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Merge commit '2446333cd5b5c985f6517dee7004e542ecacd21c' into upstream-merge
[qemu-kvm/stefanha.git] / block.c
blobda70f2968b45fce8d4020b66a0e8519c8bae9868
1 /*
2 * QEMU System Emulator block driver
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "config-host.h"
25 #include "qemu-common.h"
26 #include "monitor.h"
27 #include "block_int.h"
28 #include "module.h"
29 #include "qemu-objects.h"
30
31 #ifdef CONFIG_BSD
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 #include <sys/ioctl.h>
35 #include <sys/queue.h>
36 #ifndef __DragonFly__
37 #include <sys/disk.h>
38 #endif
39 #endif
40
41 #ifdef _WIN32
42 #include <windows.h>
43 #endif
44
45 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
46 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
47 BlockDriverCompletionFunc *cb, void *opaque);
48 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
49 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
50 BlockDriverCompletionFunc *cb, void *opaque);
51 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
52 BlockDriverCompletionFunc *cb, void *opaque);
53 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
54 BlockDriverCompletionFunc *cb, void *opaque);
55 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
56 uint8_t *buf, int nb_sectors);
57 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
58 const uint8_t *buf, int nb_sectors);
59
60 static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
61 QTAILQ_HEAD_INITIALIZER(bdrv_states);
62
63 static QLIST_HEAD(, BlockDriver) bdrv_drivers =
64 QLIST_HEAD_INITIALIZER(bdrv_drivers);
65
66 /* The device to use for VM snapshots */
67 static BlockDriverState *bs_snapshots;
68
69 /* If non-zero, use only whitelisted block drivers */
70 static int use_bdrv_whitelist;
71
72 int path_is_absolute(const char *path)
73 {
74 const char *p;
75 #ifdef _WIN32
76 /* specific case for names like: "\\.\d:" */
77 if (*path == '/' || *path == '\\')
78 return 1;
79 #endif
80 p = strchr(path, ':');
81 if (p)
82 p++;
83 else
84 p = path;
85 #ifdef _WIN32
86 return (*p == '/' || *p == '\\');
87 #else
88 return (*p == '/');
89 #endif
90 }
91
92 /* if filename is absolute, just copy it to dest. Otherwise, build a
93 path to it by considering it is relative to base_path. URL are
94 supported. */
95 void path_combine(char *dest, int dest_size,
96 const char *base_path,
97 const char *filename)
98 {
99 const char *p, *p1;
100 int len;
101
102 if (dest_size <= 0)
103 return;
104 if (path_is_absolute(filename)) {
105 pstrcpy(dest, dest_size, filename);
106 } else {
107 p = strchr(base_path, ':');
108 if (p)
109 p++;
110 else
111 p = base_path;
112 p1 = strrchr(base_path, '/');
113 #ifdef _WIN32
114 {
115 const char *p2;
116 p2 = strrchr(base_path, '\\');
117 if (!p1 || p2 > p1)
118 p1 = p2;
119 }
120 #endif
121 if (p1)
122 p1++;
123 else
124 p1 = base_path;
125 if (p1 > p)
126 p = p1;
127 len = p - base_path;
128 if (len > dest_size - 1)
129 len = dest_size - 1;
130 memcpy(dest, base_path, len);
131 dest[len] = '\0';
132 pstrcat(dest, dest_size, filename);
133 }
134 }
135
136 void bdrv_register(BlockDriver *bdrv)
137 {
138 if (!bdrv->bdrv_aio_readv) {
139 /* add AIO emulation layer */
140 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
141 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
142 } else if (!bdrv->bdrv_read) {
143 /* add synchronous IO emulation layer */
144 bdrv->bdrv_read = bdrv_read_em;
145 bdrv->bdrv_write = bdrv_write_em;
146 }
147
148 if (!bdrv->bdrv_aio_flush)
149 bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
150
151 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
152 }
153
154 /* create a new block device (by default it is empty) */
155 BlockDriverState *bdrv_new(const char *device_name)
156 {
157 BlockDriverState *bs;
158
159 bs = qemu_mallocz(sizeof(BlockDriverState));
160 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
161 if (device_name[0] != '\0') {
162 QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
163 }
164 return bs;
165 }
166
167 BlockDriver *bdrv_find_format(const char *format_name)
168 {
169 BlockDriver *drv1;
170 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
171 if (!strcmp(drv1->format_name, format_name)) {
172 return drv1;
173 }
174 }
175 return NULL;
176 }
177
178 static int bdrv_is_whitelisted(BlockDriver *drv)
179 {
180 static const char *whitelist[] = {
181 CONFIG_BDRV_WHITELIST
182 };
183 const char **p;
184
185 if (!whitelist[0])
186 return 1; /* no whitelist, anything goes */
187
188 for (p = whitelist; *p; p++) {
189 if (!strcmp(drv->format_name, *p)) {
190 return 1;
191 }
192 }
193 return 0;
194 }
195
196 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
197 {
198 BlockDriver *drv = bdrv_find_format(format_name);
199 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
200 }
201
202 int bdrv_create(BlockDriver *drv, const char* filename,
203 QEMUOptionParameter *options)
204 {
205 if (!drv->bdrv_create)
206 return -ENOTSUP;
207
208 return drv->bdrv_create(filename, options);
209 }
210
211 int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
212 {
213 BlockDriver *drv;
214
215 drv = bdrv_find_protocol(filename);
216 if (drv == NULL) {
217 drv = bdrv_find_format("file");
218 }
219
220 return bdrv_create(drv, filename, options);
221 }
222
223 #ifdef _WIN32
224 void get_tmp_filename(char *filename, int size)
225 {
226 char temp_dir[MAX_PATH];
227
228 GetTempPath(MAX_PATH, temp_dir);
229 GetTempFileName(temp_dir, "qem", 0, filename);
230 }
231 #else
232 void get_tmp_filename(char *filename, int size)
233 {
234 int fd;
235 const char *tmpdir;
236 /* XXX: race condition possible */
237 tmpdir = getenv("TMPDIR");
238 if (!tmpdir)
239 tmpdir = "/tmp";
240 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
241 fd = mkstemp(filename);
242 close(fd);
243 }
244 #endif
245
246 #ifdef _WIN32
247 static int is_windows_drive_prefix(const char *filename)
248 {
249 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
250 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
251 filename[1] == ':');
252 }
253
254 int is_windows_drive(const char *filename)
255 {
256 if (is_windows_drive_prefix(filename) &&
257 filename[2] == '\0')
258 return 1;
259 if (strstart(filename, "\\\\.\\", NULL) ||
260 strstart(filename, "//./", NULL))
261 return 1;
262 return 0;
263 }
264 #endif
265
266 /*
267 * Detect host devices. By convention, /dev/cdrom[N] is always
268 * recognized as a host CDROM.
269 */
270 static BlockDriver *find_hdev_driver(const char *filename)
271 {
272 int score_max = 0, score;
273 BlockDriver *drv = NULL, *d;
274
275 QLIST_FOREACH(d, &bdrv_drivers, list) {
276 if (d->bdrv_probe_device) {
277 score = d->bdrv_probe_device(filename);
278 if (score > score_max) {
279 score_max = score;
280 drv = d;
281 }
282 }
283 }
284
285 return drv;
286 }
287
288 BlockDriver *bdrv_find_protocol(const char *filename)
289 {
290 BlockDriver *drv1;
291 char protocol[128];
292 int len;
293 const char *p;
294
295 /* TODO Drivers without bdrv_file_open must be specified explicitly */
296
297 /*
298 * XXX(hch): we really should not let host device detection
299 * override an explicit protocol specification, but moving this
300 * later breaks access to device names with colons in them.
301 * Thanks to the brain-dead persistent naming schemes on udev-
302 * based Linux systems those actually are quite common.
