2 * QEMU System Emulator block driver
4 * Copyright (c) 2003 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 #include "qemu/osdep.h"
25 #include "block/trace.h"
26 #include "block/block_int.h"
27 #include "block/blockjob.h"
28 #include "block/nbd.h"
29 #include "qemu/error-report.h"
30 #include "module_block.h"
31 #include "qemu/module.h"
32 #include "qapi/qmp/qerror.h"
33 #include "qapi/qmp/qbool.h"
34 #include "qapi/qmp/qjson.h"
35 #include "sysemu/block-backend.h"
36 #include "sysemu/sysemu.h"
37 #include "qemu/notify.h"
38 #include "qemu/coroutine.h"
39 #include "block/qapi.h"
40 #include "qmp-commands.h"
41 #include "qemu/timer.h"
42 #include "qapi-event.h"
43 #include "qemu/cutils.h"
47 #include <sys/ioctl.h>
48 #include <sys/queue.h>
58 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
60 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
61 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
63 static QTAILQ_HEAD(, BlockDriverState
) all_bdrv_states
=
64 QTAILQ_HEAD_INITIALIZER(all_bdrv_states
);
66 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
67 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
69 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
70 const char *reference
,
71 QDict
*options
, int flags
,
72 BlockDriverState
*parent
,
73 const BdrvChildRole
*child_role
,
76 /* If non-zero, use only whitelisted block drivers */
77 static int use_bdrv_whitelist
;
80 static int is_windows_drive_prefix(const char *filename
)
82 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
83 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
87 int is_windows_drive(const char *filename
)
89 if (is_windows_drive_prefix(filename
) &&
92 if (strstart(filename
, "\\\\.\\", NULL
) ||
93 strstart(filename
, "//./", NULL
))
99 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
101 if (!bs
|| !bs
->drv
) {
102 /* page size or 4k (hdd sector size) should be on the safe side */
103 return MAX(4096, getpagesize());
106 return bs
->bl
.opt_mem_alignment
;
109 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
111 if (!bs
|| !bs
->drv
) {
112 /* page size or 4k (hdd sector size) should be on the safe side */
113 return MAX(4096, getpagesize());
116 return bs
->bl
.min_mem_alignment
;
119 /* check if the path starts with "<protocol>:" */
120 int path_has_protocol(const char *path
)
125 if (is_windows_drive(path
) ||
126 is_windows_drive_prefix(path
)) {
129 p
= path
+ strcspn(path
, ":/\\");
131 p
= path
+ strcspn(path
, ":/");
137 int path_is_absolute(const char *path
)
140 /* specific case for names like: "\\.\d:" */
141 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
144 return (*path
== '/' || *path
== '\\');
146 return (*path
== '/');
150 /* if filename is absolute, just copy it to dest. Otherwise, build a
151 path to it by considering it is relative to base_path. URL are
153 void path_combine(char *dest
, int dest_size
,
154 const char *base_path
,
155 const char *filename
)
162 if (path_is_absolute(filename
)) {
163 pstrcpy(dest
, dest_size
, filename
);
165 const char *protocol_stripped
= NULL
;
167 if (path_has_protocol(base_path
)) {
168 protocol_stripped
= strchr(base_path
, ':');
169 if (protocol_stripped
) {
173 p
= protocol_stripped
?: base_path
;
175 p1
= strrchr(base_path
, '/');
179 p2
= strrchr(base_path
, '\\');
191 if (len
> dest_size
- 1)
193 memcpy(dest
, base_path
, len
);
195 pstrcat(dest
, dest_size
, filename
);
200 * Helper function for bdrv_parse_filename() implementations to remove optional
201 * protocol prefixes (especially "file:") from a filename and for putting the
202 * stripped filename into the options QDict if there is such a prefix.
204 void bdrv_parse_filename_strip_prefix(const char *filename
, const char *prefix
,
207 if (strstart(filename
, prefix
, &filename
)) {
208 /* Stripping the explicit protocol prefix may result in a protocol
209 * prefix being (wrongly) detected (if the filename contains a colon) */
210 if (path_has_protocol(filename
)) {
211 QString
*fat_filename
;
213 /* This means there is some colon before the first slash; therefore,
214 * this cannot be an absolute path */
215 assert(!path_is_absolute(filename
));
217 /* And we can thus fix the protocol detection issue by prefixing it
219 fat_filename
= qstring_from_str("./");
220 qstring_append(fat_filename
, filename
);
222 assert(!path_has_protocol(qstring_get_str(fat_filename
)));
224 qdict_put(options
, "filename", fat_filename
);
226 /* If no protocol prefix was detected, we can use the shortened
228 qdict_put_str(options
, "filename", filename
);
234 /* Returns whether the image file is opened as read-only. Note that this can
235 * return false and writing to the image file is still not possible because the
236 * image is inactivated. */
237 bool bdrv_is_read_only(BlockDriverState
*bs
)
239 return bs
->read_only
;
242 /* Returns whether the image file can be written to right now */
243 bool bdrv_is_writable(BlockDriverState
*bs
)
245 return !bdrv_is_read_only(bs
) && !(bs
->open_flags
& BDRV_O_INACTIVE
);
248 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
249 bool ignore_allow_rdw
, Error
**errp
)
251 /* Do not set read_only if copy_on_read is enabled */
252 if (bs
->copy_on_read
&& read_only
) {
253 error_setg(errp
, "Can't set node '%s' to r/o with copy-on-read enabled",
254 bdrv_get_device_or_node_name(bs
));
258 /* Do not clear read_only if it is prohibited */
259 if (!read_only
&& !(bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
262 error_setg(errp
, "Node '%s' is read only",
263 bdrv_get_device_or_node_name(bs
));
270 int bdrv_set_read_only(BlockDriverState
*bs
, bool read_only
, Error
**errp
)
274 ret
= bdrv_can_set_read_only(bs
, read_only
, false, errp
);
279 bs
->read_only
= read_only
;
283 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
285 char *dest
, size_t sz
,
288 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
289 path_is_absolute(backing
))
291 pstrcpy(dest
, sz
, backing
);
292 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
293 error_setg(errp
, "Cannot use relative backing file names for '%s'",
296 path_combine(dest
, sz
, backed
, backing
);
300 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
303 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
305 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
309 void bdrv_register(BlockDriver
*bdrv
)
311 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
314 BlockDriverState
*bdrv_new(void)
316 BlockDriverState
*bs
;
319 bs
= g_new0(BlockDriverState
, 1);
320 QLIST_INIT(&bs
->dirty_bitmaps
);
321 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
322 QLIST_INIT(&bs
->op_blockers
[i
]);
324 notifier_with_return_list_init(&bs
->before_write_notifiers
);
325 qemu_co_mutex_init(&bs
->reqs_lock
);
326 qemu_mutex_init(&bs
->dirty_bitmap_mutex
);
328 bs
->aio_context
= qemu_get_aio_context();
330 qemu_co_queue_init(&bs
->flush_queue
);
332 QTAILQ_INSERT_TAIL(&all_bdrv_states
, bs
, bs_list
);
337 static BlockDriver
*bdrv_do_find_format(const char *format_name
)
341 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
342 if (!strcmp(drv1
->format_name
, format_name
)) {
350 BlockDriver
*bdrv_find_format(const char *format_name
)
355 drv1
= bdrv_do_find_format(format_name
);
360 /* The driver isn't registered, maybe we need to load a module */
361 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
362 if (!strcmp(block_driver_modules
[i
].format_name
, format_name
)) {
363 block_module_load_one(block_driver_modules
[i
].library_name
);
368 return bdrv_do_find_format(format_name
);
371 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
373 static const char *whitelist_rw
[] = {
374 CONFIG_BDRV_RW_WHITELIST
376 static const char *whitelist_ro
[] = {
377 CONFIG_BDRV_RO_WHITELIST
381 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
382 return 1; /* no whitelist, anything goes */
385 for (p
= whitelist_rw
; *p
; p
++) {
386 if (!strcmp(drv
->format_name
, *p
)) {
391 for (p
= whitelist_ro
; *p
; p
++) {
392 if (!strcmp(drv
->format_name
, *p
)) {
400 bool bdrv_uses_whitelist(void)
402 return use_bdrv_whitelist
;
405 typedef struct CreateCo
{
413 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
415 Error
*local_err
= NULL
;
418 CreateCo
*cco
= opaque
;
421 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
422 error_propagate(&cco
->err
, local_err
);
426 int bdrv_create(BlockDriver
*drv
, const char* filename
,
427 QemuOpts
*opts
, Error
**errp
)
434 .filename
= g_strdup(filename
),
440 if (!drv
->bdrv_create
) {
441 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
446 if (qemu_in_coroutine()) {
447 /* Fast-path if already in coroutine context */
448 bdrv_create_co_entry(&cco
);
450 co
= qemu_coroutine_create(bdrv_create_co_entry
, &cco
);
451 qemu_coroutine_enter(co
);
452 while (cco
.ret
== NOT_DONE
) {
453 aio_poll(qemu_get_aio_context(), true);
460 error_propagate(errp
, cco
.err
);
462 error_setg_errno(errp
, -ret
, "Could not create image");
467 g_free(cco
.filename
);
471 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
474 Error
*local_err
= NULL
;
477 drv
= bdrv_find_protocol(filename
, true, errp
);
482 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
483 error_propagate(errp
, local_err
);
488 * Try to get @bs's logical and physical block size.
489 * On success, store them in @bsz struct and return 0.
490 * On failure return -errno.
491 * @bs must not be empty.
493 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
495 BlockDriver
*drv
= bs
->drv
;
497 if (drv
&& drv
->bdrv_probe_blocksizes
) {
498 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
499 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
500 return bdrv_probe_blocksizes(bs
->file
->bs
, bsz
);
507 * Try to get @bs's geometry (cyls, heads, sectors).
508 * On success, store them in @geo struct and return 0.
509 * On failure return -errno.
510 * @bs must not be empty.
512 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
514 BlockDriver
*drv
= bs
->drv
;
516 if (drv
&& drv
->bdrv_probe_geometry
) {
517 return drv
->bdrv_probe_geometry(bs
, geo
);
518 } else if (drv
&& drv
->is_filter
&& bs
->file
) {
519 return bdrv_probe_geometry(bs
->file
->bs
, geo
);
526 * Create a uniquely-named empty temporary file.
527 * Return 0 upon success, otherwise a negative errno value.
529 int get_tmp_filename(char *filename
, int size
)
532 char temp_dir
[MAX_PATH
];
533 /* GetTempFileName requires that its output buffer (4th param)
534 have length MAX_PATH or greater. */
535 assert(size
>= MAX_PATH
);
536 return (GetTempPath(MAX_PATH
, temp_dir
)
537 && GetTempFileName(temp_dir
, "qem", 0, filename
)
538 ? 0 : -GetLastError());
542 tmpdir
= getenv("TMPDIR");
546 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
549 fd
= mkstemp(filename
);
553 if (close(fd
) != 0) {
562 * Detect host devices. By convention, /dev/cdrom[N] is always
563 * recognized as a host CDROM.
565 static BlockDriver
*find_hdev_driver(const char *filename
)
567 int score_max
= 0, score
;
568 BlockDriver
*drv
= NULL
, *d
;
570 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
571 if (d
->bdrv_probe_device
) {
572 score
= d
->bdrv_probe_device(filename
);
573 if (score
> score_max
) {
583 static BlockDriver
*bdrv_do_find_protocol(const char *protocol
)
587 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
588 if (drv1
->protocol_name
&& !strcmp(drv1
->protocol_name
, protocol
)) {
596 BlockDriver
*bdrv_find_protocol(const char *filename
,
597 bool allow_protocol_prefix
,
606 /* TODO Drivers without bdrv_file_open must be specified explicitly */
609 * XXX(hch): we really should not let host device detection
610 * override an explicit protocol specification, but moving this
611 * later breaks access to device names with colons in them.
612 * Thanks to the brain-dead persistent naming schemes on udev-
613 * based Linux systems those actually are quite common.
615 drv1
= find_hdev_driver(filename
);
620 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
624 p
= strchr(filename
, ':');
627 if (len
> sizeof(protocol
) - 1)
628 len
= sizeof(protocol
) - 1;
629 memcpy(protocol
, filename
, len
);
630 protocol
[len
] = '\0';
632 drv1
= bdrv_do_find_protocol(protocol
);
637 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); ++i
) {
638 if (block_driver_modules
[i
].protocol_name
&&
639 !strcmp(block_driver_modules
[i
].protocol_name
, protocol
)) {
640 block_module_load_one(block_driver_modules
[i
].library_name
);
645 drv1
= bdrv_do_find_protocol(protocol
);
647 error_setg(errp
, "Unknown protocol '%s'", protocol
);
653 * Guess image format by probing its contents.
654 * This is not a good idea when your image is raw (CVE-2008-2004), but
655 * we do it anyway for backward compatibility.
657 * @buf contains the image's first @buf_size bytes.
658 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
659 * but can be smaller if the image file is smaller)
660 * @filename is its filename.
662 * For all block drivers, call the bdrv_probe() method to get its
664 * Return the first block driver with the highest probing score.
666 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
667 const char *filename
)
669 int score_max
= 0, score
;
670 BlockDriver
*drv
= NULL
, *d
;
672 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
674 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
675 if (score
> score_max
) {
685 static int find_image_format(BlockBackend
*file
, const char *filename
,
686 BlockDriver
**pdrv
, Error
**errp
)
689 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
692 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
693 if (blk_is_sg(file
) || !blk_is_inserted(file
) || blk_getlength(file
) == 0) {
698 ret
= blk_pread(file
, 0, buf
, sizeof(buf
));
700 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
706 drv
= bdrv_probe_all(buf
, ret
, filename
);
708 error_setg(errp
, "Could not determine image format: No compatible "
717 * Set the current 'total_sectors' value
718 * Return 0 on success, -errno on error.
720 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
722 BlockDriver
*drv
= bs
->drv
;
724 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
728 /* query actual device if possible, otherwise just trust the hint */
729 if (drv
->bdrv_getlength
) {
730 int64_t length
= drv
->bdrv_getlength(bs
);
734 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
737 bs
->total_sectors
= hint
;
742 * Combines a QDict of new block driver @options with any missing options taken
743 * from @old_options, so that leaving out an option defaults to its old value.
745 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
748 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
749 bs
->drv
->bdrv_join_options(options
, old_options
);
751 qdict_join(options
, old_options
, false);
756 * Set open flags for a given discard mode
758 * Return 0 on success, -1 if the discard mode was invalid.
