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 BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
1427 QDict
*snapshot_options
,
1430 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
1431 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
1433 QemuOpts
*opts
= NULL
;
1434 BlockDriverState
*bs_snapshot
;
1435 Error
*local_err
= NULL
;
1438 /* if snapshot, we create a temporary backing file and open it
1439 instead of opening 'filename' directly */
1441 /* Get the required size from the image */
1442 total_size
= bdrv_getlength(bs
);
1443 if (total_size
< 0) {
1444 error_setg_errno(errp
, -total_size
, "Could not get image size");
1448 /* Create the temporary image */
1449 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
1451 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
1455 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
1457 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
1458 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
1459 qemu_opts_del(opts
);
1461 error_prepend(errp
, "Could not create temporary overlay '%s': ",
1466 /* Prepare options QDict for the temporary file */
1467 qdict_put(snapshot_options
, "file.driver",
1468 qstring_from_str("file"));
1469 qdict_put(snapshot_options
, "file.filename",
1470 qstring_from_str(tmp_filename
));
1471 qdict_put(snapshot_options
, "driver",
1472 qstring_from_str("qcow2"));
1475 ret
= bdrv_open(&bs_snapshot
, NULL
, NULL
, snapshot_options
,
1477 snapshot_options
= NULL
;
1479 error_propagate(errp
, local_err
);
1483 /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
1484 * call bdrv_unref() on it), so in order to be able to return one, we have
1485 * to increase bs_snapshot's refcount here */
1486 bdrv_ref(bs_snapshot
);
1487 bdrv_append(bs_snapshot
, bs
);
1489 g_free(tmp_filename
);
1493 QDECREF(snapshot_options
);
1494 g_free(tmp_filename
);
1499 * Opens a disk image (raw, qcow2, vmdk, ...)
1501 * options is a QDict of options to pass to the block drivers, or NULL for an
1502 * empty set of options. The reference to the QDict belongs to the block layer
1503 * after the call (even on failure), so if the caller intends to reuse the
1504 * dictionary, it needs to use QINCREF() before calling bdrv_open.
1506 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
1507 * If it is not NULL, the referenced BDS will be reused.
1509 * The reference parameter may be used to specify an existing block device which
1510 * should be opened. If specified, neither options nor a filename may be given,
1511 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
1513 static int bdrv_open_inherit(BlockDriverState
**pbs
, const char *filename
,
1514 const char *reference
, QDict
*options
, int flags
,
1515 BlockDriverState
*parent
,
1516 const BdrvChildRole
*child_role
, Error
**errp
)
1519 BdrvChild
*file
= NULL
;
1520 BlockDriverState
*bs
;
1521 BlockDriver
*drv
= NULL
;
1522 const char *drvname
;
1523 const char *backing
;
1524 Error
*local_err
= NULL
;
1525 QDict
*snapshot_options
= NULL
;
1526 int snapshot_flags
= 0;
1529 assert(!child_role
|| !flags
);
1530 assert(!child_role
== !parent
);
1533 bool options_non_empty
= options
? qdict_size(options
) : false;
1537 error_setg(errp
, "Cannot reuse an existing BDS when referencing "
1538 "another block device");
1542 if (filename
|| options_non_empty
) {
1543 error_setg(errp
, "Cannot reference an existing block device with "
1544 "additional options or a new filename");
1548 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
1564 /* NULL means an empty set of options */
1565 if (options
== NULL
) {
1566 options
= qdict_new();
1569 /* json: syntax counts as explicit options, as if in the QDict */
1570 parse_json_protocol(options
, &filename
, &local_err
);
1576 bs
->explicit_options
= qdict_clone_shallow(options
);
1579 bs
->inherits_from
= parent
;
1580 child_role
->inherit_options(&flags
, options
,
1581 parent
->open_flags
, parent
->options
);
1584 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
1589 bs
->open_flags
= flags
;
1590 bs
->options
= options
;
1591 options
= qdict_clone_shallow(options
);
1593 /* Find the right image format driver */
1594 drvname
= qdict_get_try_str(options
, "driver");
1596 drv
= bdrv_find_format(drvname
);
1598 error_setg(errp
, "Unknown driver: '%s'", drvname
);
1604 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
1606 backing
= qdict_get_try_str(options
, "backing");
1607 if (backing
&& *backing
== '\0') {
1608 flags
|= BDRV_O_NO_BACKING
;
1609 qdict_del(options
, "backing");
1612 /* Open image file without format layer */
1613 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
1614 if (flags
& BDRV_O_RDWR
) {
1615 flags
|= BDRV_O_ALLOW_RDWR
;
1617 if (flags
& BDRV_O_SNAPSHOT
) {
1618 snapshot_options
= qdict_new();
1619 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
1621 bdrv_backing_options(&flags
, options
, flags
, options
);
1624 bs
->open_flags
= flags
;
1626 file
= bdrv_open_child(filename
, options
, "file", bs
,
1627 &child_file
, true, &local_err
);
1634 /* Image format probing */
1637 ret
= find_image_format(file
->bs
, filename
, &drv
, &local_err
);
1642 * This option update would logically belong in bdrv_fill_options(),
1643 * but we first need to open bs->file for the probing to work, while
1644 * opening bs->file already requires the (mostly) final set of options
1645 * so that cache mode etc. can be inherited.
1647 * Adding the driver later is somewhat ugly, but it's not an option
1648 * that would ever be inherited, so it's correct. We just need to make
1649 * sure to update both bs->options (which has the full effective
1650 * options for bs) and options (which has file.* already removed).
1652 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
1653 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
1655 error_setg(errp
, "Must specify either driver or file");
1660 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
1661 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
1662 /* file must be NULL if a protocol BDS is about to be created
1663 * (the inverse results in an error message from bdrv_open_common()) */
1664 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
1666 /* Open the image */
1667 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
1672 if (file
&& (bs
->file
!= file
)) {
1673 bdrv_unref_child(bs
, file
);
1677 /* If there is a backing file, use it */
1678 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
1679 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
1681 goto close_and_fail
;
1685 bdrv_refresh_filename(bs
);
1687 /* Check if any unknown options were used */
1688 if (options
&& (qdict_size(options
) != 0)) {
1689 const QDictEntry
*entry
= qdict_first(options
);
1690 if (flags
& BDRV_O_PROTOCOL
) {
1691 error_setg(errp
, "Block protocol '%s' doesn't support the option "
1692 "'%s'", drv
->format_name
, entry
->key
);
1695 "Block format '%s' does not support the option '%s'",
1696 drv
->format_name
, entry
->key
);
1700 goto close_and_fail
;
1703 if (!bdrv_key_required(bs
)) {
1704 bdrv_parent_cb_change_media(bs
, true);
1705 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
1706 && !runstate_check(RUN_STATE_INMIGRATE
)
1707 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
1709 "Guest must be stopped for opening of encrypted image");
1711 goto close_and_fail
;
1716 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
1717 * temporary snapshot afterwards. */
1718 if (snapshot_flags
) {
1719 BlockDriverState
*snapshot_bs
;
1720 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
1721 snapshot_options
, &local_err
);
1722 snapshot_options
= NULL
;
1725 goto close_and_fail
;
1728 /* We are not going to return bs but the overlay on top of it
1729 * (snapshot_bs); thus, we have to drop the strong reference to bs
1730 * (which we obtained by calling bdrv_new()). bs will not be
1731 * deleted, though, because the overlay still has a reference to it.
