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[qemu/mdroth.git] / block.c
blob985d0b7e39e2c398d5b310ce1f1de9f4d1436d24
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 int path_is_absolute(const char *path)
74 {
75 const char *p;
76 #ifdef _WIN32
77 /* specific case for names like: "\\.\d:" */
78 if (*path == '/' || *path == '\\')
79 return 1;
80 #endif
81 p = strchr(path, ':');
82 if (p)
83 p++;
84 else
85 p = path;
86 #ifdef _WIN32
87 return (*p == '/' || *p == '\\');
88 #else
89 return (*p == '/');
90 #endif
91 }
92
93 /* if filename is absolute, just copy it to dest. Otherwise, build a
94 path to it by considering it is relative to base_path. URL are
95 supported. */
96 void path_combine(char *dest, int dest_size,
97 const char *base_path,
98 const char *filename)
99 {
100 const char *p, *p1;
101 int len;
102
103 if (dest_size <= 0)
104 return;
105 if (path_is_absolute(filename)) {
106 pstrcpy(dest, dest_size, filename);
107 } else {
108 p = strchr(base_path, ':');
109 if (p)
110 p++;
111 else
112 p = base_path;
113 p1 = strrchr(base_path, '/');
114 #ifdef _WIN32
115 {
116 const char *p2;
117 p2 = strrchr(base_path, '\\');
118 if (!p1 || p2 > p1)
119 p1 = p2;
120 }
121 #endif
122 if (p1)
123 p1++;
124 else
125 p1 = base_path;
126 if (p1 > p)
127 p = p1;
128 len = p - base_path;
129 if (len > dest_size - 1)
130 len = dest_size - 1;
131 memcpy(dest, base_path, len);
132 dest[len] = '\0';
133 pstrcat(dest, dest_size, filename);
134 }
135 }
136
137 void bdrv_register(BlockDriver *bdrv)
138 {
139 if (!bdrv->bdrv_aio_readv) {
140 /* add AIO emulation layer */
141 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
142 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
143 } else if (!bdrv->bdrv_read) {
144 /* add synchronous IO emulation layer */
145 bdrv->bdrv_read = bdrv_read_em;
146 bdrv->bdrv_write = bdrv_write_em;
147 }
148
149 if (!bdrv->bdrv_aio_flush)
150 bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
151
152 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
153 }
154
155 /* create a new block device (by default it is empty) */
156 BlockDriverState *bdrv_new(const char *device_name)
157 {
158 BlockDriverState *bs;
159
160 bs = qemu_mallocz(sizeof(BlockDriverState));
161 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
162 if (device_name[0] != '\0') {
163 QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
164 }
165 return bs;
166 }
167
168 BlockDriver *bdrv_find_format(const char *format_name)
169 {
170 BlockDriver *drv1;
171 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
172 if (!strcmp(drv1->format_name, format_name)) {
173 return drv1;
174 }
175 }
176 return NULL;
177 }
178
179 static int bdrv_is_whitelisted(BlockDriver *drv)
180 {
181 static const char *whitelist[] = {
182 CONFIG_BDRV_WHITELIST
183 };
184 const char **p;
185
186 if (!whitelist[0])
187 return 1; /* no whitelist, anything goes */
188
189 for (p = whitelist; *p; p++) {
190 if (!strcmp(drv->format_name, *p)) {
191 return 1;
192 }
193 }
194 return 0;
195 }
196
197 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
198 {
199 BlockDriver *drv = bdrv_find_format(format_name);
200 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
201 }
202
203 int bdrv_create(BlockDriver *drv, const char* filename,
204 QEMUOptionParameter *options)
205 {
206 if (!drv->bdrv_create)
207 return -ENOTSUP;
208
209 return drv->bdrv_create(filename, options);
210 }
211
212 int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
213 {
214 BlockDriver *drv;
215
216 drv = bdrv_find_protocol(filename);
217 if (drv == NULL) {
218 drv = bdrv_find_format("file");
219 }
220
221 return bdrv_create(drv, filename, options);
222 }
223
224 #ifdef _WIN32
225 void get_tmp_filename(char *filename, int size)
226 {
227 char temp_dir[MAX_PATH];
228
229 GetTempPath(MAX_PATH, temp_dir);
230 GetTempFileName(temp_dir, "qem", 0, filename);
231 }
232 #else
233 void get_tmp_filename(char *filename, int size)
234 {
235 int fd;
236 const char *tmpdir;
237 /* XXX: race condition possible */
238 tmpdir = getenv("TMPDIR");
239 if (!tmpdir)
240 tmpdir = "/tmp";
241 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
242 fd = mkstemp(filename);
243 close(fd);
244 }
245 #endif
246
247 #ifdef _WIN32
248 static int is_windows_drive_prefix(const char *filename)
249 {
250 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
251 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
252 filename[1] == ':');
253 }
254
255 int is_windows_drive(const char *filename)
256 {
257 if (is_windows_drive_prefix(filename) &&
258 filename[2] == '\0')
259 return 1;
260 if (strstart(filename, "\\\\.\\", NULL) ||
261 strstart(filename, "//./", NULL))
262 return 1;
263 return 0;
264 }
265 #endif
266
267 /*
268 * Detect host devices. By convention, /dev/cdrom[N] is always
269 * recognized as a host CDROM.
270 */
271 static BlockDriver *find_hdev_driver(const char *filename)
272 {
273 int score_max = 0, score;
274 BlockDriver *drv = NULL, *d;
275
276 QLIST_FOREACH(d, &bdrv_drivers, list) {
277 if (d->bdrv_probe_device) {
278 score = d->bdrv_probe_device(filename);
279 if (score > score_max) {
280 score_max = score;
281 drv = d;
282 }
283 }
284 }
285
286 return drv;
287 }
288
289 BlockDriver *bdrv_find_protocol(const char *filename)
290 {
291 BlockDriver *drv1;
292 char protocol[128];
293 int len;
294 const char *p;
295
296 /* TODO Drivers without bdrv_file_open must be specified explicitly */
297
298 /*
299 * XXX(hch): we really should not let host device detection
300 * override an explicit protocol specification, but moving this
301 * later breaks access to device names with colons in them.
302 * Thanks to the brain-dead persistent naming schemes on udev-
303 * based Linux systems those actually are quite common.
304 */
305 drv1 = find_hdev_driver(filename);
306 if (drv1) {
307 return drv1;
308 }
309
310 #ifdef _WIN32
311 if (is_windows_drive(filename) ||
312 is_windows_drive_prefix(filename))
313 return bdrv_find_format("file");
314 #endif
315
316 p = strchr(filename, ':');
317 if (!p) {
318 return bdrv_find_format("file");
319 }
320 len = p - filename;
321 if (len > sizeof(protocol) - 1)
322 len = sizeof(protocol) - 1;
323 memcpy(protocol, filename, len);
324 protocol[len] = '\0';
325 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
326 if (drv1->protocol_name &&
327 !strcmp(drv1->protocol_name, protocol)) {
328 return drv1;
329 }
330 }
331 return NULL;
332 }
333
334 static int find_image_format(const char *filename, BlockDriver **pdrv)
335 {
336 int ret, score, score_max;
337 BlockDriver *drv1, *drv;
338 uint8_t buf[2048];
339 BlockDriverState *bs;
340
341 ret = bdrv_file_open(&bs, filename, 0);
342 if (ret < 0) {
343 *pdrv = NULL;
344 return ret;
345 }
346
347 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
348 if (bs->sg || !bdrv_is_inserted(bs)) {
349 bdrv_delete(bs);
350 drv = bdrv_find_format("raw");
351 if (!drv) {
352 ret = -ENOENT;
353 }
354 *pdrv = drv;
355 return ret;
356 }
357
358 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
359 bdrv_delete(bs);
360 if (ret < 0) {
361 *pdrv = NULL;
362 return ret;
363 }
364
365 score_max = 0;
366 drv = NULL;
367 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
368 if (drv1->bdrv_probe) {
369 score = drv1->bdrv_probe(buf, ret, filename);
370 if (score > score_max) {
371 score_max = score;
372 drv = drv1;
373 }
374 }
375 }
376 if (!drv) {
377 ret = -ENOENT;
378 }
379 *pdrv = drv;
380 return ret;
381 }
382
383 /**
384 * Set the current 'total_sectors' value
385 */
386 static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
387 {
388 BlockDriver *drv = bs->drv;
389
390 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
391 if (bs->sg)
392 return 0;
393
394 /* query actual device if possible, otherwise just trust the hint */
395 if (drv->bdrv_getlength) {
396 int64_t length = drv->bdrv_getlength(bs);
397 if (length < 0) {
398 return length;
399 }
400 hint = length >> BDRV_SECTOR_BITS;
401 }
402
403 bs->total_sectors = hint;
404 return 0;
405 }
406
407 /*
408 * Common part for opening disk images and files
409 */
410 static int bdrv_open_common(BlockDriverState *bs, const char *filename,
411 int flags, BlockDriver *drv)
412 {
413 int ret, open_flags;
414
415 assert(drv != NULL);
416
417 bs->file = NULL;
418 bs->total_sectors = 0;
419 bs->encrypted = 0;
420 bs->valid_key = 0;
421 bs->open_flags = flags;
422 /* buffer_alignment defaulted to 512, drivers can change this value */
423 bs->buffer_alignment = 512;
424
425 pstrcpy(bs->filename, sizeof(bs->filename), filename);
426
427 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
428 return -ENOTSUP;
429 }
430
431 bs->drv = drv;
432 bs->opaque = qemu_mallocz(drv->instance_size);
433
434 /*
435 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
436 * write cache to the guest. We do need the fdatasync to flush
437 * out transactions for block allocations, and we maybe have a
438 * volatile write cache in our backing device to deal with.
