2 * QEMU System Emulator block driver
4 * Copyright (c) 2003 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 #include "qemu/osdep.h"
26 #include "block/block_int.h"
27 #include "block/blockjob.h"
28 #include "qemu/error-report.h"
29 #include "qemu/module.h"
30 #include "qapi/qmp/qerror.h"
31 #include "qapi/qmp/qbool.h"
32 #include "qapi/qmp/qjson.h"
33 #include "sysemu/block-backend.h"
34 #include "sysemu/sysemu.h"
35 #include "qemu/notify.h"
36 #include "qemu/coroutine.h"
37 #include "block/qapi.h"
38 #include "qmp-commands.h"
39 #include "qemu/timer.h"
40 #include "qapi-event.h"
41 #include "qemu/cutils.h"
45 #include <sys/ioctl.h>
46 #include <sys/queue.h>
56 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
58 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
59 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
61 static QTAILQ_HEAD(, BlockDriverState
) all_bdrv_states
=
62 QTAILQ_HEAD_INITIALIZER(all_bdrv_states
);
64 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
65 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
67 static int bdrv_open_inherit(BlockDriverState
**pbs
, const char *filename
,
68 const char *reference
, QDict
*options
, int flags
,
69 BlockDriverState
*parent
,
70 const BdrvChildRole
*child_role
, Error
**errp
);
72 /* If non-zero, use only whitelisted block drivers */
73 static int use_bdrv_whitelist
;
75 static void bdrv_close(BlockDriverState
*bs
);
78 static int is_windows_drive_prefix(const char *filename
)
80 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
81 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
85 int is_windows_drive(const char *filename
)
87 if (is_windows_drive_prefix(filename
) &&
90 if (strstart(filename
, "\\\\.\\", NULL
) ||
91 strstart(filename
, "//./", NULL
))
97 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
99 if (!bs
|| !bs
->drv
) {
100 /* page size or 4k (hdd sector size) should be on the safe side */
101 return MAX(4096, getpagesize());
104 return bs
->bl
.opt_mem_alignment
;
107 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
109 if (!bs
|| !bs
->drv
) {
110 /* page size or 4k (hdd sector size) should be on the safe side */
111 return MAX(4096, getpagesize());
114 return bs
->bl
.min_mem_alignment
;
117 /* check if the path starts with "<protocol>:" */
118 int path_has_protocol(const char *path
)
123 if (is_windows_drive(path
) ||
124 is_windows_drive_prefix(path
)) {
127 p
= path
+ strcspn(path
, ":/\\");
129 p
= path
+ strcspn(path
, ":/");
135 int path_is_absolute(const char *path
)
138 /* specific case for names like: "\\.\d:" */
139 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
142 return (*path
== '/' || *path
== '\\');
144 return (*path
== '/');
148 /* if filename is absolute, just copy it to dest. Otherwise, build a
149 path to it by considering it is relative to base_path. URL are
151 void path_combine(char *dest
, int dest_size
,
152 const char *base_path
,
153 const char *filename
)
160 if (path_is_absolute(filename
)) {
161 pstrcpy(dest
, dest_size
, filename
);
163 p
= strchr(base_path
, ':');
168 p1
= strrchr(base_path
, '/');
172 p2
= strrchr(base_path
, '\\');
184 if (len
> dest_size
- 1)
186 memcpy(dest
, base_path
, len
);
188 pstrcat(dest
, dest_size
, filename
);
192 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
194 char *dest
, size_t sz
,
197 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
198 path_is_absolute(backing
))
200 pstrcpy(dest
, sz
, backing
);
201 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
202 error_setg(errp
, "Cannot use relative backing file names for '%s'",
205 path_combine(dest
, sz
, backed
, backing
);
209 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
212 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
214 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
218 void bdrv_register(BlockDriver
*bdrv
)
220 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
223 BlockDriverState
*bdrv_new_root(void)
228 BlockDriverState
*bdrv_new(void)
230 BlockDriverState
*bs
;
233 bs
= g_new0(BlockDriverState
, 1);
234 QLIST_INIT(&bs
->dirty_bitmaps
);
235 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
236 QLIST_INIT(&bs
->op_blockers
[i
]);
238 notifier_with_return_list_init(&bs
->before_write_notifiers
);
240 bs
->aio_context
= qemu_get_aio_context();
242 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
247 BlockDriver
*bdrv_find_format(const char *format_name
)
250 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
251 if (!strcmp(drv1
->format_name
, format_name
)) {
258 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
260 static const char *whitelist_rw
[] = {
261 CONFIG_BDRV_RW_WHITELIST
263 static const char *whitelist_ro
[] = {
264 CONFIG_BDRV_RO_WHITELIST
268 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
269 return 1; /* no whitelist, anything goes */
272 for (p
= whitelist_rw
; *p
; p
++) {
273 if (!strcmp(drv
->format_name
, *p
)) {
278 for (p
= whitelist_ro
; *p
; p
++) {
279 if (!strcmp(drv
->format_name
, *p
)) {
287 bool bdrv_uses_whitelist(void)
289 return use_bdrv_whitelist
;
292 typedef struct CreateCo
{
300 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
302 Error
*local_err
= NULL
;
305 CreateCo
*cco
= opaque
;
308 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
310 error_propagate(&cco
->err
, local_err
);
315 int bdrv_create(BlockDriver
*drv
, const char* filename
,
316 QemuOpts
*opts
, Error
**errp
)
323 .filename
= g_strdup(filename
),
329 if (!drv
->bdrv_create
) {
330 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
335 if (qemu_in_coroutine()) {
336 /* Fast-path if already in coroutine context */
337 bdrv_create_co_entry(&cco
);
339 co
= qemu_coroutine_create(bdrv_create_co_entry
);
340 qemu_coroutine_enter(co
, &cco
);
341 while (cco
.ret
== NOT_DONE
) {
342 aio_poll(qemu_get_aio_context(), true);
349 error_propagate(errp
, cco
.err
);
351 error_setg_errno(errp
, -ret
, "Could not create image");
356 g_free(cco
.filename
);
360 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
363 Error
*local_err
= NULL
;
366 drv
= bdrv_find_protocol(filename
, true, errp
);
371 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
373 error_propagate(errp
, local_err
);
379 * Try to get @bs's logical and physical block size.
380 * On success, store them in @bsz struct and return 0.
381 * On failure return -errno.
382 * @bs must not be empty.
384 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
386 BlockDriver
*drv
= bs
->drv
;
388 if (drv
&& drv
->bdrv_probe_blocksizes
) {
389 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
396 * Try to get @bs's geometry (cyls, heads, sectors).
397 * On success, store them in @geo struct and return 0.
398 * On failure return -errno.
399 * @bs must not be empty.
401 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
403 BlockDriver
*drv
= bs
->drv
;
405 if (drv
&& drv
->bdrv_probe_geometry
) {
406 return drv
->bdrv_probe_geometry(bs
, geo
);
413 * Create a uniquely-named empty temporary file.
414 * Return 0 upon success, otherwise a negative errno value.
416 int get_tmp_filename(char *filename
, int size
)
419 char temp_dir
[MAX_PATH
];
420 /* GetTempFileName requires that its output buffer (4th param)
421 have length MAX_PATH or greater. */
422 assert(size
>= MAX_PATH
);
423 return (GetTempPath(MAX_PATH
, temp_dir
)
424 && GetTempFileName(temp_dir
, "qem", 0, filename
)
425 ? 0 : -GetLastError());
429 tmpdir
= getenv("TMPDIR");
433 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
436 fd
= mkstemp(filename
);
440 if (close(fd
) != 0) {
449 * Detect host devices. By convention, /dev/cdrom[N] is always
450 * recognized as a host CDROM.
452 static BlockDriver
*find_hdev_driver(const char *filename
)
454 int score_max
= 0, score
;
455 BlockDriver
*drv
= NULL
, *d
;
457 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
458 if (d
->bdrv_probe_device
) {
459 score
= d
->bdrv_probe_device(filename
);
460 if (score
> score_max
) {
470 BlockDriver
*bdrv_find_protocol(const char *filename
,
471 bool allow_protocol_prefix
,
479 /* TODO Drivers without bdrv_file_open must be specified explicitly */
482 * XXX(hch): we really should not let host device detection
483 * override an explicit protocol specification, but moving this
484 * later breaks access to device names with colons in them.
485 * Thanks to the brain-dead persistent naming schemes on udev-
486 * based Linux systems those actually are quite common.
488 drv1
= find_hdev_driver(filename
);
493 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
497 p
= strchr(filename
, ':');
500 if (len
> sizeof(protocol
) - 1)
501 len
= sizeof(protocol
) - 1;
502 memcpy(protocol
, filename
, len
);
503 protocol
[len
] = '\0';
504 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
505 if (drv1
->protocol_name
&&
506 !strcmp(drv1
->protocol_name
, protocol
)) {
511 error_setg(errp
, "Unknown protocol '%s'", protocol
);
516 * Guess image format by probing its contents.
517 * This is not a good idea when your image is raw (CVE-2008-2004), but
518 * we do it anyway for backward compatibility.
520 * @buf contains the image's first @buf_size bytes.
521 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
522 * but can be smaller if the image file is smaller)
523 * @filename is its filename.
525 * For all block drivers, call the bdrv_probe() method to get its
527 * Return the first block driver with the highest probing score.
529 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
530 const char *filename
)
532 int score_max
= 0, score
;
533 BlockDriver
*drv
= NULL
, *d
;
535 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
537 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
538 if (score
> score_max
) {
548 static int find_image_format(BlockDriverState
*bs
, const char *filename
,
549 BlockDriver
**pdrv
, Error
**errp
)
552 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
555 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
556 if (bdrv_is_sg(bs
) || !bdrv_is_inserted(bs
) || bdrv_getlength(bs
) == 0) {
561 ret
= bdrv_pread(bs
, 0, buf
, sizeof(buf
));
563 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
569 drv
= bdrv_probe_all(buf
, ret
, filename
);
571 error_setg(errp
, "Could not determine image format: No compatible "
580 * Set the current 'total_sectors' value
581 * Return 0 on success, -errno on error.
583 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
585 BlockDriver
*drv
= bs
->drv
;
587 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
591 /* query actual device if possible, otherwise just trust the hint */
592 if (drv
->bdrv_getlength
) {
593 int64_t length
= drv
->bdrv_getlength(bs
);
597 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
600 bs
->total_sectors
= hint
;
605 * Combines a QDict of new block driver @options with any missing options taken
606 * from @old_options, so that leaving out an option defaults to its old value.
