1 /*-
2 * Copyright (c) 2013 Peter Grehan <grehan@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/queue.h>
34 #include <sys/errno.h>
35 #include <sys/stat.h>
36 #include <sys/ioctl.h>
37 #include <sys/disk.h>
38
39 #include <assert.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <pthread.h>
45 #include <pthread_np.h>
46 #include <signal.h>
47 #include <unistd.h>
48
49 #include <machine/atomic.h>
50
51 #include "bhyverun.h"
52 #include "mevent.h"
53 #include "block_if.h"
54
55 #define BLOCKIF_SIG 0xb109b109
56
57 #define BLOCKIF_NUMTHR 8
58 #define BLOCKIF_MAXREQ (64 + BLOCKIF_NUMTHR)
59
60 enum blockop {
61 BOP_READ,
62 BOP_WRITE,
63 BOP_FLUSH,
64 BOP_DELETE
65 };
66
67 enum blockstat {
68 BST_FREE,
69 BST_BLOCK,
70 BST_PEND,
71 BST_BUSY,
72 BST_DONE
73 };
74
75 struct blockif_elem {
76 TAILQ_ENTRY(blockif_elem) be_link;
77 struct blockif_req *be_req;
78 enum blockop be_op;
79 enum blockstat be_status;
80 pthread_t be_tid;
81 off_t be_block;
82 };
83
84 struct blockif_ctxt {
85 int bc_magic;
86 int bc_fd;
87 int bc_ischr;
88 int bc_isgeom;
89 int bc_candelete;
90 int bc_rdonly;
91 off_t bc_size;
92 int bc_sectsz;
93 int bc_psectsz;
94 int bc_psectoff;
95 int bc_closing;
96 pthread_t bc_btid[BLOCKIF_NUMTHR];
97 pthread_mutex_t bc_mtx;
98 pthread_cond_t bc_cond;
99
100 /* Request elements and free/pending/busy queues */
101 TAILQ_HEAD(, blockif_elem) bc_freeq;
102 TAILQ_HEAD(, blockif_elem) bc_pendq;
103 TAILQ_HEAD(, blockif_elem) bc_busyq;
104 struct blockif_elem bc_reqs[BLOCKIF_MAXREQ];
105 };
106
107 static pthread_once_t blockif_once = PTHREAD_ONCE_INIT;
108
109 struct blockif_sig_elem {
110 pthread_mutex_t bse_mtx;
111 pthread_cond_t bse_cond;
112 int bse_pending;
113 struct blockif_sig_elem *bse_next;
114 };
115
116 static struct blockif_sig_elem *blockif_bse_head;
117
118 static int
blockif_enqueue(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)119 blockif_enqueue(struct blockif_ctxt *bc, struct blockif_req *breq,
120 enum blockop op)
121 {
122 struct blockif_elem *be, *tbe;
123 off_t off;
124 int i;
125
126 be = TAILQ_FIRST(&bc->bc_freeq);
127 assert(be != NULL);
128 assert(be->be_status == BST_FREE);
129 TAILQ_REMOVE(&bc->bc_freeq, be, be_link);
130 be->be_req = breq;
131 be->be_op = op;
132 switch (op) {
133 case BOP_READ:
134 case BOP_WRITE:
135 case BOP_DELETE:
136 off = breq->br_offset;
137 for (i = 0; i < breq->br_iovcnt; i++)
138 off += breq->br_iov[i].iov_len;
139 break;
140 default:
141 off = OFF_MAX;
142 }
143 be->be_block = off;
144 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
145 if (tbe->be_block == breq->br_offset)
146 break;
147 }
148 if (tbe == NULL) {
149 TAILQ_FOREACH(tbe, &bc->bc_busyq, be_link) {
150 if (tbe->be_block == breq->br_offset)
151 break;
152 }
153 }
154 if (tbe == NULL)
155 be->be_status = BST_PEND;
156 else
157 be->be_status = BST_BLOCK;
158 TAILQ_INSERT_TAIL(&bc->bc_pendq, be, be_link);
159 return (be->be_status == BST_PEND);
160 }
161
162 static int
