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Version 0.14.1
[qemu/wangdx.git] / block.c
blobb203875be6220d11913b58001d0094fd4e92d26b
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 "trace.h"
27 #include "monitor.h"
28 #include "block_int.h"
29 #include "module.h"
30 #include "qemu-objects.h"
31
32 #ifdef CONFIG_BSD
33 #include <sys/types.h>
34 #include <sys/stat.h>
35 #include <sys/ioctl.h>
36 #include <sys/queue.h>
37 #ifndef __DragonFly__
38 #include <sys/disk.h>
39 #endif
40 #endif
41
42 #ifdef _WIN32
43 #include <windows.h>
44 #endif
45
46 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
47 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
48 BlockDriverCompletionFunc *cb, void *opaque);
49 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
50 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
51 BlockDriverCompletionFunc *cb, void *opaque);
52 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
53 BlockDriverCompletionFunc *cb, void *opaque);
54 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
55 BlockDriverCompletionFunc *cb, void *opaque);
56 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
57 uint8_t *buf, int nb_sectors);
58 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
59 const uint8_t *buf, int nb_sectors);
60
61 static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
62 QTAILQ_HEAD_INITIALIZER(bdrv_states);
63
64 static QLIST_HEAD(, BlockDriver) bdrv_drivers =
65 QLIST_HEAD_INITIALIZER(bdrv_drivers);
66
67 /* The device to use for VM snapshots */
68 static BlockDriverState *bs_snapshots;
69
70 /* If non-zero, use only whitelisted block drivers */
71 static int use_bdrv_whitelist;
72
73 #ifdef _WIN32
74 static int is_windows_drive_prefix(const char *filename)
75 {
76 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
77 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
78 filename[1] == ':');
79 }
80
81 int is_windows_drive(const char *filename)
82 {
83 if (is_windows_drive_prefix(filename) &&
84 filename[2] == '\0')
85 return 1;
86 if (strstart(filename, "\\\\.\\", NULL) ||
87 strstart(filename, "//./", NULL))
88 return 1;
89 return 0;
90 }
91 #endif
92
93 /* check if the path starts with "<protocol>:" */
94 static int path_has_protocol(const char *path)
95 {
96 #ifdef _WIN32
97 if (is_windows_drive(path) ||
98 is_windows_drive_prefix(path)) {
99 return 0;
100 }
101 #endif
102
103 return strchr(path, ':') != NULL;
104 }
105
106 int path_is_absolute(const char *path)
107 {
108 const char *p;
109 #ifdef _WIN32
110 /* specific case for names like: "\\.\d:" */
111 if (*path == '/' || *path == '\\')
112 return 1;
113 #endif
114 p = strchr(path, ':');
115 if (p)
116 p++;
117 else
118 p = path;
119 #ifdef _WIN32
120 return (*p == '/' || *p == '\\');
121 #else
122 return (*p == '/');
123 #endif
124 }
125
126 /* if filename is absolute, just copy it to dest. Otherwise, build a
127 path to it by considering it is relative to base_path. URL are
128 supported. */
129 void path_combine(char *dest, int dest_size,
130 const char *base_path,
131 const char *filename)
132 {
133 const char *p, *p1;
134 int len;
135
136 if (dest_size <= 0)
137 return;
138 if (path_is_absolute(filename)) {
139 pstrcpy(dest, dest_size, filename);
140 } else {
141 p = strchr(base_path, ':');
142 if (p)
143 p++;
144 else
145 p = base_path;
146 p1 = strrchr(base_path, '/');
147 #ifdef _WIN32
148 {
149 const char *p2;
150 p2 = strrchr(base_path, '\\');
151 if (!p1 || p2 > p1)
152 p1 = p2;
153 }
154 #endif
155 if (p1)
156 p1++;
157 else
158 p1 = base_path;
159 if (p1 > p)
160 p = p1;
161 len = p - base_path;
162 if (len > dest_size - 1)
163 len = dest_size - 1;
164 memcpy(dest, base_path, len);
165 dest[len] = '\0';
166 pstrcat(dest, dest_size, filename);
167 }
168 }
169
170 void bdrv_register(BlockDriver *bdrv)
171 {
172 if (!bdrv->bdrv_aio_readv) {
173 /* add AIO emulation layer */
174 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
175 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
176 } else if (!bdrv->bdrv_read) {
177 /* add synchronous IO emulation layer */
178 bdrv->bdrv_read = bdrv_read_em;
179 bdrv->bdrv_write = bdrv_write_em;
180 }
181
182 if (!bdrv->bdrv_aio_flush)
183 bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
184
185 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
186 }
187
188 /* create a new block device (by default it is empty) */
189 BlockDriverState *bdrv_new(const char *device_name)
190 {
191 BlockDriverState *bs;
192
193 bs = qemu_mallocz(sizeof(BlockDriverState));
194 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
195 if (device_name[0] != '\0') {
196 QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
197 }
198 return bs;
199 }
200
201 BlockDriver *bdrv_find_format(const char *format_name)
202 {
203 BlockDriver *drv1;
204 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
205 if (!strcmp(drv1->format_name, format_name)) {
206 return drv1;
207 }
208 }
209 return NULL;
210 }
211
212 static int bdrv_is_whitelisted(BlockDriver *drv)
213 {
214 static const char *whitelist[] = {
215 CONFIG_BDRV_WHITELIST
216 };
217 const char **p;
218
219 if (!whitelist[0])
220 return 1; /* no whitelist, anything goes */
221
222 for (p = whitelist; *p; p++) {
223 if (!strcmp(drv->format_name, *p)) {
224 return 1;
225 }
226 }
227 return 0;
228 }
229
230 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
231 {
232 BlockDriver *drv = bdrv_find_format(format_name);
233 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
234 }
235
236 int bdrv_create(BlockDriver *drv, const char* filename,
237 QEMUOptionParameter *options)
238 {
239 if (!drv->bdrv_create)
240 return -ENOTSUP;
241
242 return drv->bdrv_create(filename, options);
243 }
244
245 int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
246 {
247 BlockDriver *drv;
248
249 drv = bdrv_find_protocol(filename);
250 if (drv == NULL) {
251 return -ENOENT;
252 }
253
254 return bdrv_create(drv, filename, options);
255 }
256
257 #ifdef _WIN32
258 void get_tmp_filename(char *filename, int size)
259 {
260 char temp_dir[MAX_PATH];
261
262 GetTempPath(MAX_PATH, temp_dir);
263 GetTempFileName(temp_dir, "qem", 0, filename);
264 }
265 #else
266 void get_tmp_filename(char *filename, int size)
267 {
268 int fd;
269 const char *tmpdir;
270 /* XXX: race condition possible */
271 tmpdir = getenv("TMPDIR");
272 if (!tmpdir)
273 tmpdir = "/tmp";
274 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
275 fd = mkstemp(filename);
276 close(fd);
277 }
278 #endif
279
280 /*
281 * Detect host devices. By convention, /dev/cdrom[N] is always
282 * recognized as a host CDROM.
283 */
284 static BlockDriver *find_hdev_driver(const char *filename)
285 {
286 int score_max = 0, score;
287 BlockDriver *drv = NULL, *d;
288
289 QLIST_FOREACH(d, &bdrv_drivers, list) {
290 if (d->bdrv_probe_device) {
291 score = d->bdrv_probe_device(filename);
292 if (score > score_max) {
293 score_max = score;
294 drv = d;
295 }
296 }
297 }
298
299 return drv;
300 }
301
302 BlockDriver *bdrv_find_protocol(const char *filename)
303 {
304 BlockDriver *drv1;
305 char protocol[128];
306 int len;
307 const char *p;
308
309 /* TODO Drivers without bdrv_file_open must be specified explicitly */
310
311 /*
312 * XXX(hch): we really should not let host device detection
313 * override an explicit protocol specification, but moving this
314 * later breaks access to device names with colons in them.
315 * Thanks to the brain-dead persistent naming schemes on udev-
316 * based Linux systems those actually are quite common.
317 */
318 drv1 = find_hdev_driver(filename);
319 if (drv1) {
320 return drv1;
321 }
322
323 if (!path_has_protocol(filename)) {
324 return bdrv_find_format("file");
325 }
326 p = strchr(filename, ':');
327 assert(p != NULL);
328 len = p - filename;
329 if (len > sizeof(protocol) - 1)
330 len = sizeof(protocol) - 1;
331 memcpy(protocol, filename, len);
332 protocol[len] = '\0';
333 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
334 if (drv1->protocol_name &&
335 !strcmp(drv1->protocol_name, protocol)) {
336 return drv1;
337 }
338 }
339 return NULL;
340 }
341
342 static int find_image_format(const char *filename, BlockDriver **pdrv)
343 {
344 int ret, score, score_max;
345 BlockDriver *drv1, *drv;
346 uint8_t buf[2048];
347 BlockDriverState *bs;
348
349 ret = bdrv_file_open(&bs, filename, 0);
350 if (ret < 0) {
351 *pdrv = NULL;
352 return ret;
353 }
354
355 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
356 if (bs->sg || !bdrv_is_inserted(bs)) {
357 bdrv_delete(bs);
358 drv = bdrv_find_format("raw");
359 if (!drv) {
360 ret = -ENOENT;
361 }
362 *pdrv = drv;
363 return ret;
364 }
365
366 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
367 bdrv_delete(bs);
368 if (ret < 0) {
369 *pdrv = NULL;
370 return ret;
371 }
372
373 score_max = 0;
374 drv = NULL;
375 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
376 if (drv1->bdrv_probe) {
377 score = drv1->bdrv_probe(buf, ret, filename);
378 if (score > score_max) {
379 score_max = score;
380 drv = drv1;
381 }
382 }
383 }
384 if (!drv) {
385 ret = -ENOENT;
386 }
387 *pdrv = drv;
388 return ret;
389 }
390
391 /**
392 * Set the current 'total_sectors' value
393 */
394 static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
395 {
396 BlockDriver *drv = bs->drv;
397
398 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
399 if (bs->sg)
400 return 0;
401
402 /* query actual device if possible, otherwise just trust the hint */
403 if (drv->bdrv_getlength) {
404 int64_t length = drv->bdrv_getlength(bs);
405 if (length < 0) {
406 return length;
407 }
408 hint = length >> BDRV_SECTOR_BITS;
409 }
410
411 bs->total_sectors = hint;
412 return 0;
413 }
414
415 /*
416 * Common part for opening disk images and files
417 */
418 static int bdrv_open_common(BlockDriverState *bs, const char *filename,
419 int flags, BlockDriver *drv)
420 {
421 int ret, open_flags;
422
423 assert(drv != NULL);
424
425 bs->file = NULL;
426 bs->total_sectors = 0;
427 bs->encrypted = 0;
428 bs->valid_key = 0;
429 bs->open_flags = flags;
430 /* buffer_alignment defaulted to 512, drivers can change this value */
431 bs->buffer_alignment = 512;
432
433 pstrcpy(bs->filename, sizeof(bs->filename), filename);
434
435 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
436 return -ENOTSUP;
437 }
438
439 bs->drv = drv;
440 bs->opaque = qemu_mallocz(drv->instance_size);
441
442 /*
443 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
444 * write cache to the guest. We do need the fdatasync to flush
445 * out transactions for block allocations, and we maybe have a
446 * volatile write cache in our backing device to deal with.
