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 BdrvChildRole BdrvChildRole
;
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 unallocated blocks read back as zeroes. This is equivalent
26 * to the LBPRZ flag in the SCSI logical block provisioning page.
28 bool unallocated_blocks_are_zero
;
30 * True if this block driver only supports compressed writes
32 bool needs_compressed_writes
;
35 typedef struct BlockFragInfo
{
36 uint64_t allocated_clusters
;
37 uint64_t total_clusters
;
38 uint64_t fragmented_clusters
;
39 uint64_t compressed_clusters
;
43 BDRV_REQ_COPY_ON_READ
= 0x1,
44 BDRV_REQ_ZERO_WRITE
= 0x2,
47 * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
48 * that the block driver should unmap (discard) blocks if it is guaranteed
49 * that the result will read back as zeroes. The flag is only passed to the
50 * driver if the block device is opened with BDRV_O_UNMAP.
52 BDRV_REQ_MAY_UNMAP
= 0x4,
55 * The BDRV_REQ_NO_SERIALISING flag is only valid for reads and means that
56 * we don't want wait_serialising_requests() during the read operation.
58 * This flag is used for backup copy-on-write operations, when we need to
59 * read old data before write (write notifier triggered). It is okay since
60 * we already waited for other serializing requests in the initiating write
61 * (see bdrv_aligned_pwritev), and it is necessary if the initiating write
62 * is already serializing (without the flag, the read would deadlock
63 * waiting for the serialising write to complete).
65 BDRV_REQ_NO_SERIALISING
= 0x8,
67 BDRV_REQ_WRITE_COMPRESSED
= 0x20,
69 /* Signifies that this write request will not change the visible disk
71 BDRV_REQ_WRITE_UNCHANGED
= 0x40,
74 * BDRV_REQ_SERIALISING forces request serialisation for writes.
75 * It is used to ensure that writes to the backing file of a backup process
76 * target cannot race with a read of the backup target that defers to the
79 * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to
80 * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be
81 * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long.
83 BDRV_REQ_SERIALISING
= 0x80,
85 /* Execute the request only if the operation can be offloaded or otherwise
86 * be executed efficiently, but return an error instead of using a slow
88 BDRV_REQ_NO_FALLBACK
= 0x100,
91 * BDRV_REQ_PREFETCH may be used only together with BDRV_REQ_COPY_ON_READ
92 * on read request and means that caller doesn't really need data to be
93 * written to qiov parameter which may be NULL.
95 BDRV_REQ_PREFETCH
= 0x200,
96 /* Mask of valid flags */
97 BDRV_REQ_MASK
= 0x3ff,
100 typedef struct BlockSizes
{
105 typedef struct HDGeometry
{
111 #define BDRV_O_RDWR 0x0002
112 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
113 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
114 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
115 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
116 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
117 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
118 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
119 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
120 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
121 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
122 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
123 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
124 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
125 select an appropriate protocol driver,
126 ignoring the format layer */
127 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
128 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
130 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
133 /* Option names of options parsed by the block layer */
135 #define BDRV_OPT_CACHE_WB "cache.writeback"
136 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
137 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
138 #define BDRV_OPT_READ_ONLY "read-only"
139 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
140 #define BDRV_OPT_DISCARD "discard"
141 #define BDRV_OPT_FORCE_SHARE "force-share"
144 #define BDRV_SECTOR_BITS 9
145 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
147 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
148 INT_MAX >> BDRV_SECTOR_BITS)
149 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
152 * Allocation status flags for bdrv_block_status() and friends.
155 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
156 * BDRV_BLOCK_ZERO: offset reads as zero
157 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
158 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
159 * layer rather than any backing, set by block layer
160 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
161 * layer, set by block layer
164 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
165 * that the block layer recompute the answer from the returned
166 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
167 * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
168 * zeroes in file child of current block node inside
169 * returned region. Only valid together with both
170 * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
171 * appear with BDRV_BLOCK_ZERO.
