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Add a JSON parser
[qemu/aliguori-queue.git] / block.c
blob6fdabff12d1159242f55e6a5042b63db55225b67
1 /*
2 * QEMU System Emulator block driver
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "config-host.h"
25 #include "qemu-common.h"
26 #include "monitor.h"
27 #include "block_int.h"
28 #include "module.h"
29
30 #ifdef CONFIG_BSD
31 #include <sys/types.h>
32 #include <sys/stat.h>
33 #include <sys/ioctl.h>
34 #include <sys/queue.h>
35 #ifndef __DragonFly__
36 #include <sys/disk.h>
37 #endif
38 #endif
39
40 #ifdef _WIN32
41 #include <windows.h>
42 #endif
43
44 #define SECTOR_BITS 9
45 #define SECTOR_SIZE (1 << SECTOR_BITS)
46 #define SECTORS_PER_DIRTY_CHUNK 8
47
48 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
49 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
50 BlockDriverCompletionFunc *cb, void *opaque);
51 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
52 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
53 BlockDriverCompletionFunc *cb, void *opaque);
54 static BlockDriverAIOCB *bdrv_aio_flush_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 BlockDriverState *bdrv_first;
62
63 static BlockDriver *first_drv;
64
65 /* If non-zero, use only whitelisted block drivers */
66 static int use_bdrv_whitelist;
67
68 int path_is_absolute(const char *path)
69 {
70 const char *p;
71 #ifdef _WIN32
72 /* specific case for names like: "\\.\d:" */
73 if (*path == '/' || *path == '\\')
74 return 1;
75 #endif
76 p = strchr(path, ':');
77 if (p)
78 p++;
79 else
80 p = path;
81 #ifdef _WIN32
82 return (*p == '/' || *p == '\\');
83 #else
84 return (*p == '/');
85 #endif
86 }
87
88 /* if filename is absolute, just copy it to dest. Otherwise, build a
89 path to it by considering it is relative to base_path. URL are
90 supported. */
91 void path_combine(char *dest, int dest_size,
92 const char *base_path,
93 const char *filename)
94 {
95 const char *p, *p1;
96 int len;
97
98 if (dest_size <= 0)
99 return;
100 if (path_is_absolute(filename)) {
101 pstrcpy(dest, dest_size, filename);
102 } else {
103 p = strchr(base_path, ':');
104 if (p)
105 p++;
106 else
107 p = base_path;
108 p1 = strrchr(base_path, '/');
109 #ifdef _WIN32
110 {
111 const char *p2;
112 p2 = strrchr(base_path, '\\');
113 if (!p1 || p2 > p1)
114 p1 = p2;
115 }
116 #endif
117 if (p1)
118 p1++;
119 else
120 p1 = base_path;
121 if (p1 > p)
122 p = p1;
123 len = p - base_path;
124 if (len > dest_size - 1)
125 len = dest_size - 1;
126 memcpy(dest, base_path, len);
127 dest[len] = '\0';
128 pstrcat(dest, dest_size, filename);
129 }
130 }
131
132 void bdrv_register(BlockDriver *bdrv)
133 {
134 if (!bdrv->bdrv_aio_readv) {
135 /* add AIO emulation layer */
136 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
137 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
138 } else if (!bdrv->bdrv_read) {
139 /* add synchronous IO emulation layer */
140 bdrv->bdrv_read = bdrv_read_em;
141 bdrv->bdrv_write = bdrv_write_em;
142 }
143
144 if (!bdrv->bdrv_aio_flush)
145 bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
146
147 bdrv->next = first_drv;
148 first_drv = bdrv;
149 }
150
151 /* create a new block device (by default it is empty) */
152 BlockDriverState *bdrv_new(const char *device_name)
153 {
154 BlockDriverState **pbs, *bs;
155
156 bs = qemu_mallocz(sizeof(BlockDriverState));
157 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
158 if (device_name[0] != '\0') {
159 /* insert at the end */
160 pbs = &bdrv_first;
161 while (*pbs != NULL)
162 pbs = &(*pbs)->next;
163 *pbs = bs;
164 }
165 return bs;
166 }
167
168 BlockDriver *bdrv_find_format(const char *format_name)
169 {
170 BlockDriver *drv1;
171 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
172 if (!strcmp(drv1->format_name, format_name))
173 return drv1;
174 }
175 return NULL;
176 }
177
178 static int bdrv_is_whitelisted(BlockDriver *drv)
179 {
180 static const char *whitelist[] = {
181 CONFIG_BDRV_WHITELIST
182 };
183 const char **p;
184
185 if (!whitelist[0])
186 return 1; /* no whitelist, anything goes */
187
188 for (p = whitelist; *p; p++) {
189 if (!strcmp(drv->format_name, *p)) {
190 return 1;
191 }
192 }
193 return 0;
194 }
195
196 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
197 {
198 BlockDriver *drv = bdrv_find_format(format_name);
199 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
200 }
201
202 int bdrv_create(BlockDriver *drv, const char* filename,
203 QEMUOptionParameter *options)
204 {
205 if (!drv->bdrv_create)
206 return -ENOTSUP;
207
208 return drv->bdrv_create(filename, options);
209 }
210
211 #ifdef _WIN32
212 void get_tmp_filename(char *filename, int size)
213 {
214 char temp_dir[MAX_PATH];
215
216 GetTempPath(MAX_PATH, temp_dir);
217 GetTempFileName(temp_dir, "qem", 0, filename);
218 }
219 #else
220 void get_tmp_filename(char *filename, int size)
221 {
222 int fd;
223 const char *tmpdir;
224 /* XXX: race condition possible */
225 tmpdir = getenv("TMPDIR");
226 if (!tmpdir)
227 tmpdir = "/tmp";
228 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
229 fd = mkstemp(filename);
230 close(fd);
231 }
232 #endif
233
234 #ifdef _WIN32
235 static int is_windows_drive_prefix(const char *filename)
236 {
237 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
238 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
239 filename[1] == ':');
240 }
241
242 int is_windows_drive(const char *filename)
243 {
244 if (is_windows_drive_prefix(filename) &&
245 filename[2] == '\0')
246 return 1;
247 if (strstart(filename, "\\\\.\\", NULL) ||
248 strstart(filename, "//./", NULL))
249 return 1;
250 return 0;
251 }
252 #endif
253
254 static BlockDriver *find_protocol(const char *filename)
255 {
256 BlockDriver *drv1;
257 char protocol[128];
258 int len;
259 const char *p;
260
261 #ifdef _WIN32
262 if (is_windows_drive(filename) ||
263 is_windows_drive_prefix(filename))
264 return bdrv_find_format("raw");
265 #endif
266 p = strchr(filename, ':');
267 if (!p)
268 return bdrv_find_format("raw");
269 len = p - filename;
270 if (len > sizeof(protocol) - 1)
271 len = sizeof(protocol) - 1;
272 memcpy(protocol, filename, len);
273 protocol[len] = '\0';
274 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
275 if (drv1->protocol_name &&
276 !strcmp(drv1->protocol_name, protocol))
277 return drv1;
278 }
279 return NULL;
280 }
281
282 /*
283 * Detect host devices. By convention, /dev/cdrom[N] is always
284 * recognized as a host CDROM.
