2 * QEMU System Emulator block driver
4 * Copyright (c) 2003 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 #include "qemu/osdep.h"
26 #include "block/block_int.h"
27 #include "block/blockjob.h"
28 #include "qemu/error-report.h"
29 #include "qemu/module.h"
30 #include "qapi/qmp/qerror.h"
31 #include "qapi/qmp/qbool.h"
32 #include "qapi/qmp/qjson.h"
33 #include "sysemu/block-backend.h"
34 #include "sysemu/sysemu.h"
35 #include "qemu/notify.h"
36 #include "qemu/coroutine.h"
37 #include "block/qapi.h"
38 #include "qmp-commands.h"
39 #include "qemu/timer.h"
40 #include "qapi-event.h"
41 #include "qemu/cutils.h"
45 #include <sys/ioctl.h>
46 #include <sys/queue.h>
56 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
58 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
59 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
61 static QTAILQ_HEAD(, BlockDriverState
) all_bdrv_states
=
62 QTAILQ_HEAD_INITIALIZER(all_bdrv_states
);
64 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
65 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
67 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
68 const char *reference
,
69 QDict
*options
, int flags
,
70 BlockDriverState
*parent
,
71 const BdrvChildRole
*child_role
,
74 /* If non-zero, use only whitelisted block drivers */
75 static int use_bdrv_whitelist
;
78 static int is_windows_drive_prefix(const char *filename
)
80 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
81 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
85 int is_windows_drive(const char *filename
)
87 if (is_windows_drive_prefix(filename
) &&
90 if (strstart(filename
, "\\\\.\\", NULL
) ||
91 strstart(filename
, "//./", NULL
))
97 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
99 if (!bs
|| !bs
->drv
) {
100 /* page size or 4k (hdd sector size) should be on the safe side */
101 return MAX(4096, getpagesize());
104 return bs
->bl
.opt_mem_alignment
;
107 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
109 if (!bs
|| !bs
->drv
) {
110 /* page size or 4k (hdd sector size) should be on the safe side */
111 return MAX(4096, getpagesize());
114 return bs
->bl
.min_mem_alignment
;
117 /* check if the path starts with "<protocol>:" */
118 int path_has_protocol(const char *path
)
123 if (is_windows_drive(path
) ||
124 is_windows_drive_prefix(path
)) {
127 p
= path
+ strcspn(path
, ":/\\");
129 p
= path
+ strcspn(path
, ":/");
135 int path_is_absolute(const char *path
)
138 /* specific case for names like: "\\.\d:" */
139 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
142 return (*path
== '/' || *path
== '\\');
144 return (*path
== '/');
148 /* if filename is absolute, just copy it to dest. Otherwise, build a
149 path to it by considering it is relative to base_path. URL are
151 void path_combine(char *dest
, int dest_size
,
152 const char *base_path
,
153 const char *filename
)
160 if (path_is_absolute(filename
)) {
161 pstrcpy(dest
, dest_size
, filename
);
163 p
= strchr(base_path
, ':');
168 p1
= strrchr(base_path
, '/');
172 p2
= strrchr(base_path
, '\\');
184 if (len
> dest_size
- 1)
186 memcpy(dest
, base_path
, len
);
188 pstrcat(dest
, dest_size
, filename
);
192 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
194 char *dest
, size_t sz
,
197 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
198 path_is_absolute(backing
))
200 pstrcpy(dest
, sz
, backing
);
201 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
202 error_setg(errp
, "Cannot use relative backing file names for '%s'",
205 path_combine(dest
, sz
, backed
, backing
);
209 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
212 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
214 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
218 void bdrv_register(BlockDriver
*bdrv
)
220 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
223 BlockDriverState
*bdrv_new(void)
225 BlockDriverState
*bs
;
228 bs
= g_new0(BlockDriverState
, 1);
229 QLIST_INIT(&bs
->dirty_bitmaps
);
230 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
231 QLIST_INIT(&bs
->op_blockers
[i
]);
233 notifier_with_return_list_init(&bs
->before_write_notifiers
);
235 bs
->aio_context
= qemu_get_aio_context();
237 qemu_co_queue_init(&bs
->flush_queue
);
239 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
244 BlockDriver
*bdrv_find_format(const char *format_name
)
247 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
248 if (!strcmp(drv1
->format_name
, format_name
)) {
255 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
257 static const char *whitelist_rw
[] = {
258 CONFIG_BDRV_RW_WHITELIST
260 static const char *whitelist_ro
[] = {
261 CONFIG_BDRV_RO_WHITELIST
265 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
266 return 1; /* no whitelist, anything goes */
269 for (p
= whitelist_rw
; *p
; p
++) {
270 if (!strcmp(drv
->format_name
, *p
)) {
275 for (p
= whitelist_ro
; *p
; p
++) {
276 if (!strcmp(drv
->format_name
, *p
)) {
284 bool bdrv_uses_whitelist(void)
286 return use_bdrv_whitelist
;
289 typedef struct CreateCo
{
297 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
299 Error
*local_err
= NULL
;
302 CreateCo
*cco
= opaque
;
305 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
306 error_propagate(&cco
->err
, local_err
);
310 int bdrv_create(BlockDriver
*drv
, const char* filename
,
311 QemuOpts
*opts
, Error
**errp
)
318 .filename
= g_strdup(filename
),
324 if (!drv
->bdrv_create
) {
325 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
330 if (qemu_in_coroutine()) {
331 /* Fast-path if already in coroutine context */
332 bdrv_create_co_entry(&cco
);
334 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
335 qemu_coroutine_enter(co
);
336 while (cco
.ret
== NOT_DONE
) {
337 aio_poll(qemu_get_aio_context(), true);
344 error_propagate(errp
, cco
.err
);
346 error_setg_errno(errp
, -ret
, "Could not create image");
351 g_free(cco
.filename
);
355 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
358 Error
*local_err
= NULL
;
361 drv
= bdrv_find_protocol(filename
, true, errp
);
366 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
367 error_propagate(errp
, local_err
);
372 * Try to get @bs's logical and physical block size.
373 * On success, store them in @bsz struct and return 0.
374 * On failure return -errno.
375 * @bs must not be empty.
377 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
379 BlockDriver
*drv
= bs
->drv
;
381 if (drv
&& drv
->bdrv_probe_blocksizes
) {
382 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
389 * Try to get @bs's geometry (cyls, heads, sectors).
390 * On success, store them in @geo struct and return 0.
391 * On failure return -errno.
392 * @bs must not be empty.
394 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
396 BlockDriver
*drv
= bs
->drv
;
398 if (drv
&& drv
->bdrv_probe_geometry
) {
399 return drv
->bdrv_probe_geometry(bs
, geo
);
406 * Create a uniquely-named empty temporary file.
407 * Return 0 upon success, otherwise a negative errno value.
409 int get_tmp_filename(char *filename
, int size
)
412 char temp_dir
[MAX_PATH
];
413 /* GetTempFileName requires that its output buffer (4th param)
414 have length MAX_PATH or greater. */
415 assert(size
>= MAX_PATH
);
416 return (GetTempPath(MAX_PATH
, temp_dir
)
417 && GetTempFileName(temp_dir
, "qem", 0, filename
)
418 ? 0 : -GetLastError());
422 tmpdir
= getenv("TMPDIR");
426 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
429 fd
= mkstemp(filename
);
433 if (close(fd
) != 0) {
442 * Detect host devices. By convention, /dev/cdrom[N] is always
443 * recognized as a host CDROM.
445 static BlockDriver
*find_hdev_driver(const char *filename
)
447 int score_max
= 0, score
;
448 BlockDriver
*drv
= NULL
, *d
;
450 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
451 if (d
->bdrv_probe_device
) {
452 score
= d
->bdrv_probe_device(filename
);
453 if (score
> score_max
) {
463 BlockDriver
*bdrv_find_protocol(const char *filename
,
464 bool allow_protocol_prefix
,
472 /* TODO Drivers without bdrv_file_open must be specified explicitly */
475 * XXX(hch): we really should not let host device detection
476 * override an explicit protocol specification, but moving this
477 * later breaks access to device names with colons in them.
478 * Thanks to the brain-dead persistent naming schemes on udev-
479 * based Linux systems those actually are quite common.
481 drv1
= find_hdev_driver(filename
);
486 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
490 p
= strchr(filename
, ':');
493 if (len
> sizeof(protocol
) - 1)
494 len
= sizeof(protocol
) - 1;
495 memcpy(protocol
, filename
, len
);
496 protocol
[len
] = '\0';
497 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
498 if (drv1
->protocol_name
&&
499 !strcmp(drv1
->protocol_name
, protocol
)) {
504 error_setg(errp
, "Unknown protocol '%s'", protocol
);
509 * Guess image format by probing its contents.
510 * This is not a good idea when your image is raw (CVE-2008-2004), but
511 * we do it anyway for backward compatibility.
513 * @buf contains the image's first @buf_size bytes.
514 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
515 * but can be smaller if the image file is smaller)
516 * @filename is its filename.
518 * For all block drivers, call the bdrv_probe() method to get its
520 * Return the first block driver with the highest probing score.
522 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
523 const char *filename
)
525 int score_max
= 0, score
;
526 BlockDriver
*drv
= NULL
, *d
;
528 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
530 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
531 if (score
> score_max
) {
541 static int find_image_format(BdrvChild
*file
, const char *filename
,
542 BlockDriver
**pdrv
, Error
**errp
)
544 BlockDriverState
*bs
= file
->bs
;
546 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
549 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
550 if (bdrv_is_sg(bs
) || !bdrv_is_inserted(bs
) || bdrv_getlength(bs
) == 0) {
555 ret
= bdrv_pread(file
, 0, buf
, sizeof(buf
));
557 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
563 drv
= bdrv_probe_all(buf
, ret
, filename
);
565 error_setg(errp
, "Could not determine image format: No compatible "
574 * Set the current 'total_sectors' value
575 * Return 0 on success, -errno on error.
