timer: drop HPET and RTC
[qemu/mdroth.git] / block.c
blobeffa86fd533a7774fbd35bedd25751e52d18e51e
1 /*
2 * QEMU System Emulator block driver
4 * Copyright (c) 2003 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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.
24 #include "config-host.h"
25 #include "qemu-common.h"
26 #include "trace.h"
27 #include "monitor.h"
28 #include "block_int.h"
29 #include "module.h"
30 #include "qemu-objects.h"
32 #ifdef CONFIG_BSD
33 #include <sys/types.h>
34 #include <sys/stat.h>
35 #include <sys/ioctl.h>
36 #include <sys/queue.h>
37 #ifndef __DragonFly__
38 #include <sys/disk.h>
39 #endif
40 #endif
42 #ifdef _WIN32
43 #include <windows.h>
44 #endif
46 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
47 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
48 BlockDriverCompletionFunc *cb, void *opaque);
49 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
50 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
51 BlockDriverCompletionFunc *cb, void *opaque);
52 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
53 BlockDriverCompletionFunc *cb, void *opaque);
54 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
55 BlockDriverCompletionFunc *cb, void *opaque);
56 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
57 uint8_t *buf, int nb_sectors);
58 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
59 const uint8_t *buf, int nb_sectors);
61 static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
62 QTAILQ_HEAD_INITIALIZER(bdrv_states);
64 static QLIST_HEAD(, BlockDriver) bdrv_drivers =
65 QLIST_HEAD_INITIALIZER(bdrv_drivers);
67 /* The device to use for VM snapshots */
68 static BlockDriverState *bs_snapshots;
70 /* If non-zero, use only whitelisted block drivers */
71 static int use_bdrv_whitelist;
73 #ifdef _WIN32
74 static int is_windows_drive_prefix(const char *filename)
76 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
77 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
78 filename[1] == ':');
81 int is_windows_drive(const char *filename)
83 if (is_windows_drive_prefix(filename) &&
84 filename[2] == '\0')
85 return 1;
86 if (strstart(filename, "\\\\.\\", NULL) ||
87 strstart(filename, "//./", NULL))
88 return 1;
89 return 0;
91 #endif
93 /* check if the path starts with "<protocol>:" */
94 static int path_has_protocol(const char *path)
96 #ifdef _WIN32
97 if (is_windows_drive(path) ||
98 is_windows_drive_prefix(path)) {
99 return 0;
101 #endif
103 return strchr(path, ':') != NULL;
106 int path_is_absolute(const char *path)
108 const char *p;
109 #ifdef _WIN32
110 /* specific case for names like: "\\.\d:" */
111 if (*path == '/' || *path == '\\')
112 return 1;
113 #endif
114 p = strchr(path, ':');
115 if (p)
116 p++;
117 else
118 p = path;
119 #ifdef _WIN32
120 return (*p == '/' || *p == '\\');
121 #else
122 return (*p == '/');
123 #endif
126 /* if filename is absolute, just copy it to dest. Otherwise, build a
127 path to it by considering it is relative to base_path. URL are
128 supported. */
129 void path_combine(char *dest, int dest_size,
130 const char *base_path,
131 const char *filename)
133 const char *p, *p1;
134 int len;
136 if (dest_size <= 0)
137 return;
138 if (path_is_absolute(filename)) {
139 pstrcpy(dest, dest_size, filename);
140 } else {
141 p = strchr(base_path, ':');
142 if (p)
143 p++;
144 else
145 p = base_path;
146 p1 = strrchr(base_path, '/');
147 #ifdef _WIN32
149 const char *p2;
150 p2 = strrchr(base_path, '\\');
151 if (!p1 || p2 > p1)
152 p1 = p2;
154 #endif
155 if (p1)
156 p1++;
157 else
158 p1 = base_path;
159 if (p1 > p)
160 p = p1;
161 len = p - base_path;
162 if (len > dest_size - 1)
163 len = dest_size - 1;
164 memcpy(dest, base_path, len);
165 dest[len] = '\0';
166 pstrcat(dest, dest_size, filename);
170 void bdrv_register(BlockDriver *bdrv)
172 if (!bdrv->bdrv_aio_readv) {
173 /* add AIO emulation layer */
174 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
175 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
176 } else if (!bdrv->bdrv_read) {
177 /* add synchronous IO emulation layer */
178 bdrv->bdrv_read = bdrv_read_em;
179 bdrv->bdrv_write = bdrv_write_em;
182 if (!bdrv->bdrv_aio_flush)
183 bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
185 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
188 /* create a new block device (by default it is empty) */
189 BlockDriverState *bdrv_new(const char *device_name)
191 BlockDriverState *bs;
193 bs = qemu_mallocz(sizeof(BlockDriverState));
194 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
195 if (device_name[0] != '\0') {
196 QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
198 return bs;
201 BlockDriver *bdrv_find_format(const char *format_name)
203 BlockDriver *drv1;
204 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
205 if (!strcmp(drv1->format_name, format_name)) {
206 return drv1;
209 return NULL;
212 static int bdrv_is_whitelisted(BlockDriver *drv)
214 static const char *whitelist[] = {
215 CONFIG_BDRV_WHITELIST
217 const char **p;
219 if (!whitelist[0])
220 return 1; /* no whitelist, anything goes */
222 for (p = whitelist; *p; p++) {
223 if (!strcmp(drv->format_name, *p)) {
224 return 1;
227 return 0;
230 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
232 BlockDriver *drv = bdrv_find_format(format_name);
233 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
236 int bdrv_create(BlockDriver *drv, const char* filename,
237 QEMUOptionParameter *options)
239 if (!drv->bdrv_create)
240 return -ENOTSUP;
242 return drv->bdrv_create(filename, options);
245 int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
247 BlockDriver *drv;
249 drv = bdrv_find_protocol(filename);
250 if (drv == NULL) {
251 return -ENOENT;
254 return bdrv_create(drv, filename, options);
257 #ifdef _WIN32
258 void get_tmp_filename(char *filename, int size)
260 char temp_dir[MAX_PATH];
262 GetTempPath(MAX_PATH, temp_dir);
263 GetTempFileName(temp_dir, "qem", 0, filename);
265 #else
266 void get_tmp_filename(char *filename, int size)
268 int fd;
269 const char *tmpdir;
270 /* XXX: race condition possible */
271 tmpdir = getenv("TMPDIR");
272 if (!tmpdir)
273 tmpdir = "/tmp";
274 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
275 fd = mkstemp(filename);
276 close(fd);
278 #endif
281 * Detect host devices. By convention, /dev/cdrom[N] is always
282 * recognized as a host CDROM.
284 static BlockDriver *find_hdev_driver(const char *filename)
286 int score_max = 0, score;
287 BlockDriver *drv = NULL, *d;
289 QLIST_FOREACH(d, &bdrv_drivers, list) {
290 if (d->bdrv_probe_device) {
291 score = d->bdrv_probe_device(filename);
292 if (score > score_max) {
293 score_max = score;
294 drv = d;
299 return drv;
302 BlockDriver *bdrv_find_protocol(const char *filename)
304 BlockDriver *drv1;
305 char protocol[128];
306 int len;
307 const char *p;
309 /* TODO Drivers without bdrv_file_open must be specified explicitly */
312 * XXX(hch): we really should not let host device detection
313 * override an explicit protocol specification, but moving this
314 * later breaks access to device names with colons in them.
315 * Thanks to the brain-dead persistent naming schemes on udev-
316 * based Linux systems those actually are quite common.
318 drv1 = find_hdev_driver(filename);
319 if (drv1) {
320 return drv1;
323 if (!path_has_protocol(filename)) {
324 return bdrv_find_format("file");
326 p = strchr(filename, ':');
327 assert(p != NULL);
328 len = p - filename;
329 if (len > sizeof(protocol) - 1)
330 len = sizeof(protocol) - 1;
331 memcpy(protocol, filename, len);
332 protocol[len] = '\0';
333 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
334 if (drv1->protocol_name &&
335 !strcmp(drv1->protocol_name, protocol)) {
336 return drv1;
339 return NULL;
342 static int find_image_format(const char *filename, BlockDriver **pdrv)
344 int ret, score, score_max;
345 BlockDriver *drv1, *drv;
346 uint8_t buf[2048];
347 BlockDriverState *bs;
349 ret = bdrv_file_open(&bs, filename, 0);
350 if (ret < 0) {
351 *pdrv = NULL;
352 return ret;
355 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
356 if (bs->sg || !bdrv_is_inserted(bs)) {
357 bdrv_delete(bs);
358 drv = bdrv_find_format("raw");
359 if (!drv) {
360 ret = -ENOENT;
362 *pdrv = drv;
363 return ret;
366 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
367 bdrv_delete(bs);
368 if (ret < 0) {
369 *pdrv = NULL;
370 return ret;
373 score_max = 0;
374 drv = NULL;
375 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
376 if (drv1->bdrv_probe) {
377 score = drv1->bdrv_probe(buf, ret, filename);
378 if (score > score_max) {
379 score_max = score;
380 drv = drv1;
384 if (!drv) {
385 ret = -ENOENT;
387 *pdrv = drv;
388 return ret;
392 * Set the current 'total_sectors' value
394 static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
396 BlockDriver *drv = bs->drv;
398 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
399 if (bs->sg)
400 return 0;
402 /* query actual device if possible, otherwise just trust the hint */
403 if (drv->bdrv_getlength) {
404 int64_t length = drv->bdrv_getlength(bs);
405 if (length < 0) {
406 return length;
408 hint = length >> BDRV_SECTOR_BITS;
411 bs->total_sectors = hint;
412 return 0;
416 * Common part for opening disk images and files
418 static int bdrv_open_common(BlockDriverState *bs, const char *filename,
419 int flags, BlockDriver *drv)
421 int ret, open_flags;
423 assert(drv != NULL);
425 bs->file = NULL;
426 bs->total_sectors = 0;
427 bs->encrypted = 0;
428 bs->valid_key = 0;
429 bs->open_flags = flags;
430 /* buffer_alignment defaulted to 512, drivers can change this value */
431 bs->buffer_alignment = 512;
433 pstrcpy(bs->filename, sizeof(bs->filename), filename);
435 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
436 return -ENOTSUP;
439 bs->drv = drv;
440 bs->opaque = qemu_mallocz(drv->instance_size);
443 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
444 * write cache to the guest. We do need the fdatasync to flush
445 * out transactions for block allocations, and we maybe have a
446 * volatile write cache in our backing device to deal with.
