 55 #include <ufs/ufs/dinode.h> 56 #include <ufs/ufs/ufs_bswap.h> 57 #include <ufs/ffs/fs.h> 58 59 #include "ffs/buf.h" 60 #include "ffs/ufs_inode.h" 61 #include "ffs/ffs_extern.h" 62 63 static int ffs_balloc_ufs1(struct inode *, off_t, int, struct buf **); 64 static int ffs_balloc_ufs2(struct inode *, off_t, int, struct buf **); 65 66 /* 67 * Balloc defines the structure of file system storage 68 * by allocating the physical blocks on a device given 69 * the inode and the logical block number in a file. 70 * 71 * Assume: flags == B_SYNC | B_CLRBUF 72 */ 73 74 int 75 ffs_balloc(struct inode *ip, off_t offset, int bufsize, struct buf **bpp) 76 { 77 if (ip->i_fs->fs_magic == FS_UFS2_MAGIC) 78 return ffs_balloc_ufs2(ip, offset, bufsize, bpp); 79 else 80 return ffs_balloc_ufs1(ip, offset, bufsize, bpp); 81 } 82 83 static int 84 ffs_balloc_ufs1(struct inode *ip, off_t offset, int bufsize, struct buf **bpp) 85 { 86 daddr_t lbn, lastlbn; 87 int size; 88 int32_t nb; 89 struct buf *bp, *nbp; 90 struct fs *fs = ip->i_fs; 91 struct indir indirs[UFS_NIADDR + 2]; 92 daddr_t newb, pref; 93 int32_t *bap; 94 int osize, nsize, num, i, error; 95 int32_t *allocblk, allociblk[UFS_NIADDR + 1]; 96 int32_t *allocib; 97 const int needswap = UFS_FSNEEDSWAP(fs); 98 99 lbn = ffs_lblkno(fs, offset); 100 size = ffs_blkoff(fs, offset) + bufsize; 101 if (bpp != NULL) { 102 *bpp = NULL; 103 } 104 105 assert(size <= fs->fs_bsize); 106 if (lbn < 0) 107 return (EFBIG); 108 109 /* 110 * If the next write will extend the file into a new block, 111 * and the file is currently composed of a fragment 112 * this fragment has to be extended to be a full block. 113 */ 114 115 lastlbn = ffs_lblkno(fs, ip->i_ffs1_size); 116 if (lastlbn < UFS_NDADDR && lastlbn < lbn) { 117 nb = lastlbn; 118 osize = ffs_blksize(fs, ip, nb); 119 if (osize < fs->fs_bsize && osize > 0) { 120 warnx("need to ffs_realloccg; not supported!"); 121 abort(); 122 } 123 } 124 125 /* 126 * The first UFS_NDADDR blocks are direct blocks 127 */ 128 129 if (lbn < UFS_NDADDR) { 130 nb = ufs_rw32(ip->i_ffs1_db[lbn], needswap); 131 if (nb != 0 && ip->i_ffs1_size >= ffs_lblktosize(fs, lbn + 1)) { 132 133 /* 134 * The block is an already-allocated direct block 135 * and the file already extends past this block, 136 * thus this must be a whole block. 137 * Just read the block (if requested). 138 */ 139 140 if (bpp != NULL) { 141 error = bread(ip->i_devvp, lbn, fs->fs_bsize, 142 0, bpp); 143 if (error) { 144 brelse(*bpp, 0); 145 return (error); 146 } 147 } 148 return (0); 149 } 150 if (nb != 0) { 151 152 /* 153 * Consider need to reallocate a fragment. 154 */ 155 156 osize = ffs_fragroundup(fs, ffs_blkoff(fs, ip->i_ffs1_size)); 157 nsize = ffs_fragroundup(fs, size); 158 if (nsize <= osize) { 159 160 /* 161 * The existing block is already 162 * at least as big as we want. 163 * Just read the block (if requested). 164 */ 165 166 if (bpp != NULL) { 167 error = bread(ip->i_devvp, lbn, osize, 168 0, bpp); 169 if (error) { 170 brelse(*bpp, 0); 171 return (error); 172 } 173 } 174 return 0; 175 } else { 176 warnx("need to ffs_realloccg; not supported!"); 177 abort(); 178 } 179 } else { 180 181 /* 182 * the block was not previously allocated, 183 * allocate a new block or fragment. 