577 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
579 BlockDriver
*drv
= bs
->drv
;
581 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
585 /* query actual device if possible, otherwise just trust the hint */
586 if (drv
->bdrv_getlength
) {
587 int64_t length
= drv
->bdrv_getlength(bs
);
591 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
594 bs
->total_sectors
= hint
;
599 * Combines a QDict of new block driver @options with any missing options taken
600 * from @old_options, so that leaving out an option defaults to its old value.
602 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
605 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
606 bs
->drv
->bdrv_join_options(options
, old_options
);
608 qdict_join(options
, old_options
, false);
613 * Set open flags for a given discard mode
615 * Return 0 on success, -1 if the discard mode was invalid.
617 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
619 *flags
&= ~BDRV_O_UNMAP
;
621 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
623 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
624 *flags
|= BDRV_O_UNMAP
;
633 * Set open flags for a given cache mode
635 * Return 0 on success, -1 if the cache mode was invalid.
637 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
639 *flags
&= ~BDRV_O_CACHE_MASK
;
641 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
642 *writethrough
= false;
643 *flags
|= BDRV_O_NOCACHE
;
644 } else if (!strcmp(mode
, "directsync")) {
645 *writethrough
= true;
646 *flags
|= BDRV_O_NOCACHE
;
647 } else if (!strcmp(mode
, "writeback")) {
648 *writethrough
= false;
649 } else if (!strcmp(mode
, "unsafe")) {
650 *writethrough
= false;
651 *flags
|= BDRV_O_NO_FLUSH
;
652 } else if (!strcmp(mode
, "writethrough")) {
653 *writethrough
= true;
661 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
663 BlockDriverState
*bs
= child
->opaque
;
664 bdrv_drained_begin(bs
);
667 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
669 BlockDriverState
*bs
= child
->opaque
;
670 bdrv_drained_end(bs
);
674 * Returns the options and flags that a temporary snapshot should get, based on
675 * the originally requested flags (the originally requested image will have
676 * flags like a backing file)
678 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
679 int parent_flags
, QDict
*parent_options
)
681 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
683 /* For temporary files, unconditional cache=unsafe is fine */
684 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
685 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
687 /* aio=native doesn't work for cache.direct=off, so disable it for the
688 * temporary snapshot */
689 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
693 * Returns the options and flags that bs->file should get if a protocol driver
694 * is expected, based on the given options and flags for the parent BDS
696 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
697 int parent_flags
, QDict
*parent_options
)
699 int flags
= parent_flags
;
701 /* Enable protocol handling, disable format probing for bs->file */
702 flags
|= BDRV_O_PROTOCOL
;
704 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
706 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
707 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
709 /* Our block drivers take care to send flushes and respect unmap policy,
710 * so we can default to enable both on lower layers regardless of the
711 * corresponding parent options. */
712 flags
|= BDRV_O_UNMAP
;
714 /* Clear flags that only apply to the top layer */
715 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
718 *child_flags
= flags
;
721 const BdrvChildRole child_file
= {
722 .inherit_options
= bdrv_inherited_options
,
723 .drained_begin
= bdrv_child_cb_drained_begin
,
724 .drained_end
= bdrv_child_cb_drained_end
,
728 * Returns the options and flags that bs->file should get if the use of formats
729 * (and not only protocols) is permitted for it, based on the given options and
730 * flags for the parent BDS
732 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
733 int parent_flags
, QDict
*parent_options
)
735 child_file
.inherit_options(child_flags
, child_options
,
736 parent_flags
, parent_options
);
738 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
741 const BdrvChildRole child_format
= {
742 .inherit_options
= bdrv_inherited_fmt_options
,
743 .drained_begin
= bdrv_child_cb_drained_begin
,
744 .drained_end
= bdrv_child_cb_drained_end
,
748 * Returns the options and flags that bs->backing should get, based on the
749 * given options and flags for the parent BDS
751 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
752 int parent_flags
, QDict
*parent_options
)
754 int flags
= parent_flags
;
756 /* The cache mode is inherited unmodified for backing files; except WCE,
757 * which is only applied on the top level (BlockBackend) */
758 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
759 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
761 /* backing files always opened read-only */
762 flags
&= ~(BDRV_O_RDWR
| BDRV_O_COPY_ON_READ
);
764 /* snapshot=on is handled on the top layer */
765 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
767 *child_flags
= flags
;
770 static const BdrvChildRole child_backing
= {
771 .inherit_options
= bdrv_backing_options
,
772 .drained_begin
= bdrv_child_cb_drained_begin
,
773 .drained_end
= bdrv_child_cb_drained_end
,
776 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
778 int open_flags
= flags
;
781 * Clear flags that are internal to the block layer before opening the
784 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
787 * Snapshots should be writable.
789 if (flags
& BDRV_O_TEMPORARY
) {
790 open_flags
|= BDRV_O_RDWR
;
796 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
798 *flags
&= ~BDRV_O_CACHE_MASK
;
800 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
801 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
802 *flags
|= BDRV_O_NO_FLUSH
;
805 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
806 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
807 *flags
|= BDRV_O_NOCACHE
;
811 static void update_options_from_flags(QDict
*options
, int flags
)
813 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
814 qdict_put(options
, BDRV_OPT_CACHE_DIRECT
,
815 qbool_from_bool(flags
& BDRV_O_NOCACHE
));
817 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
818 qdict_put(options
, BDRV_OPT_CACHE_NO_FLUSH
,
819 qbool_from_bool(flags
& BDRV_O_NO_FLUSH
));
823 static void bdrv_assign_node_name(BlockDriverState
*bs
,
824 const char *node_name
,
827 char *gen_node_name
= NULL
;
830 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
831 } else if (!id_wellformed(node_name
)) {
833 * Check for empty string or invalid characters, but not if it is
834 * generated (generated names use characters not available to the user)
836 error_setg(errp
, "Invalid node name");
840 /* takes care of avoiding namespaces collisions */
841 if (blk_by_name(node_name
)) {
842 error_setg(errp
, "node-name=%s is conflicting with a device id",
847 /* takes care of avoiding duplicates node names */
848 if (bdrv_find_node(node_name
)) {
849 error_setg(errp
, "Duplicate node name");
853 /* copy node name into the bs and insert it into the graph list */
854 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
855 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
857 g_free(gen_node_name
);
860 static QemuOptsList bdrv_runtime_opts
= {
861 .name
= "bdrv_common",
862 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
866 .type
= QEMU_OPT_STRING
,
867 .help
= "Node name of the block device node",
871 .type
= QEMU_OPT_STRING
,
872 .help
= "Block driver to use for the node",
875 .name
= BDRV_OPT_CACHE_DIRECT
,
876 .type
= QEMU_OPT_BOOL
,
877 .help
= "Bypass software writeback cache on the host",
880 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
881 .type
= QEMU_OPT_BOOL
,
882 .help
= "Ignore flush requests",
884 { /* end of list */ }
889 * Common part for opening disk images and files
891 * Removes all processed options from *options.
893 static int bdrv_open_common(BlockDriverState
*bs
, BdrvChild
*file
,
894 QDict
*options
, Error
**errp
)
897 const char *filename
;
898 const char *driver_name
= NULL
;
899 const char *node_name
= NULL
;
902 Error
*local_err
= NULL
;
904 assert(bs
->file
== NULL
);
905 assert(options
!= NULL
&& bs
->options
!= options
);
907 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
908 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
910 error_propagate(errp
, local_err
);
915 driver_name
= qemu_opt_get(opts
, "driver");
916 drv
= bdrv_find_format(driver_name
);
920 filename
= file
->bs
->filename
;
922 filename
= qdict_get_try_str(options
, "filename");
925 if (drv
->bdrv_needs_filename
&& !filename
) {
926 error_setg(errp
, "The '%s' block driver requires a file name",
932 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
935 node_name
= qemu_opt_get(opts
, "node-name");
936 bdrv_assign_node_name(bs
, node_name
, &local_err
);
938 error_propagate(errp
, local_err
);
943 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
945 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
947 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
948 ? "Driver '%s' can only be used for read-only devices"
949 : "Driver '%s' is not whitelisted",
955 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
956 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
957 if (!bs
->read_only
) {
958 bdrv_enable_copy_on_read(bs
);
960 error_setg(errp
, "Can't use copy-on-read on read-only device");
966 if (filename
!= NULL
) {
967 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
969 bs
->filename
[0] = '\0';
971 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
974 bs
->opaque
= g_malloc0(drv
->instance_size
);
976 /* Apply cache mode options */
977 update_flags_from_options(&bs
->open_flags
, opts
);
979 /* Open the image, either directly or using a protocol */
980 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
981 if (drv
->bdrv_file_open
) {
982 assert(file
== NULL
);
983 assert(!drv
->bdrv_needs_filename
|| filename
!= NULL
);
984 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
987 error_setg(errp
, "Can't use '%s' as a block driver for the "
988 "protocol level", drv
->format_name
);
993 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
998 error_propagate(errp
, local_err
);
999 } else if (bs
->filename
[0]) {
1000 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1002 error_setg_errno(errp
, -ret
, "Could not open image");
1007 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1009 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1013 bdrv_refresh_limits(bs
, &local_err
);
1015 error_propagate(errp
, local_err
);
1020 assert(bdrv_opt_mem_align(bs
) != 0);
1021 assert(bdrv_min_mem_align(bs
) != 0);
1022 assert(is_power_of_2(bs
->bl
.request_alignment
));
1024 qemu_opts_del(opts
);
1033 qemu_opts_del(opts
);
1037 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1039 QObject
*options_obj
;
1043 ret
= strstart(filename
, "json:", &filename
);
1046 options_obj
= qobject_from_json(filename
);
1048 error_setg(errp
, "Could not parse the JSON options");
1052 if (qobject_type(options_obj
) != QTYPE_QDICT
) {
1053 qobject_decref(options_obj
);
1054 error_setg(errp
, "Invalid JSON object given");
1058 options
= qobject_to_qdict(options_obj
);
1059 qdict_flatten(options
);
1064 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1067 QDict
*json_options
;
1068 Error
*local_err
= NULL
;
1070 /* Parse json: pseudo-protocol */
1071 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1075 json_options
= parse_json_filename(*pfilename
, &local_err
);
1077 error_propagate(errp
, local_err
);
1081 /* Options given in the filename have lower priority than options
1082 * specified directly */
1083 qdict_join(options
, json_options
, false);
1084 QDECREF(json_options
);
1089 * Fills in default options for opening images and converts the legacy
1090 * filename/flags pair to option QDict entries.
