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 * $FreeBSD$
37 */
38
39 #include "opt_debug_cluster.h"
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/proc.h>
45 #include <sys/buf.h>
46 #include <sys/vnode.h>
47 #include <sys/malloc.h>
48 #include <sys/mount.h>
49 #include <sys/resourcevar.h>
50 #include <vm/vm.h>
51 #include <vm/vm_prot.h>
52 #include <vm/vm_object.h>
53 #include <vm/vm_page.h>
54
55 #if defined(CLUSTERDEBUG)
56 #include <sys/sysctl.h>
57 static int rcluster= 0;
58 SYSCTL_INT(_debug, OID_AUTO, rcluster, CTLFLAG_RW, &rcluster, 0, "");
59 #endif
60
61 static MALLOC_DEFINE(M_SEGMENT, "cluster_save buffer", "cluster_save buffer");
62
63 static struct cluster_save *
64 cluster_collectbufs __P((struct vnode *vp, struct buf *last_bp));
65 static struct buf *
66 cluster_rbuild __P((struct vnode *vp, u_quad_t filesize, daddr_t lbn,
67 daddr_t blkno, long size, int run, struct buf *fbp));
68
69 extern vm_page_t bogus_page;
70
71 /*
72 * Maximum number of blocks for read-ahead.
73 */
74 #define MAXRA 32
75
76 /*
77 * This replaces bread.
78 */
79 int
80 cluster_read(vp, filesize, lblkno, size, cred, totread, seqcount, bpp)
81 struct vnode *vp;
82 u_quad_t filesize;
83 daddr_t lblkno;
84 long size;
85 struct ucred *cred;
86 long totread;
87 int seqcount;
88 struct buf **bpp;
89 {
90 struct buf *bp, *rbp, *reqbp;
91 daddr_t blkno, origblkno;
92 int error, num_ra;
93 int i;
94 int maxra, racluster;
95 long origtotread;
96
97 error = 0;
98 if (vp->v_maxio == 0)
99 vp->v_maxio = DFLTPHYS;
100
101 /*
102 * Try to limit the amount of read-ahead by a few
103 * ad-hoc parameters. This needs work!!!
104 */
105 racluster = vp->v_maxio/size;
106 maxra = 2 * racluster + (totread / size);
107 if (maxra > MAXRA)
108 maxra = MAXRA;
109 if (maxra > nbuf/8)
110 maxra = nbuf/8;
111
112 /*
113 * get the requested block
114 */
115 *bpp = reqbp = bp = getblk(vp, lblkno, size, 0, 0);
116 origblkno = lblkno;
117 origtotread = totread;
118
119 /*
120 * if it is in the cache, then check to see if the reads have been
121 * sequential. If they have, then try some read-ahead, otherwise
122 * back-off on prospective read-aheads.
123 */
124 if (bp->b_flags & B_CACHE) {
125 if (!seqcount) {
126 return 0;
127 } else if ((bp->b_flags & B_RAM) == 0) {
128 return 0;
129 } else {
130 int s;
131 struct buf *tbp;
132 bp->b_flags &= ~B_RAM;
133 /*
134 * We do the spl here so that there is no window
135 * between the incore and the b_usecount increment
136 * below. We opt to keep the spl out of the loop
137 * for efficiency.
138 */
139 s = splbio();
140 for(i=1;i<maxra;i++) {
141
142 if (!(tbp = incore(vp, lblkno+i))) {
143 break;
144 }
145
146 /*
147 * Set another read-ahead mark so we know to check
148 * again.
