5 #include "block/aio-wait.h"
7 #include "qemu/coroutine.h"
8 #include "block/accounting.h"
9 #include "block/dirty-bitmap.h"
10 #include "block/blockjob.h"
11 #include "qemu/hbitmap.h"
14 * generated_co_wrapper
16 * Function specifier, which does nothing but mark functions to be
17 * generated by scripts/block-coroutine-wrapper.py
19 * Read more in docs/devel/block-coroutine-wrapper.rst
21 #define generated_co_wrapper
24 typedef struct BlockDriver BlockDriver
;
25 typedef struct BdrvChild BdrvChild
;
26 typedef struct BdrvChildClass BdrvChildClass
;
28 typedef struct BlockDriverInfo
{
29 /* in bytes, 0 if irrelevant */
31 /* offset at which the VM state can be saved (0 if not possible) */
32 int64_t vm_state_offset
;
35 * True if this block driver only supports compressed writes
37 bool needs_compressed_writes
;
40 typedef struct BlockFragInfo
{
41 uint64_t allocated_clusters
;
42 uint64_t total_clusters
;
43 uint64_t fragmented_clusters
;
44 uint64_t compressed_clusters
;
48 BDRV_REQ_COPY_ON_READ
= 0x1,
49 BDRV_REQ_ZERO_WRITE
= 0x2,
52 * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
53 * that the block driver should unmap (discard) blocks if it is guaranteed
54 * that the result will read back as zeroes. The flag is only passed to the
55 * driver if the block device is opened with BDRV_O_UNMAP.
57 BDRV_REQ_MAY_UNMAP
= 0x4,
60 BDRV_REQ_WRITE_COMPRESSED
= 0x20,
62 /* Signifies that this write request will not change the visible disk
64 BDRV_REQ_WRITE_UNCHANGED
= 0x40,
67 * BDRV_REQ_SERIALISING forces request serialisation for writes.
68 * It is used to ensure that writes to the backing file of a backup process
69 * target cannot race with a read of the backup target that defers to the
72 * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to
73 * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be
74 * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long.
76 BDRV_REQ_SERIALISING
= 0x80,
78 /* Execute the request only if the operation can be offloaded or otherwise
79 * be executed efficiently, but return an error instead of using a slow
81 BDRV_REQ_NO_FALLBACK
= 0x100,
84 * BDRV_REQ_PREFETCH may be used only together with BDRV_REQ_COPY_ON_READ
85 * on read request and means that caller doesn't really need data to be
86 * written to qiov parameter which may be NULL.
88 BDRV_REQ_PREFETCH
= 0x200,
89 /* Mask of valid flags */
90 BDRV_REQ_MASK
= 0x3ff,
93 typedef struct BlockSizes
{
98 typedef struct HDGeometry
{
104 #define BDRV_O_RDWR 0x0002
105 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
106 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
107 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
108 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
109 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
110 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
111 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
112 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
113 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
114 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
115 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
116 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
117 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
118 select an appropriate protocol driver,
119 ignoring the format layer */
120 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
121 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
122 #define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
124 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
127 /* Option names of options parsed by the block layer */
129 #define BDRV_OPT_CACHE_WB "cache.writeback"
130 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
131 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
132 #define BDRV_OPT_READ_ONLY "read-only"
133 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
134 #define BDRV_OPT_DISCARD "discard"
135 #define BDRV_OPT_FORCE_SHARE "force-share"
138 #define BDRV_SECTOR_BITS 9
139 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
141 #define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \
142 INT_MAX >> BDRV_SECTOR_BITS)
143 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
146 * Allocation status flags for bdrv_block_status() and friends.
149 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
150 * BDRV_BLOCK_ZERO: offset reads as zero
151 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
152 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
153 * layer rather than any backing, set by block layer
154 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
155 * layer, set by block layer
158 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
159 * that the block layer recompute the answer from the returned
160 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
161 * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
162 * zeroes in file child of current block node inside
163 * returned region. Only valid together with both
164 * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
165 * appear with BDRV_BLOCK_ZERO.
