1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2013 Peter Grehan <grehan@freebsd.org>
5 * All rights reserved.
6 * Copyright 2020 Joyent, Inc.
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 AUTHOR ``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 AUTHOR 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/param.h>
31 #ifndef WITHOUT_CAPSICUM
32 #include <sys/capsicum.h>
33 #endif
34 #include <sys/queue.h>
35 #include <sys/errno.h>
36 #include <sys/stat.h>
37 #include <sys/ioctl.h>
38 #include <sys/disk.h>
39
40 #include <assert.h>
41 #ifndef WITHOUT_CAPSICUM
42 #include <capsicum_helpers.h>
43 #endif
44 #include <err.h>
45 #include <fcntl.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <pthread.h>
50 #include <pthread_np.h>
51 #include <signal.h>
52 #include <sysexits.h>
53 #include <unistd.h>
54
55 #include <machine/atomic.h>
56 #include <machine/vmm_snapshot.h>
57
58 #include "bhyverun.h"
59 #include "config.h"
60 #include "debug.h"
61 #include "mevent.h"
62 #include "pci_emul.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 unsigned 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 int bc_paused;
107 pthread_t bc_btid[BLOCKIF_NUMTHR];
108 pthread_mutex_t bc_mtx;
109 pthread_cond_t bc_cond;
110 pthread_cond_t bc_work_done_cond;
111 blockif_resize_cb *bc_resize_cb;
112 void *bc_resize_cb_arg;
113 struct mevent *bc_resize_event;
114
115 /* Request elements and free/pending/busy queues */
116 TAILQ_HEAD(, blockif_elem) bc_freeq;
117 TAILQ_HEAD(, blockif_elem) bc_pendq;
118 TAILQ_HEAD(, blockif_elem) bc_busyq;
119 struct blockif_elem bc_reqs[BLOCKIF_MAXREQ];
120 int bc_bootindex;
121 };
122
123 static pthread_once_t blockif_once = PTHREAD_ONCE_INIT;
124
125 struct blockif_sig_elem {
126 pthread_mutex_t bse_mtx;
127 pthread_cond_t bse_cond;
128 int bse_pending;
129 struct blockif_sig_elem *bse_next;
130 };
131
132 static struct blockif_sig_elem *blockif_bse_head;
133
134 static int
blockif_enqueue(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)135 blockif_enqueue(struct blockif_ctxt *bc, struct blockif_req *breq,
136 enum blockop op)
137 {
138 struct blockif_elem *be, *tbe;
139 off_t off;
140 int i;
141
142 be = TAILQ_FIRST(&bc->bc_freeq);
143 assert(be != NULL);
144 assert(be->be_status == BST_FREE);
145 TAILQ_REMOVE(&bc->bc_freeq, be, be_link);
146 be->be_req = breq;
147 be->be_op = op;
148 switch (op) {
149 case BOP_READ:
150 case BOP_WRITE:
151 case BOP_DELETE:
152 off = breq->br_offset;
153 for (i = 0; i < breq->br_iovcnt; i++)
154 off += breq->br_iov[i].iov_len;
155 break;
156 default:
157 off = OFF_MAX;
158 }
159 be->be_block = off;
160 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
161 if (tbe->be_block == breq->br_offset)
162 break;
163 }
164 if (tbe == NULL) {
165 TAILQ_FOREACH(tbe, &bc->bc_busyq, be_link) {
166 if (tbe->be_block == breq->br_offset)
167 break;
168 }
169 }
170 if (tbe == NULL)
171 be->be_status = BST_PEND;
172 else
173 be->be_status = BST_BLOCK;
