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 "config-host.h"
25 #include "qemu-common.h"
27 #include "block/block_int.h"
28 #include "block/blockjob.h"
29 #include "qemu/error-report.h"
30 #include "qemu/module.h"
31 #include "qapi/qmp/qerror.h"
32 #include "qapi/qmp/qjson.h"
33 #include "sysemu/block-backend.h"
34 #include "sysemu/sysemu.h"
35 #include "qemu/notify.h"
36 #include "qemu/coroutine.h"
37 #include "block/qapi.h"
38 #include "qmp-commands.h"
39 #include "qemu/timer.h"
40 #include "qapi-event.h"
41 #include "block/throttle-groups.h"
44 #include <sys/types.h>
46 #include <sys/ioctl.h>
47 #include <sys/queue.h>
58 * A BdrvDirtyBitmap can be in three possible states:
59 * (1) successor is NULL and disabled is false: full r/w mode
60 * (2) successor is NULL and disabled is true: read only mode ("disabled")
61 * (3) successor is set: frozen mode.
62 * A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set,
63 * or enabled. A frozen bitmap can only abdicate() or reclaim().
65 struct BdrvDirtyBitmap
{
66 HBitmap
*bitmap
; /* Dirty sector bitmap implementation */
67 BdrvDirtyBitmap
*successor
; /* Anonymous child; implies frozen status */
68 char *name
; /* Optional non-empty unique ID */
69 int64_t size
; /* Size of the bitmap (Number of sectors) */
70 bool disabled
; /* Bitmap is read-only */
71 QLIST_ENTRY(BdrvDirtyBitmap
) list
;
74 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
76 struct BdrvStates bdrv_states
= QTAILQ_HEAD_INITIALIZER(bdrv_states
);
78 static QTAILQ_HEAD(, BlockDriverState
) graph_bdrv_states
=
79 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states
);
81 static QLIST_HEAD(, BlockDriver
) bdrv_drivers
=
82 QLIST_HEAD_INITIALIZER(bdrv_drivers
);
84 static int bdrv_open_inherit(BlockDriverState
**pbs
, const char *filename
,
85 const char *reference
, QDict
*options
, int flags
,
86 BlockDriverState
*parent
,
87 const BdrvChildRole
*child_role
, Error
**errp
);
89 static void bdrv_dirty_bitmap_truncate(BlockDriverState
*bs
);
90 /* If non-zero, use only whitelisted block drivers */
91 static int use_bdrv_whitelist
;
94 static int is_windows_drive_prefix(const char *filename
)
96 return (((filename
[0] >= 'a' && filename
[0] <= 'z') ||
97 (filename
[0] >= 'A' && filename
[0] <= 'Z')) &&
101 int is_windows_drive(const char *filename
)
103 if (is_windows_drive_prefix(filename
) &&
106 if (strstart(filename
, "\\\\.\\", NULL
) ||
107 strstart(filename
, "//./", NULL
))
113 size_t bdrv_opt_mem_align(BlockDriverState
*bs
)
115 if (!bs
|| !bs
->drv
) {
116 /* page size or 4k (hdd sector size) should be on the safe side */
117 return MAX(4096, getpagesize());
120 return bs
->bl
.opt_mem_alignment
;
123 size_t bdrv_min_mem_align(BlockDriverState
*bs
)
125 if (!bs
|| !bs
->drv
) {
126 /* page size or 4k (hdd sector size) should be on the safe side */
127 return MAX(4096, getpagesize());
130 return bs
->bl
.min_mem_alignment
;
133 /* check if the path starts with "<protocol>:" */
134 int path_has_protocol(const char *path
)
139 if (is_windows_drive(path
) ||
140 is_windows_drive_prefix(path
)) {
143 p
= path
+ strcspn(path
, ":/\\");
145 p
= path
+ strcspn(path
, ":/");
151 int path_is_absolute(const char *path
)
154 /* specific case for names like: "\\.\d:" */
155 if (is_windows_drive(path
) || is_windows_drive_prefix(path
)) {
158 return (*path
== '/' || *path
== '\\');
160 return (*path
== '/');
164 /* if filename is absolute, just copy it to dest. Otherwise, build a
165 path to it by considering it is relative to base_path. URL are
167 void path_combine(char *dest
, int dest_size
,
168 const char *base_path
,
169 const char *filename
)
176 if (path_is_absolute(filename
)) {
177 pstrcpy(dest
, dest_size
, filename
);
179 p
= strchr(base_path
, ':');
184 p1
= strrchr(base_path
, '/');
188 p2
= strrchr(base_path
, '\\');
200 if (len
> dest_size
- 1)
202 memcpy(dest
, base_path
, len
);
204 pstrcat(dest
, dest_size
, filename
);
208 void bdrv_get_full_backing_filename_from_filename(const char *backed
,
210 char *dest
, size_t sz
,
213 if (backing
[0] == '\0' || path_has_protocol(backing
) ||
214 path_is_absolute(backing
))
216 pstrcpy(dest
, sz
, backing
);
217 } else if (backed
[0] == '\0' || strstart(backed
, "json:", NULL
)) {
218 error_setg(errp
, "Cannot use relative backing file names for '%s'",
221 path_combine(dest
, sz
, backed
, backing
);
225 void bdrv_get_full_backing_filename(BlockDriverState
*bs
, char *dest
, size_t sz
,
228 char *backed
= bs
->exact_filename
[0] ? bs
->exact_filename
: bs
->filename
;
230 bdrv_get_full_backing_filename_from_filename(backed
, bs
->backing_file
,
234 void bdrv_register(BlockDriver
*bdrv
)
236 bdrv_setup_io_funcs(bdrv
);
238 QLIST_INSERT_HEAD(&bdrv_drivers
, bdrv
, list
);
241 BlockDriverState
*bdrv_new_root(void)
243 BlockDriverState
*bs
= bdrv_new();
245 QTAILQ_INSERT_TAIL(&bdrv_states
, bs
, device_list
);
249 BlockDriverState
*bdrv_new(void)
251 BlockDriverState
*bs
;
254 bs
= g_new0(BlockDriverState
, 1);
255 QLIST_INIT(&bs
->dirty_bitmaps
);
256 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
257 QLIST_INIT(&bs
->op_blockers
[i
]);
259 notifier_list_init(&bs
->close_notifiers
);
260 notifier_with_return_list_init(&bs
->before_write_notifiers
);
261 qemu_co_queue_init(&bs
->throttled_reqs
[0]);
262 qemu_co_queue_init(&bs
->throttled_reqs
[1]);
264 bs
->aio_context
= qemu_get_aio_context();
269 void bdrv_add_close_notifier(BlockDriverState
*bs
, Notifier
*notify
)
271 notifier_list_add(&bs
->close_notifiers
, notify
);
274 BlockDriver
*bdrv_find_format(const char *format_name
)
277 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
278 if (!strcmp(drv1
->format_name
, format_name
)) {
285 static int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
)
287 static const char *whitelist_rw
[] = {
288 CONFIG_BDRV_RW_WHITELIST
290 static const char *whitelist_ro
[] = {
291 CONFIG_BDRV_RO_WHITELIST
295 if (!whitelist_rw
[0] && !whitelist_ro
[0]) {
296 return 1; /* no whitelist, anything goes */
299 for (p
= whitelist_rw
; *p
; p
++) {
300 if (!strcmp(drv
->format_name
, *p
)) {
305 for (p
= whitelist_ro
; *p
; p
++) {
306 if (!strcmp(drv
->format_name
, *p
)) {
314 typedef struct CreateCo
{
322 static void coroutine_fn
bdrv_create_co_entry(void *opaque
)
324 Error
*local_err
= NULL
;
327 CreateCo
*cco
= opaque
;
330 ret
= cco
->drv
->bdrv_create(cco
->filename
, cco
->opts
, &local_err
);
332 error_propagate(&cco
->err
, local_err
);
337 int bdrv_create(BlockDriver
*drv
, const char* filename
,
338 QemuOpts
*opts
, Error
**errp
)
345 .filename
= g_strdup(filename
),
351 if (!drv
->bdrv_create
) {
352 error_setg(errp
, "Driver '%s' does not support image creation", drv
->format_name
);
357 if (qemu_in_coroutine()) {
358 /* Fast-path if already in coroutine context */
359 bdrv_create_co_entry(&cco
);
361 co
= qemu_coroutine_create(bdrv_create_co_entry
);
362 qemu_coroutine_enter(co
, &cco
);
363 while (cco
.ret
== NOT_DONE
) {
364 aio_poll(qemu_get_aio_context(), true);
371 error_propagate(errp
, cco
.err
);
373 error_setg_errno(errp
, -ret
, "Could not create image");
378 g_free(cco
.filename
);
382 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
)
385 Error
*local_err
= NULL
;
388 drv
= bdrv_find_protocol(filename
, true, errp
);
393 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
395 error_propagate(errp
, local_err
);
401 * Try to get @bs's logical and physical block size.
402 * On success, store them in @bsz struct and return 0.
403 * On failure return -errno.
404 * @bs must not be empty.
406 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
)
408 BlockDriver
*drv
= bs
->drv
;
410 if (drv
&& drv
->bdrv_probe_blocksizes
) {
411 return drv
->bdrv_probe_blocksizes(bs
, bsz
);
418 * Try to get @bs's geometry (cyls, heads, sectors).
419 * On success, store them in @geo struct and return 0.
420 * On failure return -errno.
421 * @bs must not be empty.
423 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
)
425 BlockDriver
*drv
= bs
->drv
;
427 if (drv
&& drv
->bdrv_probe_geometry
) {
428 return drv
->bdrv_probe_geometry(bs
, geo
);
435 * Create a uniquely-named empty temporary file.
436 * Return 0 upon success, otherwise a negative errno value.
438 int get_tmp_filename(char *filename
, int size
)
441 char temp_dir
[MAX_PATH
];
442 /* GetTempFileName requires that its output buffer (4th param)
443 have length MAX_PATH or greater. */
444 assert(size
>= MAX_PATH
);
445 return (GetTempPath(MAX_PATH
, temp_dir
)
446 && GetTempFileName(temp_dir
, "qem", 0, filename
)
447 ? 0 : -GetLastError());
451 tmpdir
= getenv("TMPDIR");
455 if (snprintf(filename
, size
, "%s/vl.XXXXXX", tmpdir
) >= size
) {
458 fd
= mkstemp(filename
);
462 if (close(fd
) != 0) {
471 * Detect host devices. By convention, /dev/cdrom[N] is always
472 * recognized as a host CDROM.
474 static BlockDriver
*find_hdev_driver(const char *filename
)
476 int score_max
= 0, score
;
477 BlockDriver
*drv
= NULL
, *d
;
479 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
480 if (d
->bdrv_probe_device
) {
481 score
= d
->bdrv_probe_device(filename
);
482 if (score
> score_max
) {
492 BlockDriver
*bdrv_find_protocol(const char *filename
,
493 bool allow_protocol_prefix
,
501 /* TODO Drivers without bdrv_file_open must be specified explicitly */
504 * XXX(hch): we really should not let host device detection
505 * override an explicit protocol specification, but moving this
506 * later breaks access to device names with colons in them.
507 * Thanks to the brain-dead persistent naming schemes on udev-
508 * based Linux systems those actually are quite common.
510 drv1
= find_hdev_driver(filename
);
515 if (!path_has_protocol(filename
) || !allow_protocol_prefix
) {
519 p
= strchr(filename
, ':');
522 if (len
> sizeof(protocol
) - 1)
523 len
= sizeof(protocol
) - 1;
524 memcpy(protocol
, filename
, len
);
525 protocol
[len
] = '\0';
526 QLIST_FOREACH(drv1
, &bdrv_drivers
, list
) {
527 if (drv1
->protocol_name
&&
528 !strcmp(drv1
->protocol_name
, protocol
)) {
533 error_setg(errp
, "Unknown protocol '%s'", protocol
);
538 * Guess image format by probing its contents.
539 * This is not a good idea when your image is raw (CVE-2008-2004), but
540 * we do it anyway for backward compatibility.
542 * @buf contains the image's first @buf_size bytes.
543 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
544 * but can be smaller if the image file is smaller)
545 * @filename is its filename.
547 * For all block drivers, call the bdrv_probe() method to get its
549 * Return the first block driver with the highest probing score.
551 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
552 const char *filename
)
554 int score_max
= 0, score
;
555 BlockDriver
*drv
= NULL
, *d
;
557 QLIST_FOREACH(d
, &bdrv_drivers
, list
) {
559 score
= d
->bdrv_probe(buf
, buf_size
, filename
);
560 if (score
> score_max
) {
570 static int find_image_format(BlockDriverState
*bs
, const char *filename
,
571 BlockDriver
**pdrv
, Error
**errp
)
574 uint8_t buf
[BLOCK_PROBE_BUF_SIZE
];
577 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
578 if (bdrv_is_sg(bs
) || !bdrv_is_inserted(bs
) || bdrv_getlength(bs
) == 0) {
583 ret
= bdrv_pread(bs
, 0, buf
, sizeof(buf
));
585 error_setg_errno(errp
, -ret
, "Could not read image for determining its "
591 drv
= bdrv_probe_all(buf
, ret
, filename
);
593 error_setg(errp
, "Could not determine image format: No compatible "
602 * Set the current 'total_sectors' value
603 * Return 0 on success, -errno on error.
605 static int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
)
607 BlockDriver
*drv
= bs
->drv
;
609 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
613 /* query actual device if possible, otherwise just trust the hint */
614 if (drv
->bdrv_getlength
) {
615 int64_t length
= drv
->bdrv_getlength(bs
);
619 hint
= DIV_ROUND_UP(length
, BDRV_SECTOR_SIZE
);
622 bs
->total_sectors
= hint
;
627 * Combines a QDict of new block driver @options with any missing options taken
628 * from @old_options, so that leaving out an option defaults to its old value.
