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 int bdrv_set_read_only(BlockDriverState
*bs
, bool read_only
, Error
**errp
)
197 /* Do not set read_only if copy_on_read is enabled */
198 if (bs
->copy_on_read
&& read_only
) {
199 error_setg(errp
, "Can't set node '%s' to r/o with copy-on-read enabled",
200 bdrv_get_device_or_node_name(bs
));
204 bs
->read_only
= read_only
;
208 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
210 char *dest
, size_t sz
,
213 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
214 path_is_absolute(backing
))
216 pstrcpy(dest
, sz
, backing
);
217 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
218 error_setg(errp
, "Cannot use relative backing file names for '%s'",
221 path_combine(dest
, sz
, backed
, backing
);
225 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
228 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
230 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
234 void bdrv_register(BlockDriver
*bdrv
)
236 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
239 BlockDriverState
*bdrv_new(void)
241 BlockDriverState
*bs
;
244 bs
= g_new0(BlockDriverState
, 1);
245 QLIST_INIT(&bs
->dirty_bitmaps
);
246 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
247 QLIST_INIT(&bs
->op_blockers
[i
]);
249 notifier_with_return_list_init(&bs
->before_write_notifiers
);
251 bs
->aio_context
= qemu_get_aio_context();
253 qemu_co_queue_init(&bs
->flush_queue
);
255 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
260 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
264 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
265 if (!strcmp(drv1
->format_name
, format_name
)) {
273 BlockDriver
*bdrv_find_format(const char *format_name
)
278 drv1
= bdrv_do_find_format(format_name
);
283 /* The driver isn't registered, maybe we need to load a module */
284 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
285 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
286 block_module_load_one(block_driver_modules
[i
].library_name
);
291 return bdrv_do_find_format(format_name
);
294 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
296 static const char *whitelist_rw
[] = {
297 CONFIG_BDRV_RW_WHITELIST
299 static const char *whitelist_ro
[] = {
300 CONFIG_BDRV_RO_WHITELIST
304 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
305 return 1; /* no whitelist, anything goes */
308 for (p
= whitelist_rw
; *p
; p
++) {
309 if (!strcmp(drv
->format_name
, *p
)) {
314 for (p
= whitelist_ro
; *p
; p
++) {
315 if (!strcmp(drv
->format_name
, *p
)) {
323 bool bdrv_uses_whitelist(void)
325 return use_bdrv_whitelist
;
328 typedef struct CreateCo
{
336 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
338 Error
*local_err
= NULL
;
341 CreateCo
*cco
= opaque
;
344 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
345 error_propagate(&cco
->err
, local_err
);
349 int bdrv_create(BlockDriver
*drv
, const char* filename
,
350 QemuOpts
*opts
, Error
**errp
)
357 .filename
= g_strdup(filename
),
363 if (!drv
->bdrv_create
) {
364 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
369 if (qemu_in_coroutine()) {
370 /* Fast-path if already in coroutine context */
371 bdrv_create_co_entry(&cco
);
373 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
374 qemu_coroutine_enter(co
);
375 while (cco
.ret
== NOT_DONE
) {
376 aio_poll(qemu_get_aio_context(), true);
383 error_propagate(errp
, cco
.err
);
385 error_setg_errno(errp
, -ret
, "Could not create image");
390 g_free(cco
.filename
);
394 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
397 Error
*local_err
= NULL
;
400 drv
= bdrv_find_protocol(filename
, true, errp
);
405 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
406 error_propagate(errp
, local_err
);
411 * Try to get @bs's logical and physical block size.
412 * On success, store them in @bsz struct and return 0.
413 * On failure return -errno.
414 * @bs must not be empty.
416 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
418 BlockDriver
*drv
= bs
->drv
;
420 if (drv
&& drv
->bdrv_probe_blocksizes
) {
421 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
428 * Try to get @bs's geometry (cyls, heads, sectors).
429 * On success, store them in @geo struct and return 0.
430 * On failure return -errno.
431 * @bs must not be empty.
433 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
435 BlockDriver
*drv
= bs
->drv
;
437 if (drv
&& drv
->bdrv_probe_geometry
) {
438 return drv
->bdrv_probe_geometry(bs
, geo
);
445 * Create a uniquely-named empty temporary file.
446 * Return 0 upon success, otherwise a negative errno value.
448 int get_tmp_filename(char *filename
, int size
)
451 char temp_dir
[MAX_PATH
];
452 /* GetTempFileName requires that its output buffer (4th param)
453 have length MAX_PATH or greater. */
454 assert(size
>= MAX_PATH
);
455 return (GetTempPath(MAX_PATH
, temp_dir
)
456 && GetTempFileName(temp_dir
, "qem", 0, filename
)
457 ? 0 : -GetLastError());
461 tmpdir
= getenv("TMPDIR");
465 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
468 fd
= mkstemp(filename
);
472 if (close(fd
) != 0) {
481 * Detect host devices. By convention, /dev/cdrom[N] is always
482 * recognized as a host CDROM.
484 static BlockDriver
*find_hdev_driver(const char *filename
)
486 int score_max
= 0, score
;
487 BlockDriver
*drv
= NULL
, *d
;
489 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
490 if (d
->bdrv_probe_device
) {
491 score
= d
->bdrv_probe_device(filename
);
492 if (score
> score_max
) {
502 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
506 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
507 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
515 BlockDriver
*bdrv_find_protocol(const char *filename
,
516 bool allow_protocol_prefix
,
525 /* TODO Drivers without bdrv_file_open must be specified explicitly */
528 * XXX(hch): we really should not let host device detection
529 * override an explicit protocol specification, but moving this
530 * later breaks access to device names with colons in them.
531 * Thanks to the brain-dead persistent naming schemes on udev-
532 * based Linux systems those actually are quite common.
534 drv1
= find_hdev_driver(filename
);
539 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
543 p
= strchr(filename
, ':');
546 if (len
> sizeof(protocol
) - 1)
547 len
= sizeof(protocol
) - 1;
548 memcpy(protocol
, filename
, len
);
549 protocol
[len
] = '\0';
551 drv1
= bdrv_do_find_protocol(protocol
);
556 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
557 if (block_driver_modules
[i
].protocol_name
&&
558 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
559 block_module_load_one(block_driver_modules
[i
].library_name
);
564 drv1
= bdrv_do_find_protocol(protocol
);
566 error_setg(errp
, "Unknown protocol '%s'", protocol
);
572 * Guess image format by probing its contents.
573 * This is not a good idea when your image is raw (CVE-2008-2004), but
574 * we do it anyway for backward compatibility.
576 * @buf contains the image's first @buf_size bytes.
577 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
578 * but can be smaller if the image file is smaller)
579 * @filename is its filename.
581 * For all block drivers, call the bdrv_probe() method to get its
583 * Return the first block driver with the highest probing score.
585 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
586 const char *filename
)
588 int score_max
= 0, score
;
589 BlockDriver
*drv
= NULL
, *d
;
591 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
593 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
594 if (score
> score_max
) {
604 static int find_image_format(BlockBackend
*file
, const char *filename
,
605 BlockDriver
**pdrv
, Error
**errp
)
608 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
611 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
612 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
617 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
619 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
625 drv
= bdrv_probe_all(buf
, ret
, filename
);
627 error_setg(errp
, "Could not determine image format: No compatible "
636 * Set the current 'total_sectors' value
637 * Return 0 on success, -errno on error.
639 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
641 BlockDriver
*drv
= bs
->drv
;
643 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
647 /* query actual device if possible, otherwise just trust the hint */
648 if (drv
->bdrv_getlength
) {
649 int64_t length
= drv
->bdrv_getlength(bs
);
653 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
656 bs
->total_sectors
= hint
;
661 * Combines a QDict of new block driver @options with any missing options taken
662 * from @old_options, so that leaving out an option defaults to its old value.
664 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
667 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
668 bs
->drv
->bdrv_join_options(options
, old_options
);
670 qdict_join(options
, old_options
, false);
675 * Set open flags for a given discard mode
677 * Return 0 on success, -1 if the discard mode was invalid.
679 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
681 *flags
&= ~BDRV_O_UNMAP
;
683 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
685 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
686 *flags
|= BDRV_O_UNMAP
;
695 * Set open flags for a given cache mode
697 * Return 0 on success, -1 if the cache mode was invalid.
699 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
701 *flags
&= ~BDRV_O_CACHE_MASK
;
703 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
704 *writethrough
= false;
705 *flags
|= BDRV_O_NOCACHE
;
706 } else if (!strcmp(mode
, "directsync")) {
707 *writethrough
= true;
708 *flags
|= BDRV_O_NOCACHE
;
709 } else if (!strcmp(mode
, "writeback")) {
710 *writethrough
= false;
711 } else if (!strcmp(mode
, "unsafe")) {
712 *writethrough
= false;
713 *flags
|= BDRV_O_NO_FLUSH
;
714 } else if (!strcmp(mode
, "writethrough")) {
715 *writethrough
= true;
723 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
725 BlockDriverState
*parent
= c
->opaque
;
726 return g_strdup(bdrv_get_device_or_node_name(parent
));
729 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
731 BlockDriverState
*bs
= child
->opaque
;
732 bdrv_drained_begin(bs
);
735 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
737 BlockDriverState
*bs
= child
->opaque
;
738 bdrv_drained_end(bs
);
742 * Returns the options and flags that a temporary snapshot should get, based on
743 * the originally requested flags (the originally requested image will have
744 * flags like a backing file)
746 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
747 int parent_flags
, QDict
*parent_options
)
749 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
751 /* For temporary files, unconditional cache=unsafe is fine */
752 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
753 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
755 /* Copy the read-only option from the parent */
756 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
758 /* aio=native doesn't work for cache.direct=off, so disable it for the
759 * temporary snapshot */
760 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
764 * Returns the options and flags that bs->file should get if a protocol driver
765 * is expected, based on the given options and flags for the parent BDS
767 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
768 int parent_flags
, QDict
*parent_options
)
770 int flags
= parent_flags
;
772 /* Enable protocol handling, disable format probing for bs->file */
773 flags
|= BDRV_O_PROTOCOL
;
775 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
777 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
778 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
780 /* Inherit the read-only option from the parent if it's not set */
781 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
783 /* Our block drivers take care to send flushes and respect unmap policy,
784 * so we can default to enable both on lower layers regardless of the
785 * corresponding parent options. */
786 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
788 /* Clear flags that only apply to the top layer */
789 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
792 *child_flags
= flags
;
795 const BdrvChildRole child_file
= {
796 .get_parent_desc
= bdrv_child_get_parent_desc
,
797 .inherit_options
= bdrv_inherited_options
,
798 .drained_begin
= bdrv_child_cb_drained_begin
,
799 .drained_end
= bdrv_child_cb_drained_end
,
803 * Returns the options and flags that bs->file should get if the use of formats
804 * (and not only protocols) is permitted for it, based on the given options and
805 * flags for the parent BDS
807 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
808 int parent_flags
, QDict
*parent_options
)
810 child_file
.inherit_options(child_flags
, child_options
,
811 parent_flags
, parent_options
);
813 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
816 const BdrvChildRole child_format
= {
817 .get_parent_desc
= bdrv_child_get_parent_desc
,
818 .inherit_options
= bdrv_inherited_fmt_options
,
819 .drained_begin
= bdrv_child_cb_drained_begin
,
820 .drained_end
= bdrv_child_cb_drained_end
,
823 static void bdrv_backing_attach(BdrvChild
*c
)
825 BlockDriverState
*parent
= c
->opaque
;
826 BlockDriverState
*backing_hd
= c
->bs
;
828 assert(!parent
->backing_blocker
);
829 error_setg(&parent
->backing_blocker
,
830 "node is used as backing hd of '%s'",
831 bdrv_get_device_or_node_name(parent
));
833 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
834 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
835 backing_hd
->filename
);
836 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
837 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
839 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
840 /* Otherwise we won't be able to commit or stream */
841 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
842 parent
->backing_blocker
);
843 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
844 parent
->backing_blocker
);
846 * We do backup in 3 ways:
848 * The target bs is new opened, and the source is top BDS
850 * Both the source and the target are top BDSes.