303 */
304 drv1 = find_hdev_driver(filename);
305 if (drv1) {
306 return drv1;
307 }
308
309 #ifdef _WIN32
310 if (is_windows_drive(filename) ||
311 is_windows_drive_prefix(filename))
312 return bdrv_find_format("file");
313 #endif
314
315 p = strchr(filename, ':');
316 if (!p) {
317 return bdrv_find_format("file");
318 }
319 len = p - filename;
320 if (len > sizeof(protocol) - 1)
321 len = sizeof(protocol) - 1;
322 memcpy(protocol, filename, len);
323 protocol[len] = '\0';
324 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
325 if (drv1->protocol_name &&
326 !strcmp(drv1->protocol_name, protocol)) {
327 return drv1;
328 }
329 }
330 return NULL;
331 }
332
333 static int find_image_format(const char *filename, BlockDriver **pdrv)
334 {
335 int ret, score, score_max;
336 BlockDriver *drv1, *drv;
337 uint8_t buf[2048];
338 BlockDriverState *bs;
339
340 ret = bdrv_file_open(&bs, filename, 0);
341 if (ret < 0) {
342 *pdrv = NULL;
343 return ret;
344 }
345
346 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
347 if (bs->sg || !bdrv_is_inserted(bs)) {
348 bdrv_delete(bs);
349 drv = bdrv_find_format("raw");
350 if (!drv) {
351 ret = -ENOENT;
352 }
353 *pdrv = drv;
354 return ret;
355 }
356
357 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
358 bdrv_delete(bs);
359 if (ret < 0) {
360 *pdrv = NULL;
361 return ret;
362 }
363
364 score_max = 0;
365 drv = NULL;
366 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
367 if (drv1->bdrv_probe) {
368 score = drv1->bdrv_probe(buf, ret, filename);
369 if (score > score_max) {
370 score_max = score;
371 drv = drv1;
372 }
373 }
374 }
375 if (!drv) {
376 ret = -ENOENT;
377 }
378 *pdrv = drv;
379 return ret;
380 }
381
382 /**
383 * Set the current 'total_sectors' value
384 */
385 static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
386 {
387 BlockDriver *drv = bs->drv;
388
389 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
390 if (bs->sg)
391 return 0;
392
393 /* query actual device if possible, otherwise just trust the hint */
394 if (drv->bdrv_getlength) {
395 int64_t length = drv->bdrv_getlength(bs);
396 if (length < 0) {
397 return length;
398 }
399 hint = length >> BDRV_SECTOR_BITS;
400 }
401
402 bs->total_sectors = hint;
403 return 0;
404 }
405
406 /*
407 * Common part for opening disk images and files
408 */
409 static int bdrv_open_common(BlockDriverState *bs, const char *filename,
410 int flags, BlockDriver *drv)
411 {
412 int ret, open_flags;
413
414 assert(drv != NULL);
415
416 bs->file = NULL;
417 bs->total_sectors = 0;
418 bs->encrypted = 0;
419 bs->valid_key = 0;
420 bs->open_flags = flags;
421 /* buffer_alignment defaulted to 512, drivers can change this value */
422 bs->buffer_alignment = 512;
423
424 pstrcpy(bs->filename, sizeof(bs->filename), filename);
425
426 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
427 return -ENOTSUP;
428 }
429
430 bs->drv = drv;
431 bs->opaque = qemu_mallocz(drv->instance_size);
432
433 /*
434 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
435 * write cache to the guest. We do need the fdatasync to flush
436 * out transactions for block allocations, and we maybe have a
437 * volatile write cache in our backing device to deal with.
438 */
439 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
440 bs->enable_write_cache = 1;
441
442 /*
443 * Clear flags that are internal to the block layer before opening the
444 * image.
445 */
446 open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
447
448 /*
449 * Snapshots should be writeable.
450 */
451 if (bs->is_temporary) {
452 open_flags |= BDRV_O_RDWR;
453 }
454
455 /* Open the image, either directly or using a protocol */
456 if (drv->bdrv_file_open) {
457 ret = drv->bdrv_file_open(bs, filename, open_flags);
458 } else {
459 ret = bdrv_file_open(&bs->file, filename, open_flags);
460 if (ret >= 0) {
461 ret = drv->bdrv_open(bs, open_flags);
462 }
463 }
464
465 if (ret < 0) {
466 goto free_and_fail;
467 }
468
469 bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
470
471 ret = refresh_total_sectors(bs, bs->total_sectors);
472 if (ret < 0) {
473 goto free_and_fail;
474 }
475
476 #ifndef _WIN32
477 if (bs->is_temporary) {
478 unlink(filename);
479 }
480 #endif
481 return 0;
482
483 free_and_fail:
484 if (bs->file) {
485 bdrv_delete(bs->file);
486 bs->file = NULL;
487 }
488 qemu_free(bs->opaque);
489 bs->opaque = NULL;
490 bs->drv = NULL;
491 return ret;
492 }
493
494 /*
495 * Opens a file using a protocol (file, host_device, nbd, ...)
496 */
497 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
498 {
499 BlockDriverState *bs;
500 BlockDriver *drv;
501 int ret;
502
503 drv = bdrv_find_protocol(filename);
504 if (!drv) {
505 return -ENOENT;
506 }
507
508 bs = bdrv_new("");
509 ret = bdrv_open_common(bs, filename, flags, drv);
510 if (ret < 0) {
511 bdrv_delete(bs);
512 return ret;
513 }
514 bs->growable = 1;
515 *pbs = bs;
516 return 0;
517 }
518
519 /*
520 * Opens a disk image (raw, qcow2, vmdk, ...)
521 */
522 int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
523 BlockDriver *drv)
524 {
525 int ret;
526 int probed = 0;
527
528 if (flags & BDRV_O_SNAPSHOT) {
529 BlockDriverState *bs1;
530 int64_t total_size;
531 int is_protocol = 0;
532 BlockDriver *bdrv_qcow2;
533 QEMUOptionParameter *options;
534 char tmp_filename[PATH_MAX];
535 char backing_filename[PATH_MAX];
536
537 /* if snapshot, we create a temporary backing file and open it
538 instead of opening 'filename' directly */
539
540 /* if there is a backing file, use it */
541 bs1 = bdrv_new("");
542 ret = bdrv_open(bs1, filename, 0, drv);
543 if (ret < 0) {
544 bdrv_delete(bs1);
545 return ret;
546 }
547 total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
548
549 if (bs1->drv && bs1->drv->protocol_name)
550 is_protocol = 1;
551
552 bdrv_delete(bs1);
553
554 get_tmp_filename(tmp_filename, sizeof(tmp_filename));
555
556 /* Real path is meaningless for protocols */
557 if (is_protocol)
558 snprintf(backing_filename, sizeof(backing_filename),
559 "%s", filename);
560 else if (!realpath(filename, backing_filename))
561 return -errno;
562
563 bdrv_qcow2 = bdrv_find_format("qcow2");
564 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
565
566 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size);
567 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
568 if (drv) {
569 set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
570 drv->format_name);
571 }
572
573 ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
574 free_option_parameters(options);
575 if (ret < 0) {
576 return ret;
577 }
578
579 filename = tmp_filename;
580 drv = bdrv_qcow2;
581 bs->is_temporary = 1;
582 }
583
584 /* Find the right image format driver */
585 if (!drv) {
586 ret = find_image_format(filename, &drv);
587 probed = 1;
588 }
589
590 if (!drv) {
591 goto unlink_and_fail;
592 }
593
594 /* Open the image */
595 ret = bdrv_open_common(bs, filename, flags, drv);
596 if (ret < 0) {
597 goto unlink_and_fail;
598 }
599
600 bs->probed = probed;
601
602 /* If there is a backing file, use it */
603 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
604 char backing_filename[PATH_MAX];
605 int back_flags;
606 BlockDriver *back_drv = NULL;
607
608 bs->backing_hd = bdrv_new("");
609 path_combine(backing_filename, sizeof(backing_filename),
610 filename, bs->backing_file);
611 if (bs->backing_format[0] != '\0')
612 back_drv = bdrv_find_format(bs->backing_format);
613
614 /* backing files always opened read-only */
615 back_flags =
616 flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
617
618 ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
619 if (ret < 0) {
620 bdrv_close(bs);
621 return ret;
622 }
623 if (bs->is_temporary) {
624 bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
625 } else {
626 /* base image inherits from "parent" */
627 bs->backing_hd->keep_read_only = bs->keep_read_only;
628 }
629 }
630
631 if (!bdrv_key_required(bs)) {
632 /* call the change callback */
633 bs->media_changed = 1;
634 if (bs->change_cb)
635 bs->change_cb(bs->change_opaque);
636 }
637
638 return 0;
639
640 unlink_and_fail:
641 if (bs->is_temporary) {
642 unlink(filename);
643 }
644 return ret;
645 }
646
647 void bdrv_close(BlockDriverState *bs)
648 {
649 if (bs->drv) {
650 if (bs == bs_snapshots) {
651 bs_snapshots = NULL;
652 }
653 if (bs->backing_hd) {
654 bdrv_delete(bs->backing_hd);
655 bs->backing_hd = NULL;
656 }
657 bs->drv->bdrv_close(bs);
658 qemu_free(bs->opaque);
659 #ifdef _WIN32
660 if (bs->is_temporary) {
661 unlink(bs->filename);
662 }
663 #endif
664 bs->opaque = NULL;
665 bs->drv = NULL;
666
667 if (bs->file != NULL) {
668 bdrv_close(bs->file);
669 }
670
671 /* call the change callback */
672 bs->media_changed = 1;
673 if (bs->change_cb)
674 bs->change_cb(bs->change_opaque);
675 }
676 }
677
678 void bdrv_close_all(void)
679 {
680 BlockDriverState *bs;
681
682 QTAILQ_FOREACH(bs, &bdrv_states, list) {
683 bdrv_close(bs);
684 }
685 }
686
687 void bdrv_delete(BlockDriverState *bs)
688 {
689 assert(!bs->peer);
690
691 /* remove from list, if necessary */
692 if (bs->device_name[0] != '\0') {
693 QTAILQ_REMOVE(&bdrv_states, bs, list);
694 }
695
696 bdrv_close(bs);
697 if (bs->file != NULL) {
698 bdrv_delete(bs->file);
699 }
700
701 assert(bs != bs_snapshots);
702 qemu_free(bs);
703 }
704
705 int bdrv_attach(BlockDriverState *bs, DeviceState *qdev)
706 {
707 if (bs->peer) {
708 return -EBUSY;
709 }
710 bs->peer = qdev;
711 return 0;
712 }
713
714 void bdrv_detach(BlockDriverState *bs, DeviceState *qdev)
715 {
716 assert(bs->peer == qdev);
717 bs->peer = NULL;
718 }
719
720 DeviceState *bdrv_get_attached(BlockDriverState *bs)
721 {
722 return bs->peer;
723 }
724
725 /*
726 * Run consistency checks on an image
727 *
728 * Returns 0 if the check could be completed (it doesn't mean that the image is
729 * free of errors) or -errno when an internal error occured. The results of the
730 * check are stored in res.