447 */
448 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
449 bs->enable_write_cache = 1;
450
451 /*
452 * Clear flags that are internal to the block layer before opening the
453 * image.
454 */
455 open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
456
457 /*
458 * Snapshots should be writeable.
459 */
460 if (bs->is_temporary) {
461 open_flags |= BDRV_O_RDWR;
462 }
463
464 /* Open the image, either directly or using a protocol */
465 if (drv->bdrv_file_open) {
466 ret = drv->bdrv_file_open(bs, filename, open_flags);
467 } else {
468 ret = bdrv_file_open(&bs->file, filename, open_flags);
469 if (ret >= 0) {
470 ret = drv->bdrv_open(bs, open_flags);
471 }
472 }
473
474 if (ret < 0) {
475 goto free_and_fail;
476 }
477
478 bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
479
480 ret = refresh_total_sectors(bs, bs->total_sectors);
481 if (ret < 0) {
482 goto free_and_fail;
483 }
484
485 #ifndef _WIN32
486 if (bs->is_temporary) {
487 unlink(filename);
488 }
489 #endif
490 return 0;
491
492 free_and_fail:
493 if (bs->file) {
494 bdrv_delete(bs->file);
495 bs->file = NULL;
496 }
497 qemu_free(bs->opaque);
498 bs->opaque = NULL;
499 bs->drv = NULL;
500 return ret;
501 }
502
503 /*
504 * Opens a file using a protocol (file, host_device, nbd, ...)
505 */
506 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
507 {
508 BlockDriverState *bs;
509 BlockDriver *drv;
510 int ret;
511
512 drv = bdrv_find_protocol(filename);
513 if (!drv) {
514 return -ENOENT;
515 }
516
517 bs = bdrv_new("");
518 ret = bdrv_open_common(bs, filename, flags, drv);
519 if (ret < 0) {
520 bdrv_delete(bs);
521 return ret;
522 }
523 bs->growable = 1;
524 *pbs = bs;
525 return 0;
526 }
527
528 /*
529 * Opens a disk image (raw, qcow2, vmdk, ...)
530 */
531 int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
532 BlockDriver *drv)
533 {
534 int ret;
535
536 if (flags & BDRV_O_SNAPSHOT) {
537 BlockDriverState *bs1;
538 int64_t total_size;
539 int is_protocol = 0;
540 BlockDriver *bdrv_qcow2;
541 QEMUOptionParameter *options;
542 char tmp_filename[PATH_MAX];
543 char backing_filename[PATH_MAX];
544
545 /* if snapshot, we create a temporary backing file and open it
546 instead of opening 'filename' directly */
547
548 /* if there is a backing file, use it */
549 bs1 = bdrv_new("");
550 ret = bdrv_open(bs1, filename, 0, drv);
551 if (ret < 0) {
552 bdrv_delete(bs1);
553 return ret;
554 }
555 total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
556
557 if (bs1->drv && bs1->drv->protocol_name)
558 is_protocol = 1;
559
560 bdrv_delete(bs1);
561
562 get_tmp_filename(tmp_filename, sizeof(tmp_filename));
563
564 /* Real path is meaningless for protocols */
565 if (is_protocol)
566 snprintf(backing_filename, sizeof(backing_filename),
567 "%s", filename);
568 else if (!realpath(filename, backing_filename))
569 return -errno;
570
571 bdrv_qcow2 = bdrv_find_format("qcow2");
572 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
573
574 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size);
575 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
576 if (drv) {
577 set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
578 drv->format_name);
579 }
580
581 ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
582 free_option_parameters(options);
583 if (ret < 0) {
584 return ret;
585 }
586
587 filename = tmp_filename;
588 drv = bdrv_qcow2;
589 bs->is_temporary = 1;
590 }
591
592 /* Find the right image format driver */
593 if (!drv) {
594 ret = find_image_format(filename, &drv);
595 }
596
597 if (!drv) {
598 goto unlink_and_fail;
599 }
600
601 /* Open the image */
602 ret = bdrv_open_common(bs, filename, flags, drv);
603 if (ret < 0) {
604 goto unlink_and_fail;
605 }
606
607 /* If there is a backing file, use it */
608 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
609 char backing_filename[PATH_MAX];
610 int back_flags;
611 BlockDriver *back_drv = NULL;
612
613 bs->backing_hd = bdrv_new("");
614
615 if (path_has_protocol(bs->backing_file)) {
616 pstrcpy(backing_filename, sizeof(backing_filename),
617 bs->backing_file);
618 } else {
619 path_combine(backing_filename, sizeof(backing_filename),
620 filename, bs->backing_file);
621 }
622
623 if (bs->backing_format[0] != '\0') {
624 back_drv = bdrv_find_format(bs->backing_format);
625 }
626
627 /* backing files always opened read-only */
628 back_flags =
629 flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
630
631 ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
632 if (ret < 0) {
633 bdrv_close(bs);
634 return ret;
635 }
636 if (bs->is_temporary) {
637 bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
638 } else {
639 /* base image inherits from "parent" */
640 bs->backing_hd->keep_read_only = bs->keep_read_only;
641 }
642 }
643
644 if (!bdrv_key_required(bs)) {
645 /* call the change callback */
646 bs->media_changed = 1;
647 if (bs->change_cb)
648 bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
649 }
650
651 return 0;
652
653 unlink_and_fail:
654 if (bs->is_temporary) {
655 unlink(filename);
656 }
657 return ret;
658 }
659
660 void bdrv_close(BlockDriverState *bs)
661 {
662 if (bs->drv) {
663 if (bs == bs_snapshots) {
664 bs_snapshots = NULL;
665 }
666 if (bs->backing_hd) {
667 bdrv_delete(bs->backing_hd);
668 bs->backing_hd = NULL;
669 }
670 bs->drv->bdrv_close(bs);
671 qemu_free(bs->opaque);
672 #ifdef _WIN32
673 if (bs->is_temporary) {
674 unlink(bs->filename);
675 }
676 #endif
677 bs->opaque = NULL;
678 bs->drv = NULL;
679
680 if (bs->file != NULL) {
681 bdrv_close(bs->file);
682 }
683
684 /* call the change callback */
685 bs->media_changed = 1;
686 if (bs->change_cb)
687 bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
688 }
689 }
690
691 void bdrv_close_all(void)
692 {
693 BlockDriverState *bs;
694
695 QTAILQ_FOREACH(bs, &bdrv_states, list) {
696 bdrv_close(bs);
697 }
698 }
699
700 /* make a BlockDriverState anonymous by removing from bdrv_state list.
701 Also, NULL terminate the device_name to prevent double remove */
702 void bdrv_make_anon(BlockDriverState *bs)
703 {
704 if (bs->device_name[0] != '\0') {
705 QTAILQ_REMOVE(&bdrv_states, bs, list);
706 }
707 bs->device_name[0] = '\0';
708 }
709
710 void bdrv_delete(BlockDriverState *bs)
711 {
712 assert(!bs->peer);
713
714 /* remove from list, if necessary */
715 bdrv_make_anon(bs);
716
717 bdrv_close(bs);
718 if (bs->file != NULL) {
719 bdrv_delete(bs->file);
720 }
721
722 assert(bs != bs_snapshots);
723 qemu_free(bs);
724 }
725
726 int bdrv_attach(BlockDriverState *bs, DeviceState *qdev)
727 {
728 if (bs->peer) {
729 return -EBUSY;
730 }
731 bs->peer = qdev;
732 return 0;
733 }
734
735 void bdrv_detach(BlockDriverState *bs, DeviceState *qdev)
736 {
737 assert(bs->peer == qdev);
738 bs->peer = NULL;
739 }
740
741 DeviceState *bdrv_get_attached(BlockDriverState *bs)
742 {
743 return bs->peer;
744 }
745
746 /*
747 * Run consistency checks on an image
748 *
749 * Returns 0 if the check could be completed (it doesn't mean that the image is
750 * free of errors) or -errno when an internal error occured. The results of the
751 * check are stored in res.
752 */
753 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
754 {
755 if (bs->drv->bdrv_check == NULL) {
756 return -ENOTSUP;
757 }
758
759 memset(res, 0, sizeof(*res));
760 return bs->drv->bdrv_check(bs, res);
761 }
762
763 #define COMMIT_BUF_SECTORS 2048
764
765 /* commit COW file into the raw image */
766 int bdrv_commit(BlockDriverState *bs)
767 {
768 BlockDriver *drv = bs->drv;
769 BlockDriver *backing_drv;
770 int64_t sector, total_sectors;
771 int n, ro, open_flags;
772 int ret = 0, rw_ret = 0;
773 uint8_t *buf;
774 char filename[1024];
775 BlockDriverState *bs_rw, *bs_ro;
776
777 if (!drv)
778 return -ENOMEDIUM;
779
780 if (!bs->backing_hd) {
781 return -ENOTSUP;
782 }
783
784 if (bs->backing_hd->keep_read_only) {
785 return -EACCES;
786 }
787
788 backing_drv = bs->backing_hd->drv;
789 ro = bs->backing_hd->read_only;
790 strncpy(filename, bs->backing_hd->filename, sizeof(filename));
791 open_flags = bs->backing_hd->open_flags;
792
793 if (ro) {
794 /* re-open as RW */
795 bdrv_delete(bs->backing_hd);
796 bs->backing_hd = NULL;
797 bs_rw = bdrv_new("");
798 rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
799 backing_drv);
800 if (rw_ret < 0) {
801 bdrv_delete(bs_rw);
802 /* try to re-open read-only */
803 bs_ro = bdrv_new("");
804 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
805 backing_drv);
806 if (ret < 0) {
807 bdrv_delete(bs_ro);
808 /* drive not functional anymore */
809 bs->drv = NULL;
810 return ret;
811 }
812 bs->backing_hd = bs_ro;
813 return rw_ret;
814 }
815 bs->backing_hd = bs_rw;
816 }
817
818 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
819 buf = qemu_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
820
821 for (sector = 0; sector < total_sectors; sector += n) {
822 if (drv->bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
823
824 if (bdrv_read(bs, sector, buf, n) != 0) {
825 ret = -EIO;
826 goto ro_cleanup;
827 }
828
829 if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
830 ret = -EIO;
831 goto ro_cleanup;
832 }
833 }
834 }
835
836 if (drv->bdrv_make_empty) {
837 ret = drv->bdrv_make_empty(bs);
838 bdrv_flush(bs);
839 }
840
841 /*
842 * Make sure all data we wrote to the backing device is actually
843 * stable on disk.
