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device-assignment: Byte-wise ROM read
[qemu-kvm/stefanha.git] / block.c
blob452ae94eeab9d63b1900a9153d0c83d07270a672
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 /* commit COW file into the raw image */
743 int bdrv_commit(BlockDriverState *bs)
744 {
745 BlockDriver *drv = bs->drv;
746 int64_t i, total_sectors;
747 int n, j, ro, open_flags;
748 int ret = 0, rw_ret = 0;
749 unsigned char sector[BDRV_SECTOR_SIZE];
750 char filename[1024];
751 BlockDriverState *bs_rw, *bs_ro;
752
753 if (!drv)
754 return -ENOMEDIUM;
755
756 if (!bs->backing_hd) {
757 return -ENOTSUP;
758 }
759
760 if (bs->backing_hd->keep_read_only) {
761 return -EACCES;
762 }
763
764 ro = bs->backing_hd->read_only;
765 strncpy(filename, bs->backing_hd->filename, sizeof(filename));
766 open_flags = bs->backing_hd->open_flags;
767
768 if (ro) {
769 /* re-open as RW */
770 bdrv_delete(bs->backing_hd);
771 bs->backing_hd = NULL;
772 bs_rw = bdrv_new("");
773 rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR, drv);
774 if (rw_ret < 0) {
775 bdrv_delete(bs_rw);
776 /* try to re-open read-only */
777 bs_ro = bdrv_new("");
778 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, drv);
779 if (ret < 0) {
780 bdrv_delete(bs_ro);
781 /* drive not functional anymore */
782 bs->drv = NULL;
783 return ret;
784 }
785 bs->backing_hd = bs_ro;
786 return rw_ret;
787 }
788 bs->backing_hd = bs_rw;
789 }
790
791 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
792 for (i = 0; i < total_sectors;) {
793 if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
794 for(j = 0; j < n; j++) {
795 if (bdrv_read(bs, i, sector, 1) != 0) {
796 ret = -EIO;
797 goto ro_cleanup;
798 }
799
800 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
801 ret = -EIO;
802 goto ro_cleanup;
803 }
804 i++;
805 }
806 } else {
807 i += n;
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
825 if (ro) {
826 /* re-open as RO */
827 bdrv_delete(bs->backing_hd);
828 bs->backing_hd = NULL;
829 bs_ro = bdrv_new("");
830 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, drv);
831 if (ret < 0) {
832 bdrv_delete(bs_ro);
833 /* drive not functional anymore */
834 bs->drv = NULL;
835 return ret;
836 }
837 bs->backing_hd = bs_ro;
838 bs->backing_hd->keep_read_only = 0;
839 }
840
841 return ret;
842 }
843
844 void bdrv_commit_all(void)
845 {
846 BlockDriverState *bs;
847
848 QTAILQ_FOREACH(bs, &bdrv_states, list) {
849 bdrv_commit(bs);
850 }
851 }
852
853 /*
854 * Return values:
855 * 0 - success
856 * -EINVAL - backing format specified, but no file
857 * -ENOSPC - can't update the backing file because no space is left in the
858 * image file header
859 * -ENOTSUP - format driver doesn't support changing the backing file
860 */
861 int bdrv_change_backing_file(BlockDriverState *bs,
862 const char *backing_file, const char *backing_fmt)
863 {
864 BlockDriver *drv = bs->drv;
865
866 if (drv->bdrv_change_backing_file != NULL) {
867 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
868 } else {
869 return -ENOTSUP;
870 }
871 }
872
873 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
874 size_t size)
875 {
876 int64_t len;
877
878 if (!bdrv_is_inserted(bs))
879 return -ENOMEDIUM;
880
881 if (bs->growable)
882 return 0;
883
884 len = bdrv_getlength(bs);
885
886 if (offset < 0)
887 return -EIO;
888
889 if ((offset > len) || (len - offset < size))
890 return -EIO;
891
892 return 0;
893 }
894
895 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
896 int nb_sectors)
897 {
898 return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
899 nb_sectors * BDRV_SECTOR_SIZE);
900 }
901
902 /* return < 0 if error. See bdrv_write() for the return codes */
903 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
904 uint8_t *buf, int nb_sectors)
905 {
906 BlockDriver *drv = bs->drv;
907
908 if (!drv)
909 return -ENOMEDIUM;
910 if (bdrv_check_request(bs, sector_num, nb_sectors))
911 return -EIO;
912
913 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
914 }
915
916 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
917 int nb_sectors, int dirty)
918 {
919 int64_t start, end;
920 unsigned long val, idx, bit;
921
922 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
923 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
924
925 for (; start <= end; start++) {
926 idx = start / (sizeof(unsigned long) * 8);
927 bit = start % (sizeof(unsigned long) * 8);
928 val = bs->dirty_bitmap[idx];
929 if (dirty) {
930 if (!(val & (1 << bit))) {
931 bs->dirty_count++;
932 val |= 1 << bit;
933 }
934 } else {
935 if (val & (1 << bit)) {
936 bs->dirty_count--;
937 val &= ~(1 << bit);
938 }
939 }
940 bs->dirty_bitmap[idx] = val;
941 }
942 }
943
944 /* Return < 0 if error. Important errors are:
945 -EIO generic I/O error (may happen for all errors)
946 -ENOMEDIUM No media inserted.