448 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
449 bs->enable_write_cache = 1;
452 * Clear flags that are internal to the block layer before opening the
453 * image.
455 open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
458 * Snapshots should be writable.
460 if (bs->is_temporary) {
461 open_flags |= BDRV_O_RDWR;
464 /* Open the image, either directly or using a protocol */
465 if (drv->bdrv_file_open) {
466 ret = drv->bdrv_file_open(bs, filename, open_flags);
467 } else {
468 ret = bdrv_file_open(&bs->file, filename, open_flags);
469 if (ret >= 0) {
470 ret = drv->bdrv_open(bs, open_flags);
474 if (ret < 0) {
475 goto free_and_fail;
478 bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
480 ret = refresh_total_sectors(bs, bs->total_sectors);
481 if (ret < 0) {
482 goto free_and_fail;
485 #ifndef _WIN32
486 if (bs->is_temporary) {
487 unlink(filename);
489 #endif
490 return 0;
492 free_and_fail:
493 if (bs->file) {
494 bdrv_delete(bs->file);
495 bs->file = NULL;
497 qemu_free(bs->opaque);
498 bs->opaque = NULL;
499 bs->drv = NULL;
500 return ret;
504 * Opens a file using a protocol (file, host_device, nbd, ...)
506 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
508 BlockDriverState *bs;
509 BlockDriver *drv;
510 int ret;
512 drv = bdrv_find_protocol(filename);
513 if (!drv) {
514 return -ENOENT;
517 bs = bdrv_new("");
518 ret = bdrv_open_common(bs, filename, flags, drv);
519 if (ret < 0) {
520 bdrv_delete(bs);
521 return ret;
523 bs->growable = 1;
524 *pbs = bs;
525 return 0;
529 * Opens a disk image (raw, qcow2, vmdk, ...)
531 int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
532 BlockDriver *drv)
534 int ret;
536 if (flags & BDRV_O_SNAPSHOT) {
537 BlockDriverState *bs1;
538 int64_t total_size;
539 int is_protocol = 0;
540 BlockDriver *bdrv_qcow2;
541 QEMUOptionParameter *options;
542 char tmp_filename[PATH_MAX];
543 char backing_filename[PATH_MAX];
545 /* if snapshot, we create a temporary backing file and open it
546 instead of opening 'filename' directly */
548 /* if there is a backing file, use it */
549 bs1 = bdrv_new("");
550 ret = bdrv_open(bs1, filename, 0, drv);
551 if (ret < 0) {
552 bdrv_delete(bs1);
553 return ret;
555 total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
557 if (bs1->drv && bs1->drv->protocol_name)
558 is_protocol = 1;
560 bdrv_delete(bs1);
562 get_tmp_filename(tmp_filename, sizeof(tmp_filename));
564 /* Real path is meaningless for protocols */
565 if (is_protocol)
566 snprintf(backing_filename, sizeof(backing_filename),
567 "%s", filename);
568 else if (!realpath(filename, backing_filename))
569 return -errno;
571 bdrv_qcow2 = bdrv_find_format("qcow2");
572 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
574 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size);
575 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
576 if (drv) {
577 set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
578 drv->format_name);
581 ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
582 free_option_parameters(options);
583 if (ret < 0) {
584 return ret;
587 filename = tmp_filename;
588 drv = bdrv_qcow2;
589 bs->is_temporary = 1;
592 /* Find the right image format driver */
593 if (!drv) {
594 ret = find_image_format(filename, &drv);
597 if (!drv) {
598 goto unlink_and_fail;
601 /* Open the image */
602 ret = bdrv_open_common(bs, filename, flags, drv);
603 if (ret < 0) {
604 goto unlink_and_fail;
607 /* If there is a backing file, use it */
608 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
609 char backing_filename[PATH_MAX];
610 int back_flags;
611 BlockDriver *back_drv = NULL;
613 bs->backing_hd = bdrv_new("");
615 if (path_has_protocol(bs->backing_file)) {
616 pstrcpy(backing_filename, sizeof(backing_filename),
617 bs->backing_file);
618 } else {
619 path_combine(backing_filename, sizeof(backing_filename),
620 filename, bs->backing_file);
623 if (bs->backing_format[0] != '\0') {
624 back_drv = bdrv_find_format(bs->backing_format);
627 /* backing files always opened read-only */
628 back_flags =
629 flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
631 ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
632 if (ret < 0) {
633 bdrv_close(bs);
634 return ret;
636 if (bs->is_temporary) {
637 bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
638 } else {
639 /* base image inherits from "parent" */
640 bs->backing_hd->keep_read_only = bs->keep_read_only;
644 if (!bdrv_key_required(bs)) {
645 /* call the change callback */
646 bs->media_changed = 1;
647 if (bs->change_cb)
648 bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
651 return 0;
653 unlink_and_fail:
654 if (bs->is_temporary) {
655 unlink(filename);
657 return ret;
660 void bdrv_close(BlockDriverState *bs)
662 if (bs->drv) {
663 if (bs == bs_snapshots) {
664 bs_snapshots = NULL;
666 if (bs->backing_hd) {
667 bdrv_delete(bs->backing_hd);
668 bs->backing_hd = NULL;
670 bs->drv->bdrv_close(bs);
671 qemu_free(bs->opaque);
672 #ifdef _WIN32
673 if (bs->is_temporary) {
674 unlink(bs->filename);
676 #endif
677 bs->opaque = NULL;
678 bs->drv = NULL;
680 if (bs->file != NULL) {
681 bdrv_close(bs->file);
684 /* call the change callback */
685 bs->media_changed = 1;
686 if (bs->change_cb)
687 bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
691 void bdrv_close_all(void)
693 BlockDriverState *bs;
695 QTAILQ_FOREACH(bs, &bdrv_states, list) {
696 bdrv_close(bs);
700 /* make a BlockDriverState anonymous by removing from bdrv_state list.
701 Also, NULL terminate the device_name to prevent double remove */
702 void bdrv_make_anon(BlockDriverState *bs)
704 if (bs->device_name[0] != '\0') {
705 QTAILQ_REMOVE(&bdrv_states, bs, list);
707 bs->device_name[0] = '\0';
710 void bdrv_delete(BlockDriverState *bs)
712 assert(!bs->peer);
714 /* remove from list, if necessary */
715 bdrv_make_anon(bs);
717 bdrv_close(bs);
718 if (bs->file != NULL) {
719 bdrv_delete(bs->file);
722 assert(bs != bs_snapshots);
723 qemu_free(bs);
726 int bdrv_attach(BlockDriverState *bs, DeviceState *qdev)
728 if (bs->peer) {
729 return -EBUSY;
731 bs->peer = qdev;
732 return 0;
735 void bdrv_detach(BlockDriverState *bs, DeviceState *qdev)
737 assert(bs->peer == qdev);
738 bs->peer = NULL;
741 DeviceState *bdrv_get_attached(BlockDriverState *bs)
743 return bs->peer;
747 * Run consistency checks on an image
749 * Returns 0 if the check could be completed (it doesn't mean that the image is
750 * free of errors) or -errno when an internal error occurred. The results of the
751 * check are stored in res.
753 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
755 if (bs->drv->bdrv_check == NULL) {
756 return -ENOTSUP;
759 memset(res, 0, sizeof(*res));
760 return bs->drv->bdrv_check(bs, res);
763 #define COMMIT_BUF_SECTORS 2048
765 /* commit COW file into the raw image */
766 int bdrv_commit(BlockDriverState *bs)
768 BlockDriver *drv = bs->drv;
769 BlockDriver *backing_drv;
770 int64_t sector, total_sectors;
771 int n, ro, open_flags;
772 int ret = 0, rw_ret = 0;
773 uint8_t *buf;
774 char filename[1024];
775 BlockDriverState *bs_rw, *bs_ro;
777 if (!drv)
778 return -ENOMEDIUM;
780 if (!bs->backing_hd) {
781 return -ENOTSUP;
784 if (bs->backing_hd->keep_read_only) {
785 return -EACCES;
788 backing_drv = bs->backing_hd->drv;
789 ro = bs->backing_hd->read_only;
790 strncpy(filename, bs->backing_hd->filename, sizeof(filename));
791 open_flags = bs->backing_hd->open_flags;
793 if (ro) {
794 /* re-open as RW */
795 bdrv_delete(bs->backing_hd);
796 bs->backing_hd = NULL;
797 bs_rw = bdrv_new("");
798 rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
799 backing_drv);
800 if (rw_ret < 0) {
801 bdrv_delete(bs_rw);
802 /* try to re-open read-only */
803 bs_ro = bdrv_new("");
804 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
805 backing_drv);
806 if (ret < 0) {
807 bdrv_delete(bs_ro);
808 /* drive not functional anymore */
809 bs->drv = NULL;
810 return ret;
812 bs->backing_hd = bs_ro;
813 return rw_ret;
815 bs->backing_hd = bs_rw;
818 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
819 buf = qemu_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
821 for (sector = 0; sector < total_sectors; sector += n) {
822 if (drv->bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
824 if (bdrv_read(bs, sector, buf, n) != 0) {
825 ret = -EIO;
826 goto ro_cleanup;
829 if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
830 ret = -EIO;
831 goto ro_cleanup;
836 if (drv->bdrv_make_empty) {
837 ret = drv->bdrv_make_empty(bs);
838 bdrv_flush(bs);
842 * Make sure all data we wrote to the backing device is actually
843 * stable on disk.