851 * 3. internal backup(used for block replication)
852 * Both the source and the target are backing file
854 * In case 1 and 2, neither the source nor the target is the backing file.
855 * In case 3, we will block the top BDS, so there is only one block job
856 * for the top BDS and its backing chain.
858 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
859 parent
->backing_blocker
);
860 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
861 parent
->backing_blocker
);
864 static void bdrv_backing_detach(BdrvChild
*c
)
866 BlockDriverState
*parent
= c
->opaque
;
868 assert(parent
->backing_blocker
);
869 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
870 error_free(parent
->backing_blocker
);
871 parent
->backing_blocker
= NULL
;
875 * Returns the options and flags that bs->backing should get, based on the
876 * given options and flags for the parent BDS
878 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
879 int parent_flags
, QDict
*parent_options
)
881 int flags
= parent_flags
;
883 /* The cache mode is inherited unmodified for backing files; except WCE,
884 * which is only applied on the top level (BlockBackend) */
885 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
886 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
888 /* backing files always opened read-only */
889 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
890 flags
&= ~BDRV_O_COPY_ON_READ
;
892 /* snapshot=on is handled on the top layer */
893 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
895 *child_flags
= flags
;
898 const BdrvChildRole child_backing
= {
899 .get_parent_desc
= bdrv_child_get_parent_desc
,
900 .attach
= bdrv_backing_attach
,
901 .detach
= bdrv_backing_detach
,
902 .inherit_options
= bdrv_backing_options
,
903 .drained_begin
= bdrv_child_cb_drained_begin
,
904 .drained_end
= bdrv_child_cb_drained_end
,
907 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
909 int open_flags
= flags
;
912 * Clear flags that are internal to the block layer before opening the
915 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
918 * Snapshots should be writable.
920 if (flags
& BDRV_O_TEMPORARY
) {
921 open_flags
|= BDRV_O_RDWR
;
927 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
929 *flags
&= ~BDRV_O_CACHE_MASK
;
931 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
932 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
933 *flags
|= BDRV_O_NO_FLUSH
;
936 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
937 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
938 *flags
|= BDRV_O_NOCACHE
;
941 *flags
&= ~BDRV_O_RDWR
;
943 assert(qemu_opt_find(opts
, BDRV_OPT_READ_ONLY
));
944 if (!qemu_opt_get_bool(opts
, BDRV_OPT_READ_ONLY
, false)) {
945 *flags
|= BDRV_O_RDWR
;
950 static void update_options_from_flags(QDict
*options
, int flags
)
952 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
953 qdict_put(options
, BDRV_OPT_CACHE_DIRECT
,
954 qbool_from_bool(flags
& BDRV_O_NOCACHE
));
956 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
957 qdict_put(options
, BDRV_OPT_CACHE_NO_FLUSH
,
958 qbool_from_bool(flags
& BDRV_O_NO_FLUSH
));
960 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
961 qdict_put(options
, BDRV_OPT_READ_ONLY
,
962 qbool_from_bool(!(flags
& BDRV_O_RDWR
)));
966 static void bdrv_assign_node_name(BlockDriverState
*bs
,
967 const char *node_name
,
970 char *gen_node_name
= NULL
;
973 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
974 } else if (!id_wellformed(node_name
)) {
976 * Check for empty string or invalid characters, but not if it is
977 * generated (generated names use characters not available to the user)
979 error_setg(errp
, "Invalid node name");
983 /* takes care of avoiding namespaces collisions */
984 if (blk_by_name(node_name
)) {
985 error_setg(errp
, "node-name=%s is conflicting with a device id",
990 /* takes care of avoiding duplicates node names */
991 if (bdrv_find_node(node_name
)) {
992 error_setg(errp
, "Duplicate node name");
996 /* copy node name into the bs and insert it into the graph list */
997 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
998 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
1000 g_free(gen_node_name
);
1003 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
1004 const char *node_name
, QDict
*options
,
1005 int open_flags
, Error
**errp
)
1007 Error
*local_err
= NULL
;
1010 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1012 error_propagate(errp
, local_err
);
1017 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1018 bs
->opaque
= g_malloc0(drv
->instance_size
);
1020 if (drv
->bdrv_file_open
) {
1021 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1022 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1023 } else if (drv
->bdrv_open
) {
1024 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1031 error_propagate(errp
, local_err
);
1032 } else if (bs
->filename
[0]) {
1033 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1035 error_setg_errno(errp
, -ret
, "Could not open image");
1040 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1042 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1046 bdrv_refresh_limits(bs
, &local_err
);
1048 error_propagate(errp
, local_err
);
1053 assert(bdrv_opt_mem_align(bs
) != 0);
1054 assert(bdrv_min_mem_align(bs
) != 0);
1055 assert(is_power_of_2(bs
->bl
.request_alignment
));
1060 /* FIXME Close bs first if already opened*/
1067 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1068 int flags
, Error
**errp
)
1070 BlockDriverState
*bs
;
1074 bs
->open_flags
= flags
;
1075 bs
->explicit_options
= qdict_new();
1076 bs
->options
= qdict_new();
1079 update_options_from_flags(bs
->options
, flags
);
1081 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1083 QDECREF(bs
->explicit_options
);
1084 QDECREF(bs
->options
);
1092 QemuOptsList bdrv_runtime_opts
= {
1093 .name
= "bdrv_common",
1094 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1097 .name
= "node-name",
1098 .type
= QEMU_OPT_STRING
,
1099 .help
= "Node name of the block device node",
1103 .type
= QEMU_OPT_STRING
,
1104 .help
= "Block driver to use for the node",
1107 .name
= BDRV_OPT_CACHE_DIRECT
,
1108 .type
= QEMU_OPT_BOOL
,
1109 .help
= "Bypass software writeback cache on the host",
1112 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1113 .type
= QEMU_OPT_BOOL
,
1114 .help
= "Ignore flush requests",
1117 .name
= BDRV_OPT_READ_ONLY
,
1118 .type
= QEMU_OPT_BOOL
,
1119 .help
= "Node is opened in read-only mode",
1122 .name
= "detect-zeroes",
1123 .type
= QEMU_OPT_STRING
,
1124 .help
= "try to optimize zero writes (off, on, unmap)",
1128 .type
= QEMU_OPT_STRING
,
1129 .help
= "discard operation (ignore/off, unmap/on)",
1131 { /* end of list */ }
1136 * Common part for opening disk images and files
1138 * Removes all processed options from *options.
1140 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1141 QDict
*options
, Error
**errp
)
1143 int ret
, open_flags
;
1144 const char *filename
;
1145 const char *driver_name
= NULL
;
1146 const char *node_name
= NULL
;
1147 const char *discard
;
1148 const char *detect_zeroes
;
1151 Error
*local_err
= NULL
;
1153 assert(bs
->file
== NULL
);
1154 assert(options
!= NULL
&& bs
->options
!= options
);
1156 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1157 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1159 error_propagate(errp
, local_err
);
1164 update_flags_from_options(&bs
->open_flags
, opts
);
1166 driver_name
= qemu_opt_get(opts
, "driver");
1167 drv
= bdrv_find_format(driver_name
);
1168 assert(drv
!= NULL
);
1171 filename
= blk_bs(file
)->filename
;
1174 * Caution: while qdict_get_try_str() is fine, getting
1175 * non-string types would require more care. When @options
1176 * come from -blockdev or blockdev_add, its members are typed
1177 * according to the QAPI schema, but when they come from
1178 * -drive, they're all QString.
1180 filename
= qdict_get_try_str(options
, "filename");
1183 if (drv
->bdrv_needs_filename
&& !filename
) {
1184 error_setg(errp
, "The '%s' block driver requires a file name",
1190 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1193 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1195 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1197 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1198 ? "Driver '%s' can only be used for read-only devices"
1199 : "Driver '%s' is not whitelisted",
1205 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
1206 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1207 if (!bs
->read_only
) {
1208 bdrv_enable_copy_on_read(bs
);
1210 error_setg(errp
, "Can't use copy-on-read on read-only device");
1216 discard
= qemu_opt_get(opts
, "discard");
1217 if (discard
!= NULL
) {
1218 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1219 error_setg(errp
, "Invalid discard option");
1225 detect_zeroes
= qemu_opt_get(opts
, "detect-zeroes");
1226 if (detect_zeroes
) {
1227 BlockdevDetectZeroesOptions value
=
1228 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup
,
1230 BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX
,
1231 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
1234 error_propagate(errp
, local_err
);
1239 if (value
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
1240 !(bs
->open_flags
& BDRV_O_UNMAP
))
1242 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
1243 "without setting discard operation to unmap");
1248 bs
->detect_zeroes
= value
;
1251 if (filename
!= NULL
) {
1252 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1254 bs
->filename
[0] = '\0';
1256 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1258 /* Open the image, either directly or using a protocol */
1259 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1260 node_name
= qemu_opt_get(opts
, "node-name");
1262 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1263 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1268 qemu_opts_del(opts
);
1272 qemu_opts_del(opts
);
1276 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1278 QObject
*options_obj
;
1282 ret
= strstart(filename
, "json:", &filename
);
1285 options_obj
= qobject_from_json(filename
, errp
);
1287 /* Work around qobject_from_json() lossage TODO fix that */
1288 if (errp
&& !*errp
) {
1289 error_setg(errp
, "Could not parse the JSON options");
1292 error_prepend(errp
, "Could not parse the JSON options: ");
1296 options
= qobject_to_qdict(options_obj
);
1298 qobject_decref(options_obj
);
1299 error_setg(errp
, "Invalid JSON object given");
1303 qdict_flatten(options
);
1308 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1311 QDict
*json_options
;
1312 Error
*local_err
= NULL
;
1314 /* Parse json: pseudo-protocol */
1315 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1319 json_options
= parse_json_filename(*pfilename
, &local_err
);
1321 error_propagate(errp
, local_err
);
1325 /* Options given in the filename have lower priority than options
1326 * specified directly */
1327 qdict_join(options
, json_options
, false);
1328 QDECREF(json_options
);
1333 * Fills in default options for opening images and converts the legacy
1334 * filename/flags pair to option QDict entries.
1335 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1336 * block driver has been specified explicitly.
