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
24 #include "qemu/osdep.h"
26 #include "block/block_int.h"
27 #include "block/blockjob.h"
28 #include "block/nbd.h"
29 #include "qemu/error-report.h"
30 #include "module_block.h"
31 #include "qemu/module.h"
32 #include "qapi/qmp/qerror.h"
33 #include "qapi/qmp/qbool.h"
34 #include "qapi/qmp/qjson.h"
35 #include "sysemu/block-backend.h"
36 #include "sysemu/sysemu.h"
37 #include "qemu/notify.h"
38 #include "qemu/coroutine.h"
39 #include "block/qapi.h"
40 #include "qmp-commands.h"
41 #include "qemu/timer.h"
42 #include "qapi-event.h"
43 #include "qemu/cutils.h"
45 #include "qapi/util.h"
48 #include <sys/ioctl.h>
49 #include <sys/queue.h>
59 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
61 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
62 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
64 static QTAILQ_HEAD(, BlockDriverState
) all_bdrv_states
=
65 QTAILQ_HEAD_INITIALIZER(all_bdrv_states
);
67 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
68 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
70 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
71 const char *reference
,
72 QDict
*options
, int flags
,
73 BlockDriverState
*parent
,
74 const BdrvChildRole
*child_role
,
77 /* If non-zero, use only whitelisted block drivers */
78 static int use_bdrv_whitelist
;
81 static int is_windows_drive_prefix(const char *filename
)
83 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
84 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
88 int is_windows_drive(const char *filename
)
90 if (is_windows_drive_prefix(filename
) &&
93 if (strstart(filename
, "\\\\.\\", NULL
) ||
94 strstart(filename
, "//./", NULL
))
100 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
102 if (!bs
|| !bs
->drv
) {
103 /* page size or 4k (hdd sector size) should be on the safe side */
104 return MAX(4096, getpagesize());
107 return bs
->bl
.opt_mem_alignment
;
110 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
112 if (!bs
|| !bs
->drv
) {
113 /* page size or 4k (hdd sector size) should be on the safe side */
114 return MAX(4096, getpagesize());
117 return bs
->bl
.min_mem_alignment
;
120 /* check if the path starts with "<protocol>:" */
121 int path_has_protocol(const char *path
)
126 if (is_windows_drive(path
) ||
127 is_windows_drive_prefix(path
)) {
130 p
= path
+ strcspn(path
, ":/\\");
132 p
= path
+ strcspn(path
, ":/");
138 int path_is_absolute(const char *path
)
141 /* specific case for names like: "\\.\d:" */
142 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
145 return (*path
== '/' || *path
== '\\');
147 return (*path
== '/');
151 /* if filename is absolute, just copy it to dest. Otherwise, build a
152 path to it by considering it is relative to base_path. URL are
154 void path_combine(char *dest
, int dest_size
,
155 const char *base_path
,
156 const char *filename
)
163 if (path_is_absolute(filename
)) {
164 pstrcpy(dest
, dest_size
, filename
);
166 p
= strchr(base_path
, ':');
171 p1
= strrchr(base_path
, '/');
175 p2
= strrchr(base_path
, '\\');
187 if (len
> dest_size
- 1)
189 memcpy(dest
, base_path
, len
);
191 pstrcat(dest
, dest_size
, filename
);
195 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
197 char *dest
, size_t sz
,
200 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
201 path_is_absolute(backing
))
203 pstrcpy(dest
, sz
, backing
);
204 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
205 error_setg(errp
, "Cannot use relative backing file names for '%s'",
208 path_combine(dest
, sz
, backed
, backing
);
212 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
215 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
217 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
221 void bdrv_register(BlockDriver
*bdrv
)
223 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
226 BlockDriverState
*bdrv_new(void)
228 BlockDriverState
*bs
;
231 bs
= g_new0(BlockDriverState
, 1);
232 QLIST_INIT(&bs
->dirty_bitmaps
);
233 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
234 QLIST_INIT(&bs
->op_blockers
[i
]);
236 notifier_with_return_list_init(&bs
->before_write_notifiers
);
238 bs
->aio_context
= qemu_get_aio_context();
240 qemu_co_queue_init(&bs
->flush_queue
);
242 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
247 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
251 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
252 if (!strcmp(drv1
->format_name
, format_name
)) {
260 BlockDriver
*bdrv_find_format(const char *format_name
)
265 drv1
= bdrv_do_find_format(format_name
);
270 /* The driver isn't registered, maybe we need to load a module */
271 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
272 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
273 block_module_load_one(block_driver_modules
[i
].library_name
);
278 return bdrv_do_find_format(format_name
);
281 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
283 static const char *whitelist_rw
[] = {
284 CONFIG_BDRV_RW_WHITELIST
286 static const char *whitelist_ro
[] = {
287 CONFIG_BDRV_RO_WHITELIST
291 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
292 return 1; /* no whitelist, anything goes */
295 for (p
= whitelist_rw
; *p
; p
++) {
296 if (!strcmp(drv
->format_name
, *p
)) {
301 for (p
= whitelist_ro
; *p
; p
++) {
302 if (!strcmp(drv
->format_name
, *p
)) {
310 bool bdrv_uses_whitelist(void)
312 return use_bdrv_whitelist
;
315 typedef struct CreateCo
{
323 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
325 Error
*local_err
= NULL
;
328 CreateCo
*cco
= opaque
;
331 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
332 error_propagate(&cco
->err
, local_err
);
336 int bdrv_create(BlockDriver
*drv
, const char* filename
,
337 QemuOpts
*opts
, Error
**errp
)
344 .filename
= g_strdup(filename
),
350 if (!drv
->bdrv_create
) {
351 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
356 if (qemu_in_coroutine()) {
357 /* Fast-path if already in coroutine context */
358 bdrv_create_co_entry(&cco
);
360 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
361 qemu_coroutine_enter(co
);
362 while (cco
.ret
== NOT_DONE
) {
363 aio_poll(qemu_get_aio_context(), true);
370 error_propagate(errp
, cco
.err
);
372 error_setg_errno(errp
, -ret
, "Could not create image");
377 g_free(cco
.filename
);
381 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
384 Error
*local_err
= NULL
;
387 drv
= bdrv_find_protocol(filename
, true, errp
);
392 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
393 error_propagate(errp
, local_err
);
398 * Try to get @bs's logical and physical block size.
399 * On success, store them in @bsz struct and return 0.
400 * On failure return -errno.
401 * @bs must not be empty.
403 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
405 BlockDriver
*drv
= bs
->drv
;
407 if (drv
&& drv
->bdrv_probe_blocksizes
) {
408 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
415 * Try to get @bs's geometry (cyls, heads, sectors).
416 * On success, store them in @geo struct and return 0.
417 * On failure return -errno.
418 * @bs must not be empty.
420 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
422 BlockDriver
*drv
= bs
->drv
;
424 if (drv
&& drv
->bdrv_probe_geometry
) {
425 return drv
->bdrv_probe_geometry(bs
, geo
);
432 * Create a uniquely-named empty temporary file.
433 * Return 0 upon success, otherwise a negative errno value.
435 int get_tmp_filename(char *filename
, int size
)
438 char temp_dir
[MAX_PATH
];
439 /* GetTempFileName requires that its output buffer (4th param)
440 have length MAX_PATH or greater. */
441 assert(size
>= MAX_PATH
);
442 return (GetTempPath(MAX_PATH
, temp_dir
)
443 && GetTempFileName(temp_dir
, "qem", 0, filename
)
444 ? 0 : -GetLastError());
448 tmpdir
= getenv("TMPDIR");
452 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
455 fd
= mkstemp(filename
);
459 if (close(fd
) != 0) {
468 * Detect host devices. By convention, /dev/cdrom[N] is always
469 * recognized as a host CDROM.
471 static BlockDriver
*find_hdev_driver(const char *filename
)
473 int score_max
= 0, score
;
474 BlockDriver
*drv
= NULL
, *d
;
476 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
477 if (d
->bdrv_probe_device
) {
478 score
= d
->bdrv_probe_device(filename
);
479 if (score
> score_max
) {
489 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
493 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
494 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
502 BlockDriver
*bdrv_find_protocol(const char *filename
,
503 bool allow_protocol_prefix
,
512 /* TODO Drivers without bdrv_file_open must be specified explicitly */
515 * XXX(hch): we really should not let host device detection
516 * override an explicit protocol specification, but moving this
517 * later breaks access to device names with colons in them.
518 * Thanks to the brain-dead persistent naming schemes on udev-
519 * based Linux systems those actually are quite common.
521 drv1
= find_hdev_driver(filename
);
526 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
530 p
= strchr(filename
, ':');
533 if (len
> sizeof(protocol
) - 1)
534 len
= sizeof(protocol
) - 1;
535 memcpy(protocol
, filename
, len
);
536 protocol
[len
] = '\0';
538 drv1
= bdrv_do_find_protocol(protocol
);
543 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
544 if (block_driver_modules
[i
].protocol_name
&&
545 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
546 block_module_load_one(block_driver_modules
[i
].library_name
);
551 drv1
= bdrv_do_find_protocol(protocol
);
553 error_setg(errp
, "Unknown protocol '%s'", protocol
);
559 * Guess image format by probing its contents.
560 * This is not a good idea when your image is raw (CVE-2008-2004), but
561 * we do it anyway for backward compatibility.
563 * @buf contains the image's first @buf_size bytes.
564 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
565 * but can be smaller if the image file is smaller)
566 * @filename is its filename.
568 * For all block drivers, call the bdrv_probe() method to get its
570 * Return the first block driver with the highest probing score.
572 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
573 const char *filename
)
575 int score_max
= 0, score
;
576 BlockDriver
*drv
= NULL
, *d
;
578 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
580 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
581 if (score
> score_max
) {
591 static int find_image_format(BdrvChild
*file
, const char *filename
,
592 BlockDriver
**pdrv
, Error
**errp
)
594 BlockDriverState
*bs
= file
->bs
;
596 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
599 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
600 if (bdrv_is_sg(bs
) || !bdrv_is_inserted(bs
) || bdrv_getlength(bs
) == 0) {
605 ret
= bdrv_pread(file
, 0, buf
, sizeof(buf
));
607 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
613 drv
= bdrv_probe_all(buf
, ret
, filename
);
615 error_setg(errp
, "Could not determine image format: No compatible "
624 * Set the current 'total_sectors' value
625 * Return 0 on success, -errno on error.
