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
25 #include "qemu/osdep.h"
26 #include "block/trace.h"
27 #include "block/block_int.h"
28 #include "block/blockjob.h"
29 #include "block/nbd.h"
30 #include "block/qdict.h"
31 #include "qemu/error-report.h"
32 #include "module_block.h"
33 #include "qemu/module.h"
34 #include "qapi/error.h"
35 #include "qapi/qmp/qdict.h"
36 #include "qapi/qmp/qjson.h"
37 #include "qapi/qmp/qnull.h"
38 #include "qapi/qmp/qstring.h"
39 #include "qapi/qobject-output-visitor.h"
40 #include "qapi/qapi-visit-block-core.h"
41 #include "sysemu/block-backend.h"
42 #include "sysemu/sysemu.h"
43 #include "qemu/notify.h"
44 #include "qemu/option.h"
45 #include "qemu/coroutine.h"
46 #include "block/qapi.h"
47 #include "qemu/timer.h"
48 #include "qemu/cutils.h"
52 #include <sys/ioctl.h>
53 #include <sys/queue.h>
63 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
65 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
66 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
68 static QTAILQ_HEAD(, BlockDriverState
) all_bdrv_states
=
69 QTAILQ_HEAD_INITIALIZER(all_bdrv_states
);
71 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
72 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
74 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
75 const char *reference
,
76 QDict
*options
, int flags
,
77 BlockDriverState
*parent
,
78 const BdrvChildRole
*child_role
,
81 /* If non-zero, use only whitelisted block drivers */
82 static int use_bdrv_whitelist
;
85 static int is_windows_drive_prefix(const char *filename
)
87 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
88 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
92 int is_windows_drive(const char *filename
)
94 if (is_windows_drive_prefix(filename
) &&
97 if (strstart(filename
, "\\\\.\\", NULL
) ||
98 strstart(filename
, "//./", NULL
))
104 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
106 if (!bs
|| !bs
->drv
) {
107 /* page size or 4k (hdd sector size) should be on the safe side */
108 return MAX(4096, getpagesize());
111 return bs
->bl
.opt_mem_alignment
;
114 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
116 if (!bs
|| !bs
->drv
) {
117 /* page size or 4k (hdd sector size) should be on the safe side */
118 return MAX(4096, getpagesize());
121 return bs
->bl
.min_mem_alignment
;
124 /* check if the path starts with "<protocol>:" */
125 int path_has_protocol(const char *path
)
130 if (is_windows_drive(path
) ||
131 is_windows_drive_prefix(path
)) {
134 p
= path
+ strcspn(path
, ":/\\");
136 p
= path
+ strcspn(path
, ":/");
142 int path_is_absolute(const char *path
)
145 /* specific case for names like: "\\.\d:" */
146 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
149 return (*path
== '/' || *path
== '\\');
151 return (*path
== '/');
155 /* if filename is absolute, just copy it to dest. Otherwise, build a
156 path to it by considering it is relative to base_path. URL are
158 void path_combine(char *dest
, int dest_size
,
159 const char *base_path
,
160 const char *filename
)
167 if (path_is_absolute(filename
)) {
168 pstrcpy(dest
, dest_size
, filename
);
170 const char *protocol_stripped
= NULL
;
172 if (path_has_protocol(base_path
)) {
173 protocol_stripped
= strchr(base_path
, ':');
174 if (protocol_stripped
) {
178 p
= protocol_stripped
?: base_path
;
180 p1
= strrchr(base_path
, '/');
184 p2
= strrchr(base_path
, '\\');
196 if (len
> dest_size
- 1)
198 memcpy(dest
, base_path
, len
);
200 pstrcat(dest
, dest_size
, filename
);
205 * Helper function for bdrv_parse_filename() implementations to remove optional
206 * protocol prefixes (especially "file:") from a filename and for putting the
207 * stripped filename into the options QDict if there is such a prefix.
209 void bdrv_parse_filename_strip_prefix(const char *filename
, const char *prefix
,
212 if (strstart(filename
, prefix
, &filename
)) {
213 /* Stripping the explicit protocol prefix may result in a protocol
214 * prefix being (wrongly) detected (if the filename contains a colon) */
215 if (path_has_protocol(filename
)) {
216 QString
*fat_filename
;
218 /* This means there is some colon before the first slash; therefore,
219 * this cannot be an absolute path */
220 assert(!path_is_absolute(filename
));
222 /* And we can thus fix the protocol detection issue by prefixing it
224 fat_filename
= qstring_from_str("./");
225 qstring_append(fat_filename
, filename
);
227 assert(!path_has_protocol(qstring_get_str(fat_filename
)));
229 qdict_put(options
, "filename", fat_filename
);
231 /* If no protocol prefix was detected, we can use the shortened
233 qdict_put_str(options
, "filename", filename
);
239 /* Returns whether the image file is opened as read-only. Note that this can
240 * return false and writing to the image file is still not possible because the
241 * image is inactivated. */
242 bool bdrv_is_read_only(BlockDriverState
*bs
)
244 return bs
->read_only
;
247 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
248 bool ignore_allow_rdw
, Error
**errp
)
250 /* Do not set read_only if copy_on_read is enabled */
251 if (bs
->copy_on_read
&& read_only
) {
252 error_setg(errp
, "Can't set node '%s' to r/o with copy-on-read enabled",
253 bdrv_get_device_or_node_name(bs
));
257 /* Do not clear read_only if it is prohibited */
258 if (!read_only
&& !(bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
261 error_setg(errp
, "Node '%s' is read only",
262 bdrv_get_device_or_node_name(bs
));
270 * Called by a driver that can only provide a read-only image.
272 * Returns 0 if the node is already read-only or it could switch the node to
273 * read-only because BDRV_O_AUTO_RDONLY is set.
275 * Returns -EACCES if the node is read-write and BDRV_O_AUTO_RDONLY is not set
276 * or bdrv_can_set_read_only() forbids making the node read-only. If @errmsg
277 * is not NULL, it is used as the error message for the Error object.
279 int bdrv_apply_auto_read_only(BlockDriverState
*bs
, const char *errmsg
,
284 if (!(bs
->open_flags
& BDRV_O_RDWR
)) {
287 if (!(bs
->open_flags
& BDRV_O_AUTO_RDONLY
)) {
291 ret
= bdrv_can_set_read_only(bs
, true, false, NULL
);
296 bs
->read_only
= true;
297 bs
->open_flags
&= ~BDRV_O_RDWR
;
302 error_setg(errp
, "%s", errmsg
?: "Image is read-only");
306 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
308 char *dest
, size_t sz
,
311 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
312 path_is_absolute(backing
))
314 pstrcpy(dest
, sz
, backing
);
315 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
316 error_setg(errp
, "Cannot use relative backing file names for '%s'",
319 path_combine(dest
, sz
, backed
, backing
);
323 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
328 bdrv_refresh_filename(bs
);
330 backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
331 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
335 void bdrv_register(BlockDriver
*bdrv
)
337 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
340 BlockDriverState
*bdrv_new(void)
342 BlockDriverState
*bs
;
345 bs
= g_new0(BlockDriverState
, 1);
346 QLIST_INIT(&bs
->dirty_bitmaps
);
347 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
348 QLIST_INIT(&bs
->op_blockers
[i
]);
350 notifier_with_return_list_init(&bs
->before_write_notifiers
);
351 qemu_co_mutex_init(&bs
->reqs_lock
);
352 qemu_mutex_init(&bs
->dirty_bitmap_mutex
);
354 bs
->aio_context
= qemu_get_aio_context();
356 qemu_co_queue_init(&bs
->flush_queue
);
358 for (i
= 0; i
< bdrv_drain_all_count
; i
++) {
359 bdrv_drained_begin(bs
);
362 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
367 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
371 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
372 if (!strcmp(drv1
->format_name
, format_name
)) {
380 BlockDriver
*bdrv_find_format(const char *format_name
)
385 drv1
= bdrv_do_find_format(format_name
);
390 /* The driver isn't registered, maybe we need to load a module */
391 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
392 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
393 block_module_load_one(block_driver_modules
[i
].library_name
);
398 return bdrv_do_find_format(format_name
);
401 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
403 static const char *whitelist_rw
[] = {
404 CONFIG_BDRV_RW_WHITELIST
406 static const char *whitelist_ro
[] = {
407 CONFIG_BDRV_RO_WHITELIST
411 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
412 return 1; /* no whitelist, anything goes */
415 for (p
= whitelist_rw
; *p
; p
++) {
416 if (!strcmp(drv
->format_name
, *p
)) {
421 for (p
= whitelist_ro
; *p
; p
++) {
422 if (!strcmp(drv
->format_name
, *p
)) {
430 bool bdrv_uses_whitelist(void)
432 return use_bdrv_whitelist
;
435 typedef struct CreateCo
{
443 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
445 Error
*local_err
= NULL
;
448 CreateCo
*cco
= opaque
;
451 ret
= cco
->drv
->bdrv_co_create_opts(cco
->filename
, cco
->opts
, &local_err
);
452 error_propagate(&cco
->err
, local_err
);
456 int bdrv_create(BlockDriver
*drv
, const char* filename
,
457 QemuOpts
*opts
, Error
**errp
)
464 .filename
= g_strdup(filename
),
470 if (!drv
->bdrv_co_create_opts
) {
471 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
476 if (qemu_in_coroutine()) {
477 /* Fast-path if already in coroutine context */
478 bdrv_create_co_entry(&cco
);
480 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
481 qemu_coroutine_enter(co
);
482 while (cco
.ret
== NOT_DONE
) {
483 aio_poll(qemu_get_aio_context(), true);
490 error_propagate(errp
, cco
.err
);
492 error_setg_errno(errp
, -ret
, "Could not create image");
497 g_free(cco
.filename
);
501 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
504 Error
*local_err
= NULL
;
507 drv
= bdrv_find_protocol(filename
, true, errp
);
512 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
513 error_propagate(errp
, local_err
);
518 * Try to get @bs's logical and physical block size.
519 * On success, store them in @bsz struct and return 0.
520 * On failure return -errno.
521 * @bs must not be empty.
523 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
525 BlockDriver
*drv
= bs
->drv
;
527 if (drv
&& drv
->bdrv_probe_blocksizes
) {
528 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
529 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
530 return bdrv_probe_blocksizes(bs
->file
->bs
, bsz
);
537 * Try to get @bs's geometry (cyls, heads, sectors).
538 * On success, store them in @geo struct and return 0.
539 * On failure return -errno.
540 * @bs must not be empty.
542 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
544 BlockDriver
*drv
= bs
->drv
;
546 if (drv
&& drv
->bdrv_probe_geometry
) {
547 return drv
->bdrv_probe_geometry(bs
, geo
);
548 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
549 return bdrv_probe_geometry(bs
->file
->bs
, geo
);
556 * Create a uniquely-named empty temporary file.
557 * Return 0 upon success, otherwise a negative errno value.
559 int get_tmp_filename(char *filename
, int size
)
562 char temp_dir
[MAX_PATH
];
563 /* GetTempFileName requires that its output buffer (4th param)
564 have length MAX_PATH or greater. */
565 assert(size
>= MAX_PATH
);
566 return (GetTempPath(MAX_PATH
, temp_dir
)
567 && GetTempFileName(temp_dir
, "qem", 0, filename
)
568 ? 0 : -GetLastError());
572 tmpdir
= getenv("TMPDIR");
576 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
579 fd
= mkstemp(filename
);
583 if (close(fd
) != 0) {
592 * Detect host devices. By convention, /dev/cdrom[N] is always
593 * recognized as a host CDROM.
595 static BlockDriver
*find_hdev_driver(const char *filename
)
597 int score_max
= 0, score
;
598 BlockDriver
*drv
= NULL
, *d
;
600 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
601 if (d
->bdrv_probe_device
) {
602 score
= d
->bdrv_probe_device(filename
);
603 if (score
> score_max
) {
613 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
617 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
618 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
626 BlockDriver
*bdrv_find_protocol(const char *filename
,
627 bool allow_protocol_prefix
,
636 /* TODO Drivers without bdrv_file_open must be specified explicitly */
639 * XXX(hch): we really should not let host device detection
640 * override an explicit protocol specification, but moving this
641 * later breaks access to device names with colons in them.
642 * Thanks to the brain-dead persistent naming schemes on udev-
643 * based Linux systems those actually are quite common.
645 drv1
= find_hdev_driver(filename
);
650 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
654 p
= strchr(filename
, ':');
657 if (len
> sizeof(protocol
) - 1)
658 len
= sizeof(protocol
) - 1;
659 memcpy(protocol
, filename
, len
);
660 protocol
[len
] = '\0';
662 drv1
= bdrv_do_find_protocol(protocol
);
667 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
668 if (block_driver_modules
[i
].protocol_name
&&
669 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
670 block_module_load_one(block_driver_modules
[i
].library_name
);
675 drv1
= bdrv_do_find_protocol(protocol
);
677 error_setg(errp
, "Unknown protocol '%s'", protocol
);
683 * Guess image format by probing its contents.
684 * This is not a good idea when your image is raw (CVE-2008-2004), but
685 * we do it anyway for backward compatibility.
687 * @buf contains the image's first @buf_size bytes.
688 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
689 * but can be smaller if the image file is smaller)
690 * @filename is its filename.
692 * For all block drivers, call the bdrv_probe() method to get its
694 * Return the first block driver with the highest probing score.
696 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
697 const char *filename
)
699 int score_max
= 0, score
;
700 BlockDriver
*drv
= NULL
, *d
;
702 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
704 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
705 if (score
> score_max
) {
715 static int find_image_format(BlockBackend
*file
, const char *filename
,
716 BlockDriver
**pdrv
, Error
**errp
)
719 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
722 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
723 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
728 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
730 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
736 drv
= bdrv_probe_all(buf
, ret
, filename
);
738 error_setg(errp
, "Could not determine image format: No compatible "
747 * Set the current 'total_sectors' value
748 * Return 0 on success, -errno on error.
750 int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
752 BlockDriver
*drv
= bs
->drv
;
758 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
762 /* query actual device if possible, otherwise just trust the hint */
763 if (drv
->bdrv_getlength
) {
764 int64_t length
= drv
->bdrv_getlength(bs
);
768 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
771 bs
->total_sectors
= hint
;
776 * Combines a QDict of new block driver @options with any missing options taken
777 * from @old_options, so that leaving out an option defaults to its old value.
779 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
782 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
783 bs
->drv
->bdrv_join_options(options
, old_options
);
785 qdict_join(options
, old_options
, false);
789 static BlockdevDetectZeroesOptions
bdrv_parse_detect_zeroes(QemuOpts
*opts
,
793 Error
*local_err
= NULL
;
794 char *value
= qemu_opt_get_del(opts
, "detect-zeroes");
795 BlockdevDetectZeroesOptions detect_zeroes
=
796 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup
, value
,
797 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
, &local_err
);
800 error_propagate(errp
, local_err
);
801 return detect_zeroes
;
804 if (detect_zeroes
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
805 !(open_flags
& BDRV_O_UNMAP
))
807 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
808 "without setting discard operation to unmap");
811 return detect_zeroes
;
815 * Set open flags for a given discard mode
817 * Return 0 on success, -1 if the discard mode was invalid.
819 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
821 *flags
&= ~BDRV_O_UNMAP
;
823 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
825 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
826 *flags
|= BDRV_O_UNMAP
;
835 * Set open flags for a given cache mode
837 * Return 0 on success, -1 if the cache mode was invalid.
