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
)
916 BlockDriverState
*bs
= child
->opaque
;
917 bdrv_drained_end(bs
);
920 static void bdrv_child_cb_attach(BdrvChild
*child
)
922 BlockDriverState
*bs
= child
->opaque
;
923 bdrv_apply_subtree_drain(child
, bs
);
926 static void bdrv_child_cb_detach(BdrvChild
*child
)
928 BlockDriverState
*bs
= child
->opaque
;
929 bdrv_unapply_subtree_drain(child
, bs
);
932 static int bdrv_child_cb_inactivate(BdrvChild
*child
)
934 BlockDriverState
*bs
= child
->opaque
;
935 assert(bs
->open_flags
& BDRV_O_INACTIVE
);
940 * Returns the options and flags that a temporary snapshot should get, based on
941 * the originally requested flags (the originally requested image will have
942 * flags like a backing file)
944 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
945 int parent_flags
, QDict
*parent_options
)
947 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
949 /* For temporary files, unconditional cache=unsafe is fine */
950 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
951 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
953 /* Copy the read-only option from the parent */
954 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
956 /* aio=native doesn't work for cache.direct=off, so disable it for the
957 * temporary snapshot */
958 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
962 * Returns the options and flags that bs->file should get if a protocol driver
963 * is expected, based on the given options and flags for the parent BDS
965 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
966 int parent_flags
, QDict
*parent_options
)
968 int flags
= parent_flags
;
970 /* Enable protocol handling, disable format probing for bs->file */
971 flags
|= BDRV_O_PROTOCOL
;
973 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
975 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
976 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
977 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
979 /* Inherit the read-only option from the parent if it's not set */
980 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
981 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_AUTO_READ_ONLY
);
983 /* Our block drivers take care to send flushes and respect unmap policy,
984 * so we can default to enable both on lower layers regardless of the
985 * corresponding parent options. */
986 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
988 /* Clear flags that only apply to the top layer */
989 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
992 *child_flags
= flags
;
995 const BdrvChildRole child_file
= {
996 .parent_is_bds
= true,
997 .get_parent_desc
= bdrv_child_get_parent_desc
,
998 .inherit_options
= bdrv_inherited_options
,
999 .drained_begin
= bdrv_child_cb_drained_begin
,
1000 .drained_poll
= bdrv_child_cb_drained_poll
,
1001 .drained_end
= bdrv_child_cb_drained_end
,
1002 .attach
= bdrv_child_cb_attach
,
1003 .detach
= bdrv_child_cb_detach
,
1004 .inactivate
= bdrv_child_cb_inactivate
,
1008 * Returns the options and flags that bs->file should get if the use of formats
1009 * (and not only protocols) is permitted for it, based on the given options and
1010 * flags for the parent BDS
1012 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
1013 int parent_flags
, QDict
*parent_options
)
1015 child_file
.inherit_options(child_flags
, child_options
,
1016 parent_flags
, parent_options
);
1018 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
1021 const BdrvChildRole child_format
= {
1022 .parent_is_bds
= true,
1023 .get_parent_desc
= bdrv_child_get_parent_desc
,
1024 .inherit_options
= bdrv_inherited_fmt_options
,
1025 .drained_begin
= bdrv_child_cb_drained_begin
,
1026 .drained_poll
= bdrv_child_cb_drained_poll
,
1027 .drained_end
= bdrv_child_cb_drained_end
,
1028 .attach
= bdrv_child_cb_attach
,
1029 .detach
= bdrv_child_cb_detach
,
1030 .inactivate
= bdrv_child_cb_inactivate
,
1033 static void bdrv_backing_attach(BdrvChild
*c
)
1035 BlockDriverState
*parent
= c
->opaque
;
1036 BlockDriverState
*backing_hd
= c
->bs
;
1038 assert(!parent
->backing_blocker
);
1039 error_setg(&parent
->backing_blocker
,
1040 "node is used as backing hd of '%s'",
1041 bdrv_get_device_or_node_name(parent
));
1043 bdrv_refresh_filename(backing_hd
);
1045 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
1046 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
1047 backing_hd
->filename
);
1048 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
1049 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
1051 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
1052 /* Otherwise we won't be able to commit or stream */
1053 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
1054 parent
->backing_blocker
);
1055 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
1056 parent
->backing_blocker
);
1058 * We do backup in 3 ways:
1060 * The target bs is new opened, and the source is top BDS
1061 * 2. blockdev backup
1062 * Both the source and the target are top BDSes.
1063 * 3. internal backup(used for block replication)
1064 * Both the source and the target are backing file
1066 * In case 1 and 2, neither the source nor the target is the backing file.
1067 * In case 3, we will block the top BDS, so there is only one block job
1068 * for the top BDS and its backing chain.
1070 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
1071 parent
->backing_blocker
);
1072 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
1073 parent
->backing_blocker
);
1075 bdrv_child_cb_attach(c
);
1078 static void bdrv_backing_detach(BdrvChild
*c
)
1080 BlockDriverState
*parent
= c
->opaque
;
1082 assert(parent
->backing_blocker
);
1083 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
1084 error_free(parent
->backing_blocker
);
1085 parent
->backing_blocker
= NULL
;
1087 bdrv_child_cb_detach(c
);
1091 * Returns the options and flags that bs->backing should get, based on the
1092 * given options and flags for the parent BDS
1094 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
1095 int parent_flags
, QDict
*parent_options
)
1097 int flags
= parent_flags
;
1099 /* The cache mode is inherited unmodified for backing files; except WCE,
1100 * which is only applied on the top level (BlockBackend) */
1101 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
1102 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
1103 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
1105 /* backing files always opened read-only */
1106 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
1107 qdict_set_default_str(child_options
, BDRV_OPT_AUTO_READ_ONLY
, "off");
1108 flags
&= ~BDRV_O_COPY_ON_READ
;
1110 /* snapshot=on is handled on the top layer */
1111 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
1113 *child_flags
= flags
;
1116 static int bdrv_backing_update_filename(BdrvChild
*c
, BlockDriverState
*base
,
1117 const char *filename
, Error
**errp
)
1119 BlockDriverState
*parent
= c
->opaque
;
1120 bool read_only
= bdrv_is_read_only(parent
);
1124 ret
= bdrv_reopen_set_read_only(parent
, false, errp
);
1130 ret
= bdrv_change_backing_file(parent
, filename
,
1131 base
->drv
? base
->drv
->format_name
: "");
1133 error_setg_errno(errp
, -ret
, "Could not update backing file link");
1137 bdrv_reopen_set_read_only(parent
, true, NULL
);
1143 const BdrvChildRole child_backing
= {
1144 .parent_is_bds
= true,
1145 .get_parent_desc
= bdrv_child_get_parent_desc
,
1146 .attach
= bdrv_backing_attach
,
1147 .detach
= bdrv_backing_detach
,
1148 .inherit_options
= bdrv_backing_options
,
1149 .drained_begin
= bdrv_child_cb_drained_begin
,
1150 .drained_poll
= bdrv_child_cb_drained_poll
,
1151 .drained_end
= bdrv_child_cb_drained_end
,
1152 .inactivate
= bdrv_child_cb_inactivate
,
1153 .update_filename
= bdrv_backing_update_filename
,
1156 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
1158 int open_flags
= flags
;
1161 * Clear flags that are internal to the block layer before opening the
1164 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
1169 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
1171 *flags
&= ~(BDRV_O_CACHE_MASK
| BDRV_O_RDWR
| BDRV_O_AUTO_RDONLY
);
1173 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
1174 *flags
|= BDRV_O_NO_FLUSH
;
1177 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
1178 *flags
|= BDRV_O_NOCACHE
;
1181 if (!qemu_opt_get_bool_del(opts
, BDRV_OPT_READ_ONLY
, false)) {
1182 *flags
|= BDRV_O_RDWR
;
1185 if (qemu_opt_get_bool_del(opts
, BDRV_OPT_AUTO_READ_ONLY
, false)) {
1186 *flags
|= BDRV_O_AUTO_RDONLY
;
1190 static void update_options_from_flags(QDict
*options
, int flags
)
1192 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
1193 qdict_put_bool(options
, BDRV_OPT_CACHE_DIRECT
, flags
& BDRV_O_NOCACHE
);
1195 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
1196 qdict_put_bool(options
, BDRV_OPT_CACHE_NO_FLUSH
,
1197 flags
& BDRV_O_NO_FLUSH
);
1199 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
1200 qdict_put_bool(options
, BDRV_OPT_READ_ONLY
, !(flags
& BDRV_O_RDWR
));
1202 if (!qdict_haskey(options
, BDRV_OPT_AUTO_READ_ONLY
)) {
1203 qdict_put_bool(options
, BDRV_OPT_AUTO_READ_ONLY
,
1204 flags
& BDRV_O_AUTO_RDONLY
);
1208 static void bdrv_assign_node_name(BlockDriverState
*bs
,
1209 const char *node_name
,
1212 char *gen_node_name
= NULL
;
1215 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
1216 } else if (!id_wellformed(node_name
)) {
1218 * Check for empty string or invalid characters, but not if it is
1219 * generated (generated names use characters not available to the user)
1221 error_setg(errp
, "Invalid node name");
1225 /* takes care of avoiding namespaces collisions */
1226 if (blk_by_name(node_name
)) {
1227 error_setg(errp
, "node-name=%s is conflicting with a device id",
1232 /* takes care of avoiding duplicates node names */
1233 if (bdrv_find_node(node_name
)) {
1234 error_setg(errp
, "Duplicate node name");
1238 /* Make sure that the node name isn't truncated */
1239 if (strlen(node_name
) >= sizeof(bs
->node_name
)) {
1240 error_setg(errp
, "Node name too long");
1244 /* copy node name into the bs and insert it into the graph list */
1245 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
1246 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
1248 g_free(gen_node_name
);
1251 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
1252 const char *node_name
, QDict
*options
,
1253 int open_flags
, Error
**errp
)
1255 Error
*local_err
= NULL
;
1258 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1260 error_propagate(errp
, local_err
);
1265 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1266 bs
->opaque
= g_malloc0(drv
->instance_size
);
1268 if (drv
->bdrv_file_open
) {
1269 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1270 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1271 } else if (drv
->bdrv_open
) {
1272 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1279 error_propagate(errp
, local_err
);
1280 } else if (bs
->filename
[0]) {
1281 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1283 error_setg_errno(errp
, -ret
, "Could not open image");
1288 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1290 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1294 bdrv_refresh_limits(bs
, &local_err
);
1296 error_propagate(errp
, local_err
);
1300 assert(bdrv_opt_mem_align(bs
) != 0);
1301 assert(bdrv_min_mem_align(bs
) != 0);
1302 assert(is_power_of_2(bs
->bl
.request_alignment
));
1304 for (i
= 0; i
< bs
->quiesce_counter
; i
++) {
1305 if (drv
->bdrv_co_drain_begin
) {
1306 drv
->bdrv_co_drain_begin(bs
);
1313 if (bs
->file
!= NULL
) {
1314 bdrv_unref_child(bs
, bs
->file
);
1322 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1323 int flags
, Error
**errp
)
1325 BlockDriverState
*bs
;
1329 bs
->open_flags
= flags
;
1330 bs
->explicit_options
= qdict_new();
1331 bs
->options
= qdict_new();
1334 update_options_from_flags(bs
->options
, flags
);
1336 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1338 qobject_unref(bs
->explicit_options
);
1339 bs
->explicit_options
= NULL
;
1340 qobject_unref(bs
->options
);
1349 QemuOptsList bdrv_runtime_opts
= {
1350 .name
= "bdrv_common",
1351 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1354 .name
= "node-name",
1355 .type
= QEMU_OPT_STRING
,
1356 .help
= "Node name of the block device node",
1360 .type
= QEMU_OPT_STRING
,
1361 .help
= "Block driver to use for the node",
1364 .name
= BDRV_OPT_CACHE_DIRECT
,
1365 .type
= QEMU_OPT_BOOL
,
1366 .help
= "Bypass software writeback cache on the host",
1369 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1370 .type
= QEMU_OPT_BOOL
,
1371 .help
= "Ignore flush requests",
1374 .name
= BDRV_OPT_READ_ONLY
,
1375 .type
= QEMU_OPT_BOOL
,
1376 .help
= "Node is opened in read-only mode",
1379 .name
= BDRV_OPT_AUTO_READ_ONLY
,
1380 .type
= QEMU_OPT_BOOL
,
1381 .help
= "Node can become read-only if opening read-write fails",
1384 .name
= "detect-zeroes",
1385 .type
= QEMU_OPT_STRING
,
1386 .help
= "try to optimize zero writes (off, on, unmap)",
1389 .name
= BDRV_OPT_DISCARD
,
1390 .type
= QEMU_OPT_STRING
,
1391 .help
= "discard operation (ignore/off, unmap/on)",
1394 .name
= BDRV_OPT_FORCE_SHARE
,
1395 .type
= QEMU_OPT_BOOL
,
1396 .help
= "always accept other writers (default: off)",
1398 { /* end of list */ }
1403 * Common part for opening disk images and files
1405 * Removes all processed options from *options.
1407 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1408 QDict
*options
, Error
**errp
)
1410 int ret
, open_flags
;
1411 const char *filename
;
1412 const char *driver_name
= NULL
;
1413 const char *node_name
= NULL
;
1414 const char *discard
;
1417 Error
*local_err
= NULL
;
1419 assert(bs
->file
== NULL
);
1420 assert(options
!= NULL
&& bs
->options
!= options
);
1422 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1423 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1425 error_propagate(errp
, local_err
);
1430 update_flags_from_options(&bs
->open_flags
, opts
);
1432 driver_name
= qemu_opt_get(opts
, "driver");
1433 drv
= bdrv_find_format(driver_name
);
1434 assert(drv
!= NULL
);
1436 bs
->force_share
= qemu_opt_get_bool(opts
, BDRV_OPT_FORCE_SHARE
, false);
1438 if (bs
->force_share
&& (bs
->open_flags
& BDRV_O_RDWR
)) {
1440 BDRV_OPT_FORCE_SHARE
1441 "=on can only be used with read-only images");
1447 bdrv_refresh_filename(blk_bs(file
));
1448 filename
= blk_bs(file
)->filename
;
1451 * Caution: while qdict_get_try_str() is fine, getting
1452 * non-string types would require more care. When @options
1453 * come from -blockdev or blockdev_add, its members are typed
1454 * according to the QAPI schema, but when they come from
1455 * -drive, they're all QString.
