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
)(BlockDriver
*drv
,
139 const char *filename
,
142 int (*bdrv_make_empty
)(BlockDriverState
*bs
);
145 * Refreshes the bs->exact_filename field. If that is impossible,
146 * bs->exact_filename has to be left empty.
148 void (*bdrv_refresh_filename
)(BlockDriverState
*bs
);
151 * Gathers the open options for all children into @target.
152 * A simple format driver (without backing file support) might
153 * implement this function like this:
155 * QINCREF(bs->file->bs->full_open_options);
156 * qdict_put(target, "file", bs->file->bs->full_open_options);
158 * If not specified, the generic implementation will simply put
159 * all children's options under their respective name.
161 * @backing_overridden is true when bs->backing seems not to be
162 * the child that would result from opening bs->backing_file.
163 * Therefore, if it is true, the backing child's options should be
164 * gathered; otherwise, there is no need since the backing child
165 * is the one implied by the image header.
167 * Note that ideally this function would not be needed. Every
168 * block driver which implements it is probably doing something
169 * shady regarding its runtime option structure.
171 void (*bdrv_gather_child_options
)(BlockDriverState
*bs
, QDict
*target
,
172 bool backing_overridden
);
175 * Returns an allocated string which is the directory name of this BDS: It
176 * will be used to make relative filenames absolute by prepending this
177 * function's return value to them.
179 char *(*bdrv_dirname
)(BlockDriverState
*bs
, Error
**errp
);
182 BlockAIOCB
*(*bdrv_aio_preadv
)(BlockDriverState
*bs
,
183 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
,
184 BlockCompletionFunc
*cb
, void *opaque
);
185 BlockAIOCB
*(*bdrv_aio_pwritev
)(BlockDriverState
*bs
,
186 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
,
187 BlockCompletionFunc
*cb
, void *opaque
);
188 BlockAIOCB
*(*bdrv_aio_flush
)(BlockDriverState
*bs
,
189 BlockCompletionFunc
*cb
, void *opaque
);
190 BlockAIOCB
*(*bdrv_aio_pdiscard
)(BlockDriverState
*bs
,
191 int64_t offset
, int bytes
,
192 BlockCompletionFunc
*cb
, void *opaque
);
194 int coroutine_fn (*bdrv_co_readv
)(BlockDriverState
*bs
,
195 int64_t sector_num
, int nb_sectors
, QEMUIOVector
*qiov
);
198 * @offset: position in bytes to read at
199 * @bytes: number of bytes to read
200 * @qiov: the buffers to fill with read data
201 * @flags: currently unused, always 0
203 * @offset and @bytes will be a multiple of 'request_alignment',
204 * but the length of individual @qiov elements does not have to
207 * @bytes will always equal the total size of @qiov, and will be
208 * no larger than 'max_transfer'.
210 * The buffer in @qiov may point directly to guest memory.
212 int coroutine_fn (*bdrv_co_preadv
)(BlockDriverState
*bs
,
213 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
);
214 int coroutine_fn (*bdrv_co_preadv_part
)(BlockDriverState
*bs
,
215 uint64_t offset
, uint64_t bytes
,
216 QEMUIOVector
*qiov
, size_t qiov_offset
, int flags
);
217 int coroutine_fn (*bdrv_co_writev
)(BlockDriverState
*bs
,
218 int64_t sector_num
, int nb_sectors
, QEMUIOVector
*qiov
, int flags
);
220 * @offset: position in bytes to write at
221 * @bytes: number of bytes to write
222 * @qiov: the buffers containing data to write
223 * @flags: zero or more bits allowed by 'supported_write_flags'
225 * @offset and @bytes will be a multiple of 'request_alignment',
226 * but the length of individual @qiov elements does not have to
229 * @bytes will always equal the total size of @qiov, and will be
230 * no larger than 'max_transfer'.
232 * The buffer in @qiov may point directly to guest memory.
234 int coroutine_fn (*bdrv_co_pwritev
)(BlockDriverState
*bs
,
235 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
);
236 int coroutine_fn (*bdrv_co_pwritev_part
)(BlockDriverState
*bs
,
237 uint64_t offset
, uint64_t bytes
,
238 QEMUIOVector
*qiov
, size_t qiov_offset
, int flags
);
241 * Efficiently zero a region of the disk image. Typically an image format
242 * would use a compact metadata representation to implement this. This
243 * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
244 * will be called instead.
246 int coroutine_fn (*bdrv_co_pwrite_zeroes
)(BlockDriverState
*bs
,
247 int64_t offset
, int bytes
, BdrvRequestFlags flags
);
248 int coroutine_fn (*bdrv_co_pdiscard
)(BlockDriverState
*bs
,
249 int64_t offset
, int bytes
);
251 /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
252 * and invoke bdrv_co_copy_range_from(child, ...), or invoke
253 * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
255 * See the comment of bdrv_co_copy_range for the parameter and return value
258 int coroutine_fn (*bdrv_co_copy_range_from
)(BlockDriverState
*bs
,
264 BdrvRequestFlags read_flags
,
265 BdrvRequestFlags write_flags
);
267 /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
268 * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
269 * operation if @bs is the leaf and @src has the same BlockDriver. Return
270 * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
272 * See the comment of bdrv_co_copy_range for the parameter and return value
275 int coroutine_fn (*bdrv_co_copy_range_to
)(BlockDriverState
*bs
,
281 BdrvRequestFlags read_flags
,
282 BdrvRequestFlags write_flags
);
285 * Building block for bdrv_block_status[_above] and
286 * bdrv_is_allocated[_above]. The driver should answer only
287 * according to the current layer, and should only need to set
288 * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
289 * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
290 * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See
291 * block.h for the overall meaning of the bits. As a hint, the
292 * flag want_zero is true if the caller cares more about precise
293 * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
294 * overall allocation (favor larger *pnum, perhaps by reporting
295 * _DATA instead of _ZERO). The block layer guarantees input
296 * clamped to bdrv_getlength() and aligned to request_alignment,
297 * as well as non-NULL pnum, map, and file; in turn, the driver
298 * must return an error or set pnum to an aligned non-zero value.