844 */
845 if (bs->backing_hd)
846 bdrv_flush(bs->backing_hd);
847
848 ro_cleanup:
849 qemu_free(buf);
850
851 if (ro) {
852 /* re-open as RO */
853 bdrv_delete(bs->backing_hd);
854 bs->backing_hd = NULL;
855 bs_ro = bdrv_new("");
856 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
857 backing_drv);
858 if (ret < 0) {
859 bdrv_delete(bs_ro);
860 /* drive not functional anymore */
861 bs->drv = NULL;
862 return ret;
863 }
864 bs->backing_hd = bs_ro;
865 bs->backing_hd->keep_read_only = 0;
866 }
867
868 return ret;
869 }
870
871 void bdrv_commit_all(void)
872 {
873 BlockDriverState *bs;
874
875 QTAILQ_FOREACH(bs, &bdrv_states, list) {
876 bdrv_commit(bs);
877 }
878 }
879
880 /*
881 * Return values:
882 * 0 - success
883 * -EINVAL - backing format specified, but no file
884 * -ENOSPC - can't update the backing file because no space is left in the
885 * image file header
886 * -ENOTSUP - format driver doesn't support changing the backing file
887 */
888 int bdrv_change_backing_file(BlockDriverState *bs,
889 const char *backing_file, const char *backing_fmt)
890 {
891 BlockDriver *drv = bs->drv;
892
893 if (drv->bdrv_change_backing_file != NULL) {
894 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
895 } else {
896 return -ENOTSUP;
897 }
898 }
899
900 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
901 size_t size)
902 {
903 int64_t len;
904
905 if (!bdrv_is_inserted(bs))
906 return -ENOMEDIUM;
907
908 if (bs->growable)
909 return 0;
910
911 len = bdrv_getlength(bs);
912
913 if (offset < 0)
914 return -EIO;
915
916 if ((offset > len) || (len - offset < size))
917 return -EIO;
918
919 return 0;
920 }
921
922 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
923 int nb_sectors)
924 {
925 return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
926 nb_sectors * BDRV_SECTOR_SIZE);
927 }
928
929 /* return < 0 if error. See bdrv_write() for the return codes */
930 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
931 uint8_t *buf, int nb_sectors)
932 {
933 BlockDriver *drv = bs->drv;
934
935 if (!drv)
936 return -ENOMEDIUM;
937 if (bdrv_check_request(bs, sector_num, nb_sectors))
938 return -EIO;
939
940 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
941 }
942
943 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
944 int nb_sectors, int dirty)
945 {
946 int64_t start, end;
947 unsigned long val, idx, bit;
948
949 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
950 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
951
952 for (; start <= end; start++) {
953 idx = start / (sizeof(unsigned long) * 8);
954 bit = start % (sizeof(unsigned long) * 8);
955 val = bs->dirty_bitmap[idx];
956 if (dirty) {
957 if (!(val & (1UL << bit))) {
958 bs->dirty_count++;
959 val |= 1UL << bit;
960 }
961 } else {
962 if (val & (1UL << bit)) {
963 bs->dirty_count--;
964 val &= ~(1UL << bit);
965 }
966 }
967 bs->dirty_bitmap[idx] = val;
968 }
969 }
970
971 /* Return < 0 if error. Important errors are:
972 -EIO generic I/O error (may happen for all errors)
973 -ENOMEDIUM No media inserted.
974 -EINVAL Invalid sector number or nb_sectors
975 -EACCES Trying to write a read-only device
976 */
977 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
978 const uint8_t *buf, int nb_sectors)
979 {
980 BlockDriver *drv = bs->drv;
981 if (!bs->drv)
982 return -ENOMEDIUM;
983 if (bs->read_only)
984 return -EACCES;
985 if (bdrv_check_request(bs, sector_num, nb_sectors))
986 return -EIO;
987
988 if (bs->dirty_bitmap) {
989 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
990 }
991
992 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
993 bs->wr_highest_sector = sector_num + nb_sectors - 1;
994 }
995
996 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
997 }
998
999 int bdrv_pread(BlockDriverState *bs, int64_t offset,
1000 void *buf, int count1)
1001 {
1002 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1003 int len, nb_sectors, count;
1004 int64_t sector_num;
1005 int ret;
1006
1007 count = count1;
1008 /* first read to align to sector start */
1009 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1010 if (len > count)
1011 len = count;
1012 sector_num = offset >> BDRV_SECTOR_BITS;
1013 if (len > 0) {
1014 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1015 return ret;
1016 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
1017 count -= len;
1018 if (count == 0)
1019 return count1;
1020 sector_num++;
1021 buf += len;
1022 }
1023
1024 /* read the sectors "in place" */
1025 nb_sectors = count >> BDRV_SECTOR_BITS;
1026 if (nb_sectors > 0) {
1027 if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
1028 return ret;
1029 sector_num += nb_sectors;
1030 len = nb_sectors << BDRV_SECTOR_BITS;
1031 buf += len;
1032 count -= len;
1033 }
1034
1035 /* add data from the last sector */
1036 if (count > 0) {
1037 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1038 return ret;
1039 memcpy(buf, tmp_buf, count);
1040 }
1041 return count1;
1042 }
1043
1044 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
1045 const void *buf, int count1)
1046 {
1047 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1048 int len, nb_sectors, count;
1049 int64_t sector_num;
1050 int ret;
1051
1052 count = count1;
1053 /* first write to align to sector start */
1054 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1055 if (len > count)
1056 len = count;
1057 sector_num = offset >> BDRV_SECTOR_BITS;
1058 if (len > 0) {
1059 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1060 return ret;
1061 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1062 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1063 return ret;
1064 count -= len;
1065 if (count == 0)
1066 return count1;
1067 sector_num++;
1068 buf += len;
1069 }
1070
1071 /* write the sectors "in place" */
1072 nb_sectors = count >> BDRV_SECTOR_BITS;
1073 if (nb_sectors > 0) {
1074 if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
1075 return ret;
1076 sector_num += nb_sectors;
1077 len = nb_sectors << BDRV_SECTOR_BITS;
1078 buf += len;
1079 count -= len;
1080 }
1081
1082 /* add data from the last sector */
1083 if (count > 0) {
1084 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1085 return ret;
1086 memcpy(tmp_buf, buf, count);
1087 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1088 return ret;
1089 }
1090 return count1;
1091 }
1092
1093 /*
1094 * Writes to the file and ensures that no writes are reordered across this
1095 * request (acts as a barrier)
1096 *
1097 * Returns 0 on success, -errno in error cases.
1098 */
1099 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
1100 const void *buf, int count)
1101 {
1102 int ret;
1103
1104 ret = bdrv_pwrite(bs, offset, buf, count);
1105 if (ret < 0) {
1106 return ret;
1107 }
1108
1109 /* No flush needed for cache=writethrough, it uses O_DSYNC */
1110 if ((bs->open_flags & BDRV_O_CACHE_MASK) != 0) {
1111 bdrv_flush(bs);
1112 }
1113
1114 return 0;
1115 }
1116
1117 /*
1118 * Writes to the file and ensures that no writes are reordered across this
1119 * request (acts as a barrier)
1120 *
1121 * Returns 0 on success, -errno in error cases.
1122 */
1123 int bdrv_write_sync(BlockDriverState *bs, int64_t sector_num,
1124 const uint8_t *buf, int nb_sectors)
1125 {
1126 return bdrv_pwrite_sync(bs, BDRV_SECTOR_SIZE * sector_num,
1127 buf, BDRV_SECTOR_SIZE * nb_sectors);
1128 }
1129
1130 /**
1131 * Truncate file to 'offset' bytes (needed only for file protocols)
1132 */
1133 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
1134 {
1135 BlockDriver *drv = bs->drv;
1136 int ret;
1137 if (!drv)
1138 return -ENOMEDIUM;
1139 if (!drv->bdrv_truncate)
1140 return -ENOTSUP;
1141 if (bs->read_only)
1142 return -EACCES;
1143 if (bdrv_in_use(bs))
1144 return -EBUSY;
1145 ret = drv->bdrv_truncate(bs, offset);
1146 if (ret == 0) {
1147 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
1148 if (bs->change_cb) {
1149 bs->change_cb(bs->change_opaque, CHANGE_SIZE);
1150 }
1151 }
1152 return ret;
1153 }
1154
1155 /**
1156 * Length of a file in bytes. Return < 0 if error or unknown.
