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 return its duplicate. Otherwise, build a
156 path to it by considering it is relative to base_path. URL are
158 char *path_combine(const char *base_path
, const char *filename
)
160 const char *protocol_stripped
= NULL
;
165 if (path_is_absolute(filename
)) {
166 return g_strdup(filename
);
169 if (path_has_protocol(base_path
)) {
170 protocol_stripped
= strchr(base_path
, ':');
171 if (protocol_stripped
) {
175 p
= protocol_stripped
?: base_path
;
177 p1
= strrchr(base_path
, '/');
181 p2
= strrchr(base_path
, '\\');
182 if (!p1
|| p2
> p1
) {
197 result
= g_malloc(len
+ strlen(filename
) + 1);
198 memcpy(result
, base_path
, len
);
199 strcpy(result
+ len
, 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");
307 * If @backing is empty, this function returns NULL without setting
308 * @errp. In all other cases, NULL will only be returned with @errp
311 * Therefore, a return value of NULL without @errp set means that
312 * there is no backing file; if @errp is set, there is one but its
313 * absolute filename cannot be generated.
315 char *bdrv_get_full_backing_filename_from_filename(const char *backed
,
319 if (backing
[0] == '\0') {
321 } else if (path_has_protocol(backing
) || path_is_absolute(backing
)) {
322 return g_strdup(backing
);
323 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
324 error_setg(errp
, "Cannot use relative backing file names for '%s'",
328 return path_combine(backed
, backing
);
333 * If @filename is empty or NULL, this function returns NULL without
334 * setting @errp. In all other cases, NULL will only be returned with
337 static char *bdrv_make_absolute_filename(BlockDriverState
*relative_to
,
338 const char *filename
, Error
**errp
)
340 char *dir
, *full_name
;
342 if (!filename
|| filename
[0] == '\0') {
344 } else if (path_has_protocol(filename
) || path_is_absolute(filename
)) {
345 return g_strdup(filename
);
348 dir
= bdrv_dirname(relative_to
, errp
);
353 full_name
= g_strconcat(dir
, filename
, NULL
);
358 char *bdrv_get_full_backing_filename(BlockDriverState
*bs
, Error
**errp
)
360 return bdrv_make_absolute_filename(bs
, bs
->backing_file
, errp
);
363 void bdrv_register(BlockDriver
*bdrv
)
365 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
368 BlockDriverState
*bdrv_new(void)
370 BlockDriverState
*bs
;
373 bs
= g_new0(BlockDriverState
, 1);
374 QLIST_INIT(&bs
->dirty_bitmaps
);
375 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
376 QLIST_INIT(&bs
->op_blockers
[i
]);
378 notifier_with_return_list_init(&bs
->before_write_notifiers
);
379 qemu_co_mutex_init(&bs
->reqs_lock
);
380 qemu_mutex_init(&bs
->dirty_bitmap_mutex
);
382 bs
->aio_context
= qemu_get_aio_context();
384 qemu_co_queue_init(&bs
->flush_queue
);
386 for (i
= 0; i
< bdrv_drain_all_count
; i
++) {
387 bdrv_drained_begin(bs
);
390 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
395 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
399 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
400 if (!strcmp(drv1
->format_name
, format_name
)) {
408 BlockDriver
*bdrv_find_format(const char *format_name
)
413 drv1
= bdrv_do_find_format(format_name
);
418 /* The driver isn't registered, maybe we need to load a module */
419 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
420 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
421 block_module_load_one(block_driver_modules
[i
].library_name
);
426 return bdrv_do_find_format(format_name
);
429 static int bdrv_format_is_whitelisted(const char *format_name
, bool read_only
)
431 static const char *whitelist_rw
[] = {
432 CONFIG_BDRV_RW_WHITELIST
434 static const char *whitelist_ro
[] = {
435 CONFIG_BDRV_RO_WHITELIST
439 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
440 return 1; /* no whitelist, anything goes */
443 for (p
= whitelist_rw
; *p
; p
++) {
444 if (!strcmp(format_name
, *p
)) {
449 for (p
= whitelist_ro
; *p
; p
++) {
450 if (!strcmp(format_name
, *p
)) {
458 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
460 return bdrv_format_is_whitelisted(drv
->format_name
, read_only
);
463 bool bdrv_uses_whitelist(void)
465 return use_bdrv_whitelist
;
468 typedef struct CreateCo
{
476 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
478 Error
*local_err
= NULL
;
481 CreateCo
*cco
= opaque
;
484 ret
= cco
->drv
->bdrv_co_create_opts(cco
->filename
, cco
->opts
, &local_err
);
485 error_propagate(&cco
->err
, local_err
);
489 int bdrv_create(BlockDriver
*drv
, const char* filename
,
490 QemuOpts
*opts
, Error
**errp
)
497 .filename
= g_strdup(filename
),
503 if (!drv
->bdrv_co_create_opts
) {
504 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
509 if (qemu_in_coroutine()) {
510 /* Fast-path if already in coroutine context */
511 bdrv_create_co_entry(&cco
);
513 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
514 qemu_coroutine_enter(co
);
515 while (cco
.ret
== NOT_DONE
) {
516 aio_poll(qemu_get_aio_context(), true);
523 error_propagate(errp
, cco
.err
);
525 error_setg_errno(errp
, -ret
, "Could not create image");
530 g_free(cco
.filename
);
534 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
537 Error
*local_err
= NULL
;
540 drv
= bdrv_find_protocol(filename
, true, errp
);
545 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
546 error_propagate(errp
, local_err
);
551 * Try to get @bs's logical and physical block size.
552 * On success, store them in @bsz struct and return 0.
553 * On failure return -errno.
554 * @bs must not be empty.
556 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
558 BlockDriver
*drv
= bs
->drv
;
560 if (drv
&& drv
->bdrv_probe_blocksizes
) {
561 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
562 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
563 return bdrv_probe_blocksizes(bs
->file
->bs
, bsz
);
570 * Try to get @bs's geometry (cyls, heads, sectors).
571 * On success, store them in @geo struct and return 0.
572 * On failure return -errno.
573 * @bs must not be empty.
575 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
577 BlockDriver
*drv
= bs
->drv
;
579 if (drv
&& drv
->bdrv_probe_geometry
) {
580 return drv
->bdrv_probe_geometry(bs
, geo
);
581 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
582 return bdrv_probe_geometry(bs
->file
->bs
, geo
);
589 * Create a uniquely-named empty temporary file.
590 * Return 0 upon success, otherwise a negative errno value.
592 int get_tmp_filename(char *filename
, int size
)
595 char temp_dir
[MAX_PATH
];
596 /* GetTempFileName requires that its output buffer (4th param)
597 have length MAX_PATH or greater. */
598 assert(size
>= MAX_PATH
);
599 return (GetTempPath(MAX_PATH
, temp_dir
)
600 && GetTempFileName(temp_dir
, "qem", 0, filename
)
601 ? 0 : -GetLastError());
605 tmpdir
= getenv("TMPDIR");
609 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
612 fd
= mkstemp(filename
);
616 if (close(fd
) != 0) {
625 * Detect host devices. By convention, /dev/cdrom[N] is always
626 * recognized as a host CDROM.
628 static BlockDriver
*find_hdev_driver(const char *filename
)
630 int score_max
= 0, score
;
631 BlockDriver
*drv
= NULL
, *d
;
633 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
634 if (d
->bdrv_probe_device
) {
635 score
= d
->bdrv_probe_device(filename
);
636 if (score
> score_max
) {
646 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
650 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
651 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
659 BlockDriver
*bdrv_find_protocol(const char *filename
,
660 bool allow_protocol_prefix
,
669 /* TODO Drivers without bdrv_file_open must be specified explicitly */
672 * XXX(hch): we really should not let host device detection
673 * override an explicit protocol specification, but moving this
674 * later breaks access to device names with colons in them.
675 * Thanks to the brain-dead persistent naming schemes on udev-
676 * based Linux systems those actually are quite common.
678 drv1
= find_hdev_driver(filename
);
683 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
687 p
= strchr(filename
, ':');
690 if (len
> sizeof(protocol
) - 1)
691 len
= sizeof(protocol
) - 1;
692 memcpy(protocol
, filename
, len
);
693 protocol
[len
] = '\0';
695 drv1
= bdrv_do_find_protocol(protocol
);
700 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
701 if (block_driver_modules
[i
].protocol_name
&&
702 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
703 block_module_load_one(block_driver_modules
[i
].library_name
);
708 drv1
= bdrv_do_find_protocol(protocol
);
710 error_setg(errp
, "Unknown protocol '%s'", protocol
);
716 * Guess image format by probing its contents.
717 * This is not a good idea when your image is raw (CVE-2008-2004), but
718 * we do it anyway for backward compatibility.
720 * @buf contains the image's first @buf_size bytes.
721 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
722 * but can be smaller if the image file is smaller)
723 * @filename is its filename.
725 * For all block drivers, call the bdrv_probe() method to get its
727 * Return the first block driver with the highest probing score.
729 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
730 const char *filename
)
732 int score_max
= 0, score
;
733 BlockDriver
*drv
= NULL
, *d
;
735 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
737 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
738 if (score
> score_max
) {
748 static int find_image_format(BlockBackend
*file
, const char *filename
,
749 BlockDriver
**pdrv
, Error
**errp
)
752 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
755 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
756 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
761 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
763 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
769 drv
= bdrv_probe_all(buf
, ret
, filename
);
771 error_setg(errp
, "Could not determine image format: No compatible "
780 * Set the current 'total_sectors' value
781 * Return 0 on success, -errno on error.
783 int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
785 BlockDriver
*drv
= bs
->drv
;
791 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
795 /* query actual device if possible, otherwise just trust the hint */
796 if (drv
->bdrv_getlength
) {
797 int64_t length
= drv
->bdrv_getlength(bs
);
801 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
804 bs
->total_sectors
= hint
;
809 * Combines a QDict of new block driver @options with any missing options taken
810 * from @old_options, so that leaving out an option defaults to its old value.
812 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
815 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
816 bs
->drv
->bdrv_join_options(options
, old_options
);
818 qdict_join(options
, old_options
, false);
822 static BlockdevDetectZeroesOptions
bdrv_parse_detect_zeroes(QemuOpts
*opts
,
826 Error
*local_err
= NULL
;
827 char *value
= qemu_opt_get_del(opts
, "detect-zeroes");
828 BlockdevDetectZeroesOptions detect_zeroes
=
829 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup
, value
,
830 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
, &local_err
);
833 error_propagate(errp
, local_err
);
834 return detect_zeroes
;
837 if (detect_zeroes
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
838 !(open_flags
& BDRV_O_UNMAP
))
840 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
841 "without setting discard operation to unmap");
844 return detect_zeroes
;
848 * Set open flags for a given discard mode
850 * Return 0 on success, -1 if the discard mode was invalid.
852 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
854 *flags
&= ~BDRV_O_UNMAP
;
856 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
858 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
859 *flags
|= BDRV_O_UNMAP
;
868 * Set open flags for a given cache mode
870 * Return 0 on success, -1 if the cache mode was invalid.
872 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
874 *flags
&= ~BDRV_O_CACHE_MASK
;
876 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
877 *writethrough
= false;
878 *flags
|= BDRV_O_NOCACHE
;
879 } else if (!strcmp(mode
, "directsync")) {
880 *writethrough
= true;
881 *flags
|= BDRV_O_NOCACHE
;
882 } else if (!strcmp(mode
, "writeback")) {
883 *writethrough
= false;
884 } else if (!strcmp(mode
, "unsafe")) {
885 *writethrough
= false;
886 *flags
|= BDRV_O_NO_FLUSH
;
887 } else if (!strcmp(mode
, "writethrough")) {
888 *writethrough
= true;
896 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
898 BlockDriverState
*parent
= c
->opaque
;
899 return g_strdup(bdrv_get_device_or_node_name(parent
));
902 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
904 BlockDriverState
*bs
= child
->opaque
;
905 bdrv_do_drained_begin_quiesce(bs
, NULL
, false);
908 static bool bdrv_child_cb_drained_poll(BdrvChild
*child
)
910 BlockDriverState
*bs
= child
->opaque
;
911 return bdrv_drain_poll(bs
, false, NULL
, false);
914 static void bdrv_child_cb_drained_end(BdrvChild
*child
,
915 int *drained_end_counter
)
917 BlockDriverState
*bs
= child
->opaque
;
918 bdrv_drained_end_no_poll(bs
, drained_end_counter
);
921 static void bdrv_child_cb_attach(BdrvChild
*child
)
923 BlockDriverState
*bs
= child
->opaque
;
924 bdrv_apply_subtree_drain(child
, bs
);
927 static void bdrv_child_cb_detach(BdrvChild
*child
)
929 BlockDriverState
*bs
= child
->opaque
;
930 bdrv_unapply_subtree_drain(child
, bs
);
933 static int bdrv_child_cb_inactivate(BdrvChild
*child
)
935 BlockDriverState
*bs
= child
->opaque
;
936 assert(bs
->open_flags
& BDRV_O_INACTIVE
);
940 static bool bdrv_child_cb_can_set_aio_ctx(BdrvChild
*child
, AioContext
*ctx
,
941 GSList
**ignore
, Error
**errp
)
943 BlockDriverState
*bs
= child
->opaque
;
944 return bdrv_can_set_aio_context(bs
, ctx
, ignore
, errp
);
947 static void bdrv_child_cb_set_aio_ctx(BdrvChild
*child
, AioContext
*ctx
,
950 BlockDriverState
*bs
= child
->opaque
;
951 return bdrv_set_aio_context_ignore(bs
, ctx
, ignore
);
955 * Returns the options and flags that a temporary snapshot should get, based on
956 * the originally requested flags (the originally requested image will have
957 * flags like a backing file)
959 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
960 int parent_flags
, QDict
*parent_options
)
962 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
964 /* For temporary files, unconditional cache=unsafe is fine */
965 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
966 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
968 /* Copy the read-only and discard options from the parent */
969 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
970 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_DISCARD
);
972 /* aio=native doesn't work for cache.direct=off, so disable it for the
973 * temporary snapshot */
974 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
978 * Returns the options and flags that bs->file should get if a protocol driver
979 * is expected, based on the given options and flags for the parent BDS
981 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
982 int parent_flags
, QDict
*parent_options
)
984 int flags
= parent_flags
;
986 /* Enable protocol handling, disable format probing for bs->file */
987 flags
|= BDRV_O_PROTOCOL
;
989 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
991 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
992 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
993 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
995 /* Inherit the read-only option from the parent if it's not set */
996 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
997 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_AUTO_READ_ONLY
);
999 /* Our block drivers take care to send flushes and respect unmap policy,
1000 * so we can default to enable both on lower layers regardless of the
1001 * corresponding parent options. */
1002 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
1004 /* Clear flags that only apply to the top layer */
1005 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
1008 *child_flags
= flags
;
1011 const BdrvChildRole child_file
= {
1012 .parent_is_bds
= true,
1013 .get_parent_desc
= bdrv_child_get_parent_desc
,
1014 .inherit_options
= bdrv_inherited_options
,
1015 .drained_begin
= bdrv_child_cb_drained_begin
,
1016 .drained_poll
= bdrv_child_cb_drained_poll
,
1017 .drained_end
= bdrv_child_cb_drained_end
,
1018 .attach
= bdrv_child_cb_attach
,
1019 .detach
= bdrv_child_cb_detach
,
1020 .inactivate
= bdrv_child_cb_inactivate
,
1021 .can_set_aio_ctx
= bdrv_child_cb_can_set_aio_ctx
,
1022 .set_aio_ctx
= bdrv_child_cb_set_aio_ctx
,
1026 * Returns the options and flags that bs->file should get if the use of formats
1027 * (and not only protocols) is permitted for it, based on the given options and
1028 * flags for the parent BDS
1030 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
1031 int parent_flags
, QDict
*parent_options
)
1033 child_file
.inherit_options(child_flags
, child_options
,
1034 parent_flags
, parent_options
);
1036 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
1039 const BdrvChildRole child_format
= {
1040 .parent_is_bds
= true,
1041 .get_parent_desc
= bdrv_child_get_parent_desc
,
1042 .inherit_options
= bdrv_inherited_fmt_options
,
1043 .drained_begin
= bdrv_child_cb_drained_begin
,
1044 .drained_poll
= bdrv_child_cb_drained_poll
,
1045 .drained_end
= bdrv_child_cb_drained_end
,
1046 .attach
= bdrv_child_cb_attach
,
1047 .detach
= bdrv_child_cb_detach
,
1048 .inactivate
= bdrv_child_cb_inactivate
,
1049 .can_set_aio_ctx
= bdrv_child_cb_can_set_aio_ctx
,
1050 .set_aio_ctx
= bdrv_child_cb_set_aio_ctx
,
1053 static void bdrv_backing_attach(BdrvChild
*c
)
1055 BlockDriverState
*parent
= c
->opaque
;
1056 BlockDriverState
*backing_hd
= c
->bs
;
1058 assert(!parent
->backing_blocker
);
1059 error_setg(&parent
->backing_blocker
,
1060 "node is used as backing hd of '%s'",
1061 bdrv_get_device_or_node_name(parent
));
1063 bdrv_refresh_filename(backing_hd
);
1065 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
1066 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
1067 backing_hd
->filename
);
1068 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
1069 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
1071 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
1072 /* Otherwise we won't be able to commit or stream */
1073 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
1074 parent
->backing_blocker
);
1075 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
1076 parent
->backing_blocker
);
1078 * We do backup in 3 ways:
1080 * The target bs is new opened, and the source is top BDS
1081 * 2. blockdev backup
1082 * Both the source and the target are top BDSes.
1083 * 3. internal backup(used for block replication)
1084 * Both the source and the target are backing file
1086 * In case 1 and 2, neither the source nor the target is the backing file.
1087 * In case 3, we will block the top BDS, so there is only one block job
1088 * for the top BDS and its backing chain.