blockif_dequeue(struct blockif_ctxt * bc,pthread_t t,struct blockif_elem ** bep)163 blockif_dequeue(struct blockif_ctxt *bc, pthread_t t, struct blockif_elem **bep)
164 {
165 struct blockif_elem *be;
166
167 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
168 if (be->be_status == BST_PEND)
169 break;
170 assert(be->be_status == BST_BLOCK);
171 }
172 if (be == NULL)
173 return (0);
174 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
175 be->be_status = BST_BUSY;
176 be->be_tid = t;
177 TAILQ_INSERT_TAIL(&bc->bc_busyq, be, be_link);
178 *bep = be;
179 return (1);
180 }
181
182 static void
blockif_complete(struct blockif_ctxt * bc,struct blockif_elem * be)183 blockif_complete(struct blockif_ctxt *bc, struct blockif_elem *be)
184 {
185 struct blockif_elem *tbe;
186
187 if (be->be_status == BST_DONE || be->be_status == BST_BUSY)
188 TAILQ_REMOVE(&bc->bc_busyq, be, be_link);
189 else
190 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
191 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
192 if (tbe->be_req->br_offset == be->be_block)
193 tbe->be_status = BST_PEND;
194 }
195 be->be_tid = 0;
196 be->be_status = BST_FREE;
197 be->be_req = NULL;
198 TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link);
199 }
200
201 static void
blockif_proc(struct blockif_ctxt * bc,struct blockif_elem * be,uint8_t * buf)202 blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be, uint8_t *buf)
203 {
204 struct blockif_req *br;
205 off_t arg[2];
206 ssize_t clen, len, off, boff, voff;
207 int i, err;
208
209 br = be->be_req;
210 if (br->br_iovcnt <= 1)
211 buf = NULL;
212 err = 0;
213 switch (be->be_op) {
214 case BOP_READ:
215 if (buf == NULL) {
216 if ((len = preadv(bc->bc_fd, br->br_iov, br->br_iovcnt,
217 br->br_offset)) < 0)
218 err = errno;
219 else
220 br->br_resid -= len;
221 break;
222 }
223 i = 0;
224 off = voff = 0;
225 while (br->br_resid > 0) {
226 len = MIN(br->br_resid, MAXPHYS);
227 if (pread(bc->bc_fd, buf, len, br->br_offset +
228 off) < 0) {
229 err = errno;
230 break;
231 }
232 boff = 0;
233 do {
234 clen = MIN(len - boff, br->br_iov[i].iov_len -
235 voff);
236 memcpy(br->br_iov[i].iov_base + voff,
237 buf + boff, clen);
238 if (clen < br->br_iov[i].iov_len - voff)
239 voff += clen;
240 else {
241 i++;
242 voff = 0;
243 }
244 boff += clen;
245 } while (boff < len);
246 off += len;
247 br->br_resid -= len;
248 }
249 break;
250 case BOP_WRITE:
251 if (bc->bc_rdonly) {
252 err = EROFS;
253 break;
254 }
255 if (buf == NULL) {
256 if ((len = pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt,
257 br->br_offset)) < 0)
258 err = errno;
259 else
260 br->br_resid -= len;
261 break;
262 }
263 i = 0;
264 off = voff = 0;
265 while (br->br_resid > 0) {
266 len = MIN(br->br_resid, MAXPHYS);
267 boff = 0;
268 do {
269 clen = MIN(len - boff, br->br_iov[i].iov_len -
270 voff);
271 memcpy(buf + boff,
272 br->br_iov[i].iov_base + voff, clen);
273 if (clen < br->br_iov[i].iov_len - voff)
274 voff += clen;
275 else {
276 i++;
277 voff = 0;
278 }
279 boff += clen;
280 } while (boff < len);