167 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
168 * host offset within the returned BDS that is allocated for the
169 * corresponding raw guest data. However, whether that offset
170 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
172 * DATA ZERO OFFSET_VALID
173 * t t t sectors read as zero, returned file is zero at offset
174 * t f t sectors read as valid from file at offset
175 * f t t sectors preallocated, read as zero, returned file not
176 * necessarily zero at offset
177 * f f t sectors preallocated but read from backing_hd,
178 * returned file contains garbage at offset
179 * t t f sectors preallocated, read as zero, unknown offset
180 * t f f sectors read from unknown file or offset
181 * f t f not allocated or unknown offset, read as zero
182 * f f f not allocated or unknown offset, read from backing_hd
184 #define BDRV_BLOCK_DATA 0x01
185 #define BDRV_BLOCK_ZERO 0x02
186 #define BDRV_BLOCK_OFFSET_VALID 0x04
187 #define BDRV_BLOCK_RAW 0x08
188 #define BDRV_BLOCK_ALLOCATED 0x10
189 #define BDRV_BLOCK_EOF 0x20
190 #define BDRV_BLOCK_RECURSE 0x40
192 typedef QTAILQ_HEAD(BlockReopenQueue
, BlockReopenQueueEntry
) BlockReopenQueue
;
194 typedef struct BDRVReopenState
{
195 BlockDriverState
*bs
;
197 BlockdevDetectZeroesOptions detect_zeroes
;
198 bool backing_missing
;
199 bool replace_backing_bs
; /* new_backing_bs is ignored if this is false */
200 BlockDriverState
*new_backing_bs
; /* If NULL then detach the current bs */
201 uint64_t perm
, shared_perm
;
203 QDict
*explicit_options
;
208 * Block operation types
210 typedef enum BlockOpType
{
211 BLOCK_OP_TYPE_BACKUP_SOURCE
,
212 BLOCK_OP_TYPE_BACKUP_TARGET
,
213 BLOCK_OP_TYPE_CHANGE
,
214 BLOCK_OP_TYPE_COMMIT_SOURCE
,
215 BLOCK_OP_TYPE_COMMIT_TARGET
,
216 BLOCK_OP_TYPE_DATAPLANE
,
217 BLOCK_OP_TYPE_DRIVE_DEL
,
219 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT
,
220 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT
,
221 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE
,
222 BLOCK_OP_TYPE_MIRROR_SOURCE
,
223 BLOCK_OP_TYPE_MIRROR_TARGET
,
224 BLOCK_OP_TYPE_RESIZE
,
225 BLOCK_OP_TYPE_STREAM
,
226 BLOCK_OP_TYPE_REPLACE
,
230 /* Block node permission constants */
233 * A user that has the "permission" of consistent reads is guaranteed that
234 * their view of the contents of the block device is complete and
235 * self-consistent, representing the contents of a disk at a specific
238 * For most block devices (including their backing files) this is true, but
239 * the property cannot be maintained in a few situations like for
240 * intermediate nodes of a commit block job.
242 BLK_PERM_CONSISTENT_READ
= 0x01,
244 /** This permission is required to change the visible disk contents. */
245 BLK_PERM_WRITE
= 0x02,
248 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
249 * required for writes to the block node when the caller promises that
250 * the visible disk content doesn't change.
252 * As the BLK_PERM_WRITE permission is strictly stronger, either is
253 * sufficient to perform an unchanging write.
255 BLK_PERM_WRITE_UNCHANGED
= 0x04,
257 /** This permission is required to change the size of a block node. */
258 BLK_PERM_RESIZE
= 0x08,
261 * This permission is required to change the node that this BdrvChild
264 BLK_PERM_GRAPH_MOD
= 0x10,
268 DEFAULT_PERM_PASSTHROUGH
= BLK_PERM_CONSISTENT_READ
270 | BLK_PERM_WRITE_UNCHANGED
273 DEFAULT_PERM_UNCHANGED
= BLK_PERM_ALL
& ~DEFAULT_PERM_PASSTHROUGH
,
277 * Flags that parent nodes assign to child nodes to specify what kind of
280 * At least one of DATA, METADATA, FILTERED, or COW must be set for
283 enum BdrvChildRoleBits
{
285 * This child stores data.
286 * Any node may have an arbitrary number of such children.
288 BDRV_CHILD_DATA
= (1 << 0),
291 * This child stores metadata.
292 * Any node may have an arbitrary number of metadata-storing
295 BDRV_CHILD_METADATA
= (1 << 1),
298 * A child that always presents exactly the same visible data as
299 * the parent, e.g. by virtue of the parent forwarding all reads
301 * This flag is mutually exclusive with DATA, METADATA, and COW.
302 * Any node may have at most one filtered child at a time.