845 if (bs->backing_hd)
846 bdrv_flush(bs->backing_hd);
848 ro_cleanup:
849 qemu_free(buf);
851 if (ro) {
852 /* re-open as RO */
853 bdrv_delete(bs->backing_hd);
854 bs->backing_hd = NULL;
855 bs_ro = bdrv_new("");
856 ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
857 backing_drv);
858 if (ret < 0) {
859 bdrv_delete(bs_ro);
860 /* drive not functional anymore */
861 bs->drv = NULL;
862 return ret;
864 bs->backing_hd = bs_ro;
865 bs->backing_hd->keep_read_only = 0;
868 return ret;
871 void bdrv_commit_all(void)
873 BlockDriverState *bs;
875 QTAILQ_FOREACH(bs, &bdrv_states, list) {
876 bdrv_commit(bs);
881 * Return values:
882 * 0 - success
883 * -EINVAL - backing format specified, but no file
884 * -ENOSPC - can't update the backing file because no space is left in the
885 * image file header
886 * -ENOTSUP - format driver doesn't support changing the backing file
888 int bdrv_change_backing_file(BlockDriverState *bs,
889 const char *backing_file, const char *backing_fmt)
891 BlockDriver *drv = bs->drv;
893 if (drv->bdrv_change_backing_file != NULL) {
894 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
895 } else {
896 return -ENOTSUP;
900 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
901 size_t size)
903 int64_t len;
905 if (!bdrv_is_inserted(bs))
906 return -ENOMEDIUM;
908 if (bs->growable)
909 return 0;
911 len = bdrv_getlength(bs);
913 if (offset < 0)
914 return -EIO;
916 if ((offset > len) || (len - offset < size))
917 return -EIO;
919 return 0;
922 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
923 int nb_sectors)
925 return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
926 nb_sectors * BDRV_SECTOR_SIZE);
929 /* return < 0 if error. See bdrv_write() for the return codes */
930 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
931 uint8_t *buf, int nb_sectors)
933 BlockDriver *drv = bs->drv;
935 if (!drv)
936 return -ENOMEDIUM;
937 if (bdrv_check_request(bs, sector_num, nb_sectors))
938 return -EIO;
940 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
943 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
944 int nb_sectors, int dirty)
946 int64_t start, end;
947 unsigned long val, idx, bit;
949 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
950 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
952 for (; start <= end; start++) {
953 idx = start / (sizeof(unsigned long) * 8);
954 bit = start % (sizeof(unsigned long) * 8);
955 val = bs->dirty_bitmap[idx];
956 if (dirty) {
957 if (!(val & (1UL << bit))) {
958 bs->dirty_count++;
959 val |= 1UL << bit;
961 } else {
962 if (val & (1UL << bit)) {
963 bs->dirty_count--;
964 val &= ~(1UL << bit);
967 bs->dirty_bitmap[idx] = val;
971 /* Return < 0 if error. Important errors are:
972 -EIO generic I/O error (may happen for all errors)
973 -ENOMEDIUM No media inserted.
974 -EINVAL Invalid sector number or nb_sectors
975 -EACCES Trying to write a read-only device
977 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
978 const uint8_t *buf, int nb_sectors)
980 BlockDriver *drv = bs->drv;
981 if (!bs->drv)
982 return -ENOMEDIUM;
983 if (bs->read_only)
984 return -EACCES;
985 if (bdrv_check_request(bs, sector_num, nb_sectors))
986 return -EIO;
988 if (bs->dirty_bitmap) {
989 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
992 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
993 bs->wr_highest_sector = sector_num + nb_sectors - 1;
996 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
999 int bdrv_pread(BlockDriverState *bs, int64_t offset,
1000 void *buf, int count1)
1002 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1003 int len, nb_sectors, count;
1004 int64_t sector_num;
1005 int ret;
1007 count = count1;
1008 /* first read to align to sector start */
1009 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1010 if (len > count)
1011 len = count;
1012 sector_num = offset >> BDRV_SECTOR_BITS;
1013 if (len > 0) {
1014 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1015 return ret;
1016 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
1017 count -= len;
1018 if (count == 0)
1019 return count1;
1020 sector_num++;
1021 buf += len;
1024 /* read the sectors "in place" */
1025 nb_sectors = count >> BDRV_SECTOR_BITS;
1026 if (nb_sectors > 0) {
1027 if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
1028 return ret;
1029 sector_num += nb_sectors;
1030 len = nb_sectors << BDRV_SECTOR_BITS;
1031 buf += len;
1032 count -= len;
1035 /* add data from the last sector */
1036 if (count > 0) {
1037 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1038 return ret;
1039 memcpy(buf, tmp_buf, count);
1041 return count1;
1044 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
1045 const void *buf, int count1)
1047 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1048 int len, nb_sectors, count;
1049 int64_t sector_num;
1050 int ret;
1052 count = count1;
1053 /* first write to align to sector start */
1054 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1055 if (len > count)
1056 len = count;
1057 sector_num = offset >> BDRV_SECTOR_BITS;
1058 if (len > 0) {
1059 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1060 return ret;
1061 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1062 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1063 return ret;
1064 count -= len;
1065 if (count == 0)
1066 return count1;
1067 sector_num++;
1068 buf += len;
1071 /* write the sectors "in place" */
1072 nb_sectors = count >> BDRV_SECTOR_BITS;
1073 if (nb_sectors > 0) {
1074 if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
1075 return ret;
1076 sector_num += nb_sectors;
1077 len = nb_sectors << BDRV_SECTOR_BITS;
1078 buf += len;
1079 count -= len;
1082 /* add data from the last sector */
1083 if (count > 0) {
1084 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1085 return ret;
1086 memcpy(tmp_buf, buf, count);
1087 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1088 return ret;
1090 return count1;
1094 * Writes to the file and ensures that no writes are reordered across this
1095 * request (acts as a barrier)
1097 * Returns 0 on success, -errno in error cases.
1099 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
1100 const void *buf, int count)
1102 int ret;
1104 ret = bdrv_pwrite(bs, offset, buf, count);
1105 if (ret < 0) {
1106 return ret;
1109 /* No flush needed for cache=writethrough, it uses O_DSYNC */
1110 if ((bs->open_flags & BDRV_O_CACHE_MASK) != 0) {
1111 bdrv_flush(bs);
1114 return 0;
1118 * Writes to the file and ensures that no writes are reordered across this
1119 * request (acts as a barrier)
1121 * Returns 0 on success, -errno in error cases.
1123 int bdrv_write_sync(BlockDriverState *bs, int64_t sector_num,
1124 const uint8_t *buf, int nb_sectors)
1126 return bdrv_pwrite_sync(bs, BDRV_SECTOR_SIZE * sector_num,
1127 buf, BDRV_SECTOR_SIZE * nb_sectors);
1131 * Truncate file to 'offset' bytes (needed only for file protocols)
1133 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
1135 BlockDriver *drv = bs->drv;
1136 int ret;
1137 if (!drv)
1138 return -ENOMEDIUM;
1139 if (!drv->bdrv_truncate)
1140 return -ENOTSUP;
1141 if (bs->read_only)
1142 return -EACCES;
1143 if (bdrv_in_use(bs))
1144 return -EBUSY;
1145 ret = drv->bdrv_truncate(bs, offset);
1146 if (ret == 0) {
1147 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
1148 if (bs->change_cb) {
1149 bs->change_cb(bs->change_opaque, CHANGE_SIZE);
1152 return ret;
1156 * Length of a file in bytes. Return < 0 if error or unknown.