300 int coroutine_fn (*bdrv_co_block_status
)(BlockDriverState
*bs
,
301 bool want_zero
, int64_t offset
, int64_t bytes
, int64_t *pnum
,
302 int64_t *map
, BlockDriverState
**file
);
305 * Invalidate any cached meta-data.
307 void coroutine_fn (*bdrv_co_invalidate_cache
)(BlockDriverState
*bs
,
309 int (*bdrv_inactivate
)(BlockDriverState
*bs
);
312 * Flushes all data for all layers by calling bdrv_co_flush for underlying
313 * layers, if needed. This function is needed for deterministic
314 * synchronization of the flush finishing callback.
316 int coroutine_fn (*bdrv_co_flush
)(BlockDriverState
*bs
);
318 /* Delete a created file. */
319 int coroutine_fn (*bdrv_co_delete_file
)(BlockDriverState
*bs
,
323 * Flushes all data that was already written to the OS all the way down to
324 * the disk (for example file-posix.c calls fsync()).
326 int coroutine_fn (*bdrv_co_flush_to_disk
)(BlockDriverState
*bs
);
329 * Flushes all internal caches to the OS. The data may still sit in a
330 * writeback cache of the host OS, but it will survive a crash of the qemu
333 int coroutine_fn (*bdrv_co_flush_to_os
)(BlockDriverState
*bs
);
336 * Drivers setting this field must be able to work with just a plain
337 * filename with '<protocol_name>:' as a prefix, and no other options.
338 * Options may be extracted from the filename by implementing
339 * bdrv_parse_filename.
341 const char *protocol_name
;
344 * Truncate @bs to @offset bytes using the given @prealloc mode
345 * when growing. Modes other than PREALLOC_MODE_OFF should be
346 * rejected when shrinking @bs.
348 * If @exact is true, @bs must be resized to exactly @offset.
349 * Otherwise, it is sufficient for @bs (if it is a host block
350 * device and thus there is no way to resize it) to be at least
351 * @offset bytes in length.
353 * If @exact is true and this function fails but would succeed
354 * with @exact = false, it should return -ENOTSUP.
356 int coroutine_fn (*bdrv_co_truncate
)(BlockDriverState
*bs
, int64_t offset
,
357 bool exact
, PreallocMode prealloc
,
360 int64_t (*bdrv_getlength
)(BlockDriverState
*bs
);
361 bool has_variable_length
;
362 int64_t (*bdrv_get_allocated_file_size
)(BlockDriverState
*bs
);
363 BlockMeasureInfo
*(*bdrv_measure
)(QemuOpts
*opts
, BlockDriverState
*in_bs
,
366 int coroutine_fn (*bdrv_co_pwritev_compressed
)(BlockDriverState
*bs
,
367 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
);
368 int coroutine_fn (*bdrv_co_pwritev_compressed_part
)(BlockDriverState
*bs
,
369 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
,
372 int (*bdrv_snapshot_create
)(BlockDriverState
*bs
,
373 QEMUSnapshotInfo
*sn_info
);
374 int (*bdrv_snapshot_goto
)(BlockDriverState
*bs
,
375 const char *snapshot_id
);
376 int (*bdrv_snapshot_delete
)(BlockDriverState
*bs
,
377 const char *snapshot_id
,
380 int (*bdrv_snapshot_list
)(BlockDriverState
*bs
,
381 QEMUSnapshotInfo
**psn_info
);
382 int (*bdrv_snapshot_load_tmp
)(BlockDriverState
*bs
,
383 const char *snapshot_id
,
386 int (*bdrv_get_info
)(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
387 ImageInfoSpecific
*(*bdrv_get_specific_info
)(BlockDriverState
*bs
,
389 BlockStatsSpecific
*(*bdrv_get_specific_stats
)(BlockDriverState
*bs
);
391 int coroutine_fn (*bdrv_save_vmstate
)(BlockDriverState
*bs
,
394 int coroutine_fn (*bdrv_load_vmstate
)(BlockDriverState
*bs
,
398 int (*bdrv_change_backing_file
)(BlockDriverState
*bs
,
399 const char *backing_file
, const char *backing_fmt
);
401 /* removable device specific */
402 bool (*bdrv_is_inserted
)(BlockDriverState
*bs
);
403 void (*bdrv_eject
)(BlockDriverState
*bs
, bool eject_flag
);
404 void (*bdrv_lock_medium
)(BlockDriverState
*bs
, bool locked
);
406 /* to control generic scsi devices */
407 BlockAIOCB
*(*bdrv_aio_ioctl
)(BlockDriverState
*bs
,
408 unsigned long int req
, void *buf
,
409 BlockCompletionFunc
*cb
, void *opaque
);
410 int coroutine_fn (*bdrv_co_ioctl
)(BlockDriverState
*bs
,
411 unsigned long int req
, void *buf
);
413 /* List of options for creating images, terminated by name == NULL */
414 QemuOptsList
*create_opts
;
416 * If this driver supports reopening images this contains a
417 * NULL-terminated list of the runtime options that can be
418 * modified. If an option in this list is unspecified during
419 * reopen then it _must_ be reset to its default value or return
422 const char *const *mutable_opts
;
425 * Returns 0 for completed check, -errno for internal errors.
426 * The check results are stored in result.