731 */
732 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
733 {
734 if (bs->drv->bdrv_check == NULL) {
735 return -ENOTSUP;
736 }
737
738 memset(res, 0, sizeof(*res));
739 return bs->drv->bdrv_check(bs, res);
740 }
741
742 #define COMMIT_BUF_SECTORS 2048
743
744 /* commit COW file into the raw image */
745 int bdrv_commit(BlockDriverState *bs)
746 {
747 BlockDriver *drv = bs->drv;
748 int64_t sector, total_sectors;
749 int n, ro, open_flags;
750 int ret = 0, rw_ret = 0;
751 uint8_t *buf;
752 char filename[1024];
753 BlockDriverState *bs_rw, *bs_ro;
754
755 if (!drv)
756 return -ENOMEDIUM;
757
758 if (!bs->backing_hd) {
759 return -ENOTSUP;
760 }
761
762 if (bs->backing_hd->keep_read_only) {
763 return -EACCES;
764 }
765
766 ro = bs->backing_hd->read_only;
767 strncpy(filename, bs->backing_hd->filename, sizeof(filename));
768 open_flags = bs->backing_hd->open_flags;
769
770 if (ro) {
771 /* re-open as RW */
772 bdrv_delete(bs->backing_hd);
773 bs->backing_hd = NULL;
774 bs_rw = bdrv_new("");
775 rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR, drv);
776 if (rw_ret < 0) {
777 bdrv_delete(bs_rw);
778 /* try to re-open read-only */
779 bs_ro = bdrv_new("");
780 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, drv);
781 if (ret < 0) {
782 bdrv_delete(bs_ro);
783 /* drive not functional anymore */
784 bs->drv = NULL;
785 return ret;
786 }
787 bs->backing_hd = bs_ro;
788 return rw_ret;
789 }
790 bs->backing_hd = bs_rw;
791 }
792
793 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
794 buf = qemu_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
795
796 for (sector = 0; sector < total_sectors; sector += n) {
797 if (drv->bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
798
799 if (bdrv_read(bs, sector, buf, n) != 0) {
800 ret = -EIO;
801 goto ro_cleanup;
802 }
803
804 if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
805 ret = -EIO;
806 goto ro_cleanup;
807 }
808 }
809 }
810
811 if (drv->bdrv_make_empty) {
812 ret = drv->bdrv_make_empty(bs);
813 bdrv_flush(bs);
814 }
815
816 /*
817 * Make sure all data we wrote to the backing device is actually
818 * stable on disk.
819 */
820 if (bs->backing_hd)
821 bdrv_flush(bs->backing_hd);
822
823 ro_cleanup:
824 qemu_free(buf);
825
826 if (ro) {
827 /* re-open as RO */
828 bdrv_delete(bs->backing_hd);
829 bs->backing_hd = NULL;
830 bs_ro = bdrv_new("");
831 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, drv);
832 if (ret < 0) {
833 bdrv_delete(bs_ro);
834 /* drive not functional anymore */
835 bs->drv = NULL;
836 return ret;
837 }
838 bs->backing_hd = bs_ro;
839 bs->backing_hd->keep_read_only = 0;
840 }
841
842 return ret;
843 }
844
845 void bdrv_commit_all(void)
846 {
847 BlockDriverState *bs;
848
849 QTAILQ_FOREACH(bs, &bdrv_states, list) {
850 bdrv_commit(bs);
851 }
852 }
853
854 /*
855 * Return values:
856 * 0 - success
857 * -EINVAL - backing format specified, but no file
858 * -ENOSPC - can't update the backing file because no space is left in the
859 * image file header
860 * -ENOTSUP - format driver doesn't support changing the backing file
861 */
862 int bdrv_change_backing_file(BlockDriverState *bs,
863 const char *backing_file, const char *backing_fmt)
864 {
865 BlockDriver *drv = bs->drv;
866
867 if (drv->bdrv_change_backing_file != NULL) {
868 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
869 } else {
870 return -ENOTSUP;
871 }
872 }
873
874 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
875 size_t size)
876 {
877 int64_t len;
878
879 if (!bdrv_is_inserted(bs))
880 return -ENOMEDIUM;
881
882 if (bs->growable)
883 return 0;
884
885 len = bdrv_getlength(bs);
886
887 if (offset < 0)
888 return -EIO;
889
890 if ((offset > len) || (len - offset < size))
891 return -EIO;
892
893 return 0;
894 }
895
896 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
897 int nb_sectors)
898 {
899 return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
900 nb_sectors * BDRV_SECTOR_SIZE);
901 }
902
903 /* return < 0 if error. See bdrv_write() for the return codes */
904 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
905 uint8_t *buf, int nb_sectors)
906 {
907 BlockDriver *drv = bs->drv;
908
909 if (!drv)
910 return -ENOMEDIUM;
911 if (bdrv_check_request(bs, sector_num, nb_sectors))
912 return -EIO;
913
914 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
915 }
916
917 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
918 int nb_sectors, int dirty)
919 {
920 int64_t start, end;
921 unsigned long val, idx, bit;
922
923 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
924 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
925
926 for (; start <= end; start++) {
927 idx = start / (sizeof(unsigned long) * 8);
928 bit = start % (sizeof(unsigned long) * 8);
929 val = bs->dirty_bitmap[idx];
930 if (dirty) {
931 if (!(val & (1 << bit))) {
932 bs->dirty_count++;
933 val |= 1 << bit;
934 }
935 } else {
936 if (val & (1 << bit)) {
937 bs->dirty_count--;
938 val &= ~(1 << bit);
939 }
940 }
941 bs->dirty_bitmap[idx] = val;
942 }
943 }
944
945 /* Return < 0 if error. Important errors are:
946 -EIO generic I/O error (may happen for all errors)
947 -ENOMEDIUM No media inserted.
948 -EINVAL Invalid sector number or nb_sectors
949 -EACCES Trying to write a read-only device
950 */
951 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
952 const uint8_t *buf, int nb_sectors)
953 {
954 BlockDriver *drv = bs->drv;
955 if (!bs->drv)
956 return -ENOMEDIUM;
957 if (bs->read_only)
958 return -EACCES;
959 if (bdrv_check_request(bs, sector_num, nb_sectors))
960 return -EIO;
961
962 if (bs->dirty_bitmap) {
963 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
964 }
965
966 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
967 bs->wr_highest_sector = sector_num + nb_sectors - 1;
968 }
969
970 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
971 }
972
973 int bdrv_pread(BlockDriverState *bs, int64_t offset,
974 void *buf, int count1)
975 {
976 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
977 int len, nb_sectors, count;
978 int64_t sector_num;
979 int ret;
980
981 count = count1;
982 /* first read to align to sector start */
983 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
984 if (len > count)
985 len = count;
986 sector_num = offset >> BDRV_SECTOR_BITS;
987 if (len > 0) {
988 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
989 return ret;
990 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
991 count -= len;
992 if (count == 0)
993 return count1;
994 sector_num++;
995 buf += len;
996 }
997
998 /* read the sectors "in place" */
999 nb_sectors = count >> BDRV_SECTOR_BITS;
1000 if (nb_sectors > 0) {
1001 if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
1002 return ret;
1003 sector_num += nb_sectors;
1004 len = nb_sectors << BDRV_SECTOR_BITS;
1005 buf += len;
1006 count -= len;
1007 }
1008
1009 /* add data from the last sector */
1010 if (count > 0) {
1011 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1012 return ret;
1013 memcpy(buf, tmp_buf, count);
1014 }
1015 return count1;
1016 }
1017
1018 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
1019 const void *buf, int count1)
1020 {
1021 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1022 int len, nb_sectors, count;
1023 int64_t sector_num;
1024 int ret;
1025
1026 count = count1;
1027 /* first write to align to sector start */
1028 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1029 if (len > count)
1030 len = count;
1031 sector_num = offset >> BDRV_SECTOR_BITS;
1032 if (len > 0) {
1033 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1034 return ret;
1035 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1036 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1037 return ret;
1038 count -= len;
1039 if (count == 0)
1040 return count1;
1041 sector_num++;
1042 buf += len;
1043 }
1044
1045 /* write the sectors "in place" */
1046 nb_sectors = count >> BDRV_SECTOR_BITS;
1047 if (nb_sectors > 0) {
1048 if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
1049 return ret;
1050 sector_num += nb_sectors;
1051 len = nb_sectors << BDRV_SECTOR_BITS;
1052 buf += len;
1053 count -= len;
1054 }
1055
1056 /* add data from the last sector */
1057 if (count > 0) {
1058 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1059 return ret;
1060 memcpy(tmp_buf, buf, count);
1061 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1062 return ret;
1063 }
1064 return count1;
1065 }
1066
1067 /*
1068 * Writes to the file and ensures that no writes are reordered across this
1069 * request (acts as a barrier)
1070 *
1071 * Returns 0 on success, -errno in error cases.
1072 */
1073 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
1074 const void *buf, int count)
1075 {
1076 int ret;
1077
1078 ret = bdrv_pwrite(bs, offset, buf, count);
1079 if (ret < 0) {
1080 return ret;
1081 }
1082
1083 /* No flush needed for cache=writethrough, it uses O_DSYNC */
1084 if ((bs->open_flags & BDRV_O_CACHE_MASK) != 0) {
1085 bdrv_flush(bs);
1086 }
1087
1088 return 0;
1089 }
1090
1091 /*
1092 * Writes to the file and ensures that no writes are reordered across this
1093 * request (acts as a barrier)
1094 *
1095 * Returns 0 on success, -errno in error cases.
