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 bool bdrv_is_read_only(BlockDriverState
*bs
)
197 return bs
->read_only
;
200 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
, Error
**errp
)
202 /* Do not set read_only if copy_on_read is enabled */
203 if (bs
->copy_on_read
&& read_only
) {
204 error_setg(errp
, "Can't set node '%s' to r/o with copy-on-read enabled",
205 bdrv_get_device_or_node_name(bs
));
209 /* Do not clear read_only if it is prohibited */
210 if (!read_only
&& !(bs
->open_flags
& BDRV_O_ALLOW_RDWR
)) {
211 error_setg(errp
, "Node '%s' is read only",
212 bdrv_get_device_or_node_name(bs
));
219 int bdrv_set_read_only(BlockDriverState
*bs
, bool read_only
, Error
**errp
)
223 ret
= bdrv_can_set_read_only(bs
, read_only
, errp
);
228 bs
->read_only
= read_only
;
232 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
234 char *dest
, size_t sz
,
237 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
238 path_is_absolute(backing
))
240 pstrcpy(dest
, sz
, backing
);
241 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
242 error_setg(errp
, "Cannot use relative backing file names for '%s'",
245 path_combine(dest
, sz
, backed
, backing
);
249 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
252 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
254 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
258 void bdrv_register(BlockDriver
*bdrv
)
260 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
263 BlockDriverState
*bdrv_new(void)
265 BlockDriverState
*bs
;
268 bs
= g_new0(BlockDriverState
, 1);
269 QLIST_INIT(&bs
->dirty_bitmaps
);
270 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
271 QLIST_INIT(&bs
->op_blockers
[i
]);
273 notifier_with_return_list_init(&bs
->before_write_notifiers
);
275 bs
->aio_context
= qemu_get_aio_context();
277 qemu_co_queue_init(&bs
->flush_queue
);
279 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
284 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
288 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
289 if (!strcmp(drv1
->format_name
, format_name
)) {
297 BlockDriver
*bdrv_find_format(const char *format_name
)
302 drv1
= bdrv_do_find_format(format_name
);
307 /* The driver isn't registered, maybe we need to load a module */
308 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
309 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
310 block_module_load_one(block_driver_modules
[i
].library_name
);
315 return bdrv_do_find_format(format_name
);
318 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
320 static const char *whitelist_rw
[] = {
321 CONFIG_BDRV_RW_WHITELIST
323 static const char *whitelist_ro
[] = {
324 CONFIG_BDRV_RO_WHITELIST
328 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
329 return 1; /* no whitelist, anything goes */
332 for (p
= whitelist_rw
; *p
; p
++) {
333 if (!strcmp(drv
->format_name
, *p
)) {
338 for (p
= whitelist_ro
; *p
; p
++) {
339 if (!strcmp(drv
->format_name
, *p
)) {
347 bool bdrv_uses_whitelist(void)
349 return use_bdrv_whitelist
;
352 typedef struct CreateCo
{
360 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
362 Error
*local_err
= NULL
;
365 CreateCo
*cco
= opaque
;
368 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
369 error_propagate(&cco
->err
, local_err
);
373 int bdrv_create(BlockDriver
*drv
, const char* filename
,
374 QemuOpts
*opts
, Error
**errp
)
381 .filename
= g_strdup(filename
),
387 if (!drv
->bdrv_create
) {
388 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
393 if (qemu_in_coroutine()) {
394 /* Fast-path if already in coroutine context */
395 bdrv_create_co_entry(&cco
);
397 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
398 qemu_coroutine_enter(co
);
399 while (cco
.ret
== NOT_DONE
) {
400 aio_poll(qemu_get_aio_context(), true);
407 error_propagate(errp
, cco
.err
);
409 error_setg_errno(errp
, -ret
, "Could not create image");
414 g_free(cco
.filename
);
418 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
421 Error
*local_err
= NULL
;
424 drv
= bdrv_find_protocol(filename
, true, errp
);
429 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
430 error_propagate(errp
, local_err
);
435 * Try to get @bs's logical and physical block size.
436 * On success, store them in @bsz struct and return 0.
437 * On failure return -errno.
438 * @bs must not be empty.
440 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
442 BlockDriver
*drv
= bs
->drv
;
444 if (drv
&& drv
->bdrv_probe_blocksizes
) {
445 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
452 * Try to get @bs's geometry (cyls, heads, sectors).
453 * On success, store them in @geo struct and return 0.
454 * On failure return -errno.
455 * @bs must not be empty.
457 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
459 BlockDriver
*drv
= bs
->drv
;
461 if (drv
&& drv
->bdrv_probe_geometry
) {
462 return drv
->bdrv_probe_geometry(bs
, geo
);
469 * Create a uniquely-named empty temporary file.
470 * Return 0 upon success, otherwise a negative errno value.
472 int get_tmp_filename(char *filename
, int size
)
475 char temp_dir
[MAX_PATH
];
476 /* GetTempFileName requires that its output buffer (4th param)
477 have length MAX_PATH or greater. */
478 assert(size
>= MAX_PATH
);
479 return (GetTempPath(MAX_PATH
, temp_dir
)
480 && GetTempFileName(temp_dir
, "qem", 0, filename
)
481 ? 0 : -GetLastError());
485 tmpdir
= getenv("TMPDIR");
489 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
492 fd
= mkstemp(filename
);
496 if (close(fd
) != 0) {
505 * Detect host devices. By convention, /dev/cdrom[N] is always
506 * recognized as a host CDROM.
508 static BlockDriver
*find_hdev_driver(const char *filename
)
510 int score_max
= 0, score
;
511 BlockDriver
*drv
= NULL
, *d
;
513 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
514 if (d
->bdrv_probe_device
) {
515 score
= d
->bdrv_probe_device(filename
);
516 if (score
> score_max
) {
526 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
530 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
531 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
539 BlockDriver
*bdrv_find_protocol(const char *filename
,
540 bool allow_protocol_prefix
,
549 /* TODO Drivers without bdrv_file_open must be specified explicitly */
552 * XXX(hch): we really should not let host device detection
553 * override an explicit protocol specification, but moving this
554 * later breaks access to device names with colons in them.
555 * Thanks to the brain-dead persistent naming schemes on udev-
556 * based Linux systems those actually are quite common.
558 drv1
= find_hdev_driver(filename
);
563 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
567 p
= strchr(filename
, ':');
570 if (len
> sizeof(protocol
) - 1)
571 len
= sizeof(protocol
) - 1;
572 memcpy(protocol
, filename
, len
);
573 protocol
[len
] = '\0';
575 drv1
= bdrv_do_find_protocol(protocol
);
580 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
581 if (block_driver_modules
[i
].protocol_name
&&
582 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
583 block_module_load_one(block_driver_modules
[i
].library_name
);
588 drv1
= bdrv_do_find_protocol(protocol
);
590 error_setg(errp
, "Unknown protocol '%s'", protocol
);
596 * Guess image format by probing its contents.
597 * This is not a good idea when your image is raw (CVE-2008-2004), but
598 * we do it anyway for backward compatibility.
600 * @buf contains the image's first @buf_size bytes.
601 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
602 * but can be smaller if the image file is smaller)
603 * @filename is its filename.
605 * For all block drivers, call the bdrv_probe() method to get its
607 * Return the first block driver with the highest probing score.
609 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
610 const char *filename
)
612 int score_max
= 0, score
;
613 BlockDriver
*drv
= NULL
, *d
;
615 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
617 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
618 if (score
> score_max
) {
628 static int find_image_format(BlockBackend
*file
, const char *filename
,
629 BlockDriver
**pdrv
, Error
**errp
)
632 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
635 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
636 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
641 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
643 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
649 drv
= bdrv_probe_all(buf
, ret
, filename
);
651 error_setg(errp
, "Could not determine image format: No compatible "
660 * Set the current 'total_sectors' value
661 * Return 0 on success, -errno on error.
663 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
665 BlockDriver
*drv
= bs
->drv
;
667 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
671 /* query actual device if possible, otherwise just trust the hint */
672 if (drv
->bdrv_getlength
) {
673 int64_t length
= drv
->bdrv_getlength(bs
);
677 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
680 bs
->total_sectors
= hint
;
685 * Combines a QDict of new block driver @options with any missing options taken
686 * from @old_options, so that leaving out an option defaults to its old value.
688 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
691 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
692 bs
->drv
->bdrv_join_options(options
, old_options
);
694 qdict_join(options
, old_options
, false);
699 * Set open flags for a given discard mode
701 * Return 0 on success, -1 if the discard mode was invalid.
703 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
705 *flags
&= ~BDRV_O_UNMAP
;
707 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
709 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
710 *flags
|= BDRV_O_UNMAP
;
719 * Set open flags for a given cache mode
721 * Return 0 on success, -1 if the cache mode was invalid.
723 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
725 *flags
&= ~BDRV_O_CACHE_MASK
;
727 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
728 *writethrough
= false;
729 *flags
|= BDRV_O_NOCACHE
;
730 } else if (!strcmp(mode
, "directsync")) {
731 *writethrough
= true;
732 *flags
|= BDRV_O_NOCACHE
;
733 } else if (!strcmp(mode
, "writeback")) {
734 *writethrough
= false;
735 } else if (!strcmp(mode
, "unsafe")) {
736 *writethrough
= false;
737 *flags
|= BDRV_O_NO_FLUSH
;
738 } else if (!strcmp(mode
, "writethrough")) {
739 *writethrough
= true;
747 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
749 BlockDriverState
*parent
= c
->opaque
;
750 return g_strdup(bdrv_get_device_or_node_name(parent
));
753 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
755 BlockDriverState
*bs
= child
->opaque
;
756 bdrv_drained_begin(bs
);
759 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
761 BlockDriverState
*bs
= child
->opaque
;
762 bdrv_drained_end(bs
);
766 * Returns the options and flags that a temporary snapshot should get, based on
767 * the originally requested flags (the originally requested image will have
768 * flags like a backing file)
770 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
771 int parent_flags
, QDict
*parent_options
)
773 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
775 /* For temporary files, unconditional cache=unsafe is fine */
776 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
777 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
779 /* Copy the read-only option from the parent */
780 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
782 /* aio=native doesn't work for cache.direct=off, so disable it for the
783 * temporary snapshot */
784 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
788 * Returns the options and flags that bs->file should get if a protocol driver
789 * is expected, based on the given options and flags for the parent BDS
791 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
792 int parent_flags
, QDict
*parent_options
)
794 int flags
= parent_flags
;
796 /* Enable protocol handling, disable format probing for bs->file */
797 flags
|= BDRV_O_PROTOCOL
;
799 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
801 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
802 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
804 /* Inherit the read-only option from the parent if it's not set */
805 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
807 /* Our block drivers take care to send flushes and respect unmap policy,
808 * so we can default to enable both on lower layers regardless of the
809 * corresponding parent options. */
810 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
812 /* Clear flags that only apply to the top layer */
813 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
816 *child_flags
= flags
;
819 const BdrvChildRole child_file
= {
820 .get_parent_desc
= bdrv_child_get_parent_desc
,
821 .inherit_options
= bdrv_inherited_options
,
822 .drained_begin
= bdrv_child_cb_drained_begin
,
823 .drained_end
= bdrv_child_cb_drained_end
,
827 * Returns the options and flags that bs->file should get if the use of formats
828 * (and not only protocols) is permitted for it, based on the given options and
829 * flags for the parent BDS
831 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
832 int parent_flags
, QDict
*parent_options
)
834 child_file
.inherit_options(child_flags
, child_options
,
835 parent_flags
, parent_options
);
837 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
840 const BdrvChildRole child_format
= {
841 .get_parent_desc
= bdrv_child_get_parent_desc
,
842 .inherit_options
= bdrv_inherited_fmt_options
,
843 .drained_begin
= bdrv_child_cb_drained_begin
,
844 .drained_end
= bdrv_child_cb_drained_end
,
847 static void bdrv_backing_attach(BdrvChild
*c
)
849 BlockDriverState
*parent
= c
->opaque
;
850 BlockDriverState
*backing_hd
= c
->bs
;
852 assert(!parent
->backing_blocker
);
853 error_setg(&parent
->backing_blocker
,
854 "node is used as backing hd of '%s'",
855 bdrv_get_device_or_node_name(parent
));
857 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
858 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
859 backing_hd
->filename
);
860 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
861 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
863 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
864 /* Otherwise we won't be able to commit or stream */
865 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
866 parent
->backing_blocker
);
867 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
868 parent
->backing_blocker
);
870 * We do backup in 3 ways:
872 * The target bs is new opened, and the source is top BDS
874 * Both the source and the target are top BDSes.
