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 1.21 1995/09/23 21:12:45 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 struct ctldebug debug13 = {"doreallocblks", &doreallocblks}; 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 long flags; 126 int error, num_ra, alreadyincore; 127 int i; 128 int seq; 129 130 error = 0; 131 /* 132 * get the requested block 133 */ 134 origlblkno = lblkno; 135 *bpp = bp = getblk(vp, lblkno, size, 0, 0); 136 seq = ISSEQREAD(vp, lblkno); 137 /* 138 * if it is in the cache, then check to see if the reads have been 139 * sequential. If they have, then try some read-ahead, otherwise 140 * back-off on prospective read-aheads. 141 */ 142 if (bp->b_flags & B_CACHE) { 143 if (!seq) { 144 vp->v_maxra = bp->b_lblkno + bp->b_bcount / size; 145 vp->v_ralen >>= RA_SHIFTDOWN; 146 return 0; 147 } else if( vp->v_maxra > lblkno) { 148 if ( (vp->v_maxra + (vp->v_ralen / RA_MULTIPLE_SLOW)) >= (lblkno + vp->v_ralen)) { 149 if ((vp->v_ralen + 1) < RA_MULTIPLE_FAST*(MAXPHYS / size)) 150 ++vp->v_ralen; 151 return 0; 152 } 153 lblkno = vp->v_maxra; 154 } else { 155 lblkno += 1; 156 } 157 bp = NULL; 158 } else { 159 /* 160 * if it isn't in the cache, then get a chunk from disk if 161 * sequential, otherwise just get the block. 162 */ 163 bp->b_flags |= B_READ; 164 lblkno += 1; 165 curproc->p_stats->p_ru.ru_inblock++; /* XXX */ 166 vp->v_ralen = 0; 167 } 168 /* 169 * assume no read-ahead 170 */ 171 alreadyincore = 1; 172 rablkno = lblkno; 173 174 /* 175 * if we have been doing sequential I/O, then do some read-ahead 176 */ 177 if (seq) { 178 179 /* 180 * bump ralen a bit... 181 */ 182 if ((vp->v_ralen + 1) < RA_MULTIPLE_SLOW*(MAXPHYS / size)) 183 ++vp->v_ralen; 184 /* 185 * this code makes sure that the stuff that we have read-ahead 186 * is still in the cache. If it isn't, we have been reading 187 * ahead too much, and we need to back-off, otherwise we might 188 * try to read more. 189 */ 190 for (i = 0; i < vp->v_ralen; i++) { 191 rablkno = lblkno + i; 192 alreadyincore = (int) incore(vp, rablkno); 193 if (!alreadyincore) { 194 if (inmem(vp, rablkno)) { 195 struct buf *bpt; 196 if (vp->v_maxra < rablkno) 197 vp->v_maxra = rablkno + 1; 198 continue; 199 } 200 if (rablkno < vp->v_maxra) { 201 vp->v_maxra = rablkno; 202 vp->v_ralen >>= RA_SHIFTDOWN; 203 alreadyincore = 1; 204 } 205 break; 206 } else if (vp->v_maxra < rablkno) { 207 vp->v_maxra = rablkno + 1; 208 } 209 } 210 } 211 /* 212 * we now build the read-ahead buffer if it is desirable. 213 */ 214 rbp = NULL; 215 if (!alreadyincore && 216 (rablkno + 1) * size <= filesize && 217 !(error = VOP_BMAP(vp, rablkno, NULL, &blkno, &num_ra, NULL)) && 218 blkno != -1) { 219 if (num_ra > vp->v_ralen) 220 num_ra = vp->v_ralen; 221 222 if (num_ra) { 223 rbp = cluster_rbuild(vp, filesize, rablkno, blkno, size, 224 num_ra + 1); 225 } else { 226 rbp = getblk(vp, rablkno, size, 0, 0); 227 rbp->b_flags |= B_READ | B_ASYNC; 228 rbp->b_blkno = blkno; 229 } 230 } 231 232 /* 233 * handle the synchronous read 234 */ 235 if (bp) { 236 if (bp->b_flags & (B_DONE | B_DELWRI)) 237 panic("cluster_read: DONE bp"); 238 else { 239 vfs_busy_pages(bp, 0); 240 error = VOP_STRATEGY(bp); 241 vp->v_maxra = bp->b_lblkno + bp->b_bcount / size; 242 totreads++; 243 totreadblocks += bp->b_bcount / size; 244 curproc->p_stats->p_ru.ru_inblock++; 245 } 246 } 247 /* 248 * and if we have read-aheads, do them too 249 */ 250 if (rbp) { 251 vp->v_maxra = rbp->b_lblkno + rbp->b_bcount / size; 252 if (error || (rbp->b_flags & B_CACHE)) { 253 rbp->b_flags &= ~(B_ASYNC | B_READ); 254 brelse(rbp); 255 } else { 256 if ((rbp->b_flags & B_CLUSTER) == 0) 257 vfs_busy_pages(rbp, 0); 258 (void) VOP_STRATEGY(rbp); 259 totreads++; 260 totreadblocks += rbp->b_bcount / size; 261 curproc->p_stats->p_ru.ru_inblock++; 262 } 263 } 264 if (bp && ((bp->b_flags & B_ASYNC) == 0)) 265 return (biowait(bp)); 266 return (error); 267 } 268 269 /* 270 * If blocks are contiguous on disk, use this to provide clustered 271 * read ahead. We will read as many blocks as possible sequentially 272 * and then parcel them up into logical blocks in the buffer hash table. 273 */ 274 static struct buf * 275 cluster_rbuild(vp, filesize, lbn, blkno, size, run) 276 struct vnode *vp; 277 u_quad_t filesize; 278 daddr_t lbn; 279 daddr_t blkno; 280 long size; 281 int run; 282 { 283 struct cluster_save *b_save; 284 struct buf *bp, *tbp; 285 daddr_t bn; 286 int i, inc, j; 287 288 #ifdef DIAGNOSTIC 289 if (size != vp->v_mount->mnt_stat.f_iosize) 290 panic("cluster_rbuild: size %d != filesize %d\n", 291 size, vp->v_mount->mnt_stat.f_iosize); 292 #endif 293 if (size * (lbn + run) > filesize) 294 --run; 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_VMIO) == 0) || (run <= 1) ) 303 return tbp; 304 305 bp = trypbuf(); 306 if (bp == 0) 307 return tbp; 308 309 (vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK; 310 bp->b_flags = B_ASYNC | B_READ | B_CALL | B_BUSY | B_CLUSTER | B_VMIO; 311 bp->b_iodone = cluster_callback; 312 bp->b_blkno = blkno; 313 bp->b_lblkno = lbn; 314 pbgetvp(vp, bp); 315 316 b_save = malloc(sizeof(struct buf *) * run + 317 sizeof(struct cluster_save), M_SEGMENT, M_WAITOK); 318 b_save->bs_nchildren = 0; 319 b_save->bs_children = (struct buf **) (b_save + 1); 320 bp->b_saveaddr = b_save; 321 322 bp->b_bcount = 0; 323 bp->b_bufsize = 0; 324 bp->b_npages = 0; 325 326 inc = btodb(size); 327 for (bn = blkno, i = 0; i < run; ++i, bn += inc) { 328 if (i != 0) { 329 if ((bp->b_npages * PAGE_SIZE) + size > MAXPHYS) 330 break; 331 332 if (incore(vp, lbn + i)) 333 break; 334 tbp = getblk(vp, lbn + i, size, 0, 0); 335 336 if ((tbp->b_flags & B_CACHE) || 337 (tbp->b_flags & B_VMIO) == 0) { 338 brelse(tbp); 339 break; 340 } 341 342 for (j=0;j<tbp->b_npages;j++) { 343 if (tbp->b_pages[j]->valid) { 344 break; 345 } 346 } 347 348 if (j != tbp->b_npages) { 349 /* 350 * force buffer to be re-constituted later 351 */ 352 tbp->b_flags |= B_RELBUF; 353 brelse(tbp); 354 break; 355 } 356 357 tbp->b_flags |= B_READ | B_ASYNC; 358 if( tbp->b_blkno == tbp->b_lblkno) { 359 tbp->b_blkno = bn; 360 } else if (tbp->b_blkno != bn) { 361 brelse(tbp); 362 break; 363 } 364 } 365 ++b_save->bs_nchildren; 366 b_save->bs_children[i] = tbp; 367 for (j = 0; j < tbp->b_npages; j += 1) { 368 vm_page_t m; 369 m = tbp->b_pages[j]; 370 ++m->busy; 371 ++m->object->paging_in_progress; 372 if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) { 373 m = bogus_page; 374 } 375 