760 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
762 *flags
&= ~BDRV_O_UNMAP
;
764 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
766 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
767 *flags
|= BDRV_O_UNMAP
;
776 * Set open flags for a given cache mode
778 * Return 0 on success, -1 if the cache mode was invalid.
780 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
)
782 *flags
&= ~BDRV_O_CACHE_MASK
;
784 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
785 *writethrough
= false;
786 *flags
|= BDRV_O_NOCACHE
;
787 } else if (!strcmp(mode
, "directsync")) {
788 *writethrough
= true;
789 *flags
|= BDRV_O_NOCACHE
;
790 } else if (!strcmp(mode
, "writeback")) {
791 *writethrough
= false;
792 } else if (!strcmp(mode
, "unsafe")) {
793 *writethrough
= false;
794 *flags
|= BDRV_O_NO_FLUSH
;
795 } else if (!strcmp(mode
, "writethrough")) {
796 *writethrough
= true;
804 static char *bdrv_child_get_parent_desc(BdrvChild
*c
)
806 BlockDriverState
*parent
= c
->opaque
;
807 return g_strdup(bdrv_get_device_or_node_name(parent
));
810 static void bdrv_child_cb_drained_begin(BdrvChild
*child
)
812 BlockDriverState
*bs
= child
->opaque
;
813 bdrv_drained_begin(bs
);
816 static void bdrv_child_cb_drained_end(BdrvChild
*child
)
818 BlockDriverState
*bs
= child
->opaque
;
819 bdrv_drained_end(bs
);
822 static int bdrv_child_cb_inactivate(BdrvChild
*child
)
824 BlockDriverState
*bs
= child
->opaque
;
825 assert(bs
->open_flags
& BDRV_O_INACTIVE
);
830 * Returns the options and flags that a temporary snapshot should get, based on
831 * the originally requested flags (the originally requested image will have
832 * flags like a backing file)
834 static void bdrv_temp_snapshot_options(int *child_flags
, QDict
*child_options
,
835 int parent_flags
, QDict
*parent_options
)
837 *child_flags
= (parent_flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
839 /* For temporary files, unconditional cache=unsafe is fine */
840 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_DIRECT
, "off");
841 qdict_set_default_str(child_options
, BDRV_OPT_CACHE_NO_FLUSH
, "on");
843 /* Copy the read-only option from the parent */
844 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
846 /* aio=native doesn't work for cache.direct=off, so disable it for the
847 * temporary snapshot */
848 *child_flags
&= ~BDRV_O_NATIVE_AIO
;
852 * Returns the options and flags that bs->file should get if a protocol driver
853 * is expected, based on the given options and flags for the parent BDS
855 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
856 int parent_flags
, QDict
*parent_options
)
858 int flags
= parent_flags
;
860 /* Enable protocol handling, disable format probing for bs->file */
861 flags
|= BDRV_O_PROTOCOL
;
863 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
865 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
866 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
867 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
869 /* Inherit the read-only option from the parent if it's not set */
870 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_READ_ONLY
);
872 /* Our block drivers take care to send flushes and respect unmap policy,
873 * so we can default to enable both on lower layers regardless of the
874 * corresponding parent options. */
875 qdict_set_default_str(child_options
, BDRV_OPT_DISCARD
, "unmap");
877 /* Clear flags that only apply to the top layer */
878 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
|
881 *child_flags
= flags
;
884 const BdrvChildRole child_file
= {
885 .get_parent_desc
= bdrv_child_get_parent_desc
,
886 .inherit_options
= bdrv_inherited_options
,
887 .drained_begin
= bdrv_child_cb_drained_begin
,
888 .drained_end
= bdrv_child_cb_drained_end
,
889 .inactivate
= bdrv_child_cb_inactivate
,
893 * Returns the options and flags that bs->file should get if the use of formats
894 * (and not only protocols) is permitted for it, based on the given options and
895 * flags for the parent BDS
897 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
898 int parent_flags
, QDict
*parent_options
)
900 child_file
.inherit_options(child_flags
, child_options
,
901 parent_flags
, parent_options
);
903 *child_flags
&= ~(BDRV_O_PROTOCOL
| BDRV_O_NO_IO
);
906 const BdrvChildRole child_format
= {
907 .get_parent_desc
= bdrv_child_get_parent_desc
,
908 .inherit_options
= bdrv_inherited_fmt_options
,
909 .drained_begin
= bdrv_child_cb_drained_begin
,
910 .drained_end
= bdrv_child_cb_drained_end
,
911 .inactivate
= bdrv_child_cb_inactivate
,
914 static void bdrv_backing_attach(BdrvChild
*c
)
916 BlockDriverState
*parent
= c
->opaque
;
917 BlockDriverState
*backing_hd
= c
->bs
;
919 assert(!parent
->backing_blocker
);
920 error_setg(&parent
->backing_blocker
,
921 "node is used as backing hd of '%s'",
922 bdrv_get_device_or_node_name(parent
));
924 parent
->open_flags
&= ~BDRV_O_NO_BACKING
;
925 pstrcpy(parent
->backing_file
, sizeof(parent
->backing_file
),
926 backing_hd
->filename
);
927 pstrcpy(parent
->backing_format
, sizeof(parent
->backing_format
),
928 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
930 bdrv_op_block_all(backing_hd
, parent
->backing_blocker
);
931 /* Otherwise we won't be able to commit or stream */
932 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
933 parent
->backing_blocker
);
934 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_STREAM
,
935 parent
->backing_blocker
);
937 * We do backup in 3 ways:
939 * The target bs is new opened, and the source is top BDS
941 * Both the source and the target are top BDSes.
942 * 3. internal backup(used for block replication)
943 * Both the source and the target are backing file
945 * In case 1 and 2, neither the source nor the target is the backing file.
946 * In case 3, we will block the top BDS, so there is only one block job
947 * for the top BDS and its backing chain.
949 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_SOURCE
,
950 parent
->backing_blocker
);
951 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_BACKUP_TARGET
,
952 parent
->backing_blocker
);
955 static void bdrv_backing_detach(BdrvChild
*c
)
957 BlockDriverState
*parent
= c
->opaque
;
959 assert(parent
->backing_blocker
);
960 bdrv_op_unblock_all(c
->bs
, parent
->backing_blocker
);
961 error_free(parent
->backing_blocker
);
962 parent
->backing_blocker
= NULL
;
966 * Returns the options and flags that bs->backing should get, based on the
967 * given options and flags for the parent BDS
969 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
970 int parent_flags
, QDict
*parent_options
)
972 int flags
= parent_flags
;
974 /* The cache mode is inherited unmodified for backing files; except WCE,
975 * which is only applied on the top level (BlockBackend) */
976 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_DIRECT
);
977 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_CACHE_NO_FLUSH
);
978 qdict_copy_default(child_options
, parent_options
, BDRV_OPT_FORCE_SHARE
);
980 /* backing files always opened read-only */
981 qdict_set_default_str(child_options
, BDRV_OPT_READ_ONLY
, "on");
982 flags
&= ~BDRV_O_COPY_ON_READ
;
984 /* snapshot=on is handled on the top layer */
985 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
987 *child_flags
= flags
;
990 const BdrvChildRole child_backing
= {
991 .get_parent_desc
= bdrv_child_get_parent_desc
,
992 .attach
= bdrv_backing_attach
,
993 .detach
= bdrv_backing_detach
,
994 .inherit_options
= bdrv_backing_options
,
995 .drained_begin
= bdrv_child_cb_drained_begin
,
996 .drained_end
= bdrv_child_cb_drained_end
,
997 .inactivate
= bdrv_child_cb_inactivate
,
1000 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
1002 int open_flags
= flags
;
1005 * Clear flags that are internal to the block layer before opening the
1008 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
1011 * Snapshots should be writable.
1013 if (flags
& BDRV_O_TEMPORARY
) {
1014 open_flags
|= BDRV_O_RDWR
;
1020 static void update_flags_from_options(int *flags
, QemuOpts
*opts
)
1022 *flags
&= ~BDRV_O_CACHE_MASK
;
1024 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_NO_FLUSH
));
1025 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_NO_FLUSH
, false)) {
1026 *flags
|= BDRV_O_NO_FLUSH
;
1029 assert(qemu_opt_find(opts
, BDRV_OPT_CACHE_DIRECT
));
1030 if (qemu_opt_get_bool(opts
, BDRV_OPT_CACHE_DIRECT
, false)) {
1031 *flags
|= BDRV_O_NOCACHE
;
1034 *flags
&= ~BDRV_O_RDWR
;
1036 assert(qemu_opt_find(opts
, BDRV_OPT_READ_ONLY
));
1037 if (!qemu_opt_get_bool(opts
, BDRV_OPT_READ_ONLY
, false)) {
1038 *flags
|= BDRV_O_RDWR
;
1043 static void update_options_from_flags(QDict
*options
, int flags
)
1045 if (!qdict_haskey(options
, BDRV_OPT_CACHE_DIRECT
)) {
1046 qdict_put_bool(options
, BDRV_OPT_CACHE_DIRECT
, flags
& BDRV_O_NOCACHE
);
1048 if (!qdict_haskey(options
, BDRV_OPT_CACHE_NO_FLUSH
)) {
1049 qdict_put_bool(options
, BDRV_OPT_CACHE_NO_FLUSH
,
1050 flags
& BDRV_O_NO_FLUSH
);
1052 if (!qdict_haskey(options
, BDRV_OPT_READ_ONLY
)) {
1053 qdict_put_bool(options
, BDRV_OPT_READ_ONLY
, !(flags
& BDRV_O_RDWR
));
1057 static void bdrv_assign_node_name(BlockDriverState
*bs
,
1058 const char *node_name
,
1061 char *gen_node_name
= NULL
;
1064 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
1065 } else if (!id_wellformed(node_name
)) {
1067 * Check for empty string or invalid characters, but not if it is
1068 * generated (generated names use characters not available to the user)
1070 error_setg(errp
, "Invalid node name");
1074 /* takes care of avoiding namespaces collisions */
1075 if (blk_by_name(node_name
)) {
1076 error_setg(errp
, "node-name=%s is conflicting with a device id",
1081 /* takes care of avoiding duplicates node names */
1082 if (bdrv_find_node(node_name
)) {
1083 error_setg(errp
, "Duplicate node name");
1087 /* copy node name into the bs and insert it into the graph list */
1088 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
1089 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
1091 g_free(gen_node_name
);
1094 static int bdrv_open_driver(BlockDriverState
*bs
, BlockDriver
*drv
,
1095 const char *node_name
, QDict
*options
,
1096 int open_flags
, Error
**errp
)
1098 Error
*local_err
= NULL
;
1101 bdrv_assign_node_name(bs
, node_name
, &local_err
);
1103 error_propagate(errp
, local_err
);
1108 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1109 bs
->opaque
= g_malloc0(drv
->instance_size
);
1111 if (drv
->bdrv_file_open
) {
1112 assert(!drv
->bdrv_needs_filename
|| bs
->filename
[0]);
1113 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
1114 } else if (drv
->bdrv_open
) {
1115 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
1122 error_propagate(errp
, local_err
);
1123 } else if (bs
->filename
[0]) {
1124 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
1126 error_setg_errno(errp
, -ret
, "Could not open image");
1131 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
1133 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
1137 bdrv_refresh_limits(bs
, &local_err
);
1139 error_propagate(errp
, local_err
);
1143 assert(bdrv_opt_mem_align(bs
) != 0);
1144 assert(bdrv_min_mem_align(bs
) != 0);
1145 assert(is_power_of_2(bs
->bl
.request_alignment
));
1150 if (bs
->file
!= NULL
) {
1151 bdrv_unref_child(bs
, bs
->file
);
1159 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
1160 int flags
, Error
**errp
)
1162 BlockDriverState
*bs
;
1166 bs
->open_flags
= flags
;
1167 bs
->explicit_options
= qdict_new();
1168 bs
->options
= qdict_new();
1171 update_options_from_flags(bs
->options
, flags
);
1173 ret
= bdrv_open_driver(bs
, drv
, node_name
, bs
->options
, flags
, errp
);
1175 QDECREF(bs
->explicit_options
);
1176 bs
->explicit_options
= NULL
;
1177 QDECREF(bs
->options
);
1186 QemuOptsList bdrv_runtime_opts
= {
1187 .name
= "bdrv_common",
1188 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
1191 .name
= "node-name",
1192 .type
= QEMU_OPT_STRING
,
1193 .help
= "Node name of the block device node",
1197 .type
= QEMU_OPT_STRING
,
1198 .help
= "Block driver to use for the node",
1201 .name
= BDRV_OPT_CACHE_DIRECT
,
1202 .type
= QEMU_OPT_BOOL
,
1203 .help
= "Bypass software writeback cache on the host",
1206 .name
= BDRV_OPT_CACHE_NO_FLUSH
,
1207 .type
= QEMU_OPT_BOOL
,
1208 .help
= "Ignore flush requests",
1211 .name
= BDRV_OPT_READ_ONLY
,
1212 .type
= QEMU_OPT_BOOL
,
1213 .help
= "Node is opened in read-only mode",
1216 .name
= "detect-zeroes",
1217 .type
= QEMU_OPT_STRING
,
1218 .help
= "try to optimize zero writes (off, on, unmap)",
1222 .type
= QEMU_OPT_STRING
,
1223 .help
= "discard operation (ignore/off, unmap/on)",
1226 .name
= BDRV_OPT_FORCE_SHARE
,
1227 .type
= QEMU_OPT_BOOL
,
1228 .help
= "always accept other writers (default: off)",
1230 { /* end of list */ }
1235 * Common part for opening disk images and files
1237 * Removes all processed options from *options.
1239 static int bdrv_open_common(BlockDriverState
*bs
, BlockBackend
*file
,
1240 QDict
*options
, Error
**errp
)
1242 int ret
, open_flags
;
1243 const char *filename
;
1244 const char *driver_name
= NULL
;
1245 const char *node_name
= NULL
;
1246 const char *discard
;
1247 const char *detect_zeroes
;
1250 Error
*local_err
= NULL
;
1252 assert(bs
->file
== NULL
);
1253 assert(options
!= NULL
&& bs
->options
!= options
);
1255 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
1256 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
1258 error_propagate(errp
, local_err
);
1263 update_flags_from_options(&bs
->open_flags
, opts
);
1265 driver_name
= qemu_opt_get(opts
, "driver");
1266 drv
= bdrv_find_format(driver_name
);
1267 assert(drv
!= NULL
);
1269 bs
->force_share
= qemu_opt_get_bool(opts
, BDRV_OPT_FORCE_SHARE
, false);
1271 if (bs
->force_share
&& (bs
->open_flags
& BDRV_O_RDWR
)) {
1273 BDRV_OPT_FORCE_SHARE
1274 "=on can only be used with read-only images");
1280 filename
= blk_bs(file
)->filename
;
1283 * Caution: while qdict_get_try_str() is fine, getting
1284 * non-string types would require more care. When @options
1285 * come from -blockdev or blockdev_add, its members are typed
1286 * according to the QAPI schema, but when they come from
1287 * -drive, they're all QString.
