Add some missing manual pages.
[dragonfly.git] / sys / kern / vfs_cluster.c
CommitLineData
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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 1.92.2.9 2001/11/18 07:10:59 dillon Exp $
10f3fee5 37 * $DragonFly: src/sys/kern/vfs_cluster.c,v 1.22 2006/04/30 17:22:17 dillon Exp $
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38 */
39
40#include "opt_debug_cluster.h"
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/kernel.h>
45#include <sys/proc.h>
46#include <sys/buf.h>
47#include <sys/vnode.h>
48#include <sys/malloc.h>
49#include <sys/mount.h>
50#include <sys/resourcevar.h>
51#include <sys/vmmeter.h>
52#include <vm/vm.h>
53#include <vm/vm_object.h>
54#include <vm/vm_page.h>
55#include <sys/sysctl.h>
3020e3be 56#include <sys/buf2.h>
12e4aaff 57#include <vm/vm_page2.h>
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58
59#if defined(CLUSTERDEBUG)
60#include <sys/sysctl.h>
61static int rcluster= 0;
62SYSCTL_INT(_debug, OID_AUTO, rcluster, CTLFLAG_RW, &rcluster, 0, "");
63#endif
64
d1cd9d97 65static MALLOC_DEFINE(M_SEGMENT, "cluster_save", "cluster_save buffer");
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66
67static struct cluster_save *
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68 cluster_collectbufs (struct vnode *vp, struct buf *last_bp,
69 int lblocksize);
984263bc 70static struct buf *
54078292 71 cluster_rbuild (struct vnode *vp, off_t filesize, off_t loffset,
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72 off_t doffset, int size, int run,
73 struct buf *fbp, int doasync);
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74static void cluster_callback (struct bio *);
75
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76
77static int write_behind = 1;
78SYSCTL_INT(_vfs, OID_AUTO, write_behind, CTLFLAG_RW, &write_behind, 0, "");
79
80extern vm_page_t bogus_page;
81
82extern int cluster_pbuf_freecnt;
83
84/*
85 * Maximum number of blocks for read-ahead.
86 */
87#define MAXRA 32
88
89/*
90 * This replaces bread.
91 */
92int
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93cluster_read(struct vnode *vp, off_t filesize, off_t loffset,
94 int size, int totread, int seqcount, struct buf **bpp)
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95{
96 struct buf *bp, *rbp, *reqbp;
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97 off_t origoffset;
98 off_t doffset;
99 int error;
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100 int i;
101 int maxra, racluster;
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102
103 error = 0;
104
105 /*
106 * Try to limit the amount of read-ahead by a few
107 * ad-hoc parameters. This needs work!!!
108 */
109 racluster = vp->v_mount->mnt_iosize_max / size;
110 maxra = 2 * racluster + (totread / size);
111 if (maxra > MAXRA)
112 maxra = MAXRA;
113 if (maxra > nbuf/8)
114 maxra = nbuf/8;
115
116 /*
117 * get the requested block
118 */
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119 *bpp = reqbp = bp = getblk(vp, loffset, size, 0, 0);
120 origoffset = loffset;
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121
122 /*
123 * if it is in the cache, then check to see if the reads have been
124 * sequential. If they have, then try some read-ahead, otherwise
125 * back-off on prospective read-aheads.
126 */
127 if (bp->b_flags & B_CACHE) {
128 if (!seqcount) {
129 return 0;
130 } else if ((bp->b_flags & B_RAM) == 0) {
131 return 0;
132 } else {
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133 struct buf *tbp;
134 bp->b_flags &= ~B_RAM;
135 /*
e43a034f 136 * We do the crit here so that there is no window
1f1ea522 137 * between the findblk and the b_usecount increment
e43a034f 138 * below. We opt to keep the crit out of the loop
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139 * for efficiency.
140 */
e43a034f 141 crit_enter();
984263bc 142 for (i = 1; i < maxra; i++) {
54078292 143 if (!(tbp = findblk(vp, loffset + i * size))) {
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144 break;
145 }
146
147 /*
148 * Set another read-ahead mark so we know
149 * to check again.
