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"
25 #include "block/trace.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"
47 #include <sys/ioctl.h>
48 #include <sys/queue.h>
58 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
60 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
61 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
63 static QTAILQ_HEAD(, BlockDriverState
) all_bdrv_states
=
64 QTAILQ_HEAD_INITIALIZER(all_bdrv_states
);
66 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
67 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
69 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
70 const char *reference
,
71 QDict
*options
, int flags
,
72 BlockDriverState
*parent
,
73 const BdrvChildRole
*child_role
,
76 /* If non-zero, use only whitelisted block drivers */
77 static int use_bdrv_whitelist
;
80 static int is_windows_drive_prefix(const char *filename
)
82 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
83 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
87 int is_windows_drive(const char *filename
)
89 if (is_windows_drive_prefix(filename
) &&
92 if (strstart(filename
, "\\\\.\\", NULL
) ||
93 strstart(filename
, "//./", NULL
))
99 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
101 if (!bs
|| !bs
->drv
) {
102 /* page size or 4k (hdd sector size) should be on the safe side */
103 return MAX(4096, getpagesize());
106 return bs
->bl
.opt_mem_alignment
;
109 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
111 if (!bs
|| !bs
->drv
) {
112 /* page size or 4k (hdd sector size) should be on the safe side */
113 return MAX(4096, getpagesize());
116 return bs
->bl
.min_mem_alignment
;
119 /* check if the path starts with "<protocol>:" */
120 int path_has_protocol(const char *path
)
125 if (is_windows_drive(path
) ||
126 is_windows_drive_prefix(path
)) {
129 p
= path
+ strcspn(path
, ":/\\");
131 p
= path
+ strcspn(path
, ":/");
137 int path_is_absolute(const char *path
)
140 /* specific case for names like: "\\.\d:" */
141 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
144 return (*path
== '/' || *path
== '\\');
146 return (*path
== '/');
150 /* if filename is absolute, just copy it to dest. Otherwise, build a
151 path to it by considering it is relative to base_path. URL are
153 void path_combine(char *dest
, int dest_size
,
154 const char *base_path
,
155 const char *filename
)
162 if (path_is_absolute(filename
)) {
163 pstrcpy(dest
, dest_size
, filename
);
165 const char *protocol_stripped
= NULL
;
167 if (path_has_protocol(base_path
)) {
168 protocol_stripped
= strchr(base_path
, ':');
169 if (protocol_stripped
) {
173 p
= protocol_stripped
?: base_path
;
175 p1
= strrchr(base_path
, '/');
179 p2
= strrchr(base_path
, '\\');
191 if (len
> dest_size
- 1)
193 memcpy(dest
, base_path
, len
);
195 pstrcat(dest
, dest_size
, filename
);
200 * Helper function for bdrv_parse_filename() implementations to remove optional
201 * protocol prefixes (especially "file:") from a filename and for putting the
202 * stripped filename into the options QDict if there is such a prefix.
204 void bdrv_parse_filename_strip_prefix(const char *filename
, const char *prefix
,
207 if (strstart(filename
, prefix
, &filename
)) {
208 /* Stripping the explicit protocol prefix may result in a protocol
209 * prefix being (wrongly) detected (if the filename contains a colon) */
210 if (path_has_protocol(filename
)) {
211 QString
*fat_filename
;
213 /* This means there is some colon before the first slash; therefore,
214 * this cannot be an absolute path */
215 assert(!path_is_absolute(filename
));
217 /* And we can thus fix the protocol detection issue by prefixing it
219 fat_filename
= qstring_from_str("./");
220 qstring_append(fat_filename
, filename
);
222 assert(!path_has_protocol(qstring_get_str(fat_filename
)));
224 qdict_put(options
, "filename", fat_filename
);
226 /* If no protocol prefix was detected, we can use the shortened
228 qdict_put_str(options
, "filename", filename
);
234 /* Returns whether the image file is opened as read-only. Note that this can
235 * return false and writing to the image file is still not possible because the
236 * image is inactivated. */
237 bool bdrv_is_read_only(BlockDriverState
*bs
)
239 return bs
->read_only
;
242 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
243 bool ignore_allow_rdw
, Error
**errp
)
245 /* Do not set read_only if copy_on_read is enabled */
246 if (bs
->copy_on_read
&& read_only
) {
247 error_setg(errp
, "Can't set node '%s' to r/o with copy-on-read enabled",
248 bdrv_get_device_or_node_name(bs
));
252 /* Do not clear read_only if it is prohibited */
253 if (!read_only
&& !(bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
256 error_setg(errp
, "Node '%s' is read only",
257 bdrv_get_device_or_node_name(bs
));
264 int bdrv_set_read_only(BlockDriverState
*bs
, bool read_only
, Error
**errp
)
268 ret
= bdrv_can_set_read_only(bs
, read_only
, false, errp
);
273 bs
->read_only
= read_only
;
277 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
279 char *dest
, size_t sz
,
282 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
283 path_is_absolute(backing
))
285 pstrcpy(dest
, sz
, backing
);
286 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
287 error_setg(errp
, "Cannot use relative backing file names for '%s'",
290 path_combine(dest
, sz
, backed
, backing
);
294 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
297 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
299 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
303 void bdrv_register(BlockDriver
*bdrv
)
305 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
308 BlockDriverState
*bdrv_new(void)
310 BlockDriverState
*bs
;
313 bs
= g_new0(BlockDriverState
, 1);
314 QLIST_INIT(&bs
->dirty_bitmaps
);
315 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
316 QLIST_INIT(&bs
->op_blockers
[i
]);
318 notifier_with_return_list_init(&bs
->before_write_notifiers
);
319 qemu_co_mutex_init(&bs
->reqs_lock
);
320 qemu_mutex_init(&bs
->dirty_bitmap_mutex
);
322 bs
->aio_context
= qemu_get_aio_context();
324 qemu_co_queue_init(&bs
->flush_queue
);
326 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
331 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
335 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
336 if (!strcmp(drv1
->format_name
, format_name
)) {
344 BlockDriver
*bdrv_find_format(const char *format_name
)
349 drv1
= bdrv_do_find_format(format_name
);
354 /* The driver isn't registered, maybe we need to load a module */
355 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
356 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
357 block_module_load_one(block_driver_modules
[i
].library_name
);
362 return bdrv_do_find_format(format_name
);
365 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
367 static const char *whitelist_rw
[] = {
368 CONFIG_BDRV_RW_WHITELIST
370 static const char *whitelist_ro
[] = {
371 CONFIG_BDRV_RO_WHITELIST
375 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
376 return 1; /* no whitelist, anything goes */
379 for (p
= whitelist_rw
; *p
; p
++) {
380 if (!strcmp(drv
->format_name
, *p
)) {
385 for (p
= whitelist_ro
; *p
; p
++) {
386 if (!strcmp(drv
->format_name
, *p
)) {
394 bool bdrv_uses_whitelist(void)
396 return use_bdrv_whitelist
;
399 typedef struct CreateCo
{
407 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
409 Error
*local_err
= NULL
;
412 CreateCo
*cco
= opaque
;
415 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
416 error_propagate(&cco
->err
, local_err
);
420 int bdrv_create(BlockDriver
*drv
, const char* filename
,
421 QemuOpts
*opts
, Error
**errp
)
428 .filename
= g_strdup(filename
),
434 if (!drv
->bdrv_create
) {
435 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
440 if (qemu_in_coroutine()) {
441 /* Fast-path if already in coroutine context */
442 bdrv_create_co_entry(&cco
);
444 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
445 qemu_coroutine_enter(co
);
446 while (cco
.ret
== NOT_DONE
) {
447 aio_poll(qemu_get_aio_context(), true);
454 error_propagate(errp
, cco
.err
);
456 error_setg_errno(errp
, -ret
, "Could not create image");
461 g_free(cco
.filename
);
465 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
468 Error
*local_err
= NULL
;
471 drv
= bdrv_find_protocol(filename
, true, errp
);
476 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
477 error_propagate(errp
, local_err
);
482 * Try to get @bs's logical and physical block size.
483 * On success, store them in @bsz struct and return 0.
484 * On failure return -errno.
485 * @bs must not be empty.
487 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
489 BlockDriver
*drv
= bs
->drv
;
491 if (drv
&& drv
->bdrv_probe_blocksizes
) {
492 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
493 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
494 return bdrv_probe_blocksizes(bs
->file
->bs
, bsz
);
501 * Try to get @bs's geometry (cyls, heads, sectors).
502 * On success, store them in @geo struct and return 0.
503 * On failure return -errno.
504 * @bs must not be empty.
506 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
508 BlockDriver
*drv
= bs
->drv
;
510 if (drv
&& drv
->bdrv_probe_geometry
) {
511 return drv
->bdrv_probe_geometry(bs
, geo
);
512 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
513 return bdrv_probe_geometry(bs
->file
->bs
, geo
);
520 * Create a uniquely-named empty temporary file.
521 * Return 0 upon success, otherwise a negative errno value.
523 int get_tmp_filename(char *filename
, int size
)
526 char temp_dir
[MAX_PATH
];
527 /* GetTempFileName requires that its output buffer (4th param)
528 have length MAX_PATH or greater. */
529 assert(size
>= MAX_PATH
);
530 return (GetTempPath(MAX_PATH
, temp_dir
)
531 && GetTempFileName(temp_dir
, "qem", 0, filename
)
532 ? 0 : -GetLastError());
536 tmpdir
= getenv("TMPDIR");
540 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
543 fd
= mkstemp(filename
);
547 if (close(fd
) != 0) {
556 * Detect host devices. By convention, /dev/cdrom[N] is always
557 * recognized as a host CDROM.
559 static BlockDriver
*find_hdev_driver(const char *filename
)
561 int score_max
= 0, score
;
562 BlockDriver
*drv
= NULL
, *d
;
564 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
565 if (d
->bdrv_probe_device
) {
566 score
= d
->bdrv_probe_device(filename
);
567 if (score
> score_max
) {
577 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
581 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
582 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
590 BlockDriver
*bdrv_find_protocol(const char *filename
,
591 bool allow_protocol_prefix
,
600 /* TODO Drivers without bdrv_file_open must be specified explicitly */
603 * XXX(hch): we really should not let host device detection
604 * override an explicit protocol specification, but moving this
605 * later breaks access to device names with colons in them.
606 * Thanks to the brain-dead persistent naming schemes on udev-
607 * based Linux systems those actually are quite common.
609 drv1
= find_hdev_driver(filename
);
614 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
618 p
= strchr(filename
, ':');
621 if (len
> sizeof(protocol
) - 1)
622 len
= sizeof(protocol
) - 1;
623 memcpy(protocol
, filename
, len
);
624 protocol
[len
] = '\0';
626 drv1
= bdrv_do_find_protocol(protocol
);
631 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
632 if (block_driver_modules
[i
].protocol_name
&&
633 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
634 block_module_load_one(block_driver_modules
[i
].library_name
);
639 drv1
= bdrv_do_find_protocol(protocol
);
641 error_setg(errp
, "Unknown protocol '%s'", protocol
);
647 * Guess image format by probing its contents.
648 * This is not a good idea when your image is raw (CVE-2008-2004), but
649 * we do it anyway for backward compatibility.
651 * @buf contains the image's first @buf_size bytes.
652 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
653 * but can be smaller if the image file is smaller)
654 * @filename is its filename.
656 * For all block drivers, call the bdrv_probe() method to get its
658 * Return the first block driver with the highest probing score.
660 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
661 const char *filename
)
663 int score_max
= 0, score
;
664 BlockDriver
*drv
= NULL
, *d
;
666 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
668 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
669 if (score
> score_max
) {
679 static int find_image_format(BlockBackend
*file
, const char *filename
,
680 BlockDriver
**pdrv
, Error
**errp
)
683 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
686 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
687 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
692 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
694 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
700 drv
= bdrv_probe_all(buf
, ret
, filename
);
702 error_setg(errp
, "Could not determine image format: No compatible "
711 * Set the current 'total_sectors' value
712 * Return 0 on success, -errno on error.
714 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
716 BlockDriver
*drv
= bs
->drv
;
718 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
722 /* query actual device if possible, otherwise just trust the hint */
723 if (drv
->bdrv_getlength
) {
724 int64_t length
= drv
->bdrv_getlength(bs
);
728 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
731 bs
->total_sectors
= hint
;
736 * Combines a QDict of new block driver @options with any missing options taken
737 * from @old_options, so that leaving out an option defaults to its old value.
739 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
742 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
743 bs
->drv
->bdrv_join_options(options
, old_options
);
745 qdict_join(options
, old_options
, false);
750 * Set open flags for a given discard mode
752 * Return 0 on success, -1 if the discard mode was invalid.
754 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
756 *flags
&= ~BDRV_O_UNMAP
;
758 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
760 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
761 *flags
|= BDRV_O_UNMAP
;
770 * Set open flags for a given cache mode
772 * Return 0 on success, -1 if the cache mode was invalid.
