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"
12 #include "qemu/transactions.h"
15 * generated_co_wrapper
17 * Function specifier, which does nothing but mark functions to be
18 * generated by scripts/block-coroutine-wrapper.py
20 * Read more in docs/devel/block-coroutine-wrapper.rst
22 #define generated_co_wrapper
25 typedef struct BlockDriver BlockDriver
;
26 typedef struct BdrvChild BdrvChild
;
27 typedef struct BdrvChildClass BdrvChildClass
;
29 typedef struct BlockDriverInfo
{
30 /* in bytes, 0 if irrelevant */
32 /* offset at which the VM state can be saved (0 if not possible) */
33 int64_t vm_state_offset
;
36 * True if this block driver only supports compressed writes
38 bool needs_compressed_writes
;
41 typedef struct BlockFragInfo
{
42 uint64_t allocated_clusters
;
43 uint64_t total_clusters
;
44 uint64_t fragmented_clusters
;
45 uint64_t compressed_clusters
;
49 BDRV_REQ_COPY_ON_READ
= 0x1,
50 BDRV_REQ_ZERO_WRITE
= 0x2,
53 * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
54 * that the block driver should unmap (discard) blocks if it is guaranteed
55 * that the result will read back as zeroes. The flag is only passed to the
56 * driver if the block device is opened with BDRV_O_UNMAP.
58 BDRV_REQ_MAY_UNMAP
= 0x4,
61 BDRV_REQ_WRITE_COMPRESSED
= 0x20,
63 /* Signifies that this write request will not change the visible disk
65 BDRV_REQ_WRITE_UNCHANGED
= 0x40,
67 /* Forces request serialisation. Use only with write requests. */
68 BDRV_REQ_SERIALISING
= 0x80,
70 /* Execute the request only if the operation can be offloaded or otherwise
71 * be executed efficiently, but return an error instead of using a slow
73 BDRV_REQ_NO_FALLBACK
= 0x100,
76 * BDRV_REQ_PREFETCH makes sense only in the context of copy-on-read
77 * (i.e., together with the BDRV_REQ_COPY_ON_READ flag or when a COR
78 * filter is involved), in which case it signals that the COR operation
79 * need not read the data into memory (qiov) but only ensure they are
80 * copied to the top layer (i.e., that COR operation is done).
82 BDRV_REQ_PREFETCH
= 0x200,
85 * If we need to wait for other requests, just fail immediately. Used
86 * only together with BDRV_REQ_SERIALISING.
88 BDRV_REQ_NO_WAIT
= 0x400,
90 /* Mask of valid flags */
91 BDRV_REQ_MASK
= 0x7ff,
94 typedef struct BlockSizes
{
99 typedef struct HDGeometry
{
105 #define BDRV_O_NO_SHARE 0x0001 /* don't share permissions */
106 #define BDRV_O_RDWR 0x0002
107 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
108 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
109 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
110 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
111 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
112 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
113 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
114 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
115 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
116 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
117 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
118 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
119 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
120 select an appropriate protocol driver,
121 ignoring the format layer */
122 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
123 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
124 #define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
126 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
129 /* Option names of options parsed by the block layer */
131 #define BDRV_OPT_CACHE_WB "cache.writeback"
132 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
133 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
134 #define BDRV_OPT_READ_ONLY "read-only"
135 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
136 #define BDRV_OPT_DISCARD "discard"
137 #define BDRV_OPT_FORCE_SHARE "force-share"
140 #define BDRV_SECTOR_BITS 9
141 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
143 #define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \
144 INT_MAX >> BDRV_SECTOR_BITS)
145 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
148 * We want allow aligning requests and disk length up to any 32bit alignment
149 * and don't afraid of overflow.
150 * To achieve it, and in the same time use some pretty number as maximum disk
151 * size, let's define maximum "length" (a limit for any offset/bytes request and
152 * for disk size) to be the greatest power of 2 less than INT64_MAX.
154 #define BDRV_MAX_ALIGNMENT (1L << 30)
155 #define BDRV_MAX_LENGTH (QEMU_ALIGN_DOWN(INT64_MAX, BDRV_MAX_ALIGNMENT))
158 * Allocation status flags for bdrv_block_status() and friends.
