vga: compile cirrus_vga in hwlib
[qemu.git] / block.c
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 "qjson.h"
31 #include "qemu-coroutine.h"
32 #include "qmp-commands.h"
33 #include "qemu-timer.h"
34
35 #ifdef CONFIG_BSD
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <sys/ioctl.h>
39 #include <sys/queue.h>
40 #ifndef __DragonFly__
41 #include <sys/disk.h>
42 #endif
43 #endif
44
45 #ifdef _WIN32
46 #include <windows.h>
47 #endif
48
49 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
50
51 static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load);
52 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
53 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
54 BlockDriverCompletionFunc *cb, void *opaque);
55 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
56 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
57 BlockDriverCompletionFunc *cb, void *opaque);
58 static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
59 int64_t sector_num, int nb_sectors,
60 QEMUIOVector *iov);
61 static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
62 int64_t sector_num, int nb_sectors,
63 QEMUIOVector *iov);
64 static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
65 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
66 static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
67 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
68 static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
69 int64_t sector_num,
70 QEMUIOVector *qiov,
71 int nb_sectors,
72 BlockDriverCompletionFunc *cb,
73 void *opaque,
74 bool is_write);
75 static void coroutine_fn bdrv_co_do_rw(void *opaque);
76
77 static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
78 bool is_write, double elapsed_time, uint64_t *wait);
79 static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
80 double elapsed_time, uint64_t *wait);
81 static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
82 bool is_write, int64_t *wait);
83
84 static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
85 QTAILQ_HEAD_INITIALIZER(bdrv_states);
86
87 static QLIST_HEAD(, BlockDriver) bdrv_drivers =
88 QLIST_HEAD_INITIALIZER(bdrv_drivers);
89
90 /* The device to use for VM snapshots */
91 static BlockDriverState *bs_snapshots;
92
93 /* If non-zero, use only whitelisted block drivers */
94 static int use_bdrv_whitelist;
95
96 #ifdef _WIN32
97 static int is_windows_drive_prefix(const char *filename)
98 {
99 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
100 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
101 filename[1] == ':');
102 }
103
104 int is_windows_drive(const char *filename)
105 {
106 if (is_windows_drive_prefix(filename) &&
107 filename[2] == '\0')
108 return 1;
109 if (strstart(filename, "\\\\.\\", NULL) ||
110 strstart(filename, "//./", NULL))
111 return 1;
112 return 0;
113 }
114 #endif
115
116 /* throttling disk I/O limits */
117 void bdrv_io_limits_disable(BlockDriverState *bs)
118 {
119 bs->io_limits_enabled = false;
120
121 while (qemu_co_queue_next(&bs->throttled_reqs));
122
123 if (bs->block_timer) {
124 qemu_del_timer(bs->block_timer);
125 qemu_free_timer(bs->block_timer);
126 bs->block_timer = NULL;
127 }
128
129 bs->slice_start = 0;
130 bs->slice_end = 0;
131 bs->slice_time = 0;
132 memset(&bs->io_base, 0, sizeof(bs->io_base));
133 }
134
135 static void bdrv_block_timer(void *opaque)
136 {
137 BlockDriverState *bs = opaque;
138
139 qemu_co_queue_next(&bs->throttled_reqs);
140 }
141
142 void bdrv_io_limits_enable(BlockDriverState *bs)
143 {
144 qemu_co_queue_init(&bs->throttled_reqs);
145 bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs);
146 bs->slice_time = 5 * BLOCK_IO_SLICE_TIME;
147 bs->slice_start = qemu_get_clock_ns(vm_clock);
148 bs->slice_end = bs->slice_start + bs->slice_time;
149 memset(&bs->io_base, 0, sizeof(bs->io_base));
150 bs->io_limits_enabled = true;
151 }
152
153 bool bdrv_io_limits_enabled(BlockDriverState *bs)
154 {
155 BlockIOLimit *io_limits = &bs->io_limits;
156 return io_limits->bps[BLOCK_IO_LIMIT_READ]
157 || io_limits->bps[BLOCK_IO_LIMIT_WRITE]
158 || io_limits->bps[BLOCK_IO_LIMIT_TOTAL]
159 || io_limits->iops[BLOCK_IO_LIMIT_READ]
160 || io_limits->iops[BLOCK_IO_LIMIT_WRITE]
161 || io_limits->iops[BLOCK_IO_LIMIT_TOTAL];
162 }
163
164 static void bdrv_io_limits_intercept(BlockDriverState *bs,
165 bool is_write, int nb_sectors)
166 {
167 int64_t wait_time = -1;
168
169 if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
170 qemu_co_queue_wait(&bs->throttled_reqs);
171 }
172
173 /* In fact, we hope to keep each request's timing, in FIFO mode. The next
174 * throttled requests will not be dequeued until the current request is
175 * allowed to be serviced. So if the current request still exceeds the
176 * limits, it will be inserted to the head. All requests followed it will
177 * be still in throttled_reqs queue.
178 */
179
180 while (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) {
181 qemu_mod_timer(bs->block_timer,
182 wait_time + qemu_get_clock_ns(vm_clock));
183 qemu_co_queue_wait_insert_head(&bs->throttled_reqs);
184 }
185
186 qemu_co_queue_next(&bs->throttled_reqs);
187 }
188
189 /* check if the path starts with "<protocol>:" */
190 static int path_has_protocol(const char *path)
191 {
192 #ifdef _WIN32
193 if (is_windows_drive(path) ||
194 is_windows_drive_prefix(path)) {
195 return 0;
196 }
197 #endif
198
199 return strchr(path, ':') != NULL;
200 }
201
202 int path_is_absolute(const char *path)
203 {
204 const char *p;
205 #ifdef _WIN32
206 /* specific case for names like: "\\.\d:" */
207 if (*path == '/' || *path == '\\')
208 return 1;
209 #endif
210 p = strchr(path, ':');
211 if (p)
212 p++;
213 else
214 p = path;
215 #ifdef _WIN32
216 return (*p == '/' || *p == '\\');
217 #else
218 return (*p == '/');
219 #endif
220 }
221
222 /* if filename is absolute, just copy it to dest. Otherwise, build a
223 path to it by considering it is relative to base_path. URL are
224 supported. */
225 void path_combine(char *dest, int dest_size,
226 const char *base_path,
227 const char *filename)
228 {
229 const char *p, *p1;
230 int len;
231
232 if (dest_size <= 0)
233 return;
234 if (path_is_absolute(filename)) {
235 pstrcpy(dest, dest_size, filename);
236 } else {
237 p = strchr(base_path, ':');
238 if (p)
239 p++;
240 else
241 p = base_path;
242 p1 = strrchr(base_path, '/');
243 #ifdef _WIN32
244 {
245 const char *p2;
246 p2 = strrchr(base_path, '\\');
247 if (!p1 || p2 > p1)
248 p1 = p2;
249 }
250 #endif
251 if (p1)
252 p1++;
253 else
254 p1 = base_path;
255 if (p1 > p)
256 p = p1;
257 len = p - base_path;
258 if (len > dest_size - 1)
259 len = dest_size - 1;
260 memcpy(dest, base_path, len);
261 dest[len] = '\0';
262 pstrcat(dest, dest_size, filename);
263 }
264 }
265
266 void bdrv_register(BlockDriver *bdrv)
267 {
268 /* Block drivers without coroutine functions need emulation */
269 if (!bdrv->bdrv_co_readv) {
270 bdrv->bdrv_co_readv = bdrv_co_readv_em;
271 bdrv->bdrv_co_writev = bdrv_co_writev_em;
272
273 /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if
274 * the block driver lacks aio we need to emulate that too.
275 */
276 if (!bdrv->bdrv_aio_readv) {
277 /* add AIO emulation layer */
278 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
279 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
280 }
281 }
282
283 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
284 }
285
286 /* create a new block device (by default it is empty) */
287 BlockDriverState *bdrv_new(const char *device_name)
288 {
289 BlockDriverState *bs;
290
291 bs = g_malloc0(sizeof(BlockDriverState));
292 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
293 if (device_name[0] != '\0') {
294 QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
295 }
296 bdrv_iostatus_disable(bs);
297 return bs;
298 }
299
300 BlockDriver *bdrv_find_format(const char *format_name)
301 {
302 BlockDriver *drv1;
303 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
304 if (!strcmp(drv1->format_name, format_name)) {
305 return drv1;
306 }
307 }
308 return NULL;
309 }
310
311 static int bdrv_is_whitelisted(BlockDriver *drv)
312 {
313 static const char *whitelist[] = {
314 CONFIG_BDRV_WHITELIST
315 };
316 const char **p;
317
318 if (!whitelist[0])
319 return 1; /* no whitelist, anything goes */
320
321 for (p = whitelist; *p; p++) {
322 if (!strcmp(drv->format_name, *p)) {
323 return 1;
324 }
325 }
326 return 0;
327 }
328
329 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
330 {
331 BlockDriver *drv = bdrv_find_format(format_name);
332 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
333 }
334
335 int bdrv_create(BlockDriver *drv, const char* filename,
336 QEMUOptionParameter *options)
337 {
338 if (!drv->bdrv_create)
339 return -ENOTSUP;
340
341 return drv->bdrv_create(filename, options);
342 }
343
344 int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
345 {
346 BlockDriver *drv;
347
348 drv = bdrv_find_protocol(filename);
349 if (drv == NULL) {
350 return -ENOENT;
351 }
352
353 return bdrv_create(drv, filename, options);
354 }
355
356 #ifdef _WIN32
357 void get_tmp_filename(char *filename, int size)
358 {
359 char temp_dir[MAX_PATH];
360
361 GetTempPath(MAX_PATH, temp_dir);
362 GetTempFileName(temp_dir, "qem", 0, filename);
363 }
364 #else
365 void get_tmp_filename(char *filename, int size)
366 {
367 int fd;
368 const char *tmpdir;
369 /* XXX: race condition possible */
370 tmpdir = getenv("TMPDIR");
371 if (!tmpdir)
372 tmpdir = "/tmp";
373 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
374 fd = mkstemp(filename);
375 close(fd);
376 }
377 #endif
378
379 /*
380 * Detect host devices. By convention, /dev/cdrom[N] is always
381 * recognized as a host CDROM.
382 */
383 static BlockDriver *find_hdev_driver(const char *filename)
384 {
385 int score_max = 0, score;
386 BlockDriver *drv = NULL, *d;
387
388 QLIST_FOREACH(d, &bdrv_drivers, list) {
389 if (d->bdrv_probe_device) {
390 score = d->bdrv_probe_device(filename);
391 if (score > score_max) {
392 score_max = score;
393 drv = d;
394 }
395 }
396 }
397
398 return drv;
399 }
400
401 BlockDriver *bdrv_find_protocol(const char *filename)
402 {
403 BlockDriver *drv1;
404 char protocol[128];
405 int len;
406 const char *p;
407
408 /* TODO Drivers without bdrv_file_open must be specified explicitly */
409
410 /*
411 * XXX(hch): we really should not let host device detection
412 * override an explicit protocol specification, but moving this
413 * later breaks access to device names with colons in them.
414 * Thanks to the brain-dead persistent naming schemes on udev-
415 * based Linux systems those actually are quite common.
416 */
417 drv1 = find_hdev_driver(filename);
418 if (drv1) {
419 return drv1;
420 }
421
422 if (!path_has_protocol(filename)) {
423 return bdrv_find_format("file");
424 }
425 p = strchr(filename, ':');
426 assert(p != NULL);
427 len = p - filename;
428 if (len > sizeof(protocol) - 1)
429 len = sizeof(protocol) - 1;
430 memcpy(protocol, filename, len);
431 protocol[len] = '\0';
432 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
433 if (drv1->protocol_name &&
434 !strcmp(drv1->protocol_name, protocol)) {
435 return drv1;
436 }
437 }
438 return NULL;
439 }
440
441 static int find_image_format(const char *filename, BlockDriver **pdrv)
442 {
443 int ret, score, score_max;
444 BlockDriver *drv1, *drv;
445 uint8_t buf[2048];
446 BlockDriverState *bs;
447
448 ret = bdrv_file_open(&bs, filename, 0);
449 if (ret < 0) {
450 *pdrv = NULL;
451 return ret;
452 }
453
454 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
455 if (bs->sg || !bdrv_is_inserted(bs)) {
456 bdrv_delete(bs);
457 drv = bdrv_find_format("raw");
458 if (!drv) {
459 ret = -ENOENT;
460 }
461 *pdrv = drv;
462 return ret;
463 }
464
465 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
466 bdrv_delete(bs);
467 if (ret < 0) {
468 *pdrv = NULL;
469 return ret;
470 }
471
472 score_max = 0;
473 drv = NULL;
474 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
475 if (drv1->bdrv_probe) {
476 score = drv1->bdrv_probe(buf, ret, filename);
477 if (score > score_max) {
478 score_max = score;
479 drv = drv1;
480 }
481 }
482 }
483 if (!drv) {
484 ret = -ENOENT;
485 }
486 *pdrv = drv;
487 return ret;
488 }
489
490 /**
491 * Set the current 'total_sectors' value
492 */
493 static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
494 {
495 BlockDriver *drv = bs->drv;
496
497 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
498 if (bs->sg)
499 return 0;
500
501 /* query actual device if possible, otherwise just trust the hint */
502 if (drv->bdrv_getlength) {
503 int64_t length = drv->bdrv_getlength(bs);
504 if (length < 0) {
505 return length;
506 }
507 hint = length >> BDRV_SECTOR_BITS;
508 }
509
510 bs->total_sectors = hint;
511 return 0;
512 }
513
514 /**
515 * Set open flags for a given cache mode
516 *
517 * Return 0 on success, -1 if the cache mode was invalid.