1096 */
1097 int bdrv_write_sync(BlockDriverState *bs, int64_t sector_num,
1098 const uint8_t *buf, int nb_sectors)
1099 {
1100 return bdrv_pwrite_sync(bs, BDRV_SECTOR_SIZE * sector_num,
1101 buf, BDRV_SECTOR_SIZE * nb_sectors);
1102 }
1103
1104 /**
1105 * Truncate file to 'offset' bytes (needed only for file protocols)
1106 */
1107 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
1108 {
1109 BlockDriver *drv = bs->drv;
1110 int ret;
1111 if (!drv)
1112 return -ENOMEDIUM;
1113 if (!drv->bdrv_truncate)
1114 return -ENOTSUP;
1115 if (bs->read_only)
1116 return -EACCES;
1117 ret = drv->bdrv_truncate(bs, offset);
1118 if (ret == 0) {
1119 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
1120 }
1121 return ret;
1122 }
1123
1124 /**
1125 * Length of a file in bytes. Return < 0 if error or unknown.
1126 */
1127 int64_t bdrv_getlength(BlockDriverState *bs)
1128 {
1129 BlockDriver *drv = bs->drv;
1130 if (!drv)
1131 return -ENOMEDIUM;
1132
1133 /* Fixed size devices use the total_sectors value for speed instead of
1134 issuing a length query (like lseek) on each call. Also, legacy block
1135 drivers don't provide a bdrv_getlength function and must use
1136 total_sectors. */
1137 if (!bs->growable || !drv->bdrv_getlength) {
1138 return bs->total_sectors * BDRV_SECTOR_SIZE;
1139 }
1140 return drv->bdrv_getlength(bs);
1141 }
1142
1143 /* return 0 as number of sectors if no device present or error */
1144 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
1145 {
1146 int64_t length;
1147 length = bdrv_getlength(bs);
1148 if (length < 0)
1149 length = 0;
1150 else
1151 length = length >> BDRV_SECTOR_BITS;
1152 *nb_sectors_ptr = length;
1153 }
1154
1155 struct partition {
1156 uint8_t boot_ind; /* 0x80 - active */
1157 uint8_t head; /* starting head */
1158 uint8_t sector; /* starting sector */
1159 uint8_t cyl; /* starting cylinder */
1160 uint8_t sys_ind; /* What partition type */
1161 uint8_t end_head; /* end head */
1162 uint8_t end_sector; /* end sector */
1163 uint8_t end_cyl; /* end cylinder */
1164 uint32_t start_sect; /* starting sector counting from 0 */
1165 uint32_t nr_sects; /* nr of sectors in partition */
1166 } __attribute__((packed));
1167
1168 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
1169 static int guess_disk_lchs(BlockDriverState *bs,
1170 int *pcylinders, int *pheads, int *psectors)
1171 {
1172 uint8_t buf[BDRV_SECTOR_SIZE];
1173 int ret, i, heads, sectors, cylinders;
1174 struct partition *p;
1175 uint32_t nr_sects;
1176 uint64_t nb_sectors;
1177
1178 bdrv_get_geometry(bs, &nb_sectors);
1179
1180 ret = bdrv_read(bs, 0, buf, 1);
1181 if (ret < 0)
1182 return -1;
1183 /* test msdos magic */
1184 if (buf[510] != 0x55 || buf[511] != 0xaa)
1185 return -1;
1186 for(i = 0; i < 4; i++) {
1187 p = ((struct partition *)(buf + 0x1be)) + i;
1188 nr_sects = le32_to_cpu(p->nr_sects);
1189 if (nr_sects && p->end_head) {
1190 /* We make the assumption that the partition terminates on
1191 a cylinder boundary */
1192 heads = p->end_head + 1;
1193 sectors = p->end_sector & 63;
1194 if (sectors == 0)
1195 continue;
1196 cylinders = nb_sectors / (heads * sectors);
1197 if (cylinders < 1 || cylinders > 16383)
1198 continue;
1199 *pheads = heads;
1200 *psectors = sectors;
1201 *pcylinders = cylinders;
1202 #if 0
1203 printf("guessed geometry: LCHS=%d %d %d\n",
1204 cylinders, heads, sectors);
1205 #endif
1206 return 0;
1207 }
1208 }
1209 return -1;
1210 }
1211
1212 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
1213 {
1214 int translation, lba_detected = 0;
1215 int cylinders, heads, secs;
1216 uint64_t nb_sectors;
1217
1218 /* if a geometry hint is available, use it */
1219 bdrv_get_geometry(bs, &nb_sectors);
1220 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
1221 translation = bdrv_get_translation_hint(bs);
1222 if (cylinders != 0) {
1223 *pcyls = cylinders;
1224 *pheads = heads;
1225 *psecs = secs;
1226 } else {
1227 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
1228 if (heads > 16) {
1229 /* if heads > 16, it means that a BIOS LBA
1230 translation was active, so the default
1231 hardware geometry is OK */
1232 lba_detected = 1;
1233 goto default_geometry;
1234 } else {
1235 *pcyls = cylinders;
1236 *pheads = heads;
1237 *psecs = secs;
1238 /* disable any translation to be in sync with
1239 the logical geometry */
1240 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
1241 bdrv_set_translation_hint(bs,
1242 BIOS_ATA_TRANSLATION_NONE);
1243 }
1244 }
1245 } else {
1246 default_geometry:
1247 /* if no geometry, use a standard physical disk geometry */
1248 cylinders = nb_sectors / (16 * 63);
1249
1250 if (cylinders > 16383)
1251 cylinders = 16383;
1252 else if (cylinders < 2)
1253 cylinders = 2;
1254 *pcyls = cylinders;
1255 *pheads = 16;
1256 *psecs = 63;
1257 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
1258 if ((*pcyls * *pheads) <= 131072) {
1259 bdrv_set_translation_hint(bs,
1260 BIOS_ATA_TRANSLATION_LARGE);
1261 } else {
1262 bdrv_set_translation_hint(bs,
1263 BIOS_ATA_TRANSLATION_LBA);
1264 }
1265 }
1266 }
1267 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
1268 }
1269 }
1270
1271 void bdrv_set_geometry_hint(BlockDriverState *bs,
1272 int cyls, int heads, int secs)
1273 {
1274 bs->cyls = cyls;
1275 bs->heads = heads;
1276 bs->secs = secs;
1277 }
1278
1279 void bdrv_set_type_hint(BlockDriverState *bs, int type)
1280 {
1281 bs->type = type;
1282 bs->removable = ((type == BDRV_TYPE_CDROM ||
1283 type == BDRV_TYPE_FLOPPY));
1284 }
1285
1286 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
1287 {
1288 bs->translation = translation;
1289 }
1290
1291 void bdrv_get_geometry_hint(BlockDriverState *bs,
1292 int *pcyls, int *pheads, int *psecs)
1293 {
1294 *pcyls = bs->cyls;
1295 *pheads = bs->heads;
1296 *psecs = bs->secs;
1297 }
1298
1299 int bdrv_get_type_hint(BlockDriverState *bs)
1300 {
1301 return bs->type;
1302 }
1303
1304 int bdrv_get_translation_hint(BlockDriverState *bs)
1305 {
1306 return bs->translation;
1307 }
1308
1309 void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
1310 BlockErrorAction on_write_error)
1311 {
1312 bs->on_read_error = on_read_error;
1313 bs->on_write_error = on_write_error;
1314 }
1315
1316 BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
1317 {
1318 return is_read ? bs->on_read_error : bs->on_write_error;
1319 }
1320
1321 void bdrv_set_removable(BlockDriverState *bs, int removable)
1322 {
1323 bs->removable = removable;
1324 if (removable && bs == bs_snapshots) {
1325 bs_snapshots = NULL;
1326 }
1327 }
1328
1329 int bdrv_is_removable(BlockDriverState *bs)
1330 {
1331 return bs->removable;
1332 }
1333
1334 int bdrv_is_read_only(BlockDriverState *bs)
1335 {
1336 return bs->read_only;
1337 }
1338
1339 int bdrv_is_sg(BlockDriverState *bs)
1340 {
1341 return bs->sg;
1342 }
1343
1344 int bdrv_enable_write_cache(BlockDriverState *bs)
1345 {
1346 return bs->enable_write_cache;
1347 }
1348
1349 /* XXX: no longer used */
1350 void bdrv_set_change_cb(BlockDriverState *bs,
1351 void (*change_cb)(void *opaque), void *opaque)
1352 {
1353 bs->change_cb = change_cb;
1354 bs->change_opaque = opaque;
1355 }
1356
1357 int bdrv_is_encrypted(BlockDriverState *bs)
1358 {
1359 if (bs->backing_hd && bs->backing_hd->encrypted)
1360 return 1;
1361 return bs->encrypted;
1362 }
1363
1364 int bdrv_key_required(BlockDriverState *bs)
1365 {
1366 BlockDriverState *backing_hd = bs->backing_hd;
1367
1368 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1369 return 1;
1370 return (bs->encrypted && !bs->valid_key);
1371 }
1372
1373 int bdrv_set_key(BlockDriverState *bs, const char *key)
1374 {
1375 int ret;
1376 if (bs->backing_hd && bs->backing_hd->encrypted) {
1377 ret = bdrv_set_key(bs->backing_hd, key);
1378 if (ret < 0)
1379 return ret;
1380 if (!bs->encrypted)
1381 return 0;
1382 }
1383 if (!bs->encrypted) {
1384 return -EINVAL;
1385 } else if (!bs->drv || !bs->drv->bdrv_set_key) {
1386 return -ENOMEDIUM;
1387 }
1388 ret = bs->drv->bdrv_set_key(bs, key);
1389 if (ret < 0) {
1390 bs->valid_key = 0;
1391 } else if (!bs->valid_key) {
1392 bs->valid_key = 1;
1393 /* call the change callback now, we skipped it on open */
1394 bs->media_changed = 1;
1395 if (bs->change_cb)
1396 bs->change_cb(bs->change_opaque);
1397 }
1398 return ret;
1399 }
1400
1401 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1402 {
1403 if (!bs->drv) {
1404 buf[0] = '\0';
1405 } else {
1406 pstrcpy(buf, buf_size, bs->drv->format_name);
1407 }
1408 }
1409
1410 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1411 void *opaque)