285 */
286 static BlockDriver *find_hdev_driver(const char *filename)
287 {
288 int score_max = 0, score;
289 BlockDriver *drv = NULL, *d;
290
291 for (d = first_drv; d; d = d->next) {
292 if (d->bdrv_probe_device) {
293 score = d->bdrv_probe_device(filename);
294 if (score > score_max) {
295 score_max = score;
296 drv = d;
297 }
298 }
299 }
300
301 return drv;
302 }
303
304 static BlockDriver *find_image_format(const char *filename)
305 {
306 int ret, score, score_max;
307 BlockDriver *drv1, *drv;
308 uint8_t buf[2048];
309 BlockDriverState *bs;
310
311 drv = find_protocol(filename);
312 /* no need to test disk image formats for vvfat */
313 if (drv && strcmp(drv->format_name, "vvfat") == 0)
314 return drv;
315
316 ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
317 if (ret < 0)
318 return NULL;
319 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
320 bdrv_delete(bs);
321 if (ret < 0) {
322 return NULL;
323 }
324
325 score_max = 0;
326 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
327 if (drv1->bdrv_probe) {
328 score = drv1->bdrv_probe(buf, ret, filename);
329 if (score > score_max) {
330 score_max = score;
331 drv = drv1;
332 }
333 }
334 }
335 return drv;
336 }
337
338 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
339 {
340 BlockDriverState *bs;
341 int ret;
342
343 bs = bdrv_new("");
344 ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
345 if (ret < 0) {
346 bdrv_delete(bs);
347 return ret;
348 }
349 bs->growable = 1;
350 *pbs = bs;
351 return 0;
352 }
353
354 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
355 {
356 return bdrv_open2(bs, filename, flags, NULL);
357 }
358
359 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
360 BlockDriver *drv)
361 {
362 int ret, open_flags, try_rw;
363 char tmp_filename[PATH_MAX];
364 char backing_filename[PATH_MAX];
365
366 bs->is_temporary = 0;
367 bs->encrypted = 0;
368 bs->valid_key = 0;
369 /* buffer_alignment defaulted to 512, drivers can change this value */
370 bs->buffer_alignment = 512;
371
372 if (flags & BDRV_O_SNAPSHOT) {
373 BlockDriverState *bs1;
374 int64_t total_size;
375 int is_protocol = 0;
376 BlockDriver *bdrv_qcow2;
377 QEMUOptionParameter *options;
378
379 /* if snapshot, we create a temporary backing file and open it
380 instead of opening 'filename' directly */
381
382 /* if there is a backing file, use it */
383 bs1 = bdrv_new("");
384 ret = bdrv_open2(bs1, filename, 0, drv);
385 if (ret < 0) {
386 bdrv_delete(bs1);
387 return ret;
388 }
389 total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
390
391 if (bs1->drv && bs1->drv->protocol_name)
392 is_protocol = 1;
393
394 bdrv_delete(bs1);
395
396 get_tmp_filename(tmp_filename, sizeof(tmp_filename));
397
398 /* Real path is meaningless for protocols */
399 if (is_protocol)
400 snprintf(backing_filename, sizeof(backing_filename),
401 "%s", filename);
402 else
403 realpath(filename, backing_filename);
404
405 bdrv_qcow2 = bdrv_find_format("qcow2");
406 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
407
408 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size * 512);
409 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
410 if (drv) {
411 set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
412 drv->format_name);
413 }
414
415 ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
416 if (ret < 0) {
417 return ret;
418 }
419
420 filename = tmp_filename;
421 drv = bdrv_qcow2;
422 bs->is_temporary = 1;
423 }
424
425 pstrcpy(bs->filename, sizeof(bs->filename), filename);
426 if (flags & BDRV_O_FILE) {
427 drv = find_protocol(filename);
428 } else if (!drv) {
429 drv = find_hdev_driver(filename);
430 if (!drv) {
431 drv = find_image_format(filename);
432 }
433 }
434 if (!drv) {
435 ret = -ENOENT;
436 goto unlink_and_fail;
437 }
438 bs->drv = drv;
439 bs->opaque = qemu_mallocz(drv->instance_size);
440
441 /*
442 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
443 * write cache to the guest. We do need the fdatasync to flush
444 * out transactions for block allocations, and we maybe have a
445 * volatile write cache in our backing device to deal with.
446 */
447 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
448 bs->enable_write_cache = 1;
449
450 /* Note: for compatibility, we open disk image files as RDWR, and
451 RDONLY as fallback */
452 try_rw = !bs->read_only || bs->is_temporary;
453 if (!(flags & BDRV_O_FILE))
454 open_flags = (try_rw ? BDRV_O_RDWR : 0) |
455 (flags & (BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO));
456 else
457 open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
458 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv))
459 ret = -ENOTSUP;
460 else
461 ret = drv->bdrv_open(bs, filename, open_flags);
462 if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
463 ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
464 bs->read_only = 1;
465 }
466 if (ret < 0) {
467 qemu_free(bs->opaque);
468 bs->opaque = NULL;
469 bs->drv = NULL;
470 unlink_and_fail:
471 if (bs->is_temporary)
472 unlink(filename);
473 return ret;
474 }
475 if (drv->bdrv_getlength) {
476 bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
477 }
478 #ifndef _WIN32
479 if (bs->is_temporary) {
480 unlink(filename);
481 }
482 #endif
483 if (bs->backing_file[0] != '\0') {
484 /* if there is a backing file, use it */
485 BlockDriver *back_drv = NULL;
486 bs->backing_hd = bdrv_new("");
487 /* pass on read_only property to the backing_hd */
488 bs->backing_hd->read_only = bs->read_only;
489 path_combine(backing_filename, sizeof(backing_filename),
490 filename, bs->backing_file);
491 if (bs->backing_format[0] != '\0')
492 back_drv = bdrv_find_format(bs->backing_format);
493 ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
494 back_drv);
495 if (ret < 0) {
496 bdrv_close(bs);
497 return ret;
498 }
499 }
500
501 if (!bdrv_key_required(bs)) {
502 /* call the change callback */
503 bs->media_changed = 1;
504 if (bs->change_cb)
505 bs->change_cb(bs->change_opaque);
506 }
507 return 0;
508 }
509
510 void bdrv_close(BlockDriverState *bs)
511 {
512 if (bs->drv) {
513 if (bs->backing_hd)
514 bdrv_delete(bs->backing_hd);
515 bs->drv->bdrv_close(bs);
516 qemu_free(bs->opaque);
517 #ifdef _WIN32
518 if (bs->is_temporary) {
519 unlink(bs->filename);
520 }
521 #endif
522 bs->opaque = NULL;
523 bs->drv = NULL;
524
525 /* call the change callback */