1091 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1092 * block driver has been specified explicitly.
1094 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1095 int *flags
, Error
**errp
)
1097 const char *drvname
;
1098 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1099 bool parse_filename
= false;
1100 BlockDriver
*drv
= NULL
;
1101 Error
*local_err
= NULL
;
1103 drvname
= qdict_get_try_str(*options
, "driver");
1105 drv
= bdrv_find_format(drvname
);
1107 error_setg(errp
, "Unknown driver '%s'", drvname
);
1110 /* If the user has explicitly specified the driver, this choice should
1111 * override the BDRV_O_PROTOCOL flag */
1112 protocol
= drv
->bdrv_file_open
;
1116 *flags
|= BDRV_O_PROTOCOL
;
1118 *flags
&= ~BDRV_O_PROTOCOL
;
1121 /* Translate cache options from flags into options */
1122 update_options_from_flags(*options
, *flags
);
1124 /* Fetch the file name from the options QDict if necessary */
1125 if (protocol
&& filename
) {
1126 if (!qdict_haskey(*options
, "filename")) {
1127 qdict_put(*options
, "filename", qstring_from_str(filename
));
1128 parse_filename
= true;
1130 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1136 /* Find the right block driver */
1137 filename
= qdict_get_try_str(*options
, "filename");
1139 if (!drvname
&& protocol
) {
1141 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1146 drvname
= drv
->format_name
;
1147 qdict_put(*options
, "driver", qstring_from_str(drvname
));
1149 error_setg(errp
, "Must specify either driver or file");
1154 assert(drv
|| !protocol
);
1156 /* Driver-specific filename parsing */
1157 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1158 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1160 error_propagate(errp
, local_err
);
1164 if (!drv
->bdrv_needs_filename
) {
1165 qdict_del(*options
, "filename");
1172 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1174 BlockDriverState
*old_bs
= child
->bs
;
1177 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1178 child
->role
->drained_end(child
);
1180 QLIST_REMOVE(child
, next_parent
);
1186 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1187 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1188 child
->role
->drained_begin(child
);
1193 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1194 const char *child_name
,
1195 const BdrvChildRole
*child_role
,
1198 BdrvChild
*child
= g_new(BdrvChild
, 1);
1199 *child
= (BdrvChild
) {
1201 .name
= g_strdup(child_name
),
1206 bdrv_replace_child(child
, child_bs
);
1211 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1212 BlockDriverState
*child_bs
,
1213 const char *child_name
,
1214 const BdrvChildRole
*child_role
)
1216 BdrvChild
*child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
1218 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1222 static void bdrv_detach_child(BdrvChild
*child
)
1224 if (child
->next
.le_prev
) {
1225 QLIST_REMOVE(child
, next
);
1226 child
->next
.le_prev
= NULL
;
1229 bdrv_replace_child(child
, NULL
);
1231 g_free(child
->name
);
1235 void bdrv_root_unref_child(BdrvChild
*child
)
1237 BlockDriverState
*child_bs
;
1239 child_bs
= child
->bs
;
1240 bdrv_detach_child(child
);
1241 bdrv_unref(child_bs
);
1244 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1246 if (child
== NULL
) {
1250 if (child
->bs
->inherits_from
== parent
) {
1251 child
->bs
->inherits_from
= NULL
;
1254 bdrv_root_unref_child(child
);
1258 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
1261 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1262 if (c
->role
->change_media
) {
1263 c
->role
->change_media(c
, load
);
1268 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
1271 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1272 if (c
->role
->resize
) {
1279 * Sets the backing file link of a BDS. A new reference is created; callers
1280 * which don't need their own reference any more must call bdrv_unref().
1282 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
)
1285 bdrv_ref(backing_hd
);
1289 assert(bs
->backing_blocker
);
1290 bdrv_op_unblock_all(bs
->backing
->bs
, bs
->backing_blocker
);
1291 bdrv_unref_child(bs
, bs
->backing
);
1292 } else if (backing_hd
) {
1293 error_setg(&bs
->backing_blocker
,
1294 "node is used as backing hd of '%s'",
1295 bdrv_get_device_or_node_name(bs
));
1299 error_free(bs
->backing_blocker
);
1300 bs
->backing_blocker
= NULL
;
1304 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
);
1305 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1306 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_hd
->filename
);
1307 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
),
1308 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
1310 bdrv_op_block_all(backing_hd
, bs
->backing_blocker
);
1311 /* Otherwise we won't be able to commit due to check in bdrv_commit */
1312 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
1313 bs
->backing_blocker
);
1315 bdrv_refresh_limits(bs
, NULL
);
1319 * Opens the backing file for a BlockDriverState if not yet open
1321 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
1322 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1323 * itself, all options starting with "${bdref_key}." are considered part of the
1326 * TODO Can this be unified with bdrv_open_image()?
1328 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
1329 const char *bdref_key
, Error
**errp
)
1331 char *backing_filename
= g_malloc0(PATH_MAX
);
1332 char *bdref_key_dot
;
1333 const char *reference
= NULL
;
1335 BlockDriverState
*backing_hd
;
1337 QDict
*tmp_parent_options
= NULL
;
1338 Error
*local_err
= NULL
;
1340 if (bs
->backing
!= NULL
) {
1344 /* NULL means an empty set of options */
1345 if (parent_options
== NULL
) {
1346 tmp_parent_options
= qdict_new();
1347 parent_options
= tmp_parent_options
;
1350 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1352 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1353 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
1354 g_free(bdref_key_dot
);
1356 reference
= qdict_get_try_str(parent_options
, bdref_key
);
1357 if (reference
|| qdict_haskey(options
, "file.filename")) {
1358 backing_filename
[0] = '\0';
1359 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
1363 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
1367 error_propagate(errp
, local_err
);
1373 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
1375 error_setg(errp
, "Driver doesn't support backing files");
1380 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
1381 qdict_put(options
, "driver", qstring_from_str(bs
->backing_format
));
1384 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
1385 reference
, options
, 0, bs
, &child_backing
,
1388 bs
->open_flags
|= BDRV_O_NO_BACKING
;
1389 error_prepend(errp
, "Could not open backing file: ");
1394 /* Hook up the backing file link; drop our reference, bs owns the
1395 * backing_hd reference now */
1396 bdrv_set_backing_hd(bs
, backing_hd
);
1397 bdrv_unref(backing_hd
);
1399 qdict_del(parent_options
, bdref_key
);
1402 g_free(backing_filename
);
1403 QDECREF(tmp_parent_options
);
1408 * Opens a disk image whose options are given as BlockdevRef in another block
1411 * If allow_none is true, no image will be opened if filename is false and no
1412 * BlockdevRef is given. NULL will be returned, but errp remains unset.
1414 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
1415 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1416 * itself, all options starting with "${bdref_key}." are considered part of the
1419 * The BlockdevRef will be removed from the options QDict.
1421 BdrvChild
*bdrv_open_child(const char *filename
,
1422 QDict
*options
, const char *bdref_key
,
1423 BlockDriverState
* parent
,
1424 const BdrvChildRole
*child_role
,
1425 bool allow_none
, Error
**errp
)
1427 BdrvChild
*c
= NULL
;
1428 BlockDriverState
*bs
;
1429 QDict
*image_options
;
1430 char *bdref_key_dot
;
1431 const char *reference
;
1433 assert(child_role
!= NULL
);
1435 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1436 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
1437 g_free(bdref_key_dot
);
1439 reference
= qdict_get_try_str(options
, bdref_key
);
1440 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
1442 error_setg(errp
, "A block device must be specified for \"%s\"",
1445 QDECREF(image_options
);
1449 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
1450 parent
, child_role
, errp
);
1455 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
);
1458 qdict_del(options
, bdref_key
);
1462 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
1464 QDict
*snapshot_options
,
1467 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
1468 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
1470 QemuOpts
*opts
= NULL
;
1471 BlockDriverState
*bs_snapshot
;
1474 /* if snapshot, we create a temporary backing file and open it
1475 instead of opening 'filename' directly */
1477 /* Get the required size from the image */
1478 total_size
= bdrv_getlength(bs
);
1479 if (total_size
< 0) {
1480 error_setg_errno(errp
, -total_size
, "Could not get image size");
1484 /* Create the temporary image */
1485 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
1487 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
1491 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
1493 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
1494 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
1495 qemu_opts_del(opts
);
1497 error_prepend(errp
, "Could not create temporary overlay '%s': ",
1502 /* Prepare options QDict for the temporary file */
1503 qdict_put(snapshot_options
, "file.driver",
1504 qstring_from_str("file"));
1505 qdict_put(snapshot_options
, "file.filename",
1506 qstring_from_str(tmp_filename
));
1507 qdict_put(snapshot_options
, "driver",
1508 qstring_from_str("qcow2"));
1510 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
1511 snapshot_options
= NULL
;
1517 /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
1518 * call bdrv_unref() on it), so in order to be able to return one, we have
1519 * to increase bs_snapshot's refcount here */
1520 bdrv_ref(bs_snapshot
);
1521 bdrv_append(bs_snapshot
, bs
);
1523 g_free(tmp_filename
);
1527 QDECREF(snapshot_options
);
1528 g_free(tmp_filename
);
1533 * Opens a disk image (raw, qcow2, vmdk, ...)
1535 * options is a QDict of options to pass to the block drivers, or NULL for an
1536 * empty set of options. The reference to the QDict belongs to the block layer
1537 * after the call (even on failure), so if the caller intends to reuse the
1538 * dictionary, it needs to use QINCREF() before calling bdrv_open.