774 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
776 *flags
&= ~BDRV_O_CACHE_MASK
;
778 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
779 *writethrough
= false;
780 *flags
|= BDRV_O_NOCACHE
;
781 } else if (!strcmp(mode
, "directsync")) {
782 *writethrough
= true;
783 *flags
|= BDRV_O_NOCACHE
;
784 } else if (!strcmp(mode
, "writeback")) {
785 *writethrough
= false;
786 } else if (!strcmp(mode
, "unsafe")) {
787 *writethrough
= false;
788 *flags
|= BDRV_O_NO_FLUSH
;
789 } else if (!strcmp(mode
, "writethrough")) {
790 *writethrough
= true;
798 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
800 BlockDriverState
*parent
= c
->opaque
;
801 return g_strdup(bdrv_get_device_or_node_name(parent
));
804 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
806 BlockDriverState
*bs
= child
->opaque
;
807 bdrv_drained_begin(bs
);
810 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
812 BlockDriverState
*bs
= child
->opaque
;
813 bdrv_drained_end(bs
);
816 static int bdrv_child_cb_inactivate(BdrvChild
*child
)
818 BlockDriverState
*bs
= child
->opaque
;
819 assert(bs
->open_flags
& BDRV_O_INACTIVE
);
824 * Returns the options and flags that a temporary snapshot should get, based on
825 * the originally requested flags (the originally requested image will have
826 * flags like a backing file)
828 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
829 int parent_flags
, QDict
*parent_options
)
831 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
833 /* For temporary files, unconditional cache=unsafe is fine */
834 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
835 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
837 /* Copy the read-only option from the parent */
838 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
840 /* aio=native doesn't work for cache.direct=off, so disable it for the
841 * temporary snapshot */
842 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
846 * Returns the options and flags that bs->file should get if a protocol driver
847 * is expected, based on the given options and flags for the parent BDS
849 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
850 int parent_flags
, QDict
*parent_options
)
852 int flags
= parent_flags
;
854 /* Enable protocol handling, disable format probing for bs->file */
855 flags
|= BDRV_O_PROTOCOL
;
857 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
859 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
860 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
861 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
863 /* Inherit the read-only option from the parent if it's not set */
864 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
866 /* Our block drivers take care to send flushes and respect unmap policy,
867 * so we can default to enable both on lower layers regardless of the
868 * corresponding parent options. */
869 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
871 /* Clear flags that only apply to the top layer */
872 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
875 *child_flags
= flags
;
878 const BdrvChildRole child_file
= {
879 .get_parent_desc
= bdrv_child_get_parent_desc
,
880 .inherit_options
= bdrv_inherited_options
,
881 .drained_begin
= bdrv_child_cb_drained_begin
,
882 .drained_end
= bdrv_child_cb_drained_end
,
883 .inactivate
= bdrv_child_cb_inactivate
,
887 * Returns the options and flags that bs->file should get if the use of formats
888 * (and not only protocols) is permitted for it, based on the given options and
889 * flags for the parent BDS
891 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
892 int parent_flags
, QDict
*parent_options
)
894 child_file
.inherit_options(child_flags
, child_options
,
895 parent_flags
, parent_options
);
897 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
900 const BdrvChildRole child_format
= {
901 .get_parent_desc
= bdrv_child_get_parent_desc
,
902 .inherit_options
= bdrv_inherited_fmt_options
,
903 .drained_begin
= bdrv_child_cb_drained_begin
,
904 .drained_end
= bdrv_child_cb_drained_end
,
905 .inactivate
= bdrv_child_cb_inactivate
,
908 static void bdrv_backing_attach(BdrvChild
*c
)
910 BlockDriverState
*parent
= c
->opaque
;
911 BlockDriverState
*backing_hd
= c
->bs
;
913 assert(!parent
->backing_blocker
);
914 error_setg(&parent
->backing_blocker
,
915 "node is used as backing hd of '%s'",
916 bdrv_get_device_or_node_name(parent
));
918 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
919 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
920 backing_hd
->filename
);
921 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
922 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
924 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
925 /* Otherwise we won't be able to commit or stream */
926 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
927 parent
->backing_blocker
);
928 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
929 parent
->backing_blocker
);
931 * We do backup in 3 ways:
933 * The target bs is new opened, and the source is top BDS
935 * Both the source and the target are top BDSes.
936 * 3. internal backup(used for block replication)
937 * Both the source and the target are backing file
939 * In case 1 and 2, neither the source nor the target is the backing file.
940 * In case 3, we will block the top BDS, so there is only one block job
941 * for the top BDS and its backing chain.
943 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
944 parent
->backing_blocker
);
945 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
946 parent
->backing_blocker
);
949 static void bdrv_backing_detach(BdrvChild
*c
)
951 BlockDriverState
*parent
= c
->opaque
;
953 assert(parent
->backing_blocker
);
954 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
955 error_free(parent
->backing_blocker
);
956 parent
->backing_blocker
= NULL
;
960 * Returns the options and flags that bs->backing should get, based on the
961 * given options and flags for the parent BDS
963 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
964 int parent_flags
, QDict
*parent_options
)
966 int flags
= parent_flags
;
968 /* The cache mode is inherited unmodified for backing files; except WCE,
969 * which is only applied on the top level (BlockBackend) */
970 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
971 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
972 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
974 /* backing files always opened read-only */
975 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
976 flags
&= ~BDRV_O_COPY_ON_READ
;
978 /* snapshot=on is handled on the top layer */
979 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
981 *child_flags
= flags
;
984 static int bdrv_backing_update_filename(BdrvChild
*c
, BlockDriverState
*base
,
985 const char *filename
, Error
**errp
)
987 BlockDriverState
*parent
= c
->opaque
;
990 ret
= bdrv_change_backing_file(parent
, filename
,
991 base
->drv
? base
->drv
->format_name
: "");
993 error_setg_errno(errp
, ret
, "Could not update backing file link");
999 const BdrvChildRole child_backing
= {
1000 .get_parent_desc
= bdrv_child_get_parent_desc
,
1001 .attach
= bdrv_backing_attach
,
1002 .detach
= bdrv_backing_detach
,
1003 .inherit_options
= bdrv_backing_options
,
1004 .drained_begin
= bdrv_child_cb_drained_begin
,
1005 .drained_end
= bdrv_child_cb_drained_end
,
1006 .inactivate
= bdrv_child_cb_inactivate
,
1007 .update_filename
= bdrv_backing_update_filename
,
1010 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
1012 int open_flags
= flags
;
1015 * Clear flags that are internal to the block layer before opening the
1018 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
1021 * Snapshots should be writable.
1023 if (flags
& BDRV_O_TEMPORARY
) {
1024 open_flags
|= BDRV_O_RDWR
;
1030 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
1032 *flags
&= ~BDRV_O_CACHE_MASK
;
1034 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
1035 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
1036 *flags
|= BDRV_O_NO_FLUSH
;
1039 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
1040 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
1041 *flags
|= BDRV_O_NOCACHE
;
1044 *flags
&= ~BDRV_O_RDWR
;
1046 assert(qemu_opt_find(opts
, BDRV_OPT_READ_ONLY
));
1047 if (!qemu_opt_get_bool(opts
, BDRV_OPT_READ_ONLY
, false)) {
1048 *flags
|= BDRV_O_RDWR
;
1053 static void update_options_from_flags(QDict
*options
, int flags
)
1055 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
1056 qdict_put_bool(options
, BDRV_OPT_CACHE_DIRECT
, flags
& BDRV_O_NOCACHE
);
1058 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
1059 qdict_put_bool(options
, BDRV_OPT_CACHE_NO_FLUSH
,
1060 flags
& BDRV_O_NO_FLUSH
);
1062 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
1063 qdict_put_bool(options
, BDRV_OPT_READ_ONLY
, !(flags
& BDRV_O_RDWR
));
1067 static void bdrv_assign_node_name(BlockDriverState
*bs
,
1068 const char *node_name
,
1071 char *gen_node_name
= NULL
;
1074 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
1075 } else if (!id_wellformed(node_name
)) {
1077 * Check for empty string or invalid characters, but not if it is
1078 * generated (generated names use characters not available to the user)
1080 error_setg(errp
, "Invalid node name");
1084 /* takes care of avoiding namespaces collisions */
1085 if (blk_by_name(node_name
)) {
1086 error_setg(errp
, "node-name=%s is conflicting with a device id",
1091 /* takes care of avoiding duplicates node names */
1092 if (bdrv_find_node(node_name
)) {
1093 error_setg(errp
, "Duplicate node name");
1097 /* copy node name into the bs and insert it into the graph list */
1098 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
1099 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
1101 g_free(gen_node_name
);
1104 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
1105 const char *node_name
, QDict
*options
,
1106 int open_flags
, Error
**errp
)
1108 Error
*local_err
= NULL
;
1111 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1113 error_propagate(errp
, local_err
);
1118 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1119 bs
->opaque
= g_malloc0(drv
->instance_size
);
1121 if (drv
->bdrv_file_open
) {
1122 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1123 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1124 } else if (drv
->bdrv_open
) {
1125 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1132 error_propagate(errp
, local_err
);
1133 } else if (bs
->filename
[0]) {
1134 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1136 error_setg_errno(errp
, -ret
, "Could not open image");
1141 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1143 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1147 bdrv_refresh_limits(bs
, &local_err
);
1149 error_propagate(errp
, local_err
);
1153 assert(bdrv_opt_mem_align(bs
) != 0);
1154 assert(bdrv_min_mem_align(bs
) != 0);
1155 assert(is_power_of_2(bs
->bl
.request_alignment
));
1160 if (bs
->file
!= NULL
) {
1161 bdrv_unref_child(bs
, bs
->file
);
1169 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1170 int flags
, Error
**errp
)
1172 BlockDriverState
*bs
;
1176 bs
->open_flags
= flags
;
1177 bs
->explicit_options
= qdict_new();
1178 bs
->options
= qdict_new();
1181 update_options_from_flags(bs
->options
, flags
);
1183 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1185 QDECREF(bs
->explicit_options
);
1186 bs
->explicit_options
= NULL
;
1187 QDECREF(bs
->options
);
1196 QemuOptsList bdrv_runtime_opts
= {
1197 .name
= "bdrv_common",
1198 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1201 .name
= "node-name",
1202 .type
= QEMU_OPT_STRING
,
1203 .help
= "Node name of the block device node",
1207 .type
= QEMU_OPT_STRING
,
1208 .help
= "Block driver to use for the node",
1211 .name
= BDRV_OPT_CACHE_DIRECT
,
1212 .type
= QEMU_OPT_BOOL
,
1213 .help
= "Bypass software writeback cache on the host",
1216 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1217 .type
= QEMU_OPT_BOOL
,
1218 .help
= "Ignore flush requests",
1221 .name
= BDRV_OPT_READ_ONLY
,
1222 .type
= QEMU_OPT_BOOL
,
1223 .help
= "Node is opened in read-only mode",
1226 .name
= "detect-zeroes",
1227 .type
= QEMU_OPT_STRING
,
1228 .help
= "try to optimize zero writes (off, on, unmap)",
1232 .type
= QEMU_OPT_STRING
,
1233 .help
= "discard operation (ignore/off, unmap/on)",
1236 .name
= BDRV_OPT_FORCE_SHARE
,
1237 .type
= QEMU_OPT_BOOL
,
1238 .help
= "always accept other writers (default: off)",
1240 { /* end of list */ }
1245 * Common part for opening disk images and files
1247 * Removes all processed options from *options.
1249 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1250 QDict
*options
, Error
**errp
)
1252 int ret
, open_flags
;
1253 const char *filename
;
1254 const char *driver_name
= NULL
;
1255 const char *node_name
= NULL
;
1256 const char *discard
;
1257 const char *detect_zeroes
;
1260 Error
*local_err
= NULL
;
1262 assert(bs
->file
== NULL
);
1263 assert(options
!= NULL
&& bs
->options
!= options
);
1265 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1266 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1268 error_propagate(errp
, local_err
);
1273 update_flags_from_options(&bs
->open_flags
, opts
);
1275 driver_name
= qemu_opt_get(opts
, "driver");
1276 drv
= bdrv_find_format(driver_name
);
1277 assert(drv
!= NULL
);
1279 bs
->force_share
= qemu_opt_get_bool(opts
, BDRV_OPT_FORCE_SHARE
, false);
1281 if (bs
->force_share
&& (bs
->open_flags
& BDRV_O_RDWR
)) {
1283 BDRV_OPT_FORCE_SHARE
1284 "=on can only be used with read-only images");
1290 filename
= blk_bs(file
)->filename
;
1293 * Caution: while qdict_get_try_str() is fine, getting
1294 * non-string types would require more care. When @options
1295 * come from -blockdev or blockdev_add, its members are typed
1296 * according to the QAPI schema, but when they come from
1297 * -drive, they're all QString.
