1 /*-
2 * Copyright (c) 2009-2010 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Pawel Jakub Dawidek under sponsorship from
6 * the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 #include <sys/param.h> /* powerof2() */
34 #include <sys/queue.h>
35
36 #include <bitstring.h>
37 #include <errno.h>
38 #include <stdint.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42
43 #include <pjdlog.h>
44
45 #include "activemap.h"
46
47 #ifndef PJDLOG_ASSERT
48 #include <assert.h>
49 #define PJDLOG_ASSERT(...) assert(__VA_ARGS__)
50 #endif
51
52 #define ACTIVEMAP_MAGIC 0xac71e4
53 struct activemap {
54 int am_magic; /* Magic value. */
55 off_t am_mediasize; /* Media size in bytes. */
56 uint32_t am_extentsize; /* Extent size in bytes,
57 must be power of 2. */
58 uint8_t am_extentshift;/* 2 ^ extentbits == extentsize */
59 int am_nextents; /* Number of extents. */
60 size_t am_mapsize; /* Bitmap size in bytes. */
61 uint16_t *am_memtab; /* An array that holds number of pending
62 writes per extent. */
63 bitstr_t *am_diskmap; /* On-disk bitmap of dirty extents. */
64 bitstr_t *am_memmap; /* In-memory bitmap of dirty extents. */
65 size_t am_diskmapsize; /* Map size rounded up to sector size. */
66 uint64_t am_ndirty; /* Number of dirty regions. */
67 bitstr_t *am_syncmap; /* Bitmap of extents to sync. */
68 off_t am_syncoff; /* Next synchronization offset. */
69 TAILQ_HEAD(skeepdirty, keepdirty) am_keepdirty; /* List of extents that
70 we keep dirty to reduce bitmap
71 updates. */
72 int am_nkeepdirty; /* Number of am_keepdirty elements. */
73 int am_nkeepdirty_limit; /* Maximum number of am_keepdirty
74 elements. */
75 };
76
77 struct keepdirty {
78 int kd_extent;
79 TAILQ_ENTRY(keepdirty) kd_next;
80 };
81
82 /*
83 * Helper function taken from sys/systm.h to calculate extentshift.
84 */
85 static uint32_t
bitcount32(uint32_t x)86 bitcount32(uint32_t x)
87 {
88
89 x = (x & 0x55555555) + ((x & 0xaaaaaaaa) >> 1);
90 x = (x & 0x33333333) + ((x & 0xcccccccc) >> 2);
91 x = (x + (x >> 4)) & 0x0f0f0f0f;
92 x = (x + (x >> 8));
93 x = (x + (x >> 16)) & 0x000000ff;
94 return (x);
95 }
96
97 static __inline int
off2ext(const struct activemap * amp,off_t offset)98 off2ext(const struct activemap *amp, off_t offset)
99 {
100 int extent;
101
102 PJDLOG_ASSERT(offset >= 0 && offset < amp->am_mediasize);
103 extent = (offset >> amp->am_extentshift);
104 PJDLOG_ASSERT(extent >= 0 && extent < amp->am_nextents);
105 return (extent);
106 }
107
108 static __inline off_t
ext2off(const struct activemap * amp,int extent)109 ext2off(const struct activemap *amp, int extent)
110 {
111 off_t offset;
112
113 PJDLOG_ASSERT(extent >= 0 && extent < amp->am_nextents);
114 offset = ((off_t)extent << amp->am_extentshift);
115 PJDLOG_ASSERT(offset >= 0 && offset < amp->am_mediasize);
116 return (offset);
117 }
118
119 /*
120 * Function calculates number of requests needed to synchronize the given
121 * extent.
122 */
123 static __inline int
ext2reqs(const struct activemap * amp,int ext)124 ext2reqs(const struct activemap *amp, int ext)
125 {
126 off_t left;
127
128 if (ext < amp->am_nextents - 1)
129 return (((amp->am_extentsize - 1) / MAXPHYS) + 1);
130
131 PJDLOG_ASSERT(ext == amp->am_nextents - 1);
132 left = amp->am_mediasize % amp->am_extentsize;
133 if (left == 0)
134 left = amp->am_extentsize;
135 return (((left - 1) / MAXPHYS) + 1);
136 }
137
138 /*
139 * Initialize activemap structure and allocate memory for internal needs.
