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_EXTENT_SIZE_HINT "extent_size_hint"
57 #define BLOCK_OPT_OBJECT_SIZE "object_size"
58 #define BLOCK_OPT_REFCOUNT_BITS "refcount_bits"
59 #define BLOCK_OPT_DATA_FILE "data_file"
60 #define BLOCK_OPT_DATA_FILE_RAW "data_file_raw"
61 #define BLOCK_OPT_COMPRESSION_TYPE "compression_type"
62 #define BLOCK_OPT_EXTL2 "extended_l2"
64 #define BLOCK_PROBE_BUF_SIZE 512
66 enum BdrvTrackedRequestType
{
70 BDRV_TRACKED_TRUNCATE
,
74 * That is not quite good that BdrvTrackedRequest structure is public,
75 * as block/io.c is very careful about incoming offset/bytes being
76 * correct. Be sure to assert bdrv_check_request() succeeded after any
77 * modification of BdrvTrackedRequest object out of block/io.c
79 typedef struct BdrvTrackedRequest
{
83 enum BdrvTrackedRequestType type
;
86 int64_t overlap_offset
;
87 int64_t overlap_bytes
;
89 QLIST_ENTRY(BdrvTrackedRequest
) list
;
90 Coroutine
*co
; /* owner, used for deadlock detection */
91 CoQueue wait_queue
; /* coroutines blocked on this request */
93 struct BdrvTrackedRequest
*waiting_for
;
96 int bdrv_check_request(int64_t offset
, int64_t bytes
, Error
**errp
);
99 const char *format_name
;
102 /* set to true if the BlockDriver is a block filter. Block filters pass
103 * certain callbacks that refer to data (see block.c) to their bs->file
104 * or bs->backing (whichever one exists) if the driver doesn't implement
105 * them. Drivers that do not wish to forward must implement them and return
107 * Note that filters are not allowed to modify data.
109 * Filters generally cannot have more than a single filtered child,
110 * because the data they present must at all times be the same as
111 * that on their filtered child. That would be impossible to
112 * achieve for multiple filtered children.
113 * (And this filtered child must then be bs->file or bs->backing.)
117 * Set to true if the BlockDriver is a format driver. Format nodes
118 * generally do not expect their children to be other format nodes
119 * (except for backing files), and so format probing is disabled
124 * Return true if @to_replace can be replaced by a BDS with the
125 * same data as @bs without it affecting @bs's behavior (that is,
126 * without it being visible to @bs's parents).
128 bool (*bdrv_recurse_can_replace
)(BlockDriverState
*bs
,
129 BlockDriverState
*to_replace
);
131 int (*bdrv_probe
)(const uint8_t *buf
, int buf_size
, const char *filename
);
132 int (*bdrv_probe_device
)(const char *filename
);
134 /* Any driver implementing this callback is expected to be able to handle
135 * NULL file names in its .bdrv_open() implementation */
136 void (*bdrv_parse_filename
)(const char *filename
, QDict
*options
, Error
**errp
);
137 /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
138 * this field set to true, except ones that are defined only by their
140 * An example of the last type will be the quorum block driver.
142 bool bdrv_needs_filename
;
145 * Set if a driver can support backing files. This also implies the
146 * following semantics:
148 * - Return status 0 of .bdrv_co_block_status means that corresponding
149 * blocks are not allocated in this layer of backing-chain
150 * - For such (unallocated) blocks, read will:
151 * - fill buffer with zeros if there is no backing file
152 * - read from the backing file otherwise, where the block layer
153 * takes care of reading zeros beyond EOF if backing file is short
155 bool supports_backing
;
157 /* For handling image reopen for split or non-split files */
158 int (*bdrv_reopen_prepare
)(BDRVReopenState
*reopen_state
,
159 BlockReopenQueue
*queue
, Error
**errp
);
160 void (*bdrv_reopen_commit
)(BDRVReopenState
*reopen_state
);
161 void (*bdrv_reopen_commit_post
)(BDRVReopenState
*reopen_state
);
162 void (*bdrv_reopen_abort
)(BDRVReopenState
*reopen_state
);
163 void (*bdrv_join_options
)(QDict
*options
, QDict
*old_options
);
165 int (*bdrv_open
)(BlockDriverState
*bs
, QDict
*options
, int flags
,
168 /* Protocol drivers should implement this instead of bdrv_open */
169 int (*bdrv_file_open
)(BlockDriverState
*bs
, QDict
*options
, int flags
,
171 void (*bdrv_close
)(BlockDriverState
*bs
);
174 int coroutine_fn (*bdrv_co_create
)(BlockdevCreateOptions
*opts
,
176 int coroutine_fn (*bdrv_co_create_opts
)(BlockDriver
*drv
,
177 const char *filename
,
181 int coroutine_fn (*bdrv_co_amend
)(BlockDriverState
*bs
,
182 BlockdevAmendOptions
*opts
,
186 int (*bdrv_amend_options
)(BlockDriverState
*bs
,
188 BlockDriverAmendStatusCB
*status_cb
,
193 int (*bdrv_make_empty
)(BlockDriverState
*bs
);
196 * Refreshes the bs->exact_filename field. If that is impossible,
197 * bs->exact_filename has to be left empty.
199 void (*bdrv_refresh_filename
)(BlockDriverState
*bs
);
202 * Gathers the open options for all children into @target.
203 * A simple format driver (without backing file support) might
204 * implement this function like this:
206 * QINCREF(bs->file->bs->full_open_options);
207 * qdict_put(target, "file", bs->file->bs->full_open_options);
209 * If not specified, the generic implementation will simply put
210 * all children's options under their respective name.
212 * @backing_overridden is true when bs->backing seems not to be
213 * the child that would result from opening bs->backing_file.
214 * Therefore, if it is true, the backing child's options should be
215 * gathered; otherwise, there is no need since the backing child
216 * is the one implied by the image header.
218 * Note that ideally this function would not be needed. Every
219 * block driver which implements it is probably doing something
220 * shady regarding its runtime option structure.
222 void (*bdrv_gather_child_options
)(BlockDriverState
*bs
, QDict
*target
,
223 bool backing_overridden
);
226 * Returns an allocated string which is the directory name of this BDS: It
227 * will be used to make relative filenames absolute by prepending this
228 * function's return value to them.