439 */
440 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
441 bs->enable_write_cache = 1;
442
443 /*
444 * Clear flags that are internal to the block layer before opening the
445 * image.
446 */
447 open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
448
449 /*
450 * Snapshots should be writeable.
451 */
452 if (bs->is_temporary) {
453 open_flags |= BDRV_O_RDWR;
454 }
455
456 /* Open the image, either directly or using a protocol */
457 if (drv->bdrv_file_open) {
458 ret = drv->bdrv_file_open(bs, filename, open_flags);
459 } else {
460 ret = bdrv_file_open(&bs->file, filename, open_flags);
461 if (ret >= 0) {
462 ret = drv->bdrv_open(bs, open_flags);
463 }
464 }
465
466 if (ret < 0) {
467 goto free_and_fail;
468 }
469
470 bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
471
472 ret = refresh_total_sectors(bs, bs->total_sectors);
473 if (ret < 0) {
474 goto free_and_fail;
475 }
476
477 #ifndef _WIN32
478 if (bs->is_temporary) {
479 unlink(filename);
480 }
481 #endif
482 return 0;
483
484 free_and_fail:
485 if (bs->file) {
486 bdrv_delete(bs->file);
487 bs->file = NULL;
488 }
489 qemu_free(bs->opaque);
490 bs->opaque = NULL;
491 bs->drv = NULL;
492 return ret;
493 }
494
495 /*
496 * Opens a file using a protocol (file, host_device, nbd, ...)
497 */
498 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
499 {
500 BlockDriverState *bs;
501 BlockDriver *drv;
502 int ret;
503
504 drv = bdrv_find_protocol(filename);
505 if (!drv) {
506 return -ENOENT;
507 }
508
509 bs = bdrv_new("");
510 ret = bdrv_open_common(bs, filename, flags, drv);
511 if (ret < 0) {
512 bdrv_delete(bs);
513 return ret;
514 }
515 bs->growable = 1;
516 *pbs = bs;
517 return 0;
518 }
519
520 /*
521 * Opens a disk image (raw, qcow2, vmdk, ...)
522 */
523 int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
524 BlockDriver *drv)
525 {
526 int ret;
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 }
588
589 if (!drv) {
590 goto unlink_and_fail;
591 }
592
593 /* Open the image */
594 ret = bdrv_open_common(bs, filename, flags, drv);
595 if (ret < 0) {
596 goto unlink_and_fail;
597 }
598
599 /* If there is a backing file, use it */
600 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
601 char backing_filename[PATH_MAX];
602 int back_flags;
603 BlockDriver *back_drv = NULL;
604
605 bs->backing_hd = bdrv_new("");
606 path_combine(backing_filename, sizeof(backing_filename),
607 filename, bs->backing_file);
608 if (bs->backing_format[0] != '\0')
609 back_drv = bdrv_find_format(bs->backing_format);
610
611 /* backing files always opened read-only */
612 back_flags =
613 flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
614
615 ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
616 if (ret < 0) {
617 bdrv_close(bs);
618 return ret;
619 }
620 if (bs->is_temporary) {
621 bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
622 } else {
623 /* base image inherits from "parent" */
624 bs->backing_hd->keep_read_only = bs->keep_read_only;
625 }
626 }
627
628 if (!bdrv_key_required(bs)) {
629 /* call the change callback */
630 bs->media_changed = 1;
631 if (bs->change_cb)
632 bs->change_cb(bs->change_opaque);
633 }
634
635 return 0;
636
637 unlink_and_fail:
638 if (bs->is_temporary) {
639 unlink(filename);
640 }
641 return ret;
642 }
643
644 void bdrv_close(BlockDriverState *bs)
645 {
646 if (bs->drv) {
647 if (bs == bs_snapshots) {
648 bs_snapshots = NULL;
649 }
650 if (bs->backing_hd) {
651 bdrv_delete(bs->backing_hd);
652 bs->backing_hd = NULL;
653 }
654 bs->drv->bdrv_close(bs);
655 qemu_free(bs->opaque);
656 #ifdef _WIN32
657 if (bs->is_temporary) {
658 unlink(bs->filename);
659 }
660 #endif
661 bs->opaque = NULL;
662 bs->drv = NULL;
663
664 if (bs->file != NULL) {
665 bdrv_close(bs->file);
666 }
667
668 /* call the change callback */
669 bs->media_changed = 1;
670 if (bs->change_cb)
671 bs->change_cb(bs->change_opaque);
672 }
673 }
674
675 void bdrv_close_all(void)
676 {
677 BlockDriverState *bs;
678
679 QTAILQ_FOREACH(bs, &bdrv_states, list) {
680 bdrv_close(bs);
681 }
682 }
683
684 void bdrv_delete(BlockDriverState *bs)
685 {
686 assert(!bs->peer);
687
688 /* remove from list, if necessary */
689 if (bs->device_name[0] != '\0') {
690 QTAILQ_REMOVE(&bdrv_states, bs, list);
691 }
692
693 bdrv_close(bs);
694 if (bs->file != NULL) {
695 bdrv_delete(bs->file);
696 }
697
698 assert(bs != bs_snapshots);
699 qemu_free(bs);
700 }
701
702 int bdrv_attach(BlockDriverState *bs, DeviceState *qdev)
703 {
704 if (bs->peer) {
705 return -EBUSY;
706 }
707 bs->peer = qdev;
708 return 0;
709 }
710
711 void bdrv_detach(BlockDriverState *bs, DeviceState *qdev)
712 {
713 assert(bs->peer == qdev);
714 bs->peer = NULL;
715 }
716
717 DeviceState *bdrv_get_attached(BlockDriverState *bs)
718 {
719 return bs->peer;
720 }
721
722 /*
723 * Run consistency checks on an image
724 *
725 * Returns 0 if the check could be completed (it doesn't mean that the image is
726 * free of errors) or -errno when an internal error occured. The results of the
727 * check are stored in res.
728 */
729 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
730 {
731 if (bs->drv->bdrv_check == NULL) {
732 return -ENOTSUP;
733 }
734
735 memset(res, 0, sizeof(*res));
736 return bs->drv->bdrv_check(bs, res);
737 }
738
739 #define COMMIT_BUF_SECTORS 2048
740
741 /* commit COW file into the raw image */
742 int bdrv_commit(BlockDriverState *bs)
743 {
744 BlockDriver *drv = bs->drv;
745 BlockDriver *backing_drv;
746 int64_t sector, total_sectors;
747 int n, ro, open_flags;
748 int ret = 0, rw_ret = 0;
749 uint8_t *buf;
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 backing_drv = bs->backing_hd->drv;
765 ro = bs->backing_hd->read_only;
766 strncpy(filename, bs->backing_hd->filename, sizeof(filename));
767 open_flags = bs->backing_hd->open_flags;
768
769 if (ro) {
770 /* re-open as RW */
771 bdrv_delete(bs->backing_hd);
772 bs->backing_hd = NULL;
773 bs_rw = bdrv_new("");
774 rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
775 backing_drv);
776 if (rw_ret < 0) {
777 bdrv_delete(bs_rw);
778 /* try to re-open read-only */
779 bs_ro = bdrv_new("");
780 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
781 backing_drv);
782 if (ret < 0) {
783 bdrv_delete(bs_ro);
784 /* drive not functional anymore */
785 bs->drv = NULL;
786 return ret;
787 }
788 bs->backing_hd = bs_ro;
789 return rw_ret;
790 }
791 bs->backing_hd = bs_rw;
792 }
793
794 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
795 buf = qemu_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
796
797 for (sector = 0; sector < total_sectors; sector += n) {
798 if (drv->bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
799
800 if (bdrv_read(bs, sector, buf, n) != 0) {
801 ret = -EIO;
802 goto ro_cleanup;
803 }
804
805 if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
806 ret = -EIO;
807 goto ro_cleanup;
808 }
809 }
810 }
811
812 if (drv->bdrv_make_empty) {
813 ret = drv->bdrv_make_empty(bs);
814 bdrv_flush(bs);
815 }
816
817 /*
818 * Make sure all data we wrote to the backing device is actually
819 * stable on disk.
