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
27 #include "block/accounting.h"
28 #include "block/block.h"
29 #include "block/aio-wait.h"
30 #include "qemu/queue.h"
31 #include "qemu/coroutine.h"
32 #include "qemu/stats64.h"
33 #include "qemu/timer.h"
34 #include "qemu/hbitmap.h"
35 #include "block/snapshot.h"
36 #include "qemu/throttle.h"
38 #define BLOCK_FLAG_LAZY_REFCOUNTS 8
40 #define BLOCK_OPT_SIZE "size"
41 #define BLOCK_OPT_ENCRYPT "encryption"
42 #define BLOCK_OPT_ENCRYPT_FORMAT "encrypt.format"
43 #define BLOCK_OPT_COMPAT6 "compat6"
44 #define BLOCK_OPT_HWVERSION "hwversion"
45 #define BLOCK_OPT_BACKING_FILE "backing_file"
46 #define BLOCK_OPT_BACKING_FMT "backing_fmt"
47 #define BLOCK_OPT_CLUSTER_SIZE "cluster_size"
48 #define BLOCK_OPT_TABLE_SIZE "table_size"
49 #define BLOCK_OPT_PREALLOC "preallocation"
50 #define BLOCK_OPT_SUBFMT "subformat"
51 #define BLOCK_OPT_COMPAT_LEVEL "compat"
52 #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts"
53 #define BLOCK_OPT_ADAPTER_TYPE "adapter_type"
54 #define BLOCK_OPT_REDUNDANCY "redundancy"
55 #define BLOCK_OPT_NOCOW "nocow"
56 #define BLOCK_OPT_OBJECT_SIZE "object_size"
57 #define BLOCK_OPT_REFCOUNT_BITS "refcount_bits"
58 #define BLOCK_OPT_DATA_FILE "data_file"
59 #define BLOCK_OPT_DATA_FILE_RAW "data_file_raw"
61 #define BLOCK_PROBE_BUF_SIZE 512
63 enum BdrvTrackedRequestType
{
67 BDRV_TRACKED_TRUNCATE
,
70 typedef struct BdrvTrackedRequest
{
74 enum BdrvTrackedRequestType type
;
77 int64_t overlap_offset
;
78 uint64_t overlap_bytes
;
80 QLIST_ENTRY(BdrvTrackedRequest
) list
;
81 Coroutine
*co
; /* owner, used for deadlock detection */
82 CoQueue wait_queue
; /* coroutines blocked on this request */
84 struct BdrvTrackedRequest
*waiting_for
;
88 const char *format_name
;
91 /* set to true if the BlockDriver is a block filter. Block filters pass
92 * certain callbacks that refer to data (see block.c) to their bs->file if
93 * the driver doesn't implement them. Drivers that do not wish to forward
94 * must implement them and return -ENOTSUP.
98 * Return true if @to_replace can be replaced by a BDS with the
99 * same data as @bs without it affecting @bs's behavior (that is,
100 * without it being visible to @bs's parents).
102 bool (*bdrv_recurse_can_replace
)(BlockDriverState
*bs
,
103 BlockDriverState
*to_replace
);
105 int (*bdrv_probe
)(const uint8_t *buf
, int buf_size
, const char *filename
);
106 int (*bdrv_probe_device
)(const char *filename
);
108 /* Any driver implementing this callback is expected to be able to handle
109 * NULL file names in its .bdrv_open() implementation */
110 void (*bdrv_parse_filename
)(const char *filename
, QDict
*options
, Error
**errp
);
111 /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
112 * this field set to true, except ones that are defined only by their
114 * An example of the last type will be the quorum block driver.
116 bool bdrv_needs_filename
;
118 /* Set if a driver can support backing files */
119 bool supports_backing
;
121 /* For handling image reopen for split or non-split files */
122 int (*bdrv_reopen_prepare
)(BDRVReopenState
*reopen_state
,
123 BlockReopenQueue
*queue
, Error
**errp
);
124 void (*bdrv_reopen_commit
)(BDRVReopenState
*reopen_state
);
125 void (*bdrv_reopen_commit_post
)(BDRVReopenState
*reopen_state
);
126 void (*bdrv_reopen_abort
)(BDRVReopenState
*reopen_state
);
127 void (*bdrv_join_options
)(QDict
*options
, QDict
*old_options
);
129 int (*bdrv_open
)(BlockDriverState
*bs
, QDict
*options
, int flags
,
132 /* Protocol drivers should implement this instead of bdrv_open */
133 int (*bdrv_file_open
)(BlockDriverState
*bs
, QDict
*options
, int flags
,
135 void (*bdrv_close
)(BlockDriverState
*bs
);
136 int coroutine_fn (*bdrv_co_create
)(BlockdevCreateOptions
*opts
,
138 int coroutine_fn (*bdrv_co_create_opts
)(const char *filename
,
141 int (*bdrv_make_empty
)(BlockDriverState
*bs
);
144 * Refreshes the bs->exact_filename field. If that is impossible,
145 * bs->exact_filename has to be left empty.
147 void (*bdrv_refresh_filename
)(BlockDriverState
*bs
);
150 * Gathers the open options for all children into @target.
151 * A simple format driver (without backing file support) might
152 * implement this function like this:
154 * QINCREF(bs->file->bs->full_open_options);
155 * qdict_put(target, "file", bs->file->bs->full_open_options);
157 * If not specified, the generic implementation will simply put
158 * all children's options under their respective name.
160 * @backing_overridden is true when bs->backing seems not to be
161 * the child that would result from opening bs->backing_file.
162 * Therefore, if it is true, the backing child's options should be
163 * gathered; otherwise, there is no need since the backing child
164 * is the one implied by the image header.
166 * Note that ideally this function would not be needed. Every
167 * block driver which implements it is probably doing something
168 * shady regarding its runtime option structure.
170 void (*bdrv_gather_child_options
)(BlockDriverState
*bs
, QDict
*target
,
171 bool backing_overridden
);
174 * Returns an allocated string which is the directory name of this BDS: It
175 * will be used to make relative filenames absolute by prepending this
176 * function's return value to them.