230 char *(*bdrv_dirname
)(BlockDriverState
*bs
, Error
**errp
);
233 BlockAIOCB
*(*bdrv_aio_preadv
)(BlockDriverState
*bs
,
234 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
,
235 BlockCompletionFunc
*cb
, void *opaque
);
236 BlockAIOCB
*(*bdrv_aio_pwritev
)(BlockDriverState
*bs
,
237 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
,
238 BlockCompletionFunc
*cb
, void *opaque
);
239 BlockAIOCB
*(*bdrv_aio_flush
)(BlockDriverState
*bs
,
240 BlockCompletionFunc
*cb
, void *opaque
);
241 BlockAIOCB
*(*bdrv_aio_pdiscard
)(BlockDriverState
*bs
,
242 int64_t offset
, int bytes
,
243 BlockCompletionFunc
*cb
, void *opaque
);
245 int coroutine_fn (*bdrv_co_readv
)(BlockDriverState
*bs
,
246 int64_t sector_num
, int nb_sectors
, QEMUIOVector
*qiov
);
249 * @offset: position in bytes to read at
250 * @bytes: number of bytes to read
251 * @qiov: the buffers to fill with read data
252 * @flags: currently unused, always 0
254 * @offset and @bytes will be a multiple of 'request_alignment',
255 * but the length of individual @qiov elements does not have to
258 * @bytes will always equal the total size of @qiov, and will be
259 * no larger than 'max_transfer'.
261 * The buffer in @qiov may point directly to guest memory.
263 int coroutine_fn (*bdrv_co_preadv
)(BlockDriverState
*bs
,
264 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
);
265 int coroutine_fn (*bdrv_co_preadv_part
)(BlockDriverState
*bs
,
266 uint64_t offset
, uint64_t bytes
,
267 QEMUIOVector
*qiov
, size_t qiov_offset
, int flags
);
268 int coroutine_fn (*bdrv_co_writev
)(BlockDriverState
*bs
,
269 int64_t sector_num
, int nb_sectors
, QEMUIOVector
*qiov
, int flags
);
271 * @offset: position in bytes to write at
272 * @bytes: number of bytes to write
273 * @qiov: the buffers containing data to write
274 * @flags: zero or more bits allowed by 'supported_write_flags'
276 * @offset and @bytes will be a multiple of 'request_alignment',
277 * but the length of individual @qiov elements does not have to
280 * @bytes will always equal the total size of @qiov, and will be
281 * no larger than 'max_transfer'.
283 * The buffer in @qiov may point directly to guest memory.
285 int coroutine_fn (*bdrv_co_pwritev
)(BlockDriverState
*bs
,
286 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
, int flags
);
287 int coroutine_fn (*bdrv_co_pwritev_part
)(BlockDriverState
*bs
,
288 uint64_t offset
, uint64_t bytes
,
289 QEMUIOVector
*qiov
, size_t qiov_offset
, int flags
);
292 * Efficiently zero a region of the disk image. Typically an image format
293 * would use a compact metadata representation to implement this. This
294 * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
295 * will be called instead.
297 int coroutine_fn (*bdrv_co_pwrite_zeroes
)(BlockDriverState
*bs
,
298 int64_t offset
, int bytes
, BdrvRequestFlags flags
);
299 int coroutine_fn (*bdrv_co_pdiscard
)(BlockDriverState
*bs
,
300 int64_t offset
, int bytes
);
302 /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
303 * and invoke bdrv_co_copy_range_from(child, ...), or invoke
304 * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
306 * See the comment of bdrv_co_copy_range for the parameter and return value
309 int coroutine_fn (*bdrv_co_copy_range_from
)(BlockDriverState
*bs
,
315 BdrvRequestFlags read_flags
,
316 BdrvRequestFlags write_flags
);
318 /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
319 * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
320 * operation if @bs is the leaf and @src has the same BlockDriver. Return
321 * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
323 * See the comment of bdrv_co_copy_range for the parameter and return value
326 int coroutine_fn (*bdrv_co_copy_range_to
)(BlockDriverState
*bs
,
332 BdrvRequestFlags read_flags
,
333 BdrvRequestFlags write_flags
);
336 * Building block for bdrv_block_status[_above] and
337 * bdrv_is_allocated[_above]. The driver should answer only
338 * according to the current layer, and should only need to set
339 * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
340 * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
341 * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See
342 * block.h for the overall meaning of the bits. As a hint, the
343 * flag want_zero is true if the caller cares more about precise
344 * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
345 * overall allocation (favor larger *pnum, perhaps by reporting
346 * _DATA instead of _ZERO). The block layer guarantees input
347 * clamped to bdrv_getlength() and aligned to request_alignment,
348 * as well as non-NULL pnum, map, and file; in turn, the driver
349 * must return an error or set pnum to an aligned non-zero value.
351 int coroutine_fn (*bdrv_co_block_status
)(BlockDriverState
*bs
,
352 bool want_zero
, int64_t offset
, int64_t bytes
, int64_t *pnum
,
353 int64_t *map
, BlockDriverState
**file
);
356 * This informs the driver that we are no longer interested in the result
357 * of in-flight requests, so don't waste the time if possible.
359 * One example usage is to avoid waiting for an nbd target node reconnect
360 * timeout during job-cancel with force=true.
362 void (*bdrv_cancel_in_flight
)(BlockDriverState
*bs
);
365 * Invalidate any cached meta-data.
367 void coroutine_fn (*bdrv_co_invalidate_cache
)(BlockDriverState
*bs
,
369 int (*bdrv_inactivate
)(BlockDriverState
*bs
);
372 * Flushes all data for all layers by calling bdrv_co_flush for underlying
373 * layers, if needed. This function is needed for deterministic
374 * synchronization of the flush finishing callback.
376 int coroutine_fn (*bdrv_co_flush
)(BlockDriverState
*bs
);
378 /* Delete a created file. */
379 int coroutine_fn (*bdrv_co_delete_file
)(BlockDriverState
*bs
,
383 * Flushes all data that was already written to the OS all the way down to
384 * the disk (for example file-posix.c calls fsync()).
386 int coroutine_fn (*bdrv_co_flush_to_disk
)(BlockDriverState
*bs
);
389 * Flushes all internal caches to the OS. The data may still sit in a
390 * writeback cache of the host OS, but it will survive a crash of the qemu
393 int coroutine_fn (*bdrv_co_flush_to_os
)(BlockDriverState
*bs
);
396 * Drivers setting this field must be able to work with just a plain
397 * filename with '<protocol_name>:' as a prefix, and no other options.
398 * Options may be extracted from the filename by implementing
399 * bdrv_parse_filename.
401 const char *protocol_name
;
404 * Truncate @bs to @offset bytes using the given @prealloc mode
405 * when growing. Modes other than PREALLOC_MODE_OFF should be
406 * rejected when shrinking @bs.
408 * If @exact is true, @bs must be resized to exactly @offset.
409 * Otherwise, it is sufficient for @bs (if it is a host block
410 * device and thus there is no way to resize it) to be at least
411 * @offset bytes in length.
413 * If @exact is true and this function fails but would succeed
414 * with @exact = false, it should return -ENOTSUP.