174 TAILQ_INSERT_TAIL(&bc->bc_pendq, be, be_link);
175 return (be->be_status == BST_PEND);
176 }
177
178 static int
blockif_dequeue(struct blockif_ctxt * bc,pthread_t t,struct blockif_elem ** bep)179 blockif_dequeue(struct blockif_ctxt *bc, pthread_t t, struct blockif_elem **bep)
180 {
181 struct blockif_elem *be;
182
183 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
184 if (be->be_status == BST_PEND)
185 break;
186 assert(be->be_status == BST_BLOCK);
187 }
188 if (be == NULL)
189 return (0);
190 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
191 be->be_status = BST_BUSY;
192 be->be_tid = t;
193 TAILQ_INSERT_TAIL(&bc->bc_busyq, be, be_link);
194 *bep = be;
195 return (1);
196 }
197
198 static void
blockif_complete(struct blockif_ctxt * bc,struct blockif_elem * be)199 blockif_complete(struct blockif_ctxt *bc, struct blockif_elem *be)
200 {
201 struct blockif_elem *tbe;
202
203 if (be->be_status == BST_DONE || be->be_status == BST_BUSY)
204 TAILQ_REMOVE(&bc->bc_busyq, be, be_link);
205 else
206 TAILQ_REMOVE(&bc->bc_pendq, be, be_link);
207 TAILQ_FOREACH(tbe, &bc->bc_pendq, be_link) {
208 if (tbe->be_req->br_offset == be->be_block)
209 tbe->be_status = BST_PEND;
210 }
211 be->be_tid = 0;
212 be->be_status = BST_FREE;
213 be->be_req = NULL;
214 TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link);
215 }
216
217 static int
blockif_flush_bc(struct blockif_ctxt * bc)218 blockif_flush_bc(struct blockif_ctxt *bc)
219 {
220 if (bc->bc_ischr) {
221 if (ioctl(bc->bc_fd, DIOCGFLUSH))
222 return (errno);
223 } else if (fsync(bc->bc_fd))
224 return (errno);
225
226 return (0);
227 }
228
229 static void
blockif_proc(struct blockif_ctxt * bc,struct blockif_elem * be,uint8_t * buf)230 blockif_proc(struct blockif_ctxt *bc, struct blockif_elem *be, uint8_t *buf)
231 {
232 struct spacectl_range range;
233 struct blockif_req *br;
234 off_t arg[2];
235 ssize_t n;
236 size_t clen, len, off, boff, voff;
237 int i, err;
238
239 br = be->be_req;
240 assert(br->br_resid >= 0);
241
242 if (br->br_iovcnt <= 1)
243 buf = NULL;
244 err = 0;
245 switch (be->be_op) {
246 case BOP_READ:
247 if (buf == NULL) {
248 if ((n = preadv(bc->bc_fd, br->br_iov, br->br_iovcnt,
249 br->br_offset)) < 0)
250 err = errno;
251 else
252 br->br_resid -= n;
253 break;
254 }
255 i = 0;
256 off = voff = 0;
257 while (br->br_resid > 0) {
258 len = MIN(br->br_resid, MAXPHYS);
259 n = pread(bc->bc_fd, buf, len, br->br_offset + off);
260 if (n < 0) {
261 err = errno;
262 break;
263 }
264 len = (size_t)n;
265 boff = 0;
266 do {
267 clen = MIN(len - boff, br->br_iov[i].iov_len -
268 voff);
269 memcpy((uint8_t *)br->br_iov[i].iov_base + voff,
270 buf + boff, clen);
271 if (clen < br->br_iov[i].iov_len - voff)
272 voff += clen;
273 else {
274 i++;
275 voff = 0;
276 }
277 boff += clen;
278 } while (boff < len);
279 off += len;
280 br->br_resid -= len;
281 }
282 break;
283 case BOP_WRITE:
284 if (bc->bc_rdonly) {
285 err = EROFS;
286 break;
287 }
288 if (buf == NULL) {