1457 filename
= qdict_get_try_str(options
, "filename");
1460 if (drv
->bdrv_needs_filename
&& (!filename
|| !filename
[0])) {
1461 error_setg(errp
, "The '%s' block driver requires a file name",
1467 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1470 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1472 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1473 if (!bs
->read_only
&& bdrv_is_whitelisted(drv
, true)) {
1474 ret
= bdrv_apply_auto_read_only(bs
, NULL
, NULL
);
1480 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1481 ? "Driver '%s' can only be used for read-only devices"
1482 : "Driver '%s' is not whitelisted",
1488 /* bdrv_new() and bdrv_close() make it so */
1489 assert(atomic_read(&bs
->copy_on_read
) == 0);
1491 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1492 if (!bs
->read_only
) {
1493 bdrv_enable_copy_on_read(bs
);
1495 error_setg(errp
, "Can't use copy-on-read on read-only device");
1501 discard
= qemu_opt_get(opts
, BDRV_OPT_DISCARD
);
1502 if (discard
!= NULL
) {
1503 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1504 error_setg(errp
, "Invalid discard option");
1511 bdrv_parse_detect_zeroes(opts
, bs
->open_flags
, &local_err
);
1513 error_propagate(errp
, local_err
);
1518 if (filename
!= NULL
) {
1519 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1521 bs
->filename
[0] = '\0';
1523 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1525 /* Open the image, either directly or using a protocol */
1526 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1527 node_name
= qemu_opt_get(opts
, "node-name");
1529 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1530 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1535 qemu_opts_del(opts
);
1539 qemu_opts_del(opts
);
1543 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1545 QObject
*options_obj
;
1549 ret
= strstart(filename
, "json:", &filename
);
1552 options_obj
= qobject_from_json(filename
, errp
);
1554 error_prepend(errp
, "Could not parse the JSON options: ");
1558 options
= qobject_to(QDict
, options_obj
);
1560 qobject_unref(options_obj
);
1561 error_setg(errp
, "Invalid JSON object given");
1565 qdict_flatten(options
);
1570 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1573 QDict
*json_options
;
1574 Error
*local_err
= NULL
;
1576 /* Parse json: pseudo-protocol */
1577 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1581 json_options
= parse_json_filename(*pfilename
, &local_err
);
1583 error_propagate(errp
, local_err
);
1587 /* Options given in the filename have lower priority than options
1588 * specified directly */
1589 qdict_join(options
, json_options
, false);
1590 qobject_unref(json_options
);
1595 * Fills in default options for opening images and converts the legacy
1596 * filename/flags pair to option QDict entries.
1597 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1598 * block driver has been specified explicitly.
1600 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1601 int *flags
, Error
**errp
)
1603 const char *drvname
;
1604 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1605 bool parse_filename
= false;
1606 BlockDriver
*drv
= NULL
;
1607 Error
*local_err
= NULL
;
1610 * Caution: while qdict_get_try_str() is fine, getting non-string
1611 * types would require more care. When @options come from
1612 * -blockdev or blockdev_add, its members are typed according to
1613 * the QAPI schema, but when they come from -drive, they're all
1616 drvname
= qdict_get_try_str(*options
, "driver");
1618 drv
= bdrv_find_format(drvname
);
1620 error_setg(errp
, "Unknown driver '%s'", drvname
);
1623 /* If the user has explicitly specified the driver, this choice should
1624 * override the BDRV_O_PROTOCOL flag */
1625 protocol
= drv
->bdrv_file_open
;
1629 *flags
|= BDRV_O_PROTOCOL
;
1631 *flags
&= ~BDRV_O_PROTOCOL
;
1634 /* Translate cache options from flags into options */
1635 update_options_from_flags(*options
, *flags
);
1637 /* Fetch the file name from the options QDict if necessary */
1638 if (protocol
&& filename
) {
1639 if (!qdict_haskey(*options
, "filename")) {
1640 qdict_put_str(*options
, "filename", filename
);
1641 parse_filename
= true;
1643 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1649 /* Find the right block driver */
1650 /* See cautionary note on accessing @options above */
1651 filename
= qdict_get_try_str(*options
, "filename");
1653 if (!drvname
&& protocol
) {
1655 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1660 drvname
= drv
->format_name
;
1661 qdict_put_str(*options
, "driver", drvname
);
1663 error_setg(errp
, "Must specify either driver or file");
1668 assert(drv
|| !protocol
);
1670 /* Driver-specific filename parsing */
1671 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1672 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1674 error_propagate(errp
, local_err
);
1678 if (!drv
->bdrv_needs_filename
) {
1679 qdict_del(*options
, "filename");
1686 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
1687 uint64_t perm
, uint64_t shared
,
1688 GSList
*ignore_children
, Error
**errp
);
1689 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1690 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1692 typedef struct BlockReopenQueueEntry
{
1695 BDRVReopenState state
;
1696 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1697 } BlockReopenQueueEntry
;
1700 * Return the flags that @bs will have after the reopens in @q have
1701 * successfully completed. If @q is NULL (or @bs is not contained in @q),
1702 * return the current flags.
1704 static int bdrv_reopen_get_flags(BlockReopenQueue
*q
, BlockDriverState
*bs
)
1706 BlockReopenQueueEntry
*entry
;
1709 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
1710 if (entry
->state
.bs
== bs
) {
1711 return entry
->state
.flags
;
1716 return bs
->open_flags
;
1719 /* Returns whether the image file can be written to after the reopen queue @q
1720 * has been successfully applied, or right now if @q is NULL. */
1721 static bool bdrv_is_writable_after_reopen(BlockDriverState
*bs
,
1722 BlockReopenQueue
*q
)
1724 int flags
= bdrv_reopen_get_flags(q
, bs
);
1726 return (flags
& (BDRV_O_RDWR
| BDRV_O_INACTIVE
)) == BDRV_O_RDWR
;
1730 * Return whether the BDS can be written to. This is not necessarily
1731 * the same as !bdrv_is_read_only(bs), as inactivated images may not
1732 * be written to but do not count as read-only images.
1734 bool bdrv_is_writable(BlockDriverState
*bs
)
1736 return bdrv_is_writable_after_reopen(bs
, NULL
);
1739 static void bdrv_child_perm(BlockDriverState
*bs
, BlockDriverState
*child_bs
,
1740 BdrvChild
*c
, const BdrvChildRole
*role
,
1741 BlockReopenQueue
*reopen_queue
,
1742 uint64_t parent_perm
, uint64_t parent_shared
,
1743 uint64_t *nperm
, uint64_t *nshared
)
1745 if (bs
->drv
&& bs
->drv
->bdrv_child_perm
) {
1746 bs
->drv
->bdrv_child_perm(bs
, c
, role
, reopen_queue
,
1747 parent_perm
, parent_shared
,
1750 /* TODO Take force_share from reopen_queue */
1751 if (child_bs
&& child_bs
->force_share
) {
1752 *nshared
= BLK_PERM_ALL
;
1757 * Check whether permissions on this node can be changed in a way that
1758 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1759 * permissions of all its parents. This involves checking whether all necessary
1760 * permission changes to child nodes can be performed.
1762 * A call to this function must always be followed by a call to bdrv_set_perm()
1763 * or bdrv_abort_perm_update().
1765 static int bdrv_check_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
1766 uint64_t cumulative_perms
,
1767 uint64_t cumulative_shared_perms
,
1768 GSList
*ignore_children
, Error
**errp
)
1770 BlockDriver
*drv
= bs
->drv
;
1774 /* Write permissions never work with read-only images */
1775 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1776 !bdrv_is_writable_after_reopen(bs
, q
))
1778 error_setg(errp
, "Block node is read-only");
1782 /* Check this node */
1787 if (drv
->bdrv_check_perm
) {
1788 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1789 cumulative_shared_perms
, errp
);
1792 /* Drivers that never have children can omit .bdrv_child_perm() */
1793 if (!drv
->bdrv_child_perm
) {
1794 assert(QLIST_EMPTY(&bs
->children
));
1798 /* Check all children */
1799 QLIST_FOREACH(c
, &bs
->children
, next
) {
1800 uint64_t cur_perm
, cur_shared
;
1801 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, q
,
1802 cumulative_perms
, cumulative_shared_perms
,
1803 &cur_perm
, &cur_shared
);
1804 ret
= bdrv_child_check_perm(c
, q
, cur_perm
, cur_shared
,
1805 ignore_children
, errp
);
1815 * Notifies drivers that after a previous bdrv_check_perm() call, the
1816 * permission update is not performed and any preparations made for it (e.g.
1817 * taken file locks) need to be undone.
1819 * This function recursively notifies all child nodes.
1821 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1823 BlockDriver
*drv
= bs
->drv
;
1830 if (drv
->bdrv_abort_perm_update
) {
1831 drv
->bdrv_abort_perm_update(bs
);
1834 QLIST_FOREACH(c
, &bs
->children
, next
) {
1835 bdrv_child_abort_perm_update(c
);
1839 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1840 uint64_t cumulative_shared_perms
)
1842 BlockDriver
*drv
= bs
->drv
;
1849 /* Update this node */
1850 if (drv
->bdrv_set_perm
) {
1851 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1854 /* Drivers that never have children can omit .bdrv_child_perm() */
1855 if (!drv
->bdrv_child_perm
) {
1856 assert(QLIST_EMPTY(&bs
->children
));
1860 /* Update all children */
1861 QLIST_FOREACH(c
, &bs
->children
, next
) {
1862 uint64_t cur_perm
, cur_shared
;
1863 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, NULL
,
1864 cumulative_perms
, cumulative_shared_perms
,
1865 &cur_perm
, &cur_shared
);
1866 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1870 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1871 uint64_t *shared_perm
)
1874 uint64_t cumulative_perms
= 0;
1875 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1877 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1878 cumulative_perms
|= c
->perm
;
1879 cumulative_shared_perms
&= c
->shared_perm
;
1882 *perm
= cumulative_perms
;
1883 *shared_perm
= cumulative_shared_perms
;
1886 static char *bdrv_child_user_desc(BdrvChild
*c
)
1888 if (c
->role
->get_parent_desc
) {
1889 return c
->role
->get_parent_desc(c
);
1892 return g_strdup("another user");
1895 char *bdrv_perm_names(uint64_t perm
)
1901 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1902 { BLK_PERM_WRITE
, "write" },
1903 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1904 { BLK_PERM_RESIZE
, "resize" },
1905 { BLK_PERM_GRAPH_MOD
, "change children" },
1909 char *result
= g_strdup("");
1910 struct perm_name
*p
;
1912 for (p
= permissions
; p
->name
; p
++) {
1913 if (perm
& p
->perm
) {
1915 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1924 * Checks whether a new reference to @bs can be added if the new user requires
1925 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1926 * set, the BdrvChild objects in this list are ignored in the calculations;
1927 * this allows checking permission updates for an existing reference.
1929 * Needs to be followed by a call to either bdrv_set_perm() or
1930 * bdrv_abort_perm_update(). */
1931 static int bdrv_check_update_perm(BlockDriverState
*bs
, BlockReopenQueue
*q
,
1932 uint64_t new_used_perm
,
1933 uint64_t new_shared_perm
,
1934 GSList
*ignore_children
, Error
**errp
)
1937 uint64_t cumulative_perms
= new_used_perm
;
1938 uint64_t cumulative_shared_perms
= new_shared_perm
;
1940 /* There is no reason why anyone couldn't tolerate write_unchanged */
1941 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1943 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1944 if (g_slist_find(ignore_children
, c
)) {
1948 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1949 char *user
= bdrv_child_user_desc(c
);
1950 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1951 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1953 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1959 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1960 char *user
= bdrv_child_user_desc(c
);
1961 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1962 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1964 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1970 cumulative_perms
|= c
->perm
;
1971 cumulative_shared_perms
&= c
->shared_perm
;
1974 return bdrv_check_perm(bs
, q
, cumulative_perms
, cumulative_shared_perms
,
1975 ignore_children
, errp
);
1978 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1979 * bdrv_child_abort_perm_update(). */
1980 static int bdrv_child_check_perm(BdrvChild
*c
, BlockReopenQueue
*q
,
1981 uint64_t perm
, uint64_t shared
,
1982 GSList
*ignore_children
, Error
**errp
)
1986 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1987 ret
= bdrv_check_update_perm(c
->bs
, q
, perm
, shared
, ignore_children
, errp
);
1988 g_slist_free(ignore_children
);
1994 if (!c
->has_backup_perm
) {
1995 c
->has_backup_perm
= true;
1996 c
->backup_perm
= c
->perm
;
1997 c
->backup_shared_perm
= c
->shared_perm
;
2000 * Note: it's OK if c->has_backup_perm was already set, as we can find the
2001 * same child twice during check_perm procedure
2005 c
->shared_perm
= shared
;
2010 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
2012 uint64_t cumulative_perms
, cumulative_shared_perms
;
2014 c
->has_backup_perm
= false;
2017 c
->shared_perm
= shared
;
2019 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
2020 &cumulative_shared_perms
);
2021 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
2024 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
2026 if (c
->has_backup_perm
) {
2027 c
->perm
= c
->backup_perm
;
2028 c
->shared_perm
= c
->backup_shared_perm
;
2029 c
->has_backup_perm
= false;
2032 bdrv_abort_perm_update(c
->bs
);
2035 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
2040 ret
= bdrv_child_check_perm(c
, NULL
, perm
, shared
, NULL
, errp
);
2042 bdrv_child_abort_perm_update(c
);
2046 bdrv_child_set_perm(c
, perm
, shared
);
2051 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
2052 const BdrvChildRole
*role
,
2053 BlockReopenQueue
*reopen_queue
,
2054 uint64_t perm
, uint64_t shared
,
2055 uint64_t *nperm
, uint64_t *nshared
)
2058 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
2059 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
2063 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
2064 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
2065 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
2066 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
2069 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
2070 const BdrvChildRole
*role
,
2071 BlockReopenQueue
*reopen_queue
,
2072 uint64_t perm
, uint64_t shared
,
2073 uint64_t *nperm
, uint64_t *nshared
)
2075 bool backing
= (role
== &child_backing
);
2076 assert(role
== &child_backing
|| role
== &child_file
);
2079 int flags
= bdrv_reopen_get_flags(reopen_queue
, bs
);
2081 /* Apart from the modifications below, the same permissions are
2082 * forwarded and left alone as for filters */
2083 bdrv_filter_default_perms(bs
, c
, role
, reopen_queue
, perm
, shared
,
2086 /* Format drivers may touch metadata even if the guest doesn't write */
2087 if (bdrv_is_writable_after_reopen(bs
, reopen_queue
)) {
2088 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2091 /* bs->file always needs to be consistent because of the metadata. We
2092 * can never allow other users to resize or write to it. */
2093 if (!(flags
& BDRV_O_NO_IO
)) {
2094 perm
|= BLK_PERM_CONSISTENT_READ
;
2096 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
2098 /* We want consistent read from backing files if the parent needs it.
2099 * No other operations are performed on backing files. */
2100 perm
&= BLK_PERM_CONSISTENT_READ
;
2102 /* If the parent can deal with changing data, we're okay with a
2103 * writable and resizable backing file. */
2104 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
2105 if (shared
& BLK_PERM_WRITE
) {
2106 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2111 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
2112 BLK_PERM_WRITE_UNCHANGED
;
2115 if (bs
->open_flags
& BDRV_O_INACTIVE
) {
2116 shared
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
2123 static void bdrv_replace_child_noperm(BdrvChild
*child
,
2124 BlockDriverState
*new_bs
)
2126 BlockDriverState
*old_bs
= child
->bs
;
2129 assert(!child
->frozen
);
2131 if (old_bs
&& new_bs
) {
2132 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
2135 /* Detach first so that the recursive drain sections coming from @child
2136 * are already gone and we only end the drain sections that came from
2138 if (child
->role
->detach
) {
2139 child
->role
->detach(child
);
2141 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
2142 int num
= old_bs
->quiesce_counter
;
2143 if (child
->role
->parent_is_bds
) {
2144 num
-= bdrv_drain_all_count
;
2147 for (i
= 0; i
< num
; i
++) {
2148 child
->role
->drained_end(child
);
2151 QLIST_REMOVE(child
, next_parent
);
2157 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
2158 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
2159 int num
= new_bs
->quiesce_counter
;
2160 if (child
->role
->parent_is_bds
) {
2161 num
-= bdrv_drain_all_count
;
2164 for (i
= 0; i
< num
; i
++) {
2165 bdrv_parent_drained_begin_single(child
, true);
2169 /* Attach only after starting new drained sections, so that recursive
2170 * drain sections coming from @child don't get an extra .drained_begin
2172 if (child
->role
->attach
) {
2173 child
->role
->attach(child
);
2179 * Updates @child to change its reference to point to @new_bs, including
2180 * checking and applying the necessary permisson updates both to the old node
2183 * NULL is passed as @new_bs for removing the reference before freeing @child.