416 int coroutine_fn (*bdrv_co_truncate
)(BlockDriverState
*bs
, int64_t offset
,
417 bool exact
, PreallocMode prealloc
,
418 BdrvRequestFlags flags
, Error
**errp
);
420 int64_t (*bdrv_getlength
)(BlockDriverState
*bs
);
421 bool has_variable_length
;
422 int64_t (*bdrv_get_allocated_file_size
)(BlockDriverState
*bs
);
423 BlockMeasureInfo
*(*bdrv_measure
)(QemuOpts
*opts
, BlockDriverState
*in_bs
,
426 int coroutine_fn (*bdrv_co_pwritev_compressed
)(BlockDriverState
*bs
,
427 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
);
428 int coroutine_fn (*bdrv_co_pwritev_compressed_part
)(BlockDriverState
*bs
,
429 uint64_t offset
, uint64_t bytes
, QEMUIOVector
*qiov
,
432 int (*bdrv_snapshot_create
)(BlockDriverState
*bs
,
433 QEMUSnapshotInfo
*sn_info
);
434 int (*bdrv_snapshot_goto
)(BlockDriverState
*bs
,
435 const char *snapshot_id
);
436 int (*bdrv_snapshot_delete
)(BlockDriverState
*bs
,
437 const char *snapshot_id
,
440 int (*bdrv_snapshot_list
)(BlockDriverState
*bs
,
441 QEMUSnapshotInfo
**psn_info
);
442 int (*bdrv_snapshot_load_tmp
)(BlockDriverState
*bs
,
443 const char *snapshot_id
,
446 int (*bdrv_get_info
)(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
447 ImageInfoSpecific
*(*bdrv_get_specific_info
)(BlockDriverState
*bs
,
449 BlockStatsSpecific
*(*bdrv_get_specific_stats
)(BlockDriverState
*bs
);
451 int coroutine_fn (*bdrv_save_vmstate
)(BlockDriverState
*bs
,
454 int coroutine_fn (*bdrv_load_vmstate
)(BlockDriverState
*bs
,
458 int (*bdrv_change_backing_file
)(BlockDriverState
*bs
,
459 const char *backing_file
, const char *backing_fmt
);
461 /* removable device specific */
462 bool (*bdrv_is_inserted
)(BlockDriverState
*bs
);
463 void (*bdrv_eject
)(BlockDriverState
*bs
, bool eject_flag
);
464 void (*bdrv_lock_medium
)(BlockDriverState
*bs
, bool locked
);
466 /* to control generic scsi devices */
467 BlockAIOCB
*(*bdrv_aio_ioctl
)(BlockDriverState
*bs
,
468 unsigned long int req
, void *buf
,
469 BlockCompletionFunc
*cb
, void *opaque
);
470 int coroutine_fn (*bdrv_co_ioctl
)(BlockDriverState
*bs
,
471 unsigned long int req
, void *buf
);
473 /* List of options for creating images, terminated by name == NULL */
474 QemuOptsList
*create_opts
;
476 /* List of options for image amend */
477 QemuOptsList
*amend_opts
;
480 * If this driver supports reopening images this contains a
481 * NULL-terminated list of the runtime options that can be
482 * modified. If an option in this list is unspecified during
483 * reopen then it _must_ be reset to its default value or return
486 const char *const *mutable_opts
;
489 * Returns 0 for completed check, -errno for internal errors.
490 * The check results are stored in result.
492 int coroutine_fn (*bdrv_co_check
)(BlockDriverState
*bs
,
493 BdrvCheckResult
*result
,
496 void (*bdrv_debug_event
)(BlockDriverState
*bs
, BlkdebugEvent event
);
498 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
499 int (*bdrv_debug_breakpoint
)(BlockDriverState
*bs
, const char *event
,
501 int (*bdrv_debug_remove_breakpoint
)(BlockDriverState
*bs
,
503 int (*bdrv_debug_resume
)(BlockDriverState
*bs
, const char *tag
);
504 bool (*bdrv_debug_is_suspended
)(BlockDriverState
*bs
, const char *tag
);
506 void (*bdrv_refresh_limits
)(BlockDriverState
*bs
, Error
**errp
);
509 * Returns 1 if newly created images are guaranteed to contain only
510 * zeros, 0 otherwise.
512 int (*bdrv_has_zero_init
)(BlockDriverState
*bs
);
514 /* Remove fd handlers, timers, and other event loop callbacks so the event
515 * loop is no longer in use. Called with no in-flight requests and in
516 * depth-first traversal order with parents before child nodes.
518 void (*bdrv_detach_aio_context
)(BlockDriverState
*bs
);
520 /* Add fd handlers, timers, and other event loop callbacks so I/O requests
521 * can be processed again. Called with no in-flight requests and in
522 * depth-first traversal order with child nodes before parent nodes.
524 void (*bdrv_attach_aio_context
)(BlockDriverState
*bs
,
525 AioContext
*new_context
);
527 /* io queue for linux-aio */
528 void (*bdrv_io_plug
)(BlockDriverState
*bs
);
529 void (*bdrv_io_unplug
)(BlockDriverState
*bs
);
532 * Try to get @bs's logical and physical block size.
533 * On success, store them in @bsz and return zero.
534 * On failure, return negative errno.
536 int (*bdrv_probe_blocksizes
)(BlockDriverState
*bs
, BlockSizes
*bsz
);
538 * Try to get @bs's geometry (cyls, heads, sectors)
539 * On success, store them in @geo and return 0.
540 * On failure return -errno.
541 * Only drivers that want to override guest geometry implement this
542 * callback; see hd_geometry_guess().
544 int (*bdrv_probe_geometry
)(BlockDriverState
*bs
, HDGeometry
*geo
);
547 * bdrv_co_drain_begin is called if implemented in the beginning of a
548 * drain operation to drain and stop any internal sources of requests in
550 * bdrv_co_drain_end is called if implemented at the end of the drain.
552 * They should be used by the driver to e.g. manage scheduled I/O
553 * requests, or toggle an internal state. After the end of the drain new
554 * requests will continue normally.
556 void coroutine_fn (*bdrv_co_drain_begin
)(BlockDriverState
*bs
);
557 void coroutine_fn (*bdrv_co_drain_end
)(BlockDriverState
*bs
);
559 void (*bdrv_add_child
)(BlockDriverState
*parent
, BlockDriverState
*child
,
561 void (*bdrv_del_child
)(BlockDriverState
*parent
, BdrvChild
*child
,
565 * Informs the block driver that a permission change is intended. The
566 * driver checks whether the change is permissible and may take other
567 * preparations for the change (e.g. get file system locks). This operation
568 * is always followed either by a call to either .bdrv_set_perm or
569 * .bdrv_abort_perm_update.
571 * Checks whether the requested set of cumulative permissions in @perm
572 * can be granted for accessing @bs and whether no other users are using
573 * permissions other than those given in @shared (both arguments take
574 * BLK_PERM_* bitmasks).
576 * If both conditions are met, 0 is returned. Otherwise, -errno is returned
577 * and errp is set to an error describing the conflict.
579 int (*bdrv_check_perm
)(BlockDriverState
*bs
, uint64_t perm
,
580 uint64_t shared
, Error
**errp
);
583 * Called to inform the driver that the set of cumulative set of used
584 * permissions for @bs has changed to @perm, and the set of sharable
585 * permission to @shared. The driver can use this to propagate changes to
586 * its children (i.e. request permissions only if a parent actually needs
589 * This function is only invoked after bdrv_check_perm(), so block drivers
590 * may rely on preparations made in their .bdrv_check_perm implementation.