281 if (pwrite(bc->bc_fd, buf, len, br->br_offset +
282 off) < 0) {
283 err = errno;
284 break;
285 }
286 off += len;
287 br->br_resid -= len;
288 }
289 break;
290 case BOP_FLUSH:
291 if (bc->bc_ischr) {
292 if (ioctl(bc->bc_fd, DIOCGFLUSH))
293 err = errno;
294 } else if (fsync(bc->bc_fd))
295 err = errno;
296 break;
297 case BOP_DELETE:
298 if (!bc->bc_candelete)
299 err = EOPNOTSUPP;
300 else if (bc->bc_rdonly)
301 err = EROFS;
302 else if (bc->bc_ischr) {
303 arg[0] = br->br_offset;
304 arg[1] = br->br_resid;
305 if (ioctl(bc->bc_fd, DIOCGDELETE, arg))
306 err = errno;
307 else
308 br->br_resid = 0;
309 } else
310 err = EOPNOTSUPP;
311 break;
312 default:
313 err = EINVAL;
314 break;
315 }
316
317 be->be_status = BST_DONE;
318
319 (*br->br_callback)(br, err);
320 }
321
322 static void *
blockif_thr(void * arg)323 blockif_thr(void *arg)
324 {
325 struct blockif_ctxt *bc;
326 struct blockif_elem *be;
327 pthread_t t;
328 uint8_t *buf;
329
330 bc = arg;
331 if (bc->bc_isgeom)
332 buf = malloc(MAXPHYS);
333 else
334 buf = NULL;
335 t = pthread_self();
336
337 pthread_mutex_lock(&bc->bc_mtx);
338 for (;;) {
339 while (blockif_dequeue(bc, t, &be)) {
340 pthread_mutex_unlock(&bc->bc_mtx);
341 blockif_proc(bc, be, buf);
342 pthread_mutex_lock(&bc->bc_mtx);
343 blockif_complete(bc, be);
344 }
345 /* Check ctxt status here to see if exit requested */
346 if (bc->bc_closing)
347 break;
348 pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx);
349 }
350 pthread_mutex_unlock(&bc->bc_mtx);
351
352 if (buf)
353 free(buf);
354 pthread_exit(NULL);
355 return (NULL);
356 }
357
358 static void
blockif_sigcont_handler(int signal,enum ev_type type,void * arg)359 blockif_sigcont_handler(int signal, enum ev_type type, void *arg)
360 {
361 struct blockif_sig_elem *bse;
362
363 for (;;) {
364 /*
365 * Process the entire list even if not intended for
366 * this thread.
367 */
368 do {
369 bse = blockif_bse_head;
370 if (bse == NULL)
371 return;
372 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
373 (uintptr_t)bse,
374 (uintptr_t)bse->bse_next));
375
376 pthread_mutex_lock(&bse->bse_mtx);
377 bse->bse_pending = 0;
378 pthread_cond_signal(&bse->bse_cond);
379 pthread_mutex_unlock(&bse->bse_mtx);
380 }
381 }
382
383 static void
blockif_init(void)384 blockif_init(void)
385 {
386 mevent_add(SIGCONT, EVF_SIGNAL, blockif_sigcont_handler, NULL);
387 (void) signal(SIGCONT, SIG_IGN);
388 }
389
390 struct blockif_ctxt *
blockif_open(const char * optstr,const char * ident)391 blockif_open(const char *optstr, const char *ident)
392 {
393 char tname[MAXCOMLEN + 1];
394 char name[MAXPATHLEN];
395 char *nopt, *xopts;
396 struct blockif_ctxt *bc;
397 struct stat sbuf;
398 struct diocgattr_arg arg;
399 off_t size, psectsz, psectoff;
400 int extra, fd, i, sectsz;
401 int nocache, sync, ro, candelete, geom;
402
403 pthread_once(&blockif_once, blockif_init);
404
405 nocache = 0;
406 sync = 0;
407 ro = 0;
408
409 /*
410 * The first element in the optstring is always a pathname.