630 static void bdrv_join_options(BlockDriverState
*bs
, QDict
*options
,
633 if (bs
->drv
&& bs
->drv
->bdrv_join_options
) {
634 bs
->drv
->bdrv_join_options(options
, old_options
);
636 qdict_join(options
, old_options
, false);
641 * Set open flags for a given discard mode
643 * Return 0 on success, -1 if the discard mode was invalid.
645 int bdrv_parse_discard_flags(const char *mode
, int *flags
)
647 *flags
&= ~BDRV_O_UNMAP
;
649 if (!strcmp(mode
, "off") || !strcmp(mode
, "ignore")) {
651 } else if (!strcmp(mode
, "on") || !strcmp(mode
, "unmap")) {
652 *flags
|= BDRV_O_UNMAP
;
661 * Set open flags for a given cache mode
663 * Return 0 on success, -1 if the cache mode was invalid.
665 int bdrv_parse_cache_flags(const char *mode
, int *flags
)
667 *flags
&= ~BDRV_O_CACHE_MASK
;
669 if (!strcmp(mode
, "off") || !strcmp(mode
, "none")) {
670 *flags
|= BDRV_O_NOCACHE
| BDRV_O_CACHE_WB
;
671 } else if (!strcmp(mode
, "directsync")) {
672 *flags
|= BDRV_O_NOCACHE
;
673 } else if (!strcmp(mode
, "writeback")) {
674 *flags
|= BDRV_O_CACHE_WB
;
675 } else if (!strcmp(mode
, "unsafe")) {
676 *flags
|= BDRV_O_CACHE_WB
;
677 *flags
|= BDRV_O_NO_FLUSH
;
678 } else if (!strcmp(mode
, "writethrough")) {
679 /* this is the default */
688 * Returns the flags that a temporary snapshot should get, based on the
689 * originally requested flags (the originally requested image will have flags
690 * like a backing file)
692 static int bdrv_temp_snapshot_flags(int flags
)
694 return (flags
& ~BDRV_O_SNAPSHOT
) | BDRV_O_TEMPORARY
;
698 * Returns the options and flags that bs->file should get if a protocol driver
699 * is expected, based on the given options and flags for the parent BDS
701 static void bdrv_inherited_options(int *child_flags
, QDict
*child_options
,
702 int parent_flags
, QDict
*parent_options
)
704 int flags
= parent_flags
;
706 /* Enable protocol handling, disable format probing for bs->file */
707 flags
|= BDRV_O_PROTOCOL
;
709 /* Our block drivers take care to send flushes and respect unmap policy,
710 * so we can enable both unconditionally on lower layers. */
711 flags
|= BDRV_O_CACHE_WB
| BDRV_O_UNMAP
;
713 /* Clear flags that only apply to the top layer */
714 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_COPY_ON_READ
);
716 *child_flags
= flags
;
719 const BdrvChildRole child_file
= {
720 .inherit_options
= bdrv_inherited_options
,
724 * Returns the options and flags that bs->file should get if the use of formats
725 * (and not only protocols) is permitted for it, based on the given options and
726 * flags for the parent BDS
728 static void bdrv_inherited_fmt_options(int *child_flags
, QDict
*child_options
,
729 int parent_flags
, QDict
*parent_options
)
731 child_file
.inherit_options(child_flags
, child_options
,
732 parent_flags
, parent_options
);
734 *child_flags
&= ~BDRV_O_PROTOCOL
;
737 const BdrvChildRole child_format
= {
738 .inherit_options
= bdrv_inherited_fmt_options
,
742 * Returns the options and flags that bs->backing should get, based on the
743 * given options and flags for the parent BDS
745 static void bdrv_backing_options(int *child_flags
, QDict
*child_options
,
746 int parent_flags
, QDict
*parent_options
)
748 int flags
= parent_flags
;
750 /* backing files always opened read-only */
751 flags
&= ~(BDRV_O_RDWR
| BDRV_O_COPY_ON_READ
);
753 /* snapshot=on is handled on the top layer */
754 flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_TEMPORARY
);
756 *child_flags
= flags
;
759 static const BdrvChildRole child_backing
= {
760 .inherit_options
= bdrv_backing_options
,
763 static int bdrv_open_flags(BlockDriverState
*bs
, int flags
)
765 int open_flags
= flags
| BDRV_O_CACHE_WB
;
768 * Clear flags that are internal to the block layer before opening the
771 open_flags
&= ~(BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
| BDRV_O_PROTOCOL
);
774 * Snapshots should be writable.
776 if (flags
& BDRV_O_TEMPORARY
) {
777 open_flags
|= BDRV_O_RDWR
;
783 static void bdrv_assign_node_name(BlockDriverState
*bs
,
784 const char *node_name
,
787 char *gen_node_name
= NULL
;
790 node_name
= gen_node_name
= id_generate(ID_BLOCK
);
791 } else if (!id_wellformed(node_name
)) {
793 * Check for empty string or invalid characters, but not if it is
794 * generated (generated names use characters not available to the user)
796 error_setg(errp
, "Invalid node name");
800 /* takes care of avoiding namespaces collisions */
801 if (blk_by_name(node_name
)) {
802 error_setg(errp
, "node-name=%s is conflicting with a device id",
807 /* takes care of avoiding duplicates node names */
808 if (bdrv_find_node(node_name
)) {
809 error_setg(errp
, "Duplicate node name");
813 /* copy node name into the bs and insert it into the graph list */
814 pstrcpy(bs
->node_name
, sizeof(bs
->node_name
), node_name
);
815 QTAILQ_INSERT_TAIL(&graph_bdrv_states
, bs
, node_list
);
817 g_free(gen_node_name
);
820 static QemuOptsList bdrv_runtime_opts
= {
821 .name
= "bdrv_common",
822 .head
= QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts
.head
),
826 .type
= QEMU_OPT_STRING
,
827 .help
= "Node name of the block device node",
831 .type
= QEMU_OPT_STRING
,
832 .help
= "Block driver to use for the node",
834 { /* end of list */ }
839 * Common part for opening disk images and files
841 * Removes all processed options from *options.
843 static int bdrv_open_common(BlockDriverState
*bs
, BdrvChild
*file
,
844 QDict
*options
, int flags
, Error
**errp
)
847 const char *filename
;
848 const char *driver_name
= NULL
;
849 const char *node_name
= NULL
;
852 Error
*local_err
= NULL
;
854 assert(bs
->file
== NULL
);
855 assert(options
!= NULL
&& bs
->options
!= options
);
857 opts
= qemu_opts_create(&bdrv_runtime_opts
, NULL
, 0, &error_abort
);
858 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
860 error_propagate(errp
, local_err
);
865 driver_name
= qemu_opt_get(opts
, "driver");
866 drv
= bdrv_find_format(driver_name
);
870 filename
= file
->bs
->filename
;
872 filename
= qdict_get_try_str(options
, "filename");
875 if (drv
->bdrv_needs_filename
&& !filename
) {
876 error_setg(errp
, "The '%s' block driver requires a file name",
882 trace_bdrv_open_common(bs
, filename
?: "", flags
, drv
->format_name
);
884 node_name
= qemu_opt_get(opts
, "node-name");
885 bdrv_assign_node_name(bs
, node_name
, &local_err
);
887 error_propagate(errp
, local_err
);
892 bs
->request_alignment
= 512;
893 bs
->zero_beyond_eof
= true;
894 open_flags
= bdrv_open_flags(bs
, flags
);
895 bs
->read_only
= !(open_flags
& BDRV_O_RDWR
);
897 if (use_bdrv_whitelist
&& !bdrv_is_whitelisted(drv
, bs
->read_only
)) {
899 !bs
->read_only
&& bdrv_is_whitelisted(drv
, true)
900 ? "Driver '%s' can only be used for read-only devices"
901 : "Driver '%s' is not whitelisted",
907 assert(bs
->copy_on_read
== 0); /* bdrv_new() and bdrv_close() make it so */
908 if (flags
& BDRV_O_COPY_ON_READ
) {
909 if (!bs
->read_only
) {
910 bdrv_enable_copy_on_read(bs
);
912 error_setg(errp
, "Can't use copy-on-read on read-only device");
918 if (filename
!= NULL
) {
919 pstrcpy(bs
->filename
, sizeof(bs
->filename
), filename
);
921 bs
->filename
[0] = '\0';
923 pstrcpy(bs
->exact_filename
, sizeof(bs
->exact_filename
), bs
->filename
);
926 bs
->opaque
= g_malloc0(drv
->instance_size
);
928 bs
->enable_write_cache
= !!(flags
& BDRV_O_CACHE_WB
);
930 /* Open the image, either directly or using a protocol */
931 if (drv
->bdrv_file_open
) {
932 assert(file
== NULL
);
933 assert(!drv
->bdrv_needs_filename
|| filename
!= NULL
);
934 ret
= drv
->bdrv_file_open(bs
, options
, open_flags
, &local_err
);
937 error_setg(errp
, "Can't use '%s' as a block driver for the "
938 "protocol level", drv
->format_name
);
943 ret
= drv
->bdrv_open(bs
, options
, open_flags
, &local_err
);
948 error_propagate(errp
, local_err
);
949 } else if (bs
->filename
[0]) {
950 error_setg_errno(errp
, -ret
, "Could not open '%s'", bs
->filename
);
952 error_setg_errno(errp
, -ret
, "Could not open image");
958 error_report("Encrypted images are deprecated");
959 error_printf("Support for them will be removed in a future release.\n"
960 "You can use 'qemu-img convert' to convert your image"
961 " to an unencrypted one.\n");
964 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
966 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
970 bdrv_refresh_limits(bs
, &local_err
);
972 error_propagate(errp
, local_err
);
977 assert(bdrv_opt_mem_align(bs
) != 0);
978 assert(bdrv_min_mem_align(bs
) != 0);
979 assert((bs
->request_alignment
!= 0) || bdrv_is_sg(bs
));
994 static QDict
*parse_json_filename(const char *filename
, Error
**errp
)
996 QObject
*options_obj
;
1000 ret
= strstart(filename
, "json:", &filename
);
1003 options_obj
= qobject_from_json(filename
);
1005 error_setg(errp
, "Could not parse the JSON options");
1009 if (qobject_type(options_obj
) != QTYPE_QDICT
) {
1010 qobject_decref(options_obj
);
1011 error_setg(errp
, "Invalid JSON object given");
1015 options
= qobject_to_qdict(options_obj
);
1016 qdict_flatten(options
);
1021 static void parse_json_protocol(QDict
*options
, const char **pfilename
,
1024 QDict
*json_options
;
1025 Error
*local_err
= NULL
;
1027 /* Parse json: pseudo-protocol */
1028 if (!*pfilename
|| !g_str_has_prefix(*pfilename
, "json:")) {
1032 json_options
= parse_json_filename(*pfilename
, &local_err
);
1034 error_propagate(errp
, local_err
);
1038 /* Options given in the filename have lower priority than options
1039 * specified directly */
1040 qdict_join(options
, json_options
, false);
1041 QDECREF(json_options
);
1046 * Fills in default options for opening images and converts the legacy
1047 * filename/flags pair to option QDict entries.
1048 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1049 * block driver has been specified explicitly.
1051 static int bdrv_fill_options(QDict
**options
, const char *filename
,
1052 int *flags
, Error
**errp
)
1054 const char *drvname
;
1055 bool protocol
= *flags
& BDRV_O_PROTOCOL
;
1056 bool parse_filename
= false;
1057 BlockDriver
*drv
= NULL
;
1058 Error
*local_err
= NULL
;
1060 drvname
= qdict_get_try_str(*options
, "driver");
1062 drv
= bdrv_find_format(drvname
);
1064 error_setg(errp
, "Unknown driver '%s'", drvname
);
1067 /* If the user has explicitly specified the driver, this choice should
1068 * override the BDRV_O_PROTOCOL flag */
1069 protocol
= drv
->bdrv_file_open
;
1073 *flags
|= BDRV_O_PROTOCOL
;
1075 *flags
&= ~BDRV_O_PROTOCOL
;
1078 /* Fetch the file name from the options QDict if necessary */
1079 if (protocol
&& filename
) {
1080 if (!qdict_haskey(*options
, "filename")) {
1081 qdict_put(*options
, "filename", qstring_from_str(filename
));
1082 parse_filename
= true;
1084 error_setg(errp
, "Can't specify 'file' and 'filename' options at "
1090 /* Find the right block driver */
1091 filename
= qdict_get_try_str(*options
, "filename");
1093 if (!drvname
&& protocol
) {
1095 drv
= bdrv_find_protocol(filename
, parse_filename
, errp
);
1100 drvname
= drv
->format_name
;
1101 qdict_put(*options
, "driver", qstring_from_str(drvname
));
1103 error_setg(errp
, "Must specify either driver or file");
1108 assert(drv
|| !protocol
);
1110 /* Driver-specific filename parsing */
1111 if (drv
&& drv
->bdrv_parse_filename
&& parse_filename
) {
1112 drv
->bdrv_parse_filename(filename
, *options
, &local_err
);
1114 error_propagate(errp
, local_err
);
1118 if (!drv
->bdrv_needs_filename
) {
1119 qdict_del(*options
, "filename");
1123 if (runstate_check(RUN_STATE_INMIGRATE
)) {
1124 *flags
|= BDRV_O_INCOMING
;
1130 static BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
1131 BlockDriverState
*child_bs
,
1132 const char *child_name
,
1133 const BdrvChildRole
*child_role
)
1135 BdrvChild
*child
= g_new(BdrvChild
, 1);
1136 *child
= (BdrvChild
) {
1138 .name
= g_strdup(child_name
),
1142 QLIST_INSERT_HEAD(&parent_bs
->children
, child
, next
);
1143 QLIST_INSERT_HEAD(&child_bs
->parents
, child
, next_parent
);
1148 static void bdrv_detach_child(BdrvChild
*child
)
1150 QLIST_REMOVE(child
, next
);
1151 QLIST_REMOVE(child
, next_parent
);
1152 g_free(child
->name
);
1156 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
)
1158 BlockDriverState
*child_bs
;
1160 if (child
== NULL
) {
1164 if (child
->bs
->inherits_from
== parent
) {
1165 child
->bs
->inherits_from
= NULL
;
1168 child_bs
= child
->bs
;
1169 bdrv_detach_child(child
);
1170 bdrv_unref(child_bs
);
1174 * Sets the backing file link of a BDS. A new reference is created; callers
1175 * which don't need their own reference any more must call bdrv_unref().
