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 typedef struct BlockDriver BlockDriver
;
15 typedef struct BdrvChild BdrvChild
;
16 typedef struct BdrvChildClass BdrvChildClass
;
18 typedef struct BlockDriverInfo
{
19 /* in bytes, 0 if irrelevant */
21 /* offset at which the VM state can be saved (0 if not possible) */
22 int64_t vm_state_offset
;
25 * True if this block driver only supports compressed writes
27 bool needs_compressed_writes
;
30 typedef struct BlockFragInfo
{
31 uint64_t allocated_clusters
;
32 uint64_t total_clusters
;
33 uint64_t fragmented_clusters
;
34 uint64_t compressed_clusters
;
38 BDRV_REQ_COPY_ON_READ
= 0x1,
39 BDRV_REQ_ZERO_WRITE
= 0x2,
42 * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
43 * that the block driver should unmap (discard) blocks if it is guaranteed
44 * that the result will read back as zeroes. The flag is only passed to the
45 * driver if the block device is opened with BDRV_O_UNMAP.
47 BDRV_REQ_MAY_UNMAP
= 0x4,
50 BDRV_REQ_WRITE_COMPRESSED
= 0x20,
52 /* Signifies that this write request will not change the visible disk
54 BDRV_REQ_WRITE_UNCHANGED
= 0x40,
57 * BDRV_REQ_SERIALISING forces request serialisation for writes.
58 * It is used to ensure that writes to the backing file of a backup process
59 * target cannot race with a read of the backup target that defers to the
62 * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to
63 * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be
64 * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long.
66 BDRV_REQ_SERIALISING
= 0x80,
68 /* Execute the request only if the operation can be offloaded or otherwise
69 * be executed efficiently, but return an error instead of using a slow
71 BDRV_REQ_NO_FALLBACK
= 0x100,
74 * BDRV_REQ_PREFETCH may be used only together with BDRV_REQ_COPY_ON_READ
75 * on read request and means that caller doesn't really need data to be
76 * written to qiov parameter which may be NULL.
78 BDRV_REQ_PREFETCH
= 0x200,
79 /* Mask of valid flags */
80 BDRV_REQ_MASK
= 0x3ff,
83 typedef struct BlockSizes
{
88 typedef struct HDGeometry
{
94 #define BDRV_O_RDWR 0x0002
95 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
96 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
97 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
98 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
99 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
100 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
101 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
102 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
103 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
104 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
105 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
106 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
107 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
108 select an appropriate protocol driver,
109 ignoring the format layer */
110 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
111 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
112 #define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
114 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
117 /* Option names of options parsed by the block layer */
119 #define BDRV_OPT_CACHE_WB "cache.writeback"
120 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
121 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
122 #define BDRV_OPT_READ_ONLY "read-only"
123 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
124 #define BDRV_OPT_DISCARD "discard"
125 #define BDRV_OPT_FORCE_SHARE "force-share"
128 #define BDRV_SECTOR_BITS 9
129 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
131 #define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \
132 INT_MAX >> BDRV_SECTOR_BITS)
133 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
136 * Allocation status flags for bdrv_block_status() and friends.
139 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
140 * BDRV_BLOCK_ZERO: offset reads as zero
141 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
142 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
143 * layer rather than any backing, set by block layer
144 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
145 * layer, set by block layer
148 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
149 * that the block layer recompute the answer from the returned
150 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
151 * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
152 * zeroes in file child of current block node inside
153 * returned region. Only valid together with both
154 * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
155 * appear with BDRV_BLOCK_ZERO.