839 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
841 *flags
&= ~BDRV_O_CACHE_MASK
;
843 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
844 *writethrough
= false;
845 *flags
|= BDRV_O_NOCACHE
;
846 } else if (!strcmp(mode
, "directsync")) {
847 *writethrough
= true;
848 *flags
|= BDRV_O_NOCACHE
;
849 } else if (!strcmp(mode
, "writeback")) {
850 *writethrough
= false;
851 } else if (!strcmp(mode
, "unsafe")) {
852 *writethrough
= false;
853 *flags
|= BDRV_O_NO_FLUSH
;
854 } else if (!strcmp(mode
, "writethrough")) {
855 *writethrough
= true;
863 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
865 BlockDriverState
*parent
= c
->opaque
;
866 return g_strdup(bdrv_get_device_or_node_name(parent
));
869 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
871 BlockDriverState
*bs
= child
->opaque
;
872 bdrv_do_drained_begin_quiesce(bs
, NULL
, false);
875 static bool bdrv_child_cb_drained_poll(BdrvChild
*child
)
877 BlockDriverState
*bs
= child
->opaque
;
878 return bdrv_drain_poll(bs
, false, NULL
, false);
881 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
883 BlockDriverState
*bs
= child
->opaque
;
884 bdrv_drained_end(bs
);
887 static void bdrv_child_cb_attach(BdrvChild
*child
)
889 BlockDriverState
*bs
= child
->opaque
;
890 bdrv_apply_subtree_drain(child
, bs
);
893 static void bdrv_child_cb_detach(BdrvChild
*child
)
895 BlockDriverState
*bs
= child
->opaque
;
896 bdrv_unapply_subtree_drain(child
, bs
);
899 static int bdrv_child_cb_inactivate(BdrvChild
*child
)
901 BlockDriverState
*bs
= child
->opaque
;
902 assert(bs
->open_flags
& BDRV_O_INACTIVE
);
907 * Returns the options and flags that a temporary snapshot should get, based on
908 * the originally requested flags (the originally requested image will have
909 * flags like a backing file)
911 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
912 int parent_flags
, QDict
*parent_options
)
914 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
916 /* For temporary files, unconditional cache=unsafe is fine */
917 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
918 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
920 /* Copy the read-only option from the parent */
921 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
923 /* aio=native doesn't work for cache.direct=off, so disable it for the
924 * temporary snapshot */
925 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
929 * Returns the options and flags that bs->file should get if a protocol driver
930 * is expected, based on the given options and flags for the parent BDS
932 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
933 int parent_flags
, QDict
*parent_options
)
935 int flags
= parent_flags
;
937 /* Enable protocol handling, disable format probing for bs->file */
938 flags
|= BDRV_O_PROTOCOL
;
940 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
942 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
943 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
944 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
946 /* Inherit the read-only option from the parent if it's not set */
947 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
948 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_AUTO_READ_ONLY
);
950 /* Our block drivers take care to send flushes and respect unmap policy,
951 * so we can default to enable both on lower layers regardless of the
952 * corresponding parent options. */
953 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
955 /* Clear flags that only apply to the top layer */
956 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
959 *child_flags
= flags
;
962 const BdrvChildRole child_file
= {
963 .parent_is_bds
= true,
964 .get_parent_desc
= bdrv_child_get_parent_desc
,
965 .inherit_options
= bdrv_inherited_options
,
966 .drained_begin
= bdrv_child_cb_drained_begin
,
967 .drained_poll
= bdrv_child_cb_drained_poll
,
968 .drained_end
= bdrv_child_cb_drained_end
,
969 .attach
= bdrv_child_cb_attach
,
970 .detach
= bdrv_child_cb_detach
,
971 .inactivate
= bdrv_child_cb_inactivate
,
975 * Returns the options and flags that bs->file should get if the use of formats
976 * (and not only protocols) is permitted for it, based on the given options and
977 * flags for the parent BDS
979 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
980 int parent_flags
, QDict
*parent_options
)
982 child_file
.inherit_options(child_flags
, child_options
,
983 parent_flags
, parent_options
);
985 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
988 const BdrvChildRole child_format
= {
989 .parent_is_bds
= true,
990 .get_parent_desc
= bdrv_child_get_parent_desc
,
991 .inherit_options
= bdrv_inherited_fmt_options
,
992 .drained_begin
= bdrv_child_cb_drained_begin
,
993 .drained_poll
= bdrv_child_cb_drained_poll
,
994 .drained_end
= bdrv_child_cb_drained_end
,
995 .attach
= bdrv_child_cb_attach
,
996 .detach
= bdrv_child_cb_detach
,
997 .inactivate
= bdrv_child_cb_inactivate
,
1000 static void bdrv_backing_attach(BdrvChild
*c
)
1002 BlockDriverState
*parent
= c
->opaque
;
1003 BlockDriverState
*backing_hd
= c
->bs
;
1005 assert(!parent
->backing_blocker
);
1006 error_setg(&parent
->backing_blocker
,
1007 "node is used as backing hd of '%s'",
1008 bdrv_get_device_or_node_name(parent
));
1010 bdrv_refresh_filename(backing_hd
);
1012 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
1013 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
1014 backing_hd
->filename
);
1015 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
1016 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
1018 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
1019 /* Otherwise we won't be able to commit or stream */
1020 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
1021 parent
->backing_blocker
);
1022 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
1023 parent
->backing_blocker
);
1025 * We do backup in 3 ways:
1027 * The target bs is new opened, and the source is top BDS
1028 * 2. blockdev backup
1029 * Both the source and the target are top BDSes.
1030 * 3. internal backup(used for block replication)
1031 * Both the source and the target are backing file
1033 * In case 1 and 2, neither the source nor the target is the backing file.
1034 * In case 3, we will block the top BDS, so there is only one block job
1035 * for the top BDS and its backing chain.
1037 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
1038 parent
->backing_blocker
);
1039 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
1040 parent
->backing_blocker
);
1042 bdrv_child_cb_attach(c
);
1045 static void bdrv_backing_detach(BdrvChild
*c
)
1047 BlockDriverState
*parent
= c
->opaque
;
1049 assert(parent
->backing_blocker
);
1050 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
1051 error_free(parent
->backing_blocker
);
1052 parent
->backing_blocker
= NULL
;
1054 bdrv_child_cb_detach(c
);
1058 * Returns the options and flags that bs->backing should get, based on the
1059 * given options and flags for the parent BDS
1061 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
1062 int parent_flags
, QDict
*parent_options
)
1064 int flags
= parent_flags
;
1066 /* The cache mode is inherited unmodified for backing files; except WCE,
1067 * which is only applied on the top level (BlockBackend) */
1068 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
1069 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
1070 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
1072 /* backing files always opened read-only */
1073 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
1074 qdict_set_default_str(child_options
, BDRV_OPT_AUTO_READ_ONLY
, "off");
1075 flags
&= ~BDRV_O_COPY_ON_READ
;
1077 /* snapshot=on is handled on the top layer */
1078 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
1080 *child_flags
= flags
;
1083 static int bdrv_backing_update_filename(BdrvChild
*c
, BlockDriverState
*base
,
1084 const char *filename
, Error
**errp
)
1086 BlockDriverState
*parent
= c
->opaque
;
1087 bool read_only
= bdrv_is_read_only(parent
);
1091 ret
= bdrv_reopen_set_read_only(parent
, false, errp
);
1097 ret
= bdrv_change_backing_file(parent
, filename
,
1098 base
->drv
? base
->drv
->format_name
: "");
1100 error_setg_errno(errp
, -ret
, "Could not update backing file link");
1104 bdrv_reopen_set_read_only(parent
, true, NULL
);
1110 const BdrvChildRole child_backing
= {
1111 .parent_is_bds
= true,
1112 .get_parent_desc
= bdrv_child_get_parent_desc
,
1113 .attach
= bdrv_backing_attach
,
1114 .detach
= bdrv_backing_detach
,
1115 .inherit_options
= bdrv_backing_options
,
1116 .drained_begin
= bdrv_child_cb_drained_begin
,
1117 .drained_poll
= bdrv_child_cb_drained_poll
,
1118 .drained_end
= bdrv_child_cb_drained_end
,
1119 .inactivate
= bdrv_child_cb_inactivate
,
1120 .update_filename
= bdrv_backing_update_filename
,
1123 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
1125 int open_flags
= flags
;
1128 * Clear flags that are internal to the block layer before opening the
1131 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
1134 * Snapshots should be writable.
1136 if (flags
& BDRV_O_TEMPORARY
) {
1137 open_flags
|= BDRV_O_RDWR
;
1143 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
1145 *flags
&= ~(BDRV_O_CACHE_MASK
| BDRV_O_RDWR
| BDRV_O_AUTO_RDONLY
);
1147 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
1148 *flags
|= BDRV_O_NO_FLUSH
;
1151 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
1152 *flags
|= BDRV_O_NOCACHE
;
1155 if (!qemu_opt_get_bool_del(opts
, BDRV_OPT_READ_ONLY
, false)) {
1156 *flags
|= BDRV_O_RDWR
;
1159 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_AUTO_READ_ONLY
, false)) {
1160 *flags
|= BDRV_O_AUTO_RDONLY
;
1164 static void update_options_from_flags(QDict
*options
, int flags
)
1166 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
1167 qdict_put_bool(options
, BDRV_OPT_CACHE_DIRECT
, flags
& BDRV_O_NOCACHE
);
1169 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
1170 qdict_put_bool(options
, BDRV_OPT_CACHE_NO_FLUSH
,
1171 flags
& BDRV_O_NO_FLUSH
);
1173 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
1174 qdict_put_bool(options
, BDRV_OPT_READ_ONLY
, !(flags
& BDRV_O_RDWR
));
1176 if (!qdict_haskey(options
, BDRV_OPT_AUTO_READ_ONLY
)) {
1177 qdict_put_bool(options
, BDRV_OPT_AUTO_READ_ONLY
,
1178 flags
& BDRV_O_AUTO_RDONLY
);
1182 static void bdrv_assign_node_name(BlockDriverState
*bs
,
1183 const char *node_name
,
1186 char *gen_node_name
= NULL
;
1189 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
1190 } else if (!id_wellformed(node_name
)) {
1192 * Check for empty string or invalid characters, but not if it is
1193 * generated (generated names use characters not available to the user)
1195 error_setg(errp
, "Invalid node name");
1199 /* takes care of avoiding namespaces collisions */
1200 if (blk_by_name(node_name
)) {
1201 error_setg(errp
, "node-name=%s is conflicting with a device id",
1206 /* takes care of avoiding duplicates node names */
1207 if (bdrv_find_node(node_name
)) {
1208 error_setg(errp
, "Duplicate node name");
1212 /* Make sure that the node name isn't truncated */
1213 if (strlen(node_name
) >= sizeof(bs
->node_name
)) {
1214 error_setg(errp
, "Node name too long");
1218 /* copy node name into the bs and insert it into the graph list */
1219 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
1220 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
1222 g_free(gen_node_name
);
1225 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
1226 const char *node_name
, QDict
*options
,
1227 int open_flags
, Error
**errp
)
1229 Error
*local_err
= NULL
;
1232 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1234 error_propagate(errp
, local_err
);
1239 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1240 bs
->opaque
= g_malloc0(drv
->instance_size
);
1242 if (drv
->bdrv_file_open
) {
1243 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1244 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1245 } else if (drv
->bdrv_open
) {
1246 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1253 error_propagate(errp
, local_err
);
1254 } else if (bs
->filename
[0]) {
1255 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1257 error_setg_errno(errp
, -ret
, "Could not open image");
1262 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1264 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1268 bdrv_refresh_limits(bs
, &local_err
);
1270 error_propagate(errp
, local_err
);
1274 assert(bdrv_opt_mem_align(bs
) != 0);
1275 assert(bdrv_min_mem_align(bs
) != 0);
1276 assert(is_power_of_2(bs
->bl
.request_alignment
));
1278 for (i
= 0; i
< bs
->quiesce_counter
; i
++) {
1279 if (drv
->bdrv_co_drain_begin
) {
1280 drv
->bdrv_co_drain_begin(bs
);
1287 if (bs
->file
!= NULL
) {
1288 bdrv_unref_child(bs
, bs
->file
);
1296 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1297 int flags
, Error
**errp
)
1299 BlockDriverState
*bs
;
1303 bs
->open_flags
= flags
;
1304 bs
->explicit_options
= qdict_new();
1305 bs
->options
= qdict_new();
1308 update_options_from_flags(bs
->options
, flags
);
1310 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1312 qobject_unref(bs
->explicit_options
);
1313 bs
->explicit_options
= NULL
;
1314 qobject_unref(bs
->options
);
1323 QemuOptsList bdrv_runtime_opts
= {
1324 .name
= "bdrv_common",
1325 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1328 .name
= "node-name",
1329 .type
= QEMU_OPT_STRING
,
1330 .help
= "Node name of the block device node",
1334 .type
= QEMU_OPT_STRING
,
1335 .help
= "Block driver to use for the node",
1338 .name
= BDRV_OPT_CACHE_DIRECT
,
1339 .type
= QEMU_OPT_BOOL
,
1340 .help
= "Bypass software writeback cache on the host",
1343 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1344 .type
= QEMU_OPT_BOOL
,
1345 .help
= "Ignore flush requests",
1348 .name
= BDRV_OPT_READ_ONLY
,
1349 .type
= QEMU_OPT_BOOL
,
1350 .help
= "Node is opened in read-only mode",
1353 .name
= BDRV_OPT_AUTO_READ_ONLY
,
1354 .type
= QEMU_OPT_BOOL
,
1355 .help
= "Node can become read-only if opening read-write fails",
1358 .name
= "detect-zeroes",
1359 .type
= QEMU_OPT_STRING
,
1360 .help
= "try to optimize zero writes (off, on, unmap)",
1363 .name
= BDRV_OPT_DISCARD
,
1364 .type
= QEMU_OPT_STRING
,
1365 .help
= "discard operation (ignore/off, unmap/on)",
1368 .name
= BDRV_OPT_FORCE_SHARE
,
1369 .type
= QEMU_OPT_BOOL
,
1370 .help
= "always accept other writers (default: off)",
1372 { /* end of list */ }
1377 * Common part for opening disk images and files
1379 * Removes all processed options from *options.
1381 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1382 QDict
*options
, Error
**errp
)
1384 int ret
, open_flags
;
1385 const char *filename
;
1386 const char *driver_name
= NULL
;
1387 const char *node_name
= NULL
;
1388 const char *discard
;
1391 Error
*local_err
= NULL
;
1393 assert(bs
->file
== NULL
);
1394 assert(options
!= NULL
&& bs
->options
!= options
);
1396 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1397 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1399 error_propagate(errp
, local_err
);
1404 update_flags_from_options(&bs
->open_flags
, opts
);
1406 driver_name
= qemu_opt_get(opts
, "driver");
1407 drv
= bdrv_find_format(driver_name
);
1408 assert(drv
!= NULL
);
1410 bs
->force_share
= qemu_opt_get_bool(opts
, BDRV_OPT_FORCE_SHARE
, false);
1412 if (bs
->force_share
&& (bs
->open_flags
& BDRV_O_RDWR
)) {
1414 BDRV_OPT_FORCE_SHARE
1415 "=on can only be used with read-only images");
1421 bdrv_refresh_filename(blk_bs(file
));
1422 filename
= blk_bs(file
)->filename
;
1425 * Caution: while qdict_get_try_str() is fine, getting
1426 * non-string types would require more care. When @options
1427 * come from -blockdev or blockdev_add, its members are typed
1428 * according to the QAPI schema, but when they come from
1429 * -drive, they're all QString.
1431 filename
= qdict_get_try_str(options
, "filename");
1434 if (drv
->bdrv_needs_filename
&& (!filename
|| !filename
[0])) {
1435 error_setg(errp
, "The '%s' block driver requires a file name",
1441 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1444 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1446 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1447 if (!bs
->read_only
&& bdrv_is_whitelisted(drv
, true)) {
1448 ret
= bdrv_apply_auto_read_only(bs
, NULL
, NULL
);
1454 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1455 ? "Driver '%s' can only be used for read-only devices"
1456 : "Driver '%s' is not whitelisted",
1462 /* bdrv_new() and bdrv_close() make it so */
1463 assert(atomic_read(&bs
->copy_on_read
) == 0);
1465 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1466 if (!bs
->read_only
) {
1467 bdrv_enable_copy_on_read(bs
);
1469 error_setg(errp
, "Can't use copy-on-read on read-only device");
1475 discard
= qemu_opt_get(opts
, BDRV_OPT_DISCARD
);
1476 if (discard
!= NULL
) {
1477 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1478 error_setg(errp
, "Invalid discard option");
1485 bdrv_parse_detect_zeroes(opts
, bs
->open_flags
, &local_err
);
1487 error_propagate(errp
, local_err
);
1492 if (filename
!= NULL
) {
1493 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1495 bs
->filename
[0] = '\0';
1497 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1499 /* Open the image, either directly or using a protocol */
1500 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1501 node_name
= qemu_opt_get(opts
, "node-name");
1503 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1504 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1509 qemu_opts_del(opts
);
1513 qemu_opts_del(opts
);
1517 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1519 QObject
*options_obj
;
1523 ret
= strstart(filename
, "json:", &filename
);
1526 options_obj
= qobject_from_json(filename
, errp
);
1528 error_prepend(errp
, "Could not parse the JSON options: ");
1532 options
= qobject_to(QDict
, options_obj
);
1534 qobject_unref(options_obj
);
1535 error_setg(errp
, "Invalid JSON object given");
1539 qdict_flatten(options
);
1544 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1547 QDict
*json_options
;
1548 Error
*local_err
= NULL
;
1550 /* Parse json: pseudo-protocol */
1551 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1555 json_options
= parse_json_filename(*pfilename
, &local_err
);
1557 error_propagate(errp
, local_err
);
1561 /* Options given in the filename have lower priority than options
1562 * specified directly */
1563 qdict_join(options
, json_options
, false);
1564 qobject_unref(json_options
);
1569 * Fills in default options for opening images and converts the legacy
1570 * filename/flags pair to option QDict entries.