428 int coroutine_fn (*bdrv_co_check
)(BlockDriverState
*bs
,
429 BdrvCheckResult
*result
,
432 int (*bdrv_amend_options
)(BlockDriverState
*bs
, QemuOpts
*opts
,
433 BlockDriverAmendStatusCB
*status_cb
,
437 void (*bdrv_debug_event
)(BlockDriverState
*bs
, BlkdebugEvent event
);
439 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
440 int (*bdrv_debug_breakpoint
)(BlockDriverState
*bs
, const char *event
,
442 int (*bdrv_debug_remove_breakpoint
)(BlockDriverState
*bs
,
444 int (*bdrv_debug_resume
)(BlockDriverState
*bs
, const char *tag
);
445 bool (*bdrv_debug_is_suspended
)(BlockDriverState
*bs
, const char *tag
);
447 void (*bdrv_refresh_limits
)(BlockDriverState
*bs
, Error
**errp
);
450 * Returns 1 if newly created images are guaranteed to contain only
451 * zeros, 0 otherwise.
452 * Must return 0 if .bdrv_has_zero_init_truncate() returns 0.
454 int (*bdrv_has_zero_init
)(BlockDriverState
*bs
);
457 * Returns 1 if new areas added by growing the image with
458 * PREALLOC_MODE_OFF contain only zeros, 0 otherwise.
460 int (*bdrv_has_zero_init_truncate
)(BlockDriverState
*bs
);
462 /* Remove fd handlers, timers, and other event loop callbacks so the event
463 * loop is no longer in use. Called with no in-flight requests and in
464 * depth-first traversal order with parents before child nodes.
466 void (*bdrv_detach_aio_context
)(BlockDriverState
*bs
);
468 /* Add fd handlers, timers, and other event loop callbacks so I/O requests
469 * can be processed again. Called with no in-flight requests and in
470 * depth-first traversal order with child nodes before parent nodes.
472 void (*bdrv_attach_aio_context
)(BlockDriverState
*bs
,
473 AioContext
*new_context
);
475 /* io queue for linux-aio */
476 void (*bdrv_io_plug
)(BlockDriverState
*bs
);
477 void (*bdrv_io_unplug
)(BlockDriverState
*bs
);
480 * Try to get @bs's logical and physical block size.
481 * On success, store them in @bsz and return zero.
482 * On failure, return negative errno.
484 int (*bdrv_probe_blocksizes
)(BlockDriverState
*bs
, BlockSizes
*bsz
);
486 * Try to get @bs's geometry (cyls, heads, sectors)
487 * On success, store them in @geo and return 0.
488 * On failure return -errno.
489 * Only drivers that want to override guest geometry implement this
490 * callback; see hd_geometry_guess().
492 int (*bdrv_probe_geometry
)(BlockDriverState
*bs
, HDGeometry
*geo
);
495 * bdrv_co_drain_begin is called if implemented in the beginning of a
496 * drain operation to drain and stop any internal sources of requests in
498 * bdrv_co_drain_end is called if implemented at the end of the drain.
500 * They should be used by the driver to e.g. manage scheduled I/O
501 * requests, or toggle an internal state. After the end of the drain new
502 * requests will continue normally.
504 void coroutine_fn (*bdrv_co_drain_begin
)(BlockDriverState
*bs
);
505 void coroutine_fn (*bdrv_co_drain_end
)(BlockDriverState
*bs
);
507 void (*bdrv_add_child
)(BlockDriverState
*parent
, BlockDriverState
*child
,
509 void (*bdrv_del_child
)(BlockDriverState
*parent
, BdrvChild
*child
,
513 * Informs the block driver that a permission change is intended. The
514 * driver checks whether the change is permissible and may take other
515 * preparations for the change (e.g. get file system locks). This operation
516 * is always followed either by a call to either .bdrv_set_perm or
517 * .bdrv_abort_perm_update.
519 * Checks whether the requested set of cumulative permissions in @perm
520 * can be granted for accessing @bs and whether no other users are using
521 * permissions other than those given in @shared (both arguments take
522 * BLK_PERM_* bitmasks).
524 * If both conditions are met, 0 is returned. Otherwise, -errno is returned
525 * and errp is set to an error describing the conflict.
527 int (*bdrv_check_perm
)(BlockDriverState
*bs
, uint64_t perm
,
528 uint64_t shared
, Error
**errp
);
531 * Called to inform the driver that the set of cumulative set of used
532 * permissions for @bs has changed to @perm, and the set of sharable
533 * permission to @shared. The driver can use this to propagate changes to
534 * its children (i.e. request permissions only if a parent actually needs
537 * This function is only invoked after bdrv_check_perm(), so block drivers
538 * may rely on preparations made in their .bdrv_check_perm implementation.
540 void (*bdrv_set_perm
)(BlockDriverState
*bs
, uint64_t perm
, uint64_t shared
);
543 * Called to inform the driver that after a previous bdrv_check_perm()
544 * call, the permission update is not performed and any preparations made
545 * for it (e.g. taken file locks) need to be undone.
547 * This function can be called even for nodes that never saw a
548 * bdrv_check_perm() call. It is a no-op then.
550 void (*bdrv_abort_perm_update
)(BlockDriverState
*bs
);
553 * Returns in @nperm and @nshared the permissions that the driver for @bs
554 * needs on its child @c, based on the cumulative permissions requested by
555 * the parents in @parent_perm and @parent_shared.
557 * If @c is NULL, return the permissions for attaching a new child for the
560 * If @reopen_queue is non-NULL, don't return the currently needed
561 * permissions, but those that will be needed after applying the
564 void (*bdrv_child_perm
)(BlockDriverState
*bs
, BdrvChild
*c
,
565 const BdrvChildRole
*role
,
566 BlockReopenQueue
*reopen_queue
,
567 uint64_t parent_perm
, uint64_t parent_shared
,
568 uint64_t *nperm
, uint64_t *nshared
);
570 bool (*bdrv_co_can_store_new_dirty_bitmap
)(BlockDriverState
*bs
,
572 uint32_t granularity
,
574 int (*bdrv_co_remove_persistent_dirty_bitmap
)(BlockDriverState
*bs
,
579 * Register/unregister a buffer for I/O. For example, when the driver is
580 * interested to know the memory areas that will later be used in iovs, so
581 * that it can do IOMMU mapping with VFIO etc., in order to get better
582 * performance. In the case of VFIO drivers, this callback is used to do
583 * DMA mapping for hot buffers.
