1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2013 Peter Grehan <grehan@freebsd.org>
5 * 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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 #include <sys/param.h>
35 #ifndef WITHOUT_CAPSICUM
36 #include <sys/capsicum.h>
37 #endif
38 #include <sys/queue.h>
39 #include <sys/errno.h>
40 #include <sys/stat.h>
41 #include <sys/ioctl.h>
42 #include <sys/disk.h>
43
44 #include <assert.h>
45 #include <err.h>
46 #include <fcntl.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <pthread.h>
51 #include <pthread_np.h>
52 #include <signal.h>
53 #include <sysexits.h>
54 #include <unistd.h>
55
56 #include <machine/atomic.h>
57
58 #include "bhyverun.h"
59 #include "mevent.h"
60 #include "block_if.h"
61
62 #define BLOCKIF_SIG 0xb109b109
63
64 #define BLOCKIF_NUMTHR 8
65 #define BLOCKIF_MAXREQ (BLOCKIF_RING_MAX + BLOCKIF_NUMTHR)
66
67 enum blockop {
68 BOP_READ,
69 BOP_WRITE,
70 BOP_FLUSH,
71 BOP_DELETE
72 };
73
74 enum blockstat {
75 BST_FREE,
76 BST_BLOCK,
77 BST_PEND,
78 BST_BUSY,
79 BST_DONE
80 };
81
82 struct blockif_elem {
83 TAILQ_ENTRY(blockif_elem) be_link;
84 struct blockif_req *be_req;
85 enum blockop be_op;
86 enum blockstat be_status;
87 pthread_t be_tid;
88 off_t be_block;
89 };
90
91 struct blockif_ctxt {
92 int bc_magic;
93 int bc_fd;
94 int bc_ischr;
95 int bc_isgeom;
96 int bc_candelete;
97 int bc_rdonly;
98 off_t bc_size;
99 int bc_sectsz;
100 int bc_psectsz;
101 int bc_psectoff;
102 int bc_closing;
103 pthread_t bc_btid[BLOCKIF_NUMTHR];
104 pthread_mutex_t bc_mtx;
105 pthread_cond_t bc_cond;
106
107 /* Request elements and free/pending/busy queues */
108 TAILQ_HEAD(, blockif_elem) bc_freeq;
109 TAILQ_HEAD(, blockif_elem) bc_pendq;
110 TAILQ_HEAD(, blockif_elem) bc_busyq;
111 struct blockif_elem bc_reqs[BLOCKIF_MAXREQ];
112 };
113
114 static pthread_once_t blockif_once = PTHREAD_ONCE_INIT;
115
116 struct blockif_sig_elem {
117 pthread_mutex_t bse_mtx;
118 pthread_cond_t bse_cond;
119 int bse_pending;
120 struct blockif_sig_elem *bse_next;
121 };
122
123 static struct blockif_sig_elem *blockif_bse_head;
124
125 static int
blockif_enqueue(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)126 blockif_enqueue(struct blockif_ctxt *bc, struct blockif_req *breq,
127 enum blockop op)
128 {
129 struct blockif_elem *be, *tbe;
130 off_t off;
131 int i;
132
133 be = TAILQ_FIRST(&bc->bc_freeq);
134 assert(be != NULL);
135 assert(be->be_status == BST_FREE);
136 TAILQ_REMOVE(&bc->bc_freeq, be, be_link);
137 be->be_req = breq;
138 be->be_op = op;
139 switch (op) {
140 case BOP_READ:
141 case BOP_WRITE:
142 case BOP_DELETE:
143 off = breq->br_offset;
144 for (i = 0; i < breq->br_iovcnt; i++)
145 off += breq->br_iov[i].iov_len;
146 break;
147 default:
148 off = OFF_MAX;
149 }
150 be->be_block = off;
151 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
152 if (tbe->be_block == breq->br_offset)
153 break;
154 }
155 if (tbe == NULL) {
156 TAILQ_FOREACH(tbe, &bc->bc_busyq, be_link) {
157 if (tbe->be_block == breq->br_offset)
158 break;
159 }
160 }
161 if (tbe == NULL)
162 be->be_status = BST_PEND;
163 else
164 be->be_status = BST_BLOCK;