173 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
174 * host offset within the returned BDS that is allocated for the
175 * corresponding raw guest data. However, whether that offset
176 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
178 * DATA ZERO OFFSET_VALID
179 * t t t sectors read as zero, returned file is zero at offset
180 * t f t sectors read as valid from file at offset
181 * f t t sectors preallocated, read as zero, returned file not
182 * necessarily zero at offset
183 * f f t sectors preallocated but read from backing_hd,
184 * returned file contains garbage at offset
185 * t t f sectors preallocated, read as zero, unknown offset
186 * t f f sectors read from unknown file or offset
187 * f t f not allocated or unknown offset, read as zero
188 * f f f not allocated or unknown offset, read from backing_hd
190 #define BDRV_BLOCK_DATA 0x01
191 #define BDRV_BLOCK_ZERO 0x02
192 #define BDRV_BLOCK_OFFSET_VALID 0x04
193 #define BDRV_BLOCK_RAW 0x08
194 #define BDRV_BLOCK_ALLOCATED 0x10
195 #define BDRV_BLOCK_EOF 0x20
196 #define BDRV_BLOCK_RECURSE 0x40
198 typedef QTAILQ_HEAD(BlockReopenQueue
, BlockReopenQueueEntry
) BlockReopenQueue
;
200 typedef struct BDRVReopenState
{
201 BlockDriverState
*bs
;
203 BlockdevDetectZeroesOptions detect_zeroes
;
204 bool backing_missing
;
205 bool replace_backing_bs
; /* new_backing_bs is ignored if this is false */
206 BlockDriverState
*new_backing_bs
; /* If NULL then detach the current bs */
207 uint64_t perm
, shared_perm
;
209 QDict
*explicit_options
;
214 * Block operation types
216 typedef enum BlockOpType
{
217 BLOCK_OP_TYPE_BACKUP_SOURCE
,
218 BLOCK_OP_TYPE_BACKUP_TARGET
,
219 BLOCK_OP_TYPE_CHANGE
,
220 BLOCK_OP_TYPE_COMMIT_SOURCE
,
221 BLOCK_OP_TYPE_COMMIT_TARGET
,
222 BLOCK_OP_TYPE_DATAPLANE
,
223 BLOCK_OP_TYPE_DRIVE_DEL
,
225 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT
,
226 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT
,
227 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE
,
228 BLOCK_OP_TYPE_MIRROR_SOURCE
,
229 BLOCK_OP_TYPE_MIRROR_TARGET
,
230 BLOCK_OP_TYPE_RESIZE
,
231 BLOCK_OP_TYPE_STREAM
,
232 BLOCK_OP_TYPE_REPLACE
,
236 /* Block node permission constants */
239 * A user that has the "permission" of consistent reads is guaranteed that
240 * their view of the contents of the block device is complete and
241 * self-consistent, representing the contents of a disk at a specific
244 * For most block devices (including their backing files) this is true, but
245 * the property cannot be maintained in a few situations like for
246 * intermediate nodes of a commit block job.
248 BLK_PERM_CONSISTENT_READ
= 0x01,
250 /** This permission is required to change the visible disk contents. */
251 BLK_PERM_WRITE
= 0x02,
254 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
255 * required for writes to the block node when the caller promises that
256 * the visible disk content doesn't change.
258 * As the BLK_PERM_WRITE permission is strictly stronger, either is
259 * sufficient to perform an unchanging write.