526 bs->media_changed = 1;
527 if (bs->change_cb)
528 bs->change_cb(bs->change_opaque);
529 }
530 }
531
532 void bdrv_delete(BlockDriverState *bs)
533 {
534 BlockDriverState **pbs;
535
536 pbs = &bdrv_first;
537 while (*pbs != bs && *pbs != NULL)
538 pbs = &(*pbs)->next;
539 if (*pbs == bs)
540 *pbs = bs->next;
541
542 bdrv_close(bs);
543 qemu_free(bs);
544 }
545
546 /*
547 * Run consistency checks on an image
548 *
549 * Returns the number of errors or -errno when an internal error occurs
550 */
551 int bdrv_check(BlockDriverState *bs)
552 {
553 if (bs->drv->bdrv_check == NULL) {
554 return -ENOTSUP;
555 }
556
557 return bs->drv->bdrv_check(bs);
558 }
559
560 /* commit COW file into the raw image */
561 int bdrv_commit(BlockDriverState *bs)
562 {
563 BlockDriver *drv = bs->drv;
564 int64_t i, total_sectors;
565 int n, j;
566 unsigned char sector[512];
567
568 if (!drv)
569 return -ENOMEDIUM;
570
571 if (bs->read_only) {
572 return -EACCES;
573 }
574
575 if (!bs->backing_hd) {
576 return -ENOTSUP;
577 }
578
579 total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
580 for (i = 0; i < total_sectors;) {
581 if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
582 for(j = 0; j < n; j++) {
583 if (bdrv_read(bs, i, sector, 1) != 0) {
584 return -EIO;
585 }
586
587 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
588 return -EIO;
589 }
590 i++;
591 }
592 } else {
593 i += n;
594 }
595 }
596
597 if (drv->bdrv_make_empty)
598 return drv->bdrv_make_empty(bs);
599
600 return 0;
601 }
602
603 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
604 size_t size)
605 {
606 int64_t len;
607
608 if (!bdrv_is_inserted(bs))
609 return -ENOMEDIUM;
610
611 if (bs->growable)
612 return 0;
613
614 len = bdrv_getlength(bs);
615
616 if (offset < 0)
617 return -EIO;
618
619 if ((offset > len) || (len - offset < size))
620 return -EIO;
621
622 return 0;
623 }
624
625 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
626 int nb_sectors)
627 {
628 return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512);
629 }
630
631 /* return < 0 if error. See bdrv_write() for the return codes */
632 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
633 uint8_t *buf, int nb_sectors)
634 {
635 BlockDriver *drv = bs->drv;
636
637 if (!drv)
638 return -ENOMEDIUM;
639 if (bdrv_check_request(bs, sector_num, nb_sectors))
640 return -EIO;
641
642 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
643 }
644
645 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
646 int nb_sectors, int dirty)
647 {
648 int64_t start, end;
649 start = sector_num / SECTORS_PER_DIRTY_CHUNK;
650 end = (sector_num + nb_sectors) / SECTORS_PER_DIRTY_CHUNK;
651
652 for(; start <= end; start++) {
653 bs->dirty_bitmap[start] = dirty;
654 }
655 }
656
657 /* Return < 0 if error. Important errors are:
658 -EIO generic I/O error (may happen for all errors)
659 -ENOMEDIUM No media inserted.
660 -EINVAL Invalid sector number or nb_sectors
661 -EACCES Trying to write a read-only device
662 */
663 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
664 const uint8_t *buf, int nb_sectors)
665 {
666 BlockDriver *drv = bs->drv;
667 if (!bs->drv)
668 return -ENOMEDIUM;
669 if (bs->read_only)
670 return -EACCES;
671 if (bdrv_check_request(bs, sector_num, nb_sectors))
672 return -EIO;
673
674 if(bs->dirty_tracking) {
675 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
676 }
677
678 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
679 }
680
681 int bdrv_pread(BlockDriverState *bs, int64_t offset,
682 void *buf, int count1)
683 {
684 uint8_t tmp_buf[SECTOR_SIZE];
685 int len, nb_sectors, count;
686 int64_t sector_num;
687
688 count = count1;
689 /* first read to align to sector start */
690 len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
691 if (len > count)
692 len = count;
693 sector_num = offset >> SECTOR_BITS;
694 if (len > 0) {
695 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
696 return -EIO;
697 memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
698 count -= len;
699 if (count == 0)
700 return count1;
701 sector_num++;
702 buf += len;
703 }
704
705 /* read the sectors "in place" */
706 nb_sectors = count >> SECTOR_BITS;
707 if (nb_sectors > 0) {
708 if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
709 return -EIO;
710 sector_num += nb_sectors;
711 len = nb_sectors << SECTOR_BITS;
712 buf += len;
713 count -= len;
714 }
715
716 /* add data from the last sector */
717 if (count > 0) {
718 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
719 return -EIO;
720 memcpy(buf, tmp_buf, count);
721 }
722 return count1;
723 }
724
725 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
726 const void *buf, int count1)
727 {
728 uint8_t tmp_buf[SECTOR_SIZE];
729 int len, nb_sectors, count;
730 int64_t sector_num;
731
732 count = count1;
733 /* first write to align to sector start */
734 len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
735 if (len > count)
736 len = count;
737 sector_num = offset >> SECTOR_BITS;
738 if (len > 0) {
739 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
740 return -EIO;
741 memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
742 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
743 return -EIO;
744 count -= len;
745 if (count == 0)
746 return count1;
747 sector_num++;
748 buf += len;
749 }
750
751 /* write the sectors "in place" */
752 nb_sectors = count >> SECTOR_BITS;
753 if (nb_sectors > 0) {
754 if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
755 return -EIO;
756 sector_num += nb_sectors;
757 len = nb_sectors << SECTOR_BITS;
758 buf += len;
759 count -= len;
760 }
761
762 /* add data from the last sector */
763 if (count > 0) {
764 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
765 return -EIO;
766 memcpy(tmp_buf, buf, count);
767 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
768 return -EIO;
769 }
770 return count1;
771 }
772
773 /**
774 * Truncate file to 'offset' bytes (needed only for file protocols)
775 */
776 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
777 {
778 BlockDriver *drv = bs->drv;
779 if (!drv)
780 return -ENOMEDIUM;
781 if (!drv->bdrv_truncate)
782 return -ENOTSUP;
783 if (bs->read_only)
784 return -EACCES;
785 return drv->bdrv_truncate(bs, offset);
786 }
787
788 /**
789 * Length of a file in bytes. Return < 0 if error or unknown.