875 * 3. internal backup(used for block replication)
876 * Both the source and the target are backing file
878 * In case 1 and 2, neither the source nor the target is the backing file.
879 * In case 3, we will block the top BDS, so there is only one block job
880 * for the top BDS and its backing chain.
882 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
883 parent
->backing_blocker
);
884 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
885 parent
->backing_blocker
);
888 static void bdrv_backing_detach(BdrvChild
*c
)
890 BlockDriverState
*parent
= c
->opaque
;
892 assert(parent
->backing_blocker
);
893 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
894 error_free(parent
->backing_blocker
);
895 parent
->backing_blocker
= NULL
;
899 * Returns the options and flags that bs->backing should get, based on the
900 * given options and flags for the parent BDS
902 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
903 int parent_flags
, QDict
*parent_options
)
905 int flags
= parent_flags
;
907 /* The cache mode is inherited unmodified for backing files; except WCE,
908 * which is only applied on the top level (BlockBackend) */
909 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
910 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
912 /* backing files always opened read-only */
913 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
914 flags
&= ~BDRV_O_COPY_ON_READ
;
916 /* snapshot=on is handled on the top layer */
917 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
919 *child_flags
= flags
;
922 const BdrvChildRole child_backing
= {
923 .get_parent_desc
= bdrv_child_get_parent_desc
,
924 .attach
= bdrv_backing_attach
,
925 .detach
= bdrv_backing_detach
,
926 .inherit_options
= bdrv_backing_options
,
927 .drained_begin
= bdrv_child_cb_drained_begin
,
928 .drained_end
= bdrv_child_cb_drained_end
,
931 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
933 int open_flags
= flags
;
936 * Clear flags that are internal to the block layer before opening the
939 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
942 * Snapshots should be writable.
944 if (flags
& BDRV_O_TEMPORARY
) {
945 open_flags
|= BDRV_O_RDWR
;
951 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
953 *flags
&= ~BDRV_O_CACHE_MASK
;
955 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
956 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
957 *flags
|= BDRV_O_NO_FLUSH
;
960 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
961 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
962 *flags
|= BDRV_O_NOCACHE
;
965 *flags
&= ~BDRV_O_RDWR
;
967 assert(qemu_opt_find(opts
, BDRV_OPT_READ_ONLY
));
968 if (!qemu_opt_get_bool(opts
, BDRV_OPT_READ_ONLY
, false)) {
969 *flags
|= BDRV_O_RDWR
;
974 static void update_options_from_flags(QDict
*options
, int flags
)
976 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
977 qdict_put_bool(options
, BDRV_OPT_CACHE_DIRECT
, flags
& BDRV_O_NOCACHE
);
979 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
980 qdict_put_bool(options
, BDRV_OPT_CACHE_NO_FLUSH
,
981 flags
& BDRV_O_NO_FLUSH
);
983 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
984 qdict_put_bool(options
, BDRV_OPT_READ_ONLY
, !(flags
& BDRV_O_RDWR
));
988 static void bdrv_assign_node_name(BlockDriverState
*bs
,
989 const char *node_name
,
992 char *gen_node_name
= NULL
;
995 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
996 } else if (!id_wellformed(node_name
)) {
998 * Check for empty string or invalid characters, but not if it is
999 * generated (generated names use characters not available to the user)
1001 error_setg(errp
, "Invalid node name");
1005 /* takes care of avoiding namespaces collisions */
1006 if (blk_by_name(node_name
)) {
1007 error_setg(errp
, "node-name=%s is conflicting with a device id",
1012 /* takes care of avoiding duplicates node names */
1013 if (bdrv_find_node(node_name
)) {
1014 error_setg(errp
, "Duplicate node name");
1018 /* copy node name into the bs and insert it into the graph list */
1019 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
1020 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
1022 g_free(gen_node_name
);
1025 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
1026 const char *node_name
, QDict
*options
,
1027 int open_flags
, Error
**errp
)
1029 Error
*local_err
= NULL
;
1032 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1034 error_propagate(errp
, local_err
);
1039 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1040 bs
->opaque
= g_malloc0(drv
->instance_size
);
1042 if (drv
->bdrv_file_open
) {
1043 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1044 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1045 } else if (drv
->bdrv_open
) {
1046 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1053 error_propagate(errp
, local_err
);
1054 } else if (bs
->filename
[0]) {
1055 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1057 error_setg_errno(errp
, -ret
, "Could not open image");
1062 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1064 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1068 bdrv_refresh_limits(bs
, &local_err
);
1070 error_propagate(errp
, local_err
);
1075 assert(bdrv_opt_mem_align(bs
) != 0);
1076 assert(bdrv_min_mem_align(bs
) != 0);
1077 assert(is_power_of_2(bs
->bl
.request_alignment
));
1082 /* FIXME Close bs first if already opened*/
1089 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1090 int flags
, Error
**errp
)
1092 BlockDriverState
*bs
;
1096 bs
->open_flags
= flags
;
1097 bs
->explicit_options
= qdict_new();
1098 bs
->options
= qdict_new();
1101 update_options_from_flags(bs
->options
, flags
);
1103 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1105 QDECREF(bs
->explicit_options
);
1106 QDECREF(bs
->options
);
1114 QemuOptsList bdrv_runtime_opts
= {
1115 .name
= "bdrv_common",
1116 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1119 .name
= "node-name",
1120 .type
= QEMU_OPT_STRING
,
1121 .help
= "Node name of the block device node",
1125 .type
= QEMU_OPT_STRING
,
1126 .help
= "Block driver to use for the node",
1129 .name
= BDRV_OPT_CACHE_DIRECT
,
1130 .type
= QEMU_OPT_BOOL
,
1131 .help
= "Bypass software writeback cache on the host",
1134 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1135 .type
= QEMU_OPT_BOOL
,
1136 .help
= "Ignore flush requests",
1139 .name
= BDRV_OPT_READ_ONLY
,
1140 .type
= QEMU_OPT_BOOL
,
1141 .help
= "Node is opened in read-only mode",
1144 .name
= "detect-zeroes",
1145 .type
= QEMU_OPT_STRING
,
1146 .help
= "try to optimize zero writes (off, on, unmap)",
1150 .type
= QEMU_OPT_STRING
,
1151 .help
= "discard operation (ignore/off, unmap/on)",
1153 { /* end of list */ }
1158 * Common part for opening disk images and files
1160 * Removes all processed options from *options.
1162 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1163 QDict
*options
, Error
**errp
)
1165 int ret
, open_flags
;
1166 const char *filename
;
1167 const char *driver_name
= NULL
;
1168 const char *node_name
= NULL
;
1169 const char *discard
;
1170 const char *detect_zeroes
;
1173 Error
*local_err
= NULL
;
1175 assert(bs
->file
== NULL
);
1176 assert(options
!= NULL
&& bs
->options
!= options
);
1178 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1179 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1181 error_propagate(errp
, local_err
);
1186 update_flags_from_options(&bs
->open_flags
, opts
);
1188 driver_name
= qemu_opt_get(opts
, "driver");
1189 drv
= bdrv_find_format(driver_name
);
1190 assert(drv
!= NULL
);
1193 filename
= blk_bs(file
)->filename
;
1196 * Caution: while qdict_get_try_str() is fine, getting
1197 * non-string types would require more care. When @options
1198 * come from -blockdev or blockdev_add, its members are typed
1199 * according to the QAPI schema, but when they come from
1200 * -drive, they're all QString.
1202 filename
= qdict_get_try_str(options
, "filename");
1205 if (drv
->bdrv_needs_filename
&& (!filename
|| !filename
[0])) {
1206 error_setg(errp
, "The '%s' block driver requires a file name",
1212 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1215 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1217 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1219 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1220 ? "Driver '%s' can only be used for read-only devices"
1221 : "Driver '%s' is not whitelisted",
1227 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
1228 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1229 if (!bs
->read_only
) {
1230 bdrv_enable_copy_on_read(bs
);
1232 error_setg(errp
, "Can't use copy-on-read on read-only device");
1238 discard
= qemu_opt_get(opts
, "discard");
1239 if (discard
!= NULL
) {
1240 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1241 error_setg(errp
, "Invalid discard option");
1247 detect_zeroes
= qemu_opt_get(opts
, "detect-zeroes");
1248 if (detect_zeroes
) {
1249 BlockdevDetectZeroesOptions value
=
1250 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup
,
1252 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX
,
1253 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
1256 error_propagate(errp
, local_err
);
1261 if (value
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
1262 !(bs
->open_flags
& BDRV_O_UNMAP
))
1264 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
1265 "without setting discard operation to unmap");
1270 bs
->detect_zeroes
= value
;
1273 if (filename
!= NULL
) {
1274 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1276 bs
->filename
[0] = '\0';
1278 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1280 /* Open the image, either directly or using a protocol */
1281 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1282 node_name
= qemu_opt_get(opts
, "node-name");
1284 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1285 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1290 qemu_opts_del(opts
);
1294 qemu_opts_del(opts
);
1298 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1300 QObject
*options_obj
;
1304 ret
= strstart(filename
, "json:", &filename
);
1307 options_obj
= qobject_from_json(filename
, errp
);
1309 /* Work around qobject_from_json() lossage TODO fix that */
1310 if (errp
&& !*errp
) {
1311 error_setg(errp
, "Could not parse the JSON options");
1314 error_prepend(errp
, "Could not parse the JSON options: ");
1318 options
= qobject_to_qdict(options_obj
);
1320 qobject_decref(options_obj
);
1321 error_setg(errp
, "Invalid JSON object given");
1325 qdict_flatten(options
);
1330 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1333 QDict
*json_options
;
1334 Error
*local_err
= NULL
;
1336 /* Parse json: pseudo-protocol */
1337 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1341 json_options
= parse_json_filename(*pfilename
, &local_err
);
1343 error_propagate(errp
, local_err
);
1347 /* Options given in the filename have lower priority than options
1348 * specified directly */
1349 qdict_join(options
, json_options
, false);
1350 QDECREF(json_options
);
1355 * Fills in default options for opening images and converts the legacy
1356 * filename/flags pair to option QDict entries.
1357 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1358 * block driver has been specified explicitly.
