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_get_full_backing_filename_from_filename(const char *backed
,
197 char *dest
, size_t sz
,
200 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
201 path_is_absolute(backing
))
203 pstrcpy(dest
, sz
, backing
);
204 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
205 error_setg(errp
, "Cannot use relative backing file names for '%s'",
208 path_combine(dest
, sz
, backed
, backing
);
212 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
215 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
217 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
221 void bdrv_register(BlockDriver
*bdrv
)
223 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
226 BlockDriverState
*bdrv_new(void)
228 BlockDriverState
*bs
;
231 bs
= g_new0(BlockDriverState
, 1);
232 QLIST_INIT(&bs
->dirty_bitmaps
);
233 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
234 QLIST_INIT(&bs
->op_blockers
[i
]);
236 notifier_with_return_list_init(&bs
->before_write_notifiers
);
238 bs
->aio_context
= qemu_get_aio_context();
240 qemu_co_queue_init(&bs
->flush_queue
);
242 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
247 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
251 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
252 if (!strcmp(drv1
->format_name
, format_name
)) {
260 BlockDriver
*bdrv_find_format(const char *format_name
)
265 drv1
= bdrv_do_find_format(format_name
);
270 /* The driver isn't registered, maybe we need to load a module */
271 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
272 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
273 block_module_load_one(block_driver_modules
[i
].library_name
);
278 return bdrv_do_find_format(format_name
);
281 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
283 static const char *whitelist_rw
[] = {
284 CONFIG_BDRV_RW_WHITELIST
286 static const char *whitelist_ro
[] = {
287 CONFIG_BDRV_RO_WHITELIST
291 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
292 return 1; /* no whitelist, anything goes */
295 for (p
= whitelist_rw
; *p
; p
++) {
296 if (!strcmp(drv
->format_name
, *p
)) {
301 for (p
= whitelist_ro
; *p
; p
++) {
302 if (!strcmp(drv
->format_name
, *p
)) {
310 bool bdrv_uses_whitelist(void)
312 return use_bdrv_whitelist
;
315 typedef struct CreateCo
{
323 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
325 Error
*local_err
= NULL
;
328 CreateCo
*cco
= opaque
;
331 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
332 error_propagate(&cco
->err
, local_err
);
336 int bdrv_create(BlockDriver
*drv
, const char* filename
,
337 QemuOpts
*opts
, Error
**errp
)
344 .filename
= g_strdup(filename
),
350 if (!drv
->bdrv_create
) {
351 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
356 if (qemu_in_coroutine()) {
357 /* Fast-path if already in coroutine context */
358 bdrv_create_co_entry(&cco
);
360 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
361 qemu_coroutine_enter(co
);
362 while (cco
.ret
== NOT_DONE
) {
363 aio_poll(qemu_get_aio_context(), true);
370 error_propagate(errp
, cco
.err
);
372 error_setg_errno(errp
, -ret
, "Could not create image");
377 g_free(cco
.filename
);
381 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
384 Error
*local_err
= NULL
;
387 drv
= bdrv_find_protocol(filename
, true, errp
);
392 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
393 error_propagate(errp
, local_err
);
398 * Try to get @bs's logical and physical block size.
399 * On success, store them in @bsz struct and return 0.
400 * On failure return -errno.
401 * @bs must not be empty.
403 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
405 BlockDriver
*drv
= bs
->drv
;
407 if (drv
&& drv
->bdrv_probe_blocksizes
) {
408 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
415 * Try to get @bs's geometry (cyls, heads, sectors).
416 * On success, store them in @geo struct and return 0.
417 * On failure return -errno.
418 * @bs must not be empty.
420 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
422 BlockDriver
*drv
= bs
->drv
;
424 if (drv
&& drv
->bdrv_probe_geometry
) {
425 return drv
->bdrv_probe_geometry(bs
, geo
);
432 * Create a uniquely-named empty temporary file.
433 * Return 0 upon success, otherwise a negative errno value.
435 int get_tmp_filename(char *filename
, int size
)
438 char temp_dir
[MAX_PATH
];
439 /* GetTempFileName requires that its output buffer (4th param)
440 have length MAX_PATH or greater. */
441 assert(size
>= MAX_PATH
);
442 return (GetTempPath(MAX_PATH
, temp_dir
)
443 && GetTempFileName(temp_dir
, "qem", 0, filename
)
444 ? 0 : -GetLastError());
448 tmpdir
= getenv("TMPDIR");
452 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
455 fd
= mkstemp(filename
);
459 if (close(fd
) != 0) {
468 * Detect host devices. By convention, /dev/cdrom[N] is always
469 * recognized as a host CDROM.
471 static BlockDriver
*find_hdev_driver(const char *filename
)
473 int score_max
= 0, score
;
474 BlockDriver
*drv
= NULL
, *d
;
476 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
477 if (d
->bdrv_probe_device
) {
478 score
= d
->bdrv_probe_device(filename
);
479 if (score
> score_max
) {
489 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
493 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
494 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
502 BlockDriver
*bdrv_find_protocol(const char *filename
,
503 bool allow_protocol_prefix
,
512 /* TODO Drivers without bdrv_file_open must be specified explicitly */
515 * XXX(hch): we really should not let host device detection
516 * override an explicit protocol specification, but moving this
517 * later breaks access to device names with colons in them.
518 * Thanks to the brain-dead persistent naming schemes on udev-
519 * based Linux systems those actually are quite common.
521 drv1
= find_hdev_driver(filename
);
526 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
530 p
= strchr(filename
, ':');
533 if (len
> sizeof(protocol
) - 1)
534 len
= sizeof(protocol
) - 1;
535 memcpy(protocol
, filename
, len
);
536 protocol
[len
] = '\0';
538 drv1
= bdrv_do_find_protocol(protocol
);
543 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
544 if (block_driver_modules
[i
].protocol_name
&&
545 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
546 block_module_load_one(block_driver_modules
[i
].library_name
);
551 drv1
= bdrv_do_find_protocol(protocol
);
553 error_setg(errp
, "Unknown protocol '%s'", protocol
);
559 * Guess image format by probing its contents.
560 * This is not a good idea when your image is raw (CVE-2008-2004), but
561 * we do it anyway for backward compatibility.
563 * @buf contains the image's first @buf_size bytes.
564 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
565 * but can be smaller if the image file is smaller)
566 * @filename is its filename.
568 * For all block drivers, call the bdrv_probe() method to get its
570 * Return the first block driver with the highest probing score.
572 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
573 const char *filename
)
575 int score_max
= 0, score
;
576 BlockDriver
*drv
= NULL
, *d
;
578 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
580 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
581 if (score
> score_max
) {
591 static int find_image_format(BlockBackend
*file
, const char *filename
,
592 BlockDriver
**pdrv
, Error
**errp
)
595 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
598 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
599 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
604 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
606 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
612 drv
= bdrv_probe_all(buf
, ret
, filename
);
614 error_setg(errp
, "Could not determine image format: No compatible "
623 * Set the current 'total_sectors' value
624 * Return 0 on success, -errno on error.
626 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
628 BlockDriver
*drv
= bs
->drv
;
630 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
634 /* query actual device if possible, otherwise just trust the hint */
635 if (drv
->bdrv_getlength
) {
636 int64_t length
= drv
->bdrv_getlength(bs
);
640 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
643 bs
->total_sectors
= hint
;
648 * Combines a QDict of new block driver @options with any missing options taken
649 * from @old_options, so that leaving out an option defaults to its old value.
651 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
654 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
655 bs
->drv
->bdrv_join_options(options
, old_options
);
657 qdict_join(options
, old_options
, false);
662 * Set open flags for a given discard mode
664 * Return 0 on success, -1 if the discard mode was invalid.
666 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
668 *flags
&= ~BDRV_O_UNMAP
;
670 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
672 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
673 *flags
|= BDRV_O_UNMAP
;
682 * Set open flags for a given cache mode
684 * Return 0 on success, -1 if the cache mode was invalid.
686 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
688 *flags
&= ~BDRV_O_CACHE_MASK
;
690 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
691 *writethrough
= false;
692 *flags
|= BDRV_O_NOCACHE
;
693 } else if (!strcmp(mode
, "directsync")) {
694 *writethrough
= true;
695 *flags
|= BDRV_O_NOCACHE
;
696 } else if (!strcmp(mode
, "writeback")) {
697 *writethrough
= false;
698 } else if (!strcmp(mode
, "unsafe")) {
699 *writethrough
= false;
700 *flags
|= BDRV_O_NO_FLUSH
;
701 } else if (!strcmp(mode
, "writethrough")) {
702 *writethrough
= true;
710 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
712 BlockDriverState
*parent
= c
->opaque
;
713 return g_strdup(bdrv_get_device_or_node_name(parent
));
716 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
718 BlockDriverState
*bs
= child
->opaque
;
719 bdrv_drained_begin(bs
);
722 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
724 BlockDriverState
*bs
= child
->opaque
;
725 bdrv_drained_end(bs
);
729 * Returns the options and flags that a temporary snapshot should get, based on
730 * the originally requested flags (the originally requested image will have
731 * flags like a backing file)
733 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
734 int parent_flags
, QDict
*parent_options
)
736 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
738 /* For temporary files, unconditional cache=unsafe is fine */
739 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
740 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
742 /* Copy the read-only option from the parent */
743 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
745 /* aio=native doesn't work for cache.direct=off, so disable it for the
746 * temporary snapshot */
747 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
751 * Returns the options and flags that bs->file should get if a protocol driver
752 * is expected, based on the given options and flags for the parent BDS
754 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
755 int parent_flags
, QDict
*parent_options
)
757 int flags
= parent_flags
;
759 /* Enable protocol handling, disable format probing for bs->file */
760 flags
|= BDRV_O_PROTOCOL
;
762 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
764 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
765 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
767 /* Inherit the read-only option from the parent if it's not set */
768 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
770 /* Our block drivers take care to send flushes and respect unmap policy,
771 * so we can default to enable both on lower layers regardless of the
772 * corresponding parent options. */
773 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
775 /* Clear flags that only apply to the top layer */
776 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
779 *child_flags
= flags
;
782 const BdrvChildRole child_file
= {
783 .get_parent_desc
= bdrv_child_get_parent_desc
,
784 .inherit_options
= bdrv_inherited_options
,
785 .drained_begin
= bdrv_child_cb_drained_begin
,
786 .drained_end
= bdrv_child_cb_drained_end
,
790 * Returns the options and flags that bs->file should get if the use of formats
791 * (and not only protocols) is permitted for it, based on the given options and
792 * flags for the parent BDS
794 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
795 int parent_flags
, QDict
*parent_options
)
797 child_file
.inherit_options(child_flags
, child_options
,
798 parent_flags
, parent_options
);
800 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
803 const BdrvChildRole child_format
= {
804 .get_parent_desc
= bdrv_child_get_parent_desc
,
805 .inherit_options
= bdrv_inherited_fmt_options
,
806 .drained_begin
= bdrv_child_cb_drained_begin
,
807 .drained_end
= bdrv_child_cb_drained_end
,
810 static void bdrv_backing_attach(BdrvChild
*c
)
812 BlockDriverState
*parent
= c
->opaque
;
813 BlockDriverState
*backing_hd
= c
->bs
;
815 assert(!parent
->backing_blocker
);
816 error_setg(&parent
->backing_blocker
,
817 "node is used as backing hd of '%s'",
818 bdrv_get_device_or_node_name(parent
));
820 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
821 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
822 backing_hd
->filename
);
823 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
824 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
826 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
827 /* Otherwise we won't be able to commit or stream */
828 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
829 parent
->backing_blocker
);
830 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
831 parent
->backing_blocker
);
833 * We do backup in 3 ways:
835 * The target bs is new opened, and the source is top BDS
837 * Both the source and the target are top BDSes.