149 */
150 if (((i % racluster) == (racluster - 1)) ||
151 (i == (maxra - 1)))
152 tbp->b_flags |= B_RAM;
153
154 if ((tbp->b_usecount < 1) &&
155 ((tbp->b_flags & B_BUSY) == 0) &&
156 (tbp->b_qindex == QUEUE_LRU)) {
157 TAILQ_REMOVE(&bufqueues[QUEUE_LRU], tbp, b_freelist);
158 TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], tbp, b_freelist);
159 }
160 }
161 splx(s);
162 if (i >= maxra) {
163 return 0;
164 }
165 lblkno += i;
166 }
167 reqbp = bp = NULL;
168 } else {
169 off_t firstread = bp->b_offset;
170
171 KASSERT(bp->b_offset != NOOFFSET,
172 ("cluster_read: no buffer offset"));
173 if (firstread + totread > filesize)
174 totread = filesize - firstread;
175 if (totread > size) {
176 int nblks = 0;
177 int ncontigafter;
178 while (totread > 0) {
179 nblks++;
180 totread -= size;
181 }
182 if (nblks == 1)
183 goto single_block_read;
184 if (nblks > racluster)
185 nblks = racluster;
186
187 error = VOP_BMAP(vp, lblkno, NULL,
188 &blkno, &ncontigafter, NULL);
189 if (error)
190 goto single_block_read;
191 if (blkno == -1)
192 goto single_block_read;
193 if (ncontigafter == 0)
194 goto single_block_read;
195 if (ncontigafter + 1 < nblks)
196 nblks = ncontigafter + 1;
197
198 bp = cluster_rbuild(vp, filesize, lblkno,
199 blkno, size, nblks, bp);
200 lblkno += (bp->b_bufsize / size);
201 } else {
202 single_block_read:
203 /*
204 * if it isn't in the cache, then get a chunk from
205 * disk if sequential, otherwise just get the block.
206 */
207 bp->b_flags |= B_READ | B_RAM;
208 lblkno += 1;
209 }
210 }
211
212 /*
213 * if we have been doing sequential I/O, then do some read-ahead
214 */
215 rbp = NULL;
216 if (seqcount && (lblkno < (origblkno + seqcount))) {
217 /*
218 * we now build the read-ahead buffer if it is desirable.
219 */
220 if (((u_quad_t)(lblkno + 1) * size) <= filesize &&
221 !(error = VOP_BMAP(vp, lblkno, NULL, &blkno, &num_ra, NULL)) &&
222 blkno != -1) {
223 int nblksread;
224 int ntoread = num_ra + 1;
225 nblksread = (origtotread + size - 1) / size;
226 if (seqcount < nblksread)
227 seqcount = nblksread;
228 if (seqcount < ntoread)
229 ntoread = seqcount;
230 if (num_ra) {
231 rbp = cluster_rbuild(vp, filesize, lblkno,
232 blkno, size, ntoread, NULL);
233 } else {
234 rbp = getblk(vp, lblkno, size, 0, 0);
235 rbp->b_flags |= B_READ | B_ASYNC | B_RAM;
236 rbp->b_blkno = blkno;
237 }
238 }
239 }
240
241 /*
242 * handle the synchronous read
243 */
244 if (bp) {
245 #if defined(CLUSTERDEBUG)
246 if (rcluster)
247 printf("S(%ld,%ld,%d) ",
248 (long)bp->b_lblkno, bp->b_bcount, seqcount);
249 #endif
250 if ((bp->b_flags & B_CLUSTER) == 0)
251 vfs_busy_pages(bp, 0);
252 error = VOP_STRATEGY(vp, bp);
253 curproc->p_stats->p_ru.ru_inblock++;
254 }
255
256 /*
257 * and if we have read-aheads, do them too
258 */
259 if (rbp) {
260 if (error) {
261 rbp->b_flags &= ~(B_ASYNC | B_READ);
262 brelse(rbp);
263 } else if (rbp->b_flags & B_CACHE) {
264 rbp->b_flags &= ~(B_ASYNC | B_READ);
265 bqrelse(rbp);
266 } else {
267 #if defined(CLUSTERDEBUG)
268 if (rcluster) {
269 if (bp)
270 printf("A+(%ld,%ld,%ld,%d) ",
271 (long)rbp->b_lblkno, rbp->b_bcount,
272 (long)(rbp->b_lblkno - origblkno),
273 seqcount);
274 else
275 printf("A(%ld,%ld,%ld,%d) ",
276 (long)rbp->b_lblkno, rbp->b_bcount,
277 (long)(rbp->b_lblkno - origblkno),
278 seqcount);
279 }
280 #endif
281
282 if ((rbp->b_flags & B_CLUSTER) == 0)
283 vfs_busy_pages(rbp, 0);
284 (void) VOP_STRATEGY(vp, rbp);
285 curproc->p_stats->p_ru.ru_inblock++;
286 }
287 }
288 if (reqbp)
289 return (biowait(reqbp));
290 else
291 return (error);
292 }
293
294 /*
295 * If blocks are contiguous on disk, use this to provide clustered
296 * read ahead. We will read as many blocks as possible sequentially
297 * and then parcel them up into logical blocks in the buffer hash table.