261 BLK_PERM_WRITE_UNCHANGED
= 0x04,
263 /** This permission is required to change the size of a block node. */
264 BLK_PERM_RESIZE
= 0x08,
267 * This permission is required to change the node that this BdrvChild
270 BLK_PERM_GRAPH_MOD
= 0x10,
274 DEFAULT_PERM_PASSTHROUGH
= BLK_PERM_CONSISTENT_READ
276 | BLK_PERM_WRITE_UNCHANGED
279 DEFAULT_PERM_UNCHANGED
= BLK_PERM_ALL
& ~DEFAULT_PERM_PASSTHROUGH
,
282 char *bdrv_perm_names(uint64_t perm
);
283 uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm
);
285 /* disk I/O throttling */
286 void bdrv_init(void);
287 void bdrv_init_with_whitelist(void);
288 bool bdrv_uses_whitelist(void);
289 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
);
290 BlockDriver
*bdrv_find_protocol(const char *filename
,
291 bool allow_protocol_prefix
,
293 BlockDriver
*bdrv_find_format(const char *format_name
);
294 int bdrv_create(BlockDriver
*drv
, const char* filename
,
295 QemuOpts
*opts
, Error
**errp
);
296 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
);
297 BlockDriverState
*bdrv_new(void);
298 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
300 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
303 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
);
304 int bdrv_parse_discard_flags(const char *mode
, int *flags
);
305 BdrvChild
*bdrv_open_child(const char *filename
,
306 QDict
*options
, const char *bdref_key
,
307 BlockDriverState
* parent
,
308 const BdrvChildRole
*child_role
,
309 bool allow_none
, Error
**errp
);
310 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
);
311 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
313 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
314 const char *bdref_key
, Error
**errp
);
315 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
316 QDict
*options
, int flags
, Error
**errp
);
317 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
318 int flags
, Error
**errp
);
319 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
320 BlockDriverState
*bs
, QDict
*options
,
322 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
);
323 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
325 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
,
326 BlockReopenQueue
*queue
, Error
**errp
);
327 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
);
328 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
);
329 int bdrv_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
330 int bytes
, BdrvRequestFlags flags
);
331 int bdrv_make_zero(BdrvChild
*child
, BdrvRequestFlags flags
);
332 int bdrv_pread(BdrvChild
*child
, int64_t offset
, void *buf
, int bytes
);
333 int bdrv_preadv(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
334 int bdrv_pwrite(BdrvChild
*child
, int64_t offset
, const void *buf
, int bytes
);
335 int bdrv_pwritev(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
336 int bdrv_pwrite_sync(BdrvChild
*child
, int64_t offset
,
337 const void *buf
, int count
);
339 * Efficiently zero a region of the disk image. Note that this is a regular
340 * I/O request like read or write and should have a reasonable size. This
341 * function is not suitable for zeroing the entire image in a single request
342 * because it may allocate memory for the entire region.
344 int coroutine_fn
bdrv_co_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
345 int bytes
, BdrvRequestFlags flags
);
346 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
347 const char *backing_file
);
348 void bdrv_refresh_filename(BlockDriverState
*bs
);
350 int coroutine_fn
bdrv_co_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
351 PreallocMode prealloc
, Error
**errp
);
352 int bdrv_truncate(BdrvChild
*child
, int64_t offset
, bool exact
,
353 PreallocMode prealloc
, Error
**errp
);
355 int64_t bdrv_nb_sectors(BlockDriverState
*bs
);
356 int64_t bdrv_getlength(BlockDriverState
*bs
);
357 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
);
358 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
359 BlockDriverState
*in_bs
, Error
**errp
);
360 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
);
361 void bdrv_refresh_limits(BlockDriverState
*bs
, Error
**errp
);
362 int bdrv_commit(BlockDriverState
*bs
);
363 int bdrv_change_backing_file(BlockDriverState
*bs
,
364 const char *backing_file
, const char *backing_fmt
);
365 void bdrv_register(BlockDriver
*bdrv
);
366 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
367 const char *backing_file_str
);
368 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
369 BlockDriverState
*bs
);
370 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
);
371 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
373 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