947 -EINVAL Invalid sector number or nb_sectors
948 -EACCES Trying to write a read-only device
949 */
950 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
951 const uint8_t *buf, int nb_sectors)
952 {
953 BlockDriver *drv = bs->drv;
954 if (!bs->drv)
955 return -ENOMEDIUM;
956 if (bs->read_only)
957 return -EACCES;
958 if (bdrv_check_request(bs, sector_num, nb_sectors))
959 return -EIO;
960
961 if (bs->dirty_bitmap) {
962 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
963 }
964
965 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
966 bs->wr_highest_sector = sector_num + nb_sectors - 1;
967 }
968
969 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
970 }
971
972 int bdrv_pread(BlockDriverState *bs, int64_t offset,
973 void *buf, int count1)
974 {
975 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
976 int len, nb_sectors, count;
977 int64_t sector_num;
978 int ret;
979
980 count = count1;
981 /* first read to align to sector start */
982 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
983 if (len > count)
984 len = count;
985 sector_num = offset >> BDRV_SECTOR_BITS;
986 if (len > 0) {
987 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
988 return ret;
989 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
990 count -= len;
991 if (count == 0)
992 return count1;
993 sector_num++;
994 buf += len;
995 }
996
997 /* read the sectors "in place" */
998 nb_sectors = count >> BDRV_SECTOR_BITS;
999 if (nb_sectors > 0) {
1000 if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
1001 return ret;
1002 sector_num += nb_sectors;
1003 len = nb_sectors << BDRV_SECTOR_BITS;
1004 buf += len;
1005 count -= len;
1006 }
1007
1008 /* add data from the last sector */
1009 if (count > 0) {
1010 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1011 return ret;
1012 memcpy(buf, tmp_buf, count);
1013 }
1014 return count1;
1015 }
1016
1017 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
1018 const void *buf, int count1)
1019 {
1020 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1021 int len, nb_sectors, count;
1022 int64_t sector_num;
1023 int ret;
1024
1025 count = count1;
1026 /* first write to align to sector start */
1027 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1028 if (len > count)
1029 len = count;
1030 sector_num = offset >> BDRV_SECTOR_BITS;
1031 if (len > 0) {
1032 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1033 return ret;
1034 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1035 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1036 return ret;
1037 count -= len;
1038 if (count == 0)
1039 return count1;
1040 sector_num++;
1041 buf += len;
1042 }
1043
1044 /* write the sectors "in place" */
1045 nb_sectors = count >> BDRV_SECTOR_BITS;
1046 if (nb_sectors > 0) {
1047 if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
1048 return ret;
1049 sector_num += nb_sectors;
1050 len = nb_sectors << BDRV_SECTOR_BITS;
1051 buf += len;
1052 count -= len;
1053 }
1054
1055 /* add data from the last sector */
1056 if (count > 0) {
1057 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1058 return ret;
1059 memcpy(tmp_buf, buf, count);
1060 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1061 return ret;
1062 }
1063 return count1;
1064 }
1065
1066 /*
1067 * Writes to the file and ensures that no writes are reordered across this
1068 * request (acts as a barrier)
1069 *
1070 * Returns 0 on success, -errno in error cases.
1071 */
1072 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
1073 const void *buf, int count)
1074 {
1075 int ret;
1076
1077 ret = bdrv_pwrite(bs, offset, buf, count);
1078 if (ret < 0) {
1079 return ret;
1080 }
1081
1082 /* No flush needed for cache=writethrough, it uses O_DSYNC */
1083 if ((bs->open_flags & BDRV_O_CACHE_MASK) != 0) {
1084 bdrv_flush(bs);
1085 }
1086
1087 return 0;
1088 }
1089
1090 /*
1091 * Writes to the file and ensures that no writes are reordered across this
1092 * request (acts as a barrier)
1093 *
1094 * Returns 0 on success, -errno in error cases.
1095 */
1096 int bdrv_write_sync(BlockDriverState *bs, int64_t sector_num,
1097 const uint8_t *buf, int nb_sectors)
1098 {
1099 return bdrv_pwrite_sync(bs, BDRV_SECTOR_SIZE * sector_num,
1100 buf, BDRV_SECTOR_SIZE * nb_sectors);
1101 }
1102
1103 /**
1104 * Truncate file to 'offset' bytes (needed only for file protocols)
1105 */
1106 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
1107 {
1108 BlockDriver *drv = bs->drv;
1109 int ret;
1110 if (!drv)
1111 return -ENOMEDIUM;
1112 if (!drv->bdrv_truncate)
1113 return -ENOTSUP;
1114 if (bs->read_only)
1115 return -EACCES;
1116 ret = drv->bdrv_truncate(bs, offset);
1117 if (ret == 0) {
1118 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
1119 }
1120 return ret;
1121 }
1122
1123 /**
1124 * Length of a file in bytes. Return < 0 if error or unknown.
1125 */
1126 int64_t bdrv_getlength(BlockDriverState *bs)
1127 {
1128 BlockDriver *drv = bs->drv;
1129 if (!drv)
1130 return -ENOMEDIUM;
1131
1132 /* Fixed size devices use the total_sectors value for speed instead of
1133 issuing a length query (like lseek) on each call. Also, legacy block
1134 drivers don't provide a bdrv_getlength function and must use
1135 total_sectors. */
1136 if (!bs->growable || !drv->bdrv_getlength) {
1137 return bs->total_sectors * BDRV_SECTOR_SIZE;
1138 }
1139 return drv->bdrv_getlength(bs);
1140 }
1141
1142 /* return 0 as number of sectors if no device present or error */
1143 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
1144 {
1145 int64_t length;
1146 length = bdrv_getlength(bs);
1147 if (length < 0)
1148 length = 0;
1149 else
1150 length = length >> BDRV_SECTOR_BITS;
1151 *nb_sectors_ptr = length;
1152 }
1153
1154 struct partition {
1155 uint8_t boot_ind; /* 0x80 - active */
1156 uint8_t head; /* starting head */
1157 uint8_t sector; /* starting sector */
1158 uint8_t cyl; /* starting cylinder */
1159 uint8_t sys_ind; /* What partition type */
1160 uint8_t end_head; /* end head */
1161 uint8_t end_sector; /* end sector */
1162 uint8_t end_cyl; /* end cylinder */
1163 uint32_t start_sect; /* starting sector counting from 0 */
1164 uint32_t nr_sects; /* nr of sectors in partition */
1165 } __attribute__((packed));
1166
1167 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
1168 static int guess_disk_lchs(BlockDriverState *bs,
1169 int *pcylinders, int *pheads, int *psectors)
1170 {
1171 uint8_t buf[BDRV_SECTOR_SIZE];
1172 int ret, i, heads, sectors, cylinders;
1173 struct partition *p;
1174 uint32_t nr_sects;
1175 uint64_t nb_sectors;
1176
1177 bdrv_get_geometry(bs, &nb_sectors);
1178
1179 ret = bdrv_read(bs, 0, buf, 1);
1180 if (ret < 0)
1181 return -1;
1182 /* test msdos magic */
1183 if (buf[510] != 0x55 || buf[511] != 0xaa)
1184 return -1;
1185 for(i = 0; i < 4; i++) {
1186 p = ((struct partition *)(buf + 0x1be)) + i;
1187 nr_sects = le32_to_cpu(p->nr_sects);
1188 if (nr_sects && p->end_head) {
1189 /* We make the assumption that the partition terminates on
1190 a cylinder boundary */
1191 heads = p->end_head + 1;
1192 sectors = p->end_sector & 63;
1193 if (sectors == 0)
1194 continue;
1195 cylinders = nb_sectors / (heads * sectors);
1196 if (cylinders < 1 || cylinders > 16383)