411 * Optional elements follow
412 */
413 nopt = strdup(optstr);
414 for (xopts = strtok(nopt, ",");
415 xopts != NULL;
416 xopts = strtok(NULL, ",")) {
417 if (!strcmp(xopts, "nocache"))
418 nocache = 1;
419 else if (!strcmp(xopts, "sync"))
420 sync = 1;
421 else if (!strcmp(xopts, "ro"))
422 ro = 1;
423 }
424
425 extra = 0;
426 if (nocache)
427 extra |= O_DIRECT;
428 if (sync)
429 extra |= O_SYNC;
430
431 fd = open(nopt, (ro ? O_RDONLY : O_RDWR) | extra);
432 if (fd < 0 && !ro) {
433 /* Attempt a r/w fail with a r/o open */
434 fd = open(nopt, O_RDONLY | extra);
435 ro = 1;
436 }
437
438 if (fd < 0) {
439 perror("Could not open backing file");
440 return (NULL);
441 }
442
443 if (fstat(fd, &sbuf) < 0) {
444 perror("Could not stat backing file");
445 close(fd);
446 return (NULL);
447 }
448
449 /*
450 * Deal with raw devices
451 */
452 size = sbuf.st_size;
453 sectsz = DEV_BSIZE;
454 psectsz = psectoff = 0;
455 candelete = geom = 0;
456 if (S_ISCHR(sbuf.st_mode)) {
457 if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 ||
458 ioctl(fd, DIOCGSECTORSIZE, §sz)) {
459 perror("Could not fetch dev blk/sector size");
460 close(fd);
461 return (NULL);
462 }
463 assert(size != 0);
464 assert(sectsz != 0);
465 if (ioctl(fd, DIOCGSTRIPESIZE, &psectsz) == 0 && psectsz > 0)
466 ioctl(fd, DIOCGSTRIPEOFFSET, &psectoff);
467 strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
468 arg.len = sizeof(arg.value.i);
469 if (ioctl(fd, DIOCGATTR, &arg) == 0)
470 candelete = arg.value.i;
471 if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0)
472 geom = 1;
473 } else
474 psectsz = sbuf.st_blksize;
475
476 bc = calloc(1, sizeof(struct blockif_ctxt));
477 if (bc == NULL) {
478 close(fd);
479 return (NULL);
480 }
481
482 bc->bc_magic = BLOCKIF_SIG;
483 bc->bc_fd = fd;
484 bc->bc_ischr = S_ISCHR(sbuf.st_mode);
485 bc->bc_isgeom = geom;
486 bc->bc_candelete = candelete;
487 bc->bc_rdonly = ro;
488 bc->bc_size = size;
489 bc->bc_sectsz = sectsz;
490 bc->bc_psectsz = psectsz;
491 bc->bc_psectoff = psectoff;
492 pthread_mutex_init(&bc->bc_mtx, NULL);
493 pthread_cond_init(&bc->bc_cond, NULL);
494 TAILQ_INIT(&bc->bc_freeq);
495 TAILQ_INIT(&bc->bc_pendq);
496 TAILQ_INIT(&bc->bc_busyq);
497 for (i = 0; i < BLOCKIF_MAXREQ; i++) {
498 bc->bc_reqs[i].be_status = BST_FREE;
499 TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link);
500 }
501
502 for (i = 0; i < BLOCKIF_NUMTHR; i++) {
503 pthread_create(&bc->bc_btid[i], NULL, blockif_thr, bc);
504 snprintf(tname, sizeof(tname), "blk-%s-%d", ident, i);
505 pthread_set_name_np(bc->bc_btid[i], tname);
506 }
507
508 return (bc);
509 }
510
511 static int
blockif_request(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)512 blockif_request(struct blockif_ctxt *bc, struct blockif_req *breq,
513 enum blockop op)
514 {
515 int err;
516
517 err = 0;
518
519 pthread_mutex_lock(&bc->bc_mtx);
520 if (!TAILQ_EMPTY(&bc->bc_freeq)) {
521 /*
522 * Enqueue and inform the block i/o thread
523 * that there is work available
524 */
525 if (blockif_enqueue(bc, breq, op))
526 pthread_cond_signal(&bc->bc_cond);
527 } else {
528 /*
529 * Callers are not allowed to enqueue more than
530 * the specified blockif queue limit. Return an
531 * error to indicate that the queue length has been
532 * exceeded.