838 * 3. internal backup(used for block replication)
839 * Both the source and the target are backing file
841 * In case 1 and 2, neither the source nor the target is the backing file.
842 * In case 3, we will block the top BDS, so there is only one block job
843 * for the top BDS and its backing chain.
845 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
846 parent
->backing_blocker
);
847 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
848 parent
->backing_blocker
);
851 static void bdrv_backing_detach(BdrvChild
*c
)
853 BlockDriverState
*parent
= c
->opaque
;
855 assert(parent
->backing_blocker
);
856 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
857 error_free(parent
->backing_blocker
);
858 parent
->backing_blocker
= NULL
;
862 * Returns the options and flags that bs->backing should get, based on the
863 * given options and flags for the parent BDS
865 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
866 int parent_flags
, QDict
*parent_options
)
868 int flags
= parent_flags
;
870 /* The cache mode is inherited unmodified for backing files; except WCE,
871 * which is only applied on the top level (BlockBackend) */
872 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
873 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
875 /* backing files always opened read-only */
876 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
877 flags
&= ~BDRV_O_COPY_ON_READ
;
879 /* snapshot=on is handled on the top layer */
880 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
882 *child_flags
= flags
;
885 const BdrvChildRole child_backing
= {
886 .get_parent_desc
= bdrv_child_get_parent_desc
,
887 .attach
= bdrv_backing_attach
,
888 .detach
= bdrv_backing_detach
,
889 .inherit_options
= bdrv_backing_options
,
890 .drained_begin
= bdrv_child_cb_drained_begin
,
891 .drained_end
= bdrv_child_cb_drained_end
,
894 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
896 int open_flags
= flags
;
899 * Clear flags that are internal to the block layer before opening the
902 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
905 * Snapshots should be writable.
907 if (flags
& BDRV_O_TEMPORARY
) {
908 open_flags
|= BDRV_O_RDWR
;
914 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
916 *flags
&= ~BDRV_O_CACHE_MASK
;
918 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
919 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
920 *flags
|= BDRV_O_NO_FLUSH
;
923 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
924 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
925 *flags
|= BDRV_O_NOCACHE
;
928 *flags
&= ~BDRV_O_RDWR
;
930 assert(qemu_opt_find(opts
, BDRV_OPT_READ_ONLY
));
931 if (!qemu_opt_get_bool(opts
, BDRV_OPT_READ_ONLY
, false)) {
932 *flags
|= BDRV_O_RDWR
;
937 static void update_options_from_flags(QDict
*options
, int flags
)
939 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
940 qdict_put(options
, BDRV_OPT_CACHE_DIRECT
,
941 qbool_from_bool(flags
& BDRV_O_NOCACHE
));
943 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
944 qdict_put(options
, BDRV_OPT_CACHE_NO_FLUSH
,
945 qbool_from_bool(flags
& BDRV_O_NO_FLUSH
));
947 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
948 qdict_put(options
, BDRV_OPT_READ_ONLY
,
949 qbool_from_bool(!(flags
& BDRV_O_RDWR
)));
953 static void bdrv_assign_node_name(BlockDriverState
*bs
,
954 const char *node_name
,
957 char *gen_node_name
= NULL
;
960 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
961 } else if (!id_wellformed(node_name
)) {
963 * Check for empty string or invalid characters, but not if it is
964 * generated (generated names use characters not available to the user)
966 error_setg(errp
, "Invalid node name");
970 /* takes care of avoiding namespaces collisions */
971 if (blk_by_name(node_name
)) {
972 error_setg(errp
, "node-name=%s is conflicting with a device id",
977 /* takes care of avoiding duplicates node names */
978 if (bdrv_find_node(node_name
)) {
979 error_setg(errp
, "Duplicate node name");
983 /* copy node name into the bs and insert it into the graph list */
984 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
985 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
987 g_free(gen_node_name
);
990 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
991 const char *node_name
, QDict
*options
,
992 int open_flags
, Error
**errp
)
994 Error
*local_err
= NULL
;
997 bdrv_assign_node_name(bs
, node_name
, &local_err
);
999 error_propagate(errp
, local_err
);
1004 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1005 bs
->opaque
= g_malloc0(drv
->instance_size
);
1007 if (drv
->bdrv_file_open
) {
1008 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1009 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1010 } else if (drv
->bdrv_open
) {
1011 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1018 error_propagate(errp
, local_err
);
1019 } else if (bs
->filename
[0]) {
1020 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1022 error_setg_errno(errp
, -ret
, "Could not open image");
1027 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1029 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1033 bdrv_refresh_limits(bs
, &local_err
);
1035 error_propagate(errp
, local_err
);
1040 assert(bdrv_opt_mem_align(bs
) != 0);
1041 assert(bdrv_min_mem_align(bs
) != 0);
1042 assert(is_power_of_2(bs
->bl
.request_alignment
));
1047 /* FIXME Close bs first if already opened*/
1054 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1055 int flags
, Error
**errp
)
1057 BlockDriverState
*bs
;
1061 bs
->open_flags
= flags
;
1062 bs
->explicit_options
= qdict_new();
1063 bs
->options
= qdict_new();
1066 update_options_from_flags(bs
->options
, flags
);
1068 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1070 QDECREF(bs
->explicit_options
);
1071 QDECREF(bs
->options
);
1079 QemuOptsList bdrv_runtime_opts
= {
1080 .name
= "bdrv_common",
1081 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1084 .name
= "node-name",
1085 .type
= QEMU_OPT_STRING
,
1086 .help
= "Node name of the block device node",
1090 .type
= QEMU_OPT_STRING
,
1091 .help
= "Block driver to use for the node",
1094 .name
= BDRV_OPT_CACHE_DIRECT
,
1095 .type
= QEMU_OPT_BOOL
,
1096 .help
= "Bypass software writeback cache on the host",
1099 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1100 .type
= QEMU_OPT_BOOL
,
1101 .help
= "Ignore flush requests",
1104 .name
= BDRV_OPT_READ_ONLY
,
1105 .type
= QEMU_OPT_BOOL
,
1106 .help
= "Node is opened in read-only mode",
1109 .name
= "detect-zeroes",
1110 .type
= QEMU_OPT_STRING
,
1111 .help
= "try to optimize zero writes (off, on, unmap)",
1115 .type
= QEMU_OPT_STRING
,
1116 .help
= "discard operation (ignore/off, unmap/on)",
1118 { /* end of list */ }
1123 * Common part for opening disk images and files
1125 * Removes all processed options from *options.
1127 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1128 QDict
*options
, Error
**errp
)
1130 int ret
, open_flags
;
1131 const char *filename
;
1132 const char *driver_name
= NULL
;
1133 const char *node_name
= NULL
;
1134 const char *discard
;
1135 const char *detect_zeroes
;
1138 Error
*local_err
= NULL
;
1140 assert(bs
->file
== NULL
);
1141 assert(options
!= NULL
&& bs
->options
!= options
);
1143 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1144 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1146 error_propagate(errp
, local_err
);
1151 update_flags_from_options(&bs
->open_flags
, opts
);
1153 driver_name
= qemu_opt_get(opts
, "driver");
1154 drv
= bdrv_find_format(driver_name
);
1155 assert(drv
!= NULL
);
1158 filename
= blk_bs(file
)->filename
;
1160 filename
= qdict_get_try_str(options
, "filename");
1163 if (drv
->bdrv_needs_filename
&& !filename
) {
1164 error_setg(errp
, "The '%s' block driver requires a file name",
1170 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1173 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1175 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1177 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1178 ? "Driver '%s' can only be used for read-only devices"
1179 : "Driver '%s' is not whitelisted",
1185 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
1186 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1187 if (!bs
->read_only
) {
1188 bdrv_enable_copy_on_read(bs
);
1190 error_setg(errp
, "Can't use copy-on-read on read-only device");
1196 discard
= qemu_opt_get(opts
, "discard");
1197 if (discard
!= NULL
) {
1198 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1199 error_setg(errp
, "Invalid discard option");
1205 detect_zeroes
= qemu_opt_get(opts
, "detect-zeroes");
1206 if (detect_zeroes
) {
1207 BlockdevDetectZeroesOptions value
=
1208 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup
,
1210 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX
,
1211 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
1214 error_propagate(errp
, local_err
);
1219 if (value
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
1220 !(bs
->open_flags
& BDRV_O_UNMAP
))
1222 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
1223 "without setting discard operation to unmap");
1228 bs
->detect_zeroes
= value
;
1231 if (filename
!= NULL
) {
1232 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1234 bs
->filename
[0] = '\0';
1236 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1238 /* Open the image, either directly or using a protocol */
1239 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1240 node_name
= qemu_opt_get(opts
, "node-name");
1242 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1243 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1248 qemu_opts_del(opts
);
1252 qemu_opts_del(opts
);
1256 static GCC_FMT_ATTR(1, 0)
1257 QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1259 QObject
*options_obj
;
1263 ret
= strstart(filename
, "json:", &filename
);
1266 options_obj
= qobject_from_json(filename
, errp
);
1268 /* Work around qobject_from_json() lossage TODO fix that */
1269 if (errp
&& !*errp
) {
1270 error_setg(errp
, "Could not parse the JSON options");
1273 error_prepend(errp
, "Could not parse the JSON options: ");
1277 options
= qobject_to_qdict(options_obj
);
1279 qobject_decref(options_obj
);
1280 error_setg(errp
, "Invalid JSON object given");
1284 qdict_flatten(options
);
1289 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1292 QDict
*json_options
;
1293 Error
*local_err
= NULL
;
1295 /* Parse json: pseudo-protocol */
1296 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1300 json_options
= parse_json_filename(*pfilename
, &local_err
);
1302 error_propagate(errp
, local_err
);
1306 /* Options given in the filename have lower priority than options
1307 * specified directly */
1308 qdict_join(options
, json_options
, false);
1309 QDECREF(json_options
);
1314 * Fills in default options for opening images and converts the legacy
1315 * filename/flags pair to option QDict entries.
1316 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1317 * block driver has been specified explicitly.