1197 continue;
1198 *pheads = heads;
1199 *psectors = sectors;
1200 *pcylinders = cylinders;
1201 #if 0
1202 printf("guessed geometry: LCHS=%d %d %d\n",
1203 cylinders, heads, sectors);
1204 #endif
1205 return 0;
1206 }
1207 }
1208 return -1;
1209 }
1210
1211 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
1212 {
1213 int translation, lba_detected = 0;
1214 int cylinders, heads, secs;
1215 uint64_t nb_sectors;
1216
1217 /* if a geometry hint is available, use it */
1218 bdrv_get_geometry(bs, &nb_sectors);
1219 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
1220 translation = bdrv_get_translation_hint(bs);
1221 if (cylinders != 0) {
1222 *pcyls = cylinders;
1223 *pheads = heads;
1224 *psecs = secs;
1225 } else {
1226 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
1227 if (heads > 16) {
1228 /* if heads > 16, it means that a BIOS LBA
1229 translation was active, so the default
1230 hardware geometry is OK */
1231 lba_detected = 1;
1232 goto default_geometry;
1233 } else {
1234 *pcyls = cylinders;
1235 *pheads = heads;
1236 *psecs = secs;
1237 /* disable any translation to be in sync with
1238 the logical geometry */
1239 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
1240 bdrv_set_translation_hint(bs,
1241 BIOS_ATA_TRANSLATION_NONE);
1242 }
1243 }
1244 } else {
1245 default_geometry:
1246 /* if no geometry, use a standard physical disk geometry */
1247 cylinders = nb_sectors / (16 * 63);
1248
1249 if (cylinders > 16383)
1250 cylinders = 16383;
1251 else if (cylinders < 2)
1252 cylinders = 2;
1253 *pcyls = cylinders;
1254 *pheads = 16;
1255 *psecs = 63;
1256 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
1257 if ((*pcyls * *pheads) <= 131072) {
1258 bdrv_set_translation_hint(bs,
1259 BIOS_ATA_TRANSLATION_LARGE);
1260 } else {
1261 bdrv_set_translation_hint(bs,
1262 BIOS_ATA_TRANSLATION_LBA);
1263 }
1264 }
1265 }
1266 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
1267 }
1268 }
1269
1270 void bdrv_set_geometry_hint(BlockDriverState *bs,
1271 int cyls, int heads, int secs)
1272 {
1273 bs->cyls = cyls;
1274 bs->heads = heads;
1275 bs->secs = secs;
1276 }
1277
1278 void bdrv_set_type_hint(BlockDriverState *bs, int type)
1279 {
1280 bs->type = type;
1281 bs->removable = ((type == BDRV_TYPE_CDROM ||
1282 type == BDRV_TYPE_FLOPPY));
1283 }
1284
1285 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
1286 {
1287 bs->translation = translation;
1288 }
1289
1290 void bdrv_get_geometry_hint(BlockDriverState *bs,
1291 int *pcyls, int *pheads, int *psecs)
1292 {
1293 *pcyls = bs->cyls;
1294 *pheads = bs->heads;
1295 *psecs = bs->secs;
1296 }
1297
1298 int bdrv_get_type_hint(BlockDriverState *bs)
1299 {
1300 return bs->type;
1301 }
1302
1303 int bdrv_get_translation_hint(BlockDriverState *bs)
1304 {
1305 return bs->translation;
1306 }
1307
1308 void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
1309 BlockErrorAction on_write_error)
1310 {
1311 bs->on_read_error = on_read_error;
1312 bs->on_write_error = on_write_error;
1313 }
1314
1315 BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
1316 {
1317 return is_read ? bs->on_read_error : bs->on_write_error;
1318 }
1319
1320 void bdrv_set_removable(BlockDriverState *bs, int removable)
1321 {
1322 bs->removable = removable;
1323 if (removable && bs == bs_snapshots) {
1324 bs_snapshots = NULL;
1325 }
1326 }
1327
1328 int bdrv_is_removable(BlockDriverState *bs)
1329 {
1330 return bs->removable;
1331 }
1332
1333 int bdrv_is_read_only(BlockDriverState *bs)
1334 {
1335 return bs->read_only;
1336 }
1337
1338 int bdrv_is_sg(BlockDriverState *bs)
1339 {
1340 return bs->sg;
1341 }
1342
1343 int bdrv_enable_write_cache(BlockDriverState *bs)
1344 {
1345 return bs->enable_write_cache;
1346 }
1347
1348 /* XXX: no longer used */
1349 void bdrv_set_change_cb(BlockDriverState *bs,
1350 void (*change_cb)(void *opaque), void *opaque)
1351 {
1352 bs->change_cb = change_cb;
1353 bs->change_opaque = opaque;
1354 }
1355
1356 int bdrv_is_encrypted(BlockDriverState *bs)
1357 {
1358 if (bs->backing_hd && bs->backing_hd->encrypted)
1359 return 1;
1360 return bs->encrypted;
1361 }
1362
1363 int bdrv_key_required(BlockDriverState *bs)
1364 {
1365 BlockDriverState *backing_hd = bs->backing_hd;
1366
1367 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1368 return 1;
1369 return (bs->encrypted && !bs->valid_key);
1370 }
1371
1372 int bdrv_set_key(BlockDriverState *bs, const char *key)
1373 {
1374 int ret;
1375 if (bs->backing_hd && bs->backing_hd->encrypted) {
1376 ret = bdrv_set_key(bs->backing_hd, key);
1377 if (ret < 0)
1378 return ret;
1379 if (!bs->encrypted)
1380 return 0;
1381 }
1382 if (!bs->encrypted) {
1383 return -EINVAL;
1384 } else if (!bs->drv || !bs->drv->bdrv_set_key) {
1385 return -ENOMEDIUM;
1386 }
1387 ret = bs->drv->bdrv_set_key(bs, key);
1388 if (ret < 0) {
1389 bs->valid_key = 0;
1390 } else if (!bs->valid_key) {
1391 bs->valid_key = 1;
1392 /* call the change callback now, we skipped it on open */
1393 bs->media_changed = 1;
1394 if (bs->change_cb)
1395 bs->change_cb(bs->change_opaque);
1396 }
1397 return ret;
1398 }
1399
1400 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1401 {
1402 if (!bs->drv) {
1403 buf[0] = '\0';
1404 } else {
1405 pstrcpy(buf, buf_size, bs->drv->format_name);
1406 }
1407 }
1408
1409 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1410 void *opaque)
1411 {
1412 BlockDriver *drv;
1413
1414 QLIST_FOREACH(drv, &bdrv_drivers, list) {
1415 it(opaque, drv->format_name);
1416 }
1417 }
1418
1419 BlockDriverState *bdrv_find(const char *name)
1420 {
1421 BlockDriverState *bs;
1422
1423 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1424 if (!strcmp(name, bs->device_name)) {
1425 return bs;
1426 }
1427 }
1428 return NULL;
1429 }
1430
1431 BlockDriverState *bdrv_next(BlockDriverState *bs)
1432 {
1433 if (!bs) {
1434 return QTAILQ_FIRST(&bdrv_states);
1435 }
1436 return QTAILQ_NEXT(bs, list);
1437 }
1438
1439 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1440 {
1441 BlockDriverState *bs;
1442
1443 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1444 it(opaque, bs);
1445 }
1446 }
1447
1448 const char *bdrv_get_device_name(BlockDriverState *bs)
1449 {
1450 return bs->device_name;
1451 }
1452
1453 void bdrv_flush(BlockDriverState *bs)
1454 {
1455 if (bs->open_flags & BDRV_O_NO_FLUSH) {
1456 return;
1457 }
1458
1459 if (bs->drv && bs->drv->bdrv_flush)
1460 bs->drv->bdrv_flush(bs);
1461 }
1462
1463 void bdrv_flush_all(void)
1464 {
1465 BlockDriverState *bs;
1466
1467 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1468 if (bs->drv && !bdrv_is_read_only(bs) &&
1469 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) {
1470 bdrv_flush(bs);
1471 }
1472 }
1473 }
1474
1475 int bdrv_has_zero_init(BlockDriverState *bs)
1476 {
1477 assert(bs->drv);
1478
1479 if (bs->drv->no_zero_init) {
1480 return 0;
1481 } else if (bs->file) {
1482 return bdrv_has_zero_init(bs->file);
1483 }
1484
1485 return 1;
1486 }
1487
1488 /*
1489 * Returns true iff the specified sector is present in the disk image. Drivers
1490 * not implementing the functionality are assumed to not support backing files,
1491 * hence all their sectors are reported as allocated.