165 TAILQ_INSERT_TAIL(&bc->bc_pendq, be, be_link);
166 return (be->be_status == BST_PEND);
167 }
168
169 static int
blockif_dequeue(struct blockif_ctxt * bc,pthread_t t,struct blockif_elem ** bep)170 blockif_dequeue(struct blockif_ctxt *bc, pthread_t t, struct blockif_elem **bep)
171 {
172 struct blockif_elem *be;
173
174 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
175 if (be->be_status == BST_PEND)
176 break;
177 assert(be->be_status == BST_BLOCK);
178 }
179 if (be == NULL)
180 return (0);
181 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
182 be->be_status = BST_BUSY;
183 be->be_tid = t;
184 TAILQ_INSERT_TAIL(&bc->bc_busyq, be, be_link);
185 *bep = be;
186 return (1);
187 }
188
189 static void
blockif_complete(struct blockif_ctxt * bc,struct blockif_elem * be)190 blockif_complete(struct blockif_ctxt *bc, struct blockif_elem *be)
191 {
192 struct blockif_elem *tbe;
193
194 if (be->be_status == BST_DONE || be->be_status == BST_BUSY)
195 TAILQ_REMOVE(&bc->bc_busyq, be, be_link);
196 else
197 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
198 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
199 if (tbe->be_req->br_offset == be->be_block)
200 tbe->be_status = BST_PEND;
201 }
202 be->be_tid = 0;
203 be->be_status = BST_FREE;
204 be->be_req = NULL;
205 TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link);
206 }
207
208 static void
blockif_proc(struct blockif_ctxt * bc,struct blockif_elem * be,uint8_t * buf)209 blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be, uint8_t *buf)
210 {
211 struct blockif_req *br;
212 off_t arg[2];
213 ssize_t clen, len, off, boff, voff;
214 int i, err;
215
216 br = be->be_req;
217 if (br->br_iovcnt <= 1)
218 buf = NULL;
219 err = 0;
220 switch (be->be_op) {
221 case BOP_READ:
222 if (buf == NULL) {
223 if ((len = preadv(bc->bc_fd, br->br_iov, br->br_iovcnt,
224 br->br_offset)) < 0)
225 err = errno;
226 else
227 br->br_resid -= len;
228 break;
229 }
230 i = 0;
231 off = voff = 0;
232 while (br->br_resid > 0) {
233 len = MIN(br->br_resid, MAXPHYS);
234 if (pread(bc->bc_fd, buf, len, br->br_offset +
235 off) < 0) {
236 err = errno;
237 break;
238 }
239 boff = 0;
240 do {
241 clen = MIN(len - boff, br->br_iov[i].iov_len -
242 voff);
243 memcpy(br->br_iov[i].iov_base + voff,
244 buf + boff, clen);
245 if (clen < br->br_iov[i].iov_len - voff)
246 voff += clen;
247 else {
248 i++;
249 voff = 0;
250 }
251 boff += clen;
252 } while (boff < len);
253 off += len;
254 br->br_resid -= len;
255 }
256 break;
257 case BOP_WRITE:
258 if (bc->bc_rdonly) {
259 err = EROFS;
260 break;
261 }
262 if (buf == NULL) {
263 if ((len = pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt,
264 br->br_offset)) < 0)
265 err = errno;
266 else
267 br->br_resid -= len;
268 break;
269 }
270 i = 0;
271 off = voff = 0;
272 while (br->br_resid > 0) {
273 len = MIN(br->br_resid, MAXPHYS);
274 boff = 0;
275 do {
276 clen = MIN(len - boff, br->br_iov[i].iov_len -
277 voff);
278 memcpy(buf + boff,
279 br->br_iov[i].iov_base + voff, clen);
280 if (clen < br->br_iov[i].iov_len - voff)
281 voff += clen;
282 else {
283 i++;
284 voff = 0;
285 }
286 boff += clen;
287 } while (boff < len);