585 void (*bdrv_register_buf
)(BlockDriverState
*bs
, void *host
, size_t size
);
586 void (*bdrv_unregister_buf
)(BlockDriverState
*bs
, void *host
);
587 QLIST_ENTRY(BlockDriver
) list
;
589 /* Pointer to a NULL-terminated array of names of strong options
590 * that can be specified for bdrv_open(). A strong option is one
591 * that changes the data of a BDS.
592 * If this pointer is NULL, the array is considered empty.
593 * "filename" and "driver" are always considered strong. */
594 const char *const *strong_runtime_opts
;
597 static inline bool block_driver_can_compress(BlockDriver
*drv
)
599 return drv
->bdrv_co_pwritev_compressed
||
600 drv
->bdrv_co_pwritev_compressed_part
;
603 typedef struct BlockLimits
{
604 /* Alignment requirement, in bytes, for offset/length of I/O
605 * requests. Must be a power of 2 less than INT_MAX; defaults to
606 * 1 for drivers with modern byte interfaces, and to 512
608 uint32_t request_alignment
;
610 /* Maximum number of bytes that can be discarded at once (since it
611 * is signed, it must be < 2G, if set). Must be multiple of
612 * pdiscard_alignment, but need not be power of 2. May be 0 if no
613 * inherent 32-bit limit */
614 int32_t max_pdiscard
;
616 /* Optimal alignment for discard requests in bytes. A power of 2
617 * is best but not mandatory. Must be a multiple of
618 * bl.request_alignment, and must be less than max_pdiscard if
619 * that is set. May be 0 if bl.request_alignment is good enough */
620 uint32_t pdiscard_alignment
;
622 /* Maximum number of bytes that can zeroized at once (since it is
623 * signed, it must be < 2G, if set). Must be multiple of
624 * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
625 int32_t max_pwrite_zeroes
;
627 /* Optimal alignment for write zeroes requests in bytes. A power
628 * of 2 is best but not mandatory. Must be a multiple of
629 * bl.request_alignment, and must be less than max_pwrite_zeroes
630 * if that is set. May be 0 if bl.request_alignment is good
632 uint32_t pwrite_zeroes_alignment
;
634 /* Optimal transfer length in bytes. A power of 2 is best but not
635 * mandatory. Must be a multiple of bl.request_alignment, or 0 if
636 * no preferred size */
637 uint32_t opt_transfer
;
639 /* Maximal transfer length in bytes. Need not be power of 2, but
640 * must be multiple of opt_transfer and bl.request_alignment, or 0
641 * for no 32-bit limit. For now, anything larger than INT_MAX is
643 uint32_t max_transfer
;
645 /* memory alignment, in bytes so that no bounce buffer is needed */
646 size_t min_mem_alignment
;
648 /* memory alignment, in bytes, for bounce buffer */
649 size_t opt_mem_alignment
;
651 /* maximum number of iovec elements */
655 typedef struct BdrvOpBlocker BdrvOpBlocker
;
657 typedef struct BdrvAioNotifier
{
658 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
);
659 void (*detach_aio_context
)(void *opaque
);
664 QLIST_ENTRY(BdrvAioNotifier
) list
;
667 struct BdrvChildRole
{
668 /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
672 /* If true, the parent is a BlockDriverState and bdrv_next_all_states()
673 * will return it. This information is used for drain_all, where every node
674 * will be drained separately, so the drain only needs to be propagated to
675 * non-BDS parents. */
678 void (*inherit_options
)(int *child_flags
, QDict
*child_options
,
679 int parent_flags
, QDict
*parent_options
);
681 void (*change_media
)(BdrvChild
*child
, bool load
);
682 void (*resize
)(BdrvChild
*child
);
684 /* Returns a name that is supposedly more useful for human users than the
685 * node name for identifying the node in question (in particular, a BB
686 * name), or NULL if the parent can't provide a better name. */
687 const char *(*get_name
)(BdrvChild
*child
);
689 /* Returns a malloced string that describes the parent of the child for a
690 * human reader. This could be a node-name, BlockBackend name, qdev ID or
691 * QOM path of the device owning the BlockBackend, job type and ID etc. The
692 * caller is responsible for freeing the memory. */
693 char *(*get_parent_desc
)(BdrvChild
*child
);
696 * If this pair of functions is implemented, the parent doesn't issue new
697 * requests after returning from .drained_begin() until .drained_end() is
700 * These functions must not change the graph (and therefore also must not
701 * call aio_poll(), which could change the graph indirectly).
703 * If drained_end() schedules background operations, it must atomically
704 * increment *drained_end_counter for each such operation and atomically
705 * decrement it once the operation has settled.
707 * Note that this can be nested. If drained_begin() was called twice, new
708 * I/O is allowed only after drained_end() was called twice, too.
710 void (*drained_begin
)(BdrvChild
*child
);
711 void (*drained_end
)(BdrvChild
*child
, int *drained_end_counter
);
714 * Returns whether the parent has pending requests for the child. This
715 * callback is polled after .drained_begin() has been called until all
716 * activity on the child has stopped.
718 bool (*drained_poll
)(BdrvChild
*child
);
720 /* Notifies the parent that the child has been activated/inactivated (e.g.
721 * when migration is completing) and it can start/stop requesting
722 * permissions and doing I/O on it. */
723 void (*activate
)(BdrvChild
*child
, Error
**errp
);
724 int (*inactivate
)(BdrvChild
*child
);
726 void (*attach
)(BdrvChild
*child
);
727 void (*detach
)(BdrvChild
*child
);
729 /* Notifies the parent that the filename of its child has changed (e.g.