1177 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
)
1180 bdrv_ref(backing_hd
);
1184 assert(bs
->backing_blocker
);
1185 bdrv_op_unblock_all(bs
->backing
->bs
, bs
->backing_blocker
);
1186 bdrv_unref_child(bs
, bs
->backing
);
1187 } else if (backing_hd
) {
1188 error_setg(&bs
->backing_blocker
,
1189 "node is used as backing hd of '%s'",
1190 bdrv_get_device_or_node_name(bs
));
1194 error_free(bs
->backing_blocker
);
1195 bs
->backing_blocker
= NULL
;
1199 bs
->backing
= bdrv_attach_child(bs
, backing_hd
, "backing", &child_backing
);
1200 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1201 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_hd
->filename
);
1202 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
),
1203 backing_hd
->drv
? backing_hd
->drv
->format_name
: "");
1205 bdrv_op_block_all(backing_hd
, bs
->backing_blocker
);
1206 /* Otherwise we won't be able to commit due to check in bdrv_commit */
1207 bdrv_op_unblock(backing_hd
, BLOCK_OP_TYPE_COMMIT_TARGET
,
1208 bs
->backing_blocker
);
1210 bdrv_refresh_limits(bs
, NULL
);
1214 * Opens the backing file for a BlockDriverState if not yet open
1216 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
1217 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1218 * itself, all options starting with "${bdref_key}." are considered part of the
1221 * TODO Can this be unified with bdrv_open_image()?
1223 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
1224 const char *bdref_key
, Error
**errp
)
1226 char *backing_filename
= g_malloc0(PATH_MAX
);
1227 char *bdref_key_dot
;
1228 const char *reference
= NULL
;
1230 BlockDriverState
*backing_hd
;
1232 QDict
*tmp_parent_options
= NULL
;
1233 Error
*local_err
= NULL
;
1235 if (bs
->backing
!= NULL
) {
1239 /* NULL means an empty set of options */
1240 if (parent_options
== NULL
) {
1241 tmp_parent_options
= qdict_new();
1242 parent_options
= tmp_parent_options
;
1245 bs
->open_flags
&= ~BDRV_O_NO_BACKING
;
1247 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1248 qdict_extract_subqdict(parent_options
, &options
, bdref_key_dot
);
1249 g_free(bdref_key_dot
);
1251 reference
= qdict_get_try_str(parent_options
, bdref_key
);
1252 if (reference
|| qdict_haskey(options
, "file.filename")) {
1253 backing_filename
[0] = '\0';
1254 } else if (bs
->backing_file
[0] == '\0' && qdict_size(options
) == 0) {
1258 bdrv_get_full_backing_filename(bs
, backing_filename
, PATH_MAX
,
1262 error_propagate(errp
, local_err
);
1268 if (!bs
->drv
|| !bs
->drv
->supports_backing
) {
1270 error_setg(errp
, "Driver doesn't support backing files");
1275 if (bs
->backing_format
[0] != '\0' && !qdict_haskey(options
, "driver")) {
1276 qdict_put(options
, "driver", qstring_from_str(bs
->backing_format
));
1280 ret
= bdrv_open_inherit(&backing_hd
,
1281 *backing_filename
? backing_filename
: NULL
,
1282 reference
, options
, 0, bs
, &child_backing
,
1285 bs
->open_flags
|= BDRV_O_NO_BACKING
;
1286 error_setg(errp
, "Could not open backing file: %s",
1287 error_get_pretty(local_err
));
1288 error_free(local_err
);
1292 /* Hook up the backing file link; drop our reference, bs owns the
1293 * backing_hd reference now */
1294 bdrv_set_backing_hd(bs
, backing_hd
);
1295 bdrv_unref(backing_hd
);
1297 qdict_del(parent_options
, bdref_key
);
1300 g_free(backing_filename
);
1301 QDECREF(tmp_parent_options
);
1306 * Opens a disk image whose options are given as BlockdevRef in another block
1309 * If allow_none is true, no image will be opened if filename is false and no
1310 * BlockdevRef is given. NULL will be returned, but errp remains unset.
1312 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
1313 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
1314 * itself, all options starting with "${bdref_key}." are considered part of the
1317 * The BlockdevRef will be removed from the options QDict.
1319 BdrvChild
*bdrv_open_child(const char *filename
,
1320 QDict
*options
, const char *bdref_key
,
1321 BlockDriverState
* parent
,
1322 const BdrvChildRole
*child_role
,
1323 bool allow_none
, Error
**errp
)
1325 BdrvChild
*c
= NULL
;
1326 BlockDriverState
*bs
;
1327 QDict
*image_options
;
1329 char *bdref_key_dot
;
1330 const char *reference
;
1332 assert(child_role
!= NULL
);
1334 bdref_key_dot
= g_strdup_printf("%s.", bdref_key
);
1335 qdict_extract_subqdict(options
, &image_options
, bdref_key_dot
);
1336 g_free(bdref_key_dot
);
1338 reference
= qdict_get_try_str(options
, bdref_key
);
1339 if (!filename
&& !reference
&& !qdict_size(image_options
)) {
1341 error_setg(errp
, "A block device must be specified for \"%s\"",
1344 QDECREF(image_options
);
1349 ret
= bdrv_open_inherit(&bs
, filename
, reference
, image_options
, 0,
1350 parent
, child_role
, errp
);
1355 c
= bdrv_attach_child(parent
, bs
, bdref_key
, child_role
);
1358 qdict_del(options
, bdref_key
);
1362 int bdrv_append_temp_snapshot(BlockDriverState
*bs
, int flags
, Error
**errp
)
1364 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
1365 char *tmp_filename
= g_malloc0(PATH_MAX
+ 1);
1367 QemuOpts
*opts
= NULL
;
1368 QDict
*snapshot_options
;
1369 BlockDriverState
*bs_snapshot
;
1370 Error
*local_err
= NULL
;
1373 /* if snapshot, we create a temporary backing file and open it
1374 instead of opening 'filename' directly */
1376 /* Get the required size from the image */
1377 total_size
= bdrv_getlength(bs
);
1378 if (total_size
< 0) {
1380 error_setg_errno(errp
, -total_size
, "Could not get image size");
1384 /* Create the temporary image */
1385 ret
= get_tmp_filename(tmp_filename
, PATH_MAX
+ 1);
1387 error_setg_errno(errp
, -ret
, "Could not get temporary filename");
1391 opts
= qemu_opts_create(bdrv_qcow2
.create_opts
, NULL
, 0,
1393 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, total_size
, &error_abort
);
1394 ret
= bdrv_create(&bdrv_qcow2
, tmp_filename
, opts
, &local_err
);
1395 qemu_opts_del(opts
);
1397 error_setg_errno(errp
, -ret
, "Could not create temporary overlay "
1398 "'%s': %s", tmp_filename
,
1399 error_get_pretty(local_err
));
1400 error_free(local_err
);
1404 /* Prepare a new options QDict for the temporary file */
1405 snapshot_options
= qdict_new();
1406 qdict_put(snapshot_options
, "file.driver",
1407 qstring_from_str("file"));
1408 qdict_put(snapshot_options
, "file.filename",
1409 qstring_from_str(tmp_filename
));
1410 qdict_put(snapshot_options
, "driver",
1411 qstring_from_str("qcow2"));
1413 bs_snapshot
= bdrv_new();
1415 ret
= bdrv_open(&bs_snapshot
, NULL
, NULL
, snapshot_options
,
1418 error_propagate(errp
, local_err
);
1422 bdrv_append(bs_snapshot
, bs
);
1425 g_free(tmp_filename
);
1430 * Opens a disk image (raw, qcow2, vmdk, ...)
1432 * options is a QDict of options to pass to the block drivers, or NULL for an
1433 * empty set of options. The reference to the QDict belongs to the block layer
1434 * after the call (even on failure), so if the caller intends to reuse the
1435 * dictionary, it needs to use QINCREF() before calling bdrv_open.
1437 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
1438 * If it is not NULL, the referenced BDS will be reused.
1440 * The reference parameter may be used to specify an existing block device which
1441 * should be opened. If specified, neither options nor a filename may be given,
1442 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
1444 static int bdrv_open_inherit(BlockDriverState
**pbs
, const char *filename
,
1445 const char *reference
, QDict
*options
, int flags
,
1446 BlockDriverState
*parent
,
1447 const BdrvChildRole
*child_role
, Error
**errp
)
1450 BdrvChild
*file
= NULL
;
1451 BlockDriverState
*bs
;
1452 BlockDriver
*drv
= NULL
;
1453 const char *drvname
;
1454 const char *backing
;
1455 Error
*local_err
= NULL
;
1456 int snapshot_flags
= 0;
1459 assert(!child_role
|| !flags
);
1460 assert(!child_role
== !parent
);
1463 bool options_non_empty
= options
? qdict_size(options
) : false;
1467 error_setg(errp
, "Cannot reuse an existing BDS when referencing "
1468 "another block device");
1472 if (filename
|| options_non_empty
) {
1473 error_setg(errp
, "Cannot reference an existing block device with "
1474 "additional options or a new filename");
1478 bs
= bdrv_lookup_bs(reference
, reference
, errp
);
1493 /* NULL means an empty set of options */
1494 if (options
== NULL
) {
1495 options
= qdict_new();
1498 /* json: syntax counts as explicit options, as if in the QDict */
1499 parse_json_protocol(options
, &filename
, &local_err
);
1505 bs
->explicit_options
= qdict_clone_shallow(options
);
1508 bs
->inherits_from
= parent
;
1509 child_role
->inherit_options(&flags
, options
,
1510 parent
->open_flags
, parent
->options
);
1513 ret
= bdrv_fill_options(&options
, filename
, &flags
, &local_err
);
1518 bs
->open_flags
= flags
;
1519 bs
->options
= options
;
1520 options
= qdict_clone_shallow(options
);
1522 /* Find the right image format driver */
1523 drvname
= qdict_get_try_str(options
, "driver");
1525 drv
= bdrv_find_format(drvname
);
1527 error_setg(errp
, "Unknown driver: '%s'", drvname
);
1533 assert(drvname
|| !(flags
& BDRV_O_PROTOCOL
));
1535 backing
= qdict_get_try_str(options
, "backing");
1536 if (backing
&& *backing
== '\0') {
1537 flags
|= BDRV_O_NO_BACKING
;
1538 qdict_del(options
, "backing");
1541 /* Open image file without format layer */
1542 if ((flags
& BDRV_O_PROTOCOL
) == 0) {
1543 if (flags
& BDRV_O_RDWR
) {
1544 flags
|= BDRV_O_ALLOW_RDWR
;
1546 if (flags
& BDRV_O_SNAPSHOT
) {
1547 snapshot_flags
= bdrv_temp_snapshot_flags(flags
);
1548 bdrv_backing_options(&flags
, options
, flags
, options
);
1551 bs
->open_flags
= flags
;
1553 file
= bdrv_open_child(filename
, options
, "file", bs
,
1554 &child_file
, true, &local_err
);
1561 /* Image format probing */
1564 ret
= find_image_format(file
->bs
, filename
, &drv
, &local_err
);
1569 * This option update would logically belong in bdrv_fill_options(),
1570 * but we first need to open bs->file for the probing to work, while
1571 * opening bs->file already requires the (mostly) final set of options
1572 * so that cache mode etc. can be inherited.
1574 * Adding the driver later is somewhat ugly, but it's not an option
1575 * that would ever be inherited, so it's correct. We just need to make
1576 * sure to update both bs->options (which has the full effective
1577 * options for bs) and options (which has file.* already removed).
1579 qdict_put(bs
->options
, "driver", qstring_from_str(drv
->format_name
));
1580 qdict_put(options
, "driver", qstring_from_str(drv
->format_name
));
1582 error_setg(errp
, "Must specify either driver or file");
1587 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
1588 assert(!!(flags
& BDRV_O_PROTOCOL
) == !!drv
->bdrv_file_open
);
1589 /* file must be NULL if a protocol BDS is about to be created
1590 * (the inverse results in an error message from bdrv_open_common()) */
1591 assert(!(flags
& BDRV_O_PROTOCOL
) || !file
);
1593 /* Open the image */
1594 ret
= bdrv_open_common(bs
, file
, options
, flags
, &local_err
);
1599 if (file
&& (bs
->file
!= file
)) {
1600 bdrv_unref_child(bs
, file
);
1604 /* If there is a backing file, use it */
1605 if ((flags
& BDRV_O_NO_BACKING
) == 0) {
1606 ret
= bdrv_open_backing_file(bs
, options
, "backing", &local_err
);
1608 goto close_and_fail
;
1612 bdrv_refresh_filename(bs
);
1614 /* Check if any unknown options were used */
1615 if (options
&& (qdict_size(options
) != 0)) {
1616 const QDictEntry
*entry
= qdict_first(options
);
1617 if (flags
& BDRV_O_PROTOCOL
) {
1618 error_setg(errp
, "Block protocol '%s' doesn't support the option "
1619 "'%s'", drv
->format_name
, entry
->key
);
1621 error_setg(errp
, "Block format '%s' used by device '%s' doesn't "
1622 "support the option '%s'", drv
->format_name
,
1623 bdrv_get_device_name(bs
), entry
->key
);
1627 goto close_and_fail
;
1630 if (!bdrv_key_required(bs
)) {
1632 blk_dev_change_media_cb(bs
->blk
, true);
1634 } else if (!runstate_check(RUN_STATE_PRELAUNCH
)
1635 && !runstate_check(RUN_STATE_INMIGRATE
)
1636 && !runstate_check(RUN_STATE_PAUSED
)) { /* HACK */
1638 "Guest must be stopped for opening of encrypted image");
1640 goto close_and_fail
;
1646 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
1647 * temporary snapshot afterwards. */
1648 if (snapshot_flags
) {
1649 ret
= bdrv_append_temp_snapshot(bs
, snapshot_flags
, &local_err
);
1651 goto close_and_fail
;
1659 bdrv_unref_child(bs
, file
);
1661 QDECREF(bs
->explicit_options
);
1662 QDECREF(bs
->options
);
1666 /* If *pbs is NULL, a new BDS has been created in this function and
1667 needs to be freed now. Otherwise, it does not need to be closed,
1668 since it has not really been opened yet. */
1672 error_propagate(errp
, local_err
);
1677 /* See fail path, but now the BDS has to be always closed */
1685 error_propagate(errp
, local_err
);
1690 int bdrv_open(BlockDriverState
**pbs
, const char *filename
,
1691 const char *reference
, QDict
*options
, int flags
, Error
**errp
)
1693 return bdrv_open_inherit(pbs
, filename
, reference
, options
, flags
, NULL
,
1697 typedef struct BlockReopenQueueEntry
{
1699 BDRVReopenState state
;
1700 QSIMPLEQ_ENTRY(BlockReopenQueueEntry
) entry
;
1701 } BlockReopenQueueEntry
;
1704 * Adds a BlockDriverState to a simple queue for an atomic, transactional
1705 * reopen of multiple devices.