1360 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1361 int *flags
, Error
**errp
)
1363 const char *drvname
;
1364 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1365 bool parse_filename
= false;
1366 BlockDriver
*drv
= NULL
;
1367 Error
*local_err
= NULL
;
1370 * Caution: while qdict_get_try_str() is fine, getting non-string
1371 * types would require more care. When @options come from
1372 * -blockdev or blockdev_add, its members are typed according to
1373 * the QAPI schema, but when they come from -drive, they're all
1376 drvname
= qdict_get_try_str(*options
, "driver");
1378 drv
= bdrv_find_format(drvname
);
1380 error_setg(errp
, "Unknown driver '%s'", drvname
);
1383 /* If the user has explicitly specified the driver, this choice should
1384 * override the BDRV_O_PROTOCOL flag */
1385 protocol
= drv
->bdrv_file_open
;
1389 *flags
|= BDRV_O_PROTOCOL
;
1391 *flags
&= ~BDRV_O_PROTOCOL
;
1394 /* Translate cache options from flags into options */
1395 update_options_from_flags(*options
, *flags
);
1397 /* Fetch the file name from the options QDict if necessary */
1398 if (protocol
&& filename
) {
1399 if (!qdict_haskey(*options
, "filename")) {
1400 qdict_put_str(*options
, "filename", filename
);
1401 parse_filename
= true;
1403 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1409 /* Find the right block driver */
1410 /* See cautionary note on accessing @options above */
1411 filename
= qdict_get_try_str(*options
, "filename");
1413 if (!drvname
&& protocol
) {
1415 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1420 drvname
= drv
->format_name
;
1421 qdict_put_str(*options
, "driver", drvname
);
1423 error_setg(errp
, "Must specify either driver or file");
1428 assert(drv
|| !protocol
);
1430 /* Driver-specific filename parsing */
1431 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1432 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1434 error_propagate(errp
, local_err
);
1438 if (!drv
->bdrv_needs_filename
) {
1439 qdict_del(*options
, "filename");
1446 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1447 GSList
*ignore_children
, Error
**errp
);
1448 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1449 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1452 * Check whether permissions on this node can be changed in a way that
1453 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1454 * permissions of all its parents. This involves checking whether all necessary
1455 * permission changes to child nodes can be performed.
1457 * A call to this function must always be followed by a call to bdrv_set_perm()
1458 * or bdrv_abort_perm_update().
1460 static int bdrv_check_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1461 uint64_t cumulative_shared_perms
,
1462 GSList
*ignore_children
, Error
**errp
)
1464 BlockDriver
*drv
= bs
->drv
;
1468 /* Write permissions never work with read-only images */
1469 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1470 bdrv_is_read_only(bs
))
1472 error_setg(errp
, "Block node is read-only");
1476 /* Check this node */
1481 if (drv
->bdrv_check_perm
) {
1482 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1483 cumulative_shared_perms
, errp
);
1486 /* Drivers that never have children can omit .bdrv_child_perm() */
1487 if (!drv
->bdrv_child_perm
) {
1488 assert(QLIST_EMPTY(&bs
->children
));
1492 /* Check all children */
1493 QLIST_FOREACH(c
, &bs
->children
, next
) {
1494 uint64_t cur_perm
, cur_shared
;
1495 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1496 cumulative_perms
, cumulative_shared_perms
,
1497 &cur_perm
, &cur_shared
);
1498 ret
= bdrv_child_check_perm(c
, cur_perm
, cur_shared
, ignore_children
,
1509 * Notifies drivers that after a previous bdrv_check_perm() call, the
1510 * permission update is not performed and any preparations made for it (e.g.
1511 * taken file locks) need to be undone.
1513 * This function recursively notifies all child nodes.
1515 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1517 BlockDriver
*drv
= bs
->drv
;
1524 if (drv
->bdrv_abort_perm_update
) {
1525 drv
->bdrv_abort_perm_update(bs
);
1528 QLIST_FOREACH(c
, &bs
->children
, next
) {
1529 bdrv_child_abort_perm_update(c
);
1533 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1534 uint64_t cumulative_shared_perms
)
1536 BlockDriver
*drv
= bs
->drv
;
1543 /* Update this node */
1544 if (drv
->bdrv_set_perm
) {
1545 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1548 /* Drivers that never have children can omit .bdrv_child_perm() */
1549 if (!drv
->bdrv_child_perm
) {
1550 assert(QLIST_EMPTY(&bs
->children
));
1554 /* Update all children */
1555 QLIST_FOREACH(c
, &bs
->children
, next
) {
1556 uint64_t cur_perm
, cur_shared
;
1557 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1558 cumulative_perms
, cumulative_shared_perms
,
1559 &cur_perm
, &cur_shared
);
1560 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1564 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1565 uint64_t *shared_perm
)
1568 uint64_t cumulative_perms
= 0;
1569 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1571 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1572 cumulative_perms
|= c
->perm
;
1573 cumulative_shared_perms
&= c
->shared_perm
;
1576 *perm
= cumulative_perms
;
1577 *shared_perm
= cumulative_shared_perms
;
1580 static char *bdrv_child_user_desc(BdrvChild
*c
)
1582 if (c
->role
->get_parent_desc
) {
1583 return c
->role
->get_parent_desc(c
);
1586 return g_strdup("another user");
1589 static char *bdrv_perm_names(uint64_t perm
)
1595 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1596 { BLK_PERM_WRITE
, "write" },
1597 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1598 { BLK_PERM_RESIZE
, "resize" },
1599 { BLK_PERM_GRAPH_MOD
, "change children" },
1603 char *result
= g_strdup("");
1604 struct perm_name
*p
;
1606 for (p
= permissions
; p
->name
; p
++) {
1607 if (perm
& p
->perm
) {
1609 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1618 * Checks whether a new reference to @bs can be added if the new user requires
1619 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1620 * set, the BdrvChild objects in this list are ignored in the calculations;
1621 * this allows checking permission updates for an existing reference.
1623 * Needs to be followed by a call to either bdrv_set_perm() or
1624 * bdrv_abort_perm_update(). */
1625 static int bdrv_check_update_perm(BlockDriverState
*bs
, uint64_t new_used_perm
,
1626 uint64_t new_shared_perm
,
1627 GSList
*ignore_children
, Error
**errp
)
1630 uint64_t cumulative_perms
= new_used_perm
;
1631 uint64_t cumulative_shared_perms
= new_shared_perm
;
1633 /* There is no reason why anyone couldn't tolerate write_unchanged */
1634 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1636 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1637 if (g_slist_find(ignore_children
, c
)) {
1641 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1642 char *user
= bdrv_child_user_desc(c
);
1643 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1644 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1646 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1652 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1653 char *user
= bdrv_child_user_desc(c
);
1654 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1655 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1657 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1663 cumulative_perms
|= c
->perm
;
1664 cumulative_shared_perms
&= c
->shared_perm
;
1667 return bdrv_check_perm(bs
, cumulative_perms
, cumulative_shared_perms
,
1668 ignore_children
, errp
);
1671 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1672 * bdrv_child_abort_perm_update(). */
1673 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1674 GSList
*ignore_children
, Error
**errp
)
1678 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1679 ret
= bdrv_check_update_perm(c
->bs
, perm
, shared
, ignore_children
, errp
);
1680 g_slist_free(ignore_children
);
1685 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
1687 uint64_t cumulative_perms
, cumulative_shared_perms
;
1690 c
->shared_perm
= shared
;
1692 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
1693 &cumulative_shared_perms
);
1694 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
1697 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
1699 bdrv_abort_perm_update(c
->bs
);
1702 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1707 ret
= bdrv_child_check_perm(c
, perm
, shared
, NULL
, errp
);
1709 bdrv_child_abort_perm_update(c
);
1713 bdrv_child_set_perm(c
, perm
, shared
);
1718 #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1720 | BLK_PERM_WRITE_UNCHANGED \
1722 #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1724 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1725 const BdrvChildRole
*role
,
1726 uint64_t perm
, uint64_t shared
,
1727 uint64_t *nperm
, uint64_t *nshared
)
1730 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
1731 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
1735 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
1736 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
1737 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
1738 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
1741 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1742 const BdrvChildRole
*role
,
1743 uint64_t perm
, uint64_t shared
,
1744 uint64_t *nperm
, uint64_t *nshared
)
1746 bool backing
= (role
== &child_backing
);
1747 assert(role
== &child_backing
|| role
== &child_file
);
1750 /* Apart from the modifications below, the same permissions are
1751 * forwarded and left alone as for filters */
1752 bdrv_filter_default_perms(bs
, c
, role
, perm
, shared
, &perm
, &shared
);
1754 /* Format drivers may touch metadata even if the guest doesn't write */
1755 if (!bdrv_is_read_only(bs
)) {
1756 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1759 /* bs->file always needs to be consistent because of the metadata. We
1760 * can never allow other users to resize or write to it. */
1761 perm
|= BLK_PERM_CONSISTENT_READ
;
1762 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
1764 /* We want consistent read from backing files if the parent needs it.
1765 * No other operations are performed on backing files. */
1766 perm
&= BLK_PERM_CONSISTENT_READ
;
1768 /* If the parent can deal with changing data, we're okay with a
1769 * writable and resizable backing file. */
1770 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1771 if (shared
& BLK_PERM_WRITE
) {
1772 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1777 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
1778 BLK_PERM_WRITE_UNCHANGED
;
1785 static void bdrv_replace_child_noperm(BdrvChild
*child
,
1786 BlockDriverState
*new_bs
)
1788 BlockDriverState
*old_bs
= child
->bs
;
1790 if (old_bs
&& new_bs
) {
1791 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
1794 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1795 child
->role
->drained_end(child
);
1797 if (child
->role
->detach
) {
1798 child
->role
->detach(child
);
1800 QLIST_REMOVE(child
, next_parent
);
1806 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1807 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1808 child
->role
->drained_begin(child
);
1811 if (child
->role
->attach
) {
1812 child
->role
->attach(child
);
1818 * Updates @child to change its reference to point to @new_bs, including
1819 * checking and applying the necessary permisson updates both to the old node
1822 * NULL is passed as @new_bs for removing the reference before freeing @child.
1824 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
1825 * function uses bdrv_set_perm() to update the permissions according to the new
1826 * reference that @new_bs gets.
1828 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1830 BlockDriverState
*old_bs
= child
->bs
;
1831 uint64_t perm
, shared_perm
;
1834 /* Update permissions for old node. This is guaranteed to succeed
1835 * because we're just taking a parent away, so we're loosening
1837 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
1838 bdrv_check_perm(old_bs
, perm
, shared_perm
, NULL
, &error_abort
);
1839 bdrv_set_perm(old_bs
, perm
, shared_perm
);
1842 bdrv_replace_child_noperm(child
, new_bs
);
1845 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
1846 bdrv_set_perm(new_bs
, perm
, shared_perm
);
1850 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1851 const char *child_name
,
1852 const BdrvChildRole
*child_role
,
1853 uint64_t perm
, uint64_t shared_perm
,
1854 void *opaque
, Error
**errp
)
1859 ret
= bdrv_check_update_perm(child_bs
, perm
, shared_perm
, NULL
, errp
);
1861 bdrv_abort_perm_update(child_bs
);
1865 child
= g_new(BdrvChild
, 1);
1866 *child
= (BdrvChild
) {
1868 .name
= g_strdup(child_name
),
1871 .shared_perm
= shared_perm
,
1875 /* This performs the matching bdrv_set_perm() for the above check. */
1876 bdrv_replace_child(child
, child_bs
);
1881 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1882 BlockDriverState
*child_bs
,
1883 const char *child_name
,
1884 const BdrvChildRole
*child_role
,
1888 uint64_t perm
, shared_perm
;
1890 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
1892 assert(parent_bs
->drv
);
1893 assert(bdrv_get_aio_context(parent_bs
) == bdrv_get_aio_context(child_bs
));
1894 parent_bs
->drv
->bdrv_child_perm(parent_bs
, NULL
, child_role
,
1895 perm
, shared_perm
, &perm
, &shared_perm
);
1897 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
1898 perm
, shared_perm
, parent_bs
, errp
);
1899 if (child
== NULL
) {
1903 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1907 static void bdrv_detach_child(BdrvChild
*child
)
1909 if (child
->next
.le_prev
) {
1910 QLIST_REMOVE(child
, next
);
1911 child
->next
.le_prev
= NULL
;
1914 bdrv_replace_child(child
, NULL
);
1916 g_free(child
->name
);
1920 void bdrv_root_unref_child(BdrvChild
*child
)
1922 BlockDriverState
*child_bs
;
1924 child_bs
= child
->bs
;
1925 bdrv_detach_child(child
);
1926 bdrv_unref(child_bs
);
1929 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1931 if (child
== NULL
) {
1935 if (child
->bs
->inherits_from
== parent
) {
1938 /* Remove inherits_from only when the last reference between parent and
1939 * child->bs goes away. */
1940 QLIST_FOREACH(c
, &parent
->children
, next
) {
1941 if (c
!= child
&& c
->bs
== child
->bs
) {
1946 child
->bs
->inherits_from
= NULL
;
1950 bdrv_root_unref_child(child
);
1954 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
1957 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1958 if (c
->role
->change_media
) {
1959 c
->role
->change_media(c
, load
);
1964 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
1967 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1968 if (c
->role
->resize
) {
1975 * Sets the backing file link of a BDS. A new reference is created; callers
1976 * which don't need their own reference any more must call bdrv_unref().