304 BDRV_CHILD_FILTERED
= (1 << 2),
307 * Child from which to read all data that isn’t allocated in the
308 * parent (i.e., the backing child); such data is copied to the
309 * parent through COW (and optionally COR).
310 * This field is mutually exclusive with DATA, METADATA, and
312 * Any node may have at most one such backing child at a time.
314 BDRV_CHILD_COW
= (1 << 3),
317 * The primary child. For most drivers, this is the child whose
318 * filename applies best to the parent node.
319 * Any node may have at most one primary child at a time.
321 BDRV_CHILD_PRIMARY
= (1 << 4),
323 /* Useful combination of flags */
324 BDRV_CHILD_IMAGE
= BDRV_CHILD_DATA
325 | BDRV_CHILD_METADATA
326 | BDRV_CHILD_PRIMARY
,
329 /* Mask of BdrvChildRoleBits values */
330 typedef unsigned int BdrvChildRole
;
332 char *bdrv_perm_names(uint64_t perm
);
333 uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm
);
335 /* disk I/O throttling */
336 void bdrv_init(void);
337 void bdrv_init_with_whitelist(void);
338 bool bdrv_uses_whitelist(void);
339 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
);
340 BlockDriver
*bdrv_find_protocol(const char *filename
,
341 bool allow_protocol_prefix
,
343 BlockDriver
*bdrv_find_format(const char *format_name
);
344 int bdrv_create(BlockDriver
*drv
, const char* filename
,
345 QemuOpts
*opts
, Error
**errp
);
346 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
);
348 BlockDriverState
*bdrv_new(void);
349 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
351 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
354 int bdrv_parse_aio(const char *mode
, int *flags
);
355 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
);
356 int bdrv_parse_discard_flags(const char *mode
, int *flags
);
357 BdrvChild
*bdrv_open_child(const char *filename
,
358 QDict
*options
, const char *bdref_key
,
359 BlockDriverState
* parent
,
360 const BdrvChildClass
*child_class
,
361 BdrvChildRole child_role
,
362 bool allow_none
, Error
**errp
);
363 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
);
364 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
366 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
367 const char *bdref_key
, Error
**errp
);
368 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
369 QDict
*options
, int flags
, Error
**errp
);
370 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
371 int flags
, Error
**errp
);
372 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
373 BlockDriverState
*bs
, QDict
*options
,
375 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
);
376 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
378 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
,
379 BlockReopenQueue
*queue
, Error
**errp
);
380 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
);
381 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
);
382 int bdrv_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
383 int bytes
, BdrvRequestFlags flags
);
384 int bdrv_make_zero(BdrvChild
*child
, BdrvRequestFlags flags
);
385 int bdrv_pread(BdrvChild
*child
, int64_t offset
, void *buf
, int bytes
);
386 int bdrv_preadv(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
387 int bdrv_pwrite(BdrvChild
*child
, int64_t offset
, const void *buf
, int bytes
);
388 int bdrv_pwritev(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
389 int bdrv_pwrite_sync(BdrvChild
*child
, int64_t offset
,
390 const void *buf
, int count
);
392 * Efficiently zero a region of the disk image. Note that this is a regular
393 * I/O request like read or write and should have a reasonable size. This
394 * function is not suitable for zeroing the entire image in a single request
395 * because it may allocate memory for the entire region.