1157 */
1158 int64_t bdrv_getlength(BlockDriverState *bs)
1159 {
1160 BlockDriver *drv = bs->drv;
1161 if (!drv)
1162 return -ENOMEDIUM;
1163
1164 /* Fixed size devices use the total_sectors value for speed instead of
1165 issuing a length query (like lseek) on each call. Also, legacy block
1166 drivers don't provide a bdrv_getlength function and must use
1167 total_sectors. */
1168 if (!bs->growable || !drv->bdrv_getlength) {
1169 return bs->total_sectors * BDRV_SECTOR_SIZE;
1170 }
1171 return drv->bdrv_getlength(bs);
1172 }
1173
1174 /* return 0 as number of sectors if no device present or error */
1175 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
1176 {
1177 int64_t length;
1178 length = bdrv_getlength(bs);
1179 if (length < 0)
1180 length = 0;
1181 else
1182 length = length >> BDRV_SECTOR_BITS;
1183 *nb_sectors_ptr = length;
1184 }
1185
1186 struct partition {
1187 uint8_t boot_ind; /* 0x80 - active */
1188 uint8_t head; /* starting head */
1189 uint8_t sector; /* starting sector */
1190 uint8_t cyl; /* starting cylinder */
1191 uint8_t sys_ind; /* What partition type */
1192 uint8_t end_head; /* end head */
1193 uint8_t end_sector; /* end sector */
1194 uint8_t end_cyl; /* end cylinder */
1195 uint32_t start_sect; /* starting sector counting from 0 */
1196 uint32_t nr_sects; /* nr of sectors in partition */
1197 } __attribute__((packed));
1198
1199 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
1200 static int guess_disk_lchs(BlockDriverState *bs,
1201 int *pcylinders, int *pheads, int *psectors)
1202 {
1203 uint8_t buf[BDRV_SECTOR_SIZE];
1204 int ret, i, heads, sectors, cylinders;
1205 struct partition *p;
1206 uint32_t nr_sects;
1207 uint64_t nb_sectors;
1208
1209 bdrv_get_geometry(bs, &nb_sectors);
1210
1211 ret = bdrv_read(bs, 0, buf, 1);
1212 if (ret < 0)
1213 return -1;
1214 /* test msdos magic */
1215 if (buf[510] != 0x55 || buf[511] != 0xaa)
1216 return -1;
1217 for(i = 0; i < 4; i++) {
1218 p = ((struct partition *)(buf + 0x1be)) + i;
1219 nr_sects = le32_to_cpu(p->nr_sects);
1220 if (nr_sects && p->end_head) {
1221 /* We make the assumption that the partition terminates on
1222 a cylinder boundary */
1223 heads = p->end_head + 1;
1224 sectors = p->end_sector & 63;
1225 if (sectors == 0)
1226 continue;
1227 cylinders = nb_sectors / (heads * sectors);
1228 if (cylinders < 1 || cylinders > 16383)
1229 continue;
1230 *pheads = heads;
1231 *psectors = sectors;
1232 *pcylinders = cylinders;
1233 #if 0
1234 printf("guessed geometry: LCHS=%d %d %d\n",
1235 cylinders, heads, sectors);
1236 #endif
1237 return 0;
1238 }
1239 }
1240 return -1;
1241 }
1242
1243 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
1244 {
1245 int translation, lba_detected = 0;
1246 int cylinders, heads, secs;
1247 uint64_t nb_sectors;
1248
1249 /* if a geometry hint is available, use it */
1250 bdrv_get_geometry(bs, &nb_sectors);
1251 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
1252 translation = bdrv_get_translation_hint(bs);
1253 if (cylinders != 0) {
1254 *pcyls = cylinders;
1255 *pheads = heads;
1256 *psecs = secs;
1257 } else {
1258 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
1259 if (heads > 16) {
1260 /* if heads > 16, it means that a BIOS LBA
1261 translation was active, so the default
1262 hardware geometry is OK */
1263 lba_detected = 1;
1264 goto default_geometry;
1265 } else {
1266 *pcyls = cylinders;
1267 *pheads = heads;
1268 *psecs = secs;
1269 /* disable any translation to be in sync with
1270 the logical geometry */
1271 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
1272 bdrv_set_translation_hint(bs,
1273 BIOS_ATA_TRANSLATION_NONE);
1274 }
1275 }
1276 } else {
1277 default_geometry:
1278 /* if no geometry, use a standard physical disk geometry */
1279 cylinders = nb_sectors / (16 * 63);
1280
1281 if (cylinders > 16383)
1282 cylinders = 16383;
1283 else if (cylinders < 2)
1284 cylinders = 2;
1285 *pcyls = cylinders;
1286 *pheads = 16;
1287 *psecs = 63;
1288 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
1289 if ((*pcyls * *pheads) <= 131072) {
1290 bdrv_set_translation_hint(bs,
1291 BIOS_ATA_TRANSLATION_LARGE);
1292 } else {
1293 bdrv_set_translation_hint(bs,
1294 BIOS_ATA_TRANSLATION_LBA);
1295 }
1296 }
1297 }
1298 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
1299 }
1300 }
1301
1302 void bdrv_set_geometry_hint(BlockDriverState *bs,
1303 int cyls, int heads, int secs)
1304 {
1305 bs->cyls = cyls;
1306 bs->heads = heads;
1307 bs->secs = secs;
1308 }
1309
1310 void bdrv_set_type_hint(BlockDriverState *bs, int type)
1311 {
1312 bs->type = type;
1313 bs->removable = ((type == BDRV_TYPE_CDROM ||
1314 type == BDRV_TYPE_FLOPPY));
1315 }
1316
1317 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
1318 {
1319 bs->translation = translation;
1320 }
1321
1322 void bdrv_get_geometry_hint(BlockDriverState *bs,
1323 int *pcyls, int *pheads, int *psecs)
1324 {
1325 *pcyls = bs->cyls;
1326 *pheads = bs->heads;
1327 *psecs = bs->secs;
1328 }
1329
1330 int bdrv_get_type_hint(BlockDriverState *bs)
1331 {
1332 return bs->type;
1333 }
1334
1335 int bdrv_get_translation_hint(BlockDriverState *bs)
1336 {
1337 return bs->translation;
1338 }
1339
1340 void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
1341 BlockErrorAction on_write_error)
1342 {
1343 bs->on_read_error = on_read_error;
1344 bs->on_write_error = on_write_error;
1345 }
1346
1347 BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
1348 {
1349 return is_read ? bs->on_read_error : bs->on_write_error;
1350 }
1351
1352 void bdrv_set_removable(BlockDriverState *bs, int removable)
1353 {
1354 bs->removable = removable;
1355 if (removable && bs == bs_snapshots) {
1356 bs_snapshots = NULL;
1357 }
1358 }
1359
1360 int bdrv_is_removable(BlockDriverState *bs)
1361 {
1362 return bs->removable;
1363 }
1364
1365 int bdrv_is_read_only(BlockDriverState *bs)
1366 {
1367 return bs->read_only;
1368 }
1369
1370 int bdrv_is_sg(BlockDriverState *bs)
1371 {
1372 return bs->sg;
1373 }
1374
1375 int bdrv_enable_write_cache(BlockDriverState *bs)
1376 {
1377 return bs->enable_write_cache;
1378 }
1379
1380 /* XXX: no longer used */
1381 void bdrv_set_change_cb(BlockDriverState *bs,
1382 void (*change_cb)(void *opaque, int reason),
1383 void *opaque)
1384 {
1385 bs->change_cb = change_cb;
1386 bs->change_opaque = opaque;
1387 }
1388
1389 int bdrv_is_encrypted(BlockDriverState *bs)
1390 {
1391 if (bs->backing_hd && bs->backing_hd->encrypted)
1392 return 1;
1393 return bs->encrypted;
1394 }
1395
1396 int bdrv_key_required(BlockDriverState *bs)
1397 {
1398 BlockDriverState *backing_hd = bs->backing_hd;
1399
1400 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1401 return 1;
1402 return (bs->encrypted && !bs->valid_key);
1403 }
1404
1405 int bdrv_set_key(BlockDriverState *bs, const char *key)
1406 {
1407 int ret;
1408 if (bs->backing_hd && bs->backing_hd->encrypted) {
1409 ret = bdrv_set_key(bs->backing_hd, key);
1410 if (ret < 0)
1411 return ret;
1412 if (!bs->encrypted)
1413 return 0;
1414 }
1415 if (!bs->encrypted) {
1416 return -EINVAL;
1417 } else if (!bs->drv || !bs->drv->bdrv_set_key) {
1418 return -ENOMEDIUM;
1419 }
1420 ret = bs->drv->bdrv_set_key(bs, key);
1421 if (ret < 0) {
1422 bs->valid_key = 0;
1423 } else if (!bs->valid_key) {
1424 bs->valid_key = 1;
1425 /* call the change callback now, we skipped it on open */
1426 bs->media_changed = 1;
1427 if (bs->change_cb)
1428 bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
1429 }
1430 return ret;
1431 }
1432
1433 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1434 {
1435 if (!bs->drv) {
1436 buf[0] = '\0';
1437 } else {
1438 pstrcpy(buf, buf_size, bs->drv->format_name);
1439 }
1440 }
1441
1442 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1443 void *opaque)
1444 {
1445 BlockDriver *drv;
1446
1447 QLIST_FOREACH(drv, &bdrv_drivers, list) {
1448 it(opaque, drv->format_name);
1449 }
1450 }
1451
1452 BlockDriverState *bdrv_find(const char *name)
1453 {
1454 BlockDriverState *bs;
1455
1456 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1457 if (!strcmp(name, bs->device_name)) {
1458 return bs;
1459 }
1460 }
1461 return NULL;
1462 }
1463
1464 BlockDriverState *bdrv_next(BlockDriverState *bs)
1465 {
1466 if (!bs) {
1467 return QTAILQ_FIRST(&bdrv_states);
1468 }
1469 return QTAILQ_NEXT(bs, list);
1470 }
1471
1472 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1473 {
1474 BlockDriverState *bs;
1475
1476 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1477 it(opaque, bs);
1478 }
1479 }
1480
1481 const char *bdrv_get_device_name(BlockDriverState *bs)
1482 {
1483 return bs->device_name;
1484 }
1485
1486 int bdrv_flush(BlockDriverState *bs)
1487 {
1488 if (bs->open_flags & BDRV_O_NO_FLUSH) {
1489 return 0;
1490 }
1491
1492 if (bs->drv && bs->drv->bdrv_flush) {
1493 return bs->drv->bdrv_flush(bs);
1494 }
1495
1496 /*
1497 * Some block drivers always operate in either writethrough or unsafe mode
1498 * and don't support bdrv_flush therefore. Usually qemu doesn't know how
1499 * the server works (because the behaviour is hardcoded or depends on
1500 * server-side configuration), so we can't ensure that everything is safe
1501 * on disk. Returning an error doesn't work because that would break guests
1502 * even if the server operates in writethrough mode.
1503 *
1504 * Let's hope the user knows what he's doing.
1505 */
1506 return 0;
1507 }
1508
1509 void bdrv_flush_all(void)
1510 {
1511 BlockDriverState *bs;
1512
1513 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1514 if (bs->drv && !bdrv_is_read_only(bs) &&
1515 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) {
1516 bdrv_flush(bs);
1517 }
1518 }
1519 }
1520
1521 int bdrv_has_zero_init(BlockDriverState *bs)
1522 {
1523 assert(bs->drv);
1524
1525 if (bs->drv->bdrv_has_zero_init) {
1526 return bs->drv->bdrv_has_zero_init(bs);
1527 }
1528
1529 return 1;
1530 }
1531
1532 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
1533 {
1534 if (!bs->drv) {
1535 return -ENOMEDIUM;
1536 }
1537 if (!bs->drv->bdrv_discard) {
1538 return 0;
1539 }
1540 return bs->drv->bdrv_discard(bs, sector_num, nb_sectors);
1541 }
1542
1543 /*
1544 * Returns true iff the specified sector is present in the disk image. Drivers
1545 * not implementing the functionality are assumed to not support backing files,
1546 * hence all their sectors are reported as allocated.