157 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
158 * host offset within the returned BDS that is allocated for the
159 * corresponding raw guest data. However, whether that offset
160 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
162 * DATA ZERO OFFSET_VALID
163 * t t t sectors read as zero, returned file is zero at offset
164 * t f t sectors read as valid from file at offset
165 * f t t sectors preallocated, read as zero, returned file not
166 * necessarily zero at offset
167 * f f t sectors preallocated but read from backing_hd,
168 * returned file contains garbage at offset
169 * t t f sectors preallocated, read as zero, unknown offset
170 * t f f sectors read from unknown file or offset
171 * f t f not allocated or unknown offset, read as zero
172 * f f f not allocated or unknown offset, read from backing_hd
174 #define BDRV_BLOCK_DATA 0x01
175 #define BDRV_BLOCK_ZERO 0x02
176 #define BDRV_BLOCK_OFFSET_VALID 0x04
177 #define BDRV_BLOCK_RAW 0x08
178 #define BDRV_BLOCK_ALLOCATED 0x10
179 #define BDRV_BLOCK_EOF 0x20
180 #define BDRV_BLOCK_RECURSE 0x40
182 typedef QTAILQ_HEAD(BlockReopenQueue
, BlockReopenQueueEntry
) BlockReopenQueue
;
184 typedef struct BDRVReopenState
{
185 BlockDriverState
*bs
;
187 BlockdevDetectZeroesOptions detect_zeroes
;
188 bool backing_missing
;
189 bool replace_backing_bs
; /* new_backing_bs is ignored if this is false */
190 BlockDriverState
*new_backing_bs
; /* If NULL then detach the current bs */
191 uint64_t perm
, shared_perm
;
193 QDict
*explicit_options
;
198 * Block operation types
200 typedef enum BlockOpType
{
201 BLOCK_OP_TYPE_BACKUP_SOURCE
,
202 BLOCK_OP_TYPE_BACKUP_TARGET
,
203 BLOCK_OP_TYPE_CHANGE
,
204 BLOCK_OP_TYPE_COMMIT_SOURCE
,
205 BLOCK_OP_TYPE_COMMIT_TARGET
,
206 BLOCK_OP_TYPE_DATAPLANE
,
207 BLOCK_OP_TYPE_DRIVE_DEL
,
209 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT
,
210 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT
,
211 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE
,
212 BLOCK_OP_TYPE_MIRROR_SOURCE
,
213 BLOCK_OP_TYPE_MIRROR_TARGET
,
214 BLOCK_OP_TYPE_RESIZE
,
215 BLOCK_OP_TYPE_STREAM
,
216 BLOCK_OP_TYPE_REPLACE
,
220 /* Block node permission constants */
223 * A user that has the "permission" of consistent reads is guaranteed that
224 * their view of the contents of the block device is complete and
225 * self-consistent, representing the contents of a disk at a specific
228 * For most block devices (including their backing files) this is true, but
229 * the property cannot be maintained in a few situations like for
230 * intermediate nodes of a commit block job.
232 BLK_PERM_CONSISTENT_READ
= 0x01,
234 /** This permission is required to change the visible disk contents. */
235 BLK_PERM_WRITE
= 0x02,
238 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
239 * required for writes to the block node when the caller promises that
240 * the visible disk content doesn't change.
242 * As the BLK_PERM_WRITE permission is strictly stronger, either is
243 * sufficient to perform an unchanging write.
245 BLK_PERM_WRITE_UNCHANGED
= 0x04,
247 /** This permission is required to change the size of a block node. */
248 BLK_PERM_RESIZE
= 0x08,
251 * This permission is required to change the node that this BdrvChild
254 BLK_PERM_GRAPH_MOD
= 0x10,
258 DEFAULT_PERM_PASSTHROUGH
= BLK_PERM_CONSISTENT_READ
260 | BLK_PERM_WRITE_UNCHANGED
263 DEFAULT_PERM_UNCHANGED
= BLK_PERM_ALL
& ~DEFAULT_PERM_PASSTHROUGH
,
267 * Flags that parent nodes assign to child nodes to specify what kind of
270 * At least one of DATA, METADATA, FILTERED, or COW must be set for
273 enum BdrvChildRoleBits
{
275 * This child stores data.
276 * Any node may have an arbitrary number of such children.
278 BDRV_CHILD_DATA
= (1 << 0),
281 * This child stores metadata.
282 * Any node may have an arbitrary number of metadata-storing
285 BDRV_CHILD_METADATA
= (1 << 1),
288 * A child that always presents exactly the same visible data as
289 * the parent, e.g. by virtue of the parent forwarding all reads
291 * This flag is mutually exclusive with DATA, METADATA, and COW.
292 * Any node may have at most one filtered child at a time.
294 BDRV_CHILD_FILTERED
= (1 << 2),
297 * Child from which to read all data that isn’t allocated in the
298 * parent (i.e., the backing child); such data is copied to the
299 * parent through COW (and optionally COR).
300 * This field is mutually exclusive with DATA, METADATA, and
302 * Any node may have at most one such backing child at a time.