288 if (pwrite(bc->bc_fd, buf, len, br->br_offset +
289 off) < 0) {
290 err = errno;
291 break;
292 }
293 off += len;
294 br->br_resid -= len;
295 }
296 break;
297 case BOP_FLUSH:
298 if (bc->bc_ischr) {
299 if (ioctl(bc->bc_fd, DIOCGFLUSH))
300 err = errno;
301 } else if (fsync(bc->bc_fd))
302 err = errno;
303 break;
304 case BOP_DELETE:
305 if (!bc->bc_candelete)
306 err = EOPNOTSUPP;
307 else if (bc->bc_rdonly)
308 err = EROFS;
309 else if (bc->bc_ischr) {
310 arg[0] = br->br_offset;
311 arg[1] = br->br_resid;
312 if (ioctl(bc->bc_fd, DIOCGDELETE, arg))
313 err = errno;
314 else
315 br->br_resid = 0;
316 } else
317 err = EOPNOTSUPP;
318 break;
319 default:
320 err = EINVAL;
321 break;
322 }
323
324 be->be_status = BST_DONE;
325
326 (*br->br_callback)(br, err);
327 }
328
329 static void *
blockif_thr(void * arg)330 blockif_thr(void *arg)
331 {
332 struct blockif_ctxt *bc;
333 struct blockif_elem *be;
334 pthread_t t;
335 uint8_t *buf;
336
337 bc = arg;
338 if (bc->bc_isgeom)
339 buf = malloc(MAXPHYS);
340 else
341 buf = NULL;
342 t = pthread_self();
343
344 pthread_mutex_lock(&bc->bc_mtx);
345 for (;;) {
346 while (blockif_dequeue(bc, t, &be)) {
347 pthread_mutex_unlock(&bc->bc_mtx);
348 blockif_proc(bc, be, buf);
349 pthread_mutex_lock(&bc->bc_mtx);
350 blockif_complete(bc, be);
351 }
352 /* Check ctxt status here to see if exit requested */
353 if (bc->bc_closing)
354 break;
355 pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx);
356 }
357 pthread_mutex_unlock(&bc->bc_mtx);
358
359 if (buf)
360 free(buf);
361 pthread_exit(NULL);
362 return (NULL);
363 }
364
365 static void
blockif_sigcont_handler(int signal,enum ev_type type,void * arg)366 blockif_sigcont_handler(int signal, enum ev_type type, void *arg)
367 {
368 struct blockif_sig_elem *bse;
369
370 for (;;) {
371 /*
372 * Process the entire list even if not intended for
373 * this thread.
374 */
375 do {
376 bse = blockif_bse_head;
377 if (bse == NULL)
378 return;
379 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
380 (uintptr_t)bse,
381 (uintptr_t)bse->bse_next));
382
383 pthread_mutex_lock(&bse->bse_mtx);
384 bse->bse_pending = 0;
385 pthread_cond_signal(&bse->bse_cond);
386 pthread_mutex_unlock(&bse->bse_mtx);
387 }
388 }
389
390 static void
blockif_init(void)391 blockif_init(void)
392 {
393 mevent_add(SIGCONT, EVF_SIGNAL, blockif_sigcont_handler, NULL);
394 (void) signal(SIGCONT, SIG_IGN);
395 }
396
397 struct blockif_ctxt *
blockif_open(const char * optstr,const char * ident)398 blockif_open(const char *optstr, const char *ident)
399 {
400 char tname[MAXCOMLEN + 1];
401 char name[MAXPATHLEN];
402 char *nopt, *xopts, *cp;
403 struct blockif_ctxt *bc;
404 struct stat sbuf;
405 struct diocgattr_arg arg;
406 off_t size, psectsz, psectoff;
407 int extra, fd, i, sectsz;
408 int nocache, sync, ro, candelete, geom, ssopt, pssopt;
409 #ifndef WITHOUT_CAPSICUM
410 cap_rights_t rights;
411 cap_ioctl_t cmds[] = { DIOCGFLUSH, DIOCGDELETE };
412 #endif
413
414 pthread_once(&blockif_once, blockif_init);
415
416 fd = -1;
417 ssopt = 0;
418 nocache = 0;
419 sync = 0;
420 ro = 0;
421
422 /*
423 * The first element in the optstring is always a pathname.
