2 * QEMU System Emulator block driver
4 * Copyright (c) 2003 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 #include "qemu/osdep.h"
25 #include "block/trace.h"
26 #include "block/block_int.h"
27 #include "block/blockjob.h"
28 #include "block/nbd.h"
29 #include "qemu/error-report.h"
30 #include "module_block.h"
31 #include "qemu/module.h"
32 #include "qapi/qmp/qerror.h"
33 #include "qapi/qmp/qbool.h"
34 #include "qapi/qmp/qjson.h"
35 #include "sysemu/block-backend.h"
36 #include "sysemu/sysemu.h"
37 #include "qemu/notify.h"
38 #include "qemu/coroutine.h"
39 #include "block/qapi.h"
40 #include "qmp-commands.h"
41 #include "qemu/timer.h"
42 #include "qapi-event.h"
43 #include "qemu/cutils.h"
45 #include "qapi/util.h"
48 #include <sys/ioctl.h>
49 #include <sys/queue.h>
59 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
61 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
62 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
64 static QTAILQ_HEAD(, BlockDriverState
) all_bdrv_states
=
65 QTAILQ_HEAD_INITIALIZER(all_bdrv_states
);
67 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
68 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
70 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
71 const char *reference
,
72 QDict
*options
, int flags
,
73 BlockDriverState
*parent
,
74 const BdrvChildRole
*child_role
,
77 /* If non-zero, use only whitelisted block drivers */
78 static int use_bdrv_whitelist
;
81 static int is_windows_drive_prefix(const char *filename
)
83 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
84 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
88 int is_windows_drive(const char *filename
)
90 if (is_windows_drive_prefix(filename
) &&
93 if (strstart(filename
, "\\\\.\\", NULL
) ||
94 strstart(filename
, "//./", NULL
))
100 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
102 if (!bs
|| !bs
->drv
) {
103 /* page size or 4k (hdd sector size) should be on the safe side */
104 return MAX(4096, getpagesize());
107 return bs
->bl
.opt_mem_alignment
;
110 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
112 if (!bs
|| !bs
->drv
) {
113 /* page size or 4k (hdd sector size) should be on the safe side */
114 return MAX(4096, getpagesize());
117 return bs
->bl
.min_mem_alignment
;
120 /* check if the path starts with "<protocol>:" */
121 int path_has_protocol(const char *path
)
126 if (is_windows_drive(path
) ||
127 is_windows_drive_prefix(path
)) {
130 p
= path
+ strcspn(path
, ":/\\");
132 p
= path
+ strcspn(path
, ":/");
138 int path_is_absolute(const char *path
)
141 /* specific case for names like: "\\.\d:" */
142 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
145 return (*path
== '/' || *path
== '\\');
147 return (*path
== '/');
151 /* if filename is absolute, just copy it to dest. Otherwise, build a
152 path to it by considering it is relative to base_path. URL are
154 void path_combine(char *dest
, int dest_size
,
155 const char *base_path
,
156 const char *filename
)
163 if (path_is_absolute(filename
)) {
164 pstrcpy(dest
, dest_size
, filename
);
166 p
= strchr(base_path
, ':');
171 p1
= strrchr(base_path
, '/');
175 p2
= strrchr(base_path
, '\\');
187 if (len
> dest_size
- 1)
189 memcpy(dest
, base_path
, len
);
191 pstrcat(dest
, dest_size
, filename
);
195 void bdrv_set_read_only(BlockDriverState
*bs
, bool read_only
)
197 bs
->read_only
= read_only
;
200 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
202 char *dest
, size_t sz
,
205 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
206 path_is_absolute(backing
))
208 pstrcpy(dest
, sz
, backing
);
209 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
210 error_setg(errp
, "Cannot use relative backing file names for '%s'",
213 path_combine(dest
, sz
, backed
, backing
);
217 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
220 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
222 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
226 void bdrv_register(BlockDriver
*bdrv
)
228 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
231 BlockDriverState
*bdrv_new(void)
233 BlockDriverState
*bs
;
236 bs
= g_new0(BlockDriverState
, 1);
237 QLIST_INIT(&bs
->dirty_bitmaps
);
238 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
239 QLIST_INIT(&bs
->op_blockers
[i
]);
241 notifier_with_return_list_init(&bs
->before_write_notifiers
);
243 bs
->aio_context
= qemu_get_aio_context();
245 qemu_co_queue_init(&bs
->flush_queue
);
247 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
252 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
256 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
257 if (!strcmp(drv1
->format_name
, format_name
)) {
265 BlockDriver
*bdrv_find_format(const char *format_name
)
270 drv1
= bdrv_do_find_format(format_name
);
275 /* The driver isn't registered, maybe we need to load a module */
276 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
277 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
278 block_module_load_one(block_driver_modules
[i
].library_name
);
283 return bdrv_do_find_format(format_name
);
286 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
288 static const char *whitelist_rw
[] = {
289 CONFIG_BDRV_RW_WHITELIST
291 static const char *whitelist_ro
[] = {
292 CONFIG_BDRV_RO_WHITELIST
296 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
297 return 1; /* no whitelist, anything goes */
300 for (p
= whitelist_rw
; *p
; p
++) {
301 if (!strcmp(drv
->format_name
, *p
)) {
306 for (p
= whitelist_ro
; *p
; p
++) {
307 if (!strcmp(drv
->format_name
, *p
)) {
315 bool bdrv_uses_whitelist(void)
317 return use_bdrv_whitelist
;
320 typedef struct CreateCo
{
328 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
330 Error
*local_err
= NULL
;
333 CreateCo
*cco
= opaque
;
336 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
337 error_propagate(&cco
->err
, local_err
);
341 int bdrv_create(BlockDriver
*drv
, const char* filename
,
342 QemuOpts
*opts
, Error
**errp
)
349 .filename
= g_strdup(filename
),
355 if (!drv
->bdrv_create
) {
356 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
361 if (qemu_in_coroutine()) {
362 /* Fast-path if already in coroutine context */
363 bdrv_create_co_entry(&cco
);
365 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
366 qemu_coroutine_enter(co
);
367 while (cco
.ret
== NOT_DONE
) {
368 aio_poll(qemu_get_aio_context(), true);
375 error_propagate(errp
, cco
.err
);
377 error_setg_errno(errp
, -ret
, "Could not create image");
382 g_free(cco
.filename
);
386 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
389 Error
*local_err
= NULL
;
392 drv
= bdrv_find_protocol(filename
, true, errp
);
397 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
398 error_propagate(errp
, local_err
);
403 * Try to get @bs's logical and physical block size.
404 * On success, store them in @bsz struct and return 0.
405 * On failure return -errno.
406 * @bs must not be empty.
408 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
410 BlockDriver
*drv
= bs
->drv
;
412 if (drv
&& drv
->bdrv_probe_blocksizes
) {
413 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
420 * Try to get @bs's geometry (cyls, heads, sectors).
421 * On success, store them in @geo struct and return 0.
422 * On failure return -errno.
423 * @bs must not be empty.
425 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
427 BlockDriver
*drv
= bs
->drv
;
429 if (drv
&& drv
->bdrv_probe_geometry
) {
430 return drv
->bdrv_probe_geometry(bs
, geo
);
437 * Create a uniquely-named empty temporary file.
438 * Return 0 upon success, otherwise a negative errno value.
440 int get_tmp_filename(char *filename
, int size
)
443 char temp_dir
[MAX_PATH
];
444 /* GetTempFileName requires that its output buffer (4th param)
445 have length MAX_PATH or greater. */
446 assert(size
>= MAX_PATH
);
447 return (GetTempPath(MAX_PATH
, temp_dir
)
448 && GetTempFileName(temp_dir
, "qem", 0, filename
)
449 ? 0 : -GetLastError());
453 tmpdir
= getenv("TMPDIR");
457 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
460 fd
= mkstemp(filename
);
464 if (close(fd
) != 0) {
473 * Detect host devices. By convention, /dev/cdrom[N] is always
474 * recognized as a host CDROM.
476 static BlockDriver
*find_hdev_driver(const char *filename
)
478 int score_max
= 0, score
;
479 BlockDriver
*drv
= NULL
, *d
;
481 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
482 if (d
->bdrv_probe_device
) {
483 score
= d
->bdrv_probe_device(filename
);
484 if (score
> score_max
) {
494 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
498 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
499 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
507 BlockDriver
*bdrv_find_protocol(const char *filename
,
508 bool allow_protocol_prefix
,
517 /* TODO Drivers without bdrv_file_open must be specified explicitly */
520 * XXX(hch): we really should not let host device detection
521 * override an explicit protocol specification, but moving this
522 * later breaks access to device names with colons in them.
523 * Thanks to the brain-dead persistent naming schemes on udev-
524 * based Linux systems those actually are quite common.
526 drv1
= find_hdev_driver(filename
);
531 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
535 p
= strchr(filename
, ':');
538 if (len
> sizeof(protocol
) - 1)
539 len
= sizeof(protocol
) - 1;
540 memcpy(protocol
, filename
, len
);
541 protocol
[len
] = '\0';
543 drv1
= bdrv_do_find_protocol(protocol
);
548 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
549 if (block_driver_modules
[i
].protocol_name
&&
550 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
551 block_module_load_one(block_driver_modules
[i
].library_name
);
556 drv1
= bdrv_do_find_protocol(protocol
);
558 error_setg(errp
, "Unknown protocol '%s'", protocol
);
564 * Guess image format by probing its contents.
565 * This is not a good idea when your image is raw (CVE-2008-2004), but
566 * we do it anyway for backward compatibility.
568 * @buf contains the image's first @buf_size bytes.
569 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
570 * but can be smaller if the image file is smaller)
571 * @filename is its filename.
573 * For all block drivers, call the bdrv_probe() method to get its
575 * Return the first block driver with the highest probing score.
577 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
578 const char *filename
)
580 int score_max
= 0, score
;
581 BlockDriver
*drv
= NULL
, *d
;
583 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
585 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
586 if (score
> score_max
) {
596 static int find_image_format(BlockBackend
*file
, const char *filename
,
597 BlockDriver
**pdrv
, Error
**errp
)
600 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
603 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
604 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
609 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
611 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
617 drv
= bdrv_probe_all(buf
, ret
, filename
);
619 error_setg(errp
, "Could not determine image format: No compatible "
628 * Set the current 'total_sectors' value
629 * Return 0 on success, -errno on error.
631 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
633 BlockDriver
*drv
= bs
->drv
;
635 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
639 /* query actual device if possible, otherwise just trust the hint */
640 if (drv
->bdrv_getlength
) {
641 int64_t length
= drv
->bdrv_getlength(bs
);
645 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
648 bs
->total_sectors
= hint
;
653 * Combines a QDict of new block driver @options with any missing options taken
654 * from @old_options, so that leaving out an option defaults to its old value.
656 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
659 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
660 bs
->drv
->bdrv_join_options(options
, old_options
);
662 qdict_join(options
, old_options
, false);
667 * Set open flags for a given discard mode
669 * Return 0 on success, -1 if the discard mode was invalid.
671 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
673 *flags
&= ~BDRV_O_UNMAP
;
675 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
677 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
678 *flags
|= BDRV_O_UNMAP
;
687 * Set open flags for a given cache mode
689 * Return 0 on success, -1 if the cache mode was invalid.