1090 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
1091 parent
->backing_blocker
);
1092 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
1093 parent
->backing_blocker
);
1095 bdrv_child_cb_attach(c
);
1098 static void bdrv_backing_detach(BdrvChild
*c
)
1100 BlockDriverState
*parent
= c
->opaque
;
1102 assert(parent
->backing_blocker
);
1103 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
1104 error_free(parent
->backing_blocker
);
1105 parent
->backing_blocker
= NULL
;
1107 bdrv_child_cb_detach(c
);
1111 * Returns the options and flags that bs->backing should get, based on the
1112 * given options and flags for the parent BDS
1114 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
1115 int parent_flags
, QDict
*parent_options
)
1117 int flags
= parent_flags
;
1119 /* The cache mode is inherited unmodified for backing files; except WCE,
1120 * which is only applied on the top level (BlockBackend) */
1121 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
1122 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
1123 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
1125 /* backing files always opened read-only */
1126 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
1127 qdict_set_default_str(child_options
, BDRV_OPT_AUTO_READ_ONLY
, "off");
1128 flags
&= ~BDRV_O_COPY_ON_READ
;
1130 /* snapshot=on is handled on the top layer */
1131 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
1133 *child_flags
= flags
;
1136 static int bdrv_backing_update_filename(BdrvChild
*c
, BlockDriverState
*base
,
1137 const char *filename
, Error
**errp
)
1139 BlockDriverState
*parent
= c
->opaque
;
1140 bool read_only
= bdrv_is_read_only(parent
);
1144 ret
= bdrv_reopen_set_read_only(parent
, false, errp
);
1150 ret
= bdrv_change_backing_file(parent
, filename
,
1151 base
->drv
? base
->drv
->format_name
: "");
1153 error_setg_errno(errp
, -ret
, "Could not update backing file link");
1157 bdrv_reopen_set_read_only(parent
, true, NULL
);
1163 const BdrvChildRole child_backing
= {
1164 .parent_is_bds
= true,
1165 .get_parent_desc
= bdrv_child_get_parent_desc
,
1166 .attach
= bdrv_backing_attach
,
1167 .detach
= bdrv_backing_detach
,
1168 .inherit_options
= bdrv_backing_options
,
1169 .drained_begin
= bdrv_child_cb_drained_begin
,
1170 .drained_poll
= bdrv_child_cb_drained_poll
,
1171 .drained_end
= bdrv_child_cb_drained_end
,
1172 .inactivate
= bdrv_child_cb_inactivate
,
1173 .update_filename
= bdrv_backing_update_filename
,
1174 .can_set_aio_ctx
= bdrv_child_cb_can_set_aio_ctx
,
1175 .set_aio_ctx
= bdrv_child_cb_set_aio_ctx
,
1178 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
1180 int open_flags
= flags
;
1183 * Clear flags that are internal to the block layer before opening the
1186 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
1191 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
1193 *flags
&= ~(BDRV_O_CACHE_MASK
| BDRV_O_RDWR
| BDRV_O_AUTO_RDONLY
);
1195 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
1196 *flags
|= BDRV_O_NO_FLUSH
;
1199 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
1200 *flags
|= BDRV_O_NOCACHE
;
1203 if (!qemu_opt_get_bool_del(opts
, BDRV_OPT_READ_ONLY
, false)) {
1204 *flags
|= BDRV_O_RDWR
;
1207 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_AUTO_READ_ONLY
, false)) {
1208 *flags
|= BDRV_O_AUTO_RDONLY
;
1212 static void update_options_from_flags(QDict
*options
, int flags
)
1214 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
1215 qdict_put_bool(options
, BDRV_OPT_CACHE_DIRECT
, flags
& BDRV_O_NOCACHE
);
1217 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
1218 qdict_put_bool(options
, BDRV_OPT_CACHE_NO_FLUSH
,
1219 flags
& BDRV_O_NO_FLUSH
);
1221 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
1222 qdict_put_bool(options
, BDRV_OPT_READ_ONLY
, !(flags
& BDRV_O_RDWR
));
1224 if (!qdict_haskey(options
, BDRV_OPT_AUTO_READ_ONLY
)) {
1225 qdict_put_bool(options
, BDRV_OPT_AUTO_READ_ONLY
,
1226 flags
& BDRV_O_AUTO_RDONLY
);
1230 static void bdrv_assign_node_name(BlockDriverState
*bs
,
1231 const char *node_name
,
1234 char *gen_node_name
= NULL
;
1237 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
1238 } else if (!id_wellformed(node_name
)) {
1240 * Check for empty string or invalid characters, but not if it is
1241 * generated (generated names use characters not available to the user)
1243 error_setg(errp
, "Invalid node name");
1247 /* takes care of avoiding namespaces collisions */
1248 if (blk_by_name(node_name
)) {
1249 error_setg(errp
, "node-name=%s is conflicting with a device id",
1254 /* takes care of avoiding duplicates node names */
1255 if (bdrv_find_node(node_name
)) {
1256 error_setg(errp
, "Duplicate node name");
1260 /* Make sure that the node name isn't truncated */
1261 if (strlen(node_name
) >= sizeof(bs
->node_name
)) {
1262 error_setg(errp
, "Node name too long");
1266 /* copy node name into the bs and insert it into the graph list */
1267 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
1268 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
1270 g_free(gen_node_name
);
1273 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
1274 const char *node_name
, QDict
*options
,
1275 int open_flags
, Error
**errp
)
1277 Error
*local_err
= NULL
;
1280 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1282 error_propagate(errp
, local_err
);
1287 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1288 bs
->opaque
= g_malloc0(drv
->instance_size
);
1290 if (drv
->bdrv_file_open
) {
1291 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1292 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1293 } else if (drv
->bdrv_open
) {
1294 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1301 error_propagate(errp
, local_err
);
1302 } else if (bs
->filename
[0]) {
1303 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1305 error_setg_errno(errp
, -ret
, "Could not open image");
1310 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1312 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1316 bdrv_refresh_limits(bs
, &local_err
);
1318 error_propagate(errp
, local_err
);
1322 assert(bdrv_opt_mem_align(bs
) != 0);
1323 assert(bdrv_min_mem_align(bs
) != 0);
1324 assert(is_power_of_2(bs
->bl
.request_alignment
));
1326 for (i
= 0; i
< bs
->quiesce_counter
; i
++) {
1327 if (drv
->bdrv_co_drain_begin
) {
1328 drv
->bdrv_co_drain_begin(bs
);
1335 if (bs
->file
!= NULL
) {
1336 bdrv_unref_child(bs
, bs
->file
);
1344 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1345 int flags
, Error
**errp
)
1347 BlockDriverState
*bs
;
1351 bs
->open_flags
= flags
;
1352 bs
->explicit_options
= qdict_new();
1353 bs
->options
= qdict_new();
1356 update_options_from_flags(bs
->options
, flags
);
1358 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1360 qobject_unref(bs
->explicit_options
);
1361 bs
->explicit_options
= NULL
;
1362 qobject_unref(bs
->options
);
1371 QemuOptsList bdrv_runtime_opts
= {
1372 .name
= "bdrv_common",
1373 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1376 .name
= "node-name",
1377 .type
= QEMU_OPT_STRING
,
1378 .help
= "Node name of the block device node",
1382 .type
= QEMU_OPT_STRING
,
1383 .help
= "Block driver to use for the node",
1386 .name
= BDRV_OPT_CACHE_DIRECT
,
1387 .type
= QEMU_OPT_BOOL
,
1388 .help
= "Bypass software writeback cache on the host",
1391 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1392 .type
= QEMU_OPT_BOOL
,
1393 .help
= "Ignore flush requests",
1396 .name
= BDRV_OPT_READ_ONLY
,
1397 .type
= QEMU_OPT_BOOL
,
1398 .help
= "Node is opened in read-only mode",
1401 .name
= BDRV_OPT_AUTO_READ_ONLY
,
1402 .type
= QEMU_OPT_BOOL
,
1403 .help
= "Node can become read-only if opening read-write fails",
1406 .name
= "detect-zeroes",
1407 .type
= QEMU_OPT_STRING
,
1408 .help
= "try to optimize zero writes (off, on, unmap)",
1411 .name
= BDRV_OPT_DISCARD
,
1412 .type
= QEMU_OPT_STRING
,
1413 .help
= "discard operation (ignore/off, unmap/on)",
1416 .name
= BDRV_OPT_FORCE_SHARE
,
1417 .type
= QEMU_OPT_BOOL
,
1418 .help
= "always accept other writers (default: off)",
1420 { /* end of list */ }
1425 * Common part for opening disk images and files
1427 * Removes all processed options from *options.
1429 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1430 QDict
*options
, Error
**errp
)
1432 int ret
, open_flags
;
1433 const char *filename
;
1434 const char *driver_name
= NULL
;
1435 const char *node_name
= NULL
;
1436 const char *discard
;
1439 Error
*local_err
= NULL
;
1441 assert(bs
->file
== NULL
);
1442 assert(options
!= NULL
&& bs
->options
!= options
);
1444 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1445 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1447 error_propagate(errp
, local_err
);
1452 update_flags_from_options(&bs
->open_flags
, opts
);
1454 driver_name
= qemu_opt_get(opts
, "driver");
1455 drv
= bdrv_find_format(driver_name
);
1456 assert(drv
!= NULL
);
1458 bs
->force_share
= qemu_opt_get_bool(opts
, BDRV_OPT_FORCE_SHARE
, false);
1460 if (bs
->force_share
&& (bs
->open_flags
& BDRV_O_RDWR
)) {
1462 BDRV_OPT_FORCE_SHARE
1463 "=on can only be used with read-only images");
1469 bdrv_refresh_filename(blk_bs(file
));
1470 filename
= blk_bs(file
)->filename
;
1473 * Caution: while qdict_get_try_str() is fine, getting
1474 * non-string types would require more care. When @options
1475 * come from -blockdev or blockdev_add, its members are typed
1476 * according to the QAPI schema, but when they come from
1477 * -drive, they're all QString.
1479 filename
= qdict_get_try_str(options
, "filename");
1482 if (drv
->bdrv_needs_filename
&& (!filename
|| !filename
[0])) {
1483 error_setg(errp
, "The '%s' block driver requires a file name",
1489 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1492 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1494 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1495 if (!bs
->read_only
&& bdrv_is_whitelisted(drv
, true)) {
1496 ret
= bdrv_apply_auto_read_only(bs
, NULL
, NULL
);
1502 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1503 ? "Driver '%s' can only be used for read-only devices"
1504 : "Driver '%s' is not whitelisted",
1510 /* bdrv_new() and bdrv_close() make it so */
1511 assert(atomic_read(&bs
->copy_on_read
) == 0);
1513 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1514 if (!bs
->read_only
) {
1515 bdrv_enable_copy_on_read(bs
);
1517 error_setg(errp
, "Can't use copy-on-read on read-only device");
1523 discard
= qemu_opt_get(opts
, BDRV_OPT_DISCARD
);
1524 if (discard
!= NULL
) {
1525 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1526 error_setg(errp
, "Invalid discard option");
1533 bdrv_parse_detect_zeroes(opts
, bs
->open_flags
, &local_err
);
1535 error_propagate(errp
, local_err
);
1540 if (filename
!= NULL
) {
1541 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1543 bs
->filename
[0] = '\0';
1545 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1547 /* Open the image, either directly or using a protocol */
1548 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1549 node_name
= qemu_opt_get(opts
, "node-name");
1551 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1552 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1557 qemu_opts_del(opts
);
1561 qemu_opts_del(opts
);
1565 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1567 QObject
*options_obj
;
1571 ret
= strstart(filename
, "json:", &filename
);
1574 options_obj
= qobject_from_json(filename
, errp
);
1576 error_prepend(errp
, "Could not parse the JSON options: ");
1580 options
= qobject_to(QDict
, options_obj
);
1582 qobject_unref(options_obj
);
1583 error_setg(errp
, "Invalid JSON object given");
1587 qdict_flatten(options
);
1592 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1595 QDict
*json_options
;
1596 Error
*local_err
= NULL
;
1598 /* Parse json: pseudo-protocol */
1599 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1603 json_options
= parse_json_filename(*pfilename
, &local_err
);
1605 error_propagate(errp
, local_err
);
1609 /* Options given in the filename have lower priority than options
1610 * specified directly */
1611 qdict_join(options
, json_options
, false);
1612 qobject_unref(json_options
);
1617 * Fills in default options for opening images and converts the legacy
1618 * filename/flags pair to option QDict entries.
1619 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1620 * block driver has been specified explicitly.
1622 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1623 int *flags
, Error
**errp
)
1625 const char *drvname
;
1626 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1627 bool parse_filename
= false;
1628 BlockDriver
*drv
= NULL
;
1629 Error
*local_err
= NULL
;
1632 * Caution: while qdict_get_try_str() is fine, getting non-string
1633 * types would require more care. When @options come from
1634 * -blockdev or blockdev_add, its members are typed according to
1635 * the QAPI schema, but when they come from -drive, they're all
1638 drvname
= qdict_get_try_str(*options
, "driver");
1640 drv
= bdrv_find_format(drvname
);
1642 error_setg(errp
, "Unknown driver '%s'", drvname
);
1645 /* If the user has explicitly specified the driver, this choice should
1646 * override the BDRV_O_PROTOCOL flag */
1647 protocol
= drv
->bdrv_file_open
;
1651 *flags
|= BDRV_O_PROTOCOL
;
1653 *flags
&= ~BDRV_O_PROTOCOL
;
1656 /* Translate cache options from flags into options */
1657 update_options_from_flags(*options
, *flags
);
1659 /* Fetch the file name from the options QDict if necessary */
1660 if (protocol
&& filename
) {
1661 if (!qdict_haskey(*options
, "filename")) {
1662 qdict_put_str(*options
, "filename", filename
);
1663 parse_filename
= true;
1665 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1671 /* Find the right block driver */
1672 /* See cautionary note on accessing @options above */
1673 filename
= qdict_get_try_str(*options
, "filename");
1675 if (!drvname
&& protocol
) {
1677 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1682 drvname
= drv
->format_name
;
1683 qdict_put_str(*options
, "driver", drvname
);
1685 error_setg(errp
, "Must specify either driver or file");
1690 assert(drv
|| !protocol
);
1692 /* Driver-specific filename parsing */
1693 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1694 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1696 error_propagate(errp
, local_err
);
1700 if (!drv
->bdrv_needs_filename
) {
1701 qdict_del(*options
, "filename");
1708 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
1709 uint64_t perm
, uint64_t shared
,
1710 GSList
*ignore_children
,
1711 bool *tighten_restrictions
, Error
**errp
);
1712 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1713 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1714 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1715 uint64_t *shared_perm
);
1717 typedef struct BlockReopenQueueEntry
{
1720 BDRVReopenState state
;
1721 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1722 } BlockReopenQueueEntry
;
1725 * Return the flags that @bs will have after the reopens in @q have
1726 * successfully completed. If @q is NULL (or @bs is not contained in @q),
1727 * return the current flags.
1729 static int bdrv_reopen_get_flags(BlockReopenQueue
*q
, BlockDriverState
*bs
)
1731 BlockReopenQueueEntry
*entry
;
1734 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
1735 if (entry
->state
.bs
== bs
) {
1736 return entry
->state
.flags
;
1741 return bs
->open_flags
;
1744 /* Returns whether the image file can be written to after the reopen queue @q
1745 * has been successfully applied, or right now if @q is NULL. */
1746 static bool bdrv_is_writable_after_reopen(BlockDriverState
*bs
,
1747 BlockReopenQueue
*q
)
1749 int flags
= bdrv_reopen_get_flags(q
, bs
);
1751 return (flags
& (BDRV_O_RDWR
| BDRV_O_INACTIVE
)) == BDRV_O_RDWR
;
1755 * Return whether the BDS can be written to. This is not necessarily
1756 * the same as !bdrv_is_read_only(bs), as inactivated images may not
1757 * be written to but do not count as read-only images.
1759 bool bdrv_is_writable(BlockDriverState
*bs
)
1761 return bdrv_is_writable_after_reopen(bs
, NULL
);
1764 static void bdrv_child_perm(BlockDriverState
*bs
, BlockDriverState
*child_bs
,
1765 BdrvChild
*c
, const BdrvChildRole
*role
,
1766 BlockReopenQueue
*reopen_queue
,
1767 uint64_t parent_perm
, uint64_t parent_shared
,
1768 uint64_t *nperm
, uint64_t *nshared
)
1770 assert(bs
->drv
&& bs
->drv
->bdrv_child_perm
);
1771 bs
->drv
->bdrv_child_perm(bs
, c
, role
, reopen_queue
,
1772 parent_perm
, parent_shared
,
1774 /* TODO Take force_share from reopen_queue */
1775 if (child_bs
&& child_bs
->force_share
) {
1776 *nshared
= BLK_PERM_ALL
;
1781 * Check whether permissions on this node can be changed in a way that
1782 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1783 * permissions of all its parents. This involves checking whether all necessary
1784 * permission changes to child nodes can be performed.
1786 * Will set *tighten_restrictions to true if and only if new permissions have to
1787 * be taken or currently shared permissions are to be unshared. Otherwise,
1788 * errors are not fatal as long as the caller accepts that the restrictions
1789 * remain tighter than they need to be. The caller still has to abort the
1791 * @tighten_restrictions cannot be used together with @q: When reopening, we may
1792 * encounter fatal errors even though no restrictions are to be tightened. For
1793 * example, changing a node from RW to RO will fail if the WRITE permission is
1796 * A call to this function must always be followed by a call to bdrv_set_perm()
1797 * or bdrv_abort_perm_update().
1799 static int bdrv_check_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
1800 uint64_t cumulative_perms
,
1801 uint64_t cumulative_shared_perms
,
1802 GSList
*ignore_children
,
1803 bool *tighten_restrictions
, Error
**errp
)
1805 BlockDriver
*drv
= bs
->drv
;
1809 assert(!q
|| !tighten_restrictions
);
1811 if (tighten_restrictions
) {
1812 uint64_t current_perms
, current_shared
;
1813 uint64_t added_perms
, removed_shared_perms
;
1815 bdrv_get_cumulative_perm(bs
, ¤t_perms
, ¤t_shared
);
1817 added_perms
= cumulative_perms
& ~current_perms
;
1818 removed_shared_perms
= current_shared
& ~cumulative_shared_perms
;
1820 *tighten_restrictions
= added_perms
|| removed_shared_perms
;
1823 /* Write permissions never work with read-only images */
1824 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1825 !bdrv_is_writable_after_reopen(bs
, q
))
1827 if (!bdrv_is_writable_after_reopen(bs
, NULL
)) {
1828 error_setg(errp
, "Block node is read-only");
1830 uint64_t current_perms
, current_shared
;
1831 bdrv_get_cumulative_perm(bs
, ¤t_perms
, ¤t_shared
);
1832 if (current_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) {
1833 error_setg(errp
, "Cannot make block node read-only, there is "
1836 error_setg(errp
, "Cannot make block node read-only and create "
1844 /* Check this node */
1849 if (drv
->bdrv_check_perm
) {
1850 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1851 cumulative_shared_perms
, errp
);
1854 /* Drivers that never have children can omit .bdrv_child_perm() */
1855 if (!drv
->bdrv_child_perm
) {
1856 assert(QLIST_EMPTY(&bs
->children
));
1860 /* Check all children */
1861 QLIST_FOREACH(c
, &bs
->children
, next
) {
1862 uint64_t cur_perm
, cur_shared
;
1863 bool child_tighten_restr
;
1865 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, q
,
1866 cumulative_perms
, cumulative_shared_perms
,
1867 &cur_perm
, &cur_shared
);
1868 ret
= bdrv_child_check_perm(c
, q
, cur_perm
, cur_shared
, ignore_children
,
1869 tighten_restrictions
? &child_tighten_restr
1872 if (tighten_restrictions
) {
1873 *tighten_restrictions
|= child_tighten_restr
;
1884 * Notifies drivers that after a previous bdrv_check_perm() call, the
1885 * permission update is not performed and any preparations made for it (e.g.
1886 * taken file locks) need to be undone.
1888 * This function recursively notifies all child nodes.
