block: Honour BDRV_REQ_NO_SERIALISING in copy range
[qemu.git] / include / block / block.h
1 #ifndef BLOCK_H
2 #define BLOCK_H
3
4 #include "block/aio.h"
5 #include "qapi/qapi-types-block-core.h"
6 #include "block/aio-wait.h"
7 #include "qemu/iov.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"
13
14 /* block.c */
15 typedef struct BlockDriver BlockDriver;
16 typedef struct BdrvChild BdrvChild;
17 typedef struct BdrvChildRole BdrvChildRole;
18
19 typedef struct BlockDriverInfo {
20 /* in bytes, 0 if irrelevant */
21 int cluster_size;
22 /* offset at which the VM state can be saved (0 if not possible) */
23 int64_t vm_state_offset;
24 bool is_dirty;
25 /*
26 * True if unallocated blocks read back as zeroes. This is equivalent
27 * to the LBPRZ flag in the SCSI logical block provisioning page.
28 */
29 bool unallocated_blocks_are_zero;
30 /*
31 * True if this block driver only supports compressed writes
32 */
33 bool needs_compressed_writes;
34 } BlockDriverInfo;
35
36 typedef struct BlockFragInfo {
37 uint64_t allocated_clusters;
38 uint64_t total_clusters;
39 uint64_t fragmented_clusters;
40 uint64_t compressed_clusters;
41 } BlockFragInfo;
42
43 typedef enum {
44 BDRV_REQ_COPY_ON_READ = 0x1,
45 BDRV_REQ_ZERO_WRITE = 0x2,
46 /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
47 * is allowed to optimize a write zeroes request by unmapping (discarding)
48 * blocks if it is guaranteed that the result will read back as
49 * zeroes. The flag is only passed to the driver if the block device is
50 * opened with BDRV_O_UNMAP.
51 */
52 BDRV_REQ_MAY_UNMAP = 0x4,
53 BDRV_REQ_NO_SERIALISING = 0x8,
54 BDRV_REQ_FUA = 0x10,
55 BDRV_REQ_WRITE_COMPRESSED = 0x20,
56
57 /* Signifies that this write request will not change the visible disk
58 * content. */
59 BDRV_REQ_WRITE_UNCHANGED = 0x40,
60
61 /* Mask of valid flags */
62 BDRV_REQ_MASK = 0x7f,
63 } BdrvRequestFlags;
64
65 typedef struct BlockSizes {
66 uint32_t phys;
67 uint32_t log;
68 } BlockSizes;
69
70 typedef struct HDGeometry {
71 uint32_t heads;
72 uint32_t sectors;
73 uint32_t cylinders;
74 } HDGeometry;
75
76 #define BDRV_O_RDWR 0x0002
77 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
78 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
79 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
80 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
81 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
82 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
83 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
84 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
85 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
86 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
87 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
88 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
89 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
90 select an appropriate protocol driver,
91 ignoring the format layer */
92 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
93
94 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
95
96
97 /* Option names of options parsed by the block layer */
98
99 #define BDRV_OPT_CACHE_WB "cache.writeback"
100 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
101 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
102 #define BDRV_OPT_READ_ONLY "read-only"
103 #define BDRV_OPT_DISCARD "discard"
104 #define BDRV_OPT_FORCE_SHARE "force-share"
105
106
107 #define BDRV_SECTOR_BITS 9
108 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
109 #define BDRV_SECTOR_MASK ~(BDRV_SECTOR_SIZE - 1)
110
111 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
112 INT_MAX >> BDRV_SECTOR_BITS)
113 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
114
115 /*
116 * Allocation status flags for bdrv_block_status() and friends.