627 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
629 BlockDriver
*drv
= bs
->drv
;
631 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
635 /* query actual device if possible, otherwise just trust the hint */
636 if (drv
->bdrv_getlength
) {
637 int64_t length
= drv
->bdrv_getlength(bs
);
641 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
644 bs
->total_sectors
= hint
;
649 * Combines a QDict of new block driver @options with any missing options taken
650 * from @old_options, so that leaving out an option defaults to its old value.
652 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
655 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
656 bs
->drv
->bdrv_join_options(options
, old_options
);
658 qdict_join(options
, old_options
, false);
663 * Set open flags for a given discard mode
665 * Return 0 on success, -1 if the discard mode was invalid.
667 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
669 *flags
&= ~BDRV_O_UNMAP
;
671 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
673 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
674 *flags
|= BDRV_O_UNMAP
;
683 * Set open flags for a given cache mode
685 * Return 0 on success, -1 if the cache mode was invalid.
687 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
689 *flags
&= ~BDRV_O_CACHE_MASK
;
691 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
692 *writethrough
= false;
693 *flags
|= BDRV_O_NOCACHE
;
694 } else if (!strcmp(mode
, "directsync")) {
695 *writethrough
= true;
696 *flags
|= BDRV_O_NOCACHE
;
697 } else if (!strcmp(mode
, "writeback")) {
698 *writethrough
= false;
699 } else if (!strcmp(mode
, "unsafe")) {
700 *writethrough
= false;
701 *flags
|= BDRV_O_NO_FLUSH
;
702 } else if (!strcmp(mode
, "writethrough")) {
703 *writethrough
= true;
711 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
713 BlockDriverState
*bs
= child
->opaque
;
714 bdrv_drained_begin(bs
);
717 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
719 BlockDriverState
*bs
= child
->opaque
;
720 bdrv_drained_end(bs
);
724 * Returns the options and flags that a temporary snapshot should get, based on
725 * the originally requested flags (the originally requested image will have
726 * flags like a backing file)
728 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
729 int parent_flags
, QDict
*parent_options
)
731 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
733 /* For temporary files, unconditional cache=unsafe is fine */
734 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
735 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
737 /* Copy the read-only option from the parent */
738 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
740 /* aio=native doesn't work for cache.direct=off, so disable it for the
741 * temporary snapshot */
742 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
746 * Returns the options and flags that bs->file should get if a protocol driver
747 * is expected, based on the given options and flags for the parent BDS
749 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
750 int parent_flags
, QDict
*parent_options
)
752 int flags
= parent_flags
;
754 /* Enable protocol handling, disable format probing for bs->file */
755 flags
|= BDRV_O_PROTOCOL
;
757 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
759 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
760 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
762 /* Inherit the read-only option from the parent if it's not set */
763 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
765 /* Our block drivers take care to send flushes and respect unmap policy,
766 * so we can default to enable both on lower layers regardless of the
767 * corresponding parent options. */
768 flags
|= BDRV_O_UNMAP
;
770 /* Clear flags that only apply to the top layer */
771 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
774 *child_flags
= flags
;
777 const BdrvChildRole child_file
= {
778 .inherit_options
= bdrv_inherited_options
,
779 .drained_begin
= bdrv_child_cb_drained_begin
,
780 .drained_end
= bdrv_child_cb_drained_end
,
784 * Returns the options and flags that bs->file should get if the use of formats
785 * (and not only protocols) is permitted for it, based on the given options and
786 * flags for the parent BDS
788 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
789 int parent_flags
, QDict
*parent_options
)
791 child_file
.inherit_options(child_flags
, child_options
,
792 parent_flags
, parent_options
);
794 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
797 const BdrvChildRole child_format
= {
798 .inherit_options
= bdrv_inherited_fmt_options
,
799 .drained_begin
= bdrv_child_cb_drained_begin
,
800 .drained_end
= bdrv_child_cb_drained_end
,
804 * Returns the options and flags that bs->backing should get, based on the
805 * given options and flags for the parent BDS
807 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
808 int parent_flags
, QDict
*parent_options
)
810 int flags
= parent_flags
;
812 /* The cache mode is inherited unmodified for backing files; except WCE,
813 * which is only applied on the top level (BlockBackend) */
814 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
815 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
817 /* backing files always opened read-only */
818 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
819 flags
&= ~BDRV_O_COPY_ON_READ
;
821 /* snapshot=on is handled on the top layer */
822 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
824 *child_flags
= flags
;
827 static const BdrvChildRole child_backing
= {
828 .inherit_options
= bdrv_backing_options
,
829 .drained_begin
= bdrv_child_cb_drained_begin
,
830 .drained_end
= bdrv_child_cb_drained_end
,
833 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
835 int open_flags
= flags
;
838 * Clear flags that are internal to the block layer before opening the
841 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
844 * Snapshots should be writable.
846 if (flags
& BDRV_O_TEMPORARY
) {
847 open_flags
|= BDRV_O_RDWR
;
853 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
855 *flags
&= ~BDRV_O_CACHE_MASK
;
857 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
858 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
859 *flags
|= BDRV_O_NO_FLUSH
;
862 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
863 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
864 *flags
|= BDRV_O_NOCACHE
;
867 *flags
&= ~BDRV_O_RDWR
;
869 assert(qemu_opt_find(opts
, BDRV_OPT_READ_ONLY
));
870 if (!qemu_opt_get_bool(opts
, BDRV_OPT_READ_ONLY
, false)) {
871 *flags
|= BDRV_O_RDWR
;
876 static void update_options_from_flags(QDict
*options
, int flags
)
878 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
879 qdict_put(options
, BDRV_OPT_CACHE_DIRECT
,
880 qbool_from_bool(flags
& BDRV_O_NOCACHE
));
882 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
883 qdict_put(options
, BDRV_OPT_CACHE_NO_FLUSH
,
884 qbool_from_bool(flags
& BDRV_O_NO_FLUSH
));
886 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
887 qdict_put(options
, BDRV_OPT_READ_ONLY
,
888 qbool_from_bool(!(flags
& BDRV_O_RDWR
)));
892 static void bdrv_assign_node_name(BlockDriverState
*bs
,
893 const char *node_name
,
896 char *gen_node_name
= NULL
;
899 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
900 } else if (!id_wellformed(node_name
)) {
902 * Check for empty string or invalid characters, but not if it is
903 * generated (generated names use characters not available to the user)
905 error_setg(errp
, "Invalid node name");
909 /* takes care of avoiding namespaces collisions */
910 if (blk_by_name(node_name
)) {
911 error_setg(errp
, "node-name=%s is conflicting with a device id",
916 /* takes care of avoiding duplicates node names */
917 if (bdrv_find_node(node_name
)) {
918 error_setg(errp
, "Duplicate node name");
922 /* copy node name into the bs and insert it into the graph list */
923 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
924 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
926 g_free(gen_node_name
);
929 static QemuOptsList bdrv_runtime_opts
= {
930 .name
= "bdrv_common",
931 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
935 .type
= QEMU_OPT_STRING
,
936 .help
= "Node name of the block device node",
940 .type
= QEMU_OPT_STRING
,
941 .help
= "Block driver to use for the node",
944 .name
= BDRV_OPT_CACHE_DIRECT
,
945 .type
= QEMU_OPT_BOOL
,
946 .help
= "Bypass software writeback cache on the host",
949 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
950 .type
= QEMU_OPT_BOOL
,
951 .help
= "Ignore flush requests",
954 .name
= BDRV_OPT_READ_ONLY
,
955 .type
= QEMU_OPT_BOOL
,
956 .help
= "Node is opened in read-only mode",
959 .name
= "detect-zeroes",
960 .type
= QEMU_OPT_STRING
,
961 .help
= "try to optimize zero writes (off, on, unmap)",
963 { /* end of list */ }
968 * Common part for opening disk images and files
970 * Removes all processed options from *options.
972 static int bdrv_open_common(BlockDriverState
*bs
, BdrvChild
*file
,
973 QDict
*options
, Error
**errp
)
976 const char *filename
;
977 const char *driver_name
= NULL
;
978 const char *node_name
= NULL
;
979 const char *detect_zeroes
;
982 Error
*local_err
= NULL
;
984 assert(bs
->file
== NULL
);
985 assert(options
!= NULL
&& bs
->options
!= options
);
987 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
988 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
990 error_propagate(errp
, local_err
);
995 update_flags_from_options(&bs
->open_flags
, opts
);
997 driver_name
= qemu_opt_get(opts
, "driver");
998 drv
= bdrv_find_format(driver_name
);
1002 filename
= file
->bs
->filename
;
1004 filename
= qdict_get_try_str(options
, "filename");
1007 if (drv
->bdrv_needs_filename
&& !filename
) {
1008 error_setg(errp
, "The '%s' block driver requires a file name",
1014 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1017 node_name
= qemu_opt_get(opts
, "node-name");
1018 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1020 error_propagate(errp
, local_err
);
1025 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1027 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1029 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1030 ? "Driver '%s' can only be used for read-only devices"
1031 : "Driver '%s' is not whitelisted",
1037 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
1038 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1039 if (!bs
->read_only
) {
1040 bdrv_enable_copy_on_read(bs
);
1042 error_setg(errp
, "Can't use copy-on-read on read-only device");
1048 detect_zeroes
= qemu_opt_get(opts
, "detect-zeroes");
1049 if (detect_zeroes
) {
1050 BlockdevDetectZeroesOptions value
=
1051 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup
,
1053 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX
,
1054 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
1057 error_propagate(errp
, local_err
);
1062 if (value
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
1063 !(bs
->open_flags
& BDRV_O_UNMAP
))
1065 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
1066 "without setting discard operation to unmap");
1071 bs
->detect_zeroes
= value
;
1074 if (filename
!= NULL
) {
1075 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1077 bs
->filename
[0] = '\0';
1079 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1082 bs
->opaque
= g_malloc0(drv
->instance_size
);
1084 /* Open the image, either directly or using a protocol */
1085 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1086 if (drv
->bdrv_file_open
) {
1087 assert(file
== NULL
);
1088 assert(!drv
->bdrv_needs_filename
|| filename
!= NULL
);
1089 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1092 error_setg(errp
, "Can't use '%s' as a block driver for the "
1093 "protocol level", drv
->format_name
);
1098 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1103 error_propagate(errp
, local_err
);
1104 } else if (bs
->filename
[0]) {
1105 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1107 error_setg_errno(errp
, -ret
, "Could not open image");
1112 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1114 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1118 bdrv_refresh_limits(bs
, &local_err
);
1120 error_propagate(errp
, local_err
);
1125 assert(bdrv_opt_mem_align(bs
) != 0);
1126 assert(bdrv_min_mem_align(bs
) != 0);
1127 assert(is_power_of_2(bs
->bl
.request_alignment
));
1129 qemu_opts_del(opts
);
1138 qemu_opts_del(opts
);
1142 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1144 QObject
*options_obj
;
1148 ret
= strstart(filename
, "json:", &filename
);
1151 options_obj
= qobject_from_json(filename
);
1153 error_setg(errp
, "Could not parse the JSON options");
1157 if (qobject_type(options_obj
) != QTYPE_QDICT
) {
1158 qobject_decref(options_obj
);
1159 error_setg(errp
, "Invalid JSON object given");
1163 options
= qobject_to_qdict(options_obj
);
1164 qdict_flatten(options
);
1169 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1172 QDict
*json_options
;
1173 Error
*local_err
= NULL
;
1175 /* Parse json: pseudo-protocol */
1176 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1180 json_options
= parse_json_filename(*pfilename
, &local_err
);
1182 error_propagate(errp
, local_err
);
1186 /* Options given in the filename have lower priority than options
1187 * specified directly */
1188 qdict_join(options
, json_options
, false);
1189 QDECREF(json_options
);
1194 * Fills in default options for opening images and converts the legacy
1195 * filename/flags pair to option QDict entries.