161 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
162 * BDRV_BLOCK_ZERO: offset reads as zero
163 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
164 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
165 * layer rather than any backing, set by block layer
166 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
167 * layer, set by block layer
170 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
171 * that the block layer recompute the answer from the returned
172 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
173 * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
174 * zeroes in file child of current block node inside
175 * returned region. Only valid together with both
176 * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
177 * appear with BDRV_BLOCK_ZERO.
179 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
180 * host offset within the returned BDS that is allocated for the
181 * corresponding raw guest data. However, whether that offset
182 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
184 * DATA ZERO OFFSET_VALID
185 * t t t sectors read as zero, returned file is zero at offset
186 * t f t sectors read as valid from file at offset
187 * f t t sectors preallocated, read as zero, returned file not
188 * necessarily zero at offset
189 * f f t sectors preallocated but read from backing_hd,
190 * returned file contains garbage at offset
191 * t t f sectors preallocated, read as zero, unknown offset
192 * t f f sectors read from unknown file or offset
193 * f t f not allocated or unknown offset, read as zero
194 * f f f not allocated or unknown offset, read from backing_hd
196 #define BDRV_BLOCK_DATA 0x01
197 #define BDRV_BLOCK_ZERO 0x02
198 #define BDRV_BLOCK_OFFSET_VALID 0x04
199 #define BDRV_BLOCK_RAW 0x08
200 #define BDRV_BLOCK_ALLOCATED 0x10
201 #define BDRV_BLOCK_EOF 0x20
202 #define BDRV_BLOCK_RECURSE 0x40
204 typedef QTAILQ_HEAD(BlockReopenQueue
, BlockReopenQueueEntry
) BlockReopenQueue
;
206 typedef struct BDRVReopenState
{
207 BlockDriverState
*bs
;
209 BlockdevDetectZeroesOptions detect_zeroes
;
210 bool backing_missing
;
211 BlockDriverState
*old_backing_bs
; /* keep pointer for permissions update */
212 BlockDriverState
*old_file_bs
; /* keep pointer for permissions update */
214 QDict
*explicit_options
;
219 * Block operation types
221 typedef enum BlockOpType
{
222 BLOCK_OP_TYPE_BACKUP_SOURCE
,
223 BLOCK_OP_TYPE_BACKUP_TARGET
,
224 BLOCK_OP_TYPE_CHANGE
,
225 BLOCK_OP_TYPE_COMMIT_SOURCE
,
226 BLOCK_OP_TYPE_COMMIT_TARGET
,
227 BLOCK_OP_TYPE_DATAPLANE
,
228 BLOCK_OP_TYPE_DRIVE_DEL
,
230 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT
,
231 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT
,
232 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE
,
233 BLOCK_OP_TYPE_MIRROR_SOURCE
,
234 BLOCK_OP_TYPE_MIRROR_TARGET
,
235 BLOCK_OP_TYPE_RESIZE
,
236 BLOCK_OP_TYPE_STREAM
,
237 BLOCK_OP_TYPE_REPLACE
,
241 /* Block node permission constants */
244 * A user that has the "permission" of consistent reads is guaranteed that
245 * their view of the contents of the block device is complete and
246 * self-consistent, representing the contents of a disk at a specific
249 * For most block devices (including their backing files) this is true, but
250 * the property cannot be maintained in a few situations like for
251 * intermediate nodes of a commit block job.
253 BLK_PERM_CONSISTENT_READ
= 0x01,
255 /** This permission is required to change the visible disk contents. */
256 BLK_PERM_WRITE
= 0x02,
259 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
260 * required for writes to the block node when the caller promises that
261 * the visible disk content doesn't change.
263 * As the BLK_PERM_WRITE permission is strictly stronger, either is
264 * sufficient to perform an unchanging write.
266 BLK_PERM_WRITE_UNCHANGED
= 0x04,
268 /** This permission is required to change the size of a block node. */
269 BLK_PERM_RESIZE
= 0x08,
272 * There was a now-removed bit BLK_PERM_GRAPH_MOD, with value of 0x10. QEMU
273 * 6.1 and earlier may still lock the corresponding byte in block/file-posix
274 * locking. So, implementing some new permission should be very careful to
275 * not interfere with this old unused thing.