1707 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
1708 * already performed, or alternatively may be NULL a new BlockReopenQueue will
1709 * be created and initialized. This newly created BlockReopenQueue should be
1710 * passed back in for subsequent calls that are intended to be of the same
1713 * bs is the BlockDriverState to add to the reopen queue.
1715 * options contains the changed options for the associated bs
1716 * (the BlockReopenQueue takes ownership)
1718 * flags contains the open flags for the associated bs
1720 * returns a pointer to bs_queue, which is either the newly allocated
1721 * bs_queue, or the existing bs_queue being used.
1724 static BlockReopenQueue
*bdrv_reopen_queue_child(BlockReopenQueue
*bs_queue
,
1725 BlockDriverState
*bs
,
1728 const BdrvChildRole
*role
,
1729 QDict
*parent_options
,
1734 BlockReopenQueueEntry
*bs_entry
;
1736 QDict
*old_options
, *explicit_options
;
1738 if (bs_queue
== NULL
) {
1739 bs_queue
= g_new0(BlockReopenQueue
, 1);
1740 QSIMPLEQ_INIT(bs_queue
);
1744 options
= qdict_new();
1748 * Precedence of options:
1749 * 1. Explicitly passed in options (highest)
1750 * 2. TODO Set in flags (only for top level)
1751 * 3. Retained from explicitly set options of bs
1752 * 4. Inherited from parent node
1753 * 5. Retained from effective options of bs
1756 /* Old explicitly set values (don't overwrite by inherited value) */
1757 old_options
= qdict_clone_shallow(bs
->explicit_options
);
1758 bdrv_join_options(bs
, options
, old_options
);
1759 QDECREF(old_options
);
1761 explicit_options
= qdict_clone_shallow(options
);
1763 /* Inherit from parent node */
1764 if (parent_options
) {
1766 role
->inherit_options(&flags
, options
, parent_flags
, parent_options
);
1769 /* Old values are used for options that aren't set yet */
1770 old_options
= qdict_clone_shallow(bs
->options
);
1771 bdrv_join_options(bs
, options
, old_options
);
1772 QDECREF(old_options
);
1774 /* bdrv_open() masks this flag out */
1775 flags
&= ~BDRV_O_PROTOCOL
;
1777 QLIST_FOREACH(child
, &bs
->children
, next
) {
1778 QDict
*new_child_options
;
1779 char *child_key_dot
;
1781 /* reopen can only change the options of block devices that were
1782 * implicitly created and inherited options. For other (referenced)
1783 * block devices, a syntax like "backing.foo" results in an error. */
1784 if (child
->bs
->inherits_from
!= bs
) {
1788 child_key_dot
= g_strdup_printf("%s.", child
->name
);
1789 qdict_extract_subqdict(options
, &new_child_options
, child_key_dot
);
1790 g_free(child_key_dot
);
1792 bdrv_reopen_queue_child(bs_queue
, child
->bs
, new_child_options
, 0,
1793 child
->role
, options
, flags
);
1796 bs_entry
= g_new0(BlockReopenQueueEntry
, 1);
1797 QSIMPLEQ_INSERT_TAIL(bs_queue
, bs_entry
, entry
);
1799 bs_entry
->state
.bs
= bs
;
1800 bs_entry
->state
.options
= options
;
1801 bs_entry
->state
.explicit_options
= explicit_options
;
1802 bs_entry
->state
.flags
= flags
;
1807 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
1808 BlockDriverState
*bs
,
1809 QDict
*options
, int flags
)
1811 return bdrv_reopen_queue_child(bs_queue
, bs
, options
, flags
,
1816 * Reopen multiple BlockDriverStates atomically & transactionally.
1818 * The queue passed in (bs_queue) must have been built up previous
1819 * via bdrv_reopen_queue().
1821 * Reopens all BDS specified in the queue, with the appropriate
1822 * flags. All devices are prepared for reopen, and failure of any
1823 * device will cause all device changes to be abandonded, and intermediate
1826 * If all devices prepare successfully, then the changes are committed
1830 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
)
1833 BlockReopenQueueEntry
*bs_entry
, *next
;
1834 Error
*local_err
= NULL
;
1836 assert(bs_queue
!= NULL
);
1840 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1841 if (bdrv_reopen_prepare(&bs_entry
->state
, bs_queue
, &local_err
)) {
1842 error_propagate(errp
, local_err
);
1845 bs_entry
->prepared
= true;
1848 /* If we reach this point, we have success and just need to apply the
1851 QSIMPLEQ_FOREACH(bs_entry
, bs_queue
, entry
) {
1852 bdrv_reopen_commit(&bs_entry
->state
);
1858 QSIMPLEQ_FOREACH_SAFE(bs_entry
, bs_queue
, entry
, next
) {
1859 if (ret
&& bs_entry
->prepared
) {
1860 bdrv_reopen_abort(&bs_entry
->state
);
1862 QDECREF(bs_entry
->state
.explicit_options
);
1864 QDECREF(bs_entry
->state
.options
);
1872 /* Reopen a single BlockDriverState with the specified flags. */
1873 int bdrv_reopen(BlockDriverState
*bs
, int bdrv_flags
, Error
**errp
)
1876 Error
*local_err
= NULL
;
1877 BlockReopenQueue
*queue
= bdrv_reopen_queue(NULL
, bs
, NULL
, bdrv_flags
);
1879 ret
= bdrv_reopen_multiple(queue
, &local_err
);
1880 if (local_err
!= NULL
) {
1881 error_propagate(errp
, local_err
);
1888 * Prepares a BlockDriverState for reopen. All changes are staged in the
1889 * 'opaque' field of the BDRVReopenState, which is used and allocated by
1890 * the block driver layer .bdrv_reopen_prepare()
1892 * bs is the BlockDriverState to reopen
1893 * flags are the new open flags
1894 * queue is the reopen queue
1896 * Returns 0 on success, non-zero on error. On error errp will be set
1899 * On failure, bdrv_reopen_abort() will be called to clean up any data.
1900 * It is the responsibility of the caller to then call the abort() or
1901 * commit() for any other BDS that have been left in a prepare() state
1904 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
, BlockReopenQueue
*queue
,
1908 Error
*local_err
= NULL
;
1911 assert(reopen_state
!= NULL
);
1912 assert(reopen_state
->bs
->drv
!= NULL
);
1913 drv
= reopen_state
->bs
->drv
;
1915 /* if we are to stay read-only, do not allow permission change
1917 if (!(reopen_state
->bs
->open_flags
& BDRV_O_ALLOW_RDWR
) &&
1918 reopen_state
->flags
& BDRV_O_RDWR
) {
1919 error_setg(errp
, "Node '%s' is read only",
1920 bdrv_get_device_or_node_name(reopen_state
->bs
));
1925 ret
= bdrv_flush(reopen_state
->bs
);
1927 error_setg_errno(errp
, -ret
, "Error flushing drive");
1931 if (drv
->bdrv_reopen_prepare
) {
1932 ret
= drv
->bdrv_reopen_prepare(reopen_state
, queue
, &local_err
);
1934 if (local_err
!= NULL
) {
1935 error_propagate(errp
, local_err
);
1937 error_setg(errp
, "failed while preparing to reopen image '%s'",
1938 reopen_state
->bs
->filename
);
1943 /* It is currently mandatory to have a bdrv_reopen_prepare()
1944 * handler for each supported drv. */
1945 error_setg(errp
, "Block format '%s' used by node '%s' "
1946 "does not support reopening files", drv
->format_name
,
1947 bdrv_get_device_or_node_name(reopen_state
->bs
));
1952 /* Options that are not handled are only okay if they are unchanged
1953 * compared to the old state. It is expected that some options are only
1954 * used for the initial open, but not reopen (e.g. filename) */
1955 if (qdict_size(reopen_state
->options
)) {
1956 const QDictEntry
*entry
= qdict_first(reopen_state
->options
);
1959 QString
*new_obj
= qobject_to_qstring(entry
->value
);
1960 const char *new = qstring_get_str(new_obj
);
1961 const char *old
= qdict_get_try_str(reopen_state
->bs
->options
,
1964 if (!old
|| strcmp(new, old
)) {
1965 error_setg(errp
, "Cannot change the option '%s'", entry
->key
);
1969 } while ((entry
= qdict_next(reopen_state
->options
, entry
)));
1979 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
1980 * makes them final by swapping the staging BlockDriverState contents into
1981 * the active BlockDriverState contents.
1983 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
)
1987 assert(reopen_state
!= NULL
);
1988 drv
= reopen_state
->bs
->drv
;
1989 assert(drv
!= NULL
);
1991 /* If there are any driver level actions to take */
1992 if (drv
->bdrv_reopen_commit
) {
1993 drv
->bdrv_reopen_commit(reopen_state
);
1996 /* set BDS specific flags now */
1997 QDECREF(reopen_state
->bs
->explicit_options
);
1999 reopen_state
->bs
->explicit_options
= reopen_state
->explicit_options
;
2000 reopen_state
->bs
->open_flags
= reopen_state
->flags
;
2001 reopen_state
->bs
->enable_write_cache
= !!(reopen_state
->flags
&
2003 reopen_state
->bs
->read_only
= !(reopen_state
->flags
& BDRV_O_RDWR
);
2005 bdrv_refresh_limits(reopen_state
->bs
, NULL
);
2009 * Abort the reopen, and delete and free the staged changes in
2012 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
)
2016 assert(reopen_state
!= NULL
);
2017 drv
= reopen_state
->bs
->drv
;
2018 assert(drv
!= NULL
);
2020 if (drv
->bdrv_reopen_abort
) {
2021 drv
->bdrv_reopen_abort(reopen_state
);
2024 QDECREF(reopen_state
->explicit_options
);
2028 void bdrv_close(BlockDriverState
*bs
)
2030 BdrvAioNotifier
*ban
, *ban_next
;
2033 block_job_cancel_sync(bs
->job
);
2036 /* Disable I/O limits and drain all pending throttled requests */
2037 if (bs
->throttle_state
) {
2038 bdrv_io_limits_disable(bs
);
2041 bdrv_drain(bs
); /* complete I/O */
2043 bdrv_drain(bs
); /* in case flush left pending I/O */
2044 notifier_list_notify(&bs
->close_notifiers
, bs
);
2047 blk_dev_change_media_cb(bs
->blk
, false);
2051 BdrvChild
*child
, *next
;
2053 bs
->drv
->bdrv_close(bs
);
2056 bdrv_set_backing_hd(bs
, NULL
);
2058 if (bs
->file
!= NULL
) {
2059 bdrv_unref_child(bs
, bs
->file
);
2063 QLIST_FOREACH_SAFE(child
, &bs
->children
, next
, next
) {
2064 /* TODO Remove bdrv_unref() from drivers' close function and use
2065 * bdrv_unref_child() here */
2066 if (child
->bs
->inherits_from
== bs
) {
2067 child
->bs
->inherits_from
= NULL
;
2069 bdrv_detach_child(child
);
2074 bs
->copy_on_read
= 0;
2075 bs
->backing_file
[0] = '\0';
2076 bs
->backing_format
[0] = '\0';
2077 bs
->total_sectors
= 0;
2081 bs
->zero_beyond_eof
= false;
2082 QDECREF(bs
->options
);
2083 QDECREF(bs
->explicit_options
);
2085 QDECREF(bs
->full_open_options
);
2086 bs
->full_open_options
= NULL
;
2089 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
2092 QLIST_INIT(&bs
->aio_notifiers
);
2095 void bdrv_close_all(void)
2097 BlockDriverState
*bs
;
2099 QTAILQ_FOREACH(bs
, &bdrv_states
, device_list
) {
2100 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
2102 aio_context_acquire(aio_context
);
2104 aio_context_release(aio_context
);
2108 /* make a BlockDriverState anonymous by removing from bdrv_state and
2109 * graph_bdrv_state list.
2110 Also, NULL terminate the device_name to prevent double remove */
2111 void bdrv_make_anon(BlockDriverState
*bs
)
2114 * Take care to remove bs from bdrv_states only when it's actually
2115 * in it. Note that bs->device_list.tqe_prev is initially null,
2116 * and gets set to non-null by QTAILQ_INSERT_TAIL(). Establish
2117 * the useful invariant "bs in bdrv_states iff bs->tqe_prev" by
2118 * resetting it to null on remove.