820 */
821 if (bs->backing_hd)
822 bdrv_flush(bs->backing_hd);
823
824 ro_cleanup:
825 qemu_free(buf);
826
827 if (ro) {
828 /* re-open as RO */
829 bdrv_delete(bs->backing_hd);
830 bs->backing_hd = NULL;
831 bs_ro = bdrv_new("");
832 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
833 backing_drv);
834 if (ret < 0) {
835 bdrv_delete(bs_ro);
836 /* drive not functional anymore */
837 bs->drv = NULL;
838 return ret;
839 }
840 bs->backing_hd = bs_ro;
841 bs->backing_hd->keep_read_only = 0;
842 }
843
844 return ret;
845 }
846
847 void bdrv_commit_all(void)
848 {
849 BlockDriverState *bs;
850
851 QTAILQ_FOREACH(bs, &bdrv_states, list) {
852 bdrv_commit(bs);
853 }
854 }
855
856 /*
857 * Return values:
858 * 0 - success
859 * -EINVAL - backing format specified, but no file
860 * -ENOSPC - can't update the backing file because no space is left in the
861 * image file header
862 * -ENOTSUP - format driver doesn't support changing the backing file
863 */
864 int bdrv_change_backing_file(BlockDriverState *bs,
865 const char *backing_file, const char *backing_fmt)
866 {
867 BlockDriver *drv = bs->drv;
868
869 if (drv->bdrv_change_backing_file != NULL) {
870 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
871 } else {
872 return -ENOTSUP;
873 }
874 }
875
876 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
877 size_t size)
878 {
879 int64_t len;
880
881 if (!bdrv_is_inserted(bs))
882 return -ENOMEDIUM;
883
884 if (bs->growable)
885 return 0;
886
887 len = bdrv_getlength(bs);
888
889 if (offset < 0)
890 return -EIO;
891
892 if ((offset > len) || (len - offset < size))
893 return -EIO;
894
895 return 0;
896 }
897
898 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
899 int nb_sectors)
900 {
901 return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
902 nb_sectors * BDRV_SECTOR_SIZE);
903 }
904
905 /* return < 0 if error. See bdrv_write() for the return codes */
906 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
907 uint8_t *buf, int nb_sectors)
908 {
909 BlockDriver *drv = bs->drv;
910
911 if (!drv)
912 return -ENOMEDIUM;
913 if (bdrv_check_request(bs, sector_num, nb_sectors))
914 return -EIO;
915
916 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
917 }
918
919 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
920 int nb_sectors, int dirty)
921 {
922 int64_t start, end;
923 unsigned long val, idx, bit;
924
925 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
926 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
927
928 for (; start <= end; start++) {
929 idx = start / (sizeof(unsigned long) * 8);
930 bit = start % (sizeof(unsigned long) * 8);
931 val = bs->dirty_bitmap[idx];
932 if (dirty) {
933 if (!(val & (1 << bit))) {
934 bs->dirty_count++;
935 val |= 1 << bit;
936 }
937 } else {
938 if (val & (1 << bit)) {
939 bs->dirty_count--;
940 val &= ~(1 << bit);
941 }
942 }
943 bs->dirty_bitmap[idx] = val;
944 }
945 }
946
947 /* Return < 0 if error. Important errors are:
948 -EIO generic I/O error (may happen for all errors)
949 -ENOMEDIUM No media inserted.
950 -EINVAL Invalid sector number or nb_sectors
951 -EACCES Trying to write a read-only device
952 */
953 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
954 const uint8_t *buf, int nb_sectors)
955 {
956 BlockDriver *drv = bs->drv;
957 if (!bs->drv)
958 return -ENOMEDIUM;
959 if (bs->read_only)
960 return -EACCES;
961 if (bdrv_check_request(bs, sector_num, nb_sectors))
962 return -EIO;
963
964 if (bs->dirty_bitmap) {
965 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
966 }
967
968 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
969 bs->wr_highest_sector = sector_num + nb_sectors - 1;
970 }
971
972 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
973 }
974
975 int bdrv_pread(BlockDriverState *bs, int64_t offset,
976 void *buf, int count1)
977 {
978 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
979 int len, nb_sectors, count;
980 int64_t sector_num;
981 int ret;
982
983 count = count1;
984 /* first read to align to sector start */
985 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
986 if (len > count)
987 len = count;
988 sector_num = offset >> BDRV_SECTOR_BITS;
989 if (len > 0) {
990 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
991 return ret;
992 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
993 count -= len;
994 if (count == 0)
995 return count1;
996 sector_num++;
997 buf += len;
998 }
999
1000 /* read the sectors "in place" */
1001 nb_sectors = count >> BDRV_SECTOR_BITS;
1002 if (nb_sectors > 0) {
1003 if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
1004 return ret;
1005 sector_num += nb_sectors;
1006 len = nb_sectors << BDRV_SECTOR_BITS;
1007 buf += len;
1008 count -= len;
1009 }
1010
1011 /* add data from the last sector */
1012 if (count > 0) {
1013 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1014 return ret;
1015 memcpy(buf, tmp_buf, count);
1016 }
1017 return count1;
1018 }
1019
1020 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
1021 const void *buf, int count1)
1022 {
1023 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1024 int len, nb_sectors, count;
1025 int64_t sector_num;
1026 int ret;
1027
1028 count = count1;
1029 /* first write to align to sector start */
1030 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1031 if (len > count)
1032 len = count;
1033 sector_num = offset >> BDRV_SECTOR_BITS;
1034 if (len > 0) {
1035 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1036 return ret;
1037 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1038 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1039 return ret;
1040 count -= len;
1041 if (count == 0)
1042 return count1;
1043 sector_num++;
1044 buf += len;
1045 }
1046
1047 /* write the sectors "in place" */
1048 nb_sectors = count >> BDRV_SECTOR_BITS;
1049 if (nb_sectors > 0) {
1050 if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
1051 return ret;
1052 sector_num += nb_sectors;
1053 len = nb_sectors << BDRV_SECTOR_BITS;
1054 buf += len;
1055 count -= len;
1056 }
1057
1058 /* add data from the last sector */
1059 if (count > 0) {
1060 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1061 return ret;
1062 memcpy(tmp_buf, buf, count);
1063 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1064 return ret;
1065 }
1066 return count1;
1067 }
1068
1069 /*
1070 * Writes to the file and ensures that no writes are reordered across this
1071 * request (acts as a barrier)
1072 *
1073 * Returns 0 on success, -errno in error cases.
1074 */
1075 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
1076 const void *buf, int count)
1077 {
1078 int ret;
1079
1080 ret = bdrv_pwrite(bs, offset, buf, count);
1081 if (ret < 0) {
1082 return ret;
1083 }
1084
1085 /* No flush needed for cache=writethrough, it uses O_DSYNC */
1086 if ((bs->open_flags & BDRV_O_CACHE_MASK) != 0) {
1087 bdrv_flush(bs);
1088 }
1089
1090 return 0;
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_write_sync(BlockDriverState *bs, int64_t sector_num,
1100 const uint8_t *buf, int nb_sectors)
1101 {
1102 return bdrv_pwrite_sync(bs, BDRV_SECTOR_SIZE * sector_num,
1103 buf, BDRV_SECTOR_SIZE * nb_sectors);
1104 }
1105
1106 /**
1107 * Truncate file to 'offset' bytes (needed only for file protocols)
1108 */
1109 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
1110 {
1111 BlockDriver *drv = bs->drv;
1112 int ret;
1113 if (!drv)
1114 return -ENOMEDIUM;
1115 if (!drv->bdrv_truncate)
1116 return -ENOTSUP;
1117 if (bs->read_only)
1118 return -EACCES;
1119 ret = drv->bdrv_truncate(bs, offset);
1120 if (ret == 0) {
1121 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
1122 }
1123 return ret;
1124 }
1125
1126 /**
1127 * Length of a file in bytes. Return < 0 if error or unknown.