608 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
611 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
612 bs
->drv
->bdrv_join_options(options
, old_options
);
614 qdict_join(options
, old_options
, false);
619 * Set open flags for a given discard mode
621 * Return 0 on success, -1 if the discard mode was invalid.
623 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
625 *flags
&= ~BDRV_O_UNMAP
;
627 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
629 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
630 *flags
|= BDRV_O_UNMAP
;
639 * Set open flags for a given cache mode
641 * Return 0 on success, -1 if the cache mode was invalid.
643 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
645 *flags
&= ~BDRV_O_CACHE_MASK
;
647 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
648 *writethrough
= false;
649 *flags
|= BDRV_O_NOCACHE
;
650 } else if (!strcmp(mode
, "directsync")) {
651 *writethrough
= true;
652 *flags
|= BDRV_O_NOCACHE
;
653 } else if (!strcmp(mode
, "writeback")) {
654 *writethrough
= false;
655 } else if (!strcmp(mode
, "unsafe")) {
656 *writethrough
= false;
657 *flags
|= BDRV_O_NO_FLUSH
;
658 } else if (!strcmp(mode
, "writethrough")) {
659 *writethrough
= true;
668 * Returns the options and flags that a temporary snapshot should get, based on
669 * the originally requested flags (the originally requested image will have
670 * flags like a backing file)
672 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
673 int parent_flags
, QDict
*parent_options
)
675 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
677 /* For temporary files, unconditional cache=unsafe is fine */
678 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
679 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
683 * Returns the options and flags that bs->file should get if a protocol driver
684 * is expected, based on the given options and flags for the parent BDS
686 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
687 int parent_flags
, QDict
*parent_options
)
689 int flags
= parent_flags
;
691 /* Enable protocol handling, disable format probing for bs->file */
692 flags
|= BDRV_O_PROTOCOL
;
694 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
696 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
697 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
699 /* Our block drivers take care to send flushes and respect unmap policy,
700 * so we can default to enable both on lower layers regardless of the
701 * corresponding parent options. */
702 flags
|= BDRV_O_UNMAP
;
704 /* Clear flags that only apply to the top layer */
705 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
708 *child_flags
= flags
;
711 const BdrvChildRole child_file
= {
712 .inherit_options
= bdrv_inherited_options
,
716 * Returns the options and flags that bs->file should get if the use of formats
717 * (and not only protocols) is permitted for it, based on the given options and
718 * flags for the parent BDS
720 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
721 int parent_flags
, QDict
*parent_options
)
723 child_file
.inherit_options(child_flags
, child_options
,
724 parent_flags
, parent_options
);
726 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
729 const BdrvChildRole child_format
= {
730 .inherit_options
= bdrv_inherited_fmt_options
,
734 * Returns the options and flags that bs->backing should get, based on the
735 * given options and flags for the parent BDS
737 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
738 int parent_flags
, QDict
*parent_options
)
740 int flags
= parent_flags
;
742 /* The cache mode is inherited unmodified for backing files; except WCE,
743 * which is only applied on the top level (BlockBackend) */
744 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
745 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
747 /* backing files always opened read-only */
748 flags
&= ~(BDRV_O_RDWR
| BDRV_O_COPY_ON_READ
);
750 /* snapshot=on is handled on the top layer */
751 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
753 *child_flags
= flags
;
756 static const BdrvChildRole child_backing
= {
757 .inherit_options
= bdrv_backing_options
,
760 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
762 int open_flags
= flags
;
765 * Clear flags that are internal to the block layer before opening the
768 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
771 * Snapshots should be writable.
773 if (flags
& BDRV_O_TEMPORARY
) {
774 open_flags
|= BDRV_O_RDWR
;
780 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
782 *flags
&= ~BDRV_O_CACHE_MASK
;
784 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
785 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
786 *flags
|= BDRV_O_NO_FLUSH
;
789 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
790 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
791 *flags
|= BDRV_O_NOCACHE
;
795 static void update_options_from_flags(QDict
*options
, int flags
)
797 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
798 qdict_put(options
, BDRV_OPT_CACHE_DIRECT
,
799 qbool_from_bool(flags
& BDRV_O_NOCACHE
));
801 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
802 qdict_put(options
, BDRV_OPT_CACHE_NO_FLUSH
,
803 qbool_from_bool(flags
& BDRV_O_NO_FLUSH
));
807 static void bdrv_assign_node_name(BlockDriverState
*bs
,
808 const char *node_name
,
811 char *gen_node_name
= NULL
;
814 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
815 } else if (!id_wellformed(node_name
)) {
817 * Check for empty string or invalid characters, but not if it is
818 * generated (generated names use characters not available to the user)
820 error_setg(errp
, "Invalid node name");
824 /* takes care of avoiding namespaces collisions */
825 if (blk_by_name(node_name
)) {
826 error_setg(errp
, "node-name=%s is conflicting with a device id",
831 /* takes care of avoiding duplicates node names */
832 if (bdrv_find_node(node_name
)) {
833 error_setg(errp
, "Duplicate node name");
837 /* copy node name into the bs and insert it into the graph list */
838 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
839 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
841 g_free(gen_node_name
);
844 static QemuOptsList bdrv_runtime_opts
= {
845 .name
= "bdrv_common",
846 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
850 .type
= QEMU_OPT_STRING
,
851 .help
= "Node name of the block device node",
855 .type
= QEMU_OPT_STRING
,
856 .help
= "Block driver to use for the node",
859 .name
= BDRV_OPT_CACHE_DIRECT
,
860 .type
= QEMU_OPT_BOOL
,
861 .help
= "Bypass software writeback cache on the host",
864 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
865 .type
= QEMU_OPT_BOOL
,
866 .help
= "Ignore flush requests",
868 { /* end of list */ }
873 * Common part for opening disk images and files
875 * Removes all processed options from *options.
877 static int bdrv_open_common(BlockDriverState
*bs
, BdrvChild
*file
,
878 QDict
*options
, Error
**errp
)
881 const char *filename
;
882 const char *driver_name
= NULL
;
883 const char *node_name
= NULL
;
886 Error
*local_err
= NULL
;
888 assert(bs
->file
== NULL
);
889 assert(options
!= NULL
&& bs
->options
!= options
);
891 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
892 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
894 error_propagate(errp
, local_err
);
899 driver_name
= qemu_opt_get(opts
, "driver");
900 drv
= bdrv_find_format(driver_name
);
904 filename
= file
->bs
->filename
;
906 filename
= qdict_get_try_str(options
, "filename");
909 if (drv
->bdrv_needs_filename
&& !filename
) {
910 error_setg(errp
, "The '%s' block driver requires a file name",
916 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
919 node_name
= qemu_opt_get(opts
, "node-name");
920 bdrv_assign_node_name(bs
, node_name
, &local_err
);
922 error_propagate(errp
, local_err
);
927 bs
->request_alignment
= 512;
928 bs
->zero_beyond_eof
= true;
929 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
931 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
933 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
934 ? "Driver '%s' can only be used for read-only devices"
935 : "Driver '%s' is not whitelisted",
941 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
942 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
943 if (!bs
->read_only
) {
944 bdrv_enable_copy_on_read(bs
);
946 error_setg(errp
, "Can't use copy-on-read on read-only device");
952 if (filename
!= NULL
) {
953 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
955 bs
->filename
[0] = '\0';
957 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
960 bs
->opaque
= g_malloc0(drv
->instance_size
);
962 /* Apply cache mode options */
963 update_flags_from_options(&bs
->open_flags
, opts
);
965 /* Open the image, either directly or using a protocol */
966 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
967 if (drv
->bdrv_file_open
) {
968 assert(file
== NULL
);
969 assert(!drv
->bdrv_needs_filename
|| filename
!= NULL
);
970 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
973 error_setg(errp
, "Can't use '%s' as a block driver for the "
974 "protocol level", drv
->format_name
);
979 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
984 error_propagate(errp
, local_err
);
985 } else if (bs
->filename
[0]) {
986 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
988 error_setg_errno(errp
, -ret
, "Could not open image");
993 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
995 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
999 bdrv_refresh_limits(bs
, &local_err
);
1001 error_propagate(errp
, local_err
);
1006 assert(bdrv_opt_mem_align(bs
) != 0);
1007 assert(bdrv_min_mem_align(bs
) != 0);
1008 assert((bs
->request_alignment
!= 0) || bdrv_is_sg(bs
));
1010 qemu_opts_del(opts
);
1019 qemu_opts_del(opts
);
1023 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1025 QObject
*options_obj
;
1029 ret
= strstart(filename
, "json:", &filename
);
1032 options_obj
= qobject_from_json(filename
);
1034 error_setg(errp
, "Could not parse the JSON options");
1038 if (qobject_type(options_obj
) != QTYPE_QDICT
) {
1039 qobject_decref(options_obj
);
1040 error_setg(errp
, "Invalid JSON object given");
1044 options
= qobject_to_qdict(options_obj
);
1045 qdict_flatten(options
);
1050 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1053 QDict
*json_options
;
1054 Error
*local_err
= NULL
;
1056 /* Parse json: pseudo-protocol */
1057 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1061 json_options
= parse_json_filename(*pfilename
, &local_err
);
1063 error_propagate(errp
, local_err
);
1067 /* Options given in the filename have lower priority than options
1068 * specified directly */
1069 qdict_join(options
, json_options
, false);
1070 QDECREF(json_options
);
1075 * Fills in default options for opening images and converts the legacy
1076 * filename/flags pair to option QDict entries.
1077 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1078 * block driver has been specified explicitly.