1540 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
1541 * If it is not NULL, the referenced BDS will be reused.
1543 * The reference parameter may be used to specify an existing block device which
1544 * should be opened. If specified, neither options nor a filename may be given,
1545 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
1547 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
1548 const char *reference
,
1549 QDict
*options
, int flags
,
1550 BlockDriverState
*parent
,
1551 const BdrvChildRole
*child_role
,
1555 BdrvChild
*file
= NULL
;
1556 BlockDriverState
*bs
;
1557 BlockDriver
*drv
= NULL
;
1558 const char *drvname
;
1559 const char *backing
;
1560 Error
*local_err
= NULL
;
1561 QDict
*snapshot_options
= NULL
;
1562 int snapshot_flags
= 0;
1564 assert(!child_role
|| !flags
);
1565 assert(!child_role
== !parent
);
1568 bool options_non_empty
= options
? qdict_size(options
) : false;
1571 if (filename
|| options_non_empty
) {
1572 error_setg(errp
, "Cannot reference an existing block device with "
1573 "additional options or a new filename");
1577 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
1588 /* NULL means an empty set of options */
1589 if (options
== NULL
) {
1590 options
= qdict_new();
1593 /* json: syntax counts as explicit options, as if in the QDict */
1594 parse_json_protocol(options
, &filename
, &local_err
);
1599 bs
->explicit_options
= qdict_clone_shallow(options
);
1602 bs
->inherits_from
= parent
;
1603 child_role
->inherit_options(&flags
, options
,
1604 parent
->open_flags
, parent
->options
);
1607 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
1612 bs
->open_flags
= flags
;
1613 bs
->options
= options
;
1614 options
= qdict_clone_shallow(options
);
1616 /* Find the right image format driver */
1617 drvname
= qdict_get_try_str(options
, "driver");
1619 drv
= bdrv_find_format(drvname
);
1621 error_setg(errp
, "Unknown driver: '%s'", drvname
);
1626 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
1628 backing
= qdict_get_try_str(options
, "backing");
1629 if (backing
&& *backing
== '\0') {
1630 flags
|= BDRV_O_NO_BACKING
;
1631 qdict_del(options
, "backing");
1634 /* Open image file without format layer */
1635 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
1636 if (flags
& BDRV_O_RDWR
) {
1637 flags
|= BDRV_O_ALLOW_RDWR
;
1639 if (flags
& BDRV_O_SNAPSHOT
) {
1640 snapshot_options
= qdict_new();
1641 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
1643 bdrv_backing_options(&flags
, options
, flags
, options
);
1646 bs
->open_flags
= flags
;
1648 file
= bdrv_open_child(filename
, options
, "file", bs
,
1649 &child_file
, true, &local_err
);
1655 /* Image format probing */
1658 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
1663 * This option update would logically belong in bdrv_fill_options(),
1664 * but we first need to open bs->file for the probing to work, while
1665 * opening bs->file already requires the (mostly) final set of options
1666 * so that cache mode etc. can be inherited.
1668 * Adding the driver later is somewhat ugly, but it's not an option
1669 * that would ever be inherited, so it's correct. We just need to make
1670 * sure to update both bs->options (which has the full effective
1671 * options for bs) and options (which has file.* already removed).
1673 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
1674 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
1676 error_setg(errp
, "Must specify either driver or file");
1680 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
1681 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
1682 /* file must be NULL if a protocol BDS is about to be created
1683 * (the inverse results in an error message from bdrv_open_common()) */
1684 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
1686 /* Open the image */
1687 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
1692 if (file
&& (bs
->file
!= file
)) {
1693 bdrv_unref_child(bs
, file
);
1697 /* If there is a backing file, use it */
1698 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
1699 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
1701 goto close_and_fail
;
1705 bdrv_refresh_filename(bs
);
1707 /* Check if any unknown options were used */
1708 if (options
&& (qdict_size(options
) != 0)) {
1709 const QDictEntry
*entry
= qdict_first(options
);
1710 if (flags
& BDRV_O_PROTOCOL
) {
1711 error_setg(errp
, "Block protocol '%s' doesn't support the option "
1712 "'%s'", drv
->format_name
, entry
->key
);
1715 "Block format '%s' does not support the option '%s'",
1716 drv
->format_name
, entry
->key
);
1719 goto close_and_fail
;
1722 if (!bdrv_key_required(bs
)) {
1723 bdrv_parent_cb_change_media(bs
, true);
1724 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
1725 && !runstate_check(RUN_STATE_INMIGRATE
)
1726 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
1728 "Guest must be stopped for opening of encrypted image");
1729 goto close_and_fail
;
1734 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
1735 * temporary snapshot afterwards. */
1736 if (snapshot_flags
) {
1737 BlockDriverState
*snapshot_bs
;
1738 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
1739 snapshot_options
, &local_err
);
1740 snapshot_options
= NULL
;
1742 goto close_and_fail
;
1744 /* We are not going to return bs but the overlay on top of it
1745 * (snapshot_bs); thus, we have to drop the strong reference to bs
1746 * (which we obtained by calling bdrv_new()). bs will not be deleted,
1747 * though, because the overlay still has a reference to it. */
1756 bdrv_unref_child(bs
, file
);
1758 QDECREF(snapshot_options
);
1759 QDECREF(bs
->explicit_options
);
1760 QDECREF(bs
->options
);
1764 error_propagate(errp
, local_err
);
1769 QDECREF(snapshot_options
);
1771 error_propagate(errp
, local_err
);
1775 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
1776 QDict
*options
, int flags
, Error
**errp
)
1778 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
1782 typedef struct BlockReopenQueueEntry
{
1784 BDRVReopenState state
;
1785 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1786 } BlockReopenQueueEntry
;
1789 * Adds a BlockDriverState to a simple queue for an atomic, transactional
1790 * reopen of multiple devices.
1792 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
1793 * already performed, or alternatively may be NULL a new BlockReopenQueue will
1794 * be created and initialized. This newly created BlockReopenQueue should be
1795 * passed back in for subsequent calls that are intended to be of the same
1798 * bs is the BlockDriverState to add to the reopen queue.
1800 * options contains the changed options for the associated bs
1801 * (the BlockReopenQueue takes ownership)
1803 * flags contains the open flags for the associated bs
1805 * returns a pointer to bs_queue, which is either the newly allocated
1806 * bs_queue, or the existing bs_queue being used.
1809 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
1810 BlockDriverState
*bs
,
1813 const BdrvChildRole
*role
,
1814 QDict
*parent_options
,
1819 BlockReopenQueueEntry
*bs_entry
;
1821 QDict
*old_options
, *explicit_options
;
1823 if (bs_queue
== NULL
) {
1824 bs_queue
= g_new0(BlockReopenQueue
, 1);
1825 QSIMPLEQ_INIT(bs_queue
);
1829 options
= qdict_new();
1833 * Precedence of options:
1834 * 1. Explicitly passed in options (highest)
1835 * 2. Set in flags (only for top level)
1836 * 3. Retained from explicitly set options of bs
1837 * 4. Inherited from parent node
1838 * 5. Retained from effective options of bs
1841 if (!parent_options
) {
1843 * Any setting represented by flags is always updated. If the
1844 * corresponding QDict option is set, it takes precedence. Otherwise
1845 * the flag is translated into a QDict option. The old setting of bs is
1848 update_options_from_flags(options
, flags
);
1851 /* Old explicitly set values (don't overwrite by inherited value) */
1852 old_options
= qdict_clone_shallow(bs
->explicit_options
);
1853 bdrv_join_options(bs
, options
, old_options
);
1854 QDECREF(old_options
);
1856 explicit_options
= qdict_clone_shallow(options
);
1858 /* Inherit from parent node */
1859 if (parent_options
) {
1861 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
1864 /* Old values are used for options that aren't set yet */
1865 old_options
= qdict_clone_shallow(bs
->options
);
1866 bdrv_join_options(bs
, options
, old_options
);
1867 QDECREF(old_options
);
1869 /* bdrv_open() masks this flag out */
1870 flags
&= ~BDRV_O_PROTOCOL
;
1872 QLIST_FOREACH(child
, &bs
->children
, next
) {
1873 QDict
*new_child_options
;
1874 char *child_key_dot
;
1876 /* reopen can only change the options of block devices that were
1877 * implicitly created and inherited options. For other (referenced)
1878 * block devices, a syntax like "backing.foo" results in an error. */
1879 if (child
->bs
->inherits_from
!= bs
) {
1883 child_key_dot
= g_strdup_printf("%s.", child
->name
);
1884 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
1885 g_free(child_key_dot
);
1887 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
1888 child
->role
, options
, flags
);
1891 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
1892 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
1894 bs_entry
->state
.bs
= bs
;
1895 bs_entry
->state
.options
= options
;
1896 bs_entry
->state
.explicit_options
= explicit_options
;
1897 bs_entry
->state
.flags
= flags
;
1902 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
1903 BlockDriverState
*bs
,
1904 QDict
*options
, int flags
)
1906 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
1911 * Reopen multiple BlockDriverStates atomically & transactionally.
1913 * The queue passed in (bs_queue) must have been built up previous
1914 * via bdrv_reopen_queue().
1916 * Reopens all BDS specified in the queue, with the appropriate
1917 * flags. All devices are prepared for reopen, and failure of any
1918 * device will cause all device changes to be abandonded, and intermediate
1921 * If all devices prepare successfully, then the changes are committed
1925 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
)
1928 BlockReopenQueueEntry
*bs_entry
, *next
;
1929 Error
*local_err
= NULL
;
1931 assert(bs_queue
!= NULL
);
1935 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1936 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
1937 error_propagate(errp
, local_err
);
1940 bs_entry
->prepared
= true;
1943 /* If we reach this point, we have success and just need to apply the
1946 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1947 bdrv_reopen_commit(&bs_entry
->state
);
1953 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
1954 if (ret
&& bs_entry
->prepared
) {
1955 bdrv_reopen_abort(&bs_entry
->state
);
1957 QDECREF(bs_entry
->state
.explicit_options
);
1959 QDECREF(bs_entry
->state
.options
);
1967 /* Reopen a single BlockDriverState with the specified flags. */
1968 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
1971 Error
*local_err
= NULL
;
1972 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
1974 ret
= bdrv_reopen_multiple(queue
, &local_err
);
1975 if (local_err
!= NULL
) {
1976 error_propagate(errp
, local_err
);
1983 * Prepares a BlockDriverState for reopen. All changes are staged in the
1984 * 'opaque' field of the BDRVReopenState, which is used and allocated by
1985 * the block driver layer .bdrv_reopen_prepare()
1987 * bs is the BlockDriverState to reopen
1988 * flags are the new open flags
1989 * queue is the reopen queue
1991 * Returns 0 on success, non-zero on error. On error errp will be set
1994 * On failure, bdrv_reopen_abort() will be called to clean up any data.