289 if ((n = pwritev(bc->bc_fd, br->br_iov, br->br_iovcnt,
290 br->br_offset)) < 0)
291 err = errno;
292 else
293 br->br_resid -= n;
294 break;
295 }
296 i = 0;
297 off = voff = 0;
298 while (br->br_resid > 0) {
299 len = MIN(br->br_resid, MAXPHYS);
300 boff = 0;
301 do {
302 clen = MIN(len - boff, br->br_iov[i].iov_len -
303 voff);
304 memcpy(buf + boff,
305 (uint8_t *)br->br_iov[i].iov_base + voff,
306 clen);
307 if (clen < br->br_iov[i].iov_len - voff)
308 voff += clen;
309 else {
310 i++;
311 voff = 0;
312 }
313 boff += clen;
314 } while (boff < len);
315
316 n = pwrite(bc->bc_fd, buf, len, br->br_offset + off);
317 if (n < 0) {
318 err = errno;
319 break;
320 }
321 off += n;
322 br->br_resid -= n;
323 }
324 break;
325 case BOP_FLUSH:
326 err = blockif_flush_bc(bc);
327 break;
328 case BOP_DELETE:
329 if (!bc->bc_candelete)
330 err = EOPNOTSUPP;
331 else if (bc->bc_rdonly)
332 err = EROFS;
333 else if (bc->bc_ischr) {
334 arg[0] = br->br_offset;
335 arg[1] = br->br_resid;
336 if (ioctl(bc->bc_fd, DIOCGDELETE, arg))
337 err = errno;
338 else
339 br->br_resid = 0;
340 } else {
341 range.r_offset = br->br_offset;
342 range.r_len = br->br_resid;
343
344 while (range.r_len > 0) {
345 if (fspacectl(bc->bc_fd, SPACECTL_DEALLOC,
346 &range, 0, &range) != 0) {
347 err = errno;
348 break;
349 }
350 }
351 if (err == 0)
352 br->br_resid = 0;
353 }
354 break;
355 default:
356 err = EINVAL;
357 break;
358 }
359
360 be->be_status = BST_DONE;
361
362 (*br->br_callback)(br, err);
363 }
364
365 static inline bool
blockif_empty(const struct blockif_ctxt * bc)366 blockif_empty(const struct blockif_ctxt *bc)
367 {
368 return (TAILQ_EMPTY(&bc->bc_pendq) && TAILQ_EMPTY(&bc->bc_busyq));
369 }
370
371 static void *
blockif_thr(void * arg)372 blockif_thr(void *arg)
373 {
374 struct blockif_ctxt *bc;
375 struct blockif_elem *be;
376 pthread_t t;
377 uint8_t *buf;
378
379 bc = arg;
380 if (bc->bc_isgeom)
381 buf = malloc(MAXPHYS);
382 else
383 buf = NULL;
384 t = pthread_self();
385
386 pthread_mutex_lock(&bc->bc_mtx);
387 for (;;) {
388 while (blockif_dequeue(bc, t, &be)) {
389 pthread_mutex_unlock(&bc->bc_mtx);
390 blockif_proc(bc, be, buf);
391 pthread_mutex_lock(&bc->bc_mtx);
392 blockif_complete(bc, be);
393 }
394
395 /* If none to work, notify the main thread */
396 if (blockif_empty(bc))
397 pthread_cond_broadcast(&bc->bc_work_done_cond);
398
399 /* Check ctxt status here to see if exit requested */
400 if (bc->bc_closing)
401 break;
402
403 pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx);
404 }
405 pthread_mutex_unlock(&bc->bc_mtx);
406
407 if (buf)
408 free(buf);
409 pthread_exit(NULL);
410 return (NULL);
411 }
412
413 static void
blockif_sigcont_handler(int signal __unused,enum ev_type type __unused,void * arg __unused)414 blockif_sigcont_handler(int signal __unused, enum ev_type type __unused,
415 void *arg __unused)
416 {
417 struct blockif_sig_elem *bse;
418
419 for (;;) {
420 /*
421 * Process the entire list even if not intended for
422 * this thread.