140 * Function returns 0 on success and -1 if any of the allocations failed.
141 */
142 int
activemap_init(struct activemap ** ampp,uint64_t mediasize,uint32_t extentsize,uint32_t sectorsize,uint32_t keepdirty)143 activemap_init(struct activemap **ampp, uint64_t mediasize, uint32_t extentsize,
144 uint32_t sectorsize, uint32_t keepdirty)
145 {
146 struct activemap *amp;
147
148 PJDLOG_ASSERT(ampp != NULL);
149 PJDLOG_ASSERT(mediasize > 0);
150 PJDLOG_ASSERT(extentsize > 0);
151 PJDLOG_ASSERT(powerof2(extentsize));
152 PJDLOG_ASSERT(sectorsize > 0);
153 PJDLOG_ASSERT(powerof2(sectorsize));
154 PJDLOG_ASSERT(keepdirty > 0);
155
156 amp = malloc(sizeof(*amp));
157 if (amp == NULL)
158 return (-1);
159
160 amp->am_mediasize = mediasize;
161 amp->am_nkeepdirty_limit = keepdirty;
162 amp->am_extentsize = extentsize;
163 amp->am_extentshift = bitcount32(extentsize - 1);
164 amp->am_nextents = ((mediasize - 1) / extentsize) + 1;
165 amp->am_mapsize = sizeof(bitstr_t) * bitstr_size(amp->am_nextents);
166 amp->am_diskmapsize = roundup2(amp->am_mapsize, sectorsize);
167 amp->am_ndirty = 0;
168 amp->am_syncoff = -2;
169 TAILQ_INIT(&->am_keepdirty);
170 amp->am_nkeepdirty = 0;
171
172 amp->am_memtab = calloc(amp->am_nextents, sizeof(amp->am_memtab[0]));
173 amp->am_diskmap = calloc(1, amp->am_diskmapsize);
174 amp->am_memmap = bit_alloc(amp->am_nextents);
175 amp->am_syncmap = bit_alloc(amp->am_nextents);
176
177 /*
178 * Check to see if any of the allocations above failed.
179 */
180 if (amp->am_memtab == NULL || amp->am_diskmap == NULL ||
181 amp->am_memmap == NULL || amp->am_syncmap == NULL) {
182 if (amp->am_memtab != NULL)
183 free(amp->am_memtab);
184 if (amp->am_diskmap != NULL)
185 free(amp->am_diskmap);
186 if (amp->am_memmap != NULL)
187 free(amp->am_memmap);
188 if (amp->am_syncmap != NULL)
189 free(amp->am_syncmap);
190 amp->am_magic = 0;
191 free(amp);
192 errno = ENOMEM;
193 return (-1);
194 }
195
196 amp->am_magic = ACTIVEMAP_MAGIC;
197 *ampp = amp;
198
199 return (0);
200 }
201
202 static struct keepdirty *
keepdirty_find(struct activemap * amp,int extent)203 keepdirty_find(struct activemap *amp, int extent)
204 {
205 struct keepdirty *kd;
206
207 TAILQ_FOREACH(kd, &->am_keepdirty, kd_next) {
208 if (kd->kd_extent == extent)
209 break;
210 }
211 return (kd);
212 }
213
214 static bool
keepdirty_add(struct activemap * amp,int extent)215 keepdirty_add(struct activemap *amp, int extent)
216 {
217 struct keepdirty *kd;
218
219 kd = keepdirty_find(amp, extent);
220 if (kd != NULL) {
221 /*
222 * Only move element at the beginning.
223 */
224 TAILQ_REMOVE(&->am_keepdirty, kd, kd_next);
225 TAILQ_INSERT_HEAD(&->am_keepdirty, kd, kd_next);
226 return (false);
227 }
228 /*
229 * Add new element, but first remove the most unused one if
230 * we have too many.