304 BDRV_CHILD_COW
= (1 << 3),
307 * The primary child. For most drivers, this is the child whose
308 * filename applies best to the parent node.
309 * Any node may have at most one primary child at a time.
311 BDRV_CHILD_PRIMARY
= (1 << 4),
313 /* Useful combination of flags */
314 BDRV_CHILD_IMAGE
= BDRV_CHILD_DATA
315 | BDRV_CHILD_METADATA
316 | BDRV_CHILD_PRIMARY
,
319 /* Mask of BdrvChildRoleBits values */
320 typedef unsigned int BdrvChildRole
;
322 char *bdrv_perm_names(uint64_t perm
);
323 uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm
);
325 /* disk I/O throttling */
326 void bdrv_init(void);
327 void bdrv_init_with_whitelist(void);
328 bool bdrv_uses_whitelist(void);
329 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
);
330 BlockDriver
*bdrv_find_protocol(const char *filename
,
331 bool allow_protocol_prefix
,
333 BlockDriver
*bdrv_find_format(const char *format_name
);
334 int bdrv_create(BlockDriver
*drv
, const char* filename
,
335 QemuOpts
*opts
, Error
**errp
);
336 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
);
338 BlockDriverState
*bdrv_new(void);
339 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
341 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
344 int bdrv_parse_aio(const char *mode
, int *flags
);
345 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
);
346 int bdrv_parse_discard_flags(const char *mode
, int *flags
);
347 BdrvChild
*bdrv_open_child(const char *filename
,
348 QDict
*options
, const char *bdref_key
,
349 BlockDriverState
* parent
,
350 const BdrvChildClass
*child_class
,
351 BdrvChildRole child_role
,
352 bool allow_none
, Error
**errp
);
353 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
);
354 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
356 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
357 const char *bdref_key
, Error
**errp
);
358 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
359 QDict
*options
, int flags
, Error
**errp
);
360 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
361 int flags
, Error
**errp
);
362 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
363 BlockDriverState
*bs
, QDict
*options
,
365 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
);
366 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
368 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
,
369 BlockReopenQueue
*queue
, Error
**errp
);
370 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
);
371 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
);
372 int bdrv_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
373 int bytes
, BdrvRequestFlags flags
);
374 int bdrv_make_zero(BdrvChild
*child
, BdrvRequestFlags flags
);
375 int bdrv_pread(BdrvChild
*child
, int64_t offset
, void *buf
, int bytes
);
376 int bdrv_preadv(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
377 int bdrv_pwrite(BdrvChild
*child
, int64_t offset
, const void *buf
, int bytes
);
378 int bdrv_pwritev(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
379 int bdrv_pwrite_sync(BdrvChild
*child
, int64_t offset
,
380 const void *buf
, int count
);
382 * Efficiently zero a region of the disk image. Note that this is a regular
383 * I/O request like read or write and should have a reasonable size. This
384 * function is not suitable for zeroing the entire image in a single request
385 * because it may allocate memory for the entire region.
387 int coroutine_fn
bdrv_co_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
388 int bytes
, BdrvRequestFlags flags
);
389 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
390 const char *backing_file
);
391 void bdrv_refresh_filename(BlockDriverState
*bs
);
393 int coroutine_fn
bdrv_co_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
394 PreallocMode prealloc
, BdrvRequestFlags flags
,
396 int bdrv_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
397 PreallocMode prealloc
, BdrvRequestFlags flags
, Error
**errp
);
399 int64_t bdrv_nb_sectors(BlockDriverState
*bs
);
400 int64_t bdrv_getlength(BlockDriverState
*bs
);
401 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
);
402 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
403 BlockDriverState
*in_bs
, Error
**errp
);
404 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
);
405 void bdrv_refresh_limits(BlockDriverState
*bs
, Error
**errp
);
406 int bdrv_commit(BlockDriverState
*bs
);
407 int bdrv_make_empty(BdrvChild
*c
, Error
**errp
);
408 int bdrv_change_backing_file(BlockDriverState
*bs
,
409 const char *backing_file
, const char *backing_fmt
);
410 void bdrv_register(BlockDriver
*bdrv
);
411 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
412 const char *backing_file_str