423 */
424 do {
425 bse = blockif_bse_head;
426 if (bse == NULL)
427 return;
428 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
429 (uintptr_t)bse,
430 (uintptr_t)bse->bse_next));
431
432 pthread_mutex_lock(&bse->bse_mtx);
433 bse->bse_pending = 0;
434 pthread_cond_signal(&bse->bse_cond);
435 pthread_mutex_unlock(&bse->bse_mtx);
436 }
437 }
438
439 static void
blockif_init(void)440 blockif_init(void)
441 {
442 mevent_add(SIGCONT, EVF_SIGNAL, blockif_sigcont_handler, NULL);
443 (void) signal(SIGCONT, SIG_IGN);
444 }
445
446 int
blockif_legacy_config(nvlist_t * nvl,const char * opts)447 blockif_legacy_config(nvlist_t *nvl, const char *opts)
448 {
449 char *cp, *path;
450
451 if (opts == NULL)
452 return (0);
453
454 cp = strchr(opts, ',');
455 if (cp == NULL) {
456 set_config_value_node(nvl, "path", opts);
457 return (0);
458 }
459 path = strndup(opts, cp - opts);
460 set_config_value_node(nvl, "path", path);
461 free(path);
462 return (pci_parse_legacy_config(nvl, cp + 1));
463 }
464
465 int
blockif_add_boot_device(struct pci_devinst * const pi,struct blockif_ctxt * const bc)466 blockif_add_boot_device(struct pci_devinst *const pi,
467 struct blockif_ctxt *const bc)
468 {
469 if (bc->bc_bootindex < 0)
470 return (0);
471
472 return (pci_emul_add_boot_device(pi, bc->bc_bootindex));
473 }
474
475 struct blockif_ctxt *
blockif_open(nvlist_t * nvl,const char * ident)476 blockif_open(nvlist_t *nvl, const char *ident)
477 {
478 char tname[MAXCOMLEN + 1];
479 char name[MAXPATHLEN];
480 const char *path, *pssval, *ssval, *bootindex_val;
481 char *cp;
482 struct blockif_ctxt *bc;
483 struct stat sbuf;
484 struct diocgattr_arg arg;
485 off_t size, psectsz, psectoff;
486 int extra, fd, i, sectsz;
487 int ro, candelete, geom, ssopt, pssopt;
488 int nodelete;
489 int bootindex;
490
491 #ifndef WITHOUT_CAPSICUM
492 cap_rights_t rights;
493 cap_ioctl_t cmds[] = { DIOCGFLUSH, DIOCGDELETE, DIOCGMEDIASIZE };
494 #endif
495
496 pthread_once(&blockif_once, blockif_init);
497
498 fd = -1;
499 extra = 0;
500 ssopt = 0;
501 ro = 0;
502 nodelete = 0;
503 bootindex = -1;
504
505 if (get_config_bool_node_default(nvl, "nocache", false))
506 extra |= O_DIRECT;
507 if (get_config_bool_node_default(nvl, "nodelete", false))
508 nodelete = 1;
509 if (get_config_bool_node_default(nvl, "sync", false) ||
510 get_config_bool_node_default(nvl, "direct", false))
511 extra |= O_SYNC;
512 if (get_config_bool_node_default(nvl, "ro", false))
513 ro = 1;
514 ssval = get_config_value_node(nvl, "sectorsize");
515 if (ssval != NULL) {
516 ssopt = strtol(ssval, &cp, 10);
517 if (cp == ssval) {
518 EPRINTLN("Invalid sector size \"%s\"", ssval);
519 goto err;
520 }
521 if (*cp == '\0') {
522 pssopt = ssopt;
523 } else if (*cp == '/') {
524 pssval = cp + 1;
525 pssopt = strtol(pssval, &cp, 10);
526 if (cp == pssval || *cp != '\0') {
527 EPRINTLN("Invalid sector size \"%s\"", ssval);
528 goto err;
529 }
530 } else {
531 EPRINTLN("Invalid sector size \"%s\"", ssval);
532 goto err;
533 }
534 }
535
536 bootindex_val = get_config_value_node(nvl, "bootindex");
537 if (bootindex_val != NULL) {
538 bootindex = atoi(bootindex_val);
539 }
540
541 path = get_config_value_node(nvl, "path");
542 if (path == NULL) {
543 EPRINTLN("Missing \"path\" for block device.");
544 goto err;
545 }
546
547 fd = open(path, (ro ? O_RDONLY : O_RDWR) | extra);
548 if (fd < 0 && !ro) {
549 /* Attempt a r/w fail with a r/o open */
550 fd = open(path, O_RDONLY | extra);
551 ro = 1;
552 }
553
554 if (fd < 0) {
555 warn("Could not open backing file: %s", path);
556 goto err;