1995 * It is the responsibility of the caller to then call the abort() or
1996 * commit() for any other BDS that have been left in a prepare() state
1999 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2003 Error
*local_err
= NULL
;
2008 assert(reopen_state
!= NULL
);
2009 assert(reopen_state
->bs
->drv
!= NULL
);
2010 drv
= reopen_state
->bs
->drv
;
2012 /* Process generic block layer options */
2013 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2014 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2016 error_propagate(errp
, local_err
);
2021 update_flags_from_options(&reopen_state
->flags
, opts
);
2023 /* node-name and driver must be unchanged. Put them back into the QDict, so
2024 * that they are checked at the end of this function. */
2025 value
= qemu_opt_get(opts
, "node-name");
2027 qdict_put(reopen_state
->options
, "node-name", qstring_from_str(value
));
2030 value
= qemu_opt_get(opts
, "driver");
2032 qdict_put(reopen_state
->options
, "driver", qstring_from_str(value
));
2035 /* if we are to stay read-only, do not allow permission change
2037 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
2038 reopen_state
->flags
& BDRV_O_RDWR
) {
2039 error_setg(errp
, "Node '%s' is read only",
2040 bdrv_get_device_or_node_name(reopen_state
->bs
));
2045 ret
= bdrv_flush(reopen_state
->bs
);
2047 error_setg_errno(errp
, -ret
, "Error flushing drive");
2051 if (drv
->bdrv_reopen_prepare
) {
2052 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2054 if (local_err
!= NULL
) {
2055 error_propagate(errp
, local_err
);
2057 error_setg(errp
, "failed while preparing to reopen image '%s'",
2058 reopen_state
->bs
->filename
);
2063 /* It is currently mandatory to have a bdrv_reopen_prepare()
2064 * handler for each supported drv. */
2065 error_setg(errp
, "Block format '%s' used by node '%s' "
2066 "does not support reopening files", drv
->format_name
,
2067 bdrv_get_device_or_node_name(reopen_state
->bs
));
2072 /* Options that are not handled are only okay if they are unchanged
2073 * compared to the old state. It is expected that some options are only
2074 * used for the initial open, but not reopen (e.g. filename) */
2075 if (qdict_size(reopen_state
->options
)) {
2076 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2079 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2080 const char *new = qstring_get_str(new_obj
);
2081 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2084 if (!old
|| strcmp(new, old
)) {
2085 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2089 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2095 qemu_opts_del(opts
);
2100 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2101 * makes them final by swapping the staging BlockDriverState contents into
2102 * the active BlockDriverState contents.
2104 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2108 assert(reopen_state
!= NULL
);
2109 drv
= reopen_state
->bs
->drv
;
2110 assert(drv
!= NULL
);
2112 /* If there are any driver level actions to take */
2113 if (drv
->bdrv_reopen_commit
) {
2114 drv
->bdrv_reopen_commit(reopen_state
);
2117 /* set BDS specific flags now */
2118 QDECREF(reopen_state
->bs
->explicit_options
);
2120 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2121 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2122 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2124 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2128 * Abort the reopen, and delete and free the staged changes in
2131 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2135 assert(reopen_state
!= NULL
);
2136 drv
= reopen_state
->bs
->drv
;
2137 assert(drv
!= NULL
);
2139 if (drv
->bdrv_reopen_abort
) {
2140 drv
->bdrv_reopen_abort(reopen_state
);
2143 QDECREF(reopen_state
->explicit_options
);
2147 static void bdrv_close(BlockDriverState
*bs
)
2149 BdrvAioNotifier
*ban
, *ban_next
;
2152 assert(!bs
->refcnt
);
2154 bdrv_drained_begin(bs
); /* complete I/O */
2156 bdrv_drain(bs
); /* in case flush left pending I/O */
2158 bdrv_release_named_dirty_bitmaps(bs
);
2159 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2162 BdrvChild
*child
, *next
;
2164 bs
->drv
->bdrv_close(bs
);
2167 bdrv_set_backing_hd(bs
, NULL
);
2169 if (bs
->file
!= NULL
) {
2170 bdrv_unref_child(bs
, bs
->file
);
2174 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2175 /* TODO Remove bdrv_unref() from drivers' close function and use
2176 * bdrv_unref_child() here */
2177 if (child
->bs
->inherits_from
== bs
) {
2178 child
->bs
->inherits_from
= NULL
;
2180 bdrv_detach_child(child
);
2185 bs
->copy_on_read
= 0;
2186 bs
->backing_file
[0] = '\0';
2187 bs
->backing_format
[0] = '\0';
2188 bs
->total_sectors
= 0;
2189 bs
->encrypted
= false;
2190 bs
->valid_key
= false;
2192 QDECREF(bs
->options
);
2193 QDECREF(bs
->explicit_options
);
2195 QDECREF(bs
->full_open_options
);
2196 bs
->full_open_options
= NULL
;
2199 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2202 QLIST_INIT(&bs
->aio_notifiers
);
2203 bdrv_drained_end(bs
);
2206 void bdrv_close_all(void)
2208 block_job_cancel_sync_all();
2210 /* Drop references from requests still in flight, such as canceled block
2211 * jobs whose AIO context has not been polled yet */
2214 blk_remove_all_bs();
2215 blockdev_close_all_bdrv_states();
2217 assert(QTAILQ_EMPTY(&all_bdrv_states
));
2220 static void change_parent_backing_link(BlockDriverState
*from
,
2221 BlockDriverState
*to
)
2223 BdrvChild
*c
, *next
, *to_c
;
2225 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
2226 if (c
->role
== &child_backing
) {
2227 /* @from is generally not allowed to be a backing file, except for
2228 * when @to is the overlay. In that case, @from may not be replaced
2229 * by @to as @to's backing node. */
2230 QLIST_FOREACH(to_c
, &to
->children
, next
) {
2240 assert(c
->role
!= &child_backing
);
2242 bdrv_replace_child(c
, to
);
2248 * Add new bs contents at the top of an image chain while the chain is
2249 * live, while keeping required fields on the top layer.
2251 * This will modify the BlockDriverState fields, and swap contents
2252 * between bs_new and bs_top. Both bs_new and bs_top are modified.
2254 * bs_new must not be attached to a BlockBackend.
2256 * This function does not create any image files.
2258 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
2259 * that's what the callers commonly need. bs_new will be referenced by the old
2260 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
2261 * reference of its own, it must call bdrv_ref().
2263 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
)
2265 assert(!bdrv_requests_pending(bs_top
));
2266 assert(!bdrv_requests_pending(bs_new
));
2270 change_parent_backing_link(bs_top
, bs_new
);
2271 bdrv_set_backing_hd(bs_new
, bs_top
);
2274 /* bs_new is now referenced by its new parents, we don't need the
2275 * additional reference any more. */
2279 void bdrv_replace_in_backing_chain(BlockDriverState
*old
, BlockDriverState
*new)
2281 assert(!bdrv_requests_pending(old
));
2282 assert(!bdrv_requests_pending(new));
2286 change_parent_backing_link(old
, new);
2291 static void bdrv_delete(BlockDriverState
*bs
)
2294 assert(bdrv_op_blocker_is_empty(bs
));
2295 assert(!bs
->refcnt
);
2299 /* remove from list, if necessary */
2300 if (bs
->node_name
[0] != '\0') {
2301 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
2303 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
2309 * Run consistency checks on an image
2311 * Returns 0 if the check could be completed (it doesn't mean that the image is
2312 * free of errors) or -errno when an internal error occurred. The results of the
2313 * check are stored in res.
2315 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
2317 if (bs
->drv
== NULL
) {
2320 if (bs
->drv
->bdrv_check
== NULL
) {
2324 memset(res
, 0, sizeof(*res
));
2325 return bs
->drv
->bdrv_check(bs
, res
, fix
);
2331 * -EINVAL - backing format specified, but no file
2332 * -ENOSPC - can't update the backing file because no space is left in the
2334 * -ENOTSUP - format driver doesn't support changing the backing file
2336 int bdrv_change_backing_file(BlockDriverState
*bs
,
2337 const char *backing_file
, const char *backing_fmt
)
2339 BlockDriver
*drv
= bs
->drv
;
2342 /* Backing file format doesn't make sense without a backing file */
2343 if (backing_fmt
&& !backing_file
) {
2347 if (drv
->bdrv_change_backing_file
!= NULL
) {
2348 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
2354 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2355 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2361 * Finds the image layer in the chain that has 'bs' as its backing file.
2363 * active is the current topmost image.
2365 * Returns NULL if bs is not found in active's image chain,
2366 * or if active == bs.
2368 * Returns the bottommost base image if bs == NULL.
2370 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
2371 BlockDriverState
*bs
)
2373 while (active
&& bs
!= backing_bs(active
)) {
2374 active
= backing_bs(active
);
2380 /* Given a BDS, searches for the base layer. */
2381 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
2383 return bdrv_find_overlay(bs
, NULL
);
2387 * Drops images above 'base' up to and including 'top', and sets the image
2388 * above 'top' to have base as its backing file.
2390 * Requires that the overlay to 'top' is opened r/w, so that the backing file
2391 * information in 'bs' can be properly updated.