184 */ 185 186 if (ip->i_ffs1_size < ffs_lblktosize(fs, lbn + 1)) 187 nsize = ffs_fragroundup(fs, size); 188 else 189 nsize = fs->fs_bsize; 190 error = ffs_alloc(ip, lbn, 191 ffs_blkpref_ufs1(ip, lbn, (int)lbn, 192 &ip->i_ffs1_db[0]), 193 nsize, &newb); 194 if (error) 195 return (error); 196 if (bpp != NULL) { 197 bp = getblk(ip->i_devvp, lbn, nsize, 0, 0); 198 bp->b_blkno = FFS_FSBTODB(fs, newb); 199 clrbuf(bp); 200 *bpp = bp; 201 } 202 } 203 ip->i_ffs1_db[lbn] = ufs_rw32((int32_t)newb, needswap); 204 return (0); 205 } 206 207 /* 208 * Determine the number of levels of indirection. 209 */ 210 211 pref = 0; 212 if ((error = ufs_getlbns(ip, lbn, indirs, &num)) != 0) 213 return (error); 214 215 if (num < 1) { 216 warnx("ffs_balloc: ufs_getlbns returned indirect block"); 217 abort(); 218 } 219 220 /* 221 * Fetch the first indirect block allocating if necessary. 222 */ 223 224 --num; 225 nb = ufs_rw32(ip->i_ffs1_ib[indirs[0].in_off], needswap); 226 allocib = NULL; 227 allocblk = allociblk; 228 if (nb == 0) { 229 pref = ffs_blkpref_ufs1(ip, lbn, 0, (int32_t *)0); 230 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 231 if (error) 232 return error; 233 nb = newb; 234 *allocblk++ = nb; 235 bp = getblk(ip->i_devvp, indirs[1].in_lbn, fs->fs_bsize, 0, 0); 236 bp->b_blkno = FFS_FSBTODB(fs, nb); 237 clrbuf(bp); 238 /* 239 * Write synchronously so that indirect blocks 240 * never point at garbage. 241 */ 242 if ((error = bwrite(bp)) != 0) 243 return error; 244 allocib = &ip->i_ffs1_ib[indirs[0].in_off]; 245 *allocib = ufs_rw32((int32_t)nb, needswap); 246 } 247 248 /* 249 * Fetch through the indirect blocks, allocating as necessary. 250 */ 251 252 for (i = 1;;) { 253 error = bread(ip->i_devvp, indirs[i].in_lbn, fs->fs_bsize, 254 0, &bp); 255 if (error) { 256 brelse(bp, 0); 257 return error; 258 } 259 bap = (int32_t *)bp->b_data; 260 nb = ufs_rw32(bap[indirs[i].in_off], needswap); 261 if (i == num) 262 break; 263 i++; 264 if (nb != 0) { 265 brelse(bp, 0); 266 continue; 267 } 268 if (pref == 0) 269 pref = ffs_blkpref_ufs1(ip, lbn, 0, (int32_t *)0); 270 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 271 if (error) { 272 brelse(bp, 0); 273 return error; 274 } 275 nb = newb; 276 *allocblk++ = nb; 277 nbp = getblk(ip->i_devvp, indirs[i].in_lbn, fs->fs_bsize, 0, 0); 278 nbp->b_blkno = FFS_FSBTODB(fs, nb); 279 clrbuf(nbp); 280 /* 281 * Write synchronously so that indirect blocks 282 * never point at garbage. 283 */ 284 285 if ((error = bwrite(nbp)) != 0) { 286 brelse(bp, 0); 287 return error; 288 } 289 bap[indirs[i - 1].in_off] = ufs_rw32(nb, needswap); 290 291 bwrite(bp); 292 } 293 294 /* 295 * Get the data block, allocating if necessary. 296 */ 297 298 if (nb == 0) { 299 pref = ffs_blkpref_ufs1(ip, lbn, indirs[num].in_off, &bap[0]); 300 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 301 if (error) { 302 brelse(bp, 0); 303 return error; 304 } 305 nb = newb; 306 *allocblk++ = nb; 307 if (bpp != NULL) { 308 nbp = getblk(ip->i_devvp, lbn, fs->fs_bsize, 0, 0); 309 nbp->b_blkno = FFS_FSBTODB(fs, nb); 310 clrbuf(nbp); 311 *bpp = nbp; 312 } 313 bap[indirs[num].in_off] = ufs_rw32(nb, needswap); 314 315 /* 316 * If required, write synchronously, otherwise use 317 * delayed write. 