424 * Optional elements follow
425 */
426 nopt = xopts = strdup(optstr);
427 while (xopts != NULL) {
428 cp = strsep(&xopts, ",");
429 if (cp == nopt) /* file or device pathname */
430 continue;
431 else if (!strcmp(cp, "nocache"))
432 nocache = 1;
433 else if (!strcmp(cp, "sync") || !strcmp(cp, "direct"))
434 sync = 1;
435 else if (!strcmp(cp, "ro"))
436 ro = 1;
437 else if (sscanf(cp, "sectorsize=%d/%d", &ssopt, &pssopt) == 2)
438 ;
439 else if (sscanf(cp, "sectorsize=%d", &ssopt) == 1)
440 pssopt = ssopt;
441 else {
442 fprintf(stderr, "Invalid device option \"%s\"\n", cp);
443 goto err;
444 }
445 }
446
447 extra = 0;
448 if (nocache)
449 extra |= O_DIRECT;
450 if (sync)
451 extra |= O_SYNC;
452
453 fd = open(nopt, (ro ? O_RDONLY : O_RDWR) | extra);
454 if (fd < 0 && !ro) {
455 /* Attempt a r/w fail with a r/o open */
456 fd = open(nopt, O_RDONLY | extra);
457 ro = 1;
458 }
459
460 if (fd < 0) {
461 warn("Could not open backing file: %s", nopt);
462 goto err;
463 }
464
465 if (fstat(fd, &sbuf) < 0) {
466 warn("Could not stat backing file %s", nopt);
467 goto err;
468 }
469
470 #ifndef WITHOUT_CAPSICUM
471 cap_rights_init(&rights, CAP_FSYNC, CAP_IOCTL, CAP_READ, CAP_SEEK,
472 CAP_WRITE);
473 if (ro)
474 cap_rights_clear(&rights, CAP_FSYNC, CAP_WRITE);
475
476 if (cap_rights_limit(fd, &rights) == -1 && errno != ENOSYS)
477 errx(EX_OSERR, "Unable to apply rights for sandbox");
478 #endif
479
480 /*
481 * Deal with raw devices
482 */
483 size = sbuf.st_size;
484 sectsz = DEV_BSIZE;
485 psectsz = psectoff = 0;
486 candelete = geom = 0;
487 if (S_ISCHR(sbuf.st_mode)) {
488 if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 ||
489 ioctl(fd, DIOCGSECTORSIZE, §sz)) {
490 perror("Could not fetch dev blk/sector size");
491 goto err;
492 }
493 assert(size != 0);
494 assert(sectsz != 0);
495 if (ioctl(fd, DIOCGSTRIPESIZE, &psectsz) == 0 && psectsz > 0)
496 ioctl(fd, DIOCGSTRIPEOFFSET, &psectoff);
497 strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
498 arg.len = sizeof(arg.value.i);
499 if (ioctl(fd, DIOCGATTR, &arg) == 0)
500 candelete = arg.value.i;
501 if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0)
502 geom = 1;
503 } else
504 psectsz = sbuf.st_blksize;
505
506 #ifndef WITHOUT_CAPSICUM
507 if (cap_ioctls_limit(fd, cmds, nitems(cmds)) == -1 && errno != ENOSYS)
508 errx(EX_OSERR, "Unable to apply rights for sandbox");
509 #endif
510
511 if (ssopt != 0) {
512 if (!powerof2(ssopt) || !powerof2(pssopt) || ssopt < 512 ||
513 ssopt > pssopt) {
514 fprintf(stderr, "Invalid sector size %d/%d\n",
515 ssopt, pssopt);
516 goto err;
517 }
518
519 /*
520 * Some backend drivers (e.g. cd0, ada0) require that the I/O
521 * size be a multiple of the device's sector size.
522 *
523 * Validate that the emulated sector size complies with this
524 * requirement.
525 */
526 if (S_ISCHR(sbuf.st_mode)) {
527 if (ssopt < sectsz || (ssopt % sectsz) != 0) {
528 fprintf(stderr, "Sector size %d incompatible "
529 "with underlying device sector size %d\n",
530 ssopt, sectsz);
531 goto err;
532 }
533 }
534
535 sectsz = ssopt;
536 psectsz = pssopt;
537 psectoff = 0;
538 }
539
540 bc = calloc(1, sizeof(struct blockif_ctxt));
541 if (bc == NULL) {
542 perror("calloc");
543 goto err;
544 }
545
546 bc->bc_magic = BLOCKIF_SIG;
547 bc->bc_fd = fd;
548 bc->bc_ischr = S_ISCHR(sbuf.st_mode);
549 bc->bc_isgeom = geom;
550 bc->bc_candelete = candelete;
551 bc->bc_rdonly = ro;
552 bc->bc_size = size;
553 bc->bc_sectsz = sectsz;
554 bc->bc_psectsz = psectsz;
555 bc->bc_psectoff = psectoff;
556 pthread_mutex_init(&bc->bc_mtx, NULL);
557 pthread_cond_init(&bc->bc_cond, NULL);
558 TAILQ_INIT(&bc->bc_freeq);
559 TAILQ_INIT(&bc->bc_pendq);
560 TAILQ_INIT(&bc->bc_busyq);
561 for (i = 0; i < BLOCKIF_MAXREQ; i++) {
562 bc->bc_reqs[i].be_status = BST_FREE;
563 TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link);
564 }
565
566 for (i = 0; i < BLOCKIF_NUMTHR; i++) {
567 pthread_create(&bc->bc_btid[i], NULL, blockif_thr, bc);
568 snprintf(tname, sizeof(tname), "blk-%s-%d", ident, i);
569 pthread_set_name_np(bc->bc_btid[i], tname);
570 }
571
572 return (bc);
573 err:
574 if (fd >= 0)
575 close(fd);
576 return (NULL);
577 }
578
579 static int
blockif_request(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)580 blockif_request(struct blockif_ctxt *bc, struct blockif_req *breq,
581 enum blockop op)
582 {
583 int err;
584
585 err = 0;
586
587 pthread_mutex_lock(&bc->bc_mtx);
588 if (!TAILQ_EMPTY(&bc->bc_freeq)) {
589 /*
590 * Enqueue and inform the block i/o thread
591 * that there is work available
592 */
593 if (blockif_enqueue(bc, breq, op))
594 pthread_cond_signal(&bc->bc_cond);
595 } else {
596 /*
597 * Callers are not allowed to enqueue more than
598 * the specified blockif queue limit. Return an
599 * error to indicate that the queue length has been
600 * exceeded.
