5 #include "qapi/qapi-types-block-core.h"
6 #include "block/aio-wait.h"
8 #include "qemu/coroutine.h"
9 #include "block/accounting.h"
10 #include "block/dirty-bitmap.h"
11 #include "block/blockjob.h"
12 #include "qemu/hbitmap.h"
15 typedef struct BlockDriver BlockDriver
;
16 typedef struct BdrvChild BdrvChild
;
17 typedef struct BdrvChildRole BdrvChildRole
;
19 typedef struct BlockDriverInfo
{
20 /* in bytes, 0 if irrelevant */
22 /* offset at which the VM state can be saved (0 if not possible) */
23 int64_t vm_state_offset
;
26 * True if unallocated blocks read back as zeroes. This is equivalent
27 * to the LBPRZ flag in the SCSI logical block provisioning page.
29 bool unallocated_blocks_are_zero
;
31 * True if this block driver only supports compressed writes
33 bool needs_compressed_writes
;
36 typedef struct BlockFragInfo
{
37 uint64_t allocated_clusters
;
38 uint64_t total_clusters
;
39 uint64_t fragmented_clusters
;
40 uint64_t compressed_clusters
;
44 BDRV_REQ_COPY_ON_READ
= 0x1,
45 BDRV_REQ_ZERO_WRITE
= 0x2,
48 * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
49 * that the block driver should unmap (discard) blocks if it is guaranteed
50 * that the result will read back as zeroes. The flag is only passed to the
51 * driver if the block device is opened with BDRV_O_UNMAP.
53 BDRV_REQ_MAY_UNMAP
= 0x4,
56 * The BDRV_REQ_NO_SERIALISING flag is only valid for reads and means that
57 * we don't want wait_serialising_requests() during the read operation.
59 * This flag is used for backup copy-on-write operations, when we need to
60 * read old data before write (write notifier triggered). It is okay since
61 * we already waited for other serializing requests in the initiating write
62 * (see bdrv_aligned_pwritev), and it is necessary if the initiating write
63 * is already serializing (without the flag, the read would deadlock
64 * waiting for the serialising write to complete).
66 BDRV_REQ_NO_SERIALISING
= 0x8,
68 BDRV_REQ_WRITE_COMPRESSED
= 0x20,
70 /* Signifies that this write request will not change the visible disk
72 BDRV_REQ_WRITE_UNCHANGED
= 0x40,
75 * BDRV_REQ_SERIALISING forces request serialisation for writes.
76 * It is used to ensure that writes to the backing file of a backup process
77 * target cannot race with a read of the backup target that defers to the
80 * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to
81 * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be
82 * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long.
84 BDRV_REQ_SERIALISING
= 0x80,
86 /* Execute the request only if the operation can be offloaded or otherwise
87 * be executed efficiently, but return an error instead of using a slow
89 BDRV_REQ_NO_FALLBACK
= 0x100,
91 /* Mask of valid flags */
92 BDRV_REQ_MASK
= 0x1ff,
95 typedef struct BlockSizes
{
100 typedef struct HDGeometry
{
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 */
125 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
128 /* Option names of options parsed by the block layer */
130 #define BDRV_OPT_CACHE_WB "cache.writeback"
131 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
132 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
133 #define BDRV_OPT_READ_ONLY "read-only"
134 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
135 #define BDRV_OPT_DISCARD "discard"
136 #define BDRV_OPT_FORCE_SHARE "force-share"
139 #define BDRV_SECTOR_BITS 9
140 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
141 #define BDRV_SECTOR_MASK ~(BDRV_SECTOR_SIZE - 1)
143 #define BDRV_REQUEST_MAX_SECTORS MIN(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 * Allocation status flags for bdrv_block_status() and friends.