2185 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
2186 * function uses bdrv_set_perm() to update the permissions according to the new
2187 * reference that @new_bs gets.
2189 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
2191 BlockDriverState
*old_bs
= child
->bs
;
2192 uint64_t perm
, shared_perm
;
2194 bdrv_replace_child_noperm(child
, new_bs
);
2197 /* Update permissions for old node. This is guaranteed to succeed
2198 * because we're just taking a parent away, so we're loosening
2200 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
2201 bdrv_check_perm(old_bs
, NULL
, perm
, shared_perm
, NULL
, &error_abort
);
2202 bdrv_set_perm(old_bs
, perm
, shared_perm
);
2206 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
2207 bdrv_set_perm(new_bs
, perm
, shared_perm
);
2211 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
2212 const char *child_name
,
2213 const BdrvChildRole
*child_role
,
2214 uint64_t perm
, uint64_t shared_perm
,
2215 void *opaque
, Error
**errp
)
2220 ret
= bdrv_check_update_perm(child_bs
, NULL
, perm
, shared_perm
, NULL
, errp
);
2222 bdrv_abort_perm_update(child_bs
);
2226 child
= g_new(BdrvChild
, 1);
2227 *child
= (BdrvChild
) {
2229 .name
= g_strdup(child_name
),
2232 .shared_perm
= shared_perm
,
2236 /* This performs the matching bdrv_set_perm() for the above check. */
2237 bdrv_replace_child(child
, child_bs
);
2242 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
2243 BlockDriverState
*child_bs
,
2244 const char *child_name
,
2245 const BdrvChildRole
*child_role
,
2249 uint64_t perm
, shared_perm
;
2251 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
2253 assert(parent_bs
->drv
);
2254 assert(bdrv_get_aio_context(parent_bs
) == bdrv_get_aio_context(child_bs
));
2255 bdrv_child_perm(parent_bs
, child_bs
, NULL
, child_role
, NULL
,
2256 perm
, shared_perm
, &perm
, &shared_perm
);
2258 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
2259 perm
, shared_perm
, parent_bs
, errp
);
2260 if (child
== NULL
) {
2264 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
2268 static void bdrv_detach_child(BdrvChild
*child
)
2270 if (child
->next
.le_prev
) {
2271 QLIST_REMOVE(child
, next
);
2272 child
->next
.le_prev
= NULL
;
2275 bdrv_replace_child(child
, NULL
);
2277 g_free(child
->name
);
2281 void bdrv_root_unref_child(BdrvChild
*child
)
2283 BlockDriverState
*child_bs
;
2285 child_bs
= child
->bs
;
2286 bdrv_detach_child(child
);
2287 bdrv_unref(child_bs
);
2290 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
2292 if (child
== NULL
) {
2296 if (child
->bs
->inherits_from
== parent
) {
2299 /* Remove inherits_from only when the last reference between parent and
2300 * child->bs goes away. */
2301 QLIST_FOREACH(c
, &parent
->children
, next
) {
2302 if (c
!= child
&& c
->bs
== child
->bs
) {
2307 child
->bs
->inherits_from
= NULL
;
2311 bdrv_root_unref_child(child
);
2315 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
2318 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2319 if (c
->role
->change_media
) {
2320 c
->role
->change_media(c
, load
);
2325 /* Return true if you can reach parent going through child->inherits_from
2326 * recursively. If parent or child are NULL, return false */
2327 static bool bdrv_inherits_from_recursive(BlockDriverState
*child
,
2328 BlockDriverState
*parent
)
2330 while (child
&& child
!= parent
) {
2331 child
= child
->inherits_from
;
2334 return child
!= NULL
;
2338 * Sets the backing file link of a BDS. A new reference is created; callers
2339 * which don't need their own reference any more must call bdrv_unref().
2341 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
2344 bool update_inherits_from
= bdrv_chain_contains(bs
, backing_hd
) &&
2345 bdrv_inherits_from_recursive(backing_hd
, bs
);
2347 if (bdrv_is_backing_chain_frozen(bs
, backing_bs(bs
), errp
)) {
2352 bdrv_ref(backing_hd
);
2356 bdrv_unref_child(bs
, bs
->backing
);
2364 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
2366 /* If backing_hd was already part of bs's backing chain, and
2367 * inherits_from pointed recursively to bs then let's update it to
2368 * point directly to bs (else it will become NULL). */
2369 if (update_inherits_from
) {
2370 backing_hd
->inherits_from
= bs
;
2373 bdrv_unref(backing_hd
);
2377 bdrv_refresh_limits(bs
, NULL
);
2381 * Opens the backing file for a BlockDriverState if not yet open
2383 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2384 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2385 * itself, all options starting with "${bdref_key}." are considered part of the
2388 * TODO Can this be unified with bdrv_open_image()?
2390 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
2391 const char *bdref_key
, Error
**errp
)
2393 char *backing_filename
= NULL
;
2394 char *bdref_key_dot
;
2395 const char *reference
= NULL
;
2397 bool implicit_backing
= false;
2398 BlockDriverState
*backing_hd
;
2400 QDict
*tmp_parent_options
= NULL
;
2401 Error
*local_err
= NULL
;
2403 if (bs
->backing
!= NULL
) {
2407 /* NULL means an empty set of options */
2408 if (parent_options
== NULL
) {
2409 tmp_parent_options
= qdict_new();
2410 parent_options
= tmp_parent_options
;
2413 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2415 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2416 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2417 g_free(bdref_key_dot
);
2420 * Caution: while qdict_get_try_str() is fine, getting non-string
2421 * types would require more care. When @parent_options come from
2422 * -blockdev or blockdev_add, its members are typed according to
2423 * the QAPI schema, but when they come from -drive, they're all
2426 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2427 if (reference
|| qdict_haskey(options
, "file.filename")) {
2428 /* keep backing_filename NULL */
2429 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2430 qobject_unref(options
);
2433 if (qdict_size(options
) == 0) {
2434 /* If the user specifies options that do not modify the
2435 * backing file's behavior, we might still consider it the
2436 * implicit backing file. But it's easier this way, and
2437 * just specifying some of the backing BDS's options is
2438 * only possible with -drive anyway (otherwise the QAPI
2439 * schema forces the user to specify everything). */
2440 implicit_backing
= !strcmp(bs
->auto_backing_file
, bs
->backing_file
);
2443 backing_filename
= bdrv_get_full_backing_filename(bs
, &local_err
);
2446 error_propagate(errp
, local_err
);
2447 qobject_unref(options
);
2452 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2454 error_setg(errp
, "Driver doesn't support backing files");
2455 qobject_unref(options
);
2460 bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2461 qdict_put_str(options
, "driver", bs
->backing_format
);
2464 backing_hd
= bdrv_open_inherit(backing_filename
, reference
, options
, 0, bs
,
2465 &child_backing
, errp
);
2467 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2468 error_prepend(errp
, "Could not open backing file: ");
2472 bdrv_set_aio_context(backing_hd
, bdrv_get_aio_context(bs
));
2474 if (implicit_backing
) {
2475 bdrv_refresh_filename(backing_hd
);
2476 pstrcpy(bs
->auto_backing_file
, sizeof(bs
->auto_backing_file
),
2477 backing_hd
->filename
);
2480 /* Hook up the backing file link; drop our reference, bs owns the
2481 * backing_hd reference now */
2482 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2483 bdrv_unref(backing_hd
);
2485 error_propagate(errp
, local_err
);
2490 qdict_del(parent_options
, bdref_key
);
2493 g_free(backing_filename
);
2494 qobject_unref(tmp_parent_options
);
2498 static BlockDriverState
*
2499 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2500 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2501 bool allow_none
, Error
**errp
)
2503 BlockDriverState
*bs
= NULL
;
2504 QDict
*image_options
;
2505 char *bdref_key_dot
;
2506 const char *reference
;
2508 assert(child_role
!= NULL
);
2510 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2511 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2512 g_free(bdref_key_dot
);
2515 * Caution: while qdict_get_try_str() is fine, getting non-string
2516 * types would require more care. When @options come from
2517 * -blockdev or blockdev_add, its members are typed according to
2518 * the QAPI schema, but when they come from -drive, they're all
2521 reference
= qdict_get_try_str(options
, bdref_key
);
2522 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2524 error_setg(errp
, "A block device must be specified for \"%s\"",
2527 qobject_unref(image_options
);
2531 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2532 parent
, child_role
, errp
);
2538 qdict_del(options
, bdref_key
);
2543 * Opens a disk image whose options are given as BlockdevRef in another block
2546 * If allow_none is true, no image will be opened if filename is false and no
2547 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2549 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2550 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2551 * itself, all options starting with "${bdref_key}." are considered part of the
2554 * The BlockdevRef will be removed from the options QDict.
2556 BdrvChild
*bdrv_open_child(const char *filename
,
2557 QDict
*options
, const char *bdref_key
,
2558 BlockDriverState
*parent
,
2559 const BdrvChildRole
*child_role
,
2560 bool allow_none
, Error
**errp
)
2563 BlockDriverState
*bs
;
2565 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2571 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2580 /* TODO Future callers may need to specify parent/child_role in order for
2581 * option inheritance to work. Existing callers use it for the root node. */
2582 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
)
2584 BlockDriverState
*bs
= NULL
;
2585 Error
*local_err
= NULL
;
2586 QObject
*obj
= NULL
;
2587 QDict
*qdict
= NULL
;
2588 const char *reference
= NULL
;
2591 if (ref
->type
== QTYPE_QSTRING
) {
2592 reference
= ref
->u
.reference
;
2594 BlockdevOptions
*options
= &ref
->u
.definition
;
2595 assert(ref
->type
== QTYPE_QDICT
);
2597 v
= qobject_output_visitor_new(&obj
);
2598 visit_type_BlockdevOptions(v
, NULL
, &options
, &local_err
);
2600 error_propagate(errp
, local_err
);
2603 visit_complete(v
, &obj
);
2605 qdict
= qobject_to(QDict
, obj
);
2606 qdict_flatten(qdict
);
2608 /* bdrv_open_inherit() defaults to the values in bdrv_flags (for
2609 * compatibility with other callers) rather than what we want as the
2610 * real defaults. Apply the defaults here instead. */
2611 qdict_set_default_str(qdict
, BDRV_OPT_CACHE_DIRECT
, "off");
2612 qdict_set_default_str(qdict
, BDRV_OPT_CACHE_NO_FLUSH
, "off");
2613 qdict_set_default_str(qdict
, BDRV_OPT_READ_ONLY
, "off");
2614 qdict_set_default_str(qdict
, BDRV_OPT_AUTO_READ_ONLY
, "off");
2618 bs
= bdrv_open_inherit(NULL
, reference
, qdict
, 0, NULL
, NULL
, errp
);
2627 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2629 QDict
*snapshot_options
,
2632 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2633 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2635 QemuOpts
*opts
= NULL
;
2636 BlockDriverState
*bs_snapshot
= NULL
;
2637 Error
*local_err
= NULL
;
2640 /* if snapshot, we create a temporary backing file and open it
2641 instead of opening 'filename' directly */
2643 /* Get the required size from the image */
2644 total_size
= bdrv_getlength(bs
);
2645 if (total_size
< 0) {
2646 error_setg_errno(errp
, -total_size
, "Could not get image size");
2650 /* Create the temporary image */
2651 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2653 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2657 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2659 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2660 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2661 qemu_opts_del(opts
);
2663 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2668 /* Prepare options QDict for the temporary file */
2669 qdict_put_str(snapshot_options
, "file.driver", "file");
2670 qdict_put_str(snapshot_options
, "file.filename", tmp_filename
);
2671 qdict_put_str(snapshot_options
, "driver", "qcow2");
2673 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2674 snapshot_options
= NULL
;
2679 /* bdrv_append() consumes a strong reference to bs_snapshot
2680 * (i.e. it will call bdrv_unref() on it) even on error, so in
2681 * order to be able to return one, we have to increase
2682 * bs_snapshot's refcount here */
2683 bdrv_ref(bs_snapshot
);
2684 bdrv_append(bs_snapshot
, bs
, &local_err
);
2686 error_propagate(errp
, local_err
);
2692 qobject_unref(snapshot_options
);
2693 g_free(tmp_filename
);
2698 * Opens a disk image (raw, qcow2, vmdk, ...)
2700 * options is a QDict of options to pass to the block drivers, or NULL for an
2701 * empty set of options. The reference to the QDict belongs to the block layer
2702 * after the call (even on failure), so if the caller intends to reuse the
2703 * dictionary, it needs to use qobject_ref() before calling bdrv_open.
2705 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2706 * If it is not NULL, the referenced BDS will be reused.
2708 * The reference parameter may be used to specify an existing block device which
2709 * should be opened. If specified, neither options nor a filename may be given,
2710 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2712 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2713 const char *reference
,
2714 QDict
*options
, int flags
,
2715 BlockDriverState
*parent
,
2716 const BdrvChildRole
*child_role
,
2720 BlockBackend
*file
= NULL
;
2721 BlockDriverState
*bs
;
2722 BlockDriver
*drv
= NULL
;
2724 const char *drvname
;
2725 const char *backing
;
2726 Error
*local_err
= NULL
;
2727 QDict
*snapshot_options
= NULL
;
2728 int snapshot_flags
= 0;
2730 assert(!child_role
|| !flags
);
2731 assert(!child_role
== !parent
);
2734 bool options_non_empty
= options
? qdict_size(options
) : false;
2735 qobject_unref(options
);
2737 if (filename
|| options_non_empty
) {
2738 error_setg(errp
, "Cannot reference an existing block device with "
2739 "additional options or a new filename");
2743 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2754 /* NULL means an empty set of options */
2755 if (options
== NULL
) {
2756 options
= qdict_new();
2759 /* json: syntax counts as explicit options, as if in the QDict */
2760 parse_json_protocol(options
, &filename
, &local_err
);
2765 bs
->explicit_options
= qdict_clone_shallow(options
);
2768 bs
->inherits_from
= parent
;
2769 child_role
->inherit_options(&flags
, options
,
2770 parent
->open_flags
, parent
->options
);
2773 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2779 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2780 * Caution: getting a boolean member of @options requires care.
2781 * When @options come from -blockdev or blockdev_add, members are
2782 * typed according to the QAPI schema, but when they come from
2783 * -drive, they're all QString.