1338 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1339 int *flags
, Error
**errp
)
1341 const char *drvname
;
1342 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1343 bool parse_filename
= false;
1344 BlockDriver
*drv
= NULL
;
1345 Error
*local_err
= NULL
;
1348 * Caution: while qdict_get_try_str() is fine, getting non-string
1349 * types would require more care. When @options come from
1350 * -blockdev or blockdev_add, its members are typed according to
1351 * the QAPI schema, but when they come from -drive, they're all
1354 drvname
= qdict_get_try_str(*options
, "driver");
1356 drv
= bdrv_find_format(drvname
);
1358 error_setg(errp
, "Unknown driver '%s'", drvname
);
1361 /* If the user has explicitly specified the driver, this choice should
1362 * override the BDRV_O_PROTOCOL flag */
1363 protocol
= drv
->bdrv_file_open
;
1367 *flags
|= BDRV_O_PROTOCOL
;
1369 *flags
&= ~BDRV_O_PROTOCOL
;
1372 /* Translate cache options from flags into options */
1373 update_options_from_flags(*options
, *flags
);
1375 /* Fetch the file name from the options QDict if necessary */
1376 if (protocol
&& filename
) {
1377 if (!qdict_haskey(*options
, "filename")) {
1378 qdict_put(*options
, "filename", qstring_from_str(filename
));
1379 parse_filename
= true;
1381 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1387 /* Find the right block driver */
1388 /* See cautionary note on accessing @options above */
1389 filename
= qdict_get_try_str(*options
, "filename");
1391 if (!drvname
&& protocol
) {
1393 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1398 drvname
= drv
->format_name
;
1399 qdict_put(*options
, "driver", qstring_from_str(drvname
));
1401 error_setg(errp
, "Must specify either driver or file");
1406 assert(drv
|| !protocol
);
1408 /* Driver-specific filename parsing */
1409 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1410 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1412 error_propagate(errp
, local_err
);
1416 if (!drv
->bdrv_needs_filename
) {
1417 qdict_del(*options
, "filename");
1424 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1425 GSList
*ignore_children
, Error
**errp
);
1426 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1427 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1430 * Check whether permissions on this node can be changed in a way that
1431 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1432 * permissions of all its parents. This involves checking whether all necessary
1433 * permission changes to child nodes can be performed.
1435 * A call to this function must always be followed by a call to bdrv_set_perm()
1436 * or bdrv_abort_perm_update().
1438 static int bdrv_check_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1439 uint64_t cumulative_shared_perms
,
1440 GSList
*ignore_children
, Error
**errp
)
1442 BlockDriver
*drv
= bs
->drv
;
1446 /* Write permissions never work with read-only images */
1447 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1448 bdrv_is_read_only(bs
))
1450 error_setg(errp
, "Block node is read-only");
1454 /* Check this node */
1459 if (drv
->bdrv_check_perm
) {
1460 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1461 cumulative_shared_perms
, errp
);
1464 /* Drivers that never have children can omit .bdrv_child_perm() */
1465 if (!drv
->bdrv_child_perm
) {
1466 assert(QLIST_EMPTY(&bs
->children
));
1470 /* Check all children */
1471 QLIST_FOREACH(c
, &bs
->children
, next
) {
1472 uint64_t cur_perm
, cur_shared
;
1473 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1474 cumulative_perms
, cumulative_shared_perms
,
1475 &cur_perm
, &cur_shared
);
1476 ret
= bdrv_child_check_perm(c
, cur_perm
, cur_shared
, ignore_children
,
1487 * Notifies drivers that after a previous bdrv_check_perm() call, the
1488 * permission update is not performed and any preparations made for it (e.g.
1489 * taken file locks) need to be undone.
1491 * This function recursively notifies all child nodes.
1493 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1495 BlockDriver
*drv
= bs
->drv
;
1502 if (drv
->bdrv_abort_perm_update
) {
1503 drv
->bdrv_abort_perm_update(bs
);
1506 QLIST_FOREACH(c
, &bs
->children
, next
) {
1507 bdrv_child_abort_perm_update(c
);
1511 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1512 uint64_t cumulative_shared_perms
)
1514 BlockDriver
*drv
= bs
->drv
;
1521 /* Update this node */
1522 if (drv
->bdrv_set_perm
) {
1523 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1526 /* Drivers that never have children can omit .bdrv_child_perm() */
1527 if (!drv
->bdrv_child_perm
) {
1528 assert(QLIST_EMPTY(&bs
->children
));
1532 /* Update all children */
1533 QLIST_FOREACH(c
, &bs
->children
, next
) {
1534 uint64_t cur_perm
, cur_shared
;
1535 drv
->bdrv_child_perm(bs
, c
, c
->role
,
1536 cumulative_perms
, cumulative_shared_perms
,
1537 &cur_perm
, &cur_shared
);
1538 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1542 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1543 uint64_t *shared_perm
)
1546 uint64_t cumulative_perms
= 0;
1547 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1549 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1550 cumulative_perms
|= c
->perm
;
1551 cumulative_shared_perms
&= c
->shared_perm
;
1554 *perm
= cumulative_perms
;
1555 *shared_perm
= cumulative_shared_perms
;
1558 static char *bdrv_child_user_desc(BdrvChild
*c
)
1560 if (c
->role
->get_parent_desc
) {
1561 return c
->role
->get_parent_desc(c
);
1564 return g_strdup("another user");
1567 static char *bdrv_perm_names(uint64_t perm
)
1573 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1574 { BLK_PERM_WRITE
, "write" },
1575 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1576 { BLK_PERM_RESIZE
, "resize" },
1577 { BLK_PERM_GRAPH_MOD
, "change children" },
1581 char *result
= g_strdup("");
1582 struct perm_name
*p
;
1584 for (p
= permissions
; p
->name
; p
++) {
1585 if (perm
& p
->perm
) {
1587 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1596 * Checks whether a new reference to @bs can be added if the new user requires
1597 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1598 * set, the BdrvChild objects in this list are ignored in the calculations;
1599 * this allows checking permission updates for an existing reference.
1601 * Needs to be followed by a call to either bdrv_set_perm() or
1602 * bdrv_abort_perm_update(). */
1603 static int bdrv_check_update_perm(BlockDriverState
*bs
, uint64_t new_used_perm
,
1604 uint64_t new_shared_perm
,
1605 GSList
*ignore_children
, Error
**errp
)
1608 uint64_t cumulative_perms
= new_used_perm
;
1609 uint64_t cumulative_shared_perms
= new_shared_perm
;
1611 /* There is no reason why anyone couldn't tolerate write_unchanged */
1612 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1614 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1615 if (g_slist_find(ignore_children
, c
)) {
1619 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1620 char *user
= bdrv_child_user_desc(c
);
1621 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1622 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1624 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1630 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1631 char *user
= bdrv_child_user_desc(c
);
1632 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1633 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1635 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1641 cumulative_perms
|= c
->perm
;
1642 cumulative_shared_perms
&= c
->shared_perm
;
1645 return bdrv_check_perm(bs
, cumulative_perms
, cumulative_shared_perms
,
1646 ignore_children
, errp
);
1649 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1650 * bdrv_child_abort_perm_update(). */
1651 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1652 GSList
*ignore_children
, Error
**errp
)
1656 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1657 ret
= bdrv_check_update_perm(c
->bs
, perm
, shared
, ignore_children
, errp
);
1658 g_slist_free(ignore_children
);
1663 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
1665 uint64_t cumulative_perms
, cumulative_shared_perms
;
1668 c
->shared_perm
= shared
;
1670 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
1671 &cumulative_shared_perms
);
1672 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
1675 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
1677 bdrv_abort_perm_update(c
->bs
);
1680 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1685 ret
= bdrv_child_check_perm(c
, perm
, shared
, NULL
, errp
);
1687 bdrv_child_abort_perm_update(c
);
1691 bdrv_child_set_perm(c
, perm
, shared
);
1696 #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1698 | BLK_PERM_WRITE_UNCHANGED \
1700 #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1702 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1703 const BdrvChildRole
*role
,
1704 uint64_t perm
, uint64_t shared
,
1705 uint64_t *nperm
, uint64_t *nshared
)
1708 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
1709 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
1713 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
1714 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
1715 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
1716 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
1719 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1720 const BdrvChildRole
*role
,
1721 uint64_t perm
, uint64_t shared
,
1722 uint64_t *nperm
, uint64_t *nshared
)
1724 bool backing
= (role
== &child_backing
);
1725 assert(role
== &child_backing
|| role
== &child_file
);
1728 /* Apart from the modifications below, the same permissions are
1729 * forwarded and left alone as for filters */
1730 bdrv_filter_default_perms(bs
, c
, role
, perm
, shared
, &perm
, &shared
);
1732 /* Format drivers may touch metadata even if the guest doesn't write */
1733 if (!bdrv_is_read_only(bs
)) {
1734 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1737 /* bs->file always needs to be consistent because of the metadata. We
1738 * can never allow other users to resize or write to it. */
1739 perm
|= BLK_PERM_CONSISTENT_READ
;
1740 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
1742 /* We want consistent read from backing files if the parent needs it.
1743 * No other operations are performed on backing files. */
1744 perm
&= BLK_PERM_CONSISTENT_READ
;
1746 /* If the parent can deal with changing data, we're okay with a
1747 * writable and resizable backing file. */
1748 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1749 if (shared
& BLK_PERM_WRITE
) {
1750 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1755 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
1756 BLK_PERM_WRITE_UNCHANGED
;
1763 static void bdrv_replace_child_noperm(BdrvChild
*child
,
1764 BlockDriverState
*new_bs
)
1766 BlockDriverState
*old_bs
= child
->bs
;
1768 if (old_bs
&& new_bs
) {
1769 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
1772 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1773 child
->role
->drained_end(child
);
1775 if (child
->role
->detach
) {
1776 child
->role
->detach(child
);
1778 QLIST_REMOVE(child
, next_parent
);
1784 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1785 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1786 child
->role
->drained_begin(child
);
1789 if (child
->role
->attach
) {
1790 child
->role
->attach(child
);
1796 * Updates @child to change its reference to point to @new_bs, including
1797 * checking and applying the necessary permisson updates both to the old node
1800 * NULL is passed as @new_bs for removing the reference before freeing @child.
1802 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
1803 * function uses bdrv_set_perm() to update the permissions according to the new
1804 * reference that @new_bs gets.
1806 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1808 BlockDriverState
*old_bs
= child
->bs
;
1809 uint64_t perm
, shared_perm
;
1812 /* Update permissions for old node. This is guaranteed to succeed
1813 * because we're just taking a parent away, so we're loosening
1815 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
1816 bdrv_check_perm(old_bs
, perm
, shared_perm
, NULL
, &error_abort
);
1817 bdrv_set_perm(old_bs
, perm
, shared_perm
);
1820 bdrv_replace_child_noperm(child
, new_bs
);
1823 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
1824 bdrv_set_perm(new_bs
, perm
, shared_perm
);
1828 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1829 const char *child_name
,
1830 const BdrvChildRole
*child_role
,
1831 uint64_t perm
, uint64_t shared_perm
,
1832 void *opaque
, Error
**errp
)
1837 ret
= bdrv_check_update_perm(child_bs
, perm
, shared_perm
, NULL
, errp
);
1839 bdrv_abort_perm_update(child_bs
);
1843 child
= g_new(BdrvChild
, 1);
1844 *child
= (BdrvChild
) {
1846 .name
= g_strdup(child_name
),
1849 .shared_perm
= shared_perm
,
1853 /* This performs the matching bdrv_set_perm() for the above check. */
1854 bdrv_replace_child(child
, child_bs
);
1859 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1860 BlockDriverState
*child_bs
,
1861 const char *child_name
,
1862 const BdrvChildRole
*child_role
,
1866 uint64_t perm
, shared_perm
;
1868 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
1870 assert(parent_bs
->drv
);
1871 assert(bdrv_get_aio_context(parent_bs
) == bdrv_get_aio_context(child_bs
));
1872 parent_bs
->drv
->bdrv_child_perm(parent_bs
, NULL
, child_role
,
1873 perm
, shared_perm
, &perm
, &shared_perm
);
1875 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
1876 perm
, shared_perm
, parent_bs
, errp
);
1877 if (child
== NULL
) {
1881 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1885 static void bdrv_detach_child(BdrvChild
*child
)
1887 if (child
->next
.le_prev
) {
1888 QLIST_REMOVE(child
, next
);
1889 child
->next
.le_prev
= NULL
;
1892 bdrv_replace_child(child
, NULL
);
1894 g_free(child
->name
);
1898 void bdrv_root_unref_child(BdrvChild
*child
)
1900 BlockDriverState
*child_bs
;
1902 child_bs
= child
->bs
;
1903 bdrv_detach_child(child
);
1904 bdrv_unref(child_bs
);
1907 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1909 if (child
== NULL
) {
1913 if (child
->bs
->inherits_from
== parent
) {
1916 /* Remove inherits_from only when the last reference between parent and
1917 * child->bs goes away. */
1918 QLIST_FOREACH(c
, &parent
->children
, next
) {
1919 if (c
!= child
&& c
->bs
== child
->bs
) {
1924 child
->bs
->inherits_from
= NULL
;
1928 bdrv_root_unref_child(child
);
1932 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
1935 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1936 if (c
->role
->change_media
) {
1937 c
->role
->change_media(c
, load
);
1942 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
1945 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1946 if (c
->role
->resize
) {
1953 * Sets the backing file link of a BDS. A new reference is created; callers
1954 * which don't need their own reference any more must call bdrv_unref().
