ffs_balloc.c revision 1.15
1 /* $NetBSD: ffs_balloc.c,v 1.15 2013/01/26 00:19:39 christos 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 1.15 2013/01/26 00:19:39 christos 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 struct vnode vp = { ip->i_fd, ip->i_fs, NULL, 0 }; 99 100 lbn = lblkno(fs, offset); 101 size = blkoff(fs, offset) + bufsize; 102 if (bpp != NULL) { 103 *bpp = NULL; 104 } 105 106 assert(size <= fs->fs_bsize); 107 if (lbn < 0) 108 return (EFBIG); 109 110 /* 111 * If the next write will extend the file into a new block, 112 * and the file is currently composed of a fragment 113 * this fragment has to be extended to be a full block. 114 */ 115 116 lastlbn = lblkno(fs, ip->i_ffs1_size); 117 if (lastlbn < UFS_NDADDR && lastlbn < lbn) { 118 nb = lastlbn; 119 osize = blksize(fs, ip, nb); 120 if (osize < fs->fs_bsize && osize > 0) { 121 warnx("need to ffs_realloccg; not supported!"); 122 abort(); 123 } 124 } 125 126 /* 127 * The first UFS_NDADDR blocks are direct blocks 128 */ 129 130 if (lbn < UFS_NDADDR) { 131 nb = ufs_rw32(ip->i_ffs1_db[lbn], needswap); 132 if (nb != 0 && ip->i_ffs1_size >= lblktosize(fs, lbn + 1)) { 133 134 /* 135 * The block is an already-allocated direct block 136 * and the file already extends past this block, 137 * thus this must be a whole block. 138 * Just read the block (if requested). 139 */ 140 141 if (bpp != NULL) { 142 error = bread(&vp, lbn, fs->fs_bsize, NULL, 0, 143 bpp); 144 if (error) { 145 brelse(*bpp, 0); 146 return (error); 147 } 148 } 149 return (0); 150 } 151 if (nb != 0) { 152 153 /* 154 * Consider need to reallocate a fragment. 155 */ 156 157 osize = fragroundup(fs, blkoff(fs, ip->i_ffs1_size)); 158 nsize = fragroundup(fs, size); 159 if (nsize <= osize) { 160 161 /* 162 * The existing block is already 163 * at least as big as we want. 164 * Just read the block (if requested). 165 */ 166 167 if (bpp != NULL) { 168 error = bread(&vp, lbn, osize, NULL, 0, 169 bpp); 170 if (error) { 171 brelse(*bpp, 0); 172 return (error); 173 } 174 } 175 return 0; 176 } else { 177 warnx("need to ffs_realloccg; not supported!"); 178 abort(); 179 } 180 } else { 181 182 /* 183 * the block was not previously allocated, 184 * allocate a new block or fragment. 185 */ 186 187 if (ip->i_ffs1_size < lblktosize(fs, lbn + 1)) 188 nsize = fragroundup(fs, size); 189 else 190 nsize = fs->fs_bsize; 191 error = ffs_alloc(ip, lbn, 192 ffs_blkpref_ufs1(ip, lbn, (int)lbn, 193 &ip->i_ffs1_db[0]), 194 nsize, &newb); 195 if (error) 196 return (error); 197 if (bpp != NULL) { 198 bp = getblk(&vp, lbn, nsize, 0, 0); 199 bp->b_blkno = fsbtodb(fs, newb); 200 clrbuf(bp); 201 *bpp = bp; 202 } 203 } 204 ip->i_ffs1_db[lbn] = ufs_rw32((int32_t)newb, needswap); 205 return (0); 206 } 207 208 /* 209 * Determine the number of levels of indirection. 210 */ 211 212 pref = 0; 213 if ((error = ufs_getlbns(ip, lbn, indirs, &num)) != 0) 214 return (error); 215 216 if (num < 1) { 217 warnx("ffs_balloc: ufs_getlbns returned indirect block"); 218 abort(); 219 } 220 221 /* 222 * Fetch the first indirect block allocating if necessary. 223 */ 224 225 --num; 226 nb = ufs_rw32(ip->i_ffs1_ib[indirs[0].in_off], needswap); 227 allocib = NULL; 228 allocblk = allociblk; 229 if (nb == 0) { 230 pref = ffs_blkpref_ufs1(ip, lbn, 0, (int32_t *)0); 231 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 232 if (error) 233 return error; 234 nb = newb; 235 *allocblk++ = nb; 236 bp = getblk(&vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0); 237 bp->b_blkno = fsbtodb(fs, nb); 238 clrbuf(bp); 239 /* 240 * Write synchronously so that indirect blocks 241 * never point at garbage. 242 */ 243 if ((error = bwrite(bp)) != 0) 244 return error; 245 allocib = &ip->i_ffs1_ib[indirs[0].in_off]; 246 *allocib = ufs_rw32((int32_t)nb, needswap); 247 } 248 249 /* 250 * Fetch through the indirect blocks, allocating as necessary. 