397 int coroutine_fn
bdrv_co_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
398 int bytes
, BdrvRequestFlags flags
);
399 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
400 const char *backing_file
);
401 void bdrv_refresh_filename(BlockDriverState
*bs
);
403 int coroutine_fn
bdrv_co_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
404 PreallocMode prealloc
, BdrvRequestFlags flags
,
406 int bdrv_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
407 PreallocMode prealloc
, BdrvRequestFlags flags
, Error
**errp
);
409 int64_t bdrv_nb_sectors(BlockDriverState
*bs
);
410 int64_t bdrv_getlength(BlockDriverState
*bs
);
411 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
);
412 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
413 BlockDriverState
*in_bs
, Error
**errp
);
414 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
);
415 void bdrv_refresh_limits(BlockDriverState
*bs
, Error
**errp
);
416 int bdrv_commit(BlockDriverState
*bs
);
417 int bdrv_make_empty(BdrvChild
*c
, Error
**errp
);
418 int bdrv_change_backing_file(BlockDriverState
*bs
, const char *backing_file
,
419 const char *backing_fmt
, bool warn
);
420 void bdrv_register(BlockDriver
*bdrv
);
421 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
422 const char *backing_file_str
);
423 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
424 BlockDriverState
*bs
);
425 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
);
426 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
428 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
430 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
);
431 int coroutine_fn
bdrv_co_delete_file(BlockDriverState
*bs
, Error
**errp
);
434 typedef struct BdrvCheckResult
{
438 int corruptions_fixed
;
440 int64_t image_end_offset
;
449 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
);
451 /* The units of offset and total_work_size may be chosen arbitrarily by the
452 * block driver; total_work_size may change during the course of the amendment
454 typedef void BlockDriverAmendStatusCB(BlockDriverState
*bs
, int64_t offset
,
455 int64_t total_work_size
, void *opaque
);
456 int bdrv_amend_options(BlockDriverState
*bs_new
, QemuOpts
*opts
,
457 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
461 /* check if a named node can be replaced when doing drive-mirror */
462 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
463 const char *node_name
, Error
**errp
);
465 /* async block I/O */
466 void bdrv_aio_cancel(BlockAIOCB
*acb
);
467 void bdrv_aio_cancel_async(BlockAIOCB
*acb
);
469 /* sg packet commands */
470 int bdrv_co_ioctl(BlockDriverState
*bs
, int req
, void *buf
);
472 /* Invalidate any cached metadata used by image formats */
473 int bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
);
474 void bdrv_invalidate_cache_all(Error
**errp
);
475 int bdrv_inactivate_all(void);
477 /* Ensure contents are flushed to disk. */
478 int bdrv_flush(BlockDriverState
*bs
);
479 int coroutine_fn
bdrv_co_flush(BlockDriverState
*bs
);
480 int bdrv_flush_all(void);
481 void bdrv_close_all(void);
482 void bdrv_drain(BlockDriverState
*bs
);
483 void coroutine_fn
bdrv_co_drain(BlockDriverState
*bs
);
484 void bdrv_drain_all_begin(void);
485 void bdrv_drain_all_end(void);
486 void bdrv_drain_all(void);
488 #define BDRV_POLL_WHILE(bs, cond) ({ \
489 BlockDriverState *bs_ = (bs); \
490 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
493 int bdrv_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
494 int bdrv_co_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
495 int bdrv_has_zero_init_1(BlockDriverState
*bs
);
496 int bdrv_has_zero_init(BlockDriverState
*bs
);
497 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
);
498 int bdrv_block_status(BlockDriverState
*bs
, int64_t offset
,
499 int64_t bytes
, int64_t *pnum
, int64_t *map
,
500 BlockDriverState
**file
);
501 int bdrv_block_status_above(BlockDriverState
*bs
, BlockDriverState
*base
,
502 int64_t offset
, int64_t bytes
, int64_t *pnum
,
503 int64_t *map
, BlockDriverState
**file
);
504 int bdrv_is_allocated(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
,
506 int bdrv_is_allocated_above(BlockDriverState
*top
, BlockDriverState
*base
,
507 bool include_base
, int64_t offset
, int64_t bytes
,
510 bool bdrv_is_read_only(BlockDriverState
*bs
);
511 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
512 bool ignore_allow_rdw
, Error
**errp
);
513 int bdrv_apply_auto_read_only(BlockDriverState
*bs
, const char *errmsg
,
515 bool bdrv_is_writable(BlockDriverState
*bs
);
516 bool bdrv_is_sg(BlockDriverState
*bs
);
517 bool bdrv_is_inserted(BlockDriverState
*bs
);
518 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
);
519 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
);
520 const char *bdrv_get_format_name(BlockDriverState
*bs
);
521 BlockDriverState
*bdrv_find_node(const char *node_name
);
522 BlockDeviceInfoList
*bdrv_named_nodes_list(bool flat
, Error
**errp
);
523 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
);
524 BlockDriverState
*bdrv_lookup_bs(const char *device
,
525 const char *node_name
,
527 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
);
528 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
);