730 * because the direct child was removed from the backing chain), so that it
731 * can update its reference. */
732 int (*update_filename
)(BdrvChild
*child
, BlockDriverState
*new_base
,
733 const char *filename
, Error
**errp
);
735 bool (*can_set_aio_ctx
)(BdrvChild
*child
, AioContext
*ctx
,
736 GSList
**ignore
, Error
**errp
);
737 void (*set_aio_ctx
)(BdrvChild
*child
, AioContext
*ctx
, GSList
**ignore
);
740 extern const BdrvChildRole child_file
;
741 extern const BdrvChildRole child_format
;
742 extern const BdrvChildRole child_backing
;
745 BlockDriverState
*bs
;
747 const BdrvChildRole
*role
;
751 * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
756 * Permissions that can still be granted to other users of @bs while this
757 * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
759 uint64_t shared_perm
;
761 /* backup of permissions during permission update procedure */
762 bool has_backup_perm
;
763 uint64_t backup_perm
;
764 uint64_t backup_shared_perm
;
767 * This link is frozen: the child can neither be replaced nor
768 * detached from the parent.
773 * How many times the parent of this child has been drained
774 * (through role->drained_*).
775 * Usually, this is equal to bs->quiesce_counter (potentially
776 * reduced by bdrv_drain_all_count). It may differ while the
777 * child is entering or leaving a drained section.
779 int parent_quiesce_counter
;
781 QLIST_ENTRY(BdrvChild
) next
;
782 QLIST_ENTRY(BdrvChild
) next_parent
;
786 * Note: the function bdrv_append() copies and swaps contents of
787 * BlockDriverStates, so if you add new fields to this struct, please
788 * inspect bdrv_append() to determine if the new fields need to be
791 struct BlockDriverState
{
792 /* Protected by big QEMU lock or read-only after opening. No special
793 * locking needed during I/O...
795 int open_flags
; /* flags used to open the file, re-used for re-open */
796 bool read_only
; /* if true, the media is read only */
797 bool encrypted
; /* if true, the media is encrypted */
798 bool sg
; /* if true, the device is a /dev/sg* */
799 bool probed
; /* if true, format was probed rather than specified */
800 bool force_share
; /* if true, always allow all shared permissions */
801 bool implicit
; /* if true, this filter node was automatically inserted */
803 BlockDriver
*drv
; /* NULL means no media */
806 AioContext
*aio_context
; /* event loop used for fd handlers, timers, etc */
807 /* long-running tasks intended to always use the same AioContext as this
808 * BDS may register themselves in this list to be notified of changes
809 * regarding this BDS's context */
810 QLIST_HEAD(, BdrvAioNotifier
) aio_notifiers
;
811 bool walking_aio_notifiers
; /* to make removal during iteration safe */
813 char filename
[PATH_MAX
];
814 char backing_file
[PATH_MAX
]; /* if non zero, the image is a diff of
816 /* The backing filename indicated by the image header; if we ever
817 * open this file, then this is replaced by the resulting BDS's
818 * filename (i.e. after a bdrv_refresh_filename() run). */
819 char auto_backing_file
[PATH_MAX
];
820 char backing_format
[16]; /* if non-zero and backing_file exists */
822 QDict
*full_open_options
;
823 char exact_filename
[PATH_MAX
];
831 /* Flags honored during pwrite (so far: BDRV_REQ_FUA,
832 * BDRV_REQ_WRITE_UNCHANGED).
833 * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
834 * writes will be issued as normal writes without the flag set.
835 * This is important to note for drivers that do not explicitly
836 * request a WRITE permission for their children and instead take
837 * the same permissions as their parent did (this is commonly what
838 * block filters do). Such drivers have to be aware that the
839 * parent may have taken a WRITE_UNCHANGED permission only and is
840 * issuing such requests. Drivers either must make sure that
841 * these requests do not result in plain WRITE accesses (usually
842 * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
843 * every incoming write request as-is, including potentially that
844 * flag), or they have to explicitly take the WRITE permission for
846 unsigned int supported_write_flags
;
847 /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
848 * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */
849 unsigned int supported_zero_flags
;
851 /* the following member gives a name to every node on the bs graph. */
853 /* element of the list of named nodes building the graph */
854 QTAILQ_ENTRY(BlockDriverState
) node_list
;
855 /* element of the list of all BlockDriverStates (all_bdrv_states) */
856 QTAILQ_ENTRY(BlockDriverState
) bs_list
;
857 /* element of the list of monitor-owned BDS */
858 QTAILQ_ENTRY(BlockDriverState
) monitor_list
;
861 /* operation blockers */
862 QLIST_HEAD(, BdrvOpBlocker
) op_blockers
[BLOCK_OP_TYPE_MAX
];
864 /* The node that this node inherited default options from (and a reopen on
865 * which can affect this node by changing these defaults). This is always a
866 * parent node of this node. */
867 BlockDriverState
*inherits_from
;
868 QLIST_HEAD(, BdrvChild
) children
;
869 QLIST_HEAD(, BdrvChild
) parents
;
872 QDict
*explicit_options
;
873 BlockdevDetectZeroesOptions detect_zeroes
;
875 /* The error object in use for blocking operations on backing_hd */
876 Error
*backing_blocker
;
878 /* Protected by AioContext lock */
880 /* If we are reading a disk image, give its size in sectors.
881 * Generally read-only; it is written to by load_snapshot and
882 * save_snaphost, but the block layer is quiescent during those.
884 int64_t total_sectors
;
886 /* Callback before write request is processed */
887 NotifierWithReturnList before_write_notifiers
;
889 /* threshold limit for writes, in bytes. "High water mark". */
890 uint64_t write_threshold_offset
;
891 NotifierWithReturn write_threshold_notifier
;
893 /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
894 * Reading from the list can be done with either the BQL or the
895 * dirty_bitmap_mutex. Modifying a bitmap only requires
896 * dirty_bitmap_mutex. */
897 QemuMutex dirty_bitmap_mutex
;
898 QLIST_HEAD(, BdrvDirtyBitmap
) dirty_bitmaps
;
900 /* Offset after the highest byte written to */
901 Stat64 wr_highest_offset
;
903 /* If true, copy read backing sectors into image. Can be >1 if more
904 * than one client has requested copy-on-read. Accessed with atomic
909 /* number of in-flight requests; overall and serialising.