151 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
152 * BDRV_BLOCK_ZERO: offset reads as zero
153 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
154 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
155 * layer rather than any backing, set by block layer
156 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
157 * layer, set by block layer
160 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
161 * that the block layer recompute the answer from the returned
162 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
164 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
165 * host offset within the returned BDS that is allocated for the
166 * corresponding raw guest data. However, whether that offset
167 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
169 * DATA ZERO OFFSET_VALID
170 * t t t sectors read as zero, returned file is zero at offset
171 * t f t sectors read as valid from file at offset
172 * f t t sectors preallocated, read as zero, returned file not
173 * necessarily zero at offset
174 * f f t sectors preallocated but read from backing_hd,
175 * returned file contains garbage at offset
176 * t t f sectors preallocated, read as zero, unknown offset
177 * t f f sectors read from unknown file or offset
178 * f t f not allocated or unknown offset, read as zero
179 * f f f not allocated or unknown offset, read from backing_hd
181 #define BDRV_BLOCK_DATA 0x01
182 #define BDRV_BLOCK_ZERO 0x02
183 #define BDRV_BLOCK_OFFSET_VALID 0x04
184 #define BDRV_BLOCK_RAW 0x08
185 #define BDRV_BLOCK_ALLOCATED 0x10
186 #define BDRV_BLOCK_EOF 0x20
187 #define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK
189 typedef QSIMPLEQ_HEAD(BlockReopenQueue
, BlockReopenQueueEntry
) BlockReopenQueue
;
191 typedef struct BDRVReopenState
{
192 BlockDriverState
*bs
;
194 BlockdevDetectZeroesOptions detect_zeroes
;
195 bool backing_missing
;
196 bool replace_backing_bs
; /* new_backing_bs is ignored if this is false */
197 BlockDriverState
*new_backing_bs
; /* If NULL then detach the current bs */
198 uint64_t perm
, shared_perm
;
200 QDict
*explicit_options
;
205 * Block operation types
207 typedef enum BlockOpType
{
208 BLOCK_OP_TYPE_BACKUP_SOURCE
,
209 BLOCK_OP_TYPE_BACKUP_TARGET
,
210 BLOCK_OP_TYPE_CHANGE
,
211 BLOCK_OP_TYPE_COMMIT_SOURCE
,
212 BLOCK_OP_TYPE_COMMIT_TARGET
,
213 BLOCK_OP_TYPE_DATAPLANE
,
214 BLOCK_OP_TYPE_DRIVE_DEL
,
216 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT
,
217 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT
,
218 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE
,
219 BLOCK_OP_TYPE_MIRROR_SOURCE
,
220 BLOCK_OP_TYPE_MIRROR_TARGET
,
221 BLOCK_OP_TYPE_RESIZE
,
222 BLOCK_OP_TYPE_STREAM
,
223 BLOCK_OP_TYPE_REPLACE
,
227 /* Block node permission constants */
230 * A user that has the "permission" of consistent reads is guaranteed that
231 * their view of the contents of the block device is complete and
232 * self-consistent, representing the contents of a disk at a specific
235 * For most block devices (including their backing files) this is true, but
236 * the property cannot be maintained in a few situations like for
237 * intermediate nodes of a commit block job.
239 BLK_PERM_CONSISTENT_READ
= 0x01,
241 /** This permission is required to change the visible disk contents. */
242 BLK_PERM_WRITE
= 0x02,
245 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
246 * required for writes to the block node when the caller promises that
247 * the visible disk content doesn't change.
249 * As the BLK_PERM_WRITE permission is strictly stronger, either is
250 * sufficient to perform an unchanging write.