231 */
232 if (amp->am_nkeepdirty >= amp->am_nkeepdirty_limit) {
233 kd = TAILQ_LAST(&->am_keepdirty, skeepdirty);
234 PJDLOG_ASSERT(kd != NULL);
235 TAILQ_REMOVE(&->am_keepdirty, kd, kd_next);
236 amp->am_nkeepdirty--;
237 PJDLOG_ASSERT(amp->am_nkeepdirty > 0);
238 }
239 if (kd == NULL)
240 kd = malloc(sizeof(*kd));
241 /* We can ignore allocation failure. */
242 if (kd != NULL) {
243 kd->kd_extent = extent;
244 amp->am_nkeepdirty++;
245 TAILQ_INSERT_HEAD(&->am_keepdirty, kd, kd_next);
246 }
247
248 return (true);
249 }
250
251 static void
keepdirty_fill(struct activemap * amp)252 keepdirty_fill(struct activemap *amp)
253 {
254 struct keepdirty *kd;
255
256 TAILQ_FOREACH(kd, &->am_keepdirty, kd_next)
257 bit_set(amp->am_diskmap, kd->kd_extent);
258 }
259
260 static void
keepdirty_free(struct activemap * amp)261 keepdirty_free(struct activemap *amp)
262 {
263 struct keepdirty *kd;
264
265 while ((kd = TAILQ_FIRST(&->am_keepdirty)) != NULL) {
266 TAILQ_REMOVE(&->am_keepdirty, kd, kd_next);
267 amp->am_nkeepdirty--;
268 free(kd);
269 }
270 PJDLOG_ASSERT(amp->am_nkeepdirty == 0);
271 }
272
273 /*
274 * Function frees resources allocated by activemap_init() function.
275 */
276 void
activemap_free(struct activemap * amp)277 activemap_free(struct activemap *amp)
278 {
279
280 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
281
282 amp->am_magic = 0;
283
284 keepdirty_free(amp);
285 free(amp->am_memtab);
286 free(amp->am_diskmap);
287 free(amp->am_memmap);
288 free(amp->am_syncmap);
289 }
290
291 /*
292 * Function should be called before we handle write requests. It updates
293 * internal structures and returns true if on-disk metadata should be updated.
294 */
295 bool
activemap_write_start(struct activemap * amp,off_t offset,off_t length)296 activemap_write_start(struct activemap *amp, off_t offset, off_t length)
297 {
298 bool modified;
299 off_t end;
300 int ext;
301
302 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
303 PJDLOG_ASSERT(length > 0);
304
305 modified = false;
306 end = offset + length - 1;
307
308 for (ext = off2ext(amp, offset); ext <= off2ext(amp, end); ext++) {
309 /*
310 * If the number of pending writes is increased from 0,
311 * we have to mark the extent as dirty also in on-disk bitmap.
312 * By returning true we inform the caller that on-disk bitmap
313 * was modified and has to be flushed to disk.
314 */
315 if (amp->am_memtab[ext]++ == 0) {
316 PJDLOG_ASSERT(!bit_test(amp->am_memmap, ext));
317 bit_set(amp->am_memmap, ext);
318 amp->am_ndirty++;
319 }
320 if (keepdirty_add(amp, ext))
321 modified = true;
322 }
323
324 return (modified);
325 }
326
327 /*
328 * Function should be called after receiving write confirmation. It updates
329 * internal structures and returns true if on-disk metadata should be updated.
330 */
331 bool
activemap_write_complete(struct activemap * amp,off_t offset,off_t length)332 activemap_write_complete(struct activemap *amp, off_t offset, off_t length)
333 {
334 bool modified;
335 off_t end;
336 int ext;
337
338 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
339 PJDLOG_ASSERT(length > 0);
340
341 modified = false;
342 end = offset + length - 1;
343
344 for (ext = off2ext(amp, offset); ext <= off2ext(amp, end); ext++) {
345 /*
346 * If the number of pending writes goes down to 0, we have to
347 * mark the extent as clean also in on-disk bitmap.
348 * By returning true we inform the caller that on-disk bitmap
349 * was modified and has to be flushed to disk.