533 */
534 err = E2BIG;
535 }
536 pthread_mutex_unlock(&bc->bc_mtx);
537
538 return (err);
539 }
540
541 int
blockif_read(struct blockif_ctxt * bc,struct blockif_req * breq)542 blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq)
543 {
544
545 assert(bc->bc_magic == BLOCKIF_SIG);
546 return (blockif_request(bc, breq, BOP_READ));
547 }
548
549 int
blockif_write(struct blockif_ctxt * bc,struct blockif_req * breq)550 blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq)
551 {
552
553 assert(bc->bc_magic == BLOCKIF_SIG);
554 return (blockif_request(bc, breq, BOP_WRITE));
555 }
556
557 int
blockif_flush(struct blockif_ctxt * bc,struct blockif_req * breq)558 blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq)
559 {
560
561 assert(bc->bc_magic == BLOCKIF_SIG);
562 return (blockif_request(bc, breq, BOP_FLUSH));
563 }
564
565 int
blockif_delete(struct blockif_ctxt * bc,struct blockif_req * breq)566 blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq)
567 {
568
569 assert(bc->bc_magic == BLOCKIF_SIG);
570 return (blockif_request(bc, breq, BOP_DELETE));
571 }
572
573 int
blockif_cancel(struct blockif_ctxt * bc,struct blockif_req * breq)574 blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq)
575 {
576 struct blockif_elem *be;
577
578 assert(bc->bc_magic == BLOCKIF_SIG);
579
580 pthread_mutex_lock(&bc->bc_mtx);
581 /*
582 * Check pending requests.
583 */
584 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
585 if (be->be_req == breq)
586 break;
587 }
588 if (be != NULL) {
589 /*
590 * Found it.
591 */
592 blockif_complete(bc, be);
593 pthread_mutex_unlock(&bc->bc_mtx);
594
595 return (0);
596 }
597
598 /*
599 * Check in-flight requests.
600 */
601 TAILQ_FOREACH(be, &bc->bc_busyq, be_link) {
602 if (be->be_req == breq)
603 break;
604 }
605 if (be == NULL) {
606 /*
607 * Didn't find it.
608 */
609 pthread_mutex_unlock(&bc->bc_mtx);
610 return (EINVAL);
611 }
612
613 /*
614 * Interrupt the processing thread to force it return
615 * prematurely via it's normal callback path.
616 */
617 while (be->be_status == BST_BUSY) {
618 struct blockif_sig_elem bse, *old_head;
619
620 pthread_mutex_init(&bse.bse_mtx, NULL);
621 pthread_cond_init(&bse.bse_cond, NULL);
622
623 bse.bse_pending = 1;
624
625 do {
626 old_head = blockif_bse_head;
627 bse.bse_next = old_head;
628 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
629 (uintptr_t)old_head,
630 (uintptr_t)&bse));
631
632 pthread_kill(be->be_tid, SIGCONT);
633
634 pthread_mutex_lock(&bse.bse_mtx);
635 while (bse.bse_pending)
636 pthread_cond_wait(&bse.bse_cond, &bse.bse_mtx);
637 pthread_mutex_unlock(&bse.bse_mtx);
638 }
639
640 pthread_mutex_unlock(&bc->bc_mtx);
641
642 /*
643 * The processing thread has been interrupted. Since it's not
644 * clear if the callback has been invoked yet, return EBUSY.