1890 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1892 BlockDriver
*drv
= bs
->drv
;
1899 if (drv
->bdrv_abort_perm_update
) {
1900 drv
->bdrv_abort_perm_update(bs
);
1903 QLIST_FOREACH(c
, &bs
->children
, next
) {
1904 bdrv_child_abort_perm_update(c
);
1908 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1909 uint64_t cumulative_shared_perms
)
1911 BlockDriver
*drv
= bs
->drv
;
1918 /* Update this node */
1919 if (drv
->bdrv_set_perm
) {
1920 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1923 /* Drivers that never have children can omit .bdrv_child_perm() */
1924 if (!drv
->bdrv_child_perm
) {
1925 assert(QLIST_EMPTY(&bs
->children
));
1929 /* Update all children */
1930 QLIST_FOREACH(c
, &bs
->children
, next
) {
1931 uint64_t cur_perm
, cur_shared
;
1932 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, NULL
,
1933 cumulative_perms
, cumulative_shared_perms
,
1934 &cur_perm
, &cur_shared
);
1935 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1939 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1940 uint64_t *shared_perm
)
1943 uint64_t cumulative_perms
= 0;
1944 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1946 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1947 cumulative_perms
|= c
->perm
;
1948 cumulative_shared_perms
&= c
->shared_perm
;
1951 *perm
= cumulative_perms
;
1952 *shared_perm
= cumulative_shared_perms
;
1955 static char *bdrv_child_user_desc(BdrvChild
*c
)
1957 if (c
->role
->get_parent_desc
) {
1958 return c
->role
->get_parent_desc(c
);
1961 return g_strdup("another user");
1964 char *bdrv_perm_names(uint64_t perm
)
1970 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1971 { BLK_PERM_WRITE
, "write" },
1972 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1973 { BLK_PERM_RESIZE
, "resize" },
1974 { BLK_PERM_GRAPH_MOD
, "change children" },
1978 char *result
= g_strdup("");
1979 struct perm_name
*p
;
1981 for (p
= permissions
; p
->name
; p
++) {
1982 if (perm
& p
->perm
) {
1984 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1993 * Checks whether a new reference to @bs can be added if the new user requires
1994 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1995 * set, the BdrvChild objects in this list are ignored in the calculations;
1996 * this allows checking permission updates for an existing reference.
1998 * See bdrv_check_perm() for the semantics of @tighten_restrictions.
2000 * Needs to be followed by a call to either bdrv_set_perm() or
2001 * bdrv_abort_perm_update(). */
2002 static int bdrv_check_update_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
2003 uint64_t new_used_perm
,
2004 uint64_t new_shared_perm
,
2005 GSList
*ignore_children
,
2006 bool *tighten_restrictions
,
2010 uint64_t cumulative_perms
= new_used_perm
;
2011 uint64_t cumulative_shared_perms
= new_shared_perm
;
2013 assert(!q
|| !tighten_restrictions
);
2015 /* There is no reason why anyone couldn't tolerate write_unchanged */
2016 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
2018 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2019 if (g_slist_find(ignore_children
, c
)) {
2023 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
2024 char *user
= bdrv_child_user_desc(c
);
2025 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
2027 if (tighten_restrictions
) {
2028 *tighten_restrictions
= true;
2031 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
2033 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
2039 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
2040 char *user
= bdrv_child_user_desc(c
);
2041 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
2043 if (tighten_restrictions
) {
2044 *tighten_restrictions
= true;
2047 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
2049 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
2055 cumulative_perms
|= c
->perm
;
2056 cumulative_shared_perms
&= c
->shared_perm
;
2059 return bdrv_check_perm(bs
, q
, cumulative_perms
, cumulative_shared_perms
,
2060 ignore_children
, tighten_restrictions
, errp
);
2063 /* Needs to be followed by a call to either bdrv_child_set_perm() or
2064 * bdrv_child_abort_perm_update(). */
2065 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
2066 uint64_t perm
, uint64_t shared
,
2067 GSList
*ignore_children
,
2068 bool *tighten_restrictions
, Error
**errp
)
2072 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
2073 ret
= bdrv_check_update_perm(c
->bs
, q
, perm
, shared
, ignore_children
,
2074 tighten_restrictions
, errp
);
2075 g_slist_free(ignore_children
);
2081 if (!c
->has_backup_perm
) {
2082 c
->has_backup_perm
= true;
2083 c
->backup_perm
= c
->perm
;
2084 c
->backup_shared_perm
= c
->shared_perm
;
2087 * Note: it's OK if c->has_backup_perm was already set, as we can find the
2088 * same child twice during check_perm procedure
2092 c
->shared_perm
= shared
;
2097 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
2099 uint64_t cumulative_perms
, cumulative_shared_perms
;
2101 c
->has_backup_perm
= false;
2104 c
->shared_perm
= shared
;
2106 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
2107 &cumulative_shared_perms
);
2108 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
2111 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
2113 if (c
->has_backup_perm
) {
2114 c
->perm
= c
->backup_perm
;
2115 c
->shared_perm
= c
->backup_shared_perm
;
2116 c
->has_backup_perm
= false;
2119 bdrv_abort_perm_update(c
->bs
);
2122 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
2125 Error
*local_err
= NULL
;
2127 bool tighten_restrictions
;
2129 ret
= bdrv_child_check_perm(c
, NULL
, perm
, shared
, NULL
,
2130 &tighten_restrictions
, &local_err
);
2132 bdrv_child_abort_perm_update(c
);
2133 if (tighten_restrictions
) {
2134 error_propagate(errp
, local_err
);
2137 * Our caller may intend to only loosen restrictions and
2138 * does not expect this function to fail. Errors are not
2139 * fatal in such a case, so we can just hide them from our
2142 error_free(local_err
);
2148 bdrv_child_set_perm(c
, perm
, shared
);
2153 int bdrv_child_refresh_perms(BlockDriverState
*bs
, BdrvChild
*c
, Error
**errp
)
2155 uint64_t parent_perms
, parent_shared
;
2156 uint64_t perms
, shared
;
2158 bdrv_get_cumulative_perm(bs
, &parent_perms
, &parent_shared
);
2159 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, NULL
, parent_perms
, parent_shared
,
2162 return bdrv_child_try_set_perm(c
, perms
, shared
, errp
);
2165 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
2166 const BdrvChildRole
*role
,
2167 BlockReopenQueue
*reopen_queue
,
2168 uint64_t perm
, uint64_t shared
,
2169 uint64_t *nperm
, uint64_t *nshared
)
2172 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
2173 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
2177 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
2178 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
2179 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
2180 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
2183 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
2184 const BdrvChildRole
*role
,
2185 BlockReopenQueue
*reopen_queue
,
2186 uint64_t perm
, uint64_t shared
,
2187 uint64_t *nperm
, uint64_t *nshared
)
2189 bool backing
= (role
== &child_backing
);
2190 assert(role
== &child_backing
|| role
== &child_file
);
2193 int flags
= bdrv_reopen_get_flags(reopen_queue
, bs
);
2195 /* Apart from the modifications below, the same permissions are
2196 * forwarded and left alone as for filters */
2197 bdrv_filter_default_perms(bs
, c
, role
, reopen_queue
, perm
, shared
,
2200 /* Format drivers may touch metadata even if the guest doesn't write */
2201 if (bdrv_is_writable_after_reopen(bs
, reopen_queue
)) {
2202 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2205 /* bs->file always needs to be consistent because of the metadata. We
2206 * can never allow other users to resize or write to it. */
2207 if (!(flags
& BDRV_O_NO_IO
)) {
2208 perm
|= BLK_PERM_CONSISTENT_READ
;
2210 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
2212 /* We want consistent read from backing files if the parent needs it.
2213 * No other operations are performed on backing files. */
2214 perm
&= BLK_PERM_CONSISTENT_READ
;
2216 /* If the parent can deal with changing data, we're okay with a
2217 * writable and resizable backing file. */
2218 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
2219 if (shared
& BLK_PERM_WRITE
) {
2220 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2225 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
2226 BLK_PERM_WRITE_UNCHANGED
;
2229 if (bs
->open_flags
& BDRV_O_INACTIVE
) {
2230 shared
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2237 static void bdrv_replace_child_noperm(BdrvChild
*child
,
2238 BlockDriverState
*new_bs
)
2240 BlockDriverState
*old_bs
= child
->bs
;
2243 assert(!child
->frozen
);
2245 if (old_bs
&& new_bs
) {
2246 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
2249 /* Detach first so that the recursive drain sections coming from @child
2250 * are already gone and we only end the drain sections that came from
2252 if (child
->role
->detach
) {
2253 child
->role
->detach(child
);
2255 while (child
->parent_quiesce_counter
) {
2256 bdrv_parent_drained_end_single(child
);
2258 QLIST_REMOVE(child
, next_parent
);
2260 assert(child
->parent_quiesce_counter
== 0);
2266 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
2267 if (new_bs
->quiesce_counter
) {
2268 int num
= new_bs
->quiesce_counter
;
2269 if (child
->role
->parent_is_bds
) {
2270 num
-= bdrv_drain_all_count
;
2273 for (i
= 0; i
< num
; i
++) {
2274 bdrv_parent_drained_begin_single(child
, true);
2278 /* Attach only after starting new drained sections, so that recursive
2279 * drain sections coming from @child don't get an extra .drained_begin
2281 if (child
->role
->attach
) {
2282 child
->role
->attach(child
);
2288 * Updates @child to change its reference to point to @new_bs, including
2289 * checking and applying the necessary permisson updates both to the old node
2292 * NULL is passed as @new_bs for removing the reference before freeing @child.
2294 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
2295 * function uses bdrv_set_perm() to update the permissions according to the new
2296 * reference that @new_bs gets.
2298 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
2300 BlockDriverState
*old_bs
= child
->bs
;
2301 uint64_t perm
, shared_perm
;
2303 bdrv_replace_child_noperm(child
, new_bs
);
2306 * Start with the new node's permissions. If @new_bs is a (direct
2307 * or indirect) child of @old_bs, we must complete the permission
2308 * update on @new_bs before we loosen the restrictions on @old_bs.
2309 * Otherwise, bdrv_check_perm() on @old_bs would re-initiate
2310 * updating the permissions of @new_bs, and thus not purely loosen
2314 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
2315 bdrv_set_perm(new_bs
, perm
, shared_perm
);
2319 /* Update permissions for old node. This is guaranteed to succeed
2320 * because we're just taking a parent away, so we're loosening
2322 bool tighten_restrictions
;
2325 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
2326 ret
= bdrv_check_perm(old_bs
, NULL
, perm
, shared_perm
, NULL
,
2327 &tighten_restrictions
, NULL
);
2328 assert(tighten_restrictions
== false);
2330 /* We only tried to loosen restrictions, so errors are not fatal */
2331 bdrv_abort_perm_update(old_bs
);
2333 bdrv_set_perm(old_bs
, perm
, shared_perm
);
2336 /* When the parent requiring a non-default AioContext is removed, the
2337 * node moves back to the main AioContext */
2338 bdrv_try_set_aio_context(old_bs
, qemu_get_aio_context(), NULL
);
2343 * This function steals the reference to child_bs from the caller.
2344 * That reference is later dropped by bdrv_root_unref_child().
2346 * On failure NULL is returned, errp is set and the reference to
2347 * child_bs is also dropped.
2349 * The caller must hold the AioContext lock @child_bs, but not that of @ctx
2350 * (unless @child_bs is already in @ctx).
2352 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
2353 const char *child_name
,
2354 const BdrvChildRole
*child_role
,
2356 uint64_t perm
, uint64_t shared_perm
,
2357 void *opaque
, Error
**errp
)
2360 Error
*local_err
= NULL
;
2363 ret
= bdrv_check_update_perm(child_bs
, NULL
, perm
, shared_perm
, NULL
, NULL
,
2366 bdrv_abort_perm_update(child_bs
);
2367 bdrv_unref(child_bs
);
2371 child
= g_new(BdrvChild
, 1);
2372 *child
= (BdrvChild
) {
2374 .name
= g_strdup(child_name
),
2377 .shared_perm
= shared_perm
,
2381 /* If the AioContexts don't match, first try to move the subtree of
2382 * child_bs into the AioContext of the new parent. If this doesn't work,
2383 * try moving the parent into the AioContext of child_bs instead. */
2384 if (bdrv_get_aio_context(child_bs
) != ctx
) {
2385 ret
= bdrv_try_set_aio_context(child_bs
, ctx
, &local_err
);
2386 if (ret
< 0 && child_role
->can_set_aio_ctx
) {
2387 GSList
*ignore
= g_slist_prepend(NULL
, child
);;
2388 ctx
= bdrv_get_aio_context(child_bs
);
2389 if (child_role
->can_set_aio_ctx(child
, ctx
, &ignore
, NULL
)) {
2390 error_free(local_err
);
2392 g_slist_free(ignore
);
2393 ignore
= g_slist_prepend(NULL
, child
);;
2394 child_role
->set_aio_ctx(child
, ctx
, &ignore
);
2396 g_slist_free(ignore
);
2399 error_propagate(errp
, local_err
);
2401 bdrv_abort_perm_update(child_bs
);
2406 /* This performs the matching bdrv_set_perm() for the above check. */
2407 bdrv_replace_child(child
, child_bs
);
2413 * This function transfers the reference to child_bs from the caller
2414 * to parent_bs. That reference is later dropped by parent_bs on
2415 * bdrv_close() or if someone calls bdrv_unref_child().
2417 * On failure NULL is returned, errp is set and the reference to
2418 * child_bs is also dropped.
2420 * If @parent_bs and @child_bs are in different AioContexts, the caller must
2421 * hold the AioContext lock for @child_bs, but not for @parent_bs.
2423 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
2424 BlockDriverState
*child_bs
,
2425 const char *child_name
,
2426 const BdrvChildRole
*child_role
,
2430 uint64_t perm
, shared_perm
;
2432 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
2434 assert(parent_bs
->drv
);
2435 bdrv_child_perm(parent_bs
, child_bs
, NULL
, child_role
, NULL
,
2436 perm
, shared_perm
, &perm
, &shared_perm
);
2438 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
2439 bdrv_get_aio_context(parent_bs
),
2440 perm
, shared_perm
, parent_bs
, errp
);
2441 if (child
== NULL
) {
2445 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
2449 static void bdrv_detach_child(BdrvChild
*child
)
2451 if (child
->next
.le_prev
) {
2452 QLIST_REMOVE(child
, next
);
2453 child
->next
.le_prev
= NULL
;
2456 bdrv_replace_child(child
, NULL
);
2458 g_free(child
->name
);
2462 void bdrv_root_unref_child(BdrvChild
*child
)
2464 BlockDriverState
*child_bs
;
2466 child_bs
= child
->bs
;
2467 bdrv_detach_child(child
);
2468 bdrv_unref(child_bs
);
2472 * Clear all inherits_from pointers from children and grandchildren of
2473 * @root that point to @root, where necessary.
2475 static void bdrv_unset_inherits_from(BlockDriverState
*root
, BdrvChild
*child
)
2479 if (child
->bs
->inherits_from
== root
) {
2481 * Remove inherits_from only when the last reference between root and
2482 * child->bs goes away.
2484 QLIST_FOREACH(c
, &root
->children
, next
) {
2485 if (c
!= child
&& c
->bs
== child
->bs
) {
2490 child
->bs
->inherits_from
= NULL
;
2494 QLIST_FOREACH(c
, &child
->bs
->children
, next
) {
2495 bdrv_unset_inherits_from(root
, c
);
2499 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
2501 if (child
== NULL
) {
2505 bdrv_unset_inherits_from(parent
, child
);
2506 bdrv_root_unref_child(child
);
2510 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
2513 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2514 if (c
->role
->change_media
) {
2515 c
->role
->change_media(c
, load
);
2520 /* Return true if you can reach parent going through child->inherits_from
2521 * recursively. If parent or child are NULL, return false */
2522 static bool bdrv_inherits_from_recursive(BlockDriverState
*child
,
2523 BlockDriverState
*parent
)
2525 while (child
&& child
!= parent
) {
2526 child
= child
->inherits_from
;
2529 return child
!= NULL
;
2533 * Sets the backing file link of a BDS. A new reference is created; callers
2534 * which don't need their own reference any more must call bdrv_unref().
2536 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
2539 bool update_inherits_from
= bdrv_chain_contains(bs
, backing_hd
) &&
2540 bdrv_inherits_from_recursive(backing_hd
, bs
);
2542 if (bdrv_is_backing_chain_frozen(bs
, backing_bs(bs
), errp
)) {
2547 bdrv_ref(backing_hd
);
2551 bdrv_unref_child(bs
, bs
->backing
);
2559 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
2561 /* If backing_hd was already part of bs's backing chain, and
2562 * inherits_from pointed recursively to bs then let's update it to
2563 * point directly to bs (else it will become NULL). */
2564 if (bs
->backing
&& update_inherits_from
) {
2565 backing_hd
->inherits_from
= bs
;
2569 bdrv_refresh_limits(bs
, NULL
);
2573 * Opens the backing file for a BlockDriverState if not yet open
2575 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2576 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2577 * itself, all options starting with "${bdref_key}." are considered part of the
2580 * TODO Can this be unified with bdrv_open_image()?
2582 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
2583 const char *bdref_key
, Error
**errp
)
2585 char *backing_filename
= NULL
;
2586 char *bdref_key_dot
;
2587 const char *reference
= NULL
;
2589 bool implicit_backing
= false;
2590 BlockDriverState
*backing_hd
;
2592 QDict
*tmp_parent_options
= NULL
;
2593 Error
*local_err
= NULL
;
2595 if (bs
->backing
!= NULL
) {
2599 /* NULL means an empty set of options */
2600 if (parent_options
== NULL
) {
2601 tmp_parent_options
= qdict_new();
2602 parent_options
= tmp_parent_options
;
2605 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2607 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2608 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2609 g_free(bdref_key_dot
);
2612 * Caution: while qdict_get_try_str() is fine, getting non-string
2613 * types would require more care. When @parent_options come from
2614 * -blockdev or blockdev_add, its members are typed according to
2615 * the QAPI schema, but when they come from -drive, they're all
2618 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2619 if (reference
|| qdict_haskey(options
, "file.filename")) {
2620 /* keep backing_filename NULL */
2621 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2622 qobject_unref(options
);
2625 if (qdict_size(options
) == 0) {
2626 /* If the user specifies options that do not modify the
2627 * backing file's behavior, we might still consider it the
2628 * implicit backing file. But it's easier this way, and
2629 * just specifying some of the backing BDS's options is
2630 * only possible with -drive anyway (otherwise the QAPI
2631 * schema forces the user to specify everything). */
2632 implicit_backing
= !strcmp(bs
->auto_backing_file
, bs
->backing_file
);
2635 backing_filename
= bdrv_get_full_backing_filename(bs
, &local_err
);
2638 error_propagate(errp
, local_err
);
2639 qobject_unref(options
);
2644 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2646 error_setg(errp
, "Driver doesn't support backing files");
2647 qobject_unref(options
);
2652 bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2653 qdict_put_str(options
, "driver", bs
->backing_format
);
2656 backing_hd
= bdrv_open_inherit(backing_filename
, reference
, options
, 0, bs
,
2657 &child_backing
, errp
);
2659 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2660 error_prepend(errp
, "Could not open backing file: ");
2665 if (implicit_backing
) {
2666 bdrv_refresh_filename(backing_hd
);
2667 pstrcpy(bs
->auto_backing_file
, sizeof(bs
->auto_backing_file
),
2668 backing_hd
->filename
);
2671 /* Hook up the backing file link; drop our reference, bs owns the
2672 * backing_hd reference now */
2673 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2674 bdrv_unref(backing_hd
);
2676 error_propagate(errp
, local_err
);
2681 qdict_del(parent_options
, bdref_key
);
2684 g_free(backing_filename
);
2685 qobject_unref(tmp_parent_options
);
2689 static BlockDriverState
*
2690 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2691 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2692 bool allow_none
, Error
**errp
)
2694 BlockDriverState
*bs
= NULL
;
2695 QDict
*image_options
;
2696 char *bdref_key_dot
;
2697 const char *reference
;
2699 assert(child_role
!= NULL
);
2701 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2702 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2703 g_free(bdref_key_dot
);
2706 * Caution: while qdict_get_try_str() is fine, getting non-string
2707 * types would require more care. When @options come from
2708 * -blockdev or blockdev_add, its members are typed according to
2709 * the QAPI schema, but when they come from -drive, they're all
2712 reference
= qdict_get_try_str(options
, bdref_key
);
2713 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2715 error_setg(errp
, "A block device must be specified for \"%s\"",
2718 qobject_unref(image_options
);
2722 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2723 parent
, child_role
, errp
);
2729 qdict_del(options
, bdref_key
);
2734 * Opens a disk image whose options are given as BlockdevRef in another block
2737 * If allow_none is true, no image will be opened if filename is false and no
2738 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2740 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2741 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2742 * itself, all options starting with "${bdref_key}." are considered part of the
2745 * The BlockdevRef will be removed from the options QDict.