251 */ 252 253 for (i = 1;;) { 254 error = bread(&vp, indirs[i].in_lbn, fs->fs_bsize, NULL, 0, 255 &bp); 256 if (error) { 257 brelse(bp, 0); 258 return error; 259 } 260 bap = (int32_t *)bp->b_data; 261 nb = ufs_rw32(bap[indirs[i].in_off], needswap); 262 if (i == num) 263 break; 264 i++; 265 if (nb != 0) { 266 brelse(bp, 0); 267 continue; 268 } 269 if (pref == 0) 270 pref = ffs_blkpref_ufs1(ip, lbn, 0, (int32_t *)0); 271 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 272 if (error) { 273 brelse(bp, 0); 274 return error; 275 } 276 nb = newb; 277 *allocblk++ = nb; 278 nbp = getblk(&vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0); 279 nbp->b_blkno = fsbtodb(fs, nb); 280 clrbuf(nbp); 281 /* 282 * Write synchronously so that indirect blocks 283 * never point at garbage. 284 */ 285 286 if ((error = bwrite(nbp)) != 0) { 287 brelse(bp, 0); 288 return error; 289 } 290 bap[indirs[i - 1].in_off] = ufs_rw32(nb, needswap); 291 292 bwrite(bp); 293 } 294 295 /* 296 * Get the data block, allocating if necessary. 297 */ 298 299 if (nb == 0) { 300 pref = ffs_blkpref_ufs1(ip, lbn, indirs[num].in_off, &bap[0]); 301 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 302 if (error) { 303 brelse(bp, 0); 304 return error; 305 } 306 nb = newb; 307 *allocblk++ = nb; 308 if (bpp != NULL) { 309 nbp = getblk(&vp, lbn, fs->fs_bsize, 0, 0); 310 nbp->b_blkno = fsbtodb(fs, nb); 311 clrbuf(nbp); 312 *bpp = nbp; 313 } 314 bap[indirs[num].in_off] = ufs_rw32(nb, needswap); 315 316 /* 317 * If required, write synchronously, otherwise use 318 * delayed write. 319 */ 320 bwrite(bp); 321 return (0); 322 } 323 brelse(bp, 0); 324 if (bpp != NULL) { 325 error = bread(&vp, lbn, (int)fs->fs_bsize, NULL, 0, &nbp); 326 if (error) { 327 brelse(nbp, 0); 328 return error; 329 } 330 *bpp = nbp; 331 } 332 return (0); 333 } 334 335 static int 336 ffs_balloc_ufs2(struct inode *ip, off_t offset, int bufsize, struct buf **bpp) 337 { 338 daddr_t lbn, lastlbn; 339 int size; 340 struct buf *bp, *nbp; 341 struct fs *fs = ip->i_fs; 342 struct indir indirs[UFS_NIADDR + 2]; 343 daddr_t newb, pref, nb; 344 int64_t *bap; 345 int osize, nsize, num, i, error; 346 int64_t *allocblk, allociblk[UFS_NIADDR + 1]; 347 int64_t *allocib; 348 const int needswap = UFS_FSNEEDSWAP(fs); 349 struct vnode vp = { ip->i_fd, ip->i_fs, NULL, 0 }; 350 351 lbn = lblkno(fs, offset); 352 size = blkoff(fs, offset) + bufsize; 353 if (bpp != NULL) { 354 *bpp = NULL; 355 } 356 357 assert(size <= fs->fs_bsize); 358 if (lbn < 0) 359 return (EFBIG); 360 361 /* 362 * If the next write will extend the file into a new block, 363 * and the file is currently composed of a fragment 364 * this fragment has to be extended to be a full block. 365 */ 366 367 lastlbn = lblkno(fs, ip->i_ffs2_size); 368 if (lastlbn < UFS_NDADDR && lastlbn < lbn) { 369 nb = lastlbn; 370 osize = blksize(fs, ip, nb); 371 if (osize < fs->fs_bsize && osize > 0) { 372 warnx("need to ffs_realloccg; not supported!"); 373 abort(); 374 } 375 } 376 377 /* 378 * The first UFS_NDADDR blocks are direct blocks 379 */ 380 381 if (lbn < UFS_NDADDR) { 382 nb = ufs_rw64(ip->i_ffs2_db[lbn], needswap); 383 if (nb != 0 && ip->i_ffs2_size >= lblktosize(fs, lbn + 1)) { 384 385 /* 386 * The block is an already-allocated direct block 387 * and the file already extends past this block, 388 * thus this must be a whole block. 389 * Just read the block (if requested). 390 */ 391 392 if (bpp != NULL) { 393 error = bread(&vp, lbn, fs->fs_bsize, NULL, 0, 394 bpp); 395 if (error) { 396 brelse(*bpp, 0); 397 return (error); 398 } 399 } 400 return (0); 401 } 402 if (nb != 0) { 403 404 /* 405 * Consider need to reallocate a fragment. 406 */ 407 408 osize = fragroundup(fs, blkoff(fs, ip->i_ffs2_size)); 409 nsize = fragroundup(fs, size); 410 if (nsize <= osize) { 411 412 /* 413 * The existing block is already 414 * at least as big as we want. 415 * Just read the block (if requested). 