1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2013 Peter Grehan <[email protected]>
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 #ifndef WITHOUT_CAPSICUM
46 #include <capsicum_helpers.h>
47 #endif
48 #include <err.h>
49 #include <fcntl.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <pthread.h>
54 #include <pthread_np.h>
55 #include <signal.h>
56 #include <sysexits.h>
57 #include <unistd.h>
58
59 #include <machine/atomic.h>
60
61 #include "bhyverun.h"
62 #include "mevent.h"
63 #include "block_if.h"
64
65 #define BLOCKIF_SIG 0xb109b109
66
67 #define BLOCKIF_NUMTHR 8
68 #define BLOCKIF_MAXREQ (BLOCKIF_RING_MAX + BLOCKIF_NUMTHR)
69
70 enum blockop {
71 BOP_READ,
72 BOP_WRITE,
73 BOP_FLUSH,
74 BOP_DELETE
75 };
76
77 enum blockstat {
78 BST_FREE,
79 BST_BLOCK,
80 BST_PEND,
81 BST_BUSY,
82 BST_DONE
83 };
84
85 struct blockif_elem {
86 TAILQ_ENTRY(blockif_elem) be_link;
87 struct blockif_req *be_req;
88 enum blockop be_op;
89 enum blockstat be_status;
90 pthread_t be_tid;
91 off_t be_block;
92 };
93
94 struct blockif_ctxt {
95 int bc_magic;
96 int bc_fd;
97 int bc_ischr;
98 int bc_isgeom;
99 int bc_candelete;
100 int bc_rdonly;
101 off_t bc_size;
102 int bc_sectsz;
103 int bc_psectsz;
104 int bc_psectoff;
105 int bc_closing;
106 pthread_t bc_btid[BLOCKIF_NUMTHR];
107 pthread_mutex_t bc_mtx;
108 pthread_cond_t bc_cond;
109
110 /* Request elements and free/pending/busy queues */
111 TAILQ_HEAD(, blockif_elem) bc_freeq;
112 TAILQ_HEAD(, blockif_elem) bc_pendq;
113 TAILQ_HEAD(, blockif_elem) bc_busyq;
114 struct blockif_elem bc_reqs[BLOCKIF_MAXREQ];
115 };
116
117 static pthread_once_t blockif_once = PTHREAD_ONCE_INIT;
118
119 struct blockif_sig_elem {
120 pthread_mutex_t bse_mtx;
121 pthread_cond_t bse_cond;
122 int bse_pending;
123 struct blockif_sig_elem *bse_next;
124 };
125
126 static struct blockif_sig_elem *blockif_bse_head;
127
128 static int
blockif_enqueue(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)129 blockif_enqueue(struct blockif_ctxt *bc, struct blockif_req *breq,
130 enum blockop op)
131 {
132 struct blockif_elem *be, *tbe;
133 off_t off;
134 int i;
135
136 be = TAILQ_FIRST(&bc->bc_freeq);
137 assert(be != NULL);
138 assert(be->be_status == BST_FREE);
139 TAILQ_REMOVE(&bc->bc_freeq, be, be_link);
140 be->be_req = breq;
141 be->be_op = op;
142 switch (op) {
143 case BOP_READ:
144 case BOP_WRITE:
145 case BOP_DELETE:
146 off = breq->br_offset;
147 for (i = 0; i < breq->br_iovcnt; i++)
148 off += breq->br_iov[i].iov_len;
149 break;
150 default:
151 off = OFF_MAX;
152 }
153 be->be_block = off;
154 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
155 if (tbe->be_block == breq->br_offset)
156 break;
157 }
158 if (tbe == NULL) {
159 TAILQ_FOREACH(tbe, &bc->bc_busyq, be_link) {
160 if (tbe->be_block == breq->br_offset)
161 break;
162 }
163 }
164 if (tbe == NULL)
165 be->be_status = BST_PEND;
166 else
167 be->be_status = BST_BLOCK;
168 TAILQ_INSERT_TAIL(&bc->bc_pendq, be, be_link);
169 return (be->be_status == BST_PEND);
170 }
171
172 static int
