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,
66 /* Forces request serialisation. Use only with write requests. */
67 BDRV_REQ_SERIALISING
= 0x80,
69 /* Execute the request only if the operation can be offloaded or otherwise
70 * be executed efficiently, but return an error instead of using a slow
72 BDRV_REQ_NO_FALLBACK
= 0x100,
75 * BDRV_REQ_PREFETCH may be used only together with BDRV_REQ_COPY_ON_READ
76 * on read request and means that caller doesn't really need data to be
77 * written to qiov parameter which may be NULL.
79 BDRV_REQ_PREFETCH
= 0x200,
82 * If we need to wait for other requests, just fail immediately. Used
83 * only together with BDRV_REQ_SERIALISING.
85 BDRV_REQ_NO_WAIT
= 0x400,
87 /* Mask of valid flags */
88 BDRV_REQ_MASK
= 0x7ff,
91 typedef struct BlockSizes
{
96 typedef struct HDGeometry
{
102 #define BDRV_O_RDWR 0x0002
103 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
104 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
105 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
106 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
107 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
108 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
109 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
110 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
111 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
112 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
113 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
114 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
115 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
116 select an appropriate protocol driver,
117 ignoring the format layer */
118 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
119 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
120 #define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
122 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
125 /* Option names of options parsed by the block layer */
127 #define BDRV_OPT_CACHE_WB "cache.writeback"
128 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
129 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
130 #define BDRV_OPT_READ_ONLY "read-only"
131 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
132 #define BDRV_OPT_DISCARD "discard"
133 #define BDRV_OPT_FORCE_SHARE "force-share"
136 #define BDRV_SECTOR_BITS 9
137 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
139 #define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \
140 INT_MAX >> BDRV_SECTOR_BITS)
141 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
144 * We want allow aligning requests and disk length up to any 32bit alignment
145 * and don't afraid of overflow.
146 * To achieve it, and in the same time use some pretty number as maximum disk
147 * size, let's define maximum "length" (a limit for any offset/bytes request and
148 * for disk size) to be the greatest power of 2 less than INT64_MAX.
150 #define BDRV_MAX_ALIGNMENT (1L << 30)
151 #define BDRV_MAX_LENGTH (QEMU_ALIGN_DOWN(INT64_MAX, BDRV_MAX_ALIGNMENT))
154 * Allocation status flags for bdrv_block_status() and friends.
157 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
158 * BDRV_BLOCK_ZERO: offset reads as zero
159 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
160 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
161 * layer rather than any backing, set by block layer
162 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
163 * layer, set by block layer
166 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
167 * that the block layer recompute the answer from the returned
168 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
169 * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
170 * zeroes in file child of current block node inside
171 * returned region. Only valid together with both
172 * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
173 * appear with BDRV_BLOCK_ZERO.
175 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
176 * host offset within the returned BDS that is allocated for the
177 * corresponding raw guest data. However, whether that offset
178 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
180 * DATA ZERO OFFSET_VALID
181 * t t t sectors read as zero, returned file is zero at offset
182 * t f t sectors read as valid from file at offset