117 *
118 * Public flags:
119 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
120 * BDRV_BLOCK_ZERO: offset reads as zero
121 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
122 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
123 * layer rather than any backing, set by block layer
124 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
125 * layer, set by block layer
126 *
127 * Internal flag:
128 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
129 * that the block layer recompute the answer from the returned
130 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
131 *
132 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
133 * host offset within the returned BDS that is allocated for the
134 * corresponding raw guest data. However, whether that offset
135 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
136 *
137 * DATA ZERO OFFSET_VALID
138 * t t t sectors read as zero, returned file is zero at offset
139 * t f t sectors read as valid from file at offset
140 * f t t sectors preallocated, read as zero, returned file not
141 * necessarily zero at offset
142 * f f t sectors preallocated but read from backing_hd,
143 * returned file contains garbage at offset
144 * t t f sectors preallocated, read as zero, unknown offset
145 * t f f sectors read from unknown file or offset
146 * f t f not allocated or unknown offset, read as zero
147 * f f f not allocated or unknown offset, read from backing_hd
148 */
149 #define BDRV_BLOCK_DATA 0x01
150 #define BDRV_BLOCK_ZERO 0x02
151 #define BDRV_BLOCK_OFFSET_VALID 0x04
152 #define BDRV_BLOCK_RAW 0x08
153 #define BDRV_BLOCK_ALLOCATED 0x10
154 #define BDRV_BLOCK_EOF 0x20
155 #define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK
156
157 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
158
159 typedef struct BDRVReopenState {
160 BlockDriverState *bs;
161 int flags;
162 uint64_t perm, shared_perm;
163 QDict *options;
164 QDict *explicit_options;
165 void *opaque;
166 } BDRVReopenState;
167
168 /*
169 * Block operation types
170 */
171 typedef enum BlockOpType {
172 BLOCK_OP_TYPE_BACKUP_SOURCE,
173 BLOCK_OP_TYPE_BACKUP_TARGET,
174 BLOCK_OP_TYPE_CHANGE,
175 BLOCK_OP_TYPE_COMMIT_SOURCE,
176 BLOCK_OP_TYPE_COMMIT_TARGET,
177 BLOCK_OP_TYPE_DATAPLANE,
178 BLOCK_OP_TYPE_DRIVE_DEL,
179 BLOCK_OP_TYPE_EJECT,
180 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
181 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
182 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
183 BLOCK_OP_TYPE_MIRROR_SOURCE,
184 BLOCK_OP_TYPE_MIRROR_TARGET,
185 BLOCK_OP_TYPE_RESIZE,
186 BLOCK_OP_TYPE_STREAM,
187 BLOCK_OP_TYPE_REPLACE,
188 BLOCK_OP_TYPE_MAX,
189 } BlockOpType;
190
191 /* Block node permission constants */
192 enum {
193 /**
194 * A user that has the "permission" of consistent reads is guaranteed that
195 * their view of the contents of the block device is complete and
196 * self-consistent, representing the contents of a disk at a specific
197 * point.
198 *
199 * For most block devices (including their backing files) this is true, but
200 * the property cannot be maintained in a few situations like for
201 * intermediate nodes of a commit block job.
202 */
203 BLK_PERM_CONSISTENT_READ = 0x01,
204
205 /** This permission is required to change the visible disk contents. */
206 BLK_PERM_WRITE = 0x02,
207
208 /**
209 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
210 * required for writes to the block node when the caller promises that
211 * the visible disk content doesn't change.
212 *
213 * As the BLK_PERM_WRITE permission is strictly stronger, either is
214 * sufficient to perform an unchanging write.
215 */
216 BLK_PERM_WRITE_UNCHANGED = 0x04,
217
218 /** This permission is required to change the size of a block node. */
219 BLK_PERM_RESIZE = 0x08,
220
221 /**
222 * This permission is required to change the node that this BdrvChild
223 * points to.
224 */
225 BLK_PERM_GRAPH_MOD = 0x10,
226
227 BLK_PERM_ALL = 0x1f,
228 };
229
230 char *bdrv_perm_names(uint64_t perm);
231
232 /* disk I/O throttling */
233 void bdrv_init(void);
234 void bdrv_init_with_whitelist(void);
235 bool bdrv_uses_whitelist(void);
236 int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
237 BlockDriver *bdrv_find_protocol(const char *filename,
238 bool allow_protocol_prefix,
239 Error **errp);
240 BlockDriver *bdrv_find_format(const char *format_name);
241 int bdrv_create(BlockDriver *drv, const char* filename,
242 QemuOpts *opts, Error **errp);
243 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
244 BlockDriverState *bdrv_new(void);
245 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
246 Error **errp);
247 void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
248 Error **errp);
249
250 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
251 int bdrv_parse_discard_flags(const char *mode, int *flags);
252 BdrvChild *bdrv_open_child(const char *filename,
253 QDict *options, const char *bdref_key,
254 BlockDriverState* parent,
255 const BdrvChildRole *child_role,
256 bool allow_none, Error **errp);
257 BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
258 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
259 Error **errp);
260 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
261 const char *bdref_key, Error **errp);
262 BlockDriverState *bdrv_open(const char *filename, const char *reference,
263 QDict *options, int flags, Error **errp);
264 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
265 int flags, Error **errp);
266 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
267 BlockDriverState *bs,
268 QDict *options, int flags);
269 int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp);
270 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
271 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
272 BlockReopenQueue *queue, Error **errp);
273 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
274 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
275 int bdrv_read(BdrvChild *child, int64_t sector_num,
276 uint8_t *buf, int nb_sectors);
277 int bdrv_write(BdrvChild *child, int64_t sector_num,
278 const uint8_t *buf, int nb_sectors);
279 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
280 int bytes, BdrvRequestFlags flags);
281 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
282 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
283 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
284 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
285 int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
286 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
287 const void *buf, int count);
288 /*
289 * Efficiently zero a region of the disk image. Note that this is a regular
290 * I/O request like read or write and should have a reasonable size. This
291 * function is not suitable for zeroing the entire image in a single request
292 * because it may allocate memory for the entire region.