691 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
693 *flags
&= ~BDRV_O_CACHE_MASK
;
695 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
696 *writethrough
= false;
697 *flags
|= BDRV_O_NOCACHE
;
698 } else if (!strcmp(mode
, "directsync")) {
699 *writethrough
= true;
700 *flags
|= BDRV_O_NOCACHE
;
701 } else if (!strcmp(mode
, "writeback")) {
702 *writethrough
= false;
703 } else if (!strcmp(mode
, "unsafe")) {
704 *writethrough
= false;
705 *flags
|= BDRV_O_NO_FLUSH
;
706 } else if (!strcmp(mode
, "writethrough")) {
707 *writethrough
= true;
715 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
717 BlockDriverState
*parent
= c
->opaque
;
718 return g_strdup(bdrv_get_device_or_node_name(parent
));
721 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
723 BlockDriverState
*bs
= child
->opaque
;
724 bdrv_drained_begin(bs
);
727 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
729 BlockDriverState
*bs
= child
->opaque
;
730 bdrv_drained_end(bs
);
734 * Returns the options and flags that a temporary snapshot should get, based on
735 * the originally requested flags (the originally requested image will have
736 * flags like a backing file)
738 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
739 int parent_flags
, QDict
*parent_options
)
741 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
743 /* For temporary files, unconditional cache=unsafe is fine */
744 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
745 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
747 /* Copy the read-only option from the parent */
748 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
750 /* aio=native doesn't work for cache.direct=off, so disable it for the
751 * temporary snapshot */
752 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
756 * Returns the options and flags that bs->file should get if a protocol driver
757 * is expected, based on the given options and flags for the parent BDS
759 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
760 int parent_flags
, QDict
*parent_options
)
762 int flags
= parent_flags
;
764 /* Enable protocol handling, disable format probing for bs->file */
765 flags
|= BDRV_O_PROTOCOL
;
767 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
769 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
770 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
772 /* Inherit the read-only option from the parent if it's not set */
773 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
775 /* Our block drivers take care to send flushes and respect unmap policy,
776 * so we can default to enable both on lower layers regardless of the
777 * corresponding parent options. */
778 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
780 /* Clear flags that only apply to the top layer */
781 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
784 *child_flags
= flags
;
787 const BdrvChildRole child_file
= {
788 .get_parent_desc
= bdrv_child_get_parent_desc
,
789 .inherit_options
= bdrv_inherited_options
,
790 .drained_begin
= bdrv_child_cb_drained_begin
,
791 .drained_end
= bdrv_child_cb_drained_end
,
795 * Returns the options and flags that bs->file should get if the use of formats
796 * (and not only protocols) is permitted for it, based on the given options and
797 * flags for the parent BDS
799 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
800 int parent_flags
, QDict
*parent_options
)
802 child_file
.inherit_options(child_flags
, child_options
,
803 parent_flags
, parent_options
);
805 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
808 const BdrvChildRole child_format
= {
809 .get_parent_desc
= bdrv_child_get_parent_desc
,
810 .inherit_options
= bdrv_inherited_fmt_options
,
811 .drained_begin
= bdrv_child_cb_drained_begin
,
812 .drained_end
= bdrv_child_cb_drained_end
,
815 static void bdrv_backing_attach(BdrvChild
*c
)
817 BlockDriverState
*parent
= c
->opaque
;
818 BlockDriverState
*backing_hd
= c
->bs
;
820 assert(!parent
->backing_blocker
);
821 error_setg(&parent
->backing_blocker
,
822 "node is used as backing hd of '%s'",
823 bdrv_get_device_or_node_name(parent
));
825 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
826 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
827 backing_hd
->filename
);
828 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
829 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
831 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
832 /* Otherwise we won't be able to commit or stream */
833 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
834 parent
->backing_blocker
);
835 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
836 parent
->backing_blocker
);
838 * We do backup in 3 ways:
840 * The target bs is new opened, and the source is top BDS
842 * Both the source and the target are top BDSes.
843 * 3. internal backup(used for block replication)
844 * Both the source and the target are backing file
846 * In case 1 and 2, neither the source nor the target is the backing file.
847 * In case 3, we will block the top BDS, so there is only one block job
848 * for the top BDS and its backing chain.
850 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
851 parent
->backing_blocker
);
852 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
853 parent
->backing_blocker
);
856 static void bdrv_backing_detach(BdrvChild
*c
)
858 BlockDriverState
*parent
= c
->opaque
;
860 assert(parent
->backing_blocker
);
861 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
862 error_free(parent
->backing_blocker
);
863 parent
->backing_blocker
= NULL
;
867 * Returns the options and flags that bs->backing should get, based on the
868 * given options and flags for the parent BDS
870 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
871 int parent_flags
, QDict
*parent_options
)
873 int flags
= parent_flags
;
875 /* The cache mode is inherited unmodified for backing files; except WCE,
876 * which is only applied on the top level (BlockBackend) */
877 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
878 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
880 /* backing files always opened read-only */
881 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
882 flags
&= ~BDRV_O_COPY_ON_READ
;
884 /* snapshot=on is handled on the top layer */
885 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
887 *child_flags
= flags
;
890 const BdrvChildRole child_backing
= {
891 .get_parent_desc
= bdrv_child_get_parent_desc
,
892 .attach
= bdrv_backing_attach
,
893 .detach
= bdrv_backing_detach
,
894 .inherit_options
= bdrv_backing_options
,
895 .drained_begin
= bdrv_child_cb_drained_begin
,
896 .drained_end
= bdrv_child_cb_drained_end
,
899 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
901 int open_flags
= flags
;
904 * Clear flags that are internal to the block layer before opening the
907 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
910 * Snapshots should be writable.
912 if (flags
& BDRV_O_TEMPORARY
) {
913 open_flags
|= BDRV_O_RDWR
;
919 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
921 *flags
&= ~BDRV_O_CACHE_MASK
;
923 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
924 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
925 *flags
|= BDRV_O_NO_FLUSH
;
928 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
929 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
930 *flags
|= BDRV_O_NOCACHE
;
933 *flags
&= ~BDRV_O_RDWR
;
935 assert(qemu_opt_find(opts
, BDRV_OPT_READ_ONLY
));
936 if (!qemu_opt_get_bool(opts
, BDRV_OPT_READ_ONLY
, false)) {
937 *flags
|= BDRV_O_RDWR
;
942 static void update_options_from_flags(QDict
*options
, int flags
)
944 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
945 qdict_put(options
, BDRV_OPT_CACHE_DIRECT
,
946 qbool_from_bool(flags
& BDRV_O_NOCACHE
));
948 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
949 qdict_put(options
, BDRV_OPT_CACHE_NO_FLUSH
,
950 qbool_from_bool(flags
& BDRV_O_NO_FLUSH
));
952 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
953 qdict_put(options
, BDRV_OPT_READ_ONLY
,
954 qbool_from_bool(!(flags
& BDRV_O_RDWR
)));
958 static void bdrv_assign_node_name(BlockDriverState
*bs
,
959 const char *node_name
,
962 char *gen_node_name
= NULL
;
965 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
966 } else if (!id_wellformed(node_name
)) {
968 * Check for empty string or invalid characters, but not if it is
969 * generated (generated names use characters not available to the user)
971 error_setg(errp
, "Invalid node name");
975 /* takes care of avoiding namespaces collisions */
976 if (blk_by_name(node_name
)) {
977 error_setg(errp
, "node-name=%s is conflicting with a device id",
982 /* takes care of avoiding duplicates node names */
983 if (bdrv_find_node(node_name
)) {
984 error_setg(errp
, "Duplicate node name");
988 /* copy node name into the bs and insert it into the graph list */
989 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
990 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
992 g_free(gen_node_name
);
995 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
996 const char *node_name
, QDict
*options
,
997 int open_flags
, Error
**errp
)
999 Error
*local_err
= NULL
;
1002 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1004 error_propagate(errp
, local_err
);
1009 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1010 bs
->opaque
= g_malloc0(drv
->instance_size
);
1012 if (drv
->bdrv_file_open
) {
1013 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1014 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1015 } else if (drv
->bdrv_open
) {
1016 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1023 error_propagate(errp
, local_err
);
1024 } else if (bs
->filename
[0]) {
1025 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1027 error_setg_errno(errp
, -ret
, "Could not open image");
1032 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1034 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1038 bdrv_refresh_limits(bs
, &local_err
);
1040 error_propagate(errp
, local_err
);
1045 assert(bdrv_opt_mem_align(bs
) != 0);
1046 assert(bdrv_min_mem_align(bs
) != 0);
1047 assert(is_power_of_2(bs
->bl
.request_alignment
));
1052 /* FIXME Close bs first if already opened*/
1059 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1060 int flags
, Error
**errp
)
1062 BlockDriverState
*bs
;
1066 bs
->open_flags
= flags
;
1067 bs
->explicit_options
= qdict_new();
1068 bs
->options
= qdict_new();
1071 update_options_from_flags(bs
->options
, flags
);
1073 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1075 QDECREF(bs
->explicit_options
);
1076 QDECREF(bs
->options
);
1084 QemuOptsList bdrv_runtime_opts
= {
1085 .name
= "bdrv_common",
1086 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1089 .name
= "node-name",
1090 .type
= QEMU_OPT_STRING
,
1091 .help
= "Node name of the block device node",
1095 .type
= QEMU_OPT_STRING
,
1096 .help
= "Block driver to use for the node",
1099 .name
= BDRV_OPT_CACHE_DIRECT
,
1100 .type
= QEMU_OPT_BOOL
,
1101 .help
= "Bypass software writeback cache on the host",
1104 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1105 .type
= QEMU_OPT_BOOL
,
1106 .help
= "Ignore flush requests",
1109 .name
= BDRV_OPT_READ_ONLY
,
1110 .type
= QEMU_OPT_BOOL
,
1111 .help
= "Node is opened in read-only mode",
1114 .name
= "detect-zeroes",
1115 .type
= QEMU_OPT_STRING
,
1116 .help
= "try to optimize zero writes (off, on, unmap)",
1120 .type
= QEMU_OPT_STRING
,
1121 .help
= "discard operation (ignore/off, unmap/on)",
1123 { /* end of list */ }
1128 * Common part for opening disk images and files
1130 * Removes all processed options from *options.
1132 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1133 QDict
*options
, Error
**errp
)
1135 int ret
, open_flags
;
1136 const char *filename
;
1137 const char *driver_name
= NULL
;
1138 const char *node_name
= NULL
;
1139 const char *discard
;
1140 const char *detect_zeroes
;
1143 Error
*local_err
= NULL
;
1145 assert(bs
->file
== NULL
);
1146 assert(options
!= NULL
&& bs
->options
!= options
);
1148 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1149 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1151 error_propagate(errp
, local_err
);
1156 update_flags_from_options(&bs
->open_flags
, opts
);
1158 driver_name
= qemu_opt_get(opts
, "driver");
1159 drv
= bdrv_find_format(driver_name
);
1160 assert(drv
!= NULL
);
1163 filename
= blk_bs(file
)->filename
;
1166 * Caution: while qdict_get_try_str() is fine, getting
1167 * non-string types would require more care. When @options
1168 * come from -blockdev or blockdev_add, its members are typed
1169 * according to the QAPI schema, but when they come from
1170 * -drive, they're all QString.
1172 filename
= qdict_get_try_str(options
, "filename");
1175 if (drv
->bdrv_needs_filename
&& !filename
) {
1176 error_setg(errp
, "The '%s' block driver requires a file name",
1182 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1185 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1187 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1189 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1190 ? "Driver '%s' can only be used for read-only devices"
1191 : "Driver '%s' is not whitelisted",
1197 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
1198 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1199 if (!bs
->read_only
) {
1200 bdrv_enable_copy_on_read(bs
);
1202 error_setg(errp
, "Can't use copy-on-read on read-only device");
1208 discard
= qemu_opt_get(opts
, "discard");
1209 if (discard
!= NULL
) {
1210 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1211 error_setg(errp
, "Invalid discard option");
1217 detect_zeroes
= qemu_opt_get(opts
, "detect-zeroes");
1218 if (detect_zeroes
) {
1219 BlockdevDetectZeroesOptions value
=
1220 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup
,
1222 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX
,
1223 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
1226 error_propagate(errp
, local_err
);
1231 if (value
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
1232 !(bs
->open_flags
& BDRV_O_UNMAP
))
1234 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
1235 "without setting discard operation to unmap");
1240 bs
->detect_zeroes
= value
;
1243 if (filename
!= NULL
) {
1244 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1246 bs
->filename
[0] = '\0';
1248 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1250 /* Open the image, either directly or using a protocol */
1251 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1252 node_name
= qemu_opt_get(opts
, "node-name");
1254 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1255 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1260 qemu_opts_del(opts
);
1264 qemu_opts_del(opts
);
1268 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1270 QObject
*options_obj
;
1274 ret
= strstart(filename
, "json:", &filename
);
1277 options_obj
= qobject_from_json(filename
, errp
);
1279 /* Work around qobject_from_json() lossage TODO fix that */
1280 if (errp
&& !*errp
) {
1281 error_setg(errp
, "Could not parse the JSON options");
1284 error_prepend(errp
, "Could not parse the JSON options: ");
1288 options
= qobject_to_qdict(options_obj
);
1290 qobject_decref(options_obj
);
1291 error_setg(errp
, "Invalid JSON object given");
1295 qdict_flatten(options
);
1300 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1303 QDict
*json_options
;
1304 Error
*local_err
= NULL
;
1306 /* Parse json: pseudo-protocol */
1307 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1311 json_options
= parse_json_filename(*pfilename
, &local_err
);
1313 error_propagate(errp
, local_err
);
1317 /* Options given in the filename have lower priority than options
1318 * specified directly */
1319 qdict_join(options
, json_options
, false);
1320 QDECREF(json_options
);
1325 * Fills in default options for opening images and converts the legacy
1326 * filename/flags pair to option QDict entries.
