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 1.27 1995/11/20 03:55:48 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> 56 int doreallocblks = 0; 57 SYSCTL_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 */ 67 static struct buf *cluster_rbuild __P((struct vnode *, u_quad_t, 68 daddr_t, daddr_t, long, int)); 69 struct cluster_save *cluster_collectbufs __P((struct vnode *, struct buf *)); 70 71 int totreads; 72 int totreadblocks; 73 extern 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 */ 114 int 115 cluster_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 */ 272 static struct buf * 273 cluster_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_pages[bp->b_npages-1] != m)) { 370 bp->b_pages[bp->b_npages] = m; 371 bp->b_npages++; 372 } 373 } 374 bp->b_bcount += tbp->b_bcount; 375 bp->b_bufsize += tbp->b_bufsize; 376 } 377 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 378 (vm_page_t *)bp->b_pages, bp->b_npages); 379 return (bp); 380 } 381 382 /* 383 * Cleanup after a clustered read or write. 384 * This is complicated by the fact that any of the buffers might have 385 * extra memory (if there were no empty buffer headers at allocbuf time) 386 * that we will need to shift around. 387 */ 388 void 389 cluster_callback(bp) 390 struct buf *bp; 391 { 392 struct buf *nbp, *tbp; 393 int error = 0; 394 395 /* 396 * Must propogate errors to all the components. 397 */ 398 if (bp->b_flags & B_ERROR) 399 error = bp->b_error; 400 401 pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages); 402 /* 403 * Move memory from the large cluster buffer into the component 404 * buffers and mark IO as done on these. 405 */ 406 for (tbp = bp->b_cluster.cluster_head.tqh_first; 407 tbp; tbp = nbp) { 408 nbp = tbp->b_cluster.cluster_entry.tqe_next; 409 if (error) { 410 tbp->b_flags |= B_ERROR; 411 tbp->b_error = error; 412 } 413 biodone(tbp); 414 } 415 relpbuf(bp); 416 } 417 418 /* 419 * Do clustered write for FFS. 420 * 421 * Three cases: 422 * 1. Write is not sequential (write asynchronously) 423 * Write is sequential: 424 * 2. beginning of cluster - begin cluster 425 * 3. middle of a cluster - add to cluster 426 * 4. end of a cluster - asynchronously write cluster 427 */ 428 void 429 cluster_write(bp, filesize) 430 struct buf *bp; 431 u_quad_t filesize; 432 { 433 struct vnode *vp; 434 daddr_t lbn; 435 int maxclen, cursize; 436 int lblocksize; 437 int async; 438 439 vp = bp->b_vp; 440 async = (vp->v_mount && (vp->v_mount->mnt_flag & MNT_ASYNC)); 441 lblocksize = vp->v_mount->mnt_stat.f_iosize; 442 lbn = bp->b_lblkno; 443 444 /* Initialize vnode to beginning of file. */ 445 if (lbn == 0) 446 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 447 448 if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 || 449 (bp->b_blkno != vp->v_lasta + btodb(lblocksize))) { 450 maxclen = MAXPHYS / lblocksize - 1; 451 if (vp->v_clen != 0) { 452 /* 453 * Next block is not sequential. 454 * 455 * If we are not writing at end of file, the process 456 * seeked to another point in the file since its last 457 * write, or we have reached our maximum cluster size, 458 * then push the previous cluster. Otherwise try 459 * reallocating to make it sequential. 