150 */
151 if (((i % racluster) == (racluster - 1)) ||
152 (i == (maxra - 1)))
153 tbp->b_flags |= B_RAM;
154 }
e43a034f 155 crit_exit();
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156 if (i >= maxra) {
157 return 0;
158 }
54078292 159 loffset += i * size;
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160 }
161 reqbp = bp = NULL;
162 } else {
81b5c339 163 off_t firstread = bp->b_loffset;
54078292 164 int nblks;
984263bc 165
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166 KASSERT(firstread != NOOFFSET,
167 ("cluster_read: no buffer offset"));
984263bc 168 if (firstread + totread > filesize)
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169 totread = (int)(filesize - firstread);
170 nblks = totread / size;
171 if (nblks) {
172 int burstbytes;
173
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174 if (nblks > racluster)
175 nblks = racluster;
176
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177 error = VOP_BMAP(vp, loffset, NULL,
178 &doffset, &burstbytes, NULL);
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179 if (error)
180 goto single_block_read;
54078292 181 if (doffset == NOOFFSET)
984263bc 182 goto single_block_read;
54078292 183 if (burstbytes < size * 2)
984263bc 184 goto single_block_read;
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185 if (nblks > burstbytes / size)
186 nblks = burstbytes / size;
984263bc 187
54078292 188 bp = cluster_rbuild(vp, filesize, loffset,
10f3fee5 189 doffset, size, nblks, bp, 0);
54078292 190 loffset += bp->b_bufsize;
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191 } else {
192single_block_read:
193 /*
194 * if it isn't in the cache, then get a chunk from
195 * disk if sequential, otherwise just get the block.
196 */
10f3fee5 197 bp->b_flags |= B_RAM;
54078292 198 loffset += size;
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199 }
200 }
201
202 /*
6260e485 203 * If we have been doing sequential I/O, then do some read-ahead.
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204 */
205 rbp = NULL;
6260e485 206 if (seqcount &&
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207 loffset < origoffset + seqcount * size &&
208 loffset + size <= filesize
6260e485 209 ) {
54078292 210 rbp = getblk(vp, loffset, size, 0, 0);
6260e485 211 if ((rbp->b_flags & B_CACHE) == 0) {
984263bc 212 int nblksread;
6260e485 213 int ntoread;
54078292 214 int burstbytes;
6260e485 215
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216 error = VOP_BMAP(vp, loffset, NULL,
217 &doffset, &burstbytes, NULL);
218 if (error || doffset == NOOFFSET) {
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219 brelse(rbp);
220 rbp = NULL;
221 goto no_read_ahead;
222 }
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223 ntoread = burstbytes / size;
224 nblksread = (totread + size - 1) / size;
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225 if (seqcount < nblksread)
226 seqcount = nblksread;
227 if (seqcount < ntoread)
228 ntoread = seqcount;
6260e485 229
10f3fee5 230 rbp->b_flags |= B_RAM;
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231 if (burstbytes) {
232 rbp = cluster_rbuild(vp, filesize, loffset,
233 doffset, size,
10f3fee5 234 ntoread, rbp, 1);
984263bc 235 } else {
54078292 236 rbp->b_bio2.bio_offset = doffset;
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237 }
238 }
239 }
6260e485 240no_read_ahead:
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241
242 /*
a8f169e2 243 * Handle the synchronous read. This only occurs if B_CACHE was
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244 * not set. bp (and rbp) could be either a cluster bp or a normal
245 * bp depending on the what cluster_rbuild() decided to do. If
246 * it is a cluster bp, vfs_busy_pages() has already been called.
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247 */
248 if (bp) {
249#if defined(CLUSTERDEBUG)
250 if (rcluster)
591bdbe9 251 printf("S(%lld,%d,%d) ",
54078292 252 bp->b_loffset, bp->b_bcount, seqcount);
984263bc 253#endif
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254 bp->b_cmd = BUF_CMD_READ;
255 if ((bp->b_flags & B_CLUSTER) == 0)
256 vfs_busy_pages(vp, bp);
984263bc 257 bp->b_flags &= ~(B_ERROR|B_INVAL);
81b5c339 258 if ((bp->b_flags & B_ASYNC) || bp->b_bio1.bio_done != NULL)
984263bc 259 BUF_KERNPROC(bp);
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260 vn_strategy(vp, &bp->b_bio1);
261 error = bp->b_error;
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262 }
263
264 /*
10f3fee5 265 * And if we have read-aheads, do them too.
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266 */
267 if (rbp) {
268 if (error) {
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269 brelse(rbp);
270 } else if (rbp->b_flags & B_CACHE) {
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271 bqrelse(rbp);
272 } else {
273#if defined(CLUSTERDEBUG)
274 if (rcluster) {
275 if (bp)
591bdbe9 276 printf("A+(%lld,%d,%lld,%d) ",
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277 rbp->b_loffset, rbp->b_bcount,
278 rbp->b_loffset - origoffset,
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279 seqcount);
280 else
591bdbe9 281 printf("A(%lld,%d,%lld,%d) ",
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282 rbp->b_loffset, rbp->b_bcount,
283 rbp->b_loffset - origoffset,
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284 seqcount);
285 }
286#endif
984263bc 287 rbp->b_flags &= ~(B_ERROR|B_INVAL);
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288 rbp->b_flags |= B_ASYNC;
289 rbp->b_cmd = BUF_CMD_READ;
290
291 if ((rbp->b_flags & B_CLUSTER) == 0)
292 vfs_busy_pages(vp, rbp);
81b5c339 293 if ((rbp->b_flags & B_ASYNC) || rbp->b_bio1.bio_done != NULL)
984263bc 294 BUF_KERNPROC(rbp);
81b5c339 295 vn_strategy(vp, &rbp->b_bio1);
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296 }
297 }
298 if (reqbp)
299 return (biowait(reqbp));
300 else
301 return (error);
302}
303
304/*
305 * If blocks are contiguous on disk, use this to provide clustered
306 * read ahead. We will read as many blocks as possible sequentially
307 * and then parcel them up into logical blocks in the buffer hash table.