601 */
602 err = E2BIG;
603 }
604 pthread_mutex_unlock(&bc->bc_mtx);
605
606 return (err);
607 }
608
609 int
blockif_read(struct blockif_ctxt * bc,struct blockif_req * breq)610 blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq)
611 {
612
613 assert(bc->bc_magic == BLOCKIF_SIG);
614 return (blockif_request(bc, breq, BOP_READ));
615 }
616
617 int
blockif_write(struct blockif_ctxt * bc,struct blockif_req * breq)618 blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq)
619 {
620
621 assert(bc->bc_magic == BLOCKIF_SIG);
622 return (blockif_request(bc, breq, BOP_WRITE));
623 }
624
625 int
blockif_flush(struct blockif_ctxt * bc,struct blockif_req * breq)626 blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq)
627 {
628
629 assert(bc->bc_magic == BLOCKIF_SIG);
630 return (blockif_request(bc, breq, BOP_FLUSH));
631 }
632
633 int
blockif_delete(struct blockif_ctxt * bc,struct blockif_req * breq)634 blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq)
635 {
636
637 assert(bc->bc_magic == BLOCKIF_SIG);
638 return (blockif_request(bc, breq, BOP_DELETE));
639 }
640
641 int
blockif_cancel(struct blockif_ctxt * bc,struct blockif_req * breq)642 blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq)
643 {
644 struct blockif_elem *be;
645
646 assert(bc->bc_magic == BLOCKIF_SIG);
647
648 pthread_mutex_lock(&bc->bc_mtx);
649 /*
650 * Check pending requests.
651 */
652 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
653 if (be->be_req == breq)
654 break;
655 }
656 if (be != NULL) {
657 /*
658 * Found it.
659 */
660 blockif_complete(bc, be);
661 pthread_mutex_unlock(&bc->bc_mtx);
662
663 return (0);
664 }
665
666 /*
667 * Check in-flight requests.
668 */
669 TAILQ_FOREACH(be, &bc->bc_busyq, be_link) {
670 if (be->be_req == breq)
671 break;
672 }
673 if (be == NULL) {
674 /*
675 * Didn't find it.
676 */
677 pthread_mutex_unlock(&bc->bc_mtx);
678 return (EINVAL);
679 }
680
681 /*
682 * Interrupt the processing thread to force it return
683 * prematurely via it's normal callback path.
684 */
685 while (be->be_status == BST_BUSY) {
686 struct blockif_sig_elem bse, *old_head;
687
688 pthread_mutex_init(&bse.bse_mtx, NULL);
689 pthread_cond_init(&bse.bse_cond, NULL);
690
691 bse.bse_pending = 1;
692
693 do {
694 old_head = blockif_bse_head;
695 bse.bse_next = old_head;
696 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
697 (uintptr_t)old_head,
698 (uintptr_t)&bse));
699
700 pthread_kill(be->be_tid, SIGCONT);
701
702 pthread_mutex_lock(&bse.bse_mtx);
703 while (bse.bse_pending)
704 pthread_cond_wait(&bse.bse_cond, &bse.bse_mtx);
705 pthread_mutex_unlock(&bse.bse_mtx);
706 }
707
708 pthread_mutex_unlock(&bc->bc_mtx);
709
710 /*
711 * The processing thread has been interrupted. Since it's not
712 * clear if the callback has been invoked yet, return EBUSY.