1080 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1081 int *flags
, Error
**errp
)
1083 const char *drvname
;
1084 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1085 bool parse_filename
= false;
1086 BlockDriver
*drv
= NULL
;
1087 Error
*local_err
= NULL
;
1089 drvname
= qdict_get_try_str(*options
, "driver");
1091 drv
= bdrv_find_format(drvname
);
1093 error_setg(errp
, "Unknown driver '%s'", drvname
);
1096 /* If the user has explicitly specified the driver, this choice should
1097 * override the BDRV_O_PROTOCOL flag */
1098 protocol
= drv
->bdrv_file_open
;
1102 *flags
|= BDRV_O_PROTOCOL
;
1104 *flags
&= ~BDRV_O_PROTOCOL
;
1107 /* Translate cache options from flags into options */
1108 update_options_from_flags(*options
, *flags
);
1110 /* Fetch the file name from the options QDict if necessary */
1111 if (protocol
&& filename
) {
1112 if (!qdict_haskey(*options
, "filename")) {
1113 qdict_put(*options
, "filename", qstring_from_str(filename
));
1114 parse_filename
= true;
1116 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1122 /* Find the right block driver */
1123 filename
= qdict_get_try_str(*options
, "filename");
1125 if (!drvname
&& protocol
) {
1127 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1132 drvname
= drv
->format_name
;
1133 qdict_put(*options
, "driver", qstring_from_str(drvname
));
1135 error_setg(errp
, "Must specify either driver or file");
1140 assert(drv
|| !protocol
);
1142 /* Driver-specific filename parsing */
1143 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1144 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1146 error_propagate(errp
, local_err
);
1150 if (!drv
->bdrv_needs_filename
) {
1151 qdict_del(*options
, "filename");
1158 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1159 const char *child_name
,
1160 const BdrvChildRole
*child_role
)
1162 BdrvChild
*child
= g_new(BdrvChild
, 1);
1163 *child
= (BdrvChild
) {
1165 .name
= g_strdup(child_name
),
1169 QLIST_INSERT_HEAD(&child_bs
->parents
, child
, next_parent
);
1174 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1175 BlockDriverState
*child_bs
,
1176 const char *child_name
,
1177 const BdrvChildRole
*child_role
)
1179 BdrvChild
*child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
);
1180 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1184 static void bdrv_detach_child(BdrvChild
*child
)
1186 if (child
->next
.le_prev
) {
1187 QLIST_REMOVE(child
, next
);
1188 child
->next
.le_prev
= NULL
;
1190 QLIST_REMOVE(child
, next_parent
);
1191 g_free(child
->name
);
1195 void bdrv_root_unref_child(BdrvChild
*child
)
1197 BlockDriverState
*child_bs
;
1199 child_bs
= child
->bs
;
1200 bdrv_detach_child(child
);
1201 bdrv_unref(child_bs
);
1204 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1206 if (child
== NULL
) {
1210 if (child
->bs
->inherits_from
== parent
) {
1211 child
->bs
->inherits_from
= NULL
;
1214 bdrv_root_unref_child(child
);
1218 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
1221 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1222 if (c
->role
->change_media
) {
1223 c
->role
->change_media(c
, load
);
1228 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
1231 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1232 if (c
->role
->resize
) {
1239 * Sets the backing file link of a BDS. A new reference is created; callers
1240 * which don't need their own reference any more must call bdrv_unref().
1242 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
)
1245 bdrv_ref(backing_hd
);
1249 assert(bs
->backing_blocker
);
1250 bdrv_op_unblock_all(bs
->backing
->bs
, bs
->backing_blocker
);
1251 bdrv_unref_child(bs
, bs
->backing
);
1252 } else if (backing_hd
) {
1253 error_setg(&bs
->backing_blocker
,
1254 "node is used as backing hd of '%s'",
1255 bdrv_get_device_or_node_name(bs
));
1259 error_free(bs
->backing_blocker
);
1260 bs
->backing_blocker
= NULL
;
1264 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
);
1265 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1266 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_hd
->filename
);
1267 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
),
1268 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
1270 bdrv_op_block_all(backing_hd
, bs
->backing_blocker
);
1271 /* Otherwise we won't be able to commit due to check in bdrv_commit */
1272 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
1273 bs
->backing_blocker
);
1275 bdrv_refresh_limits(bs
, NULL
);
1279 * Opens the backing file for a BlockDriverState if not yet open
1281 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
1282 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1283 * itself, all options starting with "${bdref_key}." are considered part of the
1286 * TODO Can this be unified with bdrv_open_image()?
1288 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
1289 const char *bdref_key
, Error
**errp
)
1291 char *backing_filename
= g_malloc0(PATH_MAX
);
1292 char *bdref_key_dot
;
1293 const char *reference
= NULL
;
1295 BlockDriverState
*backing_hd
;
1297 QDict
*tmp_parent_options
= NULL
;
1298 Error
*local_err
= NULL
;
1300 if (bs
->backing
!= NULL
) {
1304 /* NULL means an empty set of options */
1305 if (parent_options
== NULL
) {
1306 tmp_parent_options
= qdict_new();
1307 parent_options
= tmp_parent_options
;
1310 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1312 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1313 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
1314 g_free(bdref_key_dot
);
1316 reference
= qdict_get_try_str(parent_options
, bdref_key
);
1317 if (reference
|| qdict_haskey(options
, "file.filename")) {
1318 backing_filename
[0] = '\0';
1319 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
1323 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
1327 error_propagate(errp
, local_err
);
1333 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
1335 error_setg(errp
, "Driver doesn't support backing files");
1340 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
1341 qdict_put(options
, "driver", qstring_from_str(bs
->backing_format
));
1345 ret
= bdrv_open_inherit(&backing_hd
,
1346 *backing_filename
? backing_filename
: NULL
,
1347 reference
, options
, 0, bs
, &child_backing
,
1350 bs
->open_flags
|= BDRV_O_NO_BACKING
;
1351 error_prepend(errp
, "Could not open backing file: ");
1355 /* Hook up the backing file link; drop our reference, bs owns the
1356 * backing_hd reference now */
1357 bdrv_set_backing_hd(bs
, backing_hd
);
1358 bdrv_unref(backing_hd
);
1360 qdict_del(parent_options
, bdref_key
);
1363 g_free(backing_filename
);
1364 QDECREF(tmp_parent_options
);
1369 * Opens a disk image whose options are given as BlockdevRef in another block
1372 * If allow_none is true, no image will be opened if filename is false and no
1373 * BlockdevRef is given. NULL will be returned, but errp remains unset.
1375 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
1376 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1377 * itself, all options starting with "${bdref_key}." are considered part of the
1380 * The BlockdevRef will be removed from the options QDict.
1382 BdrvChild
*bdrv_open_child(const char *filename
,
1383 QDict
*options
, const char *bdref_key
,
1384 BlockDriverState
* parent
,
1385 const BdrvChildRole
*child_role
,
1386 bool allow_none
, Error
**errp
)
1388 BdrvChild
*c
= NULL
;
1389 BlockDriverState
*bs
;
1390 QDict
*image_options
;
1392 char *bdref_key_dot
;
1393 const char *reference
;
1395 assert(child_role
!= NULL
);
1397 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1398 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
1399 g_free(bdref_key_dot
);
1401 reference
= qdict_get_try_str(options
, bdref_key
);
1402 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
1404 error_setg(errp
, "A block device must be specified for \"%s\"",
1407 QDECREF(image_options
);
1412 ret
= bdrv_open_inherit(&bs
, filename
, reference
, image_options
, 0,
1413 parent
, child_role
, errp
);
1418 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
);
1421 qdict_del(options
, bdref_key
);
1425 static int bdrv_append_temp_snapshot(BlockDriverState
*bs
, int flags
,
1426 QDict
*snapshot_options
, Error
**errp
)
1428 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
1429 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
1431 QemuOpts
*opts
= NULL
;
1432 BlockDriverState
*bs_snapshot
;
1433 Error
*local_err
= NULL
;
1436 /* if snapshot, we create a temporary backing file and open it
1437 instead of opening 'filename' directly */
1439 /* Get the required size from the image */
1440 total_size
= bdrv_getlength(bs
);
1441 if (total_size
< 0) {
1443 error_setg_errno(errp
, -total_size
, "Could not get image size");
1447 /* Create the temporary image */
1448 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
1450 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
1454 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
1456 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
1457 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
1458 qemu_opts_del(opts
);
1460 error_prepend(errp
, "Could not create temporary overlay '%s': ",
1465 /* Prepare options QDict for the temporary file */
1466 qdict_put(snapshot_options
, "file.driver",
1467 qstring_from_str("file"));
1468 qdict_put(snapshot_options
, "file.filename",
1469 qstring_from_str(tmp_filename
));
1470 qdict_put(snapshot_options
, "driver",
1471 qstring_from_str("qcow2"));
1473 bs_snapshot
= bdrv_new();
1475 ret
= bdrv_open(&bs_snapshot
, NULL
, NULL
, snapshot_options
,
1477 snapshot_options
= NULL
;
1479 error_propagate(errp
, local_err
);
1483 bdrv_append(bs_snapshot
, bs
);
1486 QDECREF(snapshot_options
);
1487 g_free(tmp_filename
);
1492 * Opens a disk image (raw, qcow2, vmdk, ...)
1494 * options is a QDict of options to pass to the block drivers, or NULL for an
1495 * empty set of options. The reference to the QDict belongs to the block layer
1496 * after the call (even on failure), so if the caller intends to reuse the
1497 * dictionary, it needs to use QINCREF() before calling bdrv_open.
1499 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
1500 * If it is not NULL, the referenced BDS will be reused.