252 BLK_PERM_WRITE_UNCHANGED
= 0x04,
254 /** This permission is required to change the size of a block node. */
255 BLK_PERM_RESIZE
= 0x08,
258 * This permission is required to change the node that this BdrvChild
261 BLK_PERM_GRAPH_MOD
= 0x10,
265 DEFAULT_PERM_PASSTHROUGH
= BLK_PERM_CONSISTENT_READ
267 | BLK_PERM_WRITE_UNCHANGED
270 DEFAULT_PERM_UNCHANGED
= BLK_PERM_ALL
& ~DEFAULT_PERM_PASSTHROUGH
,
273 char *bdrv_perm_names(uint64_t perm
);
275 /* disk I/O throttling */
276 void bdrv_init(void);
277 void bdrv_init_with_whitelist(void);
278 bool bdrv_uses_whitelist(void);
279 int bdrv_is_whitelisted(BlockDriver
*drv
, bool read_only
);
280 BlockDriver
*bdrv_find_protocol(const char *filename
,
281 bool allow_protocol_prefix
,
283 BlockDriver
*bdrv_find_format(const char *format_name
);
284 int bdrv_create(BlockDriver
*drv
, const char* filename
,
285 QemuOpts
*opts
, Error
**errp
);
286 int bdrv_create_file(const char *filename
, QemuOpts
*opts
, Error
**errp
);
287 BlockDriverState
*bdrv_new(void);
288 void bdrv_append(BlockDriverState
*bs_new
, BlockDriverState
*bs_top
,
290 void bdrv_replace_node(BlockDriverState
*from
, BlockDriverState
*to
,
293 int bdrv_parse_cache_mode(const char *mode
, int *flags
, bool *writethrough
);
294 int bdrv_parse_discard_flags(const char *mode
, int *flags
);
295 BdrvChild
*bdrv_open_child(const char *filename
,
296 QDict
*options
, const char *bdref_key
,
297 BlockDriverState
* parent
,
298 const BdrvChildRole
*child_role
,
299 bool allow_none
, Error
**errp
);
300 BlockDriverState
*bdrv_open_blockdev_ref(BlockdevRef
*ref
, Error
**errp
);
301 void bdrv_set_backing_hd(BlockDriverState
*bs
, BlockDriverState
*backing_hd
,
303 int bdrv_open_backing_file(BlockDriverState
*bs
, QDict
*parent_options
,
304 const char *bdref_key
, Error
**errp
);
305 BlockDriverState
*bdrv_open(const char *filename
, const char *reference
,
306 QDict
*options
, int flags
, Error
**errp
);
307 BlockDriverState
*bdrv_new_open_driver(BlockDriver
*drv
, const char *node_name
,
308 int flags
, Error
**errp
);
309 BlockReopenQueue
*bdrv_reopen_queue(BlockReopenQueue
*bs_queue
,
310 BlockDriverState
*bs
, QDict
*options
,
312 int bdrv_reopen_multiple(BlockReopenQueue
*bs_queue
, Error
**errp
);
313 int bdrv_reopen_set_read_only(BlockDriverState
*bs
, bool read_only
,
315 int bdrv_reopen_prepare(BDRVReopenState
*reopen_state
,
316 BlockReopenQueue
*queue
, Error
**errp
);
317 void bdrv_reopen_commit(BDRVReopenState
*reopen_state
);
318 void bdrv_reopen_abort(BDRVReopenState
*reopen_state
);
319 int bdrv_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
320 int bytes
, BdrvRequestFlags flags
);
321 int bdrv_make_zero(BdrvChild
*child
, BdrvRequestFlags flags
);
322 int bdrv_pread(BdrvChild
*child
, int64_t offset
, void *buf
, int bytes
);
323 int bdrv_preadv(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
324 int bdrv_pwrite(BdrvChild
*child
, int64_t offset
, const void *buf
, int bytes
);
325 int bdrv_pwritev(BdrvChild
*child
, int64_t offset
, QEMUIOVector
*qiov
);
326 int bdrv_pwrite_sync(BdrvChild
*child
, int64_t offset
,
327 const void *buf
, int count
);
329 * Efficiently zero a region of the disk image. Note that this is a regular
330 * I/O request like read or write and should have a reasonable size. This
331 * function is not suitable for zeroing the entire image in a single request
332 * because it may allocate memory for the entire region.
