vfs_cluster.c revision 12407
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 * $Id: vfs_cluster.c,v 1.25 1995/11/19 19:54:19 dyson 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_object.h> 51#include <vm/vm_page.h> 52 53#ifdef DEBUG 54#include <vm/vm.h> 55#include <sys/sysctl.h> 56int doreallocblks = 0; 57SYSCTL_INT(_debug, 13, doreallocblks, CTLFLAG_RW, &doreallocblks, 0, ""); 58 59#else 60/* XXX for cluster_write */ 61#define doreallocblks 0 62#endif 63 64/* 65 * Local declarations 66 */ 67static struct buf *cluster_rbuild __P((struct vnode *, u_quad_t, 68 daddr_t, daddr_t, long, int)); 69struct cluster_save *cluster_collectbufs __P((struct vnode *, struct buf *)); 70 71int totreads; 72int totreadblocks; 73extern vm_page_t bogus_page; 74 75#ifdef DIAGNOSTIC 76/* 77 * Set to 1 if reads of block zero should cause readahead to be done. 78 * Set to 0 treats a read of block zero as a non-sequential read. 79 * 80 * Setting to one assumes that most reads of block zero of files are due to 81 * sequential passes over the files (e.g. cat, sum) where additional blocks 82 * will soon be needed. Setting to zero assumes that the majority are 83 * surgical strikes to get particular info (e.g. size, file) where readahead 84 * blocks will not be used and, in fact, push out other potentially useful 85 * blocks from the cache. The former seems intuitive, but some quick tests 86 * showed that the latter performed better from a system-wide point of view. 87 */ 88 int doclusterraz = 0; 89 90#define ISSEQREAD(vp, blk) \ 91 (((blk) != 0 || doclusterraz) && \ 92 ((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr)) 93#else 94#define ISSEQREAD(vp, blk) \ 95 (/* (blk) != 0 && */ ((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr)) 96#endif 97 98/* 99 * allow for three entire read-aheads... The system will 100 * adjust downwards rapidly if needed... 101 */ 102#define RA_MULTIPLE_FAST 2 103#define RA_MULTIPLE_SLOW 3 104#define RA_SHIFTDOWN 1 /* approx lg2(RA_MULTIPLE) */ 105/* 106 * This replaces bread. If this is a bread at the beginning of a file and 107 * lastr is 0, we assume this is the first read and we'll read up to two 108 * blocks if they are sequential. After that, we'll do regular read ahead 109 * in clustered chunks. 110 * bp is the block requested. 111 * rbp is the read-ahead block. 112 * If either is NULL, then you don't have to do the I/O. 113 */ 114int 115cluster_read(vp, filesize, lblkno, size, cred, bpp) 116 struct vnode *vp; 117 u_quad_t filesize; 118 daddr_t lblkno; 119 long size; 120 struct ucred *cred; 121 struct buf **bpp; 122{ 123 struct buf *bp, *rbp; 124 daddr_t blkno, rablkno, origlblkno; 125 int error, num_ra, alreadyincore; 126 int i; 127 int seq; 128 129 error = 0; 130 /* 131 * get the requested block 132 */ 133 origlblkno = lblkno; 134 *bpp = bp = getblk(vp, lblkno, size, 0, 0); 135 seq = ISSEQREAD(vp, lblkno); 136 /* 137 * if it is in the cache, then check to see if the reads have been 138 * sequential. If they have, then try some read-ahead, otherwise 139 * back-off on prospective read-aheads. 140 */ 141 if (bp->b_flags & B_CACHE) { 142 if (!seq) { 143 vp->v_maxra = bp->b_lblkno + bp->b_bcount / size; 144 vp->v_ralen >>= RA_SHIFTDOWN; 145 return 0; 146 } else if( vp->v_maxra > lblkno) { 147 if ( (vp->v_maxra + (vp->v_ralen / RA_MULTIPLE_SLOW)) >= (lblkno + vp->v_ralen)) { 148 if ((vp->v_ralen + 1) < RA_MULTIPLE_FAST*(MAXPHYS / size)) 149 ++vp->v_ralen; 150 return 0; 151 } 152 lblkno = vp->v_maxra; 153 } else { 154 lblkno += 1; 155 } 156 bp = NULL; 157 } else { 158 /* 159 * if it isn't in the cache, then get a chunk from disk if 160 * sequential, otherwise just get the block. 