1978 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
1982 bdrv_ref(backing_hd
);
1986 bdrv_unref_child(bs
, bs
->backing
);
1994 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
1997 bdrv_unref(backing_hd
);
2000 bdrv_refresh_filename(bs
);
2003 bdrv_refresh_limits(bs
, NULL
);
2007 * Opens the backing file for a BlockDriverState if not yet open
2009 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2010 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2011 * itself, all options starting with "${bdref_key}." are considered part of the
2014 * TODO Can this be unified with bdrv_open_image()?
2016 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
2017 const char *bdref_key
, Error
**errp
)
2019 char *backing_filename
= g_malloc0(PATH_MAX
);
2020 char *bdref_key_dot
;
2021 const char *reference
= NULL
;
2023 BlockDriverState
*backing_hd
;
2025 QDict
*tmp_parent_options
= NULL
;
2026 Error
*local_err
= NULL
;
2028 if (bs
->backing
!= NULL
) {
2032 /* NULL means an empty set of options */
2033 if (parent_options
== NULL
) {
2034 tmp_parent_options
= qdict_new();
2035 parent_options
= tmp_parent_options
;
2038 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2040 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2041 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2042 g_free(bdref_key_dot
);
2045 * Caution: while qdict_get_try_str() is fine, getting non-string
2046 * types would require more care. When @parent_options come from
2047 * -blockdev or blockdev_add, its members are typed according to
2048 * the QAPI schema, but when they come from -drive, they're all
2051 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2052 if (reference
|| qdict_haskey(options
, "file.filename")) {
2053 backing_filename
[0] = '\0';
2054 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2058 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
2062 error_propagate(errp
, local_err
);
2068 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2070 error_setg(errp
, "Driver doesn't support backing files");
2075 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2076 qdict_put_str(options
, "driver", bs
->backing_format
);
2079 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
2080 reference
, options
, 0, bs
, &child_backing
,
2083 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2084 error_prepend(errp
, "Could not open backing file: ");
2089 /* Hook up the backing file link; drop our reference, bs owns the
2090 * backing_hd reference now */
2091 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2092 bdrv_unref(backing_hd
);
2094 error_propagate(errp
, local_err
);
2099 qdict_del(parent_options
, bdref_key
);
2102 g_free(backing_filename
);
2103 QDECREF(tmp_parent_options
);
2107 static BlockDriverState
*
2108 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2109 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2110 bool allow_none
, Error
**errp
)
2112 BlockDriverState
*bs
= NULL
;
2113 QDict
*image_options
;
2114 char *bdref_key_dot
;
2115 const char *reference
;
2117 assert(child_role
!= NULL
);
2119 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2120 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2121 g_free(bdref_key_dot
);
2124 * Caution: while qdict_get_try_str() is fine, getting non-string
2125 * types would require more care. When @options come from
2126 * -blockdev or blockdev_add, its members are typed according to
2127 * the QAPI schema, but when they come from -drive, they're all
2130 reference
= qdict_get_try_str(options
, bdref_key
);
2131 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2133 error_setg(errp
, "A block device must be specified for \"%s\"",
2136 QDECREF(image_options
);
2140 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2141 parent
, child_role
, errp
);
2147 qdict_del(options
, bdref_key
);
2152 * Opens a disk image whose options are given as BlockdevRef in another block
2155 * If allow_none is true, no image will be opened if filename is false and no
2156 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2158 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2159 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2160 * itself, all options starting with "${bdref_key}." are considered part of the
2163 * The BlockdevRef will be removed from the options QDict.
2165 BdrvChild
*bdrv_open_child(const char *filename
,
2166 QDict
*options
, const char *bdref_key
,
2167 BlockDriverState
*parent
,
2168 const BdrvChildRole
*child_role
,
2169 bool allow_none
, Error
**errp
)
2172 BlockDriverState
*bs
;
2174 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2180 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2189 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2191 QDict
*snapshot_options
,
2194 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2195 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2197 QemuOpts
*opts
= NULL
;
2198 BlockDriverState
*bs_snapshot
;
2199 Error
*local_err
= NULL
;
2202 /* if snapshot, we create a temporary backing file and open it
2203 instead of opening 'filename' directly */
2205 /* Get the required size from the image */
2206 total_size
= bdrv_getlength(bs
);
2207 if (total_size
< 0) {
2208 error_setg_errno(errp
, -total_size
, "Could not get image size");
2212 /* Create the temporary image */
2213 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2215 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2219 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2221 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2222 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2223 qemu_opts_del(opts
);
2225 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2230 /* Prepare options QDict for the temporary file */
2231 qdict_put_str(snapshot_options
, "file.driver", "file");
2232 qdict_put_str(snapshot_options
, "file.filename", tmp_filename
);
2233 qdict_put_str(snapshot_options
, "driver", "qcow2");
2235 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2236 snapshot_options
= NULL
;
2242 /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
2243 * call bdrv_unref() on it), so in order to be able to return one, we have
2244 * to increase bs_snapshot's refcount here */
2245 bdrv_ref(bs_snapshot
);
2246 bdrv_append(bs_snapshot
, bs
, &local_err
);
2248 error_propagate(errp
, local_err
);
2253 g_free(tmp_filename
);
2257 QDECREF(snapshot_options
);
2258 g_free(tmp_filename
);
2263 * Opens a disk image (raw, qcow2, vmdk, ...)
2265 * options is a QDict of options to pass to the block drivers, or NULL for an
2266 * empty set of options. The reference to the QDict belongs to the block layer
2267 * after the call (even on failure), so if the caller intends to reuse the
2268 * dictionary, it needs to use QINCREF() before calling bdrv_open.
2270 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2271 * If it is not NULL, the referenced BDS will be reused.
2273 * The reference parameter may be used to specify an existing block device which
2274 * should be opened. If specified, neither options nor a filename may be given,
2275 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2277 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2278 const char *reference
,
2279 QDict
*options
, int flags
,
2280 BlockDriverState
*parent
,
2281 const BdrvChildRole
*child_role
,
2285 BlockBackend
*file
= NULL
;
2286 BlockDriverState
*bs
;
2287 BlockDriver
*drv
= NULL
;
2288 const char *drvname
;
2289 const char *backing
;
2290 Error
*local_err
= NULL
;
2291 QDict
*snapshot_options
= NULL
;
2292 int snapshot_flags
= 0;
2294 assert(!child_role
|| !flags
);
2295 assert(!child_role
== !parent
);
2298 bool options_non_empty
= options
? qdict_size(options
) : false;
2301 if (filename
|| options_non_empty
) {
2302 error_setg(errp
, "Cannot reference an existing block device with "
2303 "additional options or a new filename");
2307 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2318 /* NULL means an empty set of options */
2319 if (options
== NULL
) {
2320 options
= qdict_new();
2323 /* json: syntax counts as explicit options, as if in the QDict */
2324 parse_json_protocol(options
, &filename
, &local_err
);
2329 bs
->explicit_options
= qdict_clone_shallow(options
);
2332 bs
->inherits_from
= parent
;
2333 child_role
->inherit_options(&flags
, options
,
2334 parent
->open_flags
, parent
->options
);
2337 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2343 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2344 * Caution: getting a boolean member of @options requires care.
2345 * When @options come from -blockdev or blockdev_add, members are
2346 * typed according to the QAPI schema, but when they come from
2347 * -drive, they're all QString.
2349 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2350 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2351 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2353 flags
&= ~BDRV_O_RDWR
;
2356 if (flags
& BDRV_O_SNAPSHOT
) {
2357 snapshot_options
= qdict_new();
2358 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2360 /* Let bdrv_backing_options() override "read-only" */
2361 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2362 bdrv_backing_options(&flags
, options
, flags
, options
);
2365 bs
->open_flags
= flags
;
2366 bs
->options
= options
;
2367 options
= qdict_clone_shallow(options
);
2369 /* Find the right image format driver */
2370 /* See cautionary note on accessing @options above */
2371 drvname
= qdict_get_try_str(options
, "driver");
2373 drv
= bdrv_find_format(drvname
);
2375 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2380 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2382 /* See cautionary note on accessing @options above */
2383 backing
= qdict_get_try_str(options
, "backing");
2384 if (backing
&& *backing
== '\0') {
2385 flags
|= BDRV_O_NO_BACKING
;
2386 qdict_del(options
, "backing");
2389 /* Open image file without format layer. This BlockBackend is only used for
2390 * probing, the block drivers will do their own bdrv_open_child() for the
2391 * same BDS, which is why we put the node name back into options. */
2392 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2393 BlockDriverState
*file_bs
;
2395 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2396 &child_file
, true, &local_err
);
2400 if (file_bs
!= NULL
) {
2401 file
= blk_new(BLK_PERM_CONSISTENT_READ
, BLK_PERM_ALL
);
2402 blk_insert_bs(file
, file_bs
, &local_err
);
2403 bdrv_unref(file_bs
);
2408 qdict_put_str(options
, "file", bdrv_get_node_name(file_bs
));
2412 /* Image format probing */
2415 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2420 * This option update would logically belong in bdrv_fill_options(),
2421 * but we first need to open bs->file for the probing to work, while
2422 * opening bs->file already requires the (mostly) final set of options
2423 * so that cache mode etc. can be inherited.
2425 * Adding the driver later is somewhat ugly, but it's not an option
2426 * that would ever be inherited, so it's correct. We just need to make
2427 * sure to update both bs->options (which has the full effective
2428 * options for bs) and options (which has file.* already removed).