183 * f t t sectors preallocated, read as zero, returned file not
184 * necessarily zero at offset
185 * f f t sectors preallocated but read from backing_hd,
186 * returned file contains garbage at offset
187 * t t f sectors preallocated, read as zero, unknown offset
188 * t f f sectors read from unknown file or offset
189 * f t f not allocated or unknown offset, read as zero
190 * f f f not allocated or unknown offset, read from backing_hd
192 #define BDRV_BLOCK_DATA 0x01
193 #define BDRV_BLOCK_ZERO 0x02
194 #define BDRV_BLOCK_OFFSET_VALID 0x04
195 #define BDRV_BLOCK_RAW 0x08
196 #define BDRV_BLOCK_ALLOCATED 0x10
197 #define BDRV_BLOCK_EOF 0x20
198 #define BDRV_BLOCK_RECURSE 0x40
200 typedef QTAILQ_HEAD(BlockReopenQueue
, BlockReopenQueueEntry
) BlockReopenQueue
;
202 typedef struct BDRVReopenState
{
203 BlockDriverState
*bs
;
205 BlockdevDetectZeroesOptions detect_zeroes
;
206 bool backing_missing
;
207 bool replace_backing_bs
; /* new_backing_bs is ignored if this is false */
208 BlockDriverState
*new_backing_bs
; /* If NULL then detach the current bs */
209 uint64_t perm
, shared_perm
;
211 QDict
*explicit_options
;
216 * Block operation types
218 typedef enum BlockOpType
{
219 BLOCK_OP_TYPE_BACKUP_SOURCE
,
220 BLOCK_OP_TYPE_BACKUP_TARGET
,
221 BLOCK_OP_TYPE_CHANGE
,
222 BLOCK_OP_TYPE_COMMIT_SOURCE
,
223 BLOCK_OP_TYPE_COMMIT_TARGET
,
224 BLOCK_OP_TYPE_DATAPLANE
,
225 BLOCK_OP_TYPE_DRIVE_DEL
,
227 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT
,
228 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT
,
229 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE
,
230 BLOCK_OP_TYPE_MIRROR_SOURCE
,
231 BLOCK_OP_TYPE_MIRROR_TARGET
,
232 BLOCK_OP_TYPE_RESIZE
,
233 BLOCK_OP_TYPE_STREAM
,
234 BLOCK_OP_TYPE_REPLACE
,
238 /* Block node permission constants */
241 * A user that has the "permission" of consistent reads is guaranteed that
242 * their view of the contents of the block device is complete and
243 * self-consistent, representing the contents of a disk at a specific
246 * For most block devices (including their backing files) this is true, but
247 * the property cannot be maintained in a few situations like for
248 * intermediate nodes of a commit block job.
250 BLK_PERM_CONSISTENT_READ
= 0x01,
252 /** This permission is required to change the visible disk contents. */
253 BLK_PERM_WRITE
= 0x02,
256 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
257 * required for writes to the block node when the caller promises that
258 * the visible disk content doesn't change.
260 * As the BLK_PERM_WRITE permission is strictly stronger, either is
261 * sufficient to perform an unchanging write.
263 BLK_PERM_WRITE_UNCHANGED
= 0x04,
265 /** This permission is required to change the size of a block node. */
266 BLK_PERM_RESIZE
= 0x08,
269 * This permission is required to change the node that this BdrvChild
272 BLK_PERM_GRAPH_MOD
= 0x10,
276 DEFAULT_PERM_PASSTHROUGH
= BLK_PERM_CONSISTENT_READ
278 | BLK_PERM_WRITE_UNCHANGED
281 DEFAULT_PERM_UNCHANGED
= BLK_PERM_ALL
& ~DEFAULT_PERM_PASSTHROUGH
,
285 * Flags that parent nodes assign to child nodes to specify what kind of
288 * At least one of DATA, METADATA, FILTERED, or COW must be set for
291 enum BdrvChildRoleBits
{
293 * This child stores data.
294 * Any node may have an arbitrary number of such children.
296 BDRV_CHILD_DATA
= (1 << 0),
299 * This child stores metadata.
300 * Any node may have an arbitrary number of metadata-storing
303 BDRV_CHILD_METADATA
= (1 << 1),
306 * A child that always presents exactly the same visible data as
307 * the parent, e.g. by virtue of the parent forwarding all reads
309 * This flag is mutually exclusive with DATA, METADATA, and COW.
310 * Any node may have at most one filtered child at a time.
312 BDRV_CHILD_FILTERED
= (1 << 2),
315 * Child from which to read all data that isn't allocated in the
316 * parent (i.e., the backing child); such data is copied to the
317 * parent through COW (and optionally COR).
318 * This field is mutually exclusive with DATA, METADATA, and
320 * Any node may have at most one such backing child at a time.
322 BDRV_CHILD_COW
= (1 << 3),
325 * The primary child. For most drivers, this is the child whose
326 * filename applies best to the parent node.
327 * Any node may have at most one primary child at a time.