1299 filename
= qdict_get_try_str(options
, "filename");
1302 if (drv
->bdrv_needs_filename
&& (!filename
|| !filename
[0])) {
1303 error_setg(errp
, "The '%s' block driver requires a file name",
1309 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1312 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1314 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1316 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1317 ? "Driver '%s' can only be used for read-only devices"
1318 : "Driver '%s' is not whitelisted",
1324 /* bdrv_new() and bdrv_close() make it so */
1325 assert(atomic_read(&bs
->copy_on_read
) == 0);
1327 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1328 if (!bs
->read_only
) {
1329 bdrv_enable_copy_on_read(bs
);
1331 error_setg(errp
, "Can't use copy-on-read on read-only device");
1337 discard
= qemu_opt_get(opts
, "discard");
1338 if (discard
!= NULL
) {
1339 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1340 error_setg(errp
, "Invalid discard option");
1346 detect_zeroes
= qemu_opt_get(opts
, "detect-zeroes");
1347 if (detect_zeroes
) {
1348 BlockdevDetectZeroesOptions value
=
1349 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup
,
1351 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
1354 error_propagate(errp
, local_err
);
1359 if (value
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
1360 !(bs
->open_flags
& BDRV_O_UNMAP
))
1362 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
1363 "without setting discard operation to unmap");
1368 bs
->detect_zeroes
= value
;
1371 if (filename
!= NULL
) {
1372 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1374 bs
->filename
[0] = '\0';
1376 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1378 /* Open the image, either directly or using a protocol */
1379 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1380 node_name
= qemu_opt_get(opts
, "node-name");
1382 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1383 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1388 qemu_opts_del(opts
);
1392 qemu_opts_del(opts
);
1396 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1398 QObject
*options_obj
;
1402 ret
= strstart(filename
, "json:", &filename
);
1405 options_obj
= qobject_from_json(filename
, errp
);
1407 /* Work around qobject_from_json() lossage TODO fix that */
1408 if (errp
&& !*errp
) {
1409 error_setg(errp
, "Could not parse the JSON options");
1412 error_prepend(errp
, "Could not parse the JSON options: ");
1416 options
= qobject_to_qdict(options_obj
);
1418 qobject_decref(options_obj
);
1419 error_setg(errp
, "Invalid JSON object given");
1423 qdict_flatten(options
);
1428 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1431 QDict
*json_options
;
1432 Error
*local_err
= NULL
;
1434 /* Parse json: pseudo-protocol */
1435 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1439 json_options
= parse_json_filename(*pfilename
, &local_err
);
1441 error_propagate(errp
, local_err
);
1445 /* Options given in the filename have lower priority than options
1446 * specified directly */
1447 qdict_join(options
, json_options
, false);
1448 QDECREF(json_options
);
1453 * Fills in default options for opening images and converts the legacy
1454 * filename/flags pair to option QDict entries.
1455 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1456 * block driver has been specified explicitly.
1458 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1459 int *flags
, Error
**errp
)
1461 const char *drvname
;
1462 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1463 bool parse_filename
= false;
1464 BlockDriver
*drv
= NULL
;
1465 Error
*local_err
= NULL
;
1468 * Caution: while qdict_get_try_str() is fine, getting non-string
1469 * types would require more care. When @options come from
1470 * -blockdev or blockdev_add, its members are typed according to
1471 * the QAPI schema, but when they come from -drive, they're all
1474 drvname
= qdict_get_try_str(*options
, "driver");
1476 drv
= bdrv_find_format(drvname
);
1478 error_setg(errp
, "Unknown driver '%s'", drvname
);
1481 /* If the user has explicitly specified the driver, this choice should
1482 * override the BDRV_O_PROTOCOL flag */
1483 protocol
= drv
->bdrv_file_open
;
1487 *flags
|= BDRV_O_PROTOCOL
;
1489 *flags
&= ~BDRV_O_PROTOCOL
;
1492 /* Translate cache options from flags into options */
1493 update_options_from_flags(*options
, *flags
);
1495 /* Fetch the file name from the options QDict if necessary */
1496 if (protocol
&& filename
) {
1497 if (!qdict_haskey(*options
, "filename")) {
1498 qdict_put_str(*options
, "filename", filename
);
1499 parse_filename
= true;
1501 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1507 /* Find the right block driver */
1508 /* See cautionary note on accessing @options above */
1509 filename
= qdict_get_try_str(*options
, "filename");
1511 if (!drvname
&& protocol
) {
1513 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1518 drvname
= drv
->format_name
;
1519 qdict_put_str(*options
, "driver", drvname
);
1521 error_setg(errp
, "Must specify either driver or file");
1526 assert(drv
|| !protocol
);
1528 /* Driver-specific filename parsing */
1529 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1530 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1532 error_propagate(errp
, local_err
);
1536 if (!drv
->bdrv_needs_filename
) {
1537 qdict_del(*options
, "filename");
1544 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
1545 uint64_t perm
, uint64_t shared
,
1546 GSList
*ignore_children
, Error
**errp
);
1547 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1548 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1550 typedef struct BlockReopenQueueEntry
{
1552 BDRVReopenState state
;
1553 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1554 } BlockReopenQueueEntry
;
1557 * Return the flags that @bs will have after the reopens in @q have
1558 * successfully completed. If @q is NULL (or @bs is not contained in @q),
1559 * return the current flags.
1561 static int bdrv_reopen_get_flags(BlockReopenQueue
*q
, BlockDriverState
*bs
)
1563 BlockReopenQueueEntry
*entry
;
1566 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
1567 if (entry
->state
.bs
== bs
) {
1568 return entry
->state
.flags
;
1573 return bs
->open_flags
;
1576 /* Returns whether the image file can be written to after the reopen queue @q
1577 * has been successfully applied, or right now if @q is NULL. */
1578 static bool bdrv_is_writable(BlockDriverState
*bs
, BlockReopenQueue
*q
)
1580 int flags
= bdrv_reopen_get_flags(q
, bs
);
1582 return (flags
& (BDRV_O_RDWR
| BDRV_O_INACTIVE
)) == BDRV_O_RDWR
;
1585 static void bdrv_child_perm(BlockDriverState
*bs
, BlockDriverState
*child_bs
,
1586 BdrvChild
*c
, const BdrvChildRole
*role
,
1587 BlockReopenQueue
*reopen_queue
,
1588 uint64_t parent_perm
, uint64_t parent_shared
,
1589 uint64_t *nperm
, uint64_t *nshared
)
1591 if (bs
->drv
&& bs
->drv
->bdrv_child_perm
) {
1592 bs
->drv
->bdrv_child_perm(bs
, c
, role
, reopen_queue
,
1593 parent_perm
, parent_shared
,
1596 /* TODO Take force_share from reopen_queue */
1597 if (child_bs
&& child_bs
->force_share
) {
1598 *nshared
= BLK_PERM_ALL
;
1603 * Check whether permissions on this node can be changed in a way that
1604 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1605 * permissions of all its parents. This involves checking whether all necessary
1606 * permission changes to child nodes can be performed.
1608 * A call to this function must always be followed by a call to bdrv_set_perm()
1609 * or bdrv_abort_perm_update().
1611 static int bdrv_check_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
1612 uint64_t cumulative_perms
,
1613 uint64_t cumulative_shared_perms
,
1614 GSList
*ignore_children
, Error
**errp
)
1616 BlockDriver
*drv
= bs
->drv
;
1620 /* Write permissions never work with read-only images */
1621 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1622 !bdrv_is_writable(bs
, q
))
1624 error_setg(errp
, "Block node is read-only");
1628 /* Check this node */
1633 if (drv
->bdrv_check_perm
) {
1634 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1635 cumulative_shared_perms
, errp
);
1638 /* Drivers that never have children can omit .bdrv_child_perm() */
1639 if (!drv
->bdrv_child_perm
) {
1640 assert(QLIST_EMPTY(&bs
->children
));
1644 /* Check all children */
1645 QLIST_FOREACH(c
, &bs
->children
, next
) {
1646 uint64_t cur_perm
, cur_shared
;
1647 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, q
,
1648 cumulative_perms
, cumulative_shared_perms
,
1649 &cur_perm
, &cur_shared
);
1650 ret
= bdrv_child_check_perm(c
, q
, cur_perm
, cur_shared
,
1651 ignore_children
, errp
);
1661 * Notifies drivers that after a previous bdrv_check_perm() call, the
1662 * permission update is not performed and any preparations made for it (e.g.
1663 * taken file locks) need to be undone.
1665 * This function recursively notifies all child nodes.
1667 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1669 BlockDriver
*drv
= bs
->drv
;
1676 if (drv
->bdrv_abort_perm_update
) {
1677 drv
->bdrv_abort_perm_update(bs
);
1680 QLIST_FOREACH(c
, &bs
->children
, next
) {
1681 bdrv_child_abort_perm_update(c
);
1685 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1686 uint64_t cumulative_shared_perms
)
1688 BlockDriver
*drv
= bs
->drv
;
1695 /* Update this node */
1696 if (drv
->bdrv_set_perm
) {
1697 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1700 /* Drivers that never have children can omit .bdrv_child_perm() */
1701 if (!drv
->bdrv_child_perm
) {
1702 assert(QLIST_EMPTY(&bs
->children
));
1706 /* Update all children */
1707 QLIST_FOREACH(c
, &bs
->children
, next
) {
1708 uint64_t cur_perm
, cur_shared
;
1709 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, NULL
,
1710 cumulative_perms
, cumulative_shared_perms
,
1711 &cur_perm
, &cur_shared
);
1712 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1716 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1717 uint64_t *shared_perm
)
1720 uint64_t cumulative_perms
= 0;
1721 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1723 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1724 cumulative_perms
|= c
->perm
;
1725 cumulative_shared_perms
&= c
->shared_perm
;
1728 *perm
= cumulative_perms
;
1729 *shared_perm
= cumulative_shared_perms
;
1732 static char *bdrv_child_user_desc(BdrvChild
*c
)
1734 if (c
->role
->get_parent_desc
) {
1735 return c
->role
->get_parent_desc(c
);
1738 return g_strdup("another user");
1741 char *bdrv_perm_names(uint64_t perm
)
1747 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1748 { BLK_PERM_WRITE
, "write" },
1749 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1750 { BLK_PERM_RESIZE
, "resize" },
1751 { BLK_PERM_GRAPH_MOD
, "change children" },
1755 char *result
= g_strdup("");
1756 struct perm_name
*p
;
1758 for (p
= permissions
; p
->name
; p
++) {
1759 if (perm
& p
->perm
) {
1761 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1770 * Checks whether a new reference to @bs can be added if the new user requires
1771 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1772 * set, the BdrvChild objects in this list are ignored in the calculations;
1773 * this allows checking permission updates for an existing reference.
1775 * Needs to be followed by a call to either bdrv_set_perm() or
1776 * bdrv_abort_perm_update(). */
1777 static int bdrv_check_update_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
1778 uint64_t new_used_perm
,
1779 uint64_t new_shared_perm
,
1780 GSList
*ignore_children
, Error
**errp
)
1783 uint64_t cumulative_perms
= new_used_perm
;
1784 uint64_t cumulative_shared_perms
= new_shared_perm
;
1786 /* There is no reason why anyone couldn't tolerate write_unchanged */
1787 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1789 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1790 if (g_slist_find(ignore_children
, c
)) {
1794 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1795 char *user
= bdrv_child_user_desc(c
);
1796 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1797 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1799 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1805 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1806 char *user
= bdrv_child_user_desc(c
);
1807 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1808 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1810 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1816 cumulative_perms
|= c
->perm
;
1817 cumulative_shared_perms
&= c
->shared_perm
;
1820 return bdrv_check_perm(bs
, q
, cumulative_perms
, cumulative_shared_perms
,
1821 ignore_children
, errp
);
1824 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1825 * bdrv_child_abort_perm_update(). */
1826 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
1827 uint64_t perm
, uint64_t shared
,
1828 GSList
*ignore_children
, Error
**errp
)
1832 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1833 ret
= bdrv_check_update_perm(c
->bs
, q
, perm
, shared
, ignore_children
, errp
);
1834 g_slist_free(ignore_children
);
1839 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
1841 uint64_t cumulative_perms
, cumulative_shared_perms
;
1844 c
->shared_perm
= shared
;
1846 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
1847 &cumulative_shared_perms
);
1848 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
1851 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
1853 bdrv_abort_perm_update(c
->bs
);
1856 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1861 ret
= bdrv_child_check_perm(c
, NULL
, perm
, shared
, NULL
, errp
);
1863 bdrv_child_abort_perm_update(c
);
1867 bdrv_child_set_perm(c
, perm
, shared
);
1872 #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1874 | BLK_PERM_WRITE_UNCHANGED \
1876 #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1878 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1879 const BdrvChildRole
*role
,
1880 BlockReopenQueue
*reopen_queue
,
1881 uint64_t perm
, uint64_t shared
,
1882 uint64_t *nperm
, uint64_t *nshared
)
1885 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
1886 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
1890 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
1891 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
1892 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
1893 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
1896 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1897 const BdrvChildRole
*role
,
1898 BlockReopenQueue
*reopen_queue
,
1899 uint64_t perm
, uint64_t shared
,
1900 uint64_t *nperm
, uint64_t *nshared
)
1902 bool backing
= (role
== &child_backing
);
1903 assert(role
== &child_backing
|| role
== &child_file
);
1906 /* Apart from the modifications below, the same permissions are
1907 * forwarded and left alone as for filters */
1908 bdrv_filter_default_perms(bs
, c
, role
, reopen_queue
, perm
, shared
,
1911 /* Format drivers may touch metadata even if the guest doesn't write */
1912 if (bdrv_is_writable(bs
, reopen_queue
)) {
1913 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1916 /* bs->file always needs to be consistent because of the metadata. We
1917 * can never allow other users to resize or write to it. */
1918 perm
|= BLK_PERM_CONSISTENT_READ
;
1919 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
1921 /* We want consistent read from backing files if the parent needs it.