1158 int64_t bdrv_getlength(BlockDriverState *bs)
1160 BlockDriver *drv = bs->drv;
1161 if (!drv)
1162 return -ENOMEDIUM;
1164 if (bs->growable || bs->removable) {
1165 if (drv->bdrv_getlength) {
1166 return drv->bdrv_getlength(bs);
1169 return bs->total_sectors * BDRV_SECTOR_SIZE;
1172 /* return 0 as number of sectors if no device present or error */
1173 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
1175 int64_t length;
1176 length = bdrv_getlength(bs);
1177 if (length < 0)
1178 length = 0;
1179 else
1180 length = length >> BDRV_SECTOR_BITS;
1181 *nb_sectors_ptr = length;
1184 struct partition {
1185 uint8_t boot_ind; /* 0x80 - active */
1186 uint8_t head; /* starting head */
1187 uint8_t sector; /* starting sector */
1188 uint8_t cyl; /* starting cylinder */
1189 uint8_t sys_ind; /* What partition type */
1190 uint8_t end_head; /* end head */
1191 uint8_t end_sector; /* end sector */
1192 uint8_t end_cyl; /* end cylinder */
1193 uint32_t start_sect; /* starting sector counting from 0 */
1194 uint32_t nr_sects; /* nr of sectors in partition */
1195 } __attribute__((packed));
1197 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
1198 static int guess_disk_lchs(BlockDriverState *bs,
1199 int *pcylinders, int *pheads, int *psectors)
1201 uint8_t buf[BDRV_SECTOR_SIZE];
1202 int ret, i, heads, sectors, cylinders;
1203 struct partition *p;
1204 uint32_t nr_sects;
1205 uint64_t nb_sectors;
1207 bdrv_get_geometry(bs, &nb_sectors);
1209 ret = bdrv_read(bs, 0, buf, 1);
1210 if (ret < 0)
1211 return -1;
1212 /* test msdos magic */
1213 if (buf[510] != 0x55 || buf[511] != 0xaa)
1214 return -1;
1215 for(i = 0; i < 4; i++) {
1216 p = ((struct partition *)(buf + 0x1be)) + i;
1217 nr_sects = le32_to_cpu(p->nr_sects);
1218 if (nr_sects && p->end_head) {
1219 /* We make the assumption that the partition terminates on
1220 a cylinder boundary */
1221 heads = p->end_head + 1;
1222 sectors = p->end_sector & 63;
1223 if (sectors == 0)
1224 continue;
1225 cylinders = nb_sectors / (heads * sectors);
1226 if (cylinders < 1 || cylinders > 16383)
1227 continue;
1228 *pheads = heads;
1229 *psectors = sectors;
1230 *pcylinders = cylinders;
1231 #if 0
1232 printf("guessed geometry: LCHS=%d %d %d\n",
1233 cylinders, heads, sectors);
1234 #endif
1235 return 0;
1238 return -1;
1241 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
1243 int translation, lba_detected = 0;
1244 int cylinders, heads, secs;
1245 uint64_t nb_sectors;
1247 /* if a geometry hint is available, use it */
1248 bdrv_get_geometry(bs, &nb_sectors);
1249 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
1250 translation = bdrv_get_translation_hint(bs);
1251 if (cylinders != 0) {
1252 *pcyls = cylinders;
1253 *pheads = heads;
1254 *psecs = secs;
1255 } else {
1256 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
1257 if (heads > 16) {
1258 /* if heads > 16, it means that a BIOS LBA
1259 translation was active, so the default
1260 hardware geometry is OK */
1261 lba_detected = 1;
1262 goto default_geometry;
1263 } else {
1264 *pcyls = cylinders;
1265 *pheads = heads;
1266 *psecs = secs;
1267 /* disable any translation to be in sync with
1268 the logical geometry */
1269 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
1270 bdrv_set_translation_hint(bs,
1271 BIOS_ATA_TRANSLATION_NONE);
1274 } else {
1275 default_geometry:
1276 /* if no geometry, use a standard physical disk geometry */
1277 cylinders = nb_sectors / (16 * 63);
1279 if (cylinders > 16383)
1280 cylinders = 16383;
1281 else if (cylinders < 2)
1282 cylinders = 2;
1283 *pcyls = cylinders;
1284 *pheads = 16;
1285 *psecs = 63;
1286 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
1287 if ((*pcyls * *pheads) <= 131072) {
1288 bdrv_set_translation_hint(bs,
1289 BIOS_ATA_TRANSLATION_LARGE);
1290 } else {
1291 bdrv_set_translation_hint(bs,
1292 BIOS_ATA_TRANSLATION_LBA);
1296 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
1300 void bdrv_set_geometry_hint(BlockDriverState *bs,
1301 int cyls, int heads, int secs)
1303 bs->cyls = cyls;
1304 bs->heads = heads;
1305 bs->secs = secs;
1308 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
1310 bs->translation = translation;
1313 void bdrv_get_geometry_hint(BlockDriverState *bs,
1314 int *pcyls, int *pheads, int *psecs)
1316 *pcyls = bs->cyls;
1317 *pheads = bs->heads;
1318 *psecs = bs->secs;
1321 /* Recognize floppy formats */
1322 typedef struct FDFormat {
1323 FDriveType drive;
1324 uint8_t last_sect;
1325 uint8_t max_track;
1326 uint8_t max_head;
1327 } FDFormat;
1329 static const FDFormat fd_formats[] = {
1330 /* First entry is default format */
1331 /* 1.44 MB 3"1/2 floppy disks */
1332 { FDRIVE_DRV_144, 18, 80, 1, },
1333 { FDRIVE_DRV_144, 20, 80, 1, },
1334 { FDRIVE_DRV_144, 21, 80, 1, },
1335 { FDRIVE_DRV_144, 21, 82, 1, },
1336 { FDRIVE_DRV_144, 21, 83, 1, },
1337 { FDRIVE_DRV_144, 22, 80, 1, },
1338 { FDRIVE_DRV_144, 23, 80, 1, },
1339 { FDRIVE_DRV_144, 24, 80, 1, },
1340 /* 2.88 MB 3"1/2 floppy disks */
1341 { FDRIVE_DRV_288, 36, 80, 1, },
1342 { FDRIVE_DRV_288, 39, 80, 1, },
1343 { FDRIVE_DRV_288, 40, 80, 1, },
1344 { FDRIVE_DRV_288, 44, 80, 1, },
1345 { FDRIVE_DRV_288, 48, 80, 1, },
1346 /* 720 kB 3"1/2 floppy disks */
1347 { FDRIVE_DRV_144, 9, 80, 1, },
1348 { FDRIVE_DRV_144, 10, 80, 1, },
1349 { FDRIVE_DRV_144, 10, 82, 1, },
1350 { FDRIVE_DRV_144, 10, 83, 1, },
1351 { FDRIVE_DRV_144, 13, 80, 1, },
1352 { FDRIVE_DRV_144, 14, 80, 1, },
1353 /* 1.2 MB 5"1/4 floppy disks */
1354 { FDRIVE_DRV_120, 15, 80, 1, },
1355 { FDRIVE_DRV_120, 18, 80, 1, },
1356 { FDRIVE_DRV_120, 18, 82, 1, },
1357 { FDRIVE_DRV_120, 18, 83, 1, },
1358 { FDRIVE_DRV_120, 20, 80, 1, },
1359 /* 720 kB 5"1/4 floppy disks */
1360 { FDRIVE_DRV_120, 9, 80, 1, },
1361 { FDRIVE_DRV_120, 11, 80, 1, },
1362 /* 360 kB 5"1/4 floppy disks */
1363 { FDRIVE_DRV_120, 9, 40, 1, },
1364 { FDRIVE_DRV_120, 9, 40, 0, },
1365 { FDRIVE_DRV_120, 10, 41, 1, },
1366 { FDRIVE_DRV_120, 10, 42, 1, },
1367 /* 320 kB 5"1/4 floppy disks */
1368 { FDRIVE_DRV_120, 8, 40, 1, },
1369 { FDRIVE_DRV_120, 8, 40, 0, },
1370 /* 360 kB must match 5"1/4 better than 3"1/2... */
1371 { FDRIVE_DRV_144, 9, 80, 0, },
1372 /* end */
1373 { FDRIVE_DRV_NONE, -1, -1, 0, },
1376 void bdrv_get_floppy_geometry_hint(BlockDriverState *bs, int *nb_heads,
1377 int *max_track, int *last_sect,
1378 FDriveType drive_in, FDriveType *drive)
1380 const FDFormat *parse;
1381 uint64_t nb_sectors, size;
1382 int i, first_match, match;
1384 bdrv_get_geometry_hint(bs, nb_heads, max_track, last_sect);
1385 if (*nb_heads != 0 && *max_track != 0 && *last_sect != 0) {
1386 /* User defined disk */
1387 } else {
1388 bdrv_get_geometry(bs, &nb_sectors);
1389 match = -1;
1390 first_match = -1;
1391 for (i = 0; ; i++) {
1392 parse = &fd_formats[i];
1393 if (parse->drive == FDRIVE_DRV_NONE) {
1394 break;
1396 if (drive_in == parse->drive ||
1397 drive_in == FDRIVE_DRV_NONE) {
1398 size = (parse->max_head + 1) * parse->max_track *
1399 parse->last_sect;
1400 if (nb_sectors == size) {
1401 match = i;
1402 break;
1404 if (first_match == -1) {
1405 first_match = i;
1409 if (match == -1) {
1410 if (first_match == -1) {
1411 match = 1;
1412 } else {
1413 match = first_match;
1415 parse = &fd_formats[match];
1417 *nb_heads = parse->max_head + 1;
1418 *max_track = parse->max_track;
1419 *last_sect = parse->last_sect;
1420 *drive = parse->drive;
1424 int bdrv_get_translation_hint(BlockDriverState *bs)
1426 return bs->translation;
1429 void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
1430 BlockErrorAction on_write_error)
1432 bs->on_read_error = on_read_error;
1433 bs->on_write_error = on_write_error;
1436 BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
1438 return is_read ? bs->on_read_error : bs->on_write_error;
1441 void bdrv_set_removable(BlockDriverState *bs, int removable)
1443 bs->removable = removable;
1444 if (removable && bs == bs_snapshots) {
1445 bs_snapshots = NULL;
1449 int bdrv_is_removable(BlockDriverState *bs)
1451 return bs->removable;
1454 int bdrv_is_read_only(BlockDriverState *bs)
1456 return bs->read_only;
1459 int bdrv_is_sg(BlockDriverState *bs)
1461 return bs->sg;
1464 int bdrv_enable_write_cache(BlockDriverState *bs)
1466 return bs->enable_write_cache;
1469 /* XXX: no longer used */
1470 void bdrv_set_change_cb(BlockDriverState *bs,
1471 void (*change_cb)(void *opaque, int reason),
1472 void *opaque)
1474 bs->change_cb = change_cb;
1475 bs->change_opaque = opaque;
1478 int bdrv_is_encrypted(BlockDriverState *bs)
1480 if (bs->backing_hd && bs->backing_hd->encrypted)
1481 return 1;
1482 return bs->encrypted;
1485 int bdrv_key_required(BlockDriverState *bs)
1487 BlockDriverState *backing_hd = bs->backing_hd;
1489 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1490 return 1;
1491 return (bs->encrypted && !bs->valid_key);
1494 int bdrv_set_key(BlockDriverState *bs, const char *key)
1496 int ret;
1497 if (bs->backing_hd && bs->backing_hd->encrypted) {
1498 ret = bdrv_set_key(bs->backing_hd, key);
1499 if (ret < 0)
1500 return ret;
1501 if (!bs->encrypted)
1502 return 0;
1504 if (!bs->encrypted) {
1505 return -EINVAL;
1506 } else if (!bs->drv || !bs->drv->bdrv_set_key) {
1507 return -ENOMEDIUM;
1509 ret = bs->drv->bdrv_set_key(bs, key);
1510 if (ret < 0) {
1511 bs->valid_key = 0;
1512 } else if (!bs->valid_key) {
1513 bs->valid_key = 1;
1514 /* call the change callback now, we skipped it on open */
1515 bs->media_changed = 1;
1516 if (bs->change_cb)
1517 bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
1519 return ret;
1522 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1524 if (!bs->drv) {
1525 buf[0] = '\0';
1526 } else {
1527 pstrcpy(buf, buf_size, bs->drv->format_name);
1531 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1532 void *opaque)
1534 BlockDriver *drv;
1536 QLIST_FOREACH(drv, &bdrv_drivers, list) {
1537 it(opaque, drv->format_name);
1541 BlockDriverState *bdrv_find(const char *name)
1543 BlockDriverState *bs;
1545 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1546 if (!strcmp(name, bs->device_name)) {
1547 return bs;
1550 return NULL;
1553 BlockDriverState *bdrv_next(BlockDriverState *bs)
1555 if (!bs) {
1556 return QTAILQ_FIRST(&bdrv_states);
1558 return QTAILQ_NEXT(bs, list);
1561 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1563 BlockDriverState *bs;
1565 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1566 it(opaque, bs);
1570 const char *bdrv_get_device_name(BlockDriverState *bs)
1572 return bs->device_name;
1575 int bdrv_flush(BlockDriverState *bs)
1577 if (bs->open_flags & BDRV_O_NO_FLUSH) {
1578 return 0;
1581 if (bs->drv && bs->drv->bdrv_flush) {
1582 return bs->drv->bdrv_flush(bs);
1586 * Some block drivers always operate in either writethrough or unsafe mode
1587 * and don't support bdrv_flush therefore. Usually qemu doesn't know how
1588 * the server works (because the behaviour is hardcoded or depends on
1589 * server-side configuration), so we can't ensure that everything is safe
1590 * on disk. Returning an error doesn't work because that would break guests
1591 * even if the server operates in writethrough mode.