2785 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2786 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2787 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2789 flags
&= ~BDRV_O_RDWR
;
2792 if (flags
& BDRV_O_SNAPSHOT
) {
2793 snapshot_options
= qdict_new();
2794 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2796 /* Let bdrv_backing_options() override "read-only" */
2797 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2798 bdrv_backing_options(&flags
, options
, flags
, options
);
2801 bs
->open_flags
= flags
;
2802 bs
->options
= options
;
2803 options
= qdict_clone_shallow(options
);
2805 /* Find the right image format driver */
2806 /* See cautionary note on accessing @options above */
2807 drvname
= qdict_get_try_str(options
, "driver");
2809 drv
= bdrv_find_format(drvname
);
2811 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2816 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2818 /* See cautionary note on accessing @options above */
2819 backing
= qdict_get_try_str(options
, "backing");
2820 if (qobject_to(QNull
, qdict_get(options
, "backing")) != NULL
||
2821 (backing
&& *backing
== '\0'))
2824 warn_report("Use of \"backing\": \"\" is deprecated; "
2825 "use \"backing\": null instead");
2827 flags
|= BDRV_O_NO_BACKING
;
2828 qdict_del(options
, "backing");
2831 /* Open image file without format layer. This BlockBackend is only used for
2832 * probing, the block drivers will do their own bdrv_open_child() for the
2833 * same BDS, which is why we put the node name back into options. */
2834 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2835 BlockDriverState
*file_bs
;
2837 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2838 &child_file
, true, &local_err
);
2842 if (file_bs
!= NULL
) {
2843 /* Not requesting BLK_PERM_CONSISTENT_READ because we're only
2844 * looking at the header to guess the image format. This works even
2845 * in cases where a guest would not see a consistent state. */
2846 file
= blk_new(0, BLK_PERM_ALL
);
2847 blk_insert_bs(file
, file_bs
, &local_err
);
2848 bdrv_unref(file_bs
);
2853 qdict_put_str(options
, "file", bdrv_get_node_name(file_bs
));
2857 /* Image format probing */
2860 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2865 * This option update would logically belong in bdrv_fill_options(),
2866 * but we first need to open bs->file for the probing to work, while
2867 * opening bs->file already requires the (mostly) final set of options
2868 * so that cache mode etc. can be inherited.
2870 * Adding the driver later is somewhat ugly, but it's not an option
2871 * that would ever be inherited, so it's correct. We just need to make
2872 * sure to update both bs->options (which has the full effective
2873 * options for bs) and options (which has file.* already removed).
2875 qdict_put_str(bs
->options
, "driver", drv
->format_name
);
2876 qdict_put_str(options
, "driver", drv
->format_name
);
2878 error_setg(errp
, "Must specify either driver or file");
2882 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2883 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2884 /* file must be NULL if a protocol BDS is about to be created
2885 * (the inverse results in an error message from bdrv_open_common()) */
2886 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2888 /* Open the image */
2889 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2899 /* If there is a backing file, use it */
2900 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2901 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2903 goto close_and_fail
;
2907 /* Remove all children options and references
2908 * from bs->options and bs->explicit_options */
2909 QLIST_FOREACH(child
, &bs
->children
, next
) {
2910 char *child_key_dot
;
2911 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2912 qdict_extract_subqdict(bs
->explicit_options
, NULL
, child_key_dot
);
2913 qdict_extract_subqdict(bs
->options
, NULL
, child_key_dot
);
2914 qdict_del(bs
->explicit_options
, child
->name
);
2915 qdict_del(bs
->options
, child
->name
);
2916 g_free(child_key_dot
);
2919 /* Check if any unknown options were used */
2920 if (qdict_size(options
) != 0) {
2921 const QDictEntry
*entry
= qdict_first(options
);
2922 if (flags
& BDRV_O_PROTOCOL
) {
2923 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2924 "'%s'", drv
->format_name
, entry
->key
);
2927 "Block format '%s' does not support the option '%s'",
2928 drv
->format_name
, entry
->key
);
2931 goto close_and_fail
;
2934 bdrv_parent_cb_change_media(bs
, true);
2936 qobject_unref(options
);
2939 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2940 * temporary snapshot afterwards. */
2941 if (snapshot_flags
) {
2942 BlockDriverState
*snapshot_bs
;
2943 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2944 snapshot_options
, &local_err
);
2945 snapshot_options
= NULL
;
2947 goto close_and_fail
;
2949 /* We are not going to return bs but the overlay on top of it
2950 * (snapshot_bs); thus, we have to drop the strong reference to bs
2951 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2952 * though, because the overlay still has a reference to it. */
2961 qobject_unref(snapshot_options
);
2962 qobject_unref(bs
->explicit_options
);
2963 qobject_unref(bs
->options
);
2964 qobject_unref(options
);
2966 bs
->explicit_options
= NULL
;
2968 error_propagate(errp
, local_err
);
2973 qobject_unref(snapshot_options
);
2974 qobject_unref(options
);
2975 error_propagate(errp
, local_err
);
2979 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2980 QDict
*options
, int flags
, Error
**errp
)
2982 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2987 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2988 * reopen of multiple devices.
2990 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2991 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2992 * be created and initialized. This newly created BlockReopenQueue should be
2993 * passed back in for subsequent calls that are intended to be of the same
2996 * bs is the BlockDriverState to add to the reopen queue.
2998 * options contains the changed options for the associated bs
2999 * (the BlockReopenQueue takes ownership)
3001 * flags contains the open flags for the associated bs
3003 * returns a pointer to bs_queue, which is either the newly allocated
3004 * bs_queue, or the existing bs_queue being used.
3006 * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
3008 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
3009 BlockDriverState
*bs
,
3011 const BdrvChildRole
*role
,
3012 QDict
*parent_options
,
3018 BlockReopenQueueEntry
*bs_entry
;
3020 QDict
*old_options
, *explicit_options
, *options_copy
;
3024 /* Make sure that the caller remembered to use a drained section. This is
3025 * important to avoid graph changes between the recursive queuing here and
3026 * bdrv_reopen_multiple(). */
3027 assert(bs
->quiesce_counter
> 0);
3029 if (bs_queue
== NULL
) {
3030 bs_queue
= g_new0(BlockReopenQueue
, 1);
3031 QSIMPLEQ_INIT(bs_queue
);
3035 options
= qdict_new();
3038 /* Check if this BlockDriverState is already in the queue */
3039 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3040 if (bs
== bs_entry
->state
.bs
) {
3046 * Precedence of options:
3047 * 1. Explicitly passed in options (highest)
3048 * 2. Retained from explicitly set options of bs
3049 * 3. Inherited from parent node
3050 * 4. Retained from effective options of bs
3053 /* Old explicitly set values (don't overwrite by inherited value) */
3054 if (bs_entry
|| keep_old_opts
) {
3055 old_options
= qdict_clone_shallow(bs_entry
?
3056 bs_entry
->state
.explicit_options
:
3057 bs
->explicit_options
);
3058 bdrv_join_options(bs
, options
, old_options
);
3059 qobject_unref(old_options
);
3062 explicit_options
= qdict_clone_shallow(options
);
3064 /* Inherit from parent node */
3065 if (parent_options
) {
3067 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
3069 flags
= bdrv_get_flags(bs
);
3072 if (keep_old_opts
) {
3073 /* Old values are used for options that aren't set yet */
3074 old_options
= qdict_clone_shallow(bs
->options
);
3075 bdrv_join_options(bs
, options
, old_options
);
3076 qobject_unref(old_options
);
3079 /* We have the final set of options so let's update the flags */
3080 options_copy
= qdict_clone_shallow(options
);
3081 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
3082 qemu_opts_absorb_qdict(opts
, options_copy
, NULL
);
3083 update_flags_from_options(&flags
, opts
);
3084 qemu_opts_del(opts
);
3085 qobject_unref(options_copy
);
3087 /* bdrv_open_inherit() sets and clears some additional flags internally */
3088 flags
&= ~BDRV_O_PROTOCOL
;
3089 if (flags
& BDRV_O_RDWR
) {
3090 flags
|= BDRV_O_ALLOW_RDWR
;
3094 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
3095 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
3097 qobject_unref(bs_entry
->state
.options
);
3098 qobject_unref(bs_entry
->state
.explicit_options
);
3101 bs_entry
->state
.bs
= bs
;
3102 bs_entry
->state
.options
= options
;
3103 bs_entry
->state
.explicit_options
= explicit_options
;
3104 bs_entry
->state
.flags
= flags
;
3106 /* This needs to be overwritten in bdrv_reopen_prepare() */
3107 bs_entry
->state
.perm
= UINT64_MAX
;
3108 bs_entry
->state
.shared_perm
= 0;
3111 * If keep_old_opts is false then it means that unspecified
3112 * options must be reset to their original value. We don't allow
3113 * resetting 'backing' but we need to know if the option is
3114 * missing in order to decide if we have to return an error.
3116 if (!keep_old_opts
) {
3117 bs_entry
->state
.backing_missing
=
3118 !qdict_haskey(options
, "backing") &&
3119 !qdict_haskey(options
, "backing.driver");
3122 QLIST_FOREACH(child
, &bs
->children
, next
) {
3123 QDict
*new_child_options
= NULL
;
3124 bool child_keep_old
= keep_old_opts
;
3126 /* reopen can only change the options of block devices that were
3127 * implicitly created and inherited options. For other (referenced)
3128 * block devices, a syntax like "backing.foo" results in an error. */
3129 if (child
->bs
->inherits_from
!= bs
) {
3133 /* Check if the options contain a child reference */
3134 if (qdict_haskey(options
, child
->name
)) {
3135 const char *childref
= qdict_get_try_str(options
, child
->name
);
3137 * The current child must not be reopened if the child
3138 * reference is null or points to a different node.
3140 if (g_strcmp0(childref
, child
->bs
->node_name
)) {
3144 * If the child reference points to the current child then
3145 * reopen it with its existing set of options (note that
3146 * it can still inherit new options from the parent).
3148 child_keep_old
= true;
3150 /* Extract child options ("child-name.*") */
3151 char *child_key_dot
= g_strdup_printf("%s.", child
->name
);
3152 qdict_extract_subqdict(explicit_options
, NULL
, child_key_dot
);
3153 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
3154 g_free(child_key_dot
);
3157 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
,
3158 child
->role
, options
, flags
, child_keep_old
);
3164 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
3165 BlockDriverState
*bs
,
3166 QDict
*options
, bool keep_old_opts
)
3168 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, NULL
, NULL
, 0,
3173 * Reopen multiple BlockDriverStates atomically & transactionally.
3175 * The queue passed in (bs_queue) must have been built up previous
3176 * via bdrv_reopen_queue().
3178 * Reopens all BDS specified in the queue, with the appropriate
3179 * flags. All devices are prepared for reopen, and failure of any
3180 * device will cause all device changes to be abandoned, and intermediate
3183 * If all devices prepare successfully, then the changes are committed
3186 * All affected nodes must be drained between bdrv_reopen_queue() and
3187 * bdrv_reopen_multiple().
3189 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
3192 BlockReopenQueueEntry
*bs_entry
, *next
;
3194 assert(bs_queue
!= NULL
);
3196 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3197 assert(bs_entry
->state
.bs
->quiesce_counter
> 0);
3198 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, errp
)) {
3201 bs_entry
->prepared
= true;
3204 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3205 BDRVReopenState
*state
= &bs_entry
->state
;
3206 ret
= bdrv_check_perm(state
->bs
, bs_queue
, state
->perm
,
3207 state
->shared_perm
, NULL
, errp
);
3211 bs_entry
->perms_checked
= true;
3214 /* If we reach this point, we have success and just need to apply the
3217 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
3218 bdrv_reopen_commit(&bs_entry
->state
);
3223 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
3224 BDRVReopenState
*state
= &bs_entry
->state
;
3226 if (!bs_entry
->perms_checked
) {
3231 bdrv_set_perm(state
->bs
, state
->perm
, state
->shared_perm
);
3233 bdrv_abort_perm_update(state
->bs
);
3237 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
3239 if (bs_entry
->prepared
) {
3240 bdrv_reopen_abort(&bs_entry
->state
);
3242 qobject_unref(bs_entry
->state
.explicit_options
);
3243 qobject_unref(bs_entry
->state
.options
);
3252 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
3256 BlockReopenQueue
*queue
;
3257 QDict
*opts
= qdict_new();
3259 qdict_put_bool(opts
, BDRV_OPT_READ_ONLY
, read_only
);
3261 bdrv_subtree_drained_begin(bs
);
3262 queue
= bdrv_reopen_queue(NULL
, bs
, opts
, true);
3263 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, errp
);
3264 bdrv_subtree_drained_end(bs
);
3269 static BlockReopenQueueEntry
*find_parent_in_reopen_queue(BlockReopenQueue
*q
,
3272 BlockReopenQueueEntry
*entry
;
3274 QSIMPLEQ_FOREACH(entry
, q
, entry
) {
3275 BlockDriverState
*bs
= entry
->state
.bs
;
3278 QLIST_FOREACH(child
, &bs
->children
, next
) {
3288 static void bdrv_reopen_perm(BlockReopenQueue
*q
, BlockDriverState
*bs
,
3289 uint64_t *perm
, uint64_t *shared
)
3292 BlockReopenQueueEntry
*parent
;
3293 uint64_t cumulative_perms
= 0;
3294 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
3296 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3297 parent
= find_parent_in_reopen_queue(q
, c
);
3299 cumulative_perms
|= c
->perm
;
3300 cumulative_shared_perms
&= c
->shared_perm
;
3302 uint64_t nperm
, nshared
;
3304 bdrv_child_perm(parent
->state
.bs
, bs
, c
, c
->role
, q
,
3305 parent
->state
.perm
, parent
->state
.shared_perm
,
3308 cumulative_perms
|= nperm
;
3309 cumulative_shared_perms
&= nshared
;
3312 *perm
= cumulative_perms
;
3313 *shared
= cumulative_shared_perms
;
3317 * Prepares a BlockDriverState for reopen. All changes are staged in the
3318 * 'opaque' field of the BDRVReopenState, which is used and allocated by
3319 * the block driver layer .bdrv_reopen_prepare()
3321 * bs is the BlockDriverState to reopen
3322 * flags are the new open flags
3323 * queue is the reopen queue
3325 * Returns 0 on success, non-zero on error. On error errp will be set
3328 * On failure, bdrv_reopen_abort() will be called to clean up any data.
3329 * It is the responsibility of the caller to then call the abort() or
3330 * commit() for any other BDS that have been left in a prepare() state
3333 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
3338 Error
*local_err
= NULL
;
3341 QDict
*orig_reopen_opts
;
3342 char *discard
= NULL
;
3344 bool drv_prepared
= false;
3346 assert(reopen_state
!= NULL
);
3347 assert(reopen_state
->bs
->drv
!= NULL
);
3348 drv
= reopen_state
->bs
->drv
;
3350 /* This function and each driver's bdrv_reopen_prepare() remove
3351 * entries from reopen_state->options as they are processed, so
3352 * we need to make a copy of the original QDict. */
3353 orig_reopen_opts
= qdict_clone_shallow(reopen_state
->options
);
3355 /* Process generic block layer options */
3356 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
3357 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
3359 error_propagate(errp
, local_err
);
3364 /* This was already called in bdrv_reopen_queue_child() so the flags
3365 * are up-to-date. This time we simply want to remove the options from
3366 * QemuOpts in order to indicate that they have been processed. */
3367 old_flags
= reopen_state
->flags
;
3368 update_flags_from_options(&reopen_state
->flags
, opts
);
3369 assert(old_flags
== reopen_state
->flags
);
3371 discard
= qemu_opt_get_del(opts
, BDRV_OPT_DISCARD
);
3372 if (discard
!= NULL
) {
3373 if (bdrv_parse_discard_flags(discard
, &reopen_state
->flags
) != 0) {
3374 error_setg(errp
, "Invalid discard option");
3380 reopen_state
->detect_zeroes
=
3381 bdrv_parse_detect_zeroes(opts
, reopen_state
->flags
, &local_err
);
3383 error_propagate(errp
, local_err
);
3388 /* All other options (including node-name and driver) must be unchanged.