1956 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
1960 bdrv_ref(backing_hd
);
1964 bdrv_unref_child(bs
, bs
->backing
);
1972 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
1975 bdrv_unref(backing_hd
);
1978 bdrv_refresh_filename(bs
);
1981 bdrv_refresh_limits(bs
, NULL
);
1985 * Opens the backing file for a BlockDriverState if not yet open
1987 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
1988 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1989 * itself, all options starting with "${bdref_key}." are considered part of the
1992 * TODO Can this be unified with bdrv_open_image()?
1994 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
1995 const char *bdref_key
, Error
**errp
)
1997 char *backing_filename
= g_malloc0(PATH_MAX
);
1998 char *bdref_key_dot
;
1999 const char *reference
= NULL
;
2001 BlockDriverState
*backing_hd
;
2003 QDict
*tmp_parent_options
= NULL
;
2004 Error
*local_err
= NULL
;
2006 if (bs
->backing
!= NULL
) {
2010 /* NULL means an empty set of options */
2011 if (parent_options
== NULL
) {
2012 tmp_parent_options
= qdict_new();
2013 parent_options
= tmp_parent_options
;
2016 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2018 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2019 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2020 g_free(bdref_key_dot
);
2023 * Caution: while qdict_get_try_str() is fine, getting non-string
2024 * types would require more care. When @parent_options come from
2025 * -blockdev or blockdev_add, its members are typed according to
2026 * the QAPI schema, but when they come from -drive, they're all
2029 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2030 if (reference
|| qdict_haskey(options
, "file.filename")) {
2031 backing_filename
[0] = '\0';
2032 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2036 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
2040 error_propagate(errp
, local_err
);
2046 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2048 error_setg(errp
, "Driver doesn't support backing files");
2053 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2054 qdict_put(options
, "driver", qstring_from_str(bs
->backing_format
));
2057 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
2058 reference
, options
, 0, bs
, &child_backing
,
2061 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2062 error_prepend(errp
, "Could not open backing file: ");
2067 /* Hook up the backing file link; drop our reference, bs owns the
2068 * backing_hd reference now */
2069 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2070 bdrv_unref(backing_hd
);
2072 error_propagate(errp
, local_err
);
2077 qdict_del(parent_options
, bdref_key
);
2080 g_free(backing_filename
);
2081 QDECREF(tmp_parent_options
);
2085 static BlockDriverState
*
2086 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2087 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2088 bool allow_none
, Error
**errp
)
2090 BlockDriverState
*bs
= NULL
;
2091 QDict
*image_options
;
2092 char *bdref_key_dot
;
2093 const char *reference
;
2095 assert(child_role
!= NULL
);
2097 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2098 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2099 g_free(bdref_key_dot
);
2102 * Caution: while qdict_get_try_str() is fine, getting non-string
2103 * types would require more care. When @options come from
2104 * -blockdev or blockdev_add, its members are typed according to
2105 * the QAPI schema, but when they come from -drive, they're all
2108 reference
= qdict_get_try_str(options
, bdref_key
);
2109 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2111 error_setg(errp
, "A block device must be specified for \"%s\"",
2114 QDECREF(image_options
);
2118 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2119 parent
, child_role
, errp
);
2125 qdict_del(options
, bdref_key
);
2130 * Opens a disk image whose options are given as BlockdevRef in another block
2133 * If allow_none is true, no image will be opened if filename is false and no
2134 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2136 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2137 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2138 * itself, all options starting with "${bdref_key}." are considered part of the
2141 * The BlockdevRef will be removed from the options QDict.
2143 BdrvChild
*bdrv_open_child(const char *filename
,
2144 QDict
*options
, const char *bdref_key
,
2145 BlockDriverState
*parent
,
2146 const BdrvChildRole
*child_role
,
2147 bool allow_none
, Error
**errp
)
2150 BlockDriverState
*bs
;
2152 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2158 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2167 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2169 QDict
*snapshot_options
,
2172 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2173 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2175 QemuOpts
*opts
= NULL
;
2176 BlockDriverState
*bs_snapshot
;
2177 Error
*local_err
= NULL
;
2180 /* if snapshot, we create a temporary backing file and open it
2181 instead of opening 'filename' directly */
2183 /* Get the required size from the image */
2184 total_size
= bdrv_getlength(bs
);
2185 if (total_size
< 0) {
2186 error_setg_errno(errp
, -total_size
, "Could not get image size");
2190 /* Create the temporary image */
2191 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2193 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2197 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2199 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2200 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2201 qemu_opts_del(opts
);
2203 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2208 /* Prepare options QDict for the temporary file */
2209 qdict_put(snapshot_options
, "file.driver",
2210 qstring_from_str("file"));
2211 qdict_put(snapshot_options
, "file.filename",
2212 qstring_from_str(tmp_filename
));
2213 qdict_put(snapshot_options
, "driver",
2214 qstring_from_str("qcow2"));
2216 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2217 snapshot_options
= NULL
;
2223 /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
2224 * call bdrv_unref() on it), so in order to be able to return one, we have
2225 * to increase bs_snapshot's refcount here */
2226 bdrv_ref(bs_snapshot
);
2227 bdrv_append(bs_snapshot
, bs
, &local_err
);
2229 error_propagate(errp
, local_err
);
2234 g_free(tmp_filename
);
2238 QDECREF(snapshot_options
);
2239 g_free(tmp_filename
);
2244 * Opens a disk image (raw, qcow2, vmdk, ...)
2246 * options is a QDict of options to pass to the block drivers, or NULL for an
2247 * empty set of options. The reference to the QDict belongs to the block layer
2248 * after the call (even on failure), so if the caller intends to reuse the
2249 * dictionary, it needs to use QINCREF() before calling bdrv_open.
2251 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2252 * If it is not NULL, the referenced BDS will be reused.
2254 * The reference parameter may be used to specify an existing block device which
2255 * should be opened. If specified, neither options nor a filename may be given,
2256 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2258 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2259 const char *reference
,
2260 QDict
*options
, int flags
,
2261 BlockDriverState
*parent
,
2262 const BdrvChildRole
*child_role
,
2266 BlockBackend
*file
= NULL
;
2267 BlockDriverState
*bs
;
2268 BlockDriver
*drv
= NULL
;
2269 const char *drvname
;
2270 const char *backing
;
2271 Error
*local_err
= NULL
;
2272 QDict
*snapshot_options
= NULL
;
2273 int snapshot_flags
= 0;
2275 assert(!child_role
|| !flags
);
2276 assert(!child_role
== !parent
);
2279 bool options_non_empty
= options
? qdict_size(options
) : false;
2282 if (filename
|| options_non_empty
) {
2283 error_setg(errp
, "Cannot reference an existing block device with "
2284 "additional options or a new filename");
2288 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2299 /* NULL means an empty set of options */
2300 if (options
== NULL
) {
2301 options
= qdict_new();
2304 /* json: syntax counts as explicit options, as if in the QDict */
2305 parse_json_protocol(options
, &filename
, &local_err
);
2310 bs
->explicit_options
= qdict_clone_shallow(options
);
2313 bs
->inherits_from
= parent
;
2314 child_role
->inherit_options(&flags
, options
,
2315 parent
->open_flags
, parent
->options
);
2318 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2324 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2325 * Caution: getting a boolean member of @options requires care.
2326 * When @options come from -blockdev or blockdev_add, members are
2327 * typed according to the QAPI schema, but when they come from
2328 * -drive, they're all QString.
2330 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2331 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2332 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2334 flags
&= ~BDRV_O_RDWR
;
2337 if (flags
& BDRV_O_SNAPSHOT
) {
2338 snapshot_options
= qdict_new();
2339 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2341 /* Let bdrv_backing_options() override "read-only" */
2342 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2343 bdrv_backing_options(&flags
, options
, flags
, options
);
2346 bs
->open_flags
= flags
;
2347 bs
->options
= options
;
2348 options
= qdict_clone_shallow(options
);
2350 /* Find the right image format driver */
2351 /* See cautionary note on accessing @options above */
2352 drvname
= qdict_get_try_str(options
, "driver");
2354 drv
= bdrv_find_format(drvname
);
2356 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2361 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2363 /* See cautionary note on accessing @options above */
2364 backing
= qdict_get_try_str(options
, "backing");
2365 if (backing
&& *backing
== '\0') {
2366 flags
|= BDRV_O_NO_BACKING
;
2367 qdict_del(options
, "backing");
2370 /* Open image file without format layer. This BlockBackend is only used for
2371 * probing, the block drivers will do their own bdrv_open_child() for the
2372 * same BDS, which is why we put the node name back into options. */
2373 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2374 BlockDriverState
*file_bs
;
2376 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2377 &child_file
, true, &local_err
);
2381 if (file_bs
!= NULL
) {
2382 file
= blk_new(BLK_PERM_CONSISTENT_READ
, BLK_PERM_ALL
);
2383 blk_insert_bs(file
, file_bs
, &local_err
);
2384 bdrv_unref(file_bs
);
2389 qdict_put(options
, "file",
2390 qstring_from_str(bdrv_get_node_name(file_bs
)));
2394 /* Image format probing */
2397 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2402 * This option update would logically belong in bdrv_fill_options(),
2403 * but we first need to open bs->file for the probing to work, while
2404 * opening bs->file already requires the (mostly) final set of options
2405 * so that cache mode etc. can be inherited.
2407 * Adding the driver later is somewhat ugly, but it's not an option
2408 * that would ever be inherited, so it's correct. We just need to make
2409 * sure to update both bs->options (which has the full effective
2410 * options for bs) and options (which has file.* already removed).