);
413 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
414 BlockDriverState
*bs
);
415 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
);
416 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
418 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
420 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
);
421 int coroutine_fn
bdrv_co_delete_file(BlockDriverState
*bs
, Error
**errp
);
424 typedef struct BdrvCheckResult
{
428 int corruptions_fixed
;
430 int64_t image_end_offset
;
439 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
);
441 /* The units of offset and total_work_size may be chosen arbitrarily by the
442 * block driver; total_work_size may change during the course of the amendment
444 typedef void BlockDriverAmendStatusCB(BlockDriverState
*bs
, int64_t offset
,
445 int64_t total_work_size
, void *opaque
);
446 int bdrv_amend_options(BlockDriverState
*bs_new
, QemuOpts
*opts
,
447 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
451 /* check if a named node can be replaced when doing drive-mirror */
452 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
453 const char *node_name
, Error
**errp
);
455 /* async block I/O */
456 void bdrv_aio_cancel(BlockAIOCB
*acb
);
457 void bdrv_aio_cancel_async(BlockAIOCB
*acb
);
459 /* sg packet commands */
460 int bdrv_co_ioctl(BlockDriverState
*bs
, int req
, void *buf
);
462 /* Invalidate any cached metadata used by image formats */
463 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
);
464 void bdrv_invalidate_cache_all(Error
**errp
);
465 int bdrv_inactivate_all(void);
467 /* Ensure contents are flushed to disk. */
468 int bdrv_flush(BlockDriverState
*bs
);
469 int coroutine_fn
bdrv_co_flush(BlockDriverState
*bs
);
470 int bdrv_flush_all(void);
471 void bdrv_close_all(void);
472 void bdrv_drain(BlockDriverState
*bs
);
473 void coroutine_fn
bdrv_co_drain(BlockDriverState
*bs
);
474 void bdrv_drain_all_begin(void);
475 void bdrv_drain_all_end(void);
476 void bdrv_drain_all(void);
478 #define BDRV_POLL_WHILE(bs, cond) ({ \
479 BlockDriverState *bs_ = (bs); \
480 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
483 int bdrv_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
484 int bdrv_co_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
485 int bdrv_has_zero_init_1(BlockDriverState
*bs
);
486 int bdrv_has_zero_init(BlockDriverState
*bs
);
487 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
);
488 int bdrv_block_status(BlockDriverState
*bs
, int64_t offset
,
489 int64_t bytes
, int64_t *pnum
, int64_t *map
,
490 BlockDriverState
**file
);
491 int bdrv_block_status_above(BlockDriverState
*bs
, BlockDriverState
*base
,
492 int64_t offset
, int64_t bytes
, int64_t *pnum
,
493 int64_t *map
, BlockDriverState
**file
);
494 int bdrv_is_allocated(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
,
496 int bdrv_is_allocated_above(BlockDriverState
*top
, BlockDriverState
*base
,
497 bool include_base
, int64_t offset
, int64_t bytes
,
500 bool bdrv_is_read_only(BlockDriverState
*bs
);
501 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
502 bool ignore_allow_rdw
, Error
**errp
);
503 int bdrv_apply_auto_read_only(BlockDriverState
*bs
, const char *errmsg
,
505 bool bdrv_is_writable(BlockDriverState
*bs
);
506 bool bdrv_is_sg(BlockDriverState
*bs
);
507 bool bdrv_is_inserted(BlockDriverState
*bs
);
508 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
);
509 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
);
510 const char *bdrv_get_format_name(BlockDriverState
*bs
);
511 BlockDriverState
*bdrv_find_node(const char *node_name
);
512 BlockDeviceInfoList
*bdrv_named_nodes_list(bool flat
, Error
**errp
);
513 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
);
514 BlockDriverState
*bdrv_lookup_bs(const char *device
,
515 const char *node_name
,
517 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
);
518 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
);
519 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
);
521 typedef struct BdrvNextIterator
{
523 BDRV_NEXT_BACKEND_ROOTS
,
524 BDRV_NEXT_MONITOR_OWNED
,
527 BlockDriverState
*bs
;
530 BlockDriverState
*bdrv_first(BdrvNextIterator
*it
);
531 BlockDriverState
*bdrv_next(BdrvNextIterator
*it
);
532 void bdrv_next_cleanup(BdrvNextIterator
*it
);
534 BlockDriverState
*bdrv_next_monitor_owned(BlockDriverState
*bs
);
535 bool bdrv_is_encrypted(BlockDriverState
*bs
);
536 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
537 void *opaque
, bool read_only
);
538 const char *bdrv_get_node_name(const BlockDriverState
*bs
);
539 const char *bdrv_get_device_name(const BlockDriverState
*bs
);