3389 * Put them back into the QDict, so that they are checked at the end
3390 * of this function. */
3391 qemu_opts_to_qdict(opts
, reopen_state
->options
);
3393 /* If we are to stay read-only, do not allow permission change
3394 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
3395 * not set, or if the BDS still has copy_on_read enabled */
3396 read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3397 ret
= bdrv_can_set_read_only(reopen_state
->bs
, read_only
, true, &local_err
);
3399 error_propagate(errp
, local_err
);
3403 /* Calculate required permissions after reopening */
3404 bdrv_reopen_perm(queue
, reopen_state
->bs
,
3405 &reopen_state
->perm
, &reopen_state
->shared_perm
);
3407 ret
= bdrv_flush(reopen_state
->bs
);
3409 error_setg_errno(errp
, -ret
, "Error flushing drive");
3413 if (drv
->bdrv_reopen_prepare
) {
3414 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
3416 if (local_err
!= NULL
) {
3417 error_propagate(errp
, local_err
);
3419 bdrv_refresh_filename(reopen_state
->bs
);
3420 error_setg(errp
, "failed while preparing to reopen image '%s'",
3421 reopen_state
->bs
->filename
);
3426 /* It is currently mandatory to have a bdrv_reopen_prepare()
3427 * handler for each supported drv. */
3428 error_setg(errp
, "Block format '%s' used by node '%s' "
3429 "does not support reopening files", drv
->format_name
,
3430 bdrv_get_device_or_node_name(reopen_state
->bs
));
3435 drv_prepared
= true;
3438 * We must provide the 'backing' option if the BDS has a backing
3439 * file or if the image file has a backing file name as part of
3440 * its metadata. Otherwise the 'backing' option can be omitted.
3442 if (drv
->supports_backing
&& reopen_state
->backing_missing
&&
3443 (backing_bs(reopen_state
->bs
) || reopen_state
->bs
->backing_file
[0])) {
3444 error_setg(errp
, "backing is missing for '%s'",
3445 reopen_state
->bs
->node_name
);
3450 /* Options that are not handled are only okay if they are unchanged
3451 * compared to the old state. It is expected that some options are only
3452 * used for the initial open, but not reopen (e.g. filename) */
3453 if (qdict_size(reopen_state
->options
)) {
3454 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
3457 QObject
*new = entry
->value
;
3458 QObject
*old
= qdict_get(reopen_state
->bs
->options
, entry
->key
);
3460 /* Allow child references (child_name=node_name) as long as they
3461 * point to the current child (i.e. everything stays the same). */
3462 if (qobject_type(new) == QTYPE_QSTRING
) {
3464 QLIST_FOREACH(child
, &reopen_state
->bs
->children
, next
) {
3465 if (!strcmp(child
->name
, entry
->key
)) {
3471 const char *str
= qobject_get_try_str(new);
3472 if (!strcmp(child
->bs
->node_name
, str
)) {
3473 continue; /* Found child with this name, skip option */
3479 * TODO: When using -drive to specify blockdev options, all values
3480 * will be strings; however, when using -blockdev, blockdev-add or
3481 * filenames using the json:{} pseudo-protocol, they will be
3483 * In contrast, reopening options are (currently) always strings
3484 * (because you can only specify them through qemu-io; all other
3485 * callers do not specify any options).
3486 * Therefore, when using anything other than -drive to create a BDS,
3487 * this cannot detect non-string options as unchanged, because
3488 * qobject_is_equal() always returns false for objects of different
3489 * type. In the future, this should be remedied by correctly typing
3490 * all options. For now, this is not too big of an issue because
3491 * the user can simply omit options which cannot be changed anyway,
3492 * so they will stay unchanged.
3494 if (!qobject_is_equal(new, old
)) {
3495 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
3499 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
3504 /* Restore the original reopen_state->options QDict */
3505 qobject_unref(reopen_state
->options
);
3506 reopen_state
->options
= qobject_ref(orig_reopen_opts
);
3509 if (ret
< 0 && drv_prepared
) {
3510 /* drv->bdrv_reopen_prepare() has succeeded, so we need to
3511 * call drv->bdrv_reopen_abort() before signaling an error
3512 * (bdrv_reopen_multiple() will not call bdrv_reopen_abort()
3513 * when the respective bdrv_reopen_prepare() has failed) */
3514 if (drv
->bdrv_reopen_abort
) {
3515 drv
->bdrv_reopen_abort(reopen_state
);
3518 qemu_opts_del(opts
);
3519 qobject_unref(orig_reopen_opts
);
3525 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
3526 * makes them final by swapping the staging BlockDriverState contents into
3527 * the active BlockDriverState contents.
3529 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
3532 BlockDriverState
*bs
;
3534 bool old_can_write
, new_can_write
;
3536 assert(reopen_state
!= NULL
);
3537 bs
= reopen_state
->bs
;
3539 assert(drv
!= NULL
);
3542 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3544 /* If there are any driver level actions to take */
3545 if (drv
->bdrv_reopen_commit
) {
3546 drv
->bdrv_reopen_commit(reopen_state
);
3549 /* set BDS specific flags now */
3550 qobject_unref(bs
->explicit_options
);
3551 qobject_unref(bs
->options
);
3553 bs
->explicit_options
= reopen_state
->explicit_options
;
3554 bs
->options
= reopen_state
->options
;
3555 bs
->open_flags
= reopen_state
->flags
;
3556 bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3557 bs
->detect_zeroes
= reopen_state
->detect_zeroes
;
3559 /* Remove child references from bs->options and bs->explicit_options.
3560 * Child options were already removed in bdrv_reopen_queue_child() */
3561 QLIST_FOREACH(child
, &bs
->children
, next
) {
3562 qdict_del(bs
->explicit_options
, child
->name
);
3563 qdict_del(bs
->options
, child
->name
);
3566 bdrv_refresh_limits(bs
, NULL
);
3569 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3570 if (!old_can_write
&& new_can_write
&& drv
->bdrv_reopen_bitmaps_rw
) {
3571 Error
*local_err
= NULL
;
3572 if (drv
->bdrv_reopen_bitmaps_rw(bs
, &local_err
) < 0) {
3573 /* This is not fatal, bitmaps just left read-only, so all following
3574 * writes will fail. User can remove read-only bitmaps to unblock
3577 error_reportf_err(local_err
,
3578 "%s: Failed to make dirty bitmaps writable: ",
3579 bdrv_get_node_name(bs
));
3585 * Abort the reopen, and delete and free the staged changes in
3588 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
3592 assert(reopen_state
!= NULL
);
3593 drv
= reopen_state
->bs
->drv
;
3594 assert(drv
!= NULL
);
3596 if (drv
->bdrv_reopen_abort
) {
3597 drv
->bdrv_reopen_abort(reopen_state
);
3602 static void bdrv_close(BlockDriverState
*bs
)
3604 BdrvAioNotifier
*ban
, *ban_next
;
3605 BdrvChild
*child
, *next
;
3608 assert(!bs
->refcnt
);
3610 bdrv_drained_begin(bs
); /* complete I/O */
3612 bdrv_drain(bs
); /* in case flush left pending I/O */
3615 if (bs
->drv
->bdrv_close
) {
3616 bs
->drv
->bdrv_close(bs
);
3621 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
3623 if (bs
->file
!= NULL
) {
3624 bdrv_unref_child(bs
, bs
->file
);
3628 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
3629 /* TODO Remove bdrv_unref() from drivers' close function and use
3630 * bdrv_unref_child() here */
3631 if (child
->bs
->inherits_from
== bs
) {
3632 child
->bs
->inherits_from
= NULL
;
3634 bdrv_detach_child(child
);
3639 atomic_set(&bs
->copy_on_read
, 0);
3640 bs
->backing_file
[0] = '\0';
3641 bs
->backing_format
[0] = '\0';
3642 bs
->total_sectors
= 0;
3643 bs
->encrypted
= false;
3645 qobject_unref(bs
->options
);
3646 qobject_unref(bs
->explicit_options
);
3648 bs
->explicit_options
= NULL
;
3649 qobject_unref(bs
->full_open_options
);
3650 bs
->full_open_options
= NULL
;
3652 bdrv_release_named_dirty_bitmaps(bs
);
3653 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
3655 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3658 QLIST_INIT(&bs
->aio_notifiers
);
3659 bdrv_drained_end(bs
);
3662 void bdrv_close_all(void)
3664 assert(job_next(NULL
) == NULL
);
3665 nbd_export_close_all();
3667 /* Drop references from requests still in flight, such as canceled block
3668 * jobs whose AIO context has not been polled yet */
3671 blk_remove_all_bs();
3672 blockdev_close_all_bdrv_states();
3674 assert(QTAILQ_EMPTY(&all_bdrv_states
));
3677 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
3683 if (c
->role
->stay_at_node
) {
3687 /* If the child @c belongs to the BDS @to, replacing the current
3688 * c->bs by @to would mean to create a loop.
3690 * Such a case occurs when appending a BDS to a backing chain.
3691 * For instance, imagine the following chain:
3693 * guest device -> node A -> further backing chain...
3695 * Now we create a new BDS B which we want to put on top of this
3696 * chain, so we first attach A as its backing node:
3701 * guest device -> node A -> further backing chain...
3703 * Finally we want to replace A by B. When doing that, we want to
3704 * replace all pointers to A by pointers to B -- except for the
3705 * pointer from B because (1) that would create a loop, and (2)
3706 * that pointer should simply stay intact:
3708 * guest device -> node B
3711 * node A -> further backing chain...
3713 * In general, when replacing a node A (c->bs) by a node B (@to),
3714 * if A is a child of B, that means we cannot replace A by B there
3715 * because that would create a loop. Silently detaching A from B
3716 * is also not really an option. So overall just leaving A in
3717 * place there is the most sensible choice.
3719 * We would also create a loop in any cases where @c is only
3720 * indirectly referenced by @to. Prevent this by returning false
3721 * if @c is found (by breadth-first search) anywhere in the whole
3726 found
= g_hash_table_new(NULL
, NULL
);
3727 g_hash_table_add(found
, to
);
3728 queue
= g_queue_new();
3729 g_queue_push_tail(queue
, to
);
3731 while (!g_queue_is_empty(queue
)) {
3732 BlockDriverState
*v
= g_queue_pop_head(queue
);
3735 QLIST_FOREACH(c2
, &v
->children
, next
) {
3741 if (g_hash_table_contains(found
, c2
->bs
)) {
3745 g_queue_push_tail(queue
, c2
->bs
);
3746 g_hash_table_add(found
, c2
->bs
);
3750 g_queue_free(queue
);
3751 g_hash_table_destroy(found
);
3756 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
3759 BdrvChild
*c
, *next
;
3760 GSList
*list
= NULL
, *p
;
3761 uint64_t old_perm
, old_shared
;
3762 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
3765 assert(!atomic_read(&from
->in_flight
));
3766 assert(!atomic_read(&to
->in_flight
));
3768 /* Make sure that @from doesn't go away until we have successfully attached
3769 * all of its parents to @to. */
3772 /* Put all parents into @list and calculate their cumulative permissions */
3773 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
3774 assert(c
->bs
== from
);
3775 if (!should_update_child(c
, to
)) {
3779 error_setg(errp
, "Cannot change '%s' link to '%s'",
3780 c
->name
, from
->node_name
);
3783 list
= g_slist_prepend(list
, c
);
3785 shared
&= c
->shared_perm
;
3788 /* Check whether the required permissions can be granted on @to, ignoring
3789 * all BdrvChild in @list so that they can't block themselves. */
3790 ret
= bdrv_check_update_perm(to
, NULL
, perm
, shared
, list
, errp
);
3792 bdrv_abort_perm_update(to
);
3796 /* Now actually perform the change. We performed the permission check for
3797 * all elements of @list at once, so set the permissions all at once at the
3799 for (p
= list
; p
!= NULL
; p
= p
->next
) {
3803 bdrv_replace_child_noperm(c
, to
);
3807 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3808 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3816 * Add new bs contents at the top of an image chain while the chain is
3817 * live, while keeping required fields on the top layer.
3819 * This will modify the BlockDriverState fields, and swap contents
3820 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3822 * bs_new must not be attached to a BlockBackend.
3824 * This function does not create any image files.
3826 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3827 * that's what the callers commonly need. bs_new will be referenced by the old
3828 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3829 * reference of its own, it must call bdrv_ref().
3831 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3834 Error
*local_err
= NULL
;
3836 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3838 error_propagate(errp
, local_err
);
3842 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3844 error_propagate(errp
, local_err
);
3845 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3849 /* bs_new is now referenced by its new parents, we don't need the
3850 * additional reference any more. */
3855 static void bdrv_delete(BlockDriverState
*bs
)
3858 assert(bdrv_op_blocker_is_empty(bs
));
3859 assert(!bs
->refcnt
);
3863 /* remove from list, if necessary */
3864 if (bs
->node_name
[0] != '\0') {
3865 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3867 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3873 * Run consistency checks on an image
3875 * Returns 0 if the check could be completed (it doesn't mean that the image is
3876 * free of errors) or -errno when an internal error occurred. The results of the
3877 * check are stored in res.
3879 static int coroutine_fn
bdrv_co_check(BlockDriverState
*bs
,
3880 BdrvCheckResult
*res
, BdrvCheckMode fix
)
3882 if (bs
->drv
== NULL
) {
3885 if (bs
->drv
->bdrv_co_check
== NULL
) {
3889 memset(res
, 0, sizeof(*res
));
3890 return bs
->drv
->bdrv_co_check(bs
, res
, fix
);
3893 typedef struct CheckCo
{
3894 BlockDriverState
*bs
;
3895 BdrvCheckResult
*res
;
3900 static void bdrv_check_co_entry(void *opaque
)
3902 CheckCo
*cco
= opaque
;
3903 cco
->ret
= bdrv_co_check(cco
->bs
, cco
->res
, cco
->fix
);
3907 int bdrv_check(BlockDriverState
*bs
,
3908 BdrvCheckResult
*res
, BdrvCheckMode fix
)
3914 .ret
= -EINPROGRESS
,
3918 if (qemu_in_coroutine()) {
3919 /* Fast-path if already in coroutine context */
3920 bdrv_check_co_entry(&cco
);
3922 co
= qemu_coroutine_create(bdrv_check_co_entry
, &cco
);
3923 bdrv_coroutine_enter(bs
, co
);
3924 BDRV_POLL_WHILE(bs
, cco
.ret
== -EINPROGRESS
);
3933 * -EINVAL - backing format specified, but no file
3934 * -ENOSPC - can't update the backing file because no space is left in the
3936 * -ENOTSUP - format driver doesn't support changing the backing file
3938 int bdrv_change_backing_file(BlockDriverState
*bs
,
3939 const char *backing_file
, const char *backing_fmt
)
3941 BlockDriver
*drv
= bs
->drv
;
3948 /* Backing file format doesn't make sense without a backing file */
3949 if (backing_fmt
&& !backing_file
) {
3953 if (drv
->bdrv_change_backing_file
!= NULL
) {
3954 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3960 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3961 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3962 pstrcpy(bs
->auto_backing_file
, sizeof(bs
->auto_backing_file
),
3963 backing_file
?: "");
3969 * Finds the image layer in the chain that has 'bs' as its backing file.
3971 * active is the current topmost image.
3973 * Returns NULL if bs is not found in active's image chain,
3974 * or if active == bs.
3976 * Returns the bottommost base image if bs == NULL.
3978 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3979 BlockDriverState
*bs
)
3981 while (active
&& bs
!= backing_bs(active
)) {
3982 active
= backing_bs(active
);
3988 /* Given a BDS, searches for the base layer. */
3989 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3991 return bdrv_find_overlay(bs
, NULL
);
3995 * Return true if at least one of the backing links between @bs and
3996 * @base is frozen. @errp is set if that's the case.