1327 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1328 * block driver has been specified explicitly.
1330 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1331 int *flags
, Error
**errp
)
1333 const char *drvname
;
1334 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1335 bool parse_filename
= false;
1336 BlockDriver
*drv
= NULL
;
1337 Error
*local_err
= NULL
;
1340 * Caution: while qdict_get_try_str() is fine, getting non-string
1341 * types would require more care. When @options come from
1342 * -blockdev or blockdev_add, its members are typed according to
1343 * the QAPI schema, but when they come from -drive, they're all
1346 drvname
= qdict_get_try_str(*options
, "driver");
1348 drv
= bdrv_find_format(drvname
);
1350 error_setg(errp
, "Unknown driver '%s'", drvname
);
1353 /* If the user has explicitly specified the driver, this choice should
1354 * override the BDRV_O_PROTOCOL flag */
1355 protocol
= drv
->bdrv_file_open
;
1359 *flags
|= BDRV_O_PROTOCOL
;
1361 *flags
&= ~BDRV_O_PROTOCOL
;
1364 /* Translate cache options from flags into options */
1365 update_options_from_flags(*options
, *flags
);
1367 /* Fetch the file name from the options QDict if necessary */
1368 if (protocol
&& filename
) {
1369 if (!qdict_haskey(*options
, "filename")) {
1370 qdict_put(*options
, "filename", qstring_from_str(filename
));
1371 parse_filename
= true;
1373 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1379 /* Find the right block driver */
1380 /* See cautionary note on accessing @options above */
1381 filename
= qdict_get_try_str(*options
, "filename");
1383 if (!drvname
&& protocol
) {
1385 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1390 drvname
= drv
->format_name
;
1391 qdict_put(*options
, "driver", qstring_from_str(drvname
));
1393 error_setg(errp
, "Must specify either driver or file");
1398 assert(drv
|| !protocol
);
1400 /* Driver-specific filename parsing */
1401 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1402 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1404 error_propagate(errp
, local_err
);
1408 if (!drv
->bdrv_needs_filename
) {
1409 qdict_del(*options
, "filename");
1416 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1417 GSList
*ignore_children
, Error
**errp
);
1418 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1419 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1422 * Check whether permissions on this node can be changed in a way that
1423 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1424 * permissions of all its parents. This involves checking whether all necessary
1425 * permission changes to child nodes can be performed.
1427 * A call to this function must always be followed by a call to bdrv_set_perm()
1428 * or bdrv_abort_perm_update().
1430 static int bdrv_check_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1431 uint64_t cumulative_shared_perms
,
1432 GSList
*ignore_children
, Error
**errp
)
1434 BlockDriver
*drv
= bs
->drv
;
1438 /* Write permissions never work with read-only images */
1439 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1440 bdrv_is_read_only(bs
))
1442 error_setg(errp
, "Block node is read-only");
1446 /* Check this node */
1451 if (drv
->bdrv_check_perm
) {
1452 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1453 cumulative_shared_perms
, errp
);
1456 /* Drivers that never have children can omit .bdrv_child_perm() */
1457 if (!drv
->bdrv_child_perm
) {
1458 assert(QLIST_EMPTY(&bs
->children
));
1462 /* Check all children */
1463 QLIST_FOREACH(c
, &bs
->children
, next
) {
1464 uint64_t cur_perm
, cur_shared
;
1465 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1466 cumulative_perms
, cumulative_shared_perms
,
1467 &cur_perm
, &cur_shared
);
1468 ret
= bdrv_child_check_perm(c
, cur_perm
, cur_shared
, ignore_children
,
1479 * Notifies drivers that after a previous bdrv_check_perm() call, the
1480 * permission update is not performed and any preparations made for it (e.g.
1481 * taken file locks) need to be undone.
1483 * This function recursively notifies all child nodes.
1485 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1487 BlockDriver
*drv
= bs
->drv
;
1494 if (drv
->bdrv_abort_perm_update
) {
1495 drv
->bdrv_abort_perm_update(bs
);
1498 QLIST_FOREACH(c
, &bs
->children
, next
) {
1499 bdrv_child_abort_perm_update(c
);
1503 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1504 uint64_t cumulative_shared_perms
)
1506 BlockDriver
*drv
= bs
->drv
;
1513 /* Update this node */
1514 if (drv
->bdrv_set_perm
) {
1515 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1518 /* Drivers that never have children can omit .bdrv_child_perm() */
1519 if (!drv
->bdrv_child_perm
) {
1520 assert(QLIST_EMPTY(&bs
->children
));
1524 /* Update all children */
1525 QLIST_FOREACH(c
, &bs
->children
, next
) {
1526 uint64_t cur_perm
, cur_shared
;
1527 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1528 cumulative_perms
, cumulative_shared_perms
,
1529 &cur_perm
, &cur_shared
);
1530 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1534 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1535 uint64_t *shared_perm
)
1538 uint64_t cumulative_perms
= 0;
1539 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1541 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1542 cumulative_perms
|= c
->perm
;
1543 cumulative_shared_perms
&= c
->shared_perm
;
1546 *perm
= cumulative_perms
;
1547 *shared_perm
= cumulative_shared_perms
;
1550 static char *bdrv_child_user_desc(BdrvChild
*c
)
1552 if (c
->role
->get_parent_desc
) {
1553 return c
->role
->get_parent_desc(c
);
1556 return g_strdup("another user");
1559 static char *bdrv_perm_names(uint64_t perm
)
1565 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1566 { BLK_PERM_WRITE
, "write" },
1567 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1568 { BLK_PERM_RESIZE
, "resize" },
1569 { BLK_PERM_GRAPH_MOD
, "change children" },
1573 char *result
= g_strdup("");
1574 struct perm_name
*p
;
1576 for (p
= permissions
; p
->name
; p
++) {
1577 if (perm
& p
->perm
) {
1579 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1588 * Checks whether a new reference to @bs can be added if the new user requires
1589 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1590 * set, the BdrvChild objects in this list are ignored in the calculations;
1591 * this allows checking permission updates for an existing reference.
1593 * Needs to be followed by a call to either bdrv_set_perm() or
1594 * bdrv_abort_perm_update(). */
1595 static int bdrv_check_update_perm(BlockDriverState
*bs
, uint64_t new_used_perm
,
1596 uint64_t new_shared_perm
,
1597 GSList
*ignore_children
, Error
**errp
)
1600 uint64_t cumulative_perms
= new_used_perm
;
1601 uint64_t cumulative_shared_perms
= new_shared_perm
;
1603 /* There is no reason why anyone couldn't tolerate write_unchanged */
1604 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1606 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1607 if (g_slist_find(ignore_children
, c
)) {
1611 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1612 char *user
= bdrv_child_user_desc(c
);
1613 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1614 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1616 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1622 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1623 char *user
= bdrv_child_user_desc(c
);
1624 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1625 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1627 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1633 cumulative_perms
|= c
->perm
;
1634 cumulative_shared_perms
&= c
->shared_perm
;
1637 return bdrv_check_perm(bs
, cumulative_perms
, cumulative_shared_perms
,
1638 ignore_children
, errp
);
1641 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1642 * bdrv_child_abort_perm_update(). */
1643 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1644 GSList
*ignore_children
, Error
**errp
)
1648 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1649 ret
= bdrv_check_update_perm(c
->bs
, perm
, shared
, ignore_children
, errp
);
1650 g_slist_free(ignore_children
);
1655 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
1657 uint64_t cumulative_perms
, cumulative_shared_perms
;
1660 c
->shared_perm
= shared
;
1662 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
1663 &cumulative_shared_perms
);
1664 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
1667 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
1669 bdrv_abort_perm_update(c
->bs
);
1672 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1677 ret
= bdrv_child_check_perm(c
, perm
, shared
, NULL
, errp
);
1679 bdrv_child_abort_perm_update(c
);
1683 bdrv_child_set_perm(c
, perm
, shared
);
1688 #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1690 | BLK_PERM_WRITE_UNCHANGED \
1692 #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1694 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1695 const BdrvChildRole
*role
,
1696 uint64_t perm
, uint64_t shared
,
1697 uint64_t *nperm
, uint64_t *nshared
)
1700 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
1701 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
1705 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
1706 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
1707 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
1708 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
1711 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1712 const BdrvChildRole
*role
,
1713 uint64_t perm
, uint64_t shared
,
1714 uint64_t *nperm
, uint64_t *nshared
)
1716 bool backing
= (role
== &child_backing
);
1717 assert(role
== &child_backing
|| role
== &child_file
);
1720 /* Apart from the modifications below, the same permissions are
1721 * forwarded and left alone as for filters */
1722 bdrv_filter_default_perms(bs
, c
, role
, perm
, shared
, &perm
, &shared
);
1724 /* Format drivers may touch metadata even if the guest doesn't write */
1725 if (!bdrv_is_read_only(bs
)) {
1726 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1729 /* bs->file always needs to be consistent because of the metadata. We
1730 * can never allow other users to resize or write to it. */
1731 perm
|= BLK_PERM_CONSISTENT_READ
;
1732 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
1734 /* We want consistent read from backing files if the parent needs it.
1735 * No other operations are performed on backing files. */
1736 perm
&= BLK_PERM_CONSISTENT_READ
;
1738 /* If the parent can deal with changing data, we're okay with a
1739 * writable and resizable backing file. */
1740 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1741 if (shared
& BLK_PERM_WRITE
) {
1742 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1747 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
1748 BLK_PERM_WRITE_UNCHANGED
;
1755 static void bdrv_replace_child_noperm(BdrvChild
*child
,
1756 BlockDriverState
*new_bs
)
1758 BlockDriverState
*old_bs
= child
->bs
;
1760 if (old_bs
&& new_bs
) {
1761 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
1764 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1765 child
->role
->drained_end(child
);
1767 if (child
->role
->detach
) {
1768 child
->role
->detach(child
);
1770 QLIST_REMOVE(child
, next_parent
);
1776 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1777 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1778 child
->role
->drained_begin(child
);
1781 if (child
->role
->attach
) {
1782 child
->role
->attach(child
);
1788 * Updates @child to change its reference to point to @new_bs, including
1789 * checking and applying the necessary permisson updates both to the old node
1792 * NULL is passed as @new_bs for removing the reference before freeing @child.
1794 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
1795 * function uses bdrv_set_perm() to update the permissions according to the new
1796 * reference that @new_bs gets.