1492 *
1493 * 'pnum' is set to the number of sectors (including and immediately following
1494 * the specified sector) that are known to be in the same
1495 * allocated/unallocated state.
1496 *
1497 * 'nb_sectors' is the max value 'pnum' should be set to.
1498 */
1499 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1500 int *pnum)
1501 {
1502 int64_t n;
1503 if (!bs->drv->bdrv_is_allocated) {
1504 if (sector_num >= bs->total_sectors) {
1505 *pnum = 0;
1506 return 0;
1507 }
1508 n = bs->total_sectors - sector_num;
1509 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1510 return 1;
1511 }
1512 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1513 }
1514
1515 void bdrv_mon_event(const BlockDriverState *bdrv,
1516 BlockMonEventAction action, int is_read)
1517 {
1518 QObject *data;
1519 const char *action_str;
1520
1521 switch (action) {
1522 case BDRV_ACTION_REPORT:
1523 action_str = "report";
1524 break;
1525 case BDRV_ACTION_IGNORE:
1526 action_str = "ignore";
1527 break;
1528 case BDRV_ACTION_STOP:
1529 action_str = "stop";
1530 break;
1531 default:
1532 abort();
1533 }
1534
1535 data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
1536 bdrv->device_name,
1537 action_str,
1538 is_read ? "read" : "write");
1539 monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
1540
1541 qobject_decref(data);
1542 }
1543
1544 static void bdrv_print_dict(QObject *obj, void *opaque)
1545 {
1546 QDict *bs_dict;
1547 Monitor *mon = opaque;
1548
1549 bs_dict = qobject_to_qdict(obj);
1550
1551 monitor_printf(mon, "%s: type=%s removable=%d",
1552 qdict_get_str(bs_dict, "device"),
1553 qdict_get_str(bs_dict, "type"),
1554 qdict_get_bool(bs_dict, "removable"));
1555
1556 if (qdict_get_bool(bs_dict, "removable")) {
1557 monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
1558 }
1559
1560 if (qdict_haskey(bs_dict, "inserted")) {
1561 QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
1562
1563 monitor_printf(mon, " file=");
1564 monitor_print_filename(mon, qdict_get_str(qdict, "file"));
1565 if (qdict_haskey(qdict, "backing_file")) {
1566 monitor_printf(mon, " backing_file=");
1567 monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
1568 }
1569 monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
1570 qdict_get_bool(qdict, "ro"),
1571 qdict_get_str(qdict, "drv"),
1572 qdict_get_bool(qdict, "encrypted"));
1573 } else {
1574 monitor_printf(mon, " [not inserted]");
1575 }
1576
1577 monitor_printf(mon, "\n");
1578 }
1579
1580 void bdrv_info_print(Monitor *mon, const QObject *data)
1581 {
1582 qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
1583 }
1584
1585 void bdrv_info(Monitor *mon, QObject **ret_data)
1586 {
1587 QList *bs_list;
1588 BlockDriverState *bs;
1589
1590 bs_list = qlist_new();
1591
1592 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1593 QObject *bs_obj;
1594 const char *type = "unknown";
1595
1596 switch(bs->type) {
1597 case BDRV_TYPE_HD:
1598 type = "hd";
1599 break;
1600 case BDRV_TYPE_CDROM:
1601 type = "cdrom";
1602 break;
1603 case BDRV_TYPE_FLOPPY:
1604 type = "floppy";
1605 break;
1606 }
1607
1608 bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
1609 "'removable': %i, 'locked': %i }",
1610 bs->device_name, type, bs->removable,
1611 bs->locked);
1612
1613 if (bs->drv) {
1614 QObject *obj;
1615 QDict *bs_dict = qobject_to_qdict(bs_obj);
1616
1617 obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
1618 "'encrypted': %i }",
1619 bs->filename, bs->read_only,
1620 bs->drv->format_name,
1621 bdrv_is_encrypted(bs));
1622 if (bs->backing_file[0] != '\0') {
1623 QDict *qdict = qobject_to_qdict(obj);
1624 qdict_put(qdict, "backing_file",
1625 qstring_from_str(bs->backing_file));
1626 }
1627
1628 qdict_put_obj(bs_dict, "inserted", obj);
1629 }
1630 qlist_append_obj(bs_list, bs_obj);
1631 }
1632
1633 *ret_data = QOBJECT(bs_list);
1634 }
1635
1636 static void bdrv_stats_iter(QObject *data, void *opaque)
1637 {
1638 QDict *qdict;
1639 Monitor *mon = opaque;
1640
1641 qdict = qobject_to_qdict(data);
1642 monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
1643
1644 qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
1645 monitor_printf(mon, " rd_bytes=%" PRId64
1646 " wr_bytes=%" PRId64
1647 " rd_operations=%" PRId64
1648 " wr_operations=%" PRId64
1649 "\n",
1650 qdict_get_int(qdict, "rd_bytes"),
1651 qdict_get_int(qdict, "wr_bytes"),
1652 qdict_get_int(qdict, "rd_operations"),
1653 qdict_get_int(qdict, "wr_operations"));
1654 }
1655
1656 void bdrv_stats_print(Monitor *mon, const QObject *data)
1657 {
1658 qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
1659 }
1660
1661 static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
1662 {
1663 QObject *res;
1664 QDict *dict;
1665
1666 res = qobject_from_jsonf("{ 'stats': {"
1667 "'rd_bytes': %" PRId64 ","
1668 "'wr_bytes': %" PRId64 ","
1669 "'rd_operations': %" PRId64 ","
1670 "'wr_operations': %" PRId64 ","
1671 "'wr_highest_offset': %" PRId64
1672 "} }",
1673 bs->rd_bytes, bs->wr_bytes,
1674 bs->rd_ops, bs->wr_ops,
1675 bs->wr_highest_sector *
1676 (uint64_t)BDRV_SECTOR_SIZE);
1677 dict = qobject_to_qdict(res);
1678
1679 if (*bs->device_name) {
1680 qdict_put(dict, "device", qstring_from_str(bs->device_name));
1681 }
1682
1683 if (bs->file) {
1684 QObject *parent = bdrv_info_stats_bs(bs->file);
1685 qdict_put_obj(dict, "parent", parent);
1686 }
1687
1688 return res;
1689 }