1922 * No other operations are performed on backing files. */
1923 perm
&= BLK_PERM_CONSISTENT_READ
;
1925 /* If the parent can deal with changing data, we're okay with a
1926 * writable and resizable backing file. */
1927 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1928 if (shared
& BLK_PERM_WRITE
) {
1929 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1934 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
1935 BLK_PERM_WRITE_UNCHANGED
;
1938 if (bs
->open_flags
& BDRV_O_INACTIVE
) {
1939 shared
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1946 static void bdrv_replace_child_noperm(BdrvChild
*child
,
1947 BlockDriverState
*new_bs
)
1949 BlockDriverState
*old_bs
= child
->bs
;
1951 if (old_bs
&& new_bs
) {
1952 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
1955 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1956 child
->role
->drained_end(child
);
1958 if (child
->role
->detach
) {
1959 child
->role
->detach(child
);
1961 QLIST_REMOVE(child
, next_parent
);
1967 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1968 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1969 child
->role
->drained_begin(child
);
1972 if (child
->role
->attach
) {
1973 child
->role
->attach(child
);
1979 * Updates @child to change its reference to point to @new_bs, including
1980 * checking and applying the necessary permisson updates both to the old node
1983 * NULL is passed as @new_bs for removing the reference before freeing @child.
1985 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
1986 * function uses bdrv_set_perm() to update the permissions according to the new
1987 * reference that @new_bs gets.
1989 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1991 BlockDriverState
*old_bs
= child
->bs
;
1992 uint64_t perm
, shared_perm
;
1994 bdrv_replace_child_noperm(child
, new_bs
);
1997 /* Update permissions for old node. This is guaranteed to succeed
1998 * because we're just taking a parent away, so we're loosening
2000 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
2001 bdrv_check_perm(old_bs
, NULL
, perm
, shared_perm
, NULL
, &error_abort
);
2002 bdrv_set_perm(old_bs
, perm
, shared_perm
);
2006 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
2007 bdrv_set_perm(new_bs
, perm
, shared_perm
);
2011 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
2012 const char *child_name
,
2013 const BdrvChildRole
*child_role
,
2014 uint64_t perm
, uint64_t shared_perm
,
2015 void *opaque
, Error
**errp
)
2020 ret
= bdrv_check_update_perm(child_bs
, NULL
, perm
, shared_perm
, NULL
, errp
);
2022 bdrv_abort_perm_update(child_bs
);
2026 child
= g_new(BdrvChild
, 1);
2027 *child
= (BdrvChild
) {
2029 .name
= g_strdup(child_name
),
2032 .shared_perm
= shared_perm
,
2036 /* This performs the matching bdrv_set_perm() for the above check. */
2037 bdrv_replace_child(child
, child_bs
);
2042 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
2043 BlockDriverState
*child_bs
,
2044 const char *child_name
,
2045 const BdrvChildRole
*child_role
,
2049 uint64_t perm
, shared_perm
;
2051 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
2053 assert(parent_bs
->drv
);
2054 assert(bdrv_get_aio_context(parent_bs
) == bdrv_get_aio_context(child_bs
));
2055 bdrv_child_perm(parent_bs
, child_bs
, NULL
, child_role
, NULL
,
2056 perm
, shared_perm
, &perm
, &shared_perm
);
2058 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
2059 perm
, shared_perm
, parent_bs
, errp
);
2060 if (child
== NULL
) {
2064 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
2068 static void bdrv_detach_child(BdrvChild
*child
)
2070 if (child
->next
.le_prev
) {
2071 QLIST_REMOVE(child
, next
);
2072 child
->next
.le_prev
= NULL
;
2075 bdrv_replace_child(child
, NULL
);
2077 g_free(child
->name
);
2081 void bdrv_root_unref_child(BdrvChild
*child
)
2083 BlockDriverState
*child_bs
;
2085 child_bs
= child
->bs
;
2086 bdrv_detach_child(child
);
2087 bdrv_unref(child_bs
);
2090 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
2092 if (child
== NULL
) {
2096 if (child
->bs
->inherits_from
== parent
) {
2099 /* Remove inherits_from only when the last reference between parent and
2100 * child->bs goes away. */
2101 QLIST_FOREACH(c
, &parent
->children
, next
) {
2102 if (c
!= child
&& c
->bs
== child
->bs
) {
2107 child
->bs
->inherits_from
= NULL
;
2111 bdrv_root_unref_child(child
);
2115 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
2118 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2119 if (c
->role
->change_media
) {
2120 c
->role
->change_media(c
, load
);
2125 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
2128 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2129 if (c
->role
->resize
) {
2136 * Sets the backing file link of a BDS. A new reference is created; callers
2137 * which don't need their own reference any more must call bdrv_unref().
2139 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
2143 bdrv_ref(backing_hd
);
2147 bdrv_unref_child(bs
, bs
->backing
);
2155 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
2158 bdrv_unref(backing_hd
);
2161 bdrv_refresh_filename(bs
);
2164 bdrv_refresh_limits(bs
, NULL
);
2168 * Opens the backing file for a BlockDriverState if not yet open
2170 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2171 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2172 * itself, all options starting with "${bdref_key}." are considered part of the
2175 * TODO Can this be unified with bdrv_open_image()?
2177 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
2178 const char *bdref_key
, Error
**errp
)
2180 char *backing_filename
= g_malloc0(PATH_MAX
);
2181 char *bdref_key_dot
;
2182 const char *reference
= NULL
;
2184 BlockDriverState
*backing_hd
;
2186 QDict
*tmp_parent_options
= NULL
;
2187 Error
*local_err
= NULL
;
2189 if (bs
->backing
!= NULL
) {
2193 /* NULL means an empty set of options */
2194 if (parent_options
== NULL
) {
2195 tmp_parent_options
= qdict_new();
2196 parent_options
= tmp_parent_options
;
2199 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2201 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2202 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2203 g_free(bdref_key_dot
);
2206 * Caution: while qdict_get_try_str() is fine, getting non-string
2207 * types would require more care. When @parent_options come from
2208 * -blockdev or blockdev_add, its members are typed according to
2209 * the QAPI schema, but when they come from -drive, they're all
2212 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2213 if (reference
|| qdict_haskey(options
, "file.filename")) {
2214 backing_filename
[0] = '\0';
2215 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2219 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
2223 error_propagate(errp
, local_err
);
2229 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2231 error_setg(errp
, "Driver doesn't support backing files");
2236 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2237 qdict_put_str(options
, "driver", bs
->backing_format
);
2240 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
2241 reference
, options
, 0, bs
, &child_backing
,
2244 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2245 error_prepend(errp
, "Could not open backing file: ");
2249 bdrv_set_aio_context(backing_hd
, bdrv_get_aio_context(bs
));
2251 /* Hook up the backing file link; drop our reference, bs owns the
2252 * backing_hd reference now */
2253 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2254 bdrv_unref(backing_hd
);
2256 error_propagate(errp
, local_err
);
2261 qdict_del(parent_options
, bdref_key
);
2264 g_free(backing_filename
);
2265 QDECREF(tmp_parent_options
);
2269 static BlockDriverState
*
2270 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2271 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2272 bool allow_none
, Error
**errp
)
2274 BlockDriverState
*bs
= NULL
;
2275 QDict
*image_options
;
2276 char *bdref_key_dot
;
2277 const char *reference
;
2279 assert(child_role
!= NULL
);
2281 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2282 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2283 g_free(bdref_key_dot
);
2286 * Caution: while qdict_get_try_str() is fine, getting non-string
2287 * types would require more care. When @options come from
2288 * -blockdev or blockdev_add, its members are typed according to
2289 * the QAPI schema, but when they come from -drive, they're all
2292 reference
= qdict_get_try_str(options
, bdref_key
);
2293 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2295 error_setg(errp
, "A block device must be specified for \"%s\"",
2298 QDECREF(image_options
);
2302 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2303 parent
, child_role
, errp
);
2309 qdict_del(options
, bdref_key
);
2314 * Opens a disk image whose options are given as BlockdevRef in another block
2317 * If allow_none is true, no image will be opened if filename is false and no
2318 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2320 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2321 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2322 * itself, all options starting with "${bdref_key}." are considered part of the
2325 * The BlockdevRef will be removed from the options QDict.
2327 BdrvChild
*bdrv_open_child(const char *filename
,
2328 QDict
*options
, const char *bdref_key
,
2329 BlockDriverState
*parent
,
2330 const BdrvChildRole
*child_role
,
2331 bool allow_none
, Error
**errp
)
2334 BlockDriverState
*bs
;
2336 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2342 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2351 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2353 QDict
*snapshot_options
,
2356 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2357 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2359 QemuOpts
*opts
= NULL
;
2360 BlockDriverState
*bs_snapshot
= NULL
;
2361 Error
*local_err
= NULL
;
2364 /* if snapshot, we create a temporary backing file and open it
2365 instead of opening 'filename' directly */
2367 /* Get the required size from the image */
2368 total_size
= bdrv_getlength(bs
);
2369 if (total_size
< 0) {
2370 error_setg_errno(errp
, -total_size
, "Could not get image size");
2374 /* Create the temporary image */
2375 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2377 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2381 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2383 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2384 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2385 qemu_opts_del(opts
);
2387 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2392 /* Prepare options QDict for the temporary file */
2393 qdict_put_str(snapshot_options
, "file.driver", "file");
2394 qdict_put_str(snapshot_options
, "file.filename", tmp_filename
);
2395 qdict_put_str(snapshot_options
, "driver", "qcow2");
2397 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2398 snapshot_options
= NULL
;
2403 /* bdrv_append() consumes a strong reference to bs_snapshot
2404 * (i.e. it will call bdrv_unref() on it) even on error, so in
2405 * order to be able to return one, we have to increase
2406 * bs_snapshot's refcount here */
2407 bdrv_ref(bs_snapshot
);
2408 bdrv_append(bs_snapshot
, bs
, &local_err
);
2410 error_propagate(errp
, local_err
);
2416 QDECREF(snapshot_options
);
2417 g_free(tmp_filename
);
2422 * Opens a disk image (raw, qcow2, vmdk, ...)
2424 * options is a QDict of options to pass to the block drivers, or NULL for an
2425 * empty set of options. The reference to the QDict belongs to the block layer
2426 * after the call (even on failure), so if the caller intends to reuse the
2427 * dictionary, it needs to use QINCREF() before calling bdrv_open.
2429 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2430 * If it is not NULL, the referenced BDS will be reused.
2432 * The reference parameter may be used to specify an existing block device which
2433 * should be opened. If specified, neither options nor a filename may be given,
2434 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2436 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2437 const char *reference
,
2438 QDict
*options
, int flags
,
2439 BlockDriverState
*parent
,
2440 const BdrvChildRole
*child_role
,
2444 BlockBackend
*file
= NULL
;
2445 BlockDriverState
*bs
;
2446 BlockDriver
*drv
= NULL
;
2447 const char *drvname
;
2448 const char *backing
;
2449 Error
*local_err
= NULL
;
2450 QDict
*snapshot_options
= NULL
;
2451 int snapshot_flags
= 0;
2453 assert(!child_role
|| !flags
);
2454 assert(!child_role
== !parent
);
2457 bool options_non_empty
= options
? qdict_size(options
) : false;
2460 if (filename
|| options_non_empty
) {
2461 error_setg(errp
, "Cannot reference an existing block device with "
2462 "additional options or a new filename");
2466 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2477 /* NULL means an empty set of options */
2478 if (options
== NULL
) {
2479 options
= qdict_new();
2482 /* json: syntax counts as explicit options, as if in the QDict */
2483 parse_json_protocol(options
, &filename
, &local_err
);
2488 bs
->explicit_options
= qdict_clone_shallow(options
);
2491 bs
->inherits_from
= parent
;
2492 child_role
->inherit_options(&flags
, options
,
2493 parent
->open_flags
, parent
->options
);
2496 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2502 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2503 * Caution: getting a boolean member of @options requires care.
2504 * When @options come from -blockdev or blockdev_add, members are
2505 * typed according to the QAPI schema, but when they come from
2506 * -drive, they're all QString.
2508 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2509 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2510 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2512 flags
&= ~BDRV_O_RDWR
;
2515 if (flags
& BDRV_O_SNAPSHOT
) {
2516 snapshot_options
= qdict_new();
2517 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2519 /* Let bdrv_backing_options() override "read-only" */
2520 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2521 bdrv_backing_options(&flags
, options
, flags
, options
);
2524 bs
->open_flags
= flags
;
2525 bs
->options
= options
;
2526 options
= qdict_clone_shallow(options
);
2528 /* Find the right image format driver */
2529 /* See cautionary note on accessing @options above */
2530 drvname
= qdict_get_try_str(options
, "driver");
2532 drv
= bdrv_find_format(drvname
);
2534 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2539 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2541 /* See cautionary note on accessing @options above */
2542 backing
= qdict_get_try_str(options
, "backing");
2543 if (backing
&& *backing
== '\0') {
2544 flags
|= BDRV_O_NO_BACKING
;
2545 qdict_del(options
, "backing");
2548 /* Open image file without format layer. This BlockBackend is only used for
2549 * probing, the block drivers will do their own bdrv_open_child() for the
2550 * same BDS, which is why we put the node name back into options. */
2551 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2552 BlockDriverState
*file_bs
;
2554 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2555 &child_file
, true, &local_err
);
2559 if (file_bs
!= NULL
) {
2560 file
= blk_new(BLK_PERM_CONSISTENT_READ
, BLK_PERM_ALL
);
2561 blk_insert_bs(file
, file_bs
, &local_err
);
2562 bdrv_unref(file_bs
);
2567 qdict_put_str(options
, "file", bdrv_get_node_name(file_bs
));
2571 /* Image format probing */
2574 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2579 * This option update would logically belong in bdrv_fill_options(),
2580 * but we first need to open bs->file for the probing to work, while
2581 * opening bs->file already requires the (mostly) final set of options
2582 * so that cache mode etc. can be inherited.