1412 {
1413 BlockDriver *drv;
1414
1415 QLIST_FOREACH(drv, &bdrv_drivers, list) {
1416 it(opaque, drv->format_name);
1417 }
1418 }
1419
1420 BlockDriverState *bdrv_find(const char *name)
1421 {
1422 BlockDriverState *bs;
1423
1424 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1425 if (!strcmp(name, bs->device_name)) {
1426 return bs;
1427 }
1428 }
1429 return NULL;
1430 }
1431
1432 BlockDriverState *bdrv_next(BlockDriverState *bs)
1433 {
1434 if (!bs) {
1435 return QTAILQ_FIRST(&bdrv_states);
1436 }
1437 return QTAILQ_NEXT(bs, list);
1438 }
1439
1440 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1441 {
1442 BlockDriverState *bs;
1443
1444 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1445 it(opaque, bs);
1446 }
1447 }
1448
1449 const char *bdrv_get_device_name(BlockDriverState *bs)
1450 {
1451 return bs->device_name;
1452 }
1453
1454 void bdrv_flush(BlockDriverState *bs)
1455 {
1456 if (bs->open_flags & BDRV_O_NO_FLUSH) {
1457 return;
1458 }
1459
1460 if (bs->drv && bs->drv->bdrv_flush)
1461 bs->drv->bdrv_flush(bs);
1462 }
1463
1464 void bdrv_flush_all(void)
1465 {
1466 BlockDriverState *bs;
1467
1468 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1469 if (bs->drv && !bdrv_is_read_only(bs) &&
1470 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) {
1471 bdrv_flush(bs);
1472 }
1473 }
1474 }
1475
1476 int bdrv_has_zero_init(BlockDriverState *bs)
1477 {
1478 assert(bs->drv);
1479
1480 if (bs->drv->bdrv_has_zero_init) {
1481 return bs->drv->bdrv_has_zero_init(bs);
1482 }
1483
1484 return 1;
1485 }
1486
1487 /*
1488 * Returns true iff the specified sector is present in the disk image. Drivers
1489 * not implementing the functionality are assumed to not support backing files,
1490 * hence all their sectors are reported as allocated.
1491 *
1492 * 'pnum' is set to the number of sectors (including and immediately following
1493 * the specified sector) that are known to be in the same
1494 * allocated/unallocated state.
1495 *
1496 * 'nb_sectors' is the max value 'pnum' should be set to.
1497 */
1498 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1499 int *pnum)
1500 {
1501 int64_t n;
1502 if (!bs->drv->bdrv_is_allocated) {
1503 if (sector_num >= bs->total_sectors) {
1504 *pnum = 0;
1505 return 0;
1506 }
1507 n = bs->total_sectors - sector_num;
1508 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1509 return 1;
1510 }
1511 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1512 }
1513
1514 void bdrv_mon_event(const BlockDriverState *bdrv,
1515 BlockMonEventAction action, int is_read)
1516 {
1517 QObject *data;
1518 const char *action_str;
1519
1520 switch (action) {
1521 case BDRV_ACTION_REPORT:
1522 action_str = "report";
1523 break;
1524 case BDRV_ACTION_IGNORE:
1525 action_str = "ignore";
1526 break;
1527 case BDRV_ACTION_STOP:
1528 action_str = "stop";
1529 break;
1530 default:
1531 abort();
1532 }
1533
1534 data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
1535 bdrv->device_name,
1536 action_str,
1537 is_read ? "read" : "write");
1538 monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
1539
1540 qobject_decref(data);
1541 }
1542
1543 static void bdrv_print_dict(QObject *obj, void *opaque)
1544 {
1545 QDict *bs_dict;
1546 Monitor *mon = opaque;
1547
1548 bs_dict = qobject_to_qdict(obj);
1549
1550 monitor_printf(mon, "%s: type=%s removable=%d",
1551 qdict_get_str(bs_dict, "device"),
1552 qdict_get_str(bs_dict, "type"),
1553 qdict_get_bool(bs_dict, "removable"));
1554
1555 if (qdict_get_bool(bs_dict, "removable")) {
1556 monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
1557 }
1558
1559 if (qdict_haskey(bs_dict, "inserted")) {
1560 QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
1561
1562 monitor_printf(mon, " file=");
1563 monitor_print_filename(mon, qdict_get_str(qdict, "file"));
1564 if (qdict_haskey(qdict, "backing_file")) {
1565 monitor_printf(mon, " backing_file=");
1566 monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
1567 }
1568 monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
1569 qdict_get_bool(qdict, "ro"),
1570 qdict_get_str(qdict, "drv"),
1571 qdict_get_bool(qdict, "encrypted"));
1572 } else {
1573 monitor_printf(mon, " [not inserted]");
1574 }
1575
1576 monitor_printf(mon, "\n");
1577 }
1578
1579 void bdrv_info_print(Monitor *mon, const QObject *data)
1580 {
1581 qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
1582 }
1583
1584 void bdrv_info(Monitor *mon, QObject **ret_data)
1585 {
1586 QList *bs_list;
1587 BlockDriverState *bs;
1588
1589 bs_list = qlist_new();
1590
1591 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1592 QObject *bs_obj;
1593 const char *type = "unknown";
1594
1595 switch(bs->type) {
1596 case BDRV_TYPE_HD:
1597 type = "hd";
1598 break;
1599 case BDRV_TYPE_CDROM:
1600 type = "cdrom";
1601 break;
1602 case BDRV_TYPE_FLOPPY:
1603 type = "floppy";
1604 break;
1605 }
1606
1607 bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
1608 "'removable': %i, 'locked': %i }",
1609 bs->device_name, type, bs->removable,
1610 bs->locked);
1611
1612 if (bs->drv) {
1613 QObject *obj;
1614 QDict *bs_dict = qobject_to_qdict(bs_obj);
1615
1616 obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
1617 "'encrypted': %i }",
1618 bs->filename, bs->read_only,
1619 bs->drv->format_name,
1620 bdrv_is_encrypted(bs));
1621 if (bs->backing_file[0] != '\0') {
1622 QDict *qdict = qobject_to_qdict(obj);
1623 qdict_put(qdict, "backing_file",
1624 qstring_from_str(bs->backing_file));
1625 }
1626
1627 qdict_put_obj(bs_dict, "inserted", obj);
1628 }
1629 qlist_append_obj(bs_list, bs_obj);
1630 }
1631
1632 *ret_data = QOBJECT(bs_list);
1633 }
1634
1635 static void bdrv_stats_iter(QObject *data, void *opaque)
1636 {
1637 QDict *qdict;
1638 Monitor *mon = opaque;
1639
1640 qdict = qobject_to_qdict(data);
1641 monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
1642
1643 qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
1644 monitor_printf(mon, " rd_bytes=%" PRId64
1645 " wr_bytes=%" PRId64
1646 " rd_operations=%" PRId64
1647 " wr_operations=%" PRId64
1648 "\n",
1649 qdict_get_int(qdict, "rd_bytes"),
1650 qdict_get_int(qdict, "wr_bytes"),
1651 qdict_get_int(qdict, "rd_operations"),
1652 qdict_get_int(qdict, "wr_operations"));
1653 }
1654
1655 void bdrv_stats_print(Monitor *mon, const QObject *data)
1656 {
1657 qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
1658 }
1659
1660 static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
1661 {
1662 QObject *res;
1663 QDict *dict;
1664
1665 res = qobject_from_jsonf("{ 'stats': {"
1666 "'rd_bytes': %" PRId64 ","
1667 "'wr_bytes': %" PRId64 ","
1668 "'rd_operations': %" PRId64 ","
1669 "'wr_operations': %" PRId64 ","
1670 "'wr_highest_offset': %" PRId64
1671 "} }",
1672 bs->rd_bytes, bs->wr_bytes,
1673 bs->rd_ops, bs->wr_ops,
1674 bs->wr_highest_sector *
1675 (uint64_t)BDRV_SECTOR_SIZE);
1676 dict = qobject_to_qdict(res);
1677
1678 if (*bs->device_name) {
1679 qdict_put(dict, "device", qstring_from_str(bs->device_name));
1680 }
1681
1682 if (bs->file) {
1683 QObject *parent = bdrv_info_stats_bs(bs->file);
1684 qdict_put_obj(dict, "parent", parent);
1685 }
1686
1687 return res;
1688 }
1689
1690 void bdrv_info_stats(Monitor *mon, QObject **ret_data)
1691 {
1692 QObject *obj;
1693 QList *devices;
1694 BlockDriverState *bs;
1695
1696 devices = qlist_new();
1697
1698 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1699 obj = bdrv_info_stats_bs(bs);
1700 qlist_append_obj(devices, obj);
1701 }
1702
1703 *ret_data = QOBJECT(devices);
1704 }
1705
1706 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1707 {
1708 if (bs->backing_hd && bs->backing_hd->encrypted)
1709 return bs->backing_file;
1710 else if (bs->encrypted)
1711 return bs->filename;
1712 else
1713 return NULL;
1714 }
1715
1716 void bdrv_get_backing_filename(BlockDriverState *bs,
1717 char *filename, int filename_size)
1718 {
1719 if (!bs->backing_file) {
1720 pstrcpy(filename, filename_size, "");
1721 } else {
1722 pstrcpy(filename, filename_size, bs->backing_file);
1723 }
1724 }
1725
1726 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1727 const uint8_t *buf, int nb_sectors)
1728 {
1729 BlockDriver *drv = bs->drv;
1730 if (!drv)
1731 return -ENOMEDIUM;
1732 if (!drv->bdrv_write_compressed)
1733 return -ENOTSUP;
1734 if (bdrv_check_request(bs, sector_num, nb_sectors))
1735 return -EIO;
1736
1737 if (bs->dirty_bitmap) {
1738 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1739 }
1740