1798 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1800 BlockDriverState
*old_bs
= child
->bs
;
1801 uint64_t perm
, shared_perm
;
1804 /* Update permissions for old node. This is guaranteed to succeed
1805 * because we're just taking a parent away, so we're loosening
1807 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
1808 bdrv_check_perm(old_bs
, perm
, shared_perm
, NULL
, &error_abort
);
1809 bdrv_set_perm(old_bs
, perm
, shared_perm
);
1812 bdrv_replace_child_noperm(child
, new_bs
);
1815 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
1816 bdrv_set_perm(new_bs
, perm
, shared_perm
);
1820 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1821 const char *child_name
,
1822 const BdrvChildRole
*child_role
,
1823 uint64_t perm
, uint64_t shared_perm
,
1824 void *opaque
, Error
**errp
)
1829 ret
= bdrv_check_update_perm(child_bs
, perm
, shared_perm
, NULL
, errp
);
1831 bdrv_abort_perm_update(child_bs
);
1835 child
= g_new(BdrvChild
, 1);
1836 *child
= (BdrvChild
) {
1838 .name
= g_strdup(child_name
),
1841 .shared_perm
= shared_perm
,
1845 /* This performs the matching bdrv_set_perm() for the above check. */
1846 bdrv_replace_child(child
, child_bs
);
1851 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1852 BlockDriverState
*child_bs
,
1853 const char *child_name
,
1854 const BdrvChildRole
*child_role
,
1858 uint64_t perm
, shared_perm
;
1860 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
1862 assert(parent_bs
->drv
);
1863 assert(bdrv_get_aio_context(parent_bs
) == bdrv_get_aio_context(child_bs
));
1864 parent_bs
->drv
->bdrv_child_perm(parent_bs
, NULL
, child_role
,
1865 perm
, shared_perm
, &perm
, &shared_perm
);
1867 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
1868 perm
, shared_perm
, parent_bs
, errp
);
1869 if (child
== NULL
) {
1873 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1877 static void bdrv_detach_child(BdrvChild
*child
)
1879 if (child
->next
.le_prev
) {
1880 QLIST_REMOVE(child
, next
);
1881 child
->next
.le_prev
= NULL
;
1884 bdrv_replace_child(child
, NULL
);
1886 g_free(child
->name
);
1890 void bdrv_root_unref_child(BdrvChild
*child
)
1892 BlockDriverState
*child_bs
;
1894 child_bs
= child
->bs
;
1895 bdrv_detach_child(child
);
1896 bdrv_unref(child_bs
);
1899 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1901 if (child
== NULL
) {
1905 if (child
->bs
->inherits_from
== parent
) {
1908 /* Remove inherits_from only when the last reference between parent and
1909 * child->bs goes away. */
1910 QLIST_FOREACH(c
, &parent
->children
, next
) {
1911 if (c
!= child
&& c
->bs
== child
->bs
) {
1916 child
->bs
->inherits_from
= NULL
;
1920 bdrv_root_unref_child(child
);
1924 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
1927 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1928 if (c
->role
->change_media
) {
1929 c
->role
->change_media(c
, load
);
1934 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
1937 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1938 if (c
->role
->resize
) {
1945 * Sets the backing file link of a BDS. A new reference is created; callers
1946 * which don't need their own reference any more must call bdrv_unref().
1948 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
1952 bdrv_ref(backing_hd
);
1956 bdrv_unref_child(bs
, bs
->backing
);
1964 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
1967 bdrv_unref(backing_hd
);
1970 bdrv_refresh_filename(bs
);
1973 bdrv_refresh_limits(bs
, NULL
);
1977 * Opens the backing file for a BlockDriverState if not yet open
1979 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
1980 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1981 * itself, all options starting with "${bdref_key}." are considered part of the
1984 * TODO Can this be unified with bdrv_open_image()?
1986 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
1987 const char *bdref_key
, Error
**errp
)
1989 char *backing_filename
= g_malloc0(PATH_MAX
);
1990 char *bdref_key_dot
;
1991 const char *reference
= NULL
;
1993 BlockDriverState
*backing_hd
;
1995 QDict
*tmp_parent_options
= NULL
;
1996 Error
*local_err
= NULL
;
1998 if (bs
->backing
!= NULL
) {
2002 /* NULL means an empty set of options */
2003 if (parent_options
== NULL
) {
2004 tmp_parent_options
= qdict_new();
2005 parent_options
= tmp_parent_options
;
2008 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2010 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2011 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2012 g_free(bdref_key_dot
);
2015 * Caution: while qdict_get_try_str() is fine, getting non-string
2016 * types would require more care. When @parent_options come from
2017 * -blockdev or blockdev_add, its members are typed according to
2018 * the QAPI schema, but when they come from -drive, they're all
2021 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2022 if (reference
|| qdict_haskey(options
, "file.filename")) {
2023 backing_filename
[0] = '\0';
2024 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2028 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
2032 error_propagate(errp
, local_err
);
2038 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2040 error_setg(errp
, "Driver doesn't support backing files");
2045 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2046 qdict_put(options
, "driver", qstring_from_str(bs
->backing_format
));
2049 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
2050 reference
, options
, 0, bs
, &child_backing
,
2053 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2054 error_prepend(errp
, "Could not open backing file: ");
2059 /* Hook up the backing file link; drop our reference, bs owns the
2060 * backing_hd reference now */
2061 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2062 bdrv_unref(backing_hd
);
2064 error_propagate(errp
, local_err
);
2069 qdict_del(parent_options
, bdref_key
);
2072 g_free(backing_filename
);
2073 QDECREF(tmp_parent_options
);
2077 static BlockDriverState
*
2078 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2079 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2080 bool allow_none
, Error
**errp
)
2082 BlockDriverState
*bs
= NULL
;
2083 QDict
*image_options
;
2084 char *bdref_key_dot
;
2085 const char *reference
;
2087 assert(child_role
!= NULL
);
2089 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2090 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2091 g_free(bdref_key_dot
);
2094 * Caution: while qdict_get_try_str() is fine, getting non-string
2095 * types would require more care. When @options come from
2096 * -blockdev or blockdev_add, its members are typed according to
2097 * the QAPI schema, but when they come from -drive, they're all
2100 reference
= qdict_get_try_str(options
, bdref_key
);
2101 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2103 error_setg(errp
, "A block device must be specified for \"%s\"",
2106 QDECREF(image_options
);
2110 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2111 parent
, child_role
, errp
);
2117 qdict_del(options
, bdref_key
);
2122 * Opens a disk image whose options are given as BlockdevRef in another block
2125 * If allow_none is true, no image will be opened if filename is false and no
2126 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2128 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2129 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2130 * itself, all options starting with "${bdref_key}." are considered part of the
2133 * The BlockdevRef will be removed from the options QDict.
2135 BdrvChild
*bdrv_open_child(const char *filename
,
2136 QDict
*options
, const char *bdref_key
,
2137 BlockDriverState
*parent
,
2138 const BdrvChildRole
*child_role
,
2139 bool allow_none
, Error
**errp
)
2142 BlockDriverState
*bs
;
2144 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2150 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2159 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2161 QDict
*snapshot_options
,
2164 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2165 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2167 QemuOpts
*opts
= NULL
;
2168 BlockDriverState
*bs_snapshot
;
2169 Error
*local_err
= NULL
;
2172 /* if snapshot, we create a temporary backing file and open it
2173 instead of opening 'filename' directly */
2175 /* Get the required size from the image */
2176 total_size
= bdrv_getlength(bs
);
2177 if (total_size
< 0) {
2178 error_setg_errno(errp
, -total_size
, "Could not get image size");
2182 /* Create the temporary image */
2183 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2185 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2189 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2191 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2192 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2193 qemu_opts_del(opts
);
2195 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2200 /* Prepare options QDict for the temporary file */
2201 qdict_put(snapshot_options
, "file.driver",
2202 qstring_from_str("file"));
2203 qdict_put(snapshot_options
, "file.filename",
2204 qstring_from_str(tmp_filename
));
2205 qdict_put(snapshot_options
, "driver",
2206 qstring_from_str("qcow2"));
2208 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2209 snapshot_options
= NULL
;
2215 /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
2216 * call bdrv_unref() on it), so in order to be able to return one, we have
2217 * to increase bs_snapshot's refcount here */
2218 bdrv_ref(bs_snapshot
);
2219 bdrv_append(bs_snapshot
, bs
, &local_err
);
2221 error_propagate(errp
, local_err
);
2226 g_free(tmp_filename
);
2230 QDECREF(snapshot_options
);
2231 g_free(tmp_filename
);
2236 * Opens a disk image (raw, qcow2, vmdk, ...)
2238 * options is a QDict of options to pass to the block drivers, or NULL for an
2239 * empty set of options. The reference to the QDict belongs to the block layer
2240 * after the call (even on failure), so if the caller intends to reuse the
2241 * dictionary, it needs to use QINCREF() before calling bdrv_open.
2243 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2244 * If it is not NULL, the referenced BDS will be reused.
2246 * The reference parameter may be used to specify an existing block device which
2247 * should be opened. If specified, neither options nor a filename may be given,
2248 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2250 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2251 const char *reference
,
2252 QDict
*options
, int flags
,
2253 BlockDriverState
*parent
,
2254 const BdrvChildRole
*child_role
,
2258 BlockBackend
*file
= NULL
;
2259 BlockDriverState
*bs
;
2260 BlockDriver
*drv
= NULL
;
2261 const char *drvname
;
2262 const char *backing
;
2263 Error
*local_err
= NULL
;
2264 QDict
*snapshot_options
= NULL
;
2265 int snapshot_flags
= 0;
2267 assert(!child_role
|| !flags
);
2268 assert(!child_role
== !parent
);
2271 bool options_non_empty
= options
? qdict_size(options
) : false;
2274 if (filename
|| options_non_empty
) {
2275 error_setg(errp
, "Cannot reference an existing block device with "
2276 "additional options or a new filename");
2280 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2291 /* NULL means an empty set of options */
2292 if (options
== NULL
) {
2293 options
= qdict_new();
2296 /* json: syntax counts as explicit options, as if in the QDict */
2297 parse_json_protocol(options
, &filename
, &local_err
);
2302 bs
->explicit_options
= qdict_clone_shallow(options
);
2305 bs
->inherits_from
= parent
;
2306 child_role
->inherit_options(&flags
, options
,
2307 parent
->open_flags
, parent
->options
);
2310 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2316 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2317 * Caution: getting a boolean member of @options requires care.
2318 * When @options come from -blockdev or blockdev_add, members are
2319 * typed according to the QAPI schema, but when they come from
2320 * -drive, they're all QString.
2322 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2323 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2324 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2326 flags
&= ~BDRV_O_RDWR
;
2329 if (flags
& BDRV_O_SNAPSHOT
) {
2330 snapshot_options
= qdict_new();
2331 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2333 /* Let bdrv_backing_options() override "read-only" */
2334 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2335 bdrv_backing_options(&flags
, options
, flags
, options
);
2338 bs
->open_flags
= flags
;
2339 bs
->options
= options
;
2340 options
= qdict_clone_shallow(options
);
2342 /* Find the right image format driver */
2343 /* See cautionary note on accessing @options above */
2344 drvname
= qdict_get_try_str(options
, "driver");
2346 drv
= bdrv_find_format(drvname
);
2348 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2353 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2355 /* See cautionary note on accessing @options above */
2356 backing
= qdict_get_try_str(options
, "backing");
2357 if (backing
&& *backing
== '\0') {
2358 flags
|= BDRV_O_NO_BACKING
;
2359 qdict_del(options
, "backing");
2362 /* Open image file without format layer. This BlockBackend is only used for
2363 * probing, the block drivers will do their own bdrv_open_child() for the
2364 * same BDS, which is why we put the node name back into options. */
2365 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2366 BlockDriverState
*file_bs
;
2368 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2369 &child_file
, true, &local_err
);
2373 if (file_bs
!= NULL
) {
2374 file
= blk_new(BLK_PERM_CONSISTENT_READ
, BLK_PERM_ALL
);
2375 blk_insert_bs(file
, file_bs
, &local_err
);
2376 bdrv_unref(file_bs
);
2381 qdict_put(options
, "file",
2382 qstring_from_str(bdrv_get_node_name(file_bs
)));
2386 /* Image format probing */
2389 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2394 * This option update would logically belong in bdrv_fill_options(),
2395 * but we first need to open bs->file for the probing to work, while
2396 * opening bs->file already requires the (mostly) final set of options
2397 * so that cache mode etc. can be inherited.