518 */
519 int bdrv_parse_cache_flags(const char *mode, int *flags)
520 {
521 *flags &= ~BDRV_O_CACHE_MASK;
522
523 if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
524 *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
525 } else if (!strcmp(mode, "directsync")) {
526 *flags |= BDRV_O_NOCACHE;
527 } else if (!strcmp(mode, "writeback")) {
528 *flags |= BDRV_O_CACHE_WB;
529 } else if (!strcmp(mode, "unsafe")) {
530 *flags |= BDRV_O_CACHE_WB;
531 *flags |= BDRV_O_NO_FLUSH;
532 } else if (!strcmp(mode, "writethrough")) {
533 /* this is the default */
534 } else {
535 return -1;
536 }
537
538 return 0;
539 }
540
541 /**
542 * The copy-on-read flag is actually a reference count so multiple users may
543 * use the feature without worrying about clobbering its previous state.
544 * Copy-on-read stays enabled until all users have called to disable it.
545 */
546 void bdrv_enable_copy_on_read(BlockDriverState *bs)
547 {
548 bs->copy_on_read++;
549 }
550
551 void bdrv_disable_copy_on_read(BlockDriverState *bs)
552 {
553 assert(bs->copy_on_read > 0);
554 bs->copy_on_read--;
555 }
556
557 /*
558 * Common part for opening disk images and files
559 */
560 static int bdrv_open_common(BlockDriverState *bs, const char *filename,
561 int flags, BlockDriver *drv)
562 {
563 int ret, open_flags;
564
565 assert(drv != NULL);
566
567 trace_bdrv_open_common(bs, filename, flags, drv->format_name);
568
569 bs->file = NULL;
570 bs->total_sectors = 0;
571 bs->encrypted = 0;
572 bs->valid_key = 0;
573 bs->sg = 0;
574 bs->open_flags = flags;
575 bs->growable = 0;
576 bs->buffer_alignment = 512;
577
578 assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
579 if ((flags & BDRV_O_RDWR) && (flags & BDRV_O_COPY_ON_READ)) {
580 bdrv_enable_copy_on_read(bs);
581 }
582
583 pstrcpy(bs->filename, sizeof(bs->filename), filename);
584 bs->backing_file[0] = '\0';
585
586 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
587 return -ENOTSUP;
588 }
589
590 bs->drv = drv;
591 bs->opaque = g_malloc0(drv->instance_size);
592
593 bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB);
594
595 /*
596 * Clear flags that are internal to the block layer before opening the
597 * image.
598 */
599 open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
600
601 /*
602 * Snapshots should be writable.
603 */
604 if (bs->is_temporary) {
605 open_flags |= BDRV_O_RDWR;
606 }
607
608 bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
609
610 /* Open the image, either directly or using a protocol */
611 if (drv->bdrv_file_open) {
612 ret = drv->bdrv_file_open(bs, filename, open_flags);
613 } else {
614 ret = bdrv_file_open(&bs->file, filename, open_flags);
615 if (ret >= 0) {
616 ret = drv->bdrv_open(bs, open_flags);
617 }
618 }
619
620 if (ret < 0) {
621 goto free_and_fail;
622 }
623
624 ret = refresh_total_sectors(bs, bs->total_sectors);
625 if (ret < 0) {
626 goto free_and_fail;
627 }
628
629 #ifndef _WIN32
630 if (bs->is_temporary) {
631 unlink(filename);
632 }
633 #endif
634 return 0;
635
636 free_and_fail:
637 if (bs->file) {
638 bdrv_delete(bs->file);
639 bs->file = NULL;
640 }
641 g_free(bs->opaque);
642 bs->opaque = NULL;
643 bs->drv = NULL;
644 return ret;
645 }
646
647 /*
648 * Opens a file using a protocol (file, host_device, nbd, ...)
649 */
650 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
651 {
652 BlockDriverState *bs;
653 BlockDriver *drv;
654 int ret;
655
656 drv = bdrv_find_protocol(filename);
657 if (!drv) {
658 return -ENOENT;
659 }
660
661 bs = bdrv_new("");
662 ret = bdrv_open_common(bs, filename, flags, drv);
663 if (ret < 0) {
664 bdrv_delete(bs);
665 return ret;
666 }
667 bs->growable = 1;
668 *pbs = bs;
669 return 0;
670 }
671
672 /*
673 * Opens a disk image (raw, qcow2, vmdk, ...)
674 */
675 int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
676 BlockDriver *drv)
677 {
678 int ret;
679 char tmp_filename[PATH_MAX];
680
681 if (flags & BDRV_O_SNAPSHOT) {
682 BlockDriverState *bs1;
683 int64_t total_size;
684 int is_protocol = 0;
685 BlockDriver *bdrv_qcow2;
686 QEMUOptionParameter *options;
687 char backing_filename[PATH_MAX];
688
689 /* if snapshot, we create a temporary backing file and open it
690 instead of opening 'filename' directly */
691
692 /* if there is a backing file, use it */
693 bs1 = bdrv_new("");
694 ret = bdrv_open(bs1, filename, 0, drv);
695 if (ret < 0) {
696 bdrv_delete(bs1);
697 return ret;
698 }
699 total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
700
701 if (bs1->drv && bs1->drv->protocol_name)
702 is_protocol = 1;
703
704 bdrv_delete(bs1);
705
706 get_tmp_filename(tmp_filename, sizeof(tmp_filename));
707
708 /* Real path is meaningless for protocols */
709 if (is_protocol)
710 snprintf(backing_filename, sizeof(backing_filename),
711 "%s", filename);
712 else if (!realpath(filename, backing_filename))
713 return -errno;
714
715 bdrv_qcow2 = bdrv_find_format("qcow2");
716 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
717
718 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size);
719 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
720 if (drv) {
721 set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
722 drv->format_name);
723 }
724
725 ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
726 free_option_parameters(options);
727 if (ret < 0) {
728 return ret;
729 }
730
731 filename = tmp_filename;
732 drv = bdrv_qcow2;
733 bs->is_temporary = 1;
734 }
735
736 /* Find the right image format driver */
737 if (!drv) {
738 ret = find_image_format(filename, &drv);
739 }
740
741 if (!drv) {
742 goto unlink_and_fail;
743 }
744
745 /* Open the image */
746 ret = bdrv_open_common(bs, filename, flags, drv);
747 if (ret < 0) {
748 goto unlink_and_fail;
749 }
750
751 /* If there is a backing file, use it */
752 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
753 char backing_filename[PATH_MAX];
754 int back_flags;
755 BlockDriver *back_drv = NULL;
756
757 bs->backing_hd = bdrv_new("");
758
759 if (path_has_protocol(bs->backing_file)) {
760 pstrcpy(backing_filename, sizeof(backing_filename),
761 bs->backing_file);
762 } else {
763 path_combine(backing_filename, sizeof(backing_filename),
764 filename, bs->backing_file);
765 }
766
767 if (bs->backing_format[0] != '\0') {
768 back_drv = bdrv_find_format(bs->backing_format);
769 }
770
771 /* backing files always opened read-only */
772 back_flags =
773 flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
774
775 ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
776 if (ret < 0) {
777 bdrv_close(bs);
778 return ret;
779 }
780 if (bs->is_temporary) {
781 bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
782 } else {
783 /* base image inherits from "parent" */
784 bs->backing_hd->keep_read_only = bs->keep_read_only;
785 }
786 }
787
788 if (!bdrv_key_required(bs)) {
789 bdrv_dev_change_media_cb(bs, true);
790 }
791
792 /* throttling disk I/O limits */
793 if (bs->io_limits_enabled) {
794 bdrv_io_limits_enable(bs);
795 }
796
797 return 0;
798
799 unlink_and_fail:
800 if (bs->is_temporary) {
801 unlink(filename);
802 }
803 return ret;
804 }
805
806 void bdrv_close(BlockDriverState *bs)
807 {
808 if (bs->drv) {
809 if (bs == bs_snapshots) {
810 bs_snapshots = NULL;
811 }
812 if (bs->backing_hd) {
813 bdrv_delete(bs->backing_hd);
814 bs->backing_hd = NULL;
815 }
816 bs->drv->bdrv_close(bs);
817 g_free(bs->opaque);
818 #ifdef _WIN32
819 if (bs->is_temporary) {
820 unlink(bs->filename);
821 }
822 #endif
823 bs->opaque = NULL;
824 bs->drv = NULL;
825 bs->copy_on_read = 0;
826
827 if (bs->file != NULL) {
828 bdrv_close(bs->file);
829 }
830
831 bdrv_dev_change_media_cb(bs, false);
832 }
833
834 /*throttling disk I/O limits*/
835 if (bs->io_limits_enabled) {
836 bdrv_io_limits_disable(bs);
837 }
838 }
839
840 void bdrv_close_all(void)
841 {
842 BlockDriverState *bs;
843
844 QTAILQ_FOREACH(bs, &bdrv_states, list) {
845 bdrv_close(bs);
846 }
847 }
848
849 /*
850 * Wait for pending requests to complete across all BlockDriverStates
851 *
852 * This function does not flush data to disk, use bdrv_flush_all() for that
853 * after calling this function.
854 */
855 void bdrv_drain_all(void)
856 {
857 BlockDriverState *bs;
858
859 qemu_aio_flush();
860
861 /* If requests are still pending there is a bug somewhere */
862 QTAILQ_FOREACH(bs, &bdrv_states, list) {
863 assert(QLIST_EMPTY(&bs->tracked_requests));
864 assert(qemu_co_queue_empty(&bs->throttled_reqs));
865 }
866 }
867
868 /* make a BlockDriverState anonymous by removing from bdrv_state list.
869 Also, NULL terminate the device_name to prevent double remove */
870 void bdrv_make_anon(BlockDriverState *bs)
871 {
872 if (bs->device_name[0] != '\0') {
873 QTAILQ_REMOVE(&bdrv_states, bs, list);
874 }
875 bs->device_name[0] = '\0';
876 }
877
878 void bdrv_delete(BlockDriverState *bs)
879 {
880 assert(!bs->dev);
881
882 /* remove from list, if necessary */
883 bdrv_make_anon(bs);
884
885 bdrv_close(bs);
886 if (bs->file != NULL) {
887 bdrv_delete(bs->file);
888 }
889
890 assert(bs != bs_snapshots);
891 g_free(bs);
892 }
893
894 int bdrv_attach_dev(BlockDriverState *bs, void *dev)
895 /* TODO change to DeviceState *dev when all users are qdevified */
896 {
897 if (bs->dev) {
898 return -EBUSY;
899 }
900 bs->dev = dev;
901 bdrv_iostatus_reset(bs);
902 return 0;
903 }
904
905 /* TODO qdevified devices don't use this, remove when devices are qdevified */
906 void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev)
907 {
908 if (bdrv_attach_dev(bs, dev) < 0) {
909 abort();
910 }
911 }
912
913 void bdrv_detach_dev(BlockDriverState *bs, void *dev)
914 /* TODO change to DeviceState *dev when all users are qdevified */
915 {
916 assert(bs->dev == dev);
917 bs->dev = NULL;
918 bs->dev_ops = NULL;
919 bs->dev_opaque = NULL;
920 bs->buffer_alignment = 512;
921 }
922
923 /* TODO change to return DeviceState * when all users are qdevified */
924 void *bdrv_get_attached_dev(BlockDriverState *bs)
925 {
926 return bs->dev;
927 }
928
929 void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
930 void *opaque)
931 {
932 bs->dev_ops = ops;
933 bs->dev_opaque = opaque;
934 if (bdrv_dev_has_removable_media(bs) && bs == bs_snapshots) {
935 bs_snapshots = NULL;
936 }
937 }
938
939 static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load)
940 {
941 if (bs->dev_ops && bs->dev_ops->change_media_cb) {
942 bs->dev_ops->change_media_cb(bs->dev_opaque, load);
943 }
944 }
945
946 bool bdrv_dev_has_removable_media(BlockDriverState *bs)
947 {
948 return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb);
949 }
950
951 void bdrv_dev_eject_request(BlockDriverState *bs, bool force)
952 {
953 if (bs->dev_ops && bs->dev_ops->eject_request_cb) {
954 bs->dev_ops->eject_request_cb(bs->dev_opaque, force);
955 }
956 }
957
958 bool bdrv_dev_is_tray_open(BlockDriverState *bs)
959 {
960 if (bs->dev_ops && bs->dev_ops->is_tray_open) {
961 return bs->dev_ops->is_tray_open(bs->dev_opaque);
962 }
963 return false;
964 }
965
966 static void bdrv_dev_resize_cb(BlockDriverState *bs)
967 {
968 if (bs->dev_ops && bs->dev_ops->resize_cb) {
969 bs->dev_ops->resize_cb(bs->dev_opaque);
970 }
971 }
972
973 bool bdrv_dev_is_medium_locked(BlockDriverState *bs)
974 {
975 if (bs->dev_ops && bs->dev_ops->is_medium_locked) {
976 return bs->dev_ops->is_medium_locked(bs->dev_opaque);
977 }
978 return false;
979 }
980
981 /*
982 * Run consistency checks on an image
983 *
984 * Returns 0 if the check could be completed (it doesn't mean that the image is
985 * free of errors) or -errno when an internal error occurred. The results of the
986 * check are stored in res.