329 BDRV_CHILD_PRIMARY
= (1 << 4),
331 /* Useful combination of flags */
332 BDRV_CHILD_IMAGE
= BDRV_CHILD_DATA
333 | BDRV_CHILD_METADATA
334 | BDRV_CHILD_PRIMARY
,
337 /* Mask of BdrvChildRoleBits values */
338 typedef unsigned int BdrvChildRole
;
340 char *bdrv_perm_names(uint64_t perm
);
341 uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm
);
343 /* disk I/O throttling */
344 void bdrv_init(void);
345 void bdrv_init_with_whitelist(void);
346 bool bdrv_uses_whitelist(void);
347 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
);
348 BlockDriver
*bdrv_find_protocol(const char *filename
,
349 bool allow_protocol_prefix
,
351 BlockDriver
*bdrv_find_format(const char *format_name
);
352 int bdrv_create(BlockDriver
*drv
, const char* filename
,
353 QemuOpts
*opts
, Error
**errp
);
354 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
);
356 BlockDriverState
*bdrv_new(void);
357 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
359 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
362 int bdrv_parse_aio(const char *mode
, int *flags
);
363 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
);
364 int bdrv_parse_discard_flags(const char *mode
, int *flags
);
365 BdrvChild
*bdrv_open_child(const char *filename
,
366 QDict
*options
, const char *bdref_key
,
367 BlockDriverState
* parent
,
368 const BdrvChildClass
*child_class
,
369 BdrvChildRole child_role
,
370 bool allow_none
, Error
**errp
);
371 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
);
372 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
374 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
375 const char *bdref_key
, Error
**errp
);
376 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
377 QDict
*options
, int flags
, Error
**errp
);
378 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
379 int flags
, Error
**errp
);
380 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
381 BlockDriverState
*bs
, QDict
*options
,
383 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
);
384 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
386 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
,
387 BlockReopenQueue
*queue
, Error
**errp
);
388 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
);
389 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
);
390 int bdrv_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
391 int bytes
, BdrvRequestFlags flags
);
392 int bdrv_make_zero(BdrvChild
*child
, BdrvRequestFlags flags
);
393 int bdrv_pread(BdrvChild
*child
, int64_t offset
, void *buf
, int bytes
);
394 int bdrv_pwrite(BdrvChild
*child
, int64_t offset
, const void *buf
, int bytes
);
395 int bdrv_pwrite_sync(BdrvChild
*child
, int64_t offset
,
396 const void *buf
, int count
);
398 * Efficiently zero a region of the disk image. Note that this is a regular
399 * I/O request like read or write and should have a reasonable size. This
400 * function is not suitable for zeroing the entire image in a single request
401 * because it may allocate memory for the entire region.
403 int coroutine_fn
bdrv_co_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
404 int bytes
, BdrvRequestFlags flags
);
405 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
406 const char *backing_file
);
407 void bdrv_refresh_filename(BlockDriverState
*bs
);
409 int coroutine_fn
bdrv_co_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
410 PreallocMode prealloc
, BdrvRequestFlags flags
,
412 int generated_co_wrapper
413 bdrv_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
414 PreallocMode prealloc
, BdrvRequestFlags flags
, Error
**errp
);
416 int64_t bdrv_nb_sectors(BlockDriverState
*bs
);
417 int64_t bdrv_getlength(BlockDriverState
*bs
);
418 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
);
419 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
420 BlockDriverState
*in_bs
, Error
**errp
);
421 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
);
422 void bdrv_refresh_limits(BlockDriverState
*bs
, Error
**errp
);
423 int bdrv_commit(BlockDriverState
*bs
);
424 int bdrv_make_empty(BdrvChild
*c
, Error
**errp
);
425 int bdrv_change_backing_file(BlockDriverState
*bs
, const char *backing_file
,
426 const char *backing_fmt
, bool warn
);
427 void bdrv_register(BlockDriver
*bdrv
);
428 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
429 const char *backing_file_str
);
430 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
431 BlockDriverState
*bs
);
432 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
);
433 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
435 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
437 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
);
438 int coroutine_fn
bdrv_co_delete_file(BlockDriverState
*bs
, Error
**errp
);
441 typedef struct BdrvCheckResult
{
445 int corruptions_fixed
;
447 int64_t image_end_offset
;
456 int generated_co_wrapper
bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
,