375 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
);
378 typedef struct BdrvCheckResult
{
382 int corruptions_fixed
;
384 int64_t image_end_offset
;
393 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
);
395 /* The units of offset and total_work_size may be chosen arbitrarily by the
396 * block driver; total_work_size may change during the course of the amendment
398 typedef void BlockDriverAmendStatusCB(BlockDriverState
*bs
, int64_t offset
,
399 int64_t total_work_size
, void *opaque
);
400 int bdrv_amend_options(BlockDriverState
*bs_new
, QemuOpts
*opts
,
401 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
404 /* external snapshots */
405 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
406 BlockDriverState
*candidate
);
407 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
);
409 /* check if a named node can be replaced when doing drive-mirror */
410 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
411 const char *node_name
, Error
**errp
);
413 /* async block I/O */
414 void bdrv_aio_cancel(BlockAIOCB
*acb
);
415 void bdrv_aio_cancel_async(BlockAIOCB
*acb
);
417 /* sg packet commands */
418 int bdrv_co_ioctl(BlockDriverState
*bs
, int req
, void *buf
);
420 /* Invalidate any cached metadata used by image formats */
421 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
);
422 void bdrv_invalidate_cache_all(Error
**errp
);
423 int bdrv_inactivate_all(void);
425 /* Ensure contents are flushed to disk. */
426 int bdrv_flush(BlockDriverState
*bs
);
427 int coroutine_fn
bdrv_co_flush(BlockDriverState
*bs
);
428 int bdrv_flush_all(void);
429 void bdrv_close_all(void);
430 void bdrv_drain(BlockDriverState
*bs
);
431 void coroutine_fn
bdrv_co_drain(BlockDriverState
*bs
);
432 void bdrv_drain_all_begin(void);
433 void bdrv_drain_all_end(void);
434 void bdrv_drain_all(void);
436 #define BDRV_POLL_WHILE(bs, cond) ({ \
437 BlockDriverState *bs_ = (bs); \
438 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
441 int bdrv_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
442 int bdrv_co_pdiscard(BdrvChild
*child
, int64_t offset
, int64_t bytes
);
443 int bdrv_has_zero_init_1(BlockDriverState
*bs
);
444 int bdrv_has_zero_init(BlockDriverState
*bs
);
445 int bdrv_has_zero_init_truncate(BlockDriverState
*bs
);
446 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
);
447 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
);
448 int bdrv_block_status(BlockDriverState
*bs
, int64_t offset
,
449 int64_t bytes
, int64_t *pnum
, int64_t *map
,
450 BlockDriverState
**file
);
451 int bdrv_block_status_above(BlockDriverState
*bs
, BlockDriverState
*base
,
452 int64_t offset
, int64_t bytes
, int64_t *pnum
,
453 int64_t *map
, BlockDriverState
**file
);
454 int bdrv_is_allocated(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
,
456 int bdrv_is_allocated_above(BlockDriverState
*top
, BlockDriverState
*base
,
457 bool include_base
, int64_t offset
, int64_t bytes
,
460 bool bdrv_is_read_only(BlockDriverState
*bs
);
461 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
462 bool ignore_allow_rdw
, Error
**errp
);
463 int bdrv_apply_auto_read_only(BlockDriverState
*bs
, const char *errmsg
,
465 bool bdrv_is_writable(BlockDriverState
*bs
);
466 bool bdrv_is_sg(BlockDriverState
*bs
);
467 bool bdrv_is_inserted(BlockDriverState
*bs
);
468 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
);
469 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
);
470 const char *bdrv_get_format_name(BlockDriverState
*bs
);
471 BlockDriverState
*bdrv_find_node(const char *node_name
);
472 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
);
473 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
);
474 BlockDriverState
*bdrv_lookup_bs(const char *device
,
475 const char *node_name
,
477 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
);
478 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
);
479 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
);
481 typedef struct BdrvNextIterator
{
483 BDRV_NEXT_BACKEND_ROOTS
,
484 BDRV_NEXT_MONITOR_OWNED
,
487 BlockDriverState
*bs
;
490 BlockDriverState
*bdrv_first(BdrvNextIterator
*it
);
491 BlockDriverState
*bdrv_next(BdrvNextIterator
*it
);
492 void bdrv_next_cleanup(BdrvNextIterator
*it
);
494 BlockDriverState
*bdrv_next_monitor_owned(BlockDriverState
*bs
);
495 bool bdrv_is_encrypted(BlockDriverState
*bs
);
496 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
497 void *opaque
, bool read_only
);
498 const char *bdrv_get_node_name(const BlockDriverState
*bs
);
499 const char *bdrv_get_device_name(const BlockDriverState
*bs
);
500 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
);
501 int bdrv_get_flags(BlockDriverState
*bs
);
502 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