blockif_dequeue(struct blockif_ctxt * bc,pthread_t t,struct blockif_elem ** bep)173 blockif_dequeue(struct blockif_ctxt *bc, pthread_t t, struct blockif_elem **bep)
174 {
175 struct blockif_elem *be;
176
177 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
178 if (be->be_status == BST_PEND)
179 break;
180 assert(be->be_status == BST_BLOCK);
181 }
182 if (be == NULL)
183 return (0);
184 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
185 be->be_status = BST_BUSY;
186 be->be_tid = t;
187 TAILQ_INSERT_TAIL(&bc->bc_busyq, be, be_link);
188 *bep = be;
189 return (1);
190 }
191
192 static void
blockif_complete(struct blockif_ctxt * bc,struct blockif_elem * be)193 blockif_complete(struct blockif_ctxt *bc, struct blockif_elem *be)
194 {
195 struct blockif_elem *tbe;
196
197 if (be->be_status == BST_DONE || be->be_status == BST_BUSY)
198 TAILQ_REMOVE(&bc->bc_busyq, be, be_link);
199 else
200 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
201 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
202 if (tbe->be_req->br_offset == be->be_block)
203 tbe->be_status = BST_PEND;
204 }
205 be->be_tid = 0;
206 be->be_status = BST_FREE;
207 be->be_req = NULL;
208 TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link);
209 }
210
211 static void
blockif_proc(struct blockif_ctxt * bc,struct blockif_elem * be,uint8_t * buf)212 blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be, uint8_t *buf)
213 {
214 struct blockif_req *br;
215 off_t arg[2];
216 ssize_t clen, len, off, boff, voff;
217 int i, err;
218
219 br = be->be_req;
220 if (br->br_iovcnt <= 1)
221 buf = NULL;
222 err = 0;
223 switch (be->be_op) {
224 case BOP_READ:
225 if (buf == NULL) {
226 if ((len = preadv(bc->bc_fd, br->br_iov, br->br_iovcnt,
227 br->br_offset)) < 0)
228 err = errno;
229 else
230 br->br_resid -= len;
231 break;
232 }
233 i = 0;
234 off = voff = 0;
235 while (br->br_resid > 0) {
236 len = MIN(br->br_resid, MAXPHYS);
237 if (pread(bc->bc_fd, buf, len, br->br_offset +
238 off) < 0) {
239 err = errno;
240 break;
241 }
242 boff = 0;
243 do {
244 clen = MIN(len - boff, br->br_iov[i].iov_len -
245 voff);
246 memcpy(br->br_iov[i].iov_base + voff,
247 buf + boff, clen);
248 if (clen < br->br_iov[i].iov_len - voff)
249 voff += clen;
250 else {
251 i++;
252 voff = 0;
253 }
254 boff += clen;
255 } while (boff < len);
256 off += len;
257 br->br_resid -= len;
258 }
259 break;
260 case BOP_WRITE:
261 if (bc->bc_rdonly) {
262 err = EROFS;
263 break;
264 }
265 if (buf == NULL) {
266 if ((len = pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt,
267 br->br_offset)) < 0)
268 err = errno;
269 else
270 br->br_resid -= len;
271 break;
272 }
273 i = 0;
274 off = voff = 0;
275 while (br->br_resid > 0) {
276 len = MIN(br->br_resid, MAXPHYS);
277 boff = 0;
278 do {
279 clen = MIN(len - boff, br->br_iov[i].iov_len -
280 voff);
281 memcpy(buf + boff,
282 br->br_iov[i].iov_base + voff, clen);
283 if (clen < br->br_iov[i].iov_len - voff)
284 voff += clen;
285 else {
286 i++;
287 voff = 0;
288 }
289 boff += clen;
290 } while (boff < len);
291 if (pwrite(bc->bc_fd, buf, len, br->br_offset +
292 off) < 0) {
293 err = errno;