459 /* The units of offset and total_work_size may be chosen arbitrarily by the
460 * block driver; total_work_size may change during the course of the amendment
462 typedef void BlockDriverAmendStatusCB(BlockDriverState
*bs
, int64_t offset
,
463 int64_t total_work_size
, void *opaque
);
464 int bdrv_amend_options(BlockDriverState
*bs_new
, QemuOpts
*opts
,
465 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
469 /* check if a named node can be replaced when doing drive-mirror */
470 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
471 const char *node_name
, Error
**errp
);
473 /* async block I/O */
474 void bdrv_aio_cancel(BlockAIOCB
*acb
);
475 void bdrv_aio_cancel_async(BlockAIOCB
*acb
);
477 /* sg packet commands */
478 int bdrv_co_ioctl(BlockDriverState
*bs
, int req
, void *buf
);
480 /* Invalidate any cached metadata used by image formats */
481 int generated_co_wrapper
bdrv_invalidate_cache(BlockDriverState
*bs
,
483 void bdrv_invalidate_cache_all(Error
**errp
);
484 int bdrv_inactivate_all(void);
486 /* Ensure contents are flushed to disk. */
487 int generated_co_wrapper
bdrv_flush(BlockDriverState
*bs
);
488 int coroutine_fn
bdrv_co_flush(BlockDriverState
*bs
);
489 int bdrv_flush_all(void);
490 void bdrv_close_all(void);
491 void bdrv_drain(BlockDriverState
*bs
);
492 void coroutine_fn
bdrv_co_drain(BlockDriverState
*bs
);
493 void bdrv_drain_all_begin(void);
494 void bdrv_drain_all_end(void);
495 void bdrv_drain_all(void);
497 #define BDRV_POLL_WHILE(bs, cond) ({ \
498 BlockDriverState *bs_ = (bs); \
499 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
502 int generated_co_wrapper
bdrv_pdiscard(BdrvChild
*child
, int64_t offset
,
504 int bdrv_co_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
505 int bdrv_has_zero_init_1(BlockDriverState
*bs
);
506 int bdrv_has_zero_init(BlockDriverState
*bs
);
507 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
);
508 int bdrv_block_status(BlockDriverState
*bs
, int64_t offset
,
509 int64_t bytes
, int64_t *pnum
, int64_t *map
,
510 BlockDriverState
**file
);
511 int bdrv_block_status_above(BlockDriverState
*bs
, BlockDriverState
*base
,
512 int64_t offset
, int64_t bytes
, int64_t *pnum
,
513 int64_t *map
, BlockDriverState
**file
);
514 int bdrv_is_allocated(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
,
516 int bdrv_is_allocated_above(BlockDriverState
*top
, BlockDriverState
*base
,
517 bool include_base
, int64_t offset
, int64_t bytes
,
519 int coroutine_fn
bdrv_co_is_zero_fast(BlockDriverState
*bs
, int64_t offset
,
522 bool bdrv_is_read_only(BlockDriverState
*bs
);
523 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
524 bool ignore_allow_rdw
, Error
**errp
);
525 int bdrv_apply_auto_read_only(BlockDriverState
*bs
, const char *errmsg
,
527 bool bdrv_is_writable(BlockDriverState
*bs
);
528 bool bdrv_is_sg(BlockDriverState
*bs
);
529 bool bdrv_is_inserted(BlockDriverState
*bs
);
530 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
);
531 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
);
532 const char *bdrv_get_format_name(BlockDriverState
*bs
);
533 BlockDriverState
*bdrv_find_node(const char *node_name
);
534 BlockDeviceInfoList
*bdrv_named_nodes_list(bool flat
, Error
**errp
);
535 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
);
536 BlockDriverState
*bdrv_lookup_bs(const char *device
,
537 const char *node_name
,
539 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
);
540 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
);
541 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
);
543 typedef struct BdrvNextIterator
{
545 BDRV_NEXT_BACKEND_ROOTS
,
546 BDRV_NEXT_MONITOR_OWNED
,
549 BlockDriverState
*bs
;
552 BlockDriverState
*bdrv_first(BdrvNextIterator
*it
);
553 BlockDriverState
*bdrv_next(BdrvNextIterator
*it
);
554 void bdrv_next_cleanup(BdrvNextIterator
*it
);
556 BlockDriverState
*bdrv_next_monitor_owned(BlockDriverState
*bs
);
557 bool bdrv_supports_compressed_writes(BlockDriverState
*bs
);
558 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
559 void *opaque
, bool read_only
);
560 const char *bdrv_get_node_name(const BlockDriverState
*bs
);
561 const char *bdrv_get_device_name(const BlockDriverState
*bs
);
562 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
);
563 int bdrv_get_flags(BlockDriverState
*bs
);
564 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
565 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
567 BlockStatsSpecific
*bdrv_get_specific_stats(BlockDriverState
*bs
);
568 void bdrv_round_to_clusters(BlockDriverState
*bs
,
569 int64_t offset
, int64_t bytes
,
570 int64_t *cluster_offset
,
571 int64_t *cluster_bytes
);
573 void bdrv_get_backing_filename(BlockDriverState
*bs
,
574 char *filename
, int filename_size
);
575 char *bdrv_get_full_backing_filename(BlockDriverState
*bs
, Error
**errp
);
576 char *bdrv_get_full_backing_filename_from_filename(const char *backed
,