2393 * E.g., this will convert the following chain:
2394 * bottom <- base <- intermediate <- top <- active
2398 * bottom <- base <- active
2400 * It is allowed for bottom==base, in which case it converts:
2402 * base <- intermediate <- top <- active
2408 * If backing_file_str is non-NULL, it will be used when modifying top's
2409 * overlay image metadata.
2412 * if active == top, that is considered an error
2415 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
2416 BlockDriverState
*base
, const char *backing_file_str
)
2418 BlockDriverState
*new_top_bs
= NULL
;
2421 if (!top
->drv
|| !base
->drv
) {
2425 new_top_bs
= bdrv_find_overlay(active
, top
);
2427 if (new_top_bs
== NULL
) {
2428 /* we could not find the image above 'top', this is an error */
2432 /* special case of new_top_bs->backing->bs already pointing to base - nothing
2433 * to do, no intermediate images */
2434 if (backing_bs(new_top_bs
) == base
) {
2439 /* Make sure that base is in the backing chain of top */
2440 if (!bdrv_chain_contains(top
, base
)) {
2444 /* success - we can delete the intermediate states, and link top->base */
2445 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
2446 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
2447 base
->drv
? base
->drv
->format_name
: "");
2451 bdrv_set_backing_hd(new_top_bs
, base
);
2459 * Truncate file to 'offset' bytes (needed only for file protocols)
2461 int bdrv_truncate(BlockDriverState
*bs
, int64_t offset
)
2463 BlockDriver
*drv
= bs
->drv
;
2467 if (!drv
->bdrv_truncate
)
2472 ret
= drv
->bdrv_truncate(bs
, offset
);
2474 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
2475 bdrv_dirty_bitmap_truncate(bs
);
2476 bdrv_parent_cb_resize(bs
);
2483 * Length of a allocated file in bytes. Sparse files are counted by actual
2484 * allocated space. Return < 0 if error or unknown.
2486 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
2488 BlockDriver
*drv
= bs
->drv
;
2492 if (drv
->bdrv_get_allocated_file_size
) {
2493 return drv
->bdrv_get_allocated_file_size(bs
);
2496 return bdrv_get_allocated_file_size(bs
->file
->bs
);
2502 * Return number of sectors on success, -errno on error.
2504 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
2506 BlockDriver
*drv
= bs
->drv
;
2511 if (drv
->has_variable_length
) {
2512 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
2517 return bs
->total_sectors
;
2521 * Return length in bytes on success, -errno on error.
2522 * The length is always a multiple of BDRV_SECTOR_SIZE.
2524 int64_t bdrv_getlength(BlockDriverState
*bs
)
2526 int64_t ret
= bdrv_nb_sectors(bs
);
2528 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
2529 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
2532 /* return 0 as number of sectors if no device present or error */
2533 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
2535 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
2537 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
2540 bool bdrv_is_read_only(BlockDriverState
*bs
)
2542 return bs
->read_only
;
2545 bool bdrv_is_sg(BlockDriverState
*bs
)
2550 bool bdrv_is_encrypted(BlockDriverState
*bs
)
2552 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2555 return bs
->encrypted
;
2558 bool bdrv_key_required(BlockDriverState
*bs
)
2560 BdrvChild
*backing
= bs
->backing
;
2562 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
2565 return (bs
->encrypted
&& !bs
->valid_key
);
2568 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
2571 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2572 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
2578 if (!bs
->encrypted
) {
2580 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
2583 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
2585 bs
->valid_key
= false;
2586 } else if (!bs
->valid_key
) {
2587 /* call the change callback now, we skipped it on open */
2588 bs
->valid_key
= true;
2589 bdrv_parent_cb_change_media(bs
, true);
2595 * Provide an encryption key for @bs.
2596 * If @key is non-null:
2597 * If @bs is not encrypted, fail.
2598 * Else if the key is invalid, fail.
2599 * Else set @bs's key to @key, replacing the existing key, if any.
2601 * If @bs is encrypted and still lacks a key, fail.
2603 * On failure, store an error object through @errp if non-null.
2605 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
2608 if (!bdrv_is_encrypted(bs
)) {
2609 error_setg(errp
, "Node '%s' is not encrypted",
2610 bdrv_get_device_or_node_name(bs
));
2611 } else if (bdrv_set_key(bs
, key
) < 0) {
2612 error_setg(errp
, QERR_INVALID_PASSWORD
);
2615 if (bdrv_key_required(bs
)) {
2616 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
2617 "'%s' (%s) is encrypted",
2618 bdrv_get_device_or_node_name(bs
),
2619 bdrv_get_encrypted_filename(bs
));
2624 const char *bdrv_get_format_name(BlockDriverState
*bs
)
2626 return bs
->drv
? bs
->drv
->format_name
: NULL
;
2629 static int qsort_strcmp(const void *a
, const void *b
)
2631 return strcmp(a
, b
);
2634 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
2640 const char **formats
= NULL
;
2642 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
2643 if (drv
->format_name
) {
2646 while (formats
&& i
&& !found
) {
2647 found
= !strcmp(formats
[--i
], drv
->format_name
);
2651 formats
= g_renew(const char *, formats
, count
+ 1);
2652 formats
[count
++] = drv
->format_name
;
2657 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
2659 for (i
= 0; i
< count
; i
++) {
2660 it(opaque
, formats
[i
]);
2666 /* This function is to find a node in the bs graph */
2667 BlockDriverState
*bdrv_find_node(const char *node_name
)
2669 BlockDriverState
*bs
;
2673 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2674 if (!strcmp(node_name
, bs
->node_name
)) {
2681 /* Put this QMP function here so it can access the static graph_bdrv_states. */
2682 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
2684 BlockDeviceInfoList
*list
, *entry
;
2685 BlockDriverState
*bs
;
2688 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2689 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
2691 qapi_free_BlockDeviceInfoList(list
);
2694 entry
= g_malloc0(sizeof(*entry
));
2695 entry
->value
= info
;
2703 BlockDriverState
*bdrv_lookup_bs(const char *device
,
2704 const char *node_name
,
2708 BlockDriverState
*bs
;
2711 blk
= blk_by_name(device
);
2716 error_setg(errp
, "Device '%s' has no medium", device
);
2724 bs
= bdrv_find_node(node_name
);
2731 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
2732 device
? device
: "",
2733 node_name
? node_name
: "");
2737 /* If 'base' is in the same chain as 'top', return true. Otherwise,
2738 * return false. If either argument is NULL, return false. */
2739 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
2741 while (top
&& top
!= base
) {
2742 top
= backing_bs(top
);
2748 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
2751 return QTAILQ_FIRST(&graph_bdrv_states
);
2753 return QTAILQ_NEXT(bs
, node_list
);
2756 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
2758 return bs
->node_name
;
2761 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
2766 /* If multiple parents have a name, just pick the first one. */
2767 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2768 if (c
->role
->get_name
) {
2769 name
= c
->role
->get_name(c
);
2770 if (name
&& *name
) {
2779 /* TODO check what callers really want: bs->node_name or blk_name() */
2780 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
2782 return bdrv_get_parent_name(bs
) ?: "";
2785 /* This can be used to identify nodes that might not have a device
2786 * name associated. Since node and device names live in the same
2787 * namespace, the result is unambiguous. The exception is if both are
2788 * absent, then this returns an empty (non-null) string. */
2789 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
2791 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
2794 int bdrv_get_flags(BlockDriverState
*bs
)
2796 return bs
->open_flags
;
2799 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
2804 int bdrv_has_zero_init(BlockDriverState
*bs
)
2808 /* If BS is a copy on write image, it is initialized to
2809 the contents of the base image, which may not be zeroes. */
2813 if (bs
->drv
->bdrv_has_zero_init
) {
2814 return bs
->drv
->bdrv_has_zero_init(bs
);
2821 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
2823 BlockDriverInfo bdi
;
2829 if (bdrv_get_info(bs
, &bdi
) == 0) {
2830 return bdi
.unallocated_blocks_are_zero
;
2836 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
2838 BlockDriverInfo bdi
;
2840 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
2844 if (bdrv_get_info(bs
, &bdi
) == 0) {
2845 return bdi
.can_write_zeroes_with_unmap
;
2851 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
2853 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
2854 return bs
->backing_file
;
2855 else if (bs
->encrypted
)
2856 return bs
->filename
;
2861 void bdrv_get_backing_filename(BlockDriverState
*bs
,
2862 char *filename
, int filename_size
)
2864 pstrcpy(filename
, filename_size
, bs
->backing_file
);
2867 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
2869 BlockDriver
*drv
= bs
->drv
;
2872 if (!drv
->bdrv_get_info
)
2874 memset(bdi
, 0, sizeof(*bdi
));
2875 return drv
->bdrv_get_info(bs
, bdi
);
2878 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
2880 BlockDriver
*drv
= bs
->drv
;
2881 if (drv
&& drv
->bdrv_get_specific_info
) {
2882 return drv
->bdrv_get_specific_info(bs
);
2887 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
2889 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
2893 bs
->drv
->bdrv_debug_event(bs
, event
);
2896 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
2899 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
2900 bs
= bs
->file
? bs
->file
->bs
: NULL
;
2903 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
2904 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
2910 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
2912 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
2913 bs
= bs
->file
? bs
->file
->bs
: NULL
;
2916 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
2917 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
2923 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
2925 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
2926 bs
= bs
->file
? bs
->file
->bs
: NULL
;
2929 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
2930 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
2936 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
2938 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
2939 bs
= bs
->file
? bs
->file
->bs
: NULL
;
2942 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
2943 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
2949 int bdrv_is_snapshot(BlockDriverState
*bs
)
2951 return !!(bs
->open_flags
& BDRV_O_SNAPSHOT
);
2954 /* backing_file can either be relative, or absolute, or a protocol. If it is
2955 * relative, it must be relative to the chain. So, passing in bs->filename
2956 * from a BDS as backing_file should not be done, as that may be relative to
2957 * the CWD rather than the chain. */
2958 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
2959 const char *backing_file
)
2961 char *filename_full
= NULL
;
2962 char *backing_file_full
= NULL
;
2963 char *filename_tmp
= NULL
;
2964 int is_protocol
= 0;
2965 BlockDriverState