178 char *(*bdrv_dirname
)(BlockDriverState
*bs
, Error
**errp
);
181 BlockAIOCB
*(*bdrv_aio_preadv
)(BlockDriverState
*bs
,
182 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
,
183 BlockCompletionFunc
*cb
, void *opaque
);
184 BlockAIOCB
*(*bdrv_aio_pwritev
)(BlockDriverState
*bs
,
185 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
,
186 BlockCompletionFunc
*cb
, void *opaque
);
187 BlockAIOCB
*(*bdrv_aio_flush
)(BlockDriverState
*bs
,
188 BlockCompletionFunc
*cb
, void *opaque
);
189 BlockAIOCB
*(*bdrv_aio_pdiscard
)(BlockDriverState
*bs
,
190 int64_t offset
, int bytes
,
191 BlockCompletionFunc
*cb
, void *opaque
);
193 int coroutine_fn (*bdrv_co_readv
)(BlockDriverState
*bs
,
194 int64_t sector_num
, int nb_sectors
, QEMUIOVector
*qiov
);
197 * @offset: position in bytes to read at
198 * @bytes: number of bytes to read
199 * @qiov: the buffers to fill with read data
200 * @flags: currently unused, always 0
202 * @offset and @bytes will be a multiple of 'request_alignment',
203 * but the length of individual @qiov elements does not have to
206 * @bytes will always equal the total size of @qiov, and will be
207 * no larger than 'max_transfer'.
209 * The buffer in @qiov may point directly to guest memory.
211 int coroutine_fn (*bdrv_co_preadv
)(BlockDriverState
*bs
,
212 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
);
213 int coroutine_fn (*bdrv_co_preadv_part
)(BlockDriverState
*bs
,
214 uint64_t offset
, uint64_t bytes
,
215 QEMUIOVector
*qiov
, size_t qiov_offset
, int flags
);
216 int coroutine_fn (*bdrv_co_writev
)(BlockDriverState
*bs
,
217 int64_t sector_num
, int nb_sectors
, QEMUIOVector
*qiov
, int flags
);
219 * @offset: position in bytes to write at
220 * @bytes: number of bytes to write
221 * @qiov: the buffers containing data to write
222 * @flags: zero or more bits allowed by 'supported_write_flags'
224 * @offset and @bytes will be a multiple of 'request_alignment',
225 * but the length of individual @qiov elements does not have to
228 * @bytes will always equal the total size of @qiov, and will be
229 * no larger than 'max_transfer'.
231 * The buffer in @qiov may point directly to guest memory.
233 int coroutine_fn (*bdrv_co_pwritev
)(BlockDriverState
*bs
,
234 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
);
235 int coroutine_fn (*bdrv_co_pwritev_part
)(BlockDriverState
*bs
,
236 uint64_t offset
, uint64_t bytes
,
237 QEMUIOVector
*qiov
, size_t qiov_offset
, int flags
);
240 * Efficiently zero a region of the disk image. Typically an image format
241 * would use a compact metadata representation to implement this. This
242 * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
243 * will be called instead.
245 int coroutine_fn (*bdrv_co_pwrite_zeroes
)(BlockDriverState
*bs
,
246 int64_t offset
, int bytes
, BdrvRequestFlags flags
);
247 int coroutine_fn (*bdrv_co_pdiscard
)(BlockDriverState
*bs
,
248 int64_t offset
, int bytes
);
250 /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
251 * and invoke bdrv_co_copy_range_from(child, ...), or invoke
252 * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
254 * See the comment of bdrv_co_copy_range for the parameter and return value
257 int coroutine_fn (*bdrv_co_copy_range_from
)(BlockDriverState
*bs
,
263 BdrvRequestFlags read_flags
,
264 BdrvRequestFlags write_flags
);
266 /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
267 * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
268 * operation if @bs is the leaf and @src has the same BlockDriver. Return
269 * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
271 * See the comment of bdrv_co_copy_range for the parameter and return value
274 int coroutine_fn (*bdrv_co_copy_range_to
)(BlockDriverState
*bs
,
280 BdrvRequestFlags read_flags
,
281 BdrvRequestFlags write_flags
);
284 * Building block for bdrv_block_status[_above] and
285 * bdrv_is_allocated[_above]. The driver should answer only
286 * according to the current layer, and should only need to set
287 * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
288 * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
289 * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See
290 * block.h for the overall meaning of the bits. As a hint, the
291 * flag want_zero is true if the caller cares more about precise
292 * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
293 * overall allocation (favor larger *pnum, perhaps by reporting
294 * _DATA instead of _ZERO). The block layer guarantees input
295 * clamped to bdrv_getlength() and aligned to request_alignment,
296 * as well as non-NULL pnum, map, and file; in turn, the driver
297 * must return an error or set pnum to an aligned non-zero value.
299 int coroutine_fn (*bdrv_co_block_status
)(BlockDriverState
*bs
,
300 bool want_zero
, int64_t offset
, int64_t bytes
, int64_t *pnum
,
301 int64_t *map
, BlockDriverState
**file
);
304 * Invalidate any cached meta-data.
306 void coroutine_fn (*bdrv_co_invalidate_cache
)(BlockDriverState
*bs
,
308 int (*bdrv_inactivate
)(BlockDriverState
*bs
);
311 * Flushes all data for all layers by calling bdrv_co_flush for underlying
312 * layers, if needed. This function is needed for deterministic
313 * synchronization of the flush finishing callback.
315 int coroutine_fn (*bdrv_co_flush
)(BlockDriverState
*bs
);
317 /* Delete a created file. */
318 int coroutine_fn (*bdrv_co_delete_file
)(BlockDriverState
*bs
,
322 * Flushes all data that was already written to the OS all the way down to
323 * the disk (for example file-posix.c calls fsync()).
325 int coroutine_fn (*bdrv_co_flush_to_disk
)(BlockDriverState
*bs
);
328 * Flushes all internal caches to the OS. The data may still sit in a
329 * writeback cache of the host OS, but it will survive a crash of the qemu
332 int coroutine_fn (*bdrv_co_flush_to_os
)(BlockDriverState
*bs
);
335 * Drivers setting this field must be able to work with just a plain
336 * filename with '<protocol_name>:' as a prefix, and no other options.
337 * Options may be extracted from the filename by implementing
338 * bdrv_parse_filename.
340 const char *protocol_name
;
343 * Truncate @bs to @offset bytes using the given @prealloc mode
344 * when growing. Modes other than PREALLOC_MODE_OFF should be
345 * rejected when shrinking @bs.
347 * If @exact is true, @bs must be resized to exactly @offset.
348 * Otherwise, it is sufficient for @bs (if it is a host block
349 * device and thus there is no way to resize it) to be at least
350 * @offset bytes in length.
352 * If @exact is true and this function fails but would succeed
353 * with @exact = false, it should return -ENOTSUP.