1128 */
1129 int64_t bdrv_getlength(BlockDriverState *bs)
1130 {
1131 BlockDriver *drv = bs->drv;
1132 if (!drv)
1133 return -ENOMEDIUM;
1134
1135 /* Fixed size devices use the total_sectors value for speed instead of
1136 issuing a length query (like lseek) on each call. Also, legacy block
1137 drivers don't provide a bdrv_getlength function and must use
1138 total_sectors. */
1139 if (!bs->growable || !drv->bdrv_getlength) {
1140 return bs->total_sectors * BDRV_SECTOR_SIZE;
1141 }
1142 return drv->bdrv_getlength(bs);
1143 }
1144
1145 /* return 0 as number of sectors if no device present or error */
1146 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
1147 {
1148 int64_t length;
1149 length = bdrv_getlength(bs);
1150 if (length < 0)
1151 length = 0;
1152 else
1153 length = length >> BDRV_SECTOR_BITS;
1154 *nb_sectors_ptr = length;
1155 }
1156
1157 struct partition {
1158 uint8_t boot_ind; /* 0x80 - active */
1159 uint8_t head; /* starting head */
1160 uint8_t sector; /* starting sector */
1161 uint8_t cyl; /* starting cylinder */
1162 uint8_t sys_ind; /* What partition type */
1163 uint8_t end_head; /* end head */
1164 uint8_t end_sector; /* end sector */
1165 uint8_t end_cyl; /* end cylinder */
1166 uint32_t start_sect; /* starting sector counting from 0 */
1167 uint32_t nr_sects; /* nr of sectors in partition */
1168 } __attribute__((packed));
1169
1170 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
1171 static int guess_disk_lchs(BlockDriverState *bs,
1172 int *pcylinders, int *pheads, int *psectors)
1173 {
1174 uint8_t buf[BDRV_SECTOR_SIZE];
1175 int ret, i, heads, sectors, cylinders;
1176 struct partition *p;
1177 uint32_t nr_sects;
1178 uint64_t nb_sectors;
1179
1180 bdrv_get_geometry(bs, &nb_sectors);
1181
1182 ret = bdrv_read(bs, 0, buf, 1);
1183 if (ret < 0)
1184 return -1;
1185 /* test msdos magic */
1186 if (buf[510] != 0x55 || buf[511] != 0xaa)
1187 return -1;
1188 for(i = 0; i < 4; i++) {
1189 p = ((struct partition *)(buf + 0x1be)) + i;
1190 nr_sects = le32_to_cpu(p->nr_sects);
1191 if (nr_sects && p->end_head) {
1192 /* We make the assumption that the partition terminates on
1193 a cylinder boundary */
1194 heads = p->end_head + 1;
1195 sectors = p->end_sector & 63;
1196 if (sectors == 0)
1197 continue;
1198 cylinders = nb_sectors / (heads * sectors);
1199 if (cylinders < 1 || cylinders > 16383)
1200 continue;
1201 *pheads = heads;
1202 *psectors = sectors;
1203 *pcylinders = cylinders;
1204 #if 0
1205 printf("guessed geometry: LCHS=%d %d %d\n",
1206 cylinders, heads, sectors);
1207 #endif
1208 return 0;
1209 }
1210 }
1211 return -1;
1212 }
1213
1214 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
1215 {
1216 int translation, lba_detected = 0;
1217 int cylinders, heads, secs;
1218 uint64_t nb_sectors;
1219
1220 /* if a geometry hint is available, use it */
1221 bdrv_get_geometry(bs, &nb_sectors);
1222 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
1223 translation = bdrv_get_translation_hint(bs);
1224 if (cylinders != 0) {
1225 *pcyls = cylinders;
1226 *pheads = heads;
1227 *psecs = secs;
1228 } else {
1229 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
1230 if (heads > 16) {
1231 /* if heads > 16, it means that a BIOS LBA
1232 translation was active, so the default
1233 hardware geometry is OK */
1234 lba_detected = 1;
1235 goto default_geometry;
1236 } else {
1237 *pcyls = cylinders;
1238 *pheads = heads;
1239 *psecs = secs;
1240 /* disable any translation to be in sync with
1241 the logical geometry */
1242 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
1243 bdrv_set_translation_hint(bs,
1244 BIOS_ATA_TRANSLATION_NONE);
1245 }
1246 }
1247 } else {
1248 default_geometry:
1249 /* if no geometry, use a standard physical disk geometry */
1250 cylinders = nb_sectors / (16 * 63);
1251
1252 if (cylinders > 16383)
1253 cylinders = 16383;
1254 else if (cylinders < 2)
1255 cylinders = 2;
1256 *pcyls = cylinders;
1257 *pheads = 16;
1258 *psecs = 63;
1259 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
1260 if ((*pcyls * *pheads) <= 131072) {
1261 bdrv_set_translation_hint(bs,
1262 BIOS_ATA_TRANSLATION_LARGE);
1263 } else {
1264 bdrv_set_translation_hint(bs,
1265 BIOS_ATA_TRANSLATION_LBA);
1266 }
1267 }
1268 }
1269 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
1270 }
1271 }
1272
1273 void bdrv_set_geometry_hint(BlockDriverState *bs,
1274 int cyls, int heads, int secs)
1275 {
1276 bs->cyls = cyls;
1277 bs->heads = heads;
1278 bs->secs = secs;
1279 }
1280
1281 void bdrv_set_type_hint(BlockDriverState *bs, int type)
1282 {
1283 bs->type = type;
1284 bs->removable = ((type == BDRV_TYPE_CDROM ||
1285 type == BDRV_TYPE_FLOPPY));
1286 }
1287
1288 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
1289 {
1290 bs->translation = translation;
1291 }
1292
1293 void bdrv_get_geometry_hint(BlockDriverState *bs,
1294 int *pcyls, int *pheads, int *psecs)
1295 {
1296 *pcyls = bs->cyls;
1297 *pheads = bs->heads;
1298 *psecs = bs->secs;
1299 }
1300
1301 int bdrv_get_type_hint(BlockDriverState *bs)
1302 {
1303 return bs->type;
1304 }
1305
1306 int bdrv_get_translation_hint(BlockDriverState *bs)
1307 {
1308 return bs->translation;
1309 }
1310
1311 void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
1312 BlockErrorAction on_write_error)
1313 {
1314 bs->on_read_error = on_read_error;
1315 bs->on_write_error = on_write_error;
1316 }
1317
1318 BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
1319 {
1320 return is_read ? bs->on_read_error : bs->on_write_error;
1321 }
1322
1323 void bdrv_set_removable(BlockDriverState *bs, int removable)
1324 {
1325 bs->removable = removable;
1326 if (removable && bs == bs_snapshots) {
1327 bs_snapshots = NULL;
1328 }
1329 }
1330
1331 int bdrv_is_removable(BlockDriverState *bs)
1332 {
1333 return bs->removable;
1334 }
1335
1336 int bdrv_is_read_only(BlockDriverState *bs)
1337 {
1338 return bs->read_only;
1339 }
1340
1341 int bdrv_is_sg(BlockDriverState *bs)
1342 {
1343 return bs->sg;
1344 }
1345
1346 int bdrv_enable_write_cache(BlockDriverState *bs)
1347 {
1348 return bs->enable_write_cache;
1349 }
1350
1351 /* XXX: no longer used */
1352 void bdrv_set_change_cb(BlockDriverState *bs,
1353 void (*change_cb)(void *opaque), void *opaque)
1354 {
1355 bs->change_cb = change_cb;
1356 bs->change_opaque = opaque;
1357 }
1358
1359 int bdrv_is_encrypted(BlockDriverState *bs)
1360 {
1361 if (bs->backing_hd && bs->backing_hd->encrypted)
1362 return 1;
1363 return bs->encrypted;
1364 }
1365
1366 int bdrv_key_required(BlockDriverState *bs)
1367 {
1368 BlockDriverState *backing_hd = bs->backing_hd;
1369
1370 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1371 return 1;
1372 return (bs->encrypted && !bs->valid_key);
1373 }
1374
1375 int bdrv_set_key(BlockDriverState *bs, const char *key)
1376 {
1377 int ret;
1378 if (bs->backing_hd && bs->backing_hd->encrypted) {
1379 ret = bdrv_set_key(bs->backing_hd, key);
1380 if (ret < 0)
1381 return ret;
1382 if (!bs->encrypted)
1383 return 0;
1384 }
1385 if (!bs->encrypted) {
1386 return -EINVAL;
1387 } else if (!bs->drv || !bs->drv->bdrv_set_key) {
1388 return -ENOMEDIUM;
1389 }
1390 ret = bs->drv->bdrv_set_key(bs, key);
1391 if (ret < 0) {
1392 bs->valid_key = 0;
1393 } else if (!bs->valid_key) {
1394 bs->valid_key = 1;
1395 /* call the change callback now, we skipped it on open */
1396 bs->media_changed = 1;
1397 if (bs->change_cb)
1398 bs->change_cb(bs->change_opaque);
1399 }
1400 return ret;
1401 }
1402
1403 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1404 {
1405 if (!bs->drv) {
1406 buf[0] = '\0';
1407 } else {
1408 pstrcpy(buf, buf_size, bs->drv->format_name);
1409 }
1410 }
1411
1412 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1413 void *opaque)
1414 {
1415 BlockDriver *drv;
1416
1417 QLIST_FOREACH(drv, &bdrv_drivers, list) {
1418 it(opaque, drv->format_name);
1419 }
1420 }
1421
1422 BlockDriverState *bdrv_find(const char *name)
1423 {
1424 BlockDriverState *bs;
1425
1426 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1427 if (!strcmp(name, bs->device_name)) {
1428 return bs;
1429 }
1430 }
1431 return NULL;
1432 }
1433
1434 BlockDriverState *bdrv_next(BlockDriverState *bs)
1435 {
1436 if (!bs) {
1437 return QTAILQ_FIRST(&bdrv_states);
1438 }
1439 return QTAILQ_NEXT(bs, list);
1440 }
1441
1442 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1443 {
1444 BlockDriverState *bs;
1445
1446 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1447 it(opaque, bs);
1448 }
1449 }
1450
1451 const char *bdrv_get_device_name(BlockDriverState *bs)
1452 {
1453 return bs->device_name;
1454 }
1455
1456 void bdrv_flush(BlockDriverState *bs)
1457 {
1458 if (bs->open_flags & BDRV_O_NO_FLUSH) {
1459 return;
1460 }
1461
1462 if (bs->drv && bs->drv->bdrv_flush)
1463 bs->drv->bdrv_flush(bs);
1464 }
1465
1466 void bdrv_flush_all(void)
1467 {
1468 BlockDriverState *bs;
1469
1470 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1471 if (bs->drv && !bdrv_is_read_only(bs) &&
1472 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) {
1473 bdrv_flush(bs);
1474 }
1475 }
1476 }
1477
1478 int bdrv_has_zero_init(BlockDriverState *bs)
1479 {
1480 assert(bs->drv);
1481
1482 if (bs->drv->bdrv_has_zero_init) {
1483 return bs->drv->bdrv_has_zero_init(bs);
1484 }
1485
1486 return 1;
1487 }
1488
1489 /*
1490 * Returns true iff the specified sector is present in the disk image. Drivers
1491 * not implementing the functionality are assumed to not support backing files,
1492 * hence all their sectors are reported as allocated.