540 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
);
541 int bdrv_get_flags(BlockDriverState
*bs
);
542 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
543 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
545 BlockStatsSpecific
*bdrv_get_specific_stats(BlockDriverState
*bs
);
546 void bdrv_round_to_clusters(BlockDriverState
*bs
,
547 int64_t offset
, int64_t bytes
,
548 int64_t *cluster_offset
,
549 int64_t *cluster_bytes
);
551 void bdrv_get_backing_filename(BlockDriverState
*bs
,
552 char *filename
, int filename_size
);
553 char *bdrv_get_full_backing_filename(BlockDriverState
*bs
, Error
**errp
);
554 char *bdrv_get_full_backing_filename_from_filename(const char *backed
,
557 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
);
559 int path_has_protocol(const char *path
);
560 int path_is_absolute(const char *path
);
561 char *path_combine(const char *base_path
, const char *filename
);
563 int bdrv_readv_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
564 int bdrv_writev_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
565 int bdrv_save_vmstate(BlockDriverState
*bs
, const uint8_t *buf
,
566 int64_t pos
, int size
);
568 int bdrv_load_vmstate(BlockDriverState
*bs
, uint8_t *buf
,
569 int64_t pos
, int size
);
571 void bdrv_img_create(const char *filename
, const char *fmt
,
572 const char *base_filename
, const char *base_fmt
,
573 char *options
, uint64_t img_size
, int flags
,
574 bool quiet
, Error
**errp
);
576 /* Returns the alignment in bytes that is required so that no bounce buffer
577 * is required throughout the stack */
578 size_t bdrv_min_mem_align(BlockDriverState
*bs
);
579 /* Returns optimal alignment in bytes for bounce buffer */
580 size_t bdrv_opt_mem_align(BlockDriverState
*bs
);
581 void *qemu_blockalign(BlockDriverState
*bs
, size_t size
);
582 void *qemu_blockalign0(BlockDriverState
*bs
, size_t size
);
583 void *qemu_try_blockalign(BlockDriverState
*bs
, size_t size
);
584 void *qemu_try_blockalign0(BlockDriverState
*bs
, size_t size
);
585 bool bdrv_qiov_is_aligned(BlockDriverState
*bs
, QEMUIOVector
*qiov
);
587 void bdrv_enable_copy_on_read(BlockDriverState
*bs
);
588 void bdrv_disable_copy_on_read(BlockDriverState
*bs
);
590 void bdrv_ref(BlockDriverState
*bs
);
591 void bdrv_unref(BlockDriverState
*bs
);
592 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
);
593 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
594 BlockDriverState
*child_bs
,
595 const char *child_name
,
596 const BdrvChildClass
*child_class
,
597 BdrvChildRole child_role
,
600 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
);
601 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
602 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
603 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
);
604 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
);
605 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
);
607 #define BLKDBG_EVENT(child, evt) \
610 bdrv_debug_event(child->bs, evt); \
614 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
);
616 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
618 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
);
619 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
);
620 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
);
623 * bdrv_get_aio_context:
625 * Returns: the currently bound #AioContext
627 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
);
630 * Transfer control to @co in the aio context of @bs
632 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
);
634 void bdrv_set_aio_context_ignore(BlockDriverState
*bs
,
635 AioContext
*new_context
, GSList
**ignore
);
636 int bdrv_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
638 int bdrv_child_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
639 BdrvChild
*ignore_child
, Error
**errp
);
640 bool bdrv_child_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
641 GSList
**ignore
, Error
**errp
);
642 bool bdrv_can_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
643 GSList
**ignore
, Error
**errp
);
644 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
);
645 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
);
647 void bdrv_io_plug(BlockDriverState
*bs
);
648 void bdrv_io_unplug(BlockDriverState
*bs
);
651 * bdrv_parent_drained_begin_single:
653 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
654 * any pending activity to cease.
656 void bdrv_parent_drained_begin_single(BdrvChild
*c
, bool poll
);
659 * bdrv_parent_drained_end_single:
661 * End a quiesced section for the parent of @c.
663 * This polls @bs's AioContext until all scheduled sub-drained_ends
664 * have settled, which may result in graph changes.