460 */ 461 cursize = vp->v_lastw - vp->v_cstart + 1; 462 #if 1 463 if ((lbn + 1) * lblocksize != filesize || 464 lbn != vp->v_lastw + 1 || 465 vp->v_clen <= cursize) { 466 if (!async) 467 cluster_wbuild(vp, lblocksize, 468 vp->v_cstart, cursize); 469 } 470 #else 471 if (!doreallocblks || 472 (lbn + 1) * lblocksize != filesize || 473 lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) { 474 if (!async) 475 cluster_wbuild(vp, lblocksize, 476 vp->v_cstart, cursize); 477 } else { 478 struct buf **bpp, **endbp; 479 struct cluster_save *buflist; 480 481 buflist = cluster_collectbufs(vp, bp); 482 endbp = &buflist->bs_children 483 [buflist->bs_nchildren - 1]; 484 if (VOP_REALLOCBLKS(vp, buflist)) { 485 /* 486 * Failed, push the previous cluster. 487 */ 488 for (bpp = buflist->bs_children; 489 bpp < endbp; bpp++) 490 brelse(*bpp); 491 free(buflist, M_SEGMENT); 492 cluster_wbuild(vp, lblocksize, 493 vp->v_cstart, cursize); 494 } else { 495 /* 496 * Succeeded, keep building cluster. 497 */ 498 for (bpp = buflist->bs_children; 499 bpp <= endbp; bpp++) 500 bdwrite(*bpp); 501 free(buflist, M_SEGMENT); 502 vp->v_lastw = lbn; 503 vp->v_lasta = bp->b_blkno; 504 return; 505 } 506 } 507 #endif 508 } 509 /* 510 * Consider beginning a cluster. If at end of file, make 511 * cluster as large as possible, otherwise find size of 512 * existing cluster. 513 */ 514 if ((lbn + 1) * lblocksize != filesize && 515 (bp->b_blkno == bp->b_lblkno) && 516 (VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen, NULL) || 517 bp->b_blkno == -1)) { 518 bawrite(bp); 519 vp->v_clen = 0; 520 vp->v_lasta = bp->b_blkno; 521 vp->v_cstart = lbn + 1; 522 vp->v_lastw = lbn; 523 return; 524 } 525 vp->v_clen = maxclen; 526 if (!async && maxclen == 0) { /* I/O not contiguous */ 527 vp->v_cstart = lbn + 1; 528 bawrite(bp); 529 } else { /* Wait for rest of cluster */ 530 vp->v_cstart = lbn; 531 bdwrite(bp); 532 } 533 } else if (lbn == vp->v_cstart + vp->v_clen) { 534 /* 535 * At end of cluster, write it out. 536 */ 537 bdwrite(bp); 538 cluster_wbuild(vp, lblocksize, vp->v_cstart, 539 vp->v_clen + 1); 540 vp->v_clen = 0; 541 vp->v_cstart = lbn + 1; 542 } else 543 /* 544 * In the middle of a cluster, so just delay the I/O for now. 545 */ 546 bdwrite(bp); 547 vp->v_lastw = lbn; 548 vp->v_lasta = bp->b_blkno; 549 } 550 551 552 /* 553 * This is an awful lot like cluster_rbuild...wish they could be combined. 554 * The last lbn argument is the current block on which I/O is being 555 * performed. Check to see that it doesn't fall in the middle of 556 * the current block (if last_bp == NULL). 557 */ 558 void 559 cluster_wbuild(vp, size, start_lbn, len) 560 struct vnode *vp; 561 long size; 562 daddr_t start_lbn; 563 int len; 564 { 565 struct buf *bp, *tbp; 566 int i, j, s; 567 int dbsize = btodb(size); 568 int origlen = len; 569 570 redo: 571 if (len == 0) 572 return; 573 if ( ((tbp = incore(vp, start_lbn)) == NULL) || 574 ((tbp->b_flags & (B_INVAL|B_BUSY|B_DELWRI)) != B_DELWRI)) { 575 ++start_lbn; 576 --len; 577 goto redo; 578 } 579 580 tbp = getblk(vp, start_lbn, size, 0, 0); 581 if ((tbp->b_flags & B_DELWRI) == 0) { 582 ++start_lbn; 583 --len; 584 brelse(tbp); 585 goto redo; 586 } 587 /* 588 * Extra memory in the buffer, punt on this buffer. XXX we could 589 * handle this in most cases, but we would have to push the extra 590 * memory down to after our max possible cluster size and then 591 * potentially pull it back up if the cluster was terminated 592 * prematurely--too much hassle. 