2430 qdict_put_str(bs
->options
, "driver", drv
->format_name
);
2431 qdict_put_str(options
, "driver", drv
->format_name
);
2433 error_setg(errp
, "Must specify either driver or file");
2437 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2438 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2439 /* file must be NULL if a protocol BDS is about to be created
2440 * (the inverse results in an error message from bdrv_open_common()) */
2441 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2443 /* Open the image */
2444 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2454 /* If there is a backing file, use it */
2455 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2456 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2458 goto close_and_fail
;
2462 bdrv_refresh_filename(bs
);
2464 /* Check if any unknown options were used */
2465 if (qdict_size(options
) != 0) {
2466 const QDictEntry
*entry
= qdict_first(options
);
2467 if (flags
& BDRV_O_PROTOCOL
) {
2468 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2469 "'%s'", drv
->format_name
, entry
->key
);
2472 "Block format '%s' does not support the option '%s'",
2473 drv
->format_name
, entry
->key
);
2476 goto close_and_fail
;
2479 if (!bdrv_key_required(bs
)) {
2480 bdrv_parent_cb_change_media(bs
, true);
2481 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
2482 && !runstate_check(RUN_STATE_INMIGRATE
)
2483 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
2485 "Guest must be stopped for opening of encrypted image");
2486 goto close_and_fail
;
2491 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2492 * temporary snapshot afterwards. */
2493 if (snapshot_flags
) {
2494 BlockDriverState
*snapshot_bs
;
2495 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2496 snapshot_options
, &local_err
);
2497 snapshot_options
= NULL
;
2499 goto close_and_fail
;
2501 /* We are not going to return bs but the overlay on top of it
2502 * (snapshot_bs); thus, we have to drop the strong reference to bs
2503 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2504 * though, because the overlay still has a reference to it. */
2513 if (bs
->file
!= NULL
) {
2514 bdrv_unref_child(bs
, bs
->file
);
2516 QDECREF(snapshot_options
);
2517 QDECREF(bs
->explicit_options
);
2518 QDECREF(bs
->options
);
2522 error_propagate(errp
, local_err
);
2527 QDECREF(snapshot_options
);
2529 error_propagate(errp
, local_err
);
2533 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2534 QDict
*options
, int flags
, Error
**errp
)
2536 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2540 typedef struct BlockReopenQueueEntry
{
2542 BDRVReopenState state
;
2543 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
2544 } BlockReopenQueueEntry
;
2547 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2548 * reopen of multiple devices.
2550 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2551 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2552 * be created and initialized. This newly created BlockReopenQueue should be
2553 * passed back in for subsequent calls that are intended to be of the same
2556 * bs is the BlockDriverState to add to the reopen queue.
2558 * options contains the changed options for the associated bs
2559 * (the BlockReopenQueue takes ownership)
2561 * flags contains the open flags for the associated bs
2563 * returns a pointer to bs_queue, which is either the newly allocated
2564 * bs_queue, or the existing bs_queue being used.
2567 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
2568 BlockDriverState
*bs
,
2571 const BdrvChildRole
*role
,
2572 QDict
*parent_options
,
2577 BlockReopenQueueEntry
*bs_entry
;
2579 QDict
*old_options
, *explicit_options
;
2581 if (bs_queue
== NULL
) {
2582 bs_queue
= g_new0(BlockReopenQueue
, 1);
2583 QSIMPLEQ_INIT(bs_queue
);
2587 options
= qdict_new();
2590 /* Check if this BlockDriverState is already in the queue */
2591 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2592 if (bs
== bs_entry
->state
.bs
) {
2598 * Precedence of options:
2599 * 1. Explicitly passed in options (highest)
2600 * 2. Set in flags (only for top level)
2601 * 3. Retained from explicitly set options of bs
2602 * 4. Inherited from parent node
2603 * 5. Retained from effective options of bs
2606 if (!parent_options
) {
2608 * Any setting represented by flags is always updated. If the
2609 * corresponding QDict option is set, it takes precedence. Otherwise
2610 * the flag is translated into a QDict option. The old setting of bs is
2613 update_options_from_flags(options
, flags
);
2616 /* Old explicitly set values (don't overwrite by inherited value) */
2618 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
2620 old_options
= qdict_clone_shallow(bs
->explicit_options
);
2622 bdrv_join_options(bs
, options
, old_options
);
2623 QDECREF(old_options
);
2625 explicit_options
= qdict_clone_shallow(options
);
2627 /* Inherit from parent node */
2628 if (parent_options
) {
2630 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
2633 /* Old values are used for options that aren't set yet */
2634 old_options
= qdict_clone_shallow(bs
->options
);
2635 bdrv_join_options(bs
, options
, old_options
);
2636 QDECREF(old_options
);
2638 /* bdrv_open() masks this flag out */
2639 flags
&= ~BDRV_O_PROTOCOL
;
2641 QLIST_FOREACH(child
, &bs
->children
, next
) {
2642 QDict
*new_child_options
;
2643 char *child_key_dot
;
2645 /* reopen can only change the options of block devices that were
2646 * implicitly created and inherited options. For other (referenced)
2647 * block devices, a syntax like "backing.foo" results in an error. */
2648 if (child
->bs
->inherits_from
!= bs
) {
2652 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2653 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
2654 g_free(child_key_dot
);
2656 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
2657 child
->role
, options
, flags
);
2661 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
2662 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
2664 QDECREF(bs_entry
->state
.options
);
2665 QDECREF(bs_entry
->state
.explicit_options
);
2668 bs_entry
->state
.bs
= bs
;
2669 bs_entry
->state
.options
= options
;
2670 bs_entry
->state
.explicit_options
= explicit_options
;
2671 bs_entry
->state
.flags
= flags
;
2676 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
2677 BlockDriverState
*bs
,
2678 QDict
*options
, int flags
)
2680 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
2685 * Reopen multiple BlockDriverStates atomically & transactionally.
2687 * The queue passed in (bs_queue) must have been built up previous
2688 * via bdrv_reopen_queue().
2690 * Reopens all BDS specified in the queue, with the appropriate
2691 * flags. All devices are prepared for reopen, and failure of any
2692 * device will cause all device changes to be abandonded, and intermediate
2695 * If all devices prepare successfully, then the changes are committed
2699 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
2702 BlockReopenQueueEntry
*bs_entry
, *next
;
2703 Error
*local_err
= NULL
;
2705 assert(bs_queue
!= NULL
);
2707 aio_context_release(ctx
);
2708 bdrv_drain_all_begin();
2709 aio_context_acquire(ctx
);
2711 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2712 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
2713 error_propagate(errp
, local_err
);
2716 bs_entry
->prepared
= true;
2719 /* If we reach this point, we have success and just need to apply the
2722 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2723 bdrv_reopen_commit(&bs_entry
->state
);
2729 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
2730 if (ret
&& bs_entry
->prepared
) {
2731 bdrv_reopen_abort(&bs_entry
->state
);
2733 QDECREF(bs_entry
->state
.explicit_options
);
2735 QDECREF(bs_entry
->state
.options
);
2740 bdrv_drain_all_end();
2746 /* Reopen a single BlockDriverState with the specified flags. */
2747 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
2750 Error
*local_err
= NULL
;
2751 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
2753 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, &local_err
);
2754 if (local_err
!= NULL
) {
2755 error_propagate(errp
, local_err
);
2762 * Prepares a BlockDriverState for reopen. All changes are staged in the
2763 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2764 * the block driver layer .bdrv_reopen_prepare()
2766 * bs is the BlockDriverState to reopen
2767 * flags are the new open flags
2768 * queue is the reopen queue
2770 * Returns 0 on success, non-zero on error. On error errp will be set
2773 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2774 * It is the responsibility of the caller to then call the abort() or
2775 * commit() for any other BDS that have been left in a prepare() state
2778 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2782 Error
*local_err
= NULL
;
2788 assert(reopen_state
!= NULL
);
2789 assert(reopen_state
->bs
->drv
!= NULL
);
2790 drv
= reopen_state
->bs
->drv
;
2792 /* Process generic block layer options */
2793 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2794 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2796 error_propagate(errp
, local_err
);
2801 update_flags_from_options(&reopen_state
->flags
, opts
);
2803 /* node-name and driver must be unchanged. Put them back into the QDict, so
2804 * that they are checked at the end of this function. */
2805 value
= qemu_opt_get(opts
, "node-name");
2807 qdict_put_str(reopen_state
->options
, "node-name", value
);
2810 value
= qemu_opt_get(opts
, "driver");
2812 qdict_put_str(reopen_state
->options
, "driver", value
);
2815 /* If we are to stay read-only, do not allow permission change
2816 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
2817 * not set, or if the BDS still has copy_on_read enabled */
2818 read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2819 ret
= bdrv_can_set_read_only(reopen_state
->bs
, read_only
, &local_err
);
2821 error_propagate(errp
, local_err
);
2826 ret
= bdrv_flush(reopen_state
->bs
);
2828 error_setg_errno(errp
, -ret
, "Error flushing drive");
2832 if (drv
->bdrv_reopen_prepare
) {
2833 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2835 if (local_err
!= NULL
) {
2836 error_propagate(errp
, local_err
);
2838 error_setg(errp
, "failed while preparing to reopen image '%s'",
2839 reopen_state
->bs
->filename
);
2844 /* It is currently mandatory to have a bdrv_reopen_prepare()
2845 * handler for each supported drv. */
2846 error_setg(errp
, "Block format '%s' used by node '%s' "
2847 "does not support reopening files", drv
->format_name
,
2848 bdrv_get_device_or_node_name(reopen_state
->bs
));
2853 /* Options that are not handled are only okay if they are unchanged
2854 * compared to the old state. It is expected that some options are only
2855 * used for the initial open, but not reopen (e.g. filename) */
2856 if (qdict_size(reopen_state
->options
)) {
2857 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2860 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2861 const char *new = qstring_get_str(new_obj
);
2863 * Caution: while qdict_get_try_str() is fine, getting
2864 * non-string types would require more care. When
2865 * bs->options come from -blockdev or blockdev_add, its
2866 * members are typed according to the QAPI schema, but
2867 * when they come from -drive, they're all QString.
2869 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2872 if (!old
|| strcmp(new, old
)) {
2873 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2877 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2883 qemu_opts_del(opts
);
2888 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2889 * makes them final by swapping the staging BlockDriverState contents into
2890 * the active BlockDriverState contents.
2892 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2896 assert(reopen_state
!= NULL
);
2897 drv
= reopen_state
->bs
->drv
;
2898 assert(drv
!= NULL
);
2900 /* If there are any driver level actions to take */
2901 if (drv
->bdrv_reopen_commit
) {
2902 drv
->bdrv_reopen_commit(reopen_state
);
2905 /* set BDS specific flags now */
2906 QDECREF(reopen_state
->bs
->explicit_options
);
2908 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2909 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2910 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2912 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2916 * Abort the reopen, and delete and free the staged changes in
2919 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2923 assert(reopen_state
!= NULL
);
2924 drv
= reopen_state
->bs
->drv
;
2925 assert(drv
!= NULL
);
2927 if (drv
->bdrv_reopen_abort
) {
2928 drv
->bdrv_reopen_abort(reopen_state
);
2931 QDECREF(reopen_state
->explicit_options
);
2935 static void bdrv_close(BlockDriverState
*bs
)
2937 BdrvAioNotifier
*ban
, *ban_next
;
2940 assert(!bs
->refcnt
);
2942 bdrv_drained_begin(bs
); /* complete I/O */
2944 bdrv_drain(bs
); /* in case flush left pending I/O */
2946 bdrv_release_named_dirty_bitmaps(bs
);
2947 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2950 BdrvChild
*child
, *next
;
2952 bs
->drv
->bdrv_close(bs
);
2955 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
2957 if (bs
->file
!= NULL
) {
2958 bdrv_unref_child(bs
, bs
->file
);
2962 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2963 /* TODO Remove bdrv_unref() from drivers' close function and use
2964 * bdrv_unref_child() here */
2965 if (child
->bs
->inherits_from
== bs
) {
2966 child
->bs
->inherits_from
= NULL
;
2968 bdrv_detach_child(child
);
2973 bs
->copy_on_read
= 0;
2974 bs
->backing_file
[0] = '\0';
2975 bs
->backing_format
[0] = '\0';
2976 bs
->total_sectors
= 0;
2977 bs
->encrypted
= false;
2978 bs
->valid_key
= false;
2980 QDECREF(bs
->options
);
2981 QDECREF(bs
->explicit_options
);
2983 QDECREF(bs
->full_open_options
);
2984 bs
->full_open_options
= NULL
;
2987 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2990 QLIST_INIT(&bs
->aio_notifiers
);
2991 bdrv_drained_end(bs
);
2994 void bdrv_close_all(void)
2996 block_job_cancel_sync_all();
2997 nbd_export_close_all();
2999 /* Drop references from requests still in flight, such as canceled block
3000 * jobs whose AIO context has not been polled yet */
3003 blk_remove_all_bs();
3004 blockdev_close_all_bdrv_states();
3006 assert(QTAILQ_EMPTY(&all_bdrv_states
));
3009 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
3013 if (c
->role
->stay_at_node
) {
3017 if (c
->role
== &child_backing
) {
3018 /* If @from is a backing file of @to, ignore the child to avoid
3019 * creating a loop. We only want to change the pointer of other
3021 QLIST_FOREACH(to_c
, &to
->children
, next
) {
3034 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
3037 BdrvChild
*c
, *next
;
3038 GSList
*list
= NULL
, *p
;
3039 uint64_t old_perm
, old_shared
;
3040 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
3043 assert(!atomic_read(&from
->in_flight
));
3044 assert(!atomic_read(&to
->in_flight
));
3046 /* Make sure that @from doesn't go away until we have successfully attached
3047 * all of its parents to @to. */
3050 /* Put all parents into @list and calculate their cumulative permissions */
3051 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
3052 if (!should_update_child(c
, to
)) {
3055 list
= g_slist_prepend(list
, c
);
3057 shared
&= c
->shared_perm
;
3060 /* Check whether the required permissions can be granted on @to, ignoring
3061 * all BdrvChild in @list so that they can't block themselves. */
3062 ret
= bdrv_check_update_perm(to
, perm
, shared
, list
, errp
);
3064 bdrv_abort_perm_update(to
);
3068 /* Now actually perform the change. We performed the permission check for
3069 * all elements of @list at once, so set the permissions all at once at the
3071 for (p
= list
; p
!= NULL
; p
= p
->next
) {
3075 bdrv_replace_child_noperm(c
, to
);
3079 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3080 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3088 * Add new bs contents at the top of an image chain while the chain is
3089 * live, while keeping required fields on the top layer.