280 DEFAULT_PERM_PASSTHROUGH
= BLK_PERM_CONSISTENT_READ
282 | BLK_PERM_WRITE_UNCHANGED
285 DEFAULT_PERM_UNCHANGED
= BLK_PERM_ALL
& ~DEFAULT_PERM_PASSTHROUGH
,
289 * Flags that parent nodes assign to child nodes to specify what kind of
292 * At least one of DATA, METADATA, FILTERED, or COW must be set for
295 enum BdrvChildRoleBits
{
297 * This child stores data.
298 * Any node may have an arbitrary number of such children.
300 BDRV_CHILD_DATA
= (1 << 0),
303 * This child stores metadata.
304 * Any node may have an arbitrary number of metadata-storing
307 BDRV_CHILD_METADATA
= (1 << 1),
310 * A child that always presents exactly the same visible data as
311 * the parent, e.g. by virtue of the parent forwarding all reads
313 * This flag is mutually exclusive with DATA, METADATA, and COW.
314 * Any node may have at most one filtered child at a time.
316 BDRV_CHILD_FILTERED
= (1 << 2),
319 * Child from which to read all data that isn't allocated in the
320 * parent (i.e., the backing child); such data is copied to the
321 * parent through COW (and optionally COR).
322 * This field is mutually exclusive with DATA, METADATA, and
324 * Any node may have at most one such backing child at a time.
326 BDRV_CHILD_COW
= (1 << 3),
329 * The primary child. For most drivers, this is the child whose
330 * filename applies best to the parent node.
331 * Any node may have at most one primary child at a time.
333 BDRV_CHILD_PRIMARY
= (1 << 4),
335 /* Useful combination of flags */
336 BDRV_CHILD_IMAGE
= BDRV_CHILD_DATA
337 | BDRV_CHILD_METADATA
338 | BDRV_CHILD_PRIMARY
,
341 /* Mask of BdrvChildRoleBits values */
342 typedef unsigned int BdrvChildRole
;
344 char *bdrv_perm_names(uint64_t perm
);
345 uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm
);
347 /* disk I/O throttling */
348 void bdrv_init(void);
349 void bdrv_init_with_whitelist(void);
350 bool bdrv_uses_whitelist(void);
351 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
);
352 BlockDriver
*bdrv_find_protocol(const char *filename
,
353 bool allow_protocol_prefix
,
355 BlockDriver
*bdrv_find_format(const char *format_name
);
356 int bdrv_create(BlockDriver
*drv
, const char* filename
,
357 QemuOpts
*opts
, Error
**errp
);
358 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
);
360 BlockDriverState
*bdrv_new(void);
361 int bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
363 int bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
365 int bdrv_replace_child_bs(BdrvChild
*child
, BlockDriverState
*new_bs
,
367 BlockDriverState
*bdrv_insert_node(BlockDriverState
*bs
, QDict
*node_options
,
368 int flags
, Error
**errp
);
369 int bdrv_drop_filter(BlockDriverState
*bs
, Error
**errp
);
371 int bdrv_parse_aio(const char *mode
, int *flags
);
372 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
);
373 int bdrv_parse_discard_flags(const char *mode
, int *flags
);
374 BdrvChild
*bdrv_open_child(const char *filename
,
375 QDict
*options
, const char *bdref_key
,
376 BlockDriverState
* parent
,
377 const BdrvChildClass
*child_class
,
378 BdrvChildRole child_role
,
379 bool allow_none
, Error
**errp
);
380 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
);
381 int bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
383 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
384 const char *bdref_key
, Error
**errp
);
385 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
386 QDict
*options
, int flags
, Error
**errp
);
387 BlockDriverState
*bdrv_new_open_driver_opts(BlockDriver
*drv
,
388 const char *node_name
,
389 QDict
*options
, int flags
,
391 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
392 int flags
, Error
**errp
);
393 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
394 BlockDriverState
*bs
, QDict
*options
,
396 void bdrv_reopen_queue_free(BlockReopenQueue
*bs_queue
);
397 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
);
398 int bdrv_reopen(BlockDriverState
*bs
, QDict
*opts
, bool keep_old_opts
,
400 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
402 int bdrv_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
403 int64_t bytes
, BdrvRequestFlags flags
);
404 int bdrv_make_zero(BdrvChild
*child
, BdrvRequestFlags flags
);
405 int bdrv_pread(BdrvChild
*child
, int64_t offset
, void *buf
, int64_t bytes
);
406 int bdrv_pwrite(BdrvChild
*child
, int64_t offset
, const void *buf
,
408 int bdrv_pwrite_sync(BdrvChild
*child
, int64_t offset
,
409 const void *buf
, int64_t bytes
);
411 * Efficiently zero a region of the disk image. Note that this is a regular
412 * I/O request like read or write and should have a reasonable size. This
413 * function is not suitable for zeroing the entire image in a single request
414 * because it may allocate memory for the entire region.