790 */
791 int64_t bdrv_getlength(BlockDriverState *bs)
792 {
793 BlockDriver *drv = bs->drv;
794 if (!drv)
795 return -ENOMEDIUM;
796 if (!drv->bdrv_getlength) {
797 /* legacy mode */
798 return bs->total_sectors * SECTOR_SIZE;
799 }
800 return drv->bdrv_getlength(bs);
801 }
802
803 /* return 0 as number of sectors if no device present or error */
804 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
805 {
806 int64_t length;
807 length = bdrv_getlength(bs);
808 if (length < 0)
809 length = 0;
810 else
811 length = length >> SECTOR_BITS;
812 *nb_sectors_ptr = length;
813 }
814
815 struct partition {
816 uint8_t boot_ind; /* 0x80 - active */
817 uint8_t head; /* starting head */
818 uint8_t sector; /* starting sector */
819 uint8_t cyl; /* starting cylinder */
820 uint8_t sys_ind; /* What partition type */
821 uint8_t end_head; /* end head */
822 uint8_t end_sector; /* end sector */
823 uint8_t end_cyl; /* end cylinder */
824 uint32_t start_sect; /* starting sector counting from 0 */
825 uint32_t nr_sects; /* nr of sectors in partition */
826 } __attribute__((packed));
827
828 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
829 static int guess_disk_lchs(BlockDriverState *bs,
830 int *pcylinders, int *pheads, int *psectors)
831 {
832 uint8_t buf[512];
833 int ret, i, heads, sectors, cylinders;
834 struct partition *p;
835 uint32_t nr_sects;
836 uint64_t nb_sectors;
837
838 bdrv_get_geometry(bs, &nb_sectors);
839
840 ret = bdrv_read(bs, 0, buf, 1);
841 if (ret < 0)
842 return -1;
843 /* test msdos magic */
844 if (buf[510] != 0x55 || buf[511] != 0xaa)
845 return -1;
846 for(i = 0; i < 4; i++) {
847 p = ((struct partition *)(buf + 0x1be)) + i;
848 nr_sects = le32_to_cpu(p->nr_sects);
849 if (nr_sects && p->end_head) {
850 /* We make the assumption that the partition terminates on
851 a cylinder boundary */
852 heads = p->end_head + 1;
853 sectors = p->end_sector & 63;
854 if (sectors == 0)
855 continue;
856 cylinders = nb_sectors / (heads * sectors);
857 if (cylinders < 1 || cylinders > 16383)
858 continue;
859 *pheads = heads;
860 *psectors = sectors;
861 *pcylinders = cylinders;
862 #if 0
863 printf("guessed geometry: LCHS=%d %d %d\n",
864 cylinders, heads, sectors);
865 #endif
866 return 0;
867 }
868 }
869 return -1;
870 }
871
872 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
873 {
874 int translation, lba_detected = 0;
875 int cylinders, heads, secs;
876 uint64_t nb_sectors;
877
878 /* if a geometry hint is available, use it */
879 bdrv_get_geometry(bs, &nb_sectors);
880 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
881 translation = bdrv_get_translation_hint(bs);
882 if (cylinders != 0) {
883 *pcyls = cylinders;
884 *pheads = heads;
885 *psecs = secs;
886 } else {
887 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
888 if (heads > 16) {
889 /* if heads > 16, it means that a BIOS LBA
890 translation was active, so the default
891 hardware geometry is OK */
892 lba_detected = 1;
893 goto default_geometry;
894 } else {
895 *pcyls = cylinders;
896 *pheads = heads;
897 *psecs = secs;
898 /* disable any translation to be in sync with
899 the logical geometry */
900 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
901 bdrv_set_translation_hint(bs,
902 BIOS_ATA_TRANSLATION_NONE);
903 }
904 }
905 } else {
906 default_geometry:
907 /* if no geometry, use a standard physical disk geometry */
908 cylinders = nb_sectors / (16 * 63);
909
910 if (cylinders > 16383)
911 cylinders = 16383;
912 else if (cylinders < 2)
913 cylinders = 2;
914 *pcyls = cylinders;
915 *pheads = 16;
916 *psecs = 63;
917 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
918 if ((*pcyls * *pheads) <= 131072) {
919 bdrv_set_translation_hint(bs,
920 BIOS_ATA_TRANSLATION_LARGE);
921 } else {
922 bdrv_set_translation_hint(bs,
923 BIOS_ATA_TRANSLATION_LBA);
924 }
925 }
926 }
927 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
928 }
929 }
930
931 void bdrv_set_geometry_hint(BlockDriverState *bs,
932 int cyls, int heads, int secs)
933 {
934 bs->cyls = cyls;
935 bs->heads = heads;
936 bs->secs = secs;
937 }
938
939 void bdrv_set_type_hint(BlockDriverState *bs, int type)
940 {
941 bs->type = type;
942 bs->removable = ((type == BDRV_TYPE_CDROM ||
943 type == BDRV_TYPE_FLOPPY));
944 }
945
946 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
947 {
948 bs->translation = translation;
949 }
950
951 void bdrv_get_geometry_hint(BlockDriverState *bs,
952 int *pcyls, int *pheads, int *psecs)
953 {
954 *pcyls = bs->cyls;
955 *pheads = bs->heads;
956 *psecs = bs->secs;
957 }
958
959 int bdrv_get_type_hint(BlockDriverState *bs)
960 {
961 return bs->type;
962 }
963
964 int bdrv_get_translation_hint(BlockDriverState *bs)
965 {
966 return bs->translation;
967 }
968
969 int bdrv_is_removable(BlockDriverState *bs)
970 {
971 return bs->removable;
972 }
973
974 int bdrv_is_read_only(BlockDriverState *bs)
975 {
976 return bs->read_only;
977 }
978
979 int bdrv_set_read_only(BlockDriverState *bs, int read_only)
980 {
981 int ret = bs->read_only;
982 bs->read_only = read_only;
983 return ret;
984 }
985
986 int bdrv_is_sg(BlockDriverState *bs)
987 {
988 return bs->sg;
989 }
990
991 int bdrv_enable_write_cache(BlockDriverState *bs)
992 {
993 return bs->enable_write_cache;
994 }
995
996 /* XXX: no longer used */
997 void bdrv_set_change_cb(BlockDriverState *bs,
998 void (*change_cb)(void *opaque), void *opaque)
999 {
1000 bs->change_cb = change_cb;
1001 bs->change_opaque = opaque;
1002 }
1003
1004 int bdrv_is_encrypted(BlockDriverState *bs)
1005 {
1006 if (bs->backing_hd && bs->backing_hd->encrypted)
1007 return 1;
1008 return bs->encrypted;
1009 }
1010
1011 int bdrv_key_required(BlockDriverState *bs)
1012 {
1013 BlockDriverState *backing_hd = bs->backing_hd;
1014
1015 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1016 return 1;
1017 return (bs->encrypted && !bs->valid_key);
1018 }
1019
1020 int bdrv_set_key(BlockDriverState *bs, const char *key)
1021 {
1022 int ret;
1023 if (bs->backing_hd && bs->backing_hd->encrypted) {
1024 ret = bdrv_set_key(bs->backing_hd, key);
1025 if (ret < 0)
1026 return ret;
1027 if (!bs->encrypted)
1028 return 0;
1029 }
1030 if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
1031 return -1;
1032 ret = bs->drv->bdrv_set_key(bs, key);
1033 if (ret < 0) {
1034 bs->valid_key = 0;
1035 } else if (!bs->valid_key) {
1036 bs->valid_key = 1;
1037 /* call the change callback now, we skipped it on open */
1038 bs->media_changed = 1;
1039 if (bs->change_cb)
1040 bs->change_cb(bs->change_opaque);
1041 }
1042 return ret;
1043 }
1044
1045 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1046 {
1047 if (!bs->drv) {
1048 buf[0] = '\0';
1049 } else {
1050 pstrcpy(buf, buf_size, bs->drv->format_name);
1051 }
1052 }
1053
1054 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1055 void *opaque)
1056 {
1057 BlockDriver *drv;
1058
1059 for (drv = first_drv; drv != NULL; drv = drv->next) {
1060 it(opaque, drv->format_name);
1061 }
1062 }
1063
1064 BlockDriverState *bdrv_find(const char *name)
1065 {
1066 BlockDriverState *bs;
1067
1068 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1069 if (!strcmp(name, bs->device_name))
1070 return bs;
1071 }
1072 return NULL;
1073 }
1074
1075 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1076 {
1077 BlockDriverState *bs;
1078
1079 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1080 it(opaque, bs);
1081 }
1082 }
1083
1084 const char *bdrv_get_device_name(BlockDriverState *bs)
1085 {
1086 return bs->device_name;
1087 }
1088
1089 void bdrv_flush(BlockDriverState *bs)
1090 {
1091 if (!bs->drv)
1092 return;
1093 if (bs->drv->bdrv_flush)
1094 bs->drv->bdrv_flush(bs);
1095 if (bs->backing_hd)
1096 bdrv_flush(bs->backing_hd);
1097 }
1098
1099 void bdrv_flush_all(void)
1100 {
1101 BlockDriverState *bs;
1102
1103 for (bs = bdrv_first; bs != NULL; bs = bs->next)
1104 if (bs->drv && !bdrv_is_read_only(bs) &&
1105 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1106 bdrv_flush(bs);
1107 }
1108
1109 /*
1110 * Returns true iff the specified sector is present in the disk image. Drivers
1111 * not implementing the functionality are assumed to not support backing files,
1112 * hence all their sectors are reported as allocated.