2120 if (bs
->device_list
.tqe_prev
) {
2121 QTAILQ_REMOVE(&bdrv_states
, bs
, device_list
);
2122 bs
->device_list
.tqe_prev
= NULL
;
2124 if (bs
->node_name
[0] != '\0') {
2125 QTAILQ_REMOVE(&graph_bdrv_states
, bs
, node_list
);
2127 bs
->node_name
[0] = '\0';
2130 /* Fields that need to stay with the top-level BDS */
2131 static void bdrv_move_feature_fields(BlockDriverState
*bs_dest
,
2132 BlockDriverState
*bs_src
)
2134 /* move some fields that need to stay attached to the device */
2137 bs_dest
->copy_on_read
= bs_src
->copy_on_read
;
2139 bs_dest
->enable_write_cache
= bs_src
->enable_write_cache
;
2142 bs_dest
->dirty_bitmaps
= bs_src
->dirty_bitmaps
;
2145 static void change_parent_backing_link(BlockDriverState
*from
,
2146 BlockDriverState
*to
)
2148 BdrvChild
*c
, *next
;
2150 QLIST_FOREACH_SAFE(c
, &from
->parents
, next_parent
, next
) {
2151 assert(c
->role
!= &child_backing
);
2153 QLIST_REMOVE(c
, next_parent
);
2154 QLIST_INSERT_HEAD(&to
->parents
, c
, next_parent
);
2159 blk_set_bs(from
->blk
, to
);
2160 if (!to
->device_list
.tqe_prev
) {
2161 QTAILQ_INSERT_BEFORE(from
, to
, device_list
);
2163 QTAILQ_REMOVE(&bdrv_states
, from
, device_list
);
2167 static void swap_feature_fields(BlockDriverState
*bs_top
,
2168 BlockDriverState
*bs_new
)
2170 BlockDriverState tmp
;
2172 bdrv_move_feature_fields(&tmp
, bs_top
);
2173 bdrv_move_feature_fields(bs_top
, bs_new
);
2174 bdrv_move_feature_fields(bs_new
, &tmp
);
2176 assert(!bs_new
->throttle_state
);
2177 if (bs_top
->throttle_state
) {
2178 assert(bs_top
->io_limits_enabled
);
2179 bdrv_io_limits_enable(bs_new
, throttle_group_get_name(bs_top
));
2180 bdrv_io_limits_disable(bs_top
);
2185 * Add new bs contents at the top of an image chain while the chain is
2186 * live, while keeping required fields on the top layer.
2188 * This will modify the BlockDriverState fields, and swap contents
2189 * between bs_new and bs_top. Both bs_new and bs_top are modified.
2191 * bs_new must not be attached to a BlockBackend.
2193 * This function does not create any image files.
2195 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
2196 * that's what the callers commonly need. bs_new will be referenced by the old
2197 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
2198 * reference of its own, it must call bdrv_ref().
2200 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
)
2202 assert(!bdrv_requests_pending(bs_top
));
2203 assert(!bdrv_requests_pending(bs_new
));
2206 change_parent_backing_link(bs_top
, bs_new
);
2208 /* Some fields always stay on top of the backing file chain */
2209 swap_feature_fields(bs_top
, bs_new
);
2211 bdrv_set_backing_hd(bs_new
, bs_top
);
2214 /* bs_new is now referenced by its new parents, we don't need the
2215 * additional reference any more. */
2219 void bdrv_replace_in_backing_chain(BlockDriverState
*old
, BlockDriverState
*new)
2221 assert(!bdrv_requests_pending(old
));
2222 assert(!bdrv_requests_pending(new));
2227 /* As long as these fields aren't in BlockBackend, but in the top-level
2228 * BlockDriverState, it's not possible for a BDS to have two BBs.
2230 * We really want to copy the fields from old to new, but we go for a
2231 * swap instead so that pointers aren't duplicated and cause trouble.
2232 * (Also, bdrv_swap() used to do the same.) */
2234 swap_feature_fields(old
, new);
2236 change_parent_backing_link(old
, new);
2238 /* Change backing files if a previously independent node is added to the
2239 * chain. For active commit, we replace top by its own (indirect) backing
2240 * file and don't do anything here so we don't build a loop. */
2241 if (new->backing
== NULL
&& !bdrv_chain_contains(backing_bs(old
), new)) {
2242 bdrv_set_backing_hd(new, backing_bs(old
));
2243 bdrv_set_backing_hd(old
, NULL
);
2249 static void bdrv_delete(BlockDriverState
*bs
)
2252 assert(bdrv_op_blocker_is_empty(bs
));
2253 assert(!bs
->refcnt
);
2254 assert(QLIST_EMPTY(&bs
->dirty_bitmaps
));
2258 /* remove from list, if necessary */
2265 * Run consistency checks on an image
2267 * Returns 0 if the check could be completed (it doesn't mean that the image is
2268 * free of errors) or -errno when an internal error occurred. The results of the
2269 * check are stored in res.
2271 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
)
2273 if (bs
->drv
== NULL
) {
2276 if (bs
->drv
->bdrv_check
== NULL
) {
2280 memset(res
, 0, sizeof(*res
));
2281 return bs
->drv
->bdrv_check(bs
, res
, fix
);
2284 #define COMMIT_BUF_SECTORS 2048
2286 /* commit COW file into the raw image */
2287 int bdrv_commit(BlockDriverState
*bs
)
2289 BlockDriver
*drv
= bs
->drv
;
2290 int64_t sector
, total_sectors
, length
, backing_length
;
2291 int n
, ro
, open_flags
;
2293 uint8_t *buf
= NULL
;
2302 if (bdrv_op_is_blocked(bs
, BLOCK_OP_TYPE_COMMIT_SOURCE
, NULL
) ||
2303 bdrv_op_is_blocked(bs
->backing
->bs
, BLOCK_OP_TYPE_COMMIT_TARGET
, NULL
)) {
2307 ro
= bs
->backing
->bs
->read_only
;
2308 open_flags
= bs
->backing
->bs
->open_flags
;
2311 if (bdrv_reopen(bs
->backing
->bs
, open_flags
| BDRV_O_RDWR
, NULL
)) {
2316 length
= bdrv_getlength(bs
);
2322 backing_length
= bdrv_getlength(bs
->backing
->bs
);
2323 if (backing_length
< 0) {
2324 ret
= backing_length
;
2328 /* If our top snapshot is larger than the backing file image,
2329 * grow the backing file image if possible. If not possible,
2330 * we must return an error */
2331 if (length
> backing_length
) {
2332 ret
= bdrv_truncate(bs
->backing
->bs
, length
);
2338 total_sectors
= length
>> BDRV_SECTOR_BITS
;
2340 /* qemu_try_blockalign() for bs will choose an alignment that works for
2341 * bs->backing->bs as well, so no need to compare the alignment manually. */
2342 buf
= qemu_try_blockalign(bs
, COMMIT_BUF_SECTORS
* BDRV_SECTOR_SIZE
);
2348 for (sector
= 0; sector
< total_sectors
; sector
+= n
) {
2349 ret
= bdrv_is_allocated(bs
, sector
, COMMIT_BUF_SECTORS
, &n
);
2354 ret
= bdrv_read(bs
, sector
, buf
, n
);
2359 ret
= bdrv_write(bs
->backing
->bs
, sector
, buf
, n
);
2366 if (drv
->bdrv_make_empty
) {
2367 ret
= drv
->bdrv_make_empty(bs
);
2375 * Make sure all data we wrote to the backing device is actually
2379 bdrv_flush(bs
->backing
->bs
);
2387 /* ignoring error return here */
2388 bdrv_reopen(bs
->backing
->bs
, open_flags
& ~BDRV_O_RDWR
, NULL
);
2394 int bdrv_commit_all(void)
2396 BlockDriverState
*bs
;
2398 QTAILQ_FOREACH(bs
, &bdrv_states
, device_list
) {
2399 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
2401 aio_context_acquire(aio_context
);
2402 if (bs
->drv
&& bs
->backing
) {
2403 int ret
= bdrv_commit(bs
);
2405 aio_context_release(aio_context
);
2409 aio_context_release(aio_context
);
2417 * -EINVAL - backing format specified, but no file
2418 * -ENOSPC - can't update the backing file because no space is left in the
2420 * -ENOTSUP - format driver doesn't support changing the backing file
2422 int bdrv_change_backing_file(BlockDriverState
*bs
,
2423 const char *backing_file
, const char *backing_fmt
)
2425 BlockDriver
*drv
= bs
->drv
;
2428 /* Backing file format doesn't make sense without a backing file */
2429 if (backing_fmt
&& !backing_file
) {
2433 if (drv
->bdrv_change_backing_file
!= NULL
) {
2434 ret
= drv
->bdrv_change_backing_file(bs
, backing_file
, backing_fmt
);
2440 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2441 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2447 * Finds the image layer in the chain that has 'bs' as its backing file.
2449 * active is the current topmost image.
2451 * Returns NULL if bs is not found in active's image chain,
2452 * or if active == bs.
2454 * Returns the bottommost base image if bs == NULL.
2456 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
2457 BlockDriverState
*bs
)
2459 while (active
&& bs
!= backing_bs(active
)) {
2460 active
= backing_bs(active
);
2466 /* Given a BDS, searches for the base layer. */
2467 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
)
2469 return bdrv_find_overlay(bs
, NULL
);
2473 * Drops images above 'base' up to and including 'top', and sets the image
2474 * above 'top' to have base as its backing file.
2476 * Requires that the overlay to 'top' is opened r/w, so that the backing file
2477 * information in 'bs' can be properly updated.
2479 * E.g., this will convert the following chain:
2480 * bottom <- base <- intermediate <- top <- active
2484 * bottom <- base <- active
2486 * It is allowed for bottom==base, in which case it converts:
2488 * base <- intermediate <- top <- active
2494 * If backing_file_str is non-NULL, it will be used when modifying top's
2495 * overlay image metadata.
2498 * if active == top, that is considered an error
2501 int bdrv_drop_intermediate(BlockDriverState
*active
, BlockDriverState
*top
,
2502 BlockDriverState
*base
, const char *backing_file_str
)
2504 BlockDriverState
*new_top_bs
= NULL
;
2507 if (!top
->drv
|| !base
->drv
) {
2511 new_top_bs
= bdrv_find_overlay(active
, top
);
2513 if (new_top_bs
== NULL
) {
2514 /* we could not find the image above 'top', this is an error */
2518 /* special case of new_top_bs->backing->bs already pointing to base - nothing
2519 * to do, no intermediate images */
2520 if (backing_bs(new_top_bs
) == base
) {
2525 /* Make sure that base is in the backing chain of top */
2526 if (!bdrv_chain_contains(top
, base
)) {
2530 /* success - we can delete the intermediate states, and link top->base */
2531 backing_file_str
= backing_file_str
? backing_file_str
: base
->filename
;
2532 ret
= bdrv_change_backing_file(new_top_bs
, backing_file_str
,
2533 base
->drv
? base
->drv
->format_name
: "");
2537 bdrv_set_backing_hd(new_top_bs
, base
);
2545 * Truncate file to 'offset' bytes (needed only for file protocols)
2547 int bdrv_truncate(BlockDriverState
*bs
, int64_t offset
)
2549 BlockDriver
*drv
= bs
->drv
;
2553 if (!drv
->bdrv_truncate
)
2558 ret
= drv
->bdrv_truncate(bs
, offset
);
2560 ret
= refresh_total_sectors(bs
, offset
>> BDRV_SECTOR_BITS
);
2561 bdrv_dirty_bitmap_truncate(bs
);
2563 blk_dev_resize_cb(bs
->blk
);
2570 * Length of a allocated file in bytes. Sparse files are counted by actual
2571 * allocated space. Return < 0 if error or unknown.
2573 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
)
2575 BlockDriver
*drv
= bs
->drv
;
2579 if (drv
->bdrv_get_allocated_file_size
) {
2580 return drv
->bdrv_get_allocated_file_size(bs
);
2583 return bdrv_get_allocated_file_size(bs
->file
->bs
);
2589 * Return number of sectors on success, -errno on error.
2591 int64_t bdrv_nb_sectors(BlockDriverState
*bs
)
2593 BlockDriver
*drv
= bs
->drv
;
2598 if (drv
->has_variable_length
) {
2599 int ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
2604 return bs
->total_sectors
;
2608 * Return length in bytes on success, -errno on error.
2609 * The length is always a multiple of BDRV_SECTOR_SIZE.
2611 int64_t bdrv_getlength(BlockDriverState
*bs
)
2613 int64_t ret
= bdrv_nb_sectors(bs
);
2615 ret
= ret
> INT64_MAX
/ BDRV_SECTOR_SIZE
? -EFBIG
: ret
;
2616 return ret
< 0 ? ret
: ret
* BDRV_SECTOR_SIZE
;
2619 /* return 0 as number of sectors if no device present or error */
2620 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
)
2622 int64_t nb_sectors
= bdrv_nb_sectors(bs
);
2624 *nb_sectors_ptr
= nb_sectors
< 0 ? 0 : nb_sectors
;
2627 int bdrv_is_read_only(BlockDriverState
*bs
)
2629 return bs
->read_only
;
2632 int bdrv_is_sg(BlockDriverState
*bs
)
2637 int bdrv_enable_write_cache(BlockDriverState
*bs
)
2639 return bs
->enable_write_cache
;
2642 void bdrv_set_enable_write_cache(BlockDriverState
*bs
, bool wce
)
2644 bs
->enable_write_cache
= wce
;
2646 /* so a reopen() will preserve wce */
2648 bs
->open_flags
|= BDRV_O_CACHE_WB
;
2650 bs
->open_flags
&= ~BDRV_O_CACHE_WB
;
2654 int bdrv_is_encrypted(BlockDriverState
*bs
)
2656 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2659 return bs
->encrypted
;
2662 int bdrv_key_required(BlockDriverState
*bs
)
2664 BdrvChild
*backing
= bs
->backing
;
2666 if (backing
&& backing
->bs
->encrypted
&& !backing
->bs
->valid_key
) {
2669 return (bs
->encrypted
&& !bs
->valid_key
);
2672 int bdrv_set_key(BlockDriverState
*bs
, const char *key
)
2675 if (bs
->backing
&& bs
->backing
->bs
->encrypted
) {
2676 ret
= bdrv_set_key(bs
->backing
->bs
, key
);
2682 if (!bs
->encrypted
) {
2684 } else if (!bs
->drv
|| !bs
->drv
->bdrv_set_key
) {
2687 ret
= bs
->drv
->bdrv_set_key(bs
, key
);
2690 } else if (!bs
->valid_key
) {
2693 /* call the change callback now, we skipped it on open */
2694 blk_dev_change_media_cb(bs
->blk
, true);
2701 * Provide an encryption key for @bs.