298 */
299 static struct buf *
300 cluster_rbuild(vp, filesize, lbn, blkno, size, run, fbp)
301 struct vnode *vp;
302 u_quad_t filesize;
303 daddr_t lbn;
304 daddr_t blkno;
305 long size;
306 int run;
307 struct buf *fbp;
308 {
309 struct buf *bp, *tbp;
310 daddr_t bn;
311 int i, inc, j;
312
313 KASSERT(size == vp->v_mount->mnt_stat.f_iosize,
314 ("cluster_rbuild: size %ld != filesize %ld\n",
315 size, vp->v_mount->mnt_stat.f_iosize));
316
317 /*
318 * avoid a division
319 */
320 while ((u_quad_t) size * (lbn + run) > filesize) {
321 --run;
322 }
323
324 if (fbp) {
325 tbp = fbp;
326 tbp->b_flags |= B_READ;
327 } else {
328 tbp = getblk(vp, lbn, size, 0, 0);
329 if (tbp->b_flags & B_CACHE)
330 return tbp;
331 tbp->b_flags |= B_ASYNC | B_READ | B_RAM;
332 }
333
334 tbp->b_blkno = blkno;
335 if( (tbp->b_flags & B_MALLOC) ||
336 ((tbp->b_flags & B_VMIO) == 0) || (run <= 1) )
337 return tbp;
338
339 bp = trypbuf();
340 if (bp == 0)
341 return tbp;
342
343 bp->b_data = (char *)((vm_offset_t)bp->b_data |
344 ((vm_offset_t)tbp->b_data & PAGE_MASK));
345 bp->b_flags = B_ASYNC | B_READ | B_CALL | B_BUSY | B_CLUSTER | B_VMIO;
346 bp->b_iodone = cluster_callback;
347 bp->b_blkno = blkno;
348 bp->b_lblkno = lbn;
349 bp->b_offset = tbp->b_offset;
350 KASSERT(bp->b_offset != NOOFFSET, ("cluster_rbuild: no buffer offset"));
351 pbgetvp(vp, bp);
352
353 TAILQ_INIT(&bp->b_cluster.cluster_head);
354
355 bp->b_bcount = 0;
356 bp->b_bufsize = 0;
357 bp->b_npages = 0;
358
359 if (vp->v_maxio == 0)
360 vp->v_maxio = DFLTPHYS;
361 inc = btodb(size);
362 for (bn = blkno, i = 0; i < run; ++i, bn += inc) {
363 if (i != 0) {
364 if ((bp->b_npages * PAGE_SIZE) +
365 round_page(size) > vp->v_maxio)
366 break;
367
368 if (tbp = incore(vp, lbn + i)) {
369 if (tbp->b_flags & B_BUSY)
370 break;
371
372 for (j = 0; j < tbp->b_npages; j++)
373 if (tbp->b_pages[j]->valid)
374 break;
375
376 if (j != tbp->b_npages)
377 break;
378
379 if (tbp->b_bcount != size)
380 break;
381 }
382
383 tbp = getblk(vp, lbn + i, size, 0, 0);
384
385 if ((tbp->b_flags & B_CACHE) ||
386 (tbp->b_flags & B_VMIO) == 0) {
387 bqrelse(tbp);
388 break;
389 }
390
391 for (j = 0;j < tbp->b_npages; j++)
392 if (tbp->b_pages[j]->valid)
393 break;
394
395 if (j != tbp->b_npages) {
396 bqrelse(tbp);
397 break;
398 }
399
400 if ((fbp && (i == 1)) || (i == (run - 1)))
401 tbp->b_flags |= B_RAM;
402 tbp->b_flags |= B_READ | B_ASYNC;
403 if (tbp->b_blkno == tbp->b_lblkno) {
404 tbp->b_blkno = bn;
405 } else if (tbp->b_blkno != bn) {
406 brelse(tbp);
407 break;
408 }
409 }
410 TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head,
411 tbp, b_cluster.cluster_entry);
412 for (j = 0; j < tbp->b_npages; j += 1) {
413 vm_page_t m;
414 m = tbp->b_pages[j];
415 vm_page_io_start(m);
416 vm_object_pip_add(m->object, 1);
417 if ((bp->b_npages == 0) ||
418 (bp->b_pages[bp->b_npages-1] != m)) {
419 bp->b_pages[bp->b_npages] = m;