1196 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1197 * block driver has been specified explicitly.
1199 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1200 int *flags
, Error
**errp
)
1202 const char *drvname
;
1203 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1204 bool parse_filename
= false;
1205 BlockDriver
*drv
= NULL
;
1206 Error
*local_err
= NULL
;
1208 drvname
= qdict_get_try_str(*options
, "driver");
1210 drv
= bdrv_find_format(drvname
);
1212 error_setg(errp
, "Unknown driver '%s'", drvname
);
1215 /* If the user has explicitly specified the driver, this choice should
1216 * override the BDRV_O_PROTOCOL flag */
1217 protocol
= drv
->bdrv_file_open
;
1221 *flags
|= BDRV_O_PROTOCOL
;
1223 *flags
&= ~BDRV_O_PROTOCOL
;
1226 /* Translate cache options from flags into options */
1227 update_options_from_flags(*options
, *flags
);
1229 /* Fetch the file name from the options QDict if necessary */
1230 if (protocol
&& filename
) {
1231 if (!qdict_haskey(*options
, "filename")) {
1232 qdict_put(*options
, "filename", qstring_from_str(filename
));
1233 parse_filename
= true;
1235 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1241 /* Find the right block driver */
1242 filename
= qdict_get_try_str(*options
, "filename");
1244 if (!drvname
&& protocol
) {
1246 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1251 drvname
= drv
->format_name
;
1252 qdict_put(*options
, "driver", qstring_from_str(drvname
));
1254 error_setg(errp
, "Must specify either driver or file");
1259 assert(drv
|| !protocol
);
1261 /* Driver-specific filename parsing */
1262 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1263 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1265 error_propagate(errp
, local_err
);
1269 if (!drv
->bdrv_needs_filename
) {
1270 qdict_del(*options
, "filename");
1277 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1279 BlockDriverState
*old_bs
= child
->bs
;
1282 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1283 child
->role
->drained_end(child
);
1285 QLIST_REMOVE(child
, next_parent
);
1291 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1292 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1293 child
->role
->drained_begin(child
);
1298 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1299 const char *child_name
,
1300 const BdrvChildRole
*child_role
,
1303 BdrvChild
*child
= g_new(BdrvChild
, 1);
1304 *child
= (BdrvChild
) {
1306 .name
= g_strdup(child_name
),
1311 bdrv_replace_child(child
, child_bs
);
1316 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1317 BlockDriverState
*child_bs
,
1318 const char *child_name
,
1319 const BdrvChildRole
*child_role
)
1321 BdrvChild
*child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
1323 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1327 static void bdrv_detach_child(BdrvChild
*child
)
1329 if (child
->next
.le_prev
) {
1330 QLIST_REMOVE(child
, next
);
1331 child
->next
.le_prev
= NULL
;
1334 bdrv_replace_child(child
, NULL
);
1336 g_free(child
->name
);
1340 void bdrv_root_unref_child(BdrvChild
*child
)
1342 BlockDriverState
*child_bs
;
1344 child_bs
= child
->bs
;
1345 bdrv_detach_child(child
);
1346 bdrv_unref(child_bs
);
1349 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1351 if (child
== NULL
) {
1355 if (child
->bs
->inherits_from
== parent
) {
1356 child
->bs
->inherits_from
= NULL
;
1359 bdrv_root_unref_child(child
);
1363 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
1366 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1367 if (c
->role
->change_media
) {
1368 c
->role
->change_media(c
, load
);
1373 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
1376 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1377 if (c
->role
->resize
) {
1384 * Sets the backing file link of a BDS. A new reference is created; callers
1385 * which don't need their own reference any more must call bdrv_unref().
1387 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
)
1390 bdrv_ref(backing_hd
);
1394 assert(bs
->backing_blocker
);
1395 bdrv_op_unblock_all(bs
->backing
->bs
, bs
->backing_blocker
);
1396 bdrv_unref_child(bs
, bs
->backing
);
1397 } else if (backing_hd
) {
1398 error_setg(&bs
->backing_blocker
,
1399 "node is used as backing hd of '%s'",
1400 bdrv_get_device_or_node_name(bs
));
1404 error_free(bs
->backing_blocker
);
1405 bs
->backing_blocker
= NULL
;
1409 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
);
1410 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1411 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_hd
->filename
);
1412 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
),
1413 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
1415 bdrv_op_block_all(backing_hd
, bs
->backing_blocker
);
1416 /* Otherwise we won't be able to commit due to check in bdrv_commit */
1417 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
1418 bs
->backing_blocker
);
1420 * We do backup in 3 ways:
1422 * The target bs is new opened, and the source is top BDS
1423 * 2. blockdev backup
1424 * Both the source and the target are top BDSes.
1425 * 3. internal backup(used for block replication)
1426 * Both the source and the target are backing file
1428 * In case 1 and 2, neither the source nor the target is the backing file.
1429 * In case 3, we will block the top BDS, so there is only one block job
1430 * for the top BDS and its backing chain.
1432 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
1433 bs
->backing_blocker
);
1434 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
1435 bs
->backing_blocker
);
1437 bdrv_refresh_limits(bs
, NULL
);
1441 * Opens the backing file for a BlockDriverState if not yet open
1443 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
1444 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1445 * itself, all options starting with "${bdref_key}." are considered part of the
1448 * TODO Can this be unified with bdrv_open_image()?
1450 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
1451 const char *bdref_key
, Error
**errp
)
1453 char *backing_filename
= g_malloc0(PATH_MAX
);
1454 char *bdref_key_dot
;
1455 const char *reference
= NULL
;
1457 BlockDriverState
*backing_hd
;
1459 QDict
*tmp_parent_options
= NULL
;
1460 Error
*local_err
= NULL
;
1462 if (bs
->backing
!= NULL
) {
1466 /* NULL means an empty set of options */
1467 if (parent_options
== NULL
) {
1468 tmp_parent_options
= qdict_new();
1469 parent_options
= tmp_parent_options
;
1472 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1474 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1475 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
1476 g_free(bdref_key_dot
);
1478 reference
= qdict_get_try_str(parent_options
, bdref_key
);
1479 if (reference
|| qdict_haskey(options
, "file.filename")) {
1480 backing_filename
[0] = '\0';
1481 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
1485 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
1489 error_propagate(errp
, local_err
);
1495 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
1497 error_setg(errp
, "Driver doesn't support backing files");
1502 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
1503 qdict_put(options
, "driver", qstring_from_str(bs
->backing_format
));
1506 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
1507 reference
, options
, 0, bs
, &child_backing
,
1510 bs
->open_flags
|= BDRV_O_NO_BACKING
;
1511 error_prepend(errp
, "Could not open backing file: ");
1516 /* Hook up the backing file link; drop our reference, bs owns the
1517 * backing_hd reference now */
1518 bdrv_set_backing_hd(bs
, backing_hd
);
1519 bdrv_unref(backing_hd
);
1521 qdict_del(parent_options
, bdref_key
);
1524 g_free(backing_filename
);
1525 QDECREF(tmp_parent_options
);
1530 * Opens a disk image whose options are given as BlockdevRef in another block
1533 * If allow_none is true, no image will be opened if filename is false and no
1534 * BlockdevRef is given. NULL will be returned, but errp remains unset.
1536 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
1537 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1538 * itself, all options starting with "${bdref_key}." are considered part of the
1541 * The BlockdevRef will be removed from the options QDict.