2702 * If @key is non-null:
2703 * If @bs is not encrypted, fail.
2704 * Else if the key is invalid, fail.
2705 * Else set @bs's key to @key, replacing the existing key, if any.
2707 * If @bs is encrypted and still lacks a key, fail.
2709 * On failure, store an error object through @errp if non-null.
2711 void bdrv_add_key(BlockDriverState
*bs
, const char *key
, Error
**errp
)
2714 if (!bdrv_is_encrypted(bs
)) {
2715 error_setg(errp
, "Node '%s' is not encrypted",
2716 bdrv_get_device_or_node_name(bs
));
2717 } else if (bdrv_set_key(bs
, key
) < 0) {
2718 error_setg(errp
, QERR_INVALID_PASSWORD
);
2721 if (bdrv_key_required(bs
)) {
2722 error_set(errp
, ERROR_CLASS_DEVICE_ENCRYPTED
,
2723 "'%s' (%s) is encrypted",
2724 bdrv_get_device_or_node_name(bs
),
2725 bdrv_get_encrypted_filename(bs
));
2730 const char *bdrv_get_format_name(BlockDriverState
*bs
)
2732 return bs
->drv
? bs
->drv
->format_name
: NULL
;
2735 static int qsort_strcmp(const void *a
, const void *b
)
2737 return strcmp(a
, b
);
2740 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
2746 const char **formats
= NULL
;
2748 QLIST_FOREACH(drv
, &bdrv_drivers
, list
) {
2749 if (drv
->format_name
) {
2752 while (formats
&& i
&& !found
) {
2753 found
= !strcmp(formats
[--i
], drv
->format_name
);
2757 formats
= g_renew(const char *, formats
, count
+ 1);
2758 formats
[count
++] = drv
->format_name
;
2763 qsort(formats
, count
, sizeof(formats
[0]), qsort_strcmp
);
2765 for (i
= 0; i
< count
; i
++) {
2766 it(opaque
, formats
[i
]);
2772 /* This function is to find a node in the bs graph */
2773 BlockDriverState
*bdrv_find_node(const char *node_name
)
2775 BlockDriverState
*bs
;
2779 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2780 if (!strcmp(node_name
, bs
->node_name
)) {
2787 /* Put this QMP function here so it can access the static graph_bdrv_states. */
2788 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
)
2790 BlockDeviceInfoList
*list
, *entry
;
2791 BlockDriverState
*bs
;
2794 QTAILQ_FOREACH(bs
, &graph_bdrv_states
, node_list
) {
2795 BlockDeviceInfo
*info
= bdrv_block_device_info(bs
, errp
);
2797 qapi_free_BlockDeviceInfoList(list
);
2800 entry
= g_malloc0(sizeof(*entry
));
2801 entry
->value
= info
;
2809 BlockDriverState
*bdrv_lookup_bs(const char *device
,
2810 const char *node_name
,
2814 BlockDriverState
*bs
;
2817 blk
= blk_by_name(device
);
2822 error_setg(errp
, "Device '%s' has no medium", device
);
2830 bs
= bdrv_find_node(node_name
);
2837 error_setg(errp
, "Cannot find device=%s nor node_name=%s",
2838 device
? device
: "",
2839 node_name
? node_name
: "");
2843 /* If 'base' is in the same chain as 'top', return true. Otherwise,
2844 * return false. If either argument is NULL, return false. */
2845 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
)
2847 while (top
&& top
!= base
) {
2848 top
= backing_bs(top
);
2854 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
)
2857 return QTAILQ_FIRST(&graph_bdrv_states
);
2859 return QTAILQ_NEXT(bs
, node_list
);
2862 BlockDriverState
*bdrv_next(BlockDriverState
*bs
)
2865 return QTAILQ_FIRST(&bdrv_states
);
2867 return QTAILQ_NEXT(bs
, device_list
);
2870 const char *bdrv_get_node_name(const BlockDriverState
*bs
)
2872 return bs
->node_name
;
2875 /* TODO check what callers really want: bs->node_name or blk_name() */
2876 const char *bdrv_get_device_name(const BlockDriverState
*bs
)
2878 return bs
->blk
? blk_name(bs
->blk
) : "";
2881 /* This can be used to identify nodes that might not have a device
2882 * name associated. Since node and device names live in the same
2883 * namespace, the result is unambiguous. The exception is if both are
2884 * absent, then this returns an empty (non-null) string. */
2885 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
)
2887 return bs
->blk
? blk_name(bs
->blk
) : bs
->node_name
;
2890 int bdrv_get_flags(BlockDriverState
*bs
)
2892 return bs
->open_flags
;
2895 int bdrv_has_zero_init_1(BlockDriverState
*bs
)
2900 int bdrv_has_zero_init(BlockDriverState
*bs
)
2904 /* If BS is a copy on write image, it is initialized to
2905 the contents of the base image, which may not be zeroes. */
2909 if (bs
->drv
->bdrv_has_zero_init
) {
2910 return bs
->drv
->bdrv_has_zero_init(bs
);
2917 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
)
2919 BlockDriverInfo bdi
;
2925 if (bdrv_get_info(bs
, &bdi
) == 0) {
2926 return bdi
.unallocated_blocks_are_zero
;
2932 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
)
2934 BlockDriverInfo bdi
;
2936 if (bs
->backing
|| !(bs
->open_flags
& BDRV_O_UNMAP
)) {
2940 if (bdrv_get_info(bs
, &bdi
) == 0) {
2941 return bdi
.can_write_zeroes_with_unmap
;
2947 const char *bdrv_get_encrypted_filename(BlockDriverState
*bs
)
2949 if (bs
->backing
&& bs
->backing
->bs
->encrypted
)
2950 return bs
->backing_file
;
2951 else if (bs
->encrypted
)
2952 return bs
->filename
;
2957 void bdrv_get_backing_filename(BlockDriverState
*bs
,
2958 char *filename
, int filename_size
)
2960 pstrcpy(filename
, filename_size
, bs
->backing_file
);
2963 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
2965 BlockDriver
*drv
= bs
->drv
;
2968 if (!drv
->bdrv_get_info
)
2970 memset(bdi
, 0, sizeof(*bdi
));
2971 return drv
->bdrv_get_info(bs
, bdi
);
2974 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
)
2976 BlockDriver
*drv
= bs
->drv
;
2977 if (drv
&& drv
->bdrv_get_specific_info
) {
2978 return drv
->bdrv_get_specific_info(bs
);
2983 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
)
2985 if (!bs
|| !bs
->drv
|| !bs
->drv
->bdrv_debug_event
) {
2989 bs
->drv
->bdrv_debug_event(bs
, event
);
2992 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
2995 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_breakpoint
) {
2996 bs
= bs
->file
? bs
->file
->bs
: NULL
;
2999 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_breakpoint
) {
3000 return bs
->drv
->bdrv_debug_breakpoint(bs
, event
, tag
);
3006 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
)
3008 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_remove_breakpoint
) {
3009 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3012 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_remove_breakpoint
) {
3013 return bs
->drv
->bdrv_debug_remove_breakpoint(bs
, tag
);
3019 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
)
3021 while (bs
&& (!bs
->drv
|| !bs
->drv
->bdrv_debug_resume
)) {
3022 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3025 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_resume
) {
3026 return bs
->drv
->bdrv_debug_resume(bs
, tag
);
3032 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
)
3034 while (bs
&& bs
->drv
&& !bs
->drv
->bdrv_debug_is_suspended
) {
3035 bs
= bs
->file
? bs
->file
->bs
: NULL
;
3038 if (bs
&& bs
->drv
&& bs
->drv
->bdrv_debug_is_suspended
) {
3039 return bs
->drv
->bdrv_debug_is_suspended(bs
, tag
);
3045 int bdrv_is_snapshot(BlockDriverState
*bs
)
3047 return !!(bs
->open_flags
& BDRV_O_SNAPSHOT
);
3050 /* backing_file can either be relative, or absolute, or a protocol. If it is
3051 * relative, it must be relative to the chain. So, passing in bs->filename
3052 * from a BDS as backing_file should not be done, as that may be relative to
3053 * the CWD rather than the chain. */
3054 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
3055 const char *backing_file
)
3057 char *filename_full
= NULL
;
3058 char *backing_file_full
= NULL
;
3059 char *filename_tmp
= NULL
;
3060 int is_protocol
= 0;
3061 BlockDriverState
*curr_bs
= NULL
;
3062 BlockDriverState
*retval
= NULL
;
3064 if (!bs
|| !bs
->drv
|| !backing_file
) {
3068 filename_full
= g_malloc(PATH_MAX
);
3069 backing_file_full
= g_malloc(PATH_MAX
);
3070 filename_tmp
= g_malloc(PATH_MAX
);
3072 is_protocol
= path_has_protocol(backing_file
);
3074 for (curr_bs
= bs
; curr_bs
->backing
; curr_bs
= curr_bs
->backing
->bs
) {
3076 /* If either of the filename paths is actually a protocol, then
3077 * compare unmodified paths; otherwise make paths relative */
3078 if (is_protocol
|| path_has_protocol(curr_bs
->backing_file
)) {
3079 if (strcmp(backing_file
, curr_bs
->backing_file
) == 0) {
3080 retval
= curr_bs
->backing
->bs
;
3084 /* If not an absolute filename path, make it relative to the current
3085 * image's filename path */
3086 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3089 /* We are going to compare absolute pathnames */
3090 if (!realpath(filename_tmp
, filename_full
)) {
3094 /* We need to make sure the backing filename we are comparing against
3095 * is relative to the current image filename (or absolute) */
3096 path_combine(filename_tmp
, PATH_MAX
, curr_bs
->filename
,
3097 curr_bs
->backing_file
);
3099 if (!realpath(filename_tmp
, backing_file_full
)) {
3103 if (strcmp(backing_file_full
, filename_full
) == 0) {
3104 retval
= curr_bs
->backing
->bs
;
3110 g_free(filename_full
);
3111 g_free(backing_file_full
);
3112 g_free(filename_tmp
);
3116 int bdrv_get_backing_file_depth(BlockDriverState
*bs
)
3126 return 1 + bdrv_get_backing_file_depth(bs
->backing
->bs
);
3129 void bdrv_init(void)
3131 module_call_init(MODULE_INIT_BLOCK
);
3134 void bdrv_init_with_whitelist(void)
3136 use_bdrv_whitelist
= 1;
3140 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
3142 Error
*local_err
= NULL
;
3149 if (!(bs
->open_flags
& BDRV_O_INCOMING
)) {
3152 bs
->open_flags
&= ~BDRV_O_INCOMING
;
3154 if (bs
->drv
->bdrv_invalidate_cache
) {
3155 bs
->drv
->bdrv_invalidate_cache(bs
, &local_err
);
3156 } else if (bs
->file
) {
3157 bdrv_invalidate_cache(bs
->file
->bs
, &local_err
);
3160 error_propagate(errp
, local_err
);
3164 ret
= refresh_total_sectors(bs
, bs
->total_sectors
);
3166 error_setg_errno(errp
, -ret
, "Could not refresh total sector count");
3171 void bdrv_invalidate_cache_all(Error
**errp
)
3173 BlockDriverState
*bs
;
3174 Error
*local_err
= NULL
;
3176 QTAILQ_FOREACH(bs
, &bdrv_states
, device_list
) {
3177 AioContext
*aio_context
= bdrv_get_aio_context(bs
);
3179 aio_context_acquire(aio_context
);
3180 bdrv_invalidate_cache(bs
, &local_err
);
3181 aio_context_release(aio_context
);
3183 error_propagate(errp
, local_err
);
3189 /**************************************************************/
3190 /* removable device support */
3193 * Return TRUE if the media is present
3195 bool bdrv_is_inserted(BlockDriverState
*bs
)
3197 BlockDriver
*drv
= bs
->drv
;
3203 if (drv
->bdrv_is_inserted
) {
3204 return drv
->bdrv_is_inserted(bs
);
3206 QLIST_FOREACH(child
, &bs
->children
, next
) {
3207 if (!bdrv_is_inserted(child
->bs
)) {
3215 * Return whether the media changed since the last call to this
3216 * function, or -ENOTSUP if we don't know. Most drivers don't know.
3218 int bdrv_media_changed(BlockDriverState
*bs
)
3220 BlockDriver
*drv
= bs
->drv
;
3222 if (drv
&& drv
->bdrv_media_changed
) {
3223 return drv
->bdrv_media_changed(bs
);
3229 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
3231 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
)
3233 BlockDriver
*drv
= bs
->drv
;
3234 const char *device_name
;
3236 if (drv
&& drv
->bdrv_eject
) {
3237 drv
->bdrv_eject(bs
, eject_flag
);
3240 device_name
= bdrv_get_device_name(bs
);
3241 if (device_name
[0] != '\0') {
3242 qapi_event_send_device_tray_moved(device_name
,
3243 eject_flag
, &error_abort
);
3248 * Lock or unlock the media (if it is locked, the user won't be able
3249 * to eject it manually).