1571 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1572 * block driver has been specified explicitly.
1574 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1575 int *flags
, Error
**errp
)
1577 const char *drvname
;
1578 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1579 bool parse_filename
= false;
1580 BlockDriver
*drv
= NULL
;
1581 Error
*local_err
= NULL
;
1584 * Caution: while qdict_get_try_str() is fine, getting non-string
1585 * types would require more care. When @options come from
1586 * -blockdev or blockdev_add, its members are typed according to
1587 * the QAPI schema, but when they come from -drive, they're all
1590 drvname
= qdict_get_try_str(*options
, "driver");
1592 drv
= bdrv_find_format(drvname
);
1594 error_setg(errp
, "Unknown driver '%s'", drvname
);
1597 /* If the user has explicitly specified the driver, this choice should
1598 * override the BDRV_O_PROTOCOL flag */
1599 protocol
= drv
->bdrv_file_open
;
1603 *flags
|= BDRV_O_PROTOCOL
;
1605 *flags
&= ~BDRV_O_PROTOCOL
;
1608 /* Translate cache options from flags into options */
1609 update_options_from_flags(*options
, *flags
);
1611 /* Fetch the file name from the options QDict if necessary */
1612 if (protocol
&& filename
) {
1613 if (!qdict_haskey(*options
, "filename")) {
1614 qdict_put_str(*options
, "filename", filename
);
1615 parse_filename
= true;
1617 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1623 /* Find the right block driver */
1624 /* See cautionary note on accessing @options above */
1625 filename
= qdict_get_try_str(*options
, "filename");
1627 if (!drvname
&& protocol
) {
1629 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1634 drvname
= drv
->format_name
;
1635 qdict_put_str(*options
, "driver", drvname
);
1637 error_setg(errp
, "Must specify either driver or file");
1642 assert(drv
|| !protocol
);
1644 /* Driver-specific filename parsing */
1645 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1646 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1648 error_propagate(errp
, local_err
);
1652 if (!drv
->bdrv_needs_filename
) {
1653 qdict_del(*options
, "filename");
1660 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
1661 uint64_t perm
, uint64_t shared
,
1662 GSList
*ignore_children
, Error
**errp
);
1663 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1664 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1666 typedef struct BlockReopenQueueEntry
{
1668 BDRVReopenState state
;
1669 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1670 } BlockReopenQueueEntry
;
1673 * Return the flags that @bs will have after the reopens in @q have
1674 * successfully completed. If @q is NULL (or @bs is not contained in @q),
1675 * return the current flags.
1677 static int bdrv_reopen_get_flags(BlockReopenQueue
*q
, BlockDriverState
*bs
)
1679 BlockReopenQueueEntry
*entry
;
1682 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
1683 if (entry
->state
.bs
== bs
) {
1684 return entry
->state
.flags
;
1689 return bs
->open_flags
;
1692 /* Returns whether the image file can be written to after the reopen queue @q
1693 * has been successfully applied, or right now if @q is NULL. */
1694 static bool bdrv_is_writable_after_reopen(BlockDriverState
*bs
,
1695 BlockReopenQueue
*q
)
1697 int flags
= bdrv_reopen_get_flags(q
, bs
);
1699 return (flags
& (BDRV_O_RDWR
| BDRV_O_INACTIVE
)) == BDRV_O_RDWR
;
1703 * Return whether the BDS can be written to. This is not necessarily
1704 * the same as !bdrv_is_read_only(bs), as inactivated images may not
1705 * be written to but do not count as read-only images.
1707 bool bdrv_is_writable(BlockDriverState
*bs
)
1709 return bdrv_is_writable_after_reopen(bs
, NULL
);
1712 static void bdrv_child_perm(BlockDriverState
*bs
, BlockDriverState
*child_bs
,
1713 BdrvChild
*c
, const BdrvChildRole
*role
,
1714 BlockReopenQueue
*reopen_queue
,
1715 uint64_t parent_perm
, uint64_t parent_shared
,
1716 uint64_t *nperm
, uint64_t *nshared
)
1718 if (bs
->drv
&& bs
->drv
->bdrv_child_perm
) {
1719 bs
->drv
->bdrv_child_perm(bs
, c
, role
, reopen_queue
,
1720 parent_perm
, parent_shared
,
1723 /* TODO Take force_share from reopen_queue */
1724 if (child_bs
&& child_bs
->force_share
) {
1725 *nshared
= BLK_PERM_ALL
;
1730 * Check whether permissions on this node can be changed in a way that
1731 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1732 * permissions of all its parents. This involves checking whether all necessary
1733 * permission changes to child nodes can be performed.
1735 * A call to this function must always be followed by a call to bdrv_set_perm()
1736 * or bdrv_abort_perm_update().
1738 static int bdrv_check_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
1739 uint64_t cumulative_perms
,
1740 uint64_t cumulative_shared_perms
,
1741 GSList
*ignore_children
, Error
**errp
)
1743 BlockDriver
*drv
= bs
->drv
;
1747 /* Write permissions never work with read-only images */
1748 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1749 !bdrv_is_writable_after_reopen(bs
, q
))
1751 error_setg(errp
, "Block node is read-only");
1755 /* Check this node */
1760 if (drv
->bdrv_check_perm
) {
1761 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1762 cumulative_shared_perms
, errp
);
1765 /* Drivers that never have children can omit .bdrv_child_perm() */
1766 if (!drv
->bdrv_child_perm
) {
1767 assert(QLIST_EMPTY(&bs
->children
));
1771 /* Check all children */
1772 QLIST_FOREACH(c
, &bs
->children
, next
) {
1773 uint64_t cur_perm
, cur_shared
;
1774 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, q
,
1775 cumulative_perms
, cumulative_shared_perms
,
1776 &cur_perm
, &cur_shared
);
1777 ret
= bdrv_child_check_perm(c
, q
, cur_perm
, cur_shared
,
1778 ignore_children
, errp
);
1788 * Notifies drivers that after a previous bdrv_check_perm() call, the
1789 * permission update is not performed and any preparations made for it (e.g.
1790 * taken file locks) need to be undone.
1792 * This function recursively notifies all child nodes.
1794 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1796 BlockDriver
*drv
= bs
->drv
;
1803 if (drv
->bdrv_abort_perm_update
) {
1804 drv
->bdrv_abort_perm_update(bs
);
1807 QLIST_FOREACH(c
, &bs
->children
, next
) {
1808 bdrv_child_abort_perm_update(c
);
1812 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1813 uint64_t cumulative_shared_perms
)
1815 BlockDriver
*drv
= bs
->drv
;
1822 /* Update this node */
1823 if (drv
->bdrv_set_perm
) {
1824 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1827 /* Drivers that never have children can omit .bdrv_child_perm() */
1828 if (!drv
->bdrv_child_perm
) {
1829 assert(QLIST_EMPTY(&bs
->children
));
1833 /* Update all children */
1834 QLIST_FOREACH(c
, &bs
->children
, next
) {
1835 uint64_t cur_perm
, cur_shared
;
1836 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, NULL
,
1837 cumulative_perms
, cumulative_shared_perms
,
1838 &cur_perm
, &cur_shared
);
1839 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1843 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1844 uint64_t *shared_perm
)
1847 uint64_t cumulative_perms
= 0;
1848 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1850 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1851 cumulative_perms
|= c
->perm
;
1852 cumulative_shared_perms
&= c
->shared_perm
;
1855 *perm
= cumulative_perms
;
1856 *shared_perm
= cumulative_shared_perms
;
1859 static char *bdrv_child_user_desc(BdrvChild
*c
)
1861 if (c
->role
->get_parent_desc
) {
1862 return c
->role
->get_parent_desc(c
);
1865 return g_strdup("another user");
1868 char *bdrv_perm_names(uint64_t perm
)
1874 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1875 { BLK_PERM_WRITE
, "write" },
1876 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1877 { BLK_PERM_RESIZE
, "resize" },
1878 { BLK_PERM_GRAPH_MOD
, "change children" },
1882 char *result
= g_strdup("");
1883 struct perm_name
*p
;
1885 for (p
= permissions
; p
->name
; p
++) {
1886 if (perm
& p
->perm
) {
1888 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1897 * Checks whether a new reference to @bs can be added if the new user requires
1898 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1899 * set, the BdrvChild objects in this list are ignored in the calculations;
1900 * this allows checking permission updates for an existing reference.
1902 * Needs to be followed by a call to either bdrv_set_perm() or
1903 * bdrv_abort_perm_update(). */
1904 static int bdrv_check_update_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
1905 uint64_t new_used_perm
,
1906 uint64_t new_shared_perm
,
1907 GSList
*ignore_children
, Error
**errp
)
1910 uint64_t cumulative_perms
= new_used_perm
;
1911 uint64_t cumulative_shared_perms
= new_shared_perm
;
1913 /* There is no reason why anyone couldn't tolerate write_unchanged */
1914 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1916 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1917 if (g_slist_find(ignore_children
, c
)) {
1921 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1922 char *user
= bdrv_child_user_desc(c
);
1923 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1924 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1926 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1932 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1933 char *user
= bdrv_child_user_desc(c
);
1934 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1935 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1937 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1943 cumulative_perms
|= c
->perm
;
1944 cumulative_shared_perms
&= c
->shared_perm
;
1947 return bdrv_check_perm(bs
, q
, cumulative_perms
, cumulative_shared_perms
,
1948 ignore_children
, errp
);
1951 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1952 * bdrv_child_abort_perm_update(). */
1953 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
1954 uint64_t perm
, uint64_t shared
,
1955 GSList
*ignore_children
, Error
**errp
)
1959 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1960 ret
= bdrv_check_update_perm(c
->bs
, q
, perm
, shared
, ignore_children
, errp
);
1961 g_slist_free(ignore_children
);
1967 if (!c
->has_backup_perm
) {
1968 c
->has_backup_perm
= true;
1969 c
->backup_perm
= c
->perm
;
1970 c
->backup_shared_perm
= c
->shared_perm
;
1973 * Note: it's OK if c->has_backup_perm was already set, as we can find the
1974 * same child twice during check_perm procedure
1978 c
->shared_perm
= shared
;
1983 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
1985 uint64_t cumulative_perms
, cumulative_shared_perms
;
1987 c
->has_backup_perm
= false;
1990 c
->shared_perm
= shared
;
1992 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
1993 &cumulative_shared_perms
);
1994 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
1997 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
1999 if (c
->has_backup_perm
) {
2000 c
->perm
= c
->backup_perm
;
2001 c
->shared_perm
= c
->backup_shared_perm
;
2002 c
->has_backup_perm
= false;
2005 bdrv_abort_perm_update(c
->bs
);
2008 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
2013 ret
= bdrv_child_check_perm(c
, NULL
, perm
, shared
, NULL
, errp
);
2015 bdrv_child_abort_perm_update(c
);
2019 bdrv_child_set_perm(c
, perm
, shared
);
2024 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
2025 const BdrvChildRole
*role
,
2026 BlockReopenQueue
*reopen_queue
,
2027 uint64_t perm
, uint64_t shared
,
2028 uint64_t *nperm
, uint64_t *nshared
)
2031 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
2032 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
2036 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
2037 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
2038 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
2039 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
2042 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
2043 const BdrvChildRole
*role
,
2044 BlockReopenQueue
*reopen_queue
,
2045 uint64_t perm
, uint64_t shared
,
2046 uint64_t *nperm
, uint64_t *nshared
)
2048 bool backing
= (role
== &child_backing
);
2049 assert(role
== &child_backing
|| role
== &child_file
);
2052 int flags
= bdrv_reopen_get_flags(reopen_queue
, bs
);
2054 /* Apart from the modifications below, the same permissions are
2055 * forwarded and left alone as for filters */
2056 bdrv_filter_default_perms(bs
, c
, role
, reopen_queue
, perm
, shared
,
2059 /* Format drivers may touch metadata even if the guest doesn't write */
2060 if (bdrv_is_writable_after_reopen(bs
, reopen_queue
)) {
2061 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2064 /* bs->file always needs to be consistent because of the metadata. We
2065 * can never allow other users to resize or write to it. */
2066 if (!(flags
& BDRV_O_NO_IO
)) {
2067 perm
|= BLK_PERM_CONSISTENT_READ
;
2069 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
2071 /* We want consistent read from backing files if the parent needs it.
2072 * No other operations are performed on backing files. */
2073 perm
&= BLK_PERM_CONSISTENT_READ
;
2075 /* If the parent can deal with changing data, we're okay with a
2076 * writable and resizable backing file. */
2077 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
2078 if (shared
& BLK_PERM_WRITE
) {
2079 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2084 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
2085 BLK_PERM_WRITE_UNCHANGED
;
2088 if (bs
->open_flags
& BDRV_O_INACTIVE
) {
2089 shared
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2096 static void bdrv_replace_child_noperm(BdrvChild
*child
,
2097 BlockDriverState
*new_bs
)
2099 BlockDriverState
*old_bs
= child
->bs
;
2102 if (old_bs
&& new_bs
) {
2103 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
2106 /* Detach first so that the recursive drain sections coming from @child
2107 * are already gone and we only end the drain sections that came from
2109 if (child
->role
->detach
) {
2110 child
->role
->detach(child
);
2112 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
2113 int num
= old_bs
->quiesce_counter
;
2114 if (child
->role
->parent_is_bds
) {
2115 num
-= bdrv_drain_all_count
;
2118 for (i
= 0; i
< num
; i
++) {
2119 child
->role
->drained_end(child
);
2122 QLIST_REMOVE(child
, next_parent
);
2128 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
2129 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
2130 int num
= new_bs
->quiesce_counter
;
2131 if (child
->role
->parent_is_bds
) {
2132 num
-= bdrv_drain_all_count
;
2135 for (i
= 0; i
< num
; i
++) {
2136 bdrv_parent_drained_begin_single(child
, true);
2140 /* Attach only after starting new drained sections, so that recursive
2141 * drain sections coming from @child don't get an extra .drained_begin
2143 if (child
->role
->attach
) {
2144 child
->role
->attach(child
);
2150 * Updates @child to change its reference to point to @new_bs, including
2151 * checking and applying the necessary permisson updates both to the old node
2154 * NULL is passed as @new_bs for removing the reference before freeing @child.
2156 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
2157 * function uses bdrv_set_perm() to update the permissions according to the new
2158 * reference that @new_bs gets.