503 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
505 BlockStatsSpecific
*bdrv_get_specific_stats(BlockDriverState
*bs
);
506 void bdrv_round_to_clusters(BlockDriverState
*bs
,
507 int64_t offset
, int64_t bytes
,
508 int64_t *cluster_offset
,
509 int64_t *cluster_bytes
);
511 void bdrv_get_backing_filename(BlockDriverState
*bs
,
512 char *filename
, int filename_size
);
513 char *bdrv_get_full_backing_filename(BlockDriverState
*bs
, Error
**errp
);
514 char *bdrv_get_full_backing_filename_from_filename(const char *backed
,
517 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
);
519 int path_has_protocol(const char *path
);
520 int path_is_absolute(const char *path
);
521 char *path_combine(const char *base_path
, const char *filename
);
523 int bdrv_readv_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
524 int bdrv_writev_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
525 int bdrv_save_vmstate(BlockDriverState
*bs
, const uint8_t *buf
,
526 int64_t pos
, int size
);
528 int bdrv_load_vmstate(BlockDriverState
*bs
, uint8_t *buf
,
529 int64_t pos
, int size
);
531 void bdrv_img_create(const char *filename
, const char *fmt
,
532 const char *base_filename
, const char *base_fmt
,
533 char *options
, uint64_t img_size
, int flags
,
534 bool quiet
, Error
**errp
);
536 /* Returns the alignment in bytes that is required so that no bounce buffer
537 * is required throughout the stack */
538 size_t bdrv_min_mem_align(BlockDriverState
*bs
);
539 /* Returns optimal alignment in bytes for bounce buffer */
540 size_t bdrv_opt_mem_align(BlockDriverState
*bs
);
541 void *qemu_blockalign(BlockDriverState
*bs
, size_t size
);
542 void *qemu_blockalign0(BlockDriverState
*bs
, size_t size
);
543 void *qemu_try_blockalign(BlockDriverState
*bs
, size_t size
);
544 void *qemu_try_blockalign0(BlockDriverState
*bs
, size_t size
);
545 bool bdrv_qiov_is_aligned(BlockDriverState
*bs
, QEMUIOVector
*qiov
);
547 void bdrv_enable_copy_on_read(BlockDriverState
*bs
);
548 void bdrv_disable_copy_on_read(BlockDriverState
*bs
);
550 void bdrv_ref(BlockDriverState
*bs
);
551 void bdrv_unref(BlockDriverState
*bs
);
552 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
);
553 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
554 BlockDriverState
*child_bs
,
555 const char *child_name
,
556 const BdrvChildRole
*child_role
,
559 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
);
560 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
561 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
562 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
);
563 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
);
564 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
);
566 #define BLKDBG_EVENT(child, evt) \
569 bdrv_debug_event(child->bs, evt); \
573 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
);
575 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
577 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
);
578 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
);
579 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
);
582 * bdrv_get_aio_context:
584 * Returns: the currently bound #AioContext
586 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
);
589 * Transfer control to @co in the aio context of @bs
591 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
);
593 void bdrv_set_aio_context_ignore(BlockDriverState
*bs
,
594 AioContext
*new_context
, GSList
**ignore
);
595 int bdrv_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
597 int bdrv_child_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
598 BdrvChild
*ignore_child
, Error
**errp
);
599 bool bdrv_child_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
600 GSList
**ignore
, Error
**errp
);
601 bool bdrv_can_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
602 GSList
**ignore
, Error
**errp
);
603 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
);
604 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
);
606 void bdrv_io_plug(BlockDriverState
*bs
);
607 void bdrv_io_unplug(BlockDriverState
*bs
);
610 * bdrv_parent_drained_begin_single:
612 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
613 * any pending activity to cease.
615 void bdrv_parent_drained_begin_single(BdrvChild
*c
, bool poll
);
618 * bdrv_parent_drained_end_single:
620 * End a quiesced section for the parent of @c.
622 * This polls @bs's AioContext until all scheduled sub-drained_ends
623 * have settled, which may result in graph changes.
625 void bdrv_parent_drained_end_single(BdrvChild
*c
);
630 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
631 * and if @recursive is true its children as well (used for subtree drain).
