Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/kern/vfs_cluster.c
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1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * Modifications/enhancements: 5 * Copyright (c) 1995 John S. Dyson. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)vfs_cluster.c 8.7 (Berkeley) 2/13/94 36 * $FreeBSD: src/sys/kern/vfs_cluster.c,v 1.38.2.3 1999/09/05 08:15:40 peter Exp $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/proc.h> 42 #include <sys/buf.h> 43 #include <sys/vnode.h> 44 #include <sys/mount.h> 45 #include <sys/malloc.h> 46 #include <sys/resourcevar.h> 47 #include <sys/vmmeter.h> 48 #include <miscfs/specfs/specdev.h> 49 #include <vm/vm.h> 50 #include <vm/vm_param.h> 51 #include <vm/vm_prot.h> 52 #include <vm/vm_object.h> 53 #include <vm/vm_page.h> 54 55 #ifdef notyet_block_reallocation_enabled 56 #ifdef DEBUG 57 #include <sys/sysctl.h> 58 #include <sys/kernel.h> 59 60 static int doreallocblks = 0; 61 SYSCTL_INT(_debug, 13, doreallocblks, CTLFLAG_RW, &doreallocblks, 0, ""); 62 #else 63 #define doreallocblks 0 64 #endif 65 #endif /* notyet_block_reallocation_enabled */ 66 67 #ifdef notyet_block_reallocation_enabled 68 static struct cluster_save * 69 cluster_collectbufs __P((struct vnode *vp, struct buf *last_bp)); 70 #endif 71 static struct buf * 72 cluster_rbuild __P((struct vnode *vp, u_quad_t filesize, daddr_t lbn, 73 daddr_t blkno, long size, int run)); 74 75 static int totreads; 76 static int totreadblocks; 77 extern vm_page_t bogus_page; 78 79 #ifdef DIAGNOSTIC 80 /* 81 * Set to 1 if reads of block zero should cause readahead to be done. 82 * Set to 0 treats a read of block zero as a non-sequential read. 83 * 84 * Setting to one assumes that most reads of block zero of files are due to 85 * sequential passes over the files (e.g. cat, sum) where additional blocks 86 * will soon be needed. Setting to zero assumes that the majority are 87 * surgical strikes to get particular info (e.g. size, file) where readahead 88 * blocks will not be used and, in fact, push out other potentially useful 89 * blocks from the cache. The former seems intuitive, but some quick tests 90 * showed that the latter performed better from a system-wide point of view. 91 */ 92 int doclusterraz = 0; 93 94 #define ISSEQREAD(vp, blk) \ 95 (((blk) != 0 || doclusterraz) && \ 96 ((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr)) 97 #else 98 #define ISSEQREAD(vp, blk) \ 99 (/* (blk) != 0 && */ ((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr)) 100 #endif 101 102 /* 103 * allow for three entire read-aheads... The system will 104 * adjust downwards rapidly if needed... 105 */ 106 #define RA_MULTIPLE_FAST 2 107 #define RA_MULTIPLE_SLOW 3 108 #define RA_SHIFTDOWN 1 /* approx lg2(RA_MULTIPLE) */ 109 /* 110 * This replaces bread. If this is a bread at the beginning of a file and 111 * lastr is 0, we assume this is the first read and we'll read up to two 112 * blocks if they are sequential. After that, we'll do regular read ahead 113 * in clustered chunks. 114 * bp is the block requested. 115 * rbp is the read-ahead block. 