1736 /* We are not going to return snapshot_bs, so we have to drop the
1737 * strong reference to it (which was returned by
1738 * bdrv_append_temp_snapshot()). snapshot_bs will not be deleted,
1739 * though, because bdrv_append_temp_snapshot() made all parental
1740 * references to bs (*pbs) point to snapshot_bs.
1741 * In fact, if *pbs was not NULL, we are not going to return any new
1742 * BDS. But we do not need to decrement bs's refcount here as is
1743 * done above, because with a non-NULL *pbs this function never even
1744 * had a strong reference to bs. */
1745 bdrv_unref(snapshot_bs
);
1757 bdrv_unref_child(bs
, file
);
1759 QDECREF(snapshot_options
);
1760 QDECREF(bs
->explicit_options
);
1761 QDECREF(bs
->options
);
1765 /* If *pbs is NULL, a new BDS has been created in this function and
1766 needs to be freed now. Otherwise, it does not need to be closed,
1767 since it has not really been opened yet. */
1771 error_propagate(errp
, local_err
);
1776 /* See fail path, but now the BDS has to be always closed */
1782 QDECREF(snapshot_options
);
1785 error_propagate(errp
, local_err
);
1790 int bdrv_open(BlockDriverState
**pbs
, const char *filename
,
1791 const char *reference
, QDict
*options
, int flags
, Error
**errp
)
1793 return bdrv_open_inherit(pbs
, filename
, reference
, options
, flags
, NULL
,
1797 typedef struct BlockReopenQueueEntry
{
1799 BDRVReopenState state
;
1800 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1801 } BlockReopenQueueEntry
;
1804 * Adds a BlockDriverState to a simple queue for an atomic, transactional
1805 * reopen of multiple devices.
1807 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
1808 * already performed, or alternatively may be NULL a new BlockReopenQueue will
1809 * be created and initialized. This newly created BlockReopenQueue should be
1810 * passed back in for subsequent calls that are intended to be of the same
1813 * bs is the BlockDriverState to add to the reopen queue.
1815 * options contains the changed options for the associated bs
1816 * (the BlockReopenQueue takes ownership)
1818 * flags contains the open flags for the associated bs
1820 * returns a pointer to bs_queue, which is either the newly allocated
1821 * bs_queue, or the existing bs_queue being used.
1824 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
1825 BlockDriverState
*bs
,
1828 const BdrvChildRole
*role
,
1829 QDict
*parent_options
,
1834 BlockReopenQueueEntry
*bs_entry
;
1836 QDict
*old_options
, *explicit_options
;
1838 if (bs_queue
== NULL
) {
1839 bs_queue
= g_new0(BlockReopenQueue
, 1);
1840 QSIMPLEQ_INIT(bs_queue
);
1844 options
= qdict_new();
1848 * Precedence of options:
1849 * 1. Explicitly passed in options (highest)
1850 * 2. Set in flags (only for top level)
1851 * 3. Retained from explicitly set options of bs
1852 * 4. Inherited from parent node
1853 * 5. Retained from effective options of bs
1856 if (!parent_options
) {
1858 * Any setting represented by flags is always updated. If the
1859 * corresponding QDict option is set, it takes precedence. Otherwise
1860 * the flag is translated into a QDict option. The old setting of bs is
1863 update_options_from_flags(options
, flags
);
1866 /* Old explicitly set values (don't overwrite by inherited value) */
1867 old_options
= qdict_clone_shallow(bs
->explicit_options
);
1868 bdrv_join_options(bs
, options
, old_options
);
1869 QDECREF(old_options
);
1871 explicit_options
= qdict_clone_shallow(options
);
1873 /* Inherit from parent node */
1874 if (parent_options
) {
1876 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
1879 /* Old values are used for options that aren't set yet */
1880 old_options
= qdict_clone_shallow(bs
->options
);
1881 bdrv_join_options(bs
, options
, old_options
);
1882 QDECREF(old_options
);
1884 /* bdrv_open() masks this flag out */
1885 flags
&= ~BDRV_O_PROTOCOL
;
1887 QLIST_FOREACH(child
, &bs
->children
, next
) {
1888 QDict
*new_child_options
;
1889 char *child_key_dot
;
1891 /* reopen can only change the options of block devices that were
1892 * implicitly created and inherited options. For other (referenced)
1893 * block devices, a syntax like "backing.foo" results in an error. */
1894 if (child
->bs
->inherits_from
!= bs
) {
1898 child_key_dot
= g_strdup_printf("%s.", child
->name
);
1899 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
1900 g_free(child_key_dot
);
1902 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
1903 child
->role
, options
, flags
);
1906 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
1907 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
1909 bs_entry
->state
.bs
= bs
;
1910 bs_entry
->state
.options
= options
;
1911 bs_entry
->state
.explicit_options
= explicit_options
;
1912 bs_entry
->state
.flags
= flags
;
1917 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
1918 BlockDriverState
*bs
,
1919 QDict
*options
, int flags
)
1921 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
1926 * Reopen multiple BlockDriverStates atomically & transactionally.
1928 * The queue passed in (bs_queue) must have been built up previous
1929 * via bdrv_reopen_queue().