1502 * The reference parameter may be used to specify an existing block device which
1503 * should be opened. If specified, neither options nor a filename may be given,
1504 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
1506 static int bdrv_open_inherit(BlockDriverState
**pbs
, const char *filename
,
1507 const char *reference
, QDict
*options
, int flags
,
1508 BlockDriverState
*parent
,
1509 const BdrvChildRole
*child_role
, Error
**errp
)
1512 BdrvChild
*file
= NULL
;
1513 BlockDriverState
*bs
;
1514 BlockDriver
*drv
= NULL
;
1515 const char *drvname
;
1516 const char *backing
;
1517 Error
*local_err
= NULL
;
1518 QDict
*snapshot_options
= NULL
;
1519 int snapshot_flags
= 0;
1522 assert(!child_role
|| !flags
);
1523 assert(!child_role
== !parent
);
1526 bool options_non_empty
= options
? qdict_size(options
) : false;
1530 error_setg(errp
, "Cannot reuse an existing BDS when referencing "
1531 "another block device");
1535 if (filename
|| options_non_empty
) {
1536 error_setg(errp
, "Cannot reference an existing block device with "
1537 "additional options or a new filename");
1541 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
1557 /* NULL means an empty set of options */
1558 if (options
== NULL
) {
1559 options
= qdict_new();
1562 /* json: syntax counts as explicit options, as if in the QDict */
1563 parse_json_protocol(options
, &filename
, &local_err
);
1569 bs
->explicit_options
= qdict_clone_shallow(options
);
1572 bs
->inherits_from
= parent
;
1573 child_role
->inherit_options(&flags
, options
,
1574 parent
->open_flags
, parent
->options
);
1577 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
1582 bs
->open_flags
= flags
;
1583 bs
->options
= options
;
1584 options
= qdict_clone_shallow(options
);
1586 /* Find the right image format driver */
1587 drvname
= qdict_get_try_str(options
, "driver");
1589 drv
= bdrv_find_format(drvname
);
1591 error_setg(errp
, "Unknown driver: '%s'", drvname
);
1597 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
1599 backing
= qdict_get_try_str(options
, "backing");
1600 if (backing
&& *backing
== '\0') {
1601 flags
|= BDRV_O_NO_BACKING
;
1602 qdict_del(options
, "backing");
1605 /* Open image file without format layer */
1606 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
1607 if (flags
& BDRV_O_RDWR
) {
1608 flags
|= BDRV_O_ALLOW_RDWR
;
1610 if (flags
& BDRV_O_SNAPSHOT
) {
1611 snapshot_options
= qdict_new();
1612 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
1614 bdrv_backing_options(&flags
, options
, flags
, options
);
1617 bs
->open_flags
= flags
;
1619 file
= bdrv_open_child(filename
, options
, "file", bs
,
1620 &child_file
, true, &local_err
);
1627 /* Image format probing */
1630 ret
= find_image_format(file
->bs
, filename
, &drv
, &local_err
);
1635 * This option update would logically belong in bdrv_fill_options(),
1636 * but we first need to open bs->file for the probing to work, while
1637 * opening bs->file already requires the (mostly) final set of options
1638 * so that cache mode etc. can be inherited.
1640 * Adding the driver later is somewhat ugly, but it's not an option
1641 * that would ever be inherited, so it's correct. We just need to make
1642 * sure to update both bs->options (which has the full effective
1643 * options for bs) and options (which has file.* already removed).
1645 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
1646 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
1648 error_setg(errp
, "Must specify either driver or file");
1653 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
1654 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
1655 /* file must be NULL if a protocol BDS is about to be created
1656 * (the inverse results in an error message from bdrv_open_common()) */
1657 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
1659 /* Open the image */
1660 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
1665 if (file
&& (bs
->file
!= file
)) {
1666 bdrv_unref_child(bs
, file
);
1670 /* If there is a backing file, use it */
1671 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
1672 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
1674 goto close_and_fail
;
1678 bdrv_refresh_filename(bs
);
1680 /* Check if any unknown options were used */
1681 if (options
&& (qdict_size(options
) != 0)) {
1682 const QDictEntry
*entry
= qdict_first(options
);
1683 if (flags
& BDRV_O_PROTOCOL
) {
1684 error_setg(errp
, "Block protocol '%s' doesn't support the option "
1685 "'%s'", drv
->format_name
, entry
->key
);
1688 "Block format '%s' does not support the option '%s'",
1689 drv
->format_name
, entry
->key
);
1693 goto close_and_fail
;
1696 if (!bdrv_key_required(bs
)) {
1697 bdrv_parent_cb_change_media(bs
, true);
1698 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
1699 && !runstate_check(RUN_STATE_INMIGRATE
)
1700 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
1702 "Guest must be stopped for opening of encrypted image");
1704 goto close_and_fail
;
1710 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
1711 * temporary snapshot afterwards. */
1712 if (snapshot_flags
) {
1713 ret
= bdrv_append_temp_snapshot(bs
, snapshot_flags
, snapshot_options
,
1715 snapshot_options
= NULL
;
1717 goto close_and_fail
;
1725 bdrv_unref_child(bs
, file
);
1727 QDECREF(snapshot_options
);
1728 QDECREF(bs
->explicit_options
);
1729 QDECREF(bs
->options
);
1733 /* If *pbs is NULL, a new BDS has been created in this function and
1734 needs to be freed now. Otherwise, it does not need to be closed,
1735 since it has not really been opened yet. */
1739 error_propagate(errp
, local_err
);
1744 /* See fail path, but now the BDS has to be always closed */
1750 QDECREF(snapshot_options
);
1753 error_propagate(errp
, local_err
);
1758 int bdrv_open(BlockDriverState
**pbs
, const char *filename
,
1759 const char *reference
, QDict
*options
, int flags
, Error
**errp
)
1761 return bdrv_open_inherit(pbs
, filename
, reference
, options
, flags
, NULL
,
1765 typedef struct BlockReopenQueueEntry
{
1767 BDRVReopenState state
;
1768 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1769 } BlockReopenQueueEntry
;
1772 * Adds a BlockDriverState to a simple queue for an atomic, transactional
1773 * reopen of multiple devices.
1775 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
1776 * already performed, or alternatively may be NULL a new BlockReopenQueue will
1777 * be created and initialized. This newly created BlockReopenQueue should be
1778 * passed back in for subsequent calls that are intended to be of the same
1781 * bs is the BlockDriverState to add to the reopen queue.
1783 * options contains the changed options for the associated bs
1784 * (the BlockReopenQueue takes ownership)
1786 * flags contains the open flags for the associated bs
1788 * returns a pointer to bs_queue, which is either the newly allocated
1789 * bs_queue, or the existing bs_queue being used.
1792 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
1793 BlockDriverState
*bs
,
1796 const BdrvChildRole
*role
,
1797 QDict
*parent_options
,
1802 BlockReopenQueueEntry
*bs_entry
;
1804 QDict
*old_options
, *explicit_options
;
1806 if (bs_queue
== NULL
) {
1807 bs_queue
= g_new0(BlockReopenQueue
, 1);
1808 QSIMPLEQ_INIT(bs_queue
);
1812 options
= qdict_new();
1816 * Precedence of options:
1817 * 1. Explicitly passed in options (highest)
1818 * 2. Set in flags (only for top level)
1819 * 3. Retained from explicitly set options of bs
1820 * 4. Inherited from parent node
1821 * 5. Retained from effective options of bs
1824 if (!parent_options
) {
1826 * Any setting represented by flags is always updated. If the
1827 * corresponding QDict option is set, it takes precedence. Otherwise
1828 * the flag is translated into a QDict option. The old setting of bs is
1831 update_options_from_flags(options
, flags
);
1834 /* Old explicitly set values (don't overwrite by inherited value) */
1835 old_options
= qdict_clone_shallow(bs
->explicit_options
);
1836 bdrv_join_options(bs
, options
, old_options
);
1837 QDECREF(old_options
);
1839 explicit_options
= qdict_clone_shallow(options
);
1841 /* Inherit from parent node */
1842 if (parent_options
) {
1844 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
1847 /* Old values are used for options that aren't set yet */
1848 old_options
= qdict_clone_shallow(bs
->options
);
1849 bdrv_join_options(bs
, options
, old_options
);
1850 QDECREF(old_options
);
1852 /* bdrv_open() masks this flag out */
1853 flags
&= ~BDRV_O_PROTOCOL
;
1855 QLIST_FOREACH(child
, &bs
->children
, next
) {
1856 QDict
*new_child_options
;
1857 char *child_key_dot
;
1859 /* reopen can only change the options of block devices that were
1860 * implicitly created and inherited options. For other (referenced)
1861 * block devices, a syntax like "backing.foo" results in an error. */
1862 if (child
->bs
->inherits_from
!= bs
) {
1866 child_key_dot
= g_strdup_printf("%s.", child
->name
);
1867 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
1868 g_free(child_key_dot
);
1870 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
1871 child
->role
, options
, flags
);
1874 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
1875 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
1877 bs_entry
->state
.bs
= bs
;
1878 bs_entry
->state
.options
= options
;
1879 bs_entry
->state
.explicit_options
= explicit_options
;
1880 bs_entry
->state
.flags
= flags
;
1885 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
1886 BlockDriverState
*bs
,
1887 QDict
*options
, int flags
)
1889 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
1894 * Reopen multiple BlockDriverStates atomically & transactionally.
1896 * The queue passed in (bs_queue) must have been built up previous
1897 * via bdrv_reopen_queue().
1899 * Reopens all BDS specified in the queue, with the appropriate
1900 * flags. All devices are prepared for reopen, and failure of any
1901 * device will cause all device changes to be abandonded, and intermediate
1904 * If all devices prepare successfully, then the changes are committed
1908 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
)
1911 BlockReopenQueueEntry
*bs_entry
, *next
;
1912 Error
*local_err
= NULL
;
1914 assert(bs_queue
!= NULL
);
1918 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1919 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
1920 error_propagate(errp
, local_err
);
1923 bs_entry
->prepared
= true;
1926 /* If we reach this point, we have success and just need to apply the
1929 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1930 bdrv_reopen_commit(&bs_entry
->state
);
1936 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
1937 if (ret
&& bs_entry
->prepared
) {
1938 bdrv_reopen_abort(&bs_entry
->state
);
1940 QDECREF(bs_entry
->state
.explicit_options
);
1942 QDECREF(bs_entry
->state
.options
);
1950 /* Reopen a single BlockDriverState with the specified flags. */
1951 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
1954 Error
*local_err
= NULL
;
1955 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
1957 ret
= bdrv_reopen_multiple(queue
, &local_err
);
1958 if (local_err
!= NULL
) {
1959 error_propagate(errp
, local_err
);
1966 * Prepares a BlockDriverState for reopen. All changes are staged in the
1967 * 'opaque' field of the BDRVReopenState, which is used and allocated by
1968 * the block driver layer .bdrv_reopen_prepare()
1970 * bs is the BlockDriverState to reopen
1971 * flags are the new open flags
1972 * queue is the reopen queue
1974 * Returns 0 on success, non-zero on error. On error errp will be set
1977 * On failure, bdrv_reopen_abort() will be called to clean up any data.