593 */ 594 if (((tbp->b_flags & (B_VMIO|B_CLUSTEROK)) != (B_VMIO|B_CLUSTEROK)) || 595 (tbp->b_bcount != tbp->b_bufsize) || 596 len == 1) { 597 bawrite(tbp); 598 ++start_lbn; 599 --len; 600 goto redo; 601 } 602 603 bp = trypbuf(); 604 if (bp == NULL) { 605 bawrite(tbp); 606 ++start_lbn; 607 --len; 608 goto redo; 609 } 610 611 TAILQ_INIT(&bp->b_cluster.cluster_head); 612 bp->b_bcount = 0; 613 bp->b_bufsize = 0; 614 bp->b_npages = 0; 615 616 bp->b_blkno = tbp->b_blkno; 617 bp->b_lblkno = tbp->b_lblkno; 618 (vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK; 619 bp->b_flags |= B_CALL | B_BUSY | B_CLUSTER; 620 bp->b_iodone = cluster_callback; 621 pbgetvp(vp, bp); 622 623 for (i = 0; i < len; ++i, ++start_lbn) { 624 if (i != 0) { 625 s = splbio(); 626 if ((tbp = incore(vp, start_lbn)) == NULL) { 627 splx(s); 628 break; 629 } 630 631 if ((tbp->b_flags & (B_CLUSTEROK|B_INVAL|B_BUSY|B_DELWRI)) != (B_DELWRI|B_CLUSTEROK)) { 632 splx(s); 633 break; 634 } 635 636 if ((tbp->b_bcount != size) || 637 ((bp->b_blkno + dbsize * i) != tbp->b_blkno) || 638 ((tbp->b_npages + bp->b_npages) > (MAXPHYS / PAGE_SIZE))) { 639 splx(s); 640 break; 641 } 642 bremfree(tbp); 643 tbp->b_flags |= B_BUSY; 644 tbp->b_flags &= ~B_DONE; 645 splx(s); 646 } 647 for (j = 0; j < tbp->b_npages; j += 1) { 648 vm_page_t m; 649 m = tbp->b_pages[j]; 650 ++m->busy; 651 ++m->object->paging_in_progress; 652 if ((bp->b_npages == 0) || 653 (bp->b_pages[bp->b_npages - 1] != m)) { 654 bp->b_pages[bp->b_npages] = m; 655 bp->b_npages++; 656 } 657 } 658 bp->b_bcount += size; 659 bp->b_bufsize += size; 660 661 tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI); 662 tbp->b_flags |= B_ASYNC; 663 s = splbio(); 664 reassignbuf(tbp, tbp->b_vp); /* put on clean list */ 665 ++tbp->b_vp->v_numoutput; 666 splx(s); 667 TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head, 668 tbp, b_cluster.cluster_entry); 669 } 670 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 671 (vm_page_t *) bp->b_pages, bp->b_npages); 672 bawrite(bp); 673 674 len -= i; 675 goto redo; 676 } 677 678 #if 0 679 /* 680 * Collect together all the buffers in a cluster. 681 * Plus add one additional buffer. 682 */ 683 struct cluster_save * 684 cluster_collectbufs(vp, last_bp) 685 struct vnode *vp; 686 struct buf *last_bp; 687 { 688 struct cluster_save *buflist; 689 daddr_t lbn; 690 int i, len; 691 692 len = vp->v_lastw - vp->v_cstart + 1; 693 buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist), 694 M_SEGMENT, M_WAITOK); 695 buflist->bs_nchildren = 0; 696 buflist->bs_children = (struct buf **) (buflist + 1); 697 for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++) 698 (void) bread(vp, lbn, last_bp->b_bcount, NOCRED, 699 &buflist->bs_children[i]); 700 buflist->bs_children[i] = last_bp; 701 buflist->bs_nchildren = i + 1; 702 return (buflist); 703 } 704 #endif 705