1113 *
1114 * 'pnum' is set to the number of sectors (including and immediately following
1115 * the specified sector) that are known to be in the same
1116 * allocated/unallocated state.
1117 *
1118 * 'nb_sectors' is the max value 'pnum' should be set to.
1119 */
1120 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1121 int *pnum)
1122 {
1123 int64_t n;
1124 if (!bs->drv->bdrv_is_allocated) {
1125 if (sector_num >= bs->total_sectors) {
1126 *pnum = 0;
1127 return 0;
1128 }
1129 n = bs->total_sectors - sector_num;
1130 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1131 return 1;
1132 }
1133 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1134 }
1135
1136 void bdrv_info(Monitor *mon)
1137 {
1138 BlockDriverState *bs;
1139
1140 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1141 monitor_printf(mon, "%s:", bs->device_name);
1142 monitor_printf(mon, " type=");
1143 switch(bs->type) {
1144 case BDRV_TYPE_HD:
1145 monitor_printf(mon, "hd");
1146 break;
1147 case BDRV_TYPE_CDROM:
1148 monitor_printf(mon, "cdrom");
1149 break;
1150 case BDRV_TYPE_FLOPPY:
1151 monitor_printf(mon, "floppy");
1152 break;
1153 }
1154 monitor_printf(mon, " removable=%d", bs->removable);
1155 if (bs->removable) {
1156 monitor_printf(mon, " locked=%d", bs->locked);
1157 }
1158 if (bs->drv) {
1159 monitor_printf(mon, " file=");
1160 monitor_print_filename(mon, bs->filename);
1161 if (bs->backing_file[0] != '\0') {
1162 monitor_printf(mon, " backing_file=");
1163 monitor_print_filename(mon, bs->backing_file);
1164 }
1165 monitor_printf(mon, " ro=%d", bs->read_only);
1166 monitor_printf(mon, " drv=%s", bs->drv->format_name);
1167 monitor_printf(mon, " encrypted=%d", bdrv_is_encrypted(bs));
1168 } else {
1169 monitor_printf(mon, " [not inserted]");
1170 }
1171 monitor_printf(mon, "\n");
1172 }
1173 }
1174
1175 /* The "info blockstats" command. */
1176 void bdrv_info_stats(Monitor *mon)
1177 {
1178 BlockDriverState *bs;
1179
1180 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1181 monitor_printf(mon, "%s:"
1182 " rd_bytes=%" PRIu64
1183 " wr_bytes=%" PRIu64
1184 " rd_operations=%" PRIu64
1185 " wr_operations=%" PRIu64
1186 "\n",
1187 bs->device_name,
1188 bs->rd_bytes, bs->wr_bytes,
1189 bs->rd_ops, bs->wr_ops);
1190 }
1191 }
1192
1193 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1194 {
1195 if (bs->backing_hd && bs->backing_hd->encrypted)
1196 return bs->backing_file;
1197 else if (bs->encrypted)
1198 return bs->filename;
1199 else
1200 return NULL;
1201 }
1202
1203 void bdrv_get_backing_filename(BlockDriverState *bs,
1204 char *filename, int filename_size)
1205 {
1206 if (!bs->backing_hd) {
1207 pstrcpy(filename, filename_size, "");
1208 } else {
1209 pstrcpy(filename, filename_size, bs->backing_file);
1210 }
1211 }
1212
1213 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1214 const uint8_t *buf, int nb_sectors)
1215 {
1216 BlockDriver *drv = bs->drv;
1217 if (!drv)
1218 return -ENOMEDIUM;
1219 if (!drv->bdrv_write_compressed)
1220 return -ENOTSUP;
1221 if (bdrv_check_request(bs, sector_num, nb_sectors))
1222 return -EIO;
1223
1224 if(bs->dirty_tracking) {
1225 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1226 }
1227
1228 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1229 }
1230
1231 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1232 {
1233 BlockDriver *drv = bs->drv;
1234 if (!drv)
1235 return -ENOMEDIUM;
1236 if (!drv->bdrv_get_info)
1237 return -ENOTSUP;
1238 memset(bdi, 0, sizeof(*bdi));
1239 return drv->bdrv_get_info(bs, bdi);
1240 }
1241
1242 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1243 int64_t pos, int size)
1244 {
1245 BlockDriver *drv = bs->drv;
1246 if (!drv)
1247 return -ENOMEDIUM;
1248 if (!drv->bdrv_save_vmstate)
1249 return -ENOTSUP;
1250 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1251 }
1252
1253 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1254 int64_t pos, int size)
1255 {
1256 BlockDriver *drv = bs->drv;
1257 if (!drv)
1258 return -ENOMEDIUM;
1259 if (!drv->bdrv_load_vmstate)
1260 return -ENOTSUP;
1261 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1262 }
1263
1264 /**************************************************************/
1265 /* handling of snapshots */
1266
1267 int bdrv_snapshot_create(BlockDriverState *bs,
1268 QEMUSnapshotInfo *sn_info)
1269 {
1270 BlockDriver *drv = bs->drv;
1271 if (!drv)
1272 return -ENOMEDIUM;
1273 if (!drv->bdrv_snapshot_create)
1274 return -ENOTSUP;
1275 return drv->bdrv_snapshot_create(bs, sn_info);
1276 }
1277
1278 int bdrv_snapshot_goto(BlockDriverState *bs,
1279 const char *snapshot_id)
1280 {
1281 BlockDriver *drv = bs->drv;
1282 if (!drv)
1283 return -ENOMEDIUM;
1284 if (!drv->bdrv_snapshot_goto)
1285 return -ENOTSUP;
1286 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1287 }
1288
1289 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1290 {
1291 BlockDriver *drv = bs->drv;
1292 if (!drv)
1293 return -ENOMEDIUM;
1294 if (!drv->bdrv_snapshot_delete)
1295 return -ENOTSUP;
1296 return drv->bdrv_snapshot_delete(bs, snapshot_id);
1297 }
1298
1299 int bdrv_snapshot_list(BlockDriverState *bs,
1300 QEMUSnapshotInfo **psn_info)
1301 {
1302 BlockDriver *drv = bs->drv;
1303 if (!drv)
1304 return -ENOMEDIUM;
1305 if (!drv->bdrv_snapshot_list)
1306 return -ENOTSUP;
1307 return drv->bdrv_snapshot_list(bs, psn_info);
1308 }
1309
1310 #define NB_SUFFIXES 4
1311
1312 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1313 {