2160 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
2162 BlockDriverState
*old_bs
= child
->bs
;
2163 uint64_t perm
, shared_perm
;
2165 bdrv_replace_child_noperm(child
, new_bs
);
2168 /* Update permissions for old node. This is guaranteed to succeed
2169 * because we're just taking a parent away, so we're loosening
2171 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
2172 bdrv_check_perm(old_bs
, NULL
, perm
, shared_perm
, NULL
, &error_abort
);
2173 bdrv_set_perm(old_bs
, perm
, shared_perm
);
2177 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
2178 bdrv_set_perm(new_bs
, perm
, shared_perm
);
2182 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
2183 const char *child_name
,
2184 const BdrvChildRole
*child_role
,
2185 uint64_t perm
, uint64_t shared_perm
,
2186 void *opaque
, Error
**errp
)
2191 ret
= bdrv_check_update_perm(child_bs
, NULL
, perm
, shared_perm
, NULL
, errp
);
2193 bdrv_abort_perm_update(child_bs
);
2197 child
= g_new(BdrvChild
, 1);
2198 *child
= (BdrvChild
) {
2200 .name
= g_strdup(child_name
),
2203 .shared_perm
= shared_perm
,
2207 /* This performs the matching bdrv_set_perm() for the above check. */
2208 bdrv_replace_child(child
, child_bs
);
2213 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
2214 BlockDriverState
*child_bs
,
2215 const char *child_name
,
2216 const BdrvChildRole
*child_role
,
2220 uint64_t perm
, shared_perm
;
2222 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
2224 assert(parent_bs
->drv
);
2225 assert(bdrv_get_aio_context(parent_bs
) == bdrv_get_aio_context(child_bs
));
2226 bdrv_child_perm(parent_bs
, child_bs
, NULL
, child_role
, NULL
,
2227 perm
, shared_perm
, &perm
, &shared_perm
);
2229 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
2230 perm
, shared_perm
, parent_bs
, errp
);
2231 if (child
== NULL
) {
2235 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
2239 static void bdrv_detach_child(BdrvChild
*child
)
2241 if (child
->next
.le_prev
) {
2242 QLIST_REMOVE(child
, next
);
2243 child
->next
.le_prev
= NULL
;
2246 bdrv_replace_child(child
, NULL
);
2248 g_free(child
->name
);
2252 void bdrv_root_unref_child(BdrvChild
*child
)
2254 BlockDriverState
*child_bs
;
2256 child_bs
= child
->bs
;
2257 bdrv_detach_child(child
);
2258 bdrv_unref(child_bs
);
2261 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
2263 if (child
== NULL
) {
2267 if (child
->bs
->inherits_from
== parent
) {
2270 /* Remove inherits_from only when the last reference between parent and
2271 * child->bs goes away. */
2272 QLIST_FOREACH(c
, &parent
->children
, next
) {
2273 if (c
!= child
&& c
->bs
== child
->bs
) {
2278 child
->bs
->inherits_from
= NULL
;
2282 bdrv_root_unref_child(child
);
2286 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
2289 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2290 if (c
->role
->change_media
) {
2291 c
->role
->change_media(c
, load
);
2296 /* Return true if you can reach parent going through child->inherits_from
2297 * recursively. If parent or child are NULL, return false */
2298 static bool bdrv_inherits_from_recursive(BlockDriverState
*child
,
2299 BlockDriverState
*parent
)
2301 while (child
&& child
!= parent
) {
2302 child
= child
->inherits_from
;
2305 return child
!= NULL
;
2309 * Sets the backing file link of a BDS. A new reference is created; callers
2310 * which don't need their own reference any more must call bdrv_unref().
2312 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
2315 bool update_inherits_from
= bdrv_chain_contains(bs
, backing_hd
) &&
2316 bdrv_inherits_from_recursive(backing_hd
, bs
);
2319 bdrv_ref(backing_hd
);
2323 bdrv_unref_child(bs
, bs
->backing
);
2331 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
2333 /* If backing_hd was already part of bs's backing chain, and
2334 * inherits_from pointed recursively to bs then let's update it to
2335 * point directly to bs (else it will become NULL). */
2336 if (update_inherits_from
) {
2337 backing_hd
->inherits_from
= bs
;
2340 bdrv_unref(backing_hd
);
2344 bdrv_refresh_limits(bs
, NULL
);
2348 * Opens the backing file for a BlockDriverState if not yet open
2350 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2351 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2352 * itself, all options starting with "${bdref_key}." are considered part of the
2355 * TODO Can this be unified with bdrv_open_image()?
2357 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
2358 const char *bdref_key
, Error
**errp
)
2360 char *backing_filename
= g_malloc0(PATH_MAX
);
2361 char *bdref_key_dot
;
2362 const char *reference
= NULL
;
2364 BlockDriverState
*backing_hd
;
2366 QDict
*tmp_parent_options
= NULL
;
2367 Error
*local_err
= NULL
;
2369 if (bs
->backing
!= NULL
) {
2373 /* NULL means an empty set of options */
2374 if (parent_options
== NULL
) {
2375 tmp_parent_options
= qdict_new();
2376 parent_options
= tmp_parent_options
;
2379 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2381 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2382 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2383 g_free(bdref_key_dot
);
2386 * Caution: while qdict_get_try_str() is fine, getting non-string
2387 * types would require more care. When @parent_options come from
2388 * -blockdev or blockdev_add, its members are typed according to
2389 * the QAPI schema, but when they come from -drive, they're all
2392 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2393 if (reference
|| qdict_haskey(options
, "file.filename")) {
2394 backing_filename
[0] = '\0';
2395 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2396 qobject_unref(options
);
2399 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
2403 error_propagate(errp
, local_err
);
2404 qobject_unref(options
);
2409 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2411 error_setg(errp
, "Driver doesn't support backing files");
2412 qobject_unref(options
);
2417 bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2418 qdict_put_str(options
, "driver", bs
->backing_format
);
2421 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
2422 reference
, options
, 0, bs
, &child_backing
,
2425 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2426 error_prepend(errp
, "Could not open backing file: ");
2430 bdrv_set_aio_context(backing_hd
, bdrv_get_aio_context(bs
));
2432 /* Hook up the backing file link; drop our reference, bs owns the
2433 * backing_hd reference now */
2434 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2435 bdrv_unref(backing_hd
);
2437 error_propagate(errp
, local_err
);
2442 qdict_del(parent_options
, bdref_key
);
2445 g_free(backing_filename
);
2446 qobject_unref(tmp_parent_options
);
2450 static BlockDriverState
*
2451 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2452 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2453 bool allow_none
, Error
**errp
)
2455 BlockDriverState
*bs
= NULL
;
2456 QDict
*image_options
;
2457 char *bdref_key_dot
;
2458 const char *reference
;
2460 assert(child_role
!= NULL
);
2462 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2463 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2464 g_free(bdref_key_dot
);
2467 * Caution: while qdict_get_try_str() is fine, getting non-string
2468 * types would require more care. When @options come from
2469 * -blockdev or blockdev_add, its members are typed according to
2470 * the QAPI schema, but when they come from -drive, they're all
2473 reference
= qdict_get_try_str(options
, bdref_key
);
2474 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2476 error_setg(errp
, "A block device must be specified for \"%s\"",
2479 qobject_unref(image_options
);
2483 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2484 parent
, child_role
, errp
);
2490 qdict_del(options
, bdref_key
);
2495 * Opens a disk image whose options are given as BlockdevRef in another block
2498 * If allow_none is true, no image will be opened if filename is false and no
2499 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2501 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2502 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2503 * itself, all options starting with "${bdref_key}." are considered part of the
2506 * The BlockdevRef will be removed from the options QDict.
2508 BdrvChild
*bdrv_open_child(const char *filename
,
2509 QDict
*options
, const char *bdref_key
,
2510 BlockDriverState
*parent
,
2511 const BdrvChildRole
*child_role
,
2512 bool allow_none
, Error
**errp
)
2515 BlockDriverState
*bs
;
2517 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2523 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2532 /* TODO Future callers may need to specify parent/child_role in order for
2533 * option inheritance to work. Existing callers use it for the root node. */
2534 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
)
2536 BlockDriverState
*bs
= NULL
;
2537 Error
*local_err
= NULL
;
2538 QObject
*obj
= NULL
;
2539 QDict
*qdict
= NULL
;
2540 const char *reference
= NULL
;
2543 if (ref
->type
== QTYPE_QSTRING
) {
2544 reference
= ref
->u
.reference
;
2546 BlockdevOptions
*options
= &ref
->u
.definition
;
2547 assert(ref
->type
== QTYPE_QDICT
);
2549 v
= qobject_output_visitor_new(&obj
);
2550 visit_type_BlockdevOptions(v
, NULL
, &options
, &local_err
);
2552 error_propagate(errp
, local_err
);
2555 visit_complete(v
, &obj
);
2557 qdict
= qobject_to(QDict
, obj
);
2558 qdict_flatten(qdict
);
2560 /* bdrv_open_inherit() defaults to the values in bdrv_flags (for
2561 * compatibility with other callers) rather than what we want as the
2562 * real defaults. Apply the defaults here instead. */
2563 qdict_set_default_str(qdict
, BDRV_OPT_CACHE_DIRECT
, "off");
2564 qdict_set_default_str(qdict
, BDRV_OPT_CACHE_NO_FLUSH
, "off");
2565 qdict_set_default_str(qdict
, BDRV_OPT_READ_ONLY
, "off");
2566 qdict_set_default_str(qdict
, BDRV_OPT_AUTO_READ_ONLY
, "off");
2570 bs
= bdrv_open_inherit(NULL
, reference
, qdict
, 0, NULL
, NULL
, errp
);
2579 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2581 QDict
*snapshot_options
,
2584 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2585 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2587 QemuOpts
*opts
= NULL
;
2588 BlockDriverState
*bs_snapshot
= NULL
;
2589 Error
*local_err
= NULL
;
2592 /* if snapshot, we create a temporary backing file and open it
2593 instead of opening 'filename' directly */
2595 /* Get the required size from the image */
2596 total_size
= bdrv_getlength(bs
);
2597 if (total_size
< 0) {
2598 error_setg_errno(errp
, -total_size
, "Could not get image size");
2602 /* Create the temporary image */
2603 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2605 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2609 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2611 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2612 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2613 qemu_opts_del(opts
);
2615 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2620 /* Prepare options QDict for the temporary file */
2621 qdict_put_str(snapshot_options
, "file.driver", "file");
2622 qdict_put_str(snapshot_options
, "file.filename", tmp_filename
);
2623 qdict_put_str(snapshot_options
, "driver", "qcow2");
2625 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2626 snapshot_options
= NULL
;
2631 /* bdrv_append() consumes a strong reference to bs_snapshot
2632 * (i.e. it will call bdrv_unref() on it) even on error, so in
2633 * order to be able to return one, we have to increase
2634 * bs_snapshot's refcount here */
2635 bdrv_ref(bs_snapshot
);
2636 bdrv_append(bs_snapshot
, bs
, &local_err
);
2638 error_propagate(errp
, local_err
);
2644 qobject_unref(snapshot_options
);
2645 g_free(tmp_filename
);
2650 * Opens a disk image (raw, qcow2, vmdk, ...)
2652 * options is a QDict of options to pass to the block drivers, or NULL for an
2653 * empty set of options. The reference to the QDict belongs to the block layer
2654 * after the call (even on failure), so if the caller intends to reuse the
2655 * dictionary, it needs to use qobject_ref() before calling bdrv_open.
2657 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2658 * If it is not NULL, the referenced BDS will be reused.
2660 * The reference parameter may be used to specify an existing block device which
2661 * should be opened. If specified, neither options nor a filename may be given,
2662 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2664 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2665 const char *reference
,
2666 QDict
*options
, int flags
,
2667 BlockDriverState
*parent
,
2668 const BdrvChildRole
*child_role
,
2672 BlockBackend
*file
= NULL
;
2673 BlockDriverState
*bs
;
2674 BlockDriver
*drv
= NULL
;
2676 const char *drvname
;
2677 const char *backing
;
2678 Error
*local_err
= NULL
;
2679 QDict
*snapshot_options
= NULL
;
2680 int snapshot_flags
= 0;
2682 assert(!child_role
|| !flags
);
2683 assert(!child_role
== !parent
);
2686 bool options_non_empty
= options
? qdict_size(options
) : false;
2687 qobject_unref(options
);
2689 if (filename
|| options_non_empty
) {
2690 error_setg(errp
, "Cannot reference an existing block device with "
2691 "additional options or a new filename");
2695 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2706 /* NULL means an empty set of options */
2707 if (options
== NULL
) {
2708 options
= qdict_new();
2711 /* json: syntax counts as explicit options, as if in the QDict */
2712 parse_json_protocol(options
, &filename
, &local_err
);
2717 bs
->explicit_options
= qdict_clone_shallow(options
);
2720 bs
->inherits_from
= parent
;
2721 child_role
->inherit_options(&flags
, options
,
2722 parent
->open_flags
, parent
->options
);
2725 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2731 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2732 * Caution: getting a boolean member of @options requires care.
2733 * When @options come from -blockdev or blockdev_add, members are
2734 * typed according to the QAPI schema, but when they come from
2735 * -drive, they're all QString.
2737 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2738 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2739 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2741 flags
&= ~BDRV_O_RDWR
;
2744 if (flags
& BDRV_O_SNAPSHOT
) {
2745 snapshot_options
= qdict_new();
2746 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2748 /* Let bdrv_backing_options() override "read-only" */
2749 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2750 bdrv_backing_options(&flags
, options
, flags
, options
);
2753 bs
->open_flags
= flags
;
2754 bs
->options
= options
;
2755 options
= qdict_clone_shallow(options
);
2757 /* Find the right image format driver */
2758 /* See cautionary note on accessing @options above */
2759 drvname
= qdict_get_try_str(options
, "driver");
2761 drv
= bdrv_find_format(drvname
);
2763 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2768 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2770 /* See cautionary note on accessing @options above */
2771 backing
= qdict_get_try_str(options
, "backing");
2772 if (qobject_to(QNull
, qdict_get(options
, "backing")) != NULL
||
2773 (backing
&& *backing
== '\0'))
2776 warn_report("Use of \"backing\": \"\" is deprecated; "
2777 "use \"backing\": null instead");
2779 flags
|= BDRV_O_NO_BACKING
;
2780 qdict_del(options
, "backing");
2783 /* Open image file without format layer. This BlockBackend is only used for
2784 * probing, the block drivers will do their own bdrv_open_child() for the
2785 * same BDS, which is why we put the node name back into options. */
2786 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2787 BlockDriverState
*file_bs
;
2789 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2790 &child_file
, true, &local_err
);
2794 if (file_bs
!= NULL
) {
2795 /* Not requesting BLK_PERM_CONSISTENT_READ because we're only
2796 * looking at the header to guess the image format. This works even
2797 * in cases where a guest would not see a consistent state. */
2798 file
= blk_new(0, BLK_PERM_ALL
);
2799 blk_insert_bs(file
, file_bs
, &local_err
);
2800 bdrv_unref(file_bs
);
2805 qdict_put_str(options
, "file", bdrv_get_node_name(file_bs
));
2809 /* Image format probing */
2812 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2817 * This option update would logically belong in bdrv_fill_options(),
2818 * but we first need to open bs->file for the probing to work, while
2819 * opening bs->file already requires the (mostly) final set of options
2820 * so that cache mode etc. can be inherited.
2822 * Adding the driver later is somewhat ugly, but it's not an option
2823 * that would ever be inherited, so it's correct. We just need to make
2824 * sure to update both bs->options (which has the full effective
2825 * options for bs) and options (which has file.* already removed).
2827 qdict_put_str(bs
->options
, "driver", drv
->format_name
);
2828 qdict_put_str(options
, "driver", drv
->format_name
);
2830 error_setg(errp
, "Must specify either driver or file");
2834 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2835 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2836 /* file must be NULL if a protocol BDS is about to be created
2837 * (the inverse results in an error message from bdrv_open_common()) */
2838 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2840 /* Open the image */
2841 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2851 /* If there is a backing file, use it */
2852 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2853 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2855 goto close_and_fail
;
2859 /* Remove all children options and references
2860 * from bs->options and bs->explicit_options */
2861 QLIST_FOREACH(child
, &bs
->children
, next
) {
2862 char *child_key_dot
;
2863 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2864 qdict_extract_subqdict(bs
->explicit_options
, NULL
, child_key_dot
);
2865 qdict_extract_subqdict(bs
->options
, NULL
, child_key_dot
);
2866 qdict_del(bs
->explicit_options
, child
->name
);
2867 qdict_del(bs
->options
, child
->name
);
2868 g_free(child_key_dot
);
2871 /* Check if any unknown options were used */
2872 if (qdict_size(options
) != 0) {
2873 const QDictEntry
*entry
= qdict_first(options
);
2874 if (flags
& BDRV_O_PROTOCOL
) {
2875 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2876 "'%s'", drv
->format_name
, entry
->key
);
2879 "Block format '%s' does not support the option '%s'",
2880 drv
->format_name
, entry
->key
);
2883 goto close_and_fail
;
2886 bdrv_parent_cb_change_media(bs
, true);
2888 qobject_unref(options
);
2891 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2892 * temporary snapshot afterwards. */
2893 if (snapshot_flags
) {
2894 BlockDriverState
*snapshot_bs
;
2895 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2896 snapshot_options
, &local_err
);
2897 snapshot_options
= NULL
;
2899 goto close_and_fail
;
2901 /* We are not going to return bs but the overlay on top of it
2902 * (snapshot_bs); thus, we have to drop the strong reference to bs
2903 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2904 * though, because the overlay still has a reference to it. */
2913 qobject_unref(snapshot_options
);
2914 qobject_unref(bs
->explicit_options
);
2915 qobject_unref(bs
->options
);
2916 qobject_unref(options
);
2918 bs
->explicit_options
= NULL
;
2920 error_propagate(errp
, local_err
);
2925 qobject_unref(snapshot_options
);
2926 qobject_unref(options
);
2927 error_propagate(errp
, local_err
);
2931 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2932 QDict
*options
, int flags
, Error
**errp
)
2934 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2939 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2940 * reopen of multiple devices.