1493 *
1494 * 'pnum' is set to the number of sectors (including and immediately following
1495 * the specified sector) that are known to be in the same
1496 * allocated/unallocated state.
1497 *
1498 * 'nb_sectors' is the max value 'pnum' should be set to.
1499 */
1500 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1501 int *pnum)
1502 {
1503 int64_t n;
1504 if (!bs->drv->bdrv_is_allocated) {
1505 if (sector_num >= bs->total_sectors) {
1506 *pnum = 0;
1507 return 0;
1508 }
1509 n = bs->total_sectors - sector_num;
1510 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1511 return 1;
1512 }
1513 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1514 }
1515
1516 void bdrv_mon_event(const BlockDriverState *bdrv,
1517 BlockMonEventAction action, int is_read)
1518 {
1519 QObject *data;
1520 const char *action_str;
1521
1522 switch (action) {
1523 case BDRV_ACTION_REPORT:
1524 action_str = "report";
1525 break;
1526 case BDRV_ACTION_IGNORE:
1527 action_str = "ignore";
1528 break;
1529 case BDRV_ACTION_STOP:
1530 action_str = "stop";
1531 break;
1532 default:
1533 abort();
1534 }
1535
1536 data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
1537 bdrv->device_name,
1538 action_str,
1539 is_read ? "read" : "write");
1540 monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
1541
1542 qobject_decref(data);
1543 }
1544
1545 static void bdrv_print_dict(QObject *obj, void *opaque)
1546 {
1547 QDict *bs_dict;
1548 Monitor *mon = opaque;
1549
1550 bs_dict = qobject_to_qdict(obj);
1551
1552 monitor_printf(mon, "%s: type=%s removable=%d",
1553 qdict_get_str(bs_dict, "device"),
1554 qdict_get_str(bs_dict, "type"),
1555 qdict_get_bool(bs_dict, "removable"));
1556
1557 if (qdict_get_bool(bs_dict, "removable")) {
1558 monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
1559 }
1560
1561 if (qdict_haskey(bs_dict, "inserted")) {
1562 QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
1563
1564 monitor_printf(mon, " file=");
1565 monitor_print_filename(mon, qdict_get_str(qdict, "file"));
1566 if (qdict_haskey(qdict, "backing_file")) {
1567 monitor_printf(mon, " backing_file=");
1568 monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
1569 }
1570 monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
1571 qdict_get_bool(qdict, "ro"),
1572 qdict_get_str(qdict, "drv"),
1573 qdict_get_bool(qdict, "encrypted"));
1574 } else {
1575 monitor_printf(mon, " [not inserted]");
1576 }
1577
1578 monitor_printf(mon, "\n");
1579 }
1580
1581 void bdrv_info_print(Monitor *mon, const QObject *data)
1582 {
1583 qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
1584 }
1585
1586 void bdrv_info(Monitor *mon, QObject **ret_data)
1587 {
1588 QList *bs_list;
1589 BlockDriverState *bs;
1590
1591 bs_list = qlist_new();
1592
1593 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1594 QObject *bs_obj;
1595 const char *type = "unknown";
1596
1597 switch(bs->type) {
1598 case BDRV_TYPE_HD:
1599 type = "hd";
1600 break;
1601 case BDRV_TYPE_CDROM:
1602 type = "cdrom";
1603 break;
1604 case BDRV_TYPE_FLOPPY:
1605 type = "floppy";
1606 break;
1607 }
1608
1609 bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
1610 "'removable': %i, 'locked': %i }",
1611 bs->device_name, type, bs->removable,
1612 bs->locked);
1613
1614 if (bs->drv) {
1615 QObject *obj;
1616 QDict *bs_dict = qobject_to_qdict(bs_obj);
1617
1618 obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
1619 "'encrypted': %i }",
1620 bs->filename, bs->read_only,
1621 bs->drv->format_name,
1622 bdrv_is_encrypted(bs));
1623 if (bs->backing_file[0] != '\0') {
1624 QDict *qdict = qobject_to_qdict(obj);
1625 qdict_put(qdict, "backing_file",
1626 qstring_from_str(bs->backing_file));
1627 }
1628
1629 qdict_put_obj(bs_dict, "inserted", obj);
1630 }
1631 qlist_append_obj(bs_list, bs_obj);
1632 }
1633
1634 *ret_data = QOBJECT(bs_list);
1635 }
1636
1637 static void bdrv_stats_iter(QObject *data, void *opaque)
1638 {
1639 QDict *qdict;
1640 Monitor *mon = opaque;
1641
1642 qdict = qobject_to_qdict(data);
1643 monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
1644
1645 qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
1646 monitor_printf(mon, " rd_bytes=%" PRId64
1647 " wr_bytes=%" PRId64
1648 " rd_operations=%" PRId64
1649 " wr_operations=%" PRId64
1650 "\n",
1651 qdict_get_int(qdict, "rd_bytes"),
1652 qdict_get_int(qdict, "wr_bytes"),
1653 qdict_get_int(qdict, "rd_operations"),
1654 qdict_get_int(qdict, "wr_operations"));
1655 }
1656
1657 void bdrv_stats_print(Monitor *mon, const QObject *data)
1658 {
1659 qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
1660 }
1661
1662 static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
1663 {
1664 QObject *res;
1665 QDict *dict;
1666
1667 res = qobject_from_jsonf("{ 'stats': {"
1668 "'rd_bytes': %" PRId64 ","
1669 "'wr_bytes': %" PRId64 ","
1670 "'rd_operations': %" PRId64 ","
1671 "'wr_operations': %" PRId64 ","
1672 "'wr_highest_offset': %" PRId64
1673 "} }",
1674 bs->rd_bytes, bs->wr_bytes,
1675 bs->rd_ops, bs->wr_ops,
1676 bs->wr_highest_sector *
1677 (uint64_t)BDRV_SECTOR_SIZE);
1678 dict = qobject_to_qdict(res);
1679
1680 if (*bs->device_name) {
1681 qdict_put(dict, "device", qstring_from_str(bs->device_name));
1682 }
1683
1684 if (bs->file) {
1685 QObject *parent = bdrv_info_stats_bs(bs->file);
1686 qdict_put_obj(dict, "parent", parent);
1687 }
1688
1689 return res;
1690 }
1691
1692 void bdrv_info_stats(Monitor *mon, QObject **ret_data)
1693 {
1694 QObject *obj;
1695 QList *devices;
1696 BlockDriverState *bs;
1697
1698 devices = qlist_new();
1699
1700 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1701 obj = bdrv_info_stats_bs(bs);
1702 qlist_append_obj(devices, obj);
1703 }
1704
1705 *ret_data = QOBJECT(devices);
1706 }
1707
1708 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1709 {
1710 if (bs->backing_hd && bs->backing_hd->encrypted)
1711 return bs->backing_file;
1712 else if (bs->encrypted)
1713 return bs->filename;
1714 else
1715 return NULL;
1716 }
1717
1718 void bdrv_get_backing_filename(BlockDriverState *bs,
1719 char *filename, int filename_size)
1720 {
1721 if (!bs->backing_file) {
1722 pstrcpy(filename, filename_size, "");
1723 } else {
1724 pstrcpy(filename, filename_size, bs->backing_file);
1725 }
1726 }
1727
1728 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1729 const uint8_t *buf, int nb_sectors)
1730 {
1731 BlockDriver *drv = bs->drv;
1732 if (!drv)
1733 return -ENOMEDIUM;
1734 if (!drv->bdrv_write_compressed)
1735 return -ENOTSUP;
1736 if (bdrv_check_request(bs, sector_num, nb_sectors))
1737 return -EIO;
1738
1739 if (bs->dirty_bitmap) {
1740 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1741 }
1742
1743 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1744 }
1745
1746 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1747 {
1748 BlockDriver *drv = bs->drv;
1749 if (!drv)
1750 return -ENOMEDIUM;
1751 if (!drv->bdrv_get_info)
1752 return -ENOTSUP;
1753 memset(bdi, 0, sizeof(*bdi));
1754 return drv->bdrv_get_info(bs, bdi);
1755 }
1756
1757 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1758 int64_t pos, int size)
1759 {
1760 BlockDriver *drv = bs->drv;
1761 if (!drv)
1762 return -ENOMEDIUM;
1763 if (drv->bdrv_save_vmstate)
1764 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1765 if (bs->file)
1766 return bdrv_save_vmstate(bs->file, buf, pos, size);
1767 return -ENOTSUP;
1768 }
1769
1770 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1771 int64_t pos, int size)
1772 {
1773 BlockDriver *drv = bs->drv;
1774 if (!drv)
1775 return -ENOMEDIUM;
1776 if (drv->bdrv_load_vmstate)
1777 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1778 if (bs->file)
1779 return bdrv_load_vmstate(bs->file, buf, pos, size);
1780 return -ENOTSUP;
1781 }
1782
1783 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
1784 {
1785 BlockDriver *drv = bs->drv;
1786