416 int coroutine_fn
bdrv_co_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
417 int64_t bytes
, BdrvRequestFlags flags
);
418 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
419 const char *backing_file
);
420 void bdrv_refresh_filename(BlockDriverState
*bs
);
422 int coroutine_fn
bdrv_co_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
423 PreallocMode prealloc
, BdrvRequestFlags flags
,
425 int generated_co_wrapper
426 bdrv_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
427 PreallocMode prealloc
, BdrvRequestFlags flags
, Error
**errp
);
429 int64_t bdrv_nb_sectors(BlockDriverState
*bs
);
430 int64_t bdrv_getlength(BlockDriverState
*bs
);
431 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
);
432 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
433 BlockDriverState
*in_bs
, Error
**errp
);
434 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
);
435 void bdrv_refresh_limits(BlockDriverState
*bs
, Transaction
*tran
, Error
**errp
);
436 int bdrv_commit(BlockDriverState
*bs
);
437 int bdrv_make_empty(BdrvChild
*c
, Error
**errp
);
438 int bdrv_change_backing_file(BlockDriverState
*bs
, const char *backing_file
,
439 const char *backing_fmt
, bool warn
);
440 void bdrv_register(BlockDriver
*bdrv
);
441 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
442 const char *backing_file_str
);
443 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
444 BlockDriverState
*bs
);
445 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
);
446 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
448 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
450 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
);
451 int coroutine_fn
bdrv_co_delete_file(BlockDriverState
*bs
, Error
**errp
);
452 void coroutine_fn
bdrv_co_delete_file_noerr(BlockDriverState
*bs
);
455 typedef struct BdrvCheckResult
{
459 int corruptions_fixed
;
461 int64_t image_end_offset
;
470 int generated_co_wrapper
bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
,
473 /* The units of offset and total_work_size may be chosen arbitrarily by the
474 * block driver; total_work_size may change during the course of the amendment
476 typedef void BlockDriverAmendStatusCB(BlockDriverState
*bs
, int64_t offset
,
477 int64_t total_work_size
, void *opaque
);
478 int bdrv_amend_options(BlockDriverState
*bs_new
, QemuOpts
*opts
,
479 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
483 /* check if a named node can be replaced when doing drive-mirror */
484 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
485 const char *node_name
, Error
**errp
);
487 /* async block I/O */
488 void bdrv_aio_cancel(BlockAIOCB
*acb
);
489 void bdrv_aio_cancel_async(BlockAIOCB
*acb
);
491 /* sg packet commands */
492 int bdrv_co_ioctl(BlockDriverState
*bs
, int req
, void *buf
);
494 /* Invalidate any cached metadata used by image formats */
495 int generated_co_wrapper
bdrv_invalidate_cache(BlockDriverState
*bs
,
497 void bdrv_invalidate_cache_all(Error
**errp
);
498 int bdrv_inactivate_all(void);
500 /* Ensure contents are flushed to disk. */
501 int generated_co_wrapper
bdrv_flush(BlockDriverState
*bs
);
502 int coroutine_fn
bdrv_co_flush(BlockDriverState
*bs
);
503 int bdrv_flush_all(void);
504 void bdrv_close_all(void);
505 void bdrv_drain(BlockDriverState
*bs
);
506 void coroutine_fn
bdrv_co_drain(BlockDriverState
*bs
);
507 void bdrv_drain_all_begin(void);
508 void bdrv_drain_all_end(void);
509 void bdrv_drain_all(void);
511 #define BDRV_POLL_WHILE(bs, cond) ({ \
512 BlockDriverState *bs_ = (bs); \
513 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
516 int generated_co_wrapper
bdrv_pdiscard(BdrvChild
*child
, int64_t offset
,
518 int bdrv_co_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
519 int bdrv_has_zero_init_1(BlockDriverState
*bs
);
520 int bdrv_has_zero_init(BlockDriverState
*bs
);
521 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
);
522 int bdrv_block_status(BlockDriverState
*bs
, int64_t offset
,
523 int64_t bytes
, int64_t *pnum
, int64_t *map
,
524 BlockDriverState