2399 * Adding the driver later is somewhat ugly, but it's not an option
2400 * that would ever be inherited, so it's correct. We just need to make
2401 * sure to update both bs->options (which has the full effective
2402 * options for bs) and options (which has file.* already removed).
2404 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
2405 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
2407 error_setg(errp
, "Must specify either driver or file");
2411 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2412 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2413 /* file must be NULL if a protocol BDS is about to be created
2414 * (the inverse results in an error message from bdrv_open_common()) */
2415 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2417 /* Open the image */
2418 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2428 /* If there is a backing file, use it */
2429 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2430 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2432 goto close_and_fail
;
2436 bdrv_refresh_filename(bs
);
2438 /* Check if any unknown options were used */
2439 if (qdict_size(options
) != 0) {
2440 const QDictEntry
*entry
= qdict_first(options
);
2441 if (flags
& BDRV_O_PROTOCOL
) {
2442 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2443 "'%s'", drv
->format_name
, entry
->key
);
2446 "Block format '%s' does not support the option '%s'",
2447 drv
->format_name
, entry
->key
);
2450 goto close_and_fail
;
2453 if (!bdrv_key_required(bs
)) {
2454 bdrv_parent_cb_change_media(bs
, true);
2455 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
2456 && !runstate_check(RUN_STATE_INMIGRATE
)
2457 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
2459 "Guest must be stopped for opening of encrypted image");
2460 goto close_and_fail
;
2465 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2466 * temporary snapshot afterwards. */
2467 if (snapshot_flags
) {
2468 BlockDriverState
*snapshot_bs
;
2469 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2470 snapshot_options
, &local_err
);
2471 snapshot_options
= NULL
;
2473 goto close_and_fail
;
2475 /* We are not going to return bs but the overlay on top of it
2476 * (snapshot_bs); thus, we have to drop the strong reference to bs
2477 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2478 * though, because the overlay still has a reference to it. */
2487 if (bs
->file
!= NULL
) {
2488 bdrv_unref_child(bs
, bs
->file
);
2490 QDECREF(snapshot_options
);
2491 QDECREF(bs
->explicit_options
);
2492 QDECREF(bs
->options
);
2496 error_propagate(errp
, local_err
);
2501 QDECREF(snapshot_options
);
2503 error_propagate(errp
, local_err
);
2507 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2508 QDict
*options
, int flags
, Error
**errp
)
2510 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2514 typedef struct BlockReopenQueueEntry
{
2516 BDRVReopenState state
;
2517 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
2518 } BlockReopenQueueEntry
;
2521 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2522 * reopen of multiple devices.
2524 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2525 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2526 * be created and initialized. This newly created BlockReopenQueue should be
2527 * passed back in for subsequent calls that are intended to be of the same
2530 * bs is the BlockDriverState to add to the reopen queue.
2532 * options contains the changed options for the associated bs
2533 * (the BlockReopenQueue takes ownership)
2535 * flags contains the open flags for the associated bs
2537 * returns a pointer to bs_queue, which is either the newly allocated
2538 * bs_queue, or the existing bs_queue being used.
2541 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
2542 BlockDriverState
*bs
,
2545 const BdrvChildRole
*role
,
2546 QDict
*parent_options
,
2551 BlockReopenQueueEntry
*bs_entry
;
2553 QDict
*old_options
, *explicit_options
;
2555 if (bs_queue
== NULL
) {
2556 bs_queue
= g_new0(BlockReopenQueue
, 1);
2557 QSIMPLEQ_INIT(bs_queue
);
2561 options
= qdict_new();
2564 /* Check if this BlockDriverState is already in the queue */
2565 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2566 if (bs
== bs_entry
->state
.bs
) {
2572 * Precedence of options:
2573 * 1. Explicitly passed in options (highest)
2574 * 2. Set in flags (only for top level)
2575 * 3. Retained from explicitly set options of bs
2576 * 4. Inherited from parent node
2577 * 5. Retained from effective options of bs
2580 if (!parent_options
) {
2582 * Any setting represented by flags is always updated. If the
2583 * corresponding QDict option is set, it takes precedence. Otherwise
2584 * the flag is translated into a QDict option. The old setting of bs is
2587 update_options_from_flags(options
, flags
);
2590 /* Old explicitly set values (don't overwrite by inherited value) */
2592 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
2594 old_options
= qdict_clone_shallow(bs
->explicit_options
);
2596 bdrv_join_options(bs
, options
, old_options
);
2597 QDECREF(old_options
);
2599 explicit_options
= qdict_clone_shallow(options
);
2601 /* Inherit from parent node */
2602 if (parent_options
) {
2604 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
2607 /* Old values are used for options that aren't set yet */
2608 old_options
= qdict_clone_shallow(bs
->options
);
2609 bdrv_join_options(bs
, options
, old_options
);
2610 QDECREF(old_options
);
2612 /* bdrv_open() masks this flag out */
2613 flags
&= ~BDRV_O_PROTOCOL
;
2615 QLIST_FOREACH(child
, &bs
->children
, next
) {
2616 QDict
*new_child_options
;
2617 char *child_key_dot
;
2619 /* reopen can only change the options of block devices that were
2620 * implicitly created and inherited options. For other (referenced)
2621 * block devices, a syntax like "backing.foo" results in an error. */
2622 if (child
->bs
->inherits_from
!= bs
) {
2626 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2627 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
2628 g_free(child_key_dot
);
2630 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
2631 child
->role
, options
, flags
);
2635 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
2636 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
2638 QDECREF(bs_entry
->state
.options
);
2639 QDECREF(bs_entry
->state
.explicit_options
);
2642 bs_entry
->state
.bs
= bs
;
2643 bs_entry
->state
.options
= options
;
2644 bs_entry
->state
.explicit_options
= explicit_options
;
2645 bs_entry
->state
.flags
= flags
;
2650 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
2651 BlockDriverState
*bs
,
2652 QDict
*options
, int flags
)
2654 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
2659 * Reopen multiple BlockDriverStates atomically & transactionally.
2661 * The queue passed in (bs_queue) must have been built up previous
2662 * via bdrv_reopen_queue().
2664 * Reopens all BDS specified in the queue, with the appropriate
2665 * flags. All devices are prepared for reopen, and failure of any
2666 * device will cause all device changes to be abandonded, and intermediate
2669 * If all devices prepare successfully, then the changes are committed
2673 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
2676 BlockReopenQueueEntry
*bs_entry
, *next
;
2677 Error
*local_err
= NULL
;
2679 assert(bs_queue
!= NULL
);
2681 aio_context_release(ctx
);
2682 bdrv_drain_all_begin();
2683 aio_context_acquire(ctx
);
2685 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2686 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
2687 error_propagate(errp
, local_err
);
2690 bs_entry
->prepared
= true;
2693 /* If we reach this point, we have success and just need to apply the
2696 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2697 bdrv_reopen_commit(&bs_entry
->state
);
2703 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
2704 if (ret
&& bs_entry
->prepared
) {
2705 bdrv_reopen_abort(&bs_entry
->state
);
2707 QDECREF(bs_entry
->state
.explicit_options
);
2709 QDECREF(bs_entry
->state
.options
);
2714 bdrv_drain_all_end();
2720 /* Reopen a single BlockDriverState with the specified flags. */
2721 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
2724 Error
*local_err
= NULL
;
2725 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
2727 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, &local_err
);
2728 if (local_err
!= NULL
) {
2729 error_propagate(errp
, local_err
);
2736 * Prepares a BlockDriverState for reopen. All changes are staged in the
2737 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2738 * the block driver layer .bdrv_reopen_prepare()
2740 * bs is the BlockDriverState to reopen
2741 * flags are the new open flags
2742 * queue is the reopen queue
2744 * Returns 0 on success, non-zero on error. On error errp will be set
2747 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2748 * It is the responsibility of the caller to then call the abort() or
2749 * commit() for any other BDS that have been left in a prepare() state
2752 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2756 Error
*local_err
= NULL
;
2761 assert(reopen_state
!= NULL
);
2762 assert(reopen_state
->bs
->drv
!= NULL
);
2763 drv
= reopen_state
->bs
->drv
;
2765 /* Process generic block layer options */
2766 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2767 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2769 error_propagate(errp
, local_err
);
2774 update_flags_from_options(&reopen_state
->flags
, opts
);
2776 /* node-name and driver must be unchanged. Put them back into the QDict, so
2777 * that they are checked at the end of this function. */
2778 value
= qemu_opt_get(opts
, "node-name");
2780 qdict_put(reopen_state
->options
, "node-name", qstring_from_str(value
));
2783 value
= qemu_opt_get(opts
, "driver");
2785 qdict_put(reopen_state
->options
, "driver", qstring_from_str(value
));
2788 /* if we are to stay read-only, do not allow permission change
2790 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
2791 reopen_state
->flags
& BDRV_O_RDWR
) {
2792 error_setg(errp
, "Node '%s' is read only",
2793 bdrv_get_device_or_node_name(reopen_state
->bs
));
2798 ret
= bdrv_flush(reopen_state
->bs
);
2800 error_setg_errno(errp
, -ret
, "Error flushing drive");
2804 if (drv
->bdrv_reopen_prepare
) {
2805 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2807 if (local_err
!= NULL
) {
2808 error_propagate(errp
, local_err
);
2810 error_setg(errp
, "failed while preparing to reopen image '%s'",
2811 reopen_state
->bs
->filename
);
2816 /* It is currently mandatory to have a bdrv_reopen_prepare()
2817 * handler for each supported drv. */
2818 error_setg(errp
, "Block format '%s' used by node '%s' "
2819 "does not support reopening files", drv
->format_name
,
2820 bdrv_get_device_or_node_name(reopen_state
->bs
));
2825 /* Options that are not handled are only okay if they are unchanged
2826 * compared to the old state. It is expected that some options are only
2827 * used for the initial open, but not reopen (e.g. filename) */
2828 if (qdict_size(reopen_state
->options
)) {
2829 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2832 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2833 const char *new = qstring_get_str(new_obj
);
2835 * Caution: while qdict_get_try_str() is fine, getting
2836 * non-string types would require more care. When
2837 * bs->options come from -blockdev or blockdev_add, its
2838 * members are typed according to the QAPI schema, but
2839 * when they come from -drive, they're all QString.
2841 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2844 if (!old
|| strcmp(new, old
)) {
2845 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2849 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2855 qemu_opts_del(opts
);
2860 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2861 * makes them final by swapping the staging BlockDriverState contents into
2862 * the active BlockDriverState contents.