1787 if (!drv || !drv->bdrv_debug_event) {
1788 return;
1789 }
1790
1791 return drv->bdrv_debug_event(bs, event);
1792
1793 }
1794
1795 /**************************************************************/
1796 /* handling of snapshots */
1797
1798 int bdrv_can_snapshot(BlockDriverState *bs)
1799 {
1800 BlockDriver *drv = bs->drv;
1801 if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
1802 return 0;
1803 }
1804
1805 if (!drv->bdrv_snapshot_create) {
1806 if (bs->file != NULL) {
1807 return bdrv_can_snapshot(bs->file);
1808 }
1809 return 0;
1810 }
1811
1812 return 1;
1813 }
1814
1815 int bdrv_is_snapshot(BlockDriverState *bs)
1816 {
1817 return !!(bs->open_flags & BDRV_O_SNAPSHOT);
1818 }
1819
1820 BlockDriverState *bdrv_snapshots(void)
1821 {
1822 BlockDriverState *bs;
1823
1824 if (bs_snapshots) {
1825 return bs_snapshots;
1826 }
1827
1828 bs = NULL;
1829 while ((bs = bdrv_next(bs))) {
1830 if (bdrv_can_snapshot(bs)) {
1831 bs_snapshots = bs;
1832 return bs;
1833 }
1834 }
1835 return NULL;
1836 }
1837
1838 int bdrv_snapshot_create(BlockDriverState *bs,
1839 QEMUSnapshotInfo *sn_info)
1840 {
1841 BlockDriver *drv = bs->drv;
1842 if (!drv)
1843 return -ENOMEDIUM;
1844 if (drv->bdrv_snapshot_create)
1845 return drv->bdrv_snapshot_create(bs, sn_info);
1846 if (bs->file)
1847 return bdrv_snapshot_create(bs->file, sn_info);
1848 return -ENOTSUP;
1849 }
1850
1851 int bdrv_snapshot_goto(BlockDriverState *bs,
1852 const char *snapshot_id)
1853 {
1854 BlockDriver *drv = bs->drv;
1855 int ret, open_ret;
1856
1857 if (!drv)
1858 return -ENOMEDIUM;
1859 if (drv->bdrv_snapshot_goto)
1860 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1861
1862 if (bs->file) {
1863 drv->bdrv_close(bs);
1864 ret = bdrv_snapshot_goto(bs->file, snapshot_id);
1865 open_ret = drv->bdrv_open(bs, bs->open_flags);
1866 if (open_ret < 0) {
1867 bdrv_delete(bs->file);
1868 bs->drv = NULL;
1869 return open_ret;
1870 }
1871 return ret;
1872 }
1873
1874 return -ENOTSUP;
1875 }
1876
1877 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1878 {
1879 BlockDriver *drv = bs->drv;
1880 if (!drv)
1881 return -ENOMEDIUM;
1882 if (drv->bdrv_snapshot_delete)
1883 return drv->bdrv_snapshot_delete(bs, snapshot_id);
1884 if (bs->file)
1885 return bdrv_snapshot_delete(bs->file, snapshot_id);
1886 return -ENOTSUP;
1887 }
1888
1889 int bdrv_snapshot_list(BlockDriverState *bs,
1890 QEMUSnapshotInfo **psn_info)
1891 {
1892 BlockDriver *drv = bs->drv;
1893 if (!drv)
1894 return -ENOMEDIUM;
1895 if (drv->bdrv_snapshot_list)
1896 return drv->bdrv_snapshot_list(bs, psn_info);
1897 if (bs->file)
1898 return bdrv_snapshot_list(bs->file, psn_info);
1899 return -ENOTSUP;
1900 }
1901
1902 int bdrv_snapshot_load_tmp(BlockDriverState *bs,
1903 const char *snapshot_name)
1904 {
1905 BlockDriver *drv = bs->drv;
1906 if (!drv) {
1907 return -ENOMEDIUM;
1908 }
1909 if (!bs->read_only) {
1910 return -EINVAL;
1911 }
1912 if (drv->bdrv_snapshot_load_tmp) {
1913 return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
1914 }
1915 return -ENOTSUP;
1916 }
1917
1918 #define NB_SUFFIXES 4
1919
1920 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1921 {
1922 static const char suffixes[NB_SUFFIXES] = "KMGT";
1923 int64_t base;
1924 int i;
1925
1926 if (size <= 999) {
1927 snprintf(buf, buf_size, "%" PRId64, size);
1928 } else {
1929 base = 1024;
1930 for(i = 0; i < NB_SUFFIXES; i++) {
1931 if (size < (10 * base)) {
1932 snprintf(buf, buf_size, "%0.1f%c",
1933 (double)size / base,
1934 suffixes[i]);
1935 break;
1936 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1937 snprintf(buf, buf_size, "%" PRId64 "%c",
1938 ((size + (base >> 1)) / base),
1939 suffixes[i]);
1940 break;
1941 }
1942 base = base * 1024;
1943 }
1944 }
1945 return buf;
1946 }
1947
1948 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1949 {
1950 char buf1[128], date_buf[128], clock_buf[128];
1951 #ifdef _WIN32
1952 struct tm *ptm;
1953 #else
1954 struct tm tm;
1955 #endif
1956 time_t ti;
1957 int64_t secs;
1958
1959 if (!sn) {
1960 snprintf(buf, buf_size,
1961 "%-10s%-20s%7s%20s%15s",
1962 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1963 } else {
1964 ti = sn->date_sec;
1965 #ifdef _WIN32
1966 ptm = localtime(&ti);
1967 strftime(date_buf, sizeof(date_buf),
1968 "%Y-%m-%d %H:%M:%S", ptm);
1969 #else
1970 localtime_r(&ti, &tm);
1971 strftime(date_buf, sizeof(date_buf),
1972 "%Y-%m-%d %H:%M:%S", &tm);
1973 #endif
1974 secs = sn->vm_clock_nsec / 1000000000;
1975 snprintf(clock_buf, sizeof(clock_buf),
1976 "%02d:%02d:%02d.%03d",
1977 (int)(secs / 3600),
1978 (int)((secs / 60) % 60),
1979 (int)(secs % 60),
1980 (int)((sn->vm_clock_nsec / 1000000) % 1000));
1981 snprintf(buf, buf_size,
1982 "%-10s%-20s%7s%20s%15s",
1983 sn->id_str, sn->name,
1984 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1985 date_buf,
1986 clock_buf);
1987 }
1988 return buf;
1989 }
1990
1991
1992 /**************************************************************/
1993 /* async I/Os */
1994
1995 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1996 QEMUIOVector *qiov, int nb_sectors,
1997 BlockDriverCompletionFunc *cb, void *opaque)
1998 {
1999 BlockDriver *drv = bs->drv;
2000 BlockDriverAIOCB *ret;
2001
2002 trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
2003
2004 if (!drv)
2005 return NULL;
2006 if (bdrv_check_request(bs, sector_num, nb_sectors))
2007 return NULL;
2008
2009 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
2010 cb, opaque);
2011
2012 if (ret) {
2013 /* Update stats even though technically transfer has not happened. */
2014 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2015 bs->rd_ops ++;
2016 }
2017
2018 return ret;
2019 }
2020
2021 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
2022 QEMUIOVector *qiov, int nb_sectors,
2023 BlockDriverCompletionFunc *cb, void *opaque)
2024 {
2025 BlockDriver *drv = bs->drv;
2026 BlockDriverAIOCB *ret;
2027
2028 trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
2029
2030 if (!drv)
2031 return NULL;
2032 if (bs->read_only)
2033 return NULL;
2034 if (bdrv_check_request(bs, sector_num, nb_sectors))
2035 return NULL;
2036
2037 if (bs->dirty_bitmap) {
2038 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
2039 }
2040
2041 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
2042 cb, opaque);
2043
2044 if (ret) {
2045 /* Update stats even though technically transfer has not happened. */
2046 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2047 bs->wr_ops ++;
2048 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
2049 bs->wr_highest_sector = sector_num + nb_sectors - 1;
2050 }
2051 }
2052
2053 return ret;
2054 }
2055
2056
2057 typedef struct MultiwriteCB {
2058 int error;
2059 int num_requests;
2060 int num_callbacks;
2061 struct {
2062 BlockDriverCompletionFunc *cb;
2063 void *opaque;
2064 QEMUIOVector *free_qiov;
2065 void *free_buf;
2066 } callbacks[];
2067 } MultiwriteCB;
2068
2069 static void multiwrite_user_cb(MultiwriteCB *mcb)
2070 {
2071 int i;
2072
2073 for (i = 0; i < mcb->num_callbacks; i++) {
2074 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
2075 if (mcb->callbacks[i].free_qiov) {
2076 qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
2077 }
2078 qemu_free(mcb->callbacks[i].free_qiov);
2079 qemu_vfree(mcb->callbacks[i].free_buf);
2080 }
2081 }
2082
2083 static void multiwrite_cb(void *opaque, int ret)
2084 {
2085 MultiwriteCB *mcb = opaque;
2086
2087 trace_multiwrite_cb(mcb, ret);
2088
2089 if (ret < 0 && !mcb->error) {
2090 mcb->error = ret;
2091 }
2092
2093 mcb->num_requests--;
2094 if (mcb->num_requests == 0) {
2095 multiwrite_user_cb(mcb);
2096 qemu_free(mcb);
2097 }
2098 }
2099
2100 static int multiwrite_req_compare(const void *a, const void *b)
2101 {
2102 const BlockRequest *req1 = a, *req2 = b;
2103
2104 /*
2105 * Note that we can't simply subtract req2->sector from req1->sector
2106 * here as that could overflow the return value.