1289 filename
= qdict_get_try_str(options
, "filename");
1292 if (drv
->bdrv_needs_filename
&& (!filename
|| !filename
[0])) {
1293 error_setg(errp
, "The '%s' block driver requires a file name",
1299 trace_bdrv_open_common(bs
, filename
?: "", bs
->open_flags
,
1302 bs
->read_only
= !(bs
->open_flags
& BDRV_O_RDWR
);
1304 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
1306 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
1307 ? "Driver '%s' can only be used for read-only devices"
1308 : "Driver '%s' is not whitelisted",
1314 /* bdrv_new() and bdrv_close() make it so */
1315 assert(atomic_read(&bs
->copy_on_read
) == 0);
1317 if (bs
->open_flags
& BDRV_O_COPY_ON_READ
) {
1318 if (!bs
->read_only
) {
1319 bdrv_enable_copy_on_read(bs
);
1321 error_setg(errp
, "Can't use copy-on-read on read-only device");
1327 discard
= qemu_opt_get(opts
, "discard");
1328 if (discard
!= NULL
) {
1329 if (bdrv_parse_discard_flags(discard
, &bs
->open_flags
) != 0) {
1330 error_setg(errp
, "Invalid discard option");
1336 detect_zeroes
= qemu_opt_get(opts
, "detect-zeroes");
1337 if (detect_zeroes
) {
1338 BlockdevDetectZeroesOptions value
=
1339 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup
,
1341 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
1344 error_propagate(errp
, local_err
);
1349 if (value
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
1350 !(bs
->open_flags
& BDRV_O_UNMAP
))
1352 error_setg(errp
, "setting detect-zeroes to unmap is not allowed "
1353 "without setting discard operation to unmap");
1358 bs
->detect_zeroes
= value
;
1361 if (filename
!= NULL
) {
1362 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
1364 bs
->filename
[0] = '\0';
1366 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
1368 /* Open the image, either directly or using a protocol */
1369 open_flags
= bdrv_open_flags(bs
, bs
->open_flags
);
1370 node_name
= qemu_opt_get(opts
, "node-name");
1372 assert(!drv
->bdrv_file_open
|| file
== NULL
);
1373 ret
= bdrv_open_driver(bs
, drv
, node_name
, options
, open_flags
, errp
);
1378 qemu_opts_del(opts
);
1382 qemu_opts_del(opts
);
1386 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
1388 QObject
*options_obj
;
1392 ret
= strstart(filename
, "json:", &filename
);
1395 options_obj
= qobject_from_json(filename
, errp
);
1397 /* Work around qobject_from_json() lossage TODO fix that */
1398 if (errp
&& !*errp
) {
1399 error_setg(errp
, "Could not parse the JSON options");
1402 error_prepend(errp
, "Could not parse the JSON options: ");
1406 options
= qobject_to_qdict(options_obj
);
1408 qobject_decref(options_obj
);
1409 error_setg(errp
, "Invalid JSON object given");
1413 qdict_flatten(options
);
1418 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1421 QDict
*json_options
;
1422 Error
*local_err
= NULL
;
1424 /* Parse json: pseudo-protocol */
1425 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1429 json_options
= parse_json_filename(*pfilename
, &local_err
);
1431 error_propagate(errp
, local_err
);
1435 /* Options given in the filename have lower priority than options
1436 * specified directly */
1437 qdict_join(options
, json_options
, false);
1438 QDECREF(json_options
);
1443 * Fills in default options for opening images and converts the legacy
1444 * filename/flags pair to option QDict entries.
1445 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1446 * block driver has been specified explicitly.
1448 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1449 int *flags
, Error
**errp
)
1451 const char *drvname
;
1452 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1453 bool parse_filename
= false;
1454 BlockDriver
*drv
= NULL
;
1455 Error
*local_err
= NULL
;
1458 * Caution: while qdict_get_try_str() is fine, getting non-string
1459 * types would require more care. When @options come from
1460 * -blockdev or blockdev_add, its members are typed according to
1461 * the QAPI schema, but when they come from -drive, they're all
1464 drvname
= qdict_get_try_str(*options
, "driver");
1466 drv
= bdrv_find_format(drvname
);
1468 error_setg(errp
, "Unknown driver '%s'", drvname
);
1471 /* If the user has explicitly specified the driver, this choice should
1472 * override the BDRV_O_PROTOCOL flag */
1473 protocol
= drv
->bdrv_file_open
;
1477 *flags
|= BDRV_O_PROTOCOL
;
1479 *flags
&= ~BDRV_O_PROTOCOL
;
1482 /* Translate cache options from flags into options */
1483 update_options_from_flags(*options
, *flags
);
1485 /* Fetch the file name from the options QDict if necessary */
1486 if (protocol
&& filename
) {
1487 if (!qdict_haskey(*options
, "filename")) {
1488 qdict_put_str(*options
, "filename", filename
);
1489 parse_filename
= true;
1491 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1497 /* Find the right block driver */
1498 /* See cautionary note on accessing @options above */
1499 filename
= qdict_get_try_str(*options
, "filename");
1501 if (!drvname
&& protocol
) {
1503 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1508 drvname
= drv
->format_name
;
1509 qdict_put_str(*options
, "driver", drvname
);
1511 error_setg(errp
, "Must specify either driver or file");
1516 assert(drv
|| !protocol
);
1518 /* Driver-specific filename parsing */
1519 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1520 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1522 error_propagate(errp
, local_err
);
1526 if (!drv
->bdrv_needs_filename
) {
1527 qdict_del(*options
, "filename");
1534 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1535 GSList
*ignore_children
, Error
**errp
);
1536 static void bdrv_child_abort_perm_update(BdrvChild
*c
);
1537 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
);
1539 static void bdrv_child_perm(BlockDriverState
*bs
, BlockDriverState
*child_bs
,
1540 BdrvChild
*c
, const BdrvChildRole
*role
,
1541 BlockReopenQueue
*reopen_queue
,
1542 uint64_t parent_perm
, uint64_t parent_shared
,
1543 uint64_t *nperm
, uint64_t *nshared
)
1545 if (bs
->drv
&& bs
->drv
->bdrv_child_perm
) {
1546 bs
->drv
->bdrv_child_perm(bs
, c
, role
, reopen_queue
,
1547 parent_perm
, parent_shared
,
1550 /* TODO Take force_share from reopen_queue */
1551 if (child_bs
&& child_bs
->force_share
) {
1552 *nshared
= BLK_PERM_ALL
;
1557 * Check whether permissions on this node can be changed in a way that
1558 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1559 * permissions of all its parents. This involves checking whether all necessary
1560 * permission changes to child nodes can be performed.
1562 * A call to this function must always be followed by a call to bdrv_set_perm()
1563 * or bdrv_abort_perm_update().
1565 static int bdrv_check_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1566 uint64_t cumulative_shared_perms
,
1567 GSList
*ignore_children
, Error
**errp
)
1569 BlockDriver
*drv
= bs
->drv
;
1573 /* Write permissions never work with read-only images */
1574 if ((cumulative_perms
& (BLK_PERM_WRITE
| BLK_PERM_WRITE_UNCHANGED
)) &&
1575 !bdrv_is_writable(bs
))
1577 error_setg(errp
, "Block node is read-only");
1581 /* Check this node */
1586 if (drv
->bdrv_check_perm
) {
1587 return drv
->bdrv_check_perm(bs
, cumulative_perms
,
1588 cumulative_shared_perms
, errp
);
1591 /* Drivers that never have children can omit .bdrv_child_perm() */
1592 if (!drv
->bdrv_child_perm
) {
1593 assert(QLIST_EMPTY(&bs
->children
));
1597 /* Check all children */
1598 QLIST_FOREACH(c
, &bs
->children
, next
) {
1599 uint64_t cur_perm
, cur_shared
;
1600 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, NULL
,
1601 cumulative_perms
, cumulative_shared_perms
,
1602 &cur_perm
, &cur_shared
);
1603 ret
= bdrv_child_check_perm(c
, cur_perm
, cur_shared
, ignore_children
,
1614 * Notifies drivers that after a previous bdrv_check_perm() call, the
1615 * permission update is not performed and any preparations made for it (e.g.
1616 * taken file locks) need to be undone.
1618 * This function recursively notifies all child nodes.
1620 static void bdrv_abort_perm_update(BlockDriverState
*bs
)
1622 BlockDriver
*drv
= bs
->drv
;
1629 if (drv
->bdrv_abort_perm_update
) {
1630 drv
->bdrv_abort_perm_update(bs
);
1633 QLIST_FOREACH(c
, &bs
->children
, next
) {
1634 bdrv_child_abort_perm_update(c
);
1638 static void bdrv_set_perm(BlockDriverState
*bs
, uint64_t cumulative_perms
,
1639 uint64_t cumulative_shared_perms
)
1641 BlockDriver
*drv
= bs
->drv
;
1648 /* Update this node */
1649 if (drv
->bdrv_set_perm
) {
1650 drv
->bdrv_set_perm(bs
, cumulative_perms
, cumulative_shared_perms
);
1653 /* Drivers that never have children can omit .bdrv_child_perm() */
1654 if (!drv
->bdrv_child_perm
) {
1655 assert(QLIST_EMPTY(&bs
->children
));
1659 /* Update all children */
1660 QLIST_FOREACH(c
, &bs
->children
, next
) {
1661 uint64_t cur_perm
, cur_shared
;
1662 bdrv_child_perm(bs
, c
->bs
, c
, c
->role
, NULL
,
1663 cumulative_perms
, cumulative_shared_perms
,
1664 &cur_perm
, &cur_shared
);
1665 bdrv_child_set_perm(c
, cur_perm
, cur_shared
);
1669 static void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1670 uint64_t *shared_perm
)
1673 uint64_t cumulative_perms
= 0;
1674 uint64_t cumulative_shared_perms
= BLK_PERM_ALL
;
1676 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1677 cumulative_perms
|= c
->perm
;
1678 cumulative_shared_perms
&= c
->shared_perm
;
1681 *perm
= cumulative_perms
;
1682 *shared_perm
= cumulative_shared_perms
;
1685 static char *bdrv_child_user_desc(BdrvChild
*c
)
1687 if (c
->role
->get_parent_desc
) {
1688 return c
->role
->get_parent_desc(c
);
1691 return g_strdup("another user");
1694 char *bdrv_perm_names(uint64_t perm
)
1700 { BLK_PERM_CONSISTENT_READ
, "consistent read" },
1701 { BLK_PERM_WRITE
, "write" },
1702 { BLK_PERM_WRITE_UNCHANGED
, "write unchanged" },
1703 { BLK_PERM_RESIZE
, "resize" },
1704 { BLK_PERM_GRAPH_MOD
, "change children" },
1708 char *result
= g_strdup("");
1709 struct perm_name
*p
;
1711 for (p
= permissions
; p
->name
; p
++) {
1712 if (perm
& p
->perm
) {
1714 result
= g_strdup_printf("%s%s%s", old
, *old
? ", " : "", p
->name
);
1723 * Checks whether a new reference to @bs can be added if the new user requires
1724 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1725 * set, the BdrvChild objects in this list are ignored in the calculations;
1726 * this allows checking permission updates for an existing reference.
1728 * Needs to be followed by a call to either bdrv_set_perm() or
1729 * bdrv_abort_perm_update(). */
1730 static int bdrv_check_update_perm(BlockDriverState
*bs
, uint64_t new_used_perm
,
1731 uint64_t new_shared_perm
,
1732 GSList
*ignore_children
, Error
**errp
)
1735 uint64_t cumulative_perms
= new_used_perm
;
1736 uint64_t cumulative_shared_perms
= new_shared_perm
;
1738 /* There is no reason why anyone couldn't tolerate write_unchanged */
1739 assert(new_shared_perm
& BLK_PERM_WRITE_UNCHANGED
);
1741 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
1742 if (g_slist_find(ignore_children
, c
)) {
1746 if ((new_used_perm
& c
->shared_perm
) != new_used_perm
) {
1747 char *user
= bdrv_child_user_desc(c
);
1748 char *perm_names
= bdrv_perm_names(new_used_perm
& ~c
->shared_perm
);
1749 error_setg(errp
, "Conflicts with use by %s as '%s', which does not "
1751 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1757 if ((c
->perm
& new_shared_perm
) != c
->perm
) {
1758 char *user
= bdrv_child_user_desc(c
);
1759 char *perm_names
= bdrv_perm_names(c
->perm
& ~new_shared_perm
);
1760 error_setg(errp
, "Conflicts with use by %s as '%s', which uses "
1762 user
, c
->name
, perm_names
, bdrv_get_node_name(c
->bs
));
1768 cumulative_perms
|= c
->perm
;
1769 cumulative_shared_perms
&= c
->shared_perm
;
1772 return bdrv_check_perm(bs
, cumulative_perms
, cumulative_shared_perms
,
1773 ignore_children
, errp
);
1776 /* Needs to be followed by a call to either bdrv_child_set_perm() or
1777 * bdrv_child_abort_perm_update(). */
1778 static int bdrv_child_check_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1779 GSList
*ignore_children
, Error
**errp
)
1783 ignore_children
= g_slist_prepend(g_slist_copy(ignore_children
), c
);
1784 ret
= bdrv_check_update_perm(c
->bs
, perm
, shared
, ignore_children
, errp
);
1785 g_slist_free(ignore_children
);
1790 static void bdrv_child_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
)
1792 uint64_t cumulative_perms
, cumulative_shared_perms
;
1795 c
->shared_perm
= shared
;
1797 bdrv_get_cumulative_perm(c
->bs
, &cumulative_perms
,
1798 &cumulative_shared_perms
);
1799 bdrv_set_perm(c
->bs
, cumulative_perms
, cumulative_shared_perms
);
1802 static void bdrv_child_abort_perm_update(BdrvChild
*c
)
1804 bdrv_abort_perm_update(c
->bs
);
1807 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1812 ret
= bdrv_child_check_perm(c
, perm
, shared
, NULL
, errp
);
1814 bdrv_child_abort_perm_update(c
);
1818 bdrv_child_set_perm(c
, perm
, shared
);
1823 #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1825 | BLK_PERM_WRITE_UNCHANGED \
1827 #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1829 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1830 const BdrvChildRole
*role
,
1831 BlockReopenQueue
*reopen_queue
,
1832 uint64_t perm
, uint64_t shared
,
1833 uint64_t *nperm
, uint64_t *nshared
)
1836 *nperm
= perm
& DEFAULT_PERM_PASSTHROUGH
;
1837 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) | DEFAULT_PERM_UNCHANGED
;
1841 *nperm
= (perm
& DEFAULT_PERM_PASSTHROUGH
) |
1842 (c
->perm
& DEFAULT_PERM_UNCHANGED
);
1843 *nshared
= (shared
& DEFAULT_PERM_PASSTHROUGH
) |
1844 (c
->shared_perm
& DEFAULT_PERM_UNCHANGED
);
1847 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1848 const BdrvChildRole
*role
,
1849 BlockReopenQueue
*reopen_queue
,
1850 uint64_t perm
, uint64_t shared
,
1851 uint64_t *nperm
, uint64_t *nshared
)
1853 bool backing
= (role
== &child_backing
);
1854 assert(role
== &child_backing
|| role
== &child_file
);
1857 /* Apart from the modifications below, the same permissions are
1858 * forwarded and left alone as for filters */
1859 bdrv_filter_default_perms(bs
, c
, role
, reopen_queue
, perm
, shared
,
1862 /* Format drivers may touch metadata even if the guest doesn't write */
1863 /* TODO Take flags from reopen_queue */
1864 if (bdrv_is_writable(bs
)) {
1865 perm
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1868 /* bs->file always needs to be consistent because of the metadata. We
1869 * can never allow other users to resize or write to it. */
1870 perm
|= BLK_PERM_CONSISTENT_READ
;
1871 shared
&= ~(BLK_PERM_WRITE
| BLK_PERM_RESIZE
);
1873 /* We want consistent read from backing files if the parent needs it.