2412 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
2413 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
2415 error_setg(errp
, "Must specify either driver or file");
2419 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2420 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2421 /* file must be NULL if a protocol BDS is about to be created
2422 * (the inverse results in an error message from bdrv_open_common()) */
2423 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2425 /* Open the image */
2426 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2436 /* If there is a backing file, use it */
2437 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2438 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2440 goto close_and_fail
;
2444 bdrv_refresh_filename(bs
);
2446 /* Check if any unknown options were used */
2447 if (qdict_size(options
) != 0) {
2448 const QDictEntry
*entry
= qdict_first(options
);
2449 if (flags
& BDRV_O_PROTOCOL
) {
2450 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2451 "'%s'", drv
->format_name
, entry
->key
);
2454 "Block format '%s' does not support the option '%s'",
2455 drv
->format_name
, entry
->key
);
2458 goto close_and_fail
;
2461 if (!bdrv_key_required(bs
)) {
2462 bdrv_parent_cb_change_media(bs
, true);
2463 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
2464 && !runstate_check(RUN_STATE_INMIGRATE
)
2465 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
2467 "Guest must be stopped for opening of encrypted image");
2468 goto close_and_fail
;
2473 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2474 * temporary snapshot afterwards. */
2475 if (snapshot_flags
) {
2476 BlockDriverState
*snapshot_bs
;
2477 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2478 snapshot_options
, &local_err
);
2479 snapshot_options
= NULL
;
2481 goto close_and_fail
;
2483 /* We are not going to return bs but the overlay on top of it
2484 * (snapshot_bs); thus, we have to drop the strong reference to bs
2485 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2486 * though, because the overlay still has a reference to it. */
2495 if (bs
->file
!= NULL
) {
2496 bdrv_unref_child(bs
, bs
->file
);
2498 QDECREF(snapshot_options
);
2499 QDECREF(bs
->explicit_options
);
2500 QDECREF(bs
->options
);
2504 error_propagate(errp
, local_err
);
2509 QDECREF(snapshot_options
);
2511 error_propagate(errp
, local_err
);
2515 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2516 QDict
*options
, int flags
, Error
**errp
)
2518 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2522 typedef struct BlockReopenQueueEntry
{
2524 BDRVReopenState state
;
2525 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
2526 } BlockReopenQueueEntry
;
2529 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2530 * reopen of multiple devices.
2532 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2533 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2534 * be created and initialized. This newly created BlockReopenQueue should be
2535 * passed back in for subsequent calls that are intended to be of the same
2538 * bs is the BlockDriverState to add to the reopen queue.
2540 * options contains the changed options for the associated bs
2541 * (the BlockReopenQueue takes ownership)
2543 * flags contains the open flags for the associated bs
2545 * returns a pointer to bs_queue, which is either the newly allocated
2546 * bs_queue, or the existing bs_queue being used.
2549 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
2550 BlockDriverState
*bs
,
2553 const BdrvChildRole
*role
,
2554 QDict
*parent_options
,
2559 BlockReopenQueueEntry
*bs_entry
;
2561 QDict
*old_options
, *explicit_options
;
2563 if (bs_queue
== NULL
) {
2564 bs_queue
= g_new0(BlockReopenQueue
, 1);
2565 QSIMPLEQ_INIT(bs_queue
);
2569 options
= qdict_new();
2572 /* Check if this BlockDriverState is already in the queue */
2573 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2574 if (bs
== bs_entry
->state
.bs
) {
2580 * Precedence of options:
2581 * 1. Explicitly passed in options (highest)
2582 * 2. Set in flags (only for top level)
2583 * 3. Retained from explicitly set options of bs
2584 * 4. Inherited from parent node
2585 * 5. Retained from effective options of bs
2588 if (!parent_options
) {
2590 * Any setting represented by flags is always updated. If the
2591 * corresponding QDict option is set, it takes precedence. Otherwise
2592 * the flag is translated into a QDict option. The old setting of bs is
2595 update_options_from_flags(options
, flags
);
2598 /* Old explicitly set values (don't overwrite by inherited value) */
2600 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
2602 old_options
= qdict_clone_shallow(bs
->explicit_options
);
2604 bdrv_join_options(bs
, options
, old_options
);
2605 QDECREF(old_options
);
2607 explicit_options
= qdict_clone_shallow(options
);
2609 /* Inherit from parent node */
2610 if (parent_options
) {
2612 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
2615 /* Old values are used for options that aren't set yet */
2616 old_options
= qdict_clone_shallow(bs
->options
);
2617 bdrv_join_options(bs
, options
, old_options
);
2618 QDECREF(old_options
);
2620 /* bdrv_open() masks this flag out */
2621 flags
&= ~BDRV_O_PROTOCOL
;
2623 QLIST_FOREACH(child
, &bs
->children
, next
) {
2624 QDict
*new_child_options
;
2625 char *child_key_dot
;
2627 /* reopen can only change the options of block devices that were
2628 * implicitly created and inherited options. For other (referenced)
2629 * block devices, a syntax like "backing.foo" results in an error. */
2630 if (child
->bs
->inherits_from
!= bs
) {
2634 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2635 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
2636 g_free(child_key_dot
);
2638 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
2639 child
->role
, options
, flags
);
2643 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
2644 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
2646 QDECREF(bs_entry
->state
.options
);
2647 QDECREF(bs_entry
->state
.explicit_options
);
2650 bs_entry
->state
.bs
= bs
;
2651 bs_entry
->state
.options
= options
;
2652 bs_entry
->state
.explicit_options
= explicit_options
;
2653 bs_entry
->state
.flags
= flags
;
2658 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
2659 BlockDriverState
*bs
,
2660 QDict
*options
, int flags
)
2662 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
2667 * Reopen multiple BlockDriverStates atomically & transactionally.
2669 * The queue passed in (bs_queue) must have been built up previous
2670 * via bdrv_reopen_queue().
2672 * Reopens all BDS specified in the queue, with the appropriate
2673 * flags. All devices are prepared for reopen, and failure of any
2674 * device will cause all device changes to be abandonded, and intermediate
2677 * If all devices prepare successfully, then the changes are committed
2681 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
2684 BlockReopenQueueEntry
*bs_entry
, *next
;
2685 Error
*local_err
= NULL
;
2687 assert(bs_queue
!= NULL
);
2689 aio_context_release(ctx
);
2690 bdrv_drain_all_begin();
2691 aio_context_acquire(ctx
);
2693 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2694 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
2695 error_propagate(errp
, local_err
);
2698 bs_entry
->prepared
= true;
2701 /* If we reach this point, we have success and just need to apply the
2704 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2705 bdrv_reopen_commit(&bs_entry
->state
);
2711 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
2712 if (ret
&& bs_entry
->prepared
) {
2713 bdrv_reopen_abort(&bs_entry
->state
);
2715 QDECREF(bs_entry
->state
.explicit_options
);
2717 QDECREF(bs_entry
->state
.options
);
2722 bdrv_drain_all_end();
2728 /* Reopen a single BlockDriverState with the specified flags. */
2729 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
2732 Error
*local_err
= NULL
;
2733 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
2735 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, &local_err
);
2736 if (local_err
!= NULL
) {
2737 error_propagate(errp
, local_err
);
2744 * Prepares a BlockDriverState for reopen. All changes are staged in the
2745 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2746 * the block driver layer .bdrv_reopen_prepare()
2748 * bs is the BlockDriverState to reopen
2749 * flags are the new open flags
2750 * queue is the reopen queue
2752 * Returns 0 on success, non-zero on error. On error errp will be set
2755 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2756 * It is the responsibility of the caller to then call the abort() or
2757 * commit() for any other BDS that have been left in a prepare() state
2760 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2764 Error
*local_err
= NULL
;
2769 assert(reopen_state
!= NULL
);
2770 assert(reopen_state
->bs
->drv
!= NULL
);
2771 drv
= reopen_state
->bs
->drv
;
2773 /* Process generic block layer options */
2774 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2775 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2777 error_propagate(errp
, local_err
);
2782 update_flags_from_options(&reopen_state
->flags
, opts
);
2784 /* node-name and driver must be unchanged. Put them back into the QDict, so
2785 * that they are checked at the end of this function. */
2786 value
= qemu_opt_get(opts
, "node-name");
2788 qdict_put(reopen_state
->options
, "node-name", qstring_from_str(value
));
2791 value
= qemu_opt_get(opts
, "driver");
2793 qdict_put(reopen_state
->options
, "driver", qstring_from_str(value
));
2796 /* if we are to stay read-only, do not allow permission change
2798 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
2799 reopen_state
->flags
& BDRV_O_RDWR
) {
2800 error_setg(errp
, "Node '%s' is read only",
2801 bdrv_get_device_or_node_name(reopen_state
->bs
));
2806 ret
= bdrv_flush(reopen_state
->bs
);
2808 error_setg_errno(errp
, -ret
, "Error flushing drive");
2812 if (drv
->bdrv_reopen_prepare
) {
2813 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2815 if (local_err
!= NULL
) {
2816 error_propagate(errp
, local_err
);
2818 error_setg(errp
, "failed while preparing to reopen image '%s'",
2819 reopen_state
->bs
->filename
);
2824 /* It is currently mandatory to have a bdrv_reopen_prepare()
2825 * handler for each supported drv. */
2826 error_setg(errp
, "Block format '%s' used by node '%s' "
2827 "does not support reopening files", drv
->format_name
,
2828 bdrv_get_device_or_node_name(reopen_state
->bs
));
2833 /* Options that are not handled are only okay if they are unchanged
2834 * compared to the old state. It is expected that some options are only
2835 * used for the initial open, but not reopen (e.g. filename) */
2836 if (qdict_size(reopen_state
->options
)) {
2837 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2840 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2841 const char *new = qstring_get_str(new_obj
);
2843 * Caution: while qdict_get_try_str() is fine, getting
2844 * non-string types would require more care. When
2845 * bs->options come from -blockdev or blockdev_add, its
2846 * members are typed according to the QAPI schema, but
2847 * when they come from -drive, they're all QString.
2849 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2852 if (!old
|| strcmp(new, old
)) {
2853 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2857 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2863 qemu_opts_del(opts
);
2868 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2869 * makes them final by swapping the staging BlockDriverState contents into
2870 * the active BlockDriverState contents.
2872 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2876 assert(reopen_state
!= NULL
);
2877 drv
= reopen_state
->bs
->drv
;
2878 assert(drv
!= NULL
);
2880 /* If there are any driver level actions to take */
2881 if (drv
->bdrv_reopen_commit
) {
2882 drv
->bdrv_reopen_commit(reopen_state
);
2885 /* set BDS specific flags now */
2886 QDECREF(reopen_state
->bs
->explicit_options
);
2888 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2889 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2890 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2892 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2896 * Abort the reopen, and delete and free the staged changes in
2899 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2903 assert(reopen_state
!= NULL
);
2904 drv
= reopen_state
->bs
->drv
;
2905 assert(drv
!= NULL
);
2907 if (drv
->bdrv_reopen_abort
) {
2908 drv
->bdrv_reopen_abort(reopen_state
);
2911 QDECREF(reopen_state
->explicit_options
);
2915 static void bdrv_close(BlockDriverState
*bs
)
2917 BdrvAioNotifier
*ban
, *ban_next
;
2920 assert(!bs
->refcnt
);
2922 bdrv_drained_begin(bs
); /* complete I/O */
2924 bdrv_drain(bs
); /* in case flush left pending I/O */
2926 bdrv_release_named_dirty_bitmaps(bs
);
2927 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2930 BdrvChild
*child
, *next
;
2932 bs
->drv
->bdrv_close(bs
);
2935 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
2937 if (bs
->file
!= NULL
) {
2938 bdrv_unref_child(bs
, bs
->file
);
2942 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2943 /* TODO Remove bdrv_unref() from drivers' close function and use
2944 * bdrv_unref_child() here */
2945 if (child
->bs
->inherits_from
== bs
) {
2946 child
->bs
->inherits_from
= NULL
;
2948 bdrv_detach_child(child
);
2953 bs
->copy_on_read
= 0;
2954 bs
->backing_file
[0] = '\0';
2955 bs
->backing_format
[0] = '\0';
2956 bs
->total_sectors
= 0;
2957 bs
->encrypted
= false;
2958 bs
->valid_key
= false;
2960 QDECREF(bs
->options
);
2961 QDECREF(bs
->explicit_options
);
2963 QDECREF(bs
->full_open_options
);
2964 bs
->full_open_options
= NULL
;
2967 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2970 QLIST_INIT(&bs
->aio_notifiers
);
2971 bdrv_drained_end(bs
);
2974 void bdrv_close_all(void)
2976 block_job_cancel_sync_all();
2977 nbd_export_close_all();
2979 /* Drop references from requests still in flight, such as canceled block
2980 * jobs whose AIO context has not been polled yet */
2983 blk_remove_all_bs();
2984 blockdev_close_all_bdrv_states();
2986 assert(QTAILQ_EMPTY(&all_bdrv_states
));
2989 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
2993 if (c
->role
->stay_at_node
) {
2997 if (c
->role
== &child_backing
) {
2998 /* If @from is a backing file of @to, ignore the child to avoid
2999 * creating a loop. We only want to change the pointer of other
3001 QLIST_FOREACH(to_c
, &to
->children
, next
) {
3014 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
3017 BdrvChild
*c
, *next
;
3018 GSList
*list
= NULL
, *p
;
3019 uint64_t old_perm
, old_shared
;
3020 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
3023 assert(!atomic_read(&from
->in_flight
));
3024 assert(!atomic_read(&to
->in_flight
));
3026 /* Make sure that @from doesn't go away until we have successfully attached
3027 * all of its parents to @to. */
3030 /* Put all parents into @list and calculate their cumulative permissions */
3031 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
3032 if (!should_update_child(c
, to
)) {
3035 list
= g_slist_prepend(list
, c
);
3037 shared
&= c
->shared_perm
;
3040 /* Check whether the required permissions can be granted on @to, ignoring
3041 * all BdrvChild in @list so that they can't block themselves. */
3042 ret
= bdrv_check_update_perm(to
, perm
, shared
, list
, errp
);
3044 bdrv_abort_perm_update(to
);
3048 /* Now actually perform the change. We performed the permission check for
3049 * all elements of @list at once, so set the permissions all at once at the
3051 for (p
= list
; p
!= NULL
; p
= p
->next
) {
3055 bdrv_replace_child_noperm(c
, to
);
3059 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3060 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3068 * Add new bs contents at the top of an image chain while the chain is
3069 * live, while keeping required fields on the top layer.