2942 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2943 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2944 * be created and initialized. This newly created BlockReopenQueue should be
2945 * passed back in for subsequent calls that are intended to be of the same
2948 * bs is the BlockDriverState to add to the reopen queue.
2950 * options contains the changed options for the associated bs
2951 * (the BlockReopenQueue takes ownership)
2953 * flags contains the open flags for the associated bs
2955 * returns a pointer to bs_queue, which is either the newly allocated
2956 * bs_queue, or the existing bs_queue being used.
2958 * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
2960 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
2961 BlockDriverState
*bs
,
2963 const BdrvChildRole
*role
,
2964 QDict
*parent_options
,
2969 BlockReopenQueueEntry
*bs_entry
;
2971 QDict
*old_options
, *explicit_options
, *options_copy
;
2975 /* Make sure that the caller remembered to use a drained section. This is
2976 * important to avoid graph changes between the recursive queuing here and
2977 * bdrv_reopen_multiple(). */
2978 assert(bs
->quiesce_counter
> 0);
2980 if (bs_queue
== NULL
) {
2981 bs_queue
= g_new0(BlockReopenQueue
, 1);
2982 QSIMPLEQ_INIT(bs_queue
);
2986 options
= qdict_new();
2989 /* Check if this BlockDriverState is already in the queue */
2990 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2991 if (bs
== bs_entry
->state
.bs
) {
2997 * Precedence of options:
2998 * 1. Explicitly passed in options (highest)
2999 * 2. Retained from explicitly set options of bs
3000 * 3. Inherited from parent node
3001 * 4. Retained from effective options of bs
3004 /* Old explicitly set values (don't overwrite by inherited value) */
3006 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
3008 old_options
= qdict_clone_shallow(bs
->explicit_options
);
3010 bdrv_join_options(bs
, options
, old_options
);
3011 qobject_unref(old_options
);
3013 explicit_options
= qdict_clone_shallow(options
);
3015 /* Inherit from parent node */
3016 if (parent_options
) {
3018 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
3020 flags
= bdrv_get_flags(bs
);
3023 /* Old values are used for options that aren't set yet */
3024 old_options
= qdict_clone_shallow(bs
->options
);
3025 bdrv_join_options(bs
, options
, old_options
);
3026 qobject_unref(old_options
);
3028 /* We have the final set of options so let's update the flags */
3029 options_copy
= qdict_clone_shallow(options
);
3030 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
3031 qemu_opts_absorb_qdict(opts
, options_copy
, NULL
);
3032 update_flags_from_options(&flags
, opts
);
3033 qemu_opts_del(opts
);
3034 qobject_unref(options_copy
);
3036 /* bdrv_open_inherit() sets and clears some additional flags internally */
3037 flags
&= ~BDRV_O_PROTOCOL
;
3038 if (flags
& BDRV_O_RDWR
) {
3039 flags
|= BDRV_O_ALLOW_RDWR
;
3043 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
3044 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
3046 qobject_unref(bs_entry
->state
.options
);
3047 qobject_unref(bs_entry
->state
.explicit_options
);
3050 bs_entry
->state
.bs
= bs
;
3051 bs_entry
->state
.options
= options
;
3052 bs_entry
->state
.explicit_options
= explicit_options
;
3053 bs_entry
->state
.flags
= flags
;
3055 /* This needs to be overwritten in bdrv_reopen_prepare() */
3056 bs_entry
->state
.perm
= UINT64_MAX
;
3057 bs_entry
->state
.shared_perm
= 0;
3059 QLIST_FOREACH(child
, &bs
->children
, next
) {
3060 QDict
*new_child_options
;
3061 char *child_key_dot
;
3063 /* reopen can only change the options of block devices that were
3064 * implicitly created and inherited options. For other (referenced)
3065 * block devices, a syntax like "backing.foo" results in an error. */
3066 if (child
->bs
->inherits_from
!= bs
) {
3070 child_key_dot
= g_strdup_printf("%s.", child
->name
);
3071 qdict_extract_subqdict(explicit_options
, NULL
, child_key_dot
);
3072 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
3073 g_free(child_key_dot
);
3075 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
,
3076 child
->role
, options
, flags
);
3082 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
3083 BlockDriverState
*bs
,
3086 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, NULL
, NULL
, 0);
3090 * Reopen multiple BlockDriverStates atomically & transactionally.
3092 * The queue passed in (bs_queue) must have been built up previous
3093 * via bdrv_reopen_queue().
3095 * Reopens all BDS specified in the queue, with the appropriate
3096 * flags. All devices are prepared for reopen, and failure of any
3097 * device will cause all device changes to be abandoned, and intermediate
3100 * If all devices prepare successfully, then the changes are committed
3103 * All affected nodes must be drained between bdrv_reopen_queue() and
3104 * bdrv_reopen_multiple().
3106 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
3109 BlockReopenQueueEntry
*bs_entry
, *next
;
3110 Error
*local_err
= NULL
;
3112 assert(bs_queue
!= NULL
);
3114 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3115 assert(bs_entry
->state
.bs
->quiesce_counter
> 0);
3116 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
3117 error_propagate(errp
, local_err
);
3120 bs_entry
->prepared
= true;
3123 /* If we reach this point, we have success and just need to apply the
3126 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3127 bdrv_reopen_commit(&bs_entry
->state
);
3133 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
3135 if (bs_entry
->prepared
) {
3136 bdrv_reopen_abort(&bs_entry
->state
);
3138 qobject_unref(bs_entry
->state
.explicit_options
);
3139 qobject_unref(bs_entry
->state
.options
);
3148 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
3152 BlockReopenQueue
*queue
;
3153 QDict
*opts
= qdict_new();
3155 qdict_put_bool(opts
, BDRV_OPT_READ_ONLY
, read_only
);
3157 bdrv_subtree_drained_begin(bs
);
3158 queue
= bdrv_reopen_queue(NULL
, bs
, opts
);
3159 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, errp
);
3160 bdrv_subtree_drained_end(bs
);
3165 static BlockReopenQueueEntry
*find_parent_in_reopen_queue(BlockReopenQueue
*q
,
3168 BlockReopenQueueEntry
*entry
;
3170 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
3171 BlockDriverState
*bs
= entry
->state
.bs
;
3174 QLIST_FOREACH(child
, &bs
->children
, next
) {
3184 static void bdrv_reopen_perm(BlockReopenQueue
*q
, BlockDriverState
*bs
,
3185 uint64_t *perm
, uint64_t *shared
)
3188 BlockReopenQueueEntry
*parent
;
3189 uint64_t cumulative_perms
= 0;
3190 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
3192 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3193 parent
= find_parent_in_reopen_queue(q
, c
);
3195 cumulative_perms
|= c
->perm
;
3196 cumulative_shared_perms
&= c
->shared_perm
;
3198 uint64_t nperm
, nshared
;
3200 bdrv_child_perm(parent
->state
.bs
, bs
, c
, c
->role
, q
,
3201 parent
->state
.perm
, parent
->state
.shared_perm
,
3204 cumulative_perms
|= nperm
;
3205 cumulative_shared_perms
&= nshared
;
3208 *perm
= cumulative_perms
;
3209 *shared
= cumulative_shared_perms
;
3213 * Prepares a BlockDriverState for reopen. All changes are staged in the
3214 * 'opaque' field of the BDRVReopenState, which is used and allocated by
3215 * the block driver layer .bdrv_reopen_prepare()
3217 * bs is the BlockDriverState to reopen
3218 * flags are the new open flags
3219 * queue is the reopen queue
3221 * Returns 0 on success, non-zero on error. On error errp will be set
3224 * On failure, bdrv_reopen_abort() will be called to clean up any data.
3225 * It is the responsibility of the caller to then call the abort() or
3226 * commit() for any other BDS that have been left in a prepare() state
3229 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
3234 Error
*local_err
= NULL
;
3237 QDict
*orig_reopen_opts
;
3238 char *discard
= NULL
;
3240 bool drv_prepared
= false;
3242 assert(reopen_state
!= NULL
);
3243 assert(reopen_state
->bs
->drv
!= NULL
);
3244 drv
= reopen_state
->bs
->drv
;
3246 /* This function and each driver's bdrv_reopen_prepare() remove
3247 * entries from reopen_state->options as they are processed, so
3248 * we need to make a copy of the original QDict. */
3249 orig_reopen_opts
= qdict_clone_shallow(reopen_state
->options
);
3251 /* Process generic block layer options */
3252 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
3253 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
3255 error_propagate(errp
, local_err
);
3260 /* This was already called in bdrv_reopen_queue_child() so the flags
3261 * are up-to-date. This time we simply want to remove the options from
3262 * QemuOpts in order to indicate that they have been processed. */
3263 old_flags
= reopen_state
->flags
;
3264 update_flags_from_options(&reopen_state
->flags
, opts
);
3265 assert(old_flags
== reopen_state
->flags
);
3267 discard
= qemu_opt_get_del(opts
, BDRV_OPT_DISCARD
);
3268 if (discard
!= NULL
) {
3269 if (bdrv_parse_discard_flags(discard
, &reopen_state
->flags
) != 0) {
3270 error_setg(errp
, "Invalid discard option");
3276 reopen_state
->detect_zeroes
=
3277 bdrv_parse_detect_zeroes(opts
, reopen_state
->flags
, &local_err
);
3279 error_propagate(errp
, local_err
);
3284 /* All other options (including node-name and driver) must be unchanged.
3285 * Put them back into the QDict, so that they are checked at the end
3286 * of this function. */
3287 qemu_opts_to_qdict(opts
, reopen_state
->options
);
3289 /* If we are to stay read-only, do not allow permission change
3290 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
3291 * not set, or if the BDS still has copy_on_read enabled */
3292 read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3293 ret
= bdrv_can_set_read_only(reopen_state
->bs
, read_only
, true, &local_err
);
3295 error_propagate(errp
, local_err
);
3299 /* Calculate required permissions after reopening */
3300 bdrv_reopen_perm(queue
, reopen_state
->bs
,
3301 &reopen_state
->perm
, &reopen_state
->shared_perm
);
3303 ret
= bdrv_flush(reopen_state
->bs
);
3305 error_setg_errno(errp
, -ret
, "Error flushing drive");
3309 if (drv
->bdrv_reopen_prepare
) {
3310 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
3312 if (local_err
!= NULL
) {
3313 error_propagate(errp
, local_err
);
3315 bdrv_refresh_filename(reopen_state
->bs
);
3316 error_setg(errp
, "failed while preparing to reopen image '%s'",
3317 reopen_state
->bs
->filename
);
3322 /* It is currently mandatory to have a bdrv_reopen_prepare()
3323 * handler for each supported drv. */
3324 error_setg(errp
, "Block format '%s' used by node '%s' "
3325 "does not support reopening files", drv
->format_name
,
3326 bdrv_get_device_or_node_name(reopen_state
->bs
));
3331 drv_prepared
= true;
3333 /* Options that are not handled are only okay if they are unchanged
3334 * compared to the old state. It is expected that some options are only
3335 * used for the initial open, but not reopen (e.g. filename) */
3336 if (qdict_size(reopen_state
->options
)) {
3337 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
3340 QObject
*new = entry
->value
;
3341 QObject
*old
= qdict_get(reopen_state
->bs
->options
, entry
->key
);
3343 /* Allow child references (child_name=node_name) as long as they
3344 * point to the current child (i.e. everything stays the same). */
3345 if (qobject_type(new) == QTYPE_QSTRING
) {
3347 QLIST_FOREACH(child
, &reopen_state
->bs
->children
, next
) {
3348 if (!strcmp(child
->name
, entry
->key
)) {
3354 const char *str
= qobject_get_try_str(new);
3355 if (!strcmp(child
->bs
->node_name
, str
)) {
3356 continue; /* Found child with this name, skip option */
3362 * TODO: When using -drive to specify blockdev options, all values
3363 * will be strings; however, when using -blockdev, blockdev-add or
3364 * filenames using the json:{} pseudo-protocol, they will be
3366 * In contrast, reopening options are (currently) always strings
3367 * (because you can only specify them through qemu-io; all other
3368 * callers do not specify any options).
3369 * Therefore, when using anything other than -drive to create a BDS,
3370 * this cannot detect non-string options as unchanged, because
3371 * qobject_is_equal() always returns false for objects of different
3372 * type. In the future, this should be remedied by correctly typing
3373 * all options. For now, this is not too big of an issue because
3374 * the user can simply omit options which cannot be changed anyway,
3375 * so they will stay unchanged.
3377 if (!qobject_is_equal(new, old
)) {
3378 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
3382 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
3385 ret
= bdrv_check_perm(reopen_state
->bs
, queue
, reopen_state
->perm
,
3386 reopen_state
->shared_perm
, NULL
, errp
);
3393 /* Restore the original reopen_state->options QDict */
3394 qobject_unref(reopen_state
->options
);
3395 reopen_state
->options
= qobject_ref(orig_reopen_opts
);
3398 if (ret
< 0 && drv_prepared
) {
3399 /* drv->bdrv_reopen_prepare() has succeeded, so we need to
3400 * call drv->bdrv_reopen_abort() before signaling an error
3401 * (bdrv_reopen_multiple() will not call bdrv_reopen_abort()
3402 * when the respective bdrv_reopen_prepare() has failed) */
3403 if (drv
->bdrv_reopen_abort
) {
3404 drv
->bdrv_reopen_abort(reopen_state
);
3407 qemu_opts_del(opts
);
3408 qobject_unref(orig_reopen_opts
);
3414 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
3415 * makes them final by swapping the staging BlockDriverState contents into
3416 * the active BlockDriverState contents.
3418 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
3421 BlockDriverState
*bs
;
3423 bool old_can_write
, new_can_write
;
3425 assert(reopen_state
!= NULL
);
3426 bs
= reopen_state
->bs
;
3428 assert(drv
!= NULL
);
3431 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3433 /* If there are any driver level actions to take */
3434 if (drv
->bdrv_reopen_commit
) {
3435 drv
->bdrv_reopen_commit(reopen_state
);
3438 /* set BDS specific flags now */
3439 qobject_unref(bs
->explicit_options
);
3440 qobject_unref(bs
->options
);
3442 bs
->explicit_options
= reopen_state
->explicit_options
;
3443 bs
->options
= reopen_state
->options
;
3444 bs
->open_flags
= reopen_state
->flags
;
3445 bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3446 bs
->detect_zeroes
= reopen_state
->detect_zeroes
;
3448 /* Remove child references from bs->options and bs->explicit_options.
3449 * Child options were already removed in bdrv_reopen_queue_child() */
3450 QLIST_FOREACH(child
, &bs
->children
, next
) {
3451 qdict_del(bs
->explicit_options
, child
->name
);
3452 qdict_del(bs
->options
, child
->name
);
3455 bdrv_refresh_limits(bs
, NULL
);
3457 bdrv_set_perm(reopen_state
->bs
, reopen_state
->perm
,
3458 reopen_state
->shared_perm
);
3461 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3462 if (!old_can_write
&& new_can_write
&& drv
->bdrv_reopen_bitmaps_rw
) {
3463 Error
*local_err
= NULL
;
3464 if (drv
->bdrv_reopen_bitmaps_rw(bs
, &local_err
) < 0) {
3465 /* This is not fatal, bitmaps just left read-only, so all following
3466 * writes will fail. User can remove read-only bitmaps to unblock
3469 error_reportf_err(local_err
,
3470 "%s: Failed to make dirty bitmaps writable: ",
3471 bdrv_get_node_name(bs
));
3477 * Abort the reopen, and delete and free the staged changes in
3480 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
3484 assert(reopen_state
!= NULL
);
3485 drv
= reopen_state
->bs
->drv
;
3486 assert(drv
!= NULL
);
3488 if (drv
->bdrv_reopen_abort
) {
3489 drv
->bdrv_reopen_abort(reopen_state
);
3492 bdrv_abort_perm_update(reopen_state
->bs
);
3496 static void bdrv_close(BlockDriverState
*bs
)
3498 BdrvAioNotifier
*ban
, *ban_next
;
3499 BdrvChild
*child
, *next
;
3502 assert(!bs
->refcnt
);
3504 bdrv_drained_begin(bs
); /* complete I/O */
3506 bdrv_drain(bs
); /* in case flush left pending I/O */
3509 if (bs
->drv
->bdrv_close
) {
3510 bs
->drv
->bdrv_close(bs
);
3515 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
3517 if (bs
->file
!= NULL
) {
3518 bdrv_unref_child(bs
, bs
->file
);
3522 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
3523 /* TODO Remove bdrv_unref() from drivers' close function and use
3524 * bdrv_unref_child() here */
3525 if (child
->bs
->inherits_from
== bs
) {
3526 child
->bs
->inherits_from
= NULL
;
3528 bdrv_detach_child(child
);
3533 atomic_set(&bs
->copy_on_read
, 0);
3534 bs
->backing_file
[0] = '\0';
3535 bs
->backing_format
[0] = '\0';
3536 bs
->total_sectors
= 0;
3537 bs
->encrypted
= false;
3539 qobject_unref(bs
->options
);
3540 qobject_unref(bs
->explicit_options
);
3542 bs
->explicit_options
= NULL
;
3543 qobject_unref(bs
->full_open_options
);
3544 bs
->full_open_options
= NULL
;
3546 bdrv_release_named_dirty_bitmaps(bs
);
3547 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
3549 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3552 QLIST_INIT(&bs
->aio_notifiers
);
3553 bdrv_drained_end(bs
);
3556 void bdrv_close_all(void)
3558 assert(job_next(NULL
) == NULL
);
3559 nbd_export_close_all();
3561 /* Drop references from requests still in flight, such as canceled block
3562 * jobs whose AIO context has not been polled yet */
3565 blk_remove_all_bs();
3566 blockdev_close_all_bdrv_states();
3568 assert(QTAILQ_EMPTY(&all_bdrv_states
));
3571 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
3577 if (c
->role
->stay_at_node
) {
3581 /* If the child @c belongs to the BDS @to, replacing the current
3582 * c->bs by @to would mean to create a loop.