1874 * No other operations are performed on backing files. */
1875 perm
&= BLK_PERM_CONSISTENT_READ
;
1877 /* If the parent can deal with changing data, we're okay with a
1878 * writable and resizable backing file. */
1879 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1880 if (shared
& BLK_PERM_WRITE
) {
1881 shared
= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1886 shared
|= BLK_PERM_CONSISTENT_READ
| BLK_PERM_GRAPH_MOD
|
1887 BLK_PERM_WRITE_UNCHANGED
;
1890 if (bs
->open_flags
& BDRV_O_INACTIVE
) {
1891 shared
|= BLK_PERM_WRITE
| BLK_PERM_RESIZE
;
1898 static void bdrv_replace_child_noperm(BdrvChild
*child
,
1899 BlockDriverState
*new_bs
)
1901 BlockDriverState
*old_bs
= child
->bs
;
1903 if (old_bs
&& new_bs
) {
1904 assert(bdrv_get_aio_context(old_bs
) == bdrv_get_aio_context(new_bs
));
1907 if (old_bs
->quiesce_counter
&& child
->role
->drained_end
) {
1908 child
->role
->drained_end(child
);
1910 if (child
->role
->detach
) {
1911 child
->role
->detach(child
);
1913 QLIST_REMOVE(child
, next_parent
);
1919 QLIST_INSERT_HEAD(&new_bs
->parents
, child
, next_parent
);
1920 if (new_bs
->quiesce_counter
&& child
->role
->drained_begin
) {
1921 child
->role
->drained_begin(child
);
1924 if (child
->role
->attach
) {
1925 child
->role
->attach(child
);
1931 * Updates @child to change its reference to point to @new_bs, including
1932 * checking and applying the necessary permisson updates both to the old node
1935 * NULL is passed as @new_bs for removing the reference before freeing @child.
1937 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
1938 * function uses bdrv_set_perm() to update the permissions according to the new
1939 * reference that @new_bs gets.
1941 static void bdrv_replace_child(BdrvChild
*child
, BlockDriverState
*new_bs
)
1943 BlockDriverState
*old_bs
= child
->bs
;
1944 uint64_t perm
, shared_perm
;
1946 bdrv_replace_child_noperm(child
, new_bs
);
1949 /* Update permissions for old node. This is guaranteed to succeed
1950 * because we're just taking a parent away, so we're loosening
1952 bdrv_get_cumulative_perm(old_bs
, &perm
, &shared_perm
);
1953 bdrv_check_perm(old_bs
, perm
, shared_perm
, NULL
, &error_abort
);
1954 bdrv_set_perm(old_bs
, perm
, shared_perm
);
1958 bdrv_get_cumulative_perm(new_bs
, &perm
, &shared_perm
);
1959 bdrv_set_perm(new_bs
, perm
, shared_perm
);
1963 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1964 const char *child_name
,
1965 const BdrvChildRole
*child_role
,
1966 uint64_t perm
, uint64_t shared_perm
,
1967 void *opaque
, Error
**errp
)
1972 ret
= bdrv_check_update_perm(child_bs
, perm
, shared_perm
, NULL
, errp
);
1974 bdrv_abort_perm_update(child_bs
);
1978 child
= g_new(BdrvChild
, 1);
1979 *child
= (BdrvChild
) {
1981 .name
= g_strdup(child_name
),
1984 .shared_perm
= shared_perm
,
1988 /* This performs the matching bdrv_set_perm() for the above check. */
1989 bdrv_replace_child(child
, child_bs
);
1994 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1995 BlockDriverState
*child_bs
,
1996 const char *child_name
,
1997 const BdrvChildRole
*child_role
,
2001 uint64_t perm
, shared_perm
;
2003 bdrv_get_cumulative_perm(parent_bs
, &perm
, &shared_perm
);
2005 assert(parent_bs
->drv
);
2006 assert(bdrv_get_aio_context(parent_bs
) == bdrv_get_aio_context(child_bs
));
2007 bdrv_child_perm(parent_bs
, child_bs
, NULL
, child_role
, NULL
,
2008 perm
, shared_perm
, &perm
, &shared_perm
);
2010 child
= bdrv_root_attach_child(child_bs
, child_name
, child_role
,
2011 perm
, shared_perm
, parent_bs
, errp
);
2012 if (child
== NULL
) {
2016 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
2020 static void bdrv_detach_child(BdrvChild
*child
)
2022 if (child
->next
.le_prev
) {
2023 QLIST_REMOVE(child
, next
);
2024 child
->next
.le_prev
= NULL
;
2027 bdrv_replace_child(child
, NULL
);
2029 g_free(child
->name
);
2033 void bdrv_root_unref_child(BdrvChild
*child
)
2035 BlockDriverState
*child_bs
;
2037 child_bs
= child
->bs
;
2038 bdrv_detach_child(child
);
2039 bdrv_unref(child_bs
);
2042 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
2044 if (child
== NULL
) {
2048 if (child
->bs
->inherits_from
== parent
) {
2051 /* Remove inherits_from only when the last reference between parent and
2052 * child->bs goes away. */
2053 QLIST_FOREACH(c
, &parent
->children
, next
) {
2054 if (c
!= child
&& c
->bs
== child
->bs
) {
2059 child
->bs
->inherits_from
= NULL
;
2063 bdrv_root_unref_child(child
);
2067 static void bdrv_parent_cb_change_media(BlockDriverState
*bs
, bool load
)
2070 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2071 if (c
->role
->change_media
) {
2072 c
->role
->change_media(c
, load
);
2077 static void bdrv_parent_cb_resize(BlockDriverState
*bs
)
2080 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
2081 if (c
->role
->resize
) {
2088 * Sets the backing file link of a BDS. A new reference is created; callers
2089 * which don't need their own reference any more must call bdrv_unref().
2091 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
2095 bdrv_ref(backing_hd
);
2099 bdrv_unref_child(bs
, bs
->backing
);
2107 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
,
2110 bdrv_unref(backing_hd
);
2113 bdrv_refresh_filename(bs
);
2116 bdrv_refresh_limits(bs
, NULL
);
2120 * Opens the backing file for a BlockDriverState if not yet open
2122 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2123 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2124 * itself, all options starting with "${bdref_key}." are considered part of the
2127 * TODO Can this be unified with bdrv_open_image()?
2129 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
2130 const char *bdref_key
, Error
**errp
)
2132 char *backing_filename
= g_malloc0(PATH_MAX
);
2133 char *bdref_key_dot
;
2134 const char *reference
= NULL
;
2136 BlockDriverState
*backing_hd
;
2138 QDict
*tmp_parent_options
= NULL
;
2139 Error
*local_err
= NULL
;
2141 if (bs
->backing
!= NULL
) {
2145 /* NULL means an empty set of options */
2146 if (parent_options
== NULL
) {
2147 tmp_parent_options
= qdict_new();
2148 parent_options
= tmp_parent_options
;
2151 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
2153 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2154 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
2155 g_free(bdref_key_dot
);
2158 * Caution: while qdict_get_try_str() is fine, getting non-string
2159 * types would require more care. When @parent_options come from
2160 * -blockdev or blockdev_add, its members are typed according to
2161 * the QAPI schema, but when they come from -drive, they're all
2164 reference
= qdict_get_try_str(parent_options
, bdref_key
);
2165 if (reference
|| qdict_haskey(options
, "file.filename")) {
2166 backing_filename
[0] = '\0';
2167 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
2171 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
2175 error_propagate(errp
, local_err
);
2181 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
2183 error_setg(errp
, "Driver doesn't support backing files");
2188 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
2189 qdict_put_str(options
, "driver", bs
->backing_format
);
2192 backing_hd
= bdrv_open_inherit(*backing_filename
? backing_filename
: NULL
,
2193 reference
, options
, 0, bs
, &child_backing
,
2196 bs
->open_flags
|= BDRV_O_NO_BACKING
;
2197 error_prepend(errp
, "Could not open backing file: ");
2201 bdrv_set_aio_context(backing_hd
, bdrv_get_aio_context(bs
));
2203 /* Hook up the backing file link; drop our reference, bs owns the
2204 * backing_hd reference now */
2205 bdrv_set_backing_hd(bs
, backing_hd
, &local_err
);
2206 bdrv_unref(backing_hd
);
2208 error_propagate(errp
, local_err
);
2213 qdict_del(parent_options
, bdref_key
);
2216 g_free(backing_filename
);
2217 QDECREF(tmp_parent_options
);
2221 static BlockDriverState
*
2222 bdrv_open_child_bs(const char *filename
, QDict
*options
, const char *bdref_key
,
2223 BlockDriverState
*parent
, const BdrvChildRole
*child_role
,
2224 bool allow_none
, Error
**errp
)
2226 BlockDriverState
*bs
= NULL
;
2227 QDict
*image_options
;
2228 char *bdref_key_dot
;
2229 const char *reference
;
2231 assert(child_role
!= NULL
);
2233 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
2234 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
2235 g_free(bdref_key_dot
);
2238 * Caution: while qdict_get_try_str() is fine, getting non-string
2239 * types would require more care. When @options come from
2240 * -blockdev or blockdev_add, its members are typed according to
2241 * the QAPI schema, but when they come from -drive, they're all
2244 reference
= qdict_get_try_str(options
, bdref_key
);
2245 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
2247 error_setg(errp
, "A block device must be specified for \"%s\"",
2250 QDECREF(image_options
);
2254 bs
= bdrv_open_inherit(filename
, reference
, image_options
, 0,
2255 parent
, child_role
, errp
);
2261 qdict_del(options
, bdref_key
);
2266 * Opens a disk image whose options are given as BlockdevRef in another block
2269 * If allow_none is true, no image will be opened if filename is false and no
2270 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2272 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2273 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2274 * itself, all options starting with "${bdref_key}." are considered part of the
2277 * The BlockdevRef will be removed from the options QDict.
2279 BdrvChild
*bdrv_open_child(const char *filename
,
2280 QDict
*options
, const char *bdref_key
,
2281 BlockDriverState
*parent
,
2282 const BdrvChildRole
*child_role
,
2283 bool allow_none
, Error
**errp
)
2286 BlockDriverState
*bs
;
2288 bs
= bdrv_open_child_bs(filename
, options
, bdref_key
, parent
, child_role
,
2294 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
, errp
);
2303 static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState
*bs
,
2305 QDict
*snapshot_options
,
2308 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
2309 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
2311 QemuOpts
*opts
= NULL
;
2312 BlockDriverState
*bs_snapshot
= NULL
;
2313 Error
*local_err
= NULL
;
2316 /* if snapshot, we create a temporary backing file and open it
2317 instead of opening 'filename' directly */
2319 /* Get the required size from the image */
2320 total_size
= bdrv_getlength(bs
);
2321 if (total_size
< 0) {
2322 error_setg_errno(errp
, -total_size
, "Could not get image size");
2326 /* Create the temporary image */
2327 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
2329 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
2333 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
2335 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
2336 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, errp
);
2337 qemu_opts_del(opts
);
2339 error_prepend(errp
, "Could not create temporary overlay '%s': ",
2344 /* Prepare options QDict for the temporary file */
2345 qdict_put_str(snapshot_options
, "file.driver", "file");
2346 qdict_put_str(snapshot_options
, "file.filename", tmp_filename
);
2347 qdict_put_str(snapshot_options
, "driver", "qcow2");
2349 bs_snapshot
= bdrv_open(NULL
, NULL
, snapshot_options
, flags
, errp
);
2350 snapshot_options
= NULL
;
2355 /* bdrv_append() consumes a strong reference to bs_snapshot
2356 * (i.e. it will call bdrv_unref() on it) even on error, so in
2357 * order to be able to return one, we have to increase
2358 * bs_snapshot's refcount here */
2359 bdrv_ref(bs_snapshot
);
2360 bdrv_append(bs_snapshot
, bs
, &local_err
);
2362 error_propagate(errp
, local_err
);
2368 QDECREF(snapshot_options
);
2369 g_free(tmp_filename
);
2374 * Opens a disk image (raw, qcow2, vmdk, ...)
2376 * options is a QDict of options to pass to the block drivers, or NULL for an
2377 * empty set of options. The reference to the QDict belongs to the block layer
2378 * after the call (even on failure), so if the caller intends to reuse the
2379 * dictionary, it needs to use QINCREF() before calling bdrv_open.
2381 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2382 * If it is not NULL, the referenced BDS will be reused.