350 */
351 PJDLOG_ASSERT(amp->am_memtab[ext] > 0);
352 PJDLOG_ASSERT(bit_test(amp->am_memmap, ext));
353 if (--amp->am_memtab[ext] == 0) {
354 bit_clear(amp->am_memmap, ext);
355 amp->am_ndirty--;
356 if (keepdirty_find(amp, ext) == NULL)
357 modified = true;
358 }
359 }
360
361 return (modified);
362 }
363
364 /*
365 * Function should be called after finishing synchronization of one extent.
366 * It returns true if on-disk metadata should be updated.
367 */
368 bool
activemap_extent_complete(struct activemap * amp,int extent)369 activemap_extent_complete(struct activemap *amp, int extent)
370 {
371 bool modified;
372 int reqs;
373
374 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
375 PJDLOG_ASSERT(extent >= 0 && extent < amp->am_nextents);
376
377 modified = false;
378
379 reqs = ext2reqs(amp, extent);
380 PJDLOG_ASSERT(amp->am_memtab[extent] >= reqs);
381 amp->am_memtab[extent] -= reqs;
382 PJDLOG_ASSERT(bit_test(amp->am_memmap, extent));
383 if (amp->am_memtab[extent] == 0) {
384 bit_clear(amp->am_memmap, extent);
385 amp->am_ndirty--;
386 modified = true;
387 }
388
389 return (modified);
390 }
391
392 /*
393 * Function returns number of dirty regions.
394 */
395 uint64_t
activemap_ndirty(const struct activemap * amp)396 activemap_ndirty(const struct activemap *amp)
397 {
398
399 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
400
401 return (amp->am_ndirty);
402 }
403
404 /*
405 * Function compare on-disk bitmap and in-memory bitmap and returns true if
406 * they differ and should be flushed to the disk.
407 */
408 bool
activemap_differ(const struct activemap * amp)409 activemap_differ(const struct activemap *amp)
410 {
411
412 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
413
414 return (memcmp(amp->am_diskmap, amp->am_memmap,
415 amp->am_mapsize) != 0);
416 }
417
418 /*
419 * Function returns number of bytes used by bitmap.
420 */
421 size_t
activemap_size(const struct activemap * amp)422 activemap_size(const struct activemap *amp)
423 {
424
425 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
426
427 return (amp->am_mapsize);
428 }
429
430 /*
431 * Function returns number of bytes needed for storing on-disk bitmap.
432 * This is the same as activemap_size(), but rounded up to sector size.
433 */
434 size_t
activemap_ondisk_size(const struct activemap * amp)435 activemap_ondisk_size(const struct activemap *amp)
436 {
437
438 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
439
440 return (amp->am_diskmapsize);
441 }
442
443 /*
444 * Function copies the given buffer read from disk to the internal bitmap.
445 */
446 void
activemap_copyin(struct activemap * amp,const unsigned char * buf,size_t size)447 activemap_copyin(struct activemap *amp, const unsigned char *buf, size_t size)
448 {
449 int ext;
450
451 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
452 PJDLOG_ASSERT(size >= amp->am_mapsize);
453
454 memcpy(amp->am_diskmap, buf, amp->am_mapsize);
455 memcpy(amp->am_memmap, buf, amp->am_mapsize);
456 memcpy(amp->am_syncmap, buf, amp->am_mapsize);
457
458 bit_ffs(amp->am_memmap, amp->am_nextents, &ext);
459 if (ext == -1) {
460 /* There are no dirty extents, so we can leave now. */
461 return;
462 }
463 /*
464 * Set synchronization offset to the first dirty extent.
465 */
466 activemap_sync_rewind(amp);
467 /*
468 * We have dirty extents and we want them to stay that way until
469 * we synchronize, so we set number of pending writes to number
470 * of requests needed to synchronize one extent.
471 */
472 amp->am_ndirty = 0;
473 for (; ext < amp->am_nextents; ext++) {
474 if (bit_test(amp->am_memmap, ext)) {
475 amp->am_memtab[ext] = ext2reqs(amp, ext);
476 amp->am_ndirty++;
477 }
478 }
479 }
480
481 /*
482 * Function merges the given bitmap with existing one.