1319 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1320 int *flags
, Error
**errp
)
1322 const char *drvname
;
1323 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1324 bool parse_filename
= false;
1325 BlockDriver
*drv
= NULL
;
1326 Error
*local_err
= NULL
;
1328 drvname
= qdict_get_try_str(*options
, "driver");
1330 drv
= bdrv_find_format(drvname
);
1332 error_setg(errp
, "Unknown driver '%s'", drvname
);
1335 /* If the user has explicitly specified the driver, this choice should
1336 * override the BDRV_O_PROTOCOL flag */
1337 protocol
= drv
->bdrv_file_open
;
1341 *flags
|= BDRV_O_PROTOCOL
;
1343 *flags
&= ~BDRV_O_PROTOCOL
;
1346 /* Translate cache options from flags into options */
1347 update_options_from_flags(*options
, *flags
);
1349 /* Fetch the file name from the options QDict if necessary */
1350 if (protocol
&& filename
) {
1351 if (!qdict_haskey(*options
, "filename")) {
1352 qdict_put(*options
, "filename", qstring_from_str(filename
));
1353 parse_filename
= true;
1355 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1361 /* Find the right block driver */
1362 filename
= qdict_get_try_str(*options
, "filename");
1364 if (!drvname
&& protocol
) {
1366 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1371 drvname
= drv
->format_name
;
1372 qdict_put(*options
, "driver", qstring_from_str(drvname
));
1374 error_setg(errp
, "Must specify either driver or file");
1379 assert(drv
|| !protocol
);
1381 /* Driver-specific filename parsing */
1382 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1383 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1385 error_propagate(errp
, local_err
);
1389 if (!drv
->bdrv_needs_filename
) {
1390 qdict_del(*options
, "filename");
1397 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1398 GSList
*ignore_children
, Error
**errp
);
1399 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1400 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1403 * Check whether permissions on this node can be changed in a way that
1404 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1405 * permissions of all its parents. This involves checking whether all necessary
1406 * permission changes to child nodes can be performed.
1408 * A call to this function must always be followed by a call to bdrv_set_perm()
1409 * or bdrv_abort_perm_update().
1411 static int bdrv_check_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1412 uint64_t cumulative_shared_perms
,
1413 GSList
*ignore_children
, Error
**errp
)
1415 BlockDriver
*drv
= bs
->drv
;
1419 /* Write permissions never work with read-only images */
1420 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1421 bdrv_is_read_only(bs
))
1423 error_setg(errp
, "Block node is read-only");
1427 /* Check this node */
1432 if (drv
->bdrv_check_perm
) {
1433 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1434 cumulative_shared_perms
, errp
);
1437 /* Drivers that never have children can omit .bdrv_child_perm() */
1438 if (!drv
->bdrv_child_perm
) {
1439 assert(QLIST_EMPTY(&bs
->children
));
1443 /* Check all children */
1444 QLIST_FOREACH(c
, &bs
->children
, next
) {
1445 uint64_t cur_perm
, cur_shared
;
1446 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1447 cumulative_perms
, cumulative_shared_perms
,
1448 &cur_perm
, &cur_shared
);
1449 ret
= bdrv_child_check_perm(c
, cur_perm
, cur_shared
, ignore_children
,
1460 * Notifies drivers that after a previous bdrv_check_perm() call, the
1461 * permission update is not performed and any preparations made for it (e.g.
1462 * taken file locks) need to be undone.
1464 * This function recursively notifies all child nodes.
1466 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1468 BlockDriver
*drv
= bs
->drv
;
1475 if (drv
->bdrv_abort_perm_update
) {
1476 drv
->bdrv_abort_perm_update(bs
);
1479 QLIST_FOREACH(c
, &bs
->children
, next
) {
1480 bdrv_child_abort_perm_update(c
);
1484 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1485 uint64_t cumulative_shared_perms
)
1487 BlockDriver
*drv
= bs
->drv
;
1494 /* Update this node */
1495 if (drv
->bdrv_set_perm
) {
1496 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1499 /* Drivers that never have children can omit .bdrv_child_perm() */
1500 if (!drv
->bdrv_child_perm
) {
1501 assert(QLIST_EMPTY(&bs
->children
));
1505 /* Update all children */
1506 QLIST_FOREACH(c
, &bs
->children
, next
) {
1507 uint64_t cur_perm
, cur_shared
;
1508 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1509 cumulative_perms
, cumulative_shared_perms
,
1510 &cur_perm
, &cur_shared
);
1511 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1515 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1516 uint64_t *shared_perm
)
1519 uint64_t cumulative_perms
= 0;
1520 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1522 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1523 cumulative_perms
|= c
->perm
;
1524 cumulative_shared_perms
&= c
->shared_perm
;
1527 *perm
= cumulative_perms
;
1528 *shared_perm
= cumulative_shared_perms
;
1531 static char *bdrv_child_user_desc(BdrvChild
*c
)
1533 if (c
->role
->get_parent_desc
) {
1534 return c
->role
->get_parent_desc(c
);
1537 return g_strdup("another user");
1540 static char *bdrv_perm_names(uint64_t perm
)
1546 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1547 { BLK_PERM_WRITE
, "write" },
1548 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1549 { BLK_PERM_RESIZE
, "resize" },
1550 { BLK_PERM_GRAPH_MOD
, "change children" },
1554 char *result
= g_strdup("");
1555 struct perm_name
*p
;
1557 for (p
= permissions
; p
->name
; p
++) {
1558 if (perm
& p
->perm
) {
1560 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1569 * Checks whether a new reference to @bs can be added if the new user requires
1570 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1571 * set, the BdrvChild objects in this list are ignored in the calculations;
1572 * this allows checking permission updates for an existing reference.
1574 * Needs to be followed by a call to either bdrv_set_perm() or
1575 * bdrv_abort_perm_update(). */
1576 static int bdrv_check_update_perm(BlockDriverState
*bs
, uint64_t new_used_perm
,
1577 uint64_t new_shared_perm
,
1578 GSList
*ignore_children
, Error
**errp
)
1581 uint64_t cumulative_perms
= new_used_perm
;
1582 uint64_t cumulative_shared_perms
= new_shared_perm
;
1584 /* There is no reason why anyone couldn't tolerate write_unchanged */
1585 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1587 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1588 if (g_slist_find(ignore_children
, c
)) {
1592 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1593 char *user
= bdrv_child_user_desc(c
);
1594 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1595 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1597 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1603 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1604 char *user
= bdrv_child_user_desc(c
);
1605 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1606 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1608 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1614 cumulative_perms
|= c
->perm
;
1615 cumulative_shared_perms
&= c
->shared_perm
;
1618 return bdrv_check_perm(bs
, cumulative_perms
, cumulative_shared_perms
,
1619 ignore_children
, errp
);
1622 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1623 * bdrv_child_abort_perm_update(). */
1624 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1625 GSList
*ignore_children
, Error
**errp
)
1629 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1630 ret
= bdrv_check_update_perm(c
->bs
, perm
, shared
, ignore_children
, errp
);
1631 g_slist_free(ignore_children
);
1636 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
1638 uint64_t cumulative_perms
, cumulative_shared_perms
;
1641 c
->shared_perm
= shared
;
1643 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
1644 &cumulative_shared_perms
);
1645 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
1648 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
1650 bdrv_abort_perm_update(c
->bs
);
1653 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1658 ret
= bdrv_child_check_perm(c
, perm
, shared
, NULL
, errp
);
1660 bdrv_child_abort_perm_update(c
);
1664 bdrv_child_set_perm(c
, perm
, shared
);
1669 #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1671 | BLK_PERM_WRITE_UNCHANGED \
1673 #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1675 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1676 const BdrvChildRole
*role
,
1677 uint64_t perm
, uint64_t shared
,
1678 uint64_t *nperm
, uint64_t *nshared
)
1681 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
1682 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
1686 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
1687 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
1688 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
1689 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
1692 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1693 const BdrvChildRole
*role
,
1694 uint64_t perm
, uint64_t shared
,
1695 uint64_t *nperm
, uint64_t *nshared
)
1697 bool backing
= (role
== &child_backing
);
1698 assert(role
== &child_backing
|| role
== &child_file
);
1701 /* Apart from the modifications below, the same permissions are
1702 * forwarded and left alone as for filters */
1703 bdrv_filter_default_perms(bs
, c
, role
, perm
, shared
, &perm
, &shared
);
1705 /* Format drivers may touch metadata even if the guest doesn't write */
1706 if (!bdrv_is_read_only(bs
)) {
1707 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1710 /* bs->file always needs to be consistent because of the metadata. We
1711 * can never allow other users to resize or write to it. */
1712 perm
|= BLK_PERM_CONSISTENT_READ
;
1713 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
1715 /* We want consistent read from backing files if the parent needs it.
1716 * No other operations are performed on backing files. */
1717 perm
&= BLK_PERM_CONSISTENT_READ
;
1719 /* If the parent can deal with changing data, we're okay with a
1720 * writable and resizable backing file. */
1721 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1722 if (shared
& BLK_PERM_WRITE
) {
1723 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1728 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
1729 BLK_PERM_WRITE_UNCHANGED
;
1736 static void bdrv_replace_child_noperm(BdrvChild
*child
,
1737 BlockDriverState
*new_bs
)
1739 BlockDriverState
*old_bs
= child
->bs
;
1742 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1743 child
->role
->drained_end(child
);
1745 if (child
->role
->detach
) {
1746 child
->role
->detach(child
);
1748 QLIST_REMOVE(child
, next_parent
);
1754 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1755 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1756 child
->role
->drained_begin(child
);
1759 if (child
->role
->attach
) {
1760 child
->role
->attach(child
);
1766 * Updates @child to change its reference to point to @new_bs, including
1767 * checking and applying the necessary permisson updates both to the old node
1770 * NULL is passed as @new_bs for removing the reference before freeing @child.
1772 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
1773 * function uses bdrv_set_perm() to update the permissions according to the new
1774 * reference that @new_bs gets.
1776 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1778 BlockDriverState
*old_bs
= child
->bs
;
1779 uint64_t perm
, shared_perm
;
1782 /* Update permissions for old node. This is guaranteed to succeed
1783 * because we're just taking a parent away, so we're loosening
1785 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
1786 bdrv_check_perm(old_bs
, perm
, shared_perm
, NULL
, &error_abort
);
1787 bdrv_set_perm(old_bs
, perm
, shared_perm
);
1790 bdrv_replace_child_noperm(child
, new_bs
);
1793 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
1794 bdrv_set_perm(new_bs
, perm
, shared_perm
);
1798 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1799 const char *child_name
,
1800 const BdrvChildRole
*child_role
,
1801 uint64_t perm
, uint64_t shared_perm
,
1802 void *opaque
, Error
**errp
)
1807 ret
= bdrv_check_update_perm(child_bs
, perm
, shared_perm
, NULL
, errp
);
1809 bdrv_abort_perm_update(child_bs
);
1813 child
= g_new(BdrvChild
, 1);
1814 *child
= (BdrvChild
) {
1816 .name
= g_strdup(child_name
),
1819 .shared_perm
= shared_perm
,
1823 /* This performs the matching bdrv_set_perm() for the above check. */
1824 bdrv_replace_child(child
, child_bs
);
1829 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1830 BlockDriverState
*child_bs
,
1831 const char *child_name
,
1832 const BdrvChildRole
*child_role
,
1836 uint64_t perm
, shared_perm
;
1838 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
1840 assert(parent_bs
->drv
);
1841 parent_bs
->drv
->bdrv_child_perm(parent_bs
, NULL
, child_role
,
1842 perm
, shared_perm
, &perm
, &shared_perm
);
1844 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
1845 perm
, shared_perm
, parent_bs
, errp
);
1846 if (child
== NULL
) {
1850 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1854 static void bdrv_detach_child(BdrvChild
*child
)
1856 if (child
->next
.le_prev
) {
1857 QLIST_REMOVE(child
, next
);
1858 child
->next
.le_prev
= NULL
;
1861 bdrv_replace_child(child
, NULL
);
1863 g_free(child
->name
);
1867 void bdrv_root_unref_child(BdrvChild
*child
)
1869 BlockDriverState
*child_bs
;
1871 child_bs
= child
->bs
;
1872 bdrv_detach_child(child
);
1873 bdrv_unref(child_bs
);
1876 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1878 if (child
== NULL
) {
1882 if (child
->bs
->inherits_from
== parent
) {
1885 /* Remove inherits_from only when the last reference between parent and
1886 * child->bs goes away. */
1887 QLIST_FOREACH(c
, &parent
->children
, next
) {
1888 if (c
!= child
&& c
->bs
== child
->bs
) {
1893 child
->bs
->inherits_from
= NULL
;
1897 bdrv_root_unref_child(child
);
1901 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
1904 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1905 if (c
->role
->change_media
) {
1906 c
->role
->change_media(c
, load
);
1911 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
1914 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1915 if (c
->role
->resize
) {
1922 * Sets the backing file link of a BDS. A new reference is created; callers
1923 * which don't need their own reference any more must call bdrv_unref().