1931 * Reopens all BDS specified in the queue, with the appropriate
1932 * flags. All devices are prepared for reopen, and failure of any
1933 * device will cause all device changes to be abandonded, and intermediate
1936 * If all devices prepare successfully, then the changes are committed
1940 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
)
1943 BlockReopenQueueEntry
*bs_entry
, *next
;
1944 Error
*local_err
= NULL
;
1946 assert(bs_queue
!= NULL
);
1950 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1951 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
1952 error_propagate(errp
, local_err
);
1955 bs_entry
->prepared
= true;
1958 /* If we reach this point, we have success and just need to apply the
1961 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1962 bdrv_reopen_commit(&bs_entry
->state
);
1968 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
1969 if (ret
&& bs_entry
->prepared
) {
1970 bdrv_reopen_abort(&bs_entry
->state
);
1972 QDECREF(bs_entry
->state
.explicit_options
);
1974 QDECREF(bs_entry
->state
.options
);
1982 /* Reopen a single BlockDriverState with the specified flags. */
1983 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
1986 Error
*local_err
= NULL
;
1987 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
1989 ret
= bdrv_reopen_multiple(queue
, &local_err
);
1990 if (local_err
!= NULL
) {
1991 error_propagate(errp
, local_err
);
1998 * Prepares a BlockDriverState for reopen. All changes are staged in the
1999 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2000 * the block driver layer .bdrv_reopen_prepare()
2002 * bs is the BlockDriverState to reopen
2003 * flags are the new open flags
2004 * queue is the reopen queue
2006 * Returns 0 on success, non-zero on error. On error errp will be set
2009 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2010 * It is the responsibility of the caller to then call the abort() or
2011 * commit() for any other BDS that have been left in a prepare() state
2014 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2018 Error
*local_err
= NULL
;
2023 assert(reopen_state
!= NULL
);
2024 assert(reopen_state
->bs
->drv
!= NULL
);
2025 drv
= reopen_state
->bs
->drv
;
2027 /* Process generic block layer options */
2028 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2029 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2031 error_propagate(errp
, local_err
);
2036 update_flags_from_options(&reopen_state
->flags
, opts
);
2038 /* node-name and driver must be unchanged. Put them back into the QDict, so
2039 * that they are checked at the end of this function. */
2040 value
= qemu_opt_get(opts
, "node-name");
2042 qdict_put(reopen_state
->options
, "node-name", qstring_from_str(value
));
2045 value
= qemu_opt_get(opts
, "driver");
2047 qdict_put(reopen_state
->options
, "driver", qstring_from_str(value
));
2050 /* if we are to stay read-only, do not allow permission change
2052 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
2053 reopen_state
->flags
& BDRV_O_RDWR
) {
2054 error_setg(errp
, "Node '%s' is read only",
2055 bdrv_get_device_or_node_name(reopen_state
->bs
));
2060 ret
= bdrv_flush(reopen_state
->bs
);
2062 error_setg_errno(errp
, -ret
, "Error flushing drive");
2066 if (drv
->bdrv_reopen_prepare
) {
2067 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2069 if (local_err
!= NULL
) {
2070 error_propagate(errp
, local_err
);
2072 error_setg(errp
, "failed while preparing to reopen image '%s'",
2073 reopen_state
->bs
->filename
);
2078 /* It is currently mandatory to have a bdrv_reopen_prepare()
2079 * handler for each supported drv. */
2080 error_setg(errp
, "Block format '%s' used by node '%s' "
2081 "does not support reopening files", drv
->format_name
,
2082 bdrv_get_device_or_node_name(reopen_state
->bs
));
2087 /* Options that are not handled are only okay if they are unchanged
2088 * compared to the old state. It is expected that some options are only
2089 * used for the initial open, but not reopen (e.g. filename) */
2090 if (qdict_size(reopen_state
->options
)) {
2091 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2094 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2095 const char *new = qstring_get_str(new_obj
);
2096 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2099 if (!old
|| strcmp(new, old
)) {
2100 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2104 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2110 qemu_opts_del(opts
);
2115 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2116 * makes them final by swapping the staging BlockDriverState contents into
2117 * the active BlockDriverState contents.
2119 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2123 assert(reopen_state
!= NULL
);
2124 drv
= reopen_state
->bs
->drv
;
2125 assert(drv
!= NULL
);
2127 /* If there are any driver level actions to take */
2128 if (drv
->bdrv_reopen_commit
) {
2129 drv
->bdrv_reopen_commit(reopen_state
);
2132 /* set BDS specific flags now */
2133 QDECREF(reopen_state
->bs
->explicit_options
);
2135 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2136 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2137 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2139 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2143 * Abort the reopen, and delete and free the staged changes in
2146 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2150 assert(reopen_state
!= NULL
);
2151 drv
= reopen_state
->bs
->drv
;
2152 assert(drv
!= NULL
);
2154 if (drv
->bdrv_reopen_abort
) {
2155 drv
->bdrv_reopen_abort(reopen_state
);
2158 QDECREF(reopen_state
->explicit_options
);
2162 static void bdrv_close(BlockDriverState
*bs
)
2164 BdrvAioNotifier
*ban
, *ban_next
;
2168 bdrv_drained_begin(bs
); /* complete I/O */
2170 bdrv_drain(bs
); /* in case flush left pending I/O */
2172 bdrv_release_named_dirty_bitmaps(bs
);
2173 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2175 bdrv_parent_cb_change_media(bs
, false);
2178 BdrvChild
*child
, *next
;
2180 bs
->drv
->bdrv_close(bs
);
2183 bdrv_set_backing_hd(bs
, NULL
);
2185 if (bs
->file
!= NULL
) {
2186 bdrv_unref_child(bs
, bs
->file
);
2190 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2191 /* TODO Remove bdrv_unref() from drivers' close function and use
2192 * bdrv_unref_child() here */
2193 if (child
->bs
->inherits_from
== bs
) {
2194 child
->bs
->inherits_from
= NULL
;
2196 bdrv_detach_child(child
);
2201 bs
->copy_on_read
= 0;
2202 bs
->backing_file
[0] = '\0';
2203 bs
->backing_format
[0] = '\0';
2204 bs
->total_sectors
= 0;
2208 bs
->zero_beyond_eof
= false;
2209 QDECREF(bs
->options
);
2210 QDECREF(bs
->explicit_options
);
2212 QDECREF(bs
->full_open_options
);
2213 bs
->full_open_options
= NULL
;
2216 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2219 QLIST_INIT(&bs
->aio_notifiers
);
2220 bdrv_drained_end(bs
);
2223 void bdrv_close_all(void)
2225 BlockDriverState
*bs
;
2226 AioContext
*aio_context
;
2228 /* Drop references from requests still in flight, such as canceled block
2229 * jobs whose AIO context has not been polled yet */
2232 blk_remove_all_bs();
2233 blockdev_close_all_bdrv_states();
2235 /* Cancel all block jobs */
2236 while (!QTAILQ_EMPTY(&all_bdrv_states
)) {
2237 QTAILQ_FOREACH(bs
, &all_bdrv_states
, bs_list
) {
2238 aio_context
= bdrv_get_aio_context(bs
);
2240 aio_context_acquire(aio_context
);
2242 block_job_cancel_sync(bs
->job
);
2243 aio_context_release(aio_context
);
2246 aio_context_release(aio_context
);
2249 /* All the remaining BlockDriverStates are referenced directly or
2250 * indirectly from block jobs, so there needs to be at least one BDS
2251 * directly used by a block job */
2256 static void change_parent_backing_link(BlockDriverState
*from
,
2257 BlockDriverState
*to
)
2259 BdrvChild
*c
, *next
;
2261 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
2262 assert(c
->role
!= &child_backing
);
2264 QLIST_REMOVE(c
, next_parent
);
2265 QLIST_INSERT_HEAD(&to
->parents
, c
, next_parent
);
2272 * Add new bs contents at the top of an image chain while the chain is
2273 * live, while keeping required fields on the top layer.
2275 * This will modify the BlockDriverState fields, and swap contents
2276 * between bs_new and bs_top. Both bs_new and bs_top are modified.
2278 * bs_new must not be attached to a BlockBackend.
2280 * This function does not create any image files.
2282 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
2283 * that's what the callers commonly need. bs_new will be referenced by the old
2284 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
2285 * reference of its own, it must call bdrv_ref().