308 */
309static struct buf *
54078292 310cluster_rbuild(struct vnode *vp, off_t filesize, off_t loffset,
10f3fee5 311 off_t doffset, int size, int run, struct buf *fbp, int doasync)
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312{
313 struct buf *bp, *tbp;
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314 off_t boffset;
315 int i, j;
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316
317 KASSERT(size == vp->v_mount->mnt_stat.f_iosize,
54078292 318 ("cluster_rbuild: size %d != filesize %ld\n",
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319 size, vp->v_mount->mnt_stat.f_iosize));
320
321 /*
322 * avoid a division
323 */
54078292 324 while (loffset + run * size > filesize) {
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325 --run;
326 }
327
6260e485 328 tbp = fbp;
54078292 329 tbp->b_bio2.bio_offset = doffset;
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330 if((tbp->b_flags & B_MALLOC) ||
331 ((tbp->b_flags & B_VMIO) == 0) || (run <= 1)) {
984263bc 332 return tbp;
10f3fee5 333 }
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334
335 bp = trypbuf(&cluster_pbuf_freecnt);
a8f169e2 336 if (bp == NULL)
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337 return tbp;
338
339 /*
340 * We are synthesizing a buffer out of vm_page_t's, but
341 * if the block size is not page aligned then the starting
342 * address may not be either. Inherit the b_data offset
343 * from the original buffer.
344 */
345 bp->b_data = (char *)((vm_offset_t)bp->b_data |
346 ((vm_offset_t)tbp->b_data & PAGE_MASK));
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347 bp->b_flags |= B_ASYNC | B_CLUSTER | B_VMIO;
348 bp->b_cmd = BUF_CMD_READ;
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349 bp->b_bio1.bio_done = cluster_callback;
350 bp->b_bio1.bio_caller_info1.cluster_head = NULL;
351 bp->b_bio1.bio_caller_info2.cluster_tail = NULL;
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352 bp->b_loffset = loffset;
353 bp->b_bio2.bio_offset = NOOFFSET;
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354 KASSERT(bp->b_loffset != NOOFFSET,
355 ("cluster_rbuild: no buffer offset"));
984263bc 356
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357 bp->b_bcount = 0;
358 bp->b_bufsize = 0;
54f51aeb 359 bp->b_xio.xio_npages = 0;
984263bc 360
54078292 361 for (boffset = doffset, i = 0; i < run; ++i, boffset += size) {
10f3fee5 362 if (i) {
54f51aeb 363 if ((bp->b_xio.xio_npages * PAGE_SIZE) +
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364 round_page(size) > vp->v_mount->mnt_iosize_max) {
365 break;
366 }
367
368 /*
369 * Shortcut some checks and try to avoid buffers that
370 * would block in the lock. The same checks have to
371 * be made again after we officially get the buffer.
372 */
54078292 373 if ((tbp = findblk(vp, loffset + i * size)) != NULL) {
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374 if (BUF_LOCK(tbp, LK_EXCLUSIVE | LK_NOWAIT))
375 break;
376 BUF_UNLOCK(tbp);
377
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378 for (j = 0; j < tbp->b_xio.xio_npages; j++) {
379 if (tbp->b_xio.xio_pages[j]->valid)
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380 break;
381 }
382
54f51aeb 383 if (j != tbp->b_xio.xio_npages)
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384 break;
385
386 if (tbp->b_bcount != size)
387 break;
388 }
389
54078292 390 tbp = getblk(vp, loffset + i * size, size, 0, 0);
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391
392 /*
393 * Stop scanning if the buffer is fuly valid
394 * (marked B_CACHE), or locked (may be doing a
395 * background write), or if the buffer is not
396 * VMIO backed. The clustering code can only deal
397 * with VMIO-backed buffers.
398 */
399 if ((tbp->b_flags & (B_CACHE|B_LOCKED)) ||
400 (tbp->b_flags & B_VMIO) == 0) {
401 bqrelse(tbp);
402 break;
403 }
404
405 /*
406 * The buffer must be completely invalid in order to
407 * take part in the cluster. If it is partially valid
408 * then we stop.