2747 BdrvChild
*bdrv_open_child(const char *filename
,
2748 QDict
*options
, const char *bdref_key
,
2749 BlockDriverState
*parent
,
2750 const BdrvChildRole
*child_role
,
2751 bool allow_none
, Error
**errp
)
2753 BlockDriverState
*bs
;
2755 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2761 return bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2764 /* TODO Future callers may need to specify parent/child_role in order for
2765 * option inheritance to work. Existing callers use it for the root node. */
2766 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
)
2768 BlockDriverState
*bs
= NULL
;
2769 Error
*local_err
= NULL
;
2770 QObject
*obj
= NULL
;
2771 QDict
*qdict
= NULL
;
2772 const char *reference
= NULL
;
2775 if (ref
->type
== QTYPE_QSTRING
) {
2776 reference
= ref
->u
.reference
;
2778 BlockdevOptions
*options
= &ref
->u
.definition
;
2779 assert(ref
->type
== QTYPE_QDICT
);
2781 v
= qobject_output_visitor_new(&obj
);
2782 visit_type_BlockdevOptions(v
, NULL
, &options
, &local_err
);
2784 error_propagate(errp
, local_err
);
2787 visit_complete(v
, &obj
);
2789 qdict
= qobject_to(QDict
, obj
);
2790 qdict_flatten(qdict
);
2792 /* bdrv_open_inherit() defaults to the values in bdrv_flags (for
2793 * compatibility with other callers) rather than what we want as the
2794 * real defaults. Apply the defaults here instead. */
2795 qdict_set_default_str(qdict
, BDRV_OPT_CACHE_DIRECT
, "off");
2796 qdict_set_default_str(qdict
, BDRV_OPT_CACHE_NO_FLUSH
, "off");
2797 qdict_set_default_str(qdict
, BDRV_OPT_READ_ONLY
, "off");
2798 qdict_set_default_str(qdict
, BDRV_OPT_AUTO_READ_ONLY
, "off");
2802 bs
= bdrv_open_inherit(NULL
, reference
, qdict
, 0, NULL
, NULL
, errp
);
2811 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2813 QDict
*snapshot_options
,
2816 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2817 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2819 QemuOpts
*opts
= NULL
;
2820 BlockDriverState
*bs_snapshot
= NULL
;
2821 Error
*local_err
= NULL
;
2824 /* if snapshot, we create a temporary backing file and open it
2825 instead of opening 'filename' directly */
2827 /* Get the required size from the image */
2828 total_size
= bdrv_getlength(bs
);
2829 if (total_size
< 0) {
2830 error_setg_errno(errp
, -total_size
, "Could not get image size");
2834 /* Create the temporary image */
2835 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2837 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2841 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2843 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2844 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2845 qemu_opts_del(opts
);
2847 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2852 /* Prepare options QDict for the temporary file */
2853 qdict_put_str(snapshot_options
, "file.driver", "file");
2854 qdict_put_str(snapshot_options
, "file.filename", tmp_filename
);
2855 qdict_put_str(snapshot_options
, "driver", "qcow2");
2857 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2858 snapshot_options
= NULL
;
2863 /* bdrv_append() consumes a strong reference to bs_snapshot
2864 * (i.e. it will call bdrv_unref() on it) even on error, so in
2865 * order to be able to return one, we have to increase
2866 * bs_snapshot's refcount here */
2867 bdrv_ref(bs_snapshot
);
2868 bdrv_append(bs_snapshot
, bs
, &local_err
);
2870 error_propagate(errp
, local_err
);
2876 qobject_unref(snapshot_options
);
2877 g_free(tmp_filename
);
2882 * Opens a disk image (raw, qcow2, vmdk, ...)
2884 * options is a QDict of options to pass to the block drivers, or NULL for an
2885 * empty set of options. The reference to the QDict belongs to the block layer
2886 * after the call (even on failure), so if the caller intends to reuse the
2887 * dictionary, it needs to use qobject_ref() before calling bdrv_open.
2889 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2890 * If it is not NULL, the referenced BDS will be reused.
2892 * The reference parameter may be used to specify an existing block device which
2893 * should be opened. If specified, neither options nor a filename may be given,
2894 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2896 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2897 const char *reference
,
2898 QDict
*options
, int flags
,
2899 BlockDriverState
*parent
,
2900 const BdrvChildRole
*child_role
,
2904 BlockBackend
*file
= NULL
;
2905 BlockDriverState
*bs
;
2906 BlockDriver
*drv
= NULL
;
2908 const char *drvname
;
2909 const char *backing
;
2910 Error
*local_err
= NULL
;
2911 QDict
*snapshot_options
= NULL
;
2912 int snapshot_flags
= 0;
2914 assert(!child_role
|| !flags
);
2915 assert(!child_role
== !parent
);
2918 bool options_non_empty
= options
? qdict_size(options
) : false;
2919 qobject_unref(options
);
2921 if (filename
|| options_non_empty
) {
2922 error_setg(errp
, "Cannot reference an existing block device with "
2923 "additional options or a new filename");
2927 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2938 /* NULL means an empty set of options */
2939 if (options
== NULL
) {
2940 options
= qdict_new();
2943 /* json: syntax counts as explicit options, as if in the QDict */
2944 parse_json_protocol(options
, &filename
, &local_err
);
2949 bs
->explicit_options
= qdict_clone_shallow(options
);
2952 bs
->inherits_from
= parent
;
2953 child_role
->inherit_options(&flags
, options
,
2954 parent
->open_flags
, parent
->options
);
2957 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2963 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2964 * Caution: getting a boolean member of @options requires care.
2965 * When @options come from -blockdev or blockdev_add, members are
2966 * typed according to the QAPI schema, but when they come from
2967 * -drive, they're all QString.
2969 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2970 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2971 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2973 flags
&= ~BDRV_O_RDWR
;
2976 if (flags
& BDRV_O_SNAPSHOT
) {
2977 snapshot_options
= qdict_new();
2978 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2980 /* Let bdrv_backing_options() override "read-only" */
2981 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2982 bdrv_backing_options(&flags
, options
, flags
, options
);
2985 bs
->open_flags
= flags
;
2986 bs
->options
= options
;
2987 options
= qdict_clone_shallow(options
);
2989 /* Find the right image format driver */
2990 /* See cautionary note on accessing @options above */
2991 drvname
= qdict_get_try_str(options
, "driver");
2993 drv
= bdrv_find_format(drvname
);
2995 error_setg(errp
, "Unknown driver: '%s'", drvname
);
3000 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
3002 /* See cautionary note on accessing @options above */
3003 backing
= qdict_get_try_str(options
, "backing");
3004 if (qobject_to(QNull
, qdict_get(options
, "backing")) != NULL
||
3005 (backing
&& *backing
== '\0'))
3008 warn_report("Use of \"backing\": \"\" is deprecated; "
3009 "use \"backing\": null instead");
3011 flags
|= BDRV_O_NO_BACKING
;
3012 qdict_del(options
, "backing");
3015 /* Open image file without format layer. This BlockBackend is only used for
3016 * probing, the block drivers will do their own bdrv_open_child() for the
3017 * same BDS, which is why we put the node name back into options. */
3018 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
3019 BlockDriverState
*file_bs
;
3021 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
3022 &child_file
, true, &local_err
);
3026 if (file_bs
!= NULL
) {
3027 /* Not requesting BLK_PERM_CONSISTENT_READ because we're only
3028 * looking at the header to guess the image format. This works even
3029 * in cases where a guest would not see a consistent state. */
3030 file
= blk_new(bdrv_get_aio_context(file_bs
), 0, BLK_PERM_ALL
);
3031 blk_insert_bs(file
, file_bs
, &local_err
);
3032 bdrv_unref(file_bs
);
3037 qdict_put_str(options
, "file", bdrv_get_node_name(file_bs
));
3041 /* Image format probing */
3044 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
3049 * This option update would logically belong in bdrv_fill_options(),
3050 * but we first need to open bs->file for the probing to work, while
3051 * opening bs->file already requires the (mostly) final set of options
3052 * so that cache mode etc. can be inherited.
3054 * Adding the driver later is somewhat ugly, but it's not an option
3055 * that would ever be inherited, so it's correct. We just need to make
3056 * sure to update both bs->options (which has the full effective
3057 * options for bs) and options (which has file.* already removed).
3059 qdict_put_str(bs
->options
, "driver", drv
->format_name
);
3060 qdict_put_str(options
, "driver", drv
->format_name
);
3062 error_setg(errp
, "Must specify either driver or file");
3066 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
3067 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
3068 /* file must be NULL if a protocol BDS is about to be created
3069 * (the inverse results in an error message from bdrv_open_common()) */
3070 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
3072 /* Open the image */
3073 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
3083 /* If there is a backing file, use it */
3084 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
3085 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
3087 goto close_and_fail
;
3091 /* Remove all children options and references
3092 * from bs->options and bs->explicit_options */
3093 QLIST_FOREACH(child
, &bs
->children
, next
) {
3094 char *child_key_dot
;
3095 child_key_dot
= g_strdup_printf("%s.", child
->name
);
3096 qdict_extract_subqdict(bs
->explicit_options
, NULL
, child_key_dot
);
3097 qdict_extract_subqdict(bs
->options
, NULL
, child_key_dot
);
3098 qdict_del(bs
->explicit_options
, child
->name
);
3099 qdict_del(bs
->options
, child
->name
);
3100 g_free(child_key_dot
);
3103 /* Check if any unknown options were used */
3104 if (qdict_size(options
) != 0) {
3105 const QDictEntry
*entry
= qdict_first(options
);
3106 if (flags
& BDRV_O_PROTOCOL
) {
3107 error_setg(errp
, "Block protocol '%s' doesn't support the option "
3108 "'%s'", drv
->format_name
, entry
->key
);
3111 "Block format '%s' does not support the option '%s'",
3112 drv
->format_name
, entry
->key
);
3115 goto close_and_fail
;
3118 bdrv_parent_cb_change_media(bs
, true);
3120 qobject_unref(options
);
3123 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
3124 * temporary snapshot afterwards. */
3125 if (snapshot_flags
) {
3126 BlockDriverState
*snapshot_bs
;
3127 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
3128 snapshot_options
, &local_err
);
3129 snapshot_options
= NULL
;
3131 goto close_and_fail
;
3133 /* We are not going to return bs but the overlay on top of it
3134 * (snapshot_bs); thus, we have to drop the strong reference to bs
3135 * (which we obtained by calling bdrv_new()). bs will not be deleted,
3136 * though, because the overlay still has a reference to it. */
3145 qobject_unref(snapshot_options
);
3146 qobject_unref(bs
->explicit_options
);
3147 qobject_unref(bs
->options
);
3148 qobject_unref(options
);
3150 bs
->explicit_options
= NULL
;
3152 error_propagate(errp
, local_err
);
3157 qobject_unref(snapshot_options
);
3158 qobject_unref(options
);
3159 error_propagate(errp
, local_err
);
3163 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
3164 QDict
*options
, int flags
, Error
**errp
)
3166 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
3170 /* Return true if the NULL-terminated @list contains @str */
3171 static bool is_str_in_list(const char *str
, const char *const *list
)
3175 for (i
= 0; list
[i
] != NULL
; i
++) {
3176 if (!strcmp(str
, list
[i
])) {
3185 * Check that every option set in @bs->options is also set in
3188 * Options listed in the common_options list and in
3189 * @bs->drv->mutable_opts are skipped.
3191 * Return 0 on success, otherwise return -EINVAL and set @errp.
3193 static int bdrv_reset_options_allowed(BlockDriverState
*bs
,
3194 const QDict
*new_opts
, Error
**errp
)
3196 const QDictEntry
*e
;
3197 /* These options are common to all block drivers and are handled
3198 * in bdrv_reopen_prepare() so they can be left out of @new_opts */
3199 const char *const common_options
[] = {
3200 "node-name", "discard", "cache.direct", "cache.no-flush",
3201 "read-only", "auto-read-only", "detect-zeroes", NULL
3204 for (e
= qdict_first(bs
->options
); e
; e
= qdict_next(bs
->options
, e
)) {
3205 if (!qdict_haskey(new_opts
, e
->key
) &&
3206 !is_str_in_list(e
->key
, common_options
) &&
3207 !is_str_in_list(e
->key
, bs
->drv
->mutable_opts
)) {
3208 error_setg(errp
, "Option '%s' cannot be reset "
3209 "to its default value", e
->key
);
3218 * Returns true if @child can be reached recursively from @bs
3220 static bool bdrv_recurse_has_child(BlockDriverState
*bs
,
3221 BlockDriverState
*child
)
3229 QLIST_FOREACH(c
, &bs
->children
, next
) {
3230 if (bdrv_recurse_has_child(c
->bs
, child
)) {
3239 * Adds a BlockDriverState to a simple queue for an atomic, transactional
3240 * reopen of multiple devices.
3242 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
3243 * already performed, or alternatively may be NULL a new BlockReopenQueue will
3244 * be created and initialized. This newly created BlockReopenQueue should be
3245 * passed back in for subsequent calls that are intended to be of the same
3248 * bs is the BlockDriverState to add to the reopen queue.
3250 * options contains the changed options for the associated bs
3251 * (the BlockReopenQueue takes ownership)
3253 * flags contains the open flags for the associated bs
3255 * returns a pointer to bs_queue, which is either the newly allocated
3256 * bs_queue, or the existing bs_queue being used.
3258 * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
3260 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
3261 BlockDriverState
*bs
,
3263 const BdrvChildRole
*role
,
3264 QDict
*parent_options
,
3270 BlockReopenQueueEntry
*bs_entry
;
3272 QDict
*old_options
, *explicit_options
, *options_copy
;
3276 /* Make sure that the caller remembered to use a drained section. This is
3277 * important to avoid graph changes between the recursive queuing here and
3278 * bdrv_reopen_multiple(). */
3279 assert(bs
->quiesce_counter
> 0);
3281 if (bs_queue
== NULL
) {
3282 bs_queue
= g_new0(BlockReopenQueue
, 1);
3283 QSIMPLEQ_INIT(bs_queue
);
3287 options
= qdict_new();
3290 /* Check if this BlockDriverState is already in the queue */
3291 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3292 if (bs
== bs_entry
->state
.bs
) {
3298 * Precedence of options:
3299 * 1. Explicitly passed in options (highest)
3300 * 2. Retained from explicitly set options of bs
3301 * 3. Inherited from parent node
3302 * 4. Retained from effective options of bs
3305 /* Old explicitly set values (don't overwrite by inherited value) */
3306 if (bs_entry
|| keep_old_opts
) {
3307 old_options
= qdict_clone_shallow(bs_entry
?
3308 bs_entry
->state
.explicit_options
:
3309 bs
->explicit_options
);
3310 bdrv_join_options(bs
, options
, old_options
);
3311 qobject_unref(old_options
);
3314 explicit_options
= qdict_clone_shallow(options
);
3316 /* Inherit from parent node */
3317 if (parent_options
) {
3319 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
3321 flags
= bdrv_get_flags(bs
);
3324 if (keep_old_opts
) {
3325 /* Old values are used for options that aren't set yet */
3326 old_options
= qdict_clone_shallow(bs
->options
);
3327 bdrv_join_options(bs
, options
, old_options
);
3328 qobject_unref(old_options
);
3331 /* We have the final set of options so let's update the flags */
3332 options_copy
= qdict_clone_shallow(options
);
3333 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
3334 qemu_opts_absorb_qdict(opts
, options_copy
, NULL
);
3335 update_flags_from_options(&flags
, opts
);
3336 qemu_opts_del(opts
);
3337 qobject_unref(options_copy
);
3339 /* bdrv_open_inherit() sets and clears some additional flags internally */
3340 flags
&= ~BDRV_O_PROTOCOL
;
3341 if (flags
& BDRV_O_RDWR
) {
3342 flags
|= BDRV_O_ALLOW_RDWR
;
3346 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
3347 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
3349 qobject_unref(bs_entry
->state
.options
);
3350 qobject_unref(bs_entry
->state
.explicit_options
);
3353 bs_entry
->state
.bs
= bs
;
3354 bs_entry
->state
.options
= options
;
3355 bs_entry
->state
.explicit_options
= explicit_options
;
3356 bs_entry
->state
.flags
= flags
;
3358 /* This needs to be overwritten in bdrv_reopen_prepare() */
3359 bs_entry
->state
.perm
= UINT64_MAX
;
3360 bs_entry
->state
.shared_perm
= 0;
3363 * If keep_old_opts is false then it means that unspecified
3364 * options must be reset to their original value. We don't allow
3365 * resetting 'backing' but we need to know if the option is
3366 * missing in order to decide if we have to return an error.
3368 if (!keep_old_opts
) {
3369 bs_entry
->state
.backing_missing
=
3370 !qdict_haskey(options
, "backing") &&
3371 !qdict_haskey(options
, "backing.driver");
3374 QLIST_FOREACH(child
, &bs
->children
, next
) {
3375 QDict
*new_child_options
= NULL
;
3376 bool child_keep_old
= keep_old_opts
;
3378 /* reopen can only change the options of block devices that were
3379 * implicitly created and inherited options. For other (referenced)
3380 * block devices, a syntax like "backing.foo" results in an error. */
3381 if (child
->bs
->inherits_from
!= bs
) {
3385 /* Check if the options contain a child reference */
3386 if (qdict_haskey(options
, child
->name
)) {
3387 const char *childref
= qdict_get_try_str(options
, child
->name
);
3389 * The current child must not be reopened if the child
3390 * reference is null or points to a different node.
3392 if (g_strcmp0(childref
, child
->bs
->node_name
)) {
3396 * If the child reference points to the current child then
3397 * reopen it with its existing set of options (note that
3398 * it can still inherit new options from the parent).
3400 child_keep_old
= true;
3402 /* Extract child options ("child-name.*") */
3403 char *child_key_dot
= g_strdup_printf("%s.", child
->name
);
3404 qdict_extract_subqdict(explicit_options
, NULL
, child_key_dot
);
3405 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
3406 g_free(child_key_dot
);
3409 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
,
3410 child
->role
, options
, flags
, child_keep_old
);
3416 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
3417 BlockDriverState
*bs
,
3418 QDict
*options
, bool keep_old_opts
)
3420 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, NULL
, NULL
, 0,
3425 * Reopen multiple BlockDriverStates atomically & transactionally.
3427 * The queue passed in (bs_queue) must have been built up previous
3428 * via bdrv_reopen_queue().