1925 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
1929 bdrv_ref(backing_hd
);
1933 bdrv_unref_child(bs
, bs
->backing
);
1941 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
1944 bdrv_unref(backing_hd
);
1947 bdrv_refresh_filename(bs
);
1950 bdrv_refresh_limits(bs
, NULL
);
1954 * Opens the backing file for a BlockDriverState if not yet open
1956 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
1957 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1958 * itself, all options starting with "${bdref_key}." are considered part of the
1961 * TODO Can this be unified with bdrv_open_image()?
1963 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
1964 const char *bdref_key
, Error
**errp
)
1966 char *backing_filename
= g_malloc0(PATH_MAX
);
1967 char *bdref_key_dot
;
1968 const char *reference
= NULL
;
1970 BlockDriverState
*backing_hd
;
1972 QDict
*tmp_parent_options
= NULL
;
1973 Error
*local_err
= NULL
;
1975 if (bs
->backing
!= NULL
) {
1979 /* NULL means an empty set of options */
1980 if (parent_options
== NULL
) {
1981 tmp_parent_options
= qdict_new();
1982 parent_options
= tmp_parent_options
;
1985 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1987 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1988 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
1989 g_free(bdref_key_dot
);
1991 reference
= qdict_get_try_str(parent_options
, bdref_key
);
1992 if (reference
|| qdict_haskey(options
, "file.filename")) {
1993 backing_filename
[0] = '\0';
1994 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
1998 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
2002 error_propagate(errp
, local_err
);
2008 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2010 error_setg(errp
, "Driver doesn't support backing files");
2015 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2016 qdict_put(options
, "driver", qstring_from_str(bs
->backing_format
));
2019 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
2020 reference
, options
, 0, bs
, &child_backing
,
2023 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2024 error_prepend(errp
, "Could not open backing file: ");
2029 /* Hook up the backing file link; drop our reference, bs owns the
2030 * backing_hd reference now */
2031 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2032 bdrv_unref(backing_hd
);
2034 error_propagate(errp
, local_err
);
2039 qdict_del(parent_options
, bdref_key
);
2042 g_free(backing_filename
);
2043 QDECREF(tmp_parent_options
);
2047 static BlockDriverState
*
2048 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2049 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2050 bool allow_none
, Error
**errp
)
2052 BlockDriverState
*bs
= NULL
;
2053 QDict
*image_options
;
2054 char *bdref_key_dot
;
2055 const char *reference
;
2057 assert(child_role
!= NULL
);
2059 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2060 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2061 g_free(bdref_key_dot
);
2063 reference
= qdict_get_try_str(options
, bdref_key
);
2064 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2066 error_setg(errp
, "A block device must be specified for \"%s\"",
2069 QDECREF(image_options
);
2073 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2074 parent
, child_role
, errp
);
2080 qdict_del(options
, bdref_key
);
2085 * Opens a disk image whose options are given as BlockdevRef in another block
2088 * If allow_none is true, no image will be opened if filename is false and no
2089 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2091 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2092 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2093 * itself, all options starting with "${bdref_key}." are considered part of the
2096 * The BlockdevRef will be removed from the options QDict.
2098 BdrvChild
*bdrv_open_child(const char *filename
,
2099 QDict
*options
, const char *bdref_key
,
2100 BlockDriverState
*parent
,
2101 const BdrvChildRole
*child_role
,
2102 bool allow_none
, Error
**errp
)
2105 BlockDriverState
*bs
;
2107 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2113 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2122 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2124 QDict
*snapshot_options
,
2127 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2128 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2130 QemuOpts
*opts
= NULL
;
2131 BlockDriverState
*bs_snapshot
;
2132 Error
*local_err
= NULL
;
2135 /* if snapshot, we create a temporary backing file and open it
2136 instead of opening 'filename' directly */
2138 /* Get the required size from the image */
2139 total_size
= bdrv_getlength(bs
);
2140 if (total_size
< 0) {
2141 error_setg_errno(errp
, -total_size
, "Could not get image size");
2145 /* Create the temporary image */
2146 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2148 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2152 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2154 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2155 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2156 qemu_opts_del(opts
);
2158 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2163 /* Prepare options QDict for the temporary file */
2164 qdict_put(snapshot_options
, "file.driver",
2165 qstring_from_str("file"));
2166 qdict_put(snapshot_options
, "file.filename",
2167 qstring_from_str(tmp_filename
));
2168 qdict_put(snapshot_options
, "driver",
2169 qstring_from_str("qcow2"));
2171 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2172 snapshot_options
= NULL
;
2178 /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
2179 * call bdrv_unref() on it), so in order to be able to return one, we have
2180 * to increase bs_snapshot's refcount here */
2181 bdrv_ref(bs_snapshot
);
2182 bdrv_append(bs_snapshot
, bs
, &local_err
);
2184 error_propagate(errp
, local_err
);
2189 g_free(tmp_filename
);
2193 QDECREF(snapshot_options
);
2194 g_free(tmp_filename
);
2199 * Opens a disk image (raw, qcow2, vmdk, ...)
2201 * options is a QDict of options to pass to the block drivers, or NULL for an
2202 * empty set of options. The reference to the QDict belongs to the block layer
2203 * after the call (even on failure), so if the caller intends to reuse the
2204 * dictionary, it needs to use QINCREF() before calling bdrv_open.
2206 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2207 * If it is not NULL, the referenced BDS will be reused.
2209 * The reference parameter may be used to specify an existing block device which
2210 * should be opened. If specified, neither options nor a filename may be given,
2211 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2213 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2214 const char *reference
,
2215 QDict
*options
, int flags
,
2216 BlockDriverState
*parent
,
2217 const BdrvChildRole
*child_role
,
2221 BlockBackend
*file
= NULL
;
2222 BlockDriverState
*bs
;
2223 BlockDriver
*drv
= NULL
;
2224 const char *drvname
;
2225 const char *backing
;
2226 Error
*local_err
= NULL
;
2227 QDict
*snapshot_options
= NULL
;
2228 int snapshot_flags
= 0;
2230 assert(!child_role
|| !flags
);
2231 assert(!child_role
== !parent
);
2234 bool options_non_empty
= options
? qdict_size(options
) : false;
2237 if (filename
|| options_non_empty
) {
2238 error_setg(errp
, "Cannot reference an existing block device with "
2239 "additional options or a new filename");
2243 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2254 /* NULL means an empty set of options */
2255 if (options
== NULL
) {
2256 options
= qdict_new();
2259 /* json: syntax counts as explicit options, as if in the QDict */
2260 parse_json_protocol(options
, &filename
, &local_err
);
2265 bs
->explicit_options
= qdict_clone_shallow(options
);
2268 bs
->inherits_from
= parent
;
2269 child_role
->inherit_options(&flags
, options
,
2270 parent
->open_flags
, parent
->options
);
2273 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2278 /* Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2279 * FIXME: we're parsing the QDict to avoid having to create a
2280 * QemuOpts just for this, but neither option is optimal. */
2281 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2282 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2283 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2285 flags
&= ~BDRV_O_RDWR
;
2288 if (flags
& BDRV_O_SNAPSHOT
) {
2289 snapshot_options
= qdict_new();
2290 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2292 /* Let bdrv_backing_options() override "read-only" */
2293 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2294 bdrv_backing_options(&flags
, options
, flags
, options
);
2297 bs
->open_flags
= flags
;
2298 bs
->options
= options
;
2299 options
= qdict_clone_shallow(options
);
2301 /* Find the right image format driver */
2302 drvname
= qdict_get_try_str(options
, "driver");
2304 drv
= bdrv_find_format(drvname
);
2306 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2311 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2313 backing
= qdict_get_try_str(options
, "backing");
2314 if (backing
&& *backing
== '\0') {
2315 flags
|= BDRV_O_NO_BACKING
;
2316 qdict_del(options
, "backing");
2319 /* Open image file without format layer. This BlockBackend is only used for
2320 * probing, the block drivers will do their own bdrv_open_child() for the
2321 * same BDS, which is why we put the node name back into options. */
2322 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2323 BlockDriverState
*file_bs
;
2325 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2326 &child_file
, true, &local_err
);
2330 if (file_bs
!= NULL
) {
2331 file
= blk_new(BLK_PERM_CONSISTENT_READ
, BLK_PERM_ALL
);
2332 blk_insert_bs(file
, file_bs
, &local_err
);
2333 bdrv_unref(file_bs
);
2338 qdict_put(options
, "file",
2339 qstring_from_str(bdrv_get_node_name(file_bs
)));
2343 /* Image format probing */
2346 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2351 * This option update would logically belong in bdrv_fill_options(),
2352 * but we first need to open bs->file for the probing to work, while
2353 * opening bs->file already requires the (mostly) final set of options
2354 * so that cache mode etc. can be inherited.
2356 * Adding the driver later is somewhat ugly, but it's not an option
2357 * that would ever be inherited, so it's correct. We just need to make
2358 * sure to update both bs->options (which has the full effective
2359 * options for bs) and options (which has file.* already removed).
2361 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
2362 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
2364 error_setg(errp
, "Must specify either driver or file");
2368 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2369 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2370 /* file must be NULL if a protocol BDS is about to be created
2371 * (the inverse results in an error message from bdrv_open_common()) */
2372 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2374 /* Open the image */
2375 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2385 /* If there is a backing file, use it */
2386 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2387 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2389 goto close_and_fail
;
2393 bdrv_refresh_filename(bs
);
2395 /* Check if any unknown options were used */
2396 if (qdict_size(options
) != 0) {
2397 const QDictEntry
*entry
= qdict_first(options
);
2398 if (flags
& BDRV_O_PROTOCOL
) {
2399 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2400 "'%s'", drv
->format_name
, entry
->key
);
2403 "Block format '%s' does not support the option '%s'",
2404 drv
->format_name
, entry
->key
);
2407 goto close_and_fail
;
2410 if (!bdrv_key_required(bs
)) {
2411 bdrv_parent_cb_change_media(bs
, true);
2412 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
2413 && !runstate_check(RUN_STATE_INMIGRATE
)
2414 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
2416 "Guest must be stopped for opening of encrypted image");
2417 goto close_and_fail
;
2422 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2423 * temporary snapshot afterwards. */
2424 if (snapshot_flags
) {
2425 BlockDriverState
*snapshot_bs
;
2426 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2427 snapshot_options
, &local_err
);
2428 snapshot_options
= NULL
;
2430 goto close_and_fail
;
2432 /* We are not going to return bs but the overlay on top of it
2433 * (snapshot_bs); thus, we have to drop the strong reference to bs
2434 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2435 * though, because the overlay still has a reference to it. */
2444 if (bs
->file
!= NULL
) {
2445 bdrv_unref_child(bs
, bs
->file
);
2447 QDECREF(snapshot_options
);
2448 QDECREF(bs
->explicit_options
);
2449 QDECREF(bs
->options
);
2453 error_propagate(errp
, local_err
);
2458 QDECREF(snapshot_options
);
2460 error_propagate(errp
, local_err
);
2464 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2465 QDict
*options
, int flags
, Error
**errp
)
2467 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2471 typedef struct BlockReopenQueueEntry
{
2473 BDRVReopenState state
;
2474 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
2475 } BlockReopenQueueEntry
;
2478 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2479 * reopen of multiple devices.