1593 * Let's hope the user knows what he's doing.
1595 return 0;
1598 void bdrv_flush_all(void)
1600 BlockDriverState *bs;
1602 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1603 if (bs->drv && !bdrv_is_read_only(bs) &&
1604 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) {
1605 bdrv_flush(bs);
1610 int bdrv_has_zero_init(BlockDriverState *bs)
1612 assert(bs->drv);
1614 if (bs->drv->bdrv_has_zero_init) {
1615 return bs->drv->bdrv_has_zero_init(bs);
1618 return 1;
1621 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
1623 if (!bs->drv) {
1624 return -ENOMEDIUM;
1626 if (!bs->drv->bdrv_discard) {
1627 return 0;
1629 return bs->drv->bdrv_discard(bs, sector_num, nb_sectors);
1633 * Returns true iff the specified sector is present in the disk image. Drivers
1634 * not implementing the functionality are assumed to not support backing files,
1635 * hence all their sectors are reported as allocated.
1637 * 'pnum' is set to the number of sectors (including and immediately following
1638 * the specified sector) that are known to be in the same
1639 * allocated/unallocated state.
1641 * 'nb_sectors' is the max value 'pnum' should be set to.
1643 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1644 int *pnum)
1646 int64_t n;
1647 if (!bs->drv->bdrv_is_allocated) {
1648 if (sector_num >= bs->total_sectors) {
1649 *pnum = 0;
1650 return 0;
1652 n = bs->total_sectors - sector_num;
1653 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1654 return 1;
1656 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1659 void bdrv_mon_event(const BlockDriverState *bdrv,
1660 BlockMonEventAction action, int is_read)
1662 QObject *data;
1663 const char *action_str;
1665 switch (action) {
1666 case BDRV_ACTION_REPORT:
1667 action_str = "report";
1668 break;
1669 case BDRV_ACTION_IGNORE:
1670 action_str = "ignore";
1671 break;
1672 case BDRV_ACTION_STOP:
1673 action_str = "stop";
1674 break;
1675 default:
1676 abort();
1679 data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
1680 bdrv->device_name,
1681 action_str,
1682 is_read ? "read" : "write");
1683 monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
1685 qobject_decref(data);
1688 static void bdrv_print_dict(QObject *obj, void *opaque)
1690 QDict *bs_dict;
1691 Monitor *mon = opaque;
1693 bs_dict = qobject_to_qdict(obj);
1695 monitor_printf(mon, "%s: removable=%d",
1696 qdict_get_str(bs_dict, "device"),
1697 qdict_get_bool(bs_dict, "removable"));
1699 if (qdict_get_bool(bs_dict, "removable")) {
1700 monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
1703 if (qdict_haskey(bs_dict, "inserted")) {
1704 QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
1706 monitor_printf(mon, " file=");
1707 monitor_print_filename(mon, qdict_get_str(qdict, "file"));
1708 if (qdict_haskey(qdict, "backing_file")) {
1709 monitor_printf(mon, " backing_file=");
1710 monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
1712 monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
1713 qdict_get_bool(qdict, "ro"),
1714 qdict_get_str(qdict, "drv"),
1715 qdict_get_bool(qdict, "encrypted"));
1716 } else {
1717 monitor_printf(mon, " [not inserted]");
1720 monitor_printf(mon, "\n");
1723 void bdrv_info_print(Monitor *mon, const QObject *data)
1725 qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
1728 void bdrv_info(Monitor *mon, QObject **ret_data)
1730 QList *bs_list;
1731 BlockDriverState *bs;
1733 bs_list = qlist_new();
1735 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1736 QObject *bs_obj;
1738 bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': 'unknown', "
1739 "'removable': %i, 'locked': %i }",
1740 bs->device_name, bs->removable,
1741 bs->locked);
1743 if (bs->drv) {
1744 QObject *obj;
1745 QDict *bs_dict = qobject_to_qdict(bs_obj);
1747 obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
1748 "'encrypted': %i }",
1749 bs->filename, bs->read_only,
1750 bs->drv->format_name,
1751 bdrv_is_encrypted(bs));
1752 if (bs->backing_file[0] != '\0') {
1753 QDict *qdict = qobject_to_qdict(obj);
1754 qdict_put(qdict, "backing_file",
1755 qstring_from_str(bs->backing_file));
1758 qdict_put_obj(bs_dict, "inserted", obj);
1760 qlist_append_obj(bs_list, bs_obj);
1763 *ret_data = QOBJECT(bs_list);
1766 static void bdrv_stats_iter(QObject *data, void *opaque)
1768 QDict *qdict;
1769 Monitor *mon = opaque;
1771 qdict = qobject_to_qdict(data);
1772 monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
1774 qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
1775 monitor_printf(mon, " rd_bytes=%" PRId64
1776 " wr_bytes=%" PRId64
1777 " rd_operations=%" PRId64
1778 " wr_operations=%" PRId64
1779 "\n",
1780 qdict_get_int(qdict, "rd_bytes"),
1781 qdict_get_int(qdict, "wr_bytes"),
1782 qdict_get_int(qdict, "rd_operations"),
1783 qdict_get_int(qdict, "wr_operations"));
1786 void bdrv_stats_print(Monitor *mon, const QObject *data)
1788 qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
1791 static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
1793 QObject *res;
1794 QDict *dict;
1796 res = qobject_from_jsonf("{ 'stats': {"
1797 "'rd_bytes': %" PRId64 ","
1798 "'wr_bytes': %" PRId64 ","
1799 "'rd_operations': %" PRId64 ","
1800 "'wr_operations': %" PRId64 ","
1801 "'wr_highest_offset': %" PRId64
1802 "} }",
1803 bs->rd_bytes, bs->wr_bytes,
1804 bs->rd_ops, bs->wr_ops,
1805 bs->wr_highest_sector *
1806 (uint64_t)BDRV_SECTOR_SIZE);
1807 dict = qobject_to_qdict(res);
1809 if (*bs->device_name) {
1810 qdict_put(dict, "device", qstring_from_str(bs->device_name));
1813 if (bs->file) {
1814 QObject *parent = bdrv_info_stats_bs(bs->file);
1815 qdict_put_obj(dict, "parent", parent);
1818 return res;
1821 void bdrv_info_stats(Monitor *mon, QObject **ret_data)
1823 QObject *obj;
1824 QList *devices;
1825 BlockDriverState *bs;
1827 devices = qlist_new();
1829 QTAILQ_FOREACH(bs, &bdrv_states, list) {
1830 obj = bdrv_info_stats_bs(bs);
1831 qlist_append_obj(devices, obj);
1834 *ret_data = QOBJECT(devices);
1837 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1839 if (bs->backing_hd && bs->backing_hd->encrypted)
1840 return bs->backing_file;
1841 else if (bs->encrypted)
1842 return bs->filename;
1843 else
1844 return NULL;
1847 void bdrv_get_backing_filename(BlockDriverState *bs,
1848 char *filename, int filename_size)
1850 if (!bs->backing_file) {
1851 pstrcpy(filename, filename_size, "");
1852 } else {
1853 pstrcpy(filename, filename_size, bs->backing_file);
1857 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1858 const uint8_t *buf, int nb_sectors)
1860 BlockDriver *drv = bs->drv;
1861 if (!drv)
1862 return -ENOMEDIUM;
1863 if (!drv->bdrv_write_compressed)
1864 return -ENOTSUP;
1865 if (bdrv_check_request(bs, sector_num, nb_sectors))
1866 return -EIO;
1868 if (bs->dirty_bitmap) {
1869 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1872 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1875 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1877 BlockDriver *drv = bs->drv;
1878 if (!drv)
1879 return -ENOMEDIUM;
1880 if (!drv->bdrv_get_info)
1881 return -ENOTSUP;
1882 memset(bdi, 0, sizeof(*bdi));
1883 return drv->bdrv_get_info(bs, bdi);
1886 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1887 int64_t pos, int size)
1889 BlockDriver *drv = bs->drv;
1890 if (!drv)
1891 return -ENOMEDIUM;
1892 if (drv->bdrv_save_vmstate)
1893 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1894 if (bs->file)
1895 return bdrv_save_vmstate(bs->file, buf, pos, size);
1896 return -ENOTSUP;
1899 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1900 int64_t pos, int size)
1902 BlockDriver *drv = bs->drv;
1903 if (!drv)
1904 return -ENOMEDIUM;
1905 if (drv->bdrv_load_vmstate)
1906 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1907 if (bs->file)
1908 return bdrv_load_vmstate(bs->file, buf, pos, size);
1909 return -ENOTSUP;
1912 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
1914 BlockDriver *drv = bs->drv;
1916 if (!drv || !drv->bdrv_debug_event) {
1917 return;
1920 return drv->bdrv_debug_event(bs, event);
1924 /**************************************************************/