910 * Accessed with atomic ops.
912 unsigned int in_flight
;
913 unsigned int serialising_in_flight
;
915 /* counter for nested bdrv_io_plug.
916 * Accessed with atomic ops.
920 /* do we need to tell the quest if we have a volatile write cache? */
921 int enable_write_cache
;
923 /* Accessed with atomic ops. */
925 int recursive_quiesce_counter
;
927 unsigned int write_gen
; /* Current data generation */
929 /* Protected by reqs_lock. */
931 QLIST_HEAD(, BdrvTrackedRequest
) tracked_requests
;
932 CoQueue flush_queue
; /* Serializing flush queue */
933 bool active_flush_req
; /* Flush request in flight? */
935 /* Only read/written by whoever has set active_flush_req to true. */
936 unsigned int flushed_gen
; /* Flushed write generation */
938 /* BdrvChild links to this node may never be frozen */
942 struct BlockBackendRootState
{
945 BlockdevDetectZeroesOptions detect_zeroes
;
948 typedef enum BlockMirrorBackingMode
{
949 /* Reuse the existing backing chain from the source for the target.
950 * - sync=full: Set backing BDS to NULL.
951 * - sync=top: Use source's backing BDS.
952 * - sync=none: Use source as the backing BDS. */
953 MIRROR_SOURCE_BACKING_CHAIN
,
955 /* Open the target's backing chain completely anew */
956 MIRROR_OPEN_BACKING_CHAIN
,
958 /* Do not change the target's backing BDS after job completion */
959 MIRROR_LEAVE_BACKING_CHAIN
,
960 } BlockMirrorBackingMode
;
962 static inline BlockDriverState
*backing_bs(BlockDriverState
*bs
)
964 return bs
->backing
? bs
->backing
->bs
: NULL
;
968 /* Essential block drivers which must always be statically linked into qemu, and
969 * which therefore can be accessed without using bdrv_find_format() */
970 extern BlockDriver bdrv_file
;
971 extern BlockDriver bdrv_raw
;
972 extern BlockDriver bdrv_qcow2
;
974 int coroutine_fn
bdrv_co_preadv(BdrvChild
*child
,
975 int64_t offset
, unsigned int bytes
, QEMUIOVector
*qiov
,
976 BdrvRequestFlags flags
);
977 int coroutine_fn
bdrv_co_preadv_part(BdrvChild
*child
,
978 int64_t offset
, unsigned int bytes
,
979 QEMUIOVector
*qiov
, size_t qiov_offset
, BdrvRequestFlags flags
);
980 int coroutine_fn
bdrv_co_pwritev(BdrvChild
*child
,
981 int64_t offset
, unsigned int bytes
, QEMUIOVector
*qiov
,
982 BdrvRequestFlags flags
);
983 int coroutine_fn
bdrv_co_pwritev_part(BdrvChild
*child
,
984 int64_t offset
, unsigned int bytes
,
985 QEMUIOVector
*qiov
, size_t qiov_offset
, BdrvRequestFlags flags
);
987 static inline int coroutine_fn
bdrv_co_pread(BdrvChild
*child
,
988 int64_t offset
, unsigned int bytes
, void *buf
, BdrvRequestFlags flags
)
990 QEMUIOVector qiov
= QEMU_IOVEC_INIT_BUF(qiov
, buf
, bytes
);
992 return bdrv_co_preadv(child
, offset
, bytes
, &qiov
, flags
);
995 static inline int coroutine_fn
bdrv_co_pwrite(BdrvChild
*child
,
996 int64_t offset
, unsigned int bytes
, void *buf
, BdrvRequestFlags flags
)
998 QEMUIOVector qiov
= QEMU_IOVEC_INIT_BUF(qiov
, buf
, bytes
);
1000 return bdrv_co_pwritev(child
, offset
, bytes
, &qiov
, flags
);
1003 extern unsigned int bdrv_drain_all_count
;
1004 void bdrv_apply_subtree_drain(BdrvChild
*child
, BlockDriverState
*new_parent
);
1005 void bdrv_unapply_subtree_drain(BdrvChild
*child
, BlockDriverState
*old_parent
);
1007 bool coroutine_fn
bdrv_mark_request_serialising(BdrvTrackedRequest
*req
, uint64_t align
);
1008 BdrvTrackedRequest
*coroutine_fn
bdrv_co_get_self_request(BlockDriverState
*bs
);
1010 int get_tmp_filename(char *filename
, int size
);
1011 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
1012 const char *filename
);
1014 void bdrv_parse_filename_strip_prefix(const char *filename
, const char *prefix
,
1019 * bdrv_add_before_write_notifier:
1021 * Register a callback that is invoked before write requests are processed but
1022 * after any throttling or waiting for overlapping requests.
1024 void bdrv_add_before_write_notifier(BlockDriverState
*bs
,
1025 NotifierWithReturn
*notifier
);
1028 * bdrv_add_aio_context_notifier:
1030 * If a long-running job intends to be always run in the same AioContext as a
1031 * certain BDS, it may use this function to be notified of changes regarding the
1032 * association of the BDS to an AioContext.
1034 * attached_aio_context() is called after the target BDS has been attached to a
1035 * new AioContext; detach_aio_context() is called before the target BDS is being
1036 * detached from its old AioContext.
1038 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
1039 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
1040 void (*detach_aio_context
)(void *opaque
), void *opaque
);
1043 * bdrv_remove_aio_context_notifier:
1045 * Unsubscribe of change notifications regarding the BDS's AioContext. The
1046 * parameters given here have to be the same as those given to
1047 * bdrv_add_aio_context_notifier().
1049 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
1050 void (*aio_context_attached
)(AioContext
*,
1052 void (*aio_context_detached
)(void *),
1057 * @bs: The BlockDriverState for which an I/O operation has been completed.