334 int coroutine_fn
bdrv_co_pwrite_zeroes(BdrvChild
*child
, int64_t offset
,
335 int bytes
, BdrvRequestFlags flags
);
336 BlockDriverState
*bdrv_find_backing_image(BlockDriverState
*bs
,
337 const char *backing_file
);
338 void bdrv_refresh_filename(BlockDriverState
*bs
);
340 int coroutine_fn
bdrv_co_truncate(BdrvChild
*child
, int64_t offset
,
341 PreallocMode prealloc
, Error
**errp
);
342 int bdrv_truncate(BdrvChild
*child
, int64_t offset
, PreallocMode prealloc
,
345 int64_t bdrv_nb_sectors(BlockDriverState
*bs
);
346 int64_t bdrv_getlength(BlockDriverState
*bs
);
347 int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs
);
348 BlockMeasureInfo
*bdrv_measure(BlockDriver
*drv
, QemuOpts
*opts
,
349 BlockDriverState
*in_bs
, Error
**errp
);
350 void bdrv_get_geometry(BlockDriverState
*bs
, uint64_t *nb_sectors_ptr
);
351 void bdrv_refresh_limits(BlockDriverState
*bs
, Error
**errp
);
352 int bdrv_commit(BlockDriverState
*bs
);
353 int bdrv_change_backing_file(BlockDriverState
*bs
,
354 const char *backing_file
, const char *backing_fmt
);
355 void bdrv_register(BlockDriver
*bdrv
);
356 int bdrv_drop_intermediate(BlockDriverState
*top
, BlockDriverState
*base
,
357 const char *backing_file_str
);
358 BlockDriverState
*bdrv_find_overlay(BlockDriverState
*active
,
359 BlockDriverState
*bs
);
360 BlockDriverState
*bdrv_find_base(BlockDriverState
*bs
);
361 bool bdrv_is_backing_chain_frozen(BlockDriverState
*bs
, BlockDriverState
*base
,
363 int bdrv_freeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
,
365 void bdrv_unfreeze_backing_chain(BlockDriverState
*bs
, BlockDriverState
*base
);
368 typedef struct BdrvCheckResult
{
372 int corruptions_fixed
;
374 int64_t image_end_offset
;
383 int bdrv_check(BlockDriverState
*bs
, BdrvCheckResult
*res
, BdrvCheckMode fix
);
385 /* The units of offset and total_work_size may be chosen arbitrarily by the
386 * block driver; total_work_size may change during the course of the amendment
388 typedef void BlockDriverAmendStatusCB(BlockDriverState
*bs
, int64_t offset
,
389 int64_t total_work_size
, void *opaque
);
390 int bdrv_amend_options(BlockDriverState
*bs_new
, QemuOpts
*opts
,
391 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
394 /* external snapshots */
395 bool bdrv_recurse_is_first_non_filter(BlockDriverState
*bs
,
396 BlockDriverState
*candidate
);
397 bool bdrv_is_first_non_filter(BlockDriverState
*candidate
);
399 /* check if a named node can be replaced when doing drive-mirror */
400 BlockDriverState
*check_to_replace_node(BlockDriverState
*parent_bs
,
401 const char *node_name
, Error
**errp
);
403 /* async block I/O */
404 void bdrv_aio_cancel(BlockAIOCB
*acb
);
405 void bdrv_aio_cancel_async(BlockAIOCB
*acb
);
407 /* sg packet commands */
408 int bdrv_co_ioctl(BlockDriverState
*bs
, int req
, void *buf
);
410 /* Invalidate any cached metadata used by image formats */
411 void bdrv_invalidate_cache(BlockDriverState
*bs
, Error
**errp
);
412 void bdrv_invalidate_cache_all(Error
**errp
);
413 int bdrv_inactivate_all(void);
415 /* Ensure contents are flushed to disk. */
416 int bdrv_flush(BlockDriverState
*bs
);
417 int coroutine_fn
bdrv_co_flush(BlockDriverState
*bs
);
418 int bdrv_flush_all(void);
419 void bdrv_close_all(void);
420 void bdrv_drain(BlockDriverState
*bs
);
421 void coroutine_fn
bdrv_co_drain(BlockDriverState
*bs
);
422 void bdrv_drain_all_begin(void);
423 void bdrv_drain_all_end(void);
424 void bdrv_drain_all(void);
426 #define BDRV_POLL_WHILE(bs, cond) ({ \
427 BlockDriverState *bs_ = (bs); \
428 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
431 int bdrv_pdiscard(BdrvChild
*child
, int64_t offset
, int bytes
);
432 int bdrv_co_pdiscard(BdrvChild