355 int coroutine_fn (*bdrv_co_truncate
)(BlockDriverState
*bs
, int64_t offset
,
356 bool exact
, PreallocMode prealloc
,
359 int64_t (*bdrv_getlength
)(BlockDriverState
*bs
);
360 bool has_variable_length
;
361 int64_t (*bdrv_get_allocated_file_size
)(BlockDriverState
*bs
);
362 BlockMeasureInfo
*(*bdrv_measure
)(QemuOpts
*opts
, BlockDriverState
*in_bs
,
365 int coroutine_fn (*bdrv_co_pwritev_compressed
)(BlockDriverState
*bs
,
366 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
);
367 int coroutine_fn (*bdrv_co_pwritev_compressed_part
)(BlockDriverState
*bs
,
368 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
,
371 int (*bdrv_snapshot_create
)(BlockDriverState
*bs
,
372 QEMUSnapshotInfo
*sn_info
);
373 int (*bdrv_snapshot_goto
)(BlockDriverState
*bs
,
374 const char *snapshot_id
);
375 int (*bdrv_snapshot_delete
)(BlockDriverState
*bs
,
376 const char *snapshot_id
,
379 int (*bdrv_snapshot_list
)(BlockDriverState
*bs
,
380 QEMUSnapshotInfo
**psn_info
);
381 int (*bdrv_snapshot_load_tmp
)(BlockDriverState
*bs
,
382 const char *snapshot_id
,
385 int (*bdrv_get_info
)(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
386 ImageInfoSpecific
*(*bdrv_get_specific_info
)(BlockDriverState
*bs
,
388 BlockStatsSpecific
*(*bdrv_get_specific_stats
)(BlockDriverState
*bs
);
390 int coroutine_fn (*bdrv_save_vmstate
)(BlockDriverState
*bs
,
393 int coroutine_fn (*bdrv_load_vmstate
)(BlockDriverState
*bs
,
397 int (*bdrv_change_backing_file
)(BlockDriverState
*bs
,
398 const char *backing_file
, const char *backing_fmt
);
400 /* removable device specific */
401 bool (*bdrv_is_inserted
)(BlockDriverState
*bs
);
402 void (*bdrv_eject
)(BlockDriverState
*bs
, bool eject_flag
);
403 void (*bdrv_lock_medium
)(BlockDriverState
*bs
, bool locked
);
405 /* to control generic scsi devices */
406 BlockAIOCB
*(*bdrv_aio_ioctl
)(BlockDriverState
*bs
,
407 unsigned long int req
, void *buf
,
408 BlockCompletionFunc
*cb
, void *opaque
);
409 int coroutine_fn (*bdrv_co_ioctl
)(BlockDriverState
*bs
,
410 unsigned long int req
, void *buf
);
412 /* List of options for creating images, terminated by name == NULL */
413 QemuOptsList
*create_opts
;
415 * If this driver supports reopening images this contains a
416 * NULL-terminated list of the runtime options that can be
417 * modified. If an option in this list is unspecified during
418 * reopen then it _must_ be reset to its default value or return
421 const char *const *mutable_opts
;
424 * Returns 0 for completed check, -errno for internal errors.
425 * The check results are stored in result.
427 int coroutine_fn (*bdrv_co_check
)(BlockDriverState
*bs
,
428 BdrvCheckResult
*result
,
431 int (*bdrv_amend_options
)(BlockDriverState
*bs
, QemuOpts
*opts
,
432 BlockDriverAmendStatusCB
*status_cb
,
436 void (*bdrv_debug_event
)(BlockDriverState
*bs
, BlkdebugEvent event
);
438 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
439 int (*bdrv_debug_breakpoint
)(BlockDriverState
*bs
, const char *event
,
441 int (*bdrv_debug_remove_breakpoint
)(BlockDriverState
*bs
,
443 int (*bdrv_debug_resume
)(BlockDriverState
*bs
, const char *tag
);
444 bool (*bdrv_debug_is_suspended
)(BlockDriverState
*bs
, const char *tag
);
446 void (*bdrv_refresh_limits
)(BlockDriverState
*bs
, Error
**errp
);
449 * Returns 1 if newly created images are guaranteed to contain only
450 * zeros, 0 otherwise.
451 * Must return 0 if .bdrv_has_zero_init_truncate() returns 0.
453 int (*bdrv_has_zero_init
)(BlockDriverState
*bs
);
456 * Returns 1 if new areas added by growing the image with
457 * PREALLOC_MODE_OFF contain only zeros, 0 otherwise.
459 int (*bdrv_has_zero_init_truncate
)(BlockDriverState
*bs
);
461 /* Remove fd handlers, timers, and other event loop callbacks so the event
462 * loop is no longer in use. Called with no in-flight requests and in
463 * depth-first traversal order with parents before child nodes.
465 void (*bdrv_detach_aio_context
)(BlockDriverState
*bs
);
467 /* Add fd handlers, timers, and other event loop callbacks so I/O requests
468 * can be processed again. Called with no in-flight requests and in
469 * depth-first traversal order with child nodes before parent nodes.
471 void (*bdrv_attach_aio_context
)(BlockDriverState
*bs
,
472 AioContext
*new_context
);
474 /* io queue for linux-aio */
475 void (*bdrv_io_plug
)(BlockDriverState
*bs
);
476 void (*bdrv_io_unplug
)(BlockDriverState
*bs
);
479 * Try to get @bs's logical and physical block size.
480 * On success, store them in @bsz and return zero.
481 * On failure, return negative errno.
483 int (*bdrv_probe_blocksizes
)(BlockDriverState
*bs
, BlockSizes
*bsz
);
485 * Try to get @bs's geometry (cyls, heads, sectors)
486 * On success, store them in @geo and return 0.
487 * On failure return -errno.
488 * Only drivers that want to override guest geometry implement this
489 * callback; see hd_geometry_guess().
491 int (*bdrv_probe_geometry
)(BlockDriverState
*bs
, HDGeometry
*geo
);
494 * bdrv_co_drain_begin is called if implemented in the beginning of a
495 * drain operation to drain and stop any internal sources of requests in
497 * bdrv_co_drain_end is called if implemented at the end of the drain.
499 * They should be used by the driver to e.g. manage scheduled I/O
500 * requests, or toggle an internal state. After the end of the drain new
501 * requests will continue normally.