409 */
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410 for (j = 0;j < tbp->b_xio.xio_npages; j++) {
411 if (tbp->b_xio.xio_pages[j]->valid)
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412 break;
413 }
54f51aeb 414 if (j != tbp->b_xio.xio_npages) {
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415 bqrelse(tbp);
416 break;
417 }
418
419 /*
420 * Set a read-ahead mark as appropriate
421 */
6260e485 422 if (i == 1 || i == (run - 1))
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423 tbp->b_flags |= B_RAM;
424
425 /*
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426 * Set the block number if it isn't set, otherwise
427 * if it is make sure it matches the block number we
428 * expect.
429 */
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430 if (tbp->b_bio2.bio_offset == NOOFFSET) {
431 tbp->b_bio2.bio_offset = boffset;
432 } else if (tbp->b_bio2.bio_offset != boffset) {
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433 brelse(tbp);
434 break;
435 }
436 }
437 /*
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438 * The first buffer is setup async if doasync is specified.
439 * All other buffers in the cluster are setup async. This
440 * way the caller can decide how to deal with the requested
441 * buffer.
984263bc 442 */
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443 if (i || doasync)
444 tbp->b_flags |= B_ASYNC;
445 tbp->b_cmd = BUF_CMD_READ;
984263bc 446 BUF_KERNPROC(tbp);
81b5c339 447 cluster_append(&bp->b_bio1, tbp);
54078292 448 for (j = 0; j < tbp->b_xio.xio_npages; ++j) {
984263bc 449 vm_page_t m;
54f51aeb 450 m = tbp->b_xio.xio_pages[j];
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451 vm_page_io_start(m);
452 vm_object_pip_add(m->object, 1);
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453 if ((bp->b_xio.xio_npages == 0) ||
454 (bp->b_xio.xio_pages[bp->b_xio.xio_npages-1] != m)) {
455 bp->b_xio.xio_pages[bp->b_xio.xio_npages] = m;
456 bp->b_xio.xio_npages++;
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457 }
458 if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL)
54f51aeb 459 tbp->b_xio.xio_pages[j] = bogus_page;
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460 }
461 /*
462 * XXX shouldn't this be += size for both, like in
463 * cluster_wbuild()?
464 *
465 * Don't inherit tbp->b_bufsize as it may be larger due to
466 * a non-page-aligned size. Instead just aggregate using
467 * 'size'.
468 */
469 if (tbp->b_bcount != size)
54078292 470 printf("warning: tbp->b_bcount wrong %d vs %d\n", tbp->b_bcount, size);
984263bc 471 if (tbp->b_bufsize != size)
54078292 472 printf("warning: tbp->b_bufsize wrong %d vs %d\n", tbp->b_bufsize, size);
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473 bp->b_bcount += size;
474 bp->b_bufsize += size;
475 }
476
477 /*
478 * Fully valid pages in the cluster are already good and do not need
479 * to be re-read from disk. Replace the page with bogus_page
480 */
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481 for (j = 0; j < bp->b_xio.xio_npages; j++) {
482 if ((bp->b_xio.xio_pages[j]->valid & VM_PAGE_BITS_ALL) ==
984263bc 483 VM_PAGE_BITS_ALL) {
54f51aeb 484 bp->b_xio.xio_pages[j] = bogus_page;
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485 }
486 }
487 if (bp->b_bufsize > bp->b_kvasize)
54078292 488 panic("cluster_rbuild: b_bufsize(%d) > b_kvasize(%d)",
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489 bp->b_bufsize, bp->b_kvasize);
490 bp->b_kvasize = bp->b_bufsize;
491
492 pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
54f51aeb 493 (vm_page_t *)bp->b_xio.xio_pages, bp->b_xio.xio_npages);
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494 return (bp);
495}
496
497/*
498 * Cleanup after a clustered read or write.
499 * This is complicated by the fact that any of the buffers might have
500 * extra memory (if there were no empty buffer headers at allocbuf time)
501 * that we will need to shift around.
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502 *
503 * The returned bio is &bp->b_bio1
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504 */
505void
81b5c339 506cluster_callback(struct bio *bio)
984263bc 507{
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508 struct buf *bp = bio->bio_buf;
509 struct buf *tbp;
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510 int error = 0;
511
512 /*
513 * Must propogate errors to all the components.
514 */
515 if (bp->b_flags & B_ERROR)
516 error = bp->b_error;
517
54f51aeb 518 pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_xio.xio_npages);
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519 /*
520 * Move memory from the large cluster buffer into the component
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521 * buffers and mark IO as done on these. Since the memory map
522 * is the same, no actual copying is required.