1741 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1742 }
1743
1744 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1745 {
1746 BlockDriver *drv = bs->drv;
1747 if (!drv)
1748 return -ENOMEDIUM;
1749 if (!drv->bdrv_get_info)
1750 return -ENOTSUP;
1751 memset(bdi, 0, sizeof(*bdi));
1752 return drv->bdrv_get_info(bs, bdi);
1753 }
1754
1755 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1756 int64_t pos, int size)
1757 {
1758 BlockDriver *drv = bs->drv;
1759 if (!drv)
1760 return -ENOMEDIUM;
1761 if (drv->bdrv_save_vmstate)
1762 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1763 if (bs->file)
1764 return bdrv_save_vmstate(bs->file, buf, pos, size);
1765 return -ENOTSUP;
1766 }
1767
1768 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1769 int64_t pos, int size)
1770 {
1771 BlockDriver *drv = bs->drv;
1772 if (!drv)
1773 return -ENOMEDIUM;
1774 if (drv->bdrv_load_vmstate)
1775 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1776 if (bs->file)
1777 return bdrv_load_vmstate(bs->file, buf, pos, size);
1778 return -ENOTSUP;
1779 }
1780
1781 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
1782 {
1783 BlockDriver *drv = bs->drv;
1784
1785 if (!drv || !drv->bdrv_debug_event) {
1786 return;
1787 }
1788
1789 return drv->bdrv_debug_event(bs, event);
1790
1791 }
1792
1793 /**************************************************************/
1794 /* handling of snapshots */
1795
1796 int bdrv_can_snapshot(BlockDriverState *bs)
1797 {
1798 BlockDriver *drv = bs->drv;
1799 if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
1800 return 0;
1801 }
1802
1803 if (!drv->bdrv_snapshot_create) {
1804 if (bs->file != NULL) {
1805 return bdrv_can_snapshot(bs->file);
1806 }
1807 return 0;
1808 }
1809
1810 return 1;
1811 }
1812
1813 int bdrv_is_snapshot(BlockDriverState *bs)
1814 {
1815 return !!(bs->open_flags & BDRV_O_SNAPSHOT);
1816 }
1817
1818 BlockDriverState *bdrv_snapshots(void)
1819 {
1820 BlockDriverState *bs;
1821
1822 if (bs_snapshots) {
1823 return bs_snapshots;
1824 }
1825
1826 bs = NULL;
1827 while ((bs = bdrv_next(bs))) {
1828 if (bdrv_can_snapshot(bs)) {
1829 bs_snapshots = bs;
1830 return bs;
1831 }
1832 }
1833 return NULL;
1834 }
1835
1836 int bdrv_snapshot_create(BlockDriverState *bs,
1837 QEMUSnapshotInfo *sn_info)
1838 {
1839 BlockDriver *drv = bs->drv;
1840 if (!drv)
1841 return -ENOMEDIUM;
1842 if (drv->bdrv_snapshot_create)
1843 return drv->bdrv_snapshot_create(bs, sn_info);
1844 if (bs->file)
1845 return bdrv_snapshot_create(bs->file, sn_info);
1846 return -ENOTSUP;
1847 }
1848
1849 int bdrv_snapshot_goto(BlockDriverState *bs,
1850 const char *snapshot_id)
1851 {
1852 BlockDriver *drv = bs->drv;
1853 int ret, open_ret;
1854
1855 if (!drv)
1856 return -ENOMEDIUM;
1857 if (drv->bdrv_snapshot_goto)
1858 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1859
1860 if (bs->file) {
1861 drv->bdrv_close(bs);
1862 ret = bdrv_snapshot_goto(bs->file, snapshot_id);
1863 open_ret = drv->bdrv_open(bs, bs->open_flags);
1864 if (open_ret < 0) {
1865 bdrv_delete(bs->file);
1866 bs->drv = NULL;
1867 return open_ret;
1868 }
1869 return ret;
1870 }
1871
1872 return -ENOTSUP;
1873 }
1874
1875 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1876 {
1877 BlockDriver *drv = bs->drv;
1878 if (!drv)
1879 return -ENOMEDIUM;
1880 if (drv->bdrv_snapshot_delete)
1881 return drv->bdrv_snapshot_delete(bs, snapshot_id);
1882 if (bs->file)
1883 return bdrv_snapshot_delete(bs->file, snapshot_id);
1884 return -ENOTSUP;
1885 }
1886
1887 int bdrv_snapshot_list(BlockDriverState *bs,
1888 QEMUSnapshotInfo **psn_info)
1889 {
1890 BlockDriver *drv = bs->drv;
1891 if (!drv)
1892 return -ENOMEDIUM;
1893 if (drv->bdrv_snapshot_list)
1894 return drv->bdrv_snapshot_list(bs, psn_info);
1895 if (bs->file)
1896 return bdrv_snapshot_list(bs->file, psn_info);
1897 return -ENOTSUP;
1898 }
1899
1900 #define NB_SUFFIXES 4
1901
1902 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1903 {
1904 static const char suffixes[NB_SUFFIXES] = "KMGT";
1905 int64_t base;
1906 int i;
1907
1908 if (size <= 999) {
1909 snprintf(buf, buf_size, "%" PRId64, size);
1910 } else {
1911 base = 1024;
1912 for(i = 0; i < NB_SUFFIXES; i++) {
1913 if (size < (10 * base)) {
1914 snprintf(buf, buf_size, "%0.1f%c",
1915 (double)size / base,
1916 suffixes[i]);
1917 break;
1918 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1919 snprintf(buf, buf_size, "%" PRId64 "%c",
1920 ((size + (base >> 1)) / base),
1921 suffixes[i]);
1922 break;
1923 }
1924 base = base * 1024;
1925 }
1926 }
1927 return buf;
1928 }
1929
1930 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1931 {
1932 char buf1[128], date_buf[128], clock_buf[128];
1933 #ifdef _WIN32
1934 struct tm *ptm;
1935 #else
1936 struct tm tm;
1937 #endif
1938 time_t ti;
1939 int64_t secs;
1940
1941 if (!sn) {
1942 snprintf(buf, buf_size,
1943 "%-10s%-20s%7s%20s%15s",
1944 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1945 } else {
1946 ti = sn->date_sec;
1947 #ifdef _WIN32
1948 ptm = localtime(&ti);
1949 strftime(date_buf, sizeof(date_buf),
1950 "%Y-%m-%d %H:%M:%S", ptm);
1951 #else
1952 localtime_r(&ti, &tm);
1953 strftime(date_buf, sizeof(date_buf),
1954 "%Y-%m-%d %H:%M:%S", &tm);
1955 #endif
1956 secs = sn->vm_clock_nsec / 1000000000;
1957 snprintf(clock_buf, sizeof(clock_buf),
1958 "%02d:%02d:%02d.%03d",
1959 (int)(secs / 3600),
1960 (int)((secs / 60) % 60),
1961 (int)(secs % 60),
1962 (int)((sn->vm_clock_nsec / 1000000) % 1000));
1963 snprintf(buf, buf_size,
1964 "%-10s%-20s%7s%20s%15s",
1965 sn->id_str, sn->name,
1966 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1967 date_buf,
1968 clock_buf);
1969 }
1970 return buf;
1971 }
1972
1973
1974 /**************************************************************/
1975 /* async I/Os */
1976
1977 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1978 QEMUIOVector *qiov, int nb_sectors,
1979 BlockDriverCompletionFunc *cb, void *opaque)
1980 {
1981 BlockDriver *drv = bs->drv;
1982 BlockDriverAIOCB *ret;
1983
1984 if (!drv)
1985 return NULL;
1986 if (bdrv_check_request(bs, sector_num, nb_sectors))
1987 return NULL;
1988
1989 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
1990 cb, opaque);
1991
1992 if (ret) {
1993 /* Update stats even though technically transfer has not happened. */
1994 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1995 bs->rd_ops ++;
1996 }
1997
1998 return ret;
1999 }
2000
2001 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
2002 QEMUIOVector *qiov, int nb_sectors,
2003 BlockDriverCompletionFunc *cb, void *opaque)
2004 {
2005 BlockDriver *drv = bs->drv;
2006 BlockDriverAIOCB *ret;
2007
2008 if (!drv)
2009 return NULL;
2010 if (bs->read_only)
2011 return NULL;
2012 if (bdrv_check_request(bs, sector_num, nb_sectors))
2013 return NULL;
2014
2015 if (bs->dirty_bitmap) {
2016 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
2017 }
2018
2019 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
2020 cb, opaque);
2021
2022 if (ret) {
2023 /* Update stats even though technically transfer has not happened. */
2024 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2025 bs->wr_ops ++;
2026 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
2027 bs->wr_highest_sector = sector_num + nb_sectors - 1;
2028 }
2029 }
2030
2031 return ret;
2032 }
2033
2034
2035 typedef struct MultiwriteCB {
2036 int error;
2037 int num_requests;
2038 int num_callbacks;
2039 struct {
2040 BlockDriverCompletionFunc *cb;
2041 void *opaque;
2042 QEMUIOVector *free_qiov;
2043 void *free_buf;
2044 } callbacks[];
2045 } MultiwriteCB;
2046
2047 static void multiwrite_user_cb(MultiwriteCB *mcb)
2048 {
2049 int i;
2050
2051 for (i = 0; i < mcb->num_callbacks; i++) {
2052 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
2053 if (mcb->callbacks[i].free_qiov) {
2054 qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
2055 }
2056 qemu_free(mcb->callbacks[i].free_qiov);
2057 qemu_vfree(mcb->callbacks[i].free_buf);
2058 }
2059 }
2060
2061 static void multiwrite_cb(void *opaque, int ret)
2062 {
2063 MultiwriteCB *mcb = opaque;
2064
2065 if (ret < 0 && !mcb->error) {
2066 mcb->error = ret;
2067 }
2068
2069 mcb->num_requests--;
2070 if (mcb->num_requests == 0) {
2071 multiwrite_user_cb(mcb);
2072 qemu_free(mcb);
2073 }
2074 }
2075
2076 static int multiwrite_req_compare(const void *a, const void *b)
2077 {
2078 const BlockRequest *req1 = a, *req2 = b;
2079
2080 /*
2081 * Note that we can't simply subtract req2->sector from req1->sector
2082 * here as that could overflow the return value.