3584 * Such a case occurs when appending a BDS to a backing chain.
3585 * For instance, imagine the following chain:
3587 * guest device -> node A -> further backing chain...
3589 * Now we create a new BDS B which we want to put on top of this
3590 * chain, so we first attach A as its backing node:
3595 * guest device -> node A -> further backing chain...
3597 * Finally we want to replace A by B. When doing that, we want to
3598 * replace all pointers to A by pointers to B -- except for the
3599 * pointer from B because (1) that would create a loop, and (2)
3600 * that pointer should simply stay intact:
3602 * guest device -> node B
3605 * node A -> further backing chain...
3607 * In general, when replacing a node A (c->bs) by a node B (@to),
3608 * if A is a child of B, that means we cannot replace A by B there
3609 * because that would create a loop. Silently detaching A from B
3610 * is also not really an option. So overall just leaving A in
3611 * place there is the most sensible choice.
3613 * We would also create a loop in any cases where @c is only
3614 * indirectly referenced by @to. Prevent this by returning false
3615 * if @c is found (by breadth-first search) anywhere in the whole
3620 found
= g_hash_table_new(NULL
, NULL
);
3621 g_hash_table_add(found
, to
);
3622 queue
= g_queue_new();
3623 g_queue_push_tail(queue
, to
);
3625 while (!g_queue_is_empty(queue
)) {
3626 BlockDriverState
*v
= g_queue_pop_head(queue
);
3629 QLIST_FOREACH(c2
, &v
->children
, next
) {
3635 if (g_hash_table_contains(found
, c2
->bs
)) {
3639 g_queue_push_tail(queue
, c2
->bs
);
3640 g_hash_table_add(found
, c2
->bs
);
3644 g_queue_free(queue
);
3645 g_hash_table_destroy(found
);
3650 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
3653 BdrvChild
*c
, *next
;
3654 GSList
*list
= NULL
, *p
;
3655 uint64_t old_perm
, old_shared
;
3656 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
3659 assert(!atomic_read(&from
->in_flight
));
3660 assert(!atomic_read(&to
->in_flight
));
3662 /* Make sure that @from doesn't go away until we have successfully attached
3663 * all of its parents to @to. */
3666 /* Put all parents into @list and calculate their cumulative permissions */
3667 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
3668 assert(c
->bs
== from
);
3669 if (!should_update_child(c
, to
)) {
3672 list
= g_slist_prepend(list
, c
);
3674 shared
&= c
->shared_perm
;
3677 /* Check whether the required permissions can be granted on @to, ignoring
3678 * all BdrvChild in @list so that they can't block themselves. */
3679 ret
= bdrv_check_update_perm(to
, NULL
, perm
, shared
, list
, errp
);
3681 bdrv_abort_perm_update(to
);
3685 /* Now actually perform the change. We performed the permission check for
3686 * all elements of @list at once, so set the permissions all at once at the
3688 for (p
= list
; p
!= NULL
; p
= p
->next
) {
3692 bdrv_replace_child_noperm(c
, to
);
3696 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3697 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3705 * Add new bs contents at the top of an image chain while the chain is
3706 * live, while keeping required fields on the top layer.
3708 * This will modify the BlockDriverState fields, and swap contents
3709 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3711 * bs_new must not be attached to a BlockBackend.
3713 * This function does not create any image files.
3715 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3716 * that's what the callers commonly need. bs_new will be referenced by the old
3717 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3718 * reference of its own, it must call bdrv_ref().
3720 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3723 Error
*local_err
= NULL
;
3725 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3727 error_propagate(errp
, local_err
);
3731 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3733 error_propagate(errp
, local_err
);
3734 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3738 /* bs_new is now referenced by its new parents, we don't need the
3739 * additional reference any more. */
3744 static void bdrv_delete(BlockDriverState
*bs
)
3747 assert(bdrv_op_blocker_is_empty(bs
));
3748 assert(!bs
->refcnt
);
3752 /* remove from list, if necessary */
3753 if (bs
->node_name
[0] != '\0') {
3754 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3756 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3762 * Run consistency checks on an image
3764 * Returns 0 if the check could be completed (it doesn't mean that the image is
3765 * free of errors) or -errno when an internal error occurred. The results of the
3766 * check are stored in res.
3768 static int coroutine_fn
bdrv_co_check(BlockDriverState
*bs
,
3769 BdrvCheckResult
*res
, BdrvCheckMode fix
)
3771 if (bs
->drv
== NULL
) {
3774 if (bs
->drv
->bdrv_co_check
== NULL
) {
3778 memset(res
, 0, sizeof(*res
));
3779 return bs
->drv
->bdrv_co_check(bs
, res
, fix
);
3782 typedef struct CheckCo
{
3783 BlockDriverState
*bs
;
3784 BdrvCheckResult
*res
;
3789 static void bdrv_check_co_entry(void *opaque
)
3791 CheckCo
*cco
= opaque
;
3792 cco
->ret
= bdrv_co_check(cco
->bs
, cco
->res
, cco
->fix
);
3796 int bdrv_check(BlockDriverState
*bs
,
3797 BdrvCheckResult
*res
, BdrvCheckMode fix
)
3803 .ret
= -EINPROGRESS
,
3807 if (qemu_in_coroutine()) {
3808 /* Fast-path if already in coroutine context */
3809 bdrv_check_co_entry(&cco
);
3811 co
= qemu_coroutine_create(bdrv_check_co_entry
, &cco
);
3812 bdrv_coroutine_enter(bs
, co
);
3813 BDRV_POLL_WHILE(bs
, cco
.ret
== -EINPROGRESS
);
3822 * -EINVAL - backing format specified, but no file
3823 * -ENOSPC - can't update the backing file because no space is left in the
3825 * -ENOTSUP - format driver doesn't support changing the backing file
3827 int bdrv_change_backing_file(BlockDriverState
*bs
,
3828 const char *backing_file
, const char *backing_fmt
)
3830 BlockDriver
*drv
= bs
->drv
;
3837 /* Backing file format doesn't make sense without a backing file */
3838 if (backing_fmt
&& !backing_file
) {
3842 if (drv
->bdrv_change_backing_file
!= NULL
) {
3843 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3849 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3850 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3856 * Finds the image layer in the chain that has 'bs' as its backing file.
3858 * active is the current topmost image.
3860 * Returns NULL if bs is not found in active's image chain,
3861 * or if active == bs.
3863 * Returns the bottommost base image if bs == NULL.
3865 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3866 BlockDriverState
*bs
)
3868 while (active
&& bs
!= backing_bs(active
)) {
3869 active
= backing_bs(active
);
3875 /* Given a BDS, searches for the base layer. */
3876 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3878 return bdrv_find_overlay(bs
, NULL
);
3882 * Drops images above 'base' up to and including 'top', and sets the image
3883 * above 'top' to have base as its backing file.
3885 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3886 * information in 'bs' can be properly updated.
3888 * E.g., this will convert the following chain:
3889 * bottom <- base <- intermediate <- top <- active
3893 * bottom <- base <- active
3895 * It is allowed for bottom==base, in which case it converts:
3897 * base <- intermediate <- top <- active
3903 * If backing_file_str is non-NULL, it will be used when modifying top's
3904 * overlay image metadata.
3907 * if active == top, that is considered an error
3910 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
3911 const char *backing_file_str
)
3913 BlockDriverState
*explicit_top
= top
;
3914 bool update_inherits_from
;
3915 BdrvChild
*c
, *next
;
3916 Error
*local_err
= NULL
;
3921 if (!top
->drv
|| !base
->drv
) {
3925 /* Make sure that base is in the backing chain of top */
3926 if (!bdrv_chain_contains(top
, base
)) {
3930 /* If 'base' recursively inherits from 'top' then we should set
3931 * base->inherits_from to top->inherits_from after 'top' and all
3932 * other intermediate nodes have been dropped.
3933 * If 'top' is an implicit node (e.g. "commit_top") we should skip
3934 * it because no one inherits from it. We use explicit_top for that. */
3935 while (explicit_top
&& explicit_top
->implicit
) {
3936 explicit_top
= backing_bs(explicit_top
);
3938 update_inherits_from
= bdrv_inherits_from_recursive(base
, explicit_top
);
3940 /* success - we can delete the intermediate states, and link top->base */
3941 /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
3942 * we've figured out how they should work. */
3943 if (!backing_file_str
) {
3944 bdrv_refresh_filename(base
);
3945 backing_file_str
= base
->filename
;
3948 QLIST_FOREACH_SAFE(c
, &top
->parents
, next_parent
, next
) {
3949 /* Check whether we are allowed to switch c from top to base */
3950 GSList
*ignore_children
= g_slist_prepend(NULL
, c
);
3951 bdrv_check_update_perm(base
, NULL
, c
->perm
, c
->shared_perm
,
3952 ignore_children
, &local_err
);
3953 g_slist_free(ignore_children
);
3956 error_report_err(local_err
);
3960 /* If so, update the backing file path in the image file */
3961 if (c
->role
->update_filename
) {
3962 ret
= c
->role
->update_filename(c
, base
, backing_file_str
,
3965 bdrv_abort_perm_update(base
);
3966 error_report_err(local_err
);
3971 /* Do the actual switch in the in-memory graph.
3972 * Completes bdrv_check_update_perm() transaction internally. */
3974 bdrv_replace_child(c
, base
);
3978 if (update_inherits_from
) {
3979 base
->inherits_from
= explicit_top
->inherits_from
;
3989 * Length of a allocated file in bytes. Sparse files are counted by actual
3990 * allocated space. Return < 0 if error or unknown.
3992 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
3994 BlockDriver
*drv
= bs
->drv
;
3998 if (drv
->bdrv_get_allocated_file_size
) {
3999 return drv
->bdrv_get_allocated_file_size(bs
);
4002 return bdrv_get_allocated_file_size(bs
->file
->bs
);
4009 * @drv: Format driver
4010 * @opts: Creation options for new image
4011 * @in_bs: Existing image containing data for new image (may be NULL)
4012 * @errp: Error object
4013 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
4016 * Calculate file size required to create a new image.
4018 * If @in_bs is given then space for allocated clusters and zero clusters
4019 * from that image are included in the calculation. If @opts contains a
4020 * backing file that is shared by @in_bs then backing clusters may be omitted
4021 * from the calculation.
4023 * If @in_bs is NULL then the calculation includes no allocated clusters
4024 * unless a preallocation option is given in @opts.
4026 * Note that @in_bs may use a different BlockDriver from @drv.
4028 * If an error occurs the @errp pointer is set.
4030 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
4031 BlockDriverState
*in_bs
, Error
**errp
)
4033 if (!drv
->bdrv_measure
) {
4034 error_setg(errp
, "Block driver '%s' does not support size measurement",
4039 return drv
->bdrv_measure(opts
, in_bs
, errp
);
4043 * Return number of sectors on success, -errno on error.
4045 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
4047 BlockDriver
*drv
= bs
->drv
;
4052 if (drv
->has_variable_length
) {
4053 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
4058 return bs
->total_sectors
;
4062 * Return length in bytes on success, -errno on error.
4063 * The length is always a multiple of BDRV_SECTOR_SIZE.
4065 int64_t bdrv_getlength(BlockDriverState
*bs
)
4067 int64_t ret
= bdrv_nb_sectors(bs
);
4069 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
4070 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
4073 /* return 0 as number of sectors if no device present or error */
4074 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
4076 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
4078 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
4081 bool bdrv_is_sg(BlockDriverState
*bs
)
4086 bool bdrv_is_encrypted(BlockDriverState
*bs
)
4088 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
4091 return bs
->encrypted
;
4094 const char *bdrv_get_format_name(BlockDriverState
*bs
)
4096 return bs
->drv
? bs
->drv
->format_name
: NULL
;
4099 static int qsort_strcmp(const void *a
, const void *b
)
4101 return strcmp(*(char *const *)a
, *(char *const *)b
);
4104 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
4110 const char **formats
= NULL
;
4112 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
4113 if (drv
->format_name
) {
4116 while (formats
&& i
&& !found
) {
4117 found
= !strcmp(formats
[--i
], drv
->format_name
);
4121 formats
= g_renew(const char *, formats
, count
+ 1);
4122 formats
[count
++] = drv
->format_name
;
4127 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
4128 const char *format_name
= block_driver_modules
[i
].format_name
;
4134 while (formats
&& j
&& !found
) {
4135 found
= !strcmp(formats
[--j
], format_name
);
4139 formats
= g_renew(const char *, formats
, count
+ 1);
4140 formats
[count
++] = format_name
;
4145 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
4147 for (i
= 0; i
< count
; i
++) {
4148 it(opaque
, formats
[i
]);
4154 /* This function is to find a node in the bs graph */
4155 BlockDriverState
*bdrv_find_node(const char *node_name
)
4157 BlockDriverState
*bs
;
4161 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4162 if (!strcmp(node_name
, bs
->node_name
)) {
4169 /* Put this QMP function here so it can access the static graph_bdrv_states. */
4170 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
4172 BlockDeviceInfoList
*list
, *entry
;
4173 BlockDriverState
*bs
;
4176 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4177 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
4179 qapi_free_BlockDeviceInfoList(list
);
4182 entry
= g_malloc0(sizeof(*entry
));
4183 entry
->value
= info
;
4191 #define QAPI_LIST_ADD(list, element) do { \
4192 typeof(list) _tmp = g_new(typeof(*(list)), 1); \
4193 _tmp->value = (element); \
4194 _tmp->next = (list); \
4198 typedef struct XDbgBlockGraphConstructor
{
4199 XDbgBlockGraph
*graph
;
4200 GHashTable
*graph_nodes
;
4201 } XDbgBlockGraphConstructor
;
4203 static XDbgBlockGraphConstructor
*xdbg_graph_new(void)
4205 XDbgBlockGraphConstructor
*gr
= g_new(XDbgBlockGraphConstructor
, 1);
4207 gr
->graph
= g_new0(XDbgBlockGraph
, 1);
4208 gr
->graph_nodes
= g_hash_table_new(NULL
, NULL
);
4213 static XDbgBlockGraph
*xdbg_graph_finalize(XDbgBlockGraphConstructor
*gr
)
4215 XDbgBlockGraph
*graph
= gr
->graph
;
4217 g_hash_table_destroy(gr
->graph_nodes
);
4223 static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor
*gr
, void *node
)
4225 uintptr_t ret
= (uintptr_t)g_hash_table_lookup(gr
->graph_nodes
, node
);
4232 * Start counting from 1, not 0, because 0 interferes with not-found (NULL)
4233 * answer of g_hash_table_lookup.