592 void (*bdrv_set_perm
)(BlockDriverState
*bs
, uint64_t perm
, uint64_t shared
);
595 * Called to inform the driver that after a previous bdrv_check_perm()
596 * call, the permission update is not performed and any preparations made
597 * for it (e.g. taken file locks) need to be undone.
599 * This function can be called even for nodes that never saw a
600 * bdrv_check_perm() call. It is a no-op then.
602 void (*bdrv_abort_perm_update
)(BlockDriverState
*bs
);
605 * Returns in @nperm and @nshared the permissions that the driver for @bs
606 * needs on its child @c, based on the cumulative permissions requested by
607 * the parents in @parent_perm and @parent_shared.
609 * If @c is NULL, return the permissions for attaching a new child for the
610 * given @child_class and @role.
612 * If @reopen_queue is non-NULL, don't return the currently needed
613 * permissions, but those that will be needed after applying the
616 void (*bdrv_child_perm
)(BlockDriverState
*bs
, BdrvChild
*c
,
618 BlockReopenQueue
*reopen_queue
,
619 uint64_t parent_perm
, uint64_t parent_shared
,
620 uint64_t *nperm
, uint64_t *nshared
);
622 bool (*bdrv_supports_persistent_dirty_bitmap
)(BlockDriverState
*bs
);
623 bool (*bdrv_co_can_store_new_dirty_bitmap
)(BlockDriverState
*bs
,
625 uint32_t granularity
,
627 int (*bdrv_co_remove_persistent_dirty_bitmap
)(BlockDriverState
*bs
,
632 * Register/unregister a buffer for I/O. For example, when the driver is
633 * interested to know the memory areas that will later be used in iovs, so
634 * that it can do IOMMU mapping with VFIO etc., in order to get better
635 * performance. In the case of VFIO drivers, this callback is used to do
636 * DMA mapping for hot buffers.
638 void (*bdrv_register_buf
)(BlockDriverState
*bs
, void *host
, size_t size
);
639 void (*bdrv_unregister_buf
)(BlockDriverState
*bs
, void *host
);
640 QLIST_ENTRY(BlockDriver
) list
;
642 /* Pointer to a NULL-terminated array of names of strong options
643 * that can be specified for bdrv_open(). A strong option is one
644 * that changes the data of a BDS.
645 * If this pointer is NULL, the array is considered empty.
646 * "filename" and "driver" are always considered strong. */
647 const char *const *strong_runtime_opts
;
650 static inline bool block_driver_can_compress(BlockDriver
*drv
)
652 return drv
->bdrv_co_pwritev_compressed
||
653 drv
->bdrv_co_pwritev_compressed_part
;
656 typedef struct BlockLimits
{
657 /* Alignment requirement, in bytes, for offset/length of I/O
658 * requests. Must be a power of 2 less than INT_MAX; defaults to
659 * 1 for drivers with modern byte interfaces, and to 512
661 uint32_t request_alignment
;
663 /* Maximum number of bytes that can be discarded at once (since it
664 * is signed, it must be < 2G, if set). Must be multiple of
665 * pdiscard_alignment, but need not be power of 2. May be 0 if no
666 * inherent 32-bit limit */
667 int32_t max_pdiscard
;
669 /* Optimal alignment for discard requests in bytes. A power of 2
670 * is best but not mandatory. Must be a multiple of
671 * bl.request_alignment, and must be less than max_pdiscard if
672 * that is set. May be 0 if bl.request_alignment is good enough */
673 uint32_t pdiscard_alignment
;
675 /* Maximum number of bytes that can zeroized at once (since it is
676 * signed, it must be < 2G, if set). Must be multiple of
677 * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
678 int32_t max_pwrite_zeroes
;
680 /* Optimal alignment for write zeroes requests in bytes. A power
681 * of 2 is best but not mandatory. Must be a multiple of
682 * bl.request_alignment, and must be less than max_pwrite_zeroes
683 * if that is set. May be 0 if bl.request_alignment is good
685 uint32_t pwrite_zeroes_alignment
;
687 /* Optimal transfer length in bytes. A power of 2 is best but not
688 * mandatory. Must be a multiple of bl.request_alignment, or 0 if
689 * no preferred size */
690 uint32_t opt_transfer
;
692 /* Maximal transfer length in bytes. Need not be power of 2, but
693 * must be multiple of opt_transfer and bl.request_alignment, or 0
694 * for no 32-bit limit. For now, anything larger than INT_MAX is
696 uint32_t max_transfer
;
698 /* Maximal hardware transfer length in bytes. Applies whenever
699 * transfers to the device bypass the kernel I/O scheduler, for
700 * example with SG_IO. If larger than max_transfer or if zero,
701 * blk_get_max_hw_transfer will fall back to max_transfer.
703 uint64_t max_hw_transfer
;
705 /* memory alignment, in bytes so that no bounce buffer is needed */
706 size_t min_mem_alignment
;
708 /* memory alignment, in bytes, for bounce buffer */
709 size_t opt_mem_alignment
;
711 /* maximum number of iovec elements */
715 typedef struct BdrvOpBlocker BdrvOpBlocker
;
717 typedef struct BdrvAioNotifier
{
718 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
);
719 void (*detach_aio_context
)(void *opaque
);
724 QLIST_ENTRY(BdrvAioNotifier
) list
;
727 struct BdrvChildClass
{
728 /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
732 /* If true, the parent is a BlockDriverState and bdrv_next_all_states()
733 * will return it. This information is used for drain_all, where every node
734 * will be drained separately, so the drain only needs to be propagated to
735 * non-BDS parents. */
738 void (*inherit_options
)(BdrvChildRole role
, bool parent_is_format
,
739 int *child_flags
, QDict
*child_options
,
740 int parent_flags
, QDict
*parent_options
);
742 void (*change_media
)(BdrvChild
*child
, bool load
);
743 void (*resize
)(BdrvChild
*child
);
745 /* Returns a name that is supposedly more useful for human users than the
746 * node name for identifying the node in question (in particular, a BB
747 * name), or NULL if the parent can't provide a better name. */
748 const char *(*get_name
)(BdrvChild
*child
);
750 /* Returns a malloced string that describes the parent of the child for a
751 * human reader. This could be a node-name, BlockBackend name, qdev ID or
752 * QOM path of the device owning the BlockBackend, job type and ID etc. The
753 * caller is responsible for freeing the memory. */
754 char *(*get_parent_desc
)(BdrvChild
*child
);
757 * If this pair of functions is implemented, the parent doesn't issue new
758 * requests after returning from .drained_begin() until .drained_end() is
761 * These functions must not change the graph (and therefore also must not
762 * call aio_poll(), which could change the graph indirectly).