579 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
);
581 int path_has_protocol(const char *path
);
582 int path_is_absolute(const char *path
);
583 char *path_combine(const char *base_path
, const char *filename
);
585 int generated_co_wrapper
586 bdrv_readv_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
587 int generated_co_wrapper
588 bdrv_writev_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
589 int bdrv_save_vmstate(BlockDriverState
*bs
, const uint8_t *buf
,
590 int64_t pos
, int size
);
592 int bdrv_load_vmstate(BlockDriverState
*bs
, uint8_t *buf
,
593 int64_t pos
, int size
);
595 void bdrv_img_create(const char *filename
, const char *fmt
,
596 const char *base_filename
, const char *base_fmt
,
597 char *options
, uint64_t img_size
, int flags
,
598 bool quiet
, Error
**errp
);
600 /* Returns the alignment in bytes that is required so that no bounce buffer
601 * is required throughout the stack */
602 size_t bdrv_min_mem_align(BlockDriverState
*bs
);
603 /* Returns optimal alignment in bytes for bounce buffer */
604 size_t bdrv_opt_mem_align(BlockDriverState
*bs
);
605 void *qemu_blockalign(BlockDriverState
*bs
, size_t size
);
606 void *qemu_blockalign0(BlockDriverState
*bs
, size_t size
);
607 void *qemu_try_blockalign(BlockDriverState
*bs
, size_t size
);
608 void *qemu_try_blockalign0(BlockDriverState
*bs
, size_t size
);
609 bool bdrv_qiov_is_aligned(BlockDriverState
*bs
, QEMUIOVector
*qiov
);
611 void bdrv_enable_copy_on_read(BlockDriverState
*bs
);
612 void bdrv_disable_copy_on_read(BlockDriverState
*bs
);
614 void bdrv_ref(BlockDriverState
*bs
);
615 void bdrv_unref(BlockDriverState
*bs
);
616 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
);
617 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
618 BlockDriverState
*child_bs
,
619 const char *child_name
,
620 const BdrvChildClass
*child_class
,
621 BdrvChildRole child_role
,
624 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
);
625 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
626 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
627 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
);
628 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
);
629 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
);
631 #define BLKDBG_EVENT(child, evt) \
634 bdrv_debug_event(child->bs, evt); \
638 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
);
640 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
642 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
);
643 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
);
644 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
);
647 * bdrv_get_aio_context:
649 * Returns: the currently bound #AioContext
651 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
);
654 * Move the current coroutine to the AioContext of @bs and return the old
655 * AioContext of the coroutine. Increase bs->in_flight so that draining @bs
656 * will wait for the operation to proceed until the corresponding
659 * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as
660 * this will deadlock.
662 AioContext
*coroutine_fn
bdrv_co_enter(BlockDriverState
*bs
);
665 * Ends a section started by bdrv_co_enter(). Move the current coroutine back
666 * to old_ctx and decrease bs->in_flight again.
668 void coroutine_fn
bdrv_co_leave(BlockDriverState
*bs
, AioContext
*old_ctx
);
671 * Locks the AioContext of @bs if it's not the current AioContext. This avoids
672 * double locking which could lead to deadlocks: This is a coroutine_fn, so we
673 * know we already own the lock of the current AioContext.
675 * May only be called in the main thread.
677 void coroutine_fn
bdrv_co_lock(BlockDriverState
*bs
);
680 * Unlocks the AioContext of @bs if it's not the current AioContext.
682 void coroutine_fn
bdrv_co_unlock(BlockDriverState
*bs
);
685 * Transfer control to @co in the aio context of @bs
687 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
);
689 void bdrv_set_aio_context_ignore(BlockDriverState
*bs
,
690 AioContext
*new_context
, GSList
**ignore
);
691 int bdrv_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
693 int bdrv_child_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
694 BdrvChild
*ignore_child
, Error
**errp
);
695 bool bdrv_child_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
696 GSList
**ignore
, Error
**errp
);
697 bool bdrv_can_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
698 GSList
**ignore
, Error
**errp
);
699 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
);
700 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
);
702 void bdrv_io_plug(BlockDriverState
*bs
);
703 void bdrv_io_unplug(BlockDriverState
*bs
);
706 * bdrv_parent_drained_begin_single:
708 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
709 * any pending activity to cease.
711 void bdrv_parent_drained_begin_single(BdrvChild
*c
, bool poll
);
714 * bdrv_parent_drained_end_single:
716 * End a quiesced section for the parent of @c.