1543 BdrvChild
*bdrv_open_child(const char *filename
,
1544 QDict
*options
, const char *bdref_key
,
1545 BlockDriverState
* parent
,
1546 const BdrvChildRole
*child_role
,
1547 bool allow_none
, Error
**errp
)
1549 BdrvChild
*c
= NULL
;
1550 BlockDriverState
*bs
;
1551 QDict
*image_options
;
1552 char *bdref_key_dot
;
1553 const char *reference
;
1555 assert(child_role
!= NULL
);
1557 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1558 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
1559 g_free(bdref_key_dot
);
1561 reference
= qdict_get_try_str(options
, bdref_key
);
1562 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
1564 error_setg(errp
, "A block device must be specified for \"%s\"",
1567 QDECREF(image_options
);
1571 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
1572 parent
, child_role
, errp
);
1577 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
);
1580 qdict_del(options
, bdref_key
);
1584 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
1586 QDict
*snapshot_options
,
1589 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
1590 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
1592 QemuOpts
*opts
= NULL
;
1593 BlockDriverState
*bs_snapshot
;
1596 /* if snapshot, we create a temporary backing file and open it
1597 instead of opening 'filename' directly */
1599 /* Get the required size from the image */
1600 total_size
= bdrv_getlength(bs
);
1601 if (total_size
< 0) {
1602 error_setg_errno(errp
, -total_size
, "Could not get image size");
1606 /* Create the temporary image */
1607 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
1609 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
1613 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
1615 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
1616 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
1617 qemu_opts_del(opts
);
1619 error_prepend(errp
, "Could not create temporary overlay '%s': ",
1624 /* Prepare options QDict for the temporary file */
1625 qdict_put(snapshot_options
, "file.driver",
1626 qstring_from_str("file"));
1627 qdict_put(snapshot_options
, "file.filename",
1628 qstring_from_str(tmp_filename
));
1629 qdict_put(snapshot_options
, "driver",
1630 qstring_from_str("qcow2"));
1632 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
1633 snapshot_options
= NULL
;
1639 /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
1640 * call bdrv_unref() on it), so in order to be able to return one, we have
1641 * to increase bs_snapshot's refcount here */
1642 bdrv_ref(bs_snapshot
);
1643 bdrv_append(bs_snapshot
, bs
);
1645 g_free(tmp_filename
);
1649 QDECREF(snapshot_options
);
1650 g_free(tmp_filename
);
1655 * Opens a disk image (raw, qcow2, vmdk, ...)
1657 * options is a QDict of options to pass to the block drivers, or NULL for an
1658 * empty set of options. The reference to the QDict belongs to the block layer
1659 * after the call (even on failure), so if the caller intends to reuse the
1660 * dictionary, it needs to use QINCREF() before calling bdrv_open.
1662 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
1663 * If it is not NULL, the referenced BDS will be reused.
1665 * The reference parameter may be used to specify an existing block device which
1666 * should be opened. If specified, neither options nor a filename may be given,
1667 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
1669 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
1670 const char *reference
,
1671 QDict
*options
, int flags
,
1672 BlockDriverState
*parent
,
1673 const BdrvChildRole
*child_role
,
1677 BdrvChild
*file
= NULL
;
1678 BlockDriverState
*bs
;
1679 BlockDriver
*drv
= NULL
;
1680 const char *drvname
;
1681 const char *backing
;
1682 Error
*local_err
= NULL
;
1683 QDict
*snapshot_options
= NULL
;
1684 int snapshot_flags
= 0;
1686 assert(!child_role
|| !flags
);
1687 assert(!child_role
== !parent
);
1690 bool options_non_empty
= options
? qdict_size(options
) : false;
1693 if (filename
|| options_non_empty
) {
1694 error_setg(errp
, "Cannot reference an existing block device with "
1695 "additional options or a new filename");
1699 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
1710 /* NULL means an empty set of options */
1711 if (options
== NULL
) {
1712 options
= qdict_new();
1715 /* json: syntax counts as explicit options, as if in the QDict */
1716 parse_json_protocol(options
, &filename
, &local_err
);
1721 bs
->explicit_options
= qdict_clone_shallow(options
);
1724 bs
->inherits_from
= parent
;
1725 child_role
->inherit_options(&flags
, options
,
1726 parent
->open_flags
, parent
->options
);
1729 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
1734 /* Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
1735 * FIXME: we're parsing the QDict to avoid having to create a
1736 * QemuOpts just for this, but neither option is optimal. */
1737 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
1738 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
1739 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
1741 flags
&= ~BDRV_O_RDWR
;
1744 if (flags
& BDRV_O_SNAPSHOT
) {
1745 snapshot_options
= qdict_new();
1746 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
1748 /* Let bdrv_backing_options() override "read-only" */
1749 qdict_del(options
, BDRV_OPT_READ_ONLY
);
1750 bdrv_backing_options(&flags
, options
, flags
, options
);
1753 bs
->open_flags
= flags
;
1754 bs
->options
= options
;
1755 options
= qdict_clone_shallow(options
);
1757 /* Find the right image format driver */
1758 drvname
= qdict_get_try_str(options
, "driver");
1760 drv
= bdrv_find_format(drvname
);
1762 error_setg(errp
, "Unknown driver: '%s'", drvname
);
1767 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
1769 backing
= qdict_get_try_str(options
, "backing");
1770 if (backing
&& *backing
== '\0') {
1771 flags
|= BDRV_O_NO_BACKING
;
1772 qdict_del(options
, "backing");
1775 /* Open image file without format layer */
1776 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
1777 file
= bdrv_open_child(filename
, options
, "file", bs
,
1778 &child_file
, true, &local_err
);
1784 /* Image format probing */
1787 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
1792 * This option update would logically belong in bdrv_fill_options(),
1793 * but we first need to open bs->file for the probing to work, while
1794 * opening bs->file already requires the (mostly) final set of options
1795 * so that cache mode etc. can be inherited.
1797 * Adding the driver later is somewhat ugly, but it's not an option
1798 * that would ever be inherited, so it's correct. We just need to make
1799 * sure to update both bs->options (which has the full effective
1800 * options for bs) and options (which has file.* already removed).
1802 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
1803 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
1805 error_setg(errp
, "Must specify either driver or file");
1809 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
1810 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
1811 /* file must be NULL if a protocol BDS is about to be created
1812 * (the inverse results in an error message from bdrv_open_common()) */
1813 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
1815 /* Open the image */
1816 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
1821 if (file
&& (bs
->file
!= file
)) {
1822 bdrv_unref_child(bs
, file
);
1826 /* If there is a backing file, use it */
1827 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
1828 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
1830 goto close_and_fail
;
1834 bdrv_refresh_filename(bs
);
1836 /* Check if any unknown options were used */
1837 if (options
&& (qdict_size(options
) != 0)) {
1838 const QDictEntry
*entry
= qdict_first(options
);
1839 if (flags
& BDRV_O_PROTOCOL
) {
1840 error_setg(errp
, "Block protocol '%s' doesn't support the option "
1841 "'%s'", drv
->format_name
, entry
->key
);
1844 "Block format '%s' does not support the option '%s'",
1845 drv
->format_name
, entry
->key
);
1848 goto close_and_fail
;
1851 if (!bdrv_key_required(bs
)) {
1852 bdrv_parent_cb_change_media(bs
, true);
1853 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
1854 && !runstate_check(RUN_STATE_INMIGRATE
)
1855 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
1857 "Guest must be stopped for opening of encrypted image");
1858 goto close_and_fail
;
1863 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
1864 * temporary snapshot afterwards. */
1865 if (snapshot_flags
) {
1866 BlockDriverState
*snapshot_bs
;
1867 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
1868 snapshot_options
, &local_err
);
1869 snapshot_options
= NULL
;
1871 goto close_and_fail
;
1873 /* We are not going to return bs but the overlay on top of it
1874 * (snapshot_bs); thus, we have to drop the strong reference to bs
1875 * (which we obtained by calling bdrv_new()). bs will not be deleted,
1876 * though, because the overlay still has a reference to it. */
1885 bdrv_unref_child(bs
, file
);
1887 QDECREF(snapshot_options
);
1888 QDECREF(bs
->explicit_options
);
1889 QDECREF(bs
->options
);
1893 error_propagate(errp
, local_err
);
1898 QDECREF(snapshot_options
);
1900 error_propagate(errp
, local_err
);
1904 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
1905 QDict
*options
, int flags
, Error
**errp
)
1907 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
1911 typedef struct BlockReopenQueueEntry
{
1913 BDRVReopenState state
;
1914 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1915 } BlockReopenQueueEntry
;
1918 * Adds a BlockDriverState to a simple queue for an atomic, transactional
1919 * reopen of multiple devices.
1921 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
1922 * already performed, or alternatively may be NULL a new BlockReopenQueue will
1923 * be created and initialized. This newly created BlockReopenQueue should be
1924 * passed back in for subsequent calls that are intended to be of the same
1927 * bs is the BlockDriverState to add to the reopen queue.
1929 * options contains the changed options for the associated bs
1930 * (the BlockReopenQueue takes ownership)
1932 * flags contains the open flags for the associated bs
1934 * returns a pointer to bs_queue, which is either the newly allocated
1935 * bs_queue, or the existing bs_queue being used.
1938 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
1939 BlockDriverState
*bs
,
1942 const BdrvChildRole
*role
,
1943 QDict
*parent_options
,
1948 BlockReopenQueueEntry
*bs_entry
;
1950 QDict
*old_options
, *explicit_options
;
1952 if (bs_queue
== NULL
) {
1953 bs_queue
= g_new0(BlockReopenQueue
, 1);
1954 QSIMPLEQ_INIT(bs_queue
);
1958 options
= qdict_new();
1961 /* Check if this BlockDriverState is already in the queue */
1962 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1963 if (bs
== bs_entry
->state
.bs
) {
1969 * Precedence of options:
1970 * 1. Explicitly passed in options (highest)
1971 * 2. Set in flags (only for top level)
1972 * 3. Retained from explicitly set options of bs
1973 * 4. Inherited from parent node
1974 * 5. Retained from effective options of bs
1977 if (!parent_options
) {
1979 * Any setting represented by flags is always updated. If the
1980 * corresponding QDict option is set, it takes precedence. Otherwise
1981 * the flag is translated into a QDict option. The old setting of bs is
1984 update_options_from_flags(options
, flags
);
1987 /* Old explicitly set values (don't overwrite by inherited value) */
1989 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
1991 old_options
= qdict_clone_shallow(bs
->explicit_options
);
1993 bdrv_join_options(bs
, options
, old_options
);
1994 QDECREF(old_options
);
1996 explicit_options
= qdict_clone_shallow(options
);
1998 /* Inherit from parent node */
1999 if (parent_options
) {
2001 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
2004 /* Old values are used for options that aren't set yet */
2005 old_options
= qdict_clone_shallow(bs
->options
);
2006 bdrv_join_options(bs
, options
, old_options
);
2007 QDECREF(old_options
);
2009 /* bdrv_open() masks this flag out */
2010 flags
&= ~BDRV_O_PROTOCOL
;
2012 QLIST_FOREACH(child
, &bs
->children
, next
) {
2013 QDict
*new_child_options
;
2014 char *child_key_dot
;
2016 /* reopen can only change the options of block devices that were
2017 * implicitly created and inherited options. For other (referenced)
2018 * block devices, a syntax like "backing.foo" results in an error. */
2019 if (child
->bs
->inherits_from
!= bs
) {
2023 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2024 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
2025 g_free(child_key_dot
);
2027 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
2028 child
->role
, options
, flags
);
2032 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
2033 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
2035 QDECREF(bs_entry
->state
.options
);
2036 QDECREF(bs_entry
->state
.explicit_options
);
2039 bs_entry
->state
.bs
= bs
;
2040 bs_entry
->state
.options
= options
;
2041 bs_entry
->state
.explicit_options
= explicit_options
;
2042 bs_entry
->state
.flags
= flags
;
2047 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
2048 BlockDriverState
*bs
,
2049 QDict
*options
, int flags
)
2051 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
2056 * Reopen multiple BlockDriverStates atomically & transactionally.