764 * If drained_end() schedules background operations, it must atomically
765 * increment *drained_end_counter for each such operation and atomically
766 * decrement it once the operation has settled.
768 * Note that this can be nested. If drained_begin() was called twice, new
769 * I/O is allowed only after drained_end() was called twice, too.
771 void (*drained_begin
)(BdrvChild
*child
);
772 void (*drained_end
)(BdrvChild
*child
, int *drained_end_counter
);
775 * Returns whether the parent has pending requests for the child. This
776 * callback is polled after .drained_begin() has been called until all
777 * activity on the child has stopped.
779 bool (*drained_poll
)(BdrvChild
*child
);
781 /* Notifies the parent that the child has been activated/inactivated (e.g.
782 * when migration is completing) and it can start/stop requesting
783 * permissions and doing I/O on it. */
784 void (*activate
)(BdrvChild
*child
, Error
**errp
);
785 int (*inactivate
)(BdrvChild
*child
);
787 void (*attach
)(BdrvChild
*child
);
788 void (*detach
)(BdrvChild
*child
);
790 /* Notifies the parent that the filename of its child has changed (e.g.
791 * because the direct child was removed from the backing chain), so that it
792 * can update its reference. */
793 int (*update_filename
)(BdrvChild
*child
, BlockDriverState
*new_base
,
794 const char *filename
, Error
**errp
);
796 bool (*can_set_aio_ctx
)(BdrvChild
*child
, AioContext
*ctx
,
797 GSList
**ignore
, Error
**errp
);
798 void (*set_aio_ctx
)(BdrvChild
*child
, AioContext
*ctx
, GSList
**ignore
);
800 AioContext
*(*get_parent_aio_context
)(BdrvChild
*child
);
803 extern const BdrvChildClass child_of_bds
;
806 BlockDriverState
*bs
;
808 const BdrvChildClass
*klass
;
813 * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
818 * Permissions that can still be granted to other users of @bs while this
819 * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
821 uint64_t shared_perm
;
824 * This link is frozen: the child can neither be replaced nor
825 * detached from the parent.
830 * How many times the parent of this child has been drained
831 * (through klass->drained_*).
832 * Usually, this is equal to bs->quiesce_counter (potentially
833 * reduced by bdrv_drain_all_count). It may differ while the
834 * child is entering or leaving a drained section.
836 int parent_quiesce_counter
;
838 QLIST_ENTRY(BdrvChild
) next
;
839 QLIST_ENTRY(BdrvChild
) next_parent
;
843 * Note: the function bdrv_append() copies and swaps contents of
844 * BlockDriverStates, so if you add new fields to this struct, please
845 * inspect bdrv_append() to determine if the new fields need to be
848 struct BlockDriverState
{
849 /* Protected by big QEMU lock or read-only after opening. No special
850 * locking needed during I/O...
852 int open_flags
; /* flags used to open the file, re-used for re-open */
853 bool encrypted
; /* if true, the media is encrypted */
854 bool sg
; /* if true, the device is a /dev/sg* */
855 bool probed
; /* if true, format was probed rather than specified */
856 bool force_share
; /* if true, always allow all shared permissions */
857 bool implicit
; /* if true, this filter node was automatically inserted */
859 BlockDriver
*drv
; /* NULL means no media */
862 AioContext
*aio_context
; /* event loop used for fd handlers, timers, etc */
863 /* long-running tasks intended to always use the same AioContext as this
864 * BDS may register themselves in this list to be notified of changes
865 * regarding this BDS's context */
866 QLIST_HEAD(, BdrvAioNotifier
) aio_notifiers
;
867 bool walking_aio_notifiers
; /* to make removal during iteration safe */
869 char filename
[PATH_MAX
];
871 * If not empty, this image is a diff in relation to backing_file.
872 * Note that this is the name given in the image header and
873 * therefore may or may not be equal to .backing->bs->filename.
874 * If this field contains a relative path, it is to be resolved
875 * relatively to the overlay's location.
877 char backing_file
[PATH_MAX
];
879 * The backing filename indicated by the image header. Contrary
880 * to backing_file, if we ever open this file, auto_backing_file
881 * is replaced by the resulting BDS's filename (i.e. after a
882 * bdrv_refresh_filename() run).
884 char auto_backing_file
[PATH_MAX
];
885 char backing_format
[16]; /* if non-zero and backing_file exists */
887 QDict
*full_open_options
;
888 char exact_filename
[PATH_MAX
];
897 * Flags honored during pread
899 unsigned int supported_read_flags
;
900 /* Flags honored during pwrite (so far: BDRV_REQ_FUA,
901 * BDRV_REQ_WRITE_UNCHANGED).
902 * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
903 * writes will be issued as normal writes without the flag set.
904 * This is important to note for drivers that do not explicitly
905 * request a WRITE permission for their children and instead take
906 * the same permissions as their parent did (this is commonly what
907 * block filters do). Such drivers have to be aware that the
908 * parent may have taken a WRITE_UNCHANGED permission only and is
909 * issuing such requests. Drivers either must make sure that
910 * these requests do not result in plain WRITE accesses (usually
911 * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
912 * every incoming write request as-is, including potentially that
913 * flag), or they have to explicitly take the WRITE permission for
915 unsigned int supported_write_flags
;
916 /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
917 * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */
918 unsigned int supported_zero_flags
;
920 * Flags honoured during truncate (so far: BDRV_REQ_ZERO_WRITE).
922 * If BDRV_REQ_ZERO_WRITE is given, the truncate operation must make sure
923 * that any added space reads as all zeros. If this can't be guaranteed,
924 * the operation must fail.
926 unsigned int supported_truncate_flags
;
928 /* the following member gives a name to every node on the bs graph. */
930 /* element of the list of named nodes building the graph */
931 QTAILQ_ENTRY(BlockDriverState
) node_list
;
932 /* element of the list of all BlockDriverStates (all_bdrv_states) */
933 QTAILQ_ENTRY(BlockDriverState
) bs_list
;
934 /* element of the list of monitor-owned BDS */
935 QTAILQ_ENTRY(BlockDriverState
) monitor_list
;
938 /* operation blockers */
939 QLIST_HEAD(, BdrvOpBlocker
) op_blockers
[BLOCK_OP_TYPE_MAX
];
941 /* The node that this node inherited default options from (and a reopen on
942 * which can affect this node by changing these defaults). This is always a
943 * parent node of this node. */
944 BlockDriverState
*inherits_from
;
945 QLIST_HEAD(, BdrvChild
) children
;
946 QLIST_HEAD(, BdrvChild
) parents
;
949 QDict
*explicit_options
;
950 BlockdevDetectZeroesOptions detect_zeroes
;
952 /* The error object in use for blocking operations on backing_hd */
953 Error
*backing_blocker
;
955 /* Protected by AioContext lock */
957 /* If we are reading a disk image, give its size in sectors.