2107 */
2108 if (req1->sector > req2->sector) {
2109 return 1;
2110 } else if (req1->sector < req2->sector) {
2111 return -1;
2112 } else {
2113 return 0;
2114 }
2115 }
2116
2117 /*
2118 * Takes a bunch of requests and tries to merge them. Returns the number of
2119 * requests that remain after merging.
2120 */
2121 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
2122 int num_reqs, MultiwriteCB *mcb)
2123 {
2124 int i, outidx;
2125
2126 // Sort requests by start sector
2127 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
2128
2129 // Check if adjacent requests touch the same clusters. If so, combine them,
2130 // filling up gaps with zero sectors.
2131 outidx = 0;
2132 for (i = 1; i < num_reqs; i++) {
2133 int merge = 0;
2134 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
2135
2136 // This handles the cases that are valid for all block drivers, namely
2137 // exactly sequential writes and overlapping writes.
2138 if (reqs[i].sector <= oldreq_last) {
2139 merge = 1;
2140 }
2141
2142 // The block driver may decide that it makes sense to combine requests
2143 // even if there is a gap of some sectors between them. In this case,
2144 // the gap is filled with zeros (therefore only applicable for yet
2145 // unused space in format like qcow2).
2146 if (!merge && bs->drv->bdrv_merge_requests) {
2147 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
2148 }
2149
2150 if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
2151 merge = 0;
2152 }
2153
2154 if (merge) {
2155 size_t size;
2156 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
2157 qemu_iovec_init(qiov,
2158 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
2159
2160 // Add the first request to the merged one. If the requests are
2161 // overlapping, drop the last sectors of the first request.
2162 size = (reqs[i].sector - reqs[outidx].sector) << 9;
2163 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
2164
2165 // We might need to add some zeros between the two requests
2166 if (reqs[i].sector > oldreq_last) {
2167 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
2168 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
2169 memset(buf, 0, zero_bytes);
2170 qemu_iovec_add(qiov, buf, zero_bytes);
2171 mcb->callbacks[i].free_buf = buf;
2172 }
2173
2174 // Add the second request
2175 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
2176
2177 reqs[outidx].nb_sectors = qiov->size >> 9;
2178 reqs[outidx].qiov = qiov;
2179
2180 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
2181 } else {
2182 outidx++;
2183 reqs[outidx].sector = reqs[i].sector;
2184 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
2185 reqs[outidx].qiov = reqs[i].qiov;
2186 }
2187 }
2188
2189 return outidx + 1;
2190 }
2191
2192 /*
2193 * Submit multiple AIO write requests at once.
2194 *
2195 * On success, the function returns 0 and all requests in the reqs array have
2196 * been submitted. In error case this function returns -1, and any of the
2197 * requests may or may not be submitted yet. In particular, this means that the
2198 * callback will be called for some of the requests, for others it won't. The
2199 * caller must check the error field of the BlockRequest to wait for the right
2200 * callbacks (if error != 0, no callback will be called).
2201 *
2202 * The implementation may modify the contents of the reqs array, e.g. to merge
2203 * requests. However, the fields opaque and error are left unmodified as they
2204 * are used to signal failure for a single request to the caller.
2205 */
2206 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
2207 {
2208 BlockDriverAIOCB *acb;
2209 MultiwriteCB *mcb;
2210 int i;
2211
2212 if (num_reqs == 0) {
2213 return 0;
2214 }
2215
2216 // Create MultiwriteCB structure
2217 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
2218 mcb->num_requests = 0;
2219 mcb->num_callbacks = num_reqs;
2220
2221 for (i = 0; i < num_reqs; i++) {
2222 mcb->callbacks[i].cb = reqs[i].cb;
2223 mcb->callbacks[i].opaque = reqs[i].opaque;
2224 }
2225
2226 // Check for mergable requests
2227 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
2228
2229 trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
2230
2231 /*
2232 * Run the aio requests. As soon as one request can't be submitted
2233 * successfully, fail all requests that are not yet submitted (we must
2234 * return failure for all requests anyway)
2235 *
2236 * num_requests cannot be set to the right value immediately: If
2237 * bdrv_aio_writev fails for some request, num_requests would be too high
2238 * and therefore multiwrite_cb() would never recognize the multiwrite
2239 * request as completed. We also cannot use the loop variable i to set it
2240 * when the first request fails because the callback may already have been
2241 * called for previously submitted requests. Thus, num_requests must be
2242 * incremented for each request that is submitted.
2243 *
2244 * The problem that callbacks may be called early also means that we need
2245 * to take care that num_requests doesn't become 0 before all requests are
2246 * submitted - multiwrite_cb() would consider the multiwrite request
2247 * completed. A dummy request that is "completed" by a manual call to
2248 * multiwrite_cb() takes care of this.
2249 */
2250 mcb->num_requests = 1;
2251
2252 // Run the aio requests
2253 for (i = 0; i < num_reqs; i++) {
2254 mcb->num_requests++;
2255 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
2256 reqs[i].nb_sectors, multiwrite_cb, mcb);
2257
2258 if (acb == NULL) {
2259 // We can only fail the whole thing if no request has been
2260 // submitted yet. Otherwise we'll wait for the submitted AIOs to
2261 // complete and report the error in the callback.