3091 * This will modify the BlockDriverState fields, and swap contents
3092 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3094 * bs_new must not be attached to a BlockBackend.
3096 * This function does not create any image files.
3098 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3099 * that's what the callers commonly need. bs_new will be referenced by the old
3100 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3101 * reference of its own, it must call bdrv_ref().
3103 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3106 Error
*local_err
= NULL
;
3108 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3110 error_propagate(errp
, local_err
);
3114 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3116 error_propagate(errp
, local_err
);
3117 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3121 /* bs_new is now referenced by its new parents, we don't need the
3122 * additional reference any more. */
3127 static void bdrv_delete(BlockDriverState
*bs
)
3130 assert(bdrv_op_blocker_is_empty(bs
));
3131 assert(!bs
->refcnt
);
3135 /* remove from list, if necessary */
3136 if (bs
->node_name
[0] != '\0') {
3137 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3139 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3145 * Run consistency checks on an image
3147 * Returns 0 if the check could be completed (it doesn't mean that the image is
3148 * free of errors) or -errno when an internal error occurred. The results of the
3149 * check are stored in res.
3151 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
3153 if (bs
->drv
== NULL
) {
3156 if (bs
->drv
->bdrv_check
== NULL
) {
3160 memset(res
, 0, sizeof(*res
));
3161 return bs
->drv
->bdrv_check(bs
, res
, fix
);
3167 * -EINVAL - backing format specified, but no file
3168 * -ENOSPC - can't update the backing file because no space is left in the
3170 * -ENOTSUP - format driver doesn't support changing the backing file
3172 int bdrv_change_backing_file(BlockDriverState
*bs
,
3173 const char *backing_file
, const char *backing_fmt
)
3175 BlockDriver
*drv
= bs
->drv
;
3178 /* Backing file format doesn't make sense without a backing file */
3179 if (backing_fmt
&& !backing_file
) {
3183 if (drv
->bdrv_change_backing_file
!= NULL
) {
3184 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3190 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3191 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3197 * Finds the image layer in the chain that has 'bs' as its backing file.
3199 * active is the current topmost image.
3201 * Returns NULL if bs is not found in active's image chain,
3202 * or if active == bs.
3204 * Returns the bottommost base image if bs == NULL.
3206 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3207 BlockDriverState
*bs
)
3209 while (active
&& bs
!= backing_bs(active
)) {
3210 active
= backing_bs(active
);
3216 /* Given a BDS, searches for the base layer. */
3217 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3219 return bdrv_find_overlay(bs
, NULL
);
3223 * Drops images above 'base' up to and including 'top', and sets the image
3224 * above 'top' to have base as its backing file.
3226 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3227 * information in 'bs' can be properly updated.
3229 * E.g., this will convert the following chain:
3230 * bottom <- base <- intermediate <- top <- active
3234 * bottom <- base <- active
3236 * It is allowed for bottom==base, in which case it converts:
3238 * base <- intermediate <- top <- active
3244 * If backing_file_str is non-NULL, it will be used when modifying top's
3245 * overlay image metadata.
3248 * if active == top, that is considered an error
3251 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
3252 BlockDriverState
*base
, const char *backing_file_str
)
3254 BlockDriverState
*new_top_bs
= NULL
;
3255 Error
*local_err
= NULL
;
3258 if (!top
->drv
|| !base
->drv
) {
3262 new_top_bs
= bdrv_find_overlay(active
, top
);
3264 if (new_top_bs
== NULL
) {
3265 /* we could not find the image above 'top', this is an error */
3269 /* special case of new_top_bs->backing->bs already pointing to base - nothing
3270 * to do, no intermediate images */
3271 if (backing_bs(new_top_bs
) == base
) {
3276 /* Make sure that base is in the backing chain of top */
3277 if (!bdrv_chain_contains(top
, base
)) {
3281 /* success - we can delete the intermediate states, and link top->base */
3282 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
3283 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
3284 base
->drv
? base
->drv
->format_name
: "");
3289 bdrv_set_backing_hd(new_top_bs
, base
, &local_err
);
3292 error_report_err(local_err
);
3302 * Truncate file to 'offset' bytes (needed only for file protocols)
3304 int bdrv_truncate(BdrvChild
*child
, int64_t offset
, Error
**errp
)
3306 BlockDriverState
*bs
= child
->bs
;
3307 BlockDriver
*drv
= bs
->drv
;
3310 assert(child
->perm
& BLK_PERM_RESIZE
);
3313 error_setg(errp
, "No medium inserted");
3316 if (!drv
->bdrv_truncate
) {
3317 error_setg(errp
, "Image format driver does not support resize");
3320 if (bs
->read_only
) {
3321 error_setg(errp
, "Image is read-only");
3325 assert(!(bs
->open_flags
& BDRV_O_INACTIVE
));
3327 ret
= drv
->bdrv_truncate(bs
, offset
, errp
);
3329 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
3330 bdrv_dirty_bitmap_truncate(bs
);
3331 bdrv_parent_cb_resize(bs
);
3338 * Length of a allocated file in bytes. Sparse files are counted by actual
3339 * allocated space. Return < 0 if error or unknown.
3341 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
3343 BlockDriver
*drv
= bs
->drv
;
3347 if (drv
->bdrv_get_allocated_file_size
) {
3348 return drv
->bdrv_get_allocated_file_size(bs
);
3351 return bdrv_get_allocated_file_size(bs
->file
->bs
);
3357 * Return number of sectors on success, -errno on error.
3359 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
3361 BlockDriver
*drv
= bs
->drv
;
3366 if (drv
->has_variable_length
) {
3367 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3372 return bs
->total_sectors
;
3376 * Return length in bytes on success, -errno on error.
3377 * The length is always a multiple of BDRV_SECTOR_SIZE.
3379 int64_t bdrv_getlength(BlockDriverState
*bs
)
3381 int64_t ret
= bdrv_nb_sectors(bs
);
3383 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
3384 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
3387 /* return 0 as number of sectors if no device present or error */
3388 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
3390 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
3392 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
3395 bool bdrv_is_sg(BlockDriverState
*bs
)
3400 bool bdrv_is_encrypted(BlockDriverState
*bs
)
3402 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3405 return bs
->encrypted
;
3408 bool bdrv_key_required(BlockDriverState
*bs
)
3410 BdrvChild
*backing
= bs
->backing
;
3412 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
3415 return (bs
->encrypted
&& !bs
->valid_key
);
3418 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
3421 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3422 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
3428 if (!bs
->encrypted
) {
3430 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
3433 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
3435 bs
->valid_key
= false;
3436 } else if (!bs
->valid_key
) {
3437 /* call the change callback now, we skipped it on open */
3438 bs
->valid_key
= true;
3439 bdrv_parent_cb_change_media(bs
, true);
3445 * Provide an encryption key for @bs.
3446 * If @key is non-null:
3447 * If @bs is not encrypted, fail.
3448 * Else if the key is invalid, fail.
3449 * Else set @bs's key to @key, replacing the existing key, if any.
3451 * If @bs is encrypted and still lacks a key, fail.
3453 * On failure, store an error object through @errp if non-null.