987 */
988 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
989 {
990 if (bs->drv->bdrv_check == NULL) {
991 return -ENOTSUP;
992 }
993
994 memset(res, 0, sizeof(*res));
995 return bs->drv->bdrv_check(bs, res);
996 }
997
998 #define COMMIT_BUF_SECTORS 2048
999
1000 /* commit COW file into the raw image */
1001 int bdrv_commit(BlockDriverState *bs)
1002 {
1003 BlockDriver *drv = bs->drv;
1004 BlockDriver *backing_drv;
1005 int64_t sector, total_sectors;
1006 int n, ro, open_flags;
1007 int ret = 0, rw_ret = 0;
1008 uint8_t *buf;
1009 char filename[1024];
1010 BlockDriverState *bs_rw, *bs_ro;
1011
1012 if (!drv)
1013 return -ENOMEDIUM;
1014
1015 if (!bs->backing_hd) {
1016 return -ENOTSUP;
1017 }
1018
1019 if (bs->backing_hd->keep_read_only) {
1020 return -EACCES;
1021 }
1022
1023 backing_drv = bs->backing_hd->drv;
1024 ro = bs->backing_hd->read_only;
1025 strncpy(filename, bs->backing_hd->filename, sizeof(filename));
1026 open_flags = bs->backing_hd->open_flags;
1027
1028 if (ro) {
1029 /* re-open as RW */
1030 bdrv_delete(bs->backing_hd);
1031 bs->backing_hd = NULL;
1032 bs_rw = bdrv_new("");
1033 rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
1034 backing_drv);
1035 if (rw_ret < 0) {
1036 bdrv_delete(bs_rw);
1037 /* try to re-open read-only */
1038 bs_ro = bdrv_new("");
1039 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
1040 backing_drv);
1041 if (ret < 0) {
1042 bdrv_delete(bs_ro);
1043 /* drive not functional anymore */
1044 bs->drv = NULL;
1045 return ret;
1046 }
1047 bs->backing_hd = bs_ro;
1048 return rw_ret;
1049 }
1050 bs->backing_hd = bs_rw;
1051 }
1052
1053 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
1054 buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
1055
1056 for (sector = 0; sector < total_sectors; sector += n) {
1057 if (bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
1058
1059 if (bdrv_read(bs, sector, buf, n) != 0) {
1060 ret = -EIO;
1061 goto ro_cleanup;
1062 }
1063
1064 if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
1065 ret = -EIO;
1066 goto ro_cleanup;
1067 }
1068 }
1069 }
1070
1071 if (drv->bdrv_make_empty) {
1072 ret = drv->bdrv_make_empty(bs);
1073 bdrv_flush(bs);
1074 }
1075
1076 /*
1077 * Make sure all data we wrote to the backing device is actually
1078 * stable on disk.
1079 */
1080 if (bs->backing_hd)
1081 bdrv_flush(bs->backing_hd);
1082
1083 ro_cleanup:
1084 g_free(buf);
1085
1086 if (ro) {
1087 /* re-open as RO */
1088 bdrv_delete(bs->backing_hd);
1089 bs->backing_hd = NULL;
1090 bs_ro = bdrv_new("");
1091 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
1092 backing_drv);
1093 if (ret < 0) {
1094 bdrv_delete(bs_ro);
1095 /* drive not functional anymore */
1096 bs->drv = NULL;
1097 return ret;
1098 }
1099 bs->backing_hd = bs_ro;
1100 bs->backing_hd->keep_read_only = 0;
1101 }
1102
1103 return ret;
1104 }
1105
1106 void bdrv_commit_all(void)
1107 {
1108 BlockDriverState *bs;
1109
1110 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1111 bdrv_commit(bs);
1112 }
1113 }
1114
1115 struct BdrvTrackedRequest {
1116 BlockDriverState *bs;
1117 int64_t sector_num;
1118 int nb_sectors;
1119 bool is_write;
1120 QLIST_ENTRY(BdrvTrackedRequest) list;
1121 Coroutine *co; /* owner, used for deadlock detection */
1122 CoQueue wait_queue; /* coroutines blocked on this request */
1123 };
1124
1125 /**
1126 * Remove an active request from the tracked requests list
1127 *
1128 * This function should be called when a tracked request is completing.
1129 */
1130 static void tracked_request_end(BdrvTrackedRequest *req)
1131 {
1132 QLIST_REMOVE(req, list);
1133 qemu_co_queue_restart_all(&req->wait_queue);
1134 }
1135
1136 /**
1137 * Add an active request to the tracked requests list
1138 */
1139 static void tracked_request_begin(BdrvTrackedRequest *req,
1140 BlockDriverState *bs,
1141 int64_t sector_num,
1142 int nb_sectors, bool is_write)
1143 {
1144 *req = (BdrvTrackedRequest){
1145 .bs = bs,
1146 .sector_num = sector_num,
1147 .nb_sectors = nb_sectors,
1148 .is_write = is_write,
1149 .co = qemu_coroutine_self(),
1150 };
1151
1152 qemu_co_queue_init(&req->wait_queue);
1153
1154 QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
1155 }
1156
1157 /**
1158 * Round a region to cluster boundaries
1159 */
1160 static void round_to_clusters(BlockDriverState *bs,
1161 int64_t sector_num, int nb_sectors,
1162 int64_t *cluster_sector_num,
1163 int *cluster_nb_sectors)
1164 {
1165 BlockDriverInfo bdi;
1166
1167 if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
1168 *cluster_sector_num = sector_num;
1169 *cluster_nb_sectors = nb_sectors;
1170 } else {
1171 int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE;
1172 *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c);
1173 *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num +
1174 nb_sectors, c);
1175 }
1176 }
1177
1178 static bool tracked_request_overlaps(BdrvTrackedRequest *req,
1179 int64_t sector_num, int nb_sectors) {
1180 /* aaaa bbbb */
1181 if (sector_num >= req->sector_num + req->nb_sectors) {
1182 return false;
1183 }
1184 /* bbbb aaaa */
1185 if (req->sector_num >= sector_num + nb_sectors) {
1186 return false;
1187 }
1188 return true;
1189 }
1190
1191 static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs,
1192 int64_t sector_num, int nb_sectors)
1193 {
1194 BdrvTrackedRequest *req;
1195 int64_t cluster_sector_num;
1196 int cluster_nb_sectors;
1197 bool retry;
1198
1199 /* If we touch the same cluster it counts as an overlap. This guarantees
1200 * that allocating writes will be serialized and not race with each other
1201 * for the same cluster. For example, in copy-on-read it ensures that the
1202 * CoR read and write operations are atomic and guest writes cannot
1203 * interleave between them.
1204 */
1205 round_to_clusters(bs, sector_num, nb_sectors,
1206 &cluster_sector_num, &cluster_nb_sectors);
1207
1208 do {
1209 retry = false;
1210 QLIST_FOREACH(req, &bs->tracked_requests, list) {
1211 if (tracked_request_overlaps(req, cluster_sector_num,
1212 cluster_nb_sectors)) {
1213 /* Hitting this means there was a reentrant request, for
1214 * example, a block driver issuing nested requests. This must
1215 * never happen since it means deadlock.
1216 */
1217 assert(qemu_coroutine_self() != req->co);
1218
1219 qemu_co_queue_wait(&req->wait_queue);
1220 retry = true;
1221 break;
1222 }
1223 }
1224 } while (retry);
1225 }
1226
1227 /*
1228 * Return values:
1229 * 0 - success
1230 * -EINVAL - backing format specified, but no file
1231 * -ENOSPC - can't update the backing file because no space is left in the
1232 * image file header
1233 * -ENOTSUP - format driver doesn't support changing the backing file
1234 */
1235 int bdrv_change_backing_file(BlockDriverState *bs,
1236 const char *backing_file, const char *backing_fmt)
1237 {
1238 BlockDriver *drv = bs->drv;
1239
1240 if (drv->bdrv_change_backing_file != NULL) {
1241 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
1242 } else {
1243 return -ENOTSUP;
1244 }
1245 }
1246
1247 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
1248 size_t size)
1249 {
1250 int64_t len;
1251
1252 if (!bdrv_is_inserted(bs))
1253 return -ENOMEDIUM;
1254
1255 if (bs->growable)
1256 return 0;
1257
1258 len = bdrv_getlength(bs);
1259
1260 if (offset < 0)
1261 return -EIO;
1262
1263 if ((offset > len) || (len - offset < size))
1264 return -EIO;
1265
1266 return 0;
1267 }
1268
1269 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
1270 int nb_sectors)
1271 {
1272 return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
1273 nb_sectors * BDRV_SECTOR_SIZE);
1274 }
1275
1276 typedef struct RwCo {
1277 BlockDriverState *bs;
1278 int64_t sector_num;
1279 int nb_sectors;
1280 QEMUIOVector *qiov;
1281 bool is_write;
1282 int ret;
1283 } RwCo;
1284
1285 static void coroutine_fn bdrv_rw_co_entry(void *opaque)
1286 {
1287 RwCo *rwco = opaque;
1288
1289 if (!rwco->is_write) {
1290 rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num,
1291 rwco->nb_sectors, rwco->qiov);
1292 } else {
1293 rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num,
1294 rwco->nb_sectors, rwco->qiov);
1295 }
1296 }
1297
1298 /*
1299 * Process a synchronous request using coroutines
1300 */
1301 static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
1302 int nb_sectors, bool is_write)
1303 {
1304 QEMUIOVector qiov;
1305 struct iovec iov = {
1306 .iov_base = (void *)buf,
1307 .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
1308 };
1309 Coroutine *co;
1310 RwCo rwco = {
1311 .bs = bs,
1312 .sector_num = sector_num,
1313 .nb_sectors = nb_sectors,
1314 .qiov = &qiov,
1315 .is_write = is_write,
1316 .ret = NOT_DONE,
1317 };
1318
1319 qemu_iovec_init_external(&qiov, &iov, 1);
1320
1321 if (qemu_in_coroutine()) {
1322 /* Fast-path if already in coroutine context */
1323 bdrv_rw_co_entry(&rwco);
1324 } else {
1325 co = qemu_coroutine_create(bdrv_rw_co_entry);
1326 qemu_coroutine_enter(co, &rwco);
1327 while (rwco.ret == NOT_DONE) {
1328 qemu_aio_wait();
1329 }
1330 }
1331 return rwco.ret;
1332 }
1333
1334 /* return < 0 if error. See bdrv_write() for the return codes */
1335 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
1336 uint8_t *buf, int nb_sectors)
1337 {
1338 return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false);
1339 }
1340
1341 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
1342 int nb_sectors, int dirty)
1343 {
1344 int64_t start, end;
1345 unsigned long val, idx, bit;
1346
1347 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
1348 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
1349
1350 for (; start <= end; start++) {
1351 idx = start / (sizeof(unsigned long) * 8);
1352 bit = start % (sizeof(unsigned long) * 8);
1353 val = bs->dirty_bitmap[idx];
1354 if (dirty) {
1355 if (!(val & (1UL << bit))) {
1356 bs->dirty_count++;
1357 val |= 1UL << bit;
1358 }
1359 } else {
1360 if (val & (1UL << bit)) {
1361 bs->dirty_count--;
1362 val &= ~(1UL << bit);
1363 }
1364 }
1365 bs->dirty_bitmap[idx] = val;
1366 }
1367 }
1368
1369 /* Return < 0 if error. Important errors are:
1370 -EIO generic I/O error (may happen for all errors)
1371 -ENOMEDIUM No media inserted.