161 */ 162 bp->b_flags |= B_READ; 163 lblkno += 1; 164 curproc->p_stats->p_ru.ru_inblock++; /* XXX */ 165 vp->v_ralen = 0; 166 } 167 /* 168 * assume no read-ahead 169 */ 170 alreadyincore = 1; 171 rablkno = lblkno; 172 173 /* 174 * if we have been doing sequential I/O, then do some read-ahead 175 */ 176 if (seq) { 177 178 /* 179 * bump ralen a bit... 180 */ 181 if ((vp->v_ralen + 1) < RA_MULTIPLE_SLOW*(MAXPHYS / size)) 182 ++vp->v_ralen; 183 /* 184 * this code makes sure that the stuff that we have read-ahead 185 * is still in the cache. If it isn't, we have been reading 186 * ahead too much, and we need to back-off, otherwise we might 187 * try to read more. 188 */ 189 for (i = 0; i < vp->v_ralen; i++) { 190 rablkno = lblkno + i; 191 alreadyincore = (int) incore(vp, rablkno); 192 if (!alreadyincore) { 193 if (inmem(vp, rablkno)) { 194 if (vp->v_maxra < rablkno) 195 vp->v_maxra = rablkno + 1; 196 continue; 197 } 198 if (rablkno < vp->v_maxra) { 199 vp->v_maxra = rablkno; 200 vp->v_ralen >>= RA_SHIFTDOWN; 201 alreadyincore = 1; 202 } 203 break; 204 } else if (vp->v_maxra < rablkno) { 205 vp->v_maxra = rablkno + 1; 206 } 207 } 208 } 209 /* 210 * we now build the read-ahead buffer if it is desirable. 211 */ 212 rbp = NULL; 213 if (!alreadyincore && 214 (rablkno + 1) * size <= filesize && 215 !(error = VOP_BMAP(vp, rablkno, NULL, &blkno, &num_ra, NULL)) && 216 blkno != -1) { 217 if (num_ra > vp->v_ralen) 218 num_ra = vp->v_ralen; 219 220 if (num_ra) { 221 rbp = cluster_rbuild(vp, filesize, rablkno, blkno, size, 222 num_ra + 1); 223 } else { 224 rbp = getblk(vp, rablkno, size, 0, 0); 225 rbp->b_flags |= B_READ | B_ASYNC; 226 rbp->b_blkno = blkno; 227 } 228 } 229 230 /* 231 * handle the synchronous read 232 */ 233 if (bp) { 234 if (bp->b_flags & (B_DONE | B_DELWRI)) 235 panic("cluster_read: DONE bp"); 236 else { 237 vfs_busy_pages(bp, 0); 238 error = VOP_STRATEGY(bp); 239 vp->v_maxra = bp->b_lblkno + bp->b_bcount / size; 240 totreads++; 241 totreadblocks += bp->b_bcount / size; 242 curproc->p_stats->p_ru.ru_inblock++; 243 } 244 } 245 /* 246 * and if we have read-aheads, do them too 247 */ 248 if (rbp) { 249 vp->v_maxra = rbp->b_lblkno + rbp->b_bcount / size; 250 if (error || (rbp->b_flags & B_CACHE)) { 251 rbp->b_flags &= ~(B_ASYNC | B_READ); 252 brelse(rbp); 253 } else { 254 if ((rbp->b_flags & B_CLUSTER) == 0) 255 vfs_busy_pages(rbp, 0); 256 (void) VOP_STRATEGY(rbp); 257 totreads++; 258 totreadblocks += rbp->b_bcount / size; 259 curproc->p_stats->p_ru.ru_inblock++; 260 } 261 } 262 if (bp && ((bp->b_flags & B_ASYNC) == 0)) 263 return (biowait(bp)); 264 return (error); 265} 266 267/* 268 * If blocks are contiguous on disk, use this to provide clustered 269 * read ahead. We will read as many blocks as possible sequentially 270 * and then parcel them up into logical blocks in the buffer hash table. 271 */ 272static struct buf * 273cluster_rbuild(vp, filesize, lbn, blkno, size, run) 274 struct vnode *vp; 275 u_quad_t filesize; 276 daddr_t lbn; 277 daddr_t blkno; 278 long size; 279 int run; 280{ 281 struct buf *bp, *tbp; 282 daddr_t bn; 283 int i, inc, j; 284 285#ifdef DIAGNOSTIC 286 if (size != vp->v_mount->mnt_stat.f_iosize) 287 panic("cluster_rbuild: size %d != filesize %d\n", 288 size, vp->v_mount->mnt_stat.f_iosize); 289#endif 290 if (size * (lbn + run) > filesize) 291 --run; 292 293 tbp = getblk(vp, lbn, size, 0, 0); 294 if (tbp->b_flags & B_CACHE) 295 return tbp; 296 297 tbp->b_blkno = blkno; 298 tbp->b_flags |= B_ASYNC | B_READ; 299 if( ((tbp->b_flags & B_VMIO) == 0) || (run <= 1) ) 300 return tbp; 301 302 bp = trypbuf(); 303 if (bp == 0) 304 return tbp; 305 306 (vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK; 307 bp->b_flags = B_ASYNC | B_READ | B_CALL | B_BUSY | B_CLUSTER | B_VMIO; 308 bp->b_iodone = cluster_callback; 309 bp->b_blkno = blkno; 310 bp->b_lblkno = lbn; 311 pbgetvp(vp, bp); 312 313 TAILQ_INIT(&bp->b_cluster.cluster_head); 314 315 bp->b_bcount = 0; 316 bp->b_bufsize = 0; 317 bp->b_npages = 0; 318 319 inc = btodb(size); 320 for (bn = blkno, i = 0; i < run; ++i, bn += inc) { 321 if (i != 0) { 322 if ((bp->b_npages * PAGE_SIZE) + size > MAXPHYS) 323 break; 324 325 if (incore(vp, lbn + i)) 326 break; 327 tbp = getblk(vp, lbn + i, size, 0, 0); 328 329 if ((tbp->b_flags & B_CACHE) || 330 (tbp->b_flags & B_VMIO) == 0) { 331 brelse(tbp); 332 break; 333 } 334 335 for (j=0;j<tbp->b_npages;j++) { 336 if (tbp->b_pages[j]->valid) { 337 break; 338 } 339 } 340 341 if (j != tbp->b_npages) { 342 /* 343 * force buffer to be re-constituted later 344 */ 345 tbp->b_flags |= B_RELBUF; 346 brelse(tbp); 347 break; 348 } 349 350 tbp->b_flags |= B_READ | B_ASYNC; 351 if( tbp->b_blkno == tbp->b_lblkno) { 352 tbp->b_blkno = bn; 353 } else if (tbp->b_blkno != bn) { 354 brelse(tbp); 355 break; 356 } 357 } 358 TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head, 359 tbp, b_cluster.cluster_entry); 360 for (j = 0; j < tbp->b_npages; j += 1) { 361 vm_page_t m; 362 m = tbp->b_pages[j]; 363 ++m->busy; 364 ++m->object->paging_in_progress; 365 if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) { 366 m = bogus_page; 367 } 368 if ((bp->b_npages == 0) || 369 (bp->b_bufsize & PAGE_MASK) == 0) { 370 bp->b_pages[bp->b_npages] = m; 371 bp->b_npages++; 372 } else { 373 if ( tbp->b_npages > 1) { 374 panic("cluster_rbuild: page unaligned filesystems not supported"); 375 } 376 } 377 } 378 bp->b_bcount += tbp->b_bcount; 379 bp->b_bufsize += tbp->b_bufsize; 380 } 381 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 382 (vm_page_t *)bp->b_pages, bp->b_npages); 383 return (bp); 384} 385 386/* 387 * Cleanup after a clustered read or write. 388 * This is complicated by the fact that any of the buffers might have 389 * extra memory (if there were no empty buffer headers at allocbuf time) 390 * that we will need to shift around. 391 */ 392void 393cluster_callback(bp) 394 struct buf *bp; 395{ 396 struct buf *nbp, *tbp; 397 int error = 0; 398 399 /* 400 * Must propogate errors to all the components. 401 */ 402 if (bp->b_flags & B_ERROR) 403 error = bp->b_error; 404 405 pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages); 406 /* 407 * Move memory from the large cluster buffer into the component 408 * buffers and mark IO as done on these. 409 */ 410 for (tbp = bp->b_cluster.cluster_head.tqh_first; 411 tbp; tbp = nbp) { 412 nbp = tbp->b_cluster.cluster_entry.tqe_next; 413 if (error) { 414 tbp->b_flags |= B_ERROR; 415 tbp->b_error = error; 416 } 417 biodone(tbp); 418 } 419 relpbuf(bp); 420} 421 422/* 423 * Do clustered write for FFS. 424 * 425 * Three cases: 426 * 1. Write is not sequential (write asynchronously) 427 * Write is sequential: 428 * 2. beginning of cluster - begin cluster 429 * 3. middle of a cluster - add to cluster 430 * 4. end of a cluster - asynchronously write cluster 431 */ 432void 433cluster_write(bp, filesize) 434 struct buf *bp; 435 u_quad_t filesize; 436{ 437 struct vnode *vp; 438 daddr_t lbn; 439 int maxclen, cursize; 440 int lblocksize; 441 int async; 442 443 vp = bp->b_vp; 444 async = (vp->v_mount && (vp->v_mount->mnt_flag & MNT_ASYNC)); 445 lblocksize = vp->v_mount->mnt_stat.f_iosize; 446 lbn = bp->b_lblkno; 447 448 /* Initialize vnode to beginning of file. */ 449 if (lbn == 0) 450 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 451 452 if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 || 453 (bp->b_blkno != vp->v_lasta + btodb(lblocksize))) { 454 maxclen = MAXPHYS / lblocksize - 1; 455 if (vp->v_clen != 0) { 456 /* 457 * Next block is not sequential. 