3251 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
)
3253 BlockDriver
*drv
= bs
->drv
;
3255 trace_bdrv_lock_medium(bs
, locked
);
3257 if (drv
&& drv
->bdrv_lock_medium
) {
3258 drv
->bdrv_lock_medium(bs
, locked
);
3262 BdrvDirtyBitmap
*bdrv_find_dirty_bitmap(BlockDriverState
*bs
, const char *name
)
3264 BdrvDirtyBitmap
*bm
;
3267 QLIST_FOREACH(bm
, &bs
->dirty_bitmaps
, list
) {
3268 if (bm
->name
&& !strcmp(name
, bm
->name
)) {
3275 void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap
*bitmap
)
3277 assert(!bdrv_dirty_bitmap_frozen(bitmap
));
3278 g_free(bitmap
->name
);
3279 bitmap
->name
= NULL
;
3282 BdrvDirtyBitmap
*bdrv_create_dirty_bitmap(BlockDriverState
*bs
,
3283 uint32_t granularity
,
3287 int64_t bitmap_size
;
3288 BdrvDirtyBitmap
*bitmap
;
3289 uint32_t sector_granularity
;
3291 assert((granularity
& (granularity
- 1)) == 0);
3293 if (name
&& bdrv_find_dirty_bitmap(bs
, name
)) {
3294 error_setg(errp
, "Bitmap already exists: %s", name
);
3297 sector_granularity
= granularity
>> BDRV_SECTOR_BITS
;
3298 assert(sector_granularity
);
3299 bitmap_size
= bdrv_nb_sectors(bs
);
3300 if (bitmap_size
< 0) {
3301 error_setg_errno(errp
, -bitmap_size
, "could not get length of device");
3302 errno
= -bitmap_size
;
3305 bitmap
= g_new0(BdrvDirtyBitmap
, 1);
3306 bitmap
->bitmap
= hbitmap_alloc(bitmap_size
, ctz32(sector_granularity
));
3307 bitmap
->size
= bitmap_size
;
3308 bitmap
->name
= g_strdup(name
);
3309 bitmap
->disabled
= false;
3310 QLIST_INSERT_HEAD(&bs
->dirty_bitmaps
, bitmap
, list
);
3314 bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap
*bitmap
)
3316 return bitmap
->successor
;
3319 bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap
*bitmap
)
3321 return !(bitmap
->disabled
|| bitmap
->successor
);
3324 DirtyBitmapStatus
bdrv_dirty_bitmap_status(BdrvDirtyBitmap
*bitmap
)
3326 if (bdrv_dirty_bitmap_frozen(bitmap
)) {
3327 return DIRTY_BITMAP_STATUS_FROZEN
;
3328 } else if (!bdrv_dirty_bitmap_enabled(bitmap
)) {
3329 return DIRTY_BITMAP_STATUS_DISABLED
;
3331 return DIRTY_BITMAP_STATUS_ACTIVE
;
3336 * Create a successor bitmap destined to replace this bitmap after an operation.
3337 * Requires that the bitmap is not frozen and has no successor.
3339 int bdrv_dirty_bitmap_create_successor(BlockDriverState
*bs
,
3340 BdrvDirtyBitmap
*bitmap
, Error
**errp
)
3342 uint64_t granularity
;
3343 BdrvDirtyBitmap
*child
;
3345 if (bdrv_dirty_bitmap_frozen(bitmap
)) {
3346 error_setg(errp
, "Cannot create a successor for a bitmap that is "
3347 "currently frozen");
3350 assert(!bitmap
->successor
);
3352 /* Create an anonymous successor */
3353 granularity
= bdrv_dirty_bitmap_granularity(bitmap
);
3354 child
= bdrv_create_dirty_bitmap(bs
, granularity
, NULL
, errp
);
3359 /* Successor will be on or off based on our current state. */
3360 child
->disabled
= bitmap
->disabled
;
3362 /* Install the successor and freeze the parent */
3363 bitmap
->successor
= child
;
3368 * For a bitmap with a successor, yield our name to the successor,
3369 * delete the old bitmap, and return a handle to the new bitmap.
3371 BdrvDirtyBitmap
*bdrv_dirty_bitmap_abdicate(BlockDriverState
*bs
,
3372 BdrvDirtyBitmap
*bitmap
,
3376 BdrvDirtyBitmap
*successor
= bitmap
->successor
;
3378 if (successor
== NULL
) {
3379 error_setg(errp
, "Cannot relinquish control if "
3380 "there's no successor present");
3384 name
= bitmap
->name
;
3385 bitmap
->name
= NULL
;
3386 successor
->name
= name
;
3387 bitmap
->successor
= NULL
;
3388 bdrv_release_dirty_bitmap(bs
, bitmap
);
3394 * In cases of failure where we can no longer safely delete the parent,
3395 * we may wish to re-join the parent and child/successor.
3396 * The merged parent will be un-frozen, but not explicitly re-enabled.
3398 BdrvDirtyBitmap
*bdrv_reclaim_dirty_bitmap(BlockDriverState
*bs
,
3399 BdrvDirtyBitmap
*parent
,
3402 BdrvDirtyBitmap
*successor
= parent
->successor
;
3405 error_setg(errp
, "Cannot reclaim a successor when none is present");
3409 if (!hbitmap_merge(parent
->bitmap
, successor
->bitmap
)) {
3410 error_setg(errp
, "Merging of parent and successor bitmap failed");
3413 bdrv_release_dirty_bitmap(bs
, successor
);
3414 parent
->successor
= NULL
;
3420 * Truncates _all_ bitmaps attached to a BDS.
3422 static void bdrv_dirty_bitmap_truncate(BlockDriverState
*bs
)
3424 BdrvDirtyBitmap
*bitmap
;
3425 uint64_t size
= bdrv_nb_sectors(bs
);
3427 QLIST_FOREACH(bitmap
, &bs
->dirty_bitmaps
, list
) {
3428 assert(!bdrv_dirty_bitmap_frozen(bitmap
));
3429 hbitmap_truncate(bitmap
->bitmap
, size
);
3430 bitmap
->size
= size
;
3434 void bdrv_release_dirty_bitmap(BlockDriverState
*bs
, BdrvDirtyBitmap
*bitmap
)
3436 BdrvDirtyBitmap
*bm
, *next
;
3437 QLIST_FOREACH_SAFE(bm
, &bs
->dirty_bitmaps
, list
, next
) {
3439 assert(!bdrv_dirty_bitmap_frozen(bm
));
3440 QLIST_REMOVE(bitmap
, list
);
3441 hbitmap_free(bitmap
->bitmap
);
3442 g_free(bitmap
->name
);
3449 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap
*bitmap
)
3451 assert(!bdrv_dirty_bitmap_frozen(bitmap
));
3452 bitmap
->disabled
= true;
3455 void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap
*bitmap
)
3457 assert(!bdrv_dirty_bitmap_frozen(bitmap
));
3458 bitmap
->disabled
= false;
3461 BlockDirtyInfoList
*bdrv_query_dirty_bitmaps(BlockDriverState
*bs
)
3463 BdrvDirtyBitmap
*bm
;
3464 BlockDirtyInfoList
*list
= NULL
;
3465 BlockDirtyInfoList
**plist
= &list
;
3467 QLIST_FOREACH(bm
, &bs
->dirty_bitmaps
, list
) {
3468 BlockDirtyInfo
*info
= g_new0(BlockDirtyInfo
, 1);
3469 BlockDirtyInfoList
*entry
= g_new0(BlockDirtyInfoList
, 1);
3470 info
->count
= bdrv_get_dirty_count(bm
);
3471 info
->granularity
= bdrv_dirty_bitmap_granularity(bm
);
3472 info
->has_name
= !!bm
->name
;
3473 info
->name
= g_strdup(bm
->name
);
3474 info
->status
= bdrv_dirty_bitmap_status(bm
);
3475 entry
->value
= info
;
3477 plist
= &entry
->next
;
3483 int bdrv_get_dirty(BlockDriverState
*bs
, BdrvDirtyBitmap
*bitmap
, int64_t sector
)
3486 return hbitmap_get(bitmap
->bitmap
, sector
);
3493 * Chooses a default granularity based on the existing cluster size,
3494 * but clamped between [4K, 64K]. Defaults to 64K in the case that there
3495 * is no cluster size information available.
3497 uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState
*bs
)
3499 BlockDriverInfo bdi
;
3500 uint32_t granularity
;
3502 if (bdrv_get_info(bs
, &bdi
) >= 0 && bdi
.cluster_size
> 0) {
3503 granularity
= MAX(4096, bdi
.cluster_size
);
3504 granularity
= MIN(65536, granularity
);
3506 granularity
= 65536;
3512 uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap
*bitmap
)
3514 return BDRV_SECTOR_SIZE
<< hbitmap_granularity(bitmap
->bitmap
);
3517 void bdrv_dirty_iter_init(BdrvDirtyBitmap
*bitmap
, HBitmapIter
*hbi
)
3519 hbitmap_iter_init(hbi
, bitmap
->bitmap
, 0);
3522 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap
*bitmap
,
3523 int64_t cur_sector
, int nr_sectors
)
3525 assert(bdrv_dirty_bitmap_enabled(bitmap
));
3526 hbitmap_set(bitmap
->bitmap
, cur_sector
, nr_sectors
);
3529 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap
*bitmap
,
3530 int64_t cur_sector
, int nr_sectors
)
3532 assert(bdrv_dirty_bitmap_enabled(bitmap
));
3533 hbitmap_reset(bitmap
->bitmap
, cur_sector
, nr_sectors
);
3536 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
**out
)
3538 assert(bdrv_dirty_bitmap_enabled(bitmap
));
3540 hbitmap_reset_all(bitmap
->bitmap
);
3542 HBitmap
*backup
= bitmap
->bitmap
;
3543 bitmap
->bitmap
= hbitmap_alloc(bitmap
->size
,
3544 hbitmap_granularity(backup
));
3549 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
*in
)
3551 HBitmap
*tmp
= bitmap
->bitmap
;
3552 assert(bdrv_dirty_bitmap_enabled(bitmap
));
3553 bitmap
->bitmap
= in
;
3557 void bdrv_set_dirty(BlockDriverState
*bs
, int64_t cur_sector
,
3560 BdrvDirtyBitmap
*bitmap
;
3561 QLIST_FOREACH(bitmap
, &bs
->dirty_bitmaps
, list
) {
3562 if (!bdrv_dirty_bitmap_enabled(bitmap
)) {
3565 hbitmap_set(bitmap
->bitmap
, cur_sector
, nr_sectors
);
3570 * Advance an HBitmapIter to an arbitrary offset.
3572 void bdrv_set_dirty_iter(HBitmapIter
*hbi
, int64_t offset
)
3575 hbitmap_iter_init(hbi
, hbi
->hb
, offset
);
3578 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap
*bitmap
)
3580 return hbitmap_count(bitmap
->bitmap
);
3583 /* Get a reference to bs */
3584 void bdrv_ref(BlockDriverState
*bs
)
3589 /* Release a previously grabbed reference to bs.