1372 -EINVAL Invalid sector number or nb_sectors
1373 -EACCES Trying to write a read-only device
1374 */
1375 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
1376 const uint8_t *buf, int nb_sectors)
1377 {
1378 return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true);
1379 }
1380
1381 int bdrv_pread(BlockDriverState *bs, int64_t offset,
1382 void *buf, int count1)
1383 {
1384 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1385 int len, nb_sectors, count;
1386 int64_t sector_num;
1387 int ret;
1388
1389 count = count1;
1390 /* first read to align to sector start */
1391 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1392 if (len > count)
1393 len = count;
1394 sector_num = offset >> BDRV_SECTOR_BITS;
1395 if (len > 0) {
1396 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1397 return ret;
1398 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
1399 count -= len;
1400 if (count == 0)
1401 return count1;
1402 sector_num++;
1403 buf += len;
1404 }
1405
1406 /* read the sectors "in place" */
1407 nb_sectors = count >> BDRV_SECTOR_BITS;
1408 if (nb_sectors > 0) {
1409 if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
1410 return ret;
1411 sector_num += nb_sectors;
1412 len = nb_sectors << BDRV_SECTOR_BITS;
1413 buf += len;
1414 count -= len;
1415 }
1416
1417 /* add data from the last sector */
1418 if (count > 0) {
1419 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1420 return ret;
1421 memcpy(buf, tmp_buf, count);
1422 }
1423 return count1;
1424 }
1425
1426 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
1427 const void *buf, int count1)
1428 {
1429 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1430 int len, nb_sectors, count;
1431 int64_t sector_num;
1432 int ret;
1433
1434 count = count1;
1435 /* first write to align to sector start */
1436 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1437 if (len > count)
1438 len = count;
1439 sector_num = offset >> BDRV_SECTOR_BITS;
1440 if (len > 0) {
1441 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1442 return ret;
1443 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1444 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1445 return ret;
1446 count -= len;
1447 if (count == 0)
1448 return count1;
1449 sector_num++;
1450 buf += len;
1451 }
1452
1453 /* write the sectors "in place" */
1454 nb_sectors = count >> BDRV_SECTOR_BITS;
1455 if (nb_sectors > 0) {
1456 if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
1457 return ret;
1458 sector_num += nb_sectors;
1459 len = nb_sectors << BDRV_SECTOR_BITS;
1460 buf += len;
1461 count -= len;
1462 }
1463
1464 /* add data from the last sector */
1465 if (count > 0) {
1466 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1467 return ret;
1468 memcpy(tmp_buf, buf, count);
1469 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1470 return ret;
1471 }
1472 return count1;
1473 }
1474
1475 /*
1476 * Writes to the file and ensures that no writes are reordered across this
1477 * request (acts as a barrier)
1478 *
1479 * Returns 0 on success, -errno in error cases.
1480 */
1481 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
1482 const void *buf, int count)
1483 {
1484 int ret;
1485
1486 ret = bdrv_pwrite(bs, offset, buf, count);
1487 if (ret < 0) {
1488 return ret;
1489 }
1490
1491 /* No flush needed for cache modes that use O_DSYNC */
1492 if ((bs->open_flags & BDRV_O_CACHE_WB) != 0) {
1493 bdrv_flush(bs);
1494 }
1495
1496 return 0;
1497 }
1498
1499 static int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
1500 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
1501 {
1502 /* Perform I/O through a temporary buffer so that users who scribble over
1503 * their read buffer while the operation is in progress do not end up
1504 * modifying the image file. This is critical for zero-copy guest I/O
1505 * where anything might happen inside guest memory.
1506 */
1507 void *bounce_buffer;
1508
1509 struct iovec iov;
1510 QEMUIOVector bounce_qiov;
1511 int64_t cluster_sector_num;
1512 int cluster_nb_sectors;
1513 size_t skip_bytes;
1514 int ret;
1515
1516 /* Cover entire cluster so no additional backing file I/O is required when
1517 * allocating cluster in the image file.
1518 */
1519 round_to_clusters(bs, sector_num, nb_sectors,
1520 &cluster_sector_num, &cluster_nb_sectors);
1521
1522 trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors,
1523 cluster_sector_num, cluster_nb_sectors);
1524
1525 iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
1526 iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len);
1527 qemu_iovec_init_external(&bounce_qiov, &iov, 1);
1528
1529 ret = bs->drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors,
1530 &bounce_qiov);
1531 if (ret < 0) {
1532 goto err;
1533 }
1534
1535 ret = bs->drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors,
1536 &bounce_qiov);
1537 if (ret < 0) {
1538 /* It might be okay to ignore write errors for guest requests. If this
1539 * is a deliberate copy-on-read then we don't want to ignore the error.
1540 * Simply report it in all cases.
1541 */
1542 goto err;
1543 }
1544
1545 skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
1546 qemu_iovec_from_buffer(qiov, bounce_buffer + skip_bytes,
1547 nb_sectors * BDRV_SECTOR_SIZE);
1548
1549 err:
1550 qemu_vfree(bounce_buffer);
1551 return ret;
1552 }
1553
1554 /*
1555 * Handle a read request in coroutine context
1556 */
1557 static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
1558 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
1559 {
1560 BlockDriver *drv = bs->drv;
1561 BdrvTrackedRequest req;
1562 int ret;
1563
1564 if (!drv) {
1565 return -ENOMEDIUM;
1566 }
1567 if (bdrv_check_request(bs, sector_num, nb_sectors)) {
1568 return -EIO;
1569 }
1570
1571 /* throttling disk read I/O */
1572 if (bs->io_limits_enabled) {
1573 bdrv_io_limits_intercept(bs, false, nb_sectors);
1574 }
1575
1576 if (bs->copy_on_read) {
1577 wait_for_overlapping_requests(bs, sector_num, nb_sectors);
1578 }
1579
1580 tracked_request_begin(&req, bs, sector_num, nb_sectors, false);
1581
1582 if (bs->copy_on_read) {
1583 int pnum;
1584
1585 ret = bdrv_co_is_allocated(bs, sector_num, nb_sectors, &pnum);
1586 if (ret < 0) {
1587 goto out;
1588 }
1589
1590 if (!ret || pnum != nb_sectors) {
1591 ret = bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, qiov);
1592 goto out;
1593 }
1594 }
1595
1596 ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
1597
1598 out:
1599 tracked_request_end(&req);
1600 return ret;
1601 }
1602
1603 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
1604 int nb_sectors, QEMUIOVector *qiov)
1605 {
1606 trace_bdrv_co_readv(bs, sector_num, nb_sectors);
1607
1608 return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov);
1609 }
1610
1611 /*
1612 * Handle a write request in coroutine context
1613 */
1614 static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
1615 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
1616 {
1617 BlockDriver *drv = bs->drv;
1618 BdrvTrackedRequest req;
1619 int ret;
1620
1621 if (!bs->drv) {
1622 return -ENOMEDIUM;
1623 }
1624 if (bs->read_only) {
1625 return -EACCES;
1626 }
1627 if (bdrv_check_request(bs, sector_num, nb_sectors)) {
1628 return -EIO;
1629 }
1630
1631 /* throttling disk write I/O */
1632 if (bs->io_limits_enabled) {
1633 bdrv_io_limits_intercept(bs, true, nb_sectors);
1634 }
1635
1636 if (bs->copy_on_read) {
1637 wait_for_overlapping_requests(bs, sector_num, nb_sectors);
1638 }
1639
1640 tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
1641
1642 ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
1643
1644 if (bs->dirty_bitmap) {
1645 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1646 }
1647
1648 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
1649 bs->wr_highest_sector = sector_num + nb_sectors - 1;
1650 }
1651
1652 tracked_request_end(&req);
1653
1654 return ret;
1655 }
1656
1657 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
1658 int nb_sectors, QEMUIOVector *qiov)
1659 {
1660 trace_bdrv_co_writev(bs, sector_num, nb_sectors);
1661
1662 return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov);
1663 }
1664
1665 /**
1666 * Truncate file to 'offset' bytes (needed only for file protocols)
1667 */
1668 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
1669 {
1670 BlockDriver *drv = bs->drv;
1671 int ret;
1672 if (!drv)
1673 return -ENOMEDIUM;
1674 if (!drv->bdrv_truncate)
1675 return -ENOTSUP;
1676 if (bs->read_only)
1677 return -EACCES;
1678 if (bdrv_in_use(bs))
1679 return -EBUSY;
1680 ret = drv->bdrv_truncate(bs, offset);
1681 if (ret == 0) {
1682 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
1683 bdrv_dev_resize_cb(bs);
1684 }
1685 return ret;
1686 }
1687
1688 /**
1689 * Length of a allocated file in bytes. Sparse files are counted by actual
1690 * allocated space. Return < 0 if error or unknown.
1691 */
1692 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
1693 {
1694 BlockDriver *drv = bs->drv;
1695 if (!drv) {
1696 return -ENOMEDIUM;
1697 }
1698 if (drv->bdrv_get_allocated_file_size) {
1699 return drv->bdrv_get_allocated_file_size(bs);
1700 }
1701 if (bs->file) {
1702 return bdrv_get_allocated_file_size(bs->file);
1703 }
1704 return -ENOTSUP;
1705 }
1706
1707 /**
1708 * Length of a file in bytes. Return < 0 if error or unknown.
1709 */
1710 int64_t bdrv_getlength(BlockDriverState *bs)
1711 {
1712 BlockDriver *drv = bs->drv;
1713 if (!drv)
1714 return -ENOMEDIUM;
1715
1716 if (bs->growable || bdrv_dev_has_removable_media(bs)) {
1717 if (drv->bdrv_getlength) {
1718 return drv->bdrv_getlength(bs);
1719 }
1720 }
1721 return bs->total_sectors * BDRV_SECTOR_SIZE;
1722 }
1723
1724 /* return 0 as number of sectors if no device present or error */
1725 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
1726 {
1727 int64_t length;
1728 length = bdrv_getlength(bs);
1729 if (length < 0)
1730 length = 0;
1731 else
1732 length = length >> BDRV_SECTOR_BITS;
1733 *nb_sectors_ptr = length;
1734 }
1735
1736 struct partition {
1737 uint8_t boot_ind; /* 0x80 - active */
1738 uint8_t head; /* starting head */
1739 uint8_t sector; /* starting sector */
1740 uint8_t cyl; /* starting cylinder */
1741 uint8_t sys_ind; /* What partition type */
1742 uint8_t end_head; /* end head */
1743 uint8_t end_sector; /* end sector */
1744 uint8_t end_cyl; /* end cylinder */
1745 uint32_t start_sect; /* starting sector counting from 0 */
1746 uint32_t nr_sects; /* nr of sectors in partition */
1747 } QEMU_PACKED;
1748
1749 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
1750 static int guess_disk_lchs(BlockDriverState *bs,
1751 int *pcylinders, int *pheads, int *psectors)
1752 {
1753 uint8_t buf[BDRV_SECTOR_SIZE];
1754 int ret, i, heads, sectors, cylinders;
1755 struct partition *p;
1756 uint32_t nr_sects;
1757 uint64_t nb_sectors;
1758
1759 bdrv_get_geometry(bs, &nb_sectors);
1760
1761 ret = bdrv_read(bs, 0, buf, 1);
1762 if (ret < 0)
1763 return -1;
1764 /* test msdos magic */
1765 if (buf[510] != 0x55 || buf[511] != 0xaa)
1766 return -1;
1767 for(i = 0; i < 4; i++) {
1768 p = ((struct partition *)(buf + 0x1be)) + i;
1769 nr_sects = le32_to_cpu(p->nr_sects);
1770 if (nr_sects && p->end_head) {