2481 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2482 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2483 * be created and initialized. This newly created BlockReopenQueue should be
2484 * passed back in for subsequent calls that are intended to be of the same
2487 * bs is the BlockDriverState to add to the reopen queue.
2489 * options contains the changed options for the associated bs
2490 * (the BlockReopenQueue takes ownership)
2492 * flags contains the open flags for the associated bs
2494 * returns a pointer to bs_queue, which is either the newly allocated
2495 * bs_queue, or the existing bs_queue being used.
2498 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
2499 BlockDriverState
*bs
,
2502 const BdrvChildRole
*role
,
2503 QDict
*parent_options
,
2508 BlockReopenQueueEntry
*bs_entry
;
2510 QDict
*old_options
, *explicit_options
;
2512 if (bs_queue
== NULL
) {
2513 bs_queue
= g_new0(BlockReopenQueue
, 1);
2514 QSIMPLEQ_INIT(bs_queue
);
2518 options
= qdict_new();
2521 /* Check if this BlockDriverState is already in the queue */
2522 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2523 if (bs
== bs_entry
->state
.bs
) {
2529 * Precedence of options:
2530 * 1. Explicitly passed in options (highest)
2531 * 2. Set in flags (only for top level)
2532 * 3. Retained from explicitly set options of bs
2533 * 4. Inherited from parent node
2534 * 5. Retained from effective options of bs
2537 if (!parent_options
) {
2539 * Any setting represented by flags is always updated. If the
2540 * corresponding QDict option is set, it takes precedence. Otherwise
2541 * the flag is translated into a QDict option. The old setting of bs is
2544 update_options_from_flags(options
, flags
);
2547 /* Old explicitly set values (don't overwrite by inherited value) */
2549 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
2551 old_options
= qdict_clone_shallow(bs
->explicit_options
);
2553 bdrv_join_options(bs
, options
, old_options
);
2554 QDECREF(old_options
);
2556 explicit_options
= qdict_clone_shallow(options
);
2558 /* Inherit from parent node */
2559 if (parent_options
) {
2561 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
2564 /* Old values are used for options that aren't set yet */
2565 old_options
= qdict_clone_shallow(bs
->options
);
2566 bdrv_join_options(bs
, options
, old_options
);
2567 QDECREF(old_options
);
2569 /* bdrv_open() masks this flag out */
2570 flags
&= ~BDRV_O_PROTOCOL
;
2572 QLIST_FOREACH(child
, &bs
->children
, next
) {
2573 QDict
*new_child_options
;
2574 char *child_key_dot
;
2576 /* reopen can only change the options of block devices that were
2577 * implicitly created and inherited options. For other (referenced)
2578 * block devices, a syntax like "backing.foo" results in an error. */
2579 if (child
->bs
->inherits_from
!= bs
) {
2583 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2584 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
2585 g_free(child_key_dot
);
2587 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
2588 child
->role
, options
, flags
);
2592 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
2593 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
2595 QDECREF(bs_entry
->state
.options
);
2596 QDECREF(bs_entry
->state
.explicit_options
);
2599 bs_entry
->state
.bs
= bs
;
2600 bs_entry
->state
.options
= options
;
2601 bs_entry
->state
.explicit_options
= explicit_options
;
2602 bs_entry
->state
.flags
= flags
;
2607 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
2608 BlockDriverState
*bs
,
2609 QDict
*options
, int flags
)
2611 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
2616 * Reopen multiple BlockDriverStates atomically & transactionally.
2618 * The queue passed in (bs_queue) must have been built up previous
2619 * via bdrv_reopen_queue().
2621 * Reopens all BDS specified in the queue, with the appropriate
2622 * flags. All devices are prepared for reopen, and failure of any
2623 * device will cause all device changes to be abandonded, and intermediate
2626 * If all devices prepare successfully, then the changes are committed
2630 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
2633 BlockReopenQueueEntry
*bs_entry
, *next
;
2634 Error
*local_err
= NULL
;
2636 assert(bs_queue
!= NULL
);
2638 aio_context_release(ctx
);
2639 bdrv_drain_all_begin();
2640 aio_context_acquire(ctx
);
2642 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2643 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
2644 error_propagate(errp
, local_err
);
2647 bs_entry
->prepared
= true;
2650 /* If we reach this point, we have success and just need to apply the
2653 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2654 bdrv_reopen_commit(&bs_entry
->state
);
2660 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
2661 if (ret
&& bs_entry
->prepared
) {
2662 bdrv_reopen_abort(&bs_entry
->state
);
2664 QDECREF(bs_entry
->state
.explicit_options
);
2666 QDECREF(bs_entry
->state
.options
);
2671 bdrv_drain_all_end();
2677 /* Reopen a single BlockDriverState with the specified flags. */
2678 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
2681 Error
*local_err
= NULL
;
2682 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
2684 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, &local_err
);
2685 if (local_err
!= NULL
) {
2686 error_propagate(errp
, local_err
);
2693 * Prepares a BlockDriverState for reopen. All changes are staged in the
2694 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2695 * the block driver layer .bdrv_reopen_prepare()
2697 * bs is the BlockDriverState to reopen
2698 * flags are the new open flags
2699 * queue is the reopen queue
2701 * Returns 0 on success, non-zero on error. On error errp will be set
2704 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2705 * It is the responsibility of the caller to then call the abort() or
2706 * commit() for any other BDS that have been left in a prepare() state
2709 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2713 Error
*local_err
= NULL
;
2718 assert(reopen_state
!= NULL
);
2719 assert(reopen_state
->bs
->drv
!= NULL
);
2720 drv
= reopen_state
->bs
->drv
;
2722 /* Process generic block layer options */
2723 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2724 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2726 error_propagate(errp
, local_err
);
2731 update_flags_from_options(&reopen_state
->flags
, opts
);
2733 /* node-name and driver must be unchanged. Put them back into the QDict, so
2734 * that they are checked at the end of this function. */
2735 value
= qemu_opt_get(opts
, "node-name");
2737 qdict_put(reopen_state
->options
, "node-name", qstring_from_str(value
));
2740 value
= qemu_opt_get(opts
, "driver");
2742 qdict_put(reopen_state
->options
, "driver", qstring_from_str(value
));
2745 /* if we are to stay read-only, do not allow permission change
2747 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
2748 reopen_state
->flags
& BDRV_O_RDWR
) {
2749 error_setg(errp
, "Node '%s' is read only",
2750 bdrv_get_device_or_node_name(reopen_state
->bs
));
2755 ret
= bdrv_flush(reopen_state
->bs
);
2757 error_setg_errno(errp
, -ret
, "Error flushing drive");
2761 if (drv
->bdrv_reopen_prepare
) {
2762 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2764 if (local_err
!= NULL
) {
2765 error_propagate(errp
, local_err
);
2767 error_setg(errp
, "failed while preparing to reopen image '%s'",
2768 reopen_state
->bs
->filename
);
2773 /* It is currently mandatory to have a bdrv_reopen_prepare()
2774 * handler for each supported drv. */
2775 error_setg(errp
, "Block format '%s' used by node '%s' "
2776 "does not support reopening files", drv
->format_name
,
2777 bdrv_get_device_or_node_name(reopen_state
->bs
));
2782 /* Options that are not handled are only okay if they are unchanged
2783 * compared to the old state. It is expected that some options are only
2784 * used for the initial open, but not reopen (e.g. filename) */
2785 if (qdict_size(reopen_state
->options
)) {
2786 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2789 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2790 const char *new = qstring_get_str(new_obj
);
2791 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2794 if (!old
|| strcmp(new, old
)) {
2795 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2799 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2805 qemu_opts_del(opts
);
2810 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2811 * makes them final by swapping the staging BlockDriverState contents into
2812 * the active BlockDriverState contents.
2814 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2818 assert(reopen_state
!= NULL
);
2819 drv
= reopen_state
->bs
->drv
;
2820 assert(drv
!= NULL
);
2822 /* If there are any driver level actions to take */
2823 if (drv
->bdrv_reopen_commit
) {
2824 drv
->bdrv_reopen_commit(reopen_state
);
2827 /* set BDS specific flags now */
2828 QDECREF(reopen_state
->bs
->explicit_options
);
2830 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2831 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2832 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2834 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2838 * Abort the reopen, and delete and free the staged changes in
2841 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2845 assert(reopen_state
!= NULL
);
2846 drv
= reopen_state
->bs
->drv
;
2847 assert(drv
!= NULL
);
2849 if (drv
->bdrv_reopen_abort
) {
2850 drv
->bdrv_reopen_abort(reopen_state
);
2853 QDECREF(reopen_state
->explicit_options
);
2857 static void bdrv_close(BlockDriverState
*bs
)
2859 BdrvAioNotifier
*ban
, *ban_next
;
2862 assert(!bs
->refcnt
);
2864 bdrv_drained_begin(bs
); /* complete I/O */
2866 bdrv_drain(bs
); /* in case flush left pending I/O */
2868 bdrv_release_named_dirty_bitmaps(bs
);
2869 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2872 BdrvChild
*child
, *next
;
2874 bs
->drv
->bdrv_close(bs
);
2877 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
2879 if (bs
->file
!= NULL
) {
2880 bdrv_unref_child(bs
, bs
->file
);
2884 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2885 /* TODO Remove bdrv_unref() from drivers' close function and use
2886 * bdrv_unref_child() here */
2887 if (child
->bs
->inherits_from
== bs
) {
2888 child
->bs
->inherits_from
= NULL
;
2890 bdrv_detach_child(child
);
2895 bs
->copy_on_read
= 0;
2896 bs
->backing_file
[0] = '\0';
2897 bs
->backing_format
[0] = '\0';
2898 bs
->total_sectors
= 0;
2899 bs
->encrypted
= false;
2900 bs
->valid_key
= false;
2902 QDECREF(bs
->options
);
2903 QDECREF(bs
->explicit_options
);
2905 QDECREF(bs
->full_open_options
);
2906 bs
->full_open_options
= NULL
;
2909 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2912 QLIST_INIT(&bs
->aio_notifiers
);
2913 bdrv_drained_end(bs
);
2916 void bdrv_close_all(void)
2918 block_job_cancel_sync_all();
2919 nbd_export_close_all();
2921 /* Drop references from requests still in flight, such as canceled block
2922 * jobs whose AIO context has not been polled yet */
2925 blk_remove_all_bs();
2926 blockdev_close_all_bdrv_states();
2928 assert(QTAILQ_EMPTY(&all_bdrv_states
));
2931 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
2935 if (c
->role
->stay_at_node
) {
2939 if (c
->role
== &child_backing
) {
2940 /* If @from is a backing file of @to, ignore the child to avoid
2941 * creating a loop. We only want to change the pointer of other
2943 QLIST_FOREACH(to_c
, &to
->children
, next
) {
2956 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
2959 BdrvChild
*c
, *next
;
2960 GSList
*list
= NULL
, *p
;
2961 uint64_t old_perm
, old_shared
;
2962 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
2965 assert(!atomic_read(&from
->in_flight
));
2966 assert(!atomic_read(&to
->in_flight
));
2968 /* Make sure that @from doesn't go away until we have successfully attached
2969 * all of its parents to @to. */
2972 /* Put all parents into @list and calculate their cumulative permissions */
2973 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
2974 if (!should_update_child(c
, to
)) {
2977 list
= g_slist_prepend(list
, c
);
2979 shared
&= c
->shared_perm
;
2982 /* Check whether the required permissions can be granted on @to, ignoring
2983 * all BdrvChild in @list so that they can't block themselves. */
2984 ret
= bdrv_check_update_perm(to
, perm
, shared
, list
, errp
);
2986 bdrv_abort_perm_update(to
);
2990 /* Now actually perform the change. We performed the permission check for
2991 * all elements of @list at once, so set the permissions all at once at the
2993 for (p
= list
; p
!= NULL
; p
= p
->next
) {
2997 bdrv_replace_child_noperm(c
, to
);
3001 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3002 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3010 * Add new bs contents at the top of an image chain while the chain is
3011 * live, while keeping required fields on the top layer.