416 */ 417 418 if (bpp != NULL) { 419 error = bread(&vp, lbn, osize, NULL, 0, 420 bpp); 421 if (error) { 422 brelse(*bpp, 0); 423 return (error); 424 } 425 } 426 return 0; 427 } else { 428 warnx("need to ffs_realloccg; not supported!"); 429 abort(); 430 } 431 } else { 432 433 /* 434 * the block was not previously allocated, 435 * allocate a new block or fragment. 436 */ 437 438 if (ip->i_ffs2_size < lblktosize(fs, lbn + 1)) 439 nsize = fragroundup(fs, size); 440 else 441 nsize = fs->fs_bsize; 442 error = ffs_alloc(ip, lbn, 443 ffs_blkpref_ufs2(ip, lbn, (int)lbn, 444 &ip->i_ffs2_db[0]), 445 nsize, &newb); 446 if (error) 447 return (error); 448 if (bpp != NULL) { 449 bp = getblk(&vp, lbn, nsize, 0, 0); 450 bp->b_blkno = fsbtodb(fs, newb); 451 clrbuf(bp); 452 *bpp = bp; 453 } 454 } 455 ip->i_ffs2_db[lbn] = ufs_rw64(newb, needswap); 456 return (0); 457 } 458 459 /* 460 * Determine the number of levels of indirection. 461 */ 462 463 pref = 0; 464 if ((error = ufs_getlbns(ip, lbn, indirs, &num)) != 0) 465 return (error); 466 467 if (num < 1) { 468 warnx("ffs_balloc: ufs_getlbns returned indirect block"); 469 abort(); 470 } 471 472 /* 473 * Fetch the first indirect block allocating if necessary. 474 */ 475 476 --num; 477 nb = ufs_rw64(ip->i_ffs2_ib[indirs[0].in_off], needswap); 478 allocib = NULL; 479 allocblk = allociblk; 480 if (nb == 0) { 481 pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0); 482 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 483 if (error) 484 return error; 485 nb = newb; 486 *allocblk++ = nb; 487 bp = getblk(&vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0); 488 bp->b_blkno = fsbtodb(fs, nb); 489 clrbuf(bp); 490 /* 491 * Write synchronously so that indirect blocks 492 * never point at garbage. 493 */ 494 if ((error = bwrite(bp)) != 0) 495 return error; 496 allocib = &ip->i_ffs2_ib[indirs[0].in_off]; 497 *allocib = ufs_rw64(nb, needswap); 498 } 499 500 /* 501 * Fetch through the indirect blocks, allocating as necessary. 502 */ 503 504 for (i = 1;;) { 505 error = bread(&vp, indirs[i].in_lbn, fs->fs_bsize, NULL, 0, 506 &bp); 507 if (error) { 508 brelse(bp, 0); 509 return error; 510 } 511 bap = (int64_t *)bp->b_data; 512 nb = ufs_rw64(bap[indirs[i].in_off], needswap); 513 if (i == num) 514 break; 515 i++; 516 if (nb != 0) { 517 brelse(bp, 0); 518 continue; 519 } 520 if (pref == 0) 521 pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0); 522 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 523 if (error) { 524 brelse(bp, 0); 525 return error; 526 } 527 nb = newb; 528 *allocblk++ = nb; 529 nbp = getblk(&vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0); 530 nbp->b_blkno = fsbtodb(fs, nb); 531 clrbuf(nbp); 532 /* 533 * Write synchronously so that indirect blocks 534 * never point at garbage. 535 */ 536 537 if ((error = bwrite(nbp)) != 0) { 538 brelse(bp, 0); 539 return error; 540 } 541 bap[indirs[i - 1].in_off] = ufs_rw64(nb, needswap); 542 543 bwrite(bp); 544 } 545 546 /* 547 * Get the data block, allocating if necessary. 548 */ 549 550 if (nb == 0) { 551 pref = ffs_blkpref_ufs2(ip, lbn, indirs[num].in_off, &bap[0]); 552 error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb); 553 if (error) { 554 brelse(bp, 0); 555 return error; 556 } 557 nb = newb; 558 *allocblk++ = nb; 559 if (bpp != NULL) { 560 nbp = getblk(&vp, lbn, fs->fs_bsize, 0, 0); 561 nbp->b_blkno = fsbtodb(fs, nb); 562 clrbuf(nbp); 563 *bpp = nbp; 564 } 565 bap[indirs[num].in_off] = ufs_rw64(nb, needswap); 566 567 /* 568 * If required, write synchronously, otherwise use 569 * delayed write. 570 */ 571 bwrite(bp); 572 return (0); 573 } 574 brelse(bp, 0); 575 if (bpp != NULL) { 576 error = bread(&vp, lbn, (int)fs->fs_bsize, NULL, 0, &nbp); 577 if (error) { 578 brelse(nbp, 0); 579 return error; 580 } 581 *bpp = nbp; 582 } 583 return (0); 584 } 585
Indexes created Tue Sep 30 11:09:46 GMT 2025