3430 * Reopens all BDS specified in the queue, with the appropriate
3431 * flags. All devices are prepared for reopen, and failure of any
3432 * device will cause all device changes to be abandoned, and intermediate
3435 * If all devices prepare successfully, then the changes are committed
3438 * All affected nodes must be drained between bdrv_reopen_queue() and
3439 * bdrv_reopen_multiple().
3441 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
)
3444 BlockReopenQueueEntry
*bs_entry
, *next
;
3446 assert(bs_queue
!= NULL
);
3448 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3449 assert(bs_entry
->state
.bs
->quiesce_counter
> 0);
3450 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, errp
)) {
3453 bs_entry
->prepared
= true;
3456 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3457 BDRVReopenState
*state
= &bs_entry
->state
;
3458 ret
= bdrv_check_perm(state
->bs
, bs_queue
, state
->perm
,
3459 state
->shared_perm
, NULL
, NULL
, errp
);
3463 /* Check if new_backing_bs would accept the new permissions */
3464 if (state
->replace_backing_bs
&& state
->new_backing_bs
) {
3465 uint64_t nperm
, nshared
;
3466 bdrv_child_perm(state
->bs
, state
->new_backing_bs
,
3467 NULL
, &child_backing
, bs_queue
,
3468 state
->perm
, state
->shared_perm
,
3470 ret
= bdrv_check_update_perm(state
->new_backing_bs
, NULL
,
3471 nperm
, nshared
, NULL
, NULL
, errp
);
3476 bs_entry
->perms_checked
= true;
3479 /* If we reach this point, we have success and just need to apply the
3482 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3483 bdrv_reopen_commit(&bs_entry
->state
);
3488 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
3489 BDRVReopenState
*state
= &bs_entry
->state
;
3491 if (!bs_entry
->perms_checked
) {
3496 bdrv_set_perm(state
->bs
, state
->perm
, state
->shared_perm
);
3498 bdrv_abort_perm_update(state
->bs
);
3499 if (state
->replace_backing_bs
&& state
->new_backing_bs
) {
3500 bdrv_abort_perm_update(state
->new_backing_bs
);
3505 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
3507 if (bs_entry
->prepared
) {
3508 bdrv_reopen_abort(&bs_entry
->state
);
3510 qobject_unref(bs_entry
->state
.explicit_options
);
3511 qobject_unref(bs_entry
->state
.options
);
3513 if (bs_entry
->state
.new_backing_bs
) {
3514 bdrv_unref(bs_entry
->state
.new_backing_bs
);
3523 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
3527 BlockReopenQueue
*queue
;
3528 QDict
*opts
= qdict_new();
3530 qdict_put_bool(opts
, BDRV_OPT_READ_ONLY
, read_only
);
3532 bdrv_subtree_drained_begin(bs
);
3533 queue
= bdrv_reopen_queue(NULL
, bs
, opts
, true);
3534 ret
= bdrv_reopen_multiple(queue
, errp
);
3535 bdrv_subtree_drained_end(bs
);
3540 static BlockReopenQueueEntry
*find_parent_in_reopen_queue(BlockReopenQueue
*q
,
3543 BlockReopenQueueEntry
*entry
;
3545 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
3546 BlockDriverState
*bs
= entry
->state
.bs
;
3549 QLIST_FOREACH(child
, &bs
->children
, next
) {
3559 static void bdrv_reopen_perm(BlockReopenQueue
*q
, BlockDriverState
*bs
,
3560 uint64_t *perm
, uint64_t *shared
)
3563 BlockReopenQueueEntry
*parent
;
3564 uint64_t cumulative_perms
= 0;
3565 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
3567 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3568 parent
= find_parent_in_reopen_queue(q
, c
);
3570 cumulative_perms
|= c
->perm
;
3571 cumulative_shared_perms
&= c
->shared_perm
;
3573 uint64_t nperm
, nshared
;
3575 bdrv_child_perm(parent
->state
.bs
, bs
, c
, c
->role
, q
,
3576 parent
->state
.perm
, parent
->state
.shared_perm
,
3579 cumulative_perms
|= nperm
;
3580 cumulative_shared_perms
&= nshared
;
3583 *perm
= cumulative_perms
;
3584 *shared
= cumulative_shared_perms
;
3588 * Take a BDRVReopenState and check if the value of 'backing' in the
3589 * reopen_state->options QDict is valid or not.
3591 * If 'backing' is missing from the QDict then return 0.
3593 * If 'backing' contains the node name of the backing file of
3594 * reopen_state->bs then return 0.
3596 * If 'backing' contains a different node name (or is null) then check
3597 * whether the current backing file can be replaced with the new one.
3598 * If that's the case then reopen_state->replace_backing_bs is set to
3599 * true and reopen_state->new_backing_bs contains a pointer to the new
3600 * backing BlockDriverState (or NULL).
3602 * Return 0 on success, otherwise return < 0 and set @errp.
3604 static int bdrv_reopen_parse_backing(BDRVReopenState
*reopen_state
,
3607 BlockDriverState
*bs
= reopen_state
->bs
;
3608 BlockDriverState
*overlay_bs
, *new_backing_bs
;
3612 value
= qdict_get(reopen_state
->options
, "backing");
3613 if (value
== NULL
) {
3617 switch (qobject_type(value
)) {
3619 new_backing_bs
= NULL
;
3622 str
= qobject_get_try_str(value
);
3623 new_backing_bs
= bdrv_lookup_bs(NULL
, str
, errp
);
3624 if (new_backing_bs
== NULL
) {
3626 } else if (bdrv_recurse_has_child(new_backing_bs
, bs
)) {
3627 error_setg(errp
, "Making '%s' a backing file of '%s' "
3628 "would create a cycle", str
, bs
->node_name
);
3633 /* 'backing' does not allow any other data type */
3634 g_assert_not_reached();
3638 * TODO: before removing the x- prefix from x-blockdev-reopen we
3639 * should move the new backing file into the right AioContext
3640 * instead of returning an error.
3642 if (new_backing_bs
) {
3643 if (bdrv_get_aio_context(new_backing_bs
) != bdrv_get_aio_context(bs
)) {
3644 error_setg(errp
, "Cannot use a new backing file "
3645 "with a different AioContext");
3651 * Find the "actual" backing file by skipping all links that point
3652 * to an implicit node, if any (e.g. a commit filter node).
3655 while (backing_bs(overlay_bs
) && backing_bs(overlay_bs
)->implicit
) {
3656 overlay_bs
= backing_bs(overlay_bs
);
3659 /* If we want to replace the backing file we need some extra checks */
3660 if (new_backing_bs
!= backing_bs(overlay_bs
)) {
3661 /* Check for implicit nodes between bs and its backing file */
3662 if (bs
!= overlay_bs
) {
3663 error_setg(errp
, "Cannot change backing link if '%s' has "
3664 "an implicit backing file", bs
->node_name
);
3667 /* Check if the backing link that we want to replace is frozen */
3668 if (bdrv_is_backing_chain_frozen(overlay_bs
, backing_bs(overlay_bs
),
3672 reopen_state
->replace_backing_bs
= true;
3673 if (new_backing_bs
) {
3674 bdrv_ref(new_backing_bs
);
3675 reopen_state
->new_backing_bs
= new_backing_bs
;
3683 * Prepares a BlockDriverState for reopen. All changes are staged in the
3684 * 'opaque' field of the BDRVReopenState, which is used and allocated by
3685 * the block driver layer .bdrv_reopen_prepare()
3687 * bs is the BlockDriverState to reopen
3688 * flags are the new open flags
3689 * queue is the reopen queue
3691 * Returns 0 on success, non-zero on error. On error errp will be set
3694 * On failure, bdrv_reopen_abort() will be called to clean up any data.
3695 * It is the responsibility of the caller to then call the abort() or
3696 * commit() for any other BDS that have been left in a prepare() state
3699 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
3704 Error
*local_err
= NULL
;
3707 QDict
*orig_reopen_opts
;
3708 char *discard
= NULL
;
3710 bool drv_prepared
= false;
3712 assert(reopen_state
!= NULL
);
3713 assert(reopen_state
->bs
->drv
!= NULL
);
3714 drv
= reopen_state
->bs
->drv
;
3716 /* This function and each driver's bdrv_reopen_prepare() remove
3717 * entries from reopen_state->options as they are processed, so
3718 * we need to make a copy of the original QDict. */
3719 orig_reopen_opts
= qdict_clone_shallow(reopen_state
->options
);
3721 /* Process generic block layer options */
3722 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
3723 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
3725 error_propagate(errp
, local_err
);
3730 /* This was already called in bdrv_reopen_queue_child() so the flags
3731 * are up-to-date. This time we simply want to remove the options from
3732 * QemuOpts in order to indicate that they have been processed. */
3733 old_flags
= reopen_state
->flags
;
3734 update_flags_from_options(&reopen_state
->flags
, opts
);
3735 assert(old_flags
== reopen_state
->flags
);
3737 discard
= qemu_opt_get_del(opts
, BDRV_OPT_DISCARD
);
3738 if (discard
!= NULL
) {
3739 if (bdrv_parse_discard_flags(discard
, &reopen_state
->flags
) != 0) {
3740 error_setg(errp
, "Invalid discard option");
3746 reopen_state
->detect_zeroes
=
3747 bdrv_parse_detect_zeroes(opts
, reopen_state
->flags
, &local_err
);
3749 error_propagate(errp
, local_err
);
3754 /* All other options (including node-name and driver) must be unchanged.
3755 * Put them back into the QDict, so that they are checked at the end
3756 * of this function. */
3757 qemu_opts_to_qdict(opts
, reopen_state
->options
);
3759 /* If we are to stay read-only, do not allow permission change
3760 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
3761 * not set, or if the BDS still has copy_on_read enabled */
3762 read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3763 ret
= bdrv_can_set_read_only(reopen_state
->bs
, read_only
, true, &local_err
);
3765 error_propagate(errp
, local_err
);
3769 /* Calculate required permissions after reopening */
3770 bdrv_reopen_perm(queue
, reopen_state
->bs
,
3771 &reopen_state
->perm
, &reopen_state
->shared_perm
);
3773 ret
= bdrv_flush(reopen_state
->bs
);
3775 error_setg_errno(errp
, -ret
, "Error flushing drive");
3779 if (drv
->bdrv_reopen_prepare
) {
3781 * If a driver-specific option is missing, it means that we
3782 * should reset it to its default value.
3783 * But not all options allow that, so we need to check it first.
3785 ret
= bdrv_reset_options_allowed(reopen_state
->bs
,
3786 reopen_state
->options
, errp
);
3791 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
3793 if (local_err
!= NULL
) {
3794 error_propagate(errp
, local_err
);
3796 bdrv_refresh_filename(reopen_state
->bs
);
3797 error_setg(errp
, "failed while preparing to reopen image '%s'",
3798 reopen_state
->bs
->filename
);
3803 /* It is currently mandatory to have a bdrv_reopen_prepare()
3804 * handler for each supported drv. */
3805 error_setg(errp
, "Block format '%s' used by node '%s' "
3806 "does not support reopening files", drv
->format_name
,
3807 bdrv_get_device_or_node_name(reopen_state
->bs
));
3812 drv_prepared
= true;
3815 * We must provide the 'backing' option if the BDS has a backing
3816 * file or if the image file has a backing file name as part of
3817 * its metadata. Otherwise the 'backing' option can be omitted.
3819 if (drv
->supports_backing
&& reopen_state
->backing_missing
&&
3820 (backing_bs(reopen_state
->bs
) || reopen_state
->bs
->backing_file
[0])) {
3821 error_setg(errp
, "backing is missing for '%s'",
3822 reopen_state
->bs
->node_name
);
3828 * Allow changing the 'backing' option. The new value can be
3829 * either a reference to an existing node (using its node name)
3830 * or NULL to simply detach the current backing file.
3832 ret
= bdrv_reopen_parse_backing(reopen_state
, errp
);
3836 qdict_del(reopen_state
->options
, "backing");
3838 /* Options that are not handled are only okay if they are unchanged
3839 * compared to the old state. It is expected that some options are only
3840 * used for the initial open, but not reopen (e.g. filename) */
3841 if (qdict_size(reopen_state
->options
)) {
3842 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
3845 QObject
*new = entry
->value
;
3846 QObject
*old
= qdict_get(reopen_state
->bs
->options
, entry
->key
);
3848 /* Allow child references (child_name=node_name) as long as they
3849 * point to the current child (i.e. everything stays the same). */
3850 if (qobject_type(new) == QTYPE_QSTRING
) {
3852 QLIST_FOREACH(child
, &reopen_state
->bs
->children
, next
) {
3853 if (!strcmp(child
->name
, entry
->key
)) {
3859 const char *str
= qobject_get_try_str(new);
3860 if (!strcmp(child
->bs
->node_name
, str
)) {
3861 continue; /* Found child with this name, skip option */
3867 * TODO: When using -drive to specify blockdev options, all values
3868 * will be strings; however, when using -blockdev, blockdev-add or
3869 * filenames using the json:{} pseudo-protocol, they will be
3871 * In contrast, reopening options are (currently) always strings
3872 * (because you can only specify them through qemu-io; all other
3873 * callers do not specify any options).
3874 * Therefore, when using anything other than -drive to create a BDS,
3875 * this cannot detect non-string options as unchanged, because
3876 * qobject_is_equal() always returns false for objects of different
3877 * type. In the future, this should be remedied by correctly typing
3878 * all options. For now, this is not too big of an issue because
3879 * the user can simply omit options which cannot be changed anyway,
3880 * so they will stay unchanged.
3882 if (!qobject_is_equal(new, old
)) {
3883 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
3887 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
3892 /* Restore the original reopen_state->options QDict */
3893 qobject_unref(reopen_state
->options
);
3894 reopen_state
->options
= qobject_ref(orig_reopen_opts
);
3897 if (ret
< 0 && drv_prepared
) {
3898 /* drv->bdrv_reopen_prepare() has succeeded, so we need to
3899 * call drv->bdrv_reopen_abort() before signaling an error
3900 * (bdrv_reopen_multiple() will not call bdrv_reopen_abort()
3901 * when the respective bdrv_reopen_prepare() has failed) */
3902 if (drv
->bdrv_reopen_abort
) {
3903 drv
->bdrv_reopen_abort(reopen_state
);
3906 qemu_opts_del(opts
);
3907 qobject_unref(orig_reopen_opts
);
3913 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
3914 * makes them final by swapping the staging BlockDriverState contents into
3915 * the active BlockDriverState contents.
3917 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
3920 BlockDriverState
*bs
;
3922 bool old_can_write
, new_can_write
;
3924 assert(reopen_state
!= NULL
);
3925 bs
= reopen_state
->bs
;
3927 assert(drv
!= NULL
);
3930 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3932 /* If there are any driver level actions to take */
3933 if (drv
->bdrv_reopen_commit
) {
3934 drv
->bdrv_reopen_commit(reopen_state
);
3937 /* set BDS specific flags now */
3938 qobject_unref(bs
->explicit_options
);
3939 qobject_unref(bs
->options
);
3941 bs
->explicit_options
= reopen_state
->explicit_options
;
3942 bs
->options
= reopen_state
->options
;
3943 bs
->open_flags
= reopen_state
->flags
;
3944 bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3945 bs
->detect_zeroes
= reopen_state
->detect_zeroes
;
3947 if (reopen_state
->replace_backing_bs
) {
3948 qdict_del(bs
->explicit_options
, "backing");
3949 qdict_del(bs
->options
, "backing");
3952 /* Remove child references from bs->options and bs->explicit_options.
3953 * Child options were already removed in bdrv_reopen_queue_child() */
3954 QLIST_FOREACH(child
, &bs
->children
, next
) {
3955 qdict_del(bs
->explicit_options
, child
->name
);
3956 qdict_del(bs
->options
, child
->name
);
3960 * Change the backing file if a new one was specified. We do this
3961 * after updating bs->options, so bdrv_refresh_filename() (called
3962 * from bdrv_set_backing_hd()) has the new values.
3964 if (reopen_state
->replace_backing_bs
) {
3965 BlockDriverState
*old_backing_bs
= backing_bs(bs
);
3966 assert(!old_backing_bs
|| !old_backing_bs
->implicit
);
3967 /* Abort the permission update on the backing bs we're detaching */
3968 if (old_backing_bs
) {
3969 bdrv_abort_perm_update(old_backing_bs
);
3971 bdrv_set_backing_hd(bs
, reopen_state
->new_backing_bs
, &error_abort
);
3974 bdrv_refresh_limits(bs
, NULL
);
3977 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3978 if (!old_can_write
&& new_can_write
&& drv
->bdrv_reopen_bitmaps_rw
) {
3979 Error
*local_err
= NULL
;
3980 if (drv
->bdrv_reopen_bitmaps_rw(bs
, &local_err
) < 0) {
3981 /* This is not fatal, bitmaps just left read-only, so all following
3982 * writes will fail. User can remove read-only bitmaps to unblock
3985 error_reportf_err(local_err
,
3986 "%s: Failed to make dirty bitmaps writable: ",
3987 bdrv_get_node_name(bs
));
3993 * Abort the reopen, and delete and free the staged changes in
3996 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
4000 assert(reopen_state
!= NULL
);
4001 drv
= reopen_state
->bs
->drv
;
4002 assert(drv
!= NULL
);
4004 if (drv
->bdrv_reopen_abort
) {
4005 drv
->bdrv_reopen_abort(reopen_state
);
4010 static void bdrv_close(BlockDriverState
*bs
)
4012 BdrvAioNotifier
*ban
, *ban_next
;
4013 BdrvChild
*child
, *next
;
4015 assert(!bs
->refcnt
);
4017 bdrv_drained_begin(bs
); /* complete I/O */
4019 bdrv_drain(bs
); /* in case flush left pending I/O */
4022 if (bs
->drv
->bdrv_close
) {
4023 bs
->drv
->bdrv_close(bs
);
4028 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
4029 bdrv_unref_child(bs
, child
);
4036 atomic_set(&bs
->copy_on_read
, 0);
4037 bs
->backing_file
[0] = '\0';
4038 bs
->backing_format
[0] = '\0';
4039 bs
->total_sectors
= 0;
4040 bs
->encrypted
= false;
4042 qobject_unref(bs
->options
);
4043 qobject_unref(bs
->explicit_options
);
4045 bs
->explicit_options
= NULL
;
4046 qobject_unref(bs
->full_open_options
);
4047 bs
->full_open_options
= NULL
;
4049 bdrv_release_named_dirty_bitmaps(bs
);
4050 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
4052 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
4055 QLIST_INIT(&bs
->aio_notifiers
);
4056 bdrv_drained_end(bs
);
4059 void bdrv_close_all(void)
4061 assert(job_next(NULL
) == NULL
);
4062 nbd_export_close_all();
4064 /* Drop references from requests still in flight, such as canceled block
4065 * jobs whose AIO context has not been polled yet */
4068 blk_remove_all_bs();
4069 blockdev_close_all_bdrv_states();
4071 assert(QTAILQ_EMPTY(&all_bdrv_states
));
4074 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
4080 if (c
->role
->stay_at_node
) {
4084 /* If the child @c belongs to the BDS @to, replacing the current
4085 * c->bs by @to would mean to create a loop.
4087 * Such a case occurs when appending a BDS to a backing chain.
4088 * For instance, imagine the following chain:
4090 * guest device -> node A -> further backing chain...