503 void coroutine_fn (*bdrv_co_drain_begin
)(BlockDriverState
*bs
);
504 void coroutine_fn (*bdrv_co_drain_end
)(BlockDriverState
*bs
);
506 void (*bdrv_add_child
)(BlockDriverState
*parent
, BlockDriverState
*child
,
508 void (*bdrv_del_child
)(BlockDriverState
*parent
, BdrvChild
*child
,
512 * Informs the block driver that a permission change is intended. The
513 * driver checks whether the change is permissible and may take other
514 * preparations for the change (e.g. get file system locks). This operation
515 * is always followed either by a call to either .bdrv_set_perm or
516 * .bdrv_abort_perm_update.
518 * Checks whether the requested set of cumulative permissions in @perm
519 * can be granted for accessing @bs and whether no other users are using
520 * permissions other than those given in @shared (both arguments take
521 * BLK_PERM_* bitmasks).
523 * If both conditions are met, 0 is returned. Otherwise, -errno is returned
524 * and errp is set to an error describing the conflict.
526 int (*bdrv_check_perm
)(BlockDriverState
*bs
, uint64_t perm
,
527 uint64_t shared
, Error
**errp
);
530 * Called to inform the driver that the set of cumulative set of used
531 * permissions for @bs has changed to @perm, and the set of sharable
532 * permission to @shared. The driver can use this to propagate changes to
533 * its children (i.e. request permissions only if a parent actually needs
536 * This function is only invoked after bdrv_check_perm(), so block drivers
537 * may rely on preparations made in their .bdrv_check_perm implementation.
539 void (*bdrv_set_perm
)(BlockDriverState
*bs
, uint64_t perm
, uint64_t shared
);
542 * Called to inform the driver that after a previous bdrv_check_perm()
543 * call, the permission update is not performed and any preparations made
544 * for it (e.g. taken file locks) need to be undone.
546 * This function can be called even for nodes that never saw a
547 * bdrv_check_perm() call. It is a no-op then.
549 void (*bdrv_abort_perm_update
)(BlockDriverState
*bs
);
552 * Returns in @nperm and @nshared the permissions that the driver for @bs
553 * needs on its child @c, based on the cumulative permissions requested by
554 * the parents in @parent_perm and @parent_shared.
556 * If @c is NULL, return the permissions for attaching a new child for the
559 * If @reopen_queue is non-NULL, don't return the currently needed
560 * permissions, but those that will be needed after applying the
563 void (*bdrv_child_perm
)(BlockDriverState
*bs
, BdrvChild
*c
,
564 const BdrvChildRole
*role
,
565 BlockReopenQueue
*reopen_queue
,
566 uint64_t parent_perm
, uint64_t parent_shared
,
567 uint64_t *nperm
, uint64_t *nshared
);
569 bool (*bdrv_co_can_store_new_dirty_bitmap
)(BlockDriverState
*bs
,
571 uint32_t granularity
,
573 int (*bdrv_co_remove_persistent_dirty_bitmap
)(BlockDriverState
*bs
,
578 * Register/unregister a buffer for I/O. For example, when the driver is
579 * interested to know the memory areas that will later be used in iovs, so
580 * that it can do IOMMU mapping with VFIO etc., in order to get better
581 * performance. In the case of VFIO drivers, this callback is used to do
582 * DMA mapping for hot buffers.
584 void (*bdrv_register_buf
)(BlockDriverState
*bs
, void *host
, size_t size
);
585 void (*bdrv_unregister_buf
)(BlockDriverState
*bs
, void *host
);
586 QLIST_ENTRY(BlockDriver
) list
;
588 /* Pointer to a NULL-terminated array of names of strong options
589 * that can be specified for bdrv_open(). A strong option is one
590 * that changes the data of a BDS.
591 * If this pointer is NULL, the array is considered empty.
592 * "filename" and "driver" are always considered strong. */
593 const char *const *strong_runtime_opts
;
596 static inline bool block_driver_can_compress(BlockDriver
*drv
)
598 return drv
->bdrv_co_pwritev_compressed
||
599 drv
->bdrv_co_pwritev_compressed_part
;
602 typedef struct BlockLimits
{
603 /* Alignment requirement, in bytes, for offset/length of I/O
604 * requests. Must be a power of 2 less than INT_MAX; defaults to
605 * 1 for drivers with modern byte interfaces, and to 512
607 uint32_t request_alignment
;
609 /* Maximum number of bytes that can be discarded at once (since it
610 * is signed, it must be < 2G, if set). Must be multiple of
611 * pdiscard_alignment, but need not be power of 2. May be 0 if no
612 * inherent 32-bit limit */
613 int32_t max_pdiscard
;
615 /* Optimal alignment for discard requests in bytes. A power of 2
616 * is best but not mandatory. Must be a multiple of
617 * bl.request_alignment, and must be less than max_pdiscard if
618 * that is set. May be 0 if bl.request_alignment is good enough */
619 uint32_t pdiscard_alignment
;
621 /* Maximum number of bytes that can zeroized at once (since it is
622 * signed, it must be < 2G, if set). Must be multiple of
623 * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
624 int32_t max_pwrite_zeroes
;
626 /* Optimal alignment for write zeroes requests in bytes. A power
627 * of 2 is best but not mandatory. Must be a multiple of
628 * bl.request_alignment, and must be less than max_pwrite_zeroes
629 * if that is set. May be 0 if bl.request_alignment is good
631 uint32_t pwrite_zeroes_alignment
;
633 /* Optimal transfer length in bytes. A power of 2 is best but not
634 * mandatory. Must be a multiple of bl.request_alignment, or 0 if
635 * no preferred size */
636 uint32_t opt_transfer
;
638 /* Maximal transfer length in bytes. Need not be power of 2, but
639 * must be multiple of opt_transfer and bl.request_alignment, or 0
640 * for no 32-bit limit. For now, anything larger than INT_MAX is
642 uint32_t max_transfer
;
644 /* memory alignment, in bytes so that no bounce buffer is needed */
645 size_t min_mem_alignment
;
647 /* memory alignment, in bytes, for bounce buffer */
648 size_t opt_mem_alignment
;
650 /* maximum number of iovec elements */
654 typedef struct BdrvOpBlocker BdrvOpBlocker
;
656 typedef struct BdrvAioNotifier
{
657 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
);
658 void (*detach_aio_context
)(void *opaque
);
663 QLIST_ENTRY(BdrvAioNotifier
) list
;
666 struct BdrvChildRole
{
667 /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
671 /* If true, the parent is a BlockDriverState and bdrv_next_all_states()
672 * will return it. This information is used for drain_all, where every node
673 * will be drained separately, so the drain only needs to be propagated to
674 * non-BDS parents. */
677 void (*inherit_options
)(int *child_flags
, QDict
*child_options
,
678 int parent_flags
, QDict
*parent_options
);
680 void (*change_media
)(BdrvChild
*child
, bool load
);
681 void (*resize
)(BdrvChild
*child
);
683 /* Returns a name that is supposedly more useful for human users than the
684 * node name for identifying the node in question (in particular, a BB
685 * name), or NULL if the parent can't provide a better name. */
686 const char *(*get_name
)(BdrvChild
*child
);
688 /* Returns a malloced string that describes the parent of the child for a
689 * human reader. This could be a node-name, BlockBackend name, qdev ID or
690 * QOM path of the device owning the BlockBackend, job type and ID etc. The
691 * caller is responsible for freeing the memory. */
692 char *(*get_parent_desc
)(BdrvChild
*child
);
695 * If this pair of functions is implemented, the parent doesn't issue new
696 * requests after returning from .drained_begin() until .drained_end() is
699 * These functions must not change the graph (and therefore also must not
700 * call aio_poll(), which could change the graph indirectly).