1059 * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During
1060 * synchronous I/O on a BlockDriverState that is attached to another
1061 * I/O thread, the main thread lets the I/O thread's event loop run,
1062 * waiting for the I/O operation to complete. A bdrv_wakeup will wake
1063 * up the main thread if necessary.
1065 * Manual calls to bdrv_wakeup are rarely necessary, because
1066 * bdrv_dec_in_flight already calls it.
1068 void bdrv_wakeup(BlockDriverState
*bs
);
1071 int is_windows_drive(const char *filename
);
1076 * @job_id: The id of the newly-created job, or %NULL to use the
1077 * device name of @bs.
1078 * @bs: Block device to operate on.
1079 * @base: Block device that will become the new base, or %NULL to
1080 * flatten the whole backing file chain onto @bs.
1081 * @backing_file_str: The file name that will be written to @bs as the
1082 * the new backing file if the job completes. Ignored if @base is %NULL.
1083 * @creation_flags: Flags that control the behavior of the Job lifetime.
1084 * See @BlockJobCreateFlags
1085 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1086 * @on_error: The action to take upon error.
1087 * @errp: Error object.
1089 * Start a streaming operation on @bs. Clusters that are unallocated
1090 * in @bs, but allocated in any image between @base and @bs (both
1091 * exclusive) will be written to @bs. At the end of a successful
1092 * streaming job, the backing file of @bs will be changed to
1093 * @backing_file_str in the written image and to @base in the live
1096 void stream_start(const char *job_id
, BlockDriverState
*bs
,
1097 BlockDriverState
*base
, const char *backing_file_str
,
1098 int creation_flags
, int64_t speed
,
1099 BlockdevOnError on_error
, Error
**errp
);
1103 * @job_id: The id of the newly-created job, or %NULL to use the
1104 * device name of @bs.
1105 * @bs: Active block device.
1106 * @top: Top block device to be committed.
1107 * @base: Block device that will be written into, and become the new top.
1108 * @creation_flags: Flags that control the behavior of the Job lifetime.
1109 * See @BlockJobCreateFlags
1110 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1111 * @on_error: The action to take upon error.
1112 * @backing_file_str: String to use as the backing file in @top's overlay
1113 * @filter_node_name: The node name that should be assigned to the filter
1114 * driver that the commit job inserts into the graph above @top. NULL means
1115 * that a node name should be autogenerated.
1116 * @errp: Error object.
1119 void commit_start(const char *job_id
, BlockDriverState
*bs
,
1120 BlockDriverState
*base
, BlockDriverState
*top
,
1121 int creation_flags
, int64_t speed
,
1122 BlockdevOnError on_error
, const char *backing_file_str
,
1123 const char *filter_node_name
, Error
**errp
);
1125 * commit_active_start:
1126 * @job_id: The id of the newly-created job, or %NULL to use the
1127 * device name of @bs.
1128 * @bs: Active block device to be committed.
1129 * @base: Block device that will be written into, and become the new top.
1130 * @creation_flags: Flags that control the behavior of the Job lifetime.
1131 * See @BlockJobCreateFlags
1132 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1133 * @on_error: The action to take upon error.
1134 * @filter_node_name: The node name that should be assigned to the filter
1135 * driver that the commit job inserts into the graph above @bs. NULL means that
1136 * a node name should be autogenerated.
1137 * @cb: Completion function for the job.
1138 * @opaque: Opaque pointer value passed to @cb.
1139 * @auto_complete: Auto complete the job.
1140 * @errp: Error object.
1143 BlockJob
*commit_active_start(const char *job_id
, BlockDriverState
*bs
,
1144 BlockDriverState
*base
, int creation_flags
,
1145 int64_t speed
, BlockdevOnError on_error
,
1146 const char *filter_node_name
,
1147 BlockCompletionFunc
*cb
, void *opaque
,
1148 bool auto_complete
, Error
**errp
);
1151 * @job_id: The id of the newly-created job, or %NULL to use the
1152 * device name of @bs.
1153 * @bs: Block device to operate on.
1154 * @target: Block device to write to.
1155 * @replaces: Block graph node name to replace once the mirror is done. Can
1156 * only be used when full mirroring is selected.
1157 * @creation_flags: Flags that control the behavior of the Job lifetime.
1158 * See @BlockJobCreateFlags
1159 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1160 * @granularity: The chosen granularity for the dirty bitmap.
1161 * @buf_size: The amount of data that can be in flight at one time.
1162 * @mode: Whether to collapse all images in the chain to the target.
1163 * @backing_mode: How to establish the target's backing chain after completion.
1164 * @zero_target: Whether the target should be explicitly zero-initialized
1165 * @on_source_error: The action to take upon error reading from the source.
1166 * @on_target_error: The action to take upon error writing to the target.
1167 * @unmap: Whether to unmap target where source sectors only contain zeroes.
1168 * @filter_node_name: The node name that should be assigned to the filter
1169 * driver that the mirror job inserts into the graph above @bs. NULL means that
1170 * a node name should be autogenerated.
1171 * @copy_mode: When to trigger writes to the target.
1172 * @errp: Error object.
1174 * Start a mirroring operation on @bs. Clusters that are allocated
1175 * in @bs will be written to @target until the job is cancelled or
1176 * manually completed. At the end of a successful mirroring job,
1177 * @bs will be switched to read from @target.
1179 void mirror_start(const char *job_id
, BlockDriverState
*bs
,
1180 BlockDriverState
*target
, const char *replaces
,
1181 int creation_flags
, int64_t speed
,
1182 uint32_t granularity
, int64_t buf_size
,
1183 MirrorSyncMode mode
, BlockMirrorBackingMode backing_mode
,
1185 BlockdevOnError on_source_error
,
1186 BlockdevOnError on_target_error
,
1187 bool unmap
, const char *filter_node_name
,
1188 MirrorCopyMode copy_mode
, Error
**errp
);
1191 * backup_job_create:
1192 * @job_id: The id of the newly-created job, or %NULL to use the
1193 * device name of @bs.