1690
1691 void bdrv_info_stats(Monitor *mon, QObject **ret_data)
1692 {
1693 QObject *obj;
1694 QList *devices;
1695 BlockDriverState *bs;
1696
1697 devices = qlist_new();
1698
1699 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1700 obj = bdrv_info_stats_bs(bs);
1701 qlist_append_obj(devices, obj);
1702 }
1703
1704 *ret_data = QOBJECT(devices);
1705 }
1706
1707 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1708 {
1709 if (bs->backing_hd && bs->backing_hd->encrypted)
1710 return bs->backing_file;
1711 else if (bs->encrypted)
1712 return bs->filename;
1713 else
1714 return NULL;
1715 }
1716
1717 void bdrv_get_backing_filename(BlockDriverState *bs,
1718 char *filename, int filename_size)
1719 {
1720 if (!bs->backing_file) {
1721 pstrcpy(filename, filename_size, "");
1722 } else {
1723 pstrcpy(filename, filename_size, bs->backing_file);
1724 }
1725 }
1726
1727 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1728 const uint8_t *buf, int nb_sectors)
1729 {
1730 BlockDriver *drv = bs->drv;
1731 if (!drv)
1732 return -ENOMEDIUM;
1733 if (!drv->bdrv_write_compressed)
1734 return -ENOTSUP;
1735 if (bdrv_check_request(bs, sector_num, nb_sectors))
1736 return -EIO;
1737
1738 if (bs->dirty_bitmap) {
1739 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1740 }
1741
1742 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1743 }
1744
1745 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1746 {
1747 BlockDriver *drv = bs->drv;
1748 if (!drv)
1749 return -ENOMEDIUM;
1750 if (!drv->bdrv_get_info)
1751 return -ENOTSUP;
1752 memset(bdi, 0, sizeof(*bdi));
1753 return drv->bdrv_get_info(bs, bdi);
1754 }
1755
1756 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1757 int64_t pos, int size)
1758 {
1759 BlockDriver *drv = bs->drv;
1760 if (!drv)
1761 return -ENOMEDIUM;
1762 if (drv->bdrv_save_vmstate)
1763 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1764 if (bs->file)
1765 return bdrv_save_vmstate(bs->file, buf, pos, size);
1766 return -ENOTSUP;
1767 }
1768
1769 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1770 int64_t pos, int size)
1771 {
1772 BlockDriver *drv = bs->drv;
1773 if (!drv)
1774 return -ENOMEDIUM;
1775 if (drv->bdrv_load_vmstate)
1776 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1777 if (bs->file)
1778 return bdrv_load_vmstate(bs->file, buf, pos, size);
1779 return -ENOTSUP;
1780 }
1781
1782 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
1783 {
1784 BlockDriver *drv = bs->drv;
1785
1786 if (!drv || !drv->bdrv_debug_event) {
1787 return;
1788 }
1789
1790 return drv->bdrv_debug_event(bs, event);
1791
1792 }
1793
1794 /**************************************************************/
1795 /* handling of snapshots */
1796
1797 int bdrv_can_snapshot(BlockDriverState *bs)
1798 {
1799 BlockDriver *drv = bs->drv;
1800 if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
1801 return 0;
1802 }
1803
1804 if (!drv->bdrv_snapshot_create) {
1805 if (bs->file != NULL) {
1806 return bdrv_can_snapshot(bs->file);
1807 }
1808 return 0;
1809 }
1810
1811 return 1;
1812 }
1813
1814 int bdrv_is_snapshot(BlockDriverState *bs)
1815 {
1816 return !!(bs->open_flags & BDRV_O_SNAPSHOT);
1817 }
1818
1819 BlockDriverState *bdrv_snapshots(void)
1820 {
1821 BlockDriverState *bs;
1822
1823 if (bs_snapshots) {
1824 return bs_snapshots;
1825 }
1826
1827 bs = NULL;
1828 while ((bs = bdrv_next(bs))) {
1829 if (bdrv_can_snapshot(bs)) {
1830 bs_snapshots = bs;
1831 return bs;
1832 }
1833 }
1834 return NULL;
1835 }
1836
1837 int bdrv_snapshot_create(BlockDriverState *bs,
1838 QEMUSnapshotInfo *sn_info)
1839 {
1840 BlockDriver *drv = bs->drv;
1841 if (!drv)
1842 return -ENOMEDIUM;
1843 if (drv->bdrv_snapshot_create)
1844 return drv->bdrv_snapshot_create(bs, sn_info);
1845 if (bs->file)
1846 return bdrv_snapshot_create(bs->file, sn_info);
1847 return -ENOTSUP;
1848 }
1849
1850 int bdrv_snapshot_goto(BlockDriverState *bs,
1851 const char *snapshot_id)
1852 {
1853 BlockDriver *drv = bs->drv;
1854 int ret, open_ret;
1855
1856 if (!drv)
1857 return -ENOMEDIUM;
1858 if (drv->bdrv_snapshot_goto)
1859 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1860
1861 if (bs->file) {
1862 drv->bdrv_close(bs);
1863 ret = bdrv_snapshot_goto(bs->file, snapshot_id);
1864 open_ret = drv->bdrv_open(bs, bs->open_flags);
1865 if (open_ret < 0) {
1866 bdrv_delete(bs->file);
1867 bs->drv = NULL;
1868 return open_ret;
1869 }
1870 return ret;
1871 }
1872
1873 return -ENOTSUP;
1874 }
1875
1876 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1877 {
1878 BlockDriver *drv = bs->drv;
1879 if (!drv)
1880 return -ENOMEDIUM;
1881 if (drv->bdrv_snapshot_delete)
1882 return drv->bdrv_snapshot_delete(bs, snapshot_id);
1883 if (bs->file)
1884 return bdrv_snapshot_delete(bs->file, snapshot_id);
1885 return -ENOTSUP;
1886 }
1887
1888 int bdrv_snapshot_list(BlockDriverState *bs,
1889 QEMUSnapshotInfo **psn_info)
1890 {
1891 BlockDriver *drv = bs->drv;
1892 if (!drv)
1893 return -ENOMEDIUM;
1894 if (drv->bdrv_snapshot_list)
1895 return drv->bdrv_snapshot_list(bs, psn_info);
1896 if (bs->file)
1897 return bdrv_snapshot_list(bs->file, psn_info);
1898 return -ENOTSUP;
1899 }
1900
1901 #define NB_SUFFIXES 4
1902
1903 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1904 {
1905 static const char suffixes[NB_SUFFIXES] = "KMGT";
1906 int64_t base;
1907 int i;
1908
1909 if (size <= 999) {