1771 /* We make the assumption that the partition terminates on
1772 a cylinder boundary */
1773 heads = p->end_head + 1;
1774 sectors = p->end_sector & 63;
1775 if (sectors == 0)
1776 continue;
1777 cylinders = nb_sectors / (heads * sectors);
1778 if (cylinders < 1 || cylinders > 16383)
1779 continue;
1780 *pheads = heads;
1781 *psectors = sectors;
1782 *pcylinders = cylinders;
1783 #if 0
1784 printf("guessed geometry: LCHS=%d %d %d\n",
1785 cylinders, heads, sectors);
1786 #endif
1787 return 0;
1788 }
1789 }
1790 return -1;
1791 }
1792
1793 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
1794 {
1795 int translation, lba_detected = 0;
1796 int cylinders, heads, secs;
1797 uint64_t nb_sectors;
1798
1799 /* if a geometry hint is available, use it */
1800 bdrv_get_geometry(bs, &nb_sectors);
1801 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
1802 translation = bdrv_get_translation_hint(bs);
1803 if (cylinders != 0) {
1804 *pcyls = cylinders;
1805 *pheads = heads;
1806 *psecs = secs;
1807 } else {
1808 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
1809 if (heads > 16) {
1810 /* if heads > 16, it means that a BIOS LBA
1811 translation was active, so the default
1812 hardware geometry is OK */
1813 lba_detected = 1;
1814 goto default_geometry;
1815 } else {
1816 *pcyls = cylinders;
1817 *pheads = heads;
1818 *psecs = secs;
1819 /* disable any translation to be in sync with
1820 the logical geometry */
1821 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
1822 bdrv_set_translation_hint(bs,
1823 BIOS_ATA_TRANSLATION_NONE);
1824 }
1825 }
1826 } else {
1827 default_geometry:
1828 /* if no geometry, use a standard physical disk geometry */
1829 cylinders = nb_sectors / (16 * 63);
1830
1831 if (cylinders > 16383)
1832 cylinders = 16383;
1833 else if (cylinders < 2)
1834 cylinders = 2;
1835 *pcyls = cylinders;
1836 *pheads = 16;
1837 *psecs = 63;
1838 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
1839 if ((*pcyls * *pheads) <= 131072) {
1840 bdrv_set_translation_hint(bs,
1841 BIOS_ATA_TRANSLATION_LARGE);
1842 } else {
1843 bdrv_set_translation_hint(bs,
1844 BIOS_ATA_TRANSLATION_LBA);
1845 }
1846 }
1847 }
1848 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
1849 }
1850 }
1851
1852 void bdrv_set_geometry_hint(BlockDriverState *bs,
1853 int cyls, int heads, int secs)
1854 {
1855 bs->cyls = cyls;
1856 bs->heads = heads;
1857 bs->secs = secs;
1858 }
1859
1860 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
1861 {
1862 bs->translation = translation;
1863 }
1864
1865 void bdrv_get_geometry_hint(BlockDriverState *bs,
1866 int *pcyls, int *pheads, int *psecs)
1867 {
1868 *pcyls = bs->cyls;
1869 *pheads = bs->heads;
1870 *psecs = bs->secs;
1871 }
1872
1873 /* throttling disk io limits */
1874 void bdrv_set_io_limits(BlockDriverState *bs,
1875 BlockIOLimit *io_limits)
1876 {
1877 bs->io_limits = *io_limits;
1878 bs->io_limits_enabled = bdrv_io_limits_enabled(bs);
1879 }
1880
1881 /* Recognize floppy formats */
1882 typedef struct FDFormat {
1883 FDriveType drive;
1884 uint8_t last_sect;
1885 uint8_t max_track;
1886 uint8_t max_head;
1887 } FDFormat;
1888
1889 static const FDFormat fd_formats[] = {
1890 /* First entry is default format */
1891 /* 1.44 MB 3"1/2 floppy disks */
1892 { FDRIVE_DRV_144, 18, 80, 1, },
1893 { FDRIVE_DRV_144, 20, 80, 1, },
1894 { FDRIVE_DRV_144, 21, 80, 1, },
1895 { FDRIVE_DRV_144, 21, 82, 1, },
1896 { FDRIVE_DRV_144, 21, 83, 1, },
1897 { FDRIVE_DRV_144, 22, 80, 1, },
1898 { FDRIVE_DRV_144, 23, 80, 1, },
1899 { FDRIVE_DRV_144, 24, 80, 1, },
1900 /* 2.88 MB 3"1/2 floppy disks */
1901 { FDRIVE_DRV_288, 36, 80, 1, },
1902 { FDRIVE_DRV_288, 39, 80, 1, },
1903 { FDRIVE_DRV_288, 40, 80, 1, },
1904 { FDRIVE_DRV_288, 44, 80, 1, },
1905 { FDRIVE_DRV_288, 48, 80, 1, },
1906 /* 720 kB 3"1/2 floppy disks */
1907 { FDRIVE_DRV_144, 9, 80, 1, },
1908 { FDRIVE_DRV_144, 10, 80, 1, },
1909 { FDRIVE_DRV_144, 10, 82, 1, },
1910 { FDRIVE_DRV_144, 10, 83, 1, },
1911 { FDRIVE_DRV_144, 13, 80, 1, },
1912 { FDRIVE_DRV_144, 14, 80, 1, },
1913 /* 1.2 MB 5"1/4 floppy disks */
1914 { FDRIVE_DRV_120, 15, 80, 1, },
1915 { FDRIVE_DRV_120, 18, 80, 1, },
1916 { FDRIVE_DRV_120, 18, 82, 1, },
1917 { FDRIVE_DRV_120, 18, 83, 1, },
1918 { FDRIVE_DRV_120, 20, 80, 1, },
1919 /* 720 kB 5"1/4 floppy disks */
1920 { FDRIVE_DRV_120, 9, 80, 1, },
1921 { FDRIVE_DRV_120, 11, 80, 1, },
1922 /* 360 kB 5"1/4 floppy disks */
1923 { FDRIVE_DRV_120, 9, 40, 1, },
1924 { FDRIVE_DRV_120, 9, 40, 0, },
1925 { FDRIVE_DRV_120, 10, 41, 1, },
1926 { FDRIVE_DRV_120, 10, 42, 1, },
1927 /* 320 kB 5"1/4 floppy disks */
1928 { FDRIVE_DRV_120, 8, 40, 1, },
1929 { FDRIVE_DRV_120, 8, 40, 0, },
1930 /* 360 kB must match 5"1/4 better than 3"1/2... */
1931 { FDRIVE_DRV_144, 9, 80, 0, },
1932 /* end */
1933 { FDRIVE_DRV_NONE, -1, -1, 0, },
1934 };
1935
1936 void bdrv_get_floppy_geometry_hint(BlockDriverState *bs, int *nb_heads,
1937 int *max_track, int *last_sect,
1938 FDriveType drive_in, FDriveType *drive)
1939 {
1940 const FDFormat *parse;
1941 uint64_t nb_sectors, size;
1942 int i, first_match, match;
1943
1944 bdrv_get_geometry_hint(bs, nb_heads, max_track, last_sect);
1945 if (*nb_heads != 0 && *max_track != 0 && *last_sect != 0) {
1946 /* User defined disk */
1947 } else {
1948 bdrv_get_geometry(bs, &nb_sectors);
1949 match = -1;
1950 first_match = -1;
1951 for (i = 0; ; i++) {
1952 parse = &fd_formats[i];
1953 if (parse->drive == FDRIVE_DRV_NONE) {
1954 break;
1955 }
1956 if (drive_in == parse->drive ||
1957 drive_in == FDRIVE_DRV_NONE) {
1958 size = (parse->max_head + 1) * parse->max_track *
1959 parse->last_sect;
1960 if (nb_sectors == size) {
1961 match = i;
1962 break;
1963 }
1964 if (first_match == -1) {
1965 first_match = i;
1966 }
1967 }
1968 }
1969 if (match == -1) {
1970 if (first_match == -1) {
1971 match = 1;
1972 } else {
1973 match = first_match;
1974 }
1975 parse = &fd_formats[match];
1976 }
1977 *nb_heads = parse->max_head + 1;
1978 *max_track = parse->max_track;
1979 *last_sect = parse->last_sect;
1980 *drive = parse->drive;
1981 }
1982 }
1983
1984 int bdrv_get_translation_hint(BlockDriverState *bs)
1985 {
1986 return bs->translation;
1987 }
1988
1989 void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
1990 BlockErrorAction on_write_error)
1991 {
1992 bs->on_read_error = on_read_error;
1993 bs->on_write_error = on_write_error;
1994 }
1995
1996 BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
1997 {
1998 return is_read ? bs->on_read_error : bs->on_write_error;
1999 }
2000
2001 int bdrv_is_read_only(BlockDriverState *bs)
2002 {
2003 return bs->read_only;
2004 }
2005
2006 int bdrv_is_sg(BlockDriverState *bs)
2007 {
2008 return bs->sg;
2009 }
2010
2011 int bdrv_enable_write_cache(BlockDriverState *bs)
2012 {
2013 return bs->enable_write_cache;
2014 }
2015
2016 int bdrv_is_encrypted(BlockDriverState *bs)
2017 {
2018 if (bs->backing_hd && bs->backing_hd->encrypted)
2019 return 1;
2020 return bs->encrypted;
2021 }
2022
2023 int bdrv_key_required(BlockDriverState *bs)
2024 {
2025 BlockDriverState *backing_hd = bs->backing_hd;
2026
2027 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
2028 return 1;
2029 return (bs->encrypted && !bs->valid_key);
2030 }
2031
2032 int bdrv_set_key(BlockDriverState *bs, const char *key)
2033 {
2034 int ret;
2035 if (bs->backing_hd && bs->backing_hd->encrypted) {
2036 ret = bdrv_set_key(bs->backing_hd, key);
2037 if (ret < 0)
2038 return ret;
2039 if (!bs->encrypted)
2040 return 0;
2041 }
2042 if (!bs->encrypted) {
2043 return -EINVAL;
2044 } else if (!bs->drv || !bs->drv->bdrv_set_key) {
2045 return -ENOMEDIUM;
2046 }
2047 ret = bs->drv->bdrv_set_key(bs, key);
2048 if (ret < 0) {
2049 bs->valid_key = 0;
2050 } else if (!bs->valid_key) {
2051 bs->valid_key = 1;
2052 /* call the change callback now, we skipped it on open */
2053 bdrv_dev_change_media_cb(bs, true);
2054 }
2055 return ret;
2056 }
2057
2058 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
2059 {
2060 if (!bs->drv) {
2061 buf[0] = '\0';
2062 } else {
2063 pstrcpy(buf, buf_size, bs->drv->format_name);
2064 }
2065 }
2066
2067 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
2068 void *opaque)
2069 {
2070 BlockDriver *drv;
2071
2072 QLIST_FOREACH(drv, &bdrv_drivers, list) {
2073 it(opaque, drv->format_name);
2074 }
2075 }
2076
2077 BlockDriverState *bdrv_find(const char *name)
2078 {
2079 BlockDriverState *bs;
2080
2081 QTAILQ_FOREACH(bs, &bdrv_states, list) {
2082 if (!strcmp(name, bs->device_name)) {
2083 return bs;
2084 }
2085 }
2086 return NULL;
2087 }
2088
2089 BlockDriverState *bdrv_next(BlockDriverState *bs)
2090 {
2091 if (!bs) {
2092 return QTAILQ_FIRST(&bdrv_states);
2093 }
2094 return QTAILQ_NEXT(bs, list);
2095 }
2096
2097 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
2098 {
2099 BlockDriverState *bs;
2100
2101 QTAILQ_FOREACH(bs, &bdrv_states, list) {
2102 it(opaque, bs);
2103 }
2104 }
2105
2106 const char *bdrv_get_device_name(BlockDriverState *bs)
2107 {
2108 return bs->device_name;
2109 }
2110
2111 void bdrv_flush_all(void)
2112 {
2113 BlockDriverState *bs;
2114
2115 QTAILQ_FOREACH(bs, &bdrv_states, list) {
2116 if (!bdrv_is_read_only(bs) && bdrv_is_inserted(bs)) {
2117 bdrv_flush(bs);
2118 }
2119 }
2120 }
2121
2122 int bdrv_has_zero_init(BlockDriverState *bs)
2123 {
2124 assert(bs->drv);
2125
2126 if (bs->drv->bdrv_has_zero_init) {
2127 return bs->drv->bdrv_has_zero_init(bs);
2128 }
2129
2130 return 1;
2131 }
2132
2133 typedef struct BdrvCoIsAllocatedData {
2134 BlockDriverState *bs;
2135 int64_t sector_num;
2136 int nb_sectors;
2137 int *pnum;
2138 int ret;
2139 bool done;
2140 } BdrvCoIsAllocatedData;
2141
2142 /*
2143 * Returns true iff the specified sector is present in the disk image. Drivers
2144 * not implementing the functionality are assumed to not support backing files,
2145 * hence all their sectors are reported as allocated.
2146 *
2147 * If 'sector_num' is beyond the end of the disk image the return value is 0
2148 * and 'pnum' is set to 0.
2149 *
2150 * 'pnum' is set to the number of sectors (including and immediately following
2151 * the specified sector) that are known to be in the same
2152 * allocated/unallocated state.
2153 *
2154 * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
2155 * beyond the end of the disk image it will be clamped.
2156 */
2157 int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num,
2158 int nb_sectors, int *pnum)
2159 {
2160 int64_t n;
2161
2162 if (sector_num >= bs->total_sectors) {
2163 *pnum = 0;
2164 return 0;
2165 }
2166
2167 n = bs->total_sectors - sector_num;
2168 if (n < nb_sectors) {
2169 nb_sectors = n;
2170 }
2171
2172 if (!bs->drv->bdrv_co_is_allocated) {
2173 *pnum = nb_sectors;
2174 return 1;
2175 }
2176
2177 return bs->drv->bdrv_co_is_allocated(bs, sector_num, nb_sectors, pnum);
2178 }
2179
2180 /* Coroutine wrapper for bdrv_is_allocated() */
2181 static void coroutine_fn bdrv_is_allocated_co_entry(void *opaque)
2182 {
2183 BdrvCoIsAllocatedData *data = opaque;
2184 BlockDriverState *bs = data->bs;
2185
2186 data->ret = bdrv_co_is_allocated(bs, data->sector_num, data->nb_sectors,
2187 data->pnum);
2188 data->done = true;
2189 }
2190
2191 /*
2192 * Synchronous wrapper around bdrv_co_is_allocated().
2193 *
2194 * See bdrv_co_is_allocated() for details.