3071 * This will modify the BlockDriverState fields, and swap contents
3072 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3074 * bs_new must not be attached to a BlockBackend.
3076 * This function does not create any image files.
3078 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3079 * that's what the callers commonly need. bs_new will be referenced by the old
3080 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3081 * reference of its own, it must call bdrv_ref().
3083 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3086 Error
*local_err
= NULL
;
3088 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3090 error_propagate(errp
, local_err
);
3094 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3096 error_propagate(errp
, local_err
);
3097 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3101 /* bs_new is now referenced by its new parents, we don't need the
3102 * additional reference any more. */
3107 static void bdrv_delete(BlockDriverState
*bs
)
3110 assert(bdrv_op_blocker_is_empty(bs
));
3111 assert(!bs
->refcnt
);
3115 /* remove from list, if necessary */
3116 if (bs
->node_name
[0] != '\0') {
3117 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3119 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3125 * Run consistency checks on an image
3127 * Returns 0 if the check could be completed (it doesn't mean that the image is
3128 * free of errors) or -errno when an internal error occurred. The results of the
3129 * check are stored in res.
3131 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
3133 if (bs
->drv
== NULL
) {
3136 if (bs
->drv
->bdrv_check
== NULL
) {
3140 memset(res
, 0, sizeof(*res
));
3141 return bs
->drv
->bdrv_check(bs
, res
, fix
);
3147 * -EINVAL - backing format specified, but no file
3148 * -ENOSPC - can't update the backing file because no space is left in the
3150 * -ENOTSUP - format driver doesn't support changing the backing file
3152 int bdrv_change_backing_file(BlockDriverState
*bs
,
3153 const char *backing_file
, const char *backing_fmt
)
3155 BlockDriver
*drv
= bs
->drv
;
3158 /* Backing file format doesn't make sense without a backing file */
3159 if (backing_fmt
&& !backing_file
) {
3163 if (drv
->bdrv_change_backing_file
!= NULL
) {
3164 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3170 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3171 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3177 * Finds the image layer in the chain that has 'bs' as its backing file.
3179 * active is the current topmost image.
3181 * Returns NULL if bs is not found in active's image chain,
3182 * or if active == bs.
3184 * Returns the bottommost base image if bs == NULL.
3186 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3187 BlockDriverState
*bs
)
3189 while (active
&& bs
!= backing_bs(active
)) {
3190 active
= backing_bs(active
);
3196 /* Given a BDS, searches for the base layer. */
3197 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3199 return bdrv_find_overlay(bs
, NULL
);
3203 * Drops images above 'base' up to and including 'top', and sets the image
3204 * above 'top' to have base as its backing file.
3206 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3207 * information in 'bs' can be properly updated.
3209 * E.g., this will convert the following chain:
3210 * bottom <- base <- intermediate <- top <- active
3214 * bottom <- base <- active
3216 * It is allowed for bottom==base, in which case it converts:
3218 * base <- intermediate <- top <- active
3224 * If backing_file_str is non-NULL, it will be used when modifying top's
3225 * overlay image metadata.
3228 * if active == top, that is considered an error
3231 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
3232 BlockDriverState
*base
, const char *backing_file_str
)
3234 BlockDriverState
*new_top_bs
= NULL
;
3235 Error
*local_err
= NULL
;
3238 if (!top
->drv
|| !base
->drv
) {
3242 new_top_bs
= bdrv_find_overlay(active
, top
);
3244 if (new_top_bs
== NULL
) {
3245 /* we could not find the image above 'top', this is an error */
3249 /* special case of new_top_bs->backing->bs already pointing to base - nothing
3250 * to do, no intermediate images */
3251 if (backing_bs(new_top_bs
) == base
) {
3256 /* Make sure that base is in the backing chain of top */
3257 if (!bdrv_chain_contains(top
, base
)) {
3261 /* success - we can delete the intermediate states, and link top->base */
3262 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
3263 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
3264 base
->drv
? base
->drv
->format_name
: "");
3269 bdrv_set_backing_hd(new_top_bs
, base
, &local_err
);
3272 error_report_err(local_err
);
3282 * Truncate file to 'offset' bytes (needed only for file protocols)
3284 int bdrv_truncate(BdrvChild
*child
, int64_t offset
)
3286 BlockDriverState
*bs
= child
->bs
;
3287 BlockDriver
*drv
= bs
->drv
;
3290 /* FIXME: Some format block drivers use this function instead of implicitly
3291 * growing their file by writing beyond its end.
3292 * See bdrv_aligned_pwritev() for an explanation why we currently
3293 * cannot assert this permission in that case. */
3294 // assert(child->perm & BLK_PERM_RESIZE);
3298 if (!drv
->bdrv_truncate
)
3303 ret
= drv
->bdrv_truncate(bs
, offset
);
3305 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
3306 bdrv_dirty_bitmap_truncate(bs
);
3307 bdrv_parent_cb_resize(bs
);
3314 * Length of a allocated file in bytes. Sparse files are counted by actual
3315 * allocated space. Return < 0 if error or unknown.
3317 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
3319 BlockDriver
*drv
= bs
->drv
;
3323 if (drv
->bdrv_get_allocated_file_size
) {
3324 return drv
->bdrv_get_allocated_file_size(bs
);
3327 return bdrv_get_allocated_file_size(bs
->file
->bs
);
3333 * Return number of sectors on success, -errno on error.
3335 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
3337 BlockDriver
*drv
= bs
->drv
;
3342 if (drv
->has_variable_length
) {
3343 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3348 return bs
->total_sectors
;
3352 * Return length in bytes on success, -errno on error.
3353 * The length is always a multiple of BDRV_SECTOR_SIZE.
3355 int64_t bdrv_getlength(BlockDriverState
*bs
)
3357 int64_t ret
= bdrv_nb_sectors(bs
);
3359 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
3360 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
3363 /* return 0 as number of sectors if no device present or error */
3364 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
3366 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
3368 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
3371 bool bdrv_is_read_only(BlockDriverState
*bs
)
3373 return bs
->read_only
;
3376 bool bdrv_is_sg(BlockDriverState
*bs
)
3381 bool bdrv_is_encrypted(BlockDriverState
*bs
)
3383 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3386 return bs
->encrypted
;
3389 bool bdrv_key_required(BlockDriverState
*bs
)
3391 BdrvChild
*backing
= bs
->backing
;
3393 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
3396 return (bs
->encrypted
&& !bs
->valid_key
);
3399 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
3402 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3403 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
3409 if (!bs
->encrypted
) {
3411 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
3414 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
3416 bs
->valid_key
= false;
3417 } else if (!bs
->valid_key
) {
3418 /* call the change callback now, we skipped it on open */
3419 bs
->valid_key
= true;
3420 bdrv_parent_cb_change_media(bs
, true);
3426 * Provide an encryption key for @bs.
3427 * If @key is non-null:
3428 * If @bs is not encrypted, fail.
3429 * Else if the key is invalid, fail.
3430 * Else set @bs's key to @key, replacing the existing key, if any.
3432 * If @bs is encrypted and still lacks a key, fail.
3434 * On failure, store an error object through @errp if non-null.