**file
);
525 int bdrv_block_status_above(BlockDriverState
*bs
, BlockDriverState
*base
,
526 int64_t offset
, int64_t bytes
, int64_t *pnum
,
527 int64_t *map
, BlockDriverState
**file
);
528 int bdrv_is_allocated(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
,
530 int bdrv_is_allocated_above(BlockDriverState
*top
, BlockDriverState
*base
,
531 bool include_base
, int64_t offset
, int64_t bytes
,
533 int coroutine_fn
bdrv_co_is_zero_fast(BlockDriverState
*bs
, int64_t offset
,
536 bool bdrv_is_read_only(BlockDriverState
*bs
);
537 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
538 bool ignore_allow_rdw
, Error
**errp
);
539 int bdrv_apply_auto_read_only(BlockDriverState
*bs
, const char *errmsg
,
541 bool bdrv_is_writable(BlockDriverState
*bs
);
542 bool bdrv_is_sg(BlockDriverState
*bs
);
543 bool bdrv_is_inserted(BlockDriverState
*bs
);
544 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
);
545 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
);
546 const char *bdrv_get_format_name(BlockDriverState
*bs
);
547 BlockDriverState
*bdrv_find_node(const char *node_name
);
548 BlockDeviceInfoList
*bdrv_named_nodes_list(bool flat
, Error
**errp
);
549 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
);
550 BlockDriverState
*bdrv_lookup_bs(const char *device
,
551 const char *node_name
,
553 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
);
554 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
);
555 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
);
557 typedef struct BdrvNextIterator
{
559 BDRV_NEXT_BACKEND_ROOTS
,
560 BDRV_NEXT_MONITOR_OWNED
,
563 BlockDriverState
*bs
;
566 BlockDriverState
*bdrv_first(BdrvNextIterator
*it
);
567 BlockDriverState
*bdrv_next(BdrvNextIterator
*it
);
568 void bdrv_next_cleanup(BdrvNextIterator
*it
);
570 BlockDriverState
*bdrv_next_monitor_owned(BlockDriverState
*bs
);
571 bool bdrv_supports_compressed_writes(BlockDriverState
*bs
);
572 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
573 void *opaque
, bool read_only
);
574 const char *bdrv_get_node_name(const BlockDriverState
*bs
);
575 const char *bdrv_get_device_name(const BlockDriverState
*bs
);
576 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
);
577 int bdrv_get_flags(BlockDriverState
*bs
);
578 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
579 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
581 BlockStatsSpecific
*bdrv_get_specific_stats(BlockDriverState
*bs
);
582 void bdrv_round_to_clusters(BlockDriverState
*bs
,
583 int64_t offset
, int64_t bytes
,
584 int64_t *cluster_offset
,
585 int64_t *cluster_bytes
);
587 void bdrv_get_backing_filename(BlockDriverState
*bs
,
588 char *filename
, int filename_size
);
589 char *bdrv_get_full_backing_filename(BlockDriverState
*bs
, Error
**errp
);
590 char *bdrv_get_full_backing_filename_from_filename(const char *backed
,
593 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
);
595 int path_has_protocol(const char *path
);
596 int path_is_absolute(const char *path
);
597 char *path_combine(const char *base_path
, const char *filename
);
599 int generated_co_wrapper
600 bdrv_readv_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
601 int generated_co_wrapper
602 bdrv_writev_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
603 int bdrv_save_vmstate(BlockDriverState
*bs
, const uint8_t *buf
,
604 int64_t pos
, int size
);
606 int bdrv_load_vmstate(BlockDriverState
*bs
, uint8_t *buf
,
607 int64_t pos
, int size
);
609 void bdrv_img_create(const char *filename
, const char *fmt
,
610 const char *base_filename
, const char *base_fmt
,
611 char *options
, uint64_t img_size
, int flags
,
612 bool quiet
, Error
**errp
);
614 /* Returns the alignment in bytes that is required so that no bounce buffer
615 * is required throughout the stack */
616 size_t bdrv_min_mem_align(BlockDriverState
*bs
);
617 /* Returns optimal alignment in bytes for bounce buffer */
618 size_t bdrv_opt_mem_align(BlockDriverState
*bs
);
619 void *qemu_blockalign(BlockDriverState
*bs
, size_t size
);