1925 /* handling of snapshots */
1927 int bdrv_can_snapshot(BlockDriverState *bs)
1929 BlockDriver *drv = bs->drv;
1930 if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
1931 return 0;
1934 if (!drv->bdrv_snapshot_create) {
1935 if (bs->file != NULL) {
1936 return bdrv_can_snapshot(bs->file);
1938 return 0;
1941 return 1;
1944 int bdrv_is_snapshot(BlockDriverState *bs)
1946 return !!(bs->open_flags & BDRV_O_SNAPSHOT);
1949 BlockDriverState *bdrv_snapshots(void)
1951 BlockDriverState *bs;
1953 if (bs_snapshots) {
1954 return bs_snapshots;
1957 bs = NULL;
1958 while ((bs = bdrv_next(bs))) {
1959 if (bdrv_can_snapshot(bs)) {
1960 bs_snapshots = bs;
1961 return bs;
1964 return NULL;
1967 int bdrv_snapshot_create(BlockDriverState *bs,
1968 QEMUSnapshotInfo *sn_info)
1970 BlockDriver *drv = bs->drv;
1971 if (!drv)
1972 return -ENOMEDIUM;
1973 if (drv->bdrv_snapshot_create)
1974 return drv->bdrv_snapshot_create(bs, sn_info);
1975 if (bs->file)
1976 return bdrv_snapshot_create(bs->file, sn_info);
1977 return -ENOTSUP;
1980 int bdrv_snapshot_goto(BlockDriverState *bs,
1981 const char *snapshot_id)
1983 BlockDriver *drv = bs->drv;
1984 int ret, open_ret;
1986 if (!drv)
1987 return -ENOMEDIUM;
1988 if (drv->bdrv_snapshot_goto)
1989 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1991 if (bs->file) {
1992 drv->bdrv_close(bs);
1993 ret = bdrv_snapshot_goto(bs->file, snapshot_id);
1994 open_ret = drv->bdrv_open(bs, bs->open_flags);
1995 if (open_ret < 0) {
1996 bdrv_delete(bs->file);
1997 bs->drv = NULL;
1998 return open_ret;
2000 return ret;
2003 return -ENOTSUP;
2006 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
2008 BlockDriver *drv = bs->drv;
2009 if (!drv)
2010 return -ENOMEDIUM;
2011 if (drv->bdrv_snapshot_delete)
2012 return drv->bdrv_snapshot_delete(bs, snapshot_id);
2013 if (bs->file)
2014 return bdrv_snapshot_delete(bs->file, snapshot_id);
2015 return -ENOTSUP;
2018 int bdrv_snapshot_list(BlockDriverState *bs,
2019 QEMUSnapshotInfo **psn_info)
2021 BlockDriver *drv = bs->drv;
2022 if (!drv)
2023 return -ENOMEDIUM;
2024 if (drv->bdrv_snapshot_list)
2025 return drv->bdrv_snapshot_list(bs, psn_info);
2026 if (bs->file)
2027 return bdrv_snapshot_list(bs->file, psn_info);
2028 return -ENOTSUP;
2031 int bdrv_snapshot_load_tmp(BlockDriverState *bs,
2032 const char *snapshot_name)
2034 BlockDriver *drv = bs->drv;
2035 if (!drv) {
2036 return -ENOMEDIUM;
2038 if (!bs->read_only) {
2039 return -EINVAL;
2041 if (drv->bdrv_snapshot_load_tmp) {
2042 return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
2044 return -ENOTSUP;
2047 #define NB_SUFFIXES 4
2049 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
2051 static const char suffixes[NB_SUFFIXES] = "KMGT";
2052 int64_t base;
2053 int i;
2055 if (size <= 999) {
2056 snprintf(buf, buf_size, "%" PRId64, size);
2057 } else {
2058 base = 1024;
2059 for(i = 0; i < NB_SUFFIXES; i++) {
2060 if (size < (10 * base)) {
2061 snprintf(buf, buf_size, "%0.1f%c",
2062 (double)size / base,
2063 suffixes[i]);
2064 break;
2065 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
2066 snprintf(buf, buf_size, "%" PRId64 "%c",
2067 ((size + (base >> 1)) / base),
2068 suffixes[i]);
2069 break;
2071 base = base * 1024;
2074 return buf;
2077 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
2079 char buf1[128], date_buf[128], clock_buf[128];
2080 #ifdef _WIN32
2081 struct tm *ptm;
2082 #else
2083 struct tm tm;
2084 #endif
2085 time_t ti;
2086 int64_t secs;
2088 if (!sn) {
2089 snprintf(buf, buf_size,
2090 "%-10s%-20s%7s%20s%15s",
2091 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
2092 } else {
2093 ti = sn->date_sec;
2094 #ifdef _WIN32
2095 ptm = localtime(&ti);
2096 strftime(date_buf, sizeof(date_buf),
2097 "%Y-%m-%d %H:%M:%S", ptm);
2098 #else
2099 localtime_r(&ti, &tm);
2100 strftime(date_buf, sizeof(date_buf),
2101 "%Y-%m-%d %H:%M:%S", &tm);
2102 #endif
2103 secs = sn->vm_clock_nsec / 1000000000;
2104 snprintf(clock_buf, sizeof(clock_buf),
2105 "%02d:%02d:%02d.%03d",
2106 (int)(secs / 3600),
2107 (int)((secs / 60) % 60),
2108 (int)(secs % 60),
2109 (int)((sn->vm_clock_nsec / 1000000) % 1000));
2110 snprintf(buf, buf_size,
2111 "%-10s%-20s%7s%20s%15s",
2112 sn->id_str, sn->name,
2113 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
2114 date_buf,
2115 clock_buf);
2117 return buf;
2121 /**************************************************************/
2122 /* async I/Os */
2124 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
2125 QEMUIOVector *qiov, int nb_sectors,
2126 BlockDriverCompletionFunc *cb, void *opaque)
2128 BlockDriver *drv = bs->drv;
2129 BlockDriverAIOCB *ret;
2131 trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
2133 if (!drv)
2134 return NULL;
2135 if (bdrv_check_request(bs, sector_num, nb_sectors))
2136 return NULL;
2138 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
2139 cb, opaque);
2141 if (ret) {
2142 /* Update stats even though technically transfer has not happened. */
2143 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2144 bs->rd_ops ++;
2147 return ret;
2150 typedef struct BlockCompleteData {
2151 BlockDriverCompletionFunc *cb;
2152 void *opaque;
2153 BlockDriverState *bs;
2154 int64_t sector_num;
2155 int nb_sectors;
2156 } BlockCompleteData;
2158 static void block_complete_cb(void *opaque, int ret)
2160 BlockCompleteData *b = opaque;
2162 if (b->bs->dirty_bitmap) {
2163 set_dirty_bitmap(b->bs, b->sector_num, b->nb_sectors, 1);
2165 b->cb(b->opaque, ret);
2166 qemu_free(b);
2169 static BlockCompleteData *blk_dirty_cb_alloc(BlockDriverState *bs,
2170 int64_t sector_num,
2171 int nb_sectors,
2172 BlockDriverCompletionFunc *cb,
2173 void *opaque)
2175 BlockCompleteData *blkdata = qemu_mallocz(sizeof(BlockCompleteData));
2177 blkdata->bs = bs;
2178 blkdata->cb = cb;
2179 blkdata->opaque = opaque;
2180 blkdata->sector_num = sector_num;
2181 blkdata->nb_sectors = nb_sectors;
2183 return blkdata;
2186 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
2187 QEMUIOVector *qiov, int nb_sectors,
2188 BlockDriverCompletionFunc *cb, void *opaque)
2190 BlockDriver *drv = bs->drv;
2191 BlockDriverAIOCB *ret;
2192 BlockCompleteData *blk_cb_data;
2194 trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
2196 if (!drv)
2197 return NULL;
2198 if (bs->read_only)
2199 return NULL;
2200 if (bdrv_check_request(bs, sector_num, nb_sectors))
2201 return NULL;
2203 if (bs->dirty_bitmap) {
2204 blk_cb_data = blk_dirty_cb_alloc(bs, sector_num, nb_sectors, cb,
2205 opaque);
2206 cb = &block_complete_cb;
2207 opaque = blk_cb_data;
2210 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
2211 cb, opaque);
2213 if (ret) {
2214 /* Update stats even though technically transfer has not happened. */
2215 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2216 bs->wr_ops ++;
2217 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
2218 bs->wr_highest_sector = sector_num + nb_sectors - 1;
2222 return ret;
2226 typedef struct MultiwriteCB {
2227 int error;
2228 int num_requests;
2229 int num_callbacks;
2230 struct {
2231 BlockDriverCompletionFunc *cb;
2232 void *opaque;
2233 QEMUIOVector *free_qiov;
2234 void *free_buf;
2235 } callbacks[];
2236 } MultiwriteCB;
2238 static void multiwrite_user_cb(MultiwriteCB *mcb)
2240 int i;
2242 for (i = 0; i < mcb->num_callbacks; i++) {
2243 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
2244 if (mcb->callbacks[i].free_qiov) {
2245 qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
2247 qemu_free(mcb->callbacks[i].free_qiov);
2248 qemu_vfree(mcb->callbacks[i].free_buf);
2252 static void multiwrite_cb(void *opaque, int ret)
2254 MultiwriteCB *mcb = opaque;
2256 trace_multiwrite_cb(mcb, ret);
2258 if (ret < 0 && !mcb->error) {
2259 mcb->error = ret;
2262 mcb->num_requests--;
2263 if (mcb->num_requests == 0) {
2264 multiwrite_user_cb(mcb);
2265 qemu_free(mcb);
2269 static int multiwrite_req_compare(const void *a, const void *b)
2271 const BlockRequest *req1 = a, *req2 = b;
2274 * Note that we can't simply subtract req2->sector from req1->sector
2275 * here as that could overflow the return value.