557 }
558
559 if (fstat(fd, &sbuf) < 0) {
560 warn("Could not stat backing file %s", path);
561 goto err;
562 }
563
564 #ifndef WITHOUT_CAPSICUM
565 cap_rights_init(&rights, CAP_FSYNC, CAP_IOCTL, CAP_READ, CAP_SEEK,
566 CAP_WRITE, CAP_FSTAT, CAP_EVENT, CAP_FPATHCONF);
567 if (ro)
568 cap_rights_clear(&rights, CAP_FSYNC, CAP_WRITE);
569
570 if (caph_rights_limit(fd, &rights) == -1)
571 errx(EX_OSERR, "Unable to apply rights for sandbox");
572 #endif
573
574 /*
575 * Deal with raw devices
576 */
577 size = sbuf.st_size;
578 sectsz = DEV_BSIZE;
579 psectsz = psectoff = 0;
580 candelete = geom = 0;
581 if (S_ISCHR(sbuf.st_mode)) {
582 if (ioctl(fd, DIOCGMEDIASIZE, &size) < 0 ||
583 ioctl(fd, DIOCGSECTORSIZE, §sz)) {
584 perror("Could not fetch dev blk/sector size");
585 goto err;
586 }
587 assert(size != 0);
588 assert(sectsz != 0);
589 if (ioctl(fd, DIOCGSTRIPESIZE, &psectsz) == 0 && psectsz > 0)
590 ioctl(fd, DIOCGSTRIPEOFFSET, &psectoff);
591 strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
592 arg.len = sizeof(arg.value.i);
593 if (nodelete == 0 && ioctl(fd, DIOCGATTR, &arg) == 0)
594 candelete = arg.value.i;
595 if (ioctl(fd, DIOCGPROVIDERNAME, name) == 0)
596 geom = 1;
597 } else {
598 psectsz = sbuf.st_blksize;
599 /* Avoid fallback implementation */
600 candelete = fpathconf(fd, _PC_DEALLOC_PRESENT) == 1;
601 }
602
603 #ifndef WITHOUT_CAPSICUM
604 if (caph_ioctls_limit(fd, cmds, nitems(cmds)) == -1)
605 errx(EX_OSERR, "Unable to apply rights for sandbox");
606 #endif
607
608 if (ssopt != 0) {
609 if (!powerof2(ssopt) || !powerof2(pssopt) || ssopt < 512 ||
610 ssopt > pssopt) {
611 EPRINTLN("Invalid sector size %d/%d",
612 ssopt, pssopt);
613 goto err;
614 }
615
616 /*
617 * Some backend drivers (e.g. cd0, ada0) require that the I/O
618 * size be a multiple of the device's sector size.
619 *
620 * Validate that the emulated sector size complies with this
621 * requirement.
622 */
623 if (S_ISCHR(sbuf.st_mode)) {
624 if (ssopt < sectsz || (ssopt % sectsz) != 0) {
625 EPRINTLN("Sector size %d incompatible "
626 "with underlying device sector size %d",
627 ssopt, sectsz);
628 goto err;
629 }
630 }
631
632 sectsz = ssopt;
633 psectsz = pssopt;
634 psectoff = 0;
635 }
636
637 bc = calloc(1, sizeof(struct blockif_ctxt));
638 if (bc == NULL) {
639 perror("calloc");
640 goto err;
641 }
642
643 bc->bc_magic = BLOCKIF_SIG;
644 bc->bc_fd = fd;
645 bc->bc_ischr = S_ISCHR(sbuf.st_mode);
646 bc->bc_isgeom = geom;
647 bc->bc_candelete = candelete;
648 bc->bc_rdonly = ro;
649 bc->bc_size = size;
650 bc->bc_sectsz = sectsz;
651 bc->bc_psectsz = psectsz;
652 bc->bc_psectoff = psectoff;
653 pthread_mutex_init(&bc->bc_mtx, NULL);
654 pthread_cond_init(&bc->bc_cond, NULL);
655 bc->bc_paused = 0;
656 pthread_cond_init(&bc->bc_work_done_cond, NULL);
657 TAILQ_INIT(&bc->bc_freeq);
658 TAILQ_INIT(&bc->bc_pendq);
659 TAILQ_INIT(&bc->bc_busyq);
660 bc->bc_bootindex = bootindex;
661 for (i = 0; i < BLOCKIF_MAXREQ; i++) {
662 bc->bc_reqs[i].be_status = BST_FREE;
663 TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link);
664 }
665
666 for (i = 0; i < BLOCKIF_NUMTHR; i++) {
667 pthread_create(&bc->bc_btid[i], NULL, blockif_thr, bc);
668 snprintf(tname, sizeof(tname), "blk-%s-%d", ident, i);
669 pthread_set_name_np(bc->bc_btid[i], tname);
670 }
671
672 return (bc);
673 err:
674 if (fd >= 0)
675 close(fd);
676 return (NULL);
677 }
678
679 static void
blockif_resized(int fd,enum ev_type type __unused,void * arg)680 blockif_resized(int fd, enum ev_type type __unused, void *arg)
681 {
682 struct blockif_ctxt *bc;