2058 * The queue passed in (bs_queue) must have been built up previous
2059 * via bdrv_reopen_queue().
2061 * Reopens all BDS specified in the queue, with the appropriate
2062 * flags. All devices are prepared for reopen, and failure of any
2063 * device will cause all device changes to be abandonded, and intermediate
2066 * If all devices prepare successfully, then the changes are committed
2070 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
)
2073 BlockReopenQueueEntry
*bs_entry
, *next
;
2074 Error
*local_err
= NULL
;
2076 assert(bs_queue
!= NULL
);
2080 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2081 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
2082 error_propagate(errp
, local_err
);
2085 bs_entry
->prepared
= true;
2088 /* If we reach this point, we have success and just need to apply the
2091 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2092 bdrv_reopen_commit(&bs_entry
->state
);
2098 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
2099 if (ret
&& bs_entry
->prepared
) {
2100 bdrv_reopen_abort(&bs_entry
->state
);
2102 QDECREF(bs_entry
->state
.explicit_options
);
2104 QDECREF(bs_entry
->state
.options
);
2112 /* Reopen a single BlockDriverState with the specified flags. */
2113 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
2116 Error
*local_err
= NULL
;
2117 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
2119 ret
= bdrv_reopen_multiple(queue
, &local_err
);
2120 if (local_err
!= NULL
) {
2121 error_propagate(errp
, local_err
);
2128 * Prepares a BlockDriverState for reopen. All changes are staged in the
2129 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2130 * the block driver layer .bdrv_reopen_prepare()
2132 * bs is the BlockDriverState to reopen
2133 * flags are the new open flags
2134 * queue is the reopen queue
2136 * Returns 0 on success, non-zero on error. On error errp will be set
2139 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2140 * It is the responsibility of the caller to then call the abort() or
2141 * commit() for any other BDS that have been left in a prepare() state
2144 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2148 Error
*local_err
= NULL
;
2153 assert(reopen_state
!= NULL
);
2154 assert(reopen_state
->bs
->drv
!= NULL
);
2155 drv
= reopen_state
->bs
->drv
;
2157 /* Process generic block layer options */
2158 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2159 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2161 error_propagate(errp
, local_err
);
2166 update_flags_from_options(&reopen_state
->flags
, opts
);
2168 /* node-name and driver must be unchanged. Put them back into the QDict, so
2169 * that they are checked at the end of this function. */
2170 value
= qemu_opt_get(opts
, "node-name");
2172 qdict_put(reopen_state
->options
, "node-name", qstring_from_str(value
));
2175 value
= qemu_opt_get(opts
, "driver");
2177 qdict_put(reopen_state
->options
, "driver", qstring_from_str(value
));
2180 /* if we are to stay read-only, do not allow permission change
2182 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
2183 reopen_state
->flags
& BDRV_O_RDWR
) {
2184 error_setg(errp
, "Node '%s' is read only",
2185 bdrv_get_device_or_node_name(reopen_state
->bs
));
2190 ret
= bdrv_flush(reopen_state
->bs
);
2192 error_setg_errno(errp
, -ret
, "Error flushing drive");
2196 if (drv
->bdrv_reopen_prepare
) {
2197 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2199 if (local_err
!= NULL
) {
2200 error_propagate(errp
, local_err
);
2202 error_setg(errp
, "failed while preparing to reopen image '%s'",
2203 reopen_state
->bs
->filename
);
2208 /* It is currently mandatory to have a bdrv_reopen_prepare()
2209 * handler for each supported drv. */
2210 error_setg(errp
, "Block format '%s' used by node '%s' "
2211 "does not support reopening files", drv
->format_name
,
2212 bdrv_get_device_or_node_name(reopen_state
->bs
));
2217 /* Options that are not handled are only okay if they are unchanged
2218 * compared to the old state. It is expected that some options are only
2219 * used for the initial open, but not reopen (e.g. filename) */
2220 if (qdict_size(reopen_state
->options
)) {
2221 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2224 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2225 const char *new = qstring_get_str(new_obj
);
2226 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2229 if (!old
|| strcmp(new, old
)) {
2230 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2234 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2240 qemu_opts_del(opts
);
2245 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2246 * makes them final by swapping the staging BlockDriverState contents into
2247 * the active BlockDriverState contents.
2249 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2253 assert(reopen_state
!= NULL
);
2254 drv
= reopen_state
->bs
->drv
;
2255 assert(drv
!= NULL
);
2257 /* If there are any driver level actions to take */
2258 if (drv
->bdrv_reopen_commit
) {
2259 drv
->bdrv_reopen_commit(reopen_state
);
2262 /* set BDS specific flags now */
2263 QDECREF(reopen_state
->bs
->explicit_options
);
2265 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2266 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2267 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2269 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2273 * Abort the reopen, and delete and free the staged changes in
2276 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2280 assert(reopen_state
!= NULL
);
2281 drv
= reopen_state
->bs
->drv
;
2282 assert(drv
!= NULL
);
2284 if (drv
->bdrv_reopen_abort
) {
2285 drv
->bdrv_reopen_abort(reopen_state
);
2288 QDECREF(reopen_state
->explicit_options
);
2292 static void bdrv_close(BlockDriverState
*bs
)
2294 BdrvAioNotifier
*ban
, *ban_next
;
2297 assert(!bs
->refcnt
);
2299 bdrv_drained_begin(bs
); /* complete I/O */
2301 bdrv_drain(bs
); /* in case flush left pending I/O */
2303 bdrv_release_named_dirty_bitmaps(bs
);
2304 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2307 BdrvChild
*child
, *next
;
2309 bs
->drv
->bdrv_close(bs
);
2312 bdrv_set_backing_hd(bs
, NULL
);
2314 if (bs
->file
!= NULL
) {
2315 bdrv_unref_child(bs
, bs
->file
);
2319 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2320 /* TODO Remove bdrv_unref() from drivers' close function and use
2321 * bdrv_unref_child() here */
2322 if (child
->bs
->inherits_from
== bs
) {
2323 child
->bs
->inherits_from
= NULL
;
2325 bdrv_detach_child(child
);
2330 bs
->copy_on_read
= 0;
2331 bs
->backing_file
[0] = '\0';
2332 bs
->backing_format
[0] = '\0';
2333 bs
->total_sectors
= 0;
2334 bs
->encrypted
= false;
2335 bs
->valid_key
= false;
2337 QDECREF(bs
->options
);
2338 QDECREF(bs
->explicit_options
);
2340 QDECREF(bs
->full_open_options
);
2341 bs
->full_open_options
= NULL
;
2344 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2347 QLIST_INIT(&bs
->aio_notifiers
);
2348 bdrv_drained_end(bs
);
2351 void bdrv_close_all(void)
2353 block_job_cancel_sync_all();
2354 nbd_export_close_all();
2356 /* Drop references from requests still in flight, such as canceled block
2357 * jobs whose AIO context has not been polled yet */
2360 blk_remove_all_bs();
2361 blockdev_close_all_bdrv_states();
2363 assert(QTAILQ_EMPTY(&all_bdrv_states
));
2366 static void change_parent_backing_link(BlockDriverState
*from
,
2367 BlockDriverState
*to
)
2369 BdrvChild
*c
, *next
, *to_c
;
2371 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
2372 if (c
->role
== &child_backing
) {
2373 /* @from is generally not allowed to be a backing file, except for
2374 * when @to is the overlay. In that case, @from may not be replaced
2375 * by @to as @to's backing node. */
2376 QLIST_FOREACH(to_c
, &to
->children
, next
) {
2386 assert(c
->role
!= &child_backing
);
2388 bdrv_replace_child(c
, to
);
2394 * Add new bs contents at the top of an image chain while the chain is
2395 * live, while keeping required fields on the top layer.
2397 * This will modify the BlockDriverState fields, and swap contents
2398 * between bs_new and bs_top. Both bs_new and bs_top are modified.
2400 * bs_new must not be attached to a BlockBackend.
2402 * This function does not create any image files.
2404 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
2405 * that's what the callers commonly need. bs_new will be referenced by the old
2406 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
2407 * reference of its own, it must call bdrv_ref().
2409 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
)
2411 assert(!bdrv_requests_pending(bs_top
));
2412 assert(!bdrv_requests_pending(bs_new
));
2416 change_parent_backing_link(bs_top
, bs_new
);
2417 bdrv_set_backing_hd(bs_new
, bs_top
);
2420 /* bs_new is now referenced by its new parents, we don't need the
2421 * additional reference any more. */
2425 void bdrv_replace_in_backing_chain(BlockDriverState
*old
, BlockDriverState
*new)
2427 assert(!bdrv_requests_pending(old
));
2428 assert(!bdrv_requests_pending(new));
2432 change_parent_backing_link(old
, new);
2437 static void bdrv_delete(BlockDriverState
*bs
)
2440 assert(bdrv_op_blocker_is_empty(bs
));
2441 assert(!bs
->refcnt
);
2445 /* remove from list, if necessary */
2446 if (bs
->node_name
[0] != '\0') {
2447 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
2449 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
2455 * Run consistency checks on an image
2457 * Returns 0 if the check could be completed (it doesn't mean that the image is
2458 * free of errors) or -errno when an internal error occurred. The results of the
2459 * check are stored in res.