116 * If either is NULL, then you don't have to do the I/O. 117 */ 118 int 119 cluster_read(vp, filesize, lblkno, size, cred, bpp) 120 struct vnode *vp; 121 u_quad_t filesize; 122 daddr_t lblkno; 123 long size; 124 struct ucred *cred; 125 struct buf **bpp; 126 { 127 struct buf *bp, *rbp; 128 daddr_t blkno, rablkno, origlblkno; 129 int error, num_ra, alreadyincore; 130 int i; 131 int seq; 132 133 error = 0; 134 /* 135 * get the requested block 136 */ 137 origlblkno = lblkno; 138 *bpp = bp = getblk(vp, lblkno, size, 0, 0); 139 140 seq = ISSEQREAD(vp, lblkno); 141 /* 142 * if it is in the cache, then check to see if the reads have been 143 * sequential. If they have, then try some read-ahead, otherwise 144 * back-off on prospective read-aheads. 145 */ 146 if (bp->b_flags & B_CACHE) { 147 if (!seq) { 148 vp->v_maxra = bp->b_lblkno + bp->b_bcount / size; 149 vp->v_ralen >>= RA_SHIFTDOWN; 150 return 0; 151 } else if( vp->v_maxra > lblkno) { 152 if ((vp->v_ralen + 1) < RA_MULTIPLE_FAST * (MAXPHYS / size)) 153 ++vp->v_ralen; 154 if ( vp->v_maxra > lblkno + vp->v_ralen ) { 155 return 0; 156 } 157 lblkno = vp->v_maxra; 158 } else { 159 lblkno += 1; 160 } 161 bp = NULL; 162 } else { 163 /* 164 * if it isn't in the cache, then get a chunk from disk if 165 * sequential, otherwise just get the block. 166 */ 167 bp->b_flags |= B_READ; 168 lblkno += 1; 169 curproc->p_stats->p_ru.ru_inblock++; /* XXX */ 170 vp->v_ralen = 0; 171 } 172 /* 173 * assume no read-ahead 174 */ 175 alreadyincore = 1; 176 rablkno = lblkno; 177 178 /* 179 * if we have been doing sequential I/O, then do some read-ahead 180 */ 181 if (seq) { 182 alreadyincore = 0; 183 184 /* 185 * bump ralen a bit... 186 */ 187 if ((vp->v_ralen + 1) < RA_MULTIPLE_SLOW*(MAXPHYS / size)) 188 ++vp->v_ralen; 189 /* 190 * this code makes sure that the stuff that we have read-ahead 191 * is still in the cache. If it isn't, we have been reading 192 * ahead too much, and we need to back-off, otherwise we might 193 * try to read more. 194 */ 195 for (i = 0; i < vp->v_maxra - lblkno; i++) { 196 rablkno = lblkno + i; 197 alreadyincore = (int) incore(vp, rablkno); 198 if (!alreadyincore) { 199 vp->v_maxra = rablkno; 200 vp->v_ralen >>= RA_SHIFTDOWN; 201 alreadyincore = 1; 202 } 203 } 204 } 205 /* 206 * we now build the read-ahead buffer if it is desirable. 207 */ 208 rbp = NULL; 209 if (!alreadyincore && 210 ((u_quad_t)(rablkno + 1) * size) <= filesize && 211 !(error = VOP_BMAP(vp, rablkno, NULL, &blkno, &num_ra, NULL)) && 212 blkno != -1) { 213 if (num_ra > vp->v_ralen) 214 num_ra = vp->v_ralen; 215 216 if (num_ra) { 217 rbp = cluster_rbuild(vp, filesize, rablkno, blkno, size, 218 num_ra + 1); 219 } else { 220 rbp = getblk(vp, rablkno, size, 0, 0); 221 rbp->b_flags |= B_READ | B_ASYNC; 222 rbp->b_blkno = blkno; 223 } 224 } 225 226 /* 227 * handle the synchronous read 228 */ 229 if (bp) { 230 if (bp->b_flags & (B_DONE | B_DELWRI)) 231 panic("cluster_read: DONE bp"); 232 else { 233 vfs_busy_pages(bp, 0); 234 error = VOP_STRATEGY(bp); 235 vp->v_maxra = bp->b_lblkno + bp->b_bcount / size; 236 totreads++; 237 totreadblocks += bp->b_bcount / size; 238 curproc->p_stats->p_ru.ru_inblock++; 239 } 240 } 241 /* 242 * and if we have read-aheads, do them too 243 */ 244 if (rbp) { 245 vp->v_maxra = rbp->b_lblkno + rbp->b_bcount / size; 246 if (error) { 247 rbp->b_flags &= ~(B_ASYNC | B_READ); 248 brelse(rbp); 249 } else if (rbp->b_flags & B_CACHE) { 250 rbp->b_flags &= ~(B_ASYNC | B_READ); 251 bqrelse(rbp); 252 } else { 253 if ((rbp->b_flags & B_CLUSTER) == 0) 254 vfs_busy_pages(rbp, 0); 255 (void) VOP_STRATEGY(rbp); 256 totreads++; 257 totreadblocks += rbp->b_bcount / size; 258 curproc->p_stats->p_ru.ru_inblock++; 259 } 260 } 261 if (bp && ((bp->b_flags & B_ASYNC) == 0)) 262 return (biowait(bp)); 263 return (error); 264 } 265 266 /* 267 * If blocks are contiguous on disk, use this to provide clustered 268 * read ahead. We will read as many blocks as possible sequentially 269 * and then parcel them up into logical blocks in the buffer hash table. 270 */ 271 static struct buf * 272 cluster_rbuild(vp, filesize, lbn, blkno, size, run) 273 struct vnode *vp; 274 u_quad_t filesize; 275 daddr_t lbn; 276 daddr_t blkno; 277 long size; 278 int run; 279 { 280 struct buf *bp, *tbp; 281 daddr_t bn; 282 int i, inc, j; 283 284 #ifdef DIAGNOSTIC 285 if (size != vp->v_mount->mnt_stat.f_iosize) 286 panic("cluster_rbuild: size %d != filesize %d\n", 287 size, vp->v_mount->mnt_stat.f_iosize); 288 #endif 289 /* 290 * avoid a division 291 */ 292 while ((u_quad_t) size * (lbn + run) > filesize) { 293 --run; 294 } 295 296 tbp = getblk(vp, lbn, size, 0, 0); 297 if (tbp->b_flags & B_CACHE) 298 return tbp; 299 300 tbp->b_blkno = blkno; 301 tbp->b_flags |= B_ASYNC | B_READ; 302 if( (tbp->b_flags & B_MALLOC) || 303 ((tbp->b_flags & B_VMIO) == 0) || (run <= 1) ) 304 return tbp; 305 306 bp = trypbuf(); 307 if (bp == 0) 308 return tbp; 309 310 (vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK; 311 bp->b_flags = B_ASYNC | B_READ | B_CALL | B_BUSY | B_CLUSTER | B_VMIO; 312 bp->b_iodone = cluster_callback; 313 bp->b_blkno = blkno; 314 bp->b_lblkno = lbn; 315 pbgetvp(vp, bp); 316 317 TAILQ_INIT(&bp->b_cluster.cluster_head); 318 319 bp->b_bcount = 0; 320 bp->b_bufsize = 0; 321 bp->b_npages = 0; 322 323 inc = btodb(size); 324 for (bn = blkno, i = 0; i < run; ++i, bn += inc) { 325 if (i != 0) { 326 if ((bp->b_npages * PAGE_SIZE) + 327 round_page(size) > MAXPHYS) 328 break; 329 330 if (incore(vp, lbn + i)) 331 break; 332 333 tbp = getblk(vp, lbn + i, size, 0, 0); 334 335 if ((tbp->b_flags & B_CACHE) || 336 (tbp->b_flags & B_VMIO) == 0) { 337 bqrelse(tbp); 338 break; 339 } 340 341 for (j=0;j<tbp->b_npages;j++) { 342 if (tbp->b_pages[j]->valid) { 343 break; 344 } 345 } 346 347 if (j != tbp->b_npages) { 348 /* 349 * force buffer to be re-constituted later 350 */ 351 tbp->b_flags |= B_RELBUF; 352 brelse(tbp); 353 break; 354 } 355 356 tbp->b_flags |= B_READ | B_ASYNC; 357 if (tbp->b_blkno == tbp->b_lblkno) { 358 tbp->b_blkno = bn; 359 } else if (tbp->b_blkno != bn) { 360 brelse(tbp); 361 break; 362 } 363 } 364 TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head, 365 tbp, b_cluster.cluster_entry); 366 for (j = 0; j < tbp->b_npages; j += 1) { 367 vm_page_t m; 368 m = tbp->b_pages[j]; 369 ++m->busy; 370 ++m->object->paging_in_progress; 371 if ((bp->b_npages == 0) || 372 (bp->b_pages[bp->b_npages-1] != m)) { 373 bp->b_pages[bp->b_npages] = m; 374 bp->b_npages++; 375 } 376 if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) 377 tbp->b_pages[j] = bogus_page; 378 } 379 bp->b_bcount += tbp->b_bcount; 380 bp->b_bufsize += tbp->b_bufsize; 381 } 382 383 for(j=0;j<bp->b_npages;j++) { 384 if ((bp->b_pages[j]->valid & VM_PAGE_BITS_ALL) == 385 VM_PAGE_BITS_ALL) 386 bp->b_pages[j] = bogus_page; 387 } 388 if (bp->b_bufsize > bp->b_kvasize) 389 panic("cluster_rbuild: b_bufsize(%d) > b_kvasize(%d)\n", 390 bp->b_bufsize, bp->b_kvasize); 391 bp->b_kvasize = bp->b_bufsize; 392 393 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 394 (vm_page_t *)bp->b_pages, bp->b_npages); 395 return (bp); 396 } 397 398 /* 399 * Cleanup after a clustered read or write. 