620 void *qemu_blockalign0(BlockDriverState
*bs
, size_t size
);
621 void *qemu_try_blockalign(BlockDriverState
*bs
, size_t size
);
622 void *qemu_try_blockalign0(BlockDriverState
*bs
, size_t size
);
623 bool bdrv_qiov_is_aligned(BlockDriverState
*bs
, QEMUIOVector
*qiov
);
625 void bdrv_enable_copy_on_read(BlockDriverState
*bs
);
626 void bdrv_disable_copy_on_read(BlockDriverState
*bs
);
628 void bdrv_ref(BlockDriverState
*bs
);
629 void bdrv_unref(BlockDriverState
*bs
);
630 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
);
631 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
632 BlockDriverState
*child_bs
,
633 const char *child_name
,
634 const BdrvChildClass
*child_class
,
635 BdrvChildRole child_role
,
638 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
);
639 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
640 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
641 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
);
642 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
);
643 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
);
645 #define BLKDBG_EVENT(child, evt) \
648 bdrv_debug_event(child->bs, evt); \
652 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
);
654 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
656 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
);
657 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
);
658 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
);
661 * bdrv_get_aio_context:
663 * Returns: the currently bound #AioContext
665 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
);
668 * Move the current coroutine to the AioContext of @bs and return the old
669 * AioContext of the coroutine. Increase bs->in_flight so that draining @bs
670 * will wait for the operation to proceed until the corresponding
673 * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as
674 * this will deadlock.
676 AioContext
*coroutine_fn
bdrv_co_enter(BlockDriverState
*bs
);
679 * Ends a section started by bdrv_co_enter(). Move the current coroutine back
680 * to old_ctx and decrease bs->in_flight again.
682 void coroutine_fn
bdrv_co_leave(BlockDriverState
*bs
, AioContext
*old_ctx
);
685 * Locks the AioContext of @bs if it's not the current AioContext. This avoids
686 * double locking which could lead to deadlocks: This is a coroutine_fn, so we
687 * know we already own the lock of the current AioContext.
689 * May only be called in the main thread.
691 void coroutine_fn
bdrv_co_lock(BlockDriverState
*bs
);
694 * Unlocks the AioContext of @bs if it's not the current AioContext.
696 void coroutine_fn
bdrv_co_unlock(BlockDriverState
*bs
);
699 * Transfer control to @co in the aio context of @bs
701 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
);
703 void bdrv_set_aio_context_ignore(BlockDriverState
*bs
,
704 AioContext
*new_context
, GSList
**ignore
);
705 int bdrv_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
707 int bdrv_child_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
708 BdrvChild
*ignore_child
, Error
**errp
);
709 bool bdrv_child_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
710 GSList
**ignore
, Error
**errp
);
711 bool bdrv_can_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
712 GSList
**ignore
, Error
**errp
);
713 AioContext
*bdrv_child_get_parent_aio_context(BdrvChild
*c
);
714 AioContext
*child_of_bds_get_parent_aio_context(BdrvChild
*c
);
716 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
);
717 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
);
719 void bdrv_io_plug(BlockDriverState
*bs
);
720 void bdrv_io_unplug(BlockDriverState
*bs
);
723 * bdrv_parent_drained_begin_single:
725 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
726 * any pending activity to cease.
728 void bdrv_parent_drained_begin_single(BdrvChild
*c
, bool poll
);
731 * bdrv_parent_drained_end_single:
733 * End a quiesced section for the parent of @c.
735 * This polls @bs's AioContext until all scheduled sub-drained_ends
736 * have settled, which may result in graph changes.