702 * If drained_end() schedules background operations, it must atomically
703 * increment *drained_end_counter for each such operation and atomically
704 * decrement it once the operation has settled.
706 * Note that this can be nested. If drained_begin() was called twice, new
707 * I/O is allowed only after drained_end() was called twice, too.
709 void (*drained_begin
)(BdrvChild
*child
);
710 void (*drained_end
)(BdrvChild
*child
, int *drained_end_counter
);
713 * Returns whether the parent has pending requests for the child. This
714 * callback is polled after .drained_begin() has been called until all
715 * activity on the child has stopped.
717 bool (*drained_poll
)(BdrvChild
*child
);
719 /* Notifies the parent that the child has been activated/inactivated (e.g.
720 * when migration is completing) and it can start/stop requesting
721 * permissions and doing I/O on it. */
722 void (*activate
)(BdrvChild
*child
, Error
**errp
);
723 int (*inactivate
)(BdrvChild
*child
);
725 void (*attach
)(BdrvChild
*child
);
726 void (*detach
)(BdrvChild
*child
);
728 /* Notifies the parent that the filename of its child has changed (e.g.
729 * because the direct child was removed from the backing chain), so that it
730 * can update its reference. */
731 int (*update_filename
)(BdrvChild
*child
, BlockDriverState
*new_base
,
732 const char *filename
, Error
**errp
);
734 bool (*can_set_aio_ctx
)(BdrvChild
*child
, AioContext
*ctx
,
735 GSList
**ignore
, Error
**errp
);
736 void (*set_aio_ctx
)(BdrvChild
*child
, AioContext
*ctx
, GSList
**ignore
);
739 extern const BdrvChildRole child_file
;
740 extern const BdrvChildRole child_format
;
741 extern const BdrvChildRole child_backing
;
744 BlockDriverState
*bs
;
746 const BdrvChildRole
*role
;
750 * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
755 * Permissions that can still be granted to other users of @bs while this
756 * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
758 uint64_t shared_perm
;
760 /* backup of permissions during permission update procedure */
761 bool has_backup_perm
;
762 uint64_t backup_perm
;
763 uint64_t backup_shared_perm
;
766 * This link is frozen: the child can neither be replaced nor
767 * detached from the parent.
772 * How many times the parent of this child has been drained
773 * (through role->drained_*).
774 * Usually, this is equal to bs->quiesce_counter (potentially
775 * reduced by bdrv_drain_all_count). It may differ while the
776 * child is entering or leaving a drained section.
778 int parent_quiesce_counter
;
780 QLIST_ENTRY(BdrvChild
) next
;
781 QLIST_ENTRY(BdrvChild
) next_parent
;
785 * Note: the function bdrv_append() copies and swaps contents of
786 * BlockDriverStates, so if you add new fields to this struct, please
787 * inspect bdrv_append() to determine if the new fields need to be
790 struct BlockDriverState
{
791 /* Protected by big QEMU lock or read-only after opening. No special
792 * locking needed during I/O...
794 int open_flags
; /* flags used to open the file, re-used for re-open */
795 bool read_only
; /* if true, the media is read only */
796 bool encrypted
; /* if true, the media is encrypted */
797 bool sg
; /* if true, the device is a /dev/sg* */
798 bool probed
; /* if true, format was probed rather than specified */
799 bool force_share
; /* if true, always allow all shared permissions */
800 bool implicit
; /* if true, this filter node was automatically inserted */
802 BlockDriver
*drv
; /* NULL means no media */
805 AioContext
*aio_context
; /* event loop used for fd handlers, timers, etc */
806 /* long-running tasks intended to always use the same AioContext as this
807 * BDS may register themselves in this list to be notified of changes
808 * regarding this BDS's context */
809 QLIST_HEAD(, BdrvAioNotifier
) aio_notifiers
;
810 bool walking_aio_notifiers
; /* to make removal during iteration safe */
812 char filename
[PATH_MAX
];
813 char backing_file
[PATH_MAX
]; /* if non zero, the image is a diff of
815 /* The backing filename indicated by the image header; if we ever
816 * open this file, then this is replaced by the resulting BDS's
817 * filename (i.e. after a bdrv_refresh_filename() run). */
818 char auto_backing_file
[PATH_MAX
];
819 char backing_format
[16]; /* if non-zero and backing_file exists */
821 QDict
*full_open_options
;
822 char exact_filename
[PATH_MAX
];
830 /* Flags honored during pwrite (so far: BDRV_REQ_FUA,
831 * BDRV_REQ_WRITE_UNCHANGED).
832 * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
833 * writes will be issued as normal writes without the flag set.