2864 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2868 assert(reopen_state
!= NULL
);
2869 drv
= reopen_state
->bs
->drv
;
2870 assert(drv
!= NULL
);
2872 /* If there are any driver level actions to take */
2873 if (drv
->bdrv_reopen_commit
) {
2874 drv
->bdrv_reopen_commit(reopen_state
);
2877 /* set BDS specific flags now */
2878 QDECREF(reopen_state
->bs
->explicit_options
);
2880 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2881 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2882 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2884 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2888 * Abort the reopen, and delete and free the staged changes in
2891 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2895 assert(reopen_state
!= NULL
);
2896 drv
= reopen_state
->bs
->drv
;
2897 assert(drv
!= NULL
);
2899 if (drv
->bdrv_reopen_abort
) {
2900 drv
->bdrv_reopen_abort(reopen_state
);
2903 QDECREF(reopen_state
->explicit_options
);
2907 static void bdrv_close(BlockDriverState
*bs
)
2909 BdrvAioNotifier
*ban
, *ban_next
;
2912 assert(!bs
->refcnt
);
2914 bdrv_drained_begin(bs
); /* complete I/O */
2916 bdrv_drain(bs
); /* in case flush left pending I/O */
2918 bdrv_release_named_dirty_bitmaps(bs
);
2919 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2922 BdrvChild
*child
, *next
;
2924 bs
->drv
->bdrv_close(bs
);
2927 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
2929 if (bs
->file
!= NULL
) {
2930 bdrv_unref_child(bs
, bs
->file
);
2934 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2935 /* TODO Remove bdrv_unref() from drivers' close function and use
2936 * bdrv_unref_child() here */
2937 if (child
->bs
->inherits_from
== bs
) {
2938 child
->bs
->inherits_from
= NULL
;
2940 bdrv_detach_child(child
);
2945 bs
->copy_on_read
= 0;
2946 bs
->backing_file
[0] = '\0';
2947 bs
->backing_format
[0] = '\0';
2948 bs
->total_sectors
= 0;
2949 bs
->encrypted
= false;
2950 bs
->valid_key
= false;
2952 QDECREF(bs
->options
);
2953 QDECREF(bs
->explicit_options
);
2955 QDECREF(bs
->full_open_options
);
2956 bs
->full_open_options
= NULL
;
2959 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2962 QLIST_INIT(&bs
->aio_notifiers
);
2963 bdrv_drained_end(bs
);
2966 void bdrv_close_all(void)
2968 block_job_cancel_sync_all();
2969 nbd_export_close_all();
2971 /* Drop references from requests still in flight, such as canceled block
2972 * jobs whose AIO context has not been polled yet */
2975 blk_remove_all_bs();
2976 blockdev_close_all_bdrv_states();
2978 assert(QTAILQ_EMPTY(&all_bdrv_states
));
2981 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
2985 if (c
->role
->stay_at_node
) {
2989 if (c
->role
== &child_backing
) {
2990 /* If @from is a backing file of @to, ignore the child to avoid
2991 * creating a loop. We only want to change the pointer of other
2993 QLIST_FOREACH(to_c
, &to
->children
, next
) {
3006 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
3009 BdrvChild
*c
, *next
;
3010 GSList
*list
= NULL
, *p
;
3011 uint64_t old_perm
, old_shared
;
3012 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
3015 assert(!atomic_read(&from
->in_flight
));
3016 assert(!atomic_read(&to
->in_flight
));
3018 /* Make sure that @from doesn't go away until we have successfully attached
3019 * all of its parents to @to. */
3022 /* Put all parents into @list and calculate their cumulative permissions */
3023 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
3024 if (!should_update_child(c
, to
)) {
3027 list
= g_slist_prepend(list
, c
);
3029 shared
&= c
->shared_perm
;
3032 /* Check whether the required permissions can be granted on @to, ignoring
3033 * all BdrvChild in @list so that they can't block themselves. */
3034 ret
= bdrv_check_update_perm(to
, perm
, shared
, list
, errp
);
3036 bdrv_abort_perm_update(to
);
3040 /* Now actually perform the change. We performed the permission check for
3041 * all elements of @list at once, so set the permissions all at once at the
3043 for (p
= list
; p
!= NULL
; p
= p
->next
) {
3047 bdrv_replace_child_noperm(c
, to
);
3051 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3052 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3060 * Add new bs contents at the top of an image chain while the chain is
3061 * live, while keeping required fields on the top layer.
3063 * This will modify the BlockDriverState fields, and swap contents
3064 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3066 * bs_new must not be attached to a BlockBackend.
3068 * This function does not create any image files.
3070 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3071 * that's what the callers commonly need. bs_new will be referenced by the old
3072 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3073 * reference of its own, it must call bdrv_ref().
3075 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3078 Error
*local_err
= NULL
;
3080 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3082 error_propagate(errp
, local_err
);
3086 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3088 error_propagate(errp
, local_err
);
3089 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3093 /* bs_new is now referenced by its new parents, we don't need the
3094 * additional reference any more. */
3099 static void bdrv_delete(BlockDriverState
*bs
)
3102 assert(bdrv_op_blocker_is_empty(bs
));
3103 assert(!bs
->refcnt
);
3107 /* remove from list, if necessary */
3108 if (bs
->node_name
[0] != '\0') {
3109 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3111 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3117 * Run consistency checks on an image
3119 * Returns 0 if the check could be completed (it doesn't mean that the image is
3120 * free of errors) or -errno when an internal error occurred. The results of the
3121 * check are stored in res.
3123 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
3125 if (bs
->drv
== NULL
) {
3128 if (bs
->drv
->bdrv_check
== NULL
) {
3132 memset(res
, 0, sizeof(*res
));
3133 return bs
->drv
->bdrv_check(bs
, res
, fix
);
3139 * -EINVAL - backing format specified, but no file
3140 * -ENOSPC - can't update the backing file because no space is left in the
3142 * -ENOTSUP - format driver doesn't support changing the backing file
3144 int bdrv_change_backing_file(BlockDriverState
*bs
,
3145 const char *backing_file
, const char *backing_fmt
)
3147 BlockDriver
*drv
= bs
->drv
;
3150 /* Backing file format doesn't make sense without a backing file */
3151 if (backing_fmt
&& !backing_file
) {
3155 if (drv
->bdrv_change_backing_file
!= NULL
) {
3156 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3162 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3163 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3169 * Finds the image layer in the chain that has 'bs' as its backing file.
3171 * active is the current topmost image.
3173 * Returns NULL if bs is not found in active's image chain,
3174 * or if active == bs.
3176 * Returns the bottommost base image if bs == NULL.
3178 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3179 BlockDriverState
*bs
)
3181 while (active
&& bs
!= backing_bs(active
)) {
3182 active
= backing_bs(active
);
3188 /* Given a BDS, searches for the base layer. */
3189 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3191 return bdrv_find_overlay(bs
, NULL
);
3195 * Drops images above 'base' up to and including 'top', and sets the image
3196 * above 'top' to have base as its backing file.
3198 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3199 * information in 'bs' can be properly updated.
3201 * E.g., this will convert the following chain:
3202 * bottom <- base <- intermediate <- top <- active
3206 * bottom <- base <- active
3208 * It is allowed for bottom==base, in which case it converts:
3210 * base <- intermediate <- top <- active
3216 * If backing_file_str is non-NULL, it will be used when modifying top's
3217 * overlay image metadata.
3220 * if active == top, that is considered an error
3223 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
3224 BlockDriverState
*base
, const char *backing_file_str
)
3226 BlockDriverState
*new_top_bs
= NULL
;
3227 Error
*local_err
= NULL
;
3230 if (!top
->drv
|| !base
->drv
) {
3234 new_top_bs
= bdrv_find_overlay(active
, top
);
3236 if (new_top_bs
== NULL
) {
3237 /* we could not find the image above 'top', this is an error */
3241 /* special case of new_top_bs->backing->bs already pointing to base - nothing
3242 * to do, no intermediate images */
3243 if (backing_bs(new_top_bs
) == base
) {
3248 /* Make sure that base is in the backing chain of top */
3249 if (!bdrv_chain_contains(top
, base
)) {
3253 /* success - we can delete the intermediate states, and link top->base */
3254 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
3255 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
3256 base
->drv
? base
->drv
->format_name
: "");
3261 bdrv_set_backing_hd(new_top_bs
, base
, &local_err
);
3264 error_report_err(local_err
);
3274 * Truncate file to 'offset' bytes (needed only for file protocols)
3276 int bdrv_truncate(BdrvChild
*child
, int64_t offset
)
3278 BlockDriverState
*bs
= child
->bs
;
3279 BlockDriver
*drv
= bs
->drv
;
3282 /* FIXME: Some format block drivers use this function instead of implicitly
3283 * growing their file by writing beyond its end.
3284 * See bdrv_aligned_pwritev() for an explanation why we currently
3285 * cannot assert this permission in that case. */
3286 // assert(child->perm & BLK_PERM_RESIZE);
3290 if (!drv
->bdrv_truncate
)
3295 ret
= drv
->bdrv_truncate(bs
, offset
);
3297 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
3298 bdrv_dirty_bitmap_truncate(bs
);
3299 bdrv_parent_cb_resize(bs
);
3306 * Length of a allocated file in bytes. Sparse files are counted by actual
3307 * allocated space. Return < 0 if error or unknown.
3309 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
3311 BlockDriver
*drv
= bs
->drv
;
3315 if (drv
->bdrv_get_allocated_file_size
) {
3316 return drv
->bdrv_get_allocated_file_size(bs
);
3319 return bdrv_get_allocated_file_size(bs
->file
->bs
);
3325 * Return number of sectors on success, -errno on error.
3327 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
3329 BlockDriver
*drv
= bs
->drv
;
3334 if (drv
->has_variable_length
) {
3335 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3340 return bs
->total_sectors
;
3344 * Return length in bytes on success, -errno on error.
3345 * The length is always a multiple of BDRV_SECTOR_SIZE.
3347 int64_t bdrv_getlength(BlockDriverState
*bs
)
3349 int64_t ret
= bdrv_nb_sectors(bs
);
3351 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
3352 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
3355 /* return 0 as number of sectors if no device present or error */
3356 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
3358 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
3360 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
3363 bool bdrv_is_read_only(BlockDriverState
*bs
)
3365 return bs
->read_only
;
3368 bool bdrv_is_sg(BlockDriverState
*bs
)
3373 bool bdrv_is_encrypted(BlockDriverState
*bs
)
3375 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3378 return bs
->encrypted
;
3381 bool bdrv_key_required(BlockDriverState
*bs
)
3383 BdrvChild
*backing
= bs
->backing
;
3385 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
3388 return (bs
->encrypted
&& !bs
->valid_key
);
3391 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
3394 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3395 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
3401 if (!bs
->encrypted
) {
3403 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
3406 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
3408 bs
->valid_key
= false;
3409 } else if (!bs
->valid_key
) {
3410 /* call the change callback now, we skipped it on open */
3411 bs
->valid_key
= true;
3412 bdrv_parent_cb_change_media(bs
, true);
3418 * Provide an encryption key for @bs.
3419 * If @key is non-null:
3420 * If @bs is not encrypted, fail.
3421 * Else if the key is invalid, fail.
3422 * Else set @bs's key to @key, replacing the existing key, if any.
3424 * If @bs is encrypted and still lacks a key, fail.
3426 * On failure, store an error object through @errp if non-null.