683 struct stat sb;
684 off_t mediasize;
685
686 if (fstat(fd, &sb) != 0)
687 return;
688
689 if (S_ISCHR(sb.st_mode)) {
690 if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) < 0) {
691 EPRINTLN("blockif_resized: get mediasize failed: %s",
692 strerror(errno));
693 return;
694 }
695 } else
696 mediasize = sb.st_size;
697
698 bc = arg;
699 pthread_mutex_lock(&bc->bc_mtx);
700 if (mediasize != bc->bc_size) {
701 bc->bc_size = mediasize;
702 bc->bc_resize_cb(bc, bc->bc_resize_cb_arg, bc->bc_size);
703 }
704 pthread_mutex_unlock(&bc->bc_mtx);
705 }
706
707 int
blockif_register_resize_callback(struct blockif_ctxt * bc,blockif_resize_cb * cb,void * cb_arg)708 blockif_register_resize_callback(struct blockif_ctxt *bc, blockif_resize_cb *cb,
709 void *cb_arg)
710 {
711 struct stat sb;
712 int err;
713
714 if (cb == NULL)
715 return (EINVAL);
716
717 err = 0;
718
719 pthread_mutex_lock(&bc->bc_mtx);
720 if (bc->bc_resize_cb != NULL) {
721 err = EBUSY;
722 goto out;
723 }
724
725 assert(bc->bc_closing == 0);
726
727 if (fstat(bc->bc_fd, &sb) != 0) {
728 err = errno;
729 goto out;
730 }
731
732 bc->bc_resize_event = mevent_add_flags(bc->bc_fd, EVF_VNODE,
733 EVFF_ATTRIB, blockif_resized, bc);
734 if (bc->bc_resize_event == NULL) {
735 err = ENXIO;
736 goto out;
737 }
738
739 bc->bc_resize_cb = cb;
740 bc->bc_resize_cb_arg = cb_arg;
741 out:
742 pthread_mutex_unlock(&bc->bc_mtx);
743
744 return (err);
745 }
746
747 static int
blockif_request(struct blockif_ctxt * bc,struct blockif_req * breq,enum blockop op)748 blockif_request(struct blockif_ctxt *bc, struct blockif_req *breq,
749 enum blockop op)
750 {
751 int err;
752
753 err = 0;
754
755 pthread_mutex_lock(&bc->bc_mtx);
756 assert(!bc->bc_paused);
757 if (!TAILQ_EMPTY(&bc->bc_freeq)) {
758 /*
759 * Enqueue and inform the block i/o thread
760 * that there is work available
761 */
762 if (blockif_enqueue(bc, breq, op))
763 pthread_cond_signal(&bc->bc_cond);
764 } else {
765 /*
766 * Callers are not allowed to enqueue more than
767 * the specified blockif queue limit. Return an
768 * error to indicate that the queue length has been
769 * exceeded.
770 */
771 err = E2BIG;
772 }
773 pthread_mutex_unlock(&bc->bc_mtx);
774
775 return (err);
776 }
777
778 int
blockif_read(struct blockif_ctxt * bc,struct blockif_req * breq)779 blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq)
780 {
781 assert(bc->bc_magic == BLOCKIF_SIG);
782 return (blockif_request(bc, breq, BOP_READ));
783 }
784
785 int
blockif_write(struct blockif_ctxt * bc,struct blockif_req * breq)786 blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq)
787 {
788 assert(bc->bc_magic == BLOCKIF_SIG);
789 return (blockif_request(bc, breq, BOP_WRITE));
790 }
791
792 int
blockif_flush(struct blockif_ctxt * bc,struct blockif_req * breq)793 blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq)
794 {
795 assert(bc->bc_magic == BLOCKIF_SIG);
796 return (blockif_request(bc, breq, BOP_FLUSH));
797 }
798
799 int
blockif_delete(struct blockif_ctxt * bc,struct blockif_req * breq)800 blockif_delete(struct blockif_ctxt *bc, struct blockif_req *breq)
801 {
802 assert(bc->bc_magic == BLOCKIF_SIG);
803 return (blockif_request(bc, breq, BOP_DELETE));
804 }
805
806 int
blockif_cancel(struct blockif_ctxt * bc,struct blockif_req * breq)807 blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq)
808 {
809 struct blockif_elem *be;
810
811 assert(bc->bc_magic == BLOCKIF_SIG);
812
813 pthread_mutex_lock(&bc->bc_mtx);
814 /* XXX: not waiting while paused */
815
816 /*
817 * Check pending requests.