1547 *
1548 * 'pnum' is set to the number of sectors (including and immediately following
1549 * the specified sector) that are known to be in the same
1550 * allocated/unallocated state.
1551 *
1552 * 'nb_sectors' is the max value 'pnum' should be set to.
1553 */
1554 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1555 int *pnum)
1556 {
1557 int64_t n;
1558 if (!bs->drv->bdrv_is_allocated) {
1559 if (sector_num >= bs->total_sectors) {
1560 *pnum = 0;
1561 return 0;
1562 }
1563 n = bs->total_sectors - sector_num;
1564 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1565 return 1;
1566 }
1567 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1568 }
1569
1570 void bdrv_mon_event(const BlockDriverState *bdrv,
1571 BlockMonEventAction action, int is_read)
1572 {
1573 QObject *data;
1574 const char *action_str;
1575
1576 switch (action) {
1577 case BDRV_ACTION_REPORT:
1578 action_str = "report";
1579 break;
1580 case BDRV_ACTION_IGNORE:
1581 action_str = "ignore";
1582 break;
1583 case BDRV_ACTION_STOP:
1584 action_str = "stop";
1585 break;
1586 default:
1587 abort();
1588 }
1589
1590 data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
1591 bdrv->device_name,
1592 action_str,
1593 is_read ? "read" : "write");
1594 monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
1595
1596 qobject_decref(data);
1597 }
1598
1599 static void bdrv_print_dict(QObject *obj, void *opaque)
1600 {
1601 QDict *bs_dict;
1602 Monitor *mon = opaque;
1603
1604 bs_dict = qobject_to_qdict(obj);
1605
1606 monitor_printf(mon, "%s: type=%s removable=%d",
1607 qdict_get_str(bs_dict, "device"),
1608 qdict_get_str(bs_dict, "type"),
1609 qdict_get_bool(bs_dict, "removable"));
1610
1611 if (qdict_get_bool(bs_dict, "removable")) {
1612 monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
1613 }
1614
1615 if (qdict_haskey(bs_dict, "inserted")) {
1616 QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
1617
1618 monitor_printf(mon, " file=");
1619 monitor_print_filename(mon, qdict_get_str(qdict, "file"));
1620 if (qdict_haskey(qdict, "backing_file")) {
1621 monitor_printf(mon, " backing_file=");
1622 monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
1623 }
1624 monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
1625 qdict_get_bool(qdict, "ro"),
1626 qdict_get_str(qdict, "drv"),
1627 qdict_get_bool(qdict, "encrypted"));
1628 } else {
1629 monitor_printf(mon, " [not inserted]");
1630 }
1631
1632 monitor_printf(mon, "\n");
1633 }
1634
1635 void bdrv_info_print(Monitor *mon, const QObject *data)
1636 {
1637 qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
1638 }
1639
1640 void bdrv_info(Monitor *mon, QObject **ret_data)
1641 {
1642 QList *bs_list;
1643 BlockDriverState *bs;
1644
1645 bs_list = qlist_new();
1646
1647 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1648 QObject *bs_obj;
1649 const char *type = "unknown";
1650
1651 switch(bs->type) {
1652 case BDRV_TYPE_HD:
1653 type = "hd";
1654 break;
1655 case BDRV_TYPE_CDROM:
1656 type = "cdrom";
1657 break;
1658 case BDRV_TYPE_FLOPPY:
1659 type = "floppy";
1660 break;
1661 }
1662
1663 bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
1664 "'removable': %i, 'locked': %i }",
1665 bs->device_name, type, bs->removable,
1666 bs->locked);
1667
1668 if (bs->drv) {
1669 QObject *obj;
1670 QDict *bs_dict = qobject_to_qdict(bs_obj);
1671
1672 obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
1673 "'encrypted': %i }",
1674 bs->filename, bs->read_only,
1675 bs->drv->format_name,
1676 bdrv_is_encrypted(bs));
1677 if (bs->backing_file[0] != '\0') {
1678 QDict *qdict = qobject_to_qdict(obj);
1679 qdict_put(qdict, "backing_file",
1680 qstring_from_str(bs->backing_file));
1681 }
1682
1683 qdict_put_obj(bs_dict, "inserted", obj);
1684 }
1685 qlist_append_obj(bs_list, bs_obj);
1686 }
1687
1688 *ret_data = QOBJECT(bs_list);
1689 }
1690
1691 static void bdrv_stats_iter(QObject *data, void *opaque)
1692 {
1693 QDict *qdict;
1694 Monitor *mon = opaque;
1695
1696 qdict = qobject_to_qdict(data);
1697 monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
1698
1699 qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
1700 monitor_printf(mon, " rd_bytes=%" PRId64
1701 " wr_bytes=%" PRId64
1702 " rd_operations=%" PRId64
1703 " wr_operations=%" PRId64
1704 "\n",
1705 qdict_get_int(qdict, "rd_bytes"),
1706 qdict_get_int(qdict, "wr_bytes"),
1707 qdict_get_int(qdict, "rd_operations"),
1708 qdict_get_int(qdict, "wr_operations"));
1709 }
1710
1711 void bdrv_stats_print(Monitor *mon, const QObject *data)
1712 {
1713 qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
1714 }
1715
1716 static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
1717 {
1718 QObject *res;
1719 QDict *dict;
1720
1721 res = qobject_from_jsonf("{ 'stats': {"
1722 "'rd_bytes': %" PRId64 ","
1723 "'wr_bytes': %" PRId64 ","
1724 "'rd_operations': %" PRId64 ","
1725 "'wr_operations': %" PRId64 ","
1726 "'wr_highest_offset': %" PRId64
1727 "} }",
1728 bs->rd_bytes, bs->wr_bytes,
1729 bs->rd_ops, bs->wr_ops,
1730 bs->wr_highest_sector *
1731 (uint64_t)BDRV_SECTOR_SIZE);
1732 dict = qobject_to_qdict(res);
1733
1734 if (*bs->device_name) {
1735 qdict_put(dict, "device", qstring_from_str(bs->device_name));
1736 }
1737
1738 if (bs->file) {
1739 QObject *parent = bdrv_info_stats_bs(bs->file);
1740 qdict_put_obj(dict, "parent", parent);
1741 }
1742
1743 return res;
1744 }
1745
1746 void bdrv_info_stats(Monitor *mon, QObject **ret_data)
1747 {
1748 QObject *obj;
1749 QList *devices;
1750 BlockDriverState *bs;
1751
1752 devices = qlist_new();
1753
1754 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1755 obj = bdrv_info_stats_bs(bs);
1756 qlist_append_obj(devices, obj);
1757 }
1758
1759 *ret_data = QOBJECT(devices);
1760 }
1761
1762 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1763 {
1764 if (bs->backing_hd && bs->backing_hd->encrypted)
1765 return bs->backing_file;
1766 else if (bs->encrypted)
1767 return bs->filename;
1768 else
1769 return NULL;
1770 }
1771
1772 void bdrv_get_backing_filename(BlockDriverState *bs,
1773 char *filename, int filename_size)
1774 {
1775 if (!bs->backing_file) {
1776 pstrcpy(filename, filename_size, "");
1777 } else {
1778 pstrcpy(filename, filename_size, bs->backing_file);
1779 }
1780 }
1781
1782 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1783 const uint8_t *buf, int nb_sectors)
1784 {
1785 BlockDriver *drv = bs->drv;
1786 if (!drv)
1787 return -ENOMEDIUM;
1788 if (!drv->bdrv_write_compressed)
1789 return -ENOTSUP;
1790 if (bdrv_check_request(bs, sector_num, nb_sectors))
1791 return -EIO;
1792
1793 if (bs->dirty_bitmap) {
1794 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1795 }
1796
1797 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1798 }
1799
1800 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1801 {
1802 BlockDriver *drv = bs->drv;
1803 if (!drv)
1804 return -ENOMEDIUM;
1805 if (!drv->bdrv_get_info)
1806 return -ENOTSUP;
1807 memset(bdi, 0, sizeof(*bdi));
1808 return drv->bdrv_get_info(bs, bdi);
1809 }
1810
1811 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1812 int64_t pos, int size)
1813 {
1814 BlockDriver *drv = bs->drv;
1815 if (!drv)
1816 return -ENOMEDIUM;
1817 if (drv->bdrv_save_vmstate)
1818 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1819 if (bs->file)
1820 return bdrv_save_vmstate(bs->file, buf, pos, size);
1821 return -ENOTSUP;
1822 }
1823
1824 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1825 int64_t pos, int size)
1826 {
1827 BlockDriver *drv = bs->drv;
1828 if (!drv)
1829 return -ENOMEDIUM;
1830 if (drv->bdrv_load_vmstate)
1831 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1832 if (bs->file)
1833 return bdrv_load_vmstate(bs->file, buf, pos, size);
1834 return -ENOTSUP;
1835 }
1836
1837 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
1838 {
1839 BlockDriver *drv = bs->drv;
1840
1841 if (!drv || !drv->bdrv_debug_event) {
1842 return;
1843 }
1844
1845 return drv->bdrv_debug_event(bs, event);
1846
1847 }
1848
1849 /**************************************************************/
1850 /* handling of snapshots */
1851
1852 int bdrv_can_snapshot(BlockDriverState *bs)
1853 {
1854 BlockDriver *drv = bs->drv;
1855 if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
1856 return 0;
1857 }
1858
1859 if (!drv->bdrv_snapshot_create) {
1860 if (bs->file != NULL) {
1861 return bdrv_can_snapshot(bs->file);
1862 }
1863 return 0;
1864 }
1865
1866 return 1;
1867 }
1868
1869 int bdrv_is_snapshot(BlockDriverState *bs)
1870 {
1871 return !!(bs->open_flags & BDRV_O_SNAPSHOT);
1872 }
1873
1874 BlockDriverState *bdrv_snapshots(void)
1875 {
1876 BlockDriverState *bs;
1877
1878 if (bs_snapshots) {
1879 return bs_snapshots;
1880 }
1881
1882 bs = NULL;
1883 while ((bs = bdrv_next(bs))) {
1884 if (bdrv_can_snapshot(bs)) {
1885 bs_snapshots = bs;
1886 return bs;
1887 }
1888 }
1889 return NULL;