3998 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
4001 BlockDriverState
*i
;
4003 for (i
= bs
; i
!= base
&& i
->backing
; i
= backing_bs(i
)) {
4004 if (i
->backing
->frozen
) {
4005 error_setg(errp
, "Cannot change '%s' link from '%s' to '%s'",
4006 i
->backing
->name
, i
->node_name
,
4007 backing_bs(i
)->node_name
);
4016 * Freeze all backing links between @bs and @base.
4017 * If any of the links is already frozen the operation is aborted and
4018 * none of the links are modified.
4019 * Returns 0 on success. On failure returns < 0 and sets @errp.
4021 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
4024 BlockDriverState
*i
;
4026 if (bdrv_is_backing_chain_frozen(bs
, base
, errp
)) {
4030 for (i
= bs
; i
!= base
&& i
->backing
; i
= backing_bs(i
)) {
4031 i
->backing
->frozen
= true;
4038 * Unfreeze all backing links between @bs and @base. The caller must
4039 * ensure that all links are frozen before using this function.
4041 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
)
4043 BlockDriverState
*i
;
4045 for (i
= bs
; i
!= base
&& i
->backing
; i
= backing_bs(i
)) {
4046 assert(i
->backing
->frozen
);
4047 i
->backing
->frozen
= false;
4052 * Drops images above 'base' up to and including 'top', and sets the image
4053 * above 'top' to have base as its backing file.
4055 * Requires that the overlay to 'top' is opened r/w, so that the backing file
4056 * information in 'bs' can be properly updated.
4058 * E.g., this will convert the following chain:
4059 * bottom <- base <- intermediate <- top <- active
4063 * bottom <- base <- active
4065 * It is allowed for bottom==base, in which case it converts:
4067 * base <- intermediate <- top <- active
4073 * If backing_file_str is non-NULL, it will be used when modifying top's
4074 * overlay image metadata.
4077 * if active == top, that is considered an error
4080 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
4081 const char *backing_file_str
)
4083 BlockDriverState
*explicit_top
= top
;
4084 bool update_inherits_from
;
4085 BdrvChild
*c
, *next
;
4086 Error
*local_err
= NULL
;
4091 if (!top
->drv
|| !base
->drv
) {
4095 /* Make sure that base is in the backing chain of top */
4096 if (!bdrv_chain_contains(top
, base
)) {
4100 /* This function changes all links that point to top and makes
4101 * them point to base. Check that none of them is frozen. */
4102 QLIST_FOREACH(c
, &top
->parents
, next_parent
) {
4108 /* If 'base' recursively inherits from 'top' then we should set
4109 * base->inherits_from to top->inherits_from after 'top' and all
4110 * other intermediate nodes have been dropped.
4111 * If 'top' is an implicit node (e.g. "commit_top") we should skip
4112 * it because no one inherits from it. We use explicit_top for that. */
4113 while (explicit_top
&& explicit_top
->implicit
) {
4114 explicit_top
= backing_bs(explicit_top
);
4116 update_inherits_from
= bdrv_inherits_from_recursive(base
, explicit_top
);
4118 /* success - we can delete the intermediate states, and link top->base */
4119 /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
4120 * we've figured out how they should work. */
4121 if (!backing_file_str
) {
4122 bdrv_refresh_filename(base
);
4123 backing_file_str
= base
->filename
;
4126 QLIST_FOREACH_SAFE(c
, &top
->parents
, next_parent
, next
) {
4127 /* Check whether we are allowed to switch c from top to base */
4128 GSList
*ignore_children
= g_slist_prepend(NULL
, c
);
4129 bdrv_check_update_perm(base
, NULL
, c
->perm
, c
->shared_perm
,
4130 ignore_children
, &local_err
);
4131 g_slist_free(ignore_children
);
4134 error_report_err(local_err
);
4138 /* If so, update the backing file path in the image file */
4139 if (c
->role
->update_filename
) {
4140 ret
= c
->role
->update_filename(c
, base
, backing_file_str
,
4143 bdrv_abort_perm_update(base
);
4144 error_report_err(local_err
);
4149 /* Do the actual switch in the in-memory graph.
4150 * Completes bdrv_check_update_perm() transaction internally. */
4152 bdrv_replace_child(c
, base
);
4156 if (update_inherits_from
) {
4157 base
->inherits_from
= explicit_top
->inherits_from
;
4167 * Length of a allocated file in bytes. Sparse files are counted by actual
4168 * allocated space. Return < 0 if error or unknown.
4170 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
4172 BlockDriver
*drv
= bs
->drv
;
4176 if (drv
->bdrv_get_allocated_file_size
) {
4177 return drv
->bdrv_get_allocated_file_size(bs
);
4180 return bdrv_get_allocated_file_size(bs
->file
->bs
);
4187 * @drv: Format driver
4188 * @opts: Creation options for new image
4189 * @in_bs: Existing image containing data for new image (may be NULL)
4190 * @errp: Error object
4191 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
4194 * Calculate file size required to create a new image.
4196 * If @in_bs is given then space for allocated clusters and zero clusters
4197 * from that image are included in the calculation. If @opts contains a
4198 * backing file that is shared by @in_bs then backing clusters may be omitted
4199 * from the calculation.
4201 * If @in_bs is NULL then the calculation includes no allocated clusters
4202 * unless a preallocation option is given in @opts.
4204 * Note that @in_bs may use a different BlockDriver from @drv.
4206 * If an error occurs the @errp pointer is set.
4208 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
4209 BlockDriverState
*in_bs
, Error
**errp
)
4211 if (!drv
->bdrv_measure
) {
4212 error_setg(errp
, "Block driver '%s' does not support size measurement",
4217 return drv
->bdrv_measure(opts
, in_bs
, errp
);
4221 * Return number of sectors on success, -errno on error.
4223 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
4225 BlockDriver
*drv
= bs
->drv
;
4230 if (drv
->has_variable_length
) {
4231 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
4236 return bs
->total_sectors
;
4240 * Return length in bytes on success, -errno on error.
4241 * The length is always a multiple of BDRV_SECTOR_SIZE.
4243 int64_t bdrv_getlength(BlockDriverState
*bs
)
4245 int64_t ret
= bdrv_nb_sectors(bs
);
4247 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
4248 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
4251 /* return 0 as number of sectors if no device present or error */
4252 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
4254 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
4256 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
4259 bool bdrv_is_sg(BlockDriverState
*bs
)
4264 bool bdrv_is_encrypted(BlockDriverState
*bs
)
4266 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
4269 return bs
->encrypted
;
4272 const char *bdrv_get_format_name(BlockDriverState
*bs
)
4274 return bs
->drv
? bs
->drv
->format_name
: NULL
;
4277 static int qsort_strcmp(const void *a
, const void *b
)
4279 return strcmp(*(char *const *)a
, *(char *const *)b
);
4282 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
4283 void *opaque
, bool read_only
)
4288 const char **formats
= NULL
;
4290 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
4291 if (drv
->format_name
) {
4295 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, read_only
)) {
4299 while (formats
&& i
&& !found
) {
4300 found
= !strcmp(formats
[--i
], drv
->format_name
);
4304 formats
= g_renew(const char *, formats
, count
+ 1);
4305 formats
[count
++] = drv
->format_name
;
4310 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
4311 const char *format_name
= block_driver_modules
[i
].format_name
;
4317 if (use_bdrv_whitelist
&&
4318 !bdrv_format_is_whitelisted(format_name
, read_only
)) {
4322 while (formats
&& j
&& !found
) {
4323 found
= !strcmp(formats
[--j
], format_name
);
4327 formats
= g_renew(const char *, formats
, count
+ 1);
4328 formats
[count
++] = format_name
;
4333 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
4335 for (i
= 0; i
< count
; i
++) {
4336 it(opaque
, formats
[i
]);
4342 /* This function is to find a node in the bs graph */
4343 BlockDriverState
*bdrv_find_node(const char *node_name
)
4345 BlockDriverState
*bs
;
4349 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4350 if (!strcmp(node_name
, bs
->node_name
)) {
4357 /* Put this QMP function here so it can access the static graph_bdrv_states. */
4358 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
4360 BlockDeviceInfoList
*list
, *entry
;
4361 BlockDriverState
*bs
;
4364 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4365 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
4367 qapi_free_BlockDeviceInfoList(list
);
4370 entry
= g_malloc0(sizeof(*entry
));
4371 entry
->value
= info
;
4379 #define QAPI_LIST_ADD(list, element) do { \
4380 typeof(list) _tmp = g_new(typeof(*(list)), 1); \
4381 _tmp->value = (element); \
4382 _tmp->next = (list); \
4386 typedef struct XDbgBlockGraphConstructor
{
4387 XDbgBlockGraph
*graph
;
4388 GHashTable
*graph_nodes
;
4389 } XDbgBlockGraphConstructor
;
4391 static XDbgBlockGraphConstructor
*xdbg_graph_new(void)
4393 XDbgBlockGraphConstructor
*gr
= g_new(XDbgBlockGraphConstructor
, 1);
4395 gr
->graph
= g_new0(XDbgBlockGraph
, 1);
4396 gr
->graph_nodes
= g_hash_table_new(NULL
, NULL
);
4401 static XDbgBlockGraph
*xdbg_graph_finalize(XDbgBlockGraphConstructor
*gr
)
4403 XDbgBlockGraph
*graph
= gr
->graph
;
4405 g_hash_table_destroy(gr
->graph_nodes
);
4411 static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor
*gr
, void *node
)
4413 uintptr_t ret
= (uintptr_t)g_hash_table_lookup(gr
->graph_nodes
, node
);
4420 * Start counting from 1, not 0, because 0 interferes with not-found (NULL)
4421 * answer of g_hash_table_lookup.
4423 ret
= g_hash_table_size(gr
->graph_nodes
) + 1;
4424 g_hash_table_insert(gr
->graph_nodes
, node
, (void *)ret
);
4429 static void xdbg_graph_add_node(XDbgBlockGraphConstructor
*gr
, void *node
,
4430 XDbgBlockGraphNodeType type
, const char *name
)
4432 XDbgBlockGraphNode
*n
;
4434 n
= g_new0(XDbgBlockGraphNode
, 1);
4436 n
->id
= xdbg_graph_node_num(gr
, node
);
4438 n
->name
= g_strdup(name
);
4440 QAPI_LIST_ADD(gr
->graph
->nodes
, n
);
4443 static void xdbg_graph_add_edge(XDbgBlockGraphConstructor
*gr
, void *parent
,
4444 const BdrvChild
*child
)
4448 BlockPermission num
;
4451 static const PermissionMap permissions
[] = {
4452 { BLK_PERM_CONSISTENT_READ
, BLOCK_PERMISSION_CONSISTENT_READ
},
4453 { BLK_PERM_WRITE
, BLOCK_PERMISSION_WRITE
},
4454 { BLK_PERM_WRITE_UNCHANGED
, BLOCK_PERMISSION_WRITE_UNCHANGED
},
4455 { BLK_PERM_RESIZE
, BLOCK_PERMISSION_RESIZE
},
4456 { BLK_PERM_GRAPH_MOD
, BLOCK_PERMISSION_GRAPH_MOD
},
4459 const PermissionMap
*p
;
4460 XDbgBlockGraphEdge
*edge
;
4462 QEMU_BUILD_BUG_ON(1UL << (ARRAY_SIZE(permissions
) - 1) != BLK_PERM_ALL
+ 1);
4464 edge
= g_new0(XDbgBlockGraphEdge
, 1);
4466 edge
->parent
= xdbg_graph_node_num(gr
, parent
);
4467 edge
->child
= xdbg_graph_node_num(gr
, child
->bs
);
4468 edge
->name
= g_strdup(child
->name
);
4470 for (p
= permissions
; p
->flag
; p
++) {
4471 if (p
->flag
& child
->perm
) {
4472 QAPI_LIST_ADD(edge
->perm
, p
->num
);
4474 if (p
->flag
& child
->shared_perm
) {
4475 QAPI_LIST_ADD(edge
->shared_perm
, p
->num
);
4479 QAPI_LIST_ADD(gr
->graph
->edges
, edge
);
4483 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
)
4487 BlockDriverState
*bs
;
4489 XDbgBlockGraphConstructor
*gr
= xdbg_graph_new();
4491 for (blk
= blk_all_next(NULL
); blk
; blk
= blk_all_next(blk
)) {
4492 char *allocated_name
= NULL
;
4493 const char *name
= blk_name(blk
);
4496 name
= allocated_name
= blk_get_attached_dev_id(blk
);
4498 xdbg_graph_add_node(gr
, blk
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND
,
4500 g_free(allocated_name
);
4501 if (blk_root(blk
)) {
4502 xdbg_graph_add_edge(gr
, blk
, blk_root(blk
));
4506 for (job
= block_job_next(NULL
); job
; job
= block_job_next(job
)) {
4509 xdbg_graph_add_node(gr
, job
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB
,
4511 for (el
= job
->nodes
; el
; el
= el
->next
) {
4512 xdbg_graph_add_edge(gr
, job
, (BdrvChild
*)el
->data
);
4516 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
4517 xdbg_graph_add_node(gr
, bs
, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER
,
4519 QLIST_FOREACH(child
, &bs
->children
, next
) {
4520 xdbg_graph_add_edge(gr
, bs
, child
);
4524 return xdbg_graph_finalize(gr
);
4527 BlockDriverState
*bdrv_lookup_bs(const char *device
,
4528 const char *node_name
,
4532 BlockDriverState
*bs
;
4535 blk
= blk_by_name(device
);
4540 error_setg(errp
, "Device '%s' has no medium", device
);
4548 bs
= bdrv_find_node(node_name
);
4555 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
4556 device
? device
: "",
4557 node_name
? node_name
: "");
4561 /* If 'base' is in the same chain as 'top', return true. Otherwise,
4562 * return false. If either argument is NULL, return false. */
4563 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
4565 while (top
&& top
!= base
) {
4566 top
= backing_bs(top
);
4572 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
4575 return QTAILQ_FIRST(&graph_bdrv_states
);
4577 return QTAILQ_NEXT(bs
, node_list
);
4580 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
)
4583 return QTAILQ_FIRST(&all_bdrv_states
);
4585 return QTAILQ_NEXT(bs
, bs_list
);
4588 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
4590 return bs
->node_name
;
4593 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
4598 /* If multiple parents have a name, just pick the first one. */
4599 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
4600 if (c
->role
->get_name
) {
4601 name
= c
->role
->get_name(c
);
4602 if (name
&& *name
) {
4611 /* TODO check what callers really want: bs->node_name or blk_name() */
4612 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
4614 return bdrv_get_parent_name(bs
) ?: "";
4617 /* This can be used to identify nodes that might not have a device
4618 * name associated. Since node and device names live in the same
4619 * namespace, the result is unambiguous. The exception is if both are
4620 * absent, then this returns an empty (non-null) string. */
4621 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
4623 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
4626 int bdrv_get_flags(BlockDriverState
*bs
)
4628 return bs
->open_flags
;
4631 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
4636 int bdrv_has_zero_init(BlockDriverState
*bs
)
4642 /* If BS is a copy on write image, it is initialized to
4643 the contents of the base image, which may not be zeroes. */
4647 if (bs
->drv
->bdrv_has_zero_init
) {
4648 return bs
->drv
->bdrv_has_zero_init(bs
);
4650 if (bs
->file
&& bs
->drv
->is_filter
) {
4651 return bdrv_has_zero_init(bs
->file
->bs
);
4658 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
4660 BlockDriverInfo bdi
;
4666 if (bdrv_get_info(bs
, &bdi
) == 0) {
4667 return bdi
.unallocated_blocks_are_zero
;
4673 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
4675 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
4679 return bs
->supported_zero_flags
& BDRV_REQ_MAY_UNMAP
;
4682 void bdrv_get_backing_filename(BlockDriverState
*bs
,
4683 char *filename
, int filename_size
)
4685 pstrcpy(filename
, filename_size
, bs
->backing_file
);
4688 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
4690 BlockDriver
*drv
= bs
->drv
;
4691 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
4695 if (!drv
->bdrv_get_info
) {
4696 if (bs
->file
&& drv
->is_filter
) {
4697 return bdrv_get_info(bs
->file
->bs
, bdi
);
4701 memset(bdi
, 0, sizeof(*bdi
));
4702 return drv
->bdrv_get_info(bs
, bdi
);
4705 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
4708 BlockDriver
*drv
= bs
->drv
;
4709 if (drv
&& drv
->bdrv_get_specific_info
) {
4710 return drv
->bdrv_get_specific_info(bs
, errp
);
4715 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
4717 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
4721 bs
->drv
->bdrv_debug_event(bs
, event
);
4724 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
4727 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
4728 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4731 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
4732 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
4738 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
4740 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
4741 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4744 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
4745 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
4751 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
4753 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
4754 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4757 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
4758 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
4764 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
4766 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
4767 bs
= bs
->file
? bs
->file
->bs
: NULL
;
4770 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
4771 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
4777 /* backing_file can either be relative, or absolute, or a protocol. If it is
4778 * relative, it must be relative to the chain. So, passing in bs->filename
4779 * from a BDS as backing_file should not be done, as that may be relative to
4780 * the CWD rather than the chain. */
4781 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
4782 const char *backing_file
)
4784 char *filename_full
= NULL
;
4785 char *backing_file_full
= NULL
;
4786 char *filename_tmp
= NULL
;
4787 int is_protocol
= 0;
4788 BlockDriverState
*curr_bs
= NULL
;
4789 BlockDriverState
*retval
= NULL
;
4791 if (!bs
|| !bs
->drv
|| !backing_file
) {
4795 filename_full
= g_malloc(PATH_MAX
);
4796 backing_file_full
= g_malloc(PATH_MAX
);
4798 is_protocol
= path_has_protocol(backing_file
);
4800 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
4802 /* If either of the filename paths is actually a protocol, then
4803 * compare unmodified paths; otherwise make paths relative */
4804 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
4805 char *backing_file_full_ret
;
4807 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
4808 retval
= curr_bs
->backing
->bs
;
4811 /* Also check against the full backing filename for the image */
4812 backing_file_full_ret
= bdrv_get_full_backing_filename(curr_bs
,
4814 if (backing_file_full_ret
) {
4815 bool equal
= strcmp(backing_file
, backing_file_full_ret
) == 0;
4816 g_free(backing_file_full_ret
);
4818 retval
= curr_bs
->backing
->bs
;
4823 /* If not an absolute filename path, make it relative to the current
4824 * image's filename path */
4825 filename_tmp
= bdrv_make_absolute_filename(curr_bs
, backing_file
,
4827 /* We are going to compare canonicalized absolute pathnames */
4828 if (!filename_tmp
|| !realpath(filename_tmp
, filename_full
)) {
4829 g_free(filename_tmp
);
4832 g_free(filename_tmp
);
4834 /* We need to make sure the backing filename we are comparing against
4835 * is relative to the current image filename (or absolute) */
4836 filename_tmp
= bdrv_get_full_backing_filename(curr_bs
, NULL
);
4837 if (!filename_tmp
|| !realpath(filename_tmp
, backing_file_full
)) {
4838 g_free(filename_tmp
);
4841 g_free(filename_tmp
);
4843 if (strcmp(backing_file_full
, filename_full
) == 0) {
4844 retval
= curr_bs
->backing
->bs
;
4850 g_free(filename_full
);
4851 g_free(backing_file_full
);
4855 void bdrv_init(void)
4857 module_call_init(MODULE_INIT_BLOCK
);
4860 void bdrv_init_with_whitelist(void)
4862 use_bdrv_whitelist
= 1;
4866 static void coroutine_fn
bdrv_co_invalidate_cache(BlockDriverState
*bs
,
4869 BdrvChild
*child
, *parent
;
4870 uint64_t perm
, shared_perm
;
4871 Error
*local_err
= NULL
;
4873 BdrvDirtyBitmap
*bm
;
4879 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
4883 QLIST_FOREACH(child
, &bs
->children
, next
) {
4884 bdrv_co_invalidate_cache(child
->bs
, &local_err
);
4886 error_propagate(errp
, local_err
);
4892 * Update permissions, they may differ for inactive nodes.