2584 * Adding the driver later is somewhat ugly, but it's not an option
2585 * that would ever be inherited, so it's correct. We just need to make
2586 * sure to update both bs->options (which has the full effective
2587 * options for bs) and options (which has file.* already removed).
2589 qdict_put_str(bs
->options
, "driver", drv
->format_name
);
2590 qdict_put_str(options
, "driver", drv
->format_name
);
2592 error_setg(errp
, "Must specify either driver or file");
2596 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2597 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2598 /* file must be NULL if a protocol BDS is about to be created
2599 * (the inverse results in an error message from bdrv_open_common()) */
2600 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2602 /* Open the image */
2603 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2613 /* If there is a backing file, use it */
2614 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2615 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2617 goto close_and_fail
;
2621 bdrv_refresh_filename(bs
);
2623 /* Check if any unknown options were used */
2624 if (qdict_size(options
) != 0) {
2625 const QDictEntry
*entry
= qdict_first(options
);
2626 if (flags
& BDRV_O_PROTOCOL
) {
2627 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2628 "'%s'", drv
->format_name
, entry
->key
);
2631 "Block format '%s' does not support the option '%s'",
2632 drv
->format_name
, entry
->key
);
2635 goto close_and_fail
;
2638 bdrv_parent_cb_change_media(bs
, true);
2642 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2643 * temporary snapshot afterwards. */
2644 if (snapshot_flags
) {
2645 BlockDriverState
*snapshot_bs
;
2646 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2647 snapshot_options
, &local_err
);
2648 snapshot_options
= NULL
;
2650 goto close_and_fail
;
2652 /* We are not going to return bs but the overlay on top of it
2653 * (snapshot_bs); thus, we have to drop the strong reference to bs
2654 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2655 * though, because the overlay still has a reference to it. */
2664 QDECREF(snapshot_options
);
2665 QDECREF(bs
->explicit_options
);
2666 QDECREF(bs
->options
);
2669 bs
->explicit_options
= NULL
;
2671 error_propagate(errp
, local_err
);
2676 QDECREF(snapshot_options
);
2678 error_propagate(errp
, local_err
);
2682 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2683 QDict
*options
, int flags
, Error
**errp
)
2685 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2690 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2691 * reopen of multiple devices.
2693 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2694 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2695 * be created and initialized. This newly created BlockReopenQueue should be
2696 * passed back in for subsequent calls that are intended to be of the same
2699 * bs is the BlockDriverState to add to the reopen queue.
2701 * options contains the changed options for the associated bs
2702 * (the BlockReopenQueue takes ownership)
2704 * flags contains the open flags for the associated bs
2706 * returns a pointer to bs_queue, which is either the newly allocated
2707 * bs_queue, or the existing bs_queue being used.
2710 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
2711 BlockDriverState
*bs
,
2714 const BdrvChildRole
*role
,
2715 QDict
*parent_options
,
2720 BlockReopenQueueEntry
*bs_entry
;
2722 QDict
*old_options
, *explicit_options
;
2724 if (bs_queue
== NULL
) {
2725 bs_queue
= g_new0(BlockReopenQueue
, 1);
2726 QSIMPLEQ_INIT(bs_queue
);
2730 options
= qdict_new();
2733 /* Check if this BlockDriverState is already in the queue */
2734 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2735 if (bs
== bs_entry
->state
.bs
) {
2741 * Precedence of options:
2742 * 1. Explicitly passed in options (highest)
2743 * 2. Set in flags (only for top level)
2744 * 3. Retained from explicitly set options of bs
2745 * 4. Inherited from parent node
2746 * 5. Retained from effective options of bs
2749 if (!parent_options
) {
2751 * Any setting represented by flags is always updated. If the
2752 * corresponding QDict option is set, it takes precedence. Otherwise
2753 * the flag is translated into a QDict option. The old setting of bs is
2756 update_options_from_flags(options
, flags
);
2759 /* Old explicitly set values (don't overwrite by inherited value) */
2761 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
2763 old_options
= qdict_clone_shallow(bs
->explicit_options
);
2765 bdrv_join_options(bs
, options
, old_options
);
2766 QDECREF(old_options
);
2768 explicit_options
= qdict_clone_shallow(options
);
2770 /* Inherit from parent node */
2771 if (parent_options
) {
2773 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
2776 /* Old values are used for options that aren't set yet */
2777 old_options
= qdict_clone_shallow(bs
->options
);
2778 bdrv_join_options(bs
, options
, old_options
);
2779 QDECREF(old_options
);
2781 /* bdrv_open_inherit() sets and clears some additional flags internally */
2782 flags
&= ~BDRV_O_PROTOCOL
;
2783 if (flags
& BDRV_O_RDWR
) {
2784 flags
|= BDRV_O_ALLOW_RDWR
;
2788 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
2789 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
2791 QDECREF(bs_entry
->state
.options
);
2792 QDECREF(bs_entry
->state
.explicit_options
);
2795 bs_entry
->state
.bs
= bs
;
2796 bs_entry
->state
.options
= options
;
2797 bs_entry
->state
.explicit_options
= explicit_options
;
2798 bs_entry
->state
.flags
= flags
;
2800 /* This needs to be overwritten in bdrv_reopen_prepare() */
2801 bs_entry
->state
.perm
= UINT64_MAX
;
2802 bs_entry
->state
.shared_perm
= 0;
2804 QLIST_FOREACH(child
, &bs
->children
, next
) {
2805 QDict
*new_child_options
;
2806 char *child_key_dot
;
2808 /* reopen can only change the options of block devices that were
2809 * implicitly created and inherited options. For other (referenced)
2810 * block devices, a syntax like "backing.foo" results in an error. */
2811 if (child
->bs
->inherits_from
!= bs
) {
2815 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2816 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
2817 g_free(child_key_dot
);
2819 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
2820 child
->role
, options
, flags
);
2826 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
2827 BlockDriverState
*bs
,
2828 QDict
*options
, int flags
)
2830 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
2835 * Reopen multiple BlockDriverStates atomically & transactionally.
2837 * The queue passed in (bs_queue) must have been built up previous
2838 * via bdrv_reopen_queue().
2840 * Reopens all BDS specified in the queue, with the appropriate
2841 * flags. All devices are prepared for reopen, and failure of any
2842 * device will cause all device changes to be abandonded, and intermediate
2845 * If all devices prepare successfully, then the changes are committed
2849 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
2852 BlockReopenQueueEntry
*bs_entry
, *next
;
2853 Error
*local_err
= NULL
;
2855 assert(bs_queue
!= NULL
);
2857 aio_context_release(ctx
);
2858 bdrv_drain_all_begin();
2859 aio_context_acquire(ctx
);
2861 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2862 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
2863 error_propagate(errp
, local_err
);
2866 bs_entry
->prepared
= true;
2869 /* If we reach this point, we have success and just need to apply the
2872 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2873 bdrv_reopen_commit(&bs_entry
->state
);
2879 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
2880 if (ret
&& bs_entry
->prepared
) {
2881 bdrv_reopen_abort(&bs_entry
->state
);
2883 QDECREF(bs_entry
->state
.explicit_options
);
2885 QDECREF(bs_entry
->state
.options
);
2890 bdrv_drain_all_end();
2896 /* Reopen a single BlockDriverState with the specified flags. */
2897 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
2900 Error
*local_err
= NULL
;
2901 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
2903 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, &local_err
);
2904 if (local_err
!= NULL
) {
2905 error_propagate(errp
, local_err
);
2910 static BlockReopenQueueEntry
*find_parent_in_reopen_queue(BlockReopenQueue
*q
,
2913 BlockReopenQueueEntry
*entry
;
2915 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
2916 BlockDriverState
*bs
= entry
->state
.bs
;
2919 QLIST_FOREACH(child
, &bs
->children
, next
) {
2929 static void bdrv_reopen_perm(BlockReopenQueue
*q
, BlockDriverState
*bs
,
2930 uint64_t *perm
, uint64_t *shared
)
2933 BlockReopenQueueEntry
*parent
;
2934 uint64_t cumulative_perms
= 0;
2935 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
2937 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2938 parent
= find_parent_in_reopen_queue(q
, c
);
2940 cumulative_perms
|= c
->perm
;
2941 cumulative_shared_perms
&= c
->shared_perm
;
2943 uint64_t nperm
, nshared
;
2945 bdrv_child_perm(parent
->state
.bs
, bs
, c
, c
->role
, q
,
2946 parent
->state
.perm
, parent
->state
.shared_perm
,
2949 cumulative_perms
|= nperm
;
2950 cumulative_shared_perms
&= nshared
;
2953 *perm
= cumulative_perms
;
2954 *shared
= cumulative_shared_perms
;
2958 * Prepares a BlockDriverState for reopen. All changes are staged in the
2959 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2960 * the block driver layer .bdrv_reopen_prepare()
2962 * bs is the BlockDriverState to reopen
2963 * flags are the new open flags
2964 * queue is the reopen queue
2966 * Returns 0 on success, non-zero on error. On error errp will be set
2969 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2970 * It is the responsibility of the caller to then call the abort() or
2971 * commit() for any other BDS that have been left in a prepare() state
2974 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2978 Error
*local_err
= NULL
;
2984 assert(reopen_state
!= NULL
);
2985 assert(reopen_state
->bs
->drv
!= NULL
);
2986 drv
= reopen_state
->bs
->drv
;
2988 /* Process generic block layer options */
2989 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2990 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2992 error_propagate(errp
, local_err
);
2997 update_flags_from_options(&reopen_state
->flags
, opts
);
2999 /* node-name and driver must be unchanged. Put them back into the QDict, so
3000 * that they are checked at the end of this function. */
3001 value
= qemu_opt_get(opts
, "node-name");
3003 qdict_put_str(reopen_state
->options
, "node-name", value
);
3006 value
= qemu_opt_get(opts
, "driver");
3008 qdict_put_str(reopen_state
->options
, "driver", value
);
3011 /* If we are to stay read-only, do not allow permission change
3012 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
3013 * not set, or if the BDS still has copy_on_read enabled */
3014 read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3015 ret
= bdrv_can_set_read_only(reopen_state
->bs
, read_only
, true, &local_err
);
3017 error_propagate(errp
, local_err
);
3021 /* Calculate required permissions after reopening */
3022 bdrv_reopen_perm(queue
, reopen_state
->bs
,
3023 &reopen_state
->perm
, &reopen_state
->shared_perm
);
3025 ret
= bdrv_flush(reopen_state
->bs
);
3027 error_setg_errno(errp
, -ret
, "Error flushing drive");
3031 if (drv
->bdrv_reopen_prepare
) {
3032 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
3034 if (local_err
!= NULL
) {
3035 error_propagate(errp
, local_err
);
3037 error_setg(errp
, "failed while preparing to reopen image '%s'",
3038 reopen_state
->bs
->filename
);
3043 /* It is currently mandatory to have a bdrv_reopen_prepare()
3044 * handler for each supported drv. */
3045 error_setg(errp
, "Block format '%s' used by node '%s' "
3046 "does not support reopening files", drv
->format_name
,
3047 bdrv_get_device_or_node_name(reopen_state
->bs
));
3052 /* Options that are not handled are only okay if they are unchanged
3053 * compared to the old state. It is expected that some options are only
3054 * used for the initial open, but not reopen (e.g. filename) */
3055 if (qdict_size(reopen_state
->options
)) {
3056 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
3059 QString
*new_obj
= qobject_to_qstring(entry
->value
);
3060 const char *new = qstring_get_str(new_obj
);
3062 * Caution: while qdict_get_try_str() is fine, getting
3063 * non-string types would require more care. When
3064 * bs->options come from -blockdev or blockdev_add, its
3065 * members are typed according to the QAPI schema, but
3066 * when they come from -drive, they're all QString.
3068 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
3071 if (!old
|| strcmp(new, old
)) {
3072 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
3076 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
3079 ret
= bdrv_check_perm(reopen_state
->bs
, queue
, reopen_state
->perm
,
3080 reopen_state
->shared_perm
, NULL
, errp
);
3088 qemu_opts_del(opts
);
3093 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
3094 * makes them final by swapping the staging BlockDriverState contents into
3095 * the active BlockDriverState contents.