984263bc 523 */
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524 while ((tbp = bio->bio_caller_info1.cluster_head) != NULL) {
525 bio->bio_caller_info1.cluster_head = tbp->b_cluster_next;
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526 if (error) {
527 tbp->b_flags |= B_ERROR;
528 tbp->b_error = error;
529 } else {
530 tbp->b_dirtyoff = tbp->b_dirtyend = 0;
531 tbp->b_flags &= ~(B_ERROR|B_INVAL);
532 /*
533 * XXX the bdwrite()/bqrelse() issued during
534 * cluster building clears B_RELBUF (see bqrelse()
535 * comment). If direct I/O was specified, we have
536 * to restore it here to allow the buffer and VM
537 * to be freed.
538 */
539 if (tbp->b_flags & B_DIRECT)
540 tbp->b_flags |= B_RELBUF;
541 }
81b5c339 542 biodone(&tbp->b_bio1);
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543 }
544 relpbuf(bp, &cluster_pbuf_freecnt);
545}
546
547/*
548 * cluster_wbuild_wb:
549 *
550 * Implement modified write build for cluster.
551 *
552 * write_behind = 0 write behind disabled
553 * write_behind = 1 write behind normal (default)
554 * write_behind = 2 write behind backed-off
555 */
556
557static __inline int
54078292 558cluster_wbuild_wb(struct vnode *vp, int size, off_t start_loffset, int len)
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559{
560 int r = 0;
561
562 switch(write_behind) {
563 case 2:
54078292 564 if (start_loffset < len)
984263bc 565 break;
54078292 566 start_loffset -= len;
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567 /* fall through */
568 case 1:
54078292 569 r = cluster_wbuild(vp, size, start_loffset, len);
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570 /* fall through */
571 default:
572 /* fall through */
573 break;
574 }
575 return(r);
576}
577
578/*
579 * Do clustered write for FFS.
580 *
581 * Three cases:
582 * 1. Write is not sequential (write asynchronously)
583 * Write is sequential:
584 * 2. beginning of cluster - begin cluster
585 * 3. middle of a cluster - add to cluster
586 * 4. end of a cluster - asynchronously write cluster
587 */
588void
54078292 589cluster_write(struct buf *bp, off_t filesize, int seqcount)
984263bc
MD
590{
591 struct vnode *vp;
54078292 592 off_t loffset;
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MD
593 int maxclen, cursize;
594 int lblocksize;
595 int async;
596
597 vp = bp->b_vp;
598 if (vp->v_type == VREG) {
599 async = vp->v_mount->mnt_flag & MNT_ASYNC;
600 lblocksize = vp->v_mount->mnt_stat.f_iosize;
601 } else {
602 async = 0;
603 lblocksize = bp->b_bufsize;
604 }
54078292 605 loffset = bp->b_loffset;
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MD
606 KASSERT(bp->b_loffset != NOOFFSET,
607 ("cluster_write: no buffer offset"));
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MD
608
609 /* Initialize vnode to beginning of file. */
54078292 610 if (loffset == 0)
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611 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
612
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MD
613 if (vp->v_clen == 0 || loffset != vp->v_lastw + lblocksize ||
614 bp->b_bio2.bio_offset == NOOFFSET ||
615 (bp->b_bio2.bio_offset != vp->v_lasta + lblocksize)) {
616 maxclen = vp->v_mount->mnt_iosize_max;
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617 if (vp->v_clen != 0) {
618 /*
619 * Next block is not sequential.
620 *
621 * If we are not writing at end of file, the process
622 * seeked to another point in the file since its last
623 * write, or we have reached our maximum cluster size,
624 * then push the previous cluster. Otherwise try
625 * reallocating to make it sequential.
626 *
627 * Change to algorithm: only push previous cluster if
628 * it was sequential from the point of view of the
629 * seqcount heuristic, otherwise leave the buffer
630 * intact so we can potentially optimize the I/O
631 * later on in the buf_daemon or update daemon
632 * flush.
633 */
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634 cursize = vp->v_lastw - vp->v_cstart + lblocksize;
635 if (bp->b_loffset + lblocksize != filesize ||
636 loffset != vp->v_lastw + lblocksize || vp->v_clen <= cursize) {
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637 if (!async && seqcount > 0) {
638 cluster_wbuild_wb(vp, lblocksize,
639 vp->v_cstart, cursize);
640 }
641 } else {
642 struct buf **bpp, **endbp;
643 struct cluster_save *buflist;
644
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645 buflist = cluster_collectbufs(vp, bp,
646 lblocksize);
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647 endbp = &buflist->bs_children
648 [buflist->bs_nchildren - 1];
649 if (VOP_REALLOCBLKS(vp, buflist)) {
650 /*
651 * Failed, push the previous cluster
652 * if *really* writing sequentially
653 * in the logical file (seqcount > 1),
654 * otherwise delay it in the hopes that
655 * the low level disk driver can
656 * optimize the write ordering.