2287 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
)
2289 assert(!bdrv_requests_pending(bs_top
));
2290 assert(!bdrv_requests_pending(bs_new
));
2294 change_parent_backing_link(bs_top
, bs_new
);
2295 bdrv_set_backing_hd(bs_new
, bs_top
);
2298 /* bs_new is now referenced by its new parents, we don't need the
2299 * additional reference any more. */
2303 void bdrv_replace_in_backing_chain(BlockDriverState
*old
, BlockDriverState
*new)
2305 assert(!bdrv_requests_pending(old
));
2306 assert(!bdrv_requests_pending(new));
2310 change_parent_backing_link(old
, new);
2312 /* Change backing files if a previously independent node is added to the
2313 * chain. For active commit, we replace top by its own (indirect) backing
2314 * file and don't do anything here so we don't build a loop. */
2315 if (new->backing
== NULL
&& !bdrv_chain_contains(backing_bs(old
), new)) {
2316 bdrv_set_backing_hd(new, backing_bs(old
));
2317 bdrv_set_backing_hd(old
, NULL
);
2323 static void bdrv_delete(BlockDriverState
*bs
)
2326 assert(bdrv_op_blocker_is_empty(bs
));
2327 assert(!bs
->refcnt
);
2331 /* remove from list, if necessary */
2332 if (bs
->node_name
[0] != '\0') {
2333 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
2335 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
2341 * Run consistency checks on an image
2343 * Returns 0 if the check could be completed (it doesn't mean that the image is
2344 * free of errors) or -errno when an internal error occurred. The results of the
2345 * check are stored in res.
2347 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
2349 if (bs
->drv
== NULL
) {
2352 if (bs
->drv
->bdrv_check
== NULL
) {
2356 memset(res
, 0, sizeof(*res
));
2357 return bs
->drv
->bdrv_check(bs
, res
, fix
);
2360 #define COMMIT_BUF_SECTORS 2048
2362 /* commit COW file into the raw image */
2363 int bdrv_commit(BlockDriverState
*bs
)
2365 BlockDriver
*drv
= bs
->drv
;
2366 int64_t sector
, total_sectors
, length
, backing_length
;
2367 int n
, ro
, open_flags
;
2369 uint8_t *buf
= NULL
;
2378 if (bdrv_op_is_blocked(bs
, BLOCK_OP_TYPE_COMMIT_SOURCE
, NULL
) ||
2379 bdrv_op_is_blocked(bs
->backing
->bs
, BLOCK_OP_TYPE_COMMIT_TARGET
, NULL
)) {
2383 ro
= bs
->backing
->bs
->read_only
;
2384 open_flags
= bs
->backing
->bs
->open_flags
;
2387 if (bdrv_reopen(bs
->backing
->bs
, open_flags
| BDRV_O_RDWR
, NULL
)) {
2392 length
= bdrv_getlength(bs
);
2398 backing_length
= bdrv_getlength(bs
->backing
->bs
);
2399 if (backing_length
< 0) {
2400 ret
= backing_length
;
2404 /* If our top snapshot is larger than the backing file image,
2405 * grow the backing file image if possible. If not possible,
2406 * we must return an error */
2407 if (length
> backing_length
) {
2408 ret
= bdrv_truncate(bs
->backing
->bs
, length
);
2414 total_sectors
= length
>> BDRV_SECTOR_BITS
;
2416 /* qemu_try_blockalign() for bs will choose an alignment that works for
2417 * bs->backing->bs as well, so no need to compare the alignment manually. */
2418 buf
= qemu_try_blockalign(bs
, COMMIT_BUF_SECTORS
* BDRV_SECTOR_SIZE
);
2424 for (sector
= 0; sector
< total_sectors
; sector
+= n
) {
2425 ret
= bdrv_is_allocated(bs
, sector
, COMMIT_BUF_SECTORS
, &n
);
2430 ret
= bdrv_read(bs
, sector
, buf
, n
);
2435 ret
= bdrv_write(bs
->backing
->bs
, sector
, buf
, n
);
2442 if (drv
->bdrv_make_empty
) {
2443 ret
= drv
->bdrv_make_empty(bs
);
2451 * Make sure all data we wrote to the backing device is actually
2455 bdrv_flush(bs
->backing
->bs
);
2463 /* ignoring error return here */
2464 bdrv_reopen(bs
->backing
->bs
, open_flags
& ~BDRV_O_RDWR
, NULL
);
2473 * -EINVAL - backing format specified, but no file
2474 * -ENOSPC - can't update the backing file because no space is left in the
2476 * -ENOTSUP - format driver doesn't support changing the backing file
2478 int bdrv_change_backing_file(BlockDriverState
*bs
,
2479 const char *backing_file
, const char *backing_fmt
)
2481 BlockDriver
*drv
= bs
->drv
;
2484 /* Backing file format doesn't make sense without a backing file */
2485 if (backing_fmt
&& !backing_file
) {
2489 if (drv
->bdrv_change_backing_file
!= NULL
) {
2490 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
2496 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2497 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2503 * Finds the image layer in the chain that has 'bs' as its backing file.
2505 * active is the current topmost image.
2507 * Returns NULL if bs is not found in active's image chain,
2508 * or if active == bs.
2510 * Returns the bottommost base image if bs == NULL.
2512 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
2513 BlockDriverState
*bs
)
2515 while (active
&& bs
!= backing_bs(active
)) {
2516 active
= backing_bs(active
);
2522 /* Given a BDS, searches for the base layer. */
2523 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
2525 return bdrv_find_overlay(bs
, NULL
);
2529 * Drops images above 'base' up to and including 'top', and sets the image
2530 * above 'top' to have base as its backing file.
2532 * Requires that the overlay to 'top' is opened r/w, so that the backing file
2533 * information in 'bs' can be properly updated.
2535 * E.g., this will convert the following chain:
2536 * bottom <- base <- intermediate <- top <- active
2540 * bottom <- base <- active
2542 * It is allowed for bottom==base, in which case it converts:
2544 * base <- intermediate <- top <- active
2550 * If backing_file_str is non-NULL, it will be used when modifying top's
2551 * overlay image metadata.
2554 * if active == top, that is considered an error
2557 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
2558 BlockDriverState
*base
, const char *backing_file_str
)
2560 BlockDriverState
*new_top_bs
= NULL
;
2563 if (!top
->drv
|| !base
->drv
) {
2567 new_top_bs
= bdrv_find_overlay(active
, top
);
2569 if (new_top_bs
== NULL
) {
2570 /* we could not find the image above 'top', this is an error */
2574 /* special case of new_top_bs->backing->bs already pointing to base - nothing
2575 * to do, no intermediate images */
2576 if (backing_bs(new_top_bs
) == base
) {
2581 /* Make sure that base is in the backing chain of top */
2582 if (!bdrv_chain_contains(top
, base
)) {
2586 /* success - we can delete the intermediate states, and link top->base */
2587 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
2588 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
2589 base
->drv
? base
->drv
->format_name
: "");
2593 bdrv_set_backing_hd(new_top_bs
, base
);
2601 * Truncate file to 'offset' bytes (needed only for file protocols)
2603 int bdrv_truncate(BlockDriverState
*bs
, int64_t offset
)
2605 BlockDriver
*drv
= bs
->drv
;
2609 if (!drv
->bdrv_truncate
)
2614 ret
= drv
->bdrv_truncate(bs
, offset
);
2616 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
2617 bdrv_dirty_bitmap_truncate(bs
);
2618 bdrv_parent_cb_resize(bs
);
2624 * Length of a allocated file in bytes. Sparse files are counted by actual
2625 * allocated space. Return < 0 if error or unknown.