3097 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
3100 BlockDriverState
*bs
;
3101 bool old_can_write
, new_can_write
;
3103 assert(reopen_state
!= NULL
);
3104 bs
= reopen_state
->bs
;
3106 assert(drv
!= NULL
);
3109 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3111 /* If there are any driver level actions to take */
3112 if (drv
->bdrv_reopen_commit
) {
3113 drv
->bdrv_reopen_commit(reopen_state
);
3116 /* set BDS specific flags now */
3117 QDECREF(bs
->explicit_options
);
3119 bs
->explicit_options
= reopen_state
->explicit_options
;
3120 bs
->open_flags
= reopen_state
->flags
;
3121 bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3123 bdrv_refresh_limits(bs
, NULL
);
3125 bdrv_set_perm(reopen_state
->bs
, reopen_state
->perm
,
3126 reopen_state
->shared_perm
);
3129 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3130 if (!old_can_write
&& new_can_write
&& drv
->bdrv_reopen_bitmaps_rw
) {
3131 Error
*local_err
= NULL
;
3132 if (drv
->bdrv_reopen_bitmaps_rw(bs
, &local_err
) < 0) {
3133 /* This is not fatal, bitmaps just left read-only, so all following
3134 * writes will fail. User can remove read-only bitmaps to unblock
3137 error_reportf_err(local_err
,
3138 "%s: Failed to make dirty bitmaps writable: ",
3139 bdrv_get_node_name(bs
));
3145 * Abort the reopen, and delete and free the staged changes in
3148 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
3152 assert(reopen_state
!= NULL
);
3153 drv
= reopen_state
->bs
->drv
;
3154 assert(drv
!= NULL
);
3156 if (drv
->bdrv_reopen_abort
) {
3157 drv
->bdrv_reopen_abort(reopen_state
);
3160 QDECREF(reopen_state
->explicit_options
);
3162 bdrv_abort_perm_update(reopen_state
->bs
);
3166 static void bdrv_close(BlockDriverState
*bs
)
3168 BdrvAioNotifier
*ban
, *ban_next
;
3171 assert(!bs
->refcnt
);
3173 bdrv_drained_begin(bs
); /* complete I/O */
3175 bdrv_drain(bs
); /* in case flush left pending I/O */
3178 BdrvChild
*child
, *next
;
3180 bs
->drv
->bdrv_close(bs
);
3183 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
3185 if (bs
->file
!= NULL
) {
3186 bdrv_unref_child(bs
, bs
->file
);
3190 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
3191 /* TODO Remove bdrv_unref() from drivers' close function and use
3192 * bdrv_unref_child() here */
3193 if (child
->bs
->inherits_from
== bs
) {
3194 child
->bs
->inherits_from
= NULL
;
3196 bdrv_detach_child(child
);
3201 atomic_set(&bs
->copy_on_read
, 0);
3202 bs
->backing_file
[0] = '\0';
3203 bs
->backing_format
[0] = '\0';
3204 bs
->total_sectors
= 0;
3205 bs
->encrypted
= false;
3207 QDECREF(bs
->options
);
3208 QDECREF(bs
->explicit_options
);
3210 bs
->explicit_options
= NULL
;
3211 QDECREF(bs
->full_open_options
);
3212 bs
->full_open_options
= NULL
;
3215 bdrv_release_named_dirty_bitmaps(bs
);
3216 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
3218 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3221 QLIST_INIT(&bs
->aio_notifiers
);
3222 bdrv_drained_end(bs
);
3225 void bdrv_close_all(void)
3227 block_job_cancel_sync_all();
3228 nbd_export_close_all();
3230 /* Drop references from requests still in flight, such as canceled block
3231 * jobs whose AIO context has not been polled yet */
3234 blk_remove_all_bs();
3235 blockdev_close_all_bdrv_states();
3237 assert(QTAILQ_EMPTY(&all_bdrv_states
));
3240 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
3244 if (c
->role
->stay_at_node
) {
3248 if (c
->role
== &child_backing
) {
3249 /* If @from is a backing file of @to, ignore the child to avoid
3250 * creating a loop. We only want to change the pointer of other
3252 QLIST_FOREACH(to_c
, &to
->children
, next
) {
3265 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
3268 BdrvChild
*c
, *next
;
3269 GSList
*list
= NULL
, *p
;
3270 uint64_t old_perm
, old_shared
;
3271 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
3274 assert(!atomic_read(&from
->in_flight
));
3275 assert(!atomic_read(&to
->in_flight
));
3277 /* Make sure that @from doesn't go away until we have successfully attached
3278 * all of its parents to @to. */
3281 /* Put all parents into @list and calculate their cumulative permissions */
3282 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
3283 if (!should_update_child(c
, to
)) {
3286 list
= g_slist_prepend(list
, c
);
3288 shared
&= c
->shared_perm
;
3291 /* Check whether the required permissions can be granted on @to, ignoring
3292 * all BdrvChild in @list so that they can't block themselves. */
3293 ret
= bdrv_check_update_perm(to
, NULL
, perm
, shared
, list
, errp
);
3295 bdrv_abort_perm_update(to
);
3299 /* Now actually perform the change. We performed the permission check for
3300 * all elements of @list at once, so set the permissions all at once at the
3302 for (p
= list
; p
!= NULL
; p
= p
->next
) {
3306 bdrv_replace_child_noperm(c
, to
);
3310 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3311 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3319 * Add new bs contents at the top of an image chain while the chain is
3320 * live, while keeping required fields on the top layer.
3322 * This will modify the BlockDriverState fields, and swap contents
3323 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3325 * bs_new must not be attached to a BlockBackend.
3327 * This function does not create any image files.
3329 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3330 * that's what the callers commonly need. bs_new will be referenced by the old
3331 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3332 * reference of its own, it must call bdrv_ref().
3334 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3337 Error
*local_err
= NULL
;
3339 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3341 error_propagate(errp
, local_err
);
3345 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3347 error_propagate(errp
, local_err
);
3348 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3352 /* bs_new is now referenced by its new parents, we don't need the
3353 * additional reference any more. */
3358 static void bdrv_delete(BlockDriverState
*bs
)
3361 assert(bdrv_op_blocker_is_empty(bs
));
3362 assert(!bs
->refcnt
);
3366 /* remove from list, if necessary */
3367 if (bs
->node_name
[0] != '\0') {
3368 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3370 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3376 * Run consistency checks on an image
3378 * Returns 0 if the check could be completed (it doesn't mean that the image is
3379 * free of errors) or -errno when an internal error occurred. The results of the
3380 * check are stored in res.
3382 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
3384 if (bs
->drv
== NULL
) {
3387 if (bs
->drv
->bdrv_check
== NULL
) {
3391 memset(res
, 0, sizeof(*res
));
3392 return bs
->drv
->bdrv_check(bs
, res
, fix
);
3398 * -EINVAL - backing format specified, but no file
3399 * -ENOSPC - can't update the backing file because no space is left in the
3401 * -ENOTSUP - format driver doesn't support changing the backing file
3403 int bdrv_change_backing_file(BlockDriverState
*bs
,
3404 const char *backing_file
, const char *backing_fmt
)
3406 BlockDriver
*drv
= bs
->drv
;
3409 /* Backing file format doesn't make sense without a backing file */
3410 if (backing_fmt
&& !backing_file
) {
3414 if (drv
->bdrv_change_backing_file
!= NULL
) {
3415 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3421 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3422 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3428 * Finds the image layer in the chain that has 'bs' as its backing file.
3430 * active is the current topmost image.
3432 * Returns NULL if bs is not found in active's image chain,
3433 * or if active == bs.
3435 * Returns the bottommost base image if bs == NULL.
3437 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3438 BlockDriverState
*bs
)
3440 while (active
&& bs
!= backing_bs(active
)) {
3441 active
= backing_bs(active
);
3447 /* Given a BDS, searches for the base layer. */
3448 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3450 return bdrv_find_overlay(bs
, NULL
);
3454 * Drops images above 'base' up to and including 'top', and sets the image
3455 * above 'top' to have base as its backing file.
3457 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3458 * information in 'bs' can be properly updated.
3460 * E.g., this will convert the following chain:
3461 * bottom <- base <- intermediate <- top <- active
3465 * bottom <- base <- active
3467 * It is allowed for bottom==base, in which case it converts:
3469 * base <- intermediate <- top <- active
3475 * If backing_file_str is non-NULL, it will be used when modifying top's
3476 * overlay image metadata.
3479 * if active == top, that is considered an error
3482 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
3483 BlockDriverState
*base
, const char *backing_file_str
)
3485 BlockDriverState
*new_top_bs
= NULL
;
3486 Error
*local_err
= NULL
;
3491 if (!top
->drv
|| !base
->drv
) {
3495 new_top_bs
= bdrv_find_overlay(active
, top
);
3497 if (new_top_bs
== NULL
) {
3498 /* we could not find the image above 'top', this is an error */
3502 /* special case of new_top_bs->backing->bs already pointing to base - nothing
3503 * to do, no intermediate images */
3504 if (backing_bs(new_top_bs
) == base
) {
3509 /* Make sure that base is in the backing chain of top */
3510 if (!bdrv_chain_contains(top
, base
)) {
3514 /* success - we can delete the intermediate states, and link top->base */
3515 if (new_top_bs
->backing
->role
->update_filename
) {
3516 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
3517 ret
= new_top_bs
->backing
->role
->update_filename(new_top_bs
->backing
,
3518 base
, backing_file_str
,
3521 bdrv_set_backing_hd(new_top_bs
, top
, &error_abort
);
3526 bdrv_set_backing_hd(new_top_bs
, base
, &local_err
);
3529 error_report_err(local_err
);
3540 * Truncate file to 'offset' bytes (needed only for file protocols)
3542 int bdrv_truncate(BdrvChild
*child
, int64_t offset
, PreallocMode prealloc
,
3545 BlockDriverState
*bs
= child
->bs
;
3546 BlockDriver
*drv
= bs
->drv
;
3549 assert(child
->perm
& BLK_PERM_RESIZE
);
3551 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
3553 error_setg(errp
, "No medium inserted");
3556 if (!drv
->bdrv_truncate
) {
3557 if (bs
->file
&& drv
->is_filter
) {
3558 return bdrv_truncate(bs
->file
, offset
, prealloc
, errp
);
3560 error_setg(errp
, "Image format driver does not support resize");
3563 if (bs
->read_only
) {
3564 error_setg(errp
, "Image is read-only");
3568 assert(!(bs
->open_flags
& BDRV_O_INACTIVE
));
3570 ret
= drv
->bdrv_truncate(bs
, offset
, prealloc
, errp
);
3574 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
3576 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3578 offset
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
3580 bdrv_dirty_bitmap_truncate(bs
, offset
);
3581 bdrv_parent_cb_resize(bs
);
3582 atomic_inc(&bs
->write_gen
);
3587 * Length of a allocated file in bytes. Sparse files are counted by actual
3588 * allocated space. Return < 0 if error or unknown.
3590 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
3592 BlockDriver
*drv
= bs
->drv
;
3596 if (drv
->bdrv_get_allocated_file_size
) {
3597 return drv
->bdrv_get_allocated_file_size(bs
);
3600 return bdrv_get_allocated_file_size(bs
->file
->bs
);
3607 * @drv: Format driver
3608 * @opts: Creation options for new image
3609 * @in_bs: Existing image containing data for new image (may be NULL)
3610 * @errp: Error object
3611 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
3614 * Calculate file size required to create a new image.
3616 * If @in_bs is given then space for allocated clusters and zero clusters
3617 * from that image are included in the calculation. If @opts contains a
3618 * backing file that is shared by @in_bs then backing clusters may be omitted
3619 * from the calculation.
3621 * If @in_bs is NULL then the calculation includes no allocated clusters
3622 * unless a preallocation option is given in @opts.
3624 * Note that @in_bs may use a different BlockDriver from @drv.
3626 * If an error occurs the @errp pointer is set.
3628 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
3629 BlockDriverState
*in_bs
, Error
**errp
)
3631 if (!drv
->bdrv_measure
) {
3632 error_setg(errp
, "Block driver '%s' does not support size measurement",
3637 return drv
->bdrv_measure(opts
, in_bs
, errp
);
3641 * Return number of sectors on success, -errno on error.
3643 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
3645 BlockDriver
*drv
= bs
->drv
;
3650 if (drv
->has_variable_length
) {
3651 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3656 return bs
->total_sectors
;
3660 * Return length in bytes on success, -errno on error.
3661 * The length is always a multiple of BDRV_SECTOR_SIZE.