834 * This is important to note for drivers that do not explicitly
835 * request a WRITE permission for their children and instead take
836 * the same permissions as their parent did (this is commonly what
837 * block filters do). Such drivers have to be aware that the
838 * parent may have taken a WRITE_UNCHANGED permission only and is
839 * issuing such requests. Drivers either must make sure that
840 * these requests do not result in plain WRITE accesses (usually
841 * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
842 * every incoming write request as-is, including potentially that
843 * flag), or they have to explicitly take the WRITE permission for
845 unsigned int supported_write_flags
;
846 /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
847 * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */
848 unsigned int supported_zero_flags
;
850 /* the following member gives a name to every node on the bs graph. */
852 /* element of the list of named nodes building the graph */
853 QTAILQ_ENTRY(BlockDriverState
) node_list
;
854 /* element of the list of all BlockDriverStates (all_bdrv_states) */
855 QTAILQ_ENTRY(BlockDriverState
) bs_list
;
856 /* element of the list of monitor-owned BDS */
857 QTAILQ_ENTRY(BlockDriverState
) monitor_list
;
860 /* operation blockers */
861 QLIST_HEAD(, BdrvOpBlocker
) op_blockers
[BLOCK_OP_TYPE_MAX
];
863 /* The node that this node inherited default options from (and a reopen on
864 * which can affect this node by changing these defaults). This is always a
865 * parent node of this node. */
866 BlockDriverState
*inherits_from
;
867 QLIST_HEAD(, BdrvChild
) children
;
868 QLIST_HEAD(, BdrvChild
) parents
;
871 QDict
*explicit_options
;
872 BlockdevDetectZeroesOptions detect_zeroes
;
874 /* The error object in use for blocking operations on backing_hd */
875 Error
*backing_blocker
;
877 /* Protected by AioContext lock */
879 /* If we are reading a disk image, give its size in sectors.
880 * Generally read-only; it is written to by load_snapshot and
881 * save_snaphost, but the block layer is quiescent during those.
883 int64_t total_sectors
;
885 /* Callback before write request is processed */
886 NotifierWithReturnList before_write_notifiers
;
888 /* threshold limit for writes, in bytes. "High water mark". */
889 uint64_t write_threshold_offset
;
890 NotifierWithReturn write_threshold_notifier
;
892 /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
893 * Reading from the list can be done with either the BQL or the
894 * dirty_bitmap_mutex. Modifying a bitmap only requires
895 * dirty_bitmap_mutex. */
896 QemuMutex dirty_bitmap_mutex
;
897 QLIST_HEAD(, BdrvDirtyBitmap
) dirty_bitmaps
;
899 /* Offset after the highest byte written to */
900 Stat64 wr_highest_offset
;
902 /* If true, copy read backing sectors into image. Can be >1 if more
903 * than one client has requested copy-on-read. Accessed with atomic
908 /* number of in-flight requests; overall and serialising.
909 * Accessed with atomic ops.
911 unsigned int in_flight
;
912 unsigned int serialising_in_flight
;
914 /* counter for nested bdrv_io_plug.
915 * Accessed with atomic ops.
919 /* do we need to tell the quest if we have a volatile write cache? */
920 int enable_write_cache
;
922 /* Accessed with atomic ops. */
924 int recursive_quiesce_counter
;
926 unsigned int write_gen
; /* Current data generation */
928 /* Protected by reqs_lock. */
930 QLIST_HEAD(, BdrvTrackedRequest
) tracked_requests
;
931 CoQueue flush_queue
; /* Serializing flush queue */
932 bool active_flush_req
; /* Flush request in flight? */
934 /* Only read/written by whoever has set active_flush_req to true. */
935 unsigned int flushed_gen
; /* Flushed write generation */
937 /* BdrvChild links to this node may never be frozen */
941 struct BlockBackendRootState
{
944 BlockdevDetectZeroesOptions detect_zeroes
;
947 typedef enum BlockMirrorBackingMode
{
948 /* Reuse the existing backing chain from the source for the target.
949 * - sync=full: Set backing BDS to NULL.
950 * - sync=top: Use source's backing BDS.
951 * - sync=none: Use source as the backing BDS. */
952 MIRROR_SOURCE_BACKING_CHAIN
,
954 /* Open the target's backing chain completely anew */
955 MIRROR_OPEN_BACKING_CHAIN
,
957 /* Do not change the target's backing BDS after job completion */
958 MIRROR_LEAVE_BACKING_CHAIN
,
959 } BlockMirrorBackingMode
;
961 static inline BlockDriverState
*backing_bs(BlockDriverState
*bs
)
963 return bs
->backing
? bs
->backing
->bs
: NULL
;
967 /* Essential block drivers which must always be statically linked into qemu, and
968 * which therefore can be accessed without using bdrv_find_format() */
969 extern BlockDriver bdrv_file
;
970 extern BlockDriver bdrv_raw
;
971 extern BlockDriver bdrv_qcow2
;
973 int coroutine_fn
bdrv_co_preadv(BdrvChild
*child
,
974 int64_t offset
, unsigned int bytes
, QEMUIOVector
*qiov
,
975 BdrvRequestFlags flags
);
976 int coroutine_fn
bdrv_co_preadv_part(BdrvChild
*child
,
977 int64_t offset
, unsigned int bytes
,
978 QEMUIOVector
*qiov
, size_t qiov_offset
, BdrvRequestFlags flags
);
979 int coroutine_fn
bdrv_co_pwritev(BdrvChild
*child
,
980 int64_t offset
, unsigned int bytes
, QEMUIOVector
*qiov
,
981 BdrvRequestFlags flags
);
982 int coroutine_fn
bdrv_co_pwritev_part(BdrvChild
*child
,
983 int64_t offset
, unsigned int bytes
,
984 QEMUIOVector
*qiov
, size_t qiov_offset
, BdrvRequestFlags flags
);
986 static inline int coroutine_fn
bdrv_co_pread(BdrvChild
*child
,
987 int64_t offset
, unsigned int bytes
, void *buf
, BdrvRequestFlags flags
)
989 QEMUIOVector qiov
= QEMU_IOVEC_INIT_BUF(qiov
, buf
, bytes
);
991 return bdrv_co_preadv(child
, offset
, bytes
, &qiov
, flags
);
994 static inline int coroutine_fn
bdrv_co_pwrite(BdrvChild
*child
,
995 int64_t offset
, unsigned int bytes
, void *buf
, BdrvRequestFlags flags
)
997 QEMUIOVector qiov
= QEMU_IOVEC_INIT_BUF(qiov
, buf
, bytes
);
999 return bdrv_co_pwritev(child
, offset
, bytes
, &qiov
, flags
);
1002 extern unsigned int bdrv_drain_all_count
;
1003 void bdrv_apply_subtree_drain(BdrvChild
*child
, BlockDriverState
*new_parent
);
1004 void bdrv_unapply_subtree_drain(BdrvChild
*child
, BlockDriverState
*old_parent
);
1006 bool coroutine_fn
bdrv_mark_request_serialising(BdrvTrackedRequest
*req
, uint64_t align
);
1007 BdrvTrackedRequest
*coroutine_fn
bdrv_co_get_self_request(BlockDriverState
*bs
);
1009 int get_tmp_filename(char *filename
, int size
);
1010 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
1011 const char *filename
);
1013 void bdrv_parse_filename_strip_prefix(const char *filename
, const char *prefix
,
1018 * bdrv_add_before_write_notifier:
1020 * Register a callback that is invoked before write requests are processed but
1021 * after any throttling or waiting for overlapping requests.