3455 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
3458 if (!bdrv_is_encrypted(bs
)) {
3459 error_setg(errp
, "Node '%s' is not encrypted",
3460 bdrv_get_device_or_node_name(bs
));
3461 } else if (bdrv_set_key(bs
, key
) < 0) {
3462 error_setg(errp
, QERR_INVALID_PASSWORD
);
3465 if (bdrv_key_required(bs
)) {
3466 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
3467 "'%s' (%s) is encrypted",
3468 bdrv_get_device_or_node_name(bs
),
3469 bdrv_get_encrypted_filename(bs
));
3474 const char *bdrv_get_format_name(BlockDriverState
*bs
)
3476 return bs
->drv
? bs
->drv
->format_name
: NULL
;
3479 static int qsort_strcmp(const void *a
, const void *b
)
3481 return strcmp(*(char *const *)a
, *(char *const *)b
);
3484 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
3490 const char **formats
= NULL
;
3492 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
3493 if (drv
->format_name
) {
3496 while (formats
&& i
&& !found
) {
3497 found
= !strcmp(formats
[--i
], drv
->format_name
);
3501 formats
= g_renew(const char *, formats
, count
+ 1);
3502 formats
[count
++] = drv
->format_name
;
3507 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
3508 const char *format_name
= block_driver_modules
[i
].format_name
;
3514 while (formats
&& j
&& !found
) {
3515 found
= !strcmp(formats
[--j
], format_name
);
3519 formats
= g_renew(const char *, formats
, count
+ 1);
3520 formats
[count
++] = format_name
;
3525 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
3527 for (i
= 0; i
< count
; i
++) {
3528 it(opaque
, formats
[i
]);
3534 /* This function is to find a node in the bs graph */
3535 BlockDriverState
*bdrv_find_node(const char *node_name
)
3537 BlockDriverState
*bs
;
3541 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3542 if (!strcmp(node_name
, bs
->node_name
)) {
3549 /* Put this QMP function here so it can access the static graph_bdrv_states. */
3550 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
3552 BlockDeviceInfoList
*list
, *entry
;
3553 BlockDriverState
*bs
;
3556 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3557 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
3559 qapi_free_BlockDeviceInfoList(list
);
3562 entry
= g_malloc0(sizeof(*entry
));
3563 entry
->value
= info
;
3571 BlockDriverState
*bdrv_lookup_bs(const char *device
,
3572 const char *node_name
,
3576 BlockDriverState
*bs
;
3579 blk
= blk_by_name(device
);
3584 error_setg(errp
, "Device '%s' has no medium", device
);
3592 bs
= bdrv_find_node(node_name
);
3599 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
3600 device
? device
: "",
3601 node_name
? node_name
: "");
3605 /* If 'base' is in the same chain as 'top', return true. Otherwise,
3606 * return false. If either argument is NULL, return false. */
3607 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
3609 while (top
&& top
!= base
) {
3610 top
= backing_bs(top
);
3616 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
3619 return QTAILQ_FIRST(&graph_bdrv_states
);
3621 return QTAILQ_NEXT(bs
, node_list
);
3624 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
3626 return bs
->node_name
;
3629 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
3634 /* If multiple parents have a name, just pick the first one. */
3635 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3636 if (c
->role
->get_name
) {
3637 name
= c
->role
->get_name(c
);
3638 if (name
&& *name
) {
3647 /* TODO check what callers really want: bs->node_name or blk_name() */
3648 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
3650 return bdrv_get_parent_name(bs
) ?: "";
3653 /* This can be used to identify nodes that might not have a device
3654 * name associated. Since node and device names live in the same
3655 * namespace, the result is unambiguous. The exception is if both are
3656 * absent, then this returns an empty (non-null) string. */
3657 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
3659 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
3662 int bdrv_get_flags(BlockDriverState
*bs
)
3664 return bs
->open_flags
;
3667 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
3672 int bdrv_has_zero_init(BlockDriverState
*bs
)
3676 /* If BS is a copy on write image, it is initialized to
3677 the contents of the base image, which may not be zeroes. */
3681 if (bs
->drv
->bdrv_has_zero_init
) {
3682 return bs
->drv
->bdrv_has_zero_init(bs
);
3689 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
3691 BlockDriverInfo bdi
;
3697 if (bdrv_get_info(bs
, &bdi
) == 0) {
3698 return bdi
.unallocated_blocks_are_zero
;
3704 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
3706 BlockDriverInfo bdi
;
3708 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
3712 if (bdrv_get_info(bs
, &bdi
) == 0) {
3713 return bdi
.can_write_zeroes_with_unmap
;
3719 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
3721 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
3722 return bs
->backing_file
;
3723 else if (bs
->encrypted
)
3724 return bs
->filename
;
3729 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3730 char *filename
, int filename_size
)
3732 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3735 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3737 BlockDriver
*drv
= bs
->drv
;
3740 if (!drv
->bdrv_get_info
)
3742 memset(bdi
, 0, sizeof(*bdi
));
3743 return drv
->bdrv_get_info(bs
, bdi
);
3746 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3748 BlockDriver
*drv
= bs
->drv
;
3749 if (drv
&& drv
->bdrv_get_specific_info
) {
3750 return drv
->bdrv_get_specific_info(bs
);
3755 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3757 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3761 bs
->drv
->bdrv_debug_event(bs
, event
);
3764 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3767 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3768 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3771 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3772 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3778 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3780 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3781 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3784 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3785 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3791 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3793 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3794 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3797 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3798 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3804 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3806 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3807 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3810 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3811 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3817 /* backing_file can either be relative, or absolute, or a protocol. If it is
3818 * relative, it must be relative to the chain. So, passing in bs->filename
3819 * from a BDS as backing_file should not be done, as that may be relative to
3820 * the CWD rather than the chain. */
3821 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3822 const char *backing_file
)
3824 char *filename_full
= NULL
;
3825 char *backing_file_full
= NULL
;
3826 char *filename_tmp
= NULL
;
3827 int is_protocol
= 0;
3828 BlockDriverState
*curr_bs
= NULL
;
3829 BlockDriverState
*retval
= NULL
;
3830 Error
*local_error
= NULL
;
3832 if (!bs
|| !bs
->drv
|| !backing_file
) {
3836 filename_full
= g_malloc(PATH_MAX
);
3837 backing_file_full
= g_malloc(PATH_MAX
);
3838 filename_tmp
= g_malloc(PATH_MAX
);
3840 is_protocol
= path_has_protocol(backing_file
);
3842 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3844 /* If either of the filename paths is actually a protocol, then
3845 * compare unmodified paths; otherwise make paths relative */
3846 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3847 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3848 retval
= curr_bs
->backing
->bs
;
3851 /* Also check against the full backing filename for the image */
3852 bdrv_get_full_backing_filename(curr_bs
, backing_file_full
, PATH_MAX
,
3854 if (local_error
== NULL
) {
3855 if (strcmp(backing_file
, backing_file_full
) == 0) {
3856 retval
= curr_bs
->backing
->bs
;
3860 error_free(local_error
);
3864 /* If not an absolute filename path, make it relative to the current
3865 * image's filename path */
3866 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3869 /* We are going to compare absolute pathnames */
3870 if (!realpath(filename_tmp
, filename_full
)) {
3874 /* We need to make sure the backing filename we are comparing against
3875 * is relative to the current image filename (or absolute) */
3876 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3877 curr_bs
->backing_file
);
3879 if (!realpath(filename_tmp
, backing_file_full
)) {
3883 if (strcmp(backing_file_full
, filename_full
) == 0) {
3884 retval
= curr_bs
->backing
->bs
;
3890 g_free(filename_full
);
3891 g_free(backing_file_full
);
3892 g_free(filename_tmp
);
3896 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3906 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3909 void bdrv_init(void)
3911 module_call_init(MODULE_INIT_BLOCK
);
3914 void bdrv_init_with_whitelist(void)
3916 use_bdrv_whitelist
= 1;
3920 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3923 Error
*local_err
= NULL
;
3930 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3934 QLIST_FOREACH(child
, &bs
->children
, next
) {
3935 bdrv_invalidate_cache(child
->bs
, &local_err
);
3937 error_propagate(errp
, local_err
);
3942 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3943 if (bs
->drv
->bdrv_invalidate_cache
) {
3944 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3946 bs
->open_flags
|= BDRV_O_INACTIVE
;
3947 error_propagate(errp
, local_err
);
3952 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3954 bs
->open_flags
|= BDRV_O_INACTIVE
;
3955 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3960 void bdrv_invalidate_cache_all(Error
**errp
)
3962 BlockDriverState
*bs
;
3963 Error
*local_err
= NULL
;
3964 BdrvNextIterator it
;
3966 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3967 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3969 aio_context_acquire(aio_context
);
3970 bdrv_invalidate_cache(bs
, &local_err
);
3971 aio_context_release(aio_context
);
3973 error_propagate(errp
, local_err
);
3979 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3985 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3986 ret
= bs
->drv
->bdrv_inactivate(bs
);
3992 QLIST_FOREACH(child
, &bs
->children
, next
) {
3993 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
4000 bs
->open_flags
|= BDRV_O_INACTIVE
;
4005 int bdrv_inactivate_all(void)
4007 BlockDriverState
*bs
= NULL
;
4008 BdrvNextIterator it
;
4012 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4013 aio_context_acquire(bdrv_get_aio_context(bs
));
4016 /* We do two passes of inactivation. The first pass calls to drivers'
4017 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
4018 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
4020 for (pass
= 0; pass
< 2; pass
++) {
4021 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4022 ret
= bdrv_inactivate_recurse(bs
, pass
);
4030 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4031 aio_context_release(bdrv_get_aio_context(bs
));
4037 /**************************************************************/
4038 /* removable device support */
4041 * Return TRUE if the media is present
4043 bool bdrv_is_inserted(BlockDriverState
*bs
)
4045 BlockDriver
*drv
= bs
->drv
;
4051 if (drv
->bdrv_is_inserted
) {
4052 return drv
->bdrv_is_inserted(bs
);
4054 QLIST_FOREACH(child
, &bs
->children
, next
) {
4055 if (!bdrv_is_inserted(child
->bs
)) {
4063 * Return whether the media changed since the last call to this
4064 * function, or -ENOTSUP if we don't know. Most drivers don't know.
4066 int bdrv_media_changed(BlockDriverState
*bs
)
4068 BlockDriver
*drv
= bs
->drv
;
4070 if (drv
&& drv
->bdrv_media_changed
) {
4071 return drv
->bdrv_media_changed(bs
);
4077 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4079 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
4081 BlockDriver
*drv
= bs
->drv
;
4083 if (drv
&& drv
->bdrv_eject
) {
4084 drv
->bdrv_eject(bs
, eject_flag
);
4089 * Lock or unlock the media (if it is locked, the user won't be able
4090 * to eject it manually).
4092 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
4094 BlockDriver
*drv
= bs
->drv
;
4096 trace_bdrv_lock_medium(bs
, locked
);
4098 if (drv
&& drv
->bdrv_lock_medium
) {
4099 drv
->bdrv_lock_medium(bs
, locked
);
4103 /* Get a reference to bs */
4104 void bdrv_ref(BlockDriverState
*bs
)
4109 /* Release a previously grabbed reference to bs.
4110 * If after releasing, reference count is zero, the BlockDriverState is
4112 void bdrv_unref(BlockDriverState
*bs
)
4117 assert(bs
->refcnt
> 0);
4118 if (--bs
->refcnt
== 0) {
4123 struct BdrvOpBlocker
{
4125 QLIST_ENTRY(BdrvOpBlocker
) list
;
4128 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
4130 BdrvOpBlocker
*blocker
;
4131 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4132 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
4133 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
4135 *errp
= error_copy(blocker
->reason
);
4136 error_prepend(errp
, "Node '%s' is busy: ",
4137 bdrv_get_device_or_node_name(bs
));
4144 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4146 BdrvOpBlocker
*blocker
;
4147 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4149 blocker
= g_new0(BdrvOpBlocker
, 1);
4150 blocker
->reason
= reason
;
4151 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
4154 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4156 BdrvOpBlocker
*blocker
, *next
;
4157 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4158 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
4159 if (blocker
->reason
== reason
) {
4160 QLIST_REMOVE(blocker
, list
);
4166 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
4169 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4170 bdrv_op_block(bs
, i
, reason
);
4174 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
4177 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4178 bdrv_op_unblock(bs
, i
, reason
);
4182 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
4186 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4187 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
4194 void bdrv_img_create(const char *filename
, const char *fmt
,
4195 const char *base_filename
, const char *base_fmt
,
4196 char *options
, uint64_t img_size
, int flags
, bool quiet
,
4199 QemuOptsList
*create_opts
= NULL
;
4200 QemuOpts
*opts
= NULL
;
4201 const char *backing_fmt
, *backing_file
;
4203 BlockDriver
*drv
, *proto_drv
;
4204 Error
*local_err
= NULL
;
4207 /* Find driver and parse its options */
4208 drv
= bdrv_find_format(fmt
);
4210 error_setg(errp
, "Unknown file format '%s'", fmt
);
4214 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
4219 if (!drv
->create_opts
) {
4220 error_setg(errp
, "Format driver '%s' does not support image creation",
4225 if (!proto_drv
->create_opts
) {
4226 error_setg(errp
, "Protocol driver '%s' does not support image creation",
4227 proto_drv
->format_name
);
4231 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
4232 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
4234 /* Create parameter list with default values */
4235 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
4236 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
4238 /* Parse -o options */
4240 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
4242 error_report_err(local_err
);
4244 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
4249 if (base_filename
) {
4250 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
4252 error_setg(errp
, "Backing file not supported for file format '%s'",
4259 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
4261 error_setg(errp
, "Backing file format not supported for file "
4262 "format '%s'", fmt
);
4267 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4269 if (!strcmp(filename
, backing_file
)) {
4270 error_setg(errp
, "Error: Trying to create an image with the "
4271 "same filename as the backing file");
4276 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4278 // The size for the image must always be specified, with one exception:
4279 // If we are using a backing file, we can obtain the size from there
4280 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4283 BlockDriverState
*bs
;
4284 char *full_backing
= g_new0(char, PATH_MAX
);
4287 QDict
*backing_options
= NULL
;
4289 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
4290 full_backing
, PATH_MAX
,
4293 g_free(full_backing
);
4297 /* backing files always opened read-only */
4299 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
4302 backing_options
= qdict_new();
4303 qdict_put_str(backing_options
, "driver", backing_fmt
);
4306 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
4308 g_free(full_backing
);
4312 size
= bdrv_getlength(bs
);
4314 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
4320 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
4324 error_setg(errp
, "Image creation needs a size parameter");
4330 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
4331 qemu_opts_print(opts
, " ");
4335 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
4337 if (ret
== -EFBIG
) {
4338 /* This is generally a better message than whatever the driver would
4339 * deliver (especially because of the cluster_size_hint), since that
4340 * is most probably not much different from "image too large". */
4341 const char *cluster_size_hint
= "";
4342 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
4343 cluster_size_hint
= " (try using a larger cluster size)";
4345 error_setg(errp
, "The image size is too large for file format '%s'"
4346 "%s", fmt
, cluster_size_hint
);
4347 error_free(local_err
);
4352 qemu_opts_del(opts
);
4353 qemu_opts_free(create_opts
);
4354 error_propagate(errp
, local_err
);
4357 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
4359 return bs
->aio_context
;
4362 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
4364 aio_co_enter(bdrv_get_aio_context(bs
), co
);
4367 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
4369 QLIST_REMOVE(ban
, list
);
4373 void bdrv_detach_aio_context(BlockDriverState
*bs
)
4375 BdrvAioNotifier
*baf
, *baf_tmp
;
4382 assert(!bs
->walking_aio_notifiers
);
4383 bs
->walking_aio_notifiers
= true;
4384 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
4386 bdrv_do_remove_aio_context_notifier(baf
);
4388 baf
->detach_aio_context(baf
->opaque
);
4391 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4392 * remove remaining aio notifiers if we aren't called again.