657 */
658 for (bpp = buflist->bs_children;
659 bpp < endbp; bpp++)
660 brelse(*bpp);
661 free(buflist, M_SEGMENT);
662 if (seqcount > 1) {
663 cluster_wbuild_wb(vp,
664 lblocksize, vp->v_cstart,
665 cursize);
666 }
667 } else {
668 /*
669 * Succeeded, keep building cluster.
670 */
671 for (bpp = buflist->bs_children;
672 bpp <= endbp; bpp++)
673 bdwrite(*bpp);
674 free(buflist, M_SEGMENT);
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MD
675 vp->v_lastw = loffset;
676 vp->v_lasta = bp->b_bio2.bio_offset;
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677 return;
678 }
679 }
680 }
681 /*
682 * Consider beginning a cluster. If at end of file, make
683 * cluster as large as possible, otherwise find size of
684 * existing cluster.
685 */
686 if ((vp->v_type == VREG) &&
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MD
687 bp->b_loffset + lblocksize != filesize &&
688 (bp->b_bio2.bio_offset == NOOFFSET) &&
689 (VOP_BMAP(vp, loffset, NULL, &bp->b_bio2.bio_offset, &maxclen, NULL) ||
690 bp->b_bio2.bio_offset == NOOFFSET)) {
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691 bawrite(bp);
692 vp->v_clen = 0;
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693 vp->v_lasta = bp->b_bio2.bio_offset;
694 vp->v_cstart = loffset + lblocksize;
695 vp->v_lastw = loffset;
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MD
696 return;
697 }
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MD
698 if (maxclen > lblocksize)
699 vp->v_clen = maxclen - lblocksize;
700 else
701 vp->v_clen = 0;
702 if (!async && vp->v_clen == 0) { /* I/O not contiguous */
703 vp->v_cstart = loffset + lblocksize;
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704 bawrite(bp);
705 } else { /* Wait for rest of cluster */
54078292 706 vp->v_cstart = loffset;
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707 bdwrite(bp);
708 }
54078292 709 } else if (loffset == vp->v_cstart + vp->v_clen) {
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710 /*
711 * At end of cluster, write it out if seqcount tells us we
712 * are operating sequentially, otherwise let the buf or
713 * update daemon handle it.
714 */
715 bdwrite(bp);
716 if (seqcount > 1)
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MD
717 cluster_wbuild_wb(vp, lblocksize, vp->v_cstart,
718 vp->v_clen + lblocksize);
984263bc 719 vp->v_clen = 0;
54078292 720 vp->v_cstart = loffset + lblocksize;
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MD
721 } else if (vm_page_count_severe()) {
722 /*
723 * We are low on memory, get it going NOW
724 */
725 bawrite(bp);
726 } else {
727 /*
728 * In the middle of a cluster, so just delay the I/O for now.
729 */
730 bdwrite(bp);
731 }
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732 vp->v_lastw = loffset;
733 vp->v_lasta = bp->b_bio2.bio_offset;
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MD
734}
735
736
737/*
738 * This is an awful lot like cluster_rbuild...wish they could be combined.
739 * The last lbn argument is the current block on which I/O is being
740 * performed. Check to see that it doesn't fall in the middle of
741 * the current block (if last_bp == NULL).
742 */
743int
54078292 744cluster_wbuild(struct vnode *vp, int size, off_t start_loffset, int bytes)
984263bc
MD
745{
746 struct buf *bp, *tbp;
e43a034f 747 int i, j;
984263bc 748 int totalwritten = 0;
984263bc 749
54078292 750 while (bytes > 0) {
e43a034f 751 crit_enter();
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MD
752 /*
753 * If the buffer is not delayed-write (i.e. dirty), or it
754 * is delayed-write but either locked or inval, it cannot
755 * partake in the clustered write.
756 */
54078292 757 if (((tbp = findblk(vp, start_loffset)) == NULL) ||
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MD
758 ((tbp->b_flags & (B_LOCKED | B_INVAL | B_DELWRI)) != B_DELWRI) ||
759 BUF_LOCK(tbp, LK_EXCLUSIVE | LK_NOWAIT)) {
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MD
760 start_loffset += size;
761 bytes -= size;
e43a034f 762 crit_exit();
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MD
763 continue;
764 }
765 bremfree(tbp);
10f3fee5 766 KKASSERT(tbp->b_cmd == BUF_CMD_DONE);
e43a034f 767 crit_exit();
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MD
768
769 /*
770 * Extra memory in the buffer, punt on this buffer.
771 * XXX we could handle this in most cases, but we would
772 * have to push the extra memory down to after our max
773 * possible cluster size and then potentially pull it back
774 * up if the cluster was terminated prematurely--too much
775 * hassle.