1194 * @bs: Block device to operate on.
1195 * @target: Block device to write to.
1196 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1197 * @sync_mode: What parts of the disk image should be copied to the destination.
1198 * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental'
1199 * @bitmap_mode: The bitmap synchronization policy to use.
1200 * @on_source_error: The action to take upon error reading from the source.
1201 * @on_target_error: The action to take upon error writing to the target.
1202 * @creation_flags: Flags that control the behavior of the Job lifetime.
1203 * See @BlockJobCreateFlags
1204 * @cb: Completion function for the job.
1205 * @opaque: Opaque pointer value passed to @cb.
1206 * @txn: Transaction that this job is part of (may be NULL).
1208 * Create a backup operation on @bs. Clusters in @bs are written to @target
1209 * until the job is cancelled or manually completed.
1211 BlockJob
*backup_job_create(const char *job_id
, BlockDriverState
*bs
,
1212 BlockDriverState
*target
, int64_t speed
,
1213 MirrorSyncMode sync_mode
,
1214 BdrvDirtyBitmap
*sync_bitmap
,
1215 BitmapSyncMode bitmap_mode
,
1217 const char *filter_node_name
,
1218 BlockdevOnError on_source_error
,
1219 BlockdevOnError on_target_error
,
1221 BlockCompletionFunc
*cb
, void *opaque
,
1222 JobTxn
*txn
, Error
**errp
);
1224 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1225 const char *child_name
,
1226 const BdrvChildRole
*child_role
,
1228 uint64_t perm
, uint64_t shared_perm
,
1229 void *opaque
, Error
**errp
);
1230 void bdrv_root_unref_child(BdrvChild
*child
);
1232 void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1233 uint64_t *shared_perm
);
1236 * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use
1237 * bdrv_child_refresh_perms() instead and make the parent's
1238 * .bdrv_child_perm() implementation return the correct values.
1240 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1244 * Calls bs->drv->bdrv_child_perm() and updates the child's permission
1245 * masks with the result.
1246 * Drivers should invoke this function whenever an event occurs that
1247 * makes their .bdrv_child_perm() implementation return different
1248 * values than before, but which will not result in the block layer
1249 * automatically refreshing the permissions.
1251 int bdrv_child_refresh_perms(BlockDriverState
*bs
, BdrvChild
*c
, Error
**errp
);
1253 /* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1254 * block filters: Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED and RESIZE to
1256 void bdrv_filter_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1257 const BdrvChildRole
*role
,
1258 BlockReopenQueue
*reopen_queue
,
1259 uint64_t perm
, uint64_t shared
,
1260 uint64_t *nperm
, uint64_t *nshared
);
1262 /* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1263 * (non-raw) image formats: Like above for bs->backing, but for bs->file it
1264 * requires WRITE | RESIZE for read-write images, always requires
1265 * CONSISTENT_READ and doesn't share WRITE. */
1266 void bdrv_format_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1267 const BdrvChildRole
*role
,
1268 BlockReopenQueue
*reopen_queue
,
1269 uint64_t perm
, uint64_t shared
,
1270 uint64_t *nperm
, uint64_t *nshared
);
1272 bool bdrv_recurse_can_replace(BlockDriverState
*bs
,
1273 BlockDriverState
*to_replace
);
1276 * Default implementation for drivers to pass bdrv_co_block_status() to
1279 int coroutine_fn
bdrv_co_block_status_from_file(BlockDriverState
*bs
,
1285 BlockDriverState
**file
);
1287 * Default implementation for drivers to pass bdrv_co_block_status() to
1288 * their backing file.
1290 int coroutine_fn
bdrv_co_block_status_from_backing(BlockDriverState
*bs
,
1296 BlockDriverState
**file
);
1297 const char *bdrv_get_parent_name(const BlockDriverState
*bs
);
1298 void blk_dev_change_media_cb(BlockBackend
*blk
, bool load
, Error
**errp
);
1299 bool blk_dev_has_removable_media(BlockBackend
*blk
);
1300 bool blk_dev_has_tray(BlockBackend
*blk
);
1301 void blk_dev_eject_request(BlockBackend
*blk
, bool force
);
1302 bool blk_dev_is_tray_open(BlockBackend
*blk
);
1303 bool blk_dev_is_medium_locked(BlockBackend
*blk
);
1305 void bdrv_set_dirty(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
);
1307 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
**out
);
1308 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
*backup
);
1309 bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap
*dest
,
1310 const BdrvDirtyBitmap
*src
,
1311 HBitmap
**backup
, bool lock
);
1313 void bdrv_inc_in_flight(BlockDriverState
*bs
);
1314 void bdrv_dec_in_flight(BlockDriverState
*bs
);
1316 void blockdev_close_all_bdrv_states(void);
1318 int coroutine_fn
bdrv_co_copy_range_from(BdrvChild
*src
, uint64_t src_offset
,
1319 BdrvChild
*dst
, uint64_t dst_offset
,
1321 BdrvRequestFlags read_flags
,
1322 BdrvRequestFlags write_flags
);
1323 int coroutine_fn
bdrv_co_copy_range_to(BdrvChild
*src
, uint64_t src_offset
,
1324 BdrvChild
*dst
, uint64_t dst_offset
,
1326 BdrvRequestFlags read_flags
,
1327 BdrvRequestFlags write_flags
);
1329 int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
);
1331 void bdrv_set_monitor_owned(BlockDriverState
*bs
);
1332 BlockDriverState
*bds_tree_init(QDict
*bs_opts
, Error
**errp
);
1335 * Simple implementation of bdrv_co_create_opts for protocol drivers
1336 * which only support creation via opening a file
1337 * (usually existing raw storage device)
1339 int coroutine_fn
bdrv_co_create_opts_simple(BlockDriver
*drv
,
1340 const char *filename
,
1343 extern QemuOptsList bdrv_create_opts_simple
;
1345 #endif /* BLOCK_INT_H */