458 * 459 * If we are not writing at end of file, the process 460 * seeked to another point in the file since its last 461 * write, or we have reached our maximum cluster size, 462 * then push the previous cluster. Otherwise try 463 * reallocating to make it sequential. 464 */ 465 cursize = vp->v_lastw - vp->v_cstart + 1; 466#if 1 467 if ((lbn + 1) * lblocksize != filesize || 468 lbn != vp->v_lastw + 1 || 469 vp->v_clen <= cursize) { 470 if (!async) 471 cluster_wbuild(vp, lblocksize, 472 vp->v_cstart, cursize); 473 } 474#else 475 if (!doreallocblks || 476 (lbn + 1) * lblocksize != filesize || 477 lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) { 478 if (!async) 479 cluster_wbuild(vp, lblocksize, 480 vp->v_cstart, cursize); 481 } else { 482 struct buf **bpp, **endbp; 483 struct cluster_save *buflist; 484 485 buflist = cluster_collectbufs(vp, bp); 486 endbp = &buflist->bs_children 487 [buflist->bs_nchildren - 1]; 488 if (VOP_REALLOCBLKS(vp, buflist)) { 489 /* 490 * Failed, push the previous cluster. 491 */ 492 for (bpp = buflist->bs_children; 493 bpp < endbp; bpp++) 494 brelse(*bpp); 495 free(buflist, M_SEGMENT); 496 cluster_wbuild(vp, lblocksize, 497 vp->v_cstart, cursize); 498 } else { 499 /* 500 * Succeeded, keep building cluster. 501 */ 502 for (bpp = buflist->bs_children; 503 bpp <= endbp; bpp++) 504 bdwrite(*bpp); 505 free(buflist, M_SEGMENT); 506 vp->v_lastw = lbn; 507 vp->v_lasta = bp->b_blkno; 508 return; 509 } 510 } 511#endif 512 } 513 /* 514 * Consider beginning a cluster. If at end of file, make 515 * cluster as large as possible, otherwise find size of 516 * existing cluster. 517 */ 518 if ((lbn + 1) * lblocksize != filesize && 519 (bp->b_blkno == bp->b_lblkno) && 520 (VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen, NULL) || 521 bp->b_blkno == -1)) { 522 bawrite(bp); 523 vp->v_clen = 0; 524 vp->v_lasta = bp->b_blkno; 525 vp->v_cstart = lbn + 1; 526 vp->v_lastw = lbn; 527 return; 528 } 529 vp->v_clen = maxclen; 530 if (!async && maxclen == 0) { /* I/O not contiguous */ 531 vp->v_cstart = lbn + 1; 532 bawrite(bp); 533 } else { /* Wait for rest of cluster */ 534 vp->v_cstart = lbn; 535 bdwrite(bp); 536 } 537 } else if (lbn == vp->v_cstart + vp->v_clen) { 538 /* 539 * At end of cluster, write it out. 540 */ 541 bdwrite(bp); 542 cluster_wbuild(vp, lblocksize, vp->v_cstart, 543 vp->v_clen + 1); 544 vp->v_clen = 0; 545 vp->v_cstart = lbn + 1; 546 } else 547 /* 548 * In the middle of a cluster, so just delay the I/O for now. 549 */ 550 bdwrite(bp); 551 vp->v_lastw = lbn; 552 vp->v_lasta = bp->b_blkno; 553} 554 555 556/* 557 * This is an awful lot like cluster_rbuild...wish they could be combined. 558 * The last lbn argument is the current block on which I/O is being 559 * performed. Check to see that it doesn't fall in the middle of 560 * the current block (if last_bp == NULL). 