2627 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
2629 BlockDriver
*drv
= bs
->drv
;
2633 if (drv
->bdrv_get_allocated_file_size
) {
2634 return drv
->bdrv_get_allocated_file_size(bs
);
2637 return bdrv_get_allocated_file_size(bs
->file
->bs
);
2643 * Return number of sectors on success, -errno on error.
2645 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
2647 BlockDriver
*drv
= bs
->drv
;
2652 if (drv
->has_variable_length
) {
2653 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
2658 return bs
->total_sectors
;
2662 * Return length in bytes on success, -errno on error.
2663 * The length is always a multiple of BDRV_SECTOR_SIZE.
2665 int64_t bdrv_getlength(BlockDriverState
*bs
)
2667 int64_t ret
= bdrv_nb_sectors(bs
);
2669 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
2670 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
2673 /* return 0 as number of sectors if no device present or error */
2674 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
2676 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
2678 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
2681 int bdrv_is_read_only(BlockDriverState
*bs
)
2683 return bs
->read_only
;
2686 int bdrv_is_sg(BlockDriverState
*bs
)
2691 int bdrv_is_encrypted(BlockDriverState
*bs
)
2693 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2696 return bs
->encrypted
;
2699 int bdrv_key_required(BlockDriverState
*bs
)
2701 BdrvChild
*backing
= bs
->backing
;
2703 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
2706 return (bs
->encrypted
&& !bs
->valid_key
);
2709 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
2712 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2713 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
2719 if (!bs
->encrypted
) {
2721 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
2724 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
2727 } else if (!bs
->valid_key
) {
2728 /* call the change callback now, we skipped it on open */
2730 bdrv_parent_cb_change_media(bs
, true);
2736 * Provide an encryption key for @bs.
2737 * If @key is non-null:
2738 * If @bs is not encrypted, fail.
2739 * Else if the key is invalid, fail.
2740 * Else set @bs's key to @key, replacing the existing key, if any.
2742 * If @bs is encrypted and still lacks a key, fail.
2744 * On failure, store an error object through @errp if non-null.
2746 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
2749 if (!bdrv_is_encrypted(bs
)) {
2750 error_setg(errp
, "Node '%s' is not encrypted",
2751 bdrv_get_device_or_node_name(bs
));
2752 } else if (bdrv_set_key(bs
, key
) < 0) {
2753 error_setg(errp
, QERR_INVALID_PASSWORD
);
2756 if (bdrv_key_required(bs
)) {
2757 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
2758 "'%s' (%s) is encrypted",
2759 bdrv_get_device_or_node_name(bs
),
2760 bdrv_get_encrypted_filename(bs
));
2765 const char *bdrv_get_format_name(BlockDriverState
*bs
)
2767 return bs
->drv
? bs
->drv
->format_name
: NULL
;
2770 static int qsort_strcmp(const void *a
, const void *b
)
2772 return strcmp(a
, b
);
2775 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
2781 const char **formats
= NULL
;
2783 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
2784 if (drv
->format_name
) {
2787 while (formats
&& i
&& !found
) {
2788 found
= !strcmp(formats
[--i
], drv
->format_name
);
2792 formats
= g_renew(const char *, formats
, count
+ 1);
2793 formats
[count
++] = drv
->format_name
;
2798 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
2800 for (i
= 0; i
< count
; i
++) {
2801 it(opaque
, formats
[i
]);
2807 /* This function is to find a node in the bs graph */
2808 BlockDriverState
*bdrv_find_node(const char *node_name
)
2810 BlockDriverState
*bs
;
2814 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2815 if (!strcmp(node_name
, bs
->node_name
)) {
2822 /* Put this QMP function here so it can access the static graph_bdrv_states. */
2823 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
2825 BlockDeviceInfoList
*list
, *entry
;
2826 BlockDriverState
*bs
;
2829 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2830 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
2832 qapi_free_BlockDeviceInfoList(list
);
2835 entry
= g_malloc0(sizeof(*entry
));
2836 entry
->value
= info
;
2844 BlockDriverState
*bdrv_lookup_bs(const char *device
,
2845 const char *node_name
,
2849 BlockDriverState
*bs
;
2852 blk
= blk_by_name(device
);
2857 error_setg(errp
, "Device '%s' has no medium", device
);
2865 bs
= bdrv_find_node(node_name
);
2872 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
2873 device
? device
: "",
2874 node_name
? node_name
: "");
2878 /* If 'base' is in the same chain as 'top', return true. Otherwise,
2879 * return false. If either argument is NULL, return false. */
2880 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
2882 while (top
&& top
!= base
) {
2883 top
= backing_bs(top
);
2889 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
2892 return QTAILQ_FIRST(&graph_bdrv_states
);
2894 return QTAILQ_NEXT(bs
, node_list
);
2897 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
2899 return bs
->node_name
;
2902 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
2907 /* If multiple parents have a name, just pick the first one. */
2908 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2909 if (c
->role
->get_name
) {
2910 name
= c
->role
->get_name(c
);
2911 if (name
&& *name
) {
2920 /* TODO check what callers really want: bs->node_name or blk_name() */
2921 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
2923 return bdrv_get_parent_name(bs
) ?: "";
2926 /* This can be used to identify nodes that might not have a device
2927 * name associated. Since node and device names live in the same
2928 * namespace, the result is unambiguous. The exception is if both are
2929 * absent, then this returns an empty (non-null) string. */
2930 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
2932 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
2935 int bdrv_get_flags(BlockDriverState
*bs
)
2937 return bs
->open_flags
;
2940 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
2945 int bdrv_has_zero_init(BlockDriverState
*bs
)
2949 /* If BS is a copy on write image, it is initialized to
2950 the contents of the base image, which may not be zeroes. */
2954 if (bs
->drv
->bdrv_has_zero_init
) {
2955 return bs
->drv
->bdrv_has_zero_init(bs
);
2962 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
2964 BlockDriverInfo bdi
;
2970 if (bdrv_get_info(bs
, &bdi
) == 0) {
2971 return bdi
.unallocated_blocks_are_zero
;
2977 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
2979 BlockDriverInfo bdi
;
2981 if (bs
->backing
|| !(bs
->open_flags
& BDRV_O_UNMAP
)) {
2985 if (bdrv_get_info(bs
, &bdi
) == 0) {
2986 return bdi
.can_write_zeroes_with_unmap
;
2992 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
2994 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
2995 return bs
->backing_file
;
2996 else if (bs
->encrypted
)
2997 return bs
->filename
;
3002 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3003 char *filename
, int filename_size
)
3005 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3008 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3010 BlockDriver
*drv
= bs
->drv
;
3013 if (!drv
->bdrv_get_info
)
3015 memset(bdi
, 0, sizeof(*bdi
));
3016 return drv
->bdrv_get_info(bs
, bdi
);
3019 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3021 BlockDriver