if ((bp->b_npages == 0) || 376 (bp->b_bufsize & PAGE_MASK) == 0) { 377 bp->b_pages[bp->b_npages] = m; 378 bp->b_npages++; 379 } else { 380 if ( tbp->b_npages > 1) { 381 panic("cluster_rbuild: page unaligned filesystems not supported"); 382 } 383 } 384 } 385 bp->b_bcount += tbp->b_bcount; 386 bp->b_bufsize += tbp->b_bufsize; 387 } 388 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 389 (vm_page_t *)bp->b_pages, bp->b_npages); 390 return (bp); 391 } 392 393 /* 394 * Cleanup after a clustered read or write. 395 * This is complicated by the fact that any of the buffers might have 396 * extra memory (if there were no empty buffer headers at allocbuf time) 397 * that we will need to shift around. 398 */ 399 void 400 cluster_callback(bp) 401 struct buf *bp; 402 { 403 struct cluster_save *b_save; 404 struct buf **bpp, *tbp; 405 caddr_t cp; 406 int error = 0; 407 408 /* 409 * Must propogate errors to all the components. 410 */ 411 if (bp->b_flags & B_ERROR) 412 error = bp->b_error; 413 414 b_save = (struct cluster_save *) (bp->b_saveaddr); 415 pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages); 416 /* 417 * Move memory from the large cluster buffer into the component 418 * buffers and mark IO as done on these. 419 */ 420 for (bpp = b_save->bs_children; b_save->bs_nchildren--; ++bpp) { 421 tbp = *bpp; 422 if (error) { 423 tbp->b_flags |= B_ERROR; 424 tbp->b_error = error; 425 } 426 biodone(tbp); 427 } 428 free(b_save, M_SEGMENT); 429 relpbuf(bp); 430 } 431 432 /* 433 * Do clustered write for FFS. 434 * 435 * Three cases: 436 * 1. Write is not sequential (write asynchronously) 437 * Write is sequential: 438 * 2. beginning of cluster - begin cluster 439 * 3. middle of a cluster - add to cluster 440 * 4. end of a cluster - asynchronously write cluster 441 */ 442 void 443 cluster_write(bp, filesize) 444 struct buf *bp; 445 u_quad_t filesize; 446 { 447 struct vnode *vp; 448 daddr_t lbn; 449 int maxclen, cursize; 450 int lblocksize; 451 452 vp = bp->b_vp; 453 lblocksize = vp->v_mount->mnt_stat.f_iosize; 454 lbn = bp->b_lblkno; 455 456 /* Initialize vnode to beginning of file. */ 457 if (lbn == 0) 458 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; 459 460 if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 || 461 (bp->b_blkno != vp->v_lasta + btodb(lblocksize))) { 462 maxclen = MAXPHYS / lblocksize - 1; 463 if (vp->v_clen != 0) { 464 /* 465 * Next block is not sequential. 466 * 467 * If we are not writing at end of file, the process 468 * seeked to another point in the file since its last 469 * write, or we have reached our maximum cluster size, 470 * then push the previous cluster. Otherwise try 471 * reallocating to make it sequential. 472 */ 473 cursize = vp->v_lastw - vp->v_cstart + 1; 474 if (!doreallocblks || 475 (lbn + 1) * lblocksize != filesize || 476 lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) { 477 cluster_wbuild(vp, NULL, lblocksize, 478 vp->v_cstart, cursize, lbn); 479 } else { 480 struct buf **bpp, **endbp; 481 struct cluster_save *buflist; 482 483 buflist = cluster_collectbufs(vp, bp); 484 endbp = &buflist->bs_children 485 [buflist->bs_nchildren - 1]; 486 if (VOP_REALLOCBLKS(vp, buflist)) { 487 /* 488 * Failed, push the previous cluster. 