3436 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
3439 if (!bdrv_is_encrypted(bs
)) {
3440 error_setg(errp
, "Node '%s' is not encrypted",
3441 bdrv_get_device_or_node_name(bs
));
3442 } else if (bdrv_set_key(bs
, key
) < 0) {
3443 error_setg(errp
, QERR_INVALID_PASSWORD
);
3446 if (bdrv_key_required(bs
)) {
3447 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
3448 "'%s' (%s) is encrypted",
3449 bdrv_get_device_or_node_name(bs
),
3450 bdrv_get_encrypted_filename(bs
));
3455 const char *bdrv_get_format_name(BlockDriverState
*bs
)
3457 return bs
->drv
? bs
->drv
->format_name
: NULL
;
3460 static int qsort_strcmp(const void *a
, const void *b
)
3462 return strcmp(*(char *const *)a
, *(char *const *)b
);
3465 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
3471 const char **formats
= NULL
;
3473 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
3474 if (drv
->format_name
) {
3477 while (formats
&& i
&& !found
) {
3478 found
= !strcmp(formats
[--i
], drv
->format_name
);
3482 formats
= g_renew(const char *, formats
, count
+ 1);
3483 formats
[count
++] = drv
->format_name
;
3488 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
3489 const char *format_name
= block_driver_modules
[i
].format_name
;
3495 while (formats
&& j
&& !found
) {
3496 found
= !strcmp(formats
[--j
], format_name
);
3500 formats
= g_renew(const char *, formats
, count
+ 1);
3501 formats
[count
++] = format_name
;
3506 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
3508 for (i
= 0; i
< count
; i
++) {
3509 it(opaque
, formats
[i
]);
3515 /* This function is to find a node in the bs graph */
3516 BlockDriverState
*bdrv_find_node(const char *node_name
)
3518 BlockDriverState
*bs
;
3522 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3523 if (!strcmp(node_name
, bs
->node_name
)) {
3530 /* Put this QMP function here so it can access the static graph_bdrv_states. */
3531 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
3533 BlockDeviceInfoList
*list
, *entry
;
3534 BlockDriverState
*bs
;
3537 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3538 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
3540 qapi_free_BlockDeviceInfoList(list
);
3543 entry
= g_malloc0(sizeof(*entry
));
3544 entry
->value
= info
;
3552 BlockDriverState
*bdrv_lookup_bs(const char *device
,
3553 const char *node_name
,
3557 BlockDriverState
*bs
;
3560 blk
= blk_by_name(device
);
3565 error_setg(errp
, "Device '%s' has no medium", device
);
3573 bs
= bdrv_find_node(node_name
);
3580 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
3581 device
? device
: "",
3582 node_name
? node_name
: "");
3586 /* If 'base' is in the same chain as 'top', return true. Otherwise,
3587 * return false. If either argument is NULL, return false. */
3588 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
3590 while (top
&& top
!= base
) {
3591 top
= backing_bs(top
);
3597 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
3600 return QTAILQ_FIRST(&graph_bdrv_states
);
3602 return QTAILQ_NEXT(bs
, node_list
);
3605 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
3607 return bs
->node_name
;
3610 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
3615 /* If multiple parents have a name, just pick the first one. */
3616 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3617 if (c
->role
->get_name
) {
3618 name
= c
->role
->get_name(c
);
3619 if (name
&& *name
) {
3628 /* TODO check what callers really want: bs->node_name or blk_name() */
3629 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
3631 return bdrv_get_parent_name(bs
) ?: "";
3634 /* This can be used to identify nodes that might not have a device
3635 * name associated. Since node and device names live in the same
3636 * namespace, the result is unambiguous. The exception is if both are
3637 * absent, then this returns an empty (non-null) string. */
3638 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
3640 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
3643 int bdrv_get_flags(BlockDriverState
*bs
)
3645 return bs
->open_flags
;
3648 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
3653 int bdrv_has_zero_init(BlockDriverState
*bs
)
3657 /* If BS is a copy on write image, it is initialized to
3658 the contents of the base image, which may not be zeroes. */
3662 if (bs
->drv
->bdrv_has_zero_init
) {
3663 return bs
->drv
->bdrv_has_zero_init(bs
);
3670 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
3672 BlockDriverInfo bdi
;
3678 if (bdrv_get_info(bs
, &bdi
) == 0) {
3679 return bdi
.unallocated_blocks_are_zero
;
3685 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
3687 BlockDriverInfo bdi
;
3689 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
3693 if (bdrv_get_info(bs
, &bdi
) == 0) {
3694 return bdi
.can_write_zeroes_with_unmap
;
3700 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
3702 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
3703 return bs
->backing_file
;
3704 else if (bs
->encrypted
)
3705 return bs
->filename
;
3710 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3711 char *filename
, int filename_size
)
3713 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3716 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3718 BlockDriver
*drv
= bs
->drv
;
3721 if (!drv
->bdrv_get_info
)
3723 memset(bdi
, 0, sizeof(*bdi
));
3724 return drv
->bdrv_get_info(bs
, bdi
);
3727 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3729 BlockDriver
*drv
= bs
->drv
;
3730 if (drv
&& drv
->bdrv_get_specific_info
) {
3731 return drv
->bdrv_get_specific_info(bs
);
3736 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3738 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3742 bs
->drv
->bdrv_debug_event(bs
, event
);
3745 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3748 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3749 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3752 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3753 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3759 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3761 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3762 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3765 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3766 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3772 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3774 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3775 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3778 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3779 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3785 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3787 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3788 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3791 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3792 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3798 /* backing_file can either be relative, or absolute, or a protocol. If it is
3799 * relative, it must be relative to the chain. So, passing in bs->filename
3800 * from a BDS as backing_file should not be done, as that may be relative to
3801 * the CWD rather than the chain. */
3802 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3803 const char *backing_file
)
3805 char *filename_full
= NULL
;
3806 char *backing_file_full
= NULL
;
3807 char *filename_tmp
= NULL
;
3808 int is_protocol
= 0;
3809 BlockDriverState
*curr_bs
= NULL
;
3810 BlockDriverState
*retval
= NULL
;
3811 Error
*local_error
= NULL
;
3813 if (!bs
|| !bs
->drv
|| !backing_file
) {
3817 filename_full
= g_malloc(PATH_MAX
);
3818 backing_file_full
= g_malloc(PATH_MAX
);
3819 filename_tmp
= g_malloc(PATH_MAX
);
3821 is_protocol
= path_has_protocol(backing_file
);
3823 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3825 /* If either of the filename paths is actually a protocol, then
3826 * compare unmodified paths; otherwise make paths relative */
3827 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3828 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3829 retval
= curr_bs
->backing
->bs
;
3832 /* Also check against the full backing filename for the image */
3833 bdrv_get_full_backing_filename(curr_bs
, backing_file_full
, PATH_MAX
,
3835 if (local_error
== NULL
) {
3836 if (strcmp(backing_file
, backing_file_full
) == 0) {
3837 retval
= curr_bs
->backing
->bs
;
3841 error_free(local_error
);
3845 /* If not an absolute filename path, make it relative to the current
3846 * image's filename path */
3847 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3850 /* We are going to compare absolute pathnames */
3851 if (!realpath(filename_tmp
, filename_full
)) {
3855 /* We need to make sure the backing filename we are comparing against
3856 * is relative to the current image filename (or absolute) */
3857 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3858 curr_bs
->backing_file
);
3860 if (!realpath(filename_tmp
, backing_file_full
)) {
3864 if (strcmp(backing_file_full
, filename_full
) == 0) {
3865 retval
= curr_bs
->backing
->bs
;
3871 g_free(filename_full
);
3872 g_free(backing_file_full
);
3873 g_free(filename_tmp
);
3877 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3887 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3890 void bdrv_init(void)
3892 module_call_init(MODULE_INIT_BLOCK
);
3895 void bdrv_init_with_whitelist(void)
3897 use_bdrv_whitelist
= 1;
3901 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3904 Error
*local_err
= NULL
;
3911 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3915 QLIST_FOREACH(child
, &bs
->children
, next
) {
3916 bdrv_invalidate_cache(child
->bs
, &local_err
);
3918 error_propagate(errp
, local_err
);
3923 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3924 if (bs
->drv
->bdrv_invalidate_cache
) {
3925 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3927 bs
->open_flags
|= BDRV_O_INACTIVE
;
3928 error_propagate(errp
, local_err
);
3933 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3935 bs
->open_flags
|= BDRV_O_INACTIVE
;
3936 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3941 void bdrv_invalidate_cache_all(Error
**errp
)
3943 BlockDriverState
*bs
;
3944 Error
*local_err
= NULL
;
3945 BdrvNextIterator it
;
3947 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3948 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3950 aio_context_acquire(aio_context
);
3951 bdrv_invalidate_cache(bs
, &local_err
);
3952 aio_context_release(aio_context
);
3954 error_propagate(errp
, local_err
);
3960 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3966 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3967 ret
= bs
->drv
->bdrv_inactivate(bs
);
3973 QLIST_FOREACH(child
, &bs
->children
, next
) {
3974 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
3981 bs
->open_flags
|= BDRV_O_INACTIVE
;
3986 int bdrv_inactivate_all(void)
3988 BlockDriverState
*bs
= NULL
;
3989 BdrvNextIterator it
;
3993 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3994 aio_context_acquire(bdrv_get_aio_context(bs
));
3997 /* We do two passes of inactivation. The first pass calls to drivers'
3998 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
3999 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
4001 for (pass
= 0; pass
< 2; pass
++) {
4002 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4003 ret
= bdrv_inactivate_recurse(bs
, pass
);
4011 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4012 aio_context_release(bdrv_get_aio_context(bs
));
4018 /**************************************************************/
4019 /* removable device support */
4022 * Return TRUE if the media is present
4024 bool bdrv_is_inserted(BlockDriverState
*bs
)
4026 BlockDriver
*drv
= bs
->drv
;
4032 if (drv
->bdrv_is_inserted
) {
4033 return drv
->bdrv_is_inserted(bs
);
4035 QLIST_FOREACH(child
, &bs
->children
, next
) {
4036 if (!bdrv_is_inserted(child
->bs
)) {
4044 * Return whether the media changed since the last call to this
4045 * function, or -ENOTSUP if we don't know. Most drivers don't know.
4047 int bdrv_media_changed(BlockDriverState
*bs
)
4049 BlockDriver
*drv
= bs
->drv
;
4051 if (drv
&& drv
->bdrv_media_changed
) {
4052 return drv
->bdrv_media_changed(bs
);
4058 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4060 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
4062 BlockDriver
*drv
= bs
->drv
;
4064 if (drv
&& drv
->bdrv_eject
) {
4065 drv
->bdrv_eject(bs
, eject_flag
);
4070 * Lock or unlock the media (if it is locked, the user won't be able
4071 * to eject it manually).
4073 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
4075 BlockDriver
*drv
= bs
->drv
;
4077 trace_bdrv_lock_medium(bs
, locked
);
4079 if (drv
&& drv
->bdrv_lock_medium
) {
4080 drv
->bdrv_lock_medium(bs
, locked
);
4084 /* Get a reference to bs */
4085 void bdrv_ref(BlockDriverState
*bs
)
4090 /* Release a previously grabbed reference to bs.
4091 * If after releasing, reference count is zero, the BlockDriverState is
4093 void bdrv_unref(BlockDriverState
*bs
)
4098 assert(bs
->refcnt
> 0);
4099 if (--bs
->refcnt
== 0) {
4104 struct BdrvOpBlocker
{
4106 QLIST_ENTRY(BdrvOpBlocker
) list
;
4109 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
4111 BdrvOpBlocker
*blocker
;
4112 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4113 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
4114 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
4116 *errp
= error_copy(blocker
->reason
);
4117 error_prepend(errp
, "Node '%s' is busy: ",
4118 bdrv_get_device_or_node_name(bs
));
4125 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4127 BdrvOpBlocker
*blocker
;
4128 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4130 blocker
= g_new0(BdrvOpBlocker
, 1);
4131 blocker
->reason
= reason
;
4132 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
4135 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4137 BdrvOpBlocker
*blocker
, *next
;
4138 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4139 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
4140 if (blocker
->reason
== reason
) {
4141 QLIST_REMOVE(blocker
, list
);
4147 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
4150 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4151 bdrv_op_block(bs
, i
, reason
);
4155 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
4158 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4159 bdrv_op_unblock(bs
, i
, reason
);
4163 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
4167 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4168 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
4175 void bdrv_img_create(const char *filename
, const char *fmt
,
4176 const char *base_filename
, const char *base_fmt
,
4177 char *options
, uint64_t img_size
, int flags
, bool quiet
,
4180 QemuOptsList
*create_opts
= NULL
;
4181 QemuOpts
*opts
= NULL
;
4182 const char *backing_fmt
, *backing_file
;
4184 BlockDriver
*drv
, *proto_drv
;
4185 Error
*local_err
= NULL
;
4188 /* Find driver and parse its options */
4189 drv
= bdrv_find_format(fmt
);
4191 error_setg(errp
, "Unknown file format '%s'", fmt
);
4195 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
4200 if (!drv
->create_opts
) {
4201 error_setg(errp
, "Format driver '%s' does not support image creation",
4206 if (!proto_drv
->create_opts
) {
4207 error_setg(errp
, "Protocol driver '%s' does not support image creation",
4208 proto_drv
->format_name
);
4212 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
4213 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
4215 /* Create parameter list with default values */
4216 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
4217 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
4219 /* Parse -o options */
4221 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
4223 error_report_err(local_err
);
4225 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
4230 if (base_filename
) {
4231 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
4233 error_setg(errp
, "Backing file not supported for file format '%s'",
4240 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
4242 error_setg(errp
, "Backing file format not supported for file "
4243 "format '%s'", fmt
);
4248 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4250 if (!strcmp(filename
, backing_file
)) {
4251 error_setg(errp
, "Error: Trying to create an image with the "
4252 "same filename as the backing file");
4257 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4259 // The size for the image must always be specified, with one exception:
4260 // If we are using a backing file, we can obtain the size from there
4261 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4264 BlockDriverState
*bs
;
4265 char *full_backing
= g_new0(char, PATH_MAX
);
4268 QDict
*backing_options
= NULL
;
4270 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
4271 full_backing
, PATH_MAX
,
4274 g_free(full_backing
);
4278 /* backing files always opened read-only */
4280 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
4283 backing_options
= qdict_new();
4284 qdict_put(backing_options
, "driver",
4285 qstring_from_str(backing_fmt
));
4288 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
4290 g_free(full_backing
);
4294 size
= bdrv_getlength(bs
);
4296 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
4302 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
4306 error_setg(errp
, "Image creation needs a size parameter");
4312 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
4313 qemu_opts_print(opts
, " ");
4317 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
4319 if (ret
== -EFBIG
) {
4320 /* This is generally a better message than whatever the driver would
4321 * deliver (especially because of the cluster_size_hint), since that
4322 * is most probably not much different from "image too large". */
4323 const char *cluster_size_hint
= "";
4324 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
4325 cluster_size_hint
= " (try using a larger cluster size)";
4327 error_setg(errp
, "The image size is too large for file format '%s'"
4328 "%s", fmt
, cluster_size_hint
);
4329 error_free(local_err
);
4334 qemu_opts_del(opts
);
4335 qemu_opts_free(create_opts
);
4336 error_propagate(errp
, local_err
);
4339 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
4341 return bs
->aio_context
;
4344 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
4346 aio_co_enter(bdrv_get_aio_context(bs
), co
);
4349 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
4351 QLIST_REMOVE(ban
, list
);
4355 void bdrv_detach_aio_context(BlockDriverState
*bs
)
4357 BdrvAioNotifier
*baf
, *baf_tmp
;
4364 assert(!bs
->walking_aio_notifiers
);
4365 bs
->walking_aio_notifiers
= true;
4366 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
4368 bdrv_do_remove_aio_context_notifier(baf
);
4370 baf
->detach_aio_context(baf
->opaque
);
4373 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4374 * remove remaining aio notifiers if we aren't called again.