318 */ 319 bwrite(bp); 320 return (0); 321 } 322 brelse(bp, 0); 323 if (bpp != NULL) { 324 error = bread(ip->i_devvp, lbn, (int)fs->fs_bsize, 0, &nbp); 325 if (error) { 326 brelse(nbp, 0); 327 return error; 328 } 329 *bpp = nbp; 330 } 331 return (0); 332 } 333 334 static int 335 ffs_balloc_ufs2(struct inode *ip, off_t offset, int bufsize, struct buf **bpp) 336 { 337 daddr_t lbn, lastlbn; 338 int size; 339 struct buf *bp, *nbp; 340 struct fs *fs = ip->i_fs; 341 struct indir indirs[UFS_NIADDR + 2]; 342 daddr_t newb, pref, nb; 343 int64_t *bap; 344 int osize, nsize, num, i, error; 345 int64_t *allocblk, allociblk[UFS_NIADDR + 1]; 346 int64_t *allocib; 347 const int needswap = UFS_FSNEEDSWAP(fs); 348 349 lbn = ffs_lblkno(fs, offset); 350 size = ffs_blkoff(fs, offset) + bufsize; 351 if (bpp != NULL) { 352 *bpp = NULL; 353 } 354 355 assert(size <= fs->fs_bsize); 356 if (lbn < 0) 357 return (EFBIG); 358 359 /* 360 * If the next write will extend the file into a new block, 361 * and the file is currently composed of a fragment 362 * this fragment has to be extended to be a full block. 363 */ 364 365 lastlbn = ffs_lblkno(fs, ip->i_ffs2_size); 366 if (lastlbn < UFS_NDADDR && lastlbn < lbn) { 367 nb = lastlbn; 368 osize = ffs_blksize(fs, ip, nb); 369 if (osize < fs->fs_bsize && osize > 0) { 370 warnx("need to ffs_realloccg; not supported!"); 371 abort(); 372 } 373 } 374 375 /* 376 * The first UFS_NDADDR blocks are direct blocks 377 */ 378 379 if (lbn < UFS_NDADDR) { 380 nb = ufs_rw64(ip->i_ffs2_db[lbn], needswap); 381 if (nb != 0 && ip->i_ffs2_size >= ffs_lblktosize(fs, lbn + 1)) { 382 383 /* 384 * The block is an already-allocated direct block 385 * and the file already extends past this block, 386 * thus this must be a whole block. 387 * Just read the block (if requested). 388 */ 389 390 if (bpp != NULL) { 391 error = bread(ip->i_devvp, lbn, fs->fs_bsize, 392 0, bpp); 393 if (error) { 394 brelse(*bpp, 0); 395 return (error); 396 } 397 } 398 return (0); 399 } 400 if (nb != 0) { 401 402 /* 403 * Consider need to reallocate a fragment. 404 */ 405 406 osize = ffs_fragroundup(fs, ffs_blkoff(fs, ip->i_ffs2_size)); 407 nsize = ffs_fragroundup(fs, size); 408 if (nsize <= osize) { 409 410 /* 411 * The existing block is already 412 * at least as big as we want. 413 * Just read the block (if requested). 414 */ 415 416 if (bpp != NULL) { 417 error = bread(ip->i_devvp, lbn, osize, 418 0, bpp); 419 if (error) { 420 brelse(*bpp, 0); 421 return (error); 422 } 423 } 424 return 0; 425 } else { 426 warnx("need to ffs_realloccg; not supported!"); 427 abort(); 428 } 429 } else { 430 431 /* 432 * the block was not previously allocated, 433 * allocate a new block or fragment. 434 */ 435 436 if (ip->i_ffs2_size < ffs_lblktosize(fs, lbn + 1)) 437 nsize = ffs_fragroundup(fs, size); 438 else 439 nsize = fs->fs_bsize; 440 error = ffs_alloc(ip, lbn, 441 ffs_blkpref_ufs2(ip, lbn, (int)lbn, 442 &ip->i_ffs2_db[0]), 443 nsize, &newb); 444 if (error) 445 return (error); 446 if (bpp != NULL) { 447 bp = getblk(ip->i_devvp, lbn, nsize, 0, 0); 448 bp->b_blkno = FFS_FSBTODB(fs, newb); 449 clrbuf(bp); 450 *bpp = bp; 451 } 452 } 453 ip->i_ffs2_db[lbn] = ufs_rw64(newb, needswap); 454 return (0); 455 } 456 457 /* 458 * Determine the number of levels of indirection. 