2195 */
2196 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
2197 int *pnum)
2198 {
2199 Coroutine *co;
2200 BdrvCoIsAllocatedData data = {
2201 .bs = bs,
2202 .sector_num = sector_num,
2203 .nb_sectors = nb_sectors,
2204 .pnum = pnum,
2205 .done = false,
2206 };
2207
2208 co = qemu_coroutine_create(bdrv_is_allocated_co_entry);
2209 qemu_coroutine_enter(co, &data);
2210 while (!data.done) {
2211 qemu_aio_wait();
2212 }
2213 return data.ret;
2214 }
2215
2216 void bdrv_mon_event(const BlockDriverState *bdrv,
2217 BlockMonEventAction action, int is_read)
2218 {
2219 QObject *data;
2220 const char *action_str;
2221
2222 switch (action) {
2223 case BDRV_ACTION_REPORT:
2224 action_str = "report";
2225 break;
2226 case BDRV_ACTION_IGNORE:
2227 action_str = "ignore";
2228 break;
2229 case BDRV_ACTION_STOP:
2230 action_str = "stop";
2231 break;
2232 default:
2233 abort();
2234 }
2235
2236 data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
2237 bdrv->device_name,
2238 action_str,
2239 is_read ? "read" : "write");
2240 monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
2241
2242 qobject_decref(data);
2243 }
2244
2245 BlockInfoList *qmp_query_block(Error **errp)
2246 {
2247 BlockInfoList *head = NULL, *cur_item = NULL;
2248 BlockDriverState *bs;
2249
2250 QTAILQ_FOREACH(bs, &bdrv_states, list) {
2251 BlockInfoList *info = g_malloc0(sizeof(*info));
2252
2253 info->value = g_malloc0(sizeof(*info->value));
2254 info->value->device = g_strdup(bs->device_name);
2255 info->value->type = g_strdup("unknown");
2256 info->value->locked = bdrv_dev_is_medium_locked(bs);
2257 info->value->removable = bdrv_dev_has_removable_media(bs);
2258
2259 if (bdrv_dev_has_removable_media(bs)) {
2260 info->value->has_tray_open = true;
2261 info->value->tray_open = bdrv_dev_is_tray_open(bs);
2262 }
2263
2264 if (bdrv_iostatus_is_enabled(bs)) {
2265 info->value->has_io_status = true;
2266 info->value->io_status = bs->iostatus;
2267 }
2268
2269 if (bs->drv) {
2270 info->value->has_inserted = true;
2271 info->value->inserted = g_malloc0(sizeof(*info->value->inserted));
2272 info->value->inserted->file = g_strdup(bs->filename);
2273 info->value->inserted->ro = bs->read_only;
2274 info->value->inserted->drv = g_strdup(bs->drv->format_name);
2275 info->value->inserted->encrypted = bs->encrypted;
2276 if (bs->backing_file[0]) {
2277 info->value->inserted->has_backing_file = true;
2278 info->value->inserted->backing_file = g_strdup(bs->backing_file);
2279 }
2280
2281 if (bs->io_limits_enabled) {
2282 info->value->inserted->bps =
2283 bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];
2284 info->value->inserted->bps_rd =
2285 bs->io_limits.bps[BLOCK_IO_LIMIT_READ];
2286 info->value->inserted->bps_wr =
2287 bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE];
2288 info->value->inserted->iops =
2289 bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL];
2290 info->value->inserted->iops_rd =
2291 bs->io_limits.iops[BLOCK_IO_LIMIT_READ];
2292 info->value->inserted->iops_wr =
2293 bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE];
2294 }
2295 }
2296
2297 /* XXX: waiting for the qapi to support GSList */
2298 if (!cur_item) {
2299 head = cur_item = info;
2300 } else {
2301 cur_item->next = info;
2302 cur_item = info;
2303 }
2304 }
2305
2306 return head;
2307 }
2308
2309 /* Consider exposing this as a full fledged QMP command */
2310 static BlockStats *qmp_query_blockstat(const BlockDriverState *bs, Error **errp)
2311 {
2312 BlockStats *s;
2313
2314 s = g_malloc0(sizeof(*s));
2315
2316 if (bs->device_name[0]) {
2317 s->has_device = true;
2318 s->device = g_strdup(bs->device_name);
2319 }
2320
2321 s->stats = g_malloc0(sizeof(*s->stats));
2322 s->stats->rd_bytes = bs->nr_bytes[BDRV_ACCT_READ];
2323 s->stats->wr_bytes = bs->nr_bytes[BDRV_ACCT_WRITE];
2324 s->stats->rd_operations = bs->nr_ops[BDRV_ACCT_READ];
2325 s->stats->wr_operations = bs->nr_ops[BDRV_ACCT_WRITE];
2326 s->stats->wr_highest_offset = bs->wr_highest_sector * BDRV_SECTOR_SIZE;
2327 s->stats->flush_operations = bs->nr_ops[BDRV_ACCT_FLUSH];
2328 s->stats->wr_total_time_ns = bs->total_time_ns[BDRV_ACCT_WRITE];
2329 s->stats->rd_total_time_ns = bs->total_time_ns[BDRV_ACCT_READ];
2330 s->stats->flush_total_time_ns = bs->total_time_ns[BDRV_ACCT_FLUSH];
2331
2332 if (bs->file) {
2333 s->has_parent = true;
2334 s->parent = qmp_query_blockstat(bs->file, NULL);
2335 }
2336
2337 return s;
2338 }
2339
2340 BlockStatsList *qmp_query_blockstats(Error **errp)
2341 {
2342 BlockStatsList *head = NULL, *cur_item = NULL;
2343 BlockDriverState *bs;
2344
2345 QTAILQ_FOREACH(bs, &bdrv_states, list) {
2346 BlockStatsList *info = g_malloc0(sizeof(*info));
2347 info->value = qmp_query_blockstat(bs, NULL);
2348
2349 /* XXX: waiting for the qapi to support GSList */
2350 if (!cur_item) {
2351 head = cur_item = info;
2352 } else {
2353 cur_item->next = info;
2354 cur_item = info;
2355 }
2356 }
2357
2358 return head;
2359 }
2360
2361 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
2362 {
2363 if (bs->backing_hd && bs->backing_hd->encrypted)
2364 return bs->backing_file;
2365 else if (bs->encrypted)
2366 return bs->filename;
2367 else
2368 return NULL;
2369 }
2370
2371 void bdrv_get_backing_filename(BlockDriverState *bs,
2372 char *filename, int filename_size)
2373 {
2374 pstrcpy(filename, filename_size, bs->backing_file);
2375 }
2376
2377 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
2378 const uint8_t *buf, int nb_sectors)
2379 {
2380 BlockDriver *drv = bs->drv;
2381 if (!drv)
2382 return -ENOMEDIUM;
2383 if (!drv->bdrv_write_compressed)
2384 return -ENOTSUP;
2385 if (bdrv_check_request(bs, sector_num, nb_sectors))
2386 return -EIO;
2387
2388 if (bs->dirty_bitmap) {
2389 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
2390 }
2391
2392 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
2393 }
2394
2395 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
2396 {
2397 BlockDriver *drv = bs->drv;
2398 if (!drv)
2399 return -ENOMEDIUM;
2400 if (!drv->bdrv_get_info)
2401 return -ENOTSUP;
2402 memset(bdi, 0, sizeof(*bdi));
2403 return drv->bdrv_get_info(bs, bdi);
2404 }
2405
2406 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
2407 int64_t pos, int size)
2408 {
2409 BlockDriver *drv = bs->drv;
2410 if (!drv)
2411 return -ENOMEDIUM;
2412 if (drv->bdrv_save_vmstate)
2413 return drv->bdrv_save_vmstate(bs, buf, pos, size);
2414 if (bs->file)
2415 return bdrv_save_vmstate(bs->file, buf, pos, size);
2416 return -ENOTSUP;
2417 }
2418
2419 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
2420 int64_t pos, int size)
2421 {
2422 BlockDriver *drv = bs->drv;
2423 if (!drv)
2424 return -ENOMEDIUM;
2425 if (drv->bdrv_load_vmstate)
2426 return drv->bdrv_load_vmstate(bs, buf, pos, size);
2427 if (bs->file)
2428 return bdrv_load_vmstate(bs->file, buf, pos, size);
2429 return -ENOTSUP;
2430 }
2431
2432 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
2433 {
2434 BlockDriver *drv = bs->drv;
2435
2436 if (!drv || !drv->bdrv_debug_event) {
2437 return;
2438 }
2439
2440 return drv->bdrv_debug_event(bs, event);
2441
2442 }
2443
2444 /**************************************************************/
2445 /* handling of snapshots */
2446
2447 int bdrv_can_snapshot(BlockDriverState *bs)
2448 {
2449 BlockDriver *drv = bs->drv;
2450 if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
2451 return 0;
2452 }
2453
2454 if (!drv->bdrv_snapshot_create) {
2455 if (bs->file != NULL) {
2456 return bdrv_can_snapshot(bs->file);
2457 }
2458 return 0;
2459 }
2460
2461 return 1;
2462 }
2463
2464 int bdrv_is_snapshot(BlockDriverState *bs)
2465 {
2466 return !!(bs->open_flags & BDRV_O_SNAPSHOT);
2467 }
2468
2469 BlockDriverState *bdrv_snapshots(void)
2470 {
2471 BlockDriverState *bs;
2472
2473 if (bs_snapshots) {
2474 return bs_snapshots;
2475 }
2476
2477 bs = NULL;
2478 while ((bs = bdrv_next(bs))) {
2479 if (bdrv_can_snapshot(bs)) {
2480 bs_snapshots = bs;
2481 return bs;
2482 }
2483 }
2484 return NULL;
2485 }
2486
2487 int bdrv_snapshot_create(BlockDriverState *bs,
2488 QEMUSnapshotInfo *sn_info)
2489 {
2490 BlockDriver *drv = bs->drv;
2491 if (!drv)
2492 return -ENOMEDIUM;
2493 if (drv->bdrv_snapshot_create)
2494 return drv->bdrv_snapshot_create(bs, sn_info);
2495 if (bs->file)
2496 return bdrv_snapshot_create(bs->file, sn_info);
2497 return -ENOTSUP;
2498 }
2499
2500 int bdrv_snapshot_goto(BlockDriverState *bs,
2501 const char *snapshot_id)
2502 {
2503 BlockDriver *drv = bs->drv;
2504 int ret, open_ret;
2505
2506 if (!drv)
2507 return -ENOMEDIUM;
2508 if (drv->bdrv_snapshot_goto)
2509 return drv->bdrv_snapshot_goto(bs, snapshot_id);
2510
2511 if (bs->file) {
2512 drv->bdrv_close(bs);
2513 ret = bdrv_snapshot_goto(bs->file, snapshot_id);
2514 open_ret = drv->bdrv_open(bs, bs->open_flags);
2515 if (open_ret < 0) {
2516 bdrv_delete(bs->file);
2517 bs->drv = NULL;
2518 return open_ret;
2519 }
2520 return ret;
2521 }
2522
2523 return -ENOTSUP;
2524 }
2525
2526 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
2527 {
2528 BlockDriver *drv = bs->drv;
2529 if (!drv)
2530 return -ENOMEDIUM;
2531 if (drv->bdrv_snapshot_delete)
2532 return drv->bdrv_snapshot_delete(bs, snapshot_id);
2533 if (bs->file)
2534 return bdrv_snapshot_delete(bs->file, snapshot_id);
2535 return -ENOTSUP;
2536 }
2537
2538 int bdrv_snapshot_list(BlockDriverState *bs,
2539 QEMUSnapshotInfo **psn_info)
2540 {
2541 BlockDriver *drv = bs->drv;
2542 if (!drv)
2543 return -ENOMEDIUM;
2544 if (drv->bdrv_snapshot_list)
2545 return drv->bdrv_snapshot_list(bs, psn_info);
2546 if (bs->file)
2547 return bdrv_snapshot_list(bs->file, psn_info);
2548 return -ENOTSUP;
2549 }
2550
2551 int bdrv_snapshot_load_tmp(BlockDriverState *bs,
2552 const char *snapshot_name)
2553 {
2554 BlockDriver *drv = bs->drv;
2555 if (!drv) {
2556 return -ENOMEDIUM;
2557 }
2558 if (!bs->read_only) {
2559 return -EINVAL;
2560 }
2561 if (drv->bdrv_snapshot_load_tmp) {
2562 return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
2563 }
2564 return -ENOTSUP;
2565 }
2566
2567 #define NB_SUFFIXES 4
2568
2569 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
2570 {
2571 static const char suffixes[NB_SUFFIXES] = "KMGT";
2572 int64_t base;
2573 int i;
2574
2575 if (size <= 999) {
2576 snprintf(buf, buf_size, "%" PRId64, size);
2577 } else {
2578 base = 1024;
2579 for(i = 0; i < NB_SUFFIXES; i++) {
2580 if (size < (10 * base)) {
2581 snprintf(buf, buf_size, "%0.1f%c",
2582 (double)size / base,
2583 suffixes[i]);
2584 break;
2585 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
2586 snprintf(buf, buf_size, "%" PRId64 "%c",
2587 ((size + (base >> 1)) / base),
2588 suffixes[i]);
2589 break;
2590 }
2591 base = base * 1024;
2592 }
2593 }
2594 return buf;
2595 }
2596
2597 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
2598 {
2599 char buf1[128], date_buf[128], clock_buf[128];
2600 #ifdef _WIN32
2601 struct tm *ptm;
2602 #else
2603 struct tm tm;
2604 #endif
2605 time_t ti;
2606 int64_t secs;
2607
2608 if (!sn) {
2609 snprintf(buf, buf_size,
2610 "%-10s%-20s%7s%20s%15s",
2611 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
2612 } else {
2613 ti = sn->date_sec;
2614 #ifdef _WIN32
2615 ptm = localtime(&ti);
2616 strftime(date_buf, sizeof(date_buf),
2617 "%Y-%m-%d %H:%M:%S", ptm);
2618 #else
2619 localtime_r(&ti, &tm);
2620 strftime(date_buf, sizeof(date_buf),
2621 "%Y-%m-%d %H:%M:%S", &tm);
2622 #endif
2623 secs = sn->vm_clock_nsec / 1000000000;
2624 snprintf(clock_buf, sizeof(clock_buf),
2625 "%02d:%02d:%02d.%03d",
2626 (int)(secs / 3600),
2627 (int)((secs / 60) % 60),
2628 (int)(secs % 60),
2629 (int)((sn->vm_clock_nsec / 1000000) % 1000));
2630 snprintf(buf, buf_size,
2631 "%-10s%-20s%7s%20s%15s",
2632 sn->id_str, sn->name,
2633 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
2634 date_buf,
2635 clock_buf);
2636 }
2637 return buf;
2638 }
2639
2640 /**************************************************************/
2641 /* async I/Os */
2642
2643 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
2644 QEMUIOVector *qiov, int nb_sectors,
2645 BlockDriverCompletionFunc *cb, void *opaque)
2646 {
2647 trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
2648
2649 return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
2650 cb, opaque, false);
2651 }
2652
2653 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
2654 QEMUIOVector *qiov, int nb_sectors,
2655 BlockDriverCompletionFunc *cb, void *opaque)
2656 {
2657 trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
2658
2659 return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
2660 cb, opaque, true);
2661 }
2662
2663
2664 typedef struct MultiwriteCB {
2665 int error;
2666 int num_requests;
2667 int num_callbacks;
2668 struct {
2669 BlockDriverCompletionFunc *cb;
2670 void *opaque;
2671 QEMUIOVector *free_qiov;
2672 void *free_buf;
2673 } callbacks[];
2674 } MultiwriteCB;
2675
2676 static void multiwrite_user_cb(MultiwriteCB *mcb)
2677 {
2678 int i;
2679
2680 for (i = 0; i < mcb->num_callbacks; i++) {
2681 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
2682 if (mcb->callbacks[i].free_qiov) {
2683 qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
2684 }
2685 g_free(mcb->callbacks[i].free_qiov);
2686 qemu_vfree(mcb->callbacks[i].free_buf);
2687 }
2688 }
2689
2690 static void multiwrite_cb(void *opaque, int ret)
2691 {
2692 MultiwriteCB *mcb = opaque;
2693
2694 trace_multiwrite_cb(mcb, ret);
2695
2696 if (ret < 0 && !mcb->error) {
2697 mcb->error = ret;
2698 }
2699
2700 mcb->num_requests--;
2701 if (mcb->num_requests == 0) {
2702 multiwrite_user_cb(mcb);
2703 g_free(mcb);
2704 }
2705 }
2706
2707 static int multiwrite_req_compare(const void *a, const void *b)
2708 {
2709 const BlockRequest *req1 = a, *req2 = b;
2710
2711 /*
2712 * Note that we can't simply subtract req2->sector from req1->sector
2713 * here as that could overflow the return value.