1314 static const char suffixes[NB_SUFFIXES] = "KMGT";
1315 int64_t base;
1316 int i;
1317
1318 if (size <= 999) {
1319 snprintf(buf, buf_size, "%" PRId64, size);
1320 } else {
1321 base = 1024;
1322 for(i = 0; i < NB_SUFFIXES; i++) {
1323 if (size < (10 * base)) {
1324 snprintf(buf, buf_size, "%0.1f%c",
1325 (double)size / base,
1326 suffixes[i]);
1327 break;
1328 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1329 snprintf(buf, buf_size, "%" PRId64 "%c",
1330 ((size + (base >> 1)) / base),
1331 suffixes[i]);
1332 break;
1333 }
1334 base = base * 1024;
1335 }
1336 }
1337 return buf;
1338 }
1339
1340 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1341 {
1342 char buf1[128], date_buf[128], clock_buf[128];
1343 #ifdef _WIN32
1344 struct tm *ptm;
1345 #else
1346 struct tm tm;
1347 #endif
1348 time_t ti;
1349 int64_t secs;
1350
1351 if (!sn) {
1352 snprintf(buf, buf_size,
1353 "%-10s%-20s%7s%20s%15s",
1354 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1355 } else {
1356 ti = sn->date_sec;
1357 #ifdef _WIN32
1358 ptm = localtime(&ti);
1359 strftime(date_buf, sizeof(date_buf),
1360 "%Y-%m-%d %H:%M:%S", ptm);
1361 #else
1362 localtime_r(&ti, &tm);
1363 strftime(date_buf, sizeof(date_buf),
1364 "%Y-%m-%d %H:%M:%S", &tm);
1365 #endif
1366 secs = sn->vm_clock_nsec / 1000000000;
1367 snprintf(clock_buf, sizeof(clock_buf),
1368 "%02d:%02d:%02d.%03d",
1369 (int)(secs / 3600),
1370 (int)((secs / 60) % 60),
1371 (int)(secs % 60),
1372 (int)((sn->vm_clock_nsec / 1000000) % 1000));
1373 snprintf(buf, buf_size,
1374 "%-10s%-20s%7s%20s%15s",
1375 sn->id_str, sn->name,
1376 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1377 date_buf,
1378 clock_buf);
1379 }
1380 return buf;
1381 }
1382
1383
1384 /**************************************************************/
1385 /* async I/Os */
1386
1387 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1388 QEMUIOVector *qiov, int nb_sectors,
1389 BlockDriverCompletionFunc *cb, void *opaque)
1390 {
1391 BlockDriver *drv = bs->drv;
1392 BlockDriverAIOCB *ret;
1393
1394 if (!drv)
1395 return NULL;
1396 if (bdrv_check_request(bs, sector_num, nb_sectors))
1397 return NULL;
1398
1399 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
1400 cb, opaque);
1401
1402 if (ret) {
1403 /* Update stats even though technically transfer has not happened. */
1404 bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1405 bs->rd_ops ++;
1406 }
1407
1408 return ret;
1409 }
1410
1411 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
1412 QEMUIOVector *qiov, int nb_sectors,
1413 BlockDriverCompletionFunc *cb, void *opaque)
1414 {
1415 BlockDriver *drv = bs->drv;
1416 BlockDriverAIOCB *ret;
1417
1418 if (!drv)
1419 return NULL;
1420 if (bs->read_only)
1421 return NULL;
1422 if (bdrv_check_request(bs, sector_num, nb_sectors))
1423 return NULL;
1424
1425 if(bs->dirty_tracking) {
1426 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1427 }
1428
1429 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
1430 cb, opaque);
1431
1432 if (ret) {
1433 /* Update stats even though technically transfer has not happened. */
1434 bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1435 bs->wr_ops ++;
1436 }
1437
1438 return ret;
1439 }
1440
1441
1442 typedef struct MultiwriteCB {
1443 int error;
1444 int num_requests;
1445 int num_callbacks;
1446 struct {
1447 BlockDriverCompletionFunc *cb;
1448 void *opaque;
1449 QEMUIOVector *free_qiov;
1450 void *free_buf;
1451 } callbacks[];
1452 } MultiwriteCB;
1453
1454 static void multiwrite_user_cb(MultiwriteCB *mcb)
1455 {
1456 int i;
1457
1458 for (i = 0; i < mcb->num_callbacks; i++) {
1459 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
1460 qemu_free(mcb->callbacks[i].free_qiov);
1461 qemu_free(mcb->callbacks[i].free_buf);
1462 }
1463 }
1464
1465 static void multiwrite_cb(void *opaque, int ret)
1466 {
1467 MultiwriteCB *mcb = opaque;
1468
1469 if (ret < 0) {
1470 mcb->error = ret;
1471 multiwrite_user_cb(mcb);
1472 }
1473
1474 mcb->num_requests--;
1475 if (mcb->num_requests == 0) {
1476 if (mcb->error == 0) {
1477 multiwrite_user_cb(mcb);
1478 }
1479 qemu_free(mcb);
1480 }
1481 }
1482
1483 static int multiwrite_req_compare(const void *a, const void *b)
1484 {
1485 return (((BlockRequest*) a)->sector - ((BlockRequest*) b)->sector);
1486 }
1487
1488 /*
1489 * Takes a bunch of requests and tries to merge them. Returns the number of
1490 * requests that remain after merging.
1491 */
1492 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
1493 int num_reqs, MultiwriteCB *mcb)
1494 {
1495 int i, outidx;
1496
1497 // Sort requests by start sector
1498 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
1499
1500 // Check if adjacent requests touch the same clusters. If so, combine them,
1501 // filling up gaps with zero sectors.
1502 outidx = 0;
1503 for (i = 1; i < num_reqs; i++) {
1504 int merge = 0;
1505 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
1506
1507 // This handles the cases that are valid for all block drivers, namely
1508 // exactly sequential writes and overlapping writes.
1509 if (reqs[i].sector <= oldreq_last) {
1510 merge = 1;
1511 }
1512
1513 // The block driver may decide that it makes sense to combine requests
1514 // even if there is a gap of some sectors between them. In this case,
1515 // the gap is filled with zeros (therefore only applicable for yet
1516 // unused space in format like qcow2).