4376 bs
->walking_aio_notifiers
= false;
4378 if (bs
->drv
->bdrv_detach_aio_context
) {
4379 bs
->drv
->bdrv_detach_aio_context(bs
);
4381 QLIST_FOREACH(child
, &bs
->children
, next
) {
4382 bdrv_detach_aio_context(child
->bs
);
4385 bs
->aio_context
= NULL
;
4388 void bdrv_attach_aio_context(BlockDriverState
*bs
,
4389 AioContext
*new_context
)
4391 BdrvAioNotifier
*ban
, *ban_tmp
;
4398 bs
->aio_context
= new_context
;
4400 QLIST_FOREACH(child
, &bs
->children
, next
) {
4401 bdrv_attach_aio_context(child
->bs
, new_context
);
4403 if (bs
->drv
->bdrv_attach_aio_context
) {
4404 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
4407 assert(!bs
->walking_aio_notifiers
);
4408 bs
->walking_aio_notifiers
= true;
4409 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
4411 bdrv_do_remove_aio_context_notifier(ban
);
4413 ban
->attached_aio_context(new_context
, ban
->opaque
);
4416 bs
->walking_aio_notifiers
= false;
4419 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
4421 AioContext
*ctx
= bdrv_get_aio_context(bs
);
4423 aio_disable_external(ctx
);
4424 bdrv_parent_drained_begin(bs
);
4425 bdrv_drain(bs
); /* ensure there are no in-flight requests */
4427 while (aio_poll(ctx
, false)) {
4428 /* wait for all bottom halves to execute */
4431 bdrv_detach_aio_context(bs
);
4433 /* This function executes in the old AioContext so acquire the new one in
4434 * case it runs in a different thread.
4436 aio_context_acquire(new_context
);
4437 bdrv_attach_aio_context(bs
, new_context
);
4438 bdrv_parent_drained_end(bs
);
4439 aio_enable_external(ctx
);
4440 aio_context_release(new_context
);
4443 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
4444 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
4445 void (*detach_aio_context
)(void *opaque
), void *opaque
)
4447 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
4448 *ban
= (BdrvAioNotifier
){
4449 .attached_aio_context
= attached_aio_context
,
4450 .detach_aio_context
= detach_aio_context
,
4454 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
4457 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
4458 void (*attached_aio_context
)(AioContext
*,
4460 void (*detach_aio_context
)(void *),
4463 BdrvAioNotifier
*ban
, *ban_next
;
4465 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
4466 if (ban
->attached_aio_context
== attached_aio_context
&&
4467 ban
->detach_aio_context
== detach_aio_context
&&
4468 ban
->opaque
== opaque
&&
4469 ban
->deleted
== false)
4471 if (bs
->walking_aio_notifiers
) {
4472 ban
->deleted
= true;
4474 bdrv_do_remove_aio_context_notifier(ban
);
4483 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4484 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
4486 if (!bs
->drv
->bdrv_amend_options
) {
4489 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
4492 /* This function will be called by the bdrv_recurse_is_first_non_filter method
4493 * of block filter and by bdrv_is_first_non_filter.
4494 * It is used to test if the given bs is the candidate or recurse more in the
4497 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
4498 BlockDriverState
*candidate
)
4500 /* return false if basic checks fails */
4501 if (!bs
|| !bs
->drv
) {
4505 /* the code reached a non block filter driver -> check if the bs is
4506 * the same as the candidate. It's the recursion termination condition.
4508 if (!bs
->drv
->is_filter
) {
4509 return bs
== candidate
;
4511 /* Down this path the driver is a block filter driver */
4513 /* If the block filter recursion method is defined use it to recurse down
4516 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
4517 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
4520 /* the driver is a block filter but don't allow to recurse -> return false
4525 /* This function checks if the candidate is the first non filter bs down it's
4526 * bs chain. Since we don't have pointers to parents it explore all bs chains
4527 * from the top. Some filters can choose not to pass down the recursion.
4529 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
4531 BlockDriverState
*bs
;
4532 BdrvNextIterator it
;
4534 /* walk down the bs forest recursively */
4535 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4538 /* try to recurse in this top level bs */
4539 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
4541 /* candidate is the first non filter */
4550 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
4551 const char *node_name
, Error
**errp
)
4553 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
4554 AioContext
*aio_context
;
4556 if (!to_replace_bs
) {
4557 error_setg(errp
, "Node name '%s' not found", node_name
);
4561 aio_context
= bdrv_get_aio_context(to_replace_bs
);
4562 aio_context_acquire(aio_context
);
4564 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
4565 to_replace_bs
= NULL
;
4569 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4570 * most non filter in order to prevent data corruption.
4571 * Another benefit is that this tests exclude backing files which are
4572 * blocked by the backing blockers.
4574 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
4575 error_setg(errp
, "Only top most non filter can be replaced");
4576 to_replace_bs
= NULL
;
4581 aio_context_release(aio_context
);
4582 return to_replace_bs
;
4585 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
4587 const QDictEntry
*entry
;
4590 bool found_any
= false;
4593 for (entry
= qdict_first(bs
->options
); entry
;
4594 entry
= qdict_next(bs
->options
, entry
))
4596 /* Exclude options for children */
4597 QLIST_FOREACH(child
, &bs
->children
, next
) {
4598 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
4599 && (!*p
|| *p
== '.'))
4608 /* And exclude all non-driver-specific options */
4609 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
4610 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
4618 qobject_incref(qdict_entry_value(entry
));
4619 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
4626 /* Updates the following BDS fields:
4627 * - exact_filename: A filename which may be used for opening a block device
4628 * which (mostly) equals the given BDS (even without any
4629 * other options; so reading and writing must return the same
4630 * results, but caching etc. may be different)
4631 * - full_open_options: Options which, when given when opening a block device
4632 * (without a filename), result in a BDS (mostly)
4633 * equalling the given one
4634 * - filename: If exact_filename is set, it is copied here. Otherwise,
4635 * full_open_options is converted to a JSON object, prefixed with
4636 * "json:" (for use through the JSON pseudo protocol) and put here.
4638 void bdrv_refresh_filename(BlockDriverState
*bs
)
4640 BlockDriver
*drv
= bs
->drv
;
4647 /* This BDS's file name will most probably depend on its file's name, so
4648 * refresh that first */
4650 bdrv_refresh_filename(bs
->file
->bs
);
4653 if (drv
->bdrv_refresh_filename
) {
4654 /* Obsolete information is of no use here, so drop the old file name
4655 * information before refreshing it */
4656 bs
->exact_filename
[0] = '\0';
4657 if (bs
->full_open_options
) {
4658 QDECREF(bs
->full_open_options
);
4659 bs
->full_open_options
= NULL
;
4663 append_open_options(opts
, bs
);
4664 drv
->bdrv_refresh_filename(bs
, opts
);
4666 } else if (bs
->file
) {
4667 /* Try to reconstruct valid information from the underlying file */
4668 bool has_open_options
;
4670 bs
->exact_filename
[0] = '\0';
4671 if (bs
->full_open_options
) {
4672 QDECREF(bs
->full_open_options
);
4673 bs
->full_open_options
= NULL
;
4677 has_open_options
= append_open_options(opts
, bs
);
4679 /* If no specific options have been given for this BDS, the filename of
4680 * the underlying file should suffice for this one as well */
4681 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
4682 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
4684 /* Reconstructing the full options QDict is simple for most format block
4685 * drivers, as long as the full options are known for the underlying
4686 * file BDS. The full options QDict of that file BDS should somehow
4687 * contain a representation of the filename, therefore the following
4688 * suffices without querying the (exact_)filename of this BDS. */
4689 if (bs
->file
->bs
->full_open_options
) {
4690 qdict_put_obj(opts
, "driver",
4691 QOBJECT(qstring_from_str(drv
->format_name
)));
4692 QINCREF(bs
->file
->bs
->full_open_options
);
4693 qdict_put_obj(opts
, "file",
4694 QOBJECT(bs
->file
->bs
->full_open_options
));
4696 bs
->full_open_options
= opts
;
4700 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
4701 /* There is no underlying file BDS (at least referenced by BDS.file),
4702 * so the full options QDict should be equal to the options given
4703 * specifically for this block device when it was opened (plus the
4704 * driver specification).
4705 * Because those options don't change, there is no need to update
4706 * full_open_options when it's already set. */
4709 append_open_options(opts
, bs
);
4710 qdict_put_obj(opts
, "driver",
4711 QOBJECT(qstring_from_str(drv
->format_name
)));
4713 if (bs
->exact_filename
[0]) {
4714 /* This may not work for all block protocol drivers (some may
4715 * require this filename to be parsed), but we have to find some
4716 * default solution here, so just include it. If some block driver
4717 * does not support pure options without any filename at all or
4718 * needs some special format of the options QDict, it needs to
4719 * implement the driver-specific bdrv_refresh_filename() function.
4721 qdict_put_obj(opts
, "filename",
4722 QOBJECT(qstring_from_str(bs
->exact_filename
)));
4725 bs
->full_open_options
= opts
;
4728 if (bs
->exact_filename
[0]) {
4729 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4730 } else if (bs
->full_open_options
) {
4731 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4732 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4733 qstring_get_str(json
));
4739 * Hot add/remove a BDS's child. So the user can take a child offline when
4740 * it is broken and take a new child online
4742 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
4746 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
4747 error_setg(errp
, "The node %s does not support adding a child",
4748 bdrv_get_device_or_node_name(parent_bs
));
4752 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4753 error_setg(errp
, "The node %s already has a parent",
4754 child_bs
->node_name
);
4758 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4761 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4765 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4766 error_setg(errp
, "The node %s does not support removing a child",
4767 bdrv_get_device_or_node_name(parent_bs
));
4771 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4778 error_setg(errp
, "The node %s does not have a child named %s",
4779 bdrv_get_device_or_node_name(parent_bs
),
4780 bdrv_get_device_or_node_name(child
->bs
));
4784 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);