3013 * This will modify the BlockDriverState fields, and swap contents
3014 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3016 * bs_new must not be attached to a BlockBackend.
3018 * This function does not create any image files.
3020 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3021 * that's what the callers commonly need. bs_new will be referenced by the old
3022 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3023 * reference of its own, it must call bdrv_ref().
3025 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3028 Error
*local_err
= NULL
;
3030 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3032 error_propagate(errp
, local_err
);
3036 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3038 error_propagate(errp
, local_err
);
3039 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3043 /* bs_new is now referenced by its new parents, we don't need the
3044 * additional reference any more. */
3049 static void bdrv_delete(BlockDriverState
*bs
)
3052 assert(bdrv_op_blocker_is_empty(bs
));
3053 assert(!bs
->refcnt
);
3057 /* remove from list, if necessary */
3058 if (bs
->node_name
[0] != '\0') {
3059 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3061 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3067 * Run consistency checks on an image
3069 * Returns 0 if the check could be completed (it doesn't mean that the image is
3070 * free of errors) or -errno when an internal error occurred. The results of the
3071 * check are stored in res.
3073 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
3075 if (bs
->drv
== NULL
) {
3078 if (bs
->drv
->bdrv_check
== NULL
) {
3082 memset(res
, 0, sizeof(*res
));
3083 return bs
->drv
->bdrv_check(bs
, res
, fix
);
3089 * -EINVAL - backing format specified, but no file
3090 * -ENOSPC - can't update the backing file because no space is left in the
3092 * -ENOTSUP - format driver doesn't support changing the backing file
3094 int bdrv_change_backing_file(BlockDriverState
*bs
,
3095 const char *backing_file
, const char *backing_fmt
)
3097 BlockDriver
*drv
= bs
->drv
;
3100 /* Backing file format doesn't make sense without a backing file */
3101 if (backing_fmt
&& !backing_file
) {
3105 if (drv
->bdrv_change_backing_file
!= NULL
) {
3106 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3112 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3113 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3119 * Finds the image layer in the chain that has 'bs' as its backing file.
3121 * active is the current topmost image.
3123 * Returns NULL if bs is not found in active's image chain,
3124 * or if active == bs.
3126 * Returns the bottommost base image if bs == NULL.
3128 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3129 BlockDriverState
*bs
)
3131 while (active
&& bs
!= backing_bs(active
)) {
3132 active
= backing_bs(active
);
3138 /* Given a BDS, searches for the base layer. */
3139 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3141 return bdrv_find_overlay(bs
, NULL
);
3145 * Drops images above 'base' up to and including 'top', and sets the image
3146 * above 'top' to have base as its backing file.
3148 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3149 * information in 'bs' can be properly updated.
3151 * E.g., this will convert the following chain:
3152 * bottom <- base <- intermediate <- top <- active
3156 * bottom <- base <- active
3158 * It is allowed for bottom==base, in which case it converts:
3160 * base <- intermediate <- top <- active
3166 * If backing_file_str is non-NULL, it will be used when modifying top's
3167 * overlay image metadata.
3170 * if active == top, that is considered an error
3173 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
3174 BlockDriverState
*base
, const char *backing_file_str
)
3176 BlockDriverState
*new_top_bs
= NULL
;
3177 Error
*local_err
= NULL
;
3180 if (!top
->drv
|| !base
->drv
) {
3184 new_top_bs
= bdrv_find_overlay(active
, top
);
3186 if (new_top_bs
== NULL
) {
3187 /* we could not find the image above 'top', this is an error */
3191 /* special case of new_top_bs->backing->bs already pointing to base - nothing
3192 * to do, no intermediate images */
3193 if (backing_bs(new_top_bs
) == base
) {
3198 /* Make sure that base is in the backing chain of top */
3199 if (!bdrv_chain_contains(top
, base
)) {
3203 /* success - we can delete the intermediate states, and link top->base */
3204 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
3205 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
3206 base
->drv
? base
->drv
->format_name
: "");
3211 bdrv_set_backing_hd(new_top_bs
, base
, &local_err
);
3214 error_report_err(local_err
);
3224 * Truncate file to 'offset' bytes (needed only for file protocols)
3226 int bdrv_truncate(BdrvChild
*child
, int64_t offset
)
3228 BlockDriverState
*bs
= child
->bs
;
3229 BlockDriver
*drv
= bs
->drv
;
3232 assert(child
->perm
& BLK_PERM_RESIZE
);
3236 if (!drv
->bdrv_truncate
)
3241 ret
= drv
->bdrv_truncate(bs
, offset
);
3243 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
3244 bdrv_dirty_bitmap_truncate(bs
);
3245 bdrv_parent_cb_resize(bs
);
3252 * Length of a allocated file in bytes. Sparse files are counted by actual
3253 * allocated space. Return < 0 if error or unknown.
3255 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
3257 BlockDriver
*drv
= bs
->drv
;
3261 if (drv
->bdrv_get_allocated_file_size
) {
3262 return drv
->bdrv_get_allocated_file_size(bs
);
3265 return bdrv_get_allocated_file_size(bs
->file
->bs
);
3271 * Return number of sectors on success, -errno on error.
3273 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
3275 BlockDriver
*drv
= bs
->drv
;
3280 if (drv
->has_variable_length
) {
3281 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3286 return bs
->total_sectors
;
3290 * Return length in bytes on success, -errno on error.
3291 * The length is always a multiple of BDRV_SECTOR_SIZE.
3293 int64_t bdrv_getlength(BlockDriverState
*bs
)
3295 int64_t ret
= bdrv_nb_sectors(bs
);
3297 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
3298 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
3301 /* return 0 as number of sectors if no device present or error */
3302 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
3304 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
3306 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
3309 bool bdrv_is_read_only(BlockDriverState
*bs
)
3311 return bs
->read_only
;
3314 bool bdrv_is_sg(BlockDriverState
*bs
)
3319 bool bdrv_is_encrypted(BlockDriverState
*bs
)
3321 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3324 return bs
->encrypted
;
3327 bool bdrv_key_required(BlockDriverState
*bs
)
3329 BdrvChild
*backing
= bs
->backing
;
3331 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
3334 return (bs
->encrypted
&& !bs
->valid_key
);
3337 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
3340 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3341 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
3347 if (!bs
->encrypted
) {
3349 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
3352 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
3354 bs
->valid_key
= false;
3355 } else if (!bs
->valid_key
) {
3356 /* call the change callback now, we skipped it on open */
3357 bs
->valid_key
= true;
3358 bdrv_parent_cb_change_media(bs
, true);
3364 * Provide an encryption key for @bs.
3365 * If @key is non-null:
3366 * If @bs is not encrypted, fail.
3367 * Else if the key is invalid, fail.
3368 * Else set @bs's key to @key, replacing the existing key, if any.
3370 * If @bs is encrypted and still lacks a key, fail.
3372 * On failure, store an error object through @errp if non-null.