*child
, int64_t offset
, int bytes
);
433 int bdrv_has_zero_init_1(BlockDriverState
*bs
);
434 int bdrv_has_zero_init(BlockDriverState
*bs
);
435 bool bdrv_unallocated_blocks_are_zero(BlockDriverState
*bs
);
436 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState
*bs
);
437 int bdrv_block_status(BlockDriverState
*bs
, int64_t offset
,
438 int64_t bytes
, int64_t *pnum
, int64_t *map
,
439 BlockDriverState
**file
);
440 int bdrv_block_status_above(BlockDriverState
*bs
, BlockDriverState
*base
,
441 int64_t offset
, int64_t bytes
, int64_t *pnum
,
442 int64_t *map
, BlockDriverState
**file
);
443 int bdrv_is_allocated(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
,
445 int bdrv_is_allocated_above(BlockDriverState
*top
, BlockDriverState
*base
,
446 int64_t offset
, int64_t bytes
, int64_t *pnum
);
448 bool bdrv_is_read_only(BlockDriverState
*bs
);
449 int bdrv_can_set_read_only(BlockDriverState
*bs
, bool read_only
,
450 bool ignore_allow_rdw
, Error
**errp
);
451 int bdrv_apply_auto_read_only(BlockDriverState
*bs
, const char *errmsg
,
453 bool bdrv_is_writable(BlockDriverState
*bs
);
454 bool bdrv_is_sg(BlockDriverState
*bs
);
455 bool bdrv_is_inserted(BlockDriverState
*bs
);
456 void bdrv_lock_medium(BlockDriverState
*bs
, bool locked
);
457 void bdrv_eject(BlockDriverState
*bs
, bool eject_flag
);
458 const char *bdrv_get_format_name(BlockDriverState
*bs
);
459 BlockDriverState
*bdrv_find_node(const char *node_name
);
460 BlockDeviceInfoList
*bdrv_named_nodes_list(Error
**errp
);
461 XDbgBlockGraph
*bdrv_get_xdbg_block_graph(Error
**errp
);
462 BlockDriverState
*bdrv_lookup_bs(const char *device
,
463 const char *node_name
,
465 bool bdrv_chain_contains(BlockDriverState
*top
, BlockDriverState
*base
);
466 BlockDriverState
*bdrv_next_node(BlockDriverState
*bs
);
467 BlockDriverState
*bdrv_next_all_states(BlockDriverState
*bs
);
469 typedef struct BdrvNextIterator
{
471 BDRV_NEXT_BACKEND_ROOTS
,
472 BDRV_NEXT_MONITOR_OWNED
,
475 BlockDriverState
*bs
;
478 BlockDriverState
*bdrv_first(BdrvNextIterator
*it
);
479 BlockDriverState
*bdrv_next(BdrvNextIterator
*it
);
480 void bdrv_next_cleanup(BdrvNextIterator
*it
);
482 BlockDriverState
*bdrv_next_monitor_owned(BlockDriverState
*bs
);
483 bool bdrv_is_encrypted(BlockDriverState
*bs
);
484 void bdrv_iterate_format(void (*it
)(void *opaque
, const char *name
),
485 void *opaque
, bool read_only
);
486 const char *bdrv_get_node_name(const BlockDriverState
*bs
);
487 const char *bdrv_get_device_name(const BlockDriverState
*bs
);
488 const char *bdrv_get_device_or_node_name(const BlockDriverState
*bs
);
489 int bdrv_get_flags(BlockDriverState
*bs
);
490 int bdrv_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
);
491 ImageInfoSpecific
*bdrv_get_specific_info(BlockDriverState
*bs
,
493 void bdrv_round_to_clusters(BlockDriverState
*bs
,
494 int64_t offset
, int64_t bytes
,
495 int64_t *cluster_offset
,
496 int64_t *cluster_bytes
);
498 void bdrv_get_backing_filename(BlockDriverState
*bs
,
499 char *filename
, int filename_size
);
500 char *bdrv_get_full_backing_filename(BlockDriverState
*bs
, Error
**errp
);
501 char *bdrv_get_full_backing_filename_from_filename(const char *backed
,
504 char *bdrv_dirname(BlockDriverState
*bs
, Error
**errp
);
506 int path_has_protocol(const char *path
);
507 int path_is_absolute(const char *path
);
508 char *path_combine(const char *base_path
, const char *filename
);
510 int bdrv_readv_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
511 int bdrv_writev_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
, int64_t pos
);
512 int bdrv_save_vmstate(BlockDriverState
*bs
, const uint8_t *buf
,
513 int64_t pos
, int size