483 */
484 void
activemap_merge(struct activemap * amp,const unsigned char * buf,size_t size)485 activemap_merge(struct activemap *amp, const unsigned char *buf, size_t size)
486 {
487 bitstr_t *remmap = __DECONST(bitstr_t *, buf);
488 int ext;
489
490 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
491 PJDLOG_ASSERT(size >= amp->am_mapsize);
492
493 bit_ffs(remmap, amp->am_nextents, &ext);
494 if (ext == -1) {
495 /* There are no dirty extents, so we can leave now. */
496 return;
497 }
498 /*
499 * We have dirty extents and we want them to stay that way until
500 * we synchronize, so we set number of pending writes to number
501 * of requests needed to synchronize one extent.
502 */
503 for (; ext < amp->am_nextents; ext++) {
504 /* Local extent already dirty. */
505 if (bit_test(amp->am_syncmap, ext))
506 continue;
507 /* Remote extent isn't dirty. */
508 if (!bit_test(remmap, ext))
509 continue;
510 bit_set(amp->am_syncmap, ext);
511 bit_set(amp->am_memmap, ext);
512 bit_set(amp->am_diskmap, ext);
513 if (amp->am_memtab[ext] == 0)
514 amp->am_ndirty++;
515 amp->am_memtab[ext] = ext2reqs(amp, ext);
516 }
517 /*
518 * Set synchronization offset to the first dirty extent.
519 */
520 activemap_sync_rewind(amp);
521 }
522
523 /*
524 * Function returns pointer to internal bitmap that should be written to disk.
525 */
526 const unsigned char *
activemap_bitmap(struct activemap * amp,size_t * sizep)527 activemap_bitmap(struct activemap *amp, size_t *sizep)
528 {
529
530 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
531
532 if (sizep != NULL)
533 *sizep = amp->am_diskmapsize;
534 memcpy(amp->am_diskmap, amp->am_memmap, amp->am_mapsize);
535 keepdirty_fill(amp);
536 return ((const unsigned char *)amp->am_diskmap);
537 }
538
539 /*
540 * Function calculates size needed to store bitmap on disk.
541 */
542 size_t
activemap_calc_ondisk_size(uint64_t mediasize,uint32_t extentsize,uint32_t sectorsize)543 activemap_calc_ondisk_size(uint64_t mediasize, uint32_t extentsize,
544 uint32_t sectorsize)
545 {
546 uint64_t nextents, mapsize;
547
548 PJDLOG_ASSERT(mediasize > 0);
549 PJDLOG_ASSERT(extentsize > 0);
550 PJDLOG_ASSERT(powerof2(extentsize));
551 PJDLOG_ASSERT(sectorsize > 0);
552 PJDLOG_ASSERT(powerof2(sectorsize));
553
554 nextents = ((mediasize - 1) / extentsize) + 1;
555 mapsize = sizeof(bitstr_t) * bitstr_size(nextents);
556 return (roundup2(mapsize, sectorsize));
557 }
558
559 /*
560 * Set synchronization offset to the first dirty extent.
561 */
562 void
activemap_sync_rewind(struct activemap * amp)563 activemap_sync_rewind(struct activemap *amp)
564 {
565 int ext;
566
567 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
568
569 bit_ffs(amp->am_syncmap, amp->am_nextents, &ext);
570 if (ext == -1) {
571 /* There are no extents to synchronize. */
572 amp->am_syncoff = -2;
573 return;
574 }
575 /*
576 * Mark that we want to start synchronization from the beginning.
577 */
578 amp->am_syncoff = -1;
579 }
580
581 /*
582 * Return next offset of where we should synchronize.