4092 * Now we create a new BDS B which we want to put on top of this
4093 * chain, so we first attach A as its backing node:
4098 * guest device -> node A -> further backing chain...
4100 * Finally we want to replace A by B. When doing that, we want to
4101 * replace all pointers to A by pointers to B -- except for the
4102 * pointer from B because (1) that would create a loop, and (2)
4103 * that pointer should simply stay intact:
4105 * guest device -> node B
4108 * node A -> further backing chain...
4110 * In general, when replacing a node A (c->bs) by a node B (@to),
4111 * if A is a child of B, that means we cannot replace A by B there
4112 * because that would create a loop. Silently detaching A from B
4113 * is also not really an option. So overall just leaving A in
4114 * place there is the most sensible choice.
4116 * We would also create a loop in any cases where @c is only
4117 * indirectly referenced by @to. Prevent this by returning false
4118 * if @c is found (by breadth-first search) anywhere in the whole
4123 found
= g_hash_table_new(NULL
, NULL
);
4124 g_hash_table_add(found
, to
);
4125 queue
= g_queue_new();
4126 g_queue_push_tail(queue
, to
);
4128 while (!g_queue_is_empty(queue
)) {
4129 BlockDriverState
*v
= g_queue_pop_head(queue
);
4132 QLIST_FOREACH(c2
, &v
->children
, next
) {
4138 if (g_hash_table_contains(found
, c2
->bs
)) {
4142 g_queue_push_tail(queue
, c2
->bs
);
4143 g_hash_table_add(found
, c2
->bs
);
4147 g_queue_free(queue
);
4148 g_hash_table_destroy(found
);
4153 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
4156 BdrvChild
*c
, *next
;
4157 GSList
*list
= NULL
, *p
;
4158 uint64_t old_perm
, old_shared
;
4159 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
4162 /* Make sure that @from doesn't go away until we have successfully attached
4163 * all of its parents to @to. */
4166 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
4167 bdrv_drained_begin(from
);
4169 /* Put all parents into @list and calculate their cumulative permissions */
4170 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
4171 assert(c
->bs
== from
);
4172 if (!should_update_child(c
, to
)) {
4176 error_setg(errp
, "Cannot change '%s' link to '%s'",
4177 c
->name
, from
->node_name
);
4180 list
= g_slist_prepend(list
, c
);
4182 shared
&= c
->shared_perm
;
4185 /* Check whether the required permissions can be granted on @to, ignoring
4186 * all BdrvChild in @list so that they can't block themselves. */
4187 ret
= bdrv_check_update_perm(to
, NULL
, perm
, shared
, list
, NULL
, errp
);
4189 bdrv_abort_perm_update(to
);
4193 /* Now actually perform the change. We performed the permission check for
4194 * all elements of @list at once, so set the permissions all at once at the
4196 for (p
= list
; p
!= NULL
; p
= p
->next
) {
4200 bdrv_replace_child_noperm(c
, to
);
4204 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
4205 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
4209 bdrv_drained_end(from
);
4214 * Add new bs contents at the top of an image chain while the chain is
4215 * live, while keeping required fields on the top layer.
4217 * This will modify the BlockDriverState fields, and swap contents
4218 * between bs_new and bs_top. Both bs_new and bs_top are modified.
4220 * bs_new must not be attached to a BlockBackend.
4222 * This function does not create any image files.
4224 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
4225 * that's what the callers commonly need. bs_new will be referenced by the old
4226 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
4227 * reference of its own, it must call bdrv_ref().
4229 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
4232 Error
*local_err
= NULL
;
4234 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
4236 error_propagate(errp
, local_err
);
4240 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
4242 error_propagate(errp
, local_err
);
4243 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
4247 /* bs_new is now referenced by its new parents, we don't need the
4248 * additional reference any more. */
4253 static void bdrv_delete(BlockDriverState
*bs
)
4255 assert(bdrv_op_blocker_is_empty(bs
));
4256 assert(!bs
->refcnt
);
4258 /* remove from list, if necessary */
4259 if (bs
->node_name
[0] != '\0') {
4260 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
4262 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
4270 * Run consistency checks on an image
4272 * Returns 0 if the check could be completed (it doesn't mean that the image is
4273 * free of errors) or -errno when an internal error occurred. The results of the
4274 * check are stored in res.
4276 static int coroutine_fn
bdrv_co_check(BlockDriverState
*bs
,
4277 BdrvCheckResult
*res
, BdrvCheckMode fix
)
4279 if (bs
->drv
== NULL
) {
4282 if (bs
->drv
->bdrv_co_check
== NULL
) {
4286 memset(res
, 0, sizeof(*res
));
4287 return bs
->drv
->bdrv_co_check(bs
, res
, fix
);
4290 typedef struct CheckCo
{
4291 BlockDriverState
*bs
;
4292 BdrvCheckResult
*res
;
4297 static void coroutine_fn
bdrv_check_co_entry(void *opaque
)
4299 CheckCo
*cco
= opaque
;
4300 cco
->ret
= bdrv_co_check(cco
->bs
, cco
->res
, cco
->fix
);
4304 int bdrv_check(BlockDriverState
*bs
,
4305 BdrvCheckResult
*res
, BdrvCheckMode fix
)
4311 .ret
= -EINPROGRESS
,
4315 if (qemu_in_coroutine()) {
4316 /* Fast-path if already in coroutine context */
4317 bdrv_check_co_entry(&cco
);
4319 co
= qemu_coroutine_create(bdrv_check_co_entry
, &cco
);
4320 bdrv_coroutine_enter(bs
, co
);
4321 BDRV_POLL_WHILE(bs
, cco
.ret
== -EINPROGRESS
);
4330 * -EINVAL - backing format specified, but no file
4331 * -ENOSPC - can't update the backing file because no space is left in the
4333 * -ENOTSUP - format driver doesn't support changing the backing file
4335 int bdrv_change_backing_file(BlockDriverState
*bs
,
4336 const char *backing_file
, const char *backing_fmt
)
4338 BlockDriver
*drv
= bs
->drv
;
4345 /* Backing file format doesn't make sense without a backing file */
4346 if (backing_fmt
&& !backing_file
) {
4350 if (drv
->bdrv_change_backing_file
!= NULL
) {
4351 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
4357 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
4358 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
4359 pstrcpy(bs
->auto_backing_file
, sizeof(bs
->auto_backing_file
),
4360 backing_file
?: "");
4366 * Finds the image layer in the chain that has 'bs' as its backing file.
4368 * active is the current topmost image.
4370 * Returns NULL if bs is not found in active's image chain,
4371 * or if active == bs.
4373 * Returns the bottommost base image if bs == NULL.
4375 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
4376 BlockDriverState
*bs
)
4378 while (active
&& bs
!= backing_bs(active
)) {
4379 active
= backing_bs(active
);
4385 /* Given a BDS, searches for the base layer. */
4386 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
4388 return bdrv_find_overlay(bs
, NULL
);
4392 * Return true if at least one of the backing links between @bs and
4393 * @base is frozen. @errp is set if that's the case.
4394 * @base must be reachable from @bs, or NULL.
4396 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
4399 BlockDriverState
*i
;
4401 for (i
= bs
; i
!= base
; i
= backing_bs(i
)) {
4402 if (i
->backing
&& i
->backing
->frozen
) {
4403 error_setg(errp
, "Cannot change '%s' link from '%s' to '%s'",
4404 i
->backing
->name
, i
->node_name
,
4405 backing_bs(i
)->node_name
);
4414 * Freeze all backing links between @bs and @base.
4415 * If any of the links is already frozen the operation is aborted and
4416 * none of the links are modified.
4417 * @base must be reachable from @bs, or NULL.
4418 * Returns 0 on success. On failure returns < 0 and sets @errp.
4420 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
4423 BlockDriverState
*i
;
4425 if (bdrv_is_backing_chain_frozen(bs
, base
, errp
)) {
4429 for (i
= bs
; i
!= base
; i
= backing_bs(i
)) {
4430 if (i
->backing
&& backing_bs(i
)->never_freeze
) {
4431 error_setg(errp
, "Cannot freeze '%s' link to '%s'",
4432 i
->backing
->name
, backing_bs(i
)->node_name
);
4437 for (i
= bs
; i
!= base
; i
= backing_bs(i
)) {
4439 i
->backing
->frozen
= true;
4447 * Unfreeze all backing links between @bs and @base. The caller must
4448 * ensure that all links are frozen before using this function.
4449 * @base must be reachable from @bs, or NULL.
4451 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
)
4453 BlockDriverState
*i
;
4455 for (i
= bs
; i
!= base
; i
= backing_bs(i
)) {
4457 assert(i
->backing
->frozen
);
4458 i
->backing
->frozen
= false;
4464 * Drops images above 'base' up to and including 'top', and sets the image
4465 * above 'top' to have base as its backing file.
4467 * Requires that the overlay to 'top' is opened r/w, so that the backing file
4468 * information in 'bs' can be properly updated.
4470 * E.g., this will convert the following chain:
4471 * bottom <- base <- intermediate <- top <- active
4475 * bottom <- base <- active
4477 * It is allowed for bottom==base, in which case it converts:
4479 * base <- intermediate <- top <- active
4485 * If backing_file_str is non-NULL, it will be used when modifying top's
4486 * overlay image metadata.
4489 * if active == top, that is considered an error
4492 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
4493 const char *backing_file_str
)
4495 BlockDriverState
*explicit_top
= top
;
4496 bool update_inherits_from
;
4497 BdrvChild
*c
, *next
;
4498 Error
*local_err
= NULL
;
4503 if (!top
->drv
|| !base
->drv
) {
4507 /* Make sure that base is in the backing chain of top */
4508 if (!bdrv_chain_contains(top
, base
)) {
4512 /* This function changes all links that point to top and makes
4513 * them point to base. Check that none of them is frozen. */
4514 QLIST_FOREACH(c
, &top
->parents
, next_parent
) {
4520 /* If 'base' recursively inherits from 'top' then we should set
4521 * base->inherits_from to top->inherits_from after 'top' and all
4522 * other intermediate nodes have been dropped.
4523 * If 'top' is an implicit node (e.g. "commit_top") we should skip
4524 * it because no one inherits from it. We use explicit_top for that. */
4525 while (explicit_top
&& explicit_top
->implicit
) {
4526 explicit_top
= backing_bs(explicit_top
);
4528 update_inherits_from
= bdrv_inherits_from_recursive(base
, explicit_top
);
4530 /* success - we can delete the intermediate states, and link top->base */
4531 /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
4532 * we've figured out how they should work. */
4533 if (!backing_file_str
) {
4534 bdrv_refresh_filename(base
);
4535 backing_file_str
= base
->filename
;
4538 QLIST_FOREACH_SAFE(c
, &top
->parents
, next_parent
, next
) {
4539 /* Check whether we are allowed to switch c from top to base */
4540 GSList
*ignore_children
= g_slist_prepend(NULL
, c
);
4541 ret
= bdrv_check_update_perm(base
, NULL
, c
->perm
, c
->shared_perm
,
4542 ignore_children
, NULL
, &local_err
);
4543 g_slist_free(ignore_children
);
4545 error_report_err(local_err
);
4549 /* If so, update the backing file path in the image file */
4550 if (c
->role
->update_filename
) {
4551 ret
= c
->role
->update_filename(c
, base
, backing_file_str
,
4554 bdrv_abort_perm_update(base
);
4555 error_report_err(local_err
);
4560 /* Do the actual switch in the in-memory graph.
4561 * Completes bdrv_check_update_perm() transaction internally. */
4563 bdrv_replace_child(c
, base
);
4567 if (update_inherits_from
) {
4568 base
->inherits_from
= explicit_top
->inherits_from
;
4578 * Length of a allocated file in bytes. Sparse files are counted by actual
4579 * allocated space. Return < 0 if error or unknown.
4581 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
4583 BlockDriver
*drv
= bs
->drv
;
4587 if (drv
->bdrv_get_allocated_file_size
) {
4588 return drv
->bdrv_get_allocated_file_size(bs
);
4591 return bdrv_get_allocated_file_size(bs
->file
->bs
);
4598 * @drv: Format driver
4599 * @opts: Creation options for new image
4600 * @in_bs: Existing image containing data for new image (may be NULL)
4601 * @errp: Error object
4602 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
4605 * Calculate file size required to create a new image.
4607 * If @in_bs is given then space for allocated clusters and zero clusters
4608 * from that image are included in the calculation. If @opts contains a
4609 * backing file that is shared by @in_bs then backing clusters may be omitted
4610 * from the calculation.
4612 * If @in_bs is NULL then the calculation includes no allocated clusters
4613 * unless a preallocation option is given in @opts.
4615 * Note that @in_bs may use a different BlockDriver from @drv.
4617 * If an error occurs the @errp pointer is set.
4619 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
4620 BlockDriverState
*in_bs
, Error
**errp
)
4622 if (!drv
->bdrv_measure
) {
4623 error_setg(errp
, "Block driver '%s' does not support size measurement",
4628 return drv
->bdrv_measure(opts
, in_bs
, errp
);
4632 * Return number of sectors on success, -errno on error.
4634 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
4636 BlockDriver
*drv
= bs
->drv
;
4641 if (drv
->has_variable_length
) {
4642 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
4647 return bs
->total_sectors
;
4651 * Return length in bytes on success, -errno on error.
4652 * The length is always a multiple of BDRV_SECTOR_SIZE.
4654 int64_t bdrv_getlength(BlockDriverState
*bs
)
4656 int64_t ret
= bdrv_nb_sectors(bs
);
4658 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
4659 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
4662 /* return 0 as number of sectors if no device present or error */
4663 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
4665 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
4667 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
4670 bool bdrv_is_sg(BlockDriverState
*bs
)
4675 bool bdrv_is_encrypted(BlockDriverState
*bs
)
4677 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
4680 return bs
->encrypted
;
4683 const char *bdrv_get_format_name(BlockDriverState
*bs
)
4685 return bs
->drv
? bs
->drv
->format_name
: NULL
;
4688 static int qsort_strcmp(const void *a
, const void *b
)
4690 return strcmp(*(char *const *)a
, *(char *const *)b
);
4693 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
4694 void *opaque
, bool read_only
)
4699 const char **formats
= NULL
;
4701 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
4702 if (drv
->format_name
) {
4706 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, read_only
)) {
4710 while (formats
&& i
&& !found
) {
4711 found
= !strcmp(formats
[--i
], drv
->format_name
);
4715 formats
= g_renew(const char *, formats
, count
+ 1);
4716 formats
[count
++] = drv
->format_name
;
4721 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
4722 const char *format_name
= block_driver_modules
[i
].format_name
;
4728 if (use_bdrv_whitelist
&&
4729 !bdrv_format_is_whitelisted(format_name
, read_only
)) {
4733 while (formats
&& j
&& !found
) {
4734 found
= !strcmp(formats
[--j
], format_name
);
4738 formats
= g_renew(const char *, formats
, count
+ 1);
4739 formats
[count
++] = format_name
;
4744 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
4746 for (i
= 0; i
< count
; i
++) {
4747 it(opaque
, formats
[i
]);
4753 /* This function is to find a node in the bs graph */
4754 BlockDriverState
*bdrv_find_node(const char *node_name
)
4756 BlockDriverState
*bs
;
4760 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4761 if (!strcmp(node_name
, bs
->node_name
)) {
4768 /* Put this QMP function here so it can access the static graph_bdrv_states. */
4769 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
4771 BlockDeviceInfoList
*list
, *entry
;
4772 BlockDriverState
*bs
;
4775 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4776 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
4778 qapi_free_BlockDeviceInfoList(list
);
4781 entry
= g_malloc0(sizeof(*entry
));
4782 entry
->value
= info
;
4790 #define QAPI_LIST_ADD(list, element) do { \
4791 typeof(list) _tmp = g_new(typeof(*(list)), 1); \
4792 _tmp->value = (element); \
4793 _tmp->next = (list); \
4797 typedef struct XDbgBlockGraphConstructor
{
4798 XDbgBlockGraph
*graph
;
4799 GHashTable
*graph_nodes
;
4800 } XDbgBlockGraphConstructor
;
4802 static XDbgBlockGraphConstructor
*xdbg_graph_new(void)
4804 XDbgBlockGraphConstructor
*gr
= g_new(XDbgBlockGraphConstructor
, 1);
4806 gr
->graph
= g_new0(XDbgBlockGraph
, 1);
4807 gr
->graph_nodes
= g_hash_table_new(NULL
, NULL
);
4812 static XDbgBlockGraph
*xdbg_graph_finalize(XDbgBlockGraphConstructor
*gr
)
4814 XDbgBlockGraph
*graph
= gr
->graph
;
4816 g_hash_table_destroy(gr
->graph_nodes
);
4822 static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor
*gr
, void *node
)
4824 uintptr_t ret
= (uintptr_t)g_hash_table_lookup(gr
->graph_nodes
, node
);
4831 * Start counting from 1, not 0, because 0 interferes with not-found (NULL)
4832 * answer of g_hash_table_lookup.