1910 snprintf(buf, buf_size, "%" PRId64, size);
1911 } else {
1912 base = 1024;
1913 for(i = 0; i < NB_SUFFIXES; i++) {
1914 if (size < (10 * base)) {
1915 snprintf(buf, buf_size, "%0.1f%c",
1916 (double)size / base,
1917 suffixes[i]);
1918 break;
1919 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1920 snprintf(buf, buf_size, "%" PRId64 "%c",
1921 ((size + (base >> 1)) / base),
1922 suffixes[i]);
1923 break;
1924 }
1925 base = base * 1024;
1926 }
1927 }
1928 return buf;
1929 }
1930
1931 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1932 {
1933 char buf1[128], date_buf[128], clock_buf[128];
1934 #ifdef _WIN32
1935 struct tm *ptm;
1936 #else
1937 struct tm tm;
1938 #endif
1939 time_t ti;
1940 int64_t secs;
1941
1942 if (!sn) {
1943 snprintf(buf, buf_size,
1944 "%-10s%-20s%7s%20s%15s",
1945 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1946 } else {
1947 ti = sn->date_sec;
1948 #ifdef _WIN32
1949 ptm = localtime(&ti);
1950 strftime(date_buf, sizeof(date_buf),
1951 "%Y-%m-%d %H:%M:%S", ptm);
1952 #else
1953 localtime_r(&ti, &tm);
1954 strftime(date_buf, sizeof(date_buf),
1955 "%Y-%m-%d %H:%M:%S", &tm);
1956 #endif
1957 secs = sn->vm_clock_nsec / 1000000000;
1958 snprintf(clock_buf, sizeof(clock_buf),
1959 "%02d:%02d:%02d.%03d",
1960 (int)(secs / 3600),
1961 (int)((secs / 60) % 60),
1962 (int)(secs % 60),
1963 (int)((sn->vm_clock_nsec / 1000000) % 1000));
1964 snprintf(buf, buf_size,
1965 "%-10s%-20s%7s%20s%15s",
1966 sn->id_str, sn->name,
1967 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1968 date_buf,
1969 clock_buf);
1970 }
1971 return buf;
1972 }
1973
1974
1975 /**************************************************************/
1976 /* async I/Os */
1977
1978 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1979 QEMUIOVector *qiov, int nb_sectors,
1980 BlockDriverCompletionFunc *cb, void *opaque)
1981 {
1982 BlockDriver *drv = bs->drv;
1983 BlockDriverAIOCB *ret;
1984
1985 if (!drv)
1986 return NULL;
1987 if (bdrv_check_request(bs, sector_num, nb_sectors))
1988 return NULL;
1989
1990 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
1991 cb, opaque);
1992
1993 if (ret) {
1994 /* Update stats even though technically transfer has not happened. */
1995 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1996 bs->rd_ops ++;
1997 }
1998
1999 return ret;
2000 }
2001
2002 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
2003 QEMUIOVector *qiov, int nb_sectors,
2004 BlockDriverCompletionFunc *cb, void *opaque)
2005 {
2006 BlockDriver *drv = bs->drv;
2007 BlockDriverAIOCB *ret;
2008
2009 if (!drv)
2010 return NULL;
2011 if (bs->read_only)
2012 return NULL;
2013 if (bdrv_check_request(bs, sector_num, nb_sectors))
2014 return NULL;
2015
2016 if (bs->dirty_bitmap) {
2017 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
2018 }
2019
2020 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
2021 cb, opaque);
2022
2023 if (ret) {
2024 /* Update stats even though technically transfer has not happened. */
2025 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2026 bs->wr_ops ++;
2027 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
2028 bs->wr_highest_sector = sector_num + nb_sectors - 1;
2029 }
2030 }
2031
2032 return ret;
2033 }
2034
2035
2036 typedef struct MultiwriteCB {
2037 int error;
2038 int num_requests;
2039 int num_callbacks;
2040 struct {
2041 BlockDriverCompletionFunc *cb;
2042 void *opaque;
2043 QEMUIOVector *free_qiov;
2044 void *free_buf;
2045 } callbacks[];
2046 } MultiwriteCB;
2047
2048 static void multiwrite_user_cb(MultiwriteCB *mcb)
2049 {
2050 int i;
2051
2052 for (i = 0; i < mcb->num_callbacks; i++) {
2053 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
2054 if (mcb->callbacks[i].free_qiov) {
2055 qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
2056 }
2057 qemu_free(mcb->callbacks[i].free_qiov);
2058 qemu_vfree(mcb->callbacks[i].free_buf);
2059 }
2060 }
2061
2062 static void multiwrite_cb(void *opaque, int ret)
2063 {
2064 MultiwriteCB *mcb = opaque;
2065
2066 if (ret < 0 && !mcb->error) {
2067 mcb->error = ret;
2068 }
2069
2070 mcb->num_requests--;
2071 if (mcb->num_requests == 0) {
2072 multiwrite_user_cb(mcb);
2073 qemu_free(mcb);
2074 }
2075 }
2076
2077 static int multiwrite_req_compare(const void *a, const void *b)
2078 {
2079 const BlockRequest *req1 = a, *req2 = b;
2080
2081 /*
2082 * Note that we can't simply subtract req2->sector from req1->sector
2083 * here as that could overflow the return value.
2084 */
2085 if (req1->sector > req2->sector) {
2086 return 1;
2087 } else if (req1->sector < req2->sector) {
2088 return -1;
2089 } else {
2090 return 0;
2091 }
2092 }
2093
2094 /*
2095 * Takes a bunch of requests and tries to merge them. Returns the number of
2096 * requests that remain after merging.
2097 */
2098 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
2099 int num_reqs, MultiwriteCB *mcb)
2100 {
2101 int i, outidx;
2102
2103 // Sort requests by start sector
2104 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
2105
2106 // Check if adjacent requests touch the same clusters. If so, combine them,
2107 // filling up gaps with zero sectors.
2108 outidx = 0;
2109 for (i = 1; i < num_reqs; i++) {
2110 int merge = 0;
2111 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
2112
2113 // This handles the cases that are valid for all block drivers, namely
2114 // exactly sequential writes and overlapping writes.