2262 if (i == 0) {
2263 trace_bdrv_aio_multiwrite_earlyfail(mcb);
2264 goto fail;
2265 } else {
2266 trace_bdrv_aio_multiwrite_latefail(mcb, i);
2267 multiwrite_cb(mcb, -EIO);
2268 break;
2269 }
2270 }
2271 }
2272
2273 /* Complete the dummy request */
2274 multiwrite_cb(mcb, 0);
2275
2276 return 0;
2277
2278 fail:
2279 for (i = 0; i < mcb->num_callbacks; i++) {
2280 reqs[i].error = -EIO;
2281 }
2282 qemu_free(mcb);
2283 return -1;
2284 }
2285
2286 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
2287 BlockDriverCompletionFunc *cb, void *opaque)
2288 {
2289 BlockDriver *drv = bs->drv;
2290
2291 if (bs->open_flags & BDRV_O_NO_FLUSH) {
2292 return bdrv_aio_noop_em(bs, cb, opaque);
2293 }
2294
2295 if (!drv)
2296 return NULL;
2297 return drv->bdrv_aio_flush(bs, cb, opaque);
2298 }
2299
2300 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
2301 {
2302 acb->pool->cancel(acb);
2303 }
2304
2305
2306 /**************************************************************/
2307 /* async block device emulation */
2308
2309 typedef struct BlockDriverAIOCBSync {
2310 BlockDriverAIOCB common;
2311 QEMUBH *bh;
2312 int ret;
2313 /* vector translation state */
2314 QEMUIOVector *qiov;
2315 uint8_t *bounce;
2316 int is_write;
2317 } BlockDriverAIOCBSync;
2318
2319 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
2320 {
2321 BlockDriverAIOCBSync *acb =
2322 container_of(blockacb, BlockDriverAIOCBSync, common);
2323 qemu_bh_delete(acb->bh);
2324 acb->bh = NULL;
2325 qemu_aio_release(acb);
2326 }
2327
2328 static AIOPool bdrv_em_aio_pool = {
2329 .aiocb_size = sizeof(BlockDriverAIOCBSync),
2330 .cancel = bdrv_aio_cancel_em,
2331 };
2332
2333 static void bdrv_aio_bh_cb(void *opaque)
2334 {
2335 BlockDriverAIOCBSync *acb = opaque;
2336
2337 if (!acb->is_write)
2338 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
2339 qemu_vfree(acb->bounce);
2340 acb->common.cb(acb->common.opaque, acb->ret);
2341 qemu_bh_delete(acb->bh);
2342 acb->bh = NULL;
2343 qemu_aio_release(acb);
2344 }
2345
2346 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
2347 int64_t sector_num,
2348 QEMUIOVector *qiov,
2349 int nb_sectors,
2350 BlockDriverCompletionFunc *cb,
2351 void *opaque,
2352 int is_write)
2353
2354 {
2355 BlockDriverAIOCBSync *acb;
2356
2357 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2358 acb->is_write = is_write;
2359 acb->qiov = qiov;
2360 acb->bounce = qemu_blockalign(bs, qiov->size);
2361
2362 if (!acb->bh)
2363 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2364
2365 if (is_write) {
2366 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
2367 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
2368 } else {
2369 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
2370 }
2371
2372 qemu_bh_schedule(acb->bh);
2373
2374 return &acb->common;
2375 }
2376
2377 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
2378 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2379 BlockDriverCompletionFunc *cb, void *opaque)
2380 {
2381 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
2382 }
2383
2384 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
2385 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2386 BlockDriverCompletionFunc *cb, void *opaque)
2387 {
2388 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
2389 }
2390
2391 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
2392 BlockDriverCompletionFunc *cb, void *opaque)
2393 {
2394 BlockDriverAIOCBSync *acb;
2395
2396 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2397 acb->is_write = 1; /* don't bounce in the completion hadler */
2398 acb->qiov = NULL;
2399 acb->bounce = NULL;
2400 acb->ret = 0;
2401
2402 if (!acb->bh)
2403 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2404
2405 bdrv_flush(bs);
2406 qemu_bh_schedule(acb->bh);
2407 return &acb->common;
2408 }
2409
2410 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
2411 BlockDriverCompletionFunc *cb, void *opaque)
2412 {
2413 BlockDriverAIOCBSync *acb;
2414
2415 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2416 acb->is_write = 1; /* don't bounce in the completion handler */
2417 acb->qiov = NULL;
2418 acb->bounce = NULL;
2419 acb->ret = 0;
2420
2421 if (!acb->bh) {
2422 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2423 }
2424
2425 qemu_bh_schedule(acb->bh);
2426 return &acb->common;
2427 }
2428
2429 /**************************************************************/
2430 /* sync block device emulation */
2431
2432 static void bdrv_rw_em_cb(void *opaque, int ret)
2433 {
2434 *(int *)opaque = ret;
2435 }
2436
2437 #define NOT_DONE 0x7fffffff
2438
2439 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
2440 uint8_t *buf, int nb_sectors)
2441 {
2442 int async_ret;
2443 BlockDriverAIOCB *acb;
2444 struct iovec iov;
2445 QEMUIOVector qiov;
2446
2447 async_context_push();
2448
2449 async_ret = NOT_DONE;
2450 iov.iov_base = (void *)buf;
2451 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2452 qemu_iovec_init_external(&qiov, &iov, 1);
2453 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
2454 bdrv_rw_em_cb, &async_ret);
2455 if (acb == NULL) {
2456 async_ret = -1;
2457 goto fail;
2458 }
2459
2460 while (async_ret == NOT_DONE) {
2461 qemu_aio_wait();
2462 }
2463
2464
2465 fail:
2466 async_context_pop();
2467 return async_ret;
2468 }
2469
2470 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
2471 const uint8_t *buf, int nb_sectors)
2472 {
2473 int async_ret;
2474 BlockDriverAIOCB *acb;
2475 struct iovec iov;
2476 QEMUIOVector qiov;
2477
2478 async_context_push();
2479
2480 async_ret = NOT_DONE;
2481 iov.iov_base = (void *)buf;
2482 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2483 qemu_iovec_init_external(&qiov, &iov, 1);
2484 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
2485 bdrv_rw_em_cb, &async_ret);
2486 if (acb == NULL) {
2487 async_ret = -1;
2488 goto fail;
2489 }
2490 while (async_ret == NOT_DONE) {
2491 qemu_aio_wait();
2492 }
2493
2494 fail:
2495 async_context_pop();
2496 return async_ret;
2497 }
2498
2499 void bdrv_init(void)
2500 {
2501 module_call_init(MODULE_INIT_BLOCK);
2502 }
2503
2504 void bdrv_init_with_whitelist(void)
2505 {
2506 use_bdrv_whitelist = 1;
2507 bdrv_init();
2508 }
2509
2510 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
2511 BlockDriverCompletionFunc *cb, void *opaque)
2512 {
2513 BlockDriverAIOCB *acb;
2514
2515 if (pool->free_aiocb) {
2516 acb = pool->free_aiocb;
2517 pool->free_aiocb = acb->next;
2518 } else {
2519 acb = qemu_mallocz(pool->aiocb_size);
2520 acb->pool = pool;
2521 }
2522 acb->bs = bs;
2523 acb->cb = cb;
2524 acb->opaque = opaque;
2525 return acb;
2526 }
2527
2528 void qemu_aio_release(void *p)
2529 {
2530 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
2531 AIOPool *pool = acb->pool;
2532 acb->next = pool->free_aiocb;
2533 pool->free_aiocb = acb;
2534 }
2535
2536 /**************************************************************/
2537 /* removable device support */
2538
2539 /**
2540 * Return TRUE if the media is present
2541 */
2542 int bdrv_is_inserted(BlockDriverState *bs)
2543 {
2544 BlockDriver *drv = bs->drv;
2545 int ret;
2546 if (!drv)
2547 return 0;
2548 if (!drv->bdrv_is_inserted)
2549 return !bs->tray_open;
2550 ret = drv->bdrv_is_inserted(bs);
2551 return ret;
2552 }
2553
2554 /**
2555 * Return TRUE if the media changed since the last call to this
2556 * function. It is currently only used for floppy disks
2557 */
2558 int bdrv_media_changed(BlockDriverState *bs)
2559 {
2560 BlockDriver *drv = bs->drv;
2561 int ret;
2562
2563 if (!drv || !drv->bdrv_media_changed)
2564 ret = -ENOTSUP;
2565 else
2566 ret = drv->bdrv_media_changed(bs);
2567 if (ret == -ENOTSUP)
2568 ret = bs->media_changed;
2569 bs->media_changed = 0;
2570 return ret;
2571 }
2572
2573 /**
2574 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
2575 */
2576 int bdrv_eject(BlockDriverState *bs, int eject_flag)
2577 {
2578 BlockDriver *drv = bs->drv;
2579 int ret;
2580
2581 if (bs->locked) {
2582 return -EBUSY;
2583 }
2584
2585 if (!drv || !drv->bdrv_eject) {
2586 ret = -ENOTSUP;
2587 } else {
2588 ret = drv->bdrv_eject(bs, eject_flag);
2589 }
2590 if (ret == -ENOTSUP) {
2591 ret = 0;
2592 }
2593 if (ret >= 0) {
2594 bs->tray_open = eject_flag;
2595 }
2596
2597 return ret;
2598 }
2599
2600 int bdrv_is_locked(BlockDriverState *bs)
2601 {
2602 return bs->locked;
2603 }
2604
2605 /**
2606 * Lock or unlock the media (if it is locked, the user won't be able
2607 * to eject it manually).
2608 */
2609 void bdrv_set_locked(BlockDriverState *bs, int locked)
2610 {
2611 BlockDriver *drv = bs->drv;
2612
2613 bs->locked = locked;
2614 if (drv && drv->bdrv_set_locked) {
2615 drv->bdrv_set_locked(bs, locked);
2616 }
2617 }
2618
2619 /* needed for generic scsi interface */
2620
2621 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
2622 {
2623 BlockDriver *drv = bs->drv;
2624
2625 if (drv && drv->bdrv_ioctl)
2626 return drv->bdrv_ioctl(bs, req, buf);
2627 return -ENOTSUP;
2628 }
2629
2630 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
2631 unsigned long int req, void *buf,
2632 BlockDriverCompletionFunc *cb, void *opaque)
2633 {
2634 BlockDriver *drv = bs->drv;
2635
2636 if (drv && drv->bdrv_aio_ioctl)
2637 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
2638 return NULL;
2639 }
2640
2641
2642
2643 void *qemu_blockalign(BlockDriverState *bs, size_t size)
2644 {
2645 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
2646 }
2647
2648 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
2649 {
2650 int64_t bitmap_size;
2651
2652 bs->dirty_count = 0;
2653 if (enable) {
2654 if (!bs->dirty_bitmap) {
2655 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
2656 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
2657 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
2658
2659 bs->dirty_bitmap = qemu_mallocz(bitmap_size);
2660 }
2661 } else {
2662 if (bs->dirty_bitmap) {
2663 qemu_free(bs->dirty_bitmap);
2664 bs->dirty_bitmap = NULL;
2665 }
2666 }
2667 }
2668
2669 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
2670 {
2671 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
2672
2673 if (bs->dirty_bitmap &&
2674 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
2675 return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
2676 (1 << (chunk % (sizeof(unsigned long) * 8)));
2677 } else {
2678 return 0;
2679 }
2680 }
2681
2682 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2683 int nr_sectors)
2684 {
2685 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2686 }
2687
2688 int64_t bdrv_get_dirty_count(BlockDriverState *bs)
2689 {
2690 return bs->dirty_count;
2691 }
various patches