958 * Generally read-only; it is written to by load_snapshot and
959 * save_snaphost, but the block layer is quiescent during those.
961 int64_t total_sectors
;
963 /* threshold limit for writes, in bytes. "High water mark". */
964 uint64_t write_threshold_offset
;
966 /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
967 * Reading from the list can be done with either the BQL or the
968 * dirty_bitmap_mutex. Modifying a bitmap only requires
969 * dirty_bitmap_mutex. */
970 QemuMutex dirty_bitmap_mutex
;
971 QLIST_HEAD(, BdrvDirtyBitmap
) dirty_bitmaps
;
973 /* Offset after the highest byte written to */
974 Stat64 wr_highest_offset
;
976 /* If true, copy read backing sectors into image. Can be >1 if more
977 * than one client has requested copy-on-read. Accessed with atomic
982 /* number of in-flight requests; overall and serialising.
983 * Accessed with atomic ops.
985 unsigned int in_flight
;
986 unsigned int serialising_in_flight
;
988 /* counter for nested bdrv_io_plug.
989 * Accessed with atomic ops.
993 /* do we need to tell the quest if we have a volatile write cache? */
994 int enable_write_cache
;
996 /* Accessed with atomic ops. */
998 int recursive_quiesce_counter
;
1000 unsigned int write_gen
; /* Current data generation */
1002 /* Protected by reqs_lock. */
1004 QLIST_HEAD(, BdrvTrackedRequest
) tracked_requests
;
1005 CoQueue flush_queue
; /* Serializing flush queue */
1006 bool active_flush_req
; /* Flush request in flight? */
1008 /* Only read/written by whoever has set active_flush_req to true. */
1009 unsigned int flushed_gen
; /* Flushed write generation */
1011 /* BdrvChild links to this node may never be frozen */
1015 struct BlockBackendRootState
{
1017 BlockdevDetectZeroesOptions detect_zeroes
;
1020 typedef enum BlockMirrorBackingMode
{
1021 /* Reuse the existing backing chain from the source for the target.
1022 * - sync=full: Set backing BDS to NULL.
1023 * - sync=top: Use source's backing BDS.
1024 * - sync=none: Use source as the backing BDS. */
1025 MIRROR_SOURCE_BACKING_CHAIN
,
1027 /* Open the target's backing chain completely anew */
1028 MIRROR_OPEN_BACKING_CHAIN
,
1030 /* Do not change the target's backing BDS after job completion */
1031 MIRROR_LEAVE_BACKING_CHAIN
,
1032 } BlockMirrorBackingMode
;
1035 /* Essential block drivers which must always be statically linked into qemu, and
1036 * which therefore can be accessed without using bdrv_find_format() */
1037 extern BlockDriver bdrv_file
;
1038 extern BlockDriver bdrv_raw
;
1039 extern BlockDriver bdrv_qcow2
;
1041 int coroutine_fn
bdrv_co_preadv(BdrvChild
*child
,
1042 int64_t offset
, int64_t bytes
, QEMUIOVector
*qiov
,
1043 BdrvRequestFlags flags
);
1044 int coroutine_fn
bdrv_co_preadv_part(BdrvChild
*child
,
1045 int64_t offset
, int64_t bytes
,
1046 QEMUIOVector
*qiov
, size_t qiov_offset
, BdrvRequestFlags flags
);
1047 int coroutine_fn
bdrv_co_pwritev(BdrvChild
*child
,
1048 int64_t offset
, int64_t bytes
, QEMUIOVector
*qiov
,
1049 BdrvRequestFlags flags
);
1050 int coroutine_fn
bdrv_co_pwritev_part(BdrvChild
*child
,
1051 int64_t offset
, int64_t bytes
,
1052 QEMUIOVector
*qiov
, size_t qiov_offset
, BdrvRequestFlags flags
);
1054 static inline int coroutine_fn
bdrv_co_pread(BdrvChild
*child
,
1055 int64_t offset
, unsigned int bytes
, void *buf
, BdrvRequestFlags flags
)
1057 QEMUIOVector qiov
= QEMU_IOVEC_INIT_BUF(qiov
, buf
, bytes
);
1059 return bdrv_co_preadv(child
, offset
, bytes
, &qiov
, flags
);
1062 static inline int coroutine_fn
bdrv_co_pwrite(BdrvChild
*child
,
1063 int64_t offset
, unsigned int bytes
, void *buf
, BdrvRequestFlags flags
)
1065 QEMUIOVector qiov
= QEMU_IOVEC_INIT_BUF(qiov
, buf
, bytes
);
1067 return bdrv_co_pwritev(child
, offset
, bytes
, &qiov
, flags
);
1070 extern unsigned int bdrv_drain_all_count
;
1071 void bdrv_apply_subtree_drain(BdrvChild
*child
, BlockDriverState
*new_parent
);
1072 void bdrv_unapply_subtree_drain(BdrvChild
*child
, BlockDriverState
*old_parent
);
1074 bool coroutine_fn
bdrv_make_request_serialising(BdrvTrackedRequest
*req
,
1076 BdrvTrackedRequest
*coroutine_fn
bdrv_co_get_self_request(BlockDriverState
*bs
);
1078 int get_tmp_filename(char *filename
, int size
);
1079 BlockDriver
*bdrv_probe_all(const uint8_t *buf
, int buf_size
,
1080 const char *filename
);
1082 void bdrv_parse_filename_strip_prefix(const char *filename
, const char *prefix
,
1085 bool bdrv_backing_overridden(BlockDriverState
*bs
);
1089 * bdrv_add_aio_context_notifier:
1091 * If a long-running job intends to be always run in the same AioContext as a
1092 * certain BDS, it may use this function to be notified of changes regarding the
1093 * association of the BDS to an AioContext.
1095 * attached_aio_context() is called after the target BDS has been attached to a
1096 * new AioContext; detach_aio_context() is called before the target BDS is being
1097 * detached from its old AioContext.
1099 void bdrv_add_aio_context_notifier(BlockDriverState
*bs
,
1100 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
1101 void (*detach_aio_context
)(void *opaque
), void *opaque
);
1104 * bdrv_remove_aio_context_notifier:
1106 * Unsubscribe of change notifications regarding the BDS's AioContext. The
1107 * parameters given here have to be the same as those given to
1108 * bdrv_add_aio_context_notifier().
1110 void bdrv_remove_aio_context_notifier(BlockDriverState
*bs
,
1111 void (*aio_context_attached
)(AioContext
*,
1113 void (*aio_context_detached
)(void *),
1118 * @bs: The BlockDriverState for which an I/O operation has been completed.
1120 * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During
1121 * synchronous I/O on a BlockDriverState that is attached to another
1122 * I/O thread, the main thread lets the I/O thread's event loop run,
1123 * waiting for the I/O operation to complete. A bdrv_wakeup will wake
1124 * up the main thread if necessary.
1126 * Manual calls to bdrv_wakeup are rarely necessary, because
1127 * bdrv_dec_in_flight already calls it.