718 * This polls @bs's AioContext until all scheduled sub-drained_ends
719 * have settled, which may result in graph changes.
721 void bdrv_parent_drained_end_single(BdrvChild
*c
);
726 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
727 * and if @recursive is true its children as well (used for subtree drain).
729 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
730 * ignore the drain request because they will be drained separately (used for
733 * This is part of bdrv_drained_begin.
735 bool bdrv_drain_poll(BlockDriverState
*bs
, bool recursive
,
736 BdrvChild
*ignore_parent
, bool ignore_bds_parents
);
739 * bdrv_drained_begin:
741 * Begin a quiesced section for exclusive access to the BDS, by disabling
742 * external request sources including NBD server and device model. Note that
743 * this doesn't block timers or coroutines from submitting more requests, which
744 * means block_job_pause is still necessary.
746 * This function can be recursive.
748 void bdrv_drained_begin(BlockDriverState
*bs
);
751 * bdrv_do_drained_begin_quiesce:
753 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
754 * running requests to complete.
756 void bdrv_do_drained_begin_quiesce(BlockDriverState
*bs
,
757 BdrvChild
*parent
, bool ignore_bds_parents
);
760 * Like bdrv_drained_begin, but recursively begins a quiesced section for
761 * exclusive access to all child nodes as well.
763 void bdrv_subtree_drained_begin(BlockDriverState
*bs
);
768 * End a quiescent section started by bdrv_drained_begin().
770 * This polls @bs's AioContext until all scheduled sub-drained_ends
771 * have settled. On one hand, that may result in graph changes. On
772 * the other, this requires that the caller either runs in the main
773 * loop; or that all involved nodes (@bs and all of its parents) are
774 * in the caller's AioContext.
776 void bdrv_drained_end(BlockDriverState
*bs
);
779 * bdrv_drained_end_no_poll:
781 * Same as bdrv_drained_end(), but do not poll for the subgraph to
782 * actually become unquiesced. Therefore, no graph changes will occur
783 * with this function.
785 * *drained_end_counter is incremented for every background operation
786 * that is scheduled, and will be decremented for every operation once
787 * it settles. The caller must poll until it reaches 0. The counter
788 * should be accessed using atomic operations only.
790 void bdrv_drained_end_no_poll(BlockDriverState
*bs
, int *drained_end_counter
);
793 * End a quiescent section started by bdrv_subtree_drained_begin().
795 void bdrv_subtree_drained_end(BlockDriverState
*bs
);
797 void bdrv_add_child(BlockDriverState
*parent
, BlockDriverState
*child
,
799 void bdrv_del_child(BlockDriverState
*parent
, BdrvChild
*child
, Error
**errp
);
801 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
802 uint32_t granularity
, Error
**errp
);
805 * bdrv_register_buf/bdrv_unregister_buf:
807 * Register/unregister a buffer for I/O. For example, VFIO drivers are
808 * interested to know the memory areas that would later be used for I/O, so
809 * that they can prepare IOMMU mapping etc., to get better performance.
811 void bdrv_register_buf(BlockDriverState
*bs
, void *host
, size_t size
);
812 void bdrv_unregister_buf(BlockDriverState
*bs
, void *host
);
816 * bdrv_co_copy_range:
818 * Do offloaded copy between two children. If the operation is not implemented
819 * by the driver, or if the backend storage doesn't support it, a negative
820 * error code will be returned.
822 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
823 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
824 * calling copy_file_range(2)) after the first error, thus it should fall back
825 * to a read+write path in the caller level.
827 * @src: Source child to copy data from
828 * @src_offset: offset in @src image to read data
829 * @dst: Destination child to copy data to
830 * @dst_offset: offset in @dst image to write data
831 * @bytes: number of bytes to copy
832 * @flags: request flags. Supported flags:
833 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
834 * write on @dst as if bdrv_co_pwrite_zeroes is
835 * called. Used to simplify caller code, or
836 * during BlockDriver.bdrv_co_copy_range_from()
838 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
839 * requests currently in flight.
841 * Returns: 0 if succeeded; negative error code if failed.
843 int coroutine_fn
bdrv_co_copy_range(BdrvChild
*src
, uint64_t src_offset
,
844 BdrvChild
*dst
, uint64_t dst_offset
,
845 uint64_t bytes
, BdrvRequestFlags read_flags
,
846 BdrvRequestFlags write_flags
);