3428 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
3431 if (!bdrv_is_encrypted(bs
)) {
3432 error_setg(errp
, "Node '%s' is not encrypted",
3433 bdrv_get_device_or_node_name(bs
));
3434 } else if (bdrv_set_key(bs
, key
) < 0) {
3435 error_setg(errp
, QERR_INVALID_PASSWORD
);
3438 if (bdrv_key_required(bs
)) {
3439 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
3440 "'%s' (%s) is encrypted",
3441 bdrv_get_device_or_node_name(bs
),
3442 bdrv_get_encrypted_filename(bs
));
3447 const char *bdrv_get_format_name(BlockDriverState
*bs
)
3449 return bs
->drv
? bs
->drv
->format_name
: NULL
;
3452 static int qsort_strcmp(const void *a
, const void *b
)
3454 return strcmp(*(char *const *)a
, *(char *const *)b
);
3457 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
3463 const char **formats
= NULL
;
3465 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
3466 if (drv
->format_name
) {
3469 while (formats
&& i
&& !found
) {
3470 found
= !strcmp(formats
[--i
], drv
->format_name
);
3474 formats
= g_renew(const char *, formats
, count
+ 1);
3475 formats
[count
++] = drv
->format_name
;
3480 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
3481 const char *format_name
= block_driver_modules
[i
].format_name
;
3487 while (formats
&& j
&& !found
) {
3488 found
= !strcmp(formats
[--j
], format_name
);
3492 formats
= g_renew(const char *, formats
, count
+ 1);
3493 formats
[count
++] = format_name
;
3498 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
3500 for (i
= 0; i
< count
; i
++) {
3501 it(opaque
, formats
[i
]);
3507 /* This function is to find a node in the bs graph */
3508 BlockDriverState
*bdrv_find_node(const char *node_name
)
3510 BlockDriverState
*bs
;
3514 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3515 if (!strcmp(node_name
, bs
->node_name
)) {
3522 /* Put this QMP function here so it can access the static graph_bdrv_states. */
3523 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
3525 BlockDeviceInfoList
*list
, *entry
;
3526 BlockDriverState
*bs
;
3529 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3530 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
3532 qapi_free_BlockDeviceInfoList(list
);
3535 entry
= g_malloc0(sizeof(*entry
));
3536 entry
->value
= info
;
3544 BlockDriverState
*bdrv_lookup_bs(const char *device
,
3545 const char *node_name
,
3549 BlockDriverState
*bs
;
3552 blk
= blk_by_name(device
);
3557 error_setg(errp
, "Device '%s' has no medium", device
);
3565 bs
= bdrv_find_node(node_name
);
3572 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
3573 device
? device
: "",
3574 node_name
? node_name
: "");
3578 /* If 'base' is in the same chain as 'top', return true. Otherwise,
3579 * return false. If either argument is NULL, return false. */
3580 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
3582 while (top
&& top
!= base
) {
3583 top
= backing_bs(top
);
3589 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
3592 return QTAILQ_FIRST(&graph_bdrv_states
);
3594 return QTAILQ_NEXT(bs
, node_list
);
3597 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
3599 return bs
->node_name
;
3602 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
3607 /* If multiple parents have a name, just pick the first one. */
3608 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3609 if (c
->role
->get_name
) {
3610 name
= c
->role
->get_name(c
);
3611 if (name
&& *name
) {
3620 /* TODO check what callers really want: bs->node_name or blk_name() */
3621 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
3623 return bdrv_get_parent_name(bs
) ?: "";
3626 /* This can be used to identify nodes that might not have a device
3627 * name associated. Since node and device names live in the same
3628 * namespace, the result is unambiguous. The exception is if both are
3629 * absent, then this returns an empty (non-null) string. */
3630 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
3632 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
3635 int bdrv_get_flags(BlockDriverState
*bs
)
3637 return bs
->open_flags
;
3640 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
3645 int bdrv_has_zero_init(BlockDriverState
*bs
)
3649 /* If BS is a copy on write image, it is initialized to
3650 the contents of the base image, which may not be zeroes. */
3654 if (bs
->drv
->bdrv_has_zero_init
) {
3655 return bs
->drv
->bdrv_has_zero_init(bs
);
3662 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
3664 BlockDriverInfo bdi
;
3670 if (bdrv_get_info(bs
, &bdi
) == 0) {
3671 return bdi
.unallocated_blocks_are_zero
;
3677 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
3679 BlockDriverInfo bdi
;
3681 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
3685 if (bdrv_get_info(bs
, &bdi
) == 0) {
3686 return bdi
.can_write_zeroes_with_unmap
;
3692 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
3694 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
3695 return bs
->backing_file
;
3696 else if (bs
->encrypted
)
3697 return bs
->filename
;
3702 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3703 char *filename
, int filename_size
)
3705 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3708 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3710 BlockDriver
*drv
= bs
->drv
;
3713 if (!drv
->bdrv_get_info
)
3715 memset(bdi
, 0, sizeof(*bdi
));
3716 return drv
->bdrv_get_info(bs
, bdi
);
3719 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3721 BlockDriver
*drv
= bs
->drv
;
3722 if (drv
&& drv
->bdrv_get_specific_info
) {
3723 return drv
->bdrv_get_specific_info(bs
);
3728 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3730 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3734 bs
->drv
->bdrv_debug_event(bs
, event
);
3737 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3740 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3741 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3744 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3745 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3751 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3753 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3754 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3757 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3758 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3764 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3766 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3767 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3770 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3771 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3777 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3779 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3780 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3783 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3784 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3790 /* backing_file can either be relative, or absolute, or a protocol. If it is
3791 * relative, it must be relative to the chain. So, passing in bs->filename
3792 * from a BDS as backing_file should not be done, as that may be relative to
3793 * the CWD rather than the chain. */
3794 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3795 const char *backing_file
)
3797 char *filename_full
= NULL
;
3798 char *backing_file_full
= NULL
;
3799 char *filename_tmp
= NULL
;
3800 int is_protocol
= 0;
3801 BlockDriverState
*curr_bs
= NULL
;
3802 BlockDriverState
*retval
= NULL
;
3803 Error
*local_error
= NULL
;
3805 if (!bs
|| !bs
->drv
|| !backing_file
) {
3809 filename_full
= g_malloc(PATH_MAX
);
3810 backing_file_full
= g_malloc(PATH_MAX
);
3811 filename_tmp
= g_malloc(PATH_MAX
);
3813 is_protocol
= path_has_protocol(backing_file
);
3815 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3817 /* If either of the filename paths is actually a protocol, then
3818 * compare unmodified paths; otherwise make paths relative */
3819 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3820 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3821 retval
= curr_bs
->backing
->bs
;
3824 /* Also check against the full backing filename for the image */
3825 bdrv_get_full_backing_filename(curr_bs
, backing_file_full
, PATH_MAX
,
3827 if (local_error
== NULL
) {
3828 if (strcmp(backing_file
, backing_file_full
) == 0) {
3829 retval
= curr_bs
->backing
->bs
;
3833 error_free(local_error
);
3837 /* If not an absolute filename path, make it relative to the current
3838 * image's filename path */
3839 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3842 /* We are going to compare absolute pathnames */
3843 if (!realpath(filename_tmp
, filename_full
)) {
3847 /* We need to make sure the backing filename we are comparing against
3848 * is relative to the current image filename (or absolute) */
3849 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3850 curr_bs
->backing_file
);
3852 if (!realpath(filename_tmp
, backing_file_full
)) {
3856 if (strcmp(backing_file_full
, filename_full
) == 0) {
3857 retval
= curr_bs
->backing
->bs
;
3863 g_free(filename_full
);
3864 g_free(backing_file_full
);
3865 g_free(filename_tmp
);
3869 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3879 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3882 void bdrv_init(void)
3884 module_call_init(MODULE_INIT_BLOCK
);
3887 void bdrv_init_with_whitelist(void)
3889 use_bdrv_whitelist
= 1;
3893 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3896 Error
*local_err
= NULL
;
3903 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3907 QLIST_FOREACH(child
, &bs
->children
, next
) {
3908 bdrv_invalidate_cache(child
->bs
, &local_err
);
3910 error_propagate(errp
, local_err
);
3915 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3916 if (bs
->drv
->bdrv_invalidate_cache
) {
3917 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3919 bs
->open_flags
|= BDRV_O_INACTIVE
;
3920 error_propagate(errp
, local_err
);
3925 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3927 bs
->open_flags
|= BDRV_O_INACTIVE
;
3928 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3933 void bdrv_invalidate_cache_all(Error
**errp
)
3935 BlockDriverState
*bs
;
3936 Error
*local_err
= NULL
;
3937 BdrvNextIterator it
;
3939 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3940 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3942 aio_context_acquire(aio_context
);
3943 bdrv_invalidate_cache(bs
, &local_err
);
3944 aio_context_release(aio_context
);
3946 error_propagate(errp
, local_err
);
3952 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3958 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3959 ret
= bs
->drv
->bdrv_inactivate(bs
);
3965 QLIST_FOREACH(child
, &bs
->children
, next
) {
3966 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
3973 bs
->open_flags
|= BDRV_O_INACTIVE
;
3978 int bdrv_inactivate_all(void)
3980 BlockDriverState
*bs
= NULL
;
3981 BdrvNextIterator it
;
3985 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3986 aio_context_acquire(bdrv_get_aio_context(bs
));
3989 /* We do two passes of inactivation. The first pass calls to drivers'
3990 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
3991 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
3993 for (pass
= 0; pass
< 2; pass
++) {
3994 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3995 ret
= bdrv_inactivate_recurse(bs
, pass
);
4003 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4004 aio_context_release(bdrv_get_aio_context(bs
));
4010 /**************************************************************/
4011 /* removable device support */
4014 * Return TRUE if the media is present
4016 bool bdrv_is_inserted(BlockDriverState
*bs
)
4018 BlockDriver
*drv
= bs
->drv
;
4024 if (drv
->bdrv_is_inserted
) {
4025 return drv
->bdrv_is_inserted(bs
);
4027 QLIST_FOREACH(child
, &bs
->children
, next
) {
4028 if (!bdrv_is_inserted(child
->bs
)) {
4036 * Return whether the media changed since the last call to this
4037 * function, or -ENOTSUP if we don't know. Most drivers don't know.
4039 int bdrv_media_changed(BlockDriverState
*bs
)
4041 BlockDriver
*drv
= bs
->drv
;
4043 if (drv
&& drv
->bdrv_media_changed
) {
4044 return drv
->bdrv_media_changed(bs
);
4050 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4052 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
4054 BlockDriver
*drv
= bs
->drv
;
4056 if (drv
&& drv
->bdrv_eject
) {
4057 drv
->bdrv_eject(bs
, eject_flag
);
4062 * Lock or unlock the media (if it is locked, the user won't be able
4063 * to eject it manually).
4065 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
4067 BlockDriver
*drv
= bs
->drv
;
4069 trace_bdrv_lock_medium(bs
, locked
);
4071 if (drv
&& drv
->bdrv_lock_medium
) {
4072 drv
->bdrv_lock_medium(bs
, locked
);
4076 /* Get a reference to bs */
4077 void bdrv_ref(BlockDriverState
*bs
)
4082 /* Release a previously grabbed reference to bs.
4083 * If after releasing, reference count is zero, the BlockDriverState is
4085 void bdrv_unref(BlockDriverState
*bs
)
4090 assert(bs
->refcnt
> 0);
4091 if (--bs
->refcnt
== 0) {
4096 struct BdrvOpBlocker
{
4098 QLIST_ENTRY(BdrvOpBlocker
) list
;
4101 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
4103 BdrvOpBlocker
*blocker
;
4104 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4105 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
4106 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
4108 *errp
= error_copy(blocker
->reason
);
4109 error_prepend(errp
, "Node '%s' is busy: ",
4110 bdrv_get_device_or_node_name(bs
));
4117 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4119 BdrvOpBlocker
*blocker
;
4120 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4122 blocker
= g_new0(BdrvOpBlocker
, 1);
4123 blocker
->reason
= reason
;
4124 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
4127 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4129 BdrvOpBlocker
*blocker
, *next
;
4130 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4131 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
4132 if (blocker
->reason
== reason
) {
4133 QLIST_REMOVE(blocker
, list
);
4139 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
4142 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4143 bdrv_op_block(bs
, i
, reason
);
4147 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
4150 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4151 bdrv_op_unblock(bs
, i
, reason
);
4155 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
4159 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4160 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
4167 void bdrv_img_create(const char *filename
, const char *fmt
,
4168 const char *base_filename
, const char *base_fmt
,
4169 char *options
, uint64_t img_size
, int flags
, bool quiet
,
4172 QemuOptsList
*create_opts
= NULL
;
4173 QemuOpts
*opts
= NULL
;
4174 const char *backing_fmt
, *backing_file
;
4176 BlockDriver
*drv
, *proto_drv
;
4177 Error
*local_err
= NULL
;
4180 /* Find driver and parse its options */
4181 drv
= bdrv_find_format(fmt
);
4183 error_setg(errp
, "Unknown file format '%s'", fmt
);
4187 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
4192 if (!drv
->create_opts
) {
4193 error_setg(errp
, "Format driver '%s' does not support image creation",
4198 if (!proto_drv
->create_opts
) {
4199 error_setg(errp
, "Protocol driver '%s' does not support image creation",
4200 proto_drv
->format_name
);
4204 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
4205 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
4207 /* Create parameter list with default values */
4208 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
4209 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
4211 /* Parse -o options */
4213 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
4215 error_report_err(local_err
);
4217 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
4222 if (base_filename
) {
4223 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
4225 error_setg(errp
, "Backing file not supported for file format '%s'",
4232 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
4234 error_setg(errp
, "Backing file format not supported for file "
4235 "format '%s'", fmt
);
4240 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4242 if (!strcmp(filename
, backing_file
)) {
4243 error_setg(errp
, "Error: Trying to create an image with the "
4244 "same filename as the backing file");
4249 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4251 // The size for the image must always be specified, with one exception:
4252 // If we are using a backing file, we can obtain the size from there
4253 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4256 BlockDriverState
*bs
;
4257 char *full_backing
= g_new0(char, PATH_MAX
);
4260 QDict
*backing_options
= NULL
;
4262 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
4263 full_backing
, PATH_MAX
,
4266 g_free(full_backing
);
4270 /* backing files always opened read-only */
4272 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
4275 backing_options
= qdict_new();
4276 qdict_put(backing_options
, "driver",
4277 qstring_from_str(backing_fmt
));
4280 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
4282 g_free(full_backing
);
4286 size
= bdrv_getlength(bs
);
4288 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
4294 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
4298 error_setg(errp
, "Image creation needs a size parameter");
4304 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
4305 qemu_opts_print(opts
, " ");
4309 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
4311 if (ret
== -EFBIG
) {
4312 /* This is generally a better message than whatever the driver would
4313 * deliver (especially because of the cluster_size_hint), since that
4314 * is most probably not much different from "image too large". */
4315 const char *cluster_size_hint
= "";
4316 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
4317 cluster_size_hint
= " (try using a larger cluster size)";
4319 error_setg(errp
, "The image size is too large for file format '%s'"
4320 "%s", fmt
, cluster_size_hint
);
4321 error_free(local_err
);
4326 qemu_opts_del(opts
);
4327 qemu_opts_free(create_opts
);
4328 error_propagate(errp
, local_err
);
4331 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
4333 return bs
->aio_context
;
4336 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
4338 aio_co_enter(bdrv_get_aio_context(bs
), co
);
4341 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
4343 QLIST_REMOVE(ban
, list
);
4347 void bdrv_detach_aio_context(BlockDriverState
*bs
)
4349 BdrvAioNotifier
*baf
, *baf_tmp
;
4356 assert(!bs
->walking_aio_notifiers
);
4357 bs
->walking_aio_notifiers
= true;
4358 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
4360 bdrv_do_remove_aio_context_notifier(baf
);
4362 baf
->detach_aio_context(baf
->opaque
);
4365 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4366 * remove remaining aio notifiers if we aren't called again.