738 void bdrv_parent_drained_end_single(BdrvChild
*c
);
743 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
744 * and if @recursive is true its children as well (used for subtree drain).
746 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
747 * ignore the drain request because they will be drained separately (used for
750 * This is part of bdrv_drained_begin.
752 bool bdrv_drain_poll(BlockDriverState
*bs
, bool recursive
,
753 BdrvChild
*ignore_parent
, bool ignore_bds_parents
);
756 * bdrv_drained_begin:
758 * Begin a quiesced section for exclusive access to the BDS, by disabling
759 * external request sources including NBD server, block jobs, and device model.
761 * This function can be recursive.
763 void bdrv_drained_begin(BlockDriverState
*bs
);
766 * bdrv_do_drained_begin_quiesce:
768 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
769 * running requests to complete.
771 void bdrv_do_drained_begin_quiesce(BlockDriverState
*bs
,
772 BdrvChild
*parent
, bool ignore_bds_parents
);
775 * Like bdrv_drained_begin, but recursively begins a quiesced section for
776 * exclusive access to all child nodes as well.
778 void bdrv_subtree_drained_begin(BlockDriverState
*bs
);
783 * End a quiescent section started by bdrv_drained_begin().
785 * This polls @bs's AioContext until all scheduled sub-drained_ends
786 * have settled. On one hand, that may result in graph changes. On
787 * the other, this requires that the caller either runs in the main
788 * loop; or that all involved nodes (@bs and all of its parents) are
789 * in the caller's AioContext.
791 void bdrv_drained_end(BlockDriverState
*bs
);
794 * bdrv_drained_end_no_poll:
796 * Same as bdrv_drained_end(), but do not poll for the subgraph to
797 * actually become unquiesced. Therefore, no graph changes will occur
798 * with this function.
800 * *drained_end_counter is incremented for every background operation
801 * that is scheduled, and will be decremented for every operation once
802 * it settles. The caller must poll until it reaches 0. The counter
803 * should be accessed using atomic operations only.
805 void bdrv_drained_end_no_poll(BlockDriverState
*bs
, int *drained_end_counter
);
808 * End a quiescent section started by bdrv_subtree_drained_begin().
810 void bdrv_subtree_drained_end(BlockDriverState
*bs
);
812 void bdrv_add_child(BlockDriverState
*parent
, BlockDriverState
*child
,
814 void bdrv_del_child(BlockDriverState
*parent
, BdrvChild
*child
, Error
**errp
);
816 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
817 uint32_t granularity
, Error
**errp
);
820 * bdrv_register_buf/bdrv_unregister_buf:
822 * Register/unregister a buffer for I/O. For example, VFIO drivers are
823 * interested to know the memory areas that would later be used for I/O, so
824 * that they can prepare IOMMU mapping etc., to get better performance.
826 void bdrv_register_buf(BlockDriverState
*bs
, void *host
, size_t size
);
827 void bdrv_unregister_buf(BlockDriverState
*bs
, void *host
);
831 * bdrv_co_copy_range:
833 * Do offloaded copy between two children. If the operation is not implemented
834 * by the driver, or if the backend storage doesn't support it, a negative
835 * error code will be returned.
837 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
838 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
839 * calling copy_file_range(2)) after the first error, thus it should fall back
840 * to a read+write path in the caller level.
842 * @src: Source child to copy data from
843 * @src_offset: offset in @src image to read data
844 * @dst: Destination child to copy data to
845 * @dst_offset: offset in @dst image to write data
846 * @bytes: number of bytes to copy
847 * @flags: request flags. Supported flags:
848 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
849 * write on @dst as if bdrv_co_pwrite_zeroes is
850 * called. Used to simplify caller code, or
851 * during BlockDriver.bdrv_co_copy_range_from()
853 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
854 * requests currently in flight.
856 * Returns: 0 if succeeded; negative error code if failed.
858 int coroutine_fn
bdrv_co_copy_range(BdrvChild
*src
, int64_t src_offset
,
859 BdrvChild
*dst
, int64_t dst_offset
,
860 int64_t bytes
, BdrvRequestFlags read_flags
,
861 BdrvRequestFlags write_flags
);
863 void bdrv_cancel_in_flight(BlockDriverState
*bs
);