4834 ret
= g_hash_table_size(gr
->graph_nodes
) + 1;
4835 g_hash_table_insert(gr
->graph_nodes
, node
, (void *)ret
);
4840 static void xdbg_graph_add_node(XDbgBlockGraphConstructor
*gr
, void *node
,
4841 XDbgBlockGraphNodeType type
, const char *name
)
4843 XDbgBlockGraphNode
*n
;
4845 n
= g_new0(XDbgBlockGraphNode
, 1);
4847 n
->id
= xdbg_graph_node_num(gr
, node
);
4849 n
->name
= g_strdup(name
);
4851 QAPI_LIST_ADD(gr
->graph
->nodes
, n
);
4854 static void xdbg_graph_add_edge(XDbgBlockGraphConstructor
*gr
, void *parent
,
4855 const BdrvChild
*child
)
4859 BlockPermission num
;
4862 static const PermissionMap permissions
[] = {
4863 { BLK_PERM_CONSISTENT_READ
, BLOCK_PERMISSION_CONSISTENT_READ
},
4864 { BLK_PERM_WRITE
, BLOCK_PERMISSION_WRITE
},
4865 { BLK_PERM_WRITE_UNCHANGED
, BLOCK_PERMISSION_WRITE_UNCHANGED
},
4866 { BLK_PERM_RESIZE
, BLOCK_PERMISSION_RESIZE
},
4867 { BLK_PERM_GRAPH_MOD
, BLOCK_PERMISSION_GRAPH_MOD
},
4870 const PermissionMap
*p
;
4871 XDbgBlockGraphEdge
*edge
;
4873 QEMU_BUILD_BUG_ON(1UL << (ARRAY_SIZE(permissions
) - 1) != BLK_PERM_ALL
+ 1);
4875 edge
= g_new0(XDbgBlockGraphEdge
, 1);
4877 edge
->parent
= xdbg_graph_node_num(gr
, parent
);
4878 edge
->child
= xdbg_graph_node_num(gr
, child
->bs
);
4879 edge
->name
= g_strdup(child
->name
);
4881 for (p
= permissions
; p
->flag
; p
++) {
4882 if (p
->flag
& child
->perm
) {
4883 QAPI_LIST_ADD(edge
->perm
, p
->num
);
4885 if (p
->flag
& child
->shared_perm
) {
4886 QAPI_LIST_ADD(edge
->shared_perm
, p
->num
);
4890 QAPI_LIST_ADD(gr
->graph
->edges
, edge
);
4894 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
)
4898 BlockDriverState
*bs
;
4900 XDbgBlockGraphConstructor
*gr
= xdbg_graph_new();
4902 for (blk
= blk_all_next(NULL
); blk
; blk
= blk_all_next(blk
)) {
4903 char *allocated_name
= NULL
;
4904 const char *name
= blk_name(blk
);
4907 name
= allocated_name
= blk_get_attached_dev_id(blk
);
4909 xdbg_graph_add_node(gr
, blk
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND
,
4911 g_free(allocated_name
);
4912 if (blk_root(blk
)) {
4913 xdbg_graph_add_edge(gr
, blk
, blk_root(blk
));
4917 for (job
= block_job_next(NULL
); job
; job
= block_job_next(job
)) {
4920 xdbg_graph_add_node(gr
, job
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB
,
4922 for (el
= job
->nodes
; el
; el
= el
->next
) {
4923 xdbg_graph_add_edge(gr
, job
, (BdrvChild
*)el
->data
);
4927 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4928 xdbg_graph_add_node(gr
, bs
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER
,
4930 QLIST_FOREACH(child
, &bs
->children
, next
) {
4931 xdbg_graph_add_edge(gr
, bs
, child
);
4935 return xdbg_graph_finalize(gr
);
4938 BlockDriverState
*bdrv_lookup_bs(const char *device
,
4939 const char *node_name
,
4943 BlockDriverState
*bs
;
4946 blk
= blk_by_name(device
);
4951 error_setg(errp
, "Device '%s' has no medium", device
);
4959 bs
= bdrv_find_node(node_name
);
4966 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
4967 device
? device
: "",
4968 node_name
? node_name
: "");
4972 /* If 'base' is in the same chain as 'top', return true. Otherwise,
4973 * return false. If either argument is NULL, return false. */
4974 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
4976 while (top
&& top
!= base
) {
4977 top
= backing_bs(top
);
4983 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
4986 return QTAILQ_FIRST(&graph_bdrv_states
);
4988 return QTAILQ_NEXT(bs
, node_list
);
4991 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
)
4994 return QTAILQ_FIRST(&all_bdrv_states
);
4996 return QTAILQ_NEXT(bs
, bs_list
);
4999 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
5001 return bs
->node_name
;
5004 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
5009 /* If multiple parents have a name, just pick the first one. */
5010 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
5011 if (c
->role
->get_name
) {
5012 name
= c
->role
->get_name(c
);
5013 if (name
&& *name
) {
5022 /* TODO check what callers really want: bs->node_name or blk_name() */
5023 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
5025 return bdrv_get_parent_name(bs
) ?: "";
5028 /* This can be used to identify nodes that might not have a device
5029 * name associated. Since node and device names live in the same
5030 * namespace, the result is unambiguous. The exception is if both are
5031 * absent, then this returns an empty (non-null) string. */
5032 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
5034 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
5037 int bdrv_get_flags(BlockDriverState
*bs
)
5039 return bs
->open_flags
;
5042 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
5047 int bdrv_has_zero_init(BlockDriverState
*bs
)
5053 /* If BS is a copy on write image, it is initialized to
5054 the contents of the base image, which may not be zeroes. */
5058 if (bs
->drv
->bdrv_has_zero_init
) {
5059 return bs
->drv
->bdrv_has_zero_init(bs
);
5061 if (bs
->file
&& bs
->drv
->is_filter
) {
5062 return bdrv_has_zero_init(bs
->file
->bs
);
5069 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
5071 BlockDriverInfo bdi
;
5077 if (bdrv_get_info(bs
, &bdi
) == 0) {
5078 return bdi
.unallocated_blocks_are_zero
;
5084 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
5086 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
5090 return bs
->supported_zero_flags
& BDRV_REQ_MAY_UNMAP
;
5093 void bdrv_get_backing_filename(BlockDriverState
*bs
,
5094 char *filename
, int filename_size
)
5096 pstrcpy(filename
, filename_size
, bs
->backing_file
);
5099 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
5101 BlockDriver
*drv
= bs
->drv
;
5102 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
5106 if (!drv
->bdrv_get_info
) {
5107 if (bs
->file
&& drv
->is_filter
) {
5108 return bdrv_get_info(bs
->file
->bs
, bdi
);
5112 memset(bdi
, 0, sizeof(*bdi
));
5113 return drv
->bdrv_get_info(bs
, bdi
);
5116 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
5119 BlockDriver
*drv
= bs
->drv
;
5120 if (drv
&& drv
->bdrv_get_specific_info
) {
5121 return drv
->bdrv_get_specific_info(bs
, errp
);
5126 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
5128 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
5132 bs
->drv
->bdrv_debug_event(bs
, event
);
5135 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
5138 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
5139 bs
= bs
->file
? bs
->file
->bs
: NULL
;
5142 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
5143 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
5149 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
5151 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
5152 bs
= bs
->file
? bs
->file
->bs
: NULL
;
5155 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
5156 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
5162 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
5164 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
5165 bs
= bs
->file
? bs
->file
->bs
: NULL
;
5168 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
5169 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
5175 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
5177 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
5178 bs
= bs
->file
? bs
->file
->bs
: NULL
;
5181 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
5182 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
5188 /* backing_file can either be relative, or absolute, or a protocol. If it is
5189 * relative, it must be relative to the chain. So, passing in bs->filename
5190 * from a BDS as backing_file should not be done, as that may be relative to
5191 * the CWD rather than the chain. */
5192 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
5193 const char *backing_file
)
5195 char *filename_full
= NULL
;
5196 char *backing_file_full
= NULL
;
5197 char *filename_tmp
= NULL
;
5198 int is_protocol
= 0;
5199 BlockDriverState
*curr_bs
= NULL
;
5200 BlockDriverState
*retval
= NULL
;
5202 if (!bs
|| !bs
->drv
|| !backing_file
) {
5206 filename_full
= g_malloc(PATH_MAX
);
5207 backing_file_full
= g_malloc(PATH_MAX
);
5209 is_protocol
= path_has_protocol(backing_file
);
5211 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
5213 /* If either of the filename paths is actually a protocol, then
5214 * compare unmodified paths; otherwise make paths relative */
5215 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
5216 char *backing_file_full_ret
;
5218 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
5219 retval
= curr_bs
->backing
->bs
;
5222 /* Also check against the full backing filename for the image */
5223 backing_file_full_ret
= bdrv_get_full_backing_filename(curr_bs
,
5225 if (backing_file_full_ret
) {
5226 bool equal
= strcmp(backing_file
, backing_file_full_ret
) == 0;
5227 g_free(backing_file_full_ret
);
5229 retval
= curr_bs
->backing
->bs
;
5234 /* If not an absolute filename path, make it relative to the current
5235 * image's filename path */
5236 filename_tmp
= bdrv_make_absolute_filename(curr_bs
, backing_file
,
5238 /* We are going to compare canonicalized absolute pathnames */
5239 if (!filename_tmp
|| !realpath(filename_tmp
, filename_full
)) {
5240 g_free(filename_tmp
);
5243 g_free(filename_tmp
);
5245 /* We need to make sure the backing filename we are comparing against
5246 * is relative to the current image filename (or absolute) */
5247 filename_tmp
= bdrv_get_full_backing_filename(curr_bs
, NULL
);
5248 if (!filename_tmp
|| !realpath(filename_tmp
, backing_file_full
)) {
5249 g_free(filename_tmp
);
5252 g_free(filename_tmp
);
5254 if (strcmp(backing_file_full
, filename_full
) == 0) {
5255 retval
= curr_bs
->backing
->bs
;
5261 g_free(filename_full
);
5262 g_free(backing_file_full
);
5266 void bdrv_init(void)
5268 module_call_init(MODULE_INIT_BLOCK
);
5271 void bdrv_init_with_whitelist(void)
5273 use_bdrv_whitelist
= 1;
5277 static void coroutine_fn
bdrv_co_invalidate_cache(BlockDriverState
*bs
,
5280 BdrvChild
*child
, *parent
;
5281 uint64_t perm
, shared_perm
;
5282 Error
*local_err
= NULL
;
5284 BdrvDirtyBitmap
*bm
;
5290 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
5294 QLIST_FOREACH(child
, &bs
->children
, next
) {
5295 bdrv_co_invalidate_cache(child
->bs
, &local_err
);
5297 error_propagate(errp
, local_err
);
5303 * Update permissions, they may differ for inactive nodes.
5305 * Note that the required permissions of inactive images are always a
5306 * subset of the permissions required after activating the image. This
5307 * allows us to just get the permissions upfront without restricting
5308 * drv->bdrv_invalidate_cache().
5310 * It also means that in error cases, we don't have to try and revert to
5311 * the old permissions (which is an operation that could fail, too). We can
5312 * just keep the extended permissions for the next time that an activation
5313 * of the image is tried.
5315 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
5316 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
5317 ret
= bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
, NULL
, &local_err
);
5319 bs
->open_flags
|= BDRV_O_INACTIVE
;
5320 error_propagate(errp
, local_err
);
5323 bdrv_set_perm(bs
, perm
, shared_perm
);
5325 if (bs
->drv
->bdrv_co_invalidate_cache
) {
5326 bs
->drv
->bdrv_co_invalidate_cache(bs
, &local_err
);
5328 bs
->open_flags
|= BDRV_O_INACTIVE
;
5329 error_propagate(errp
, local_err
);
5334 for (bm
= bdrv_dirty_bitmap_next(bs
, NULL
); bm
;
5335 bm
= bdrv_dirty_bitmap_next(bs
, bm
))
5337 bdrv_dirty_bitmap_set_migration(bm
, false);
5340 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
5342 bs
->open_flags
|= BDRV_O_INACTIVE
;
5343 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
5347 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
5348 if (parent
->role
->activate
) {
5349 parent
->role
->activate(parent
, &local_err
);
5351 bs
->open_flags
|= BDRV_O_INACTIVE
;
5352 error_propagate(errp
, local_err
);
5359 typedef struct InvalidateCacheCo
{
5360 BlockDriverState
*bs
;
5363 } InvalidateCacheCo
;
5365 static void coroutine_fn
bdrv_invalidate_cache_co_entry(void *opaque
)
5367 InvalidateCacheCo
*ico
= opaque
;
5368 bdrv_co_invalidate_cache(ico
->bs
, ico
->errp
);
5373 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
5376 InvalidateCacheCo ico
= {
5382 if (qemu_in_coroutine()) {
5383 /* Fast-path if already in coroutine context */
5384 bdrv_invalidate_cache_co_entry(&ico
);
5386 co
= qemu_coroutine_create(bdrv_invalidate_cache_co_entry
, &ico
);
5387 bdrv_coroutine_enter(bs
, co
);
5388 BDRV_POLL_WHILE(bs
, !ico
.done
);
5392 void bdrv_invalidate_cache_all(Error
**errp
)
5394 BlockDriverState
*bs
;
5395 Error
*local_err
= NULL
;
5396 BdrvNextIterator it
;
5398 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
5399 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
5401 aio_context_acquire(aio_context
);
5402 bdrv_invalidate_cache(bs
, &local_err
);
5403 aio_context_release(aio_context
);
5405 error_propagate(errp
, local_err
);
5406 bdrv_next_cleanup(&it
);
5412 static bool bdrv_has_bds_parent(BlockDriverState
*bs
, bool only_active
)
5416 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
5417 if (parent
->role
->parent_is_bds
) {
5418 BlockDriverState
*parent_bs
= parent
->opaque
;
5419 if (!only_active
|| !(parent_bs
->open_flags
& BDRV_O_INACTIVE
)) {
5428 static int bdrv_inactivate_recurse(BlockDriverState
*bs
)
5430 BdrvChild
*child
, *parent
;
5431 bool tighten_restrictions
;
5432 uint64_t perm
, shared_perm
;
5439 /* Make sure that we don't inactivate a child before its parent.
5440 * It will be covered by recursion from the yet active parent. */
5441 if (bdrv_has_bds_parent(bs
, true)) {
5445 assert(!(bs
->open_flags
& BDRV_O_INACTIVE
));
5447 /* Inactivate this node */
5448 if (bs
->drv
->bdrv_inactivate
) {
5449 ret
= bs
->drv
->bdrv_inactivate(bs
);
5455 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
5456 if (parent
->role
->inactivate
) {
5457 ret
= parent
->role
->inactivate(parent
);
5464 bs
->open_flags
|= BDRV_O_INACTIVE
;
5466 /* Update permissions, they may differ for inactive nodes */
5467 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
5468 ret
= bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
,
5469 &tighten_restrictions
, NULL
);
5470 assert(tighten_restrictions
== false);
5472 /* We only tried to loosen restrictions, so errors are not fatal */
5473 bdrv_abort_perm_update(bs
);
5475 bdrv_set_perm(bs
, perm
, shared_perm
);
5479 /* Recursively inactivate children */
5480 QLIST_FOREACH(child
, &bs
->children
, next
) {
5481 ret
= bdrv_inactivate_recurse(child
->bs
);
5490 int bdrv_inactivate_all(void)
5492 BlockDriverState
*bs
= NULL
;
5493 BdrvNextIterator it
;
5495 GSList
*aio_ctxs
= NULL
, *ctx
;
5497 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
5498 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
5500 if (!g_slist_find(aio_ctxs
, aio_context
)) {
5501 aio_ctxs
= g_slist_prepend(aio_ctxs
, aio_context
);
5502 aio_context_acquire(aio_context
);
5506 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
5507 /* Nodes with BDS parents are covered by recursion from the last
5508 * parent that gets inactivated. Don't inactivate them a second
5509 * time if that has already happened. */
5510 if (bdrv_has_bds_parent(bs
, false)) {
5513 ret
= bdrv_inactivate_recurse(bs
);
5515 bdrv_next_cleanup(&it
);
5521 for (ctx
= aio_ctxs
; ctx
!= NULL
; ctx
= ctx
->next
) {
5522 AioContext
*aio_context
= ctx
->data
;
5523 aio_context_release(aio_context
);
5525 g_slist_free(aio_ctxs
);
5530 /**************************************************************/
5531 /* removable device support */
5534 * Return TRUE if the media is present
5536 bool bdrv_is_inserted(BlockDriverState
*bs
)
5538 BlockDriver
*drv
= bs
->drv
;
5544 if (drv
->bdrv_is_inserted
) {
5545 return drv
->bdrv_is_inserted(bs
);
5547 QLIST_FOREACH(child
, &bs
->children
, next
) {
5548 if (!bdrv_is_inserted(child
->bs
)) {
5556 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
5558 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
5560 BlockDriver
*drv
= bs
->drv
;
5562 if (drv
&& drv
->bdrv_eject
) {
5563 drv
->bdrv_eject(bs
, eject_flag
);
5568 * Lock or unlock the media (if it is locked, the user won't be able
5569 * to eject it manually).
5571 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
5573 BlockDriver
*drv
= bs
->drv
;
5575 trace_bdrv_lock_medium(bs
, locked
);
5577 if (drv
&& drv
->bdrv_lock_medium
) {
5578 drv
->bdrv_lock_medium(bs
, locked
);
5582 /* Get a reference to bs */
5583 void bdrv_ref(BlockDriverState
*bs
)
5588 /* Release a previously grabbed reference to bs.
5589 * If after releasing, reference count is zero, the BlockDriverState is
5591 void bdrv_unref(BlockDriverState
*bs
)
5596 assert(bs
->refcnt
> 0);
5597 if (--bs
->refcnt
== 0) {
5602 struct BdrvOpBlocker
{
5604 QLIST_ENTRY(BdrvOpBlocker
) list
;
5607 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
5609 BdrvOpBlocker
*blocker
;
5610 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5611 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
5612 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
5613 error_propagate_prepend(errp
, error_copy(blocker
->reason
),
5614 "Node '%s' is busy: ",
5615 bdrv_get_device_or_node_name(bs
));
5621 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
5623 BdrvOpBlocker
*blocker
;
5624 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5626 blocker
= g_new0(BdrvOpBlocker
, 1);
5627 blocker
->reason
= reason
;
5628 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
5631 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
5633 BdrvOpBlocker
*blocker
, *next
;
5634 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5635 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
5636 if (blocker
->reason
== reason
) {
5637 QLIST_REMOVE(blocker
, list
);
5643 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
5646 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5647 bdrv_op_block(bs
, i
, reason
);
5651 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
5654 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5655 bdrv_op_unblock(bs
, i
, reason
);
5659 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
5663 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5664 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
5671 void bdrv_img_create(const char *filename
, const char *fmt
,
5672 const char *base_filename
, const char *base_fmt
,
5673 char *options
, uint64_t img_size
, int flags
, bool quiet
,
5676 QemuOptsList
*create_opts
= NULL
;
5677 QemuOpts
*opts
= NULL
;
5678 const char *backing_fmt
, *backing_file
;
5680 BlockDriver
*drv
, *proto_drv
;
5681 Error
*local_err
= NULL
;
5684 /* Find driver and parse its options */
5685 drv
= bdrv_find_format(fmt
);
5687 error_setg(errp
, "Unknown file format '%s'", fmt
);
5691 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
5696 if (!drv
->create_opts
) {
5697 error_setg(errp
, "Format driver '%s' does not support image creation",
5702 if (!proto_drv
->create_opts
) {
5703 error_setg(errp
, "Protocol driver '%s' does not support image creation",
5704 proto_drv
->format_name
);
5708 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
5709 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
5711 /* Create parameter list with default values */
5712 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
5713 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
5715 /* Parse -o options */
5717 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
5723 if (base_filename
) {
5724 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
5726 error_setg(errp
, "Backing file not supported for file format '%s'",
5733 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
5735 error_setg(errp
, "Backing file format not supported for file "
5736 "format '%s'", fmt
);
5741 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
5743 if (!strcmp(filename
, backing_file
)) {
5744 error_setg(errp
, "Error: Trying to create an image with the "
5745 "same filename as the backing file");
5750 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
5752 /* The size for the image must always be specified, unless we have a backing
5753 * file and we have not been forbidden from opening it. */
5754 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, img_size
);
5755 if (backing_file
&& !(flags
& BDRV_O_NO_BACKING
)) {
5756 BlockDriverState
*bs
;
5759 QDict
*backing_options
= NULL
;
5762 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
5767 assert(full_backing
);
5769 /* backing files always opened read-only */
5771 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
5773 backing_options
= qdict_new();
5775 qdict_put_str(backing_options
, "driver", backing_fmt
);
5777 qdict_put_bool(backing_options
, BDRV_OPT_FORCE_SHARE
, true);
5779 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
5781 g_free(full_backing
);
5782 if (!bs
&& size
!= -1) {
5783 /* Couldn't open BS, but we have a size, so it's nonfatal */
5784 warn_reportf_err(local_err
,
5785 "Could not verify backing image. "
5786 "This may become an error in future versions.\n");
5789 /* Couldn't open bs, do not have size */
5790 error_append_hint(&local_err
,
5791 "Could not open backing image to determine size.\n");
5795 /* Opened BS, have no size */
5796 size
= bdrv_getlength(bs
);
5798 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
5803 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
5807 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
5810 error_setg(errp
, "Image creation needs a size parameter");
5815 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
5816 qemu_opts_print(opts
, " ");
5820 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
5822 if (ret
== -EFBIG
) {
5823 /* This is generally a better message than whatever the driver would
5824 * deliver (especially because of the cluster_size_hint), since that
5825 * is most probably not much different from "image too large". */
5826 const char *cluster_size_hint
= "";
5827 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
5828 cluster_size_hint
= " (try using a larger cluster size)";
5830 error_setg(errp
, "The image size is too large for file format '%s'"
5831 "%s", fmt
, cluster_size_hint
);
5832 error_free(local_err
);
5837 qemu_opts_del(opts
);
5838 qemu_opts_free(create_opts
);
5839 error_propagate(errp
, local_err
);
5842 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
5844 return bs
? bs
->aio_context
: qemu_get_aio_context();
5847 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
5849 aio_co_enter(bdrv_get_aio_context(bs
), co
);
5852 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
5854 QLIST_REMOVE(ban
, list
);
5858 static void bdrv_detach_aio_context(BlockDriverState
*bs
)
5860 BdrvAioNotifier
*baf
, *baf_tmp
;
5862 assert(!bs
->walking_aio_notifiers
);
5863 bs
->walking_aio_notifiers
= true;
5864 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
5866 bdrv_do_remove_aio_context_notifier(baf
);
5868 baf
->detach_aio_context(baf
->opaque
);
5871 /* Never mind iterating again to check for ->deleted. bdrv_close() will
5872 * remove remaining aio notifiers if we aren't called again.