);
515 int bdrv_load_vmstate(BlockDriverState
*bs
, uint8_t *buf
,
516 int64_t pos
, int size
);
518 void bdrv_img_create(const char *filename
, const char *fmt
,
519 const char *base_filename
, const char *base_fmt
,
520 char *options
, uint64_t img_size
, int flags
,
521 bool quiet
, Error
**errp
);
523 /* Returns the alignment in bytes that is required so that no bounce buffer
524 * is required throughout the stack */
525 size_t bdrv_min_mem_align(BlockDriverState
*bs
);
526 /* Returns optimal alignment in bytes for bounce buffer */
527 size_t bdrv_opt_mem_align(BlockDriverState
*bs
);
528 void *qemu_blockalign(BlockDriverState
*bs
, size_t size
);
529 void *qemu_blockalign0(BlockDriverState
*bs
, size_t size
);
530 void *qemu_try_blockalign(BlockDriverState
*bs
, size_t size
);
531 void *qemu_try_blockalign0(BlockDriverState
*bs
, size_t size
);
532 bool bdrv_qiov_is_aligned(BlockDriverState
*bs
, QEMUIOVector
*qiov
);
534 void bdrv_enable_copy_on_read(BlockDriverState
*bs
);
535 void bdrv_disable_copy_on_read(BlockDriverState
*bs
);
537 void bdrv_ref(BlockDriverState
*bs
);
538 void bdrv_unref(BlockDriverState
*bs
);
539 void bdrv_unref_child(BlockDriverState
*parent
, BdrvChild
*child
);
540 BdrvChild
*bdrv_attach_child(BlockDriverState
*parent_bs
,
541 BlockDriverState
*child_bs
,
542 const char *child_name
,
543 const BdrvChildRole
*child_role
,
546 bool bdrv_op_is_blocked(BlockDriverState
*bs
, BlockOpType op
, Error
**errp
);
547 void bdrv_op_block(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
548 void bdrv_op_unblock(BlockDriverState
*bs
, BlockOpType op
, Error
*reason
);
549 void bdrv_op_block_all(BlockDriverState
*bs
, Error
*reason
);
550 void bdrv_op_unblock_all(BlockDriverState
*bs
, Error
*reason
);
551 bool bdrv_op_blocker_is_empty(BlockDriverState
*bs
);
553 #define BLKDBG_EVENT(child, evt) \
556 bdrv_debug_event(child->bs, evt); \
560 void bdrv_debug_event(BlockDriverState
*bs
, BlkdebugEvent event
);
562 int bdrv_debug_breakpoint(BlockDriverState
*bs
, const char *event
,
564 int bdrv_debug_remove_breakpoint(BlockDriverState
*bs
, const char *tag
);
565 int bdrv_debug_resume(BlockDriverState
*bs
, const char *tag
);
566 bool bdrv_debug_is_suspended(BlockDriverState
*bs
, const char *tag
);
569 * bdrv_get_aio_context:
571 * Returns: the currently bound #AioContext
573 AioContext
*bdrv_get_aio_context(BlockDriverState
*bs
);
576 * Transfer control to @co in the aio context of @bs
578 void bdrv_coroutine_enter(BlockDriverState
*bs
, Coroutine
*co
);
581 * bdrv_set_aio_context:
583 * Changes the #AioContext used for fd handlers, timers, and BHs by this
584 * BlockDriverState and all its children.
586 * This function must be called with iothread lock held.
588 void bdrv_set_aio_context(BlockDriverState
*bs
, AioContext
*new_context
);
589 void bdrv_set_aio_context_ignore(BlockDriverState
*bs
,
590 AioContext
*new_context
, GSList
**ignore
);
591 int bdrv_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
593 int bdrv_child_try_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
594 BdrvChild
*ignore_child
, Error
**errp
);
595 bool bdrv_child_can_set_aio_context(BdrvChild
*c
, AioContext
*ctx
,
596 GSList
**ignore
, Error
**errp
);
597 bool bdrv_can_set_aio_context(BlockDriverState
*bs
, AioContext
*ctx
,
598 GSList
**ignore
, Error
**errp
);
599 int bdrv_probe_blocksizes(BlockDriverState
*bs
, BlockSizes
*bsz
);
600 int bdrv_probe_geometry(BlockDriverState
*bs
, HDGeometry
*geo
);
602 void bdrv_io_plug(BlockDriverState
*bs
);
603 void bdrv_io_unplug(BlockDriverState
*bs
);
606 * bdrv_parent_drained_begin:
608 * Begin a quiesced section of all users of @bs. This is part of
609 * bdrv_drained_begin.