2083 */
2084 if (req1->sector > req2->sector) {
2085 return 1;
2086 } else if (req1->sector < req2->sector) {
2087 return -1;
2088 } else {
2089 return 0;
2090 }
2091 }
2092
2093 /*
2094 * Takes a bunch of requests and tries to merge them. Returns the number of
2095 * requests that remain after merging.
2096 */
2097 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
2098 int num_reqs, MultiwriteCB *mcb)
2099 {
2100 int i, outidx;
2101
2102 // Sort requests by start sector
2103 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
2104
2105 // Check if adjacent requests touch the same clusters. If so, combine them,
2106 // filling up gaps with zero sectors.
2107 outidx = 0;
2108 for (i = 1; i < num_reqs; i++) {
2109 int merge = 0;
2110 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
2111
2112 // This handles the cases that are valid for all block drivers, namely
2113 // exactly sequential writes and overlapping writes.
2114 if (reqs[i].sector <= oldreq_last) {
2115 merge = 1;
2116 }
2117
2118 // The block driver may decide that it makes sense to combine requests
2119 // even if there is a gap of some sectors between them. In this case,
2120 // the gap is filled with zeros (therefore only applicable for yet
2121 // unused space in format like qcow2).
2122 if (!merge && bs->drv->bdrv_merge_requests) {
2123 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
2124 }
2125
2126 if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
2127 merge = 0;
2128 }
2129
2130 if (merge) {
2131 size_t size;
2132 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
2133 qemu_iovec_init(qiov,
2134 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
2135
2136 // Add the first request to the merged one. If the requests are
2137 // overlapping, drop the last sectors of the first request.
2138 size = (reqs[i].sector - reqs[outidx].sector) << 9;
2139 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
2140
2141 // We might need to add some zeros between the two requests
2142 if (reqs[i].sector > oldreq_last) {
2143 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
2144 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
2145 memset(buf, 0, zero_bytes);
2146 qemu_iovec_add(qiov, buf, zero_bytes);
2147 mcb->callbacks[i].free_buf = buf;
2148 }
2149
2150 // Add the second request
2151 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
2152
2153 reqs[outidx].nb_sectors = qiov->size >> 9;
2154 reqs[outidx].qiov = qiov;
2155
2156 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
2157 } else {
2158 outidx++;
2159 reqs[outidx].sector = reqs[i].sector;
2160 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
2161 reqs[outidx].qiov = reqs[i].qiov;
2162 }
2163 }
2164
2165 return outidx + 1;
2166 }
2167
2168 /*
2169 * Submit multiple AIO write requests at once.
2170 *
2171 * On success, the function returns 0 and all requests in the reqs array have
2172 * been submitted. In error case this function returns -1, and any of the
2173 * requests may or may not be submitted yet. In particular, this means that the
2174 * callback will be called for some of the requests, for others it won't. The
2175 * caller must check the error field of the BlockRequest to wait for the right
2176 * callbacks (if error != 0, no callback will be called).
2177 *
2178 * The implementation may modify the contents of the reqs array, e.g. to merge
2179 * requests. However, the fields opaque and error are left unmodified as they
2180 * are used to signal failure for a single request to the caller.
2181 */
2182 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
2183 {
2184 BlockDriverAIOCB *acb;
2185 MultiwriteCB *mcb;
2186 int i;
2187
2188 if (num_reqs == 0) {
2189 return 0;
2190 }
2191
2192 // Create MultiwriteCB structure
2193 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
2194 mcb->num_requests = 0;
2195 mcb->num_callbacks = num_reqs;
2196
2197 for (i = 0; i < num_reqs; i++) {
2198 mcb->callbacks[i].cb = reqs[i].cb;
2199 mcb->callbacks[i].opaque = reqs[i].opaque;
2200 }
2201
2202 // Check for mergable requests
2203 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
2204
2205 /*
2206 * Run the aio requests. As soon as one request can't be submitted
2207 * successfully, fail all requests that are not yet submitted (we must
2208 * return failure for all requests anyway)
2209 *
2210 * num_requests cannot be set to the right value immediately: If
2211 * bdrv_aio_writev fails for some request, num_requests would be too high
2212 * and therefore multiwrite_cb() would never recognize the multiwrite
2213 * request as completed. We also cannot use the loop variable i to set it
2214 * when the first request fails because the callback may already have been
2215 * called for previously submitted requests. Thus, num_requests must be
2216 * incremented for each request that is submitted.
2217 *
2218 * The problem that callbacks may be called early also means that we need
2219 * to take care that num_requests doesn't become 0 before all requests are
2220 * submitted - multiwrite_cb() would consider the multiwrite request
2221 * completed. A dummy request that is "completed" by a manual call to
2222 * multiwrite_cb() takes care of this.
2223 */
2224 mcb->num_requests = 1;
2225
2226 for (i = 0; i < num_reqs; i++) {
2227 mcb->num_requests++;
2228 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
2229 reqs[i].nb_sectors, multiwrite_cb, mcb);
2230
2231 if (acb == NULL) {
2232 // We can only fail the whole thing if no request has been
2233 // submitted yet. Otherwise we'll wait for the submitted AIOs to
2234 // complete and report the error in the callback.