2461 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
2463 if (bs
->drv
== NULL
) {
2466 if (bs
->drv
->bdrv_check
== NULL
) {
2470 memset(res
, 0, sizeof(*res
));
2471 return bs
->drv
->bdrv_check(bs
, res
, fix
);
2477 * -EINVAL - backing format specified, but no file
2478 * -ENOSPC - can't update the backing file because no space is left in the
2480 * -ENOTSUP - format driver doesn't support changing the backing file
2482 int bdrv_change_backing_file(BlockDriverState
*bs
,
2483 const char *backing_file
, const char *backing_fmt
)
2485 BlockDriver
*drv
= bs
->drv
;
2488 /* Backing file format doesn't make sense without a backing file */
2489 if (backing_fmt
&& !backing_file
) {
2493 if (drv
->bdrv_change_backing_file
!= NULL
) {
2494 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
2500 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2501 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2507 * Finds the image layer in the chain that has 'bs' as its backing file.
2509 * active is the current topmost image.
2511 * Returns NULL if bs is not found in active's image chain,
2512 * or if active == bs.
2514 * Returns the bottommost base image if bs == NULL.
2516 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
2517 BlockDriverState
*bs
)
2519 while (active
&& bs
!= backing_bs(active
)) {
2520 active
= backing_bs(active
);
2526 /* Given a BDS, searches for the base layer. */
2527 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
2529 return bdrv_find_overlay(bs
, NULL
);
2533 * Drops images above 'base' up to and including 'top', and sets the image
2534 * above 'top' to have base as its backing file.
2536 * Requires that the overlay to 'top' is opened r/w, so that the backing file
2537 * information in 'bs' can be properly updated.
2539 * E.g., this will convert the following chain:
2540 * bottom <- base <- intermediate <- top <- active
2544 * bottom <- base <- active
2546 * It is allowed for bottom==base, in which case it converts:
2548 * base <- intermediate <- top <- active
2554 * If backing_file_str is non-NULL, it will be used when modifying top's
2555 * overlay image metadata.
2558 * if active == top, that is considered an error
2561 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
2562 BlockDriverState
*base
, const char *backing_file_str
)
2564 BlockDriverState
*new_top_bs
= NULL
;
2567 if (!top
->drv
|| !base
->drv
) {
2571 new_top_bs
= bdrv_find_overlay(active
, top
);
2573 if (new_top_bs
== NULL
) {
2574 /* we could not find the image above 'top', this is an error */
2578 /* special case of new_top_bs->backing->bs already pointing to base - nothing
2579 * to do, no intermediate images */
2580 if (backing_bs(new_top_bs
) == base
) {
2585 /* Make sure that base is in the backing chain of top */
2586 if (!bdrv_chain_contains(top
, base
)) {
2590 /* success - we can delete the intermediate states, and link top->base */
2591 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
2592 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
2593 base
->drv
? base
->drv
->format_name
: "");
2597 bdrv_set_backing_hd(new_top_bs
, base
);
2605 * Truncate file to 'offset' bytes (needed only for file protocols)
2607 int bdrv_truncate(BlockDriverState
*bs
, int64_t offset
)
2609 BlockDriver
*drv
= bs
->drv
;
2613 if (!drv
->bdrv_truncate
)
2618 ret
= drv
->bdrv_truncate(bs
, offset
);
2620 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
2621 bdrv_dirty_bitmap_truncate(bs
);
2622 bdrv_parent_cb_resize(bs
);
2629 * Length of a allocated file in bytes. Sparse files are counted by actual
2630 * allocated space. Return < 0 if error or unknown.
2632 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
2634 BlockDriver
*drv
= bs
->drv
;
2638 if (drv
->bdrv_get_allocated_file_size
) {
2639 return drv
->bdrv_get_allocated_file_size(bs
);
2642 return bdrv_get_allocated_file_size(bs
->file
->bs
);
2648 * Return number of sectors on success, -errno on error.
2650 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
2652 BlockDriver
*drv
= bs
->drv
;
2657 if (drv
->has_variable_length
) {
2658 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
2663 return bs
->total_sectors
;
2667 * Return length in bytes on success, -errno on error.
2668 * The length is always a multiple of BDRV_SECTOR_SIZE.
2670 int64_t bdrv_getlength(BlockDriverState
*bs
)
2672 int64_t ret
= bdrv_nb_sectors(bs
);
2674 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
2675 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
2678 /* return 0 as number of sectors if no device present or error */
2679 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
2681 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
2683 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
2686 bool bdrv_is_read_only(BlockDriverState
*bs
)
2688 return bs
->read_only
;
2691 bool bdrv_is_sg(BlockDriverState
*bs
)
2696 bool bdrv_is_encrypted(BlockDriverState
*bs
)
2698 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2701 return bs
->encrypted
;
2704 bool bdrv_key_required(BlockDriverState
*bs
)
2706 BdrvChild
*backing
= bs
->backing
;
2708 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
2711 return (bs
->encrypted
&& !bs
->valid_key
);
2714 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
2717 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2718 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
2724 if (!bs
->encrypted
) {
2726 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
2729 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
2731 bs
->valid_key
= false;
2732 } else if (!bs
->valid_key
) {
2733 /* call the change callback now, we skipped it on open */
2734 bs
->valid_key
= true;
2735 bdrv_parent_cb_change_media(bs
, true);
2741 * Provide an encryption key for @bs.
2742 * If @key is non-null:
2743 * If @bs is not encrypted, fail.
2744 * Else if the key is invalid, fail.
2745 * Else set @bs's key to @key, replacing the existing key, if any.
2747 * If @bs is encrypted and still lacks a key, fail.
2749 * On failure, store an error object through @errp if non-null.
2751 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
2754 if (!bdrv_is_encrypted(bs
)) {
2755 error_setg(errp
, "Node '%s' is not encrypted",
2756 bdrv_get_device_or_node_name(bs
));
2757 } else if (bdrv_set_key(bs
, key
) < 0) {
2758 error_setg(errp
, QERR_INVALID_PASSWORD
);
2761 if (bdrv_key_required(bs
)) {
2762 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
2763 "'%s' (%s) is encrypted",
2764 bdrv_get_device_or_node_name(bs
),
2765 bdrv_get_encrypted_filename(bs
));
2770 const char *bdrv_get_format_name(BlockDriverState
*bs
)
2772 return bs
->drv
? bs
->drv
->format_name
: NULL
;
2775 static int qsort_strcmp(const void *a
, const void *b
)
2777 return strcmp(a
, b
);
2780 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
2786 const char **formats
= NULL
;
2788 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
2789 if (drv
->format_name
) {
2792 while (formats
&& i
&& !found
) {
2793 found
= !strcmp(formats
[--i
], drv
->format_name
);
2797 formats
= g_renew(const char *, formats
, count
+ 1);
2798 formats
[count
++] = drv
->format_name
;
2803 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
2805 for (i
= 0; i
< count
; i
++) {
2806 it(opaque
, formats
[i
]);
2812 /* This function is to find a node in the bs graph */
2813 BlockDriverState
*bdrv_find_node(const char *node_name
)
2815 BlockDriverState
*bs
;
2819 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2820 if (!strcmp(node_name
, bs
->node_name
)) {
2827 /* Put this QMP function here so it can access the static graph_bdrv_states. */
2828 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
2830 BlockDeviceInfoList
*list
, *entry
;
2831 BlockDriverState
*bs
;
2834 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2835 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
2837 qapi_free_BlockDeviceInfoList(list
);
2840 entry
= g_malloc0(sizeof(*entry
));
2841 entry
->value
= info
;
2849 BlockDriverState
*bdrv_lookup_bs(const char *device
,
2850 const char *node_name
,
2854 BlockDriverState
*bs
;
2857 blk
= blk_by_name(device
);
2862 error_setg(errp
, "Device '%s' has no medium", device
);
2870 bs
= bdrv_find_node(node_name
);
2877 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
2878 device
? device
: "",
2879 node_name
? node_name
: "");
2883 /* If 'base' is in the same chain as 'top', return true. Otherwise,
2884 * return false. If either argument is NULL, return false. */
2885 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
2887 while (top
&& top
!= base
) {
2888 top
= backing_bs(top
);
2894 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
2897 return QTAILQ_FIRST(&graph_bdrv_states
);
2899 return QTAILQ_NEXT(bs
, node_list
);
2902 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
2904 return bs
->node_name
;
2907 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
2912 /* If multiple parents have a name, just pick the first one. */
2913 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2914 if (c
->role
->get_name
) {
2915 name
= c
->role
->get_name(c
);
2916 if (name
&& *name
) {
2925 /* TODO check what callers really want: bs->node_name or blk_name() */
2926 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
2928 return bdrv_get_parent_name(bs
) ?: "";
2931 /* This can be used to identify nodes that might not have a device
2932 * name associated. Since node and device names live in the same
2933 * namespace, the result is unambiguous. The exception is if both are
2934 * absent, then this returns an empty (non-null) string. */
2935 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
2937 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
2940 int bdrv_get_flags(BlockDriverState
*bs
)
2942 return bs
->open_flags
;
2945 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
2950 int bdrv_has_zero_init(BlockDriverState
*bs
)
2954 /* If BS is a copy on write image, it is initialized to
2955 the contents of the base image, which may not be zeroes. */
2959 if (bs
->drv
->bdrv_has_zero_init
) {
2960 return bs
->drv
->bdrv_has_zero_init(bs
);
2967 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
2969 BlockDriverInfo bdi
;
2975 if (bdrv_get_info(bs
, &bdi
) == 0) {
2976 return bdi
.unallocated_blocks_are_zero
;
2982 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
2984 BlockDriverInfo bdi
;
2986 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
2990 if (bdrv_get_info(bs
, &bdi
) == 0) {
2991 return bdi
.can_write_zeroes_with_unmap
;
2997 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
2999 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
3000 return bs
->backing_file
;
3001 else if (bs
->encrypted
)
3002 return bs
->filename
;
3007 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3008 char *filename
, int filename_size
)
3010 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3013 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3015 BlockDriver
*drv
= bs
->drv
;
3018 if (!drv
->bdrv_get_info
)
3020 memset(bdi
, 0, sizeof(*bdi
));
3021 return drv
->bdrv_get_info(bs
, bdi
);
3024 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3026 BlockDriver
*drv
= bs
->drv
;
3027 if (drv
&& drv
->bdrv_get_specific_info
) {
3028 return drv
->bdrv_get_specific_info(bs
);
3033 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3035 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3039 bs
->drv
->bdrv_debug_event(bs
, event
);
3042 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3045 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3046 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3049 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3050 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3056 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3058 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3059 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3062 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3063 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3069 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3071 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3072 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3075 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3076 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3082 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3084 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3085 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3088 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3089 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3095 /* backing_file can either be relative, or absolute, or a protocol. If it is