*curr_bs
= NULL
;
2966 BlockDriverState
*retval
= NULL
;
2968 if (!bs
|| !bs
->drv
|| !backing_file
) {
2972 filename_full
= g_malloc(PATH_MAX
);
2973 backing_file_full
= g_malloc(PATH_MAX
);
2974 filename_tmp
= g_malloc(PATH_MAX
);
2976 is_protocol
= path_has_protocol(backing_file
);
2978 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
2980 /* If either of the filename paths is actually a protocol, then
2981 * compare unmodified paths; otherwise make paths relative */
2982 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
2983 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
2984 retval
= curr_bs
->backing
->bs
;
2988 /* If not an absolute filename path, make it relative to the current
2989 * image's filename path */
2990 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
2993 /* We are going to compare absolute pathnames */
2994 if (!realpath(filename_tmp
, filename_full
)) {
2998 /* We need to make sure the backing filename we are comparing against
2999 * is relative to the current image filename (or absolute) */
3000 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3001 curr_bs
->backing_file
);
3003 if (!realpath(filename_tmp
, backing_file_full
)) {
3007 if (strcmp(backing_file_full
, filename_full
) == 0) {
3008 retval
= curr_bs
->backing
->bs
;
3014 g_free(filename_full
);
3015 g_free(backing_file_full
);
3016 g_free(filename_tmp
);
3020 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3030 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3033 void bdrv_init(void)
3035 module_call_init(MODULE_INIT_BLOCK
);
3038 void bdrv_init_with_whitelist(void)
3040 use_bdrv_whitelist
= 1;
3044 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3047 Error
*local_err
= NULL
;
3054 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3057 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3059 if (bs
->drv
->bdrv_invalidate_cache
) {
3060 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3062 bs
->open_flags
|= BDRV_O_INACTIVE
;
3063 error_propagate(errp
, local_err
);
3068 QLIST_FOREACH(child
, &bs
->children
, next
) {
3069 bdrv_invalidate_cache(child
->bs
, &local_err
);
3071 bs
->open_flags
|= BDRV_O_INACTIVE
;
3072 error_propagate(errp
, local_err
);
3077 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3079 bs
->open_flags
|= BDRV_O_INACTIVE
;
3080 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3085 void bdrv_invalidate_cache_all(Error
**errp
)
3087 BlockDriverState
*bs
;
3088 Error
*local_err
= NULL
;
3089 BdrvNextIterator it
;
3091 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3092 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3094 aio_context_acquire(aio_context
);
3095 bdrv_invalidate_cache(bs
, &local_err
);
3096 aio_context_release(aio_context
);
3098 error_propagate(errp
, local_err
);
3104 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3110 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3111 ret
= bs
->drv
->bdrv_inactivate(bs
);
3117 QLIST_FOREACH(child
, &bs
->children
, next
) {
3118 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
3125 bs
->open_flags
|= BDRV_O_INACTIVE
;
3130 int bdrv_inactivate_all(void)
3132 BlockDriverState
*bs
= NULL
;
3133 BdrvNextIterator it
;
3137 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3138 aio_context_acquire(bdrv_get_aio_context(bs
));
3141 /* We do two passes of inactivation. The first pass calls to drivers'
3142 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
3143 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
3145 for (pass
= 0; pass
< 2; pass
++) {
3146 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3147 ret
= bdrv_inactivate_recurse(bs
, pass
);
3155 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3156 aio_context_release(bdrv_get_aio_context(bs
));
3162 /**************************************************************/
3163 /* removable device support */
3166 * Return TRUE if the media is present
3168 bool bdrv_is_inserted(BlockDriverState
*bs
)
3170 BlockDriver
*drv
= bs
->drv
;
3176 if (drv
->bdrv_is_inserted
) {
3177 return drv
->bdrv_is_inserted(bs
);
3179 QLIST_FOREACH(child
, &bs
->children
, next
) {
3180 if (!bdrv_is_inserted(child
->bs
)) {
3188 * Return whether the media changed since the last call to this
3189 * function, or -ENOTSUP if we don't know. Most drivers don't know.
3191 int bdrv_media_changed(BlockDriverState
*bs
)
3193 BlockDriver
*drv
= bs
->drv
;
3195 if (drv
&& drv
->bdrv_media_changed
) {
3196 return drv
->bdrv_media_changed(bs
);
3202 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
3204 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
3206 BlockDriver
*drv
= bs
->drv
;
3207 const char *device_name
;
3209 if (drv
&& drv
->bdrv_eject
) {
3210 drv
->bdrv_eject(bs
, eject_flag
);
3213 device_name
= bdrv_get_device_name(bs
);
3214 if (device_name
[0] != '\0') {
3215 qapi_event_send_device_tray_moved(device_name
,
3216 eject_flag
, &error_abort
);
3221 * Lock or unlock the media (if it is locked, the user won't be able
3222 * to eject it manually).
3224 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
3226 BlockDriver
*drv
= bs
->drv
;
3228 trace_bdrv_lock_medium(bs
, locked
);
3230 if (drv
&& drv
->bdrv_lock_medium
) {
3231 drv
->bdrv_lock_medium(bs
, locked
);
3235 /* Get a reference to bs */
3236 void bdrv_ref(BlockDriverState
*bs
)
3241 /* Release a previously grabbed reference to bs.
3242 * If after releasing, reference count is zero, the BlockDriverState is
3244 void bdrv_unref(BlockDriverState
*bs
)
3249 assert(bs
->refcnt
> 0);
3250 if (--bs
->refcnt
== 0) {
3255 struct BdrvOpBlocker
{
3257 QLIST_ENTRY(BdrvOpBlocker
) list
;
3260 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
3262 BdrvOpBlocker
*blocker
;
3263 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3264 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
3265 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
3267 *errp
= error_copy(blocker
->reason
);
3268 error_prepend(errp
, "Node '%s' is busy: ",
3269 bdrv_get_device_or_node_name(bs
));
3276 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3278 BdrvOpBlocker
*blocker
;
3279 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3281 blocker
= g_new0(BdrvOpBlocker
, 1);
3282 blocker
->reason
= reason
;
3283 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
3286 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3288 BdrvOpBlocker
*blocker
, *next
;
3289 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3290 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
3291 if (blocker
->reason
== reason
) {
3292 QLIST_REMOVE(blocker
, list
);
3298 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
3301 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3302 bdrv_op_block(bs
, i
, reason
);
3306 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
3309 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3310 bdrv_op_unblock(bs
, i
, reason
);
3314 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
3318 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3319 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
3326 void bdrv_img_create(const char *filename
, const char *fmt
,
3327 const char *base_filename
, const char *base_fmt
,
3328 char *options
, uint64_t img_size
, int flags
,
3329 Error
**errp
, bool quiet
)
3331 QemuOptsList
*create_opts
= NULL
;
3332 QemuOpts
*opts
= NULL
;
3333 const char *backing_fmt
, *backing_file
;
3335 BlockDriver
*drv
, *proto_drv
;
3336 Error
*local_err
= NULL
;
3339 /* Find driver and parse its options */
3340 drv
= bdrv_find_format(fmt
);
3342 error_setg(errp
, "Unknown file format '%s'", fmt
);
3346 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
3351 if (!drv
->create_opts
) {
3352 error_setg(errp
, "Format driver '%s' does not support image creation",
3357 if (!proto_drv
->create_opts
) {
3358 error_setg(errp
, "Protocol driver '%s' does not support image creation",
3359 proto_drv
->format_name
);
3363 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
3364 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
3366 /* Create parameter list with default values */
3367 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
3368 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
3370 /* Parse -o options */
3372 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
3374 error_report_err(local_err
);
3376 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
3381 if (base_filename
) {
3382 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
3384 error_setg(errp
, "Backing file not supported for file format '%s'",
3391 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
3393 error_setg(errp
, "Backing file format not supported for file "
3394 "format '%s'", fmt
);
3399 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
3401 if (!strcmp(filename
, backing_file
)) {
3402 error_setg(errp
, "Error: Trying to create an image with the "
3403 "same filename as the backing file");
3408 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
3410 // The size for the image must always be specified, with one exception:
3411 // If we are using a backing file, we can obtain the size from there
3412 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
3415 BlockDriverState
*bs
;
3416 char *full_backing
= g_new0(char, PATH_MAX
);
3419 QDict
*backing_options
= NULL
;
3421 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
3422 full_backing
, PATH_MAX
,
3425 g_free(full_backing
);
3429 /* backing files always opened read-only */
3431 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
3434 backing_options
= qdict_new();
3435 qdict_put(backing_options
, "driver",
3436 qstring_from_str(backing_fmt
));
3439 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
3441 g_free(full_backing
);
3445 size
= bdrv_getlength(bs
);
3447 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
3453 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
3457 error_setg(errp
, "Image creation needs a size parameter");
3463 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
3464 qemu_opts_print(opts
, " ");
3468 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
3470 if (ret
== -EFBIG
) {
3471 /* This is generally a better message than whatever the driver would
3472 * deliver (especially because of the cluster_size_hint), since that
3473 * is most probably not much different from "image too large". */
3474 const char *cluster_size_hint
= "";
3475 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
3476 cluster_size_hint
= " (try using a larger cluster size)";
3478 error_setg(errp
, "The image size is too large for file format '%s'"
3479 "%s", fmt
, cluster_size_hint
);
3480 error_free(local_err
);
3485 qemu_opts_del(opts
);
3486 qemu_opts_free(create_opts
);
3487 error_propagate(errp
, local_err
);
3490 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
3492 return bs
->aio_context
;
3495 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
3497 QLIST_REMOVE(ban
, list
);
3501 void bdrv_detach_aio_context(BlockDriverState
*bs
)
3503 BdrvAioNotifier
*baf
, *baf_tmp
;
3510 assert(!bs
->walking_aio_notifiers
);
3511 bs
->walking_aio_notifiers
= true;
3512 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
3514 bdrv_do_remove_aio_context_notifier(baf
);
3516 baf
->detach_aio_context(baf
->opaque
);
3519 /* Never mind iterating again to check for ->deleted. bdrv_close() will
3520 * remove remaining aio notifiers if we aren't called again.