2384 * The reference parameter may be used to specify an existing block device which
2385 * should be opened. If specified, neither options nor a filename may be given,
2386 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
2388 static BlockDriverState
*bdrv_open_inherit(const char *filename
,
2389 const char *reference
,
2390 QDict
*options
, int flags
,
2391 BlockDriverState
*parent
,
2392 const BdrvChildRole
*child_role
,
2396 BlockBackend
*file
= NULL
;
2397 BlockDriverState
*bs
;
2398 BlockDriver
*drv
= NULL
;
2399 const char *drvname
;
2400 const char *backing
;
2401 Error
*local_err
= NULL
;
2402 QDict
*snapshot_options
= NULL
;
2403 int snapshot_flags
= 0;
2405 assert(!child_role
|| !flags
);
2406 assert(!child_role
== !parent
);
2409 bool options_non_empty
= options
? qdict_size(options
) : false;
2412 if (filename
|| options_non_empty
) {
2413 error_setg(errp
, "Cannot reference an existing block device with "
2414 "additional options or a new filename");
2418 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
2429 /* NULL means an empty set of options */
2430 if (options
== NULL
) {
2431 options
= qdict_new();
2434 /* json: syntax counts as explicit options, as if in the QDict */
2435 parse_json_protocol(options
, &filename
, &local_err
);
2440 bs
->explicit_options
= qdict_clone_shallow(options
);
2443 bs
->inherits_from
= parent
;
2444 child_role
->inherit_options(&flags
, options
,
2445 parent
->open_flags
, parent
->options
);
2448 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
2454 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2455 * Caution: getting a boolean member of @options requires care.
2456 * When @options come from -blockdev or blockdev_add, members are
2457 * typed according to the QAPI schema, but when they come from
2458 * -drive, they're all QString.
2460 if (g_strcmp0(qdict_get_try_str(options
, BDRV_OPT_READ_ONLY
), "on") &&
2461 !qdict_get_try_bool(options
, BDRV_OPT_READ_ONLY
, false)) {
2462 flags
|= (BDRV_O_RDWR
| BDRV_O_ALLOW_RDWR
);
2464 flags
&= ~BDRV_O_RDWR
;
2467 if (flags
& BDRV_O_SNAPSHOT
) {
2468 snapshot_options
= qdict_new();
2469 bdrv_temp_snapshot_options(&snapshot_flags
, snapshot_options
,
2471 /* Let bdrv_backing_options() override "read-only" */
2472 qdict_del(options
, BDRV_OPT_READ_ONLY
);
2473 bdrv_backing_options(&flags
, options
, flags
, options
);
2476 bs
->open_flags
= flags
;
2477 bs
->options
= options
;
2478 options
= qdict_clone_shallow(options
);
2480 /* Find the right image format driver */
2481 /* See cautionary note on accessing @options above */
2482 drvname
= qdict_get_try_str(options
, "driver");
2484 drv
= bdrv_find_format(drvname
);
2486 error_setg(errp
, "Unknown driver: '%s'", drvname
);
2491 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
2493 /* See cautionary note on accessing @options above */
2494 backing
= qdict_get_try_str(options
, "backing");
2495 if (backing
&& *backing
== '\0') {
2496 flags
|= BDRV_O_NO_BACKING
;
2497 qdict_del(options
, "backing");
2500 /* Open image file without format layer. This BlockBackend is only used for
2501 * probing, the block drivers will do their own bdrv_open_child() for the
2502 * same BDS, which is why we put the node name back into options. */
2503 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
2504 BlockDriverState
*file_bs
;
2506 file_bs
= bdrv_open_child_bs(filename
, options
, "file", bs
,
2507 &child_file
, true, &local_err
);
2511 if (file_bs
!= NULL
) {
2512 file
= blk_new(BLK_PERM_CONSISTENT_READ
, BLK_PERM_ALL
);
2513 blk_insert_bs(file
, file_bs
, &local_err
);
2514 bdrv_unref(file_bs
);
2519 qdict_put_str(options
, "file", bdrv_get_node_name(file_bs
));
2523 /* Image format probing */
2526 ret
= find_image_format(file
, filename
, &drv
, &local_err
);
2531 * This option update would logically belong in bdrv_fill_options(),
2532 * but we first need to open bs->file for the probing to work, while
2533 * opening bs->file already requires the (mostly) final set of options
2534 * so that cache mode etc. can be inherited.
2536 * Adding the driver later is somewhat ugly, but it's not an option
2537 * that would ever be inherited, so it's correct. We just need to make
2538 * sure to update both bs->options (which has the full effective
2539 * options for bs) and options (which has file.* already removed).
2541 qdict_put_str(bs
->options
, "driver", drv
->format_name
);
2542 qdict_put_str(options
, "driver", drv
->format_name
);
2544 error_setg(errp
, "Must specify either driver or file");
2548 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2549 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
2550 /* file must be NULL if a protocol BDS is about to be created
2551 * (the inverse results in an error message from bdrv_open_common()) */
2552 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
2554 /* Open the image */
2555 ret
= bdrv_open_common(bs
, file
, options
, &local_err
);
2565 /* If there is a backing file, use it */
2566 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
2567 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
2569 goto close_and_fail
;
2573 bdrv_refresh_filename(bs
);
2575 /* Check if any unknown options were used */
2576 if (qdict_size(options
) != 0) {
2577 const QDictEntry
*entry
= qdict_first(options
);
2578 if (flags
& BDRV_O_PROTOCOL
) {
2579 error_setg(errp
, "Block protocol '%s' doesn't support the option "
2580 "'%s'", drv
->format_name
, entry
->key
);
2583 "Block format '%s' does not support the option '%s'",
2584 drv
->format_name
, entry
->key
);
2587 goto close_and_fail
;
2590 bdrv_parent_cb_change_media(bs
, true);
2594 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2595 * temporary snapshot afterwards. */
2596 if (snapshot_flags
) {
2597 BlockDriverState
*snapshot_bs
;
2598 snapshot_bs
= bdrv_append_temp_snapshot(bs
, snapshot_flags
,
2599 snapshot_options
, &local_err
);
2600 snapshot_options
= NULL
;
2602 goto close_and_fail
;
2604 /* We are not going to return bs but the overlay on top of it
2605 * (snapshot_bs); thus, we have to drop the strong reference to bs
2606 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2607 * though, because the overlay still has a reference to it. */
2616 QDECREF(snapshot_options
);
2617 QDECREF(bs
->explicit_options
);
2618 QDECREF(bs
->options
);
2621 bs
->explicit_options
= NULL
;
2623 error_propagate(errp
, local_err
);
2628 QDECREF(snapshot_options
);
2630 error_propagate(errp
, local_err
);
2634 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
2635 QDict
*options
, int flags
, Error
**errp
)
2637 return bdrv_open_inherit(filename
, reference
, options
, flags
, NULL
,
2641 typedef struct BlockReopenQueueEntry
{
2643 BDRVReopenState state
;
2644 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
2645 } BlockReopenQueueEntry
;
2648 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2649 * reopen of multiple devices.
2651 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2652 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2653 * be created and initialized. This newly created BlockReopenQueue should be
2654 * passed back in for subsequent calls that are intended to be of the same
2657 * bs is the BlockDriverState to add to the reopen queue.
2659 * options contains the changed options for the associated bs
2660 * (the BlockReopenQueue takes ownership)
2662 * flags contains the open flags for the associated bs
2664 * returns a pointer to bs_queue, which is either the newly allocated
2665 * bs_queue, or the existing bs_queue being used.
2668 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
2669 BlockDriverState
*bs
,
2672 const BdrvChildRole
*role
,
2673 QDict
*parent_options
,
2678 BlockReopenQueueEntry
*bs_entry
;
2680 QDict
*old_options
, *explicit_options
;
2682 if (bs_queue
== NULL
) {
2683 bs_queue
= g_new0(BlockReopenQueue
, 1);
2684 QSIMPLEQ_INIT(bs_queue
);
2688 options
= qdict_new();
2691 /* Check if this BlockDriverState is already in the queue */
2692 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2693 if (bs
== bs_entry
->state
.bs
) {
2699 * Precedence of options:
2700 * 1. Explicitly passed in options (highest)
2701 * 2. Set in flags (only for top level)
2702 * 3. Retained from explicitly set options of bs
2703 * 4. Inherited from parent node
2704 * 5. Retained from effective options of bs
2707 if (!parent_options
) {
2709 * Any setting represented by flags is always updated. If the
2710 * corresponding QDict option is set, it takes precedence. Otherwise
2711 * the flag is translated into a QDict option. The old setting of bs is
2714 update_options_from_flags(options
, flags
);
2717 /* Old explicitly set values (don't overwrite by inherited value) */
2719 old_options
= qdict_clone_shallow(bs_entry
->state
.explicit_options
);
2721 old_options
= qdict_clone_shallow(bs
->explicit_options
);
2723 bdrv_join_options(bs
, options
, old_options
);
2724 QDECREF(old_options
);
2726 explicit_options
= qdict_clone_shallow(options
);
2728 /* Inherit from parent node */
2729 if (parent_options
) {
2731 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
2734 /* Old values are used for options that aren't set yet */
2735 old_options
= qdict_clone_shallow(bs
->options
);
2736 bdrv_join_options(bs
, options
, old_options
);
2737 QDECREF(old_options
);
2739 /* bdrv_open_inherit() sets and clears some additional flags internally */
2740 flags
&= ~BDRV_O_PROTOCOL
;
2741 if (flags
& BDRV_O_RDWR
) {
2742 flags
|= BDRV_O_ALLOW_RDWR
;
2745 QLIST_FOREACH(child
, &bs
->children
, next
) {
2746 QDict
*new_child_options
;
2747 char *child_key_dot
;
2749 /* reopen can only change the options of block devices that were
2750 * implicitly created and inherited options. For other (referenced)
2751 * block devices, a syntax like "backing.foo" results in an error. */
2752 if (child
->bs
->inherits_from
!= bs
) {
2756 child_key_dot
= g_strdup_printf("%s.", child
->name
);
2757 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
2758 g_free(child_key_dot
);
2760 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
2761 child
->role
, options
, flags
);
2765 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
2766 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
2768 QDECREF(bs_entry
->state
.options
);
2769 QDECREF(bs_entry
->state
.explicit_options
);
2772 bs_entry
->state
.bs
= bs
;
2773 bs_entry
->state
.options
= options
;
2774 bs_entry
->state
.explicit_options
= explicit_options
;
2775 bs_entry
->state
.flags
= flags
;
2780 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
2781 BlockDriverState
*bs
,
2782 QDict
*options
, int flags
)
2784 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
2789 * Reopen multiple BlockDriverStates atomically & transactionally.
2791 * The queue passed in (bs_queue) must have been built up previous
2792 * via bdrv_reopen_queue().
2794 * Reopens all BDS specified in the queue, with the appropriate
2795 * flags. All devices are prepared for reopen, and failure of any
2796 * device will cause all device changes to be abandonded, and intermediate
2799 * If all devices prepare successfully, then the changes are committed
2803 int bdrv_reopen_multiple(AioContext
*ctx
, BlockReopenQueue
*bs_queue
, Error
**errp
)
2806 BlockReopenQueueEntry
*bs_entry
, *next
;
2807 Error
*local_err
= NULL
;
2809 assert(bs_queue
!= NULL
);
2811 aio_context_release(ctx
);
2812 bdrv_drain_all_begin();
2813 aio_context_acquire(ctx
);
2815 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2816 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
2817 error_propagate(errp
, local_err
);
2820 bs_entry
->prepared
= true;
2823 /* If we reach this point, we have success and just need to apply the
2826 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
2827 bdrv_reopen_commit(&bs_entry
->state
);
2833 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
2834 if (ret
&& bs_entry
->prepared
) {
2835 bdrv_reopen_abort(&bs_entry
->state
);
2837 QDECREF(bs_entry
->state
.explicit_options
);
2839 QDECREF(bs_entry
->state
.options
);
2844 bdrv_drain_all_end();
2850 /* Reopen a single BlockDriverState with the specified flags. */
2851 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
2854 Error
*local_err
= NULL
;
2855 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
2857 ret
= bdrv_reopen_multiple(bdrv_get_aio_context(bs
), queue
, &local_err
);
2858 if (local_err
!= NULL
) {
2859 error_propagate(errp
, local_err
);
2866 * Prepares a BlockDriverState for reopen. All changes are staged in the
2867 * 'opaque' field of the BDRVReopenState, which is used and allocated by
2868 * the block driver layer .bdrv_reopen_prepare()
2870 * bs is the BlockDriverState to reopen
2871 * flags are the new open flags
2872 * queue is the reopen queue
2874 * Returns 0 on success, non-zero on error. On error errp will be set
2877 * On failure, bdrv_reopen_abort() will be called to clean up any data.
2878 * It is the responsibility of the caller to then call the abort() or
2879 * commit() for any other BDS that have been left in a prepare() state
2882 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
2886 Error
*local_err
= NULL
;
2892 assert(reopen_state
!= NULL
);
2893 assert(reopen_state
->bs
->drv
!= NULL
);
2894 drv
= reopen_state
->bs
->drv
;
2896 /* Process generic block layer options */
2897 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
2898 qemu_opts_absorb_qdict(opts
, reopen_state
->options
, &local_err
);
2900 error_propagate(errp
, local_err
);
2905 update_flags_from_options(&reopen_state
->flags
, opts
);
2907 /* node-name and driver must be unchanged. Put them back into the QDict, so
2908 * that they are checked at the end of this function. */
2909 value
= qemu_opt_get(opts
, "node-name");
2911 qdict_put_str(reopen_state
->options
, "node-name", value
);
2914 value
= qemu_opt_get(opts
, "driver");
2916 qdict_put_str(reopen_state
->options
, "driver", value
);
2919 /* If we are to stay read-only, do not allow permission change
2920 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
2921 * not set, or if the BDS still has copy_on_read enabled */
2922 read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2923 ret
= bdrv_can_set_read_only(reopen_state
->bs
, read_only
, true, &local_err
);
2925 error_propagate(errp
, local_err
);
2930 ret
= bdrv_flush(reopen_state
->bs
);
2932 error_setg_errno(errp
, -ret
, "Error flushing drive");
2936 if (drv
->bdrv_reopen_prepare
) {
2937 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
2939 if (local_err
!= NULL
) {
2940 error_propagate(errp
, local_err
);
2942 error_setg(errp
, "failed while preparing to reopen image '%s'",
2943 reopen_state
->bs
->filename
);
2948 /* It is currently mandatory to have a bdrv_reopen_prepare()
2949 * handler for each supported drv. */
2950 error_setg(errp
, "Block format '%s' used by node '%s' "
2951 "does not support reopening files", drv
->format_name
,
2952 bdrv_get_device_or_node_name(reopen_state
->bs
));
2957 /* Options that are not handled are only okay if they are unchanged
2958 * compared to the old state. It is expected that some options are only
2959 * used for the initial open, but not reopen (e.g. filename) */
2960 if (qdict_size(reopen_state
->options
)) {
2961 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
2964 QString
*new_obj
= qobject_to_qstring(entry
->value
);
2965 const char *new = qstring_get_str(new_obj
);
2967 * Caution: while qdict_get_try_str() is fine, getting
2968 * non-string types would require more care. When
2969 * bs->options come from -blockdev or blockdev_add, its
2970 * members are typed according to the QAPI schema, but
2971 * when they come from -drive, they're all QString.