4235 ret
= g_hash_table_size(gr
->graph_nodes
) + 1;
4236 g_hash_table_insert(gr
->graph_nodes
, node
, (void *)ret
);
4241 static void xdbg_graph_add_node(XDbgBlockGraphConstructor
*gr
, void *node
,
4242 XDbgBlockGraphNodeType type
, const char *name
)
4244 XDbgBlockGraphNode
*n
;
4246 n
= g_new0(XDbgBlockGraphNode
, 1);
4248 n
->id
= xdbg_graph_node_num(gr
, node
);
4250 n
->name
= g_strdup(name
);
4252 QAPI_LIST_ADD(gr
->graph
->nodes
, n
);
4255 static void xdbg_graph_add_edge(XDbgBlockGraphConstructor
*gr
, void *parent
,
4256 const BdrvChild
*child
)
4260 BlockPermission num
;
4263 static const PermissionMap permissions
[] = {
4264 { BLK_PERM_CONSISTENT_READ
, BLOCK_PERMISSION_CONSISTENT_READ
},
4265 { BLK_PERM_WRITE
, BLOCK_PERMISSION_WRITE
},
4266 { BLK_PERM_WRITE_UNCHANGED
, BLOCK_PERMISSION_WRITE_UNCHANGED
},
4267 { BLK_PERM_RESIZE
, BLOCK_PERMISSION_RESIZE
},
4268 { BLK_PERM_GRAPH_MOD
, BLOCK_PERMISSION_GRAPH_MOD
},
4271 const PermissionMap
*p
;
4272 XDbgBlockGraphEdge
*edge
;
4274 QEMU_BUILD_BUG_ON(1UL << (ARRAY_SIZE(permissions
) - 1) != BLK_PERM_ALL
+ 1);
4276 edge
= g_new0(XDbgBlockGraphEdge
, 1);
4278 edge
->parent
= xdbg_graph_node_num(gr
, parent
);
4279 edge
->child
= xdbg_graph_node_num(gr
, child
->bs
);
4280 edge
->name
= g_strdup(child
->name
);
4282 for (p
= permissions
; p
->flag
; p
++) {
4283 if (p
->flag
& child
->perm
) {
4284 QAPI_LIST_ADD(edge
->perm
, p
->num
);
4286 if (p
->flag
& child
->shared_perm
) {
4287 QAPI_LIST_ADD(edge
->shared_perm
, p
->num
);
4291 QAPI_LIST_ADD(gr
->graph
->edges
, edge
);
4295 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
)
4299 BlockDriverState
*bs
;
4301 XDbgBlockGraphConstructor
*gr
= xdbg_graph_new();
4303 for (blk
= blk_all_next(NULL
); blk
; blk
= blk_all_next(blk
)) {
4304 char *allocated_name
= NULL
;
4305 const char *name
= blk_name(blk
);
4308 name
= allocated_name
= blk_get_attached_dev_id(blk
);
4310 xdbg_graph_add_node(gr
, blk
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND
,
4312 g_free(allocated_name
);
4313 if (blk_root(blk
)) {
4314 xdbg_graph_add_edge(gr
, blk
, blk_root(blk
));
4318 for (job
= block_job_next(NULL
); job
; job
= block_job_next(job
)) {
4321 xdbg_graph_add_node(gr
, job
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB
,
4323 for (el
= job
->nodes
; el
; el
= el
->next
) {
4324 xdbg_graph_add_edge(gr
, job
, (BdrvChild
*)el
->data
);
4328 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4329 xdbg_graph_add_node(gr
, bs
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER
,
4331 QLIST_FOREACH(child
, &bs
->children
, next
) {
4332 xdbg_graph_add_edge(gr
, bs
, child
);
4336 return xdbg_graph_finalize(gr
);
4339 BlockDriverState
*bdrv_lookup_bs(const char *device
,
4340 const char *node_name
,
4344 BlockDriverState
*bs
;
4347 blk
= blk_by_name(device
);
4352 error_setg(errp
, "Device '%s' has no medium", device
);
4360 bs
= bdrv_find_node(node_name
);
4367 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
4368 device
? device
: "",
4369 node_name
? node_name
: "");
4373 /* If 'base' is in the same chain as 'top', return true. Otherwise,
4374 * return false. If either argument is NULL, return false. */
4375 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
4377 while (top
&& top
!= base
) {
4378 top
= backing_bs(top
);
4384 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
4387 return QTAILQ_FIRST(&graph_bdrv_states
);
4389 return QTAILQ_NEXT(bs
, node_list
);
4392 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
)
4395 return QTAILQ_FIRST(&all_bdrv_states
);
4397 return QTAILQ_NEXT(bs
, bs_list
);
4400 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
4402 return bs
->node_name
;
4405 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
4410 /* If multiple parents have a name, just pick the first one. */
4411 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
4412 if (c
->role
->get_name
) {
4413 name
= c
->role
->get_name(c
);
4414 if (name
&& *name
) {
4423 /* TODO check what callers really want: bs->node_name or blk_name() */
4424 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
4426 return bdrv_get_parent_name(bs
) ?: "";
4429 /* This can be used to identify nodes that might not have a device
4430 * name associated. Since node and device names live in the same
4431 * namespace, the result is unambiguous. The exception is if both are
4432 * absent, then this returns an empty (non-null) string. */
4433 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
4435 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
4438 int bdrv_get_flags(BlockDriverState
*bs
)
4440 return bs
->open_flags
;
4443 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
4448 int bdrv_has_zero_init(BlockDriverState
*bs
)
4454 /* If BS is a copy on write image, it is initialized to
4455 the contents of the base image, which may not be zeroes. */
4459 if (bs
->drv
->bdrv_has_zero_init
) {
4460 return bs
->drv
->bdrv_has_zero_init(bs
);
4462 if (bs
->file
&& bs
->drv
->is_filter
) {
4463 return bdrv_has_zero_init(bs
->file
->bs
);
4470 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
4472 BlockDriverInfo bdi
;
4478 if (bdrv_get_info(bs
, &bdi
) == 0) {
4479 return bdi
.unallocated_blocks_are_zero
;
4485 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
4487 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
4491 return bs
->supported_zero_flags
& BDRV_REQ_MAY_UNMAP
;
4494 void bdrv_get_backing_filename(BlockDriverState
*bs
,
4495 char *filename
, int filename_size
)
4497 pstrcpy(filename
, filename_size
, bs
->backing_file
);
4500 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
4502 BlockDriver
*drv
= bs
->drv
;
4503 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
4507 if (!drv
->bdrv_get_info
) {
4508 if (bs
->file
&& drv
->is_filter
) {
4509 return bdrv_get_info(bs
->file
->bs
, bdi
);
4513 memset(bdi
, 0, sizeof(*bdi
));
4514 return drv
->bdrv_get_info(bs
, bdi
);
4517 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
4520 BlockDriver
*drv
= bs
->drv
;
4521 if (drv
&& drv
->bdrv_get_specific_info
) {
4522 return drv
->bdrv_get_specific_info(bs
, errp
);
4527 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
4529 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
4533 bs
->drv
->bdrv_debug_event(bs
, event
);
4536 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
4539 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
4540 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4543 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
4544 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
4550 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
4552 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
4553 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4556 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
4557 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
4563 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
4565 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
4566 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4569 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
4570 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
4576 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
4578 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
4579 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4582 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
4583 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
4589 /* backing_file can either be relative, or absolute, or a protocol. If it is
4590 * relative, it must be relative to the chain. So, passing in bs->filename
4591 * from a BDS as backing_file should not be done, as that may be relative to
4592 * the CWD rather than the chain. */
4593 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
4594 const char *backing_file
)
4596 char *filename_full
= NULL
;
4597 char *backing_file_full
= NULL
;
4598 char *filename_tmp
= NULL
;
4599 int is_protocol
= 0;
4600 BlockDriverState
*curr_bs
= NULL
;
4601 BlockDriverState
*retval
= NULL
;
4602 Error
*local_error
= NULL
;
4604 if (!bs
|| !bs
->drv
|| !backing_file
) {
4608 filename_full
= g_malloc(PATH_MAX
);
4609 backing_file_full
= g_malloc(PATH_MAX
);
4610 filename_tmp
= g_malloc(PATH_MAX
);
4612 is_protocol
= path_has_protocol(backing_file
);
4614 /* This will recursively refresh everything in the backing chain */
4615 bdrv_refresh_filename(bs
);
4617 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
4619 /* If either of the filename paths is actually a protocol, then
4620 * compare unmodified paths; otherwise make paths relative */
4621 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
4622 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
4623 retval
= curr_bs
->backing
->bs
;
4626 /* Also check against the full backing filename for the image */
4627 bdrv_get_full_backing_filename(curr_bs
, backing_file_full
, PATH_MAX
,
4629 if (local_error
== NULL
) {
4630 if (strcmp(backing_file
, backing_file_full
) == 0) {
4631 retval
= curr_bs
->backing
->bs
;
4635 error_free(local_error
);
4639 /* If not an absolute filename path, make it relative to the current
4640 * image's filename path */
4641 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
4644 /* We are going to compare absolute pathnames */
4645 if (!realpath(filename_tmp
, filename_full
)) {
4649 /* We need to make sure the backing filename we are comparing against
4650 * is relative to the current image filename (or absolute) */
4651 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
4652 curr_bs
->backing_file
);
4654 if (!realpath(filename_tmp
, backing_file_full
)) {
4658 if (strcmp(backing_file_full
, filename_full
) == 0) {
4659 retval
= curr_bs
->backing
->bs
;
4665 g_free(filename_full
);
4666 g_free(backing_file_full
);
4667 g_free(filename_tmp
);
4671 void bdrv_init(void)
4673 module_call_init(MODULE_INIT_BLOCK
);
4676 void bdrv_init_with_whitelist(void)
4678 use_bdrv_whitelist
= 1;
4682 static void coroutine_fn
bdrv_co_invalidate_cache(BlockDriverState
*bs
,
4685 BdrvChild
*child
, *parent
;
4686 uint64_t perm
, shared_perm
;
4687 Error
*local_err
= NULL
;
4689 BdrvDirtyBitmap
*bm
;
4695 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
4699 QLIST_FOREACH(child
, &bs
->children
, next
) {
4700 bdrv_co_invalidate_cache(child
->bs
, &local_err
);
4702 error_propagate(errp
, local_err
);
4708 * Update permissions, they may differ for inactive nodes.
4710 * Note that the required permissions of inactive images are always a
4711 * subset of the permissions required after activating the image. This
4712 * allows us to just get the permissions upfront without restricting
4713 * drv->bdrv_invalidate_cache().
4715 * It also means that in error cases, we don't have to try and revert to
4716 * the old permissions (which is an operation that could fail, too). We can
4717 * just keep the extended permissions for the next time that an activation
4718 * of the image is tried.
4720 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
4721 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
4722 ret
= bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
, &local_err
);
4724 bs
->open_flags
|= BDRV_O_INACTIVE
;
4725 error_propagate(errp
, local_err
);
4728 bdrv_set_perm(bs
, perm
, shared_perm
);
4730 if (bs
->drv
->bdrv_co_invalidate_cache
) {
4731 bs
->drv
->bdrv_co_invalidate_cache(bs
, &local_err
);
4733 bs
->open_flags
|= BDRV_O_INACTIVE
;
4734 error_propagate(errp
, local_err
);
4739 for (bm
= bdrv_dirty_bitmap_next(bs
, NULL
); bm
;
4740 bm
= bdrv_dirty_bitmap_next(bs
, bm
))
4742 bdrv_dirty_bitmap_set_migration(bm
, false);
4745 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
4747 bs
->open_flags
|= BDRV_O_INACTIVE
;
4748 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
4752 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4753 if (parent
->role
->activate
) {
4754 parent
->role
->activate(parent
, &local_err
);
4756 bs
->open_flags
|= BDRV_O_INACTIVE
;
4757 error_propagate(errp
, local_err
);
4764 typedef struct InvalidateCacheCo
{
4765 BlockDriverState
*bs
;
4768 } InvalidateCacheCo
;
4770 static void coroutine_fn
bdrv_invalidate_cache_co_entry(void *opaque
)
4772 InvalidateCacheCo
*ico
= opaque
;
4773 bdrv_co_invalidate_cache(ico
->bs
, ico
->errp
);
4778 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
4781 InvalidateCacheCo ico
= {
4787 if (qemu_in_coroutine()) {
4788 /* Fast-path if already in coroutine context */
4789 bdrv_invalidate_cache_co_entry(&ico
);
4791 co
= qemu_coroutine_create(bdrv_invalidate_cache_co_entry
, &ico
);
4792 bdrv_coroutine_enter(bs
, co
);
4793 BDRV_POLL_WHILE(bs
, !ico
.done
);
4797 void bdrv_invalidate_cache_all(Error
**errp
)
4799 BlockDriverState
*bs
;
4800 Error
*local_err
= NULL
;
4801 BdrvNextIterator it
;
4803 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4804 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
4806 aio_context_acquire(aio_context
);
4807 bdrv_invalidate_cache(bs
, &local_err
);
4808 aio_context_release(aio_context
);
4810 error_propagate(errp
, local_err
);
4811 bdrv_next_cleanup(&it
);
4817 static bool bdrv_has_bds_parent(BlockDriverState
*bs
, bool only_active
)
4821 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4822 if (parent
->role
->parent_is_bds
) {
4823 BlockDriverState
*parent_bs
= parent
->opaque
;
4824 if (!only_active
|| !(parent_bs
->open_flags
& BDRV_O_INACTIVE
)) {
4833 static int bdrv_inactivate_recurse(BlockDriverState
*bs
)
4835 BdrvChild
*child
, *parent
;
4836 uint64_t perm
, shared_perm
;
4843 /* Make sure that we don't inactivate a child before its parent.
4844 * It will be covered by recursion from the yet active parent. */
4845 if (bdrv_has_bds_parent(bs
, true)) {
4849 assert(!(bs
->open_flags
& BDRV_O_INACTIVE
));
4851 /* Inactivate this node */
4852 if (bs
->drv
->bdrv_inactivate
) {
4853 ret
= bs
->drv
->bdrv_inactivate(bs
);
4859 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4860 if (parent
->role
->inactivate
) {
4861 ret
= parent
->role
->inactivate(parent
);
4868 bs
->open_flags
|= BDRV_O_INACTIVE
;
4870 /* Update permissions, they may differ for inactive nodes */
4871 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
4872 bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
, &error_abort
);
4873 bdrv_set_perm(bs
, perm
, shared_perm
);
4876 /* Recursively inactivate children */
4877 QLIST_FOREACH(child
, &bs
->children
, next
) {
4878 ret
= bdrv_inactivate_recurse(child
->bs
);
4887 int bdrv_inactivate_all(void)
4889 BlockDriverState
*bs
= NULL
;
4890 BdrvNextIterator it
;
4892 GSList
*aio_ctxs
= NULL
, *ctx
;
4894 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4895 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
4897 if (!g_slist_find(aio_ctxs
, aio_context
)) {
4898 aio_ctxs
= g_slist_prepend(aio_ctxs
, aio_context
);
4899 aio_context_acquire(aio_context
);
4903 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4904 /* Nodes with BDS parents are covered by recursion from the last
4905 * parent that gets inactivated. Don't inactivate them a second
4906 * time if that has already happened. */
4907 if (bdrv_has_bds_parent(bs
, false)) {
4910 ret
= bdrv_inactivate_recurse(bs
);
4912 bdrv_next_cleanup(&it
);
4918 for (ctx
= aio_ctxs
; ctx
!= NULL
; ctx
= ctx
->next
) {
4919 AioContext
*aio_context
= ctx
->data
;
4920 aio_context_release(aio_context
);
4922 g_slist_free(aio_ctxs
);
4927 /**************************************************************/
4928 /* removable device support */
4931 * Return TRUE if the media is present
4933 bool bdrv_is_inserted(BlockDriverState
*bs
)
4935 BlockDriver
*drv
= bs
->drv
;
4941 if (drv
->bdrv_is_inserted
) {
4942 return drv
->bdrv_is_inserted(bs
);
4944 QLIST_FOREACH(child
, &bs
->children
, next
) {
4945 if (!bdrv_is_inserted(child
->bs
)) {
4953 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4955 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
4957 BlockDriver
*drv
= bs
->drv
;
4959 if (drv
&& drv
->bdrv_eject
) {
4960 drv
->bdrv_eject(bs
, eject_flag
);
4965 * Lock or unlock the media (if it is locked, the user won't be able
4966 * to eject it manually).
4968 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
4970 BlockDriver
*drv
= bs
->drv
;
4972 trace_bdrv_lock_medium(bs
, locked
);
4974 if (drv
&& drv
->bdrv_lock_medium
) {
4975 drv
->bdrv_lock_medium(bs
, locked
);
4979 /* Get a reference to bs */
4980 void bdrv_ref(BlockDriverState
*bs
)
4985 /* Release a previously grabbed reference to bs.