420 bp->b_npages++;
421 }
422 if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL)
423 tbp->b_pages[j] = bogus_page;
424 }
425 bp->b_bcount += tbp->b_bcount;
426 bp->b_bufsize += tbp->b_bufsize;
427 }
428
429 for(j=0;j<bp->b_npages;j++) {
430 if ((bp->b_pages[j]->valid & VM_PAGE_BITS_ALL) ==
431 VM_PAGE_BITS_ALL)
432 bp->b_pages[j] = bogus_page;
433 }
434 if (bp->b_bufsize > bp->b_kvasize)
435 panic("cluster_rbuild: b_bufsize(%ld) > b_kvasize(%d)\n",
436 bp->b_bufsize, bp->b_kvasize);
437 bp->b_kvasize = bp->b_bufsize;
438
439 pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
440 (vm_page_t *)bp->b_pages, bp->b_npages);
441 return (bp);
442 }
443
444 /*
445 * Cleanup after a clustered read or write.
446 * This is complicated by the fact that any of the buffers might have
447 * extra memory (if there were no empty buffer headers at allocbuf time)
448 * that we will need to shift around.
449 */
450 void
451 cluster_callback(bp)
452 struct buf *bp;
453 {
454 struct buf *nbp, *tbp;
455 int error = 0;
456
457 /*
458 * Must propogate errors to all the components.
459 */
460 if (bp->b_flags & B_ERROR)
461 error = bp->b_error;
462
463 pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages);
464 /*
465 * Move memory from the large cluster buffer into the component
466 * buffers and mark IO as done on these.
467 */
468 for (tbp = TAILQ_FIRST(&bp->b_cluster.cluster_head);
469 tbp; tbp = nbp) {
470 nbp = TAILQ_NEXT(&tbp->b_cluster, cluster_entry);
471 if (error) {
472 tbp->b_flags |= B_ERROR;
473 tbp->b_error = error;
474 } else
475 tbp->b_dirtyoff = tbp->b_dirtyend = 0;
476 biodone(tbp);
477 }
478 relpbuf(bp);
479 }
480
481 /*
482 * Do clustered write for FFS.
483 *
484 * Three cases:
485 * 1. Write is not sequential (write asynchronously)
486 * Write is sequential:
487 * 2. beginning of cluster - begin cluster
488 * 3. middle of a cluster - add to cluster
489 * 4. end of a cluster - asynchronously write cluster
490 */
491 void
492 cluster_write(bp, filesize)
493 struct buf *bp;
494 u_quad_t filesize;
495 {
496 struct vnode *vp;
497 daddr_t lbn;
498 int maxclen, cursize;
499 int lblocksize;
500 int async;
501
502 vp = bp->b_vp;
503 if (vp->v_maxio == 0)
504 vp->v_maxio = DFLTPHYS;
505 if (vp->v_type == VREG) {
506 async = vp->v_mount->mnt_flag & MNT_ASYNC;
507 lblocksize = vp->v_mount->mnt_stat.f_iosize;
508 } else {
509 async = 0;
510 lblocksize = bp->b_bufsize;
511 }
512 lbn = bp->b_lblkno;
513 KASSERT(bp->b_offset != NOOFFSET, ("cluster_write: no buffer offset"));
514
515 /* Initialize vnode to beginning of file. */
516 if (lbn == 0)
517 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
518
519 if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 ||
520 (bp->b_blkno != vp->v_lasta + btodb(lblocksize))) {
521 maxclen = vp->v_maxio / lblocksize - 1;
522 if (vp->v_clen != 0) {
523 /*
524 * Next block is not sequential.