400 * This is complicated by the fact that any of the buffers might have 401 * extra memory (if there were no empty buffer headers at allocbuf time) 402 * that we will need to shift around. 403 */ 404 void 405 cluster_callback(bp) 406 struct buf *bp; 407 { 408 struct buf *nbp, *tbp; 409 int error = 0; 410 411 /* 412 * Must propogate errors to all the components. 413 */ 414 if (bp->b_flags & B_ERROR) 415 error = bp->b_error; 416 417 pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages); 418 /* 419 * Move memory from the large cluster buffer into the component 420 * buffers and mark IO as done on these. 421 */ 422 for (tbp = bp->b_cluster.cluster_head.tqh_first; 423 tbp; tbp = nbp) { 424 nbp = tbp->b_cluster.cluster_entry.tqe_next; 425 if (error) { 426 tbp->b_flags |= B_ERROR; 427 tbp->b_error = error; 428 } else 429 tbp->b_dirtyoff = tbp->b_dirtyend = 0; 430 biodone(tbp); 431 } 432 relpbuf(bp); 433 } 434 435 /* 436 * Do clustered write for FFS. 437 * 438 * Three cases: 439 * 1. Write is not sequential (write asynchronously) 440 * Write is sequential: 441 * 2. beginning of cluster - begin cluster 442 * 3. middle of a cluster - add to cluster 443 * 4. end of a cluster - asynchronously write cluster 444 */ 445 void 446 cluster_write(bp, filesize) 447 struct buf *bp; 448 u_quad_t filesize; 449 { 450 struct vnode *vp; 451 daddr_t lbn; 452 int maxclen, cursize; 453 int lblocksize; 454 int async; 455 456 vp = bp->b_vp; 457 async = (vp->v_mount && (vp->v_mount->mnt_flag & MNT_ASYNC)); 458 lblocksize = vp->v_mount->mnt_stat.f_iosize; 459 lbn = bp->b_lblkno; 460 461 /* Initialize vnode to beginning of file. */ 462 if (lbn == 0) 463 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 464 465 if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 || 466 (bp->b_blkno != vp->v_lasta + btodb(lblocksize))) { 467 maxclen = MAXPHYS / lblocksize - 1; 468 if (vp->v_clen != 0) { 469 /* 470 * Next block is not sequential. 471 * 472 * If we are not writing at end of file, the process 473 * seeked to another point in the file since its last 474 * write, or we have reached our maximum cluster size, 475 * then push the previous cluster. Otherwise try 476 * reallocating to make it sequential. 477 */ 478 cursize = vp->v_lastw - vp->v_cstart + 1; 479 #ifndef notyet_block_reallocation_enabled 480 if (((u_quad_t)(lbn + 1) * lblocksize) != filesize || 481 lbn != vp->v_lastw + 1 || 482 vp->v_clen <= cursize) { 483 if (!async) 484 cluster_wbuild(vp, lblocksize, 485 vp->v_cstart, cursize); 486 } 487 #else 488 if (!doreallocblks || 489 (lbn + 1) * lblocksize != filesize || 490 lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) { 491 if (!async) 492 cluster_wbuild(vp, lblocksize, 493 vp->v_cstart, cursize); 494 } else { 495 struct buf **bpp, **endbp; 496 struct cluster_save *buflist; 497 498 buflist = cluster_collectbufs(vp, bp); 499 endbp = &buflist->bs_children 500 [buflist->bs_nchildren - 1]; 501 if (VOP_REALLOCBLKS(vp, buflist)) { 502 /* 503 * Failed, push the previous cluster. 