1129 void bdrv_wakeup(BlockDriverState
*bs
);
1132 int is_windows_drive(const char *filename
);
1137 * @job_id: The id of the newly-created job, or %NULL to use the
1138 * device name of @bs.
1139 * @bs: Block device to operate on.
1140 * @base: Block device that will become the new base, or %NULL to
1141 * flatten the whole backing file chain onto @bs.
1142 * @backing_file_str: The file name that will be written to @bs as the
1143 * the new backing file if the job completes. Ignored if @base is %NULL.
1144 * @creation_flags: Flags that control the behavior of the Job lifetime.
1145 * See @BlockJobCreateFlags
1146 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1147 * @on_error: The action to take upon error.
1148 * @filter_node_name: The node name that should be assigned to the filter
1149 * driver that the stream job inserts into the graph above
1150 * @bs. NULL means that a node name should be autogenerated.
1151 * @errp: Error object.
1153 * Start a streaming operation on @bs. Clusters that are unallocated
1154 * in @bs, but allocated in any image between @base and @bs (both
1155 * exclusive) will be written to @bs. At the end of a successful
1156 * streaming job, the backing file of @bs will be changed to
1157 * @backing_file_str in the written image and to @base in the live
1160 void stream_start(const char *job_id
, BlockDriverState
*bs
,
1161 BlockDriverState
*base
, const char *backing_file_str
,
1162 BlockDriverState
*bottom
,
1163 int creation_flags
, int64_t speed
,
1164 BlockdevOnError on_error
,
1165 const char *filter_node_name
,
1170 * @job_id: The id of the newly-created job, or %NULL to use the
1171 * device name of @bs.
1172 * @bs: Active block device.
1173 * @top: Top block device to be committed.
1174 * @base: Block device that will be written into, and become the new top.
1175 * @creation_flags: Flags that control the behavior of the Job lifetime.
1176 * See @BlockJobCreateFlags
1177 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1178 * @on_error: The action to take upon error.
1179 * @backing_file_str: String to use as the backing file in @top's overlay
1180 * @filter_node_name: The node name that should be assigned to the filter
1181 * driver that the commit job inserts into the graph above @top. NULL means
1182 * that a node name should be autogenerated.
1183 * @errp: Error object.
1186 void commit_start(const char *job_id
, BlockDriverState
*bs
,
1187 BlockDriverState
*base
, BlockDriverState
*top
,
1188 int creation_flags
, int64_t speed
,
1189 BlockdevOnError on_error
, const char *backing_file_str
,
1190 const char *filter_node_name
, Error
**errp
);
1192 * commit_active_start:
1193 * @job_id: The id of the newly-created job, or %NULL to use the
1194 * device name of @bs.
1195 * @bs: Active block device to be committed.
1196 * @base: Block device that will be written into, and become the new top.
1197 * @creation_flags: Flags that control the behavior of the Job lifetime.
1198 * See @BlockJobCreateFlags
1199 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1200 * @on_error: The action to take upon error.
1201 * @filter_node_name: The node name that should be assigned to the filter
1202 * driver that the commit job inserts into the graph above @bs. NULL means that
1203 * a node name should be autogenerated.
1204 * @cb: Completion function for the job.
1205 * @opaque: Opaque pointer value passed to @cb.
1206 * @auto_complete: Auto complete the job.
1207 * @errp: Error object.
1210 BlockJob
*commit_active_start(const char *job_id
, BlockDriverState
*bs
,
1211 BlockDriverState
*base
, int creation_flags
,
1212 int64_t speed
, BlockdevOnError on_error
,
1213 const char *filter_node_name
,
1214 BlockCompletionFunc
*cb
, void *opaque
,
1215 bool auto_complete
, Error
**errp
);
1218 * @job_id: The id of the newly-created job, or %NULL to use the
1219 * device name of @bs.
1220 * @bs: Block device to operate on.
1221 * @target: Block device to write to.
1222 * @replaces: Block graph node name to replace once the mirror is done. Can
1223 * only be used when full mirroring is selected.
1224 * @creation_flags: Flags that control the behavior of the Job lifetime.
1225 * See @BlockJobCreateFlags
1226 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1227 * @granularity: The chosen granularity for the dirty bitmap.
1228 * @buf_size: The amount of data that can be in flight at one time.
1229 * @mode: Whether to collapse all images in the chain to the target.
1230 * @backing_mode: How to establish the target's backing chain after completion.
1231 * @zero_target: Whether the target should be explicitly zero-initialized
1232 * @on_source_error: The action to take upon error reading from the source.
1233 * @on_target_error: The action to take upon error writing to the target.
1234 * @unmap: Whether to unmap target where source sectors only contain zeroes.
1235 * @filter_node_name: The node name that should be assigned to the filter
1236 * driver that the mirror job inserts into the graph above @bs. NULL means that
1237 * a node name should be autogenerated.
1238 * @copy_mode: When to trigger writes to the target.
1239 * @errp: Error object.
1241 * Start a mirroring operation on @bs. Clusters that are allocated
1242 * in @bs will be written to @target until the job is cancelled or
1243 * manually completed. At the end of a successful mirroring job,
1244 * @bs will be switched to read from @target.
1246 void mirror_start(const char *job_id
, BlockDriverState
*bs
,
1247 BlockDriverState
*target
, const char *replaces
,
1248 int creation_flags
, int64_t speed
,
1249 uint32_t granularity
, int64_t buf_size
,
1250 MirrorSyncMode mode
, BlockMirrorBackingMode backing_mode
,
1252 BlockdevOnError on_source_error
,
1253 BlockdevOnError on_target_error
,
1254 bool unmap
, const char *filter_node_name
,
1255 MirrorCopyMode copy_mode
, Error
**errp
);
1258 * backup_job_create:
1259 * @job_id: The id of the newly-created job, or %NULL to use the
1260 * device name of @bs.
1261 * @bs: Block device to operate on.
1262 * @target: Block device to write to.
1263 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1264 * @sync_mode: What parts of the disk image should be copied to the destination.
1265 * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental'
1266 * @bitmap_mode: The bitmap synchronization policy to use.
1267 * @perf: Performance options. All actual fields assumed to be present,
1268 * all ".has_*" fields are ignored.
1269 * @on_source_error: The action to take upon error reading from the source.
1270 * @on_target_error: The action to take upon error writing to the target.
1271 * @creation_flags: Flags that control the behavior of the Job lifetime.
1272 * See @BlockJobCreateFlags
1273 * @cb: Completion function for the job.
1274 * @opaque: Opaque pointer value passed to @cb.
1275 * @txn: Transaction that this job is part of (may be NULL).
1277 * Create a backup operation on @bs. Clusters in @bs are written to @target
1278 * until the job is cancelled or manually completed.