818 */
819 TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
820 if (be->be_req == breq)
821 break;
822 }
823 if (be != NULL) {
824 /*
825 * Found it.
826 */
827 blockif_complete(bc, be);
828 pthread_mutex_unlock(&bc->bc_mtx);
829
830 return (0);
831 }
832
833 /*
834 * Check in-flight requests.
835 */
836 TAILQ_FOREACH(be, &bc->bc_busyq, be_link) {
837 if (be->be_req == breq)
838 break;
839 }
840 if (be == NULL) {
841 /*
842 * Didn't find it.
843 */
844 pthread_mutex_unlock(&bc->bc_mtx);
845 return (EINVAL);
846 }
847
848 /*
849 * Interrupt the processing thread to force it return
850 * prematurely via it's normal callback path.
851 */
852 while (be->be_status == BST_BUSY) {
853 struct blockif_sig_elem bse, *old_head;
854
855 pthread_mutex_init(&bse.bse_mtx, NULL);
856 pthread_cond_init(&bse.bse_cond, NULL);
857
858 bse.bse_pending = 1;
859
860 do {
861 old_head = blockif_bse_head;
862 bse.bse_next = old_head;
863 } while (!atomic_cmpset_ptr((uintptr_t *)&blockif_bse_head,
864 (uintptr_t)old_head,
865 (uintptr_t)&bse));
866
867 pthread_kill(be->be_tid, SIGCONT);
868
869 pthread_mutex_lock(&bse.bse_mtx);
870 while (bse.bse_pending)
871 pthread_cond_wait(&bse.bse_cond, &bse.bse_mtx);
872 pthread_mutex_unlock(&bse.bse_mtx);
873 }
874
875 pthread_mutex_unlock(&bc->bc_mtx);
876
877 /*
878 * The processing thread has been interrupted. Since it's not
879 * clear if the callback has been invoked yet, return EBUSY.
880 */
881 return (EBUSY);
882 }
883
884 int
blockif_close(struct blockif_ctxt * bc)885 blockif_close(struct blockif_ctxt *bc)
886 {
887 void *jval;
888 int i;
889
890 assert(bc->bc_magic == BLOCKIF_SIG);
891
892 /*
893 * Stop the block i/o thread
894 */
895 pthread_mutex_lock(&bc->bc_mtx);
896 bc->bc_closing = 1;
897 if (bc->bc_resize_event != NULL)
898 mevent_disable(bc->bc_resize_event);
899 pthread_mutex_unlock(&bc->bc_mtx);
900 pthread_cond_broadcast(&bc->bc_cond);
901 for (i = 0; i < BLOCKIF_NUMTHR; i++)
902 pthread_join(bc->bc_btid[i], &jval);
903
904 /* XXX Cancel queued i/o's ??? */
905
906 /*
907 * Release resources
908 */
909 bc->bc_magic = 0;
910 close(bc->bc_fd);
911 free(bc);
912
913 return (0);
914 }
915
916 /*
917 * Return virtual C/H/S values for a given block. Use the algorithm
918 * outlined in the VHD specification to calculate values.