2115 if (reqs[i].sector <= oldreq_last) {
2116 merge = 1;
2117 }
2118
2119 // The block driver may decide that it makes sense to combine requests
2120 // even if there is a gap of some sectors between them. In this case,
2121 // the gap is filled with zeros (therefore only applicable for yet
2122 // unused space in format like qcow2).
2123 if (!merge && bs->drv->bdrv_merge_requests) {
2124 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
2125 }
2126
2127 if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
2128 merge = 0;
2129 }
2130
2131 if (merge) {
2132 size_t size;
2133 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
2134 qemu_iovec_init(qiov,
2135 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
2136
2137 // Add the first request to the merged one. If the requests are
2138 // overlapping, drop the last sectors of the first request.
2139 size = (reqs[i].sector - reqs[outidx].sector) << 9;
2140 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
2141
2142 // We might need to add some zeros between the two requests
2143 if (reqs[i].sector > oldreq_last) {
2144 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
2145 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
2146 memset(buf, 0, zero_bytes);
2147 qemu_iovec_add(qiov, buf, zero_bytes);
2148 mcb->callbacks[i].free_buf = buf;
2149 }
2150
2151 // Add the second request
2152 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
2153
2154 reqs[outidx].nb_sectors = qiov->size >> 9;
2155 reqs[outidx].qiov = qiov;
2156
2157 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
2158 } else {
2159 outidx++;
2160 reqs[outidx].sector = reqs[i].sector;
2161 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
2162 reqs[outidx].qiov = reqs[i].qiov;
2163 }
2164 }
2165
2166 return outidx + 1;
2167 }
2168
2169 /*
2170 * Submit multiple AIO write requests at once.
2171 *
2172 * On success, the function returns 0 and all requests in the reqs array have
2173 * been submitted. In error case this function returns -1, and any of the
2174 * requests may or may not be submitted yet. In particular, this means that the
2175 * callback will be called for some of the requests, for others it won't. The
2176 * caller must check the error field of the BlockRequest to wait for the right
2177 * callbacks (if error != 0, no callback will be called).
2178 *
2179 * The implementation may modify the contents of the reqs array, e.g. to merge
2180 * requests. However, the fields opaque and error are left unmodified as they
2181 * are used to signal failure for a single request to the caller.
2182 */
2183 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
2184 {
2185 BlockDriverAIOCB *acb;
2186 MultiwriteCB *mcb;
2187 int i;
2188
2189 if (num_reqs == 0) {
2190 return 0;
2191 }
2192
2193 // Create MultiwriteCB structure
2194 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
2195 mcb->num_requests = 0;
2196 mcb->num_callbacks = num_reqs;
2197
2198 for (i = 0; i < num_reqs; i++) {
2199 mcb->callbacks[i].cb = reqs[i].cb;
2200 mcb->callbacks[i].opaque = reqs[i].opaque;
2201 }
2202
2203 // Check for mergable requests
2204 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
2205
2206 /*
2207 * Run the aio requests. As soon as one request can't be submitted
2208 * successfully, fail all requests that are not yet submitted (we must
2209 * return failure for all requests anyway)
2210 *
2211 * num_requests cannot be set to the right value immediately: If
2212 * bdrv_aio_writev fails for some request, num_requests would be too high
2213 * and therefore multiwrite_cb() would never recognize the multiwrite
2214 * request as completed. We also cannot use the loop variable i to set it
2215 * when the first request fails because the callback may already have been
2216 * called for previously submitted requests. Thus, num_requests must be
2217 * incremented for each request that is submitted.
2218 *
2219 * The problem that callbacks may be called early also means that we need
2220 * to take care that num_requests doesn't become 0 before all requests are
2221 * submitted - multiwrite_cb() would consider the multiwrite request
2222 * completed. A dummy request that is "completed" by a manual call to
2223 * multiwrite_cb() takes care of this.
2224 */
2225 mcb->num_requests = 1;
2226
2227 for (i = 0; i < num_reqs; i++) {
2228 mcb->num_requests++;
2229 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
2230 reqs[i].nb_sectors, multiwrite_cb, mcb);
2231
2232 if (acb == NULL) {
2233 // We can only fail the whole thing if no request has been
2234 // submitted yet. Otherwise we'll wait for the submitted AIOs to
2235 // complete and report the error in the callback.
2236 if (i == 0) {
2237 goto fail;
2238 } else {
2239 multiwrite_cb(mcb, -EIO);
2240 break;
2241 }
2242 }
2243 }
2244
2245 /* Complete the dummy request */
2246 multiwrite_cb(mcb, 0);
2247
2248 return 0;
2249
2250 fail:
2251 for (i = 0; i < mcb->num_callbacks; i++) {
2252 reqs[i].error = -EIO;
2253 }
2254 qemu_free(mcb);
2255 return -1;
2256 }
2257
2258 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
2259 BlockDriverCompletionFunc *cb, void *opaque)
2260 {
2261 BlockDriver *drv = bs->drv;
2262
2263 if (bs->open_flags & BDRV_O_NO_FLUSH) {
2264 return bdrv_aio_noop_em(bs, cb, opaque);
2265 }
2266
2267 if (!drv)
2268 return NULL;
2269 return drv->bdrv_aio_flush(bs, cb, opaque);
2270 }
2271
2272 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
2273 {
2274 acb->pool->cancel(acb);
2275 }
2276
2277
2278 /**************************************************************/
2279 /* async block device emulation */
2280
2281 typedef struct BlockDriverAIOCBSync {
2282 BlockDriverAIOCB common;
2283 QEMUBH *bh;
2284 int ret;
2285 /* vector translation state */
2286 QEMUIOVector *qiov;
2287 uint8_t *bounce;
2288 int is_write;
2289 } BlockDriverAIOCBSync;
2290
2291 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
2292 {
2293 BlockDriverAIOCBSync *acb =
2294 container_of(blockacb, BlockDriverAIOCBSync, common);
2295 qemu_bh_delete(acb->bh);
2296 acb->bh = NULL;
2297 qemu_aio_release(acb);
2298 }
2299
2300 static AIOPool bdrv_em_aio_pool = {
2301 .aiocb_size = sizeof(BlockDriverAIOCBSync),
2302 .cancel = bdrv_aio_cancel_em,
2303 };
2304
2305 static void bdrv_aio_bh_cb(void *opaque)
2306 {
2307 BlockDriverAIOCBSync *acb = opaque;
2308
2309 if (!acb->is_write)
2310 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
2311 qemu_vfree(acb->bounce);