*drv
= bs
->drv
;
3022 if (drv
&& drv
->bdrv_get_specific_info
) {
3023 return drv
->bdrv_get_specific_info(bs
);
3028 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3030 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3034 bs
->drv
->bdrv_debug_event(bs
, event
);
3037 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3040 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3041 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3044 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3045 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3051 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3053 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3054 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3057 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3058 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3064 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3066 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3067 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3070 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3071 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3077 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3079 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3080 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3083 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3084 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3090 int bdrv_is_snapshot(BlockDriverState
*bs
)
3092 return !!(bs
->open_flags
& BDRV_O_SNAPSHOT
);
3095 /* backing_file can either be relative, or absolute, or a protocol. If it is
3096 * relative, it must be relative to the chain. So, passing in bs->filename
3097 * from a BDS as backing_file should not be done, as that may be relative to
3098 * the CWD rather than the chain. */
3099 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3100 const char *backing_file
)
3102 char *filename_full
= NULL
;
3103 char *backing_file_full
= NULL
;
3104 char *filename_tmp
= NULL
;
3105 int is_protocol
= 0;
3106 BlockDriverState
*curr_bs
= NULL
;
3107 BlockDriverState
*retval
= NULL
;
3109 if (!bs
|| !bs
->drv
|| !backing_file
) {
3113 filename_full
= g_malloc(PATH_MAX
);
3114 backing_file_full
= g_malloc(PATH_MAX
);
3115 filename_tmp
= g_malloc(PATH_MAX
);
3117 is_protocol
= path_has_protocol(backing_file
);
3119 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3121 /* If either of the filename paths is actually a protocol, then
3122 * compare unmodified paths; otherwise make paths relative */
3123 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3124 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3125 retval
= curr_bs
->backing
->bs
;
3129 /* If not an absolute filename path, make it relative to the current
3130 * image's filename path */
3131 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3134 /* We are going to compare absolute pathnames */
3135 if (!realpath(filename_tmp
, filename_full
)) {
3139 /* We need to make sure the backing filename we are comparing against
3140 * is relative to the current image filename (or absolute) */
3141 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3142 curr_bs
->backing_file
);
3144 if (!realpath(filename_tmp
, backing_file_full
)) {
3148 if (strcmp(backing_file_full
, filename_full
) == 0) {
3149 retval
= curr_bs
->backing
->bs
;
3155 g_free(filename_full
);
3156 g_free(backing_file_full
);
3157 g_free(filename_tmp
);
3161 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3171 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3174 void bdrv_init(void)
3176 module_call_init(MODULE_INIT_BLOCK
);
3179 void bdrv_init_with_whitelist(void)
3181 use_bdrv_whitelist
= 1;
3185 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3188 Error
*local_err
= NULL
;
3195 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
3198 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
3200 if (bs
->drv
->bdrv_invalidate_cache
) {
3201 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3203 bs
->open_flags
|= BDRV_O_INACTIVE
;
3204 error_propagate(errp
, local_err
);
3209 QLIST_FOREACH(child
, &bs
->children
, next
) {
3210 bdrv_invalidate_cache(child
->bs
, &local_err
);
3212 bs
->open_flags
|= BDRV_O_INACTIVE
;
3213 error_propagate(errp
, local_err
);
3218 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3220 bs
->open_flags
|= BDRV_O_INACTIVE
;
3221 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3226 void bdrv_invalidate_cache_all(Error
**errp
)
3228 BlockDriverState
*bs
;
3229 Error
*local_err
= NULL
;
3230 BdrvNextIterator it
;
3232 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3233 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3235 aio_context_acquire(aio_context
);
3236 bdrv_invalidate_cache(bs
, &local_err
);
3237 aio_context_release(aio_context
);
3239 error_propagate(errp
, local_err
);
3245 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
3251 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
3252 ret
= bs
->drv
->bdrv_inactivate(bs
);
3258 QLIST_FOREACH(child
, &bs
->children
, next
) {
3259 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
3266 bs
->open_flags
|= BDRV_O_INACTIVE
;
3271 int bdrv_inactivate_all(void)
3273 BlockDriverState
*bs
= NULL
;
3274 BdrvNextIterator it
;
3278 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3279 aio_context_acquire(bdrv_get_aio_context(bs
));
3282 /* We do two passes of inactivation. The first pass calls to drivers'
3283 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
3284 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
3286 for (pass
= 0; pass
< 2; pass
++) {
3287 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3288 ret
= bdrv_inactivate_recurse(bs
, pass
);
3296 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3297 aio_context_release(bdrv_get_aio_context(bs
));
3303 /**************************************************************/
3304 /* removable device support */
3307 * Return TRUE if the media is present
3309 bool bdrv_is_inserted(BlockDriverState
*bs
)
3311 BlockDriver
*drv
= bs
->drv
;
3317 if (drv
->bdrv_is_inserted
) {
3318 return drv
->bdrv_is_inserted(bs
);
3320 QLIST_FOREACH(child
, &bs
->children
, next
) {
3321 if (!bdrv_is_inserted(child
->bs
)) {
3329 * Return whether the media changed since the last call to this
3330 * function, or -ENOTSUP if we don't know. Most drivers don't know.
3332 int bdrv_media_changed(BlockDriverState
*bs
)
3334 BlockDriver
*drv
= bs
->drv
;
3336 if (drv
&& drv
->bdrv_media_changed
) {
3337 return drv
->bdrv_media_changed(bs
);
3343 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
3345 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
3347 BlockDriver
*drv
= bs
->drv
;
3348 const char *device_name
;
3350 if (drv
&& drv
->bdrv_eject
) {
3351 drv
->bdrv_eject(bs
, eject_flag
);
3354 device_name
= bdrv_get_device_name(bs
);
3355 if (device_name
[0] != '\0') {
3356 qapi_event_send_device_tray_moved(device_name
,
3357 eject_flag
, &error_abort
);
3362 * Lock or unlock the media (if it is locked, the user won't be able
3363 * to eject it manually).
3365 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
3367 BlockDriver
*drv
= bs
->drv
;
3369 trace_bdrv_lock_medium(bs
, locked
);
3371 if (drv
&& drv
->bdrv_lock_medium
) {
3372 drv
->bdrv_lock_medium(bs
, locked
);
3376 /* Get a reference to bs */
3377 void bdrv_ref(BlockDriverState
*bs
)
3382 /* Release a previously grabbed reference to bs.