5874 bs
->walking_aio_notifiers
= false;
5876 if (bs
->drv
&& bs
->drv
->bdrv_detach_aio_context
) {
5877 bs
->drv
->bdrv_detach_aio_context(bs
);
5880 if (bs
->quiesce_counter
) {
5881 aio_enable_external(bs
->aio_context
);
5883 bs
->aio_context
= NULL
;
5886 static void bdrv_attach_aio_context(BlockDriverState
*bs
,
5887 AioContext
*new_context
)
5889 BdrvAioNotifier
*ban
, *ban_tmp
;
5891 if (bs
->quiesce_counter
) {
5892 aio_disable_external(new_context
);
5895 bs
->aio_context
= new_context
;
5897 if (bs
->drv
&& bs
->drv
->bdrv_attach_aio_context
) {
5898 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
5901 assert(!bs
->walking_aio_notifiers
);
5902 bs
->walking_aio_notifiers
= true;
5903 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
5905 bdrv_do_remove_aio_context_notifier(ban
);
5907 ban
->attached_aio_context(new_context
, ban
->opaque
);
5910 bs
->walking_aio_notifiers
= false;
5914 * Changes the AioContext used for fd handlers, timers, and BHs by this
5915 * BlockDriverState and all its children and parents.
5917 * Must be called from the main AioContext.
5919 * The caller must own the AioContext lock for the old AioContext of bs, but it
5920 * must not own the AioContext lock for new_context (unless new_context is the
5921 * same as the current context of bs).
5923 * @ignore will accumulate all visited BdrvChild object. The caller is
5924 * responsible for freeing the list afterwards.
5926 void bdrv_set_aio_context_ignore(BlockDriverState
*bs
,
5927 AioContext
*new_context
, GSList
**ignore
)
5929 AioContext
*old_context
= bdrv_get_aio_context(bs
);
5932 g_assert(qemu_get_current_aio_context() == qemu_get_aio_context());
5934 if (old_context
== new_context
) {
5938 bdrv_drained_begin(bs
);
5940 QLIST_FOREACH(child
, &bs
->children
, next
) {
5941 if (g_slist_find(*ignore
, child
)) {
5944 *ignore
= g_slist_prepend(*ignore
, child
);
5945 bdrv_set_aio_context_ignore(child
->bs
, new_context
, ignore
);
5947 QLIST_FOREACH(child
, &bs
->parents
, next_parent
) {
5948 if (g_slist_find(*ignore
, child
)) {
5951 assert(child
->role
->set_aio_ctx
);
5952 *ignore
= g_slist_prepend(*ignore
, child
);
5953 child
->role
->set_aio_ctx(child
, new_context
, ignore
);
5956 bdrv_detach_aio_context(bs
);
5958 /* Acquire the new context, if necessary */
5959 if (qemu_get_aio_context() != new_context
) {
5960 aio_context_acquire(new_context
);
5963 bdrv_attach_aio_context(bs
, new_context
);
5966 * If this function was recursively called from
5967 * bdrv_set_aio_context_ignore(), there may be nodes in the
5968 * subtree that have not yet been moved to the new AioContext.
5969 * Release the old one so bdrv_drained_end() can poll them.
5971 if (qemu_get_aio_context() != old_context
) {
5972 aio_context_release(old_context
);
5975 bdrv_drained_end(bs
);
5977 if (qemu_get_aio_context() != old_context
) {
5978 aio_context_acquire(old_context
);
5980 if (qemu_get_aio_context() != new_context
) {
5981 aio_context_release(new_context
);
5985 static bool bdrv_parent_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
5986 GSList
**ignore
, Error
**errp
)
5988 if (g_slist_find(*ignore
, c
)) {
5991 *ignore
= g_slist_prepend(*ignore
, c
);
5993 /* A BdrvChildRole that doesn't handle AioContext changes cannot
5994 * tolerate any AioContext changes */
5995 if (!c
->role
->can_set_aio_ctx
) {
5996 char *user
= bdrv_child_user_desc(c
);
5997 error_setg(errp
, "Changing iothreads is not supported by %s", user
);
6001 if (!c
->role
->can_set_aio_ctx(c
, ctx
, ignore
, errp
)) {
6002 assert(!errp
|| *errp
);
6008 bool bdrv_child_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
6009 GSList
**ignore
, Error
**errp
)
6011 if (g_slist_find(*ignore
, c
)) {
6014 *ignore
= g_slist_prepend(*ignore
, c
);
6015 return bdrv_can_set_aio_context(c
->bs
, ctx
, ignore
, errp
);
6018 /* @ignore will accumulate all visited BdrvChild object. The caller is
6019 * responsible for freeing the list afterwards. */
6020 bool bdrv_can_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
6021 GSList
**ignore
, Error
**errp
)
6025 if (bdrv_get_aio_context(bs
) == ctx
) {
6029 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
6030 if (!bdrv_parent_can_set_aio_context(c
, ctx
, ignore
, errp
)) {
6034 QLIST_FOREACH(c
, &bs
->children
, next
) {
6035 if (!bdrv_child_can_set_aio_context(c
, ctx
, ignore
, errp
)) {
6043 int bdrv_child_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
6044 BdrvChild
*ignore_child
, Error
**errp
)
6049 ignore
= ignore_child
? g_slist_prepend(NULL
, ignore_child
) : NULL
;
6050 ret
= bdrv_can_set_aio_context(bs
, ctx
, &ignore
, errp
);
6051 g_slist_free(ignore
);
6057 ignore
= ignore_child
? g_slist_prepend(NULL
, ignore_child
) : NULL
;
6058 bdrv_set_aio_context_ignore(bs
, ctx
, &ignore
);
6059 g_slist_free(ignore
);
6064 int bdrv_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
6067 return bdrv_child_try_set_aio_context(bs
, ctx
, NULL
, errp
);
6070 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
6071 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
6072 void (*detach_aio_context
)(void *opaque
), void *opaque
)
6074 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
6075 *ban
= (BdrvAioNotifier
){
6076 .attached_aio_context
= attached_aio_context
,
6077 .detach_aio_context
= detach_aio_context
,
6081 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
6084 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
6085 void (*attached_aio_context
)(AioContext
*,
6087 void (*detach_aio_context
)(void *),
6090 BdrvAioNotifier
*ban
, *ban_next
;
6092 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
6093 if (ban
->attached_aio_context
== attached_aio_context
&&
6094 ban
->detach_aio_context
== detach_aio_context
&&
6095 ban
->opaque
== opaque
&&
6096 ban
->deleted
== false)
6098 if (bs
->walking_aio_notifiers
) {
6099 ban
->deleted
= true;
6101 bdrv_do_remove_aio_context_notifier(ban
);
6110 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
6111 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
6115 error_setg(errp
, "Node is ejected");
6118 if (!bs
->drv
->bdrv_amend_options
) {
6119 error_setg(errp
, "Block driver '%s' does not support option amendment",
6120 bs
->drv
->format_name
);
6123 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
, errp
);
6126 /* This function will be called by the bdrv_recurse_is_first_non_filter method
6127 * of block filter and by bdrv_is_first_non_filter.
6128 * It is used to test if the given bs is the candidate or recurse more in the
6131 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
6132 BlockDriverState
*candidate
)
6134 /* return false if basic checks fails */
6135 if (!bs
|| !bs
->drv
) {
6139 /* the code reached a non block filter driver -> check if the bs is
6140 * the same as the candidate. It's the recursion termination condition.
6142 if (!bs
->drv
->is_filter
) {
6143 return bs
== candidate
;
6145 /* Down this path the driver is a block filter driver */
6147 /* If the block filter recursion method is defined use it to recurse down
6150 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
6151 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
6154 /* the driver is a block filter but don't allow to recurse -> return false
6159 /* This function checks if the candidate is the first non filter bs down it's
6160 * bs chain. Since we don't have pointers to parents it explore all bs chains
6161 * from the top. Some filters can choose not to pass down the recursion.
6163 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
6165 BlockDriverState
*bs
;
6166 BdrvNextIterator it
;
6168 /* walk down the bs forest recursively */
6169 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
6172 /* try to recurse in this top level bs */
6173 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
6175 /* candidate is the first non filter */
6177 bdrv_next_cleanup(&it
);
6185 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
6186 const char *node_name
, Error
**errp
)
6188 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
6189 AioContext
*aio_context
;
6191 if (!to_replace_bs
) {
6192 error_setg(errp
, "Node name '%s' not found", node_name
);
6196 aio_context
= bdrv_get_aio_context(to_replace_bs
);
6197 aio_context_acquire(aio_context
);
6199 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
6200 to_replace_bs
= NULL
;
6204 /* We don't want arbitrary node of the BDS chain to be replaced only the top
6205 * most non filter in order to prevent data corruption.
6206 * Another benefit is that this tests exclude backing files which are
6207 * blocked by the backing blockers.
6209 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
6210 error_setg(errp
, "Only top most non filter can be replaced");
6211 to_replace_bs
= NULL
;
6216 aio_context_release(aio_context
);
6217 return to_replace_bs
;
6221 * Iterates through the list of runtime option keys that are said to
6222 * be "strong" for a BDS. An option is called "strong" if it changes
6223 * a BDS's data. For example, the null block driver's "size" and
6224 * "read-zeroes" options are strong, but its "latency-ns" option is
6227 * If a key returned by this function ends with a dot, all options
6228 * starting with that prefix are strong.
6230 static const char *const *strong_options(BlockDriverState
*bs
,
6231 const char *const *curopt
)
6233 static const char *const global_options
[] = {
6234 "driver", "filename", NULL
6238 return &global_options
[0];
6242 if (curopt
== &global_options
[ARRAY_SIZE(global_options
) - 1] && bs
->drv
) {
6243 curopt
= bs
->drv
->strong_runtime_opts
;
6246 return (curopt
&& *curopt
) ? curopt
: NULL
;
6250 * Copies all strong runtime options from bs->options to the given
6251 * QDict. The set of strong option keys is determined by invoking
6254 * Returns true iff any strong option was present in bs->options (and
6255 * thus copied to the target QDict) with the exception of "filename"
6256 * and "driver". The caller is expected to use this value to decide
6257 * whether the existence of strong options prevents the generation of
6260 static bool append_strong_runtime_options(QDict
*d
, BlockDriverState
*bs
)
6262 bool found_any
= false;
6263 const char *const *option_name
= NULL
;
6269 while ((option_name
= strong_options(bs
, option_name
))) {
6270 bool option_given
= false;
6272 assert(strlen(*option_name
) > 0);
6273 if ((*option_name
)[strlen(*option_name
) - 1] != '.') {
6274 QObject
*entry
= qdict_get(bs
->options
, *option_name
);
6279 qdict_put_obj(d
, *option_name
, qobject_ref(entry
));
6280 option_given
= true;
6282 const QDictEntry
*entry
;
6283 for (entry
= qdict_first(bs
->options
); entry
;
6284 entry
= qdict_next(bs
->options
, entry
))
6286 if (strstart(qdict_entry_key(entry
), *option_name
, NULL
)) {
6287 qdict_put_obj(d
, qdict_entry_key(entry
),
6288 qobject_ref(qdict_entry_value(entry
)));
6289 option_given
= true;
6294 /* While "driver" and "filename" need to be included in a JSON filename,
6295 * their existence does not prohibit generation of a plain filename. */
6296 if (!found_any
&& option_given
&&
6297 strcmp(*option_name
, "driver") && strcmp(*option_name
, "filename"))
6303 if (!qdict_haskey(d
, "driver")) {
6304 /* Drivers created with bdrv_new_open_driver() may not have a
6305 * @driver option. Add it here. */
6306 qdict_put_str(d
, "driver", bs
->drv
->format_name
);
6312 /* Note: This function may return false positives; it may return true
6313 * even if opening the backing file specified by bs's image header
6314 * would result in exactly bs->backing. */
6315 static bool bdrv_backing_overridden(BlockDriverState
*bs
)
6318 return strcmp(bs
->auto_backing_file
,
6319 bs
->backing
->bs
->filename
);
6321 /* No backing BDS, so if the image header reports any backing
6322 * file, it must have been suppressed */
6323 return bs
->auto_backing_file
[0] != '\0';
6327 /* Updates the following BDS fields:
6328 * - exact_filename: A filename which may be used for opening a block device
6329 * which (mostly) equals the given BDS (even without any
6330 * other options; so reading and writing must return the same
6331 * results, but caching etc. may be different)
6332 * - full_open_options: Options which, when given when opening a block device
6333 * (without a filename), result in a BDS (mostly)
6334 * equalling the given one
6335 * - filename: If exact_filename is set, it is copied here. Otherwise,
6336 * full_open_options is converted to a JSON object, prefixed with
6337 * "json:" (for use through the JSON pseudo protocol) and put here.
6339 void bdrv_refresh_filename(BlockDriverState
*bs
)
6341 BlockDriver
*drv
= bs
->drv
;
6344 bool backing_overridden
;
6345 bool generate_json_filename
; /* Whether our default implementation should
6346 fill exact_filename (false) or not (true) */
6352 /* This BDS's file name may depend on any of its children's file names, so
6353 * refresh those first */
6354 QLIST_FOREACH(child
, &bs
->children
, next
) {
6355 bdrv_refresh_filename(child
->bs
);
6359 /* For implicit nodes, just copy everything from the single child */
6360 child
= QLIST_FIRST(&bs
->children
);
6361 assert(QLIST_NEXT(child
, next
) == NULL
);
6363 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
),
6364 child
->bs
->exact_filename
);
6365 pstrcpy(bs
->filename
, sizeof(bs
->filename
), child
->bs
->filename
);
6367 bs
->full_open_options
= qobject_ref(child
->bs
->full_open_options
);
6372 backing_overridden
= bdrv_backing_overridden(bs
);
6374 if (bs
->open_flags
& BDRV_O_NO_IO
) {
6375 /* Without I/O, the backing file does not change anything.
6376 * Therefore, in such a case (primarily qemu-img), we can
6377 * pretend the backing file has not been overridden even if
6378 * it technically has been. */
6379 backing_overridden
= false;
6382 /* Gather the options QDict */
6384 generate_json_filename
= append_strong_runtime_options(opts
, bs
);
6385 generate_json_filename
|= backing_overridden
;
6387 if (drv
->bdrv_gather_child_options
) {
6388 /* Some block drivers may not want to present all of their children's
6389 * options, or name them differently from BdrvChild.name */
6390 drv
->bdrv_gather_child_options(bs
, opts
, backing_overridden
);
6392 QLIST_FOREACH(child
, &bs
->children
, next
) {
6393 if (child
->role
== &child_backing
&& !backing_overridden
) {
6394 /* We can skip the backing BDS if it has not been overridden */
6398 qdict_put(opts
, child
->name
,
6399 qobject_ref(child
->bs
->full_open_options
));
6402 if (backing_overridden
&& !bs
->backing
) {
6403 /* Force no backing file */
6404 qdict_put_null(opts
, "backing");
6408 qobject_unref(bs
->full_open_options
);
6409 bs
->full_open_options
= opts
;
6411 if (drv
->bdrv_refresh_filename
) {
6412 /* Obsolete information is of no use here, so drop the old file name
6413 * information before refreshing it */
6414 bs
->exact_filename
[0] = '\0';
6416 drv
->bdrv_refresh_filename(bs
);
6417 } else if (bs
->file
) {
6418 /* Try to reconstruct valid information from the underlying file */
6420 bs
->exact_filename
[0] = '\0';
6423 * We can use the underlying file's filename if:
6424 * - it has a filename,
6425 * - the file is a protocol BDS, and
6426 * - opening that file (as this BDS's format) will automatically create
6427 * the BDS tree we have right now, that is:
6428 * - the user did not significantly change this BDS's behavior with
6429 * some explicit (strong) options
6430 * - no non-file child of this BDS has been overridden by the user
6431 * Both of these conditions are represented by generate_json_filename.
6433 if (bs
->file
->bs
->exact_filename
[0] &&
6434 bs
->file
->bs
->drv
->bdrv_file_open
&&
6435 !generate_json_filename
)
6437 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
6441 if (bs
->exact_filename
[0]) {
6442 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
6444 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
6445 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
6446 qstring_get_str(json
));
6447 qobject_unref(json
);
6451 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
)
6453 BlockDriver
*drv
= bs
->drv
;
6456 error_setg(errp
, "Node '%s' is ejected", bs
->node_name
);
6460 if (drv
->bdrv_dirname
) {
6461 return drv
->bdrv_dirname(bs
, errp
);
6465 return bdrv_dirname(bs
->file
->bs
, errp
);
6468 bdrv_refresh_filename(bs
);
6469 if (bs
->exact_filename
[0] != '\0') {
6470 return path_combine(bs
->exact_filename
, "");
6473 error_setg(errp
, "Cannot generate a base directory for %s nodes",
6479 * Hot add/remove a BDS's child. So the user can take a child offline when
6480 * it is broken and take a new child online
6482 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
6486 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
6487 error_setg(errp
, "The node %s does not support adding a child",
6488 bdrv_get_device_or_node_name(parent_bs
));
6492 if (!QLIST_EMPTY(&child_bs
->parents
)) {
6493 error_setg(errp
, "The node %s already has a parent",
6494 child_bs
->node_name
);
6498 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
6501 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
6505 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
6506 error_setg(errp
, "The node %s does not support removing a child",
6507 bdrv_get_device_or_node_name(parent_bs
));
6511 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
6518 error_setg(errp
, "The node %s does not have a child named %s",
6519 bdrv_get_device_or_node_name(parent_bs
),
6520 bdrv_get_device_or_node_name(child
->bs
));
6524 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);
6527 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
6528 uint32_t granularity
, Error
**errp
)
6530 BlockDriver
*drv
= bs
->drv
;
6533 error_setg_errno(errp
, ENOMEDIUM
,
6534 "Can't store persistent bitmaps to %s",
6535 bdrv_get_device_or_node_name(bs
));
6539 if (!drv
->bdrv_can_store_new_dirty_bitmap
) {
6540 error_setg_errno(errp
, ENOTSUP
,
6541 "Can't store persistent bitmaps to %s",
6542 bdrv_get_device_or_node_name(bs
));
6546 return drv
->bdrv_can_store_new_dirty_bitmap(bs
, name
, granularity
, errp
);