294 break;
295 }
296 off += len;
297 br->br_resid -= len;
298 }
299 break;
300 case BOP_FLUSH:
301 if (bc->bc_ischr) {
302 if (ioctl(bc->bc_fd, DIOCGFLUSH))
303 err = errno;
304 } else if (fsync(bc->bc_fd))
305 err = errno;
306 break;
307 case BOP_DELETE:
308 if (!bc->bc_candelete)
309 err = EOPNOTSUPP;
310 else if (bc->bc_rdonly)
311 err = EROFS;
312 else if (bc->bc_ischr) {
313 arg[0] = br->br_offset;
314 arg[1] = br->br_resid;
315 if (ioctl(bc->bc_fd, DIOCGDELETE, arg))
316 err = errno;
317 else
318 br->br_resid = 0;
319 } else
320 err = EOPNOTSUPP;
321 break;
322 default:
323 err = EINVAL;
324 break;
325 }
326
327 be->be_status = BST_DONE;
328
329 (*br->br_callback)(br, err);
330 }
331
332 static void *
blockif_thr(void * arg)333 blockif_thr(void *arg)
334 {
335 struct blockif_ctxt *bc;
336 struct blockif_elem *be;
337 pthread_t t;
338 uint8_t *buf;
339
340 bc = arg;
341 if (bc->bc_isgeom)
342 buf = malloc(MAXPHYS);
343 else
344 buf = NULL;
345 t = pthread_self();
346
347 pthread_mutex_lock(&bc->bc_mtx);
348 for (;;) {
349 while (blockif_dequeue(bc, t, &be)) {
350 pthread_mutex_unlock(&bc->bc_mtx);
351 blockif_proc(bc, be, buf);
352 pthread_mutex_lock(&bc->bc_mtx);
353 blockif_complete(bc, be);
354 }
355 /* Check ctxt status here to see if exit requested */
356 if (bc->bc_closing)
357 break;
358 pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx);
359 }
360 pthread_mutex_unlock(&bc->bc_mtx);
361
362 if (buf)
363 free(buf);
364 pthread_exit(NULL);
365 return (NULL);
366 }
367
368 static void
blockif_sigcont_handler(int signal,enum ev_type type,void * arg)369 blockif_sigcont_handler(int signal, enum ev_type type, void *arg)
370 {
371 struct blockif_sig_elem *bse;
372
373 for (;;) {
374 /*
375 * Process the entire list even if not intended for
376 * this thread.
377 */
378 do {
379 bse = blockif_bse_head;
380 if (bse == NULL)
381 return;
382 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
383 (uintptr_t)bse,
384 (uintptr_t)bse->bse_next));
385
386 pthread_mutex_lock(&bse->bse_mtx);
387 bse->bse_pending = 0;
388 pthread_cond_signal(&bse->bse_cond);
389 pthread_mutex_unlock(&bse->bse_mtx);
390 }
391 }
392
393 static void
blockif_init(void)394 blockif_init(void)
395 {
396 mevent_add(SIGCONT, EVF_SIGNAL, blockif_sigcont_handler, NULL);
397 (void) signal(SIGCONT, SIG_IGN);
398 }
399
400 struct blockif_ctxt *
blockif_open(const char * optstr,const char * ident)401 blockif_open(const char *optstr, const char *ident)
402 {
403 char tname[MAXCOMLEN + 1];
404 char name[MAXPATHLEN];
405 char *nopt, *xopts, *cp;
406 struct blockif_ctxt *bc;
407 struct stat sbuf;
408 struct diocgattr_arg arg;
409 off_t size, psectsz, psectoff;
410 int extra, fd, i, sectsz;
411 int nocache, sync, ro, candelete, geom, ssopt, pssopt;
412 #ifndef WITHOUT_CAPSICUM
413 cap_rights_t rights;
414 cap_ioctl_t cmds[] = { DIOCGFLUSH, DIOCGDELETE };
415 #endif
416
417 pthread_once(&blockif_once, blockif_init);
418
419 fd = -1;
420 ssopt = 0;
421 nocache = 0;
422 sync = 0;
423 ro = 0;
424
425 /*
426 * The first element in the optstring is always a pathname.