2973 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
2976 if (!old
|| strcmp(new, old
)) {
2977 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
2981 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
2987 qemu_opts_del(opts
);
2992 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
2993 * makes them final by swapping the staging BlockDriverState contents into
2994 * the active BlockDriverState contents.
2996 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
2999 BlockDriverState
*bs
;
3000 bool old_can_write
, new_can_write
;
3002 assert(reopen_state
!= NULL
);
3003 bs
= reopen_state
->bs
;
3005 assert(drv
!= NULL
);
3008 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3010 /* If there are any driver level actions to take */
3011 if (drv
->bdrv_reopen_commit
) {
3012 drv
->bdrv_reopen_commit(reopen_state
);
3015 /* set BDS specific flags now */
3016 QDECREF(bs
->explicit_options
);
3018 bs
->explicit_options
= reopen_state
->explicit_options
;
3019 bs
->open_flags
= reopen_state
->flags
;
3020 bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
3022 bdrv_refresh_limits(bs
, NULL
);
3025 !bdrv_is_read_only(bs
) && !(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
);
3026 if (!old_can_write
&& new_can_write
&& drv
->bdrv_reopen_bitmaps_rw
) {
3027 Error
*local_err
= NULL
;
3028 if (drv
->bdrv_reopen_bitmaps_rw(bs
, &local_err
) < 0) {
3029 /* This is not fatal, bitmaps just left read-only, so all following
3030 * writes will fail. User can remove read-only bitmaps to unblock
3033 error_reportf_err(local_err
,
3034 "%s: Failed to make dirty bitmaps writable: ",
3035 bdrv_get_node_name(bs
));
3041 * Abort the reopen, and delete and free the staged changes in
3044 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
3048 assert(reopen_state
!= NULL
);
3049 drv
= reopen_state
->bs
->drv
;
3050 assert(drv
!= NULL
);
3052 if (drv
->bdrv_reopen_abort
) {
3053 drv
->bdrv_reopen_abort(reopen_state
);
3056 QDECREF(reopen_state
->explicit_options
);
3060 static void bdrv_close(BlockDriverState
*bs
)
3062 BdrvAioNotifier
*ban
, *ban_next
;
3065 assert(!bs
->refcnt
);
3067 bdrv_drained_begin(bs
); /* complete I/O */
3069 bdrv_drain(bs
); /* in case flush left pending I/O */
3072 BdrvChild
*child
, *next
;
3074 bs
->drv
->bdrv_close(bs
);
3077 bdrv_set_backing_hd(bs
, NULL
, &error_abort
);
3079 if (bs
->file
!= NULL
) {
3080 bdrv_unref_child(bs
, bs
->file
);
3084 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
3085 /* TODO Remove bdrv_unref() from drivers' close function and use
3086 * bdrv_unref_child() here */
3087 if (child
->bs
->inherits_from
== bs
) {
3088 child
->bs
->inherits_from
= NULL
;
3090 bdrv_detach_child(child
);
3095 atomic_set(&bs
->copy_on_read
, 0);
3096 bs
->backing_file
[0] = '\0';
3097 bs
->backing_format
[0] = '\0';
3098 bs
->total_sectors
= 0;
3099 bs
->encrypted
= false;
3101 QDECREF(bs
->options
);
3102 QDECREF(bs
->explicit_options
);
3104 bs
->explicit_options
= NULL
;
3105 QDECREF(bs
->full_open_options
);
3106 bs
->full_open_options
= NULL
;
3109 bdrv_release_named_dirty_bitmaps(bs
);
3110 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
3112 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3115 QLIST_INIT(&bs
->aio_notifiers
);
3116 bdrv_drained_end(bs
);
3119 void bdrv_close_all(void)
3121 block_job_cancel_sync_all();
3122 nbd_export_close_all();
3124 /* Drop references from requests still in flight, such as canceled block
3125 * jobs whose AIO context has not been polled yet */
3128 blk_remove_all_bs();
3129 blockdev_close_all_bdrv_states();
3131 assert(QTAILQ_EMPTY(&all_bdrv_states
));
3134 static bool should_update_child(BdrvChild
*c
, BlockDriverState
*to
)
3138 if (c
->role
->stay_at_node
) {
3142 if (c
->role
== &child_backing
) {
3143 /* If @from is a backing file of @to, ignore the child to avoid
3144 * creating a loop. We only want to change the pointer of other
3146 QLIST_FOREACH(to_c
, &to
->children
, next
) {
3159 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
3162 BdrvChild
*c
, *next
;
3163 GSList
*list
= NULL
, *p
;
3164 uint64_t old_perm
, old_shared
;
3165 uint64_t perm
= 0, shared
= BLK_PERM_ALL
;
3168 assert(!atomic_read(&from
->in_flight
));
3169 assert(!atomic_read(&to
->in_flight
));
3171 /* Make sure that @from doesn't go away until we have successfully attached
3172 * all of its parents to @to. */
3175 /* Put all parents into @list and calculate their cumulative permissions */
3176 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
3177 if (!should_update_child(c
, to
)) {
3180 list
= g_slist_prepend(list
, c
);
3182 shared
&= c
->shared_perm
;
3185 /* Check whether the required permissions can be granted on @to, ignoring
3186 * all BdrvChild in @list so that they can't block themselves. */
3187 ret
= bdrv_check_update_perm(to
, perm
, shared
, list
, errp
);
3189 bdrv_abort_perm_update(to
);
3193 /* Now actually perform the change. We performed the permission check for
3194 * all elements of @list at once, so set the permissions all at once at the
3196 for (p
= list
; p
!= NULL
; p
= p
->next
) {
3200 bdrv_replace_child_noperm(c
, to
);
3204 bdrv_get_cumulative_perm(to
, &old_perm
, &old_shared
);
3205 bdrv_set_perm(to
, old_perm
| perm
, old_shared
| shared
);
3213 * Add new bs contents at the top of an image chain while the chain is
3214 * live, while keeping required fields on the top layer.
3216 * This will modify the BlockDriverState fields, and swap contents
3217 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3219 * bs_new must not be attached to a BlockBackend.
3221 * This function does not create any image files.
3223 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3224 * that's what the callers commonly need. bs_new will be referenced by the old
3225 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3226 * reference of its own, it must call bdrv_ref().
3228 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
3231 Error
*local_err
= NULL
;
3233 bdrv_set_backing_hd(bs_new
, bs_top
, &local_err
);
3235 error_propagate(errp
, local_err
);
3239 bdrv_replace_node(bs_top
, bs_new
, &local_err
);
3241 error_propagate(errp
, local_err
);
3242 bdrv_set_backing_hd(bs_new
, NULL
, &error_abort
);
3246 /* bs_new is now referenced by its new parents, we don't need the
3247 * additional reference any more. */
3252 static void bdrv_delete(BlockDriverState
*bs
)
3255 assert(bdrv_op_blocker_is_empty(bs
));
3256 assert(!bs
->refcnt
);
3260 /* remove from list, if necessary */
3261 if (bs
->node_name
[0] != '\0') {
3262 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
3264 QTAILQ_REMOVE(&all_bdrv_states
, bs
, bs_list
);
3270 * Run consistency checks on an image
3272 * Returns 0 if the check could be completed (it doesn't mean that the image is
3273 * free of errors) or -errno when an internal error occurred. The results of the
3274 * check are stored in res.
3276 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
3278 if (bs
->drv
== NULL
) {
3281 if (bs
->drv
->bdrv_check
== NULL
) {
3285 memset(res
, 0, sizeof(*res
));
3286 return bs
->drv
->bdrv_check(bs
, res
, fix
);
3292 * -EINVAL - backing format specified, but no file
3293 * -ENOSPC - can't update the backing file because no space is left in the
3295 * -ENOTSUP - format driver doesn't support changing the backing file
3297 int bdrv_change_backing_file(BlockDriverState
*bs
,
3298 const char *backing_file
, const char *backing_fmt
)
3300 BlockDriver
*drv
= bs
->drv
;
3303 /* Backing file format doesn't make sense without a backing file */
3304 if (backing_fmt
&& !backing_file
) {
3308 if (drv
->bdrv_change_backing_file
!= NULL
) {
3309 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
3315 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
3316 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
3322 * Finds the image layer in the chain that has 'bs' as its backing file.
3324 * active is the current topmost image.
3326 * Returns NULL if bs is not found in active's image chain,
3327 * or if active == bs.
3329 * Returns the bottommost base image if bs == NULL.
3331 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
3332 BlockDriverState
*bs
)
3334 while (active
&& bs
!= backing_bs(active
)) {
3335 active
= backing_bs(active
);
3341 /* Given a BDS, searches for the base layer. */
3342 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
3344 return bdrv_find_overlay(bs
, NULL
);
3348 * Drops images above 'base' up to and including 'top', and sets the image
3349 * above 'top' to have base as its backing file.
3351 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3352 * information in 'bs' can be properly updated.
3354 * E.g., this will convert the following chain:
3355 * bottom <- base <- intermediate <- top <- active
3359 * bottom <- base <- active
3361 * It is allowed for bottom==base, in which case it converts:
3363 * base <- intermediate <- top <- active
3369 * If backing_file_str is non-NULL, it will be used when modifying top's
3370 * overlay image metadata.
3373 * if active == top, that is considered an error
3376 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
3377 BlockDriverState
*base
, const char *backing_file_str
)
3379 BlockDriverState
*new_top_bs
= NULL
;
3380 Error
*local_err
= NULL
;
3383 if (!top
->drv
|| !base
->drv
) {
3387 new_top_bs
= bdrv_find_overlay(active
, top
);
3389 if (new_top_bs
== NULL
) {
3390 /* we could not find the image above 'top', this is an error */
3394 /* special case of new_top_bs->backing->bs already pointing to base - nothing
3395 * to do, no intermediate images */
3396 if (backing_bs(new_top_bs
) == base
) {
3401 /* Make sure that base is in the backing chain of top */
3402 if (!bdrv_chain_contains(top
, base
)) {
3406 /* success - we can delete the intermediate states, and link top->base */
3407 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
3408 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
3409 base
->drv
? base
->drv
->format_name
: "");
3414 bdrv_set_backing_hd(new_top_bs
, base
, &local_err
);
3417 error_report_err(local_err
);
3427 * Truncate file to 'offset' bytes (needed only for file protocols)
3429 int bdrv_truncate(BdrvChild
*child
, int64_t offset
, PreallocMode prealloc
,
3432 BlockDriverState
*bs
= child
->bs
;
3433 BlockDriver
*drv
= bs
->drv
;
3436 assert(child
->perm
& BLK_PERM_RESIZE
);
3438 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
3440 error_setg(errp
, "No medium inserted");
3443 if (!drv
->bdrv_truncate
) {
3444 if (bs
->file
&& drv
->is_filter
) {
3445 return bdrv_truncate(bs
->file
, offset
, prealloc
, errp
);
3447 error_setg(errp
, "Image format driver does not support resize");
3450 if (bs
->read_only
) {
3451 error_setg(errp
, "Image is read-only");
3455 assert(!(bs
->open_flags
& BDRV_O_INACTIVE
));
3457 ret
= drv
->bdrv_truncate(bs
, offset
, prealloc
, errp
);
3459 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
3460 bdrv_dirty_bitmap_truncate(bs
);
3461 bdrv_parent_cb_resize(bs
);
3462 atomic_inc(&bs
->write_gen
);
3468 * Length of a allocated file in bytes. Sparse files are counted by actual
3469 * allocated space. Return < 0 if error or unknown.
3471 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
3473 BlockDriver
*drv
= bs
->drv
;
3477 if (drv
->bdrv_get_allocated_file_size
) {
3478 return drv
->bdrv_get_allocated_file_size(bs
);
3481 return bdrv_get_allocated_file_size(bs
->file
->bs
);
3488 * @drv: Format driver
3489 * @opts: Creation options for new image
3490 * @in_bs: Existing image containing data for new image (may be NULL)
3491 * @errp: Error object
3492 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
3495 * Calculate file size required to create a new image.
3497 * If @in_bs is given then space for allocated clusters and zero clusters
3498 * from that image are included in the calculation. If @opts contains a
3499 * backing file that is shared by @in_bs then backing clusters may be omitted
3500 * from the calculation.
3502 * If @in_bs is NULL then the calculation includes no allocated clusters
3503 * unless a preallocation option is given in @opts.
3505 * Note that @in_bs may use a different BlockDriver from @drv.
3507 * If an error occurs the @errp pointer is set.
3509 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
3510 BlockDriverState
*in_bs
, Error
**errp
)
3512 if (!drv
->bdrv_measure
) {
3513 error_setg(errp
, "Block driver '%s' does not support size measurement",
3518 return drv
->bdrv_measure(opts
, in_bs
, errp
);
3522 * Return number of sectors on success, -errno on error.
3524 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
3526 BlockDriver
*drv
= bs
->drv
;
3531 if (drv
->has_variable_length
) {
3532 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3537 return bs
->total_sectors
;
3541 * Return length in bytes on success, -errno on error.
3542 * The length is always a multiple of BDRV_SECTOR_SIZE.