489 */ 490 for (bpp = buflist->bs_children; 491 bpp < endbp; bpp++) 492 brelse(*bpp); 493 free(buflist, M_SEGMENT); 494 cluster_wbuild(vp, NULL, lblocksize, 495 vp->v_cstart, cursize, lbn); 496 } else { 497 /* 498 * Succeeded, keep building cluster. 499 */ 500 for (bpp = buflist->bs_children; 501 bpp <= endbp; bpp++) 502 bdwrite(*bpp); 503 free(buflist, M_SEGMENT); 504 vp->v_lastw = lbn; 505 vp->v_lasta = bp->b_blkno; 506 return; 507 } 508 } 509 } 510 /* 511 * Consider beginning a cluster. If at end of file, make 512 * cluster as large as possible, otherwise find size of 513 * existing cluster. 514 */ 515 if ((lbn + 1) * lblocksize != filesize && 516 (bp->b_blkno == bp->b_lblkno) && 517 (VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen, NULL) || 518 bp->b_blkno == -1)) { 519 bawrite(bp); 520 vp->v_clen = 0; 521 vp->v_lasta = bp->b_blkno; 522 vp->v_cstart = lbn + 1; 523 vp->v_lastw = lbn; 524 return; 525 } 526 vp->v_clen = maxclen; 527 if (maxclen == 0) { /* I/O not contiguous */ 528 vp->v_cstart = lbn + 1; 529 bawrite(bp); 530 } else { /* Wait for rest of cluster */ 531 vp->v_cstart = lbn; 532 bdwrite(bp); 533 } 534 } else if (lbn == vp->v_cstart + vp->v_clen) { 535 /* 536 * At end of cluster, write it out. 537 */ 538 cluster_wbuild(vp, bp, bp->b_bcount, vp->v_cstart, 539 vp->v_clen + 1, lbn); 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, last_bp, size, start_lbn, len, lbn) 560 struct vnode *vp; 561 struct buf *last_bp; 562 long size; 563 daddr_t start_lbn; 564 int len; 565 daddr_t lbn; 566 { 567 struct cluster_save *b_save; 568 struct buf *bp, *tbp, *pb; 569 caddr_t cp; 570 int i, j, s; 571 572 #ifdef DIAGNOSTIC 573 if (size != vp->v_mount->mnt_stat.f_iosize) 574 panic("cluster_wbuild: size %d != filesize %d\n", 575 size, vp->v_mount->mnt_stat.f_iosize); 576 #endif 577 redo: 578 if( (lbn != -1) || (last_bp == 0)) { 579 while ((!(tbp = incore(vp, start_lbn)) || (tbp->b_flags & B_BUSY) 580 || (start_lbn == lbn)) && len) { 581 ++start_lbn; 582 --len; 583 } 584 585 pb = trypbuf(); 586 /* Get more memory for current buffer */ 587 if (len <= 1 || pb == NULL) { 588 if (pb != NULL) 589 relpbuf(pb); 590 if (last_bp) { 591 bawrite(last_bp); 592 } else if (len) { 593 bp = getblk(vp, start_lbn, size, 0, 0); 594 bawrite(bp); 595 } 596 return; 597 } 598 tbp = getblk(vp, start_lbn, size, 0, 0); 599 } else { 600 tbp = last_bp; 601 if( tbp->b_flags & B_BUSY) { 602 printf("vfs_cluster: warning: buffer already busy\n"); 603 } 604 tbp->b_flags |= B_BUSY; 605 last_bp = 0; 606 pb = trypbuf(); 607 if (pb == NULL) { 608 bawrite(tbp); 609 return; 610 } 611 } 612 613 if (!(tbp->b_flags & B_DELWRI)) { 614 relpbuf(pb); 615 ++start_lbn; 616 --len; 617 brelse(tbp); 618 goto redo; 619 } 620 /* 621 * Extra memory in the buffer, punt on this buffer. XXX we could 622 * handle this in most cases, but we would have to push the extra 623 * memory down to after our max possible cluster size and then 624 * potentially pull it back up if the cluster was terminated 625 * prematurely--too much hassle. 