3383 * If after releasing, reference count is zero, the BlockDriverState is
3385 void bdrv_unref(BlockDriverState
*bs
)
3390 assert(bs
->refcnt
> 0);
3391 if (--bs
->refcnt
== 0) {
3396 struct BdrvOpBlocker
{
3398 QLIST_ENTRY(BdrvOpBlocker
) list
;
3401 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
3403 BdrvOpBlocker
*blocker
;
3404 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3405 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
3406 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
3408 *errp
= error_copy(blocker
->reason
);
3409 error_prepend(errp
, "Node '%s' is busy: ",
3410 bdrv_get_device_or_node_name(bs
));
3417 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3419 BdrvOpBlocker
*blocker
;
3420 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3422 blocker
= g_new0(BdrvOpBlocker
, 1);
3423 blocker
->reason
= reason
;
3424 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
3427 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3429 BdrvOpBlocker
*blocker
, *next
;
3430 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3431 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
3432 if (blocker
->reason
== reason
) {
3433 QLIST_REMOVE(blocker
, list
);
3439 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
3442 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3443 bdrv_op_block(bs
, i
, reason
);
3447 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
3450 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3451 bdrv_op_unblock(bs
, i
, reason
);
3455 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
3459 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3460 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
3467 void bdrv_img_create(const char *filename
, const char *fmt
,
3468 const char *base_filename
, const char *base_fmt
,
3469 char *options
, uint64_t img_size
, int flags
,
3470 Error
**errp
, bool quiet
)
3472 QemuOptsList
*create_opts
= NULL
;
3473 QemuOpts
*opts
= NULL
;
3474 const char *backing_fmt
, *backing_file
;
3476 BlockDriver
*drv
, *proto_drv
;
3477 Error
*local_err
= NULL
;
3480 /* Find driver and parse its options */
3481 drv
= bdrv_find_format(fmt
);
3483 error_setg(errp
, "Unknown file format '%s'", fmt
);
3487 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
3492 if (!drv
->create_opts
) {
3493 error_setg(errp
, "Format driver '%s' does not support image creation",
3498 if (!proto_drv
->create_opts
) {
3499 error_setg(errp
, "Protocol driver '%s' does not support image creation",
3500 proto_drv
->format_name
);
3504 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
3505 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
3507 /* Create parameter list with default values */
3508 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
3509 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
3511 /* Parse -o options */
3513 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
3515 error_report_err(local_err
);
3517 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
3522 if (base_filename
) {
3523 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
3525 error_setg(errp
, "Backing file not supported for file format '%s'",
3532 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
3534 error_setg(errp
, "Backing file format not supported for file "
3535 "format '%s'", fmt
);
3540 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
3542 if (!strcmp(filename
, backing_file
)) {
3543 error_setg(errp
, "Error: Trying to create an image with the "
3544 "same filename as the backing file");
3549 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
3551 // The size for the image must always be specified, with one exception:
3552 // If we are using a backing file, we can obtain the size from there
3553 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
3556 BlockDriverState
*bs
;
3557 char *full_backing
= g_new0(char, PATH_MAX
);
3560 QDict
*backing_options
= NULL
;
3562 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
3563 full_backing
, PATH_MAX
,
3566 g_free(full_backing
);
3570 /* backing files always opened read-only */
3572 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
3575 backing_options
= qdict_new();
3576 qdict_put(backing_options
, "driver",
3577 qstring_from_str(backing_fmt
));
3581 ret
= bdrv_open(&bs
, full_backing
, NULL
, backing_options
,
3582 back_flags
, &local_err
);
3583 g_free(full_backing
);
3587 size
= bdrv_getlength(bs
);
3589 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
3595 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
3599 error_setg(errp
, "Image creation needs a size parameter");
3605 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
3606 qemu_opts_print(opts
, " ");
3610 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
3612 if (ret
== -EFBIG
) {
3613 /* This is generally a better message than whatever the driver would
3614 * deliver (especially because of the cluster_size_hint), since that
3615 * is most probably not much different from "image too large". */
3616 const char *cluster_size_hint
= "";
3617 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
3618 cluster_size_hint
= " (try using a larger cluster size)";
3620 error_setg(errp
, "The image size is too large for file format '%s'"
3621 "%s", fmt
, cluster_size_hint
);
3622 error_free(local_err
);
3627 qemu_opts_del(opts
);
3628 qemu_opts_free(create_opts
);
3630 error_propagate(errp
, local_err
);
3634 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
3636 return bs
->aio_context
;
3639 void bdrv_detach_aio_context(BlockDriverState
*bs
)
3641 BdrvAioNotifier
*baf
;
3648 QLIST_FOREACH(baf
, &bs
->aio_notifiers
, list
) {
3649 baf
->detach_aio_context(baf
->opaque
);
3652 if (bs
->drv
->bdrv_detach_aio_context
) {
3653 bs
->drv
->bdrv_detach_aio_context(bs
);
3655 QLIST_FOREACH(child
, &bs
->children
, next
) {
3656 bdrv_detach_aio_context(child
->bs
);
3659 bs
->aio_context
= NULL
;
3662 void bdrv_attach_aio_context(BlockDriverState
*bs
,
3663 AioContext
*new_context
)
3665 BdrvAioNotifier
*ban
;
3672 bs
->aio_context
= new_context
;
3674 QLIST_FOREACH(child
, &bs
->children
, next
) {
3675 bdrv_attach_aio_context(child
->bs
, new_context
);
3677 if (bs
->drv
->bdrv_attach_aio_context
) {
3678 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
3681 QLIST_FOREACH(ban
, &bs
->aio_notifiers
, list
) {
3682 ban
->attached_aio_context(new_context
, ban
->opaque
);
3686 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
3688 bdrv_drain(bs
); /* ensure there are no in-flight requests */
3690 bdrv_detach_aio_context(bs
);
3692 /* This function executes in the old AioContext so acquire the new one in
3693 * case it runs in a different thread.
3695 aio_context_acquire(new_context
);
3696 bdrv_attach_aio_context(bs
, new_context
);
3697 aio_context_release(new_context
);
3700 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
3701 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
3702 void (*detach_aio_context
)(void *opaque
), void *opaque
)
3704 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
3705 *ban
= (BdrvAioNotifier
){
3706 .attached_aio_context
= attached_aio_context
,
3707 .detach_aio_context
= detach_aio_context
,
3711 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
3714 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
3715 void (*attached_aio_context
)(AioContext
*,
3717 void (*detach_aio_context
)(void *),
3720 BdrvAioNotifier
*ban
, *ban_next
;
3722 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3723 if (ban
->attached_aio_context
== attached_aio_context
&&
3724 ban
->detach_aio_context
== detach_aio_context
&&
3725 ban
->opaque
== opaque
)
3727 QLIST_REMOVE(ban
, list
);
3737 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
3738 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
3740 if (!bs
->drv
->bdrv_amend_options
) {
3743 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
3746 /* This function will be called by the bdrv_recurse_is_first_non_filter method
3747 * of block filter and by bdrv_is_first_non_filter.