459 */ 460 461 pref = 0; 462 if ((error = ufs_getlbns(ip, lbn, indirs, &num)) != 0) 463 return (error); 464 465 if (num < 1) { 466 warnx("ffs_balloc: ufs_getlbns returned indirect block"); 467 abort(); 468 } 469 470 /* 471 * Fetch the first indirect block allocating if necessary. 472 */ 473 474 --num; 475 nb = ufs_rw64(ip->i_ffs2_ib[indirs[0].in_off], needswap); 476 allocib = NULL; 477 allocblk = allociblk; 478 if (nb == 0) { 479 pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0); 480 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 481 if (error) 482 return error; 483 nb = newb; 484 *allocblk++ = nb; 485 bp = getblk(ip->i_devvp, indirs[1].in_lbn, fs->fs_bsize, 0, 0); 486 bp->b_blkno = FFS_FSBTODB(fs, nb); 487 clrbuf(bp); 488 /* 489 * Write synchronously so that indirect blocks 490 * never point at garbage. 491 */ 492 if ((error = bwrite(bp)) != 0) 493 return error; 494 allocib = &ip->i_ffs2_ib[indirs[0].in_off]; 495 *allocib = ufs_rw64(nb, needswap); 496 } 497 498 /* 499 * Fetch through the indirect blocks, allocating as necessary. 500 */ 501 502 for (i = 1;;) { 503 error = bread(ip->i_devvp, indirs[i].in_lbn, fs->fs_bsize, 504 0, &bp); 505 if (error) { 506 brelse(bp, 0); 507 return error; 508 } 509 bap = (int64_t *)bp->b_data; 510 nb = ufs_rw64(bap[indirs[i].in_off], needswap); 511 if (i == num) 512 break; 513 i++; 514 if (nb != 0) { 515 brelse(bp, 0); 516 continue; 517 } 518 if (pref == 0) 519 pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0); 520 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 521 if (error) { 522 brelse(bp, 0); 523 return error; 524 } 525 nb = newb; 526 *allocblk++ = nb; 527 nbp = getblk(ip->i_devvp, indirs[i].in_lbn, fs->fs_bsize, 0, 0); 528 nbp->b_blkno = FFS_FSBTODB(fs, nb); 529 clrbuf(nbp); 530 /* 531 * Write synchronously so that indirect blocks 532 * never point at garbage. 533 */ 534 535 if ((error = bwrite(nbp)) != 0) { 536 brelse(bp, 0); 537 return error; 538 } 539 bap[indirs[i - 1].in_off] = ufs_rw64(nb, needswap); 540 541 bwrite(bp); 542 } 543 544 /* 545 * Get the data block, allocating if necessary. 546 */ 547 548 if (nb == 0) { 549 pref = ffs_blkpref_ufs2(ip, lbn, indirs[num].in_off, &bap[0]); 550 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 551 if (error) { 552 brelse(bp, 0); 553 return error; 554 } 555 nb = newb; 556 *allocblk++ = nb; 557 if (bpp != NULL) { 558 nbp = getblk(ip->i_devvp, lbn, fs->fs_bsize, 0, 0); 559 nbp->b_blkno = FFS_FSBTODB(fs, nb); 560 clrbuf(nbp); 561 *bpp = nbp; 562 } 563 bap[indirs[num].in_off] = ufs_rw64(nb, needswap); 564 565 /* 566 * If required, write synchronously, otherwise use 567 * delayed write. 568 */ 569 bwrite(bp); 570 return (0); 571 } 572 brelse(bp, 0); 573 if (bpp != NULL) { 574 error = bread(ip->i_devvp, lbn, (int)fs->fs_bsize, 0, 575 &nbp); 576 if (error) { 577 brelse(nbp, 0); 578 return error; 579 } 580 *bpp = nbp; 581 } 582 return (0); 583 } 584
Indexes created Mon Sep 29 03:10:08 GMT 2025