666 void bdrv_parent_drained_end_single(BdrvChild
*c
);
671 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
672 * and if @recursive is true its children as well (used for subtree drain).
674 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
675 * ignore the drain request because they will be drained separately (used for
678 * This is part of bdrv_drained_begin.
680 bool bdrv_drain_poll(BlockDriverState
*bs
, bool recursive
,
681 BdrvChild
*ignore_parent
, bool ignore_bds_parents
);
684 * bdrv_drained_begin:
686 * Begin a quiesced section for exclusive access to the BDS, by disabling
687 * external request sources including NBD server and device model. Note that
688 * this doesn't block timers or coroutines from submitting more requests, which
689 * means block_job_pause is still necessary.
691 * This function can be recursive.
693 void bdrv_drained_begin(BlockDriverState
*bs
);
696 * bdrv_do_drained_begin_quiesce:
698 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
699 * running requests to complete.
701 void bdrv_do_drained_begin_quiesce(BlockDriverState
*bs
,
702 BdrvChild
*parent
, bool ignore_bds_parents
);
705 * Like bdrv_drained_begin, but recursively begins a quiesced section for
706 * exclusive access to all child nodes as well.
708 void bdrv_subtree_drained_begin(BlockDriverState
*bs
);
713 * End a quiescent section started by bdrv_drained_begin().
715 * This polls @bs's AioContext until all scheduled sub-drained_ends
716 * have settled. On one hand, that may result in graph changes. On
717 * the other, this requires that the caller either runs in the main
718 * loop; or that all involved nodes (@bs and all of its parents) are
719 * in the caller's AioContext.
721 void bdrv_drained_end(BlockDriverState
*bs
);
724 * bdrv_drained_end_no_poll:
726 * Same as bdrv_drained_end(), but do not poll for the subgraph to
727 * actually become unquiesced. Therefore, no graph changes will occur
728 * with this function.
730 * *drained_end_counter is incremented for every background operation
731 * that is scheduled, and will be decremented for every operation once
732 * it settles. The caller must poll until it reaches 0. The counter
733 * should be accessed using atomic operations only.
735 void bdrv_drained_end_no_poll(BlockDriverState
*bs
, int *drained_end_counter
);
738 * End a quiescent section started by bdrv_subtree_drained_begin().
740 void bdrv_subtree_drained_end(BlockDriverState
*bs
);
742 void bdrv_add_child(BlockDriverState
*parent
, BlockDriverState
*child
,
744 void bdrv_del_child(BlockDriverState
*parent
, BdrvChild
*child
, Error
**errp
);
746 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
747 uint32_t granularity
, Error
**errp
);
750 * bdrv_register_buf/bdrv_unregister_buf:
752 * Register/unregister a buffer for I/O. For example, VFIO drivers are
753 * interested to know the memory areas that would later be used for I/O, so
754 * that they can prepare IOMMU mapping etc., to get better performance.
756 void bdrv_register_buf(BlockDriverState
*bs
, void *host
, size_t size
);
757 void bdrv_unregister_buf(BlockDriverState
*bs
, void *host
);
761 * bdrv_co_copy_range:
763 * Do offloaded copy between two children. If the operation is not implemented
764 * by the driver, or if the backend storage doesn't support it, a negative
765 * error code will be returned.
767 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
768 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
769 * calling copy_file_range(2)) after the first error, thus it should fall back
770 * to a read+write path in the caller level.
772 * @src: Source child to copy data from
773 * @src_offset: offset in @src image to read data
774 * @dst: Destination child to copy data to
775 * @dst_offset: offset in @dst image to write data
776 * @bytes: number of bytes to copy
777 * @flags: request flags. Supported flags:
778 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
779 * write on @dst as if bdrv_co_pwrite_zeroes is
780 * called. Used to simplify caller code, or
781 * during BlockDriver.bdrv_co_copy_range_from()
783 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
784 * requests currently in flight.
786 * Returns: 0 if succeeded; negative error code if failed.
788 int coroutine_fn
bdrv_co_copy_range(BdrvChild
*src
, uint64_t src_offset
,
789 BdrvChild
*dst
, uint64_t dst_offset
,
790 uint64_t bytes
, BdrvRequestFlags read_flags
,
791 BdrvRequestFlags write_flags
);