776 */
777 if (((tbp->b_flags & (B_CLUSTEROK|B_MALLOC)) != B_CLUSTEROK) ||
778 (tbp->b_bcount != tbp->b_bufsize) ||
779 (tbp->b_bcount != size) ||
54078292 780 (bytes == size) ||
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MD
781 ((bp = getpbuf(&cluster_pbuf_freecnt)) == NULL)) {
782 totalwritten += tbp->b_bufsize;
783 bawrite(tbp);
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MD
784 start_loffset += size;
785 bytes -= size;
984263bc
MD
786 continue;
787 }
788
789 /*
790 * We got a pbuf to make the cluster in.
791 * so initialise it.
792 */
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MD
793 bp->b_bcount = 0;
794 bp->b_bufsize = 0;
54f51aeb 795 bp->b_xio.xio_npages = 0;
81b5c339 796 bp->b_loffset = tbp->b_loffset;
54078292 797 bp->b_bio2.bio_offset = tbp->b_bio2.bio_offset;
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MD
798
799 /*
800 * We are synthesizing a buffer out of vm_page_t's, but
801 * if the block size is not page aligned then the starting
802 * address may not be either. Inherit the b_data offset
803 * from the original buffer.
804 */
805 bp->b_data = (char *)((vm_offset_t)bp->b_data |
806 ((vm_offset_t)tbp->b_data & PAGE_MASK));
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MD
807 bp->b_flags &= ~B_ERROR;
808 bp->b_flags |= B_CLUSTER |
984263bc 809 (tbp->b_flags & (B_VMIO | B_NEEDCOMMIT | B_NOWDRAIN));
81b5c339
MD
810 bp->b_bio1.bio_done = cluster_callback;
811 bp->b_bio1.bio_caller_info1.cluster_head = NULL;
812 bp->b_bio1.bio_caller_info2.cluster_tail = NULL;
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MD
813 /*
814 * From this location in the file, scan forward to see
815 * if there are buffers with adjacent data that need to
816 * be written as well.
817 */
54078292 818 for (i = 0; i < bytes; (i += size), (start_loffset += size)) {
984263bc 819 if (i != 0) { /* If not the first buffer */
e43a034f 820 crit_enter();
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MD
821 /*
822 * If the adjacent data is not even in core it
823 * can't need to be written.
824 */
54078292 825 if ((tbp = findblk(vp, start_loffset)) == NULL) {
e43a034f 826 crit_exit();
984263bc
MD
827 break;
828 }
829
830 /*
831 * If it IS in core, but has different
832 * characteristics, or is locked (which
833 * means it could be undergoing a background
834 * I/O or be in a weird state), then don't
835 * cluster with it.
836 */
837 if ((tbp->b_flags & (B_VMIO | B_CLUSTEROK |
838 B_INVAL | B_DELWRI | B_NEEDCOMMIT))
839 != (B_DELWRI | B_CLUSTEROK |
840 (bp->b_flags & (B_VMIO | B_NEEDCOMMIT))) ||
841 (tbp->b_flags & B_LOCKED) ||
984263bc 842 BUF_LOCK(tbp, LK_EXCLUSIVE | LK_NOWAIT)) {
e43a034f 843 crit_exit();
984263bc
MD
844 break;
845 }
846
847 /*
848 * Check that the combined cluster
849 * would make sense with regard to pages
850 * and would not be too large
851 */
852 if ((tbp->b_bcount != size) ||
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MD
853 ((bp->b_bio2.bio_offset + i) !=
854 tbp->b_bio2.bio_offset) ||
54f51aeb 855 ((tbp->b_xio.xio_npages + bp->b_xio.xio_npages) >
984263bc
MD
856 (vp->v_mount->mnt_iosize_max / PAGE_SIZE))) {
857 BUF_UNLOCK(tbp);
e43a034f 858 crit_exit();
984263bc
MD
859 break;
860 }
861 /*
862 * Ok, it's passed all the tests,
863 * so remove it from the free list
864 * and mark it busy. We will use it.
865 */
866 bremfree(tbp);
10f3fee5 867 KKASSERT(tbp->b_cmd == BUF_CMD_DONE);
e43a034f 868 crit_exit();
984263bc 869 } /* end of code for non-first buffers only */
81b5c339 870
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MD
871 /*
872 * If the IO is via the VM then we do some
873 * special VM hackery (yuck). Since the buffer's
874 * block size may not be page-aligned it is possible
875 * for a page to be shared between two buffers. We
876 * have to get rid of the duplication when building
877 * the cluster.