2277 if (req1->sector > req2->sector) {
2278 return 1;
2279 } else if (req1->sector < req2->sector) {
2280 return -1;
2281 } else {
2282 return 0;
2287 * Takes a bunch of requests and tries to merge them. Returns the number of
2288 * requests that remain after merging.
2290 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
2291 int num_reqs, MultiwriteCB *mcb)
2293 int i, outidx;
2295 // Sort requests by start sector
2296 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
2298 // Check if adjacent requests touch the same clusters. If so, combine them,
2299 // filling up gaps with zero sectors.
2300 outidx = 0;
2301 for (i = 1; i < num_reqs; i++) {
2302 int merge = 0;
2303 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
2305 // This handles the cases that are valid for all block drivers, namely
2306 // exactly sequential writes and overlapping writes.
2307 if (reqs[i].sector <= oldreq_last) {
2308 merge = 1;
2311 // The block driver may decide that it makes sense to combine requests
2312 // even if there is a gap of some sectors between them. In this case,
2313 // the gap is filled with zeros (therefore only applicable for yet
2314 // unused space in format like qcow2).
2315 if (!merge && bs->drv->bdrv_merge_requests) {
2316 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
2319 if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
2320 merge = 0;
2323 if (merge) {
2324 size_t size;
2325 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
2326 qemu_iovec_init(qiov,
2327 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
2329 // Add the first request to the merged one. If the requests are
2330 // overlapping, drop the last sectors of the first request.
2331 size = (reqs[i].sector - reqs[outidx].sector) << 9;
2332 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
2334 // We might need to add some zeros between the two requests
2335 if (reqs[i].sector > oldreq_last) {
2336 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
2337 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
2338 memset(buf, 0, zero_bytes);
2339 qemu_iovec_add(qiov, buf, zero_bytes);
2340 mcb->callbacks[i].free_buf = buf;
2343 // Add the second request
2344 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
2346 reqs[outidx].nb_sectors = qiov->size >> 9;
2347 reqs[outidx].qiov = qiov;
2349 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
2350 } else {
2351 outidx++;
2352 reqs[outidx].sector = reqs[i].sector;
2353 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
2354 reqs[outidx].qiov = reqs[i].qiov;
2358 return outidx + 1;
2362 * Submit multiple AIO write requests at once.
2364 * On success, the function returns 0 and all requests in the reqs array have
2365 * been submitted. In error case this function returns -1, and any of the
2366 * requests may or may not be submitted yet. In particular, this means that the
2367 * callback will be called for some of the requests, for others it won't. The
2368 * caller must check the error field of the BlockRequest to wait for the right
2369 * callbacks (if error != 0, no callback will be called).
2371 * The implementation may modify the contents of the reqs array, e.g. to merge
2372 * requests. However, the fields opaque and error are left unmodified as they
2373 * are used to signal failure for a single request to the caller.
2375 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
2377 BlockDriverAIOCB *acb;
2378 MultiwriteCB *mcb;
2379 int i;
2381 /* don't submit writes if we don't have a medium */
2382 if (bs->drv == NULL) {
2383 for (i = 0; i < num_reqs; i++) {
2384 reqs[i].error = -ENOMEDIUM;
2386 return -1;
2389 if (num_reqs == 0) {
2390 return 0;
2393 // Create MultiwriteCB structure
2394 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
2395 mcb->num_requests = 0;
2396 mcb->num_callbacks = num_reqs;
2398 for (i = 0; i < num_reqs; i++) {
2399 mcb->callbacks[i].cb = reqs[i].cb;
2400 mcb->callbacks[i].opaque = reqs[i].opaque;
2403 // Check for mergable requests
2404 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
2406 trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
2409 * Run the aio requests. As soon as one request can't be submitted
2410 * successfully, fail all requests that are not yet submitted (we must
2411 * return failure for all requests anyway)
2413 * num_requests cannot be set to the right value immediately: If
2414 * bdrv_aio_writev fails for some request, num_requests would be too high
2415 * and therefore multiwrite_cb() would never recognize the multiwrite
2416 * request as completed. We also cannot use the loop variable i to set it
2417 * when the first request fails because the callback may already have been
2418 * called for previously submitted requests. Thus, num_requests must be
2419 * incremented for each request that is submitted.
2421 * The problem that callbacks may be called early also means that we need
2422 * to take care that num_requests doesn't become 0 before all requests are
2423 * submitted - multiwrite_cb() would consider the multiwrite request
2424 * completed. A dummy request that is "completed" by a manual call to
2425 * multiwrite_cb() takes care of this.
2427 mcb->num_requests = 1;
2429 // Run the aio requests
2430 for (i = 0; i < num_reqs; i++) {
2431 mcb->num_requests++;
2432 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
2433 reqs[i].nb_sectors, multiwrite_cb, mcb);
2435 if (acb == NULL) {
2436 // We can only fail the whole thing if no request has been
2437 // submitted yet. Otherwise we'll wait for the submitted AIOs to
2438 // complete and report the error in the callback.
2439 if (i == 0) {
2440 trace_bdrv_aio_multiwrite_earlyfail(mcb);
2441 goto fail;
2442 } else {
2443 trace_bdrv_aio_multiwrite_latefail(mcb, i);
2444 multiwrite_cb(mcb, -EIO);
2445 break;
2450 /* Complete the dummy request */
2451 multiwrite_cb(mcb, 0);
2453 return 0;
2455 fail:
2456 for (i = 0; i < mcb->num_callbacks; i++) {
2457 reqs[i].error = -EIO;
2459 qemu_free(mcb);
2460 return -1;
2463 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
2464 BlockDriverCompletionFunc *cb, void *opaque)
2466 BlockDriver *drv = bs->drv;
2468 trace_bdrv_aio_flush(bs, opaque);
2470 if (bs->open_flags & BDRV_O_NO_FLUSH) {
2471 return bdrv_aio_noop_em(bs, cb, opaque);
2474 if (!drv)
2475 return NULL;
2476 return drv->bdrv_aio_flush(bs, cb, opaque);
2479 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
2481 acb->pool->cancel(acb);
2485 /**************************************************************/
2486 /* async block device emulation */
2488 typedef struct BlockDriverAIOCBSync {
2489 BlockDriverAIOCB common;
2490 QEMUBH *bh;
2491 int ret;
2492 /* vector translation state */
2493 QEMUIOVector *qiov;
2494 uint8_t *bounce;
2495 int is_write;
2496 } BlockDriverAIOCBSync;
2498 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
2500 BlockDriverAIOCBSync *acb =
2501 container_of(blockacb, BlockDriverAIOCBSync, common);
2502 qemu_bh_delete(acb->bh);
2503 acb->bh = NULL;
2504 qemu_aio_release(acb);
2507 static AIOPool bdrv_em_aio_pool = {
2508 .aiocb_size = sizeof(BlockDriverAIOCBSync),
2509 .cancel = bdrv_aio_cancel_em,
2512 static void bdrv_aio_bh_cb(void *opaque)
2514 BlockDriverAIOCBSync *acb = opaque;
2516 if (!acb->is_write)
2517 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
2518 qemu_vfree(acb->bounce);
2519 acb->common.cb(acb->common.opaque, acb->ret);
2520 qemu_bh_delete(acb->bh);
2521 acb->bh = NULL;
2522 qemu_aio_release(acb);
2525 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
2526 int64_t sector_num,
2527 QEMUIOVector *qiov,
2528 int nb_sectors,
2529 BlockDriverCompletionFunc *cb,
2530 void *opaque,
2531 int is_write)
2534 BlockDriverAIOCBSync *acb;
2536 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2537 acb->is_write = is_write;
2538 acb->qiov = qiov;
2539 acb->bounce = qemu_blockalign(bs, qiov->size);
2541 if (!acb->bh)
2542 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2544 if (is_write) {
2545 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
2546 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
2547 } else {
2548 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
2551 qemu_bh_schedule(acb->bh);
2553 return &acb->common;
2556 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
2557 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2558 BlockDriverCompletionFunc *cb, void *opaque)
2560 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
2563 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
2564 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2565 BlockDriverCompletionFunc *cb, void *opaque)
2567 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
2570 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
2571 BlockDriverCompletionFunc *cb, void *opaque)
2573 BlockDriverAIOCBSync *acb;
2575 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2576 acb->is_write = 1; /* don't bounce in the completion hadler */
2577 acb->qiov = NULL;
2578 acb->bounce = NULL;
2579 acb->ret = 0;
2581 if (!acb->bh)
2582 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2584 bdrv_flush(bs);
2585 qemu_bh_schedule(acb->bh);
2586 return &acb->common;
2589 static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
2590 BlockDriverCompletionFunc *cb, void *opaque)
2592 BlockDriverAIOCBSync *acb;
2594 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2595 acb->is_write = 1; /* don't bounce in the completion handler */
2596 acb->qiov = NULL;
2597 acb->bounce = NULL;
2598 acb->ret = 0;
2600 if (!acb->bh) {
2601 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2604 qemu_bh_schedule(acb->bh);
2605 return &acb->common;
2608 /**************************************************************/