3374 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
3377 if (!bdrv_is_encrypted(bs
)) {
3378 error_setg(errp
, "Node '%s' is not encrypted",
3379 bdrv_get_device_or_node_name(bs
));
3380 } else if (bdrv_set_key(bs
, key
) < 0) {
3381 error_setg(errp
, QERR_INVALID_PASSWORD
);
3384 if (bdrv_key_required(bs
)) {
3385 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
3386 "'%s' (%s) is encrypted",
3387 bdrv_get_device_or_node_name(bs
),
3388 bdrv_get_encrypted_filename(bs
));
3393 const char *bdrv_get_format_name(BlockDriverState
*bs
)
3395 return bs
->drv
? bs
->drv
->format_name
: NULL
;
3398 static int qsort_strcmp(const void *a
, const void *b
)
3400 return strcmp(*(char *const *)a
, *(char *const *)b
);
3403 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
3409 const char **formats
= NULL
;
3411 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
3412 if (drv
->format_name
) {
3415 while (formats
&& i
&& !found
) {
3416 found
= !strcmp(formats
[--i
], drv
->format_name
);
3420 formats
= g_renew(const char *, formats
, count
+ 1);
3421 formats
[count
++] = drv
->format_name
;
3426 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
3427 const char *format_name
= block_driver_modules
[i
].format_name
;
3433 while (formats
&& j
&& !found
) {
3434 found
= !strcmp(formats
[--j
], format_name
);
3438 formats
= g_renew(const char *, formats
, count
+ 1);
3439 formats
[count
++] = format_name
;
3444 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
3446 for (i
= 0; i
< count
; i
++) {
3447 it(opaque
, formats
[i
]);
3453 /* This function is to find a node in the bs graph */
3454 BlockDriverState
*bdrv_find_node(const char *node_name
)
3456 BlockDriverState
*bs
;
3460 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3461 if (!strcmp(node_name
, bs
->node_name
)) {
3468 /* Put this QMP function here so it can access the static graph_bdrv_states. */
3469 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
3471 BlockDeviceInfoList
*list
, *entry
;
3472 BlockDriverState
*bs
;
3475 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3476 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
3478 qapi_free_BlockDeviceInfoList(list
);
3481 entry
= g_malloc0(sizeof(*entry
));
3482 entry
->value
= info
;
3490 BlockDriverState
*bdrv_lookup_bs(const char *device
,
3491 const char *node_name
,
3495 BlockDriverState
*bs
;
3498 blk
= blk_by_name(device
);
3503 error_setg(errp
, "Device '%s' has no medium", device
);
3511 bs
= bdrv_find_node(node_name
);
3518 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
3519 device
? device
: "",
3520 node_name
? node_name
: "");
3524 /* If 'base' is in the same chain as 'top', return true. Otherwise,
3525 * return false. If either argument is NULL, return false. */
3526 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
3528 while (top
&& top
!= base
) {
3529 top
= backing_bs(top
);
3535 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
3538 return QTAILQ_FIRST(&graph_bdrv_states
);
3540 return QTAILQ_NEXT(bs
, node_list
);
3543 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
3545 return bs
->node_name
;
3548 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
3553 /* If multiple parents have a name, just pick the first one. */
3554 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3555 if (c
->role
->get_name
) {
3556 name
= c
->role
->get_name(c
);
3557 if (name
&& *name
) {
3566 /* TODO check what callers really want: bs->node_name or blk_name() */
3567 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
3569 return bdrv_get_parent_name(bs
) ?: "";
3572 /* This can be used to identify nodes that might not have a device
3573 * name associated. Since node and device names live in the same
3574 * namespace, the result is unambiguous. The exception is if both are
3575 * absent, then this returns an empty (non-null) string. */
3576 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
3578 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
3581 int bdrv_get_flags(BlockDriverState
*bs
)
3583 return bs
->open_flags
;
3586 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
3591 int bdrv_has_zero_init(BlockDriverState
*bs
)
3595 /* If BS is a copy on write image, it is initialized to
3596 the contents of the base image, which may not be zeroes. */
3600 if (bs
->drv
->bdrv_has_zero_init
) {
3601 return bs
->drv
->bdrv_has_zero_init(bs
);
3608 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
3610 BlockDriverInfo bdi
;
3616 if (bdrv_get_info(bs
, &bdi
) == 0) {
3617 return bdi
.unallocated_blocks_are_zero
;
3623 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
3625 BlockDriverInfo bdi
;
3627 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
3631 if (bdrv_get_info(bs
, &bdi
) == 0) {
3632 return bdi
.can_write_zeroes_with_unmap
;
3638 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
3640 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
3641 return bs
->backing_file
;
3642 else if (bs
->encrypted
)
3643 return bs
->filename
;
3648 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3649 char *filename
, int filename_size
)
3651 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3654 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3656 BlockDriver
*drv
= bs
->drv
;
3659 if (!drv
->bdrv_get_info
)
3661 memset(bdi
, 0, sizeof(*bdi
));
3662 return drv
->bdrv_get_info(bs
, bdi
);
3665 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3667 BlockDriver
*drv
= bs
->drv
;
3668 if (drv
&& drv
->bdrv_get_specific_info
) {
3669 return drv
->bdrv_get_specific_info(bs
);
3674 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3676 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3680 bs
->drv
->bdrv_debug_event(bs
, event
);
3683 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3686 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3687 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3690 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3691 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3697 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3699 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3700 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3703 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3704 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3710 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3712 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3713 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3716 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3717 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3723 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3725 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3726 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3729 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3730 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3736 /* backing_file can either be relative, or absolute, or a protocol. If it is
3737 * relative, it must be relative to the chain. So, passing in bs->filename
3738 * from a BDS as backing_file should not be done, as that may be relative to
3739 * the CWD rather than the chain. */
3740 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3741 const char *backing_file
)
3743 char *filename_full
= NULL
;
3744 char *backing_file_full
= NULL
;
3745 char *filename_tmp
= NULL
;
3746 int is_protocol
= 0;
3747 BlockDriverState
*curr_bs
= NULL
;
3748 BlockDriverState
*retval
= NULL
;
3749 Error
*local_error
= NULL
;
3751 if (!bs
|| !bs
->drv
|| !backing_file
) {
3755 filename_full
= g_malloc(PATH_MAX
);
3756 backing_file_full
= g_malloc(PATH_MAX
);
3757 filename_tmp
= g_malloc(PATH_MAX
);
3759 is_protocol
= path_has_protocol(backing_file
);
3761 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3763 /* If either of the filename paths is actually a protocol, then
3764 * compare unmodified paths; otherwise make paths relative */
3765 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3766 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3767 retval
= curr_bs
->backing
->bs
;
3770 /* Also check against the full backing filename for the image */
3771 bdrv_get_full_backing_filename(curr_bs
, backing_file_full
, PATH_MAX
,
3773 if (local_error
== NULL
) {
3774 if (strcmp(backing_file
, backing_file_full
) == 0) {
3775 retval
= curr_bs
->backing
->bs
;
3779 error_free(local_error
);
3783 /* If not an absolute filename path, make it relative to the current
3784 * image's filename path */
3785 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3788 /* We are going to compare absolute pathnames */
3789 if (!realpath(filename_tmp
, filename_full
)) {
3793 /* We need to make sure the backing filename we are comparing against
3794 * is relative to the current image filename (or absolute) */
3795 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3796 curr_bs
->backing_file
);
3798 if (!realpath(filename_tmp
, backing_file_full
)) {
3802 if (strcmp(backing_file_full
, filename_full
) == 0) {
3803 retval
= curr_bs
->backing
->bs
;
3809 g_free(filename_full
);
3810 g_free(backing_file_full
);
3811 g_free(filename_tmp
);
3815 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3825 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3828 void bdrv_init(void)
3830 module_call_init(MODULE_INIT_BLOCK
);
3833 void bdrv_init_with_whitelist(void)
3835 use_bdrv_whitelist
= 1;
3839 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3842 Error
*local_err
= NULL
;
3849 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3853 QLIST_FOREACH(child
, &bs
->children
, next
) {
3854 bdrv_invalidate_cache(child
->bs
, &local_err
);
3856 error_propagate(errp
, local_err
);
3861 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3862 if (bs
->drv
->bdrv_invalidate_cache
) {
3863 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3865 bs
->open_flags
|= BDRV_O_INACTIVE
;
3866 error_propagate(errp
, local_err
);
3871 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3873 bs
->open_flags
|= BDRV_O_INACTIVE
;
3874 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3879 void bdrv_invalidate_cache_all(Error
**errp
)
3881 BlockDriverState
*bs
;
3882 Error
*local_err
= NULL
;
3883 BdrvNextIterator it
;
3885 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3886 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3888 aio_context_acquire(aio_context
);
3889 bdrv_invalidate_cache(bs
, &local_err
);
3890 aio_context_release(aio_context
);
3892 error_propagate(errp
, local_err
);
3898 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3904 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3905 ret
= bs
->drv
->bdrv_inactivate(bs
);
3911 QLIST_FOREACH(child
, &bs
->children
, next
) {
3912 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
3919 bs
->open_flags
|= BDRV_O_INACTIVE
;
3924 int bdrv_inactivate_all(void)
3926 BlockDriverState
*bs
= NULL
;
3927 BdrvNextIterator it
;
3931 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3932 aio_context_acquire(bdrv_get_aio_context(bs
));
3935 /* We do two passes of inactivation. The first pass calls to drivers'
3936 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
3937 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
3939 for (pass
= 0; pass
< 2; pass
++) {
3940 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3941 ret
= bdrv_inactivate_recurse(bs
, pass
);
3949 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3950 aio_context_release(bdrv_get_aio_context(bs
));
3956 /**************************************************************/
3957 /* removable device support */
3960 * Return TRUE if the media is present
3962 bool bdrv_is_inserted(BlockDriverState
*bs
)
3964 BlockDriver
*drv
= bs
->drv
;
3970 if (drv
->bdrv_is_inserted
) {
3971 return drv
->bdrv_is_inserted(bs
);
3973 QLIST_FOREACH(child
, &bs
->children
, next
) {
3974 if (!bdrv_is_inserted(child
->bs
)) {
3982 * Return whether the media changed since the last call to this
3983 * function, or -ENOTSUP if we don't know. Most drivers don't know.
3985 int bdrv_media_changed(BlockDriverState
*bs
)
3987 BlockDriver
*drv
= bs
->drv
;
3989 if (drv
&& drv
->bdrv_media_changed
) {
3990 return drv
->bdrv_media_changed(bs
);
3996 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
3998 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
4000 BlockDriver
*drv
= bs
->drv
;
4002 if (drv
&& drv
->bdrv_eject
) {
4003 drv
->bdrv_eject(bs
, eject_flag
);
4008 * Lock or unlock the media (if it is locked, the user won't be able
4009 * to eject it manually).
4011 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
4013 BlockDriver
*drv
= bs
->drv
;
4015 trace_bdrv_lock_medium(bs
, locked
);
4017 if (drv
&& drv
->bdrv_lock_medium
) {
4018 drv
->bdrv_lock_medium(bs
, locked
);
4022 /* Get a reference to bs */
4023 void bdrv_ref(BlockDriverState
*bs
)
4028 /* Release a previously grabbed reference to bs.
4029 * If after releasing, reference count is zero, the BlockDriverState is
4031 void bdrv_unref(BlockDriverState
*bs
)
4036 assert(bs
->refcnt
> 0);
4037 if (--bs
->refcnt
== 0) {
4042 struct BdrvOpBlocker
{
4044 QLIST_ENTRY(BdrvOpBlocker
) list
;
4047 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
4049 BdrvOpBlocker
*blocker
;
4050 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4051 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
4052 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
4054 *errp
= error_copy(blocker
->reason
);
4055 error_prepend(errp
, "Node '%s' is busy: ",
4056 bdrv_get_device_or_node_name(bs
));
4063 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4065 BdrvOpBlocker
*blocker
;
4066 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4068 blocker
= g_new0(BdrvOpBlocker
, 1);
4069 blocker
->reason
= reason
;
4070 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
4073 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4075 BdrvOpBlocker
*blocker
, *next
;
4076 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4077 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
4078 if (blocker
->reason
== reason
) {
4079 QLIST_REMOVE(blocker
, list
);
4085 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
4088 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4089 bdrv_op_block(bs
, i
, reason
);
4093 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
4096 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4097 bdrv_op_unblock(bs
, i
, reason
);
4101 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
4105 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4106 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
4113 void bdrv_img_create(const char *filename
, const char *fmt
,
4114 const char *base_filename
, const char *base_fmt
,
4115 char *options
, uint64_t img_size
, int flags
,
4116 Error
**errp
, bool quiet
)
4118 QemuOptsList
*create_opts
= NULL
;
4119 QemuOpts
*opts
= NULL
;
4120 const char *backing_fmt
, *backing_file
;
4122 BlockDriver
*drv
, *proto_drv
;
4123 Error
*local_err
= NULL
;
4126 /* Find driver and parse its options */
4127 drv
= bdrv_find_format(fmt
);
4129 error_setg(errp
, "Unknown file format '%s'", fmt
);
4133 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
4138 if (!drv
->create_opts
) {
4139 error_setg(errp
, "Format driver '%s' does not support image creation",
4144 if (!proto_drv
->create_opts
) {
4145 error_setg(errp
, "Protocol driver '%s' does not support image creation",
4146 proto_drv
->format_name
);
4150 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
4151 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
4153 /* Create parameter list with default values */
4154 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
4155 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
4157 /* Parse -o options */
4159 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
4161 error_report_err(local_err
);
4163 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
4168 if (base_filename
) {
4169 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
4171 error_setg(errp
, "Backing file not supported for file format '%s'",
4178 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
4180 error_setg(errp
, "Backing file format not supported for file "
4181 "format '%s'", fmt
);
4186 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4188 if (!strcmp(filename
, backing_file
)) {
4189 error_setg(errp
, "Error: Trying to create an image with the "
4190 "same filename as the backing file");
4195 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4197 // The size for the image must always be specified, with one exception:
4198 // If we are using a backing file, we can obtain the size from there
4199 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4202 BlockDriverState
*bs
;
4203 char *full_backing
= g_new0(char, PATH_MAX
);
4206 QDict
*backing_options
= NULL
;
4208 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
4209 full_backing
, PATH_MAX
,
4212 g_free(full_backing
);
4216 /* backing files always opened read-only */
4218 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
4221 backing_options
= qdict_new();
4222 qdict_put(backing_options
, "driver",
4223 qstring_from_str(backing_fmt
));
4226 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
4228 g_free(full_backing
);
4232 size
= bdrv_getlength(bs
);
4234 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
4240 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
4244 error_setg(errp
, "Image creation needs a size parameter");
4250 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
4251 qemu_opts_print(opts
, " ");
4255 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
4257 if (ret
== -EFBIG
) {
4258 /* This is generally a better message than whatever the driver would
4259 * deliver (especially because of the cluster_size_hint), since that
4260 * is most probably not much different from "image too large". */
4261 const char *cluster_size_hint
= "";
4262 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
4263 cluster_size_hint
= " (try using a larger cluster size)";
4265 error_setg(errp
, "The image size is too large for file format '%s'"
4266 "%s", fmt
, cluster_size_hint
);
4267 error_free(local_err
);
4272 qemu_opts_del(opts
);
4273 qemu_opts_free(create_opts
);
4274 error_propagate(errp
, local_err
);
4277 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
4279 return bs
->aio_context
;
4282 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
4284 QLIST_REMOVE(ban
, list
);
4288 void bdrv_detach_aio_context(BlockDriverState
*bs
)
4290 BdrvAioNotifier
*baf
, *baf_tmp
;
4297 assert(!bs
->walking_aio_notifiers
);
4298 bs
->walking_aio_notifiers
= true;
4299 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
4301 bdrv_do_remove_aio_context_notifier(baf
);
4303 baf
->detach_aio_context(baf
->opaque
);
4306 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4307 * remove remaining aio notifiers if we aren't called again.