525 *
526 * If we are not writing at end of file, the process
527 * seeked to another point in the file since its last
528 * write, or we have reached our maximum cluster size,
529 * then push the previous cluster. Otherwise try
530 * reallocating to make it sequential.
531 */
532 cursize = vp->v_lastw - vp->v_cstart + 1;
533 if (((u_quad_t) bp->b_offset + lblocksize) != filesize ||
534 lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) {
535 if (!async)
536 cluster_wbuild(vp, lblocksize,
537 vp->v_cstart, cursize);
538 } else {
539 struct buf **bpp, **endbp;
540 struct cluster_save *buflist;
541
542 buflist = cluster_collectbufs(vp, bp);
543 endbp = &buflist->bs_children
544 [buflist->bs_nchildren - 1];
545 if (VOP_REALLOCBLKS(vp, buflist)) {
546 /*
547 * Failed, push the previous cluster.
548 */
549 for (bpp = buflist->bs_children;
550 bpp < endbp; bpp++)
551 brelse(*bpp);
552 free(buflist, M_SEGMENT);
553 cluster_wbuild(vp, lblocksize,
554 vp->v_cstart, cursize);
555 } else {
556 /*
557 * Succeeded, keep building cluster.
558 */
559 for (bpp = buflist->bs_children;
560 bpp <= endbp; bpp++)
561 bdwrite(*bpp);
562 free(buflist, M_SEGMENT);
563 vp->v_lastw = lbn;
564 vp->v_lasta = bp->b_blkno;
565 return;
566 }
567 }
568 }
569 /*
570 * Consider beginning a cluster. If at end of file, make
571 * cluster as large as possible, otherwise find size of
572 * existing cluster.
573 */
574 if ((vp->v_type == VREG) &&
575 ((u_quad_t) bp->b_offset + lblocksize) != filesize &&
576 (bp->b_blkno == bp->b_lblkno) &&
577 (VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen, NULL) ||
578 bp->b_blkno == -1)) {
579 bawrite(bp);
580 vp->v_clen = 0;
581 vp->v_lasta = bp->b_blkno;
582 vp->v_cstart = lbn + 1;
583 vp->v_lastw = lbn;
584 return;
585 }
586 vp->v_clen = maxclen;
587 if (!async && maxclen == 0) { /* I/O not contiguous */
588 vp->v_cstart = lbn + 1;
589 bawrite(bp);
590 } else { /* Wait for rest of cluster */
591 vp->v_cstart = lbn;
592 bdwrite(bp);
593 }
594 } else if (lbn == vp->v_cstart + vp->v_clen) {
595 /*
596 * At end of cluster, write it out.
597 */
598 bdwrite(bp);
599 cluster_wbuild(vp, lblocksize, vp->v_cstart, vp->v_clen + 1);
600 vp->v_clen = 0;
601 vp->v_cstart = lbn + 1;
602 } else
603 /*
604 * In the middle of a cluster, so just delay the I/O for now.
605 */
606 bdwrite(bp);
607 vp->v_lastw = lbn;
608 vp->v_lasta = bp->b_blkno;
609 }
610
611
612 /*
613 * This is an awful lot like cluster_rbuild...wish they could be combined.
614 * The last lbn argument is the current block on which I/O is being
615 * performed. Check to see that it doesn't fall in the middle of
616 * the current block (if last_bp == NULL).