427 * Optional elements follow
428 */
429 nopt = xopts = strdup(optstr);
430 while (xopts != NULL) {
431 cp = strsep(&xopts, ",");
432 if (cp == nopt) /* file or device pathname */
433 continue;
434 else if (!strcmp(cp, "nocache"))
435 nocache = 1;
436 else if (!strcmp(cp, "sync") || !strcmp(cp, "direct"))
437 sync = 1;
438 else if (!strcmp(cp, "ro"))
439 ro = 1;
440 else if (sscanf(cp, "sectorsize=%d/%d", &ssopt, &pssopt) == 2)
441 ;
442 else if (sscanf(cp, "sectorsize=%d", &ssopt) == 1)
443 pssopt = ssopt;
444 else {
445 fprintf(stderr, "Invalid device option \"%s\"\n", cp);
446 goto err;
447 }
448 }
449
450 extra = 0;
451 if (nocache)
452 extra |= O_DIRECT;
453 if (sync)
454 extra |= O_SYNC;
455
456 fd = open(nopt, (ro ? O_RDONLY : O_RDWR) | extra);
457 if (fd < 0 && !ro) {
458 /* Attempt a r/w fail with a r/o open */
459 fd = open(nopt, O_RDONLY | extra);
460 ro = 1;
461 }
462
463 if (fd < 0) {
464 warn("Could not open backing file: %s", nopt);
465 goto err;
466 }
467
468 if (fstat(fd, &sbuf) < 0) {
469 warn("Could not stat backing file %s", nopt);
470 goto err;
471 }
472
473 #ifndef WITHOUT_CAPSICUM
474 cap_rights_init(&rights, CAP_FSYNC, CAP_IOCTL, CAP_READ, CAP_SEEK,
475 CAP_WRITE);
476 if (ro)
477 cap_rights_clear(&rights, CAP_FSYNC, CAP_WRITE);
478
479 if (caph_rights_limit(fd, &rights) == -1)
480 errx(EX_OSERR, "Unable to apply rights for sandbox");
481 #endif
482
483 /*
484 * Deal with raw devices
485 */
486 size = sbuf.st_size;
487 sectsz = DEV_BSIZE;
488 psectsz = psectoff = 0;
489 candelete = geom = 0;
490 if (S_ISCHR(sbuf.st_mode)) {
491 if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 ||
492 ioctl(fd, DIOCGSECTORSIZE, §sz)) {
493 perror("Could not fetch dev blk/sector size");
494 goto err;
495 }
496 assert(size != 0);
497 assert(sectsz != 0);
498 if (ioctl(fd, DIOCGSTRIPESIZE, &psectsz) == 0 && psectsz > 0)
499 ioctl(fd, DIOCGSTRIPEOFFSET, &psectoff);
500 strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
501 arg.len = sizeof(arg.value.i);
502 if (ioctl(fd, DIOCGATTR, &arg) == 0)
503 candelete = arg.value.i;
504 if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0)
505 geom = 1;
506 } else
507 psectsz = sbuf.st_blksize;
508
509 #ifndef WITHOUT_CAPSICUM
510 if (caph_ioctls_limit(fd, cmds, nitems(cmds)) == -1)
511 errx(EX_OSERR, "Unable to apply rights for sandbox");
512 #endif
513
514 if (ssopt != 0) {
515 if (!powerof2(ssopt) || !powerof2(pssopt) || ssopt < 512 ||
516 ssopt > pssopt) {
517 fprintf(stderr, "Invalid sector size %d/%d\n",
518 ssopt, pssopt);
519 goto err;
520 }
521
522 /*
523 * Some backend drivers (e.g. cd0, ada0) require that the I/O
524 * size be a multiple of the device's sector size.
525 *
526 * Validate that the emulated sector size complies with this
527 * requirement.
528 */
529 if (S_ISCHR(sbuf.st_mode)) {
530 if (ssopt < sectsz || (ssopt % sectsz) != 0) {
531 fprintf(stderr, "Sector size %d incompatible "
532 "with underlying device sector size %d\n",
533 ssopt, sectsz);
534 goto err;
535 }
536 }
537
538 sectsz = ssopt;
539 psectsz = pssopt;
540 psectoff = 0;
541 }
542
543 bc = calloc(1, sizeof(struct blockif_ctxt));
544 if (bc == NULL) {
545 perror("calloc");
546 goto err;
547 }
548
549 bc->bc_magic = BLOCKIF_SIG;
550 bc->bc_fd = fd;
551 bc->bc_ischr = S_ISCHR(sbuf.st_mode);
552 bc->bc_isgeom = geom;
553 bc->bc_candelete = candelete;
554 bc->bc_rdonly = ro;
555 bc->bc_size = size;
556 bc->bc_sectsz = sectsz;
557 bc->bc_psectsz = psectsz;
558 bc->bc_psectoff = psectoff;
559 pthread_mutex_init(&bc->bc_mtx, NULL);
560 pthread_cond_init(&bc->bc_cond, NULL);
561 TAILQ_INIT(&bc->bc_freeq);
562 TAILQ_INIT(&bc->bc_pendq);
563 TAILQ_INIT(&bc->bc_busyq);
564 for (i = 0; i < BLOCKIF_MAXREQ; i++) {
565 bc->bc_reqs[i].be_status = BST_FREE;
566 TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link);
567 }
568
569 for (i = 0; i < BLOCKIF_NUMTHR; i++) {
570 pthread_create(&bc->bc_btid[i], NULL, blockif_thr, bc);
571 snprintf(tname, sizeof(tname), "blk-%s-%d", ident, i);
572 pthread_set_name_np(bc->bc_btid[i], tname);
573 }
574
575 return (bc);
576 err:
577 if (fd >= 0)
578 close(fd);
579 return (NULL);
580 }
581
582 static int
blockif_request(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)583 blockif_request(struct blockif_ctxt *bc, struct blockif_req *breq,
584 enum blockop op)
585 {
586 int err;
587
588 err = 0;
589
590 pthread_mutex_lock(&bc->bc_mtx);
591 if (!TAILQ_EMPTY(&bc->bc_freeq)) {
592 /*
593 * Enqueue and inform the block i/o thread
594 * that there is work available
595 */
596 if (blockif_enqueue(bc, breq, op))
597 pthread_cond_signal(&bc->bc_cond);
598 } else {
599 /*
600 * Callers are not allowed to enqueue more than
601 * the specified blockif queue limit. Return an
602 * error to indicate that the queue length has been
603 * exceeded.