4368 bs
->walking_aio_notifiers
= false;
4370 if (bs
->drv
->bdrv_detach_aio_context
) {
4371 bs
->drv
->bdrv_detach_aio_context(bs
);
4373 QLIST_FOREACH(child
, &bs
->children
, next
) {
4374 bdrv_detach_aio_context(child
->bs
);
4377 bs
->aio_context
= NULL
;
4380 void bdrv_attach_aio_context(BlockDriverState
*bs
,
4381 AioContext
*new_context
)
4383 BdrvAioNotifier
*ban
, *ban_tmp
;
4390 bs
->aio_context
= new_context
;
4392 QLIST_FOREACH(child
, &bs
->children
, next
) {
4393 bdrv_attach_aio_context(child
->bs
, new_context
);
4395 if (bs
->drv
->bdrv_attach_aio_context
) {
4396 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
4399 assert(!bs
->walking_aio_notifiers
);
4400 bs
->walking_aio_notifiers
= true;
4401 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
4403 bdrv_do_remove_aio_context_notifier(ban
);
4405 ban
->attached_aio_context(new_context
, ban
->opaque
);
4408 bs
->walking_aio_notifiers
= false;
4411 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
4413 AioContext
*ctx
= bdrv_get_aio_context(bs
);
4415 aio_disable_external(ctx
);
4416 bdrv_parent_drained_begin(bs
);
4417 bdrv_drain(bs
); /* ensure there are no in-flight requests */
4419 while (aio_poll(ctx
, false)) {
4420 /* wait for all bottom halves to execute */
4423 bdrv_detach_aio_context(bs
);
4425 /* This function executes in the old AioContext so acquire the new one in
4426 * case it runs in a different thread.
4428 aio_context_acquire(new_context
);
4429 bdrv_attach_aio_context(bs
, new_context
);
4430 bdrv_parent_drained_end(bs
);
4431 aio_enable_external(ctx
);
4432 aio_context_release(new_context
);
4435 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
4436 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
4437 void (*detach_aio_context
)(void *opaque
), void *opaque
)
4439 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
4440 *ban
= (BdrvAioNotifier
){
4441 .attached_aio_context
= attached_aio_context
,
4442 .detach_aio_context
= detach_aio_context
,
4446 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
4449 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
4450 void (*attached_aio_context
)(AioContext
*,
4452 void (*detach_aio_context
)(void *),
4455 BdrvAioNotifier
*ban
, *ban_next
;
4457 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
4458 if (ban
->attached_aio_context
== attached_aio_context
&&
4459 ban
->detach_aio_context
== detach_aio_context
&&
4460 ban
->opaque
== opaque
&&
4461 ban
->deleted
== false)
4463 if (bs
->walking_aio_notifiers
) {
4464 ban
->deleted
= true;
4466 bdrv_do_remove_aio_context_notifier(ban
);
4475 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4476 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
4478 if (!bs
->drv
->bdrv_amend_options
) {
4481 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
4484 /* This function will be called by the bdrv_recurse_is_first_non_filter method
4485 * of block filter and by bdrv_is_first_non_filter.
4486 * It is used to test if the given bs is the candidate or recurse more in the
4489 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
4490 BlockDriverState
*candidate
)
4492 /* return false if basic checks fails */
4493 if (!bs
|| !bs
->drv
) {
4497 /* the code reached a non block filter driver -> check if the bs is
4498 * the same as the candidate. It's the recursion termination condition.
4500 if (!bs
->drv
->is_filter
) {
4501 return bs
== candidate
;
4503 /* Down this path the driver is a block filter driver */
4505 /* If the block filter recursion method is defined use it to recurse down
4508 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
4509 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
4512 /* the driver is a block filter but don't allow to recurse -> return false
4517 /* This function checks if the candidate is the first non filter bs down it's
4518 * bs chain. Since we don't have pointers to parents it explore all bs chains
4519 * from the top. Some filters can choose not to pass down the recursion.
4521 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
4523 BlockDriverState
*bs
;
4524 BdrvNextIterator it
;
4526 /* walk down the bs forest recursively */
4527 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4530 /* try to recurse in this top level bs */
4531 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
4533 /* candidate is the first non filter */
4542 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
4543 const char *node_name
, Error
**errp
)
4545 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
4546 AioContext
*aio_context
;
4548 if (!to_replace_bs
) {
4549 error_setg(errp
, "Node name '%s' not found", node_name
);
4553 aio_context
= bdrv_get_aio_context(to_replace_bs
);
4554 aio_context_acquire(aio_context
);
4556 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
4557 to_replace_bs
= NULL
;
4561 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4562 * most non filter in order to prevent data corruption.
4563 * Another benefit is that this tests exclude backing files which are
4564 * blocked by the backing blockers.
4566 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
4567 error_setg(errp
, "Only top most non filter can be replaced");
4568 to_replace_bs
= NULL
;
4573 aio_context_release(aio_context
);
4574 return to_replace_bs
;
4577 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
4579 const QDictEntry
*entry
;
4582 bool found_any
= false;
4585 for (entry
= qdict_first(bs
->options
); entry
;
4586 entry
= qdict_next(bs
->options
, entry
))
4588 /* Exclude options for children */
4589 QLIST_FOREACH(child
, &bs
->children
, next
) {
4590 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
4591 && (!*p
|| *p
== '.'))
4600 /* And exclude all non-driver-specific options */
4601 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
4602 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
4610 qobject_incref(qdict_entry_value(entry
));
4611 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
4618 /* Updates the following BDS fields:
4619 * - exact_filename: A filename which may be used for opening a block device
4620 * which (mostly) equals the given BDS (even without any
4621 * other options; so reading and writing must return the same
4622 * results, but caching etc. may be different)
4623 * - full_open_options: Options which, when given when opening a block device
4624 * (without a filename), result in a BDS (mostly)
4625 * equalling the given one
4626 * - filename: If exact_filename is set, it is copied here. Otherwise,
4627 * full_open_options is converted to a JSON object, prefixed with
4628 * "json:" (for use through the JSON pseudo protocol) and put here.
4630 void bdrv_refresh_filename(BlockDriverState
*bs
)
4632 BlockDriver
*drv
= bs
->drv
;
4639 /* This BDS's file name will most probably depend on its file's name, so
4640 * refresh that first */
4642 bdrv_refresh_filename(bs
->file
->bs
);
4645 if (drv
->bdrv_refresh_filename
) {
4646 /* Obsolete information is of no use here, so drop the old file name
4647 * information before refreshing it */
4648 bs
->exact_filename
[0] = '\0';
4649 if (bs
->full_open_options
) {
4650 QDECREF(bs
->full_open_options
);
4651 bs
->full_open_options
= NULL
;
4655 append_open_options(opts
, bs
);
4656 drv
->bdrv_refresh_filename(bs
, opts
);
4658 } else if (bs
->file
) {
4659 /* Try to reconstruct valid information from the underlying file */
4660 bool has_open_options
;
4662 bs
->exact_filename
[0] = '\0';
4663 if (bs
->full_open_options
) {
4664 QDECREF(bs
->full_open_options
);
4665 bs
->full_open_options
= NULL
;
4669 has_open_options
= append_open_options(opts
, bs
);
4671 /* If no specific options have been given for this BDS, the filename of
4672 * the underlying file should suffice for this one as well */
4673 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
4674 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
4676 /* Reconstructing the full options QDict is simple for most format block
4677 * drivers, as long as the full options are known for the underlying
4678 * file BDS. The full options QDict of that file BDS should somehow
4679 * contain a representation of the filename, therefore the following
4680 * suffices without querying the (exact_)filename of this BDS. */
4681 if (bs
->file
->bs
->full_open_options
) {
4682 qdict_put_obj(opts
, "driver",
4683 QOBJECT(qstring_from_str(drv
->format_name
)));
4684 QINCREF(bs
->file
->bs
->full_open_options
);
4685 qdict_put_obj(opts
, "file",
4686 QOBJECT(bs
->file
->bs
->full_open_options
));
4688 bs
->full_open_options
= opts
;
4692 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
4693 /* There is no underlying file BDS (at least referenced by BDS.file),
4694 * so the full options QDict should be equal to the options given
4695 * specifically for this block device when it was opened (plus the
4696 * driver specification).
4697 * Because those options don't change, there is no need to update
4698 * full_open_options when it's already set. */
4701 append_open_options(opts
, bs
);
4702 qdict_put_obj(opts
, "driver",
4703 QOBJECT(qstring_from_str(drv
->format_name
)));
4705 if (bs
->exact_filename
[0]) {
4706 /* This may not work for all block protocol drivers (some may
4707 * require this filename to be parsed), but we have to find some
4708 * default solution here, so just include it. If some block driver
4709 * does not support pure options without any filename at all or
4710 * needs some special format of the options QDict, it needs to
4711 * implement the driver-specific bdrv_refresh_filename() function.
4713 qdict_put_obj(opts
, "filename",
4714 QOBJECT(qstring_from_str(bs
->exact_filename
)));
4717 bs
->full_open_options
= opts
;
4720 if (bs
->exact_filename
[0]) {
4721 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4722 } else if (bs
->full_open_options
) {
4723 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4724 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4725 qstring_get_str(json
));
4731 * Hot add/remove a BDS's child. So the user can take a child offline when
4732 * it is broken and take a new child online
4734 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
4738 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
4739 error_setg(errp
, "The node %s does not support adding a child",
4740 bdrv_get_device_or_node_name(parent_bs
));
4744 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4745 error_setg(errp
, "The node %s already has a parent",
4746 child_bs
->node_name
);
4750 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4753 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4757 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4758 error_setg(errp
, "The node %s does not support removing a child",
4759 bdrv_get_device_or_node_name(parent_bs
));
4763 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4770 error_setg(errp
, "The node %s does not have a child named %s",
4771 bdrv_get_device_or_node_name(parent_bs
),
4772 bdrv_get_device_or_node_name(child
->bs
));
4776 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);