3544 int64_t bdrv_getlength(BlockDriverState
*bs
)
3546 int64_t ret
= bdrv_nb_sectors(bs
);
3548 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
3549 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
3552 /* return 0 as number of sectors if no device present or error */
3553 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
3555 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
3557 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
3560 bool bdrv_is_sg(BlockDriverState
*bs
)
3565 bool bdrv_is_encrypted(BlockDriverState
*bs
)
3567 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
3570 return bs
->encrypted
;
3573 const char *bdrv_get_format_name(BlockDriverState
*bs
)
3575 return bs
->drv
? bs
->drv
->format_name
: NULL
;
3578 static int qsort_strcmp(const void *a
, const void *b
)
3580 return strcmp(*(char *const *)a
, *(char *const *)b
);
3583 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
3589 const char **formats
= NULL
;
3591 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
3592 if (drv
->format_name
) {
3595 while (formats
&& i
&& !found
) {
3596 found
= !strcmp(formats
[--i
], drv
->format_name
);
3600 formats
= g_renew(const char *, formats
, count
+ 1);
3601 formats
[count
++] = drv
->format_name
;
3606 for (i
= 0; i
< (int)ARRAY_SIZE(block_driver_modules
); i
++) {
3607 const char *format_name
= block_driver_modules
[i
].format_name
;
3613 while (formats
&& j
&& !found
) {
3614 found
= !strcmp(formats
[--j
], format_name
);
3618 formats
= g_renew(const char *, formats
, count
+ 1);
3619 formats
[count
++] = format_name
;
3624 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
3626 for (i
= 0; i
< count
; i
++) {
3627 it(opaque
, formats
[i
]);
3633 /* This function is to find a node in the bs graph */
3634 BlockDriverState
*bdrv_find_node(const char *node_name
)
3636 BlockDriverState
*bs
;
3640 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3641 if (!strcmp(node_name
, bs
->node_name
)) {
3648 /* Put this QMP function here so it can access the static graph_bdrv_states. */
3649 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
3651 BlockDeviceInfoList
*list
, *entry
;
3652 BlockDriverState
*bs
;
3655 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
3656 BlockDeviceInfo
*info
= bdrv_block_device_info(NULL
, bs
, errp
);
3658 qapi_free_BlockDeviceInfoList(list
);
3661 entry
= g_malloc0(sizeof(*entry
));
3662 entry
->value
= info
;
3670 BlockDriverState
*bdrv_lookup_bs(const char *device
,
3671 const char *node_name
,
3675 BlockDriverState
*bs
;
3678 blk
= blk_by_name(device
);
3683 error_setg(errp
, "Device '%s' has no medium", device
);
3691 bs
= bdrv_find_node(node_name
);
3698 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
3699 device
? device
: "",
3700 node_name
? node_name
: "");
3704 /* If 'base' is in the same chain as 'top', return true. Otherwise,
3705 * return false. If either argument is NULL, return false. */
3706 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
3708 while (top
&& top
!= base
) {
3709 top
= backing_bs(top
);
3715 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
3718 return QTAILQ_FIRST(&graph_bdrv_states
);
3720 return QTAILQ_NEXT(bs
, node_list
);
3723 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
3725 return bs
->node_name
;
3728 const char *bdrv_get_parent_name(const BlockDriverState
*bs
)
3733 /* If multiple parents have a name, just pick the first one. */
3734 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
3735 if (c
->role
->get_name
) {
3736 name
= c
->role
->get_name(c
);
3737 if (name
&& *name
) {
3746 /* TODO check what callers really want: bs->node_name or blk_name() */
3747 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
3749 return bdrv_get_parent_name(bs
) ?: "";
3752 /* This can be used to identify nodes that might not have a device
3753 * name associated. Since node and device names live in the same
3754 * namespace, the result is unambiguous. The exception is if both are
3755 * absent, then this returns an empty (non-null) string. */
3756 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
3758 return bdrv_get_parent_name(bs
) ?: bs
->node_name
;
3761 int bdrv_get_flags(BlockDriverState
*bs
)
3763 return bs
->open_flags
;
3766 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
3771 int bdrv_has_zero_init(BlockDriverState
*bs
)
3775 /* If BS is a copy on write image, it is initialized to
3776 the contents of the base image, which may not be zeroes. */
3780 if (bs
->drv
->bdrv_has_zero_init
) {
3781 return bs
->drv
->bdrv_has_zero_init(bs
);
3783 if (bs
->file
&& bs
->drv
->is_filter
) {
3784 return bdrv_has_zero_init(bs
->file
->bs
);
3791 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
3793 BlockDriverInfo bdi
;
3799 if (bdrv_get_info(bs
, &bdi
) == 0) {
3800 return bdi
.unallocated_blocks_are_zero
;
3806 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
3808 BlockDriverInfo bdi
;
3810 if (!(bs
->open_flags
& BDRV_O_UNMAP
)) {
3814 if (bdrv_get_info(bs
, &bdi
) == 0) {
3815 return bdi
.can_write_zeroes_with_unmap
;
3821 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
3823 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
3824 return bs
->backing_file
;
3825 else if (bs
->encrypted
)
3826 return bs
->filename
;
3831 void bdrv_get_backing_filename(BlockDriverState
*bs
,
3832 char *filename
, int filename_size
)
3834 pstrcpy(filename
, filename_size
, bs
->backing_file
);
3837 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3839 BlockDriver
*drv
= bs
->drv
;
3840 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
3844 if (!drv
->bdrv_get_info
) {
3845 if (bs
->file
&& drv
->is_filter
) {
3846 return bdrv_get_info(bs
->file
->bs
, bdi
);
3850 memset(bdi
, 0, sizeof(*bdi
));
3851 return drv
->bdrv_get_info(bs
, bdi
);
3854 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
3856 BlockDriver
*drv
= bs
->drv
;
3857 if (drv
&& drv
->bdrv_get_specific_info
) {
3858 return drv
->bdrv_get_specific_info(bs
);
3863 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
3865 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
3869 bs
->drv
->bdrv_debug_event(bs
, event
);
3872 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
3875 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
3876 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3879 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3880 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3886 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3888 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3889 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3892 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3893 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3899 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3901 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3902 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3905 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3906 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3912 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3914 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3915 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3918 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3919 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3925 /* backing_file can either be relative, or absolute, or a protocol. If it is
3926 * relative, it must be relative to the chain. So, passing in bs->filename
3927 * from a BDS as backing_file should not be done, as that may be relative to
3928 * the CWD rather than the chain. */
3929 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3930 const char *backing_file
)
3932 char *filename_full
= NULL
;
3933 char *backing_file_full
= NULL
;
3934 char *filename_tmp
= NULL
;
3935 int is_protocol
= 0;
3936 BlockDriverState
*curr_bs
= NULL
;
3937 BlockDriverState
*retval
= NULL
;
3938 Error
*local_error
= NULL
;
3940 if (!bs
|| !bs
->drv
|| !backing_file
) {
3944 filename_full
= g_malloc(PATH_MAX
);
3945 backing_file_full
= g_malloc(PATH_MAX
);
3946 filename_tmp
= g_malloc(PATH_MAX
);
3948 is_protocol
= path_has_protocol(backing_file
);
3950 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3952 /* If either of the filename paths is actually a protocol, then
3953 * compare unmodified paths; otherwise make paths relative */
3954 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3955 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3956 retval
= curr_bs
->backing
->bs
;
3959 /* Also check against the full backing filename for the image */
3960 bdrv_get_full_backing_filename(curr_bs
, backing_file_full
, PATH_MAX
,
3962 if (local_error
== NULL
) {
3963 if (strcmp(backing_file
, backing_file_full
) == 0) {
3964 retval
= curr_bs
->backing
->bs
;
3968 error_free(local_error
);
3972 /* If not an absolute filename path, make it relative to the current
3973 * image's filename path */
3974 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3977 /* We are going to compare absolute pathnames */
3978 if (!realpath(filename_tmp
, filename_full
)) {
3982 /* We need to make sure the backing filename we are comparing against
3983 * is relative to the current image filename (or absolute) */
3984 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3985 curr_bs
->backing_file
);
3987 if (!realpath(filename_tmp
, backing_file_full
)) {
3991 if (strcmp(backing_file_full
, filename_full
) == 0) {
3992 retval
= curr_bs
->backing
->bs
;
3998 g_free(filename_full
);
3999 g_free(backing_file_full
);
4000 g_free(filename_tmp
);
4004 void bdrv_init(void)
4006 module_call_init(MODULE_INIT_BLOCK
);
4009 void bdrv_init_with_whitelist(void)
4011 use_bdrv_whitelist
= 1;
4015 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
4017 BdrvChild
*child
, *parent
;
4018 uint64_t perm
, shared_perm
;
4019 Error
*local_err
= NULL
;
4026 if (!(bs
->open_flags
& BDRV_O_INACTIVE
)) {
4030 QLIST_FOREACH(child
, &bs
->children
, next
) {
4031 bdrv_invalidate_cache(child
->bs
, &local_err
);
4033 error_propagate(errp
, local_err
);
4038 bs
->open_flags
&= ~BDRV_O_INACTIVE
;
4039 if (bs
->drv
->bdrv_invalidate_cache
) {
4040 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
4042 bs
->open_flags
|= BDRV_O_INACTIVE
;
4043 error_propagate(errp
, local_err
);
4048 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
4050 bs
->open_flags
|= BDRV_O_INACTIVE
;
4051 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
4055 /* Update permissions, they may differ for inactive nodes */
4056 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
4057 ret
= bdrv_check_perm(bs
, perm
, shared_perm
, NULL
, &local_err
);
4059 bs
->open_flags
|= BDRV_O_INACTIVE
;
4060 error_propagate(errp
, local_err
);
4063 bdrv_set_perm(bs
, perm
, shared_perm
);
4065 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4066 if (parent
->role
->activate
) {
4067 parent
->role
->activate(parent
, &local_err
);
4069 error_propagate(errp
, local_err
);
4076 void bdrv_invalidate_cache_all(Error
**errp
)
4078 BlockDriverState
*bs
;
4079 Error
*local_err
= NULL
;
4080 BdrvNextIterator it
;
4082 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4083 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
4085 aio_context_acquire(aio_context
);
4086 bdrv_invalidate_cache(bs
, &local_err
);
4087 aio_context_release(aio_context
);
4089 error_propagate(errp
, local_err
);
4095 static int bdrv_inactivate_recurse(BlockDriverState
*bs
,
4098 BdrvChild
*child
, *parent
;
4101 if (!setting_flag
&& bs
->drv
->bdrv_inactivate
) {
4102 ret
= bs
->drv
->bdrv_inactivate(bs
);
4108 if (setting_flag
&& !(bs
->open_flags
& BDRV_O_INACTIVE
)) {
4109 uint64_t perm
, shared_perm
;
4111 QLIST_FOREACH(parent
, &bs
->parents
, next_parent
) {
4112 if (parent
->role
->inactivate
) {
4113 ret
= parent
->role
->inactivate(parent
);
4120 bs
->open_flags
|= BDRV_O_INACTIVE
;
4122 /* Update permissions, they may differ for inactive nodes */
4123 bdrv_get_cumulative_perm(bs
, &perm
, &shared_perm
);
4124 bdrv_check_perm(bs
, perm
, shared_perm
, NULL
, &error_abort
);
4125 bdrv_set_perm(bs
, perm
, shared_perm
);
4128 QLIST_FOREACH(child
, &bs
->children
, next
) {
4129 ret
= bdrv_inactivate_recurse(child
->bs
, setting_flag
);
4135 /* At this point persistent bitmaps should be already stored by the format
4137 bdrv_release_persistent_dirty_bitmaps(bs
);
4142 int bdrv_inactivate_all(void)
4144 BlockDriverState
*bs
= NULL
;
4145 BdrvNextIterator it
;
4149 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4150 aio_context_acquire(bdrv_get_aio_context(bs
));
4153 /* We do two passes of inactivation. The first pass calls to drivers'
4154 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
4155 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
4157 for (pass
= 0; pass
< 2; pass
++) {
4158 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4159 ret
= bdrv_inactivate_recurse(bs
, pass
);
4167 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4168 aio_context_release(bdrv_get_aio_context(bs
));
4174 /**************************************************************/
4175 /* removable device support */
4178 * Return TRUE if the media is present
4180 bool bdrv_is_inserted(BlockDriverState
*bs
)
4182 BlockDriver
*drv
= bs
->drv
;
4188 if (drv
->bdrv_is_inserted
) {
4189 return drv
->bdrv_is_inserted(bs
);
4191 QLIST_FOREACH(child
, &bs
->children
, next
) {
4192 if (!bdrv_is_inserted(child
->bs
)) {
4200 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4202 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
4204 BlockDriver
*drv
= bs
->drv
;
4206 if (drv
&& drv
->bdrv_eject
) {
4207 drv
->bdrv_eject(bs
, eject_flag
);
4212 * Lock or unlock the media (if it is locked, the user won't be able
4213 * to eject it manually).
4215 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
4217 BlockDriver
*drv
= bs
->drv
;
4219 trace_bdrv_lock_medium(bs
, locked
);
4221 if (drv
&& drv
->bdrv_lock_medium
) {
4222 drv
->bdrv_lock_medium(bs
, locked
);
4226 /* Get a reference to bs */
4227 void bdrv_ref(BlockDriverState
*bs
)
4232 /* Release a previously grabbed reference to bs.