4894 * Note that the required permissions of inactive images are always a
4895 * subset of the permissions required after activating the image. This
4896 * allows us to just get the permissions upfront without restricting
4897 * drv->bdrv_invalidate_cache().
4899 * It also means that in error cases, we don't have to try and revert to
4900 * the old permissions (which is an operation that could fail, too). We can
4901 * just keep the extended permissions for the next time that an activation
4902 * of the image is tried.
4904 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
4905 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
4906 ret
= bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
, &local_err
);
4908 bs
->open_flags
|= BDRV_O_INACTIVE
;
4909 error_propagate(errp
, local_err
);
4912 bdrv_set_perm(bs
, perm
, shared_perm
);
4914 if (bs
->drv
->bdrv_co_invalidate_cache
) {
4915 bs
->drv
->bdrv_co_invalidate_cache(bs
, &local_err
);
4917 bs
->open_flags
|= BDRV_O_INACTIVE
;
4918 error_propagate(errp
, local_err
);
4923 for (bm
= bdrv_dirty_bitmap_next(bs
, NULL
); bm
;
4924 bm
= bdrv_dirty_bitmap_next(bs
, bm
))
4926 bdrv_dirty_bitmap_set_migration(bm
, false);
4929 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
4931 bs
->open_flags
|= BDRV_O_INACTIVE
;
4932 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
4936 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4937 if (parent
->role
->activate
) {
4938 parent
->role
->activate(parent
, &local_err
);
4940 bs
->open_flags
|= BDRV_O_INACTIVE
;
4941 error_propagate(errp
, local_err
);
4948 typedef struct InvalidateCacheCo
{
4949 BlockDriverState
*bs
;
4952 } InvalidateCacheCo
;
4954 static void coroutine_fn
bdrv_invalidate_cache_co_entry(void *opaque
)
4956 InvalidateCacheCo
*ico
= opaque
;
4957 bdrv_co_invalidate_cache(ico
->bs
, ico
->errp
);
4962 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
4965 InvalidateCacheCo ico
= {
4971 if (qemu_in_coroutine()) {
4972 /* Fast-path if already in coroutine context */
4973 bdrv_invalidate_cache_co_entry(&ico
);
4975 co
= qemu_coroutine_create(bdrv_invalidate_cache_co_entry
, &ico
);
4976 bdrv_coroutine_enter(bs
, co
);
4977 BDRV_POLL_WHILE(bs
, !ico
.done
);
4981 void bdrv_invalidate_cache_all(Error
**errp
)
4983 BlockDriverState
*bs
;
4984 Error
*local_err
= NULL
;
4985 BdrvNextIterator it
;
4987 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4988 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
4990 aio_context_acquire(aio_context
);
4991 bdrv_invalidate_cache(bs
, &local_err
);
4992 aio_context_release(aio_context
);
4994 error_propagate(errp
, local_err
);
4995 bdrv_next_cleanup(&it
);
5001 static bool bdrv_has_bds_parent(BlockDriverState
*bs
, bool only_active
)
5005 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
5006 if (parent
->role
->parent_is_bds
) {
5007 BlockDriverState
*parent_bs
= parent
->opaque
;
5008 if (!only_active
|| !(parent_bs
->open_flags
& BDRV_O_INACTIVE
)) {
5017 static int bdrv_inactivate_recurse(BlockDriverState
*bs
)
5019 BdrvChild
*child
, *parent
;
5020 uint64_t perm
, shared_perm
;
5027 /* Make sure that we don't inactivate a child before its parent.
5028 * It will be covered by recursion from the yet active parent. */
5029 if (bdrv_has_bds_parent(bs
, true)) {
5033 assert(!(bs
->open_flags
& BDRV_O_INACTIVE
));
5035 /* Inactivate this node */
5036 if (bs
->drv
->bdrv_inactivate
) {
5037 ret
= bs
->drv
->bdrv_inactivate(bs
);
5043 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
5044 if (parent
->role
->inactivate
) {
5045 ret
= parent
->role
->inactivate(parent
);
5052 bs
->open_flags
|= BDRV_O_INACTIVE
;
5054 /* Update permissions, they may differ for inactive nodes */
5055 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
5056 bdrv_check_perm(bs
, NULL
, perm
, shared_perm
, NULL
, &error_abort
);
5057 bdrv_set_perm(bs
, perm
, shared_perm
);
5060 /* Recursively inactivate children */
5061 QLIST_FOREACH(child
, &bs
->children
, next
) {
5062 ret
= bdrv_inactivate_recurse(child
->bs
);
5071 int bdrv_inactivate_all(void)
5073 BlockDriverState
*bs
= NULL
;
5074 BdrvNextIterator it
;
5076 GSList
*aio_ctxs
= NULL
, *ctx
;
5078 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
5079 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
5081 if (!g_slist_find(aio_ctxs
, aio_context
)) {
5082 aio_ctxs
= g_slist_prepend(aio_ctxs
, aio_context
);
5083 aio_context_acquire(aio_context
);
5087 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
5088 /* Nodes with BDS parents are covered by recursion from the last
5089 * parent that gets inactivated. Don't inactivate them a second
5090 * time if that has already happened. */
5091 if (bdrv_has_bds_parent(bs
, false)) {
5094 ret
= bdrv_inactivate_recurse(bs
);
5096 bdrv_next_cleanup(&it
);
5102 for (ctx
= aio_ctxs
; ctx
!= NULL
; ctx
= ctx
->next
) {
5103 AioContext
*aio_context
= ctx
->data
;
5104 aio_context_release(aio_context
);
5106 g_slist_free(aio_ctxs
);
5111 /**************************************************************/
5112 /* removable device support */
5115 * Return TRUE if the media is present
5117 bool bdrv_is_inserted(BlockDriverState
*bs
)
5119 BlockDriver
*drv
= bs
->drv
;
5125 if (drv
->bdrv_is_inserted
) {
5126 return drv
->bdrv_is_inserted(bs
);
5128 QLIST_FOREACH(child
, &bs
->children
, next
) {
5129 if (!bdrv_is_inserted(child
->bs
)) {
5137 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
5139 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
5141 BlockDriver
*drv
= bs
->drv
;
5143 if (drv
&& drv
->bdrv_eject
) {
5144 drv
->bdrv_eject(bs
, eject_flag
);
5149 * Lock or unlock the media (if it is locked, the user won't be able
5150 * to eject it manually).
5152 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
5154 BlockDriver
*drv
= bs
->drv
;
5156 trace_bdrv_lock_medium(bs
, locked
);
5158 if (drv
&& drv
->bdrv_lock_medium
) {
5159 drv
->bdrv_lock_medium(bs
, locked
);
5163 /* Get a reference to bs */
5164 void bdrv_ref(BlockDriverState
*bs
)
5169 /* Release a previously grabbed reference to bs.
5170 * If after releasing, reference count is zero, the BlockDriverState is
5172 void bdrv_unref(BlockDriverState
*bs
)
5177 assert(bs
->refcnt
> 0);
5178 if (--bs
->refcnt
== 0) {
5183 struct BdrvOpBlocker
{
5185 QLIST_ENTRY(BdrvOpBlocker
) list
;
5188 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
5190 BdrvOpBlocker
*blocker
;
5191 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5192 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
5193 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
5194 error_propagate_prepend(errp
, error_copy(blocker
->reason
),
5195 "Node '%s' is busy: ",
5196 bdrv_get_device_or_node_name(bs
));
5202 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
5204 BdrvOpBlocker
*blocker
;
5205 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5207 blocker
= g_new0(BdrvOpBlocker
, 1);
5208 blocker
->reason
= reason
;
5209 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
5212 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
5214 BdrvOpBlocker
*blocker
, *next
;
5215 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
5216 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
5217 if (blocker
->reason
== reason
) {
5218 QLIST_REMOVE(blocker
, list
);
5224 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
5227 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5228 bdrv_op_block(bs
, i
, reason
);
5232 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
5235 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5236 bdrv_op_unblock(bs
, i
, reason
);
5240 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
5244 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
5245 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
5252 void bdrv_img_create(const char *filename
, const char *fmt
,
5253 const char *base_filename
, const char *base_fmt
,
5254 char *options
, uint64_t img_size
, int flags
, bool quiet
,
5257 QemuOptsList
*create_opts
= NULL
;
5258 QemuOpts
*opts
= NULL
;
5259 const char *backing_fmt
, *backing_file
;
5261 BlockDriver
*drv
, *proto_drv
;
5262 Error
*local_err
= NULL
;
5265 /* Find driver and parse its options */
5266 drv
= bdrv_find_format(fmt
);
5268 error_setg(errp
, "Unknown file format '%s'", fmt
);
5272 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
5277 if (!drv
->create_opts
) {
5278 error_setg(errp
, "Format driver '%s' does not support image creation",
5283 if (!proto_drv
->create_opts
) {
5284 error_setg(errp
, "Protocol driver '%s' does not support image creation",
5285 proto_drv
->format_name
);
5289 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
5290 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
5292 /* Create parameter list with default values */
5293 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
5294 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
5296 /* Parse -o options */
5298 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
5304 if (base_filename
) {
5305 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
5307 error_setg(errp
, "Backing file not supported for file format '%s'",
5314 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
5316 error_setg(errp
, "Backing file format not supported for file "
5317 "format '%s'", fmt
);
5322 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
5324 if (!strcmp(filename
, backing_file
)) {
5325 error_setg(errp
, "Error: Trying to create an image with the "
5326 "same filename as the backing file");
5331 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
5333 /* The size for the image must always be specified, unless we have a backing
5334 * file and we have not been forbidden from opening it. */
5335 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, img_size
);
5336 if (backing_file
&& !(flags
& BDRV_O_NO_BACKING
)) {
5337 BlockDriverState
*bs
;
5340 QDict
*backing_options
= NULL
;
5343 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
5348 assert(full_backing
);
5350 /* backing files always opened read-only */
5352 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
5354 backing_options
= qdict_new();
5356 qdict_put_str(backing_options
, "driver", backing_fmt
);
5358 qdict_put_bool(backing_options
, BDRV_OPT_FORCE_SHARE
, true);
5360 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
5362 g_free(full_backing
);
5363 if (!bs
&& size
!= -1) {
5364 /* Couldn't open BS, but we have a size, so it's nonfatal */
5365 warn_reportf_err(local_err
,
5366 "Could not verify backing image. "
5367 "This may become an error in future versions.\n");
5370 /* Couldn't open bs, do not have size */
5371 error_append_hint(&local_err
,
5372 "Could not open backing image to determine size.\n");
5376 /* Opened BS, have no size */
5377 size
= bdrv_getlength(bs
);
5379 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
5384 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
5388 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
5391 error_setg(errp
, "Image creation needs a size parameter");
5396 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
5397 qemu_opts_print(opts
, " ");
5401 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
5403 if (ret
== -EFBIG
) {
5404 /* This is generally a better message than whatever the driver would
5405 * deliver (especially because of the cluster_size_hint), since that
5406 * is most probably not much different from "image too large". */
5407 const char *cluster_size_hint
= "";
5408 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
5409 cluster_size_hint
= " (try using a larger cluster size)";
5411 error_setg(errp
, "The image size is too large for file format '%s'"
5412 "%s", fmt
, cluster_size_hint
);
5413 error_free(local_err
);
5418 qemu_opts_del(opts
);
5419 qemu_opts_free(create_opts
);
5420 error_propagate(errp
, local_err
);
5423 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
5425 return bs
? bs
->aio_context
: qemu_get_aio_context();
5428 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
5430 aio_co_enter(bdrv_get_aio_context(bs
), co
);
5433 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
5435 QLIST_REMOVE(ban
, list
);
5439 void bdrv_detach_aio_context(BlockDriverState
*bs
)
5441 BdrvAioNotifier
*baf
, *baf_tmp
;
5448 assert(!bs
->walking_aio_notifiers
);
5449 bs
->walking_aio_notifiers
= true;
5450 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
5452 bdrv_do_remove_aio_context_notifier(baf
);
5454 baf
->detach_aio_context(baf
->opaque
);
5457 /* Never mind iterating again to check for ->deleted. bdrv_close() will
5458 * remove remaining aio notifiers if we aren't called again.