3663 int64_t bdrv_getlength(BlockDriverState
*bs
)
3665 int64_t ret
= bdrv_nb_sectors(bs
);
3667 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
3668 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
3671 /* return 0 as number of sectors if no device present or error */
3672 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
3674 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
3676 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
3679 bool bdrv_is_sg(BlockDriverState
*bs
)
3684 bool bdrv_is_encrypted(BlockDriverState
*bs
)
3686 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3689 return bs
->encrypted
;
3692 const char *bdrv_get_format_name(BlockDriverState
*bs
)
3694 return bs
->drv
? bs
->drv
->format_name
: NULL
;
3697 static int qsort_strcmp(const void *a
, const void *b
)
3699 return strcmp(*(char *const *)a
, *(char *const *)b
);
3702 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
3708 const char **formats
= NULL
;
3710 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
3711 if (drv
->format_name
) {
3714 while (formats
&& i
&& !found
) {
3715 found
= !strcmp(formats
[--i
], drv
->format_name
);
3719 formats
= g_renew(const char *, formats
, count
+ 1);
3720 formats
[count
++] = drv
->format_name
;
3725 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
3726 const char *format_name
= block_driver_modules
[i
].format_name
;
3732 while (formats
&& j
&& !found
) {
3733 found
= !strcmp(formats
[--j
], format_name
);
3737 formats
= g_renew(const char *, formats
, count
+ 1);
3738 formats
[count
++] = format_name
;
3743 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
3745 for (i
= 0; i
< count
; i
++) {
3746 it(opaque
, formats
[i
]);
3752 /* This function is to find a node in the bs graph */
3753 BlockDriverState
*bdrv_find_node(const char *node_name
)
3755 BlockDriverState
*bs
;
3759 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3760 if (!strcmp(node_name
, bs
->node_name
)) {
3767 /* Put this QMP function here so it can access the static graph_bdrv_states. */
3768 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
3770 BlockDeviceInfoList
*list
, *entry
;
3771 BlockDriverState
*bs
;
3774 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3775 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
3777 qapi_free_BlockDeviceInfoList(list
);
3780 entry
= g_malloc0(sizeof(*entry
));
3781 entry
->value
= info
;
3789 BlockDriverState
*bdrv_lookup_bs(const char *device
,
3790 const char *node_name
,
3794 BlockDriverState
*bs
;
3797 blk
= blk_by_name(device
);
3802 error_setg(errp
, "Device '%s' has no medium", device
);
3810 bs
= bdrv_find_node(node_name
);
3817 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
3818 device
? device
: "",
3819 node_name
? node_name
: "");
3823 /* If 'base' is in the same chain as 'top', return true. Otherwise,
3824 * return false. If either argument is NULL, return false. */
3825 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
3827 while (top
&& top
!= base
) {
3828 top
= backing_bs(top
);
3834 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
3837 return QTAILQ_FIRST(&graph_bdrv_states
);
3839 return QTAILQ_NEXT(bs
, node_list
);
3842 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
3844 return bs
->node_name
;
3847 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
3852 /* If multiple parents have a name, just pick the first one. */
3853 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3854 if (c
->role
->get_name
) {
3855 name
= c
->role
->get_name(c
);
3856 if (name
&& *name
) {
3865 /* TODO check what callers really want: bs->node_name or blk_name() */
3866 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
3868 return bdrv_get_parent_name(bs
) ?: "";
3871 /* This can be used to identify nodes that might not have a device
3872 * name associated. Since node and device names live in the same
3873 * namespace, the result is unambiguous. The exception is if both are
3874 * absent, then this returns an empty (non-null) string. */
3875 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
3877 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
3880 int bdrv_get_flags(BlockDriverState
*bs
)
3882 return bs
->open_flags
;
3885 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
3890 int bdrv_has_zero_init(BlockDriverState
*bs
)
3894 /* If BS is a copy on write image, it is initialized to
3895 the contents of the base image, which may not be zeroes. */
3899 if (bs
->drv
->bdrv_has_zero_init
) {
3900 return bs
->drv
->bdrv_has_zero_init(bs
);
3902 if (bs
->file
&& bs
->drv
->is_filter
) {
3903 return bdrv_has_zero_init(bs
->file
->bs
);
3910 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
3912 BlockDriverInfo bdi
;
3918 if (bdrv_get_info(bs
, &bdi
) == 0) {
3919 return bdi
.unallocated_blocks_are_zero
;
3925 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
3927 BlockDriverInfo bdi
;
3929 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
3933 if (bdrv_get_info(bs
, &bdi
) == 0) {
3934 return bdi
.can_write_zeroes_with_unmap
;
3940 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
3942 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
3943 return bs
->backing_file
;
3944 else if (bs
->encrypted
)
3945 return bs
->filename
;
3950 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3951 char *filename
, int filename_size
)
3953 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3956 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3958 BlockDriver
*drv
= bs
->drv
;
3959 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
3963 if (!drv
->bdrv_get_info
) {
3964 if (bs
->file
&& drv
->is_filter
) {
3965 return bdrv_get_info(bs
->file
->bs
, bdi
);
3969 memset(bdi
, 0, sizeof(*bdi
));
3970 return drv
->bdrv_get_info(bs
, bdi
);
3973 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3975 BlockDriver
*drv
= bs
->drv
;
3976 if (drv
&& drv
->bdrv_get_specific_info
) {
3977 return drv
->bdrv_get_specific_info(bs
);
3982 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3984 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3988 bs
->drv
->bdrv_debug_event(bs
, event
);
3991 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3994 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3995 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3998 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3999 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
4005 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
4007 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
4008 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4011 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
4012 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
4018 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
4020 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
4021 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4024 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
4025 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
4031 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
4033 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
4034 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4037 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
4038 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
4044 /* backing_file can either be relative, or absolute, or a protocol. If it is
4045 * relative, it must be relative to the chain. So, passing in bs->filename
4046 * from a BDS as backing_file should not be done, as that may be relative to
4047 * the CWD rather than the chain. */
4048 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
4049 const char *backing_file
)
4051 char *filename_full
= NULL
;
4052 char *backing_file_full
= NULL
;
4053 char *filename_tmp
= NULL
;
4054 int is_protocol
= 0;
4055 BlockDriverState
*curr_bs
= NULL
;
4056 BlockDriverState
*retval
= NULL
;
4057 Error
*local_error
= NULL
;
4059 if (!bs
|| !bs
->drv
|| !backing_file
) {
4063 filename_full
= g_malloc(PATH_MAX
);
4064 backing_file_full
= g_malloc(PATH_MAX
);
4065 filename_tmp
= g_malloc(PATH_MAX
);
4067 is_protocol
= path_has_protocol(backing_file
);
4069 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
4071 /* If either of the filename paths is actually a protocol, then
4072 * compare unmodified paths; otherwise make paths relative */
4073 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
4074 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
4075 retval
= curr_bs
->backing
->bs
;
4078 /* Also check against the full backing filename for the image */
4079 bdrv_get_full_backing_filename(curr_bs
, backing_file_full
, PATH_MAX
,
4081 if (local_error
== NULL
) {
4082 if (strcmp(backing_file
, backing_file_full
) == 0) {
4083 retval
= curr_bs
->backing
->bs
;
4087 error_free(local_error
);
4091 /* If not an absolute filename path, make it relative to the current
4092 * image's filename path */
4093 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
4096 /* We are going to compare absolute pathnames */
4097 if (!realpath(filename_tmp
, filename_full
)) {
4101 /* We need to make sure the backing filename we are comparing against
4102 * is relative to the current image filename (or absolute) */
4103 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
4104 curr_bs
->backing_file
);
4106 if (!realpath(filename_tmp
, backing_file_full
)) {
4110 if (strcmp(backing_file_full
, filename_full
) == 0) {
4111 retval
= curr_bs
->backing
->bs
;
4117 g_free(filename_full
);
4118 g_free(backing_file_full
);
4119 g_free(filename_tmp
);
4123 void bdrv_init(void)
4125 module_call_init(MODULE_INIT_BLOCK
);
4128 void bdrv_init_with_whitelist(void)
4130 use_bdrv_whitelist
= 1;
4134 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
4136 BdrvChild
*child
, *parent
;
4137 uint64_t perm
, shared_perm
;
4138 Error
*local_err
= NULL
;
4145 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
4149 QLIST_FOREACH(child
, &bs
->children
, next
) {
4150 bdrv_invalidate_cache(child
->bs
, &local_err
);
4152 error_propagate(errp
, local_err
);
4157 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
4158 if (bs
->drv
->bdrv_invalidate_cache
) {
4159 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
4161 bs
->open_flags
|= BDRV_O_INACTIVE
;
4162 error_propagate(errp
, local_err
);
4167 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
4169 bs
->open_flags
|= BDRV_O_INACTIVE
;
4170 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
4174 /* Update permissions, they may differ for inactive nodes */
4175 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
4176 ret
= bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
, &local_err
);
4178 bs
->open_flags
|= BDRV_O_INACTIVE
;
4179 error_propagate(errp
, local_err
);
4182 bdrv_set_perm(bs
, perm
, shared_perm
);
4184 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4185 if (parent
->role
->activate
) {
4186 parent
->role
->activate(parent
, &local_err
);
4188 error_propagate(errp
, local_err
);
4195 void bdrv_invalidate_cache_all(Error
**errp
)
4197 BlockDriverState
*bs
;
4198 Error
*local_err
= NULL
;
4199 BdrvNextIterator it
;
4201 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4202 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
4204 aio_context_acquire(aio_context
);
4205 bdrv_invalidate_cache(bs
, &local_err
);
4206 aio_context_release(aio_context
);
4208 error_propagate(errp
, local_err
);
4214 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
4217 BdrvChild
*child
, *parent
;
4220 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
4221 ret
= bs
->drv
->bdrv_inactivate(bs
);
4227 if (setting_flag
&& !(bs
->open_flags
& BDRV_O_INACTIVE
)) {
4228 uint64_t perm
, shared_perm
;
4230 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4231 if (parent
->role
->inactivate
) {
4232 ret
= parent
->role
->inactivate(parent
);
4239 bs
->open_flags
|= BDRV_O_INACTIVE
;
4241 /* Update permissions, they may differ for inactive nodes */
4242 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
4243 bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
, &error_abort
);
4244 bdrv_set_perm(bs
, perm
, shared_perm
);
4247 QLIST_FOREACH(child
, &bs
->children
, next
) {
4248 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
4254 /* At this point persistent bitmaps should be already stored by the format
4256 bdrv_release_persistent_dirty_bitmaps(bs
);
4261 int bdrv_inactivate_all(void)
4263 BlockDriverState
*bs
= NULL
;
4264 BdrvNextIterator it
;
4268 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4269 aio_context_acquire(bdrv_get_aio_context(bs
));
4272 /* We do two passes of inactivation. The first pass calls to drivers'
4273 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
4274 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
4276 for (pass
= 0; pass
< 2; pass
++) {
4277 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4278 ret
= bdrv_inactivate_recurse(bs
, pass
);
4286 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4287 aio_context_release(bdrv_get_aio_context(bs
));
4293 /**************************************************************/
4294 /* removable device support */
4297 * Return TRUE if the media is present
4299 bool bdrv_is_inserted(BlockDriverState
*bs
)
4301 BlockDriver
*drv
= bs
->drv
;
4307 if (drv
->bdrv_is_inserted
) {
4308 return drv
->bdrv_is_inserted(bs
);
4310 QLIST_FOREACH(child
, &bs
->children
, next
) {
4311 if (!bdrv_is_inserted(child
->bs
)) {
4319 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4321 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
4323 BlockDriver
*drv
= bs
->drv
;
4325 if (drv
&& drv
->bdrv_eject
) {
4326 drv
->bdrv_eject(bs
, eject_flag
);
4331 * Lock or unlock the media (if it is locked, the user won't be able
4332 * to eject it manually).
4334 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
4336 BlockDriver
*drv
= bs
->drv
;
4338 trace_bdrv_lock_medium(bs
, locked
);
4340 if (drv
&& drv
->bdrv_lock_medium
) {
4341 drv
->bdrv_lock_medium(bs
, locked
);
4345 /* Get a reference to bs */
4346 void bdrv_ref(BlockDriverState
*bs
)
4351 /* Release a previously grabbed reference to bs.