4986 * If after releasing, reference count is zero, the BlockDriverState is
4988 void bdrv_unref(BlockDriverState
*bs
)
4993 assert(bs
->refcnt
> 0);
4994 if (--bs
->refcnt
== 0) {
4999 struct BdrvOpBlocker
{
5001 QLIST_ENTRY(BdrvOpBlocker
) list
;
5004 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
5006 BdrvOpBlocker
*blocker
;
5007 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5008 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
5009 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
5010 error_propagate_prepend(errp
, error_copy(blocker
->reason
),
5011 "Node '%s' is busy: ",
5012 bdrv_get_device_or_node_name(bs
));
5018 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
5020 BdrvOpBlocker
*blocker
;
5021 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5023 blocker
= g_new0(BdrvOpBlocker
, 1);
5024 blocker
->reason
= reason
;
5025 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
5028 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
5030 BdrvOpBlocker
*blocker
, *next
;
5031 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5032 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
5033 if (blocker
->reason
== reason
) {
5034 QLIST_REMOVE(blocker
, list
);
5040 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
5043 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5044 bdrv_op_block(bs
, i
, reason
);
5048 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
5051 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5052 bdrv_op_unblock(bs
, i
, reason
);
5056 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
5060 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5061 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
5068 void bdrv_img_create(const char *filename
, const char *fmt
,
5069 const char *base_filename
, const char *base_fmt
,
5070 char *options
, uint64_t img_size
, int flags
, bool quiet
,
5073 QemuOptsList
*create_opts
= NULL
;
5074 QemuOpts
*opts
= NULL
;
5075 const char *backing_fmt
, *backing_file
;
5077 BlockDriver
*drv
, *proto_drv
;
5078 Error
*local_err
= NULL
;
5081 /* Find driver and parse its options */
5082 drv
= bdrv_find_format(fmt
);
5084 error_setg(errp
, "Unknown file format '%s'", fmt
);
5088 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
5093 if (!drv
->create_opts
) {
5094 error_setg(errp
, "Format driver '%s' does not support image creation",
5099 if (!proto_drv
->create_opts
) {
5100 error_setg(errp
, "Protocol driver '%s' does not support image creation",
5101 proto_drv
->format_name
);
5105 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
5106 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
5108 /* Create parameter list with default values */
5109 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
5110 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
5112 /* Parse -o options */
5114 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
5120 if (base_filename
) {
5121 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
5123 error_setg(errp
, "Backing file not supported for file format '%s'",
5130 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
5132 error_setg(errp
, "Backing file format not supported for file "
5133 "format '%s'", fmt
);
5138 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
5140 if (!strcmp(filename
, backing_file
)) {
5141 error_setg(errp
, "Error: Trying to create an image with the "
5142 "same filename as the backing file");
5147 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
5149 /* The size for the image must always be specified, unless we have a backing
5150 * file and we have not been forbidden from opening it. */
5151 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, img_size
);
5152 if (backing_file
&& !(flags
& BDRV_O_NO_BACKING
)) {
5153 BlockDriverState
*bs
;
5154 char *full_backing
= g_new0(char, PATH_MAX
);
5156 QDict
*backing_options
= NULL
;
5158 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
5159 full_backing
, PATH_MAX
,
5162 g_free(full_backing
);
5166 /* backing files always opened read-only */
5168 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
5170 backing_options
= qdict_new();
5172 qdict_put_str(backing_options
, "driver", backing_fmt
);
5174 qdict_put_bool(backing_options
, BDRV_OPT_FORCE_SHARE
, true);
5176 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
5178 g_free(full_backing
);
5179 if (!bs
&& size
!= -1) {
5180 /* Couldn't open BS, but we have a size, so it's nonfatal */
5181 warn_reportf_err(local_err
,
5182 "Could not verify backing image. "
5183 "This may become an error in future versions.\n");
5186 /* Couldn't open bs, do not have size */
5187 error_append_hint(&local_err
,
5188 "Could not open backing image to determine size.\n");
5192 /* Opened BS, have no size */
5193 size
= bdrv_getlength(bs
);
5195 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
5200 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
5204 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
5207 error_setg(errp
, "Image creation needs a size parameter");
5212 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
5213 qemu_opts_print(opts
, " ");
5217 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
5219 if (ret
== -EFBIG
) {
5220 /* This is generally a better message than whatever the driver would
5221 * deliver (especially because of the cluster_size_hint), since that
5222 * is most probably not much different from "image too large". */
5223 const char *cluster_size_hint
= "";
5224 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
5225 cluster_size_hint
= " (try using a larger cluster size)";
5227 error_setg(errp
, "The image size is too large for file format '%s'"
5228 "%s", fmt
, cluster_size_hint
);
5229 error_free(local_err
);
5234 qemu_opts_del(opts
);
5235 qemu_opts_free(create_opts
);
5236 error_propagate(errp
, local_err
);
5239 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
5241 return bs
? bs
->aio_context
: qemu_get_aio_context();
5244 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
5246 aio_co_enter(bdrv_get_aio_context(bs
), co
);
5249 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
5251 QLIST_REMOVE(ban
, list
);
5255 void bdrv_detach_aio_context(BlockDriverState
*bs
)
5257 BdrvAioNotifier
*baf
, *baf_tmp
;
5264 assert(!bs
->walking_aio_notifiers
);
5265 bs
->walking_aio_notifiers
= true;
5266 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
5268 bdrv_do_remove_aio_context_notifier(baf
);
5270 baf
->detach_aio_context(baf
->opaque
);
5273 /* Never mind iterating again to check for ->deleted. bdrv_close() will
5274 * remove remaining aio notifiers if we aren't called again.
5276 bs
->walking_aio_notifiers
= false;
5278 if (bs
->drv
->bdrv_detach_aio_context
) {
5279 bs
->drv
->bdrv_detach_aio_context(bs
);
5281 QLIST_FOREACH(child
, &bs
->children
, next
) {
5282 bdrv_detach_aio_context(child
->bs
);
5285 if (bs
->quiesce_counter
) {
5286 aio_enable_external(bs
->aio_context
);
5288 bs
->aio_context
= NULL
;
5291 void bdrv_attach_aio_context(BlockDriverState
*bs
,
5292 AioContext
*new_context
)
5294 BdrvAioNotifier
*ban
, *ban_tmp
;
5301 if (bs
->quiesce_counter
) {
5302 aio_disable_external(new_context
);
5305 bs
->aio_context
= new_context
;
5307 QLIST_FOREACH(child
, &bs
->children
, next
) {
5308 bdrv_attach_aio_context(child
->bs
, new_context
);
5310 if (bs
->drv
->bdrv_attach_aio_context
) {
5311 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
5314 assert(!bs
->walking_aio_notifiers
);
5315 bs
->walking_aio_notifiers
= true;
5316 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
5318 bdrv_do_remove_aio_context_notifier(ban
);
5320 ban
->attached_aio_context(new_context
, ban
->opaque
);
5323 bs
->walking_aio_notifiers
= false;
5326 /* The caller must own the AioContext lock for the old AioContext of bs, but it
5327 * must not own the AioContext lock for new_context (unless new_context is
5328 * the same as the current context of bs). */
5329 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
5331 if (bdrv_get_aio_context(bs
) == new_context
) {
5335 bdrv_drained_begin(bs
);
5336 bdrv_detach_aio_context(bs
);
5338 /* This function executes in the old AioContext so acquire the new one in
5339 * case it runs in a different thread.
5341 aio_context_acquire(new_context
);
5342 bdrv_attach_aio_context(bs
, new_context
);
5343 bdrv_drained_end(bs
);
5344 aio_context_release(new_context
);
5347 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
5348 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
5349 void (*detach_aio_context
)(void *opaque
), void *opaque
)
5351 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
5352 *ban
= (BdrvAioNotifier
){
5353 .attached_aio_context
= attached_aio_context
,
5354 .detach_aio_context
= detach_aio_context
,
5358 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
5361 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
5362 void (*attached_aio_context
)(AioContext
*,
5364 void (*detach_aio_context
)(void *),
5367 BdrvAioNotifier
*ban
, *ban_next
;
5369 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
5370 if (ban
->attached_aio_context
== attached_aio_context
&&
5371 ban
->detach_aio_context
== detach_aio_context
&&
5372 ban
->opaque
== opaque
&&
5373 ban
->deleted
== false)
5375 if (bs
->walking_aio_notifiers
) {
5376 ban
->deleted
= true;
5378 bdrv_do_remove_aio_context_notifier(ban
);
5387 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
5388 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
5392 error_setg(errp
, "Node is ejected");
5395 if (!bs
->drv
->bdrv_amend_options
) {
5396 error_setg(errp
, "Block driver '%s' does not support option amendment",
5397 bs
->drv
->format_name
);
5400 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
, errp
);
5403 /* This function will be called by the bdrv_recurse_is_first_non_filter method
5404 * of block filter and by bdrv_is_first_non_filter.
5405 * It is used to test if the given bs is the candidate or recurse more in the
5408 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
5409 BlockDriverState
*candidate
)
5411 /* return false if basic checks fails */
5412 if (!bs
|| !bs
->drv
) {
5416 /* the code reached a non block filter driver -> check if the bs is
5417 * the same as the candidate. It's the recursion termination condition.
5419 if (!bs
->drv
->is_filter
) {
5420 return bs
== candidate
;
5422 /* Down this path the driver is a block filter driver */
5424 /* If the block filter recursion method is defined use it to recurse down
5427 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
5428 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
5431 /* the driver is a block filter but don't allow to recurse -> return false
5436 /* This function checks if the candidate is the first non filter bs down it's
5437 * bs chain. Since we don't have pointers to parents it explore all bs chains
5438 * from the top. Some filters can choose not to pass down the recursion.
5440 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
5442 BlockDriverState
*bs
;
5443 BdrvNextIterator it
;
5445 /* walk down the bs forest recursively */
5446 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
5449 /* try to recurse in this top level bs */
5450 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
5452 /* candidate is the first non filter */
5454 bdrv_next_cleanup(&it
);
5462 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
5463 const char *node_name
, Error
**errp
)
5465 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
5466 AioContext
*aio_context
;
5468 if (!to_replace_bs
) {
5469 error_setg(errp
, "Node name '%s' not found", node_name
);
5473 aio_context
= bdrv_get_aio_context(to_replace_bs
);
5474 aio_context_acquire(aio_context
);
5476 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
5477 to_replace_bs
= NULL
;
5481 /* We don't want arbitrary node of the BDS chain to be replaced only the top
5482 * most non filter in order to prevent data corruption.
5483 * Another benefit is that this tests exclude backing files which are
5484 * blocked by the backing blockers.
5486 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
5487 error_setg(errp
, "Only top most non filter can be replaced");
5488 to_replace_bs
= NULL
;
5493 aio_context_release(aio_context
);
5494 return to_replace_bs
;
5497 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
5499 const QDictEntry
*entry
;
5501 bool found_any
= false;
5503 for (entry
= qdict_first(bs
->options
); entry
;
5504 entry
= qdict_next(bs
->options
, entry
))
5506 /* Exclude all non-driver-specific options */
5507 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
5508 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
5516 qdict_put_obj(d
, qdict_entry_key(entry
),
5517 qobject_ref(qdict_entry_value(entry
)));
5524 /* Updates the following BDS fields:
5525 * - exact_filename: A filename which may be used for opening a block device
5526 * which (mostly) equals the given BDS (even without any
5527 * other options; so reading and writing must return the same
5528 * results, but caching etc. may be different)
5529 * - full_open_options: Options which, when given when opening a block device
5530 * (without a filename), result in a BDS (mostly)
5531 * equalling the given one
5532 * - filename: If exact_filename is set, it is copied here. Otherwise,
5533 * full_open_options is converted to a JSON object, prefixed with
5534 * "json:" (for use through the JSON pseudo protocol) and put here.
5536 void bdrv_refresh_filename(BlockDriverState
*bs
)
5538 BlockDriver
*drv
= bs
->drv
;
5546 /* This BDS's file name may depend on any of its children's file names, so
5547 * refresh those first */
5548 QLIST_FOREACH(child
, &bs
->children
, next
) {
5549 bdrv_refresh_filename(child
->bs
);
5553 /* For implicit nodes, just copy everything from the single child */
5554 child
= QLIST_FIRST(&bs
->children
);
5555 assert(QLIST_NEXT(child
, next
) == NULL
);
5557 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
),
5558 child
->bs
->exact_filename
);
5559 pstrcpy(bs
->filename
, sizeof(bs
->filename
), child
->bs
->filename
);
5561 bs
->full_open_options
= qobject_ref(child
->bs
->full_open_options
);
5566 if (drv
->bdrv_refresh_filename
) {
5567 /* Obsolete information is of no use here, so drop the old file name
5568 * information before refreshing it */
5569 bs
->exact_filename
[0] = '\0';
5570 if (bs
->full_open_options
) {
5571 qobject_unref(bs
->full_open_options
);
5572 bs
->full_open_options
= NULL
;
5576 append_open_options(opts
, bs
);
5577 drv
->bdrv_refresh_filename(bs
, opts
);
5578 qobject_unref(opts
);
5579 } else if (bs
->file
) {
5580 /* Try to reconstruct valid information from the underlying file */
5581 bool has_open_options
;
5583 bs
->exact_filename
[0] = '\0';
5584 if (bs
->full_open_options
) {
5585 qobject_unref(bs
->full_open_options
);
5586 bs
->full_open_options
= NULL
;
5590 has_open_options
= append_open_options(opts
, bs
);
5592 /* If no specific options have been given for this BDS, the filename of
5593 * the underlying file should suffice for this one as well */
5594 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
5595 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
5597 /* Reconstructing the full options QDict is simple for most format block
5598 * drivers, as long as the full options are known for the underlying
5599 * file BDS. The full options QDict of that file BDS should somehow
5600 * contain a representation of the filename, therefore the following
5601 * suffices without querying the (exact_)filename of this BDS. */
5602 if (bs
->file
->bs
->full_open_options
) {
5603 qdict_put_str(opts
, "driver", drv
->format_name
);
5604 qdict_put(opts
, "file",
5605 qobject_ref(bs
->file
->bs
->full_open_options
));
5607 bs
->full_open_options
= opts
;
5609 qobject_unref(opts
);
5611 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
5612 /* There is no underlying file BDS (at least referenced by BDS.file),
5613 * so the full options QDict should be equal to the options given
5614 * specifically for this block device when it was opened (plus the
5615 * driver specification).
5616 * Because those options don't change, there is no need to update
5617 * full_open_options when it's already set. */
5620 append_open_options(opts
, bs
);
5621 qdict_put_str(opts
, "driver", drv
->format_name
);
5623 if (bs
->exact_filename
[0]) {
5624 /* This may not work for all block protocol drivers (some may
5625 * require this filename to be parsed), but we have to find some
5626 * default solution here, so just include it. If some block driver
5627 * does not support pure options without any filename at all or
5628 * needs some special format of the options QDict, it needs to
5629 * implement the driver-specific bdrv_refresh_filename() function.
5631 qdict_put_str(opts
, "filename", bs
->exact_filename
);
5634 bs
->full_open_options
= opts
;
5637 if (bs
->exact_filename
[0]) {
5638 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
5639 } else if (bs
->full_open_options
) {
5640 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
5641 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
5642 qstring_get_str(json
));
5643 qobject_unref(json
);
5648 * Hot add/remove a BDS's child. So the user can take a child offline when
5649 * it is broken and take a new child online
5651 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
5655 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
5656 error_setg(errp
, "The node %s does not support adding a child",
5657 bdrv_get_device_or_node_name(parent_bs
));
5661 if (!QLIST_EMPTY(&child_bs
->parents
)) {
5662 error_setg(errp
, "The node %s already has a parent",
5663 child_bs
->node_name
);
5667 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
5670 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
5674 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
5675 error_setg(errp
, "The node %s does not support removing a child",
5676 bdrv_get_device_or_node_name(parent_bs
));
5680 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
5687 error_setg(errp
, "The node %s does not have a child named %s",
5688 bdrv_get_device_or_node_name(parent_bs
),
5689 bdrv_get_device_or_node_name(child
->bs
));
5693 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);
5696 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
5697 uint32_t granularity
, Error
**errp
)
5699 BlockDriver
*drv
= bs
->drv
;
5702 error_setg_errno(errp
, ENOMEDIUM
,
5703 "Can't store persistent bitmaps to %s",
5704 bdrv_get_device_or_node_name(bs
));
5708 if (!drv
->bdrv_can_store_new_dirty_bitmap
) {
5709 error_setg_errno(errp
, ENOTSUP
,
5710 "Can't store persistent bitmaps to %s",
5711 bdrv_get_device_or_node_name(bs
));
5715 return drv
->bdrv_can_store_new_dirty_bitmap(bs
, name
, granularity
, errp
);