878 */
879 if (tbp->b_flags & B_VMIO) {
880 vm_page_t m;
881
882 if (i != 0) { /* if not first buffer */
54078292 883 for (j = 0; j < tbp->b_xio.xio_npages; ++j) {
54f51aeb 884 m = tbp->b_xio.xio_pages[j];
984263bc
MD
885 if (m->flags & PG_BUSY) {
886 bqrelse(tbp);
887 goto finishcluster;
888 }
889 }
890 }
891
54078292 892 for (j = 0; j < tbp->b_xio.xio_npages; ++j) {
54f51aeb 893 m = tbp->b_xio.xio_pages[j];
984263bc
MD
894 vm_page_io_start(m);
895 vm_object_pip_add(m->object, 1);
54f51aeb
HP
896 if ((bp->b_xio.xio_npages == 0) ||
897 (bp->b_xio.xio_pages[bp->b_xio.xio_npages - 1] != m)) {
898 bp->b_xio.xio_pages[bp->b_xio.xio_npages] = m;
899 bp->b_xio.xio_npages++;
984263bc
MD
900 }
901 }
902 }
903 bp->b_bcount += size;
904 bp->b_bufsize += size;
905
e43a034f 906 crit_enter();
984263bc 907 bundirty(tbp);
10f3fee5 908 tbp->b_flags &= ~B_ERROR;
984263bc 909 tbp->b_flags |= B_ASYNC;
10f3fee5 910 tbp->b_cmd = BUF_CMD_WRITE;
e43a034f 911 crit_exit();
984263bc 912 BUF_KERNPROC(tbp);
81b5c339 913 cluster_append(&bp->b_bio1, tbp);
2aee763b
MD
914
915 /*
916 * check for latent dependencies to be handled
917 */
918 if (LIST_FIRST(&tbp->b_dep) != NULL && bioops.io_start)
919 (*bioops.io_start)(tbp);
920
984263bc
MD
921 }
922 finishcluster:
923 pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
54f51aeb 924 (vm_page_t *) bp->b_xio.xio_pages, bp->b_xio.xio_npages);
984263bc
MD
925 if (bp->b_bufsize > bp->b_kvasize)
926 panic(
54078292 927 "cluster_wbuild: b_bufsize(%d) > b_kvasize(%d)\n",
984263bc
MD
928 bp->b_bufsize, bp->b_kvasize);
929 bp->b_kvasize = bp->b_bufsize;
930 totalwritten += bp->b_bufsize;
931 bp->b_dirtyoff = 0;
932 bp->b_dirtyend = bp->b_bufsize;
10f3fee5
MD
933 bp->b_flags |= B_ASYNC;
934 bp->b_cmd = BUF_CMD_WRITE;
935 vfs_busy_pages(vp, bp);
a8f169e2
MD
936 bp->b_runningbufspace = bp->b_bufsize;
937 runningbufspace += bp->b_runningbufspace;
938 BUF_KERNPROC(bp); /* B_ASYNC */
939 vn_strategy(vp, &bp->b_bio1);
984263bc 940
54078292 941 bytes -= i;
984263bc
MD
942 }
943 return totalwritten;
944}
945
946/*
947 * Collect together all the buffers in a cluster.
948 * Plus add one additional buffer.
949 */
950static struct cluster_save *
54078292 951cluster_collectbufs(struct vnode *vp, struct buf *last_bp, int lblocksize)
984263bc
MD
952{
953 struct cluster_save *buflist;
954 struct buf *bp;
54078292 955 off_t loffset;
984263bc
MD
956 int i, len;
957
54078292 958 len = (int)(vp->v_lastw - vp->v_cstart + lblocksize) / lblocksize;
984263bc 959 buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist),
54078292 960 M_SEGMENT, M_WAITOK);
984263bc
MD
961 buflist->bs_nchildren = 0;
962 buflist->bs_children = (struct buf **) (buflist + 1);
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MD
963 for (loffset = vp->v_cstart, i = 0; i < len; (loffset += lblocksize), i++) {
964 (void) bread(vp, loffset, last_bp->b_bcount, &bp);
984263bc 965 buflist->bs_children[i] = bp;
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MD
966 if (bp->b_bio2.bio_offset == NOOFFSET) {
967 VOP_BMAP(bp->b_vp, bp->b_loffset, NULL,
968 &bp->b_bio2.bio_offset, NULL, NULL);
969 }
984263bc
MD
970 }
971 buflist->bs_children[i] = bp = last_bp;
54078292
MD
972 if (bp->b_bio2.bio_offset == NOOFFSET) {
973 VOP_BMAP(bp->b_vp, bp->b_loffset, NULL,
974 &bp->b_bio2.bio_offset, NULL, NULL);
975 }
984263bc
MD
976 buflist->bs_nchildren = i + 1;
977 return (buflist);
978}
81b5c339
MD
979
980void
981cluster_append(struct bio *bio, struct buf *tbp)
982{
983 tbp->b_cluster_next = NULL;
984 if (bio->bio_caller_info1.cluster_head == NULL) {
985 bio->bio_caller_info1.cluster_head = tbp;
986 bio->bio_caller_info2.cluster_tail = tbp;
987 } else {
988 bio->bio_caller_info2.cluster_tail->b_cluster_next = tbp;
989 bio->bio_caller_info2.cluster_tail = tbp;
990 }
991}
992