4233 * If after releasing, reference count is zero, the BlockDriverState is
4235 void bdrv_unref(BlockDriverState
*bs
)
4240 assert(bs
->refcnt
> 0);
4241 if (--bs
->refcnt
== 0) {
4246 struct BdrvOpBlocker
{
4248 QLIST_ENTRY(BdrvOpBlocker
) list
;
4251 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
4253 BdrvOpBlocker
*blocker
;
4254 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4255 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
4256 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
4257 error_propagate(errp
, error_copy(blocker
->reason
));
4258 error_prepend(errp
, "Node '%s' is busy: ",
4259 bdrv_get_device_or_node_name(bs
));
4265 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4267 BdrvOpBlocker
*blocker
;
4268 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4270 blocker
= g_new0(BdrvOpBlocker
, 1);
4271 blocker
->reason
= reason
;
4272 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
4275 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
4277 BdrvOpBlocker
*blocker
, *next
;
4278 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
4279 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
4280 if (blocker
->reason
== reason
) {
4281 QLIST_REMOVE(blocker
, list
);
4287 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
4290 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4291 bdrv_op_block(bs
, i
, reason
);
4295 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
4298 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4299 bdrv_op_unblock(bs
, i
, reason
);
4303 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
4307 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
4308 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
4315 void bdrv_img_create(const char *filename
, const char *fmt
,
4316 const char *base_filename
, const char *base_fmt
,
4317 char *options
, uint64_t img_size
, int flags
, bool quiet
,
4320 QemuOptsList
*create_opts
= NULL
;
4321 QemuOpts
*opts
= NULL
;
4322 const char *backing_fmt
, *backing_file
;
4324 BlockDriver
*drv
, *proto_drv
;
4325 Error
*local_err
= NULL
;
4328 /* Find driver and parse its options */
4329 drv
= bdrv_find_format(fmt
);
4331 error_setg(errp
, "Unknown file format '%s'", fmt
);
4335 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
4340 if (!drv
->create_opts
) {
4341 error_setg(errp
, "Format driver '%s' does not support image creation",
4346 if (!proto_drv
->create_opts
) {
4347 error_setg(errp
, "Protocol driver '%s' does not support image creation",
4348 proto_drv
->format_name
);
4352 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
4353 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
4355 /* Create parameter list with default values */
4356 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
4357 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
4359 /* Parse -o options */
4361 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
4363 error_report_err(local_err
);
4365 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
4370 if (base_filename
) {
4371 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
4373 error_setg(errp
, "Backing file not supported for file format '%s'",
4380 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
4382 error_setg(errp
, "Backing file format not supported for file "
4383 "format '%s'", fmt
);
4388 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4390 if (!strcmp(filename
, backing_file
)) {
4391 error_setg(errp
, "Error: Trying to create an image with the "
4392 "same filename as the backing file");
4397 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4399 /* The size for the image must always be specified, unless we have a backing
4400 * file and we have not been forbidden from opening it. */
4401 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4402 if (backing_file
&& !(flags
& BDRV_O_NO_BACKING
)) {
4403 BlockDriverState
*bs
;
4404 char *full_backing
= g_new0(char, PATH_MAX
);
4406 QDict
*backing_options
= NULL
;
4408 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
4409 full_backing
, PATH_MAX
,
4412 g_free(full_backing
);
4416 /* backing files always opened read-only */
4418 back_flags
&= ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
4421 backing_options
= qdict_new();
4422 qdict_put_str(backing_options
, "driver", backing_fmt
);
4425 bs
= bdrv_open(full_backing
, NULL
, backing_options
, back_flags
,
4427 g_free(full_backing
);
4428 if (!bs
&& size
!= -1) {
4429 /* Couldn't open BS, but we have a size, so it's nonfatal */
4430 warn_reportf_err(local_err
,
4431 "Could not verify backing image. "
4432 "This may become an error in future versions.\n");
4435 /* Couldn't open bs, do not have size */
4436 error_append_hint(&local_err
,
4437 "Could not open backing image to determine size.\n");
4441 /* Opened BS, have no size */
4442 size
= bdrv_getlength(bs
);
4444 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
4449 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
4453 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
4456 error_setg(errp
, "Image creation needs a size parameter");
4461 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
4462 qemu_opts_print(opts
, " ");
4466 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
4468 if (ret
== -EFBIG
) {
4469 /* This is generally a better message than whatever the driver would
4470 * deliver (especially because of the cluster_size_hint), since that
4471 * is most probably not much different from "image too large". */
4472 const char *cluster_size_hint
= "";
4473 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
4474 cluster_size_hint
= " (try using a larger cluster size)";
4476 error_setg(errp
, "The image size is too large for file format '%s'"
4477 "%s", fmt
, cluster_size_hint
);
4478 error_free(local_err
);
4483 qemu_opts_del(opts
);
4484 qemu_opts_free(create_opts
);
4485 error_propagate(errp
, local_err
);
4488 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
4490 return bs
->aio_context
;
4493 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
)
4495 aio_co_enter(bdrv_get_aio_context(bs
), co
);
4498 static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier
*ban
)
4500 QLIST_REMOVE(ban
, list
);
4504 void bdrv_detach_aio_context(BlockDriverState
*bs
)
4506 BdrvAioNotifier
*baf
, *baf_tmp
;
4513 assert(!bs
->walking_aio_notifiers
);
4514 bs
->walking_aio_notifiers
= true;
4515 QLIST_FOREACH_SAFE(baf
, &bs
->aio_notifiers
, list
, baf_tmp
) {
4517 bdrv_do_remove_aio_context_notifier(baf
);
4519 baf
->detach_aio_context(baf
->opaque
);
4522 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4523 * remove remaining aio notifiers if we aren't called again.
4525 bs
->walking_aio_notifiers
= false;
4527 if (bs
->drv
->bdrv_detach_aio_context
) {
4528 bs
->drv
->bdrv_detach_aio_context(bs
);
4530 QLIST_FOREACH(child
, &bs
->children
, next
) {
4531 bdrv_detach_aio_context(child
->bs
);
4534 bs
->aio_context
= NULL
;
4537 void bdrv_attach_aio_context(BlockDriverState
*bs
,
4538 AioContext
*new_context
)
4540 BdrvAioNotifier
*ban
, *ban_tmp
;
4547 bs
->aio_context
= new_context
;
4549 QLIST_FOREACH(child
, &bs
->children
, next
) {
4550 bdrv_attach_aio_context(child
->bs
, new_context
);
4552 if (bs
->drv
->bdrv_attach_aio_context
) {
4553 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
4556 assert(!bs
->walking_aio_notifiers
);
4557 bs
->walking_aio_notifiers
= true;
4558 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_tmp
) {
4560 bdrv_do_remove_aio_context_notifier(ban
);
4562 ban
->attached_aio_context(new_context
, ban
->opaque
);
4565 bs
->walking_aio_notifiers
= false;
4568 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
4570 AioContext
*ctx
= bdrv_get_aio_context(bs
);
4572 aio_disable_external(ctx
);
4573 bdrv_parent_drained_begin(bs
);
4574 bdrv_drain(bs
); /* ensure there are no in-flight requests */
4576 while (aio_poll(ctx
, false)) {
4577 /* wait for all bottom halves to execute */
4580 bdrv_detach_aio_context(bs
);
4582 /* This function executes in the old AioContext so acquire the new one in
4583 * case it runs in a different thread.
4585 aio_context_acquire(new_context
);
4586 bdrv_attach_aio_context(bs
, new_context
);
4587 bdrv_parent_drained_end(bs
);
4588 aio_enable_external(ctx
);
4589 aio_context_release(new_context
);
4592 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
4593 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
4594 void (*detach_aio_context
)(void *opaque
), void *opaque
)
4596 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
4597 *ban
= (BdrvAioNotifier
){
4598 .attached_aio_context
= attached_aio_context
,
4599 .detach_aio_context
= detach_aio_context
,
4603 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
4606 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
4607 void (*attached_aio_context
)(AioContext
*,
4609 void (*detach_aio_context
)(void *),
4612 BdrvAioNotifier
*ban
, *ban_next
;
4614 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
4615 if (ban
->attached_aio_context
== attached_aio_context
&&
4616 ban
->detach_aio_context
== detach_aio_context
&&
4617 ban
->opaque
== opaque
&&
4618 ban
->deleted
== false)
4620 if (bs
->walking_aio_notifiers
) {
4621 ban
->deleted
= true;
4623 bdrv_do_remove_aio_context_notifier(ban
);
4632 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4633 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
4635 if (!bs
->drv
->bdrv_amend_options
) {
4638 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
, cb_opaque
);
4641 /* This function will be called by the bdrv_recurse_is_first_non_filter method
4642 * of block filter and by bdrv_is_first_non_filter.
4643 * It is used to test if the given bs is the candidate or recurse more in the
4646 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
4647 BlockDriverState
*candidate
)
4649 /* return false if basic checks fails */
4650 if (!bs
|| !bs
->drv
) {
4654 /* the code reached a non block filter driver -> check if the bs is
4655 * the same as the candidate. It's the recursion termination condition.
4657 if (!bs
->drv
->is_filter
) {
4658 return bs
== candidate
;
4660 /* Down this path the driver is a block filter driver */
4662 /* If the block filter recursion method is defined use it to recurse down
4665 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
4666 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
4669 /* the driver is a block filter but don't allow to recurse -> return false
4674 /* This function checks if the candidate is the first non filter bs down it's
4675 * bs chain. Since we don't have pointers to parents it explore all bs chains
4676 * from the top. Some filters can choose not to pass down the recursion.
4678 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
4680 BlockDriverState
*bs
;
4681 BdrvNextIterator it
;
4683 /* walk down the bs forest recursively */
4684 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
4687 /* try to recurse in this top level bs */
4688 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
4690 /* candidate is the first non filter */
4699 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
4700 const char *node_name
, Error
**errp
)
4702 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
4703 AioContext
*aio_context
;
4705 if (!to_replace_bs
) {
4706 error_setg(errp
, "Node name '%s' not found", node_name
);
4710 aio_context
= bdrv_get_aio_context(to_replace_bs
);
4711 aio_context_acquire(aio_context
);
4713 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
4714 to_replace_bs
= NULL
;
4718 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4719 * most non filter in order to prevent data corruption.
4720 * Another benefit is that this tests exclude backing files which are
4721 * blocked by the backing blockers.
4723 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
4724 error_setg(errp
, "Only top most non filter can be replaced");
4725 to_replace_bs
= NULL
;
4730 aio_context_release(aio_context
);
4731 return to_replace_bs
;
4734 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
4736 const QDictEntry
*entry
;
4739 bool found_any
= false;
4742 for (entry
= qdict_first(bs
->options
); entry
;
4743 entry
= qdict_next(bs
->options
, entry
))
4745 /* Exclude options for children */
4746 QLIST_FOREACH(child
, &bs
->children
, next
) {
4747 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
4748 && (!*p
|| *p
== '.'))
4757 /* And exclude all non-driver-specific options */
4758 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
4759 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
4767 qobject_incref(qdict_entry_value(entry
));
4768 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
4775 /* Updates the following BDS fields:
4776 * - exact_filename: A filename which may be used for opening a block device
4777 * which (mostly) equals the given BDS (even without any
4778 * other options; so reading and writing must return the same
4779 * results, but caching etc. may be different)
4780 * - full_open_options: Options which, when given when opening a block device
4781 * (without a filename), result in a BDS (mostly)
4782 * equalling the given one
4783 * - filename: If exact_filename is set, it is copied here. Otherwise,
4784 * full_open_options is converted to a JSON object, prefixed with
4785 * "json:" (for use through the JSON pseudo protocol) and put here.
4787 void bdrv_refresh_filename(BlockDriverState
*bs
)
4789 BlockDriver
*drv
= bs
->drv
;
4796 /* This BDS's file name will most probably depend on its file's name, so
4797 * refresh that first */
4799 bdrv_refresh_filename(bs
->file
->bs
);
4802 if (drv
->bdrv_refresh_filename
) {
4803 /* Obsolete information is of no use here, so drop the old file name
4804 * information before refreshing it */
4805 bs
->exact_filename
[0] = '\0';
4806 if (bs
->full_open_options
) {
4807 QDECREF(bs
->full_open_options
);
4808 bs
->full_open_options
= NULL
;
4812 append_open_options(opts
, bs
);
4813 drv
->bdrv_refresh_filename(bs
, opts
);
4815 } else if (bs
->file
) {
4816 /* Try to reconstruct valid information from the underlying file */
4817 bool has_open_options
;
4819 bs
->exact_filename
[0] = '\0';
4820 if (bs
->full_open_options
) {
4821 QDECREF(bs
->full_open_options
);
4822 bs
->full_open_options
= NULL
;
4826 has_open_options
= append_open_options(opts
, bs
);
4828 /* If no specific options have been given for this BDS, the filename of
4829 * the underlying file should suffice for this one as well */
4830 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
4831 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
4833 /* Reconstructing the full options QDict is simple for most format block
4834 * drivers, as long as the full options are known for the underlying
4835 * file BDS. The full options QDict of that file BDS should somehow
4836 * contain a representation of the filename, therefore the following
4837 * suffices without querying the (exact_)filename of this BDS. */
4838 if (bs
->file
->bs
->full_open_options
) {
4839 qdict_put_str(opts
, "driver", drv
->format_name
);
4840 QINCREF(bs
->file
->bs
->full_open_options
);
4841 qdict_put(opts
, "file", bs
->file
->bs
->full_open_options
);
4843 bs
->full_open_options
= opts
;
4847 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
4848 /* There is no underlying file BDS (at least referenced by BDS.file),
4849 * so the full options QDict should be equal to the options given
4850 * specifically for this block device when it was opened (plus the
4851 * driver specification).
4852 * Because those options don't change, there is no need to update
4853 * full_open_options when it's already set. */
4856 append_open_options(opts
, bs
);
4857 qdict_put_str(opts
, "driver", drv
->format_name
);
4859 if (bs
->exact_filename
[0]) {
4860 /* This may not work for all block protocol drivers (some may
4861 * require this filename to be parsed), but we have to find some
4862 * default solution here, so just include it. If some block driver
4863 * does not support pure options without any filename at all or
4864 * needs some special format of the options QDict, it needs to
4865 * implement the driver-specific bdrv_refresh_filename() function.
4867 qdict_put_str(opts
, "filename", bs
->exact_filename
);
4870 bs
->full_open_options
= opts
;
4873 if (bs
->exact_filename
[0]) {
4874 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4875 } else if (bs
->full_open_options
) {
4876 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4877 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4878 qstring_get_str(json
));
4884 * Hot add/remove a BDS's child. So the user can take a child offline when
4885 * it is broken and take a new child online
4887 void bdrv_add_child(BlockDriverState
*parent_bs
, BlockDriverState
*child_bs
,
4891 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_add_child
) {
4892 error_setg(errp
, "The node %s does not support adding a child",
4893 bdrv_get_device_or_node_name(parent_bs
));
4897 if (!QLIST_EMPTY(&child_bs
->parents
)) {
4898 error_setg(errp
, "The node %s already has a parent",
4899 child_bs
->node_name
);
4903 parent_bs
->drv
->bdrv_add_child(parent_bs
, child_bs
, errp
);
4906 void bdrv_del_child(BlockDriverState
*parent_bs
, BdrvChild
*child
, Error
**errp
)
4910 if (!parent_bs
->drv
|| !parent_bs
->drv
->bdrv_del_child
) {
4911 error_setg(errp
, "The node %s does not support removing a child",
4912 bdrv_get_device_or_node_name(parent_bs
));
4916 QLIST_FOREACH(tmp
, &parent_bs
->children
, next
) {
4923 error_setg(errp
, "The node %s does not have a child named %s",
4924 bdrv_get_device_or_node_name(parent_bs
),
4925 bdrv_get_device_or_node_name(child
->bs
));
4929 parent_bs
->drv
->bdrv_del_child(parent_bs
, child
, errp
);
4932 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
4933 uint32_t granularity
, Error
**errp
)
4935 BlockDriver
*drv
= bs
->drv
;
4938 error_setg_errno(errp
, ENOMEDIUM
,
4939 "Can't store persistent bitmaps to %s",
4940 bdrv_get_device_or_node_name(bs
));
4944 if (!drv
->bdrv_can_store_new_dirty_bitmap
) {
4945 error_setg_errno(errp
, ENOTSUP
,
4946 "Can't store persistent bitmaps to %s",
4947 bdrv_get_device_or_node_name(bs
));
4951 return drv
->bdrv_can_store_new_dirty_bitmap(bs
, name
, granularity
, errp
);