1978 * It is the responsibility of the caller to then call the abort() or
1979 * commit() for any other BDS that have been left in a prepare() state
1982 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
1986 Error
*local_err
= NULL
;
1991 assert(reopen_state
!= NULL
);
1992 assert(reopen_state
->bs
->drv
!= NULL
);
1993 drv
= reopen_state
->bs
->drv
;
1995 /* Process generic block layer options */
1996 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1997 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
1999 error_propagate(errp
, local_err
);
2004 update_flags_from_options(&reopen_state
->flags
, opts
);
2006 /* node-name and driver must be unchanged. Put them back into the QDict, so
2007 * that they are checked at the end of this function. */
2008 value
= qemu_opt_get(opts
, "node-name");
2010 qdict_put(reopen_state
->options
, "node-name", qstring_from_str(value
));
2013 value
= qemu_opt_get(opts
, "driver");
2015 qdict_put(reopen_state
->options
, "driver", qstring_from_str(value
));
2018 /* if we are to stay read-only, do not allow permission change
2020 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
2021 reopen_state
->flags
& BDRV_O_RDWR
) {
2022 error_setg(errp
, "Node '%s' is read only",
2023 bdrv_get_device_or_node_name(reopen_state
->bs
));
2028 ret
= bdrv_flush(reopen_state
->bs
);
2030 error_setg_errno(errp
, -ret
, "Error flushing drive");
2034 if (drv
->bdrv_reopen_prepare
) {
2035 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2037 if (local_err
!= NULL
) {
2038 error_propagate(errp
, local_err
);
2040 error_setg(errp
, "failed while preparing to reopen image '%s'",
2041 reopen_state
->bs
->filename
);
2046 /* It is currently mandatory to have a bdrv_reopen_prepare()
2047 * handler for each supported drv. */
2048 error_setg(errp
, "Block format '%s' used by node '%s' "
2049 "does not support reopening files", drv
->format_name
,
2050 bdrv_get_device_or_node_name(reopen_state
->bs
));
2055 /* Options that are not handled are only okay if they are unchanged
2056 * compared to the old state. It is expected that some options are only
2057 * used for the initial open, but not reopen (e.g. filename) */
2058 if (qdict_size(reopen_state
->options
)) {
2059 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2062 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2063 const char *new = qstring_get_str(new_obj
);
2064 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2067 if (!old
|| strcmp(new, old
)) {
2068 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2072 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2078 qemu_opts_del(opts
);
2083 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2084 * makes them final by swapping the staging BlockDriverState contents into
2085 * the active BlockDriverState contents.
2087 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2091 assert(reopen_state
!= NULL
);
2092 drv
= reopen_state
->bs
->drv
;
2093 assert(drv
!= NULL
);
2095 /* If there are any driver level actions to take */
2096 if (drv
->bdrv_reopen_commit
) {
2097 drv
->bdrv_reopen_commit(reopen_state
);
2100 /* set BDS specific flags now */
2101 QDECREF(reopen_state
->bs
->explicit_options
);
2103 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2104 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2105 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2107 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2111 * Abort the reopen, and delete and free the staged changes in
2114 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2118 assert(reopen_state
!= NULL
);
2119 drv
= reopen_state
->bs
->drv
;
2120 assert(drv
!= NULL
);
2122 if (drv
->bdrv_reopen_abort
) {
2123 drv
->bdrv_reopen_abort(reopen_state
);
2126 QDECREF(reopen_state
->explicit_options
);
2130 static void bdrv_close(BlockDriverState
*bs
)
2132 BdrvAioNotifier
*ban
, *ban_next
;
2136 bdrv_drained_begin(bs
); /* complete I/O */
2138 bdrv_drain(bs
); /* in case flush left pending I/O */
2140 bdrv_release_named_dirty_bitmaps(bs
);
2141 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2143 bdrv_parent_cb_change_media(bs
, false);
2146 BdrvChild
*child
, *next
;
2148 bs
->drv
->bdrv_close(bs
);
2151 bdrv_set_backing_hd(bs
, NULL
);
2153 if (bs
->file
!= NULL
) {
2154 bdrv_unref_child(bs
, bs
->file
);
2158 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2159 /* TODO Remove bdrv_unref() from drivers' close function and use
2160 * bdrv_unref_child() here */
2161 if (child
->bs
->inherits_from
== bs
) {
2162 child
->bs
->inherits_from
= NULL
;
2164 bdrv_detach_child(child
);
2169 bs
->copy_on_read
= 0;
2170 bs
->backing_file
[0] = '\0';
2171 bs
->backing_format
[0] = '\0';
2172 bs
->total_sectors
= 0;
2176 bs
->zero_beyond_eof
= false;
2177 QDECREF(bs
->options
);
2178 QDECREF(bs
->explicit_options
);
2180 QDECREF(bs
->full_open_options
);
2181 bs
->full_open_options
= NULL
;
2184 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2187 QLIST_INIT(&bs
->aio_notifiers
);
2188 bdrv_drained_end(bs
);
2191 void bdrv_close_all(void)
2193 BlockDriverState
*bs
;
2194 AioContext
*aio_context
;
2196 /* Drop references from requests still in flight, such as canceled block
2197 * jobs whose AIO context has not been polled yet */
2200 blk_remove_all_bs();
2201 blockdev_close_all_bdrv_states();
2203 /* Cancel all block jobs */
2204 while (!QTAILQ_EMPTY(&all_bdrv_states
)) {
2205 QTAILQ_FOREACH(bs
, &all_bdrv_states
, bs_list
) {
2206 aio_context
= bdrv_get_aio_context(bs
);
2208 aio_context_acquire(aio_context
);
2210 block_job_cancel_sync(bs
->job
);
2211 aio_context_release(aio_context
);
2214 aio_context_release(aio_context
);
2217 /* All the remaining BlockDriverStates are referenced directly or
2218 * indirectly from block jobs, so there needs to be at least one BDS
2219 * directly used by a block job */
2224 static void change_parent_backing_link(BlockDriverState
*from
,
2225 BlockDriverState
*to
)
2227 BdrvChild
*c
, *next
;
2230 /* FIXME We bypass blk_set_bs(), so we need to make these updates
2231 * manually. The root problem is not in this change function, but the
2232 * existence of BlockDriverState.blk. */
2233 to
->blk
= from
->blk
;
2237 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
2238 assert(c
->role
!= &child_backing
);
2240 QLIST_REMOVE(c
, next_parent
);
2241 QLIST_INSERT_HEAD(&to
->parents
, c
, next_parent
);
2248 * Add new bs contents at the top of an image chain while the chain is
2249 * live, while keeping required fields on the top layer.
2251 * This will modify the BlockDriverState fields, and swap contents
2252 * between bs_new and bs_top. Both bs_new and bs_top are modified.
2254 * bs_new must not be attached to a BlockBackend.
2256 * This function does not create any image files.
2258 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
2259 * that's what the callers commonly need. bs_new will be referenced by the old
2260 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
2261 * reference of its own, it must call bdrv_ref().
2263 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
)
2265 assert(!bdrv_requests_pending(bs_top
));
2266 assert(!bdrv_requests_pending(bs_new
));
2270 change_parent_backing_link(bs_top
, bs_new
);
2271 bdrv_set_backing_hd(bs_new
, bs_top
);
2274 /* bs_new is now referenced by its new parents, we don't need the
2275 * additional reference any more. */
2279 void bdrv_replace_in_backing_chain(BlockDriverState
*old
, BlockDriverState
*new)
2281 assert(!bdrv_requests_pending(old
));
2282 assert(!bdrv_requests_pending(new));
2286 change_parent_backing_link(old
, new);
2288 /* Change backing files if a previously independent node is added to the
2289 * chain. For active commit, we replace top by its own (indirect) backing
2290 * file and don't do anything here so we don't build a loop. */
2291 if (new->backing
== NULL
&& !bdrv_chain_contains(backing_bs(old
), new)) {
2292 bdrv_set_backing_hd(new, backing_bs(old
));
2293 bdrv_set_backing_hd(old
, NULL
);
2299 static void bdrv_delete(BlockDriverState
*bs
)
2302 assert(bdrv_op_blocker_is_empty(bs
));
2303 assert(!bs
->refcnt
);
2307 /* remove from list, if necessary */
2308 if (bs
->node_name
[0] != '\0') {
2309 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
2311 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
2317 * Run consistency checks on an image
2319 * Returns 0 if the check could be completed (it doesn't mean that the image is
2320 * free of errors) or -errno when an internal error occurred. The results of the
2321 * check are stored in res.
2323 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
2325 if (bs
->drv
== NULL
) {
2328 if (bs
->drv
->bdrv_check
== NULL
) {
2332 memset(res
, 0, sizeof(*res
));
2333 return bs
->drv
->bdrv_check(bs
, res
, fix
);
2336 #define COMMIT_BUF_SECTORS 2048
2338 /* commit COW file into the raw image */
2339 int bdrv_commit(BlockDriverState
*bs
)
2341 BlockDriver
*drv
= bs
->drv
;
2342 int64_t sector
, total_sectors
, length
, backing_length
;
2343 int n
, ro
, open_flags
;
2345 uint8_t *buf
= NULL
;
2354 if (bdrv_op_is_blocked(bs
, BLOCK_OP_TYPE_COMMIT_SOURCE
, NULL
) ||
2355 bdrv_op_is_blocked(bs
->backing
->bs
, BLOCK_OP_TYPE_COMMIT_TARGET
, NULL
)) {
2359 ro
= bs
->backing
->bs
->read_only
;
2360 open_flags
= bs
->backing
->bs
->open_flags
;
2363 if (bdrv_reopen(bs
->backing
->bs
, open_flags
| BDRV_O_RDWR
, NULL
)) {
2368 length
= bdrv_getlength(bs
);
2374 backing_length
= bdrv_getlength(bs
->backing
->bs
);
2375 if (backing_length
< 0) {
2376 ret
= backing_length
;
2380 /* If our top snapshot is larger than the backing file image,
2381 * grow the backing file image if possible. If not possible,
2382 * we must return an error */
2383 if (length
> backing_length
) {
2384 ret
= bdrv_truncate(bs
->backing
->bs
, length
);
2390 total_sectors
= length
>> BDRV_SECTOR_BITS
;
2392 /* qemu_try_blockalign() for bs will choose an alignment that works for
2393 * bs->backing->bs as well, so no need to compare the alignment manually. */
2394 buf
= qemu_try_blockalign(bs
, COMMIT_BUF_SECTORS
* BDRV_SECTOR_SIZE
);
2400 for (sector
= 0; sector
< total_sectors
; sector
+= n
) {
2401 ret
= bdrv_is_allocated(bs
, sector
, COMMIT_BUF_SECTORS
, &n
);
2406 ret
= bdrv_read(bs
, sector
, buf
, n
);
2411 ret
= bdrv_write(bs
->backing
->bs
, sector
, buf
, n
);
2418 if (drv
->bdrv_make_empty
) {
2419 ret
= drv
->bdrv_make_empty(bs
);
2427 * Make sure all data we wrote to the backing device is actually
2431 bdrv_flush(bs
->backing
->bs
);
2439 /* ignoring error return here */
2440 bdrv_reopen(bs
->backing
->bs
, open_flags
& ~BDRV_O_RDWR
, NULL
);
2449 * -EINVAL - backing format specified, but no file
2450 * -ENOSPC - can't update the backing file because no space is left in the
2452 * -ENOTSUP - format driver doesn't support changing the backing file
2454 int bdrv_change_backing_file(BlockDriverState
*bs
,
2455 const char *backing_file
, const char *backing_fmt
)
2457 BlockDriver
*drv
= bs
->drv
;
2460 /* Backing file format doesn't make sense without a backing file */
2461 if (backing_fmt
&& !backing_file
) {
2465 if (drv
->bdrv_change_backing_file
!= NULL
) {
2466 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
2472 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2473 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2479 * Finds the image layer in the chain that has 'bs' as its backing file.