1890 }
1891
1892 int bdrv_snapshot_create(BlockDriverState *bs,
1893 QEMUSnapshotInfo *sn_info)
1894 {
1895 BlockDriver *drv = bs->drv;
1896 if (!drv)
1897 return -ENOMEDIUM;
1898 if (drv->bdrv_snapshot_create)
1899 return drv->bdrv_snapshot_create(bs, sn_info);
1900 if (bs->file)
1901 return bdrv_snapshot_create(bs->file, sn_info);
1902 return -ENOTSUP;
1903 }
1904
1905 int bdrv_snapshot_goto(BlockDriverState *bs,
1906 const char *snapshot_id)
1907 {
1908 BlockDriver *drv = bs->drv;
1909 int ret, open_ret;
1910
1911 if (!drv)
1912 return -ENOMEDIUM;
1913 if (drv->bdrv_snapshot_goto)
1914 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1915
1916 if (bs->file) {
1917 drv->bdrv_close(bs);
1918 ret = bdrv_snapshot_goto(bs->file, snapshot_id);
1919 open_ret = drv->bdrv_open(bs, bs->open_flags);
1920 if (open_ret < 0) {
1921 bdrv_delete(bs->file);
1922 bs->drv = NULL;
1923 return open_ret;
1924 }
1925 return ret;
1926 }
1927
1928 return -ENOTSUP;
1929 }
1930
1931 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1932 {
1933 BlockDriver *drv = bs->drv;
1934 if (!drv)
1935 return -ENOMEDIUM;
1936 if (drv->bdrv_snapshot_delete)
1937 return drv->bdrv_snapshot_delete(bs, snapshot_id);
1938 if (bs->file)
1939 return bdrv_snapshot_delete(bs->file, snapshot_id);
1940 return -ENOTSUP;
1941 }
1942
1943 int bdrv_snapshot_list(BlockDriverState *bs,
1944 QEMUSnapshotInfo **psn_info)
1945 {
1946 BlockDriver *drv = bs->drv;
1947 if (!drv)
1948 return -ENOMEDIUM;
1949 if (drv->bdrv_snapshot_list)
1950 return drv->bdrv_snapshot_list(bs, psn_info);
1951 if (bs->file)
1952 return bdrv_snapshot_list(bs->file, psn_info);
1953 return -ENOTSUP;
1954 }
1955
1956 int bdrv_snapshot_load_tmp(BlockDriverState *bs,
1957 const char *snapshot_name)
1958 {
1959 BlockDriver *drv = bs->drv;
1960 if (!drv) {
1961 return -ENOMEDIUM;
1962 }
1963 if (!bs->read_only) {
1964 return -EINVAL;
1965 }
1966 if (drv->bdrv_snapshot_load_tmp) {
1967 return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
1968 }
1969 return -ENOTSUP;
1970 }
1971
1972 #define NB_SUFFIXES 4
1973
1974 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1975 {
1976 static const char suffixes[NB_SUFFIXES] = "KMGT";
1977 int64_t base;
1978 int i;
1979
1980 if (size <= 999) {
1981 snprintf(buf, buf_size, "%" PRId64, size);
1982 } else {
1983 base = 1024;
1984 for(i = 0; i < NB_SUFFIXES; i++) {
1985 if (size < (10 * base)) {
1986 snprintf(buf, buf_size, "%0.1f%c",
1987 (double)size / base,
1988 suffixes[i]);
1989 break;
1990 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1991 snprintf(buf, buf_size, "%" PRId64 "%c",
1992 ((size + (base >> 1)) / base),
1993 suffixes[i]);
1994 break;
1995 }
1996 base = base * 1024;
1997 }
1998 }
1999 return buf;
2000 }
2001
2002 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
2003 {
2004 char buf1[128], date_buf[128], clock_buf[128];
2005 #ifdef _WIN32
2006 struct tm *ptm;
2007 #else
2008 struct tm tm;
2009 #endif
2010 time_t ti;
2011 int64_t secs;
2012
2013 if (!sn) {
2014 snprintf(buf, buf_size,
2015 "%-10s%-20s%7s%20s%15s",
2016 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
2017 } else {
2018 ti = sn->date_sec;
2019 #ifdef _WIN32
2020 ptm = localtime(&ti);
2021 strftime(date_buf, sizeof(date_buf),
2022 "%Y-%m-%d %H:%M:%S", ptm);
2023 #else
2024 localtime_r(&ti, &tm);
2025 strftime(date_buf, sizeof(date_buf),
2026 "%Y-%m-%d %H:%M:%S", &tm);
2027 #endif
2028 secs = sn->vm_clock_nsec / 1000000000;
2029 snprintf(clock_buf, sizeof(clock_buf),
2030 "%02d:%02d:%02d.%03d",
2031 (int)(secs / 3600),
2032 (int)((secs / 60) % 60),
2033 (int)(secs % 60),
2034 (int)((sn->vm_clock_nsec / 1000000) % 1000));
2035 snprintf(buf, buf_size,
2036 "%-10s%-20s%7s%20s%15s",
2037 sn->id_str, sn->name,
2038 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
2039 date_buf,
2040 clock_buf);
2041 }
2042 return buf;
2043 }
2044
2045
2046 /**************************************************************/
2047 /* async I/Os */
2048
2049 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
2050 QEMUIOVector *qiov, int nb_sectors,
2051 BlockDriverCompletionFunc *cb, void *opaque)
2052 {
2053 BlockDriver *drv = bs->drv;
2054 BlockDriverAIOCB *ret;
2055
2056 trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
2057
2058 if (!drv)
2059 return NULL;
2060 if (bdrv_check_request(bs, sector_num, nb_sectors))
2061 return NULL;
2062
2063 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
2064 cb, opaque);
2065
2066 if (ret) {
2067 /* Update stats even though technically transfer has not happened. */
2068 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2069 bs->rd_ops ++;
2070 }
2071
2072 return ret;
2073 }
2074
2075 typedef struct BlockCompleteData {
2076 BlockDriverCompletionFunc *cb;
2077 void *opaque;
2078 BlockDriverState *bs;
2079 int64_t sector_num;
2080 int nb_sectors;
2081 } BlockCompleteData;
2082
2083 static void block_complete_cb(void *opaque, int ret)
2084 {
2085 BlockCompleteData *b = opaque;
2086
2087 if (b->bs->dirty_bitmap) {
2088 set_dirty_bitmap(b->bs, b->sector_num, b->nb_sectors, 1);
2089 }
2090 b->cb(b->opaque, ret);
2091 qemu_free(b);
2092 }
2093
2094 static BlockCompleteData *blk_dirty_cb_alloc(BlockDriverState *bs,
2095 int64_t sector_num,
2096 int nb_sectors,
2097 BlockDriverCompletionFunc *cb,
2098 void *opaque)
2099 {
2100 BlockCompleteData *blkdata = qemu_mallocz(sizeof(BlockCompleteData));
2101
2102 blkdata->bs = bs;
2103 blkdata->cb = cb;
2104 blkdata->opaque = opaque;
2105 blkdata->sector_num = sector_num;
2106 blkdata->nb_sectors = nb_sectors;
2107
2108 return blkdata;
2109 }
2110
2111 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
2112 QEMUIOVector *qiov, int nb_sectors,
2113 BlockDriverCompletionFunc *cb, void *opaque)
2114 {
2115 BlockDriver *drv = bs->drv;
2116 BlockDriverAIOCB *ret;
2117 BlockCompleteData *blk_cb_data;
2118
2119 trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
2120
2121 if (!drv)
2122 return NULL;
2123 if (bs->read_only)
2124 return NULL;
2125 if (bdrv_check_request(bs, sector_num, nb_sectors))
2126 return NULL;
2127
2128 if (bs->dirty_bitmap) {
2129 blk_cb_data = blk_dirty_cb_alloc(bs, sector_num, nb_sectors, cb,
2130 opaque);
2131 cb = &block_complete_cb;
2132 opaque = blk_cb_data;
2133 }
2134
2135 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
2136 cb, opaque);
2137
2138 if (ret) {
2139 /* Update stats even though technically transfer has not happened. */
2140 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2141 bs->wr_ops ++;
2142 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
2143 bs->wr_highest_sector = sector_num + nb_sectors - 1;
2144 }
2145 }
2146
2147 return ret;
2148 }
2149
2150
2151 typedef struct MultiwriteCB {
2152 int error;
2153 int num_requests;
2154 int num_callbacks;
2155 struct {
2156 BlockDriverCompletionFunc *cb;
2157 void *opaque;
2158 QEMUIOVector *free_qiov;
2159 void *free_buf;
2160 } callbacks[];
2161 } MultiwriteCB;
2162
2163 static void multiwrite_user_cb(MultiwriteCB *mcb)
2164 {
2165 int i;
2166
2167 for (i = 0; i < mcb->num_callbacks; i++) {
2168 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
2169 if (mcb->callbacks[i].free_qiov) {
2170 qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
2171 }
2172 qemu_free(mcb->callbacks[i].free_qiov);
2173 qemu_vfree(mcb->callbacks[i].free_buf);
2174 }
2175 }
2176
2177 static void multiwrite_cb(void *opaque, int ret)
2178 {
2179 MultiwriteCB *mcb = opaque;
2180
2181 trace_multiwrite_cb(mcb, ret);
2182
2183 if (ret < 0 && !mcb->error) {
2184 mcb->error = ret;
2185 }
2186
2187 mcb->num_requests--;
2188 if (mcb->num_requests == 0) {
2189 multiwrite_user_cb(mcb);
2190 qemu_free(mcb);
2191 }
2192 }
2193
2194 static int multiwrite_req_compare(const void *a, const void *b)
2195 {
2196 const BlockRequest *req1 = a, *req2 = b;
2197
2198 /*
2199 * Note that we can't simply subtract req2->sector from req1->sector
2200 * here as that could overflow the return value.
2201 */
2202 if (req1->sector > req2->sector) {
2203 return 1;
2204 } else if (req1->sector < req2->sector) {
2205 return -1;
2206 } else {
2207 return 0;
2208 }
2209 }
2210
2211 /*
2212 * Takes a bunch of requests and tries to merge them. Returns the number of
2213 * requests that remain after merging.
2214 */
2215 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
2216 int num_reqs, MultiwriteCB *mcb)
2217 {
2218 int i, outidx;
2219
2220 // Sort requests by start sector
2221 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
2222
2223 // Check if adjacent requests touch the same clusters. If so, combine them,
2224 // filling up gaps with zero sectors.
2225 outidx = 0;
2226 for (i = 1; i < num_reqs; i++) {
2227 int merge = 0;
2228 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
2229
2230 // This handles the cases that are valid for all block drivers, namely
2231 // exactly sequential writes and overlapping writes.