633 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
634 * ignore the drain request because they will be drained separately (used for
637 * This is part of bdrv_drained_begin.
639 bool bdrv_drain_poll(BlockDriverState
*bs
, bool recursive
,
640 BdrvChild
*ignore_parent
, bool ignore_bds_parents
);
643 * bdrv_drained_begin:
645 * Begin a quiesced section for exclusive access to the BDS, by disabling
646 * external request sources including NBD server and device model. Note that
647 * this doesn't block timers or coroutines from submitting more requests, which
648 * means block_job_pause is still necessary.
650 * This function can be recursive.
652 void bdrv_drained_begin(BlockDriverState
*bs
);
655 * bdrv_do_drained_begin_quiesce:
657 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
658 * running requests to complete.
660 void bdrv_do_drained_begin_quiesce(BlockDriverState
*bs
,
661 BdrvChild
*parent
, bool ignore_bds_parents
);
664 * Like bdrv_drained_begin, but recursively begins a quiesced section for
665 * exclusive access to all child nodes as well.
667 void bdrv_subtree_drained_begin(BlockDriverState
*bs
);
672 * End a quiescent section started by bdrv_drained_begin().
674 * This polls @bs's AioContext until all scheduled sub-drained_ends
675 * have settled. On one hand, that may result in graph changes. On
676 * the other, this requires that the caller either runs in the main
677 * loop; or that all involved nodes (@bs and all of its parents) are
678 * in the caller's AioContext.
680 void bdrv_drained_end(BlockDriverState
*bs
);
683 * bdrv_drained_end_no_poll:
685 * Same as bdrv_drained_end(), but do not poll for the subgraph to
686 * actually become unquiesced. Therefore, no graph changes will occur
687 * with this function.
689 * *drained_end_counter is incremented for every background operation
690 * that is scheduled, and will be decremented for every operation once
691 * it settles. The caller must poll until it reaches 0. The counter
692 * should be accessed using atomic operations only.
694 void bdrv_drained_end_no_poll(BlockDriverState
*bs
, int *drained_end_counter
);
697 * End a quiescent section started by bdrv_subtree_drained_begin().
699 void bdrv_subtree_drained_end(BlockDriverState
*bs
);
701 void bdrv_add_child(BlockDriverState
*parent
, BlockDriverState
*child
,
703 void bdrv_del_child(BlockDriverState
*parent
, BdrvChild
*child
, Error
**errp
);
705 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
706 uint32_t granularity
, Error
**errp
);
709 * bdrv_register_buf/bdrv_unregister_buf:
711 * Register/unregister a buffer for I/O. For example, VFIO drivers are
712 * interested to know the memory areas that would later be used for I/O, so
713 * that they can prepare IOMMU mapping etc., to get better performance.
715 void bdrv_register_buf(BlockDriverState
*bs
, void *host
, size_t size
);
716 void bdrv_unregister_buf(BlockDriverState
*bs
, void *host
);
720 * bdrv_co_copy_range:
722 * Do offloaded copy between two children. If the operation is not implemented
723 * by the driver, or if the backend storage doesn't support it, a negative
724 * error code will be returned.
726 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
727 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
728 * calling copy_file_range(2)) after the first error, thus it should fall back
729 * to a read+write path in the caller level.
731 * @src: Source child to copy data from
732 * @src_offset: offset in @src image to read data
733 * @dst: Destination child to copy data to
734 * @dst_offset: offset in @dst image to write data
735 * @bytes: number of bytes to copy
736 * @flags: request flags. Supported flags:
737 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
738 * write on @dst as if bdrv_co_pwrite_zeroes is
739 * called. Used to simplify caller code, or
740 * during BlockDriver.bdrv_co_copy_range_from()
742 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
743 * requests currently in flight.
745 * Returns: 0 if succeeded; negative error code if failed.
747 int coroutine_fn
bdrv_co_copy_range(BdrvChild
*src
, uint64_t src_offset
,
748 BdrvChild
*dst
, uint64_t dst_offset
,
749 uint64_t bytes
, BdrvRequestFlags read_flags
,
750 BdrvRequestFlags write_flags
);