504 */ 505 for (bpp = buflist->bs_children; 506 bpp < endbp; bpp++) 507 brelse(*bpp); 508 free(buflist, M_SEGMENT); 509 cluster_wbuild(vp, lblocksize, 510 vp->v_cstart, cursize); 511 } else { 512 /* 513 * Succeeded, keep building cluster. 514 */ 515 for (bpp = buflist->bs_children; 516 bpp <= endbp; bpp++) 517 bdwrite(*bpp); 518 free(buflist, M_SEGMENT); 519 vp->v_lastw = lbn; 520 vp->v_lasta = bp->b_blkno; 521 return; 522 } 523 } 524 #endif /* notyet_block_reallocation_enabled */ 525 } 526 /* 527 * Consider beginning a cluster. If at end of file, make 528 * cluster as large as possible, otherwise find size of 529 * existing cluster. 530 */ 531 if (((u_quad_t) (lbn + 1) * lblocksize) != filesize && 532 (bp->b_blkno == bp->b_lblkno) && 533 (VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen, NULL) || 534 bp->b_blkno == -1)) { 535 bawrite(bp); 536 vp->v_clen = 0; 537 vp->v_lasta = bp->b_blkno; 538 vp->v_cstart = lbn + 1; 539 vp->v_lastw = lbn; 540 return; 541 } 542 vp->v_clen = maxclen; 543 if (!async && maxclen == 0) { /* I/O not contiguous */ 544 vp->v_cstart = lbn + 1; 545 bawrite(bp); 546 } else { /* Wait for rest of cluster */ 547 vp->v_cstart = lbn; 548 bdwrite(bp); 549 } 550 } else if (lbn == vp->v_cstart + vp->v_clen) { 551 /* 552 * At end of cluster, write it out. 553 */ 554 bdwrite(bp); 555 cluster_wbuild(vp, lblocksize, vp->v_cstart, vp->v_clen + 1); 556 vp->v_clen = 0; 557 vp->v_cstart = lbn + 1; 558 } else 559 /* 560 * In the middle of a cluster, so just delay the I/O for now. 561 */ 562 bdwrite(bp); 563 vp->v_lastw = lbn; 564 vp->v_lasta = bp->b_blkno; 565 } 566 567 568 /* 569 * This is an awful lot like cluster_rbuild...wish they could be combined. 570 * The last lbn argument is the current block on which I/O is being 571 * performed. Check to see that it doesn't fall in the middle of 572 * the current block (if last_bp == NULL). 573 */ 574 int 575 cluster_wbuild(vp, size, start_lbn, len) 576 struct vnode *vp; 577 long size; 578 daddr_t start_lbn; 579 int len; 580 { 581 struct buf *bp, *tbp; 582 int i, j, s; 583 int totalwritten = 0; 584 int dbsize = btodb(size); 585 while (len > 0) { 586 s = splbio(); 587 if ( ((tbp = gbincore(vp, start_lbn)) == NULL) || 588 ((tbp->b_flags & (B_INVAL|B_BUSY|B_DELWRI)) != B_DELWRI)) { 589 ++start_lbn; 590 --len; 591 splx(s); 592 continue; 593 } 594 bremfree(tbp); 595 tbp->b_flags |= B_BUSY; 596 tbp->b_flags &= ~B_DONE; 597 splx(s); 598 599 /* 600 * Extra memory in the buffer, punt on this buffer. XXX we could 601 * handle this in most cases, but we would have to push the extra 602 * memory down to after our max possible cluster size and then 603 * potentially pull it back up if the cluster was terminated 604 * prematurely--too much hassle. 