2481 * active is the current topmost image.
2483 * Returns NULL if bs is not found in active's image chain,
2484 * or if active == bs.
2486 * Returns the bottommost base image if bs == NULL.
2488 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
2489 BlockDriverState
*bs
)
2491 while (active
&& bs
!= backing_bs(active
)) {
2492 active
= backing_bs(active
);
2498 /* Given a BDS, searches for the base layer. */
2499 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
2501 return bdrv_find_overlay(bs
, NULL
);
2505 * Drops images above 'base' up to and including 'top', and sets the image
2506 * above 'top' to have base as its backing file.
2508 * Requires that the overlay to 'top' is opened r/w, so that the backing file
2509 * information in 'bs' can be properly updated.
2511 * E.g., this will convert the following chain:
2512 * bottom <- base <- intermediate <- top <- active
2516 * bottom <- base <- active
2518 * It is allowed for bottom==base, in which case it converts:
2520 * base <- intermediate <- top <- active
2526 * If backing_file_str is non-NULL, it will be used when modifying top's
2527 * overlay image metadata.
2530 * if active == top, that is considered an error
2533 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
2534 BlockDriverState
*base
, const char *backing_file_str
)
2536 BlockDriverState
*new_top_bs
= NULL
;
2539 if (!top
->drv
|| !base
->drv
) {
2543 new_top_bs
= bdrv_find_overlay(active
, top
);
2545 if (new_top_bs
== NULL
) {
2546 /* we could not find the image above 'top', this is an error */
2550 /* special case of new_top_bs->backing->bs already pointing to base - nothing
2551 * to do, no intermediate images */
2552 if (backing_bs(new_top_bs
) == base
) {
2557 /* Make sure that base is in the backing chain of top */
2558 if (!bdrv_chain_contains(top
, base
)) {
2562 /* success - we can delete the intermediate states, and link top->base */
2563 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
2564 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
2565 base
->drv
? base
->drv
->format_name
: "");
2569 bdrv_set_backing_hd(new_top_bs
, base
);
2577 * Truncate file to 'offset' bytes (needed only for file protocols)
2579 int bdrv_truncate(BlockDriverState
*bs
, int64_t offset
)
2581 BlockDriver
*drv
= bs
->drv
;
2585 if (!drv
->bdrv_truncate
)
2590 ret
= drv
->bdrv_truncate(bs
, offset
);
2592 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
2593 bdrv_dirty_bitmap_truncate(bs
);
2594 bdrv_parent_cb_resize(bs
);
2600 * Length of a allocated file in bytes. Sparse files are counted by actual
2601 * allocated space. Return < 0 if error or unknown.
2603 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
2605 BlockDriver
*drv
= bs
->drv
;
2609 if (drv
->bdrv_get_allocated_file_size
) {
2610 return drv
->bdrv_get_allocated_file_size(bs
);
2613 return bdrv_get_allocated_file_size(bs
->file
->bs
);
2619 * Return number of sectors on success, -errno on error.
2621 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
2623 BlockDriver
*drv
= bs
->drv
;
2628 if (drv
->has_variable_length
) {
2629 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
2634 return bs
->total_sectors
;
2638 * Return length in bytes on success, -errno on error.
2639 * The length is always a multiple of BDRV_SECTOR_SIZE.
2641 int64_t bdrv_getlength(BlockDriverState
*bs
)
2643 int64_t ret
= bdrv_nb_sectors(bs
);
2645 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
2646 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
2649 /* return 0 as number of sectors if no device present or error */
2650 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
2652 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
2654 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
2657 int bdrv_is_read_only(BlockDriverState
*bs
)
2659 return bs
->read_only
;
2662 int bdrv_is_sg(BlockDriverState
*bs
)
2667 int bdrv_is_encrypted(BlockDriverState
*bs
)
2669 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2672 return bs
->encrypted
;
2675 int bdrv_key_required(BlockDriverState
*bs
)
2677 BdrvChild
*backing
= bs
->backing
;
2679 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
2682 return (bs
->encrypted
&& !bs
->valid_key
);
2685 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
2688 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2689 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
2695 if (!bs
->encrypted
) {
2697 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
2700 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
2703 } else if (!bs
->valid_key
) {
2704 /* call the change callback now, we skipped it on open */
2706 bdrv_parent_cb_change_media(bs
, true);
2712 * Provide an encryption key for @bs.
2713 * If @key is non-null:
2714 * If @bs is not encrypted, fail.
2715 * Else if the key is invalid, fail.
2716 * Else set @bs's key to @key, replacing the existing key, if any.
2718 * If @bs is encrypted and still lacks a key, fail.
2720 * On failure, store an error object through @errp if non-null.
2722 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
2725 if (!bdrv_is_encrypted(bs
)) {
2726 error_setg(errp
, "Node '%s' is not encrypted",
2727 bdrv_get_device_or_node_name(bs
));
2728 } else if (bdrv_set_key(bs
, key
) < 0) {
2729 error_setg(errp
, QERR_INVALID_PASSWORD
);
2732 if (bdrv_key_required(bs
)) {
2733 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
2734 "'%s' (%s) is encrypted",
2735 bdrv_get_device_or_node_name(bs
),
2736 bdrv_get_encrypted_filename(bs
));
2741 const char *bdrv_get_format_name(BlockDriverState
*bs
)
2743 return bs
->drv
? bs
->drv
->format_name
: NULL
;
2746 static int qsort_strcmp(const void *a
, const void *b
)
2748 return strcmp(a
, b
);
2751 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
2757 const char **formats
= NULL
;
2759 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
2760 if (drv
->format_name
) {
2763 while (formats
&& i
&& !found
) {
2764 found
= !strcmp(formats
[--i
], drv
->format_name
);
2768 formats
= g_renew(const char *, formats
, count
+ 1);
2769 formats
[count
++] = drv
->format_name
;
2774 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
2776 for (i
= 0; i
< count
; i
++) {
2777 it(opaque
, formats
[i
]);
2783 /* This function is to find a node in the bs graph */
2784 BlockDriverState
*bdrv_find_node(const char *node_name
)
2786 BlockDriverState
*bs
;
2790 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2791 if (!strcmp(node_name
, bs
->node_name
)) {
2798 /* Put this QMP function here so it can access the static graph_bdrv_states. */
2799 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
2801 BlockDeviceInfoList
*list
, *entry
;
2802 BlockDriverState
*bs
;
2805 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2806 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
2808 qapi_free_BlockDeviceInfoList(list
);
2811 entry
= g_malloc0(sizeof(*entry
));
2812 entry
->value
= info
;
2820 BlockDriverState
*bdrv_lookup_bs(const char *device
,
2821 const char *node_name
,
2825 BlockDriverState
*bs
;
2828 blk
= blk_by_name(device
);
2833 error_setg(errp
, "Device '%s' has no medium", device
);
2841 bs
= bdrv_find_node(node_name
);
2848 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
2849 device
? device
: "",
2850 node_name
? node_name
: "");
2854 /* If 'base' is in the same chain as 'top', return true. Otherwise,
2855 * return false. If either argument is NULL, return false. */
2856 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
2858 while (top
&& top
!= base
) {
2859 top
= backing_bs(top
);
2865 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
2868 return QTAILQ_FIRST(&graph_bdrv_states
);
2870 return QTAILQ_NEXT(bs
, node_list
);
2873 /* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by
2874 * the monitor or attached to a BlockBackend */
2875 BlockDriverState
*bdrv_next(BlockDriverState
*bs
)
2877 if (!bs
|| bs
->blk
) {
2878 bs
= blk_next_root_bs(bs
);
2884 /* Ignore all BDSs that are attached to a BlockBackend here; they have been
2885 * handled by the above block already */
2887 bs
= bdrv_next_monitor_owned(bs
);
2888 } while (bs
&& bs
->blk
);
2892 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
2894 return bs
->node_name
;
2897 static const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
2902 /* If multiple parents have a name, just pick the first one. */
2903 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2904 if (c
->role
->get_name
) {
2905 name
= c
->role
->get_name(c
);
2906 if (name
&& *name
) {
2915 /* TODO check what callers really want: bs->node_name or blk_name() */
2916 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
2918 return bdrv_get_parent_name(bs
) ?: "";
2921 /* This can be used to identify nodes that might not have a device
2922 * name associated. Since node and device names live in the same
2923 * namespace, the result is unambiguous. The exception is if both are
2924 * absent, then this returns an empty (non-null) string. */
2925 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
2927 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
2930 int bdrv_get_flags(BlockDriverState
*bs
)
2932 return bs
->open_flags
;
2935 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
2940 int bdrv_has_zero_init(BlockDriverState
*bs
)
2944 /* If BS is a copy on write image, it is initialized to
2945 the contents of the base image, which may not be zeroes. */
2949 if (bs
->drv
->bdrv_has_zero_init
) {
2950 return bs
->drv
->bdrv_has_zero_init(bs
);
2957 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
2959 BlockDriverInfo bdi
;
2965 if (bdrv_get_info(bs
, &bdi
) == 0) {
2966 return bdi
.unallocated_blocks_are_zero
;
2972 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
2974 BlockDriverInfo bdi
;
2976 if (bs
->backing
|| !(bs
->open_flags
& BDRV_O_UNMAP
)) {
2980 if (bdrv_get_info(bs
, &bdi
) == 0) {
2981 return bdi
.can_write_zeroes_with_unmap
;
2987 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
2989 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
2990 return bs
->backing_file
;
2991 else if (bs
->encrypted
)
2992 return bs
->filename
;
2997 void bdrv_get_backing_filename(BlockDriverState
*bs
,
2998 char *filename
, int filename_size
)
3000 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3003 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3005 BlockDriver
*drv
= bs
->drv
;
3008 if (!drv
->bdrv_get_info
)
3010 memset(bdi
, 0, sizeof(*bdi
));
3011 return drv
->bdrv_get_info(bs
, bdi
);
3014 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3016 BlockDriver
*drv
= bs
->drv
;
3017 if (drv
&& drv
->bdrv_get_specific_info
) {
3018 return drv
->bdrv_get_specific_info(bs
);
3023 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3025 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3029 bs
->drv
->bdrv_debug_event(bs
, event
);
3032 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3035 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3036 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3039 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3040 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3046 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3048 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3049 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3052 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3053 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3059 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3061 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3062 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3065 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3066 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3072 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3074 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3075 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3078 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3079 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3085 int bdrv_is_snapshot(BlockDriverState
*bs
)
3087 return !!(bs
->open_flags
& BDRV_O_SNAPSHOT
);
3090 /* backing_file can either be relative, or absolute, or a protocol. If it is
3091 * relative, it must be relative to the chain. So, passing in bs->filename
3092 * from a BDS as backing_file should not be done, as that may be relative to