4352 * If after releasing, reference count is zero, the BlockDriverState is
4354 void bdrv_unref(BlockDriverState
*bs
)
4359 assert(bs
->refcnt
> 0);
4360 if (--bs
->refcnt
== 0) {
4365 struct BdrvOpBlocker
{
4367 QLIST_ENTRY(BdrvOpBlocker
) list
;
4370 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
4372 BdrvOpBlocker
*blocker
;
4373 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4374 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
4375 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
4376 error_propagate(errp
, error_copy(blocker
->reason
));
4377 error_prepend(errp
, "Node '%s' is busy: ",
4378 bdrv_get_device_or_node_name(bs
));
4384 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4386 BdrvOpBlocker
*blocker
;
4387 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4389 blocker
= g_new0(BdrvOpBlocker
, 1);
4390 blocker
->reason
= reason
;
4391 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
4394 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4396 BdrvOpBlocker
*blocker
, *next
;
4397 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4398 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
4399 if (blocker
->reason
== reason
) {
4400 QLIST_REMOVE(blocker
, list
);
4406 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
4409 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4410 bdrv_op_block(bs
, i
, reason
);
4414 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
4417 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4418 bdrv_op_unblock(bs
, i
, reason
);
4422 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
4426 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4427 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
4434 void bdrv_img_create(const char *filename
, const char *fmt
,
4435 const char *base_filename
, const char *base_fmt
,
4436 char *options
, uint64_t img_size
, int flags
, bool quiet
,
4439 QemuOptsList
*create_opts
= NULL
;
4440 QemuOpts
*opts
= NULL
;
4441 const char *backing_fmt
, *backing_file
;
4443 BlockDriver
*drv
, *proto_drv
;
4444 Error
*local_err
= NULL
;
4447 /* Find driver and parse its options */
4448 drv
= bdrv_find_format(fmt
);
4450 error_setg(errp
, "Unknown file format '%s'", fmt
);
4454 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
4459 if (!drv
->create_opts
) {
4460 error_setg(errp
, "Format driver '%s' does not support image creation",
4465 if (!proto_drv
->create_opts
) {
4466 error_setg(errp
, "Protocol driver '%s' does not support image creation",
4467 proto_drv
->format_name
);
4471 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
4472 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
4474 /* Create parameter list with default values */
4475 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
4476 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
4478 /* Parse -o options */
4480 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
4482 error_report_err(local_err
);
4484 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
4489 if (base_filename
) {
4490 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
4492 error_setg(errp
, "Backing file not supported for file format '%s'",
4499 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
4501 error_setg(errp
, "Backing file format not supported for file "
4502 "format '%s'", fmt
);
4507 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4509 if (!strcmp(filename
, backing_file
)) {
4510 error_setg(errp
, "Error: Trying to create an image with the "
4511 "same filename as the backing file");
4516 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4518 /* The size for the image must always be specified, unless we have a backing
4519 * file and we have not been forbidden from opening it. */
4520 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, img_size
);
4521 if (backing_file
&& !(flags
& BDRV_O_NO_BACKING
)) {
4522 BlockDriverState
*bs
;
4523 char *full_backing
= g_new0(char, PATH_MAX
);
4525 QDict
*backing_options
= NULL
;
4527 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
4528 full_backing
, PATH_MAX
,
4531 g_free(full_backing
);
4535 /* backing files always opened read-only */
4537 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
4540 backing_options
= qdict_new();
4541 qdict_put_str(backing_options
, "driver", backing_fmt
);
4544 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
4546 g_free(full_backing
);
4547 if (!bs
&& size
!= -1) {
4548 /* Couldn't open BS, but we have a size, so it's nonfatal */
4549 warn_reportf_err(local_err
,
4550 "Could not verify backing image. "
4551 "This may become an error in future versions.\n");
4554 /* Couldn't open bs, do not have size */
4555 error_append_hint(&local_err
,
4556 "Could not open backing image to determine size.\n");
4560 /* Opened BS, have no size */
4561 size
= bdrv_getlength(bs
);
4563 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
4568 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
4572 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
4575 error_setg(errp
, "Image creation needs a size parameter");
4580 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
4581 qemu_opts_print(opts
, " ");
4585 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
4587 if (ret
== -EFBIG
) {
4588 /* This is generally a better message than whatever the driver would
4589 * deliver (especially because of the cluster_size_hint), since that
4590 * is most probably not much different from "image too large". */
4591 const char *cluster_size_hint
= "";
4592 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
4593 cluster_size_hint
= " (try using a larger cluster size)";
4595 error_setg(errp
, "The image size is too large for file format '%s'"
4596 "%s", fmt
, cluster_size_hint
);
4597 error_free(local_err
);
4602 qemu_opts_del(opts
);
4603 qemu_opts_free(create_opts
);
4604 error_propagate(errp
, local_err
);
4607 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
4609 return bs
->aio_context
;
4612 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
4614 aio_co_enter(bdrv_get_aio_context(bs
), co
);
4617 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
4619 QLIST_REMOVE(ban
, list
);
4623 void bdrv_detach_aio_context(BlockDriverState
*bs
)
4625 BdrvAioNotifier
*baf
, *baf_tmp
;
4632 assert(!bs
->walking_aio_notifiers
);
4633 bs
->walking_aio_notifiers
= true;
4634 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
4636 bdrv_do_remove_aio_context_notifier(baf
);
4638 baf
->detach_aio_context(baf
->opaque
);
4641 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4642 * remove remaining aio notifiers if we aren't called again.
4644 bs
->walking_aio_notifiers
= false;
4646 if (bs
->drv
->bdrv_detach_aio_context
) {
4647 bs
->drv
->bdrv_detach_aio_context(bs
);
4649 QLIST_FOREACH(child
, &bs
->children
, next
) {
4650 bdrv_detach_aio_context(child
->bs
);
4653 bs
->aio_context
= NULL
;
4656 void bdrv_attach_aio_context(BlockDriverState
*bs
,
4657 AioContext
*new_context
)
4659 BdrvAioNotifier
*ban
, *ban_tmp
;
4666 bs
->aio_context
= new_context
;
4668 QLIST_FOREACH(child
, &bs
->children
, next
) {
4669 bdrv_attach_aio_context(child
->bs
, new_context
);
4671 if (bs
->drv
->bdrv_attach_aio_context
) {
4672 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
4675 assert(!bs
->walking_aio_notifiers
);
4676 bs
->walking_aio_notifiers
= true;
4677 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
4679 bdrv_do_remove_aio_context_notifier(ban
);
4681 ban
->attached_aio_context(new_context
, ban
->opaque
);
4684 bs
->walking_aio_notifiers
= false;
4687 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
4689 AioContext
*ctx
= bdrv_get_aio_context(bs
);
4691 aio_disable_external(ctx
);
4692 bdrv_parent_drained_begin(bs
);
4693 bdrv_drain(bs
); /* ensure there are no in-flight requests */
4695 while (aio_poll(ctx
, false)) {
4696 /* wait for all bottom halves to execute */
4699 bdrv_detach_aio_context(bs
);
4701 /* This function executes in the old AioContext so acquire the new one in
4702 * case it runs in a different thread.
4704 aio_context_acquire(new_context
);
4705 bdrv_attach_aio_context(bs
, new_context
);
4706 bdrv_parent_drained_end(bs
);
4707 aio_enable_external(ctx
);
4708 aio_context_release(new_context
);
4711 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
4712 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
4713 void (*detach_aio_context
)(void *opaque
), void *opaque
)
4715 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
4716 *ban
= (BdrvAioNotifier
){
4717 .attached_aio_context
= attached_aio_context
,
4718 .detach_aio_context
= detach_aio_context
,
4722 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
4725 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
4726 void (*attached_aio_context
)(AioContext
*,
4728 void (*detach_aio_context
)(void *),
4731 BdrvAioNotifier
*ban
, *ban_next
;
4733 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
4734 if (ban
->attached_aio_context
== attached_aio_context
&&
4735 ban
->detach_aio_context
== detach_aio_context
&&
4736 ban
->opaque
== opaque
&&
4737 ban
->deleted
== false)
4739 if (bs
->walking_aio_notifiers
) {
4740 ban
->deleted
= true;
4742 bdrv_do_remove_aio_context_notifier(ban
);
4751 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4752 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
4754 if (!bs
->drv
->bdrv_amend_options
) {
4757 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
4760 /* This function will be called by the bdrv_recurse_is_first_non_filter method
4761 * of block filter and by bdrv_is_first_non_filter.
4762 * It is used to test if the given bs is the candidate or recurse more in the
4765 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
4766 BlockDriverState
*candidate
)
4768 /* return false if basic checks fails */
4769 if (!bs
|| !bs
->drv
) {
4773 /* the code reached a non block filter driver -> check if the bs is
4774 * the same as the candidate. It's the recursion termination condition.
4776 if (!bs
->drv
->is_filter
) {
4777 return bs
== candidate
;
4779 /* Down this path the driver is a block filter driver */
4781 /* If the block filter recursion method is defined use it to recurse down
4784 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
4785 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
4788 /* the driver is a block filter but don't allow to recurse -> return false
4793 /* This function checks if the candidate is the first non filter bs down it's
4794 * bs chain. Since we don't have pointers to parents it explore all bs chains
4795 * from the top. Some filters can choose not to pass down the recursion.
4797 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
4799 BlockDriverState
*bs
;
4800 BdrvNextIterator it
;
4802 /* walk down the bs forest recursively */
4803 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4806 /* try to recurse in this top level bs */
4807 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
4809 /* candidate is the first non filter */
4818 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
4819 const char *node_name
, Error
**errp
)
4821 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
4822 AioContext
*aio_context
;
4824 if (!to_replace_bs
) {
4825 error_setg(errp
, "Node name '%s' not found", node_name
);
4829 aio_context
= bdrv_get_aio_context(to_replace_bs
);
4830 aio_context_acquire(aio_context
);
4832 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
4833 to_replace_bs
= NULL
;
4837 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4838 * most non filter in order to prevent data corruption.
4839 * Another benefit is that this tests exclude backing files which are
4840 * blocked by the backing blockers.
4842 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
4843 error_setg(errp
, "Only top most non filter can be replaced");
4844 to_replace_bs
= NULL
;
4849 aio_context_release(aio_context
);
4850 return to_replace_bs
;
4853 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
4855 const QDictEntry
*entry
;
4858 bool found_any
= false;
4861 for (entry
= qdict_first(bs
->options
); entry
;
4862 entry
= qdict_next(bs
->options
, entry
))
4864 /* Exclude options for children */
4865 QLIST_FOREACH(child
, &bs
->children
, next
) {
4866 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
4867 && (!*p
|| *p
== '.'))
4876 /* And exclude all non-driver-specific options */
4877 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
4878 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
4886 qobject_incref(qdict_entry_value(entry
));
4887 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
4894 /* Updates the following BDS fields:
4895 * - exact_filename: A filename which may be used for opening a block device
4896 * which (mostly) equals the given BDS (even without any
4897 * other options; so reading and writing must return the same
4898 * results, but caching etc. may be different)
4899 * - full_open_options: Options which, when given when opening a block device
4900 * (without a filename), result in a BDS (mostly)
4901 * equalling the given one
4902 * - filename: If exact_filename is set, it is copied here. Otherwise,
4903 * full_open_options is converted to a JSON object, prefixed with
4904 * "json:" (for use through the JSON pseudo protocol) and put here.
4906 void bdrv_refresh_filename(BlockDriverState
*bs
)
4908 BlockDriver
*drv
= bs
->drv
;
4915 /* This BDS's file name will most probably depend on its file's name, so
4916 * refresh that first */
4918 bdrv_refresh_filename(bs
->file
->bs
);
4921 if (drv
->bdrv_refresh_filename
) {
4922 /* Obsolete information is of no use here, so drop the old file name
4923 * information before refreshing it */
4924 bs
->exact_filename
[0] = '\0';
4925 if (bs
->full_open_options
) {
4926 QDECREF(bs
->full_open_options
);
4927 bs
->full_open_options
= NULL
;
4931 append_open_options(opts
, bs
);
4932 drv
->bdrv_refresh_filename(bs
, opts
);
4934 } else if (bs
->file
) {
4935 /* Try to reconstruct valid information from the underlying file */
4936 bool has_open_options
;
4938 bs
->exact_filename
[0] = '\0';
4939 if (bs
->full_open_options
) {
4940 QDECREF(bs
->full_open_options
);
4941 bs
->full_open_options
= NULL
;
4945 has_open_options
= append_open_options(opts
, bs
);
4947 /* If no specific options have been given for this BDS, the filename of
4948 * the underlying file should suffice for this one as well */
4949 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
4950 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
4952 /* Reconstructing the full options QDict is simple for most format block
4953 * drivers, as long as the full options are known for the underlying
4954 * file BDS. The full options QDict of that file BDS should somehow
4955 * contain a representation of the filename, therefore the following
4956 * suffices without querying the (exact_)filename of this BDS. */
4957 if (bs
->file
->bs
->full_open_options
) {
4958 qdict_put_str(opts
, "driver", drv
->format_name
);
4959 QINCREF(bs
->file
->bs
->full_open_options
);
4960 qdict_put(opts
, "file", bs
->file
->bs
->full_open_options
);
4962 bs
->full_open_options
= opts
;
4966 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
4967 /* There is no underlying file BDS (at least referenced by BDS.file),
4968 * so the full options QDict should be equal to the options given
4969 * specifically for this block device when it was opened (plus the
4970 * driver specification).
4971 * Because those options don't change, there is no need to update
4972 * full_open_options when it's already set. */
4975 append_open_options(opts
, bs
);
4976 qdict_put_str(opts
, "driver", drv
->format_name
);
4978 if (bs
->exact_filename
[0]) {
4979 /* This may not work for all block protocol drivers (some may
4980 * require this filename to be parsed), but we have to find some
4981 * default solution here, so just include it. If some block driver
4982 * does not support pure options without any filename at all or
4983 * needs some special format of the options QDict, it needs to
4984 * implement the driver-specific bdrv_refresh_filename() function.
4986 qdict_put_str(opts
, "filename", bs
->exact_filename
);
4989 bs
->full_open_options
= opts
;
4992 if (bs
->exact_filename
[0]) {
4993 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4994 } else if (bs
->full_open_options
) {
4995 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4996 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4997 qstring_get_str(json
));
5003 * Hot add/remove a BDS's child. So the user can take a child offline when
5004 * it is broken and take a new child online
5006 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
5010 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
5011 error_setg(errp
, "The node %s does not support adding a child",
5012 bdrv_get_device_or_node_name(parent_bs
));
5016 if (!QLIST_EMPTY(&child_bs
->parents
)) {
5017 error_setg(errp
, "The node %s already has a parent",
5018 child_bs
->node_name
);
5022 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
5025 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
5029 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
5030 error_setg(errp
, "The node %s does not support removing a child",
5031 bdrv_get_device_or_node_name(parent_bs
));
5035 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
5042 error_setg(errp
, "The node %s does not have a child named %s",
5043 bdrv_get_device_or_node_name(parent_bs
),
5044 bdrv_get_device_or_node_name(child
->bs
));
5048 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);
5051 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
5052 uint32_t granularity
, Error
**errp
)
5054 BlockDriver
*drv
= bs
->drv
;
5057 error_setg_errno(errp
, ENOMEDIUM
,
5058 "Can't store persistent bitmaps to %s",
5059 bdrv_get_device_or_node_name(bs
));
5063 if (!drv
->bdrv_can_store_new_dirty_bitmap
) {
5064 error_setg_errno(errp
, ENOTSUP
,
5065 "Can't store persistent bitmaps to %s",
5066 bdrv_get_device_or_node_name(bs
));
5070 return drv
->bdrv_can_store_new_dirty_bitmap(bs
, name
, granularity
, errp
);