3590 * If after releasing, reference count is zero, the BlockDriverState is
3592 void bdrv_unref(BlockDriverState
*bs
)
3597 assert(bs
->refcnt
> 0);
3598 if (--bs
->refcnt
== 0) {
3603 struct BdrvOpBlocker
{
3605 QLIST_ENTRY(BdrvOpBlocker
) list
;
3608 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
)
3610 BdrvOpBlocker
*blocker
;
3611 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3612 if (!QLIST_EMPTY(&bs
->op_blockers
[op
])) {
3613 blocker
= QLIST_FIRST(&bs
->op_blockers
[op
]);
3615 error_setg(errp
, "Node '%s' is busy: %s",
3616 bdrv_get_device_or_node_name(bs
),
3617 error_get_pretty(blocker
->reason
));
3624 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3626 BdrvOpBlocker
*blocker
;
3627 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3629 blocker
= g_new0(BdrvOpBlocker
, 1);
3630 blocker
->reason
= reason
;
3631 QLIST_INSERT_HEAD(&bs
->op_blockers
[op
], blocker
, list
);
3634 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
)
3636 BdrvOpBlocker
*blocker
, *next
;
3637 assert((int) op
>= 0 && op
< BLOCK_OP_TYPE_MAX
);
3638 QLIST_FOREACH_SAFE(blocker
, &bs
->op_blockers
[op
], list
, next
) {
3639 if (blocker
->reason
== reason
) {
3640 QLIST_REMOVE(blocker
, list
);
3646 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
)
3649 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3650 bdrv_op_block(bs
, i
, reason
);
3654 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
)
3657 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3658 bdrv_op_unblock(bs
, i
, reason
);
3662 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
)
3666 for (i
= 0; i
< BLOCK_OP_TYPE_MAX
; i
++) {
3667 if (!QLIST_EMPTY(&bs
->op_blockers
[i
])) {
3674 void bdrv_img_create(const char *filename
, const char *fmt
,
3675 const char *base_filename
, const char *base_fmt
,
3676 char *options
, uint64_t img_size
, int flags
,
3677 Error
**errp
, bool quiet
)
3679 QemuOptsList
*create_opts
= NULL
;
3680 QemuOpts
*opts
= NULL
;
3681 const char *backing_fmt
, *backing_file
;
3683 BlockDriver
*drv
, *proto_drv
;
3684 Error
*local_err
= NULL
;
3687 /* Find driver and parse its options */
3688 drv
= bdrv_find_format(fmt
);
3690 error_setg(errp
, "Unknown file format '%s'", fmt
);
3694 proto_drv
= bdrv_find_protocol(filename
, true, errp
);
3699 if (!drv
->create_opts
) {
3700 error_setg(errp
, "Format driver '%s' does not support image creation",
3705 if (!proto_drv
->create_opts
) {
3706 error_setg(errp
, "Protocol driver '%s' does not support image creation",
3707 proto_drv
->format_name
);
3711 create_opts
= qemu_opts_append(create_opts
, drv
->create_opts
);
3712 create_opts
= qemu_opts_append(create_opts
, proto_drv
->create_opts
);
3714 /* Create parameter list with default values */
3715 opts
= qemu_opts_create(create_opts
, NULL
, 0, &error_abort
);
3716 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, img_size
, &error_abort
);
3718 /* Parse -o options */
3720 qemu_opts_do_parse(opts
, options
, NULL
, &local_err
);
3722 error_report_err(local_err
);
3724 error_setg(errp
, "Invalid options for file format '%s'", fmt
);
3729 if (base_filename
) {
3730 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FILE
, base_filename
, &local_err
);
3732 error_setg(errp
, "Backing file not supported for file format '%s'",
3739 qemu_opt_set(opts
, BLOCK_OPT_BACKING_FMT
, base_fmt
, &local_err
);
3741 error_setg(errp
, "Backing file format not supported for file "
3742 "format '%s'", fmt
);
3747 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
3749 if (!strcmp(filename
, backing_file
)) {
3750 error_setg(errp
, "Error: Trying to create an image with the "
3751 "same filename as the backing file");
3756 backing_fmt
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
3758 // The size for the image must always be specified, with one exception:
3759 // If we are using a backing file, we can obtain the size from there
3760 size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
3763 BlockDriverState
*bs
;
3764 char *full_backing
= g_new0(char, PATH_MAX
);
3767 QDict
*backing_options
= NULL
;
3769 bdrv_get_full_backing_filename_from_filename(filename
, backing_file
,
3770 full_backing
, PATH_MAX
,
3773 g_free(full_backing
);
3777 /* backing files always opened read-only */
3779 flags
& ~(BDRV_O_RDWR
| BDRV_O_SNAPSHOT
| BDRV_O_NO_BACKING
);
3782 backing_options
= qdict_new();
3783 qdict_put(backing_options
, "driver",
3784 qstring_from_str(backing_fmt
));
3788 ret
= bdrv_open(&bs
, full_backing
, NULL
, backing_options
,
3789 back_flags
, &local_err
);
3790 g_free(full_backing
);
3794 size
= bdrv_getlength(bs
);
3796 error_setg_errno(errp
, -size
, "Could not get size of '%s'",
3802 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, size
, &error_abort
);
3806 error_setg(errp
, "Image creation needs a size parameter");
3812 printf("Formatting '%s', fmt=%s ", filename
, fmt
);
3813 qemu_opts_print(opts
, " ");
3817 ret
= bdrv_create(drv
, filename
, opts
, &local_err
);
3819 if (ret
== -EFBIG
) {
3820 /* This is generally a better message than whatever the driver would
3821 * deliver (especially because of the cluster_size_hint), since that
3822 * is most probably not much different from "image too large". */
3823 const char *cluster_size_hint
= "";
3824 if (qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
, 0)) {
3825 cluster_size_hint
= " (try using a larger cluster size)";
3827 error_setg(errp
, "The image size is too large for file format '%s'"
3828 "%s", fmt
, cluster_size_hint
);
3829 error_free(local_err
);
3834 qemu_opts_del(opts
);
3835 qemu_opts_free(create_opts
);
3837 error_propagate(errp
, local_err
);
3841 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
)
3843 return bs
->aio_context
;
3846 void bdrv_detach_aio_context(BlockDriverState
*bs
)
3848 BdrvAioNotifier
*baf
;
3854 QLIST_FOREACH(baf
, &bs
->aio_notifiers
, list
) {
3855 baf
->detach_aio_context(baf
->opaque
);
3858 if (bs
->throttle_state
) {
3859 throttle_timers_detach_aio_context(&bs
->throttle_timers
);
3861 if (bs
->drv
->bdrv_detach_aio_context
) {
3862 bs
->drv
->bdrv_detach_aio_context(bs
);
3865 bdrv_detach_aio_context(bs
->file
->bs
);
3868 bdrv_detach_aio_context(bs
->backing
->bs
);
3871 bs
->aio_context
= NULL
;
3874 void bdrv_attach_aio_context(BlockDriverState
*bs
,
3875 AioContext
*new_context
)
3877 BdrvAioNotifier
*ban
;
3883 bs
->aio_context
= new_context
;
3886 bdrv_attach_aio_context(bs
->backing
->bs
, new_context
);
3889 bdrv_attach_aio_context(bs
->file
->bs
, new_context
);
3891 if (bs
->drv
->bdrv_attach_aio_context
) {
3892 bs
->drv
->bdrv_attach_aio_context(bs
, new_context
);
3894 if (bs
->throttle_state
) {
3895 throttle_timers_attach_aio_context(&bs
->throttle_timers
, new_context
);
3898 QLIST_FOREACH(ban
, &bs
->aio_notifiers
, list
) {
3899 ban
->attached_aio_context(new_context
, ban
->opaque
);
3903 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
)
3905 bdrv_drain(bs
); /* ensure there are no in-flight requests */
3907 bdrv_detach_aio_context(bs
);
3909 /* This function executes in the old AioContext so acquire the new one in
3910 * case it runs in a different thread.
3912 aio_context_acquire(new_context
);
3913 bdrv_attach_aio_context(bs
, new_context
);
3914 aio_context_release(new_context
);
3917 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
3918 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
3919 void (*detach_aio_context
)(void *opaque
), void *opaque
)
3921 BdrvAioNotifier
*ban
= g_new(BdrvAioNotifier
, 1);
3922 *ban
= (BdrvAioNotifier
){
3923 .attached_aio_context
= attached_aio_context
,
3924 .detach_aio_context
= detach_aio_context
,
3928 QLIST_INSERT_HEAD(&bs
->aio_notifiers
, ban
, list
);
3931 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
3932 void (*attached_aio_context
)(AioContext
*,
3934 void (*detach_aio_context
)(void *),
3937 BdrvAioNotifier
*ban
, *ban_next
;
3939 QLIST_FOREACH_SAFE(ban
, &bs
->aio_notifiers
, list
, ban_next
) {
3940 if (ban
->attached_aio_context
== attached_aio_context
&&
3941 ban
->detach_aio_context
== detach_aio_context
&&
3942 ban
->opaque
== opaque
)
3944 QLIST_REMOVE(ban
, list
);
3954 int bdrv_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
3955 BlockDriverAmendStatusCB
*status_cb
)
3957 if (!bs
->drv
->bdrv_amend_options
) {
3960 return bs
->drv
->bdrv_amend_options(bs
, opts
, status_cb
);
3963 /* This function will be called by the bdrv_recurse_is_first_non_filter method
3964 * of block filter and by bdrv_is_first_non_filter.
3965 * It is used to test if the given bs is the candidate or recurse more in the
3968 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
3969 BlockDriverState
*candidate
)
3971 /* return false if basic checks fails */
3972 if (!bs
|| !bs
->drv
) {
3976 /* the code reached a non block filter driver -> check if the bs is
3977 * the same as the candidate. It's the recursion termination condition.
3979 if (!bs
->drv
->is_filter
) {
3980 return bs
== candidate
;
3982 /* Down this path the driver is a block filter driver */
3984 /* If the block filter recursion method is defined use it to recurse down
3987 if (bs
->drv
->bdrv_recurse_is_first_non_filter
) {
3988 return bs
->drv
->bdrv_recurse_is_first_non_filter(bs
, candidate
);
3991 /* the driver is a block filter but don't allow to recurse -> return false
3996 /* This function checks if the candidate is the first non filter bs down it's
3997 * bs chain. Since we don't have pointers to parents it explore all bs chains
3998 * from the top. Some filters can choose not to pass down the recursion.
4000 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
)
4002 BlockDriverState
*bs
;
4004 /* walk down the bs forest recursively */
4005 QTAILQ_FOREACH(bs
, &bdrv_states
, device_list
) {
4008 /* try to recurse in this top level bs */
4009 perm
= bdrv_recurse_is_first_non_filter(bs
, candidate
);
4011 /* candidate is the first non filter */
4020 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
4021 const char *node_name
, Error
**errp
)
4023 BlockDriverState
*to_replace_bs
= bdrv_find_node(node_name
);
4024 AioContext
*aio_context
;
4026 if (!to_replace_bs
) {
4027 error_setg(errp
, "Node name '%s' not found", node_name
);
4031 aio_context
= bdrv_get_aio_context(to_replace_bs
);
4032 aio_context_acquire(aio_context
);
4034 if (bdrv_op_is_blocked(to_replace_bs
, BLOCK_OP_TYPE_REPLACE
, errp
)) {
4035 to_replace_bs
= NULL
;
4039 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4040 * most non filter in order to prevent data corruption.
4041 * Another benefit is that this tests exclude backing files which are
4042 * blocked by the backing blockers.
4044 if (!bdrv_recurse_is_first_non_filter(parent_bs
, to_replace_bs
)) {
4045 error_setg(errp
, "Only top most non filter can be replaced");
4046 to_replace_bs
= NULL
;
4051 aio_context_release(aio_context
);
4052 return to_replace_bs
;
4055 static bool append_open_options(QDict
*d
, BlockDriverState
*bs
)
4057 const QDictEntry
*entry
;
4060 bool found_any
= false;
4063 for (entry
= qdict_first(bs
->options
); entry
;
4064 entry
= qdict_next(bs
->options
, entry
))
4066 /* Exclude options for children */
4067 QLIST_FOREACH(child
, &bs
->children
, next
) {
4068 if (strstart(qdict_entry_key(entry
), child
->name
, &p
)
4069 && (!*p
|| *p
== '.'))
4078 /* And exclude all non-driver-specific options */
4079 for (desc
= bdrv_runtime_opts
.desc
; desc
->name
; desc
++) {
4080 if (!strcmp(qdict_entry_key(entry
), desc
->name
)) {
4088 qobject_incref(qdict_entry_value(entry
));
4089 qdict_put_obj(d
, qdict_entry_key(entry
), qdict_entry_value(entry
));
4096 /* Updates the following BDS fields:
4097 * - exact_filename: A filename which may be used for opening a block device
4098 * which (mostly) equals the given BDS (even without any
4099 * other options; so reading and writing must return the same
4100 * results, but caching etc. may be different)
4101 * - full_open_options: Options which, when given when opening a block device
4102 * (without a filename), result in a BDS (mostly)
4103 * equalling the given one
4104 * - filename: If exact_filename is set, it is copied here. Otherwise,
4105 * full_open_options is converted to a JSON object, prefixed with
4106 * "json:" (for use through the JSON pseudo protocol) and put here.
4108 void bdrv_refresh_filename(BlockDriverState
*bs
)
4110 BlockDriver
*drv
= bs
->drv
;
4117 /* This BDS's file name will most probably depend on its file's name, so
4118 * refresh that first */
4120 bdrv_refresh_filename(bs
->file
->bs
);
4123 if (drv
->bdrv_refresh_filename
) {
4124 /* Obsolete information is of no use here, so drop the old file name
4125 * information before refreshing it */
4126 bs
->exact_filename
[0] = '\0';
4127 if (bs
->full_open_options
) {
4128 QDECREF(bs
->full_open_options
);
4129 bs
->full_open_options
= NULL
;
4133 append_open_options(opts
, bs
);
4134 drv
->bdrv_refresh_filename(bs
, opts
);
4136 } else if (bs
->file
) {
4137 /* Try to reconstruct valid information from the underlying file */
4138 bool has_open_options
;
4140 bs
->exact_filename
[0] = '\0';
4141 if (bs
->full_open_options
) {
4142 QDECREF(bs
->full_open_options
);
4143 bs
->full_open_options
= NULL
;
4147 has_open_options
= append_open_options(opts
, bs
);
4149 /* If no specific options have been given for this BDS, the filename of
4150 * the underlying file should suffice for this one as well */
4151 if (bs
->file
->bs
->exact_filename
[0] && !has_open_options
) {
4152 strcpy(bs
->exact_filename
, bs
->file
->bs
->exact_filename
);
4154 /* Reconstructing the full options QDict is simple for most format block
4155 * drivers, as long as the full options are known for the underlying
4156 * file BDS. The full options QDict of that file BDS should somehow
4157 * contain a representation of the filename, therefore the following
4158 * suffices without querying the (exact_)filename of this BDS. */
4159 if (bs
->file
->bs
->full_open_options
) {
4160 qdict_put_obj(opts
, "driver",
4161 QOBJECT(qstring_from_str(drv
->format_name
)));
4162 QINCREF(bs
->file
->bs
->full_open_options
);
4163 qdict_put_obj(opts
, "file",
4164 QOBJECT(bs
->file
->bs
->full_open_options
));
4166 bs
->full_open_options
= opts
;
4170 } else if (!bs
->full_open_options
&& qdict_size(bs
->options
)) {
4171 /* There is no underlying file BDS (at least referenced by BDS.file),
4172 * so the full options QDict should be equal to the options given
4173 * specifically for this block device when it was opened (plus the
4174 * driver specification).
4175 * Because those options don't change, there is no need to update
4176 * full_open_options when it's already set. */
4179 append_open_options(opts
, bs
);
4180 qdict_put_obj(opts
, "driver",
4181 QOBJECT(qstring_from_str(drv
->format_name
)));
4183 if (bs
->exact_filename
[0]) {
4184 /* This may not work for all block protocol drivers (some may
4185 * require this filename to be parsed), but we have to find some
4186 * default solution here, so just include it. If some block driver
4187 * does not support pure options without any filename at all or
4188 * needs some special format of the options QDict, it needs to
4189 * implement the driver-specific bdrv_refresh_filename() function.
4191 qdict_put_obj(opts
, "filename",
4192 QOBJECT(qstring_from_str(bs
->exact_filename
)));
4195 bs
->full_open_options
= opts
;
4198 if (bs
->exact_filename
[0]) {
4199 pstrcpy(bs
->filename
, sizeof(bs
->filename
), bs
->exact_filename
);
4200 } else if (bs
->full_open_options
) {
4201 QString
*json
= qobject_to_json(QOBJECT(bs
->full_open_options
));
4202 snprintf(bs
->filename
, sizeof(bs
->filename
), "json:%s",
4203 qstring_get_str(json
));