2714 */
2715 if (req1->sector > req2->sector) {
2716 return 1;
2717 } else if (req1->sector < req2->sector) {
2718 return -1;
2719 } else {
2720 return 0;
2721 }
2722 }
2723
2724 /*
2725 * Takes a bunch of requests and tries to merge them. Returns the number of
2726 * requests that remain after merging.
2727 */
2728 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
2729 int num_reqs, MultiwriteCB *mcb)
2730 {
2731 int i, outidx;
2732
2733 // Sort requests by start sector
2734 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
2735
2736 // Check if adjacent requests touch the same clusters. If so, combine them,
2737 // filling up gaps with zero sectors.
2738 outidx = 0;
2739 for (i = 1; i < num_reqs; i++) {
2740 int merge = 0;
2741 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
2742
2743 // This handles the cases that are valid for all block drivers, namely
2744 // exactly sequential writes and overlapping writes.
2745 if (reqs[i].sector <= oldreq_last) {
2746 merge = 1;
2747 }
2748
2749 // The block driver may decide that it makes sense to combine requests
2750 // even if there is a gap of some sectors between them. In this case,
2751 // the gap is filled with zeros (therefore only applicable for yet
2752 // unused space in format like qcow2).
2753 if (!merge && bs->drv->bdrv_merge_requests) {
2754 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
2755 }
2756
2757 if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
2758 merge = 0;
2759 }
2760
2761 if (merge) {
2762 size_t size;
2763 QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
2764 qemu_iovec_init(qiov,
2765 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
2766
2767 // Add the first request to the merged one. If the requests are
2768 // overlapping, drop the last sectors of the first request.
2769 size = (reqs[i].sector - reqs[outidx].sector) << 9;
2770 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
2771
2772 // We might need to add some zeros between the two requests
2773 if (reqs[i].sector > oldreq_last) {
2774 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
2775 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
2776 memset(buf, 0, zero_bytes);
2777 qemu_iovec_add(qiov, buf, zero_bytes);
2778 mcb->callbacks[i].free_buf = buf;
2779 }
2780
2781 // Add the second request
2782 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
2783
2784 reqs[outidx].nb_sectors = qiov->size >> 9;
2785 reqs[outidx].qiov = qiov;
2786
2787 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
2788 } else {
2789 outidx++;
2790 reqs[outidx].sector = reqs[i].sector;
2791 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
2792 reqs[outidx].qiov = reqs[i].qiov;
2793 }
2794 }
2795
2796 return outidx + 1;
2797 }
2798
2799 /*
2800 * Submit multiple AIO write requests at once.
2801 *
2802 * On success, the function returns 0 and all requests in the reqs array have
2803 * been submitted. In error case this function returns -1, and any of the
2804 * requests may or may not be submitted yet. In particular, this means that the
2805 * callback will be called for some of the requests, for others it won't. The
2806 * caller must check the error field of the BlockRequest to wait for the right
2807 * callbacks (if error != 0, no callback will be called).
2808 *
2809 * The implementation may modify the contents of the reqs array, e.g. to merge
2810 * requests. However, the fields opaque and error are left unmodified as they
2811 * are used to signal failure for a single request to the caller.
2812 */
2813 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
2814 {
2815 MultiwriteCB *mcb;
2816 int i;
2817
2818 /* don't submit writes if we don't have a medium */
2819 if (bs->drv == NULL) {
2820 for (i = 0; i < num_reqs; i++) {
2821 reqs[i].error = -ENOMEDIUM;
2822 }
2823 return -1;
2824 }
2825
2826 if (num_reqs == 0) {
2827 return 0;
2828 }
2829
2830 // Create MultiwriteCB structure
2831 mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
2832 mcb->num_requests = 0;
2833 mcb->num_callbacks = num_reqs;
2834
2835 for (i = 0; i < num_reqs; i++) {
2836 mcb->callbacks[i].cb = reqs[i].cb;
2837 mcb->callbacks[i].opaque = reqs[i].opaque;
2838 }
2839
2840 // Check for mergable requests
2841 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
2842
2843 trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
2844
2845 /* Run the aio requests. */
2846 mcb->num_requests = num_reqs;
2847 for (i = 0; i < num_reqs; i++) {
2848 bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
2849 reqs[i].nb_sectors, multiwrite_cb, mcb);
2850 }
2851
2852 return 0;
2853 }
2854
2855 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
2856 {
2857 acb->pool->cancel(acb);
2858 }
2859
2860 /* block I/O throttling */
2861 static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
2862 bool is_write, double elapsed_time, uint64_t *wait)
2863 {
2864 uint64_t bps_limit = 0;
2865 double bytes_limit, bytes_base, bytes_res;
2866 double slice_time, wait_time;
2867
2868 if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) {
2869 bps_limit = bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];
2870 } else if (bs->io_limits.bps[is_write]) {
2871 bps_limit = bs->io_limits.bps[is_write];
2872 } else {
2873 if (wait) {
2874 *wait = 0;
2875 }
2876
2877 return false;
2878 }
2879
2880 slice_time = bs->slice_end - bs->slice_start;
2881 slice_time /= (NANOSECONDS_PER_SECOND);
2882 bytes_limit = bps_limit * slice_time;
2883 bytes_base = bs->nr_bytes[is_write] - bs->io_base.bytes[is_write];
2884 if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) {
2885 bytes_base += bs->nr_bytes[!is_write] - bs->io_base.bytes[!is_write];
2886 }
2887
2888 /* bytes_base: the bytes of data which have been read/written; and
2889 * it is obtained from the history statistic info.
2890 * bytes_res: the remaining bytes of data which need to be read/written.
2891 * (bytes_base + bytes_res) / bps_limit: used to calcuate
2892 * the total time for completing reading/writting all data.
2893 */
2894 bytes_res = (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2895
2896 if (bytes_base + bytes_res <= bytes_limit) {
2897 if (wait) {
2898 *wait = 0;
2899 }
2900
2901 return false;
2902 }
2903
2904 /* Calc approx time to dispatch */
2905 wait_time = (bytes_base + bytes_res) / bps_limit - elapsed_time;
2906
2907 /* When the I/O rate at runtime exceeds the limits,
2908 * bs->slice_end need to be extended in order that the current statistic
2909 * info can be kept until the timer fire, so it is increased and tuned
2910 * based on the result of experiment.
2911 */
2912 bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
2913 bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
2914 if (wait) {
2915 *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
2916 }
2917
2918 return true;
2919 }
2920
2921 static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
2922 double elapsed_time, uint64_t *wait)
2923 {
2924 uint64_t iops_limit = 0;
2925 double ios_limit, ios_base;
2926 double slice_time, wait_time;
2927
2928 if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
2929 iops_limit = bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL];
2930 } else if (bs->io_limits.iops[is_write]) {
2931 iops_limit = bs->io_limits.iops[is_write];
2932 } else {
2933 if (wait) {
2934 *wait = 0;
2935 }
2936
2937 return false;
2938 }
2939
2940 slice_time = bs->slice_end - bs->slice_start;
2941 slice_time /= (NANOSECONDS_PER_SECOND);
2942 ios_limit = iops_limit * slice_time;
2943 ios_base = bs->nr_ops[is_write] - bs->io_base.ios[is_write];
2944 if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
2945 ios_base += bs->nr_ops[!is_write] - bs->io_base.ios[!is_write];
2946 }
2947
2948 if (ios_base + 1 <= ios_limit) {
2949 if (wait) {
2950 *wait = 0;
2951 }
2952
2953 return false;
2954 }
2955
2956 /* Calc approx time to dispatch */
2957 wait_time = (ios_base + 1) / iops_limit;
2958 if (wait_time > elapsed_time) {
2959 wait_time = wait_time - elapsed_time;
2960 } else {
2961 wait_time = 0;
2962 }
2963
2964 bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
2965 bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
2966 if (wait) {
2967 *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
2968 }
2969
2970 return true;
2971 }
2972
2973 static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
2974 bool is_write, int64_t *wait)
2975 {
2976 int64_t now, max_wait;
2977 uint64_t bps_wait = 0, iops_wait = 0;
2978 double elapsed_time;
2979 int bps_ret, iops_ret;
2980
2981 now = qemu_get_clock_ns(vm_clock);
2982 if ((bs->slice_start < now)
2983 && (bs->slice_end > now)) {
2984 bs->slice_end = now + bs->slice_time;
2985 } else {
2986 bs->slice_time = 5 * BLOCK_IO_SLICE_TIME;
2987 bs->slice_start = now;
2988 bs->slice_end = now + bs->slice_time;
2989
2990 bs->io_base.bytes[is_write] = bs->nr_bytes[is_write];
2991 bs->io_base.bytes[!is_write] = bs->nr_bytes[!is_write];
2992
2993 bs->io_base.ios[is_write] = bs->nr_ops[is_write];
2994 bs->io_base.ios[!is_write] = bs->nr_ops[!is_write];
2995 }
2996
2997 elapsed_time = now - bs->slice_start;
2998 elapsed_time /= (NANOSECONDS_PER_SECOND);
2999
3000 bps_ret = bdrv_exceed_bps_limits(bs, nb_sectors,
3001 is_write, elapsed_time, &bps_wait);
3002 iops_ret = bdrv_exceed_iops_limits(bs, is_write,
3003 elapsed_time, &iops_wait);
3004 if (bps_ret || iops_ret) {
3005 max_wait = bps_wait > iops_wait ? bps_wait : iops_wait;
3006 if (wait) {
3007 *wait = max_wait;
3008 }
3009
3010 now = qemu_get_clock_ns(vm_clock);
3011 if (bs->slice_end < now + max_wait) {
3012 bs->slice_end = now + max_wait;
3013 }
3014
3015 return true;
3016 }
3017
3018 if (wait) {
3019 *wait = 0;
3020 }
3021
3022 return false;
3023 }
3024
3025 /**************************************************************/
3026 /* async block device emulation */
3027
3028 typedef struct BlockDriverAIOCBSync {
3029 BlockDriverAIOCB common;
3030 QEMUBH *bh;
3031 int ret;
3032 /* vector translation state */
3033 QEMUIOVector *qiov;
3034 uint8_t *bounce;
3035 int is_write;
3036 } BlockDriverAIOCBSync;
3037
3038 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
3039 {
3040 BlockDriverAIOCBSync *acb =
3041 container_of(blockacb, BlockDriverAIOCBSync, common);
3042 qemu_bh_delete(acb->bh);
3043 acb->bh = NULL;
3044 qemu_aio_release(acb);
3045 }
3046
3047 static AIOPool bdrv_em_aio_pool = {
3048 .aiocb_size = sizeof(BlockDriverAIOCBSync),
3049 .cancel = bdrv_aio_cancel_em,
3050 };
3051
3052 static void bdrv_aio_bh_cb(void *opaque)
3053 {
3054 BlockDriverAIOCBSync *acb = opaque;
3055
3056 if (!acb->is_write)
3057 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
3058 qemu_vfree(acb->bounce);
3059 acb->common.cb(acb->common.opaque, acb->ret);
3060 qemu_bh_delete(acb->bh);
3061 acb->bh = NULL;
3062 qemu_aio_release(acb);
3063 }
3064
3065 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
3066 int64_t sector_num,
3067 QEMUIOVector *qiov,
3068 int nb_sectors,
3069 BlockDriverCompletionFunc *cb,
3070 void *opaque,
3071 int is_write)
3072
3073 {
3074 BlockDriverAIOCBSync *acb;
3075
3076 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
3077 acb->is_write = is_write;
3078 acb->qiov = qiov;
3079 acb->bounce = qemu_blockalign(bs, qiov->size);
3080 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