529 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
);
531 typedef struct BdrvNextIterator
{
533 BDRV_NEXT_BACKEND_ROOTS
,
534 BDRV_NEXT_MONITOR_OWNED
,
537 BlockDriverState
*bs
;
540 BlockDriverState
*bdrv_first(BdrvNextIterator
*it
);
541 BlockDriverState
*bdrv_next(BdrvNextIterator
*it
);
542 void bdrv_next_cleanup(BdrvNextIterator
*it
);
544 BlockDriverState
*bdrv_next_monitor_owned(BlockDriverState
*bs
);
545 bool bdrv_supports_compressed_writes(BlockDriverState
*bs
);
546 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
547 void *opaque
, bool read_only
);
548 const char *bdrv_get_node_name(const BlockDriverState
*bs
);
549 const char *bdrv_get_device_name(const BlockDriverState
*bs
);
550 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
);
551 int bdrv_get_flags(BlockDriverState
*bs
);
552 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
553 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
555 BlockStatsSpecific
*bdrv_get_specific_stats(BlockDriverState
*bs
);
556 void bdrv_round_to_clusters(BlockDriverState
*bs
,
557 int64_t offset
, int64_t bytes
,
558 int64_t *cluster_offset
,
559 int64_t *cluster_bytes
);
561 void bdrv_get_backing_filename(BlockDriverState
*bs
,
562 char *filename
, int filename_size
);
563 char *bdrv_get_full_backing_filename(BlockDriverState
*bs
, Error
**errp
);
564 char *bdrv_get_full_backing_filename_from_filename(const char *backed
,
567 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
);
569 int path_has_protocol(const char *path
);
570 int path_is_absolute(const char *path
);
571 char *path_combine(const char *base_path
, const char *filename
);
573 int bdrv_readv_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
574 int bdrv_writev_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
575 int bdrv_save_vmstate(BlockDriverState
*bs
, const uint8_t *buf
,
576 int64_t pos
, int size
);
578 int bdrv_load_vmstate(BlockDriverState
*bs
, uint8_t *buf
,
579 int64_t pos
, int size
);
581 void bdrv_img_create(const char *filename
, const char *fmt
,
582 const char *base_filename
, const char *base_fmt
,
583 char *options
, uint64_t img_size
, int flags
,
584 bool quiet
, Error
**errp
);
586 /* Returns the alignment in bytes that is required so that no bounce buffer
587 * is required throughout the stack */
588 size_t bdrv_min_mem_align(BlockDriverState
*bs
);
589 /* Returns optimal alignment in bytes for bounce buffer */
590 size_t bdrv_opt_mem_align(BlockDriverState
*bs
);
591 void *qemu_blockalign(BlockDriverState
*bs
, size_t size
);
592 void *qemu_blockalign0(BlockDriverState
*bs
, size_t size
);
593 void *qemu_try_blockalign(BlockDriverState
*bs
, size_t size
);
594 void *qemu_try_blockalign0(BlockDriverState
*bs
, size_t size
);
595 bool bdrv_qiov_is_aligned(BlockDriverState
*bs
, QEMUIOVector
*qiov
);
597 void bdrv_enable_copy_on_read(BlockDriverState
*bs
);
598 void bdrv_disable_copy_on_read(BlockDriverState
*bs
);
600 void bdrv_ref(BlockDriverState
*bs
);
601 void bdrv_unref(BlockDriverState
*bs
);
602 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
);
603 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
604 BlockDriverState
*child_bs
,
605 const char *child_name
,
606 const BdrvChildClass
*child_class
,
607 BdrvChildRole child_role
,
610 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
);
611 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
612 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
613 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
);
614 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
);
615 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
);
617 #define BLKDBG_EVENT(child, evt) \
620 bdrv_debug_event(child->bs, evt); \
624 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
);
626 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
628 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
);
629 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
);
630 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
);
633 * bdrv_get_aio_context:
635 * Returns: the currently bound #AioContext
637 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
);
640 * Transfer control to @co in the aio context of @bs
642 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
);
644 void bdrv_set_aio_context_ignore(BlockDriverState
*bs
,
645 AioContext
*new_context
, GSList
**ignore
);
646 int bdrv_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
648 int bdrv_child_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
649 BdrvChild
*ignore_child
, Error
**errp
);
650 bool bdrv_child_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
651 GSList
**ignore
, Error
**errp
);
652 bool bdrv_can_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
653 GSList
**ignore
, Error
**errp
);
654 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
);
655 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
);
657 void bdrv_io_plug(BlockDriverState
*bs
);
658 void bdrv_io_unplug(BlockDriverState
*bs
);
661 * bdrv_parent_drained_begin_single:
663 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
664 * any pending activity to cease.
666 void bdrv_parent_drained_begin_single(BdrvChild
*c
, bool poll
);
669 * bdrv_parent_drained_end_single:
671 * End a quiesced section for the parent of @c.