3748 * It is used to test if the given bs is the candidate or recurse more in the
3751 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
3752 BlockDriverState
*candidate
)
3754 /* return false if basic checks fails */
3755 if (!bs
|| !bs
->drv
) {
3759 /* the code reached a non block filter driver -> check if the bs is
3760 * the same as the candidate. It's the recursion termination condition.
3762 if (!bs
->drv
->is_filter
) {
3763 return bs
== candidate
;
3765 /* Down this path the driver is a block filter driver */
3767 /* If the block filter recursion method is defined use it to recurse down
3770 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
3771 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
3774 /* the driver is a block filter but don't allow to recurse -> return false
3779 /* This function checks if the candidate is the first non filter bs down it's
3780 * bs chain. Since we don't have pointers to parents it explore all bs chains
3781 * from the top. Some filters can choose not to pass down the recursion.
3783 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
3785 BlockDriverState
*bs
;
3786 BdrvNextIterator it
;
3788 /* walk down the bs forest recursively */
3789 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
3792 /* try to recurse in this top level bs */
3793 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
3795 /* candidate is the first non filter */
3804 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
3805 const char *node_name
, Error
**errp
)
3807 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
3808 AioContext
*aio_context
;
3810 if (!to_replace_bs
) {
3811 error_setg(errp
, "Node name '%s' not found", node_name
);
3815 aio_context
= bdrv_get_aio_context(to_replace_bs
);
3816 aio_context_acquire(aio_context
);
3818 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
3819 to_replace_bs
= NULL
;
3823 /* We don't want arbitrary node of the BDS chain to be replaced only the top
3824 * most non filter in order to prevent data corruption.
3825 * Another benefit is that this tests exclude backing files which are
3826 * blocked by the backing blockers.
3828 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
3829 error_setg(errp
, "Only top most non filter can be replaced");
3830 to_replace_bs
= NULL
;
3835 aio_context_release(aio_context
);
3836 return to_replace_bs
;
3839 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
3841 const QDictEntry
*entry
;
3844 bool found_any
= false;
3847 for (entry
= qdict_first(bs
->options
); entry
;
3848 entry
= qdict_next(bs
->options
, entry
))
3850 /* Exclude options for children */
3851 QLIST_FOREACH(child
, &bs
->children
, next
) {
3852 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
3853 && (!*p
|| *p
== '.'))
3862 /* And exclude all non-driver-specific options */
3863 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
3864 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
3872 qobject_incref(qdict_entry_value(entry
));
3873 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
3880 /* Updates the following BDS fields:
3881 * - exact_filename: A filename which may be used for opening a block device
3882 * which (mostly) equals the given BDS (even without any
3883 * other options; so reading and writing must return the same
3884 * results, but caching etc. may be different)
3885 * - full_open_options: Options which, when given when opening a block device
3886 * (without a filename), result in a BDS (mostly)
3887 * equalling the given one
3888 * - filename: If exact_filename is set, it is copied here. Otherwise,
3889 * full_open_options is converted to a JSON object, prefixed with
3890 * "json:" (for use through the JSON pseudo protocol) and put here.
3892 void bdrv_refresh_filename(BlockDriverState
*bs
)
3894 BlockDriver
*drv
= bs
->drv
;
3901 /* This BDS's file name will most probably depend on its file's name, so
3902 * refresh that first */
3904 bdrv_refresh_filename(bs
->file
->bs
);
3907 if (drv
->bdrv_refresh_filename
) {
3908 /* Obsolete information is of no use here, so drop the old file name
3909 * information before refreshing it */
3910 bs
->exact_filename
[0] = '\0';
3911 if (bs
->full_open_options
) {
3912 QDECREF(bs
->full_open_options
);
3913 bs
->full_open_options
= NULL
;
3917 append_open_options(opts
, bs
);
3918 drv
->bdrv_refresh_filename(bs
, opts
);
3920 } else if (bs
->file
) {
3921 /* Try to reconstruct valid information from the underlying file */
3922 bool has_open_options
;
3924 bs
->exact_filename
[0] = '\0';
3925 if (bs
->full_open_options
) {
3926 QDECREF(bs
->full_open_options
);
3927 bs
->full_open_options
= NULL
;
3931 has_open_options
= append_open_options(opts
, bs
);
3933 /* If no specific options have been given for this BDS, the filename of
3934 * the underlying file should suffice for this one as well */
3935 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
3936 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
3938 /* Reconstructing the full options QDict is simple for most format block
3939 * drivers, as long as the full options are known for the underlying
3940 * file BDS. The full options QDict of that file BDS should somehow
3941 * contain a representation of the filename, therefore the following
3942 * suffices without querying the (exact_)filename of this BDS. */
3943 if (bs
->file
->bs
->full_open_options
) {
3944 qdict_put_obj(opts
, "driver",
3945 QOBJECT(qstring_from_str(drv
->format_name
)));
3946 QINCREF(bs
->file
->bs
->full_open_options
);
3947 qdict_put_obj(opts
, "file",
3948 QOBJECT(bs
->file
->bs
->full_open_options
));
3950 bs
->full_open_options
= opts
;
3954 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
3955 /* There is no underlying file BDS (at least referenced by BDS.file),
3956 * so the full options QDict should be equal to the options given
3957 * specifically for this block device when it was opened (plus the
3958 * driver specification).
3959 * Because those options don't change, there is no need to update
3960 * full_open_options when it's already set. */
3963 append_open_options(opts
, bs
);
3964 qdict_put_obj(opts
, "driver",
3965 QOBJECT(qstring_from_str(drv
->format_name
)));
3967 if (bs
->exact_filename
[0]) {
3968 /* This may not work for all block protocol drivers (some may
3969 * require this filename to be parsed), but we have to find some
3970 * default solution here, so just include it. If some block driver
3971 * does not support pure options without any filename at all or
3972 * needs some special format of the options QDict, it needs to
3973 * implement the driver-specific bdrv_refresh_filename() function.
3975 qdict_put_obj(opts
, "filename",
3976 QOBJECT(qstring_from_str(bs
->exact_filename
)));
3979 bs
->full_open_options
= opts
;
3982 if (bs
->exact_filename
[0]) {
3983 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
3984 } else if (bs
->full_open_options
) {
3985 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
3986 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
3987 qstring_get_str(json
));
3993 * Hot add/remove a BDS's child. So the user can take a child offline when
3994 * it is broken and take a new child online
3996 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
4000 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
4001 error_setg(errp
, "The node %s does not support adding a child",
4002 bdrv_get_device_or_node_name(parent_bs
));
4006 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4007 error_setg(errp
, "The node %s already has a parent",
4008 child_bs
->node_name
);
4012 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4015 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4019 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4020 error_setg(errp
, "The node %s does not support removing a child",
4021 bdrv_get_device_or_node_name(parent_bs
));
4025 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4032 error_setg(errp
, "The node %s does not have a child named %s",
4033 bdrv_get_device_or_node_name(parent_bs
),
4034 bdrv_get_device_or_node_name(child
->bs
));
4038 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);