604 */
605 err = E2BIG;
606 }
607 pthread_mutex_unlock(&bc->bc_mtx);
608
609 return (err);
610 }
611
612 int
blockif_read(struct blockif_ctxt * bc,struct blockif_req * breq)613 blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq)
614 {
615
616 assert(bc->bc_magic == BLOCKIF_SIG);
617 return (blockif_request(bc, breq, BOP_READ));
618 }
619
620 int
blockif_write(struct blockif_ctxt * bc,struct blockif_req * breq)621 blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq)
622 {
623
624 assert(bc->bc_magic == BLOCKIF_SIG);
625 return (blockif_request(bc, breq, BOP_WRITE));
626 }
627
628 int
blockif_flush(struct blockif_ctxt * bc,struct blockif_req * breq)629 blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq)
630 {
631
632 assert(bc->bc_magic == BLOCKIF_SIG);
633 return (blockif_request(bc, breq, BOP_FLUSH));
634 }
635
636 int
blockif_delete(struct blockif_ctxt * bc,struct blockif_req * breq)637 blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq)
638 {
639
640 assert(bc->bc_magic == BLOCKIF_SIG);
641 return (blockif_request(bc, breq, BOP_DELETE));
642 }
643
644 int
blockif_cancel(struct blockif_ctxt * bc,struct blockif_req * breq)645 blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq)
646 {
647 struct blockif_elem *be;
648
649 assert(bc->bc_magic == BLOCKIF_SIG);
650
651 pthread_mutex_lock(&bc->bc_mtx);
652 /*
653 * Check pending requests.
654 */
655 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
656 if (be->be_req == breq)
657 break;
658 }
659 if (be != NULL) {
660 /*
661 * Found it.
662 */
663 blockif_complete(bc, be);
664 pthread_mutex_unlock(&bc->bc_mtx);
665
666 return (0);
667 }
668
669 /*
670 * Check in-flight requests.
671 */
672 TAILQ_FOREACH(be, &bc->bc_busyq, be_link) {
673 if (be->be_req == breq)
674 break;
675 }
676 if (be == NULL) {
677 /*
678 * Didn't find it.
679 */
680 pthread_mutex_unlock(&bc->bc_mtx);
681 return (EINVAL);
682 }
683
684 /*
685 * Interrupt the processing thread to force it return
686 * prematurely via it's normal callback path.
687 */
688 while (be->be_status == BST_BUSY) {
689 struct blockif_sig_elem bse, *old_head;
690
691 pthread_mutex_init(&bse.bse_mtx, NULL);
692 pthread_cond_init(&bse.bse_cond, NULL);
693
694 bse.bse_pending = 1;
695
696 do {
697 old_head = blockif_bse_head;
698 bse.bse_next = old_head;
699 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
700 (uintptr_t)old_head,
701 (uintptr_t)&bse));
702
703 pthread_kill(be->be_tid, SIGCONT);
704
705 pthread_mutex_lock(&bse.bse_mtx);
706 while (bse.bse_pending)
707 pthread_cond_wait(&bse.bse_cond, &bse.bse_mtx);
708 pthread_mutex_unlock(&bse.bse_mtx);
709 }
710
711 pthread_mutex_unlock(&bc->bc_mtx);
712
713 /*
714 * The processing thread has been interrupted. Since it's not
715 * clear if the callback has been invoked yet, return EBUSY.