2609 /* sync block device emulation */
2611 static void bdrv_rw_em_cb(void *opaque, int ret)
2613 *(int *)opaque = ret;
2616 #define NOT_DONE 0x7fffffff
2618 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
2619 uint8_t *buf, int nb_sectors)
2621 int async_ret;
2622 BlockDriverAIOCB *acb;
2623 struct iovec iov;
2624 QEMUIOVector qiov;
2626 async_context_push();
2628 async_ret = NOT_DONE;
2629 iov.iov_base = (void *)buf;
2630 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2631 qemu_iovec_init_external(&qiov, &iov, 1);
2632 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
2633 bdrv_rw_em_cb, &async_ret);
2634 if (acb == NULL) {
2635 async_ret = -1;
2636 goto fail;
2639 while (async_ret == NOT_DONE) {
2640 qemu_aio_wait();
2644 fail:
2645 async_context_pop();
2646 return async_ret;
2649 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
2650 const uint8_t *buf, int nb_sectors)
2652 int async_ret;
2653 BlockDriverAIOCB *acb;
2654 struct iovec iov;
2655 QEMUIOVector qiov;
2657 async_context_push();
2659 async_ret = NOT_DONE;
2660 iov.iov_base = (void *)buf;
2661 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2662 qemu_iovec_init_external(&qiov, &iov, 1);
2663 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
2664 bdrv_rw_em_cb, &async_ret);
2665 if (acb == NULL) {
2666 async_ret = -1;
2667 goto fail;
2669 while (async_ret == NOT_DONE) {
2670 qemu_aio_wait();
2673 fail:
2674 async_context_pop();
2675 return async_ret;
2678 void bdrv_init(void)
2680 module_call_init(MODULE_INIT_BLOCK);
2683 void bdrv_init_with_whitelist(void)
2685 use_bdrv_whitelist = 1;
2686 bdrv_init();
2689 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
2690 BlockDriverCompletionFunc *cb, void *opaque)
2692 BlockDriverAIOCB *acb;
2694 if (pool->free_aiocb) {
2695 acb = pool->free_aiocb;
2696 pool->free_aiocb = acb->next;
2697 } else {
2698 acb = qemu_mallocz(pool->aiocb_size);
2699 acb->pool = pool;
2701 acb->bs = bs;
2702 acb->cb = cb;
2703 acb->opaque = opaque;
2704 return acb;
2707 void qemu_aio_release(void *p)
2709 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
2710 AIOPool *pool = acb->pool;
2711 acb->next = pool->free_aiocb;
2712 pool->free_aiocb = acb;
2715 /**************************************************************/
2716 /* removable device support */
2719 * Return TRUE if the media is present
2721 int bdrv_is_inserted(BlockDriverState *bs)
2723 BlockDriver *drv = bs->drv;
2724 int ret;
2725 if (!drv)
2726 return 0;
2727 if (!drv->bdrv_is_inserted)
2728 return !bs->tray_open;
2729 ret = drv->bdrv_is_inserted(bs);
2730 return ret;
2734 * Return TRUE if the media changed since the last call to this
2735 * function. It is currently only used for floppy disks
2737 int bdrv_media_changed(BlockDriverState *bs)
2739 BlockDriver *drv = bs->drv;
2740 int ret;
2742 if (!drv || !drv->bdrv_media_changed)
2743 ret = -ENOTSUP;
2744 else
2745 ret = drv->bdrv_media_changed(bs);
2746 if (ret == -ENOTSUP)
2747 ret = bs->media_changed;
2748 bs->media_changed = 0;
2749 return ret;
2753 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
2755 int bdrv_eject(BlockDriverState *bs, int eject_flag)
2757 BlockDriver *drv = bs->drv;
2758 int ret;
2760 if (bs->locked) {
2761 return -EBUSY;
2764 if (!drv || !drv->bdrv_eject) {
2765 ret = -ENOTSUP;
2766 } else {
2767 ret = drv->bdrv_eject(bs, eject_flag);
2769 if (ret == -ENOTSUP) {
2770 ret = 0;
2772 if (ret >= 0) {
2773 bs->tray_open = eject_flag;
2776 return ret;
2779 int bdrv_is_locked(BlockDriverState *bs)
2781 return bs->locked;
2785 * Lock or unlock the media (if it is locked, the user won't be able
2786 * to eject it manually).
2788 void bdrv_set_locked(BlockDriverState *bs, int locked)
2790 BlockDriver *drv = bs->drv;
2792 trace_bdrv_set_locked(bs, locked);
2794 bs->locked = locked;
2795 if (drv && drv->bdrv_set_locked) {
2796 drv->bdrv_set_locked(bs, locked);
2800 /* needed for generic scsi interface */
2802 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
2804 BlockDriver *drv = bs->drv;
2806 if (drv && drv->bdrv_ioctl)
2807 return drv->bdrv_ioctl(bs, req, buf);
2808 return -ENOTSUP;
2811 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
2812 unsigned long int req, void *buf,
2813 BlockDriverCompletionFunc *cb, void *opaque)
2815 BlockDriver *drv = bs->drv;
2817 if (drv && drv->bdrv_aio_ioctl)
2818 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
2819 return NULL;
2824 void *qemu_blockalign(BlockDriverState *bs, size_t size)
2826 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
2829 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
2831 int64_t bitmap_size;
2833 bs->dirty_count = 0;
2834 if (enable) {
2835 if (!bs->dirty_bitmap) {
2836 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
2837 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
2838 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
2840 bs->dirty_bitmap = qemu_mallocz(bitmap_size);
2842 } else {
2843 if (bs->dirty_bitmap) {
2844 qemu_free(bs->dirty_bitmap);
2845 bs->dirty_bitmap = NULL;
2850 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
2852 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
2854 if (bs->dirty_bitmap &&
2855 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
2856 return !!(bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
2857 (1UL << (chunk % (sizeof(unsigned long) * 8))));
2858 } else {
2859 return 0;
2863 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2864 int nr_sectors)
2866 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2869 int64_t bdrv_get_dirty_count(BlockDriverState *bs)
2871 return bs->dirty_count;
2874 void bdrv_set_in_use(BlockDriverState *bs, int in_use)
2876 assert(bs->in_use != in_use);
2877 bs->in_use = in_use;
2880 int bdrv_in_use(BlockDriverState *bs)
2882 return bs->in_use;
2885 int bdrv_img_create(const char *filename, const char *fmt,
2886 const char *base_filename, const char *base_fmt,
2887 char *options, uint64_t img_size, int flags)
2889 QEMUOptionParameter *param = NULL, *create_options = NULL;
2890 QEMUOptionParameter *backing_fmt, *backing_file;
2891 BlockDriverState *bs = NULL;
2892 BlockDriver *drv, *proto_drv;
2893 BlockDriver *backing_drv = NULL;
2894 int ret = 0;
2896 /* Find driver and parse its options */
2897 drv = bdrv_find_format(fmt);
2898 if (!drv) {
2899 error_report("Unknown file format '%s'", fmt);
2900 ret = -EINVAL;
2901 goto out;
2904 proto_drv = bdrv_find_protocol(filename);
2905 if (!proto_drv) {
2906 error_report("Unknown protocol '%s'", filename);
2907 ret = -EINVAL;
2908 goto out;
2911 create_options = append_option_parameters(create_options,
2912 drv->create_options);
2913 create_options = append_option_parameters(create_options,
2914 proto_drv->create_options);
2916 /* Create parameter list with default values */
2917 param = parse_option_parameters("", create_options, param);
2919 set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size);
2921 /* Parse -o options */
2922 if (options) {
2923 param = parse_option_parameters(options, create_options, param);
2924 if (param == NULL) {
2925 error_report("Invalid options for file format '%s'.", fmt);
2926 ret = -EINVAL;
2927 goto out;
2931 if (base_filename) {
2932 if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE,
2933 base_filename)) {
2934 error_report("Backing file not supported for file format '%s'",
2935 fmt);
2936 ret = -EINVAL;
2937 goto out;
2941 if (base_fmt) {
2942 if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) {
2943 error_report("Backing file format not supported for file "
2944 "format '%s'", fmt);
2945 ret = -EINVAL;
2946 goto out;
2950 backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
2951 if (backing_file && backing_file->value.s) {
2952 if (!strcmp(filename, backing_file->value.s)) {
2953 error_report("Error: Trying to create an image with the "
2954 "same filename as the backing file");
2955 ret = -EINVAL;
2956 goto out;
2960 backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT);
2961 if (backing_fmt && backing_fmt->value.s) {
2962 backing_drv = bdrv_find_format(backing_fmt->value.s);
2963 if (!backing_drv) {
2964 error_report("Unknown backing file format '%s'",
2965 backing_fmt->value.s);
2966 ret = -EINVAL;
2967 goto out;
2971 // The size for the image must always be specified, with one exception:
2972 // If we are using a backing file, we can obtain the size from there
2973 if (get_option_parameter(param, BLOCK_OPT_SIZE)->value.n == -1) {
2974 if (backing_file && backing_file->value.s) {
2975 uint64_t size;
2976 char buf[32];
2978 bs = bdrv_new("");
2980 ret = bdrv_open(bs, backing_file->value.s, flags, backing_drv);
2981 if (ret < 0) {
2982 error_report("Could not open '%s'", backing_file->value.s);
2983 goto out;
2985 bdrv_get_geometry(bs, &size);
2986 size *= 512;
2988 snprintf(buf, sizeof(buf), "%" PRId64, size);
2989 set_option_parameter(param, BLOCK_OPT_SIZE, buf);
2990 } else {
2991 error_report("Image creation needs a size parameter");
2992 ret = -EINVAL;
2993 goto out;
2997 printf("Formatting '%s', fmt=%s ", filename, fmt);
2998 print_option_parameters(param);
2999 puts("");
3001 ret = bdrv_create(drv, filename, param);
3003 if (ret < 0) {
3004 if (ret == -ENOTSUP) {
3005 error_report("Formatting or formatting option not supported for "
3006 "file format '%s'", fmt);
3007 } else if (ret == -EFBIG) {
3008 error_report("The image size is too large for file format '%s'",
3009 fmt);
3010 } else {
3011 error_report("%s: error while creating %s: %s", filename, fmt,
3012 strerror(-ret));
3016 out:
3017 free_option_parameters(create_options);
3018 free_option_parameters(param);
3020 if (bs) {
3021 bdrv_delete(bs);
3024 return ret;