2235 if (i == 0) {
2236 goto fail;
2237 } else {
2238 multiwrite_cb(mcb, -EIO);
2239 break;
2240 }
2241 }
2242 }
2243
2244 /* Complete the dummy request */
2245 multiwrite_cb(mcb, 0);
2246
2247 return 0;
2248
2249 fail:
2250 for (i = 0; i < mcb->num_callbacks; i++) {
2251 reqs[i].error = -EIO;
2252 }
2253 qemu_free(mcb);
2254 return -1;
2255 }
2256
2257 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
2258 BlockDriverCompletionFunc *cb, void *opaque)
2259 {
2260 BlockDriver *drv = bs->drv;
2261
2262 if (bs->open_flags & BDRV_O_NO_FLUSH) {
2263 return bdrv_aio_noop_em(bs, cb, opaque);
2264 }
2265
2266 if (!drv)
2267 return NULL;
2268 return drv->bdrv_aio_flush(bs, cb, opaque);
2269 }
2270
2271 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
2272 {
2273 acb->pool->cancel(acb);
2274 }
2275
2276
2277 /**************************************************************/
2278 /* async block device emulation */
2279
2280 typedef struct BlockDriverAIOCBSync {
2281 BlockDriverAIOCB common;
2282 QEMUBH *bh;
2283 int ret;
2284 /* vector translation state */
2285 QEMUIOVector *qiov;
2286 uint8_t *bounce;
2287 int is_write;
2288 } BlockDriverAIOCBSync;
2289
2290 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
2291 {
2292 BlockDriverAIOCBSync *acb =
2293 container_of(blockacb, BlockDriverAIOCBSync, common);
2294 qemu_bh_delete(acb->bh);
2295 acb->bh = NULL;
2296 qemu_aio_release(acb);
2297 }
2298
2299 static AIOPool bdrv_em_aio_pool = {
2300 .aiocb_size = sizeof(BlockDriverAIOCBSync),
2301 .cancel = bdrv_aio_cancel_em,
2302 };
2303
2304 static void bdrv_aio_bh_cb(void *opaque)
2305 {
2306 BlockDriverAIOCBSync *acb = opaque;
2307
2308 if (!acb->is_write)
2309 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
2310 qemu_vfree(acb->bounce);
2311 acb->common.cb(acb->common.opaque, acb->ret);
2312 qemu_bh_delete(acb->bh);
2313 acb->bh = NULL;
2314 qemu_aio_release(acb);
2315 }
2316
2317 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
2318 int64_t sector_num,
2319 QEMUIOVector *qiov,
2320 int nb_sectors,
2321 BlockDriverCompletionFunc *cb,
2322 void *opaque,
2323 int is_write)
2324
2325 {
2326 BlockDriverAIOCBSync *acb;
2327
2328 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2329 acb->is_write = is_write;
2330 acb->qiov = qiov;
2331 acb->bounce = qemu_blockalign(bs, qiov->size);
2332
2333 if (!acb->bh)
2334 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2335
2336 if (is_write) {
2337 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
2338 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
2339 } else {
2340 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
2341 }
2342
2343 qemu_bh_schedule(acb->bh);
2344
2345 return &acb->common;
2346 }
2347
2348 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
2349 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2350 BlockDriverCompletionFunc *cb, void *opaque)
2351 {
2352 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
2353 }
2354
2355 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
2356 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2357 BlockDriverCompletionFunc *cb, void *opaque)
2358 {
2359 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
2360 }
2361
2362 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
2363 BlockDriverCompletionFunc *cb, void *opaque)
2364 {
2365 BlockDriverAIOCBSync *acb;
2366
2367 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2368 acb->is_write = 1; /* don't bounce in the completion hadler */
2369 acb->qiov = NULL;
2370 acb->bounce = NULL;
2371 acb->ret = 0;
2372
2373 if (!acb->bh)
2374 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2375
2376 bdrv_flush(bs);
2377 qemu_bh_schedule(acb->bh);
2378 return &acb->common;
2379 }
2380
2381 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
2382 BlockDriverCompletionFunc *cb, void *opaque)
2383 {
2384 BlockDriverAIOCBSync *acb;
2385
2386 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2387 acb->is_write = 1; /* don't bounce in the completion handler */
2388 acb->qiov = NULL;
2389 acb->bounce = NULL;
2390 acb->ret = 0;
2391
2392 if (!acb->bh) {
2393 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2394 }
2395
2396 qemu_bh_schedule(acb->bh);
2397 return &acb->common;
2398 }
2399
2400 /**************************************************************/
2401 /* sync block device emulation */
2402
2403 static void bdrv_rw_em_cb(void *opaque, int ret)
2404 {
2405 *(int *)opaque = ret;
2406 }
2407
2408 #define NOT_DONE 0x7fffffff
2409
2410 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
2411 uint8_t *buf, int nb_sectors)
2412 {
2413 int async_ret;
2414 BlockDriverAIOCB *acb;
2415 struct iovec iov;
2416 QEMUIOVector qiov;
2417
2418 async_context_push();
2419
2420 async_ret = NOT_DONE;
2421 iov.iov_base = (void *)buf;
2422 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2423 qemu_iovec_init_external(&qiov, &iov, 1);
2424 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
2425 bdrv_rw_em_cb, &async_ret);
2426 if (acb == NULL) {
2427 async_ret = -1;
2428 goto fail;
2429 }
2430
2431 while (async_ret == NOT_DONE) {
2432 qemu_aio_wait();
2433 }
2434
2435
2436 fail:
2437 async_context_pop();
2438 return async_ret;
2439 }
2440
2441 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
2442 const uint8_t *buf, int nb_sectors)
2443 {
2444 int async_ret;
2445 BlockDriverAIOCB *acb;
2446 struct iovec iov;
2447 QEMUIOVector qiov;
2448
2449 async_context_push();
2450
2451 async_ret = NOT_DONE;
2452 iov.iov_base = (void *)buf;
2453 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2454 qemu_iovec_init_external(&qiov, &iov, 1);
2455 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
2456 bdrv_rw_em_cb, &async_ret);
2457 if (acb == NULL) {
2458 async_ret = -1;
2459 goto fail;
2460 }
2461 while (async_ret == NOT_DONE) {
2462 qemu_aio_wait();
2463 }
2464
2465 fail:
2466 async_context_pop();
2467 return async_ret;
2468 }
2469
2470 void bdrv_init(void)
2471 {
2472 module_call_init(MODULE_INIT_BLOCK);
2473 }
2474
2475 void bdrv_init_with_whitelist(void)
2476 {
2477 use_bdrv_whitelist = 1;
2478 bdrv_init();
2479 }
2480
2481 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
2482 BlockDriverCompletionFunc *cb, void *opaque)
2483 {
2484 BlockDriverAIOCB *acb;
2485
2486 if (pool->free_aiocb) {
2487 acb = pool->free_aiocb;
2488 pool->free_aiocb = acb->next;
2489 } else {
2490 acb = qemu_mallocz(pool->aiocb_size);
2491 acb->pool = pool;
2492 }
2493 acb->bs = bs;
2494 acb->cb = cb;
2495 acb->opaque = opaque;
2496 return acb;
2497 }
2498
2499 void qemu_aio_release(void *p)
2500 {
2501 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
2502 AIOPool *pool = acb->pool;
2503 acb->next = pool->free_aiocb;
2504 pool->free_aiocb = acb;
2505 }
2506
2507 /**************************************************************/
2508 /* removable device support */
2509
2510 /**
2511 * Return TRUE if the media is present
2512 */
2513 int bdrv_is_inserted(BlockDriverState *bs)
2514 {
2515 BlockDriver *drv = bs->drv;
2516 int ret;
2517 if (!drv)
2518 return 0;
2519 if (!drv->bdrv_is_inserted)
2520 return !bs->tray_open;
2521 ret = drv->bdrv_is_inserted(bs);
2522 return ret;
2523 }
2524
2525 /**
2526 * Return TRUE if the media changed since the last call to this
2527 * function. It is currently only used for floppy disks
2528 */
2529 int bdrv_media_changed(BlockDriverState *bs)
2530 {
2531 BlockDriver *drv = bs->drv;
2532 int ret;
2533
2534 if (!drv || !drv->bdrv_media_changed)
2535 ret = -ENOTSUP;
2536 else
2537 ret = drv->bdrv_media_changed(bs);
2538 if (ret == -ENOTSUP)
2539 ret = bs->media_changed;
2540 bs->media_changed = 0;
2541 return ret;
2542 }
2543
2544 /**
2545 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
2546 */
2547 int bdrv_eject(BlockDriverState *bs, int eject_flag)
2548 {
2549 BlockDriver *drv = bs->drv;
2550 int ret;
2551
2552 if (bs->locked) {
2553 return -EBUSY;
2554 }
2555
2556 if (!drv || !drv->bdrv_eject) {
2557 ret = -ENOTSUP;
2558 } else {
2559 ret = drv->bdrv_eject(bs, eject_flag);
2560 }
2561 if (ret == -ENOTSUP) {
2562 ret = 0;
2563 }
2564 if (ret >= 0) {
2565 bs->tray_open = eject_flag;
2566 }
2567
2568 return ret;
2569 }
2570
2571 int bdrv_is_locked(BlockDriverState *bs)
2572 {
2573 return bs->locked;
2574 }
2575
2576 /**
2577 * Lock or unlock the media (if it is locked, the user won't be able
2578 * to eject it manually).
2579 */
2580 void bdrv_set_locked(BlockDriverState *bs, int locked)
2581 {
2582 BlockDriver *drv = bs->drv;
2583
2584 bs->locked = locked;
2585 if (drv && drv->bdrv_set_locked) {
2586 drv->bdrv_set_locked(bs, locked);
2587 }
2588 }
2589
2590 /* needed for generic scsi interface */
2591
2592 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
2593 {
2594 BlockDriver *drv = bs->drv;
2595
2596 if (drv && drv->bdrv_ioctl)
2597 return drv->bdrv_ioctl(bs, req, buf);
2598 return -ENOTSUP;
2599 }
2600
2601 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
2602 unsigned long int req, void *buf,
2603 BlockDriverCompletionFunc *cb, void *opaque)
2604 {
2605 BlockDriver *drv = bs->drv;
2606
2607 if (drv && drv->bdrv_aio_ioctl)
2608 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
2609 return NULL;
2610 }
2611
2612
2613
2614 void *qemu_blockalign(BlockDriverState *bs, size_t size)
2615 {
2616 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
2617 }
2618
2619 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
2620 {
2621 int64_t bitmap_size;
2622
2623 bs->dirty_count = 0;
2624 if (enable) {
2625 if (!bs->dirty_bitmap) {
2626 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
2627 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
2628 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
2629
2630 bs->dirty_bitmap = qemu_mallocz(bitmap_size);
2631 }
2632 } else {
2633 if (bs->dirty_bitmap) {
2634 qemu_free(bs->dirty_bitmap);
2635 bs->dirty_bitmap = NULL;
2636 }
2637 }
2638 }
2639
2640 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
2641 {
2642 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
2643
2644 if (bs->dirty_bitmap &&
2645 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
2646 return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
2647 (1 << (chunk % (sizeof(unsigned long) * 8)));
2648 } else {
2649 return 0;
2650 }
2651 }
2652
2653 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2654 int nr_sectors)
2655 {
2656 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2657 }
2658
2659 int64_t bdrv_get_dirty_count(BlockDriverState *bs)
2660 {
2661 return bs->dirty_count;
2662 }
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