645 */
646 return (EBUSY);
647 }
648
649 int
blockif_close(struct blockif_ctxt * bc)650 blockif_close(struct blockif_ctxt *bc)
651 {
652 void *jval;
653 int err, i;
654
655 err = 0;
656
657 assert(bc->bc_magic == BLOCKIF_SIG);
658
659 /*
660 * Stop the block i/o thread
661 */
662 pthread_mutex_lock(&bc->bc_mtx);
663 bc->bc_closing = 1;
664 pthread_mutex_unlock(&bc->bc_mtx);
665 pthread_cond_broadcast(&bc->bc_cond);
666 for (i = 0; i < BLOCKIF_NUMTHR; i++)
667 pthread_join(bc->bc_btid[i], &jval);
668
669 /* XXX Cancel queued i/o's ??? */
670
671 /*
672 * Release resources
673 */
674 bc->bc_magic = 0;
675 close(bc->bc_fd);
676 free(bc);
677
678 return (0);
679 }
680
681 /*
682 * Return virtual C/H/S values for a given block. Use the algorithm
683 * outlined in the VHD specification to calculate values.
684 */
685 void
blockif_chs(struct blockif_ctxt * bc,uint16_t * c,uint8_t * h,uint8_t * s)686 blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s)
687 {
688 off_t sectors; /* total sectors of the block dev */
689 off_t hcyl; /* cylinders times heads */
690 uint16_t secpt; /* sectors per track */
691 uint8_t heads;
692
693 assert(bc->bc_magic == BLOCKIF_SIG);
694
695 sectors = bc->bc_size / bc->bc_sectsz;
696
697 /* Clamp the size to the largest possible with CHS */
698 if (sectors > 65535UL*16*255)
699 sectors = 65535UL*16*255;
700
701 if (sectors >= 65536UL*16*63) {
702 secpt = 255;
703 heads = 16;
704 hcyl = sectors / secpt;
705 } else {
706 secpt = 17;
707 hcyl = sectors / secpt;
708 heads = (hcyl + 1023) / 1024;
709
710 if (heads < 4)
711 heads = 4;
712
713 if (hcyl >= (heads * 1024) || heads > 16) {
714 secpt = 31;
715 heads = 16;
716 hcyl = sectors / secpt;
717 }
718 if (hcyl >= (heads * 1024)) {
719 secpt = 63;
720 heads = 16;
721 hcyl = sectors / secpt;
722 }
723 }
724
725 *c = hcyl / heads;
726 *h = heads;
727 *s = secpt;
728 }
729
730 /*
731 * Accessors
732 */
733 off_t
blockif_size(struct blockif_ctxt * bc)734 blockif_size(struct blockif_ctxt *bc)
735 {
736
737 assert(bc->bc_magic == BLOCKIF_SIG);
738 return (bc->bc_size);
739 }
740
741 int
blockif_sectsz(struct blockif_ctxt * bc)742 blockif_sectsz(struct blockif_ctxt *bc)
743 {
744
745 assert(bc->bc_magic == BLOCKIF_SIG);
746 return (bc->bc_sectsz);
747 }
748
749 void
blockif_psectsz(struct blockif_ctxt * bc,int * size,int * off)750 blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off)
751 {
752
753 assert(bc->bc_magic == BLOCKIF_SIG);
754 *size = bc->bc_psectsz;
755 *off = bc->bc_psectoff;
756 }
757
758 int
blockif_queuesz(struct blockif_ctxt * bc)759 blockif_queuesz(struct blockif_ctxt *bc)
760 {
761
762 assert(bc->bc_magic == BLOCKIF_SIG);
763 return (BLOCKIF_MAXREQ - 1);
764 }
765
766 int
blockif_is_ro(struct blockif_ctxt * bc)767 blockif_is_ro(struct blockif_ctxt *bc)
768 {
769
770 assert(bc->bc_magic == BLOCKIF_SIG);
771 return (bc->bc_rdonly);
772 }
773
774 int
blockif_candelete(struct blockif_ctxt * bc)775 blockif_candelete(struct blockif_ctxt *bc)
776 {
777
778 assert(bc->bc_magic == BLOCKIF_SIG);
779 return (bc->bc_candelete);
780 }
781