919 */
920 void
blockif_chs(struct blockif_ctxt * bc,uint16_t * c,uint8_t * h,uint8_t * s)921 blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s)
922 {
923 off_t sectors; /* total sectors of the block dev */
924 off_t hcyl; /* cylinders times heads */
925 uint16_t secpt; /* sectors per track */
926 uint8_t heads;
927
928 assert(bc->bc_magic == BLOCKIF_SIG);
929
930 sectors = bc->bc_size / bc->bc_sectsz;
931
932 /* Clamp the size to the largest possible with CHS */
933 if (sectors > 65535L * 16 * 255)
934 sectors = 65535L * 16 * 255;
935
936 if (sectors >= 65536L * 16 * 63) {
937 secpt = 255;
938 heads = 16;
939 hcyl = sectors / secpt;
940 } else {
941 secpt = 17;
942 hcyl = sectors / secpt;
943 heads = (hcyl + 1023) / 1024;
944
945 if (heads < 4)
946 heads = 4;
947
948 if (hcyl >= (heads * 1024) || heads > 16) {
949 secpt = 31;
950 heads = 16;
951 hcyl = sectors / secpt;
952 }
953 if (hcyl >= (heads * 1024)) {
954 secpt = 63;
955 heads = 16;
956 hcyl = sectors / secpt;
957 }
958 }
959
960 *c = hcyl / heads;
961 *h = heads;
962 *s = secpt;
963 }
964
965 /*
966 * Accessors
967 */
968 off_t
blockif_size(struct blockif_ctxt * bc)969 blockif_size(struct blockif_ctxt *bc)
970 {
971 assert(bc->bc_magic == BLOCKIF_SIG);
972 return (bc->bc_size);
973 }
974
975 int
blockif_sectsz(struct blockif_ctxt * bc)976 blockif_sectsz(struct blockif_ctxt *bc)
977 {
978 assert(bc->bc_magic == BLOCKIF_SIG);
979 return (bc->bc_sectsz);
980 }
981
982 void
blockif_psectsz(struct blockif_ctxt * bc,int * size,int * off)983 blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off)
984 {
985 assert(bc->bc_magic == BLOCKIF_SIG);
986 *size = bc->bc_psectsz;
987 *off = bc->bc_psectoff;
988 }
989
990 int
blockif_queuesz(struct blockif_ctxt * bc)991 blockif_queuesz(struct blockif_ctxt *bc)
992 {
993 assert(bc->bc_magic == BLOCKIF_SIG);
994 return (BLOCKIF_MAXREQ - 1);
995 }
996
997 int
blockif_is_ro(struct blockif_ctxt * bc)998 blockif_is_ro(struct blockif_ctxt *bc)
999 {
1000 assert(bc->bc_magic == BLOCKIF_SIG);
1001 return (bc->bc_rdonly);
1002 }
1003
1004 int
blockif_candelete(struct blockif_ctxt * bc)1005 blockif_candelete(struct blockif_ctxt *bc)
1006 {
1007 assert(bc->bc_magic == BLOCKIF_SIG);
1008 return (bc->bc_candelete);
1009 }
1010
1011 #ifdef BHYVE_SNAPSHOT
1012 void
blockif_pause(struct blockif_ctxt * bc)1013 blockif_pause(struct blockif_ctxt *bc)
1014 {
1015 assert(bc != NULL);
1016 assert(bc->bc_magic == BLOCKIF_SIG);
1017
1018 pthread_mutex_lock(&bc->bc_mtx);
1019 bc->bc_paused = 1;
1020
1021 /* The interface is paused. Wait for workers to finish their work */
1022 while (!blockif_empty(bc))
1023 pthread_cond_wait(&bc->bc_work_done_cond, &bc->bc_mtx);
1024 pthread_mutex_unlock(&bc->bc_mtx);
1025
1026 if (!bc->bc_rdonly && blockif_flush_bc(bc))
1027 EPRINTLN("%s: [WARN] failed to flush backing file.",
1028 __func__);
1029 }
1030
1031 void
blockif_resume(struct blockif_ctxt * bc)1032 blockif_resume(struct blockif_ctxt *bc)
1033 {
1034 assert(bc != NULL);
1035 assert(bc->bc_magic == BLOCKIF_SIG);
1036
1037 pthread_mutex_lock(&bc->bc_mtx);
1038 bc->bc_paused = 0;
1039 pthread_mutex_unlock(&bc->bc_mtx);
1040 }
1041 #endif /* BHYVE_SNAPSHOT */
1042