617 */
618 int
619 cluster_wbuild(vp, size, start_lbn, len)
620 struct vnode *vp;
621 long size;
622 daddr_t start_lbn;
623 int len;
624 {
625 struct buf *bp, *tbp;
626 int i, j, s;
627 int totalwritten = 0;
628 int dbsize = btodb(size);
629
630 if (vp->v_maxio == 0)
631 vp->v_maxio = DFLTPHYS;
632 while (len > 0) {
633 s = splbio();
634 if (((tbp = gbincore(vp, start_lbn)) == NULL) ||
635 ((tbp->b_flags & (B_INVAL|B_BUSY|B_DELWRI)) != B_DELWRI)) {
636 ++start_lbn;
637 --len;
638 splx(s);
639 continue;
640 }
641 bremfree(tbp);
642 tbp->b_flags |= B_BUSY;
643 tbp->b_flags &= ~B_DONE;
644 splx(s);
645
646 /*
647 * Extra memory in the buffer, punt on this buffer. XXX we could
648 * handle this in most cases, but we would have to push the extra
649 * memory down to after our max possible cluster size and then
650 * potentially pull it back up if the cluster was terminated
651 * prematurely--too much hassle.
652 */
653 if (((tbp->b_flags & (B_CLUSTEROK|B_MALLOC)) != B_CLUSTEROK) ||
654 (tbp->b_bcount != tbp->b_bufsize) ||
655 (tbp->b_bcount != size) ||
656 (len == 1) ||
657 ((bp = trypbuf()) == NULL)) {
658 totalwritten += tbp->b_bufsize;
659 bawrite(tbp);
660 ++start_lbn;
661 --len;
662 continue;
663 }
664
665 /*
666 * We got a pbuf to make the cluster in.
667 * so initialise it.
668 */
669 TAILQ_INIT(&bp->b_cluster.cluster_head);
670 bp->b_bcount = 0;
671 bp->b_bufsize = 0;
672 bp->b_npages = 0;
673 if (tbp->b_wcred != NOCRED) {
674 bp->b_wcred = tbp->b_wcred;
675 crhold(bp->b_wcred);
676 }
677
678 bp->b_blkno = tbp->b_blkno;
679 bp->b_lblkno = tbp->b_lblkno;
680 bp->b_offset = tbp->b_offset;
681 bp->b_data = (char *)((vm_offset_t)bp->b_data |
682 ((vm_offset_t)tbp->b_data & PAGE_MASK));
683 bp->b_flags |= B_CALL | B_BUSY | B_CLUSTER |
684 (tbp->b_flags & (B_VMIO | B_NEEDCOMMIT));
685 bp->b_iodone = cluster_callback;
686 pbgetvp(vp, bp);
687 /*
688 * From this location in the file, scan forward to see
689 * if there are buffers with adjacent data that need to
690 * be written as well.
691 */
692 for (i = 0; i < len; ++i, ++start_lbn) {
693 if (i != 0) { /* If not the first buffer */
694 s = splbio();
695 /*
696 * If the adjacent data is not even in core it
697 * can't need to be written.
698 */
699 if ((tbp = gbincore(vp, start_lbn)) == NULL) {
700 splx(s);
701 break;
702 }
703
704 /*
705 * If it IS in core, but has different
706 * characteristics, don't cluster with it.
707 */
708 if ((tbp->b_flags &
709 (B_VMIO | B_CLUSTEROK | B_INVAL | B_BUSY |
710 B_DELWRI | B_NEEDCOMMIT))
711 != (B_DELWRI | B_CLUSTEROK |
712 (bp->b_flags & (B_VMIO | B_NEEDCOMMIT)))) {
713 splx(s);
714 break;
715 }
716
717 if (tbp->b_wcred != bp->b_wcred) {
718 splx(s);
719 break;
720 }
721
722 /*
723 * Check that the combined cluster
724 * would make sense with regard to pages
725 * and would not be too large
726 */
727 if ((tbp->b_bcount != size) ||
728 ((bp->b_blkno + (dbsize * i)) !=
729 tbp->b_blkno) ||
730 ((tbp->b_npages + bp->b_npages) >
731 (vp->v_maxio / PAGE_SIZE))) {
732 splx(s);
733 break;
734 }
735 /*
736 * Ok, it's passed all the tests,
737 * so remove it from the free list
738 * and mark it busy. We will use it.