3093 * the CWD rather than the chain. */
3094 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3095 const char *backing_file
)
3097 char *filename_full
= NULL
;
3098 char *backing_file_full
= NULL
;
3099 char *filename_tmp
= NULL
;
3100 int is_protocol
= 0;
3101 BlockDriverState
*curr_bs
= NULL
;
3102 BlockDriverState
*retval
= NULL
;
3104 if (!bs
|| !bs
->drv
|| !backing_file
) {
3108 filename_full
= g_malloc(PATH_MAX
);
3109 backing_file_full
= g_malloc(PATH_MAX
);
3110 filename_tmp
= g_malloc(PATH_MAX
);
3112 is_protocol
= path_has_protocol(backing_file
);
3114 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3116 /* If either of the filename paths is actually a protocol, then
3117 * compare unmodified paths; otherwise make paths relative */
3118 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3119 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3120 retval
= curr_bs
->backing
->bs
;
3124 /* If not an absolute filename path, make it relative to the current
3125 * image's filename path */
3126 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3129 /* We are going to compare absolute pathnames */
3130 if (!realpath(filename_tmp
, filename_full
)) {
3134 /* We need to make sure the backing filename we are comparing against
3135 * is relative to the current image filename (or absolute) */
3136 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3137 curr_bs
->backing_file
);
3139 if (!realpath(filename_tmp
, backing_file_full
)) {
3143 if (strcmp(backing_file_full
, filename_full
) == 0) {
3144 retval
= curr_bs
->backing
->bs
;
3150 g_free(filename_full
);
3151 g_free(backing_file_full
);
3152 g_free(filename_tmp
);
3156 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3166 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3169 void bdrv_init(void)
3171 module_call_init(MODULE_INIT_BLOCK
);
3174 void bdrv_init_with_whitelist(void)
3176 use_bdrv_whitelist
= 1;
3180 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3183 Error
*local_err
= NULL
;
3190 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3193 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3195 if (bs
->drv
->bdrv_invalidate_cache
) {
3196 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3198 bs
->open_flags
|= BDRV_O_INACTIVE
;
3199 error_propagate(errp
, local_err
);
3204 QLIST_FOREACH(child
, &bs
->children
, next
) {
3205 bdrv_invalidate_cache(child
->bs
, &local_err
);
3207 bs
->open_flags
|= BDRV_O_INACTIVE
;
3208 error_propagate(errp
, local_err
);
3213 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3215 bs
->open_flags
|= BDRV_O_INACTIVE
;
3216 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3221 void bdrv_invalidate_cache_all(Error
**errp
)
3223 BlockDriverState
*bs
= NULL
;
3224 Error
*local_err
= NULL
;
3226 while ((bs
= bdrv_next(bs
)) != NULL
) {
3227 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3229 aio_context_acquire(aio_context
);
3230 bdrv_invalidate_cache(bs
, &local_err
);
3231 aio_context_release(aio_context
);
3233 error_propagate(errp
, local_err
);
3239 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3245 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3246 ret
= bs
->drv
->bdrv_inactivate(bs
);
3252 QLIST_FOREACH(child
, &bs
->children
, next
) {
3253 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
3260 bs
->open_flags
|= BDRV_O_INACTIVE
;
3265 int bdrv_inactivate_all(void)
3267 BlockDriverState
*bs
= NULL
;
3271 while ((bs
= bdrv_next(bs
)) != NULL
) {
3272 aio_context_acquire(bdrv_get_aio_context(bs
));
3275 /* We do two passes of inactivation. The first pass calls to drivers'
3276 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
3277 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
3279 for (pass
= 0; pass
< 2; pass
++) {
3281 while ((bs
= bdrv_next(bs
)) != NULL
) {
3282 ret
= bdrv_inactivate_recurse(bs
, pass
);
3291 while ((bs
= bdrv_next(bs
)) != NULL
) {
3292 aio_context_release(bdrv_get_aio_context(bs
));
3298 /**************************************************************/
3299 /* removable device support */
3302 * Return TRUE if the media is present
3304 bool bdrv_is_inserted(BlockDriverState
*bs
)
3306 BlockDriver
*drv
= bs
->drv
;
3312 if (drv
->bdrv_is_inserted
) {
3313 return drv
->bdrv_is_inserted(bs
);
3315 QLIST_FOREACH(child
, &bs
->children
, next
) {
3316 if (!bdrv_is_inserted(child
->bs
)) {
3324 * Return whether the media changed since the last call to this
3325 * function, or -ENOTSUP if we don't know. Most drivers don't know.
3327 int bdrv_media_changed(BlockDriverState
*bs
)
3329 BlockDriver
*drv
= bs
->drv
;
3331 if (drv
&& drv
->bdrv_media_changed
) {
3332 return drv
->bdrv_media_changed(bs
);
3338 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
3340 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
3342 BlockDriver
*drv
= bs
->drv
;
3343 const char *device_name
;
3345 if (drv
&& drv
->bdrv_eject
) {
3346 drv
->bdrv_eject(bs
, eject_flag
);
3349 device_name
= bdrv_get_device_name(bs
);
3350 if (device_name
[0] != '\0') {
3351 qapi_event_send_device_tray_moved(device_name
,
3352 eject_flag
, &error_abort
);
3357 * Lock or unlock the media (if it is locked, the user won't be able
3358 * to eject it manually).
3360 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
3362 BlockDriver
*drv
= bs
->drv
;
3364 trace_bdrv_lock_medium(bs
, locked
);
3366 if (drv
&& drv
->bdrv_lock_medium
) {
3367 drv
->bdrv_lock_medium(bs
, locked
);
3371 /* Get a reference to bs */
3372 void bdrv_ref(BlockDriverState
*bs
)
3377 /* Release a previously grabbed reference to bs.
3378 * If after releasing, reference count is zero, the BlockDriverState is
3380 void bdrv_unref(BlockDriverState
*bs
)
3385 assert(bs
->refcnt
> 0);
3386 if (--bs
->refcnt
== 0) {
3391 struct BdrvOpBlocker
{
3393 QLIST_ENTRY(BdrvOpBlocker
) list
;
3396 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
3398 BdrvOpBlocker
*blocker
;
3399 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3400 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
3401 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
3403 *errp
= error_copy(blocker
->reason
);
3404 error_prepend(errp
, "Node '%s' is busy: ",
3405 bdrv_get_device_or_node_name(bs
));
3412 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3414 BdrvOpBlocker
*blocker
;
3415 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3417 blocker
= g_new0(BdrvOpBlocker
, 1);
3418 blocker
->reason
= reason
;
3419 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
3422 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3424 BdrvOpBlocker
*blocker
, *next
;
3425 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3426 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
3427 if (blocker
->reason
== reason
) {
3428 QLIST_REMOVE(blocker
, list
);
3434 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
3437 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3438 bdrv_op_block(bs
, i
, reason
);
3442 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
3445 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3446 bdrv_op_unblock(bs
, i
, reason
);
3450 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
3454 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3455 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
3462 void bdrv_img_create(const char *filename
, const char *fmt
,
3463 const char *base_filename
, const char *base_fmt
,
3464 char *options
, uint64_t img_size
, int flags
,
3465 Error
**errp
, bool quiet
)
3467 QemuOptsList
*create_opts
= NULL
;
3468 QemuOpts
*opts
= NULL
;
3469 const char *backing_fmt
, *backing_file
;
3471 BlockDriver
*drv
, *proto_drv
;
3472 Error
*local_err
= NULL
;
3475 /* Find driver and parse its options */
3476 drv
= bdrv_find_format(fmt
);
3478 error_setg(errp
, "Unknown file format '%s'", fmt
);
3482 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
3487 if (!drv
->create_opts
) {
3488 error_setg(errp
, "Format driver '%s' does not support image creation",
3493 if (!proto_drv
->create_opts
) {
3494 error_setg(errp
, "Protocol driver '%s' does not support image creation",
3495 proto_drv
->format_name
);
3499 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
3500 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
3502 /* Create parameter list with default values */
3503 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
3504 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
3506 /* Parse -o options */
3508 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
3510 error_report_err(local_err
);
3512 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
3517 if (base_filename
) {
3518 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
3520 error_setg(errp
, "Backing file not supported for file format '%s'",
3527 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
3529 error_setg(errp
, "Backing file format not supported for file "
3530 "format '%s'", fmt
);
3535 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
3537 if (!strcmp(filename
, backing_file
)) {
3538 error_setg(errp
, "Error: Trying to create an image with the "
3539 "same filename as the backing file");
3544 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
3546 // The size for the image must always be specified, with one exception:
3547 // If we are using a backing file, we can obtain the size from there
3548 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
3551 BlockDriverState
*bs
;
3552 char *full_backing
= g_new0(char, PATH_MAX
);
3555 QDict
*backing_options
= NULL
;
3557 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
3558 full_backing
, PATH_MAX
,
3561 g_free(full_backing
);
3565 /* backing files always opened read-only */
3567 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
3570 backing_options
= qdict_new();
3571 qdict_put(backing_options
, "driver",
3572 qstring_from_str(backing_fmt
));
3576 ret
= bdrv_open(&bs
, full_backing
, NULL
, backing_options
,
3577 back_flags
, &local_err
);
3578 g_free(full_backing
);
3582 size
= bdrv_getlength(bs
);
3584 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
3590 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
3594 error_setg(errp
, "Image creation needs a size parameter");
3600 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
3601 qemu_opts_print(opts
, " ");
3605 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
3607 if (ret
== -EFBIG
) {
3608 /* This is generally a better message than whatever the driver would
3609 * deliver (especially because of the cluster_size_hint), since that
3610 * is most probably not much different from "image too large". */
3611 const char *cluster_size_hint
= "";
3612 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
3613 cluster_size_hint
= " (try using a larger cluster size)";
3615 error_setg(errp
, "The image size is too large for file format '%s'"
3616 "%s", fmt
, cluster_size_hint
);
3617 error_free(local_err
);
3622 qemu_opts_del(opts
);
3623 qemu_opts_free(create_opts
);
3625 error_propagate(errp
, local_err
);
3629 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
3631 return bs
->aio_context
;
3634 void bdrv_detach_aio_context(BlockDriverState
*bs
)
3636 BdrvAioNotifier
*baf
;
3642 QLIST_FOREACH(baf
, &bs
->aio_notifiers
, list
) {
3643 baf
->detach_aio_context(baf
->opaque
);
3646 if (bs
->drv
->bdrv_detach_aio_context
) {
3647 bs
->drv
->bdrv_detach_aio_context(bs
);
3650 bdrv_detach_aio_context(bs
->file
->bs
);
3653 bdrv_detach_aio_context(bs
->backing
->bs
);
3656 bs
->aio_context
= NULL
;
3659 void bdrv_attach_aio_context(BlockDriverState
*bs
,
3660 AioContext
*new_context
)
3662 BdrvAioNotifier
*ban
;
3668 bs
->aio_context
= new_context
;
3671 bdrv_attach_aio_context(bs
->backing
->bs
, new_context
);
3674 bdrv_attach_aio_context(bs
->file
->bs
, new_context
);
3676 if (bs
->drv
->bdrv_attach_aio_context
) {
3677 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
3680 QLIST_FOREACH(ban
, &bs
->aio_notifiers
, list
) {
3681 ban
->attached_aio_context(new_context
, ban
->opaque
);
3685 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
3687 bdrv_drain(bs
); /* ensure there are no in-flight requests */
3689 bdrv_detach_aio_context(bs
);
3691 /* This function executes in the old AioContext so acquire the new one in
3692 * case it runs in a different thread.