5460 bs
->walking_aio_notifiers
= false;
5462 if (bs
->drv
->bdrv_detach_aio_context
) {
5463 bs
->drv
->bdrv_detach_aio_context(bs
);
5465 QLIST_FOREACH(child
, &bs
->children
, next
) {
5466 bdrv_detach_aio_context(child
->bs
);
5469 if (bs
->quiesce_counter
) {
5470 aio_enable_external(bs
->aio_context
);
5472 bs
->aio_context
= NULL
;
5475 void bdrv_attach_aio_context(BlockDriverState
*bs
,
5476 AioContext
*new_context
)
5478 BdrvAioNotifier
*ban
, *ban_tmp
;
5485 if (bs
->quiesce_counter
) {
5486 aio_disable_external(new_context
);
5489 bs
->aio_context
= new_context
;
5491 QLIST_FOREACH(child
, &bs
->children
, next
) {
5492 bdrv_attach_aio_context(child
->bs
, new_context
);
5494 if (bs
->drv
->bdrv_attach_aio_context
) {
5495 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
5498 assert(!bs
->walking_aio_notifiers
);
5499 bs
->walking_aio_notifiers
= true;
5500 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
5502 bdrv_do_remove_aio_context_notifier(ban
);
5504 ban
->attached_aio_context(new_context
, ban
->opaque
);
5507 bs
->walking_aio_notifiers
= false;
5510 /* The caller must own the AioContext lock for the old AioContext of bs, but it
5511 * must not own the AioContext lock for new_context (unless new_context is
5512 * the same as the current context of bs). */
5513 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
5515 if (bdrv_get_aio_context(bs
) == new_context
) {
5519 bdrv_drained_begin(bs
);
5520 bdrv_detach_aio_context(bs
);
5522 /* This function executes in the old AioContext so acquire the new one in
5523 * case it runs in a different thread.
5525 aio_context_acquire(new_context
);
5526 bdrv_attach_aio_context(bs
, new_context
);
5527 bdrv_drained_end(bs
);
5528 aio_context_release(new_context
);
5531 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
5532 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
5533 void (*detach_aio_context
)(void *opaque
), void *opaque
)
5535 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
5536 *ban
= (BdrvAioNotifier
){
5537 .attached_aio_context
= attached_aio_context
,
5538 .detach_aio_context
= detach_aio_context
,
5542 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
5545 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
5546 void (*attached_aio_context
)(AioContext
*,
5548 void (*detach_aio_context
)(void *),
5551 BdrvAioNotifier
*ban
, *ban_next
;
5553 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
5554 if (ban
->attached_aio_context
== attached_aio_context
&&
5555 ban
->detach_aio_context
== detach_aio_context
&&
5556 ban
->opaque
== opaque
&&
5557 ban
->deleted
== false)
5559 if (bs
->walking_aio_notifiers
) {
5560 ban
->deleted
= true;
5562 bdrv_do_remove_aio_context_notifier(ban
);
5571 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
5572 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
5576 error_setg(errp
, "Node is ejected");
5579 if (!bs
->drv
->bdrv_amend_options
) {
5580 error_setg(errp
, "Block driver '%s' does not support option amendment",
5581 bs
->drv
->format_name
);
5584 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
, errp
);
5587 /* This function will be called by the bdrv_recurse_is_first_non_filter method
5588 * of block filter and by bdrv_is_first_non_filter.
5589 * It is used to test if the given bs is the candidate or recurse more in the
5592 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
5593 BlockDriverState
*candidate
)
5595 /* return false if basic checks fails */
5596 if (!bs
|| !bs
->drv
) {
5600 /* the code reached a non block filter driver -> check if the bs is
5601 * the same as the candidate. It's the recursion termination condition.
5603 if (!bs
->drv
->is_filter
) {
5604 return bs
== candidate
;
5606 /* Down this path the driver is a block filter driver */
5608 /* If the block filter recursion method is defined use it to recurse down
5611 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
5612 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
5615 /* the driver is a block filter but don't allow to recurse -> return false
5620 /* This function checks if the candidate is the first non filter bs down it's
5621 * bs chain. Since we don't have pointers to parents it explore all bs chains
5622 * from the top. Some filters can choose not to pass down the recursion.
5624 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
5626 BlockDriverState
*bs
;
5627 BdrvNextIterator it
;
5629 /* walk down the bs forest recursively */
5630 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
5633 /* try to recurse in this top level bs */
5634 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
5636 /* candidate is the first non filter */
5638 bdrv_next_cleanup(&it
);
5646 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
5647 const char *node_name
, Error
**errp
)
5649 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
5650 AioContext
*aio_context
;
5652 if (!to_replace_bs
) {
5653 error_setg(errp
, "Node name '%s' not found", node_name
);
5657 aio_context
= bdrv_get_aio_context(to_replace_bs
);
5658 aio_context_acquire(aio_context
);
5660 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
5661 to_replace_bs
= NULL
;
5665 /* We don't want arbitrary node of the BDS chain to be replaced only the top
5666 * most non filter in order to prevent data corruption.
5667 * Another benefit is that this tests exclude backing files which are
5668 * blocked by the backing blockers.
5670 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
5671 error_setg(errp
, "Only top most non filter can be replaced");
5672 to_replace_bs
= NULL
;
5677 aio_context_release(aio_context
);
5678 return to_replace_bs
;
5682 * Iterates through the list of runtime option keys that are said to
5683 * be "strong" for a BDS. An option is called "strong" if it changes
5684 * a BDS's data. For example, the null block driver's "size" and
5685 * "read-zeroes" options are strong, but its "latency-ns" option is
5688 * If a key returned by this function ends with a dot, all options
5689 * starting with that prefix are strong.
5691 static const char *const *strong_options(BlockDriverState
*bs
,
5692 const char *const *curopt
)
5694 static const char *const global_options
[] = {
5695 "driver", "filename", NULL
5699 return &global_options
[0];
5703 if (curopt
== &global_options
[ARRAY_SIZE(global_options
) - 1] && bs
->drv
) {
5704 curopt
= bs
->drv
->strong_runtime_opts
;
5707 return (curopt
&& *curopt
) ? curopt
: NULL
;
5711 * Copies all strong runtime options from bs->options to the given
5712 * QDict. The set of strong option keys is determined by invoking
5715 * Returns true iff any strong option was present in bs->options (and
5716 * thus copied to the target QDict) with the exception of "filename"
5717 * and "driver". The caller is expected to use this value to decide
5718 * whether the existence of strong options prevents the generation of
5721 static bool append_strong_runtime_options(QDict
*d
, BlockDriverState
*bs
)
5723 bool found_any
= false;
5724 const char *const *option_name
= NULL
;
5730 while ((option_name
= strong_options(bs
, option_name
))) {
5731 bool option_given
= false;
5733 assert(strlen(*option_name
) > 0);
5734 if ((*option_name
)[strlen(*option_name
) - 1] != '.') {
5735 QObject
*entry
= qdict_get(bs
->options
, *option_name
);
5740 qdict_put_obj(d
, *option_name
, qobject_ref(entry
));
5741 option_given
= true;
5743 const QDictEntry
*entry
;
5744 for (entry
= qdict_first(bs
->options
); entry
;
5745 entry
= qdict_next(bs
->options
, entry
))
5747 if (strstart(qdict_entry_key(entry
), *option_name
, NULL
)) {
5748 qdict_put_obj(d
, qdict_entry_key(entry
),
5749 qobject_ref(qdict_entry_value(entry
)));
5750 option_given
= true;
5755 /* While "driver" and "filename" need to be included in a JSON filename,
5756 * their existence does not prohibit generation of a plain filename. */
5757 if (!found_any
&& option_given
&&
5758 strcmp(*option_name
, "driver") && strcmp(*option_name
, "filename"))
5764 if (!qdict_haskey(d
, "driver")) {
5765 /* Drivers created with bdrv_new_open_driver() may not have a
5766 * @driver option. Add it here. */
5767 qdict_put_str(d
, "driver", bs
->drv
->format_name
);
5773 /* Note: This function may return false positives; it may return true
5774 * even if opening the backing file specified by bs's image header
5775 * would result in exactly bs->backing. */
5776 static bool bdrv_backing_overridden(BlockDriverState
*bs
)
5779 return strcmp(bs
->auto_backing_file
,
5780 bs
->backing
->bs
->filename
);
5782 /* No backing BDS, so if the image header reports any backing
5783 * file, it must have been suppressed */
5784 return bs
->auto_backing_file
[0] != '\0';
5788 /* Updates the following BDS fields:
5789 * - exact_filename: A filename which may be used for opening a block device
5790 * which (mostly) equals the given BDS (even without any
5791 * other options; so reading and writing must return the same
5792 * results, but caching etc. may be different)
5793 * - full_open_options: Options which, when given when opening a block device
5794 * (without a filename), result in a BDS (mostly)
5795 * equalling the given one
5796 * - filename: If exact_filename is set, it is copied here. Otherwise,
5797 * full_open_options is converted to a JSON object, prefixed with
5798 * "json:" (for use through the JSON pseudo protocol) and put here.
5800 void bdrv_refresh_filename(BlockDriverState
*bs
)
5802 BlockDriver
*drv
= bs
->drv
;
5805 bool backing_overridden
;
5806 bool generate_json_filename
; /* Whether our default implementation should
5807 fill exact_filename (false) or not (true) */
5813 /* This BDS's file name may depend on any of its children's file names, so
5814 * refresh those first */
5815 QLIST_FOREACH(child
, &bs
->children
, next
) {
5816 bdrv_refresh_filename(child
->bs
);
5820 /* For implicit nodes, just copy everything from the single child */
5821 child
= QLIST_FIRST(&bs
->children
);
5822 assert(QLIST_NEXT(child
, next
) == NULL
);
5824 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
),
5825 child
->bs
->exact_filename
);
5826 pstrcpy(bs
->filename
, sizeof(bs
->filename
), child
->bs
->filename
);
5828 bs
->full_open_options
= qobject_ref(child
->bs
->full_open_options
);
5833 backing_overridden
= bdrv_backing_overridden(bs
);
5835 if (bs
->open_flags
& BDRV_O_NO_IO
) {
5836 /* Without I/O, the backing file does not change anything.
5837 * Therefore, in such a case (primarily qemu-img), we can
5838 * pretend the backing file has not been overridden even if
5839 * it technically has been. */
5840 backing_overridden
= false;
5843 /* Gather the options QDict */
5845 generate_json_filename
= append_strong_runtime_options(opts
, bs
);
5846 generate_json_filename
|= backing_overridden
;
5848 if (drv
->bdrv_gather_child_options
) {
5849 /* Some block drivers may not want to present all of their children's
5850 * options, or name them differently from BdrvChild.name */
5851 drv
->bdrv_gather_child_options(bs
, opts
, backing_overridden
);
5853 QLIST_FOREACH(child
, &bs
->children
, next
) {
5854 if (child
->role
== &child_backing
&& !backing_overridden
) {
5855 /* We can skip the backing BDS if it has not been overridden */
5859 qdict_put(opts
, child
->name
,
5860 qobject_ref(child
->bs
->full_open_options
));
5863 if (backing_overridden
&& !bs
->backing
) {
5864 /* Force no backing file */
5865 qdict_put_null(opts
, "backing");
5869 qobject_unref(bs
->full_open_options
);
5870 bs
->full_open_options
= opts
;
5872 if (drv
->bdrv_refresh_filename
) {
5873 /* Obsolete information is of no use here, so drop the old file name
5874 * information before refreshing it */
5875 bs
->exact_filename
[0] = '\0';
5877 drv
->bdrv_refresh_filename(bs
);
5878 } else if (bs
->file
) {
5879 /* Try to reconstruct valid information from the underlying file */
5881 bs
->exact_filename
[0] = '\0';
5884 * We can use the underlying file's filename if:
5885 * - it has a filename,
5886 * - the file is a protocol BDS, and
5887 * - opening that file (as this BDS's format) will automatically create
5888 * the BDS tree we have right now, that is:
5889 * - the user did not significantly change this BDS's behavior with
5890 * some explicit (strong) options
5891 * - no non-file child of this BDS has been overridden by the user
5892 * Both of these conditions are represented by generate_json_filename.
5894 if (bs
->file
->bs
->exact_filename
[0] &&
5895 bs
->file
->bs
->drv
->bdrv_file_open
&&
5896 !generate_json_filename
)
5898 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
5902 if (bs
->exact_filename
[0]) {
5903 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
5905 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
5906 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
5907 qstring_get_str(json
));
5908 qobject_unref(json
);
5912 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
)
5914 BlockDriver
*drv
= bs
->drv
;
5917 error_setg(errp
, "Node '%s' is ejected", bs
->node_name
);
5921 if (drv
->bdrv_dirname
) {
5922 return drv
->bdrv_dirname(bs
, errp
);
5926 return bdrv_dirname(bs
->file
->bs
, errp
);
5929 bdrv_refresh_filename(bs
);
5930 if (bs
->exact_filename
[0] != '\0') {
5931 return path_combine(bs
->exact_filename
, "");
5934 error_setg(errp
, "Cannot generate a base directory for %s nodes",
5940 * Hot add/remove a BDS's child. So the user can take a child offline when
5941 * it is broken and take a new child online
5943 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
5947 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
5948 error_setg(errp
, "The node %s does not support adding a child",
5949 bdrv_get_device_or_node_name(parent_bs
));
5953 if (!QLIST_EMPTY(&child_bs
->parents
)) {
5954 error_setg(errp
, "The node %s already has a parent",
5955 child_bs
->node_name
);
5959 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
5962 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
5966 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
5967 error_setg(errp
, "The node %s does not support removing a child",
5968 bdrv_get_device_or_node_name(parent_bs
));
5972 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
5979 error_setg(errp
, "The node %s does not have a child named %s",
5980 bdrv_get_device_or_node_name(parent_bs
),
5981 bdrv_get_device_or_node_name(child
->bs
));
5985 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);
5988 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
5989 uint32_t granularity
, Error
**errp
)
5991 BlockDriver
*drv
= bs
->drv
;
5994 error_setg_errno(errp
, ENOMEDIUM
,
5995 "Can't store persistent bitmaps to %s",
5996 bdrv_get_device_or_node_name(bs
));
6000 if (!drv
->bdrv_can_store_new_dirty_bitmap
) {
6001 error_setg_errno(errp
, ENOTSUP
,
6002 "Can't store persistent bitmaps to %s",
6003 bdrv_get_device_or_node_name(bs
));
6007 return drv
->bdrv_can_store_new_dirty_bitmap(bs
, name
, granularity
, errp
);