3096 * relative, it must be relative to the chain. So, passing in bs->filename
3097 * from a BDS as backing_file should not be done, as that may be relative to
3098 * the CWD rather than the chain. */
3099 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3100 const char *backing_file
)
3102 char *filename_full
= NULL
;
3103 char *backing_file_full
= NULL
;
3104 char *filename_tmp
= NULL
;
3105 int is_protocol
= 0;
3106 BlockDriverState
*curr_bs
= NULL
;
3107 BlockDriverState
*retval
= NULL
;
3109 if (!bs
|| !bs
->drv
|| !backing_file
) {
3113 filename_full
= g_malloc(PATH_MAX
);
3114 backing_file_full
= g_malloc(PATH_MAX
);
3115 filename_tmp
= g_malloc(PATH_MAX
);
3117 is_protocol
= path_has_protocol(backing_file
);
3119 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3121 /* If either of the filename paths is actually a protocol, then
3122 * compare unmodified paths; otherwise make paths relative */
3123 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3124 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3125 retval
= curr_bs
->backing
->bs
;
3129 /* If not an absolute filename path, make it relative to the current
3130 * image's filename path */
3131 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3134 /* We are going to compare absolute pathnames */
3135 if (!realpath(filename_tmp
, filename_full
)) {
3139 /* We need to make sure the backing filename we are comparing against
3140 * is relative to the current image filename (or absolute) */
3141 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3142 curr_bs
->backing_file
);
3144 if (!realpath(filename_tmp
, backing_file_full
)) {
3148 if (strcmp(backing_file_full
, filename_full
) == 0) {
3149 retval
= curr_bs
->backing
->bs
;
3155 g_free(filename_full
);
3156 g_free(backing_file_full
);
3157 g_free(filename_tmp
);
3161 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3171 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3174 void bdrv_init(void)
3176 module_call_init(MODULE_INIT_BLOCK
);
3179 void bdrv_init_with_whitelist(void)
3181 use_bdrv_whitelist
= 1;
3185 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3188 Error
*local_err
= NULL
;
3195 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3198 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3200 if (bs
->drv
->bdrv_invalidate_cache
) {
3201 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3203 bs
->open_flags
|= BDRV_O_INACTIVE
;
3204 error_propagate(errp
, local_err
);
3209 QLIST_FOREACH(child
, &bs
->children
, next
) {
3210 bdrv_invalidate_cache(child
->bs
, &local_err
);
3212 bs
->open_flags
|= BDRV_O_INACTIVE
;
3213 error_propagate(errp
, local_err
);
3218 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3220 bs
->open_flags
|= BDRV_O_INACTIVE
;
3221 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3226 void bdrv_invalidate_cache_all(Error
**errp
)
3228 BlockDriverState
*bs
;
3229 Error
*local_err
= NULL
;
3230 BdrvNextIterator it
;
3232 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3233 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3235 aio_context_acquire(aio_context
);
3236 bdrv_invalidate_cache(bs
, &local_err
);
3237 aio_context_release(aio_context
);
3239 error_propagate(errp
, local_err
);
3245 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3251 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3252 ret
= bs
->drv
->bdrv_inactivate(bs
);
3258 QLIST_FOREACH(child
, &bs
->children
, next
) {
3259 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
3266 bs
->open_flags
|= BDRV_O_INACTIVE
;
3271 int bdrv_inactivate_all(void)
3273 BlockDriverState
*bs
= NULL
;
3274 BdrvNextIterator it
;
3278 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3279 aio_context_acquire(bdrv_get_aio_context(bs
));
3282 /* We do two passes of inactivation. The first pass calls to drivers'
3283 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
3284 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
3286 for (pass
= 0; pass
< 2; pass
++) {
3287 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3288 ret
= bdrv_inactivate_recurse(bs
, pass
);
3296 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3297 aio_context_release(bdrv_get_aio_context(bs
));
3303 /**************************************************************/
3304 /* removable device support */
3307 * Return TRUE if the media is present
3309 bool bdrv_is_inserted(BlockDriverState
*bs
)
3311 BlockDriver
*drv
= bs
->drv
;
3317 if (drv
->bdrv_is_inserted
) {
3318 return drv
->bdrv_is_inserted(bs
);
3320 QLIST_FOREACH(child
, &bs
->children
, next
) {
3321 if (!bdrv_is_inserted(child
->bs
)) {
3329 * Return whether the media changed since the last call to this
3330 * function, or -ENOTSUP if we don't know. Most drivers don't know.
3332 int bdrv_media_changed(BlockDriverState
*bs
)
3334 BlockDriver
*drv
= bs
->drv
;
3336 if (drv
&& drv
->bdrv_media_changed
) {
3337 return drv
->bdrv_media_changed(bs
);
3343 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
3345 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
3347 BlockDriver
*drv
= bs
->drv
;
3348 const char *device_name
;
3350 if (drv
&& drv
->bdrv_eject
) {
3351 drv
->bdrv_eject(bs
, eject_flag
);
3354 device_name
= bdrv_get_device_name(bs
);
3355 if (device_name
[0] != '\0') {
3356 qapi_event_send_device_tray_moved(device_name
,
3357 eject_flag
, &error_abort
);
3362 * Lock or unlock the media (if it is locked, the user won't be able
3363 * to eject it manually).
3365 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
3367 BlockDriver
*drv
= bs
->drv
;
3369 trace_bdrv_lock_medium(bs
, locked
);
3371 if (drv
&& drv
->bdrv_lock_medium
) {
3372 drv
->bdrv_lock_medium(bs
, locked
);
3376 /* Get a reference to bs */
3377 void bdrv_ref(BlockDriverState
*bs
)
3382 /* Release a previously grabbed reference to bs.
3383 * If after releasing, reference count is zero, the BlockDriverState is
3385 void bdrv_unref(BlockDriverState
*bs
)
3390 assert(bs
->refcnt
> 0);
3391 if (--bs
->refcnt
== 0) {
3396 struct BdrvOpBlocker
{
3398 QLIST_ENTRY(BdrvOpBlocker
) list
;
3401 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
3403 BdrvOpBlocker
*blocker
;
3404 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3405 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
3406 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
3408 *errp
= error_copy(blocker
->reason
);
3409 error_prepend(errp
, "Node '%s' is busy: ",
3410 bdrv_get_device_or_node_name(bs
));
3417 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3419 BdrvOpBlocker
*blocker
;
3420 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3422 blocker
= g_new0(BdrvOpBlocker
, 1);
3423 blocker
->reason
= reason
;
3424 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
3427 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3429 BdrvOpBlocker
*blocker
, *next
;
3430 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3431 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
3432 if (blocker
->reason
== reason
) {
3433 QLIST_REMOVE(blocker
, list
);
3439 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
3442 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3443 bdrv_op_block(bs
, i
, reason
);
3447 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
3450 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3451 bdrv_op_unblock(bs
, i
, reason
);
3455 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
3459 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3460 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
3467 void bdrv_img_create(const char *filename
, const char *fmt
,
3468 const char *base_filename
, const char *base_fmt
,
3469 char *options
, uint64_t img_size
, int flags
,
3470 Error
**errp
, bool quiet
)
3472 QemuOptsList
*create_opts
= NULL
;
3473 QemuOpts
*opts
= NULL
;
3474 const char *backing_fmt
, *backing_file
;
3476 BlockDriver
*drv
, *proto_drv
;
3477 Error
*local_err
= NULL
;
3480 /* Find driver and parse its options */
3481 drv
= bdrv_find_format(fmt
);
3483 error_setg(errp
, "Unknown file format '%s'", fmt
);
3487 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
3492 if (!drv
->create_opts
) {
3493 error_setg(errp
, "Format driver '%s' does not support image creation",
3498 if (!proto_drv
->create_opts
) {
3499 error_setg(errp
, "Protocol driver '%s' does not support image creation",
3500 proto_drv
->format_name
);
3504 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
3505 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
3507 /* Create parameter list with default values */
3508 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
3509 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
3511 /* Parse -o options */
3513 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
3515 error_report_err(local_err
);
3517 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
3522 if (base_filename
) {
3523 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
3525 error_setg(errp
, "Backing file not supported for file format '%s'",
3532 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
3534 error_setg(errp
, "Backing file format not supported for file "
3535 "format '%s'", fmt
);
3540 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
3542 if (!strcmp(filename
, backing_file
)) {
3543 error_setg(errp
, "Error: Trying to create an image with the "
3544 "same filename as the backing file");
3549 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
3551 // The size for the image must always be specified, with one exception:
3552 // If we are using a backing file, we can obtain the size from there
3553 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
3556 BlockDriverState
*bs
;
3557 char *full_backing
= g_new0(char, PATH_MAX
);
3560 QDict
*backing_options
= NULL
;
3562 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
3563 full_backing
, PATH_MAX
,
3566 g_free(full_backing
);
3570 /* backing files always opened read-only */
3572 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
3575 backing_options
= qdict_new();
3576 qdict_put(backing_options
, "driver",
3577 qstring_from_str(backing_fmt
));
3580 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
3582 g_free(full_backing
);
3586 size
= bdrv_getlength(bs
);
3588 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
3594 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
3598 error_setg(errp
, "Image creation needs a size parameter");
3604 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
3605 qemu_opts_print(opts
, " ");
3609 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
3611 if (ret
== -EFBIG
) {
3612 /* This is generally a better message than whatever the driver would
3613 * deliver (especially because of the cluster_size_hint), since that
3614 * is most probably not much different from "image too large". */
3615 const char *cluster_size_hint
= "";
3616 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
3617 cluster_size_hint
= " (try using a larger cluster size)";
3619 error_setg(errp
, "The image size is too large for file format '%s'"
3620 "%s", fmt
, cluster_size_hint
);
3621 error_free(local_err
);
3626 qemu_opts_del(opts
);
3627 qemu_opts_free(create_opts
);
3628 error_propagate(errp
, local_err
);
3631 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
3633 return bs
->aio_context
;
3636 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
3638 QLIST_REMOVE(ban
, list
);
3642 void bdrv_detach_aio_context(BlockDriverState
*bs
)
3644 BdrvAioNotifier
*baf
, *baf_tmp
;
3651 assert(!bs
->walking_aio_notifiers
);
3652 bs
->walking_aio_notifiers
= true;
3653 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
3655 bdrv_do_remove_aio_context_notifier(baf
);
3657 baf
->detach_aio_context(baf
->opaque
);
3660 /* Never mind iterating again to check for ->deleted. bdrv_close() will
3661 * remove remaining aio notifiers if we aren't called again.