1023 void bdrv_add_before_write_notifier(BlockDriverState
*bs
,
1024 NotifierWithReturn
*notifier
);
1027 * bdrv_add_aio_context_notifier:
1029 * If a long-running job intends to be always run in the same AioContext as a
1030 * certain BDS, it may use this function to be notified of changes regarding the
1031 * association of the BDS to an AioContext.
1033 * attached_aio_context() is called after the target BDS has been attached to a
1034 * new AioContext; detach_aio_context() is called before the target BDS is being
1035 * detached from its old AioContext.
1037 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
1038 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
1039 void (*detach_aio_context
)(void *opaque
), void *opaque
);
1042 * bdrv_remove_aio_context_notifier:
1044 * Unsubscribe of change notifications regarding the BDS's AioContext. The
1045 * parameters given here have to be the same as those given to
1046 * bdrv_add_aio_context_notifier().
1048 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
1049 void (*aio_context_attached
)(AioContext
*,
1051 void (*aio_context_detached
)(void *),
1056 * @bs: The BlockDriverState for which an I/O operation has been completed.
1058 * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During
1059 * synchronous I/O on a BlockDriverState that is attached to another
1060 * I/O thread, the main thread lets the I/O thread's event loop run,
1061 * waiting for the I/O operation to complete. A bdrv_wakeup will wake
1062 * up the main thread if necessary.
1064 * Manual calls to bdrv_wakeup are rarely necessary, because
1065 * bdrv_dec_in_flight already calls it.
1067 void bdrv_wakeup(BlockDriverState
*bs
);
1070 int is_windows_drive(const char *filename
);
1075 * @job_id: The id of the newly-created job, or %NULL to use the
1076 * device name of @bs.
1077 * @bs: Block device to operate on.
1078 * @base: Block device that will become the new base, or %NULL to
1079 * flatten the whole backing file chain onto @bs.
1080 * @backing_file_str: The file name that will be written to @bs as the
1081 * the new backing file if the job completes. Ignored if @base is %NULL.
1082 * @creation_flags: Flags that control the behavior of the Job lifetime.
1083 * See @BlockJobCreateFlags
1084 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1085 * @on_error: The action to take upon error.
1086 * @errp: Error object.
1088 * Start a streaming operation on @bs. Clusters that are unallocated
1089 * in @bs, but allocated in any image between @base and @bs (both
1090 * exclusive) will be written to @bs. At the end of a successful
1091 * streaming job, the backing file of @bs will be changed to
1092 * @backing_file_str in the written image and to @base in the live
1095 void stream_start(const char *job_id
, BlockDriverState
*bs
,
1096 BlockDriverState
*base
, const char *backing_file_str
,
1097 int creation_flags
, int64_t speed
,
1098 BlockdevOnError on_error
, Error
**errp
);
1102 * @job_id: The id of the newly-created job, or %NULL to use the
1103 * device name of @bs.
1104 * @bs: Active block device.
1105 * @top: Top block device to be committed.
1106 * @base: Block device that will be written into, and become the new top.
1107 * @creation_flags: Flags that control the behavior of the Job lifetime.
1108 * See @BlockJobCreateFlags
1109 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1110 * @on_error: The action to take upon error.
1111 * @backing_file_str: String to use as the backing file in @top's overlay
1112 * @filter_node_name: The node name that should be assigned to the filter
1113 * driver that the commit job inserts into the graph above @top. NULL means
1114 * that a node name should be autogenerated.
1115 * @errp: Error object.
1118 void commit_start(const char *job_id
, BlockDriverState
*bs
,
1119 BlockDriverState
*base
, BlockDriverState
*top
,
1120 int creation_flags
, int64_t speed
,
1121 BlockdevOnError on_error
, const char *backing_file_str
,
1122 const char *filter_node_name
, Error
**errp
);
1124 * commit_active_start:
1125 * @job_id: The id of the newly-created job, or %NULL to use the
1126 * device name of @bs.
1127 * @bs: Active block device to be committed.
1128 * @base: Block device that will be written into, and become the new top.
1129 * @creation_flags: Flags that control the behavior of the Job lifetime.
1130 * See @BlockJobCreateFlags
1131 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1132 * @on_error: The action to take upon error.
1133 * @filter_node_name: The node name that should be assigned to the filter
1134 * driver that the commit job inserts into the graph above @bs. NULL means that
1135 * a node name should be autogenerated.
1136 * @cb: Completion function for the job.
1137 * @opaque: Opaque pointer value passed to @cb.
1138 * @auto_complete: Auto complete the job.
1139 * @errp: Error object.
1142 BlockJob
*commit_active_start(const char *job_id
, BlockDriverState
*bs
,
1143 BlockDriverState
*base
, int creation_flags
,
1144 int64_t speed
, BlockdevOnError on_error
,
1145 const char *filter_node_name
,
1146 BlockCompletionFunc
*cb
, void *opaque
,
1147 bool auto_complete
, Error
**errp
);
1150 * @job_id: The id of the newly-created job, or %NULL to use the
1151 * device name of @bs.
1152 * @bs: Block device to operate on.
1153 * @target: Block device to write to.
1154 * @replaces: Block graph node name to replace once the mirror is done. Can
1155 * only be used when full mirroring is selected.
1156 * @creation_flags: Flags that control the behavior of the Job lifetime.
1157 * See @BlockJobCreateFlags
1158 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1159 * @granularity: The chosen granularity for the dirty bitmap.
1160 * @buf_size: The amount of data that can be in flight at one time.
1161 * @mode: Whether to collapse all images in the chain to the target.
1162 * @backing_mode: How to establish the target's backing chain after completion.
1163 * @zero_target: Whether the target should be explicitly zero-initialized
1164 * @on_source_error: The action to take upon error reading from the source.
1165 * @on_target_error: The action to take upon error writing to the target.
1166 * @unmap: Whether to unmap target where source sectors only contain zeroes.
1167 * @filter_node_name: The node name that should be assigned to the filter
1168 * driver that the mirror job inserts into the graph above @bs. NULL means that
1169 * a node name should be autogenerated.
1170 * @copy_mode: When to trigger writes to the target.