626 */ 627 if (((tbp->b_flags & B_VMIO) == 0) || 628 (tbp->b_bcount != tbp->b_bufsize)) { 629 relpbuf(pb); 630 ++start_lbn; 631 --len; 632 bawrite(tbp); 633 goto redo; 634 } 635 bp = pb; 636 b_save = malloc(sizeof(struct buf *) * (len + 1) + sizeof(struct cluster_save), 637 M_SEGMENT, M_WAITOK); 638 b_save->bs_nchildren = 0; 639 b_save->bs_children = (struct buf **) (b_save + 1); 640 bp->b_saveaddr = b_save; 641 bp->b_bcount = 0; 642 bp->b_bufsize = 0; 643 bp->b_npages = 0; 644 645 if (tbp->b_flags & B_VMIO) 646 bp->b_flags |= B_VMIO; 647 648 bp->b_blkno = tbp->b_blkno; 649 bp->b_lblkno = tbp->b_lblkno; 650 (vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK; 651 bp->b_flags |= B_CALL | B_BUSY | B_CLUSTER; 652 bp->b_iodone = cluster_callback; 653 pbgetvp(vp, bp); 654 655 for (i = 0; i < len; ++i, ++start_lbn) { 656 if (i != 0) { 657 /* 658 * Block is not in core or the non-sequential block 659 * ending our cluster was part of the cluster (in 660 * which case we don't want to write it twice). 661 */ 662 if (!(tbp = incore(vp, start_lbn)) || 663 (last_bp == NULL && start_lbn == lbn)) 664 break; 665 666 if ((tbp->b_flags & (B_INVAL | B_CLUSTEROK)) != B_CLUSTEROK) 667 break; 668 669 if ((tbp->b_npages + bp->b_npages) > (MAXPHYS / PAGE_SIZE)) 670 break; 671 672 if ( (tbp->b_blkno != tbp->b_lblkno) && 673 ((bp->b_blkno + btodb(size) * i) != tbp->b_blkno)) 674 break; 675 676 /* 677 * Get the desired block buffer (unless it is the 678 * final sequential block whose buffer was passed in 679 * explictly as last_bp). 680 */ 681 if (last_bp == NULL || start_lbn != lbn) { 682 if( tbp->b_flags & B_BUSY) 683 break; 684 tbp = getblk(vp, start_lbn, size, 0, 0); 685 if (!(tbp->b_flags & B_DELWRI) || 686 ((tbp->b_flags & B_VMIO) != (bp->b_flags & B_VMIO))) { 687 brelse(tbp); 688 break; 689 } 690 } else 691 tbp = last_bp; 692 } 693 for (j = 0; j < tbp->b_npages; j += 1) { 694 vm_page_t m; 695 m = tbp->b_pages[j]; 696 ++m->busy; 697 ++m->object->paging_in_progress; 698 if ((bp->b_npages == 0) || 699 (bp->b_pages[bp->b_npages - 1] != m)) { 700 bp->b_pages[bp->b_npages] = m; 701 bp->b_npages++; 702 } 703 } 704 bp->b_bcount += size; 705 bp->b_bufsize += size; 706 707 tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI); 708 tbp->b_flags |= B_ASYNC; 709 s = splbio(); 710 reassignbuf(tbp, tbp->b_vp); /* put on clean list */ 711 ++tbp->b_vp->v_numoutput; 712 splx(s); 713 b_save->bs_children[i] = tbp; 714 } 715 b_save->bs_nchildren = i; 716 pmap_qenter(trunc_page((vm_offset_t) bp->b_data), 717 (vm_page_t *) bp->b_pages, bp->b_npages); 718 bawrite(bp); 719 720 if (i < len) { 721 len -= i; 722 goto redo; 723 } 724 } 725 726 /* 727 * Collect together all the buffers in a cluster. 728 * Plus add one additional buffer. 729 */ 730 struct cluster_save * 731 cluster_collectbufs(vp, last_bp) 732 struct vnode *vp; 733 struct buf *last_bp; 734 { 735 struct cluster_save *buflist; 736 daddr_t lbn; 737 int i, len; 738 739 len = vp->v_lastw - vp->v_cstart + 1; 740 buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist), 741 M_SEGMENT, M_WAITOK); 742 buflist->bs_nchildren = 0; 743 buflist->bs_children = (struct buf **) (buflist + 1); 744 for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++) 745 (void) bread(vp, lbn, last_bp->b_bcount, NOCRED, 746 &buflist->bs_children[i]); 747 buflist->bs_children[i] = last_bp; 748 buflist->bs_nchildren = i + 1; 749 return (buflist); 750 } 751