739 */
740 bremfree(tbp);
741 tbp->b_flags |= B_BUSY;
742 tbp->b_flags &= ~B_DONE;
743 splx(s);
744 } /* end of code for non-first buffers only */
745 /* check for latent dependencies to be handled */
746 if ((LIST_FIRST(&tbp->b_dep)) != NULL &&
747 bioops.io_start)
748 (*bioops.io_start)(tbp);
749 /*
750 * If the IO is via the VM then we do some
751 * special VM hackery. (yuck)
752 */
753 if (tbp->b_flags & B_VMIO) {
754 vm_page_t m;
755
756 if (i != 0) { /* if not first buffer */
757 for (j = 0; j < tbp->b_npages; j += 1) {
758 m = tbp->b_pages[j];
759 if (m->flags & PG_BUSY)
760 goto finishcluster;
761 }
762 }
763
764 for (j = 0; j < tbp->b_npages; j += 1) {
765 m = tbp->b_pages[j];
766 vm_page_io_start(m);
767 vm_object_pip_add(m->object, 1);
768 if ((bp->b_npages == 0) ||
769 (bp->b_pages[bp->b_npages - 1] != m)) {
770 bp->b_pages[bp->b_npages] = m;
771 bp->b_npages++;
772 }
773 }
774 }
775 bp->b_bcount += size;
776 bp->b_bufsize += size;
777
778 s = splbio();
779 --numdirtybuffers;
780 tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
781 tbp->b_flags |= B_ASYNC;
782 reassignbuf(tbp, tbp->b_vp); /* put on clean list */
783 ++tbp->b_vp->v_numoutput;
784 splx(s);
785 TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head,
786 tbp, b_cluster.cluster_entry);
787 }
788 finishcluster:
789 pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
790 (vm_page_t *) bp->b_pages, bp->b_npages);
791 if (bp->b_bufsize > bp->b_kvasize)
792 panic(
793 "cluster_wbuild: b_bufsize(%ld) > b_kvasize(%d)\n",
794 bp->b_bufsize, bp->b_kvasize);
795 bp->b_kvasize = bp->b_bufsize;
796 totalwritten += bp->b_bufsize;
797 bp->b_dirtyoff = 0;
798 bp->b_dirtyend = bp->b_bufsize;
799 bawrite(bp);
800
801 len -= i;
802 }
803 return totalwritten;
804 }
805
806 /*
807 * Collect together all the buffers in a cluster.
808 * Plus add one additional buffer.
809 */
810 static struct cluster_save *
811 cluster_collectbufs(vp, last_bp)
812 struct vnode *vp;
813 struct buf *last_bp;
814 {
815 struct cluster_save *buflist;
816 struct buf *bp;
817 daddr_t lbn;
818 int i, len;
819
820 len = vp->v_lastw - vp->v_cstart + 1;
821 buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist),
822 M_SEGMENT, M_WAITOK);
823 buflist->bs_nchildren = 0;
824 buflist->bs_children = (struct buf **) (buflist + 1);
825 for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++) {
826 (void) bread(vp, lbn, last_bp->b_bcount, NOCRED, &bp);
827 buflist->bs_children[i] = bp;
828 if (bp->b_blkno == bp->b_lblkno)
829 VOP_BMAP(bp->b_vp, bp->b_lblkno, NULL, &bp->b_blkno,
830 NULL, NULL);
831 }
832 buflist->bs_children[i] = bp = last_bp;
833 if (bp->b_blkno == bp->b_lblkno)
834 VOP_BMAP(bp->b_vp, bp->b_lblkno, NULL, &bp->b_blkno,
835 NULL, NULL);
836 buflist->bs_nchildren = i + 1;
837 return (buflist);
838 }
Cache object: d25ef45840c3621cd8ddb4e87576f686
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