2232 if (reqs[i].sector <= oldreq_last) {
2233 merge = 1;
2234 }
2235
2236 // The block driver may decide that it makes sense to combine requests
2237 // even if there is a gap of some sectors between them. In this case,
2238 // the gap is filled with zeros (therefore only applicable for yet
2239 // unused space in format like qcow2).
2240 if (!merge && bs->drv->bdrv_merge_requests) {
2241 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
2242 }
2243
2244 if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
2245 merge = 0;
2246 }
2247
2248 if (merge) {
2249 size_t size;
2250 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
2251 qemu_iovec_init(qiov,
2252 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
2253
2254 // Add the first request to the merged one. If the requests are
2255 // overlapping, drop the last sectors of the first request.
2256 size = (reqs[i].sector - reqs[outidx].sector) << 9;
2257 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
2258
2259 // We might need to add some zeros between the two requests
2260 if (reqs[i].sector > oldreq_last) {
2261 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
2262 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
2263 memset(buf, 0, zero_bytes);
2264 qemu_iovec_add(qiov, buf, zero_bytes);
2265 mcb->callbacks[i].free_buf = buf;
2266 }
2267
2268 // Add the second request
2269 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
2270
2271 reqs[outidx].nb_sectors = qiov->size >> 9;
2272 reqs[outidx].qiov = qiov;
2273
2274 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
2275 } else {
2276 outidx++;
2277 reqs[outidx].sector = reqs[i].sector;
2278 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
2279 reqs[outidx].qiov = reqs[i].qiov;
2280 }
2281 }
2282
2283 return outidx + 1;
2284 }
2285
2286 /*
2287 * Submit multiple AIO write requests at once.
2288 *
2289 * On success, the function returns 0 and all requests in the reqs array have
2290 * been submitted. In error case this function returns -1, and any of the
2291 * requests may or may not be submitted yet. In particular, this means that the
2292 * callback will be called for some of the requests, for others it won't. The
2293 * caller must check the error field of the BlockRequest to wait for the right
2294 * callbacks (if error != 0, no callback will be called).
2295 *
2296 * The implementation may modify the contents of the reqs array, e.g. to merge
2297 * requests. However, the fields opaque and error are left unmodified as they
2298 * are used to signal failure for a single request to the caller.
2299 */
2300 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
2301 {
2302 BlockDriverAIOCB *acb;
2303 MultiwriteCB *mcb;
2304 int i;
2305
2306 /* don't submit writes if we don't have a medium */
2307 if (bs->drv == NULL) {
2308 for (i = 0; i < num_reqs; i++) {
2309 reqs[i].error = -ENOMEDIUM;
2310 }
2311 return -1;
2312 }
2313
2314 if (num_reqs == 0) {
2315 return 0;
2316 }
2317
2318 // Create MultiwriteCB structure
2319 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
2320 mcb->num_requests = 0;
2321 mcb->num_callbacks = num_reqs;
2322
2323 for (i = 0; i < num_reqs; i++) {
2324 mcb->callbacks[i].cb = reqs[i].cb;
2325 mcb->callbacks[i].opaque = reqs[i].opaque;
2326 }
2327
2328 // Check for mergable requests
2329 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
2330
2331 trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
2332
2333 /*
2334 * Run the aio requests. As soon as one request can't be submitted
2335 * successfully, fail all requests that are not yet submitted (we must
2336 * return failure for all requests anyway)
2337 *
2338 * num_requests cannot be set to the right value immediately: If
2339 * bdrv_aio_writev fails for some request, num_requests would be too high
2340 * and therefore multiwrite_cb() would never recognize the multiwrite
2341 * request as completed. We also cannot use the loop variable i to set it
2342 * when the first request fails because the callback may already have been
2343 * called for previously submitted requests. Thus, num_requests must be
2344 * incremented for each request that is submitted.
2345 *
2346 * The problem that callbacks may be called early also means that we need
2347 * to take care that num_requests doesn't become 0 before all requests are
2348 * submitted - multiwrite_cb() would consider the multiwrite request
2349 * completed. A dummy request that is "completed" by a manual call to
2350 * multiwrite_cb() takes care of this.
2351 */
2352 mcb->num_requests = 1;
2353
2354 // Run the aio requests
2355 for (i = 0; i < num_reqs; i++) {
2356 mcb->num_requests++;
2357 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
2358 reqs[i].nb_sectors, multiwrite_cb, mcb);
2359
2360 if (acb == NULL) {
2361 // We can only fail the whole thing if no request has been
2362 // submitted yet. Otherwise we'll wait for the submitted AIOs to
2363 // complete and report the error in the callback.
2364 if (i == 0) {
2365 trace_bdrv_aio_multiwrite_earlyfail(mcb);
2366 goto fail;
2367 } else {
2368 trace_bdrv_aio_multiwrite_latefail(mcb, i);
2369 multiwrite_cb(mcb, -EIO);
2370 break;
2371 }
2372 }
2373 }
2374
2375 /* Complete the dummy request */
2376 multiwrite_cb(mcb, 0);
2377
2378 return 0;
2379
2380 fail:
2381 for (i = 0; i < mcb->num_callbacks; i++) {
2382 reqs[i].error = -EIO;
2383 }
2384 qemu_free(mcb);
2385 return -1;
2386 }
2387
2388 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
2389 BlockDriverCompletionFunc *cb, void *opaque)
2390 {
2391 BlockDriver *drv = bs->drv;
2392
2393 if (bs->open_flags & BDRV_O_NO_FLUSH) {
2394 return bdrv_aio_noop_em(bs, cb, opaque);
2395 }
2396
2397 if (!drv)
2398 return NULL;
2399 return drv->bdrv_aio_flush(bs, cb, opaque);
2400 }
2401
2402 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
2403 {
2404 acb->pool->cancel(acb);
2405 }
2406
2407
2408 /**************************************************************/
2409 /* async block device emulation */
2410
2411 typedef struct BlockDriverAIOCBSync {
2412 BlockDriverAIOCB common;
2413 QEMUBH *bh;
2414 int ret;
2415 /* vector translation state */
2416 QEMUIOVector *qiov;
2417 uint8_t *bounce;
2418 int is_write;
2419 } BlockDriverAIOCBSync;
2420
2421 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
2422 {
2423 BlockDriverAIOCBSync *acb =
2424 container_of(blockacb, BlockDriverAIOCBSync, common);
2425 qemu_bh_delete(acb->bh);
2426 acb->bh = NULL;
2427 qemu_aio_release(acb);
2428 }
2429
2430 static AIOPool bdrv_em_aio_pool = {
2431 .aiocb_size = sizeof(BlockDriverAIOCBSync),
2432 .cancel = bdrv_aio_cancel_em,
2433 };
2434
2435 static void bdrv_aio_bh_cb(void *opaque)
2436 {
2437 BlockDriverAIOCBSync *acb = opaque;
2438
2439 if (!acb->is_write)
2440 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
2441 qemu_vfree(acb->bounce);
2442 acb->common.cb(acb->common.opaque, acb->ret);
2443 qemu_bh_delete(acb->bh);
2444 acb->bh = NULL;
2445 qemu_aio_release(acb);
2446 }
2447
2448 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
2449 int64_t sector_num,
2450 QEMUIOVector *qiov,
2451 int nb_sectors,
2452 BlockDriverCompletionFunc *cb,
2453 void *opaque,
2454 int is_write)
2455
2456 {
2457 BlockDriverAIOCBSync *acb;
2458
2459 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2460 acb->is_write = is_write;
2461 acb->qiov = qiov;
2462 acb->bounce = qemu_blockalign(bs, qiov->size);
2463
2464 if (!acb->bh)
2465 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2466
2467 if (is_write) {
2468 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
2469 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
2470 } else {
2471 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
2472 }
2473
2474 qemu_bh_schedule(acb->bh);
2475
2476 return &acb->common;
2477 }
2478
2479 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
2480 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2481 BlockDriverCompletionFunc *cb, void *opaque)
2482 {
2483 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
2484 }
2485
2486 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
2487 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2488 BlockDriverCompletionFunc *cb, void *opaque)
2489 {
2490 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
2491 }
2492
2493 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
2494 BlockDriverCompletionFunc *cb, void *opaque)
2495 {
2496 BlockDriverAIOCBSync *acb;
2497
2498 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2499 acb->is_write = 1; /* don't bounce in the completion hadler */
2500 acb->qiov = NULL;
2501 acb->bounce = NULL;
2502 acb->ret = 0;
2503
2504 if (!acb->bh)
2505 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2506
2507 bdrv_flush(bs);
2508 qemu_bh_schedule(acb->bh);
2509 return &acb->common;
2510 }
2511
2512 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
2513 BlockDriverCompletionFunc *cb, void *opaque)
2514 {
2515 BlockDriverAIOCBSync *acb;
2516
2517 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2518 acb->is_write = 1; /* don't bounce in the completion handler */
2519 acb->qiov = NULL;
2520 acb->bounce = NULL;
2521 acb->ret = 0;
2522
2523 if (!acb->bh) {
2524 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2525 }
2526
2527 qemu_bh_schedule(acb->bh);
2528 return &acb->common;
2529 }
2530
2531 /**************************************************************/
2532 /* sync block device emulation */
2533
2534 static void bdrv_rw_em_cb(void *opaque, int ret)
2535 {
2536 *(int *)opaque = ret;
2537 }
2538
2539 #define NOT_DONE 0x7fffffff
2540
2541 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
2542 uint8_t *buf, int nb_sectors)
2543 {
2544 int async_ret;
2545 BlockDriverAIOCB *acb;
2546 struct iovec iov;
2547 QEMUIOVector qiov;
2548
2549 async_context_push();
2550
2551 async_ret = NOT_DONE;
2552 iov.iov_base = (void *)buf;
2553 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2554 qemu_iovec_init_external(&qiov, &iov, 1);