4394 bs
->walking_aio_notifiers
= false;
4396 if (bs
->drv
->bdrv_detach_aio_context
) {
4397 bs
->drv
->bdrv_detach_aio_context(bs
);
4399 QLIST_FOREACH(child
, &bs
->children
, next
) {
4400 bdrv_detach_aio_context(child
->bs
);
4403 bs
->aio_context
= NULL
;
4406 void bdrv_attach_aio_context(BlockDriverState
*bs
,
4407 AioContext
*new_context
)
4409 BdrvAioNotifier
*ban
, *ban_tmp
;
4416 bs
->aio_context
= new_context
;
4418 QLIST_FOREACH(child
, &bs
->children
, next
) {
4419 bdrv_attach_aio_context(child
->bs
, new_context
);
4421 if (bs
->drv
->bdrv_attach_aio_context
) {
4422 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
4425 assert(!bs
->walking_aio_notifiers
);
4426 bs
->walking_aio_notifiers
= true;
4427 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
4429 bdrv_do_remove_aio_context_notifier(ban
);
4431 ban
->attached_aio_context(new_context
, ban
->opaque
);
4434 bs
->walking_aio_notifiers
= false;
4437 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
4439 AioContext
*ctx
= bdrv_get_aio_context(bs
);
4441 aio_disable_external(ctx
);
4442 bdrv_parent_drained_begin(bs
);
4443 bdrv_drain(bs
); /* ensure there are no in-flight requests */
4445 while (aio_poll(ctx
, false)) {
4446 /* wait for all bottom halves to execute */
4449 bdrv_detach_aio_context(bs
);
4451 /* This function executes in the old AioContext so acquire the new one in
4452 * case it runs in a different thread.
4454 aio_context_acquire(new_context
);
4455 bdrv_attach_aio_context(bs
, new_context
);
4456 bdrv_parent_drained_end(bs
);
4457 aio_enable_external(ctx
);
4458 aio_context_release(new_context
);
4461 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
4462 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
4463 void (*detach_aio_context
)(void *opaque
), void *opaque
)
4465 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
4466 *ban
= (BdrvAioNotifier
){
4467 .attached_aio_context
= attached_aio_context
,
4468 .detach_aio_context
= detach_aio_context
,
4472 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
4475 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
4476 void (*attached_aio_context
)(AioContext
*,
4478 void (*detach_aio_context
)(void *),
4481 BdrvAioNotifier
*ban
, *ban_next
;
4483 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
4484 if (ban
->attached_aio_context
== attached_aio_context
&&
4485 ban
->detach_aio_context
== detach_aio_context
&&
4486 ban
->opaque
== opaque
&&
4487 ban
->deleted
== false)
4489 if (bs
->walking_aio_notifiers
) {
4490 ban
->deleted
= true;
4492 bdrv_do_remove_aio_context_notifier(ban
);
4501 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4502 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
4504 if (!bs
->drv
->bdrv_amend_options
) {
4507 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
4510 /* This function will be called by the bdrv_recurse_is_first_non_filter method
4511 * of block filter and by bdrv_is_first_non_filter.
4512 * It is used to test if the given bs is the candidate or recurse more in the
4515 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
4516 BlockDriverState
*candidate
)
4518 /* return false if basic checks fails */
4519 if (!bs
|| !bs
->drv
) {
4523 /* the code reached a non block filter driver -> check if the bs is
4524 * the same as the candidate. It's the recursion termination condition.
4526 if (!bs
->drv
->is_filter
) {
4527 return bs
== candidate
;
4529 /* Down this path the driver is a block filter driver */
4531 /* If the block filter recursion method is defined use it to recurse down
4534 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
4535 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
4538 /* the driver is a block filter but don't allow to recurse -> return false
4543 /* This function checks if the candidate is the first non filter bs down it's
4544 * bs chain. Since we don't have pointers to parents it explore all bs chains
4545 * from the top. Some filters can choose not to pass down the recursion.
4547 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
4549 BlockDriverState
*bs
;
4550 BdrvNextIterator it
;
4552 /* walk down the bs forest recursively */
4553 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4556 /* try to recurse in this top level bs */
4557 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
4559 /* candidate is the first non filter */
4568 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
4569 const char *node_name
, Error
**errp
)
4571 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
4572 AioContext
*aio_context
;
4574 if (!to_replace_bs
) {
4575 error_setg(errp
, "Node name '%s' not found", node_name
);
4579 aio_context
= bdrv_get_aio_context(to_replace_bs
);
4580 aio_context_acquire(aio_context
);
4582 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
4583 to_replace_bs
= NULL
;
4587 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4588 * most non filter in order to prevent data corruption.
4589 * Another benefit is that this tests exclude backing files which are
4590 * blocked by the backing blockers.
4592 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
4593 error_setg(errp
, "Only top most non filter can be replaced");
4594 to_replace_bs
= NULL
;
4599 aio_context_release(aio_context
);
4600 return to_replace_bs
;
4603 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
4605 const QDictEntry
*entry
;
4608 bool found_any
= false;
4611 for (entry
= qdict_first(bs
->options
); entry
;
4612 entry
= qdict_next(bs
->options
, entry
))
4614 /* Exclude options for children */
4615 QLIST_FOREACH(child
, &bs
->children
, next
) {
4616 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
4617 && (!*p
|| *p
== '.'))
4626 /* And exclude all non-driver-specific options */
4627 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
4628 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
4636 qobject_incref(qdict_entry_value(entry
));
4637 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
4644 /* Updates the following BDS fields:
4645 * - exact_filename: A filename which may be used for opening a block device
4646 * which (mostly) equals the given BDS (even without any
4647 * other options; so reading and writing must return the same
4648 * results, but caching etc. may be different)
4649 * - full_open_options: Options which, when given when opening a block device
4650 * (without a filename), result in a BDS (mostly)
4651 * equalling the given one
4652 * - filename: If exact_filename is set, it is copied here. Otherwise,
4653 * full_open_options is converted to a JSON object, prefixed with
4654 * "json:" (for use through the JSON pseudo protocol) and put here.
4656 void bdrv_refresh_filename(BlockDriverState
*bs
)
4658 BlockDriver
*drv
= bs
->drv
;
4665 /* This BDS's file name will most probably depend on its file's name, so
4666 * refresh that first */
4668 bdrv_refresh_filename(bs
->file
->bs
);
4671 if (drv
->bdrv_refresh_filename
) {
4672 /* Obsolete information is of no use here, so drop the old file name
4673 * information before refreshing it */
4674 bs
->exact_filename
[0] = '\0';
4675 if (bs
->full_open_options
) {
4676 QDECREF(bs
->full_open_options
);
4677 bs
->full_open_options
= NULL
;
4681 append_open_options(opts
, bs
);
4682 drv
->bdrv_refresh_filename(bs
, opts
);
4684 } else if (bs
->file
) {
4685 /* Try to reconstruct valid information from the underlying file */
4686 bool has_open_options
;
4688 bs
->exact_filename
[0] = '\0';
4689 if (bs
->full_open_options
) {
4690 QDECREF(bs
->full_open_options
);
4691 bs
->full_open_options
= NULL
;
4695 has_open_options
= append_open_options(opts
, bs
);
4697 /* If no specific options have been given for this BDS, the filename of
4698 * the underlying file should suffice for this one as well */
4699 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
4700 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
4702 /* Reconstructing the full options QDict is simple for most format block
4703 * drivers, as long as the full options are known for the underlying
4704 * file BDS. The full options QDict of that file BDS should somehow
4705 * contain a representation of the filename, therefore the following
4706 * suffices without querying the (exact_)filename of this BDS. */
4707 if (bs
->file
->bs
->full_open_options
) {
4708 qdict_put_str(opts
, "driver", drv
->format_name
);
4709 QINCREF(bs
->file
->bs
->full_open_options
);
4710 qdict_put(opts
, "file", bs
->file
->bs
->full_open_options
);
4712 bs
->full_open_options
= opts
;
4716 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
4717 /* There is no underlying file BDS (at least referenced by BDS.file),
4718 * so the full options QDict should be equal to the options given
4719 * specifically for this block device when it was opened (plus the
4720 * driver specification).
4721 * Because those options don't change, there is no need to update
4722 * full_open_options when it's already set. */
4725 append_open_options(opts
, bs
);
4726 qdict_put_str(opts
, "driver", drv
->format_name
);
4728 if (bs
->exact_filename
[0]) {
4729 /* This may not work for all block protocol drivers (some may
4730 * require this filename to be parsed), but we have to find some
4731 * default solution here, so just include it. If some block driver
4732 * does not support pure options without any filename at all or
4733 * needs some special format of the options QDict, it needs to
4734 * implement the driver-specific bdrv_refresh_filename() function.
4736 qdict_put_str(opts
, "filename", bs
->exact_filename
);
4739 bs
->full_open_options
= opts
;
4742 if (bs
->exact_filename
[0]) {
4743 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4744 } else if (bs
->full_open_options
) {
4745 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4746 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4747 qstring_get_str(json
));
4753 * Hot add/remove a BDS's child. So the user can take a child offline when
4754 * it is broken and take a new child online
4756 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
4760 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
4761 error_setg(errp
, "The node %s does not support adding a child",
4762 bdrv_get_device_or_node_name(parent_bs
));
4766 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4767 error_setg(errp
, "The node %s already has a parent",
4768 child_bs
->node_name
);
4772 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4775 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4779 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4780 error_setg(errp
, "The node %s does not support removing a child",
4781 bdrv_get_device_or_node_name(parent_bs
));
4785 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4792 error_setg(errp
, "The node %s does not have a child named %s",
4793 bdrv_get_device_or_node_name(parent_bs
),
4794 bdrv_get_device_or_node_name(child
->bs
));
4798 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);