3522 bs
->walking_aio_notifiers
= false;
3524 if (bs
->drv
->bdrv_detach_aio_context
) {
3525 bs
->drv
->bdrv_detach_aio_context(bs
);
3527 QLIST_FOREACH(child
, &bs
->children
, next
) {
3528 bdrv_detach_aio_context(child
->bs
);
3531 bs
->aio_context
= NULL
;
3534 void bdrv_attach_aio_context(BlockDriverState
*bs
,
3535 AioContext
*new_context
)
3537 BdrvAioNotifier
*ban
, *ban_tmp
;
3544 bs
->aio_context
= new_context
;
3546 QLIST_FOREACH(child
, &bs
->children
, next
) {
3547 bdrv_attach_aio_context(child
->bs
, new_context
);
3549 if (bs
->drv
->bdrv_attach_aio_context
) {
3550 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
3553 assert(!bs
->walking_aio_notifiers
);
3554 bs
->walking_aio_notifiers
= true;
3555 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
3557 bdrv_do_remove_aio_context_notifier(ban
);
3559 ban
->attached_aio_context(new_context
, ban
->opaque
);
3562 bs
->walking_aio_notifiers
= false;
3565 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
3567 bdrv_drain(bs
); /* ensure there are no in-flight requests */
3569 bdrv_detach_aio_context(bs
);
3571 /* This function executes in the old AioContext so acquire the new one in
3572 * case it runs in a different thread.
3574 aio_context_acquire(new_context
);
3575 bdrv_attach_aio_context(bs
, new_context
);
3576 aio_context_release(new_context
);
3579 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
3580 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
3581 void (*detach_aio_context
)(void *opaque
), void *opaque
)
3583 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
3584 *ban
= (BdrvAioNotifier
){
3585 .attached_aio_context
= attached_aio_context
,
3586 .detach_aio_context
= detach_aio_context
,
3590 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
3593 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
3594 void (*attached_aio_context
)(AioContext
*,
3596 void (*detach_aio_context
)(void *),
3599 BdrvAioNotifier
*ban
, *ban_next
;
3601 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3602 if (ban
->attached_aio_context
== attached_aio_context
&&
3603 ban
->detach_aio_context
== detach_aio_context
&&
3604 ban
->opaque
== opaque
&&
3605 ban
->deleted
== false)
3607 if (bs
->walking_aio_notifiers
) {
3608 ban
->deleted
= true;
3610 bdrv_do_remove_aio_context_notifier(ban
);
3619 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
3620 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
3622 if (!bs
->drv
->bdrv_amend_options
) {
3625 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
3628 /* This function will be called by the bdrv_recurse_is_first_non_filter method
3629 * of block filter and by bdrv_is_first_non_filter.
3630 * It is used to test if the given bs is the candidate or recurse more in the
3633 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
3634 BlockDriverState
*candidate
)
3636 /* return false if basic checks fails */
3637 if (!bs
|| !bs
->drv
) {
3641 /* the code reached a non block filter driver -> check if the bs is
3642 * the same as the candidate. It's the recursion termination condition.
3644 if (!bs
->drv
->is_filter
) {
3645 return bs
== candidate
;
3647 /* Down this path the driver is a block filter driver */
3649 /* If the block filter recursion method is defined use it to recurse down
3652 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
3653 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
3656 /* the driver is a block filter but don't allow to recurse -> return false
3661 /* This function checks if the candidate is the first non filter bs down it's
3662 * bs chain. Since we don't have pointers to parents it explore all bs chains
3663 * from the top. Some filters can choose not to pass down the recursion.
3665 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
3667 BlockDriverState
*bs
;
3668 BdrvNextIterator it
;
3670 /* walk down the bs forest recursively */
3671 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3674 /* try to recurse in this top level bs */
3675 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
3677 /* candidate is the first non filter */
3686 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
3687 const char *node_name
, Error
**errp
)
3689 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
3690 AioContext
*aio_context
;
3692 if (!to_replace_bs
) {
3693 error_setg(errp
, "Node name '%s' not found", node_name
);
3697 aio_context
= bdrv_get_aio_context(to_replace_bs
);
3698 aio_context_acquire(aio_context
);
3700 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
3701 to_replace_bs
= NULL
;
3705 /* We don't want arbitrary node of the BDS chain to be replaced only the top
3706 * most non filter in order to prevent data corruption.
3707 * Another benefit is that this tests exclude backing files which are
3708 * blocked by the backing blockers.
3710 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
3711 error_setg(errp
, "Only top most non filter can be replaced");
3712 to_replace_bs
= NULL
;
3717 aio_context_release(aio_context
);
3718 return to_replace_bs
;
3721 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
3723 const QDictEntry
*entry
;
3726 bool found_any
= false;
3729 for (entry
= qdict_first(bs
->options
); entry
;
3730 entry
= qdict_next(bs
->options
, entry
))
3732 /* Exclude options for children */
3733 QLIST_FOREACH(child
, &bs
->children
, next
) {
3734 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
3735 && (!*p
|| *p
== '.'))
3744 /* And exclude all non-driver-specific options */
3745 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
3746 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
3754 qobject_incref(qdict_entry_value(entry
));
3755 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
3762 /* Updates the following BDS fields:
3763 * - exact_filename: A filename which may be used for opening a block device
3764 * which (mostly) equals the given BDS (even without any
3765 * other options; so reading and writing must return the same
3766 * results, but caching etc. may be different)
3767 * - full_open_options: Options which, when given when opening a block device
3768 * (without a filename), result in a BDS (mostly)
3769 * equalling the given one
3770 * - filename: If exact_filename is set, it is copied here. Otherwise,
3771 * full_open_options is converted to a JSON object, prefixed with
3772 * "json:" (for use through the JSON pseudo protocol) and put here.
3774 void bdrv_refresh_filename(BlockDriverState
*bs
)
3776 BlockDriver
*drv
= bs
->drv
;
3783 /* This BDS's file name will most probably depend on its file's name, so
3784 * refresh that first */
3786 bdrv_refresh_filename(bs
->file
->bs
);
3789 if (drv
->bdrv_refresh_filename
) {
3790 /* Obsolete information is of no use here, so drop the old file name
3791 * information before refreshing it */
3792 bs
->exact_filename
[0] = '\0';
3793 if (bs
->full_open_options
) {
3794 QDECREF(bs
->full_open_options
);
3795 bs
->full_open_options
= NULL
;
3799 append_open_options(opts
, bs
);
3800 drv
->bdrv_refresh_filename(bs
, opts
);
3802 } else if (bs
->file
) {
3803 /* Try to reconstruct valid information from the underlying file */
3804 bool has_open_options
;
3806 bs
->exact_filename
[0] = '\0';
3807 if (bs
->full_open_options
) {
3808 QDECREF(bs
->full_open_options
);
3809 bs
->full_open_options
= NULL
;
3813 has_open_options
= append_open_options(opts
, bs
);
3815 /* If no specific options have been given for this BDS, the filename of
3816 * the underlying file should suffice for this one as well */
3817 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
3818 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
3820 /* Reconstructing the full options QDict is simple for most format block
3821 * drivers, as long as the full options are known for the underlying
3822 * file BDS. The full options QDict of that file BDS should somehow
3823 * contain a representation of the filename, therefore the following
3824 * suffices without querying the (exact_)filename of this BDS. */
3825 if (bs
->file
->bs
->full_open_options
) {
3826 qdict_put_obj(opts
, "driver",
3827 QOBJECT(qstring_from_str(drv
->format_name
)));
3828 QINCREF(bs
->file
->bs
->full_open_options
);
3829 qdict_put_obj(opts
, "file",
3830 QOBJECT(bs
->file
->bs
->full_open_options
));
3832 bs
->full_open_options
= opts
;
3836 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
3837 /* There is no underlying file BDS (at least referenced by BDS.file),
3838 * so the full options QDict should be equal to the options given
3839 * specifically for this block device when it was opened (plus the
3840 * driver specification).
3841 * Because those options don't change, there is no need to update
3842 * full_open_options when it's already set. */
3845 append_open_options(opts
, bs
);
3846 qdict_put_obj(opts
, "driver",
3847 QOBJECT(qstring_from_str(drv
->format_name
)));
3849 if (bs
->exact_filename
[0]) {
3850 /* This may not work for all block protocol drivers (some may
3851 * require this filename to be parsed), but we have to find some
3852 * default solution here, so just include it. If some block driver
3853 * does not support pure options without any filename at all or
3854 * needs some special format of the options QDict, it needs to
3855 * implement the driver-specific bdrv_refresh_filename() function.
3857 qdict_put_obj(opts
, "filename",
3858 QOBJECT(qstring_from_str(bs
->exact_filename
)));
3861 bs
->full_open_options
= opts
;
3864 if (bs
->exact_filename
[0]) {
3865 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
3866 } else if (bs
->full_open_options
) {
3867 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
3868 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
3869 qstring_get_str(json
));
3875 * Hot add/remove a BDS's child. So the user can take a child offline when
3876 * it is broken and take a new child online
3878 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
3882 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
3883 error_setg(errp
, "The node %s does not support adding a child",
3884 bdrv_get_device_or_node_name(parent_bs
));
3888 if (!QLIST_EMPTY(&child_bs
->parents
)) {
3889 error_setg(errp
, "The node %s already has a parent",
3890 child_bs
->node_name
);
3894 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
3897 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
3901 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
3902 error_setg(errp
, "The node %s does not support removing a child",
3903 bdrv_get_device_or_node_name(parent_bs
));
3907 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
3914 error_setg(errp
, "The node %s does not have a child named %s",
3915 bdrv_get_device_or_node_name(parent_bs
),
3916 bdrv_get_device_or_node_name(child
->bs
));
3920 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);