1517 if (!merge && bs->drv->bdrv_merge_requests) {
1518 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
1519 }
1520
1521 if (merge) {
1522 size_t size;
1523 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
1524 qemu_iovec_init(qiov,
1525 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
1526
1527 // Add the first request to the merged one. If the requests are
1528 // overlapping, drop the last sectors of the first request.
1529 size = (reqs[i].sector - reqs[outidx].sector) << 9;
1530 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
1531
1532 // We might need to add some zeros between the two requests
1533 if (reqs[i].sector > oldreq_last) {
1534 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
1535 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
1536 memset(buf, 0, zero_bytes);
1537 qemu_iovec_add(qiov, buf, zero_bytes);
1538 mcb->callbacks[i].free_buf = buf;
1539 }
1540
1541 // Add the second request
1542 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
1543
1544 reqs[outidx].nb_sectors += reqs[i].nb_sectors;
1545 reqs[outidx].qiov = qiov;
1546
1547 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
1548 } else {
1549 outidx++;
1550 reqs[outidx].sector = reqs[i].sector;
1551 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
1552 reqs[outidx].qiov = reqs[i].qiov;
1553 }
1554 }
1555
1556 return outidx + 1;
1557 }
1558
1559 /*
1560 * Submit multiple AIO write requests at once.
1561 *
1562 * On success, the function returns 0 and all requests in the reqs array have
1563 * been submitted. In error case this function returns -1, and any of the
1564 * requests may or may not be submitted yet. In particular, this means that the
1565 * callback will be called for some of the requests, for others it won't. The
1566 * caller must check the error field of the BlockRequest to wait for the right
1567 * callbacks (if error != 0, no callback will be called).
1568 *
1569 * The implementation may modify the contents of the reqs array, e.g. to merge
1570 * requests. However, the fields opaque and error are left unmodified as they
1571 * are used to signal failure for a single request to the caller.
1572 */
1573 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
1574 {
1575 BlockDriverAIOCB *acb;
1576 MultiwriteCB *mcb;
1577 int i;
1578
1579 if (num_reqs == 0) {
1580 return 0;
1581 }
1582
1583 // Create MultiwriteCB structure
1584 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
1585 mcb->num_requests = 0;
1586 mcb->num_callbacks = num_reqs;
1587
1588 for (i = 0; i < num_reqs; i++) {
1589 mcb->callbacks[i].cb = reqs[i].cb;
1590 mcb->callbacks[i].opaque = reqs[i].opaque;
1591 }
1592
1593 // Check for mergable requests
1594 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
1595
1596 // Run the aio requests
1597 for (i = 0; i < num_reqs; i++) {
1598 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
1599 reqs[i].nb_sectors, multiwrite_cb, mcb);
1600
1601 if (acb == NULL) {
1602 // We can only fail the whole thing if no request has been
1603 // submitted yet. Otherwise we'll wait for the submitted AIOs to
1604 // complete and report the error in the callback.
1605 if (mcb->num_requests == 0) {
1606 reqs[i].error = EIO;
1607 goto fail;
1608 } else {
1609 mcb->error = EIO;
1610 break;
1611 }
1612 } else {
1613 mcb->num_requests++;
1614 }
1615 }
1616
1617 return 0;
1618
1619 fail:
1620 free(mcb);
1621 return -1;
1622 }
1623
1624 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
1625 BlockDriverCompletionFunc *cb, void *opaque)
1626 {
1627 BlockDriver *drv = bs->drv;
1628
1629 if (!drv)
1630 return NULL;
1631
1632 /*
1633 * Note that unlike bdrv_flush the driver is reponsible for flushing a
1634 * backing image if it exists.
1635 */
1636 return drv->bdrv_aio_flush(bs, cb, opaque);
1637 }
1638
1639 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1640 {
1641 acb->pool->cancel(acb);
1642 }
1643
1644
1645 /**************************************************************/
1646 /* async block device emulation */
1647
1648 typedef struct BlockDriverAIOCBSync {
1649 BlockDriverAIOCB common;
1650 QEMUBH *bh;
1651 int ret;
1652 /* vector translation state */
1653 QEMUIOVector *qiov;
1654 uint8_t *bounce;
1655 int is_write;
1656 } BlockDriverAIOCBSync;
1657
1658 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1659 {
1660 BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1661 qemu_bh_delete(acb->bh);
1662 acb->bh = NULL;
1663 qemu_aio_release(acb);
1664 }
1665
1666 static AIOPool bdrv_em_aio_pool = {
1667 .aiocb_size = sizeof(BlockDriverAIOCBSync),
1668 .cancel = bdrv_aio_cancel_em,
1669 };
1670
1671 static void bdrv_aio_bh_cb(void *opaque)
1672 {
1673 BlockDriverAIOCBSync *acb = opaque;
1674
1675 if (!acb->is_write)
1676 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
1677 qemu_vfree(acb->bounce);
1678 acb->common.cb(acb->common.opaque, acb->ret);
1679 qemu_bh_delete(acb->bh);
1680 acb->bh = NULL;
1681 qemu_aio_release(acb);
1682 }
1683
1684 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
1685 int64_t sector_num,
1686 QEMUIOVector *qiov,
1687 int nb_sectors,
1688 BlockDriverCompletionFunc *cb,
1689 void *opaque,
1690 int is_write)
1691
1692 {
1693 BlockDriverAIOCBSync *acb;
1694
1695 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
1696 acb->is_write = is_write;
1697 acb->qiov = qiov;
1698 acb->bounce = qemu_blockalign(bs, qiov->size);
1699
1700 if (!acb->bh)
1701 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1702
1703 if (is_write) {
1704 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
1705 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
1706 } else {
1707 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
1708 }
1709
1710 qemu_bh_schedule(acb->bh);
1711
1712 return &acb->common;
1713 }
1714
1715 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
1716 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1717 BlockDriverCompletionFunc *cb, void *opaque)
1718 {
1719 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
1720 }
1721
1722 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
1723 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1724 BlockDriverCompletionFunc *cb, void *opaque)
1725 {
1726 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
1727 }
1728
1729 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
1730 BlockDriverCompletionFunc *cb, void *opaque)
1731 {
1732 BlockDriverAIOCBSync *acb;
1733
1734 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
1735 acb->is_write = 1; /* don't bounce in the completion hadler */