561 */ 562void 563cluster_wbuild(vp, size, start_lbn, len) 564 struct vnode *vp; 565 long size; 566 daddr_t start_lbn; 567 int len; 568{ 569 struct buf *bp, *tbp; 570 int i, j, s; 571 int dbsize = btodb(size); 572 int origlen = len; 573 574redo: 575 if (len == 0) 576 return; 577 if ( ((tbp = incore(vp, start_lbn)) == NULL) || 578 ((tbp->b_flags & (B_INVAL|B_BUSY|B_DELWRI)) != B_DELWRI)) { 579 ++start_lbn; 580 --len; 581 goto redo; 582 } 583 584 tbp = getblk(vp, start_lbn, size, 0, 0); 585 if ((tbp->b_flags & B_DELWRI) == 0) { 586 ++start_lbn; 587 --len; 588 brelse(tbp); 589 goto redo; 590 } 591 /* 592 * Extra memory in the buffer, punt on this buffer. XXX we could 593 * handle this in most cases, but we would have to push the extra 594 * memory down to after our max possible cluster size and then 595 * potentially pull it back up if the cluster was terminated 596 * prematurely--too much hassle. 597 */ 598 if (((tbp->b_flags & (B_VMIO|B_CLUSTEROK)) != (B_VMIO|B_CLUSTEROK)) || 599 (tbp->b_bcount != tbp->b_bufsize) || 600 len == 1) { 601 bawrite(tbp); 602 ++start_lbn; 603 --len; 604 goto redo; 605 } 606 607 bp = trypbuf(); 608 if (bp == NULL) { 609 bawrite(tbp); 610 ++start_lbn; 611 --len; 612 goto redo; 613 } 614 615 TAILQ_INIT(&bp->b_cluster.cluster_head); 616 bp->b_bcount = 0; 617 bp->b_bufsize = 0; 618 bp->b_npages = 0; 619 620 bp->b_blkno = tbp->b_blkno; 621 bp->b_lblkno = tbp->b_lblkno; 622 (vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK; 623 bp->b_flags |= B_CALL | B_BUSY | B_CLUSTER; 624 bp->b_iodone = cluster_callback; 625 pbgetvp(vp, bp); 626 627 for (i = 0; i < len; ++i, ++start_lbn) { 628 if (i != 0) { 629 s = splbio(); 630 if ((tbp = incore(vp, start_lbn)) == NULL) { 631 splx(s); 632 break; 633 } 634 635 if ((tbp->b_flags & (B_CLUSTEROK|B_INVAL|B_BUSY|B_DELWRI)) != (B_DELWRI|B_CLUSTEROK)) { 636 splx(s); 637 break; 638 } 639 640 if ((tbp->b_bcount != size) || 641 ((bp->b_blkno + dbsize * i) != tbp->b_blkno) || 642 ((tbp->b_npages + bp->b_npages) > (MAXPHYS / PAGE_SIZE))) { 643 splx(s); 644 break; 645 } 646 bremfree(tbp); 647 tbp->b_flags |= B_BUSY; 648 tbp->b_flags &= ~B_DONE; 649 splx(s); 650 } 651 for (j = 0; j < tbp->b_npages; j += 1) { 652 vm_page_t m; 653 m = tbp->b_pages[j]; 654 ++m->busy; 655 ++m->object->paging_in_progress; 656 if ((bp->b_npages == 0) || 657 (bp->b_pages[bp->b_npages - 1] != m)) { 658 bp->b_pages[bp->b_npages] = m; 659 bp->b_npages++; 660 } 661 } 662 bp->b_bcount += size; 663 bp->b_bufsize += size; 664 665 tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI); 666 tbp->b_flags |= B_ASYNC; 667 s = splbio(); 668 reassignbuf(tbp, tbp->b_vp); /* put on clean list */ 669 ++tbp->b_vp->v_numoutput; 670 splx(s); 671 TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head, 672 tbp, b_cluster.cluster_entry); 673 } 674 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 675 (vm_page_t *) bp->b_pages, bp->b_npages); 676 bawrite(bp); 677 678 len -= i; 679 goto redo; 680} 681 682#if 0 683/* 684 * Collect together all the buffers in a cluster. 685 * Plus add one additional buffer. 686 */ 687struct cluster_save * 688cluster_collectbufs(vp, last_bp) 689 struct vnode *vp; 690 struct buf *last_bp; 691{ 692 struct cluster_save *buflist; 693 daddr_t lbn; 694 int i, len; 695 696 len = vp->v_lastw - vp->v_cstart + 1; 697 buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist), 698 M_SEGMENT, M_WAITOK); 699 buflist->bs_nchildren = 0; 700 buflist->bs_children = (struct buf **) (buflist + 1); 701 for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++) 702 (void) bread(vp, lbn, last_bp->b_bcount, NOCRED, 703 &buflist->bs_children[i]); 704 buflist->bs_children[i] = last_bp; 705 buflist->bs_nchildren = i + 1; 706 return (buflist); 707} 708#endif 709