2312 acb->common.cb(acb->common.opaque, acb->ret);
2313 qemu_bh_delete(acb->bh);
2314 acb->bh = NULL;
2315 qemu_aio_release(acb);
2316 }
2317
2318 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
2319 int64_t sector_num,
2320 QEMUIOVector *qiov,
2321 int nb_sectors,
2322 BlockDriverCompletionFunc *cb,
2323 void *opaque,
2324 int is_write)
2325
2326 {
2327 BlockDriverAIOCBSync *acb;
2328
2329 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2330 acb->is_write = is_write;
2331 acb->qiov = qiov;
2332 acb->bounce = qemu_blockalign(bs, qiov->size);
2333
2334 if (!acb->bh)
2335 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2336
2337 if (is_write) {
2338 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
2339 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
2340 } else {
2341 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
2342 }
2343
2344 qemu_bh_schedule(acb->bh);
2345
2346 return &acb->common;
2347 }
2348
2349 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
2350 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2351 BlockDriverCompletionFunc *cb, void *opaque)
2352 {
2353 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
2354 }
2355
2356 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
2357 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2358 BlockDriverCompletionFunc *cb, void *opaque)
2359 {
2360 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
2361 }
2362
2363 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
2364 BlockDriverCompletionFunc *cb, void *opaque)
2365 {
2366 BlockDriverAIOCBSync *acb;
2367
2368 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2369 acb->is_write = 1; /* don't bounce in the completion hadler */
2370 acb->qiov = NULL;
2371 acb->bounce = NULL;
2372 acb->ret = 0;
2373
2374 if (!acb->bh)
2375 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2376
2377 bdrv_flush(bs);
2378 qemu_bh_schedule(acb->bh);
2379 return &acb->common;
2380 }
2381
2382 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
2383 BlockDriverCompletionFunc *cb, void *opaque)
2384 {
2385 BlockDriverAIOCBSync *acb;
2386
2387 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2388 acb->is_write = 1; /* don't bounce in the completion handler */
2389 acb->qiov = NULL;
2390 acb->bounce = NULL;
2391 acb->ret = 0;
2392
2393 if (!acb->bh) {
2394 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2395 }
2396
2397 qemu_bh_schedule(acb->bh);
2398 return &acb->common;
2399 }
2400
2401 /**************************************************************/
2402 /* sync block device emulation */
2403
2404 static void bdrv_rw_em_cb(void *opaque, int ret)
2405 {
2406 *(int *)opaque = ret;
2407 }
2408
2409 #define NOT_DONE 0x7fffffff
2410
2411 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
2412 uint8_t *buf, int nb_sectors)
2413 {
2414 int async_ret;
2415 BlockDriverAIOCB *acb;
2416 struct iovec iov;
2417 QEMUIOVector qiov;
2418
2419 async_context_push();
2420
2421 async_ret = NOT_DONE;
2422 iov.iov_base = (void *)buf;
2423 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2424 qemu_iovec_init_external(&qiov, &iov, 1);
2425 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
2426 bdrv_rw_em_cb, &async_ret);
2427 if (acb == NULL) {
2428 async_ret = -1;
2429 goto fail;
2430 }
2431
2432 while (async_ret == NOT_DONE) {
2433 qemu_aio_wait();
2434 }
2435
2436
2437 fail:
2438 async_context_pop();
2439 return async_ret;
2440 }
2441
2442 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
2443 const uint8_t *buf, int nb_sectors)
2444 {
2445 int async_ret;
2446 BlockDriverAIOCB *acb;
2447 struct iovec iov;
2448 QEMUIOVector qiov;
2449
2450 async_context_push();
2451
2452 async_ret = NOT_DONE;
2453 iov.iov_base = (void *)buf;
2454 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2455 qemu_iovec_init_external(&qiov, &iov, 1);
2456 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
2457 bdrv_rw_em_cb, &async_ret);
2458 if (acb == NULL) {
2459 async_ret = -1;
2460 goto fail;
2461 }
2462 while (async_ret == NOT_DONE) {
2463 qemu_aio_wait();
2464 }
2465
2466 fail:
2467 async_context_pop();
2468 return async_ret;
2469 }
2470
2471 void bdrv_init(void)
2472 {
2473 module_call_init(MODULE_INIT_BLOCK);
2474 }
2475
2476 void bdrv_init_with_whitelist(void)
2477 {
2478 use_bdrv_whitelist = 1;
2479 bdrv_init();
2480 }
2481
2482 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
2483 BlockDriverCompletionFunc *cb, void *opaque)
2484 {
2485 BlockDriverAIOCB *acb;
2486
2487 if (pool->free_aiocb) {
2488 acb = pool->free_aiocb;
2489 pool->free_aiocb = acb->next;
2490 } else {
2491 acb = qemu_mallocz(pool->aiocb_size);
2492 acb->pool = pool;
2493 }
2494 acb->bs = bs;
2495 acb->cb = cb;
2496 acb->opaque = opaque;
2497 return acb;
2498 }
2499
2500 void qemu_aio_release(void *p)
2501 {
2502 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
2503 AIOPool *pool = acb->pool;
2504 acb->next = pool->free_aiocb;
2505 pool->free_aiocb = acb;
2506 }
2507
2508 /**************************************************************/
2509 /* removable device support */
2510
2511 /**
2512 * Return TRUE if the media is present
2513 */
2514 int bdrv_is_inserted(BlockDriverState *bs)
2515 {
2516 BlockDriver *drv = bs->drv;
2517 int ret;
2518 if (!drv)
2519 return 0;
2520 if (!drv->bdrv_is_inserted)
2521 return 1;
2522 ret = drv->bdrv_is_inserted(bs);
2523 return ret;
2524 }
2525
2526 /**
2527 * Return TRUE if the media changed since the last call to this
2528 * function. It is currently only used for floppy disks
2529 */
2530 int bdrv_media_changed(BlockDriverState *bs)
2531 {
2532 BlockDriver *drv = bs->drv;
2533 int ret;
2534
2535 if (!drv || !drv->bdrv_media_changed)
2536 ret = -ENOTSUP;
2537 else
2538 ret = drv->bdrv_media_changed(bs);
2539 if (ret == -ENOTSUP)
2540 ret = bs->media_changed;
2541 bs->media_changed = 0;
2542 return ret;
2543 }
2544
2545 /**
2546 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
2547 */
2548 int bdrv_eject(BlockDriverState *bs, int eject_flag)
2549 {
2550 BlockDriver *drv = bs->drv;
2551 int ret;
2552
2553 if (bs->locked) {
2554 return -EBUSY;
2555 }
2556
2557 if (!drv || !drv->bdrv_eject) {
2558 ret = -ENOTSUP;
2559 } else {
2560 ret = drv->bdrv_eject(bs, eject_flag);
2561 }
2562 if (ret == -ENOTSUP) {
2563 if (eject_flag)
2564 bdrv_close(bs);
2565 ret = 0;
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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