716 */
717 return (EBUSY);
718 }
719
720 int
blockif_close(struct blockif_ctxt * bc)721 blockif_close(struct blockif_ctxt *bc)
722 {
723 void *jval;
724 int i;
725
726 assert(bc->bc_magic == BLOCKIF_SIG);
727
728 /*
729 * Stop the block i/o thread
730 */
731 pthread_mutex_lock(&bc->bc_mtx);
732 bc->bc_closing = 1;
733 pthread_mutex_unlock(&bc->bc_mtx);
734 pthread_cond_broadcast(&bc->bc_cond);
735 for (i = 0; i < BLOCKIF_NUMTHR; i++)
736 pthread_join(bc->bc_btid[i], &jval);
737
738 /* XXX Cancel queued i/o's ??? */
739
740 /*
741 * Release resources
742 */
743 bc->bc_magic = 0;
744 close(bc->bc_fd);
745 free(bc);
746
747 return (0);
748 }
749
750 /*
751 * Return virtual C/H/S values for a given block. Use the algorithm
752 * outlined in the VHD specification to calculate values.
753 */
754 void
blockif_chs(struct blockif_ctxt * bc,uint16_t * c,uint8_t * h,uint8_t * s)755 blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s)
756 {
757 off_t sectors; /* total sectors of the block dev */
758 off_t hcyl; /* cylinders times heads */
759 uint16_t secpt; /* sectors per track */
760 uint8_t heads;
761
762 assert(bc->bc_magic == BLOCKIF_SIG);
763
764 sectors = bc->bc_size / bc->bc_sectsz;
765
766 /* Clamp the size to the largest possible with CHS */
767 if (sectors > 65535UL*16*255)
768 sectors = 65535UL*16*255;
769
770 if (sectors >= 65536UL*16*63) {
771 secpt = 255;
772 heads = 16;
773 hcyl = sectors / secpt;
774 } else {
775 secpt = 17;
776 hcyl = sectors / secpt;
777 heads = (hcyl + 1023) / 1024;
778
779 if (heads < 4)
780 heads = 4;
781
782 if (hcyl >= (heads * 1024) || heads > 16) {
783 secpt = 31;
784 heads = 16;
785 hcyl = sectors / secpt;
786 }
787 if (hcyl >= (heads * 1024)) {
788 secpt = 63;
789 heads = 16;
790 hcyl = sectors / secpt;
791 }
792 }
793
794 *c = hcyl / heads;
795 *h = heads;
796 *s = secpt;
797 }
798
799 /*
800 * Accessors
801 */
802 off_t
blockif_size(struct blockif_ctxt * bc)803 blockif_size(struct blockif_ctxt *bc)
804 {
805
806 assert(bc->bc_magic == BLOCKIF_SIG);
807 return (bc->bc_size);
808 }
809
810 int
blockif_sectsz(struct blockif_ctxt * bc)811 blockif_sectsz(struct blockif_ctxt *bc)
812 {
813
814 assert(bc->bc_magic == BLOCKIF_SIG);
815 return (bc->bc_sectsz);
816 }
817
818 void
blockif_psectsz(struct blockif_ctxt * bc,int * size,int * off)819 blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off)
820 {
821
822 assert(bc->bc_magic == BLOCKIF_SIG);
823 *size = bc->bc_psectsz;
824 *off = bc->bc_psectoff;
825 }
826
827 int
blockif_queuesz(struct blockif_ctxt * bc)828 blockif_queuesz(struct blockif_ctxt *bc)
829 {
830
831 assert(bc->bc_magic == BLOCKIF_SIG);
832 return (BLOCKIF_MAXREQ - 1);
833 }
834
835 int
blockif_is_ro(struct blockif_ctxt * bc)836 blockif_is_ro(struct blockif_ctxt *bc)
837 {
838
839 assert(bc->bc_magic == BLOCKIF_SIG);
840 return (bc->bc_rdonly);
841 }
842
843 int
blockif_candelete(struct blockif_ctxt * bc)844 blockif_candelete(struct blockif_ctxt *bc)
845 {
846
847 assert(bc->bc_magic == BLOCKIF_SIG);
848 return (bc->bc_candelete);
849 }
850