1280 BlockJob
*backup_job_create(const char *job_id
, BlockDriverState
*bs
,
1281 BlockDriverState
*target
, int64_t speed
,
1282 MirrorSyncMode sync_mode
,
1283 BdrvDirtyBitmap
*sync_bitmap
,
1284 BitmapSyncMode bitmap_mode
,
1286 const char *filter_node_name
,
1288 BlockdevOnError on_source_error
,
1289 BlockdevOnError on_target_error
,
1291 BlockCompletionFunc
*cb
, void *opaque
,
1292 JobTxn
*txn
, Error
**errp
);
1294 BdrvChild
*bdrv_root_attach_child(BlockDriverState
*child_bs
,
1295 const char *child_name
,
1296 const BdrvChildClass
*child_class
,
1297 BdrvChildRole child_role
,
1298 uint64_t perm
, uint64_t shared_perm
,
1299 void *opaque
, Error
**errp
);
1300 void bdrv_root_unref_child(BdrvChild
*child
);
1302 void bdrv_get_cumulative_perm(BlockDriverState
*bs
, uint64_t *perm
,
1303 uint64_t *shared_perm
);
1306 * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use
1307 * bdrv_child_refresh_perms() instead and make the parent's
1308 * .bdrv_child_perm() implementation return the correct values.
1310 int bdrv_child_try_set_perm(BdrvChild
*c
, uint64_t perm
, uint64_t shared
,
1314 * Calls bs->drv->bdrv_child_perm() and updates the child's permission
1315 * masks with the result.
1316 * Drivers should invoke this function whenever an event occurs that
1317 * makes their .bdrv_child_perm() implementation return different
1318 * values than before, but which will not result in the block layer
1319 * automatically refreshing the permissions.
1321 int bdrv_child_refresh_perms(BlockDriverState
*bs
, BdrvChild
*c
, Error
**errp
);
1323 bool bdrv_recurse_can_replace(BlockDriverState
*bs
,
1324 BlockDriverState
*to_replace
);
1327 * Default implementation for BlockDriver.bdrv_child_perm() that can
1328 * be used by block filters and image formats, as long as they use the
1329 * child_of_bds child class and set an appropriate BdrvChildRole.
1331 void bdrv_default_perms(BlockDriverState
*bs
, BdrvChild
*c
,
1332 BdrvChildRole role
, BlockReopenQueue
*reopen_queue
,
1333 uint64_t perm
, uint64_t shared
,
1334 uint64_t *nperm
, uint64_t *nshared
);
1336 const char *bdrv_get_parent_name(const BlockDriverState
*bs
);
1337 void blk_dev_change_media_cb(BlockBackend
*blk
, bool load
, Error
**errp
);
1338 bool blk_dev_has_removable_media(BlockBackend
*blk
);
1339 bool blk_dev_has_tray(BlockBackend
*blk
);
1340 void blk_dev_eject_request(BlockBackend
*blk
, bool force
);
1341 bool blk_dev_is_tray_open(BlockBackend
*blk
);
1342 bool blk_dev_is_medium_locked(BlockBackend
*blk
);
1344 void bdrv_set_dirty(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
);
1346 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
**out
);
1347 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap
*bitmap
, HBitmap
*backup
);
1348 bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap
*dest
,
1349 const BdrvDirtyBitmap
*src
,
1350 HBitmap
**backup
, bool lock
);
1352 void bdrv_inc_in_flight(BlockDriverState
*bs
);
1353 void bdrv_dec_in_flight(BlockDriverState
*bs
);
1355 void blockdev_close_all_bdrv_states(void);
1357 int coroutine_fn
bdrv_co_copy_range_from(BdrvChild
*src
, int64_t src_offset
,
1358 BdrvChild
*dst
, int64_t dst_offset
,
1360 BdrvRequestFlags read_flags
,
1361 BdrvRequestFlags write_flags
);
1362 int coroutine_fn
bdrv_co_copy_range_to(BdrvChild
*src
, int64_t src_offset
,
1363 BdrvChild
*dst
, int64_t dst_offset
,
1365 BdrvRequestFlags read_flags
,
1366 BdrvRequestFlags write_flags
);
1368 int refresh_total_sectors(BlockDriverState
*bs
, int64_t hint
);
1370 void bdrv_set_monitor_owned(BlockDriverState
*bs
);
1371 BlockDriverState
*bds_tree_init(QDict
*bs_opts
, Error
**errp
);
1374 * Simple implementation of bdrv_co_create_opts for protocol drivers
1375 * which only support creation via opening a file
1376 * (usually existing raw storage device)
1378 int coroutine_fn
bdrv_co_create_opts_simple(BlockDriver
*drv
,
1379 const char *filename
,
1382 extern QemuOptsList bdrv_create_opts_simple
;
1384 BdrvDirtyBitmap
*block_dirty_bitmap_lookup(const char *node
,
1386 BlockDriverState
**pbs
,
1388 BdrvDirtyBitmap
*block_dirty_bitmap_merge(const char *node
, const char *target
,
1389 BlockDirtyBitmapMergeSourceList
*bms
,
1390 HBitmap
**backup
, Error
**errp
);
1391 BdrvDirtyBitmap
*block_dirty_bitmap_remove(const char *node
, const char *name
,
1393 BlockDriverState
**bitmap_bs
,
1396 BdrvChild
*bdrv_cow_child(BlockDriverState
*bs
);
1397 BdrvChild
*bdrv_filter_child(BlockDriverState
*bs
);
1398 BdrvChild
*bdrv_filter_or_cow_child(BlockDriverState
*bs
);
1399 BdrvChild
*bdrv_primary_child(BlockDriverState
*bs
);
1400 BlockDriverState
*bdrv_skip_implicit_filters(BlockDriverState
*bs
);
1401 BlockDriverState
*bdrv_skip_filters(BlockDriverState
*bs
);
1402 BlockDriverState
*bdrv_backing_chain_next(BlockDriverState
*bs
);
1404 static inline BlockDriverState
*child_bs(BdrvChild
*child
)
1406 return child
? child
->bs
: NULL
;
1409 static inline BlockDriverState
*bdrv_cow_bs(BlockDriverState
*bs
)
1411 return child_bs(bdrv_cow_child(bs
));
1414 static inline BlockDriverState
*bdrv_filter_bs(BlockDriverState
*bs
)
1416 return child_bs(bdrv_filter_child(bs
));
1419 static inline BlockDriverState
*bdrv_filter_or_cow_bs(BlockDriverState
*bs
)
1421 return child_bs(bdrv_filter_or_cow_child(bs
));
1424 static inline BlockDriverState
*bdrv_primary_bs(BlockDriverState
*bs
)
1426 return child_bs(bdrv_primary_child(bs
));
1430 * End all quiescent sections started by bdrv_drain_all_begin(). This is
1431 * needed when deleting a BDS before bdrv_drain_all_end() is called.
1433 * NOTE: this is an internal helper for bdrv_close() *only*. No one else
1436 void bdrv_drain_all_end_quiesce(BlockDriverState
*bs
);
1438 #endif /* BLOCK_INT_H */