3663 bs
->walking_aio_notifiers
= false;
3665 if (bs
->drv
->bdrv_detach_aio_context
) {
3666 bs
->drv
->bdrv_detach_aio_context(bs
);
3668 QLIST_FOREACH(child
, &bs
->children
, next
) {
3669 bdrv_detach_aio_context(child
->bs
);
3672 bs
->aio_context
= NULL
;
3675 void bdrv_attach_aio_context(BlockDriverState
*bs
,
3676 AioContext
*new_context
)
3678 BdrvAioNotifier
*ban
, *ban_tmp
;
3685 bs
->aio_context
= new_context
;
3687 QLIST_FOREACH(child
, &bs
->children
, next
) {
3688 bdrv_attach_aio_context(child
->bs
, new_context
);
3690 if (bs
->drv
->bdrv_attach_aio_context
) {
3691 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
3694 assert(!bs
->walking_aio_notifiers
);
3695 bs
->walking_aio_notifiers
= true;
3696 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
3698 bdrv_do_remove_aio_context_notifier(ban
);
3700 ban
->attached_aio_context(new_context
, ban
->opaque
);
3703 bs
->walking_aio_notifiers
= false;
3706 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
3708 bdrv_drain(bs
); /* ensure there are no in-flight requests */
3710 bdrv_detach_aio_context(bs
);
3712 /* This function executes in the old AioContext so acquire the new one in
3713 * case it runs in a different thread.
3715 aio_context_acquire(new_context
);
3716 bdrv_attach_aio_context(bs
, new_context
);
3717 aio_context_release(new_context
);
3720 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
3721 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
3722 void (*detach_aio_context
)(void *opaque
), void *opaque
)
3724 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
3725 *ban
= (BdrvAioNotifier
){
3726 .attached_aio_context
= attached_aio_context
,
3727 .detach_aio_context
= detach_aio_context
,
3731 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
3734 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
3735 void (*attached_aio_context
)(AioContext
*,
3737 void (*detach_aio_context
)(void *),
3740 BdrvAioNotifier
*ban
, *ban_next
;
3742 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3743 if (ban
->attached_aio_context
== attached_aio_context
&&
3744 ban
->detach_aio_context
== detach_aio_context
&&
3745 ban
->opaque
== opaque
&&
3746 ban
->deleted
== false)
3748 if (bs
->walking_aio_notifiers
) {
3749 ban
->deleted
= true;
3751 bdrv_do_remove_aio_context_notifier(ban
);
3760 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
3761 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
3763 if (!bs
->drv
->bdrv_amend_options
) {
3766 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
3769 /* This function will be called by the bdrv_recurse_is_first_non_filter method
3770 * of block filter and by bdrv_is_first_non_filter.
3771 * It is used to test if the given bs is the candidate or recurse more in the
3774 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
3775 BlockDriverState
*candidate
)
3777 /* return false if basic checks fails */
3778 if (!bs
|| !bs
->drv
) {
3782 /* the code reached a non block filter driver -> check if the bs is
3783 * the same as the candidate. It's the recursion termination condition.
3785 if (!bs
->drv
->is_filter
) {
3786 return bs
== candidate
;
3788 /* Down this path the driver is a block filter driver */
3790 /* If the block filter recursion method is defined use it to recurse down
3793 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
3794 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
3797 /* the driver is a block filter but don't allow to recurse -> return false
3802 /* This function checks if the candidate is the first non filter bs down it's
3803 * bs chain. Since we don't have pointers to parents it explore all bs chains
3804 * from the top. Some filters can choose not to pass down the recursion.
3806 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
3808 BlockDriverState
*bs
;
3809 BdrvNextIterator it
;
3811 /* walk down the bs forest recursively */
3812 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3815 /* try to recurse in this top level bs */
3816 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
3818 /* candidate is the first non filter */
3827 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
3828 const char *node_name
, Error
**errp
)
3830 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
3831 AioContext
*aio_context
;
3833 if (!to_replace_bs
) {
3834 error_setg(errp
, "Node name '%s' not found", node_name
);
3838 aio_context
= bdrv_get_aio_context(to_replace_bs
);
3839 aio_context_acquire(aio_context
);
3841 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
3842 to_replace_bs
= NULL
;
3846 /* We don't want arbitrary node of the BDS chain to be replaced only the top
3847 * most non filter in order to prevent data corruption.
3848 * Another benefit is that this tests exclude backing files which are
3849 * blocked by the backing blockers.
3851 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
3852 error_setg(errp
, "Only top most non filter can be replaced");
3853 to_replace_bs
= NULL
;
3858 aio_context_release(aio_context
);
3859 return to_replace_bs
;
3862 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
3864 const QDictEntry
*entry
;
3867 bool found_any
= false;
3870 for (entry
= qdict_first(bs
->options
); entry
;
3871 entry
= qdict_next(bs
->options
, entry
))
3873 /* Exclude options for children */
3874 QLIST_FOREACH(child
, &bs
->children
, next
) {
3875 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
3876 && (!*p
|| *p
== '.'))
3885 /* And exclude all non-driver-specific options */
3886 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
3887 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
3895 qobject_incref(qdict_entry_value(entry
));
3896 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
3903 /* Updates the following BDS fields:
3904 * - exact_filename: A filename which may be used for opening a block device
3905 * which (mostly) equals the given BDS (even without any
3906 * other options; so reading and writing must return the same
3907 * results, but caching etc. may be different)
3908 * - full_open_options: Options which, when given when opening a block device
3909 * (without a filename), result in a BDS (mostly)
3910 * equalling the given one
3911 * - filename: If exact_filename is set, it is copied here. Otherwise,
3912 * full_open_options is converted to a JSON object, prefixed with
3913 * "json:" (for use through the JSON pseudo protocol) and put here.
3915 void bdrv_refresh_filename(BlockDriverState
*bs
)
3917 BlockDriver
*drv
= bs
->drv
;
3924 /* This BDS's file name will most probably depend on its file's name, so
3925 * refresh that first */
3927 bdrv_refresh_filename(bs
->file
->bs
);
3930 if (drv
->bdrv_refresh_filename
) {
3931 /* Obsolete information is of no use here, so drop the old file name
3932 * information before refreshing it */
3933 bs
->exact_filename
[0] = '\0';
3934 if (bs
->full_open_options
) {
3935 QDECREF(bs
->full_open_options
);
3936 bs
->full_open_options
= NULL
;
3940 append_open_options(opts
, bs
);
3941 drv
->bdrv_refresh_filename(bs
, opts
);
3943 } else if (bs
->file
) {
3944 /* Try to reconstruct valid information from the underlying file */
3945 bool has_open_options
;
3947 bs
->exact_filename
[0] = '\0';
3948 if (bs
->full_open_options
) {
3949 QDECREF(bs
->full_open_options
);
3950 bs
->full_open_options
= NULL
;
3954 has_open_options
= append_open_options(opts
, bs
);
3956 /* If no specific options have been given for this BDS, the filename of
3957 * the underlying file should suffice for this one as well */
3958 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
3959 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
3961 /* Reconstructing the full options QDict is simple for most format block
3962 * drivers, as long as the full options are known for the underlying
3963 * file BDS. The full options QDict of that file BDS should somehow
3964 * contain a representation of the filename, therefore the following
3965 * suffices without querying the (exact_)filename of this BDS. */
3966 if (bs
->file
->bs
->full_open_options
) {
3967 qdict_put_obj(opts
, "driver",
3968 QOBJECT(qstring_from_str(drv
->format_name
)));
3969 QINCREF(bs
->file
->bs
->full_open_options
);
3970 qdict_put_obj(opts
, "file",
3971 QOBJECT(bs
->file
->bs
->full_open_options
));
3973 bs
->full_open_options
= opts
;
3977 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
3978 /* There is no underlying file BDS (at least referenced by BDS.file),
3979 * so the full options QDict should be equal to the options given
3980 * specifically for this block device when it was opened (plus the
3981 * driver specification).
3982 * Because those options don't change, there is no need to update
3983 * full_open_options when it's already set. */
3986 append_open_options(opts
, bs
);
3987 qdict_put_obj(opts
, "driver",
3988 QOBJECT(qstring_from_str(drv
->format_name
)));
3990 if (bs
->exact_filename
[0]) {
3991 /* This may not work for all block protocol drivers (some may
3992 * require this filename to be parsed), but we have to find some
3993 * default solution here, so just include it. If some block driver
3994 * does not support pure options without any filename at all or
3995 * needs some special format of the options QDict, it needs to
3996 * implement the driver-specific bdrv_refresh_filename() function.
3998 qdict_put_obj(opts
, "filename",
3999 QOBJECT(qstring_from_str(bs
->exact_filename
)));
4002 bs
->full_open_options
= opts
;
4005 if (bs
->exact_filename
[0]) {
4006 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4007 } else if (bs
->full_open_options
) {
4008 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4009 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4010 qstring_get_str(json
));
4016 * Hot add/remove a BDS's child. So the user can take a child offline when
4017 * it is broken and take a new child online
4019 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
4023 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
4024 error_setg(errp
, "The node %s does not support adding a child",
4025 bdrv_get_device_or_node_name(parent_bs
));
4029 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4030 error_setg(errp
, "The node %s already has a parent",
4031 child_bs
->node_name
);
4035 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4038 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4042 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4043 error_setg(errp
, "The node %s does not support removing a child",
4044 bdrv_get_device_or_node_name(parent_bs
));
4048 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4055 error_setg(errp
, "The node %s does not have a child named %s",
4056 bdrv_get_device_or_node_name(parent_bs
),
4057 bdrv_get_device_or_node_name(child
->bs
));
4061 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);