583 */
584 off_t
activemap_sync_offset(struct activemap * amp,off_t * lengthp,int * syncextp)585 activemap_sync_offset(struct activemap *amp, off_t *lengthp, int *syncextp)
586 {
587 off_t syncoff, left;
588 int ext;
589
590 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
591 PJDLOG_ASSERT(lengthp != NULL);
592 PJDLOG_ASSERT(syncextp != NULL);
593
594 *syncextp = -1;
595
596 if (amp->am_syncoff == -2)
597 return (-1);
598
599 if (amp->am_syncoff >= 0 &&
600 (amp->am_syncoff + MAXPHYS >= amp->am_mediasize ||
601 off2ext(amp, amp->am_syncoff) !=
602 off2ext(amp, amp->am_syncoff + MAXPHYS))) {
603 /*
604 * We are about to change extent, so mark previous one as clean.
605 */
606 ext = off2ext(amp, amp->am_syncoff);
607 bit_clear(amp->am_syncmap, ext);
608 *syncextp = ext;
609 amp->am_syncoff = -1;
610 }
611
612 if (amp->am_syncoff == -1) {
613 /*
614 * Let's find first extent to synchronize.
615 */
616 bit_ffs(amp->am_syncmap, amp->am_nextents, &ext);
617 if (ext == -1) {
618 amp->am_syncoff = -2;
619 return (-1);
620 }
621 amp->am_syncoff = ext2off(amp, ext);
622 } else {
623 /*
624 * We don't change extent, so just increase offset.
625 */
626 amp->am_syncoff += MAXPHYS;
627 if (amp->am_syncoff >= amp->am_mediasize) {
628 amp->am_syncoff = -2;
629 return (-1);
630 }
631 }
632
633 syncoff = amp->am_syncoff;
634 left = ext2off(amp, off2ext(amp, syncoff)) +
635 amp->am_extentsize - syncoff;
636 if (syncoff + left > amp->am_mediasize)
637 left = amp->am_mediasize - syncoff;
638 if (left > MAXPHYS)
639 left = MAXPHYS;
640
641 PJDLOG_ASSERT(left >= 0 && left <= MAXPHYS);
642 PJDLOG_ASSERT(syncoff >= 0 && syncoff < amp->am_mediasize);
643 PJDLOG_ASSERT(syncoff + left >= 0 &&
644 syncoff + left <= amp->am_mediasize);
645
646 *lengthp = left;
647 return (syncoff);
648 }
649
650 /*
651 * Mark extent(s) containing the given region for synchronization.
652 * Most likely one of the components is unavailable.
653 */
654 bool
activemap_need_sync(struct activemap * amp,off_t offset,off_t length)655 activemap_need_sync(struct activemap *amp, off_t offset, off_t length)
656 {
657 bool modified;
658 off_t end;
659 int ext;
660
661 PJDLOG_ASSERT(amp->am_magic == ACTIVEMAP_MAGIC);
662
663 modified = false;
664 end = offset + length - 1;
665
666 for (ext = off2ext(amp, offset); ext <= off2ext(amp, end); ext++) {
667 if (bit_test(amp->am_syncmap, ext)) {
668 /* Already marked for synchronization. */
669 PJDLOG_ASSERT(bit_test(amp->am_memmap, ext));
670 continue;
671 }
672 bit_set(amp->am_syncmap, ext);
673 if (!bit_test(amp->am_memmap, ext)) {
674 bit_set(amp->am_memmap, ext);
675 amp->am_ndirty++;
676 }
677 amp->am_memtab[ext] += ext2reqs(amp, ext);
678 modified = true;
679 }
680
681 return (modified);
682 }
683
684 void
activemap_dump(const struct activemap * amp)685 activemap_dump(const struct activemap *amp)
686 {
687 int bit;
688
689 printf("M: ");
690 for (bit = 0; bit < amp->am_nextents; bit++)
691 printf("%d", bit_test(amp->am_memmap, bit) ? 1 : 0);
692 printf("\n");
693 printf("D: ");
694 for (bit = 0; bit < amp->am_nextents; bit++)
695 printf("%d", bit_test(amp->am_diskmap, bit) ? 1 : 0);
696 printf("\n");
697 printf("S: ");
698 for (bit = 0; bit < amp->am_nextents; bit++)
699 printf("%d", bit_test(amp->am_syncmap, bit) ? 1 : 0);
700 printf("\n");
701 }
702