2555 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
2556 bdrv_rw_em_cb, &async_ret);
2557 if (acb == NULL) {
2558 async_ret = -1;
2559 goto fail;
2560 }
2561
2562 while (async_ret == NOT_DONE) {
2563 qemu_aio_wait();
2564 }
2565
2566
2567 fail:
2568 async_context_pop();
2569 return async_ret;
2570 }
2571
2572 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
2573 const uint8_t *buf, int nb_sectors)
2574 {
2575 int async_ret;
2576 BlockDriverAIOCB *acb;
2577 struct iovec iov;
2578 QEMUIOVector qiov;
2579
2580 async_context_push();
2581
2582 async_ret = NOT_DONE;
2583 iov.iov_base = (void *)buf;
2584 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2585 qemu_iovec_init_external(&qiov, &iov, 1);
2586 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
2587 bdrv_rw_em_cb, &async_ret);
2588 if (acb == NULL) {
2589 async_ret = -1;
2590 goto fail;
2591 }
2592 while (async_ret == NOT_DONE) {
2593 qemu_aio_wait();
2594 }
2595
2596 fail:
2597 async_context_pop();
2598 return async_ret;
2599 }
2600
2601 void bdrv_init(void)
2602 {
2603 module_call_init(MODULE_INIT_BLOCK);
2604 }
2605
2606 void bdrv_init_with_whitelist(void)
2607 {
2608 use_bdrv_whitelist = 1;
2609 bdrv_init();
2610 }
2611
2612 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
2613 BlockDriverCompletionFunc *cb, void *opaque)
2614 {
2615 BlockDriverAIOCB *acb;
2616
2617 if (pool->free_aiocb) {
2618 acb = pool->free_aiocb;
2619 pool->free_aiocb = acb->next;
2620 } else {
2621 acb = qemu_mallocz(pool->aiocb_size);
2622 acb->pool = pool;
2623 }
2624 acb->bs = bs;
2625 acb->cb = cb;
2626 acb->opaque = opaque;
2627 return acb;
2628 }
2629
2630 void qemu_aio_release(void *p)
2631 {
2632 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
2633 AIOPool *pool = acb->pool;
2634 acb->next = pool->free_aiocb;
2635 pool->free_aiocb = acb;
2636 }
2637
2638 /**************************************************************/
2639 /* removable device support */
2640
2641 /**
2642 * Return TRUE if the media is present
2643 */
2644 int bdrv_is_inserted(BlockDriverState *bs)
2645 {
2646 BlockDriver *drv = bs->drv;
2647 int ret;
2648 if (!drv)
2649 return 0;
2650 if (!drv->bdrv_is_inserted)
2651 return !bs->tray_open;
2652 ret = drv->bdrv_is_inserted(bs);
2653 return ret;
2654 }
2655
2656 /**
2657 * Return TRUE if the media changed since the last call to this
2658 * function. It is currently only used for floppy disks
2659 */
2660 int bdrv_media_changed(BlockDriverState *bs)
2661 {
2662 BlockDriver *drv = bs->drv;
2663 int ret;
2664
2665 if (!drv || !drv->bdrv_media_changed)
2666 ret = -ENOTSUP;
2667 else
2668 ret = drv->bdrv_media_changed(bs);
2669 if (ret == -ENOTSUP)
2670 ret = bs->media_changed;
2671 bs->media_changed = 0;
2672 return ret;
2673 }
2674
2675 /**
2676 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
2677 */
2678 int bdrv_eject(BlockDriverState *bs, int eject_flag)
2679 {
2680 BlockDriver *drv = bs->drv;
2681 int ret;
2682
2683 if (bs->locked) {
2684 return -EBUSY;
2685 }
2686
2687 if (!drv || !drv->bdrv_eject) {
2688 ret = -ENOTSUP;
2689 } else {
2690 ret = drv->bdrv_eject(bs, eject_flag);
2691 }
2692 if (ret == -ENOTSUP) {
2693 ret = 0;
2694 }
2695 if (ret >= 0) {
2696 bs->tray_open = eject_flag;
2697 }
2698
2699 return ret;
2700 }
2701
2702 int bdrv_is_locked(BlockDriverState *bs)
2703 {
2704 return bs->locked;
2705 }
2706
2707 /**
2708 * Lock or unlock the media (if it is locked, the user won't be able
2709 * to eject it manually).
2710 */
2711 void bdrv_set_locked(BlockDriverState *bs, int locked)
2712 {
2713 BlockDriver *drv = bs->drv;
2714
2715 bs->locked = locked;
2716 if (drv && drv->bdrv_set_locked) {
2717 drv->bdrv_set_locked(bs, locked);
2718 }
2719 }
2720
2721 /* needed for generic scsi interface */
2722
2723 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
2724 {
2725 BlockDriver *drv = bs->drv;
2726
2727 if (drv && drv->bdrv_ioctl)
2728 return drv->bdrv_ioctl(bs, req, buf);
2729 return -ENOTSUP;
2730 }
2731
2732 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
2733 unsigned long int req, void *buf,
2734 BlockDriverCompletionFunc *cb, void *opaque)
2735 {
2736 BlockDriver *drv = bs->drv;
2737
2738 if (drv && drv->bdrv_aio_ioctl)
2739 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
2740 return NULL;
2741 }
2742
2743
2744
2745 void *qemu_blockalign(BlockDriverState *bs, size_t size)
2746 {
2747 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
2748 }
2749
2750 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
2751 {
2752 int64_t bitmap_size;
2753
2754 bs->dirty_count = 0;
2755 if (enable) {
2756 if (!bs->dirty_bitmap) {
2757 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
2758 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
2759 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
2760
2761 bs->dirty_bitmap = qemu_mallocz(bitmap_size);
2762 }
2763 } else {
2764 if (bs->dirty_bitmap) {
2765 qemu_free(bs->dirty_bitmap);
2766 bs->dirty_bitmap = NULL;
2767 }
2768 }
2769 }
2770
2771 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
2772 {
2773 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
2774
2775 if (bs->dirty_bitmap &&
2776 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
2777 return !!(bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
2778 (1UL << (chunk % (sizeof(unsigned long) * 8))));
2779 } else {
2780 return 0;
2781 }
2782 }
2783
2784 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2785 int nr_sectors)
2786 {
2787 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2788 }
2789
2790 int64_t bdrv_get_dirty_count(BlockDriverState *bs)
2791 {
2792 return bs->dirty_count;
2793 }
2794
2795 void bdrv_set_in_use(BlockDriverState *bs, int in_use)
2796 {
2797 assert(bs->in_use != in_use);
2798 bs->in_use = in_use;
2799 }
2800
2801 int bdrv_in_use(BlockDriverState *bs)
2802 {
2803 return bs->in_use;
2804 }
2805
2806 int bdrv_img_create(const char *filename, const char *fmt,
2807 const char *base_filename, const char *base_fmt,
2808 char *options, uint64_t img_size, int flags)
2809 {
2810 QEMUOptionParameter *param = NULL, *create_options = NULL;
2811 QEMUOptionParameter *backing_fmt, *backing_file;
2812 BlockDriverState *bs = NULL;
2813 BlockDriver *drv, *proto_drv;
2814 BlockDriver *backing_drv = NULL;
2815 int ret = 0;
2816
2817 /* Find driver and parse its options */
2818 drv = bdrv_find_format(fmt);
2819 if (!drv) {
2820 error_report("Unknown file format '%s'", fmt);
2821 ret = -EINVAL;
2822 goto out;
2823 }
2824
2825 proto_drv = bdrv_find_protocol(filename);
2826 if (!proto_drv) {
2827 error_report("Unknown protocol '%s'", filename);
2828 ret = -EINVAL;
2829 goto out;
2830 }
2831
2832 create_options = append_option_parameters(create_options,
2833 drv->create_options);
2834 create_options = append_option_parameters(create_options,
2835 proto_drv->create_options);
2836
2837 /* Create parameter list with default values */
2838 param = parse_option_parameters("", create_options, param);
2839
2840 set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size);
2841
2842 /* Parse -o options */
2843 if (options) {
2844 param = parse_option_parameters(options, create_options, param);
2845 if (param == NULL) {
2846 error_report("Invalid options for file format '%s'.", fmt);
2847 ret = -EINVAL;
2848 goto out;
2849 }
2850 }
2851
2852 if (base_filename) {
2853 if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE,
2854 base_filename)) {
2855 error_report("Backing file not supported for file format '%s'",
2856 fmt);
2857 ret = -EINVAL;
2858 goto out;
2859 }
2860 }
2861
2862 if (base_fmt) {
2863 if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) {
2864 error_report("Backing file format not supported for file "
2865 "format '%s'", fmt);
2866 ret = -EINVAL;
2867 goto out;
2868 }
2869 }
2870
2871 backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
2872 if (backing_file && backing_file->value.s) {
2873 if (!strcmp(filename, backing_file->value.s)) {
2874 error_report("Error: Trying to create an image with the "
2875 "same filename as the backing file");
2876 ret = -EINVAL;
2877 goto out;
2878 }
2879 }
2880
2881 backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT);
2882 if (backing_fmt && backing_fmt->value.s) {
2883 backing_drv = bdrv_find_format(backing_fmt->value.s);
2884 if (!backing_drv) {
2885 error_report("Unknown backing file format '%s'",
2886 backing_fmt->value.s);
2887 ret = -EINVAL;
2888 goto out;
2889 }
2890 }
2891
2892 // The size for the image must always be specified, with one exception:
2893 // If we are using a backing file, we can obtain the size from there
2894 if (get_option_parameter(param, BLOCK_OPT_SIZE)->value.n == -1) {
2895 if (backing_file && backing_file->value.s) {
2896 uint64_t size;
2897 char buf[32];
2898
2899 bs = bdrv_new("");
2900
2901 ret = bdrv_open(bs, backing_file->value.s, flags, backing_drv);
2902 if (ret < 0) {
2903 error_report("Could not open '%s'", backing_file->value.s);
2904 goto out;
2905 }
2906 bdrv_get_geometry(bs, &size);
2907 size *= 512;
2908
2909 snprintf(buf, sizeof(buf), "%" PRId64, size);
2910 set_option_parameter(param, BLOCK_OPT_SIZE, buf);
2911 } else {
2912 error_report("Image creation needs a size parameter");
2913 ret = -EINVAL;
2914 goto out;
2915 }
2916 }
2917
2918 printf("Formatting '%s', fmt=%s ", filename, fmt);
2919 print_option_parameters(param);
2920 puts("");
2921
2922 ret = bdrv_create(drv, filename, param);
2923
2924 if (ret < 0) {
2925 if (ret == -ENOTSUP) {
2926 error_report("Formatting or formatting option not supported for "
2927 "file format '%s'", fmt);
2928 } else if (ret == -EFBIG) {
2929 error_report("The image size is too large for file format '%s'",
2930 fmt);
2931 } else {
2932 error_report("%s: error while creating %s: %s", filename, fmt,
2933 strerror(-ret));
2934 }
2935 }
2936
2937 out:
2938 free_option_parameters(create_options);
2939 free_option_parameters(param);
2940
2941 if (bs) {
2942 bdrv_delete(bs);
2943 }
2944
2945 return ret;
2946 }