713 */
714 return (EBUSY);
715 }
716
717 int
blockif_close(struct blockif_ctxt * bc)718 blockif_close(struct blockif_ctxt *bc)
719 {
720 void *jval;
721 int i;
722
723 assert(bc->bc_magic == BLOCKIF_SIG);
724
725 /*
726 * Stop the block i/o thread
727 */
728 pthread_mutex_lock(&bc->bc_mtx);
729 bc->bc_closing = 1;
730 pthread_mutex_unlock(&bc->bc_mtx);
731 pthread_cond_broadcast(&bc->bc_cond);
732 for (i = 0; i < BLOCKIF_NUMTHR; i++)
733 pthread_join(bc->bc_btid[i], &jval);
734
735 /* XXX Cancel queued i/o's ??? */
736
737 /*
738 * Release resources
739 */
740 bc->bc_magic = 0;
741 close(bc->bc_fd);
742 free(bc);
743
744 return (0);
745 }
746
747 /*
748 * Return virtual C/H/S values for a given block. Use the algorithm
749 * outlined in the VHD specification to calculate values.
750 */
751 void
blockif_chs(struct blockif_ctxt * bc,uint16_t * c,uint8_t * h,uint8_t * s)752 blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s)
753 {
754 off_t sectors; /* total sectors of the block dev */
755 off_t hcyl; /* cylinders times heads */
756 uint16_t secpt; /* sectors per track */
757 uint8_t heads;
758
759 assert(bc->bc_magic == BLOCKIF_SIG);
760
761 sectors = bc->bc_size / bc->bc_sectsz;
762
763 /* Clamp the size to the largest possible with CHS */
764 if (sectors > 65535UL*16*255)
765 sectors = 65535UL*16*255;
766
767 if (sectors >= 65536UL*16*63) {
768 secpt = 255;
769 heads = 16;
770 hcyl = sectors / secpt;
771 } else {
772 secpt = 17;
773 hcyl = sectors / secpt;
774 heads = (hcyl + 1023) / 1024;
775
776 if (heads < 4)
777 heads = 4;
778
779 if (hcyl >= (heads * 1024) || heads > 16) {
780 secpt = 31;
781 heads = 16;
782 hcyl = sectors / secpt;
783 }
784 if (hcyl >= (heads * 1024)) {
785 secpt = 63;
786 heads = 16;
787 hcyl = sectors / secpt;
788 }
789 }
790
791 *c = hcyl / heads;
792 *h = heads;
793 *s = secpt;
794 }
795
796 /*
797 * Accessors
798 */
799 off_t
blockif_size(struct blockif_ctxt * bc)800 blockif_size(struct blockif_ctxt *bc)
801 {
802
803 assert(bc->bc_magic == BLOCKIF_SIG);
804 return (bc->bc_size);
805 }
806
807 int
blockif_sectsz(struct blockif_ctxt * bc)808 blockif_sectsz(struct blockif_ctxt *bc)
809 {
810
811 assert(bc->bc_magic == BLOCKIF_SIG);
812 return (bc->bc_sectsz);
813 }
814
815 void
blockif_psectsz(struct blockif_ctxt * bc,int * size,int * off)816 blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off)
817 {
818
819 assert(bc->bc_magic == BLOCKIF_SIG);
820 *size = bc->bc_psectsz;
821 *off = bc->bc_psectoff;
822 }
823
824 int
blockif_queuesz(struct blockif_ctxt * bc)825 blockif_queuesz(struct blockif_ctxt *bc)
826 {
827
828 assert(bc->bc_magic == BLOCKIF_SIG);
829 return (BLOCKIF_MAXREQ - 1);
830 }
831
832 int
blockif_is_ro(struct blockif_ctxt * bc)833 blockif_is_ro(struct blockif_ctxt *bc)
834 {
835
836 assert(bc->bc_magic == BLOCKIF_SIG);
837 return (bc->bc_rdonly);
838 }
839
840 int
blockif_candelete(struct blockif_ctxt * bc)841 blockif_candelete(struct blockif_ctxt *bc)
842 {
843
844 assert(bc->bc_magic == BLOCKIF_SIG);
845 return (bc->bc_candelete);
846 }
847