3081
3082 if (is_write) {
3083 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
3084 acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
3085 } else {
3086 acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
3087 }
3088
3089 qemu_bh_schedule(acb->bh);
3090
3091 return &acb->common;
3092 }
3093
3094 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
3095 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
3096 BlockDriverCompletionFunc *cb, void *opaque)
3097 {
3098 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
3099 }
3100
3101 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
3102 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
3103 BlockDriverCompletionFunc *cb, void *opaque)
3104 {
3105 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
3106 }
3107
3108
3109 typedef struct BlockDriverAIOCBCoroutine {
3110 BlockDriverAIOCB common;
3111 BlockRequest req;
3112 bool is_write;
3113 QEMUBH* bh;
3114 } BlockDriverAIOCBCoroutine;
3115
3116 static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb)
3117 {
3118 qemu_aio_flush();
3119 }
3120
3121 static AIOPool bdrv_em_co_aio_pool = {
3122 .aiocb_size = sizeof(BlockDriverAIOCBCoroutine),
3123 .cancel = bdrv_aio_co_cancel_em,
3124 };
3125
3126 static void bdrv_co_em_bh(void *opaque)
3127 {
3128 BlockDriverAIOCBCoroutine *acb = opaque;
3129
3130 acb->common.cb(acb->common.opaque, acb->req.error);
3131 qemu_bh_delete(acb->bh);
3132 qemu_aio_release(acb);
3133 }
3134
3135 /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
3136 static void coroutine_fn bdrv_co_do_rw(void *opaque)
3137 {
3138 BlockDriverAIOCBCoroutine *acb = opaque;
3139 BlockDriverState *bs = acb->common.bs;
3140
3141 if (!acb->is_write) {
3142 acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
3143 acb->req.nb_sectors, acb->req.qiov);
3144 } else {
3145 acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
3146 acb->req.nb_sectors, acb->req.qiov);
3147 }
3148
3149 acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
3150 qemu_bh_schedule(acb->bh);
3151 }
3152
3153 static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
3154 int64_t sector_num,
3155 QEMUIOVector *qiov,
3156 int nb_sectors,
3157 BlockDriverCompletionFunc *cb,
3158 void *opaque,
3159 bool is_write)
3160 {
3161 Coroutine *co;
3162 BlockDriverAIOCBCoroutine *acb;
3163
3164 acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque);
3165 acb->req.sector = sector_num;
3166 acb->req.nb_sectors = nb_sectors;
3167 acb->req.qiov = qiov;
3168 acb->is_write = is_write;
3169
3170 co = qemu_coroutine_create(bdrv_co_do_rw);
3171 qemu_coroutine_enter(co, acb);
3172
3173 return &acb->common;
3174 }
3175
3176 static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
3177 {
3178 BlockDriverAIOCBCoroutine *acb = opaque;
3179 BlockDriverState *bs = acb->common.bs;
3180
3181 acb->req.error = bdrv_co_flush(bs);
3182 acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
3183 qemu_bh_schedule(acb->bh);
3184 }
3185
3186 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
3187 BlockDriverCompletionFunc *cb, void *opaque)
3188 {
3189 trace_bdrv_aio_flush(bs, opaque);
3190
3191 Coroutine *co;
3192 BlockDriverAIOCBCoroutine *acb;
3193
3194 acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque);
3195 co = qemu_coroutine_create(bdrv_aio_flush_co_entry);
3196 qemu_coroutine_enter(co, acb);
3197
3198 return &acb->common;
3199 }
3200
3201 static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
3202 {
3203 BlockDriverAIOCBCoroutine *acb = opaque;
3204 BlockDriverState *bs = acb->common.bs;
3205
3206 acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
3207 acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
3208 qemu_bh_schedule(acb->bh);
3209 }
3210
3211 BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs,
3212 int64_t sector_num, int nb_sectors,
3213 BlockDriverCompletionFunc *cb, void *opaque)
3214 {
3215 Coroutine *co;
3216 BlockDriverAIOCBCoroutine *acb;
3217
3218 trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
3219
3220 acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque);
3221 acb->req.sector = sector_num;
3222 acb->req.nb_sectors = nb_sectors;
3223 co = qemu_coroutine_create(bdrv_aio_discard_co_entry);
3224 qemu_coroutine_enter(co, acb);
3225
3226 return &acb->common;
3227 }
3228
3229 void bdrv_init(void)
3230 {
3231 module_call_init(MODULE_INIT_BLOCK);
3232 }
3233
3234 void bdrv_init_with_whitelist(void)
3235 {
3236 use_bdrv_whitelist = 1;
3237 bdrv_init();
3238 }
3239
3240 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
3241 BlockDriverCompletionFunc *cb, void *opaque)
3242 {
3243 BlockDriverAIOCB *acb;
3244
3245 if (pool->free_aiocb) {
3246 acb = pool->free_aiocb;
3247 pool->free_aiocb = acb->next;
3248 } else {
3249 acb = g_malloc0(pool->aiocb_size);
3250 acb->pool = pool;
3251 }
3252 acb->bs = bs;
3253 acb->cb = cb;
3254 acb->opaque = opaque;
3255 return acb;
3256 }
3257
3258 void qemu_aio_release(void *p)
3259 {
3260 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
3261 AIOPool *pool = acb->pool;
3262 acb->next = pool->free_aiocb;
3263 pool->free_aiocb = acb;
3264 }
3265
3266 /**************************************************************/
3267 /* Coroutine block device emulation */
3268
3269 typedef struct CoroutineIOCompletion {
3270 Coroutine *coroutine;
3271 int ret;
3272 } CoroutineIOCompletion;
3273
3274 static void bdrv_co_io_em_complete(void *opaque, int ret)
3275 {
3276 CoroutineIOCompletion *co = opaque;
3277
3278 co->ret = ret;
3279 qemu_coroutine_enter(co->coroutine, NULL);
3280 }
3281
3282 static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num,
3283 int nb_sectors, QEMUIOVector *iov,
3284 bool is_write)
3285 {
3286 CoroutineIOCompletion co = {
3287 .coroutine = qemu_coroutine_self(),
3288 };
3289 BlockDriverAIOCB *acb;
3290
3291 if (is_write) {
3292 acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors,
3293 bdrv_co_io_em_complete, &co);
3294 } else {
3295 acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors,
3296 bdrv_co_io_em_complete, &co);
3297 }
3298
3299 trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb);
3300 if (!acb) {
3301 return -EIO;
3302 }
3303 qemu_coroutine_yield();
3304
3305 return co.ret;
3306 }
3307
3308 static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
3309 int64_t sector_num, int nb_sectors,
3310 QEMUIOVector *iov)
3311 {
3312 return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false);
3313 }
3314
3315 static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
3316 int64_t sector_num, int nb_sectors,
3317 QEMUIOVector *iov)
3318 {
3319 return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true);
3320 }
3321
3322 static void coroutine_fn bdrv_flush_co_entry(void *opaque)
3323 {
3324 RwCo *rwco = opaque;
3325
3326 rwco->ret = bdrv_co_flush(rwco->bs);
3327 }
3328
3329 int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
3330 {
3331 int ret;
3332
3333 if (!bs->drv) {
3334 return 0;
3335 }
3336
3337 /* Write back cached data to the OS even with cache=unsafe */
3338 if (bs->drv->bdrv_co_flush_to_os) {
3339 ret = bs->drv->bdrv_co_flush_to_os(bs);
3340 if (ret < 0) {
3341 return ret;
3342 }
3343 }
3344
3345 /* But don't actually force it to the disk with cache=unsafe */
3346 if (bs->open_flags & BDRV_O_NO_FLUSH) {
3347 return 0;
3348 }
3349
3350 if (bs->drv->bdrv_co_flush_to_disk) {
3351 return bs->drv->bdrv_co_flush_to_disk(bs);
3352 } else if (bs->drv->bdrv_aio_flush) {
3353 BlockDriverAIOCB *acb;
3354 CoroutineIOCompletion co = {
3355 .coroutine = qemu_coroutine_self(),
3356 };
3357
3358 acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co);
3359 if (acb == NULL) {
3360 return -EIO;
3361 } else {
3362 qemu_coroutine_yield();
3363 return co.ret;
3364 }
3365 } else {
3366 /*
3367 * Some block drivers always operate in either writethrough or unsafe
3368 * mode and don't support bdrv_flush therefore. Usually qemu doesn't
3369 * know how the server works (because the behaviour is hardcoded or
3370 * depends on server-side configuration), so we can't ensure that
3371 * everything is safe on disk. Returning an error doesn't work because
3372 * that would break guests even if the server operates in writethrough
3373 * mode.
3374 *
3375 * Let's hope the user knows what he's doing.
3376 */
3377 return 0;
3378 }
3379 }
3380
3381 void bdrv_invalidate_cache(BlockDriverState *bs)
3382 {
3383 if (bs->drv && bs->drv->bdrv_invalidate_cache) {
3384 bs->drv->bdrv_invalidate_cache(bs);
3385 }
3386 }
3387
3388 void bdrv_invalidate_cache_all(void)
3389 {
3390 BlockDriverState *bs;
3391
3392 QTAILQ_FOREACH(bs, &bdrv_states, list) {
3393 bdrv_invalidate_cache(bs);
3394 }
3395 }
3396
3397 int bdrv_flush(BlockDriverState *bs)
3398 {
3399 Coroutine *co;
3400 RwCo rwco = {
3401 .bs = bs,
3402 .ret = NOT_DONE,
3403 };
3404
3405 if (qemu_in_coroutine()) {
3406 /* Fast-path if already in coroutine context */
3407 bdrv_flush_co_entry(&rwco);
3408 } else {
3409 co = qemu_coroutine_create(bdrv_flush_co_entry);
3410 qemu_coroutine_enter(co, &rwco);
3411 while (rwco.ret == NOT_DONE) {
3412 qemu_aio_wait();
3413 }
3414 }
3415
3416 return rwco.ret;
3417 }
3418
3419 static void coroutine_fn bdrv_discard_co_entry(void *opaque)
3420 {
3421 RwCo *rwco = opaque;
3422
3423 rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
3424 }
3425
3426 int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
3427 int nb_sectors)
3428 {
3429 if (!bs->drv) {
3430 return -ENOMEDIUM;
3431 } else if (bdrv_check_request(bs, sector_num, nb_sectors)) {
3432 return -EIO;
3433 } else if (bs->read_only) {
3434 return -EROFS;
3435 } else if (bs->drv->bdrv_co_discard) {
3436 return bs->drv->bdrv_co_discard(bs, sector_num, nb_sectors);
3437 } else if (bs->drv->bdrv_aio_discard) {
3438 BlockDriverAIOCB *acb;
3439 CoroutineIOCompletion co = {
3440 .coroutine = qemu_coroutine_self(),
3441 };
3442
3443 acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
3444 bdrv_co_io_em_complete, &co);
3445 if (acb == NULL) {
3446 return -EIO;
3447 } else {
3448 qemu_coroutine_yield();
3449 return co.ret;
3450 }
3451 } else {
3452 return 0;
3453 }
3454 }
3455
3456 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
3457 {
3458 Coroutine *co;
3459 RwCo rwco = {
3460 .bs = bs,
3461 .sector_num = sector_num,
3462 .nb_sectors = nb_sectors,
3463 .ret = NOT_DONE,
3464 };
3465
3466 if (qemu_in_coroutine()) {
3467 /* Fast-path if already in coroutine context */
3468 bdrv_discard_co_entry(&rwco);
3469 } else {
3470 co = qemu_coroutine_create(bdrv_discard_co_entry);
3471 qemu_coroutine_enter(co, &rwco);
3472 while (rwco.ret == NOT_DONE) {
3473 qemu_aio_wait();
3474 }
3475 }
3476
3477 return rwco.ret;
3478 }
3479
3480 /**************************************************************/
3481 /* removable device support */
3482
3483 /**
3484 * Return TRUE if the media is present
3485 */
3486 int bdrv_is_inserted(BlockDriverState *bs)
3487 {
3488 BlockDriver *drv = bs->drv;
3489
3490 if (!drv)
3491 return 0;
3492 if (!drv->bdrv_is_inserted)
3493 return 1;
3494 return drv->bdrv_is_inserted(bs);
3495 }
3496
3497 /**
3498 * Return whether the media changed since the last call to this
3499 * function, or -ENOTSUP if we don't know. Most drivers don't know.
3500 */
3501 int bdrv_media_changed(BlockDriverState *bs)