611 void bdrv_parent_drained_begin(BlockDriverState
*bs
, BdrvChild
*ignore
,
612 bool ignore_bds_parents
);
615 * bdrv_parent_drained_begin_single:
617 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
618 * any pending activity to cease.
620 void bdrv_parent_drained_begin_single(BdrvChild
*c
, bool poll
);
623 * bdrv_parent_drained_end:
625 * End a quiesced section of all users of @bs. This is part of
628 void bdrv_parent_drained_end(BlockDriverState
*bs
, BdrvChild
*ignore
,
629 bool ignore_bds_parents
);
634 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
635 * and if @recursive is true its children as well (used for subtree drain).
637 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
638 * ignore the drain request because they will be drained separately (used for
641 * This is part of bdrv_drained_begin.
643 bool bdrv_drain_poll(BlockDriverState
*bs
, bool recursive
,
644 BdrvChild
*ignore_parent
, bool ignore_bds_parents
);
647 * bdrv_drained_begin:
649 * Begin a quiesced section for exclusive access to the BDS, by disabling
650 * external request sources including NBD server and device model. Note that
651 * this doesn't block timers or coroutines from submitting more requests, which
652 * means block_job_pause is still necessary.
654 * This function can be recursive.
656 void bdrv_drained_begin(BlockDriverState
*bs
);
659 * bdrv_do_drained_begin_quiesce:
661 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
662 * running requests to complete.
664 void bdrv_do_drained_begin_quiesce(BlockDriverState
*bs
,
665 BdrvChild
*parent
, bool ignore_bds_parents
);
668 * Like bdrv_drained_begin, but recursively begins a quiesced section for
669 * exclusive access to all child nodes as well.
671 void bdrv_subtree_drained_begin(BlockDriverState
*bs
);
676 * End a quiescent section started by bdrv_drained_begin().
678 void bdrv_drained_end(BlockDriverState
*bs
);
681 * End a quiescent section started by bdrv_subtree_drained_begin().
683 void bdrv_subtree_drained_end(BlockDriverState
*bs
);
685 void bdrv_add_child(BlockDriverState
*parent
, BlockDriverState
*child
,
687 void bdrv_del_child(BlockDriverState
*parent
, BdrvChild
*child
, Error
**errp
);
689 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState
*bs
, const char *name
,
690 uint32_t granularity
, Error
**errp
);
693 * bdrv_register_buf/bdrv_unregister_buf:
695 * Register/unregister a buffer for I/O. For example, VFIO drivers are
696 * interested to know the memory areas that would later be used for I/O, so
697 * that they can prepare IOMMU mapping etc., to get better performance.
699 void bdrv_register_buf(BlockDriverState
*bs
, void *host
, size_t size
);
700 void bdrv_unregister_buf(BlockDriverState
*bs
, void *host
);
704 * bdrv_co_copy_range:
706 * Do offloaded copy between two children. If the operation is not implemented
707 * by the driver, or if the backend storage doesn't support it, a negative
708 * error code will be returned.
710 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
711 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
712 * calling copy_file_range(2)) after the first error, thus it should fall back
713 * to a read+write path in the caller level.
715 * @src: Source child to copy data from
716 * @src_offset: offset in @src image to read data
717 * @dst: Destination child to copy data to
718 * @dst_offset: offset in @dst image to write data
719 * @bytes: number of bytes to copy
720 * @flags: request flags. Supported flags:
721 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
722 * write on @dst as if bdrv_co_pwrite_zeroes is
723 * called. Used to simplify caller code, or
724 * during BlockDriver.bdrv_co_copy_range_from()
726 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
727 * requests currently in flight.
729 * Returns: 0 if succeeded; negative error code if failed.
731 int coroutine_fn
bdrv_co_copy_range(BdrvChild
*src
, uint64_t src_offset
,
732 BdrvChild
*dst
, uint64_t dst_offset
,
733 uint64_t bytes
, BdrvRequestFlags read_flags
,
734 BdrvRequestFlags write_flags
);