605 */ 606 if (((tbp->b_flags & (B_CLUSTEROK|B_MALLOC)) != B_CLUSTEROK) || 607 (tbp->b_bcount != tbp->b_bufsize) || 608 (tbp->b_bcount != size) || 609 len == 1) { 610 totalwritten += tbp->b_bufsize; 611 bawrite(tbp); 612 ++start_lbn; 613 --len; 614 continue; 615 } 616 617 bp = trypbuf(); 618 if (bp == NULL) { 619 totalwritten += tbp->b_bufsize; 620 bawrite(tbp); 621 ++start_lbn; 622 --len; 623 continue; 624 } 625 626 TAILQ_INIT(&bp->b_cluster.cluster_head); 627 bp->b_bcount = 0; 628 bp->b_bufsize = 0; 629 bp->b_npages = 0; 630 if (tbp->b_wcred != NOCRED) { 631 bp->b_wcred = tbp->b_wcred; 632 crhold(bp->b_wcred); 633 } 634 635 bp->b_blkno = tbp->b_blkno; 636 bp->b_lblkno = tbp->b_lblkno; 637 (vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK; 638 bp->b_flags |= B_CALL | B_BUSY | B_CLUSTER | (tbp->b_flags & (B_VMIO|B_NEEDCOMMIT)); 639 bp->b_iodone = cluster_callback; 640 pbgetvp(vp, bp); 641 642 for (i = 0; i < len; ++i, ++start_lbn) { 643 if (i != 0) { 644 s = splbio(); 645 if ((tbp = gbincore(vp, start_lbn)) == NULL) { 646 splx(s); 647 break; 648 } 649 650 if ((tbp->b_flags & (B_VMIO|B_CLUSTEROK|B_INVAL|B_BUSY|B_DELWRI|B_NEEDCOMMIT)) != (B_DELWRI|B_CLUSTEROK|(bp->b_flags & (B_VMIO|B_NEEDCOMMIT)))) { 651 splx(s); 652 break; 653 } 654 655 if (tbp->b_wcred != bp->b_wcred) { 656 splx(s); 657 break; 658 } 659 660 if ((tbp->b_bcount != size) || 661 ((bp->b_blkno + dbsize * i) != tbp->b_blkno) || 662 ((tbp->b_npages + bp->b_npages) > (MAXPHYS / PAGE_SIZE))) { 663 splx(s); 664 break; 665 } 666 bremfree(tbp); 667 tbp->b_flags |= B_BUSY; 668 tbp->b_flags &= ~B_DONE; 669 splx(s); 670 } 671 if (tbp->b_flags & B_VMIO) { 672 for (j = 0; j < tbp->b_npages; j += 1) { 673 vm_page_t m; 674 m = tbp->b_pages[j]; 675 ++m->busy; 676 ++m->object->paging_in_progress; 677 if ((bp->b_npages == 0) || 678 (bp->b_pages[bp->b_npages - 1] != m)) { 679 bp->b_pages[bp->b_npages] = m; 680 bp->b_npages++; 681 } 682 } 683 } 684 bp->b_bcount += size; 685 bp->b_bufsize += size; 686 687 tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI); 688 tbp->b_flags |= B_ASYNC; 689 s = splbio(); 690 reassignbuf(tbp, tbp->b_vp); /* put on clean list */ 691 ++tbp->b_vp->v_numoutput; 692 splx(s); 693 TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head, 694 tbp, b_cluster.cluster_entry); 695 } 696 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 697 (vm_page_t *) bp->b_pages, bp->b_npages); 698 if (bp->b_bufsize > bp->b_kvasize) 699 panic("cluster_wbuild: b_bufsize(%d) > b_kvasize(%d)\n", 700 bp->b_bufsize, bp->b_kvasize); 701 bp->b_kvasize = bp->b_bufsize; 702 totalwritten += bp->b_bufsize; 703 bp->b_dirtyoff = 0; 704 bp->b_dirtyend = bp->b_bufsize; 705 bawrite(bp); 706 707 len -= i; 708 } 709 return totalwritten; 710 } 711 712 #ifdef notyet_block_reallocation_enabled 713 /* 714 * Collect together all the buffers in a cluster. 715 * Plus add one additional buffer. 716 */ 717 static struct cluster_save * 718 cluster_collectbufs(vp, last_bp) 719 struct vnode *vp; 720 struct buf *last_bp; 721 { 722 struct cluster_save *buflist; 723 daddr_t lbn; 724 int i, len; 725 726 len = vp->v_lastw - vp->v_cstart + 1; 727 buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist), 728 M_SEGMENT, M_WAITOK); 729 buflist->bs_nchildren = 0; 730 buflist->bs_children = (struct buf **) (buflist + 1); 731 for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++) 732 (void) bread(vp, lbn, last_bp->b_bcount, NOCRED, 733 &buflist->bs_children[i]); 734 buflist->bs_children[i] = last_bp; 735 buflist->bs_nchildren = i + 1; 736 return (buflist); 737 } 738 #endif /* notyet_block_reallocation_enabled */
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