1736 acb->qiov = NULL;
1737 acb->bounce = NULL;
1738 acb->ret = 0;
1739
1740 if (!acb->bh)
1741 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1742
1743 bdrv_flush(bs);
1744 qemu_bh_schedule(acb->bh);
1745 return &acb->common;
1746 }
1747
1748 /**************************************************************/
1749 /* sync block device emulation */
1750
1751 static void bdrv_rw_em_cb(void *opaque, int ret)
1752 {
1753 *(int *)opaque = ret;
1754 }
1755
1756 #define NOT_DONE 0x7fffffff
1757
1758 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1759 uint8_t *buf, int nb_sectors)
1760 {
1761 int async_ret;
1762 BlockDriverAIOCB *acb;
1763 struct iovec iov;
1764 QEMUIOVector qiov;
1765
1766 async_context_push();
1767
1768 async_ret = NOT_DONE;
1769 iov.iov_base = (void *)buf;
1770 iov.iov_len = nb_sectors * 512;
1771 qemu_iovec_init_external(&qiov, &iov, 1);
1772 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
1773 bdrv_rw_em_cb, &async_ret);
1774 if (acb == NULL) {
1775 async_ret = -1;
1776 goto fail;
1777 }
1778
1779 while (async_ret == NOT_DONE) {
1780 qemu_aio_wait();
1781 }
1782
1783
1784 fail:
1785 async_context_pop();
1786 return async_ret;
1787 }
1788
1789 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1790 const uint8_t *buf, int nb_sectors)
1791 {
1792 int async_ret;
1793 BlockDriverAIOCB *acb;
1794 struct iovec iov;
1795 QEMUIOVector qiov;
1796
1797 async_context_push();
1798
1799 async_ret = NOT_DONE;
1800 iov.iov_base = (void *)buf;
1801 iov.iov_len = nb_sectors * 512;
1802 qemu_iovec_init_external(&qiov, &iov, 1);
1803 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
1804 bdrv_rw_em_cb, &async_ret);
1805 if (acb == NULL) {
1806 async_ret = -1;
1807 goto fail;
1808 }
1809 while (async_ret == NOT_DONE) {
1810 qemu_aio_wait();
1811 }
1812
1813 fail:
1814 async_context_pop();
1815 return async_ret;
1816 }
1817
1818 void bdrv_init(void)
1819 {
1820 module_call_init(MODULE_INIT_BLOCK);
1821 }
1822
1823 void bdrv_init_with_whitelist(void)
1824 {
1825 use_bdrv_whitelist = 1;
1826 bdrv_init();
1827 }
1828
1829 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
1830 BlockDriverCompletionFunc *cb, void *opaque)
1831 {
1832 BlockDriverAIOCB *acb;
1833
1834 if (pool->free_aiocb) {
1835 acb = pool->free_aiocb;
1836 pool->free_aiocb = acb->next;
1837 } else {
1838 acb = qemu_mallocz(pool->aiocb_size);
1839 acb->pool = pool;
1840 }
1841 acb->bs = bs;
1842 acb->cb = cb;
1843 acb->opaque = opaque;
1844 return acb;
1845 }
1846
1847 void qemu_aio_release(void *p)
1848 {
1849 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
1850 AIOPool *pool = acb->pool;
1851 acb->next = pool->free_aiocb;
1852 pool->free_aiocb = acb;
1853 }
1854
1855 /**************************************************************/
1856 /* removable device support */
1857
1858 /**
1859 * Return TRUE if the media is present
1860 */
1861 int bdrv_is_inserted(BlockDriverState *bs)
1862 {
1863 BlockDriver *drv = bs->drv;
1864 int ret;
1865 if (!drv)
1866 return 0;
1867 if (!drv->bdrv_is_inserted)
1868 return 1;
1869 ret = drv->bdrv_is_inserted(bs);
1870 return ret;
1871 }
1872
1873 /**
1874 * Return TRUE if the media changed since the last call to this
1875 * function. It is currently only used for floppy disks
1876 */
1877 int bdrv_media_changed(BlockDriverState *bs)
1878 {
1879 BlockDriver *drv = bs->drv;
1880 int ret;
1881
1882 if (!drv || !drv->bdrv_media_changed)
1883 ret = -ENOTSUP;
1884 else
1885 ret = drv->bdrv_media_changed(bs);
1886 if (ret == -ENOTSUP)
1887 ret = bs->media_changed;
1888 bs->media_changed = 0;
1889 return ret;
1890 }
1891
1892 /**
1893 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1894 */
1895 int bdrv_eject(BlockDriverState *bs, int eject_flag)
1896 {
1897 BlockDriver *drv = bs->drv;
1898 int ret;
1899
1900 if (bs->locked) {
1901 return -EBUSY;
1902 }
1903
1904 if (!drv || !drv->bdrv_eject) {
1905 ret = -ENOTSUP;
1906 } else {
1907 ret = drv->bdrv_eject(bs, eject_flag);
1908 }
1909 if (ret == -ENOTSUP) {
1910 if (eject_flag)
1911 bdrv_close(bs);
1912 ret = 0;
1913 }
1914
1915 return ret;
1916 }
1917
1918 int bdrv_is_locked(BlockDriverState *bs)
1919 {
1920 return bs->locked;
1921 }
1922
1923 /**
1924 * Lock or unlock the media (if it is locked, the user won't be able
1925 * to eject it manually).
1926 */
1927 void bdrv_set_locked(BlockDriverState *bs, int locked)
1928 {
1929 BlockDriver *drv = bs->drv;
1930
1931 bs->locked = locked;
1932 if (drv && drv->bdrv_set_locked) {
1933 drv->bdrv_set_locked(bs, locked);
1934 }
1935 }
1936
1937 /* needed for generic scsi interface */
1938
1939 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1940 {
1941 BlockDriver *drv = bs->drv;
1942
1943 if (drv && drv->bdrv_ioctl)
1944 return drv->bdrv_ioctl(bs, req, buf);
1945 return -ENOTSUP;
1946 }
1947
1948 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
1949 unsigned long int req, void *buf,
1950 BlockDriverCompletionFunc *cb, void *opaque)
1951 {
1952 BlockDriver *drv = bs->drv;
1953
1954 if (drv && drv->bdrv_aio_ioctl)
1955 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
1956 return NULL;
1957 }
1958
1959
1960
1961 void *qemu_blockalign(BlockDriverState *bs, size_t size)
1962 {
1963 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
1964 }
1965
1966 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
1967 {
1968 int64_t bitmap_size;
1969 if(enable) {
1970 if(bs->dirty_tracking == 0) {
1971 int64_t i;
1972 uint8_t test;
1973 bitmap_size = (bdrv_getlength(bs) >> SECTOR_BITS);
1974 bitmap_size /= SECTORS_PER_DIRTY_CHUNK;
1975 bitmap_size++;
1976
1977 bs->dirty_bitmap = qemu_mallocz(bitmap_size);
1978
1979 bs->dirty_tracking = enable;
1980 for(i = 0; i < bitmap_size; i++) test = bs->dirty_bitmap[i];
1981 }
1982 } else {
1983 if(bs->dirty_tracking != 0) {
1984 qemu_free(bs->dirty_bitmap);
1985 bs->dirty_tracking = enable;
1986 }
1987 }
1988 }
1989
1990 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
1991 {
1992 int64_t chunk = sector / (int64_t)SECTORS_PER_DIRTY_CHUNK;
1993
1994 if(bs->dirty_bitmap != NULL &&
1995 (sector << SECTOR_BITS) <= bdrv_getlength(bs)) {
1996 return bs->dirty_bitmap[chunk];
1997 } else {
1998 return 0;
1999 }
2000 }
2001
2002 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2003 int nr_sectors)
2004 {
2005 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2006 }
2007
2008 int bdrv_get_sectors_per_chunk(void)
2009 {
2010 /* size must be 2^x */
2011 return SECTORS_PER_DIRTY_CHUNK;
2012 }
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