4309 bs
->walking_aio_notifiers
= false;
4311 if (bs
->drv
->bdrv_detach_aio_context
) {
4312 bs
->drv
->bdrv_detach_aio_context(bs
);
4314 QLIST_FOREACH(child
, &bs
->children
, next
) {
4315 bdrv_detach_aio_context(child
->bs
);
4318 bs
->aio_context
= NULL
;
4321 void bdrv_attach_aio_context(BlockDriverState
*bs
,
4322 AioContext
*new_context
)
4324 BdrvAioNotifier
*ban
, *ban_tmp
;
4331 bs
->aio_context
= new_context
;
4333 QLIST_FOREACH(child
, &bs
->children
, next
) {
4334 bdrv_attach_aio_context(child
->bs
, new_context
);
4336 if (bs
->drv
->bdrv_attach_aio_context
) {
4337 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
4340 assert(!bs
->walking_aio_notifiers
);
4341 bs
->walking_aio_notifiers
= true;
4342 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
4344 bdrv_do_remove_aio_context_notifier(ban
);
4346 ban
->attached_aio_context(new_context
, ban
->opaque
);
4349 bs
->walking_aio_notifiers
= false;
4352 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
4356 bdrv_drain(bs
); /* ensure there are no in-flight requests */
4358 ctx
= bdrv_get_aio_context(bs
);
4359 while (aio_poll(ctx
, false)) {
4360 /* wait for all bottom halves to execute */
4363 bdrv_detach_aio_context(bs
);
4365 /* This function executes in the old AioContext so acquire the new one in
4366 * case it runs in a different thread.
4368 aio_context_acquire(new_context
);
4369 bdrv_attach_aio_context(bs
, new_context
);
4370 aio_context_release(new_context
);
4373 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
4374 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
4375 void (*detach_aio_context
)(void *opaque
), void *opaque
)
4377 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
4378 *ban
= (BdrvAioNotifier
){
4379 .attached_aio_context
= attached_aio_context
,
4380 .detach_aio_context
= detach_aio_context
,
4384 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
4387 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
4388 void (*attached_aio_context
)(AioContext
*,
4390 void (*detach_aio_context
)(void *),
4393 BdrvAioNotifier
*ban
, *ban_next
;
4395 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
4396 if (ban
->attached_aio_context
== attached_aio_context
&&
4397 ban
->detach_aio_context
== detach_aio_context
&&
4398 ban
->opaque
== opaque
&&
4399 ban
->deleted
== false)
4401 if (bs
->walking_aio_notifiers
) {
4402 ban
->deleted
= true;
4404 bdrv_do_remove_aio_context_notifier(ban
);
4413 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4414 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
4416 if (!bs
->drv
->bdrv_amend_options
) {
4419 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
4422 /* This function will be called by the bdrv_recurse_is_first_non_filter method
4423 * of block filter and by bdrv_is_first_non_filter.
4424 * It is used to test if the given bs is the candidate or recurse more in the
4427 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
4428 BlockDriverState
*candidate
)
4430 /* return false if basic checks fails */
4431 if (!bs
|| !bs
->drv
) {
4435 /* the code reached a non block filter driver -> check if the bs is
4436 * the same as the candidate. It's the recursion termination condition.
4438 if (!bs
->drv
->is_filter
) {
4439 return bs
== candidate
;
4441 /* Down this path the driver is a block filter driver */
4443 /* If the block filter recursion method is defined use it to recurse down
4446 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
4447 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
4450 /* the driver is a block filter but don't allow to recurse -> return false
4455 /* This function checks if the candidate is the first non filter bs down it's
4456 * bs chain. Since we don't have pointers to parents it explore all bs chains
4457 * from the top. Some filters can choose not to pass down the recursion.
4459 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
4461 BlockDriverState
*bs
;
4462 BdrvNextIterator it
;
4464 /* walk down the bs forest recursively */
4465 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4468 /* try to recurse in this top level bs */
4469 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
4471 /* candidate is the first non filter */
4480 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
4481 const char *node_name
, Error
**errp
)
4483 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
4484 AioContext
*aio_context
;
4486 if (!to_replace_bs
) {
4487 error_setg(errp
, "Node name '%s' not found", node_name
);
4491 aio_context
= bdrv_get_aio_context(to_replace_bs
);
4492 aio_context_acquire(aio_context
);
4494 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
4495 to_replace_bs
= NULL
;
4499 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4500 * most non filter in order to prevent data corruption.
4501 * Another benefit is that this tests exclude backing files which are
4502 * blocked by the backing blockers.
4504 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
4505 error_setg(errp
, "Only top most non filter can be replaced");
4506 to_replace_bs
= NULL
;
4511 aio_context_release(aio_context
);
4512 return to_replace_bs
;
4515 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
4517 const QDictEntry
*entry
;
4520 bool found_any
= false;
4523 for (entry
= qdict_first(bs
->options
); entry
;
4524 entry
= qdict_next(bs
->options
, entry
))
4526 /* Exclude options for children */
4527 QLIST_FOREACH(child
, &bs
->children
, next
) {
4528 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
4529 && (!*p
|| *p
== '.'))
4538 /* And exclude all non-driver-specific options */
4539 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
4540 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
4548 qobject_incref(qdict_entry_value(entry
));
4549 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
4556 /* Updates the following BDS fields:
4557 * - exact_filename: A filename which may be used for opening a block device
4558 * which (mostly) equals the given BDS (even without any
4559 * other options; so reading and writing must return the same
4560 * results, but caching etc. may be different)
4561 * - full_open_options: Options which, when given when opening a block device
4562 * (without a filename), result in a BDS (mostly)
4563 * equalling the given one
4564 * - filename: If exact_filename is set, it is copied here. Otherwise,
4565 * full_open_options is converted to a JSON object, prefixed with
4566 * "json:" (for use through the JSON pseudo protocol) and put here.
4568 void bdrv_refresh_filename(BlockDriverState
*bs
)
4570 BlockDriver
*drv
= bs
->drv
;
4577 /* This BDS's file name will most probably depend on its file's name, so
4578 * refresh that first */
4580 bdrv_refresh_filename(bs
->file
->bs
);
4583 if (drv
->bdrv_refresh_filename
) {
4584 /* Obsolete information is of no use here, so drop the old file name
4585 * information before refreshing it */
4586 bs
->exact_filename
[0] = '\0';
4587 if (bs
->full_open_options
) {
4588 QDECREF(bs
->full_open_options
);
4589 bs
->full_open_options
= NULL
;
4593 append_open_options(opts
, bs
);
4594 drv
->bdrv_refresh_filename(bs
, opts
);
4596 } else if (bs
->file
) {
4597 /* Try to reconstruct valid information from the underlying file */
4598 bool has_open_options
;
4600 bs
->exact_filename
[0] = '\0';
4601 if (bs
->full_open_options
) {
4602 QDECREF(bs
->full_open_options
);
4603 bs
->full_open_options
= NULL
;
4607 has_open_options
= append_open_options(opts
, bs
);
4609 /* If no specific options have been given for this BDS, the filename of
4610 * the underlying file should suffice for this one as well */
4611 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
4612 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
4614 /* Reconstructing the full options QDict is simple for most format block
4615 * drivers, as long as the full options are known for the underlying
4616 * file BDS. The full options QDict of that file BDS should somehow
4617 * contain a representation of the filename, therefore the following
4618 * suffices without querying the (exact_)filename of this BDS. */
4619 if (bs
->file
->bs
->full_open_options
) {
4620 qdict_put_obj(opts
, "driver",
4621 QOBJECT(qstring_from_str(drv
->format_name
)));
4622 QINCREF(bs
->file
->bs
->full_open_options
);
4623 qdict_put_obj(opts
, "file",
4624 QOBJECT(bs
->file
->bs
->full_open_options
));
4626 bs
->full_open_options
= opts
;
4630 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
4631 /* There is no underlying file BDS (at least referenced by BDS.file),
4632 * so the full options QDict should be equal to the options given
4633 * specifically for this block device when it was opened (plus the
4634 * driver specification).
4635 * Because those options don't change, there is no need to update
4636 * full_open_options when it's already set. */
4639 append_open_options(opts
, bs
);
4640 qdict_put_obj(opts
, "driver",
4641 QOBJECT(qstring_from_str(drv
->format_name
)));
4643 if (bs
->exact_filename
[0]) {
4644 /* This may not work for all block protocol drivers (some may
4645 * require this filename to be parsed), but we have to find some
4646 * default solution here, so just include it. If some block driver
4647 * does not support pure options without any filename at all or
4648 * needs some special format of the options QDict, it needs to
4649 * implement the driver-specific bdrv_refresh_filename() function.
4651 qdict_put_obj(opts
, "filename",
4652 QOBJECT(qstring_from_str(bs
->exact_filename
)));
4655 bs
->full_open_options
= opts
;
4658 if (bs
->exact_filename
[0]) {
4659 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4660 } else if (bs
->full_open_options
) {
4661 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4662 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4663 qstring_get_str(json
));
4669 * Hot add/remove a BDS's child. So the user can take a child offline when
4670 * it is broken and take a new child online
4672 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
4676 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
4677 error_setg(errp
, "The node %s does not support adding a child",
4678 bdrv_get_device_or_node_name(parent_bs
));
4682 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4683 error_setg(errp
, "The node %s already has a parent",
4684 child_bs
->node_name
);
4688 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4691 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4695 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4696 error_setg(errp
, "The node %s does not support removing a child",
4697 bdrv_get_device_or_node_name(parent_bs
));
4701 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4708 error_setg(errp
, "The node %s does not have a child named %s",
4709 bdrv_get_device_or_node_name(parent_bs
),
4710 bdrv_get_device_or_node_name(child
->bs
));
4714 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);