673 * This polls @bs's AioContext until all scheduled sub-drained_ends
674 * have settled, which may result in graph changes.
676 void bdrv_parent_drained_end_single(BdrvChild
*c
);
681 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
682 * and if @recursive is true its children as well (used for subtree drain).
684 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
685 * ignore the drain request because they will be drained separately (used for
688 * This is part of bdrv_drained_begin.
690 bool bdrv_drain_poll(BlockDriverState
*bs
, bool recursive
,
691 BdrvChild
*ignore_parent
, bool ignore_bds_parents
);
694 * bdrv_drained_begin:
696 * Begin a quiesced section for exclusive access to the BDS, by disabling
697 * external request sources including NBD server and device model. Note that
698 * this doesn't block timers or coroutines from submitting more requests, which
699 * means block_job_pause is still necessary.
701 * This function can be recursive.
703 void bdrv_drained_begin(BlockDriverState
*bs
);
706 * bdrv_do_drained_begin_quiesce:
708 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
709 * running requests to complete.
711 void bdrv_do_drained_begin_quiesce(BlockDriverState
*bs
,
712 BdrvChild
*parent
, bool ignore_bds_parents
);
715 * Like bdrv_drained_begin, but recursively begins a quiesced section for
716 * exclusive access to all child nodes as well.
718 void bdrv_subtree_drained_begin(BlockDriverState
*bs
);
723 * End a quiescent section started by bdrv_drained_begin().
725 * This polls @bs's AioContext until all scheduled sub-drained_ends
726 * have settled. On one hand, that may result in graph changes. On
727 * the other, this requires that the caller either runs in the main
728 * loop; or that all involved nodes (@bs and all of its parents) are
729 * in the caller's AioContext.
731 void bdrv_drained_end(BlockDriverState
*bs
);
734 * bdrv_drained_end_no_poll:
736 * Same as bdrv_drained_end(), but do not poll for the subgraph to
737 * actually become unquiesced. Therefore, no graph changes will occur
738 * with this function.
740 * *drained_end_counter is incremented for every background operation
741 * that is scheduled, and will be decremented for every operation once
742 * it settles. The caller must poll until it reaches 0. The counter
743 * should be accessed using atomic operations only.
745 void bdrv_drained_end_no_poll(BlockDriverState
*bs
, int *drained_end_counter
);
748 * End a quiescent section started by bdrv_subtree_drained_begin().
750 void bdrv_subtree_drained_end(BlockDriverState
*bs
);
752 void bdrv_add_child(BlockDriverState
*parent
, BlockDriverState
*child
,
754 void bdrv_del_child(BlockDriverState
*parent
, BdrvChild
*child
, Error
**errp
);
756 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
757 uint32_t granularity
, Error
**errp
);
760 * bdrv_register_buf/bdrv_unregister_buf:
762 * Register/unregister a buffer for I/O. For example, VFIO drivers are
763 * interested to know the memory areas that would later be used for I/O, so
764 * that they can prepare IOMMU mapping etc., to get better performance.
766 void bdrv_register_buf(BlockDriverState
*bs
, void *host
, size_t size
);
767 void bdrv_unregister_buf(BlockDriverState
*bs
, void *host
);
771 * bdrv_co_copy_range:
773 * Do offloaded copy between two children. If the operation is not implemented
774 * by the driver, or if the backend storage doesn't support it, a negative
775 * error code will be returned.
777 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
778 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
779 * calling copy_file_range(2)) after the first error, thus it should fall back
780 * to a read+write path in the caller level.
782 * @src: Source child to copy data from
783 * @src_offset: offset in @src image to read data
784 * @dst: Destination child to copy data to
785 * @dst_offset: offset in @dst image to write data
786 * @bytes: number of bytes to copy
787 * @flags: request flags. Supported flags:
788 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
789 * write on @dst as if bdrv_co_pwrite_zeroes is
790 * called. Used to simplify caller code, or
791 * during BlockDriver.bdrv_co_copy_range_from()
793 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
794 * requests currently in flight.
796 * Returns: 0 if succeeded; negative error code if failed.
798 int coroutine_fn
bdrv_co_copy_range(BdrvChild
*src
, uint64_t src_offset
,
799 BdrvChild
*dst
, uint64_t dst_offset
,
800 uint64_t bytes
, BdrvRequestFlags read_flags
,
801 BdrvRequestFlags write_flags
);