3694 aio_context_acquire(new_context
);
3695 bdrv_attach_aio_context(bs
, new_context
);
3696 aio_context_release(new_context
);
3699 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
3700 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
3701 void (*detach_aio_context
)(void *opaque
), void *opaque
)
3703 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
3704 *ban
= (BdrvAioNotifier
){
3705 .attached_aio_context
= attached_aio_context
,
3706 .detach_aio_context
= detach_aio_context
,
3710 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
3713 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
3714 void (*attached_aio_context
)(AioContext
*,
3716 void (*detach_aio_context
)(void *),
3719 BdrvAioNotifier
*ban
, *ban_next
;
3721 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3722 if (ban
->attached_aio_context
== attached_aio_context
&&
3723 ban
->detach_aio_context
== detach_aio_context
&&
3724 ban
->opaque
== opaque
)
3726 QLIST_REMOVE(ban
, list
);
3736 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
3737 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
3739 if (!bs
->drv
->bdrv_amend_options
) {
3742 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
3745 /* This function will be called by the bdrv_recurse_is_first_non_filter method
3746 * of block filter and by bdrv_is_first_non_filter.
3747 * It is used to test if the given bs is the candidate or recurse more in the
3750 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
3751 BlockDriverState
*candidate
)
3753 /* return false if basic checks fails */
3754 if (!bs
|| !bs
->drv
) {
3758 /* the code reached a non block filter driver -> check if the bs is
3759 * the same as the candidate. It's the recursion termination condition.
3761 if (!bs
->drv
->is_filter
) {
3762 return bs
== candidate
;
3764 /* Down this path the driver is a block filter driver */
3766 /* If the block filter recursion method is defined use it to recurse down
3769 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
3770 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
3773 /* the driver is a block filter but don't allow to recurse -> return false
3778 /* This function checks if the candidate is the first non filter bs down it's
3779 * bs chain. Since we don't have pointers to parents it explore all bs chains
3780 * from the top. Some filters can choose not to pass down the recursion.
3782 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
3784 BlockDriverState
*bs
= NULL
;
3786 /* walk down the bs forest recursively */
3787 while ((bs
= bdrv_next(bs
)) != NULL
) {
3790 /* try to recurse in this top level bs */
3791 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
3793 /* candidate is the first non filter */
3802 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
3803 const char *node_name
, Error
**errp
)
3805 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
3806 AioContext
*aio_context
;
3808 if (!to_replace_bs
) {
3809 error_setg(errp
, "Node name '%s' not found", node_name
);
3813 aio_context
= bdrv_get_aio_context(to_replace_bs
);
3814 aio_context_acquire(aio_context
);
3816 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
3817 to_replace_bs
= NULL
;
3821 /* We don't want arbitrary node of the BDS chain to be replaced only the top
3822 * most non filter in order to prevent data corruption.
3823 * Another benefit is that this tests exclude backing files which are
3824 * blocked by the backing blockers.
3826 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
3827 error_setg(errp
, "Only top most non filter can be replaced");
3828 to_replace_bs
= NULL
;
3833 aio_context_release(aio_context
);
3834 return to_replace_bs
;
3837 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
3839 const QDictEntry
*entry
;
3842 bool found_any
= false;
3845 for (entry
= qdict_first(bs
->options
); entry
;
3846 entry
= qdict_next(bs
->options
, entry
))
3848 /* Exclude options for children */
3849 QLIST_FOREACH(child
, &bs
->children
, next
) {
3850 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
3851 && (!*p
|| *p
== '.'))
3860 /* And exclude all non-driver-specific options */
3861 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
3862 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
3870 qobject_incref(qdict_entry_value(entry
));
3871 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
3878 /* Updates the following BDS fields:
3879 * - exact_filename: A filename which may be used for opening a block device
3880 * which (mostly) equals the given BDS (even without any
3881 * other options; so reading and writing must return the same
3882 * results, but caching etc. may be different)
3883 * - full_open_options: Options which, when given when opening a block device
3884 * (without a filename), result in a BDS (mostly)
3885 * equalling the given one
3886 * - filename: If exact_filename is set, it is copied here. Otherwise,
3887 * full_open_options is converted to a JSON object, prefixed with
3888 * "json:" (for use through the JSON pseudo protocol) and put here.
3890 void bdrv_refresh_filename(BlockDriverState
*bs
)
3892 BlockDriver
*drv
= bs
->drv
;
3899 /* This BDS's file name will most probably depend on its file's name, so
3900 * refresh that first */
3902 bdrv_refresh_filename(bs
->file
->bs
);
3905 if (drv
->bdrv_refresh_filename
) {
3906 /* Obsolete information is of no use here, so drop the old file name
3907 * information before refreshing it */
3908 bs
->exact_filename
[0] = '\0';
3909 if (bs
->full_open_options
) {
3910 QDECREF(bs
->full_open_options
);
3911 bs
->full_open_options
= NULL
;
3915 append_open_options(opts
, bs
);
3916 drv
->bdrv_refresh_filename(bs
, opts
);
3918 } else if (bs
->file
) {
3919 /* Try to reconstruct valid information from the underlying file */
3920 bool has_open_options
;
3922 bs
->exact_filename
[0] = '\0';
3923 if (bs
->full_open_options
) {
3924 QDECREF(bs
->full_open_options
);
3925 bs
->full_open_options
= NULL
;
3929 has_open_options
= append_open_options(opts
, bs
);
3931 /* If no specific options have been given for this BDS, the filename of
3932 * the underlying file should suffice for this one as well */
3933 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
3934 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
3936 /* Reconstructing the full options QDict is simple for most format block
3937 * drivers, as long as the full options are known for the underlying
3938 * file BDS. The full options QDict of that file BDS should somehow
3939 * contain a representation of the filename, therefore the following
3940 * suffices without querying the (exact_)filename of this BDS. */
3941 if (bs
->file
->bs
->full_open_options
) {
3942 qdict_put_obj(opts
, "driver",
3943 QOBJECT(qstring_from_str(drv
->format_name
)));
3944 QINCREF(bs
->file
->bs
->full_open_options
);
3945 qdict_put_obj(opts
, "file",
3946 QOBJECT(bs
->file
->bs
->full_open_options
));
3948 bs
->full_open_options
= opts
;
3952 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
3953 /* There is no underlying file BDS (at least referenced by BDS.file),
3954 * so the full options QDict should be equal to the options given
3955 * specifically for this block device when it was opened (plus the
3956 * driver specification).
3957 * Because those options don't change, there is no need to update
3958 * full_open_options when it's already set. */
3961 append_open_options(opts
, bs
);
3962 qdict_put_obj(opts
, "driver",
3963 QOBJECT(qstring_from_str(drv
->format_name
)));
3965 if (bs
->exact_filename
[0]) {
3966 /* This may not work for all block protocol drivers (some may
3967 * require this filename to be parsed), but we have to find some
3968 * default solution here, so just include it. If some block driver
3969 * does not support pure options without any filename at all or
3970 * needs some special format of the options QDict, it needs to
3971 * implement the driver-specific bdrv_refresh_filename() function.
3973 qdict_put_obj(opts
, "filename",
3974 QOBJECT(qstring_from_str(bs
->exact_filename
)));
3977 bs
->full_open_options
= opts
;
3980 if (bs
->exact_filename
[0]) {
3981 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
3982 } else if (bs
->full_open_options
) {
3983 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
3984 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
3985 qstring_get_str(json
));
3991 * Hot add/remove a BDS's child. So the user can take a child offline when
3992 * it is broken and take a new child online
3994 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
3998 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
3999 error_setg(errp
, "The node %s does not support adding a child",
4000 bdrv_get_device_or_node_name(parent_bs
));
4004 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4005 error_setg(errp
, "The node %s already has a parent",
4006 child_bs
->node_name
);
4010 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4013 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4017 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4018 error_setg(errp
, "The node %s does not support removing a child",
4019 bdrv_get_device_or_node_name(parent_bs
));
4023 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4030 error_setg(errp
, "The node %s does not have a child named %s",
4031 bdrv_get_device_or_node_name(parent_bs
),
4032 bdrv_get_device_or_node_name(child
->bs
));
4036 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);