1171 * @errp: Error object.
1173 * Start a mirroring operation on @bs. Clusters that are allocated
1174 * in @bs will be written to @target until the job is cancelled or
1175 * manually completed. At the end of a successful mirroring job,
1176 * @bs will be switched to read from @target.
1178 void mirror_start(const char *job_id
, BlockDriverState
*bs
,
1179 BlockDriverState
*target
, const char *replaces
,
1180 int creation_flags
, int64_t speed
,
1181 uint32_t granularity
, int64_t buf_size
,
1182 MirrorSyncMode mode
, BlockMirrorBackingMode backing_mode
,
1184 BlockdevOnError on_source_error
,
1185 BlockdevOnError on_target_error
,
1186 bool unmap
, const char *filter_node_name
,
1187 MirrorCopyMode copy_mode
, Error
**errp
);
1190 * backup_job_create:
1191 * @job_id: The id of the newly-created job, or %NULL to use the
1192 * device name of @bs.
1193 * @bs: Block device to operate on.
1194 * @target: Block device to write to.
1195 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1196 * @sync_mode: What parts of the disk image should be copied to the destination.
1197 * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental'
1198 * @bitmap_mode: The bitmap synchronization policy to use.
1199 * @on_source_error: The action to take upon error reading from the source.
1200 * @on_target_error: The action to take upon error writing to the target.
1201 * @creation_flags: Flags that control the behavior of the Job lifetime.
1202 * See @BlockJobCreateFlags
1203 * @cb: Completion function for the job.
1204 * @opaque: Opaque pointer value passed to @cb.
1205 * @txn: Transaction that this job is part of (may be NULL).
1207 * Create a backup operation on @bs. Clusters in @bs are written to @target
1208 * until the job is cancelled or manually completed.
1210 BlockJob
*backup_job_create(const char *job_id
, BlockDriverState
*bs
,
1211 BlockDriverState
*target
, int64_t speed
,
1212 MirrorSyncMode sync_mode
,
1213 BdrvDirtyBitmap
*sync_bitmap
,
1214 BitmapSyncMode bitmap_mode
,
1216 const char *filter_node_name
,
1217 BlockdevOnError on_source_error
,
1218 BlockdevOnError on_target_error
,
1220 BlockCompletionFunc
*cb
, void *opaque
,
1221 JobTxn
*txn
, Error
**errp
);
1223 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1224 const char *child_name
,
1225 const BdrvChildRole
*child_role
,
1227 uint64_t perm
, uint64_t shared_perm
,
1228 void *opaque
, Error
**errp
);
1229 void bdrv_root_unref_child(BdrvChild
*child
);
1231 void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1232 uint64_t *shared_perm
);
1235 * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use
1236 * bdrv_child_refresh_perms() instead and make the parent's
1237 * .bdrv_child_perm() implementation return the correct values.
1239 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1243 * Calls bs->drv->bdrv_child_perm() and updates the child's permission
1244 * masks with the result.
1245 * Drivers should invoke this function whenever an event occurs that
1246 * makes their .bdrv_child_perm() implementation return different
1247 * values than before, but which will not result in the block layer
1248 * automatically refreshing the permissions.
1250 int bdrv_child_refresh_perms(BlockDriverState
*bs
, BdrvChild
*c
, Error
**errp
);
1252 /* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1253 * block filters: Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED and RESIZE to
1255 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1256 const BdrvChildRole
*role
,
1257 BlockReopenQueue
*reopen_queue
,
1258 uint64_t perm
, uint64_t shared
,
1259 uint64_t *nperm
, uint64_t *nshared
);
1261 /* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1262 * (non-raw) image formats: Like above for bs->backing, but for bs->file it
1263 * requires WRITE | RESIZE for read-write images, always requires
1264 * CONSISTENT_READ and doesn't share WRITE. */
1265 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1266 const BdrvChildRole
*role
,
1267 BlockReopenQueue
*reopen_queue
,
1268 uint64_t perm
, uint64_t shared
,
1269 uint64_t *nperm
, uint64_t *nshared
);
1271 bool bdrv_recurse_can_replace(BlockDriverState
*bs
,
1272 BlockDriverState
*to_replace
);
1275 * Default implementation for drivers to pass bdrv_co_block_status() to
1278 int coroutine_fn
bdrv_co_block_status_from_file(BlockDriverState
*bs
,
1284 BlockDriverState
**file
);
1286 * Default implementation for drivers to pass bdrv_co_block_status() to
1287 * their backing file.
1289 int coroutine_fn
bdrv_co_block_status_from_backing(BlockDriverState
*bs
,
1295 BlockDriverState
**file
);
1296 const char *bdrv_get_parent_name(const BlockDriverState
*bs
);
1297 void blk_dev_change_media_cb(BlockBackend
*blk
, bool load
, Error
**errp
);
1298 bool blk_dev_has_removable_media(BlockBackend
*blk
);
1299 bool blk_dev_has_tray(BlockBackend
*blk
);
1300 void blk_dev_eject_request(BlockBackend
*blk
, bool force
);
1301 bool blk_dev_is_tray_open(BlockBackend
*blk
);
1302 bool blk_dev_is_medium_locked(BlockBackend
*blk
);
1304 void bdrv_set_dirty(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
);
1306 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
**out
);
1307 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
*backup
);
1308 bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap
*dest
,
1309 const BdrvDirtyBitmap
*src
,
1310 HBitmap
**backup
, bool lock
);
1312 void bdrv_inc_in_flight(BlockDriverState
*bs
);
1313 void bdrv_dec_in_flight(BlockDriverState
*bs
);
1315 void blockdev_close_all_bdrv_states(void);
1317 int coroutine_fn
bdrv_co_copy_range_from(BdrvChild
*src
, uint64_t src_offset
,
1318 BdrvChild
*dst
, uint64_t dst_offset
,
1320 BdrvRequestFlags read_flags
,
1321 BdrvRequestFlags write_flags
);
1322 int coroutine_fn
bdrv_co_copy_range_to(BdrvChild
*src
, uint64_t src_offset
,
1323 BdrvChild
*dst
, uint64_t dst_offset
,
1325 BdrvRequestFlags read_flags
,
1326 BdrvRequestFlags write_flags
);
1328 int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
);
1330 void bdrv_set_monitor_owned(BlockDriverState
*bs
);
1331 BlockDriverState
*bds_tree_init(QDict
*bs_opts
, Error
**errp
);
1333 #endif /* BLOCK_INT_H */