293 */
294 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
295 int bytes, BdrvRequestFlags flags);
296 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
297 const char *backing_file);
298 void bdrv_refresh_filename(BlockDriverState *bs);
299
300 int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset,
301 PreallocMode prealloc, Error **errp);
302 int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
303 Error **errp);
304
305 int64_t bdrv_nb_sectors(BlockDriverState *bs);
306 int64_t bdrv_getlength(BlockDriverState *bs);
307 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
308 BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
309 BlockDriverState *in_bs, Error **errp);
310 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
311 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
312 int bdrv_commit(BlockDriverState *bs);
313 int bdrv_change_backing_file(BlockDriverState *bs,
314 const char *backing_file, const char *backing_fmt);
315 void bdrv_register(BlockDriver *bdrv);
316 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
317 const char *backing_file_str);
318 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
319 BlockDriverState *bs);
320 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
321
322
323 typedef struct BdrvCheckResult {
324 int corruptions;
325 int leaks;
326 int check_errors;
327 int corruptions_fixed;
328 int leaks_fixed;
329 int64_t image_end_offset;
330 BlockFragInfo bfi;
331 } BdrvCheckResult;
332
333 typedef enum {
334 BDRV_FIX_LEAKS = 1,
335 BDRV_FIX_ERRORS = 2,
336 } BdrvCheckMode;
337
338 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
339
340 /* The units of offset and total_work_size may be chosen arbitrarily by the
341 * block driver; total_work_size may change during the course of the amendment
342 * operation */
343 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
344 int64_t total_work_size, void *opaque);
345 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
346 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
347 Error **errp);
348
349 /* external snapshots */
350 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
351 BlockDriverState *candidate);
352 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
353
354 /* check if a named node can be replaced when doing drive-mirror */
355 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
356 const char *node_name, Error **errp);
357
358 /* async block I/O */
359 void bdrv_aio_cancel(BlockAIOCB *acb);
360 void bdrv_aio_cancel_async(BlockAIOCB *acb);
361
362 /* sg packet commands */
363 int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
364
365 /* Invalidate any cached metadata used by image formats */
366 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
367 void bdrv_invalidate_cache_all(Error **errp);
368 int bdrv_inactivate_all(void);
369
370 /* Ensure contents are flushed to disk. */
371 int bdrv_flush(BlockDriverState *bs);
372 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
373 int bdrv_flush_all(void);
374 void bdrv_close_all(void);
375 void bdrv_drain(BlockDriverState *bs);
376 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
377 void bdrv_drain_all_begin(void);
378 void bdrv_drain_all_end(void);
379 void bdrv_drain_all(void);
380
381 /* Returns NULL when bs == NULL */
382 AioWait *bdrv_get_aio_wait(BlockDriverState *bs);
383
384 #define BDRV_POLL_WHILE(bs, cond) ({ \
385 BlockDriverState *bs_ = (bs); \
386 AIO_WAIT_WHILE(bdrv_get_aio_wait(bs_), \
387 bdrv_get_aio_context(bs_), \
388 cond); })
389
390 int bdrv_pdiscard(BlockDriverState *bs, int64_t offset, int bytes);
391 int bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes);
392 int bdrv_has_zero_init_1(BlockDriverState *bs);
393 int bdrv_has_zero_init(BlockDriverState *bs);
394 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
395 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
396 int bdrv_block_status(BlockDriverState *bs, int64_t offset,
397 int64_t bytes, int64_t *pnum, int64_t *map,
398 BlockDriverState **file);
399 int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
400 int64_t offset, int64_t bytes, int64_t *pnum,
401 int64_t *map, BlockDriverState **file);
402 int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
403 int64_t *pnum);
404 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
405 int64_t offset, int64_t bytes, int64_t *pnum);
406
407 bool bdrv_is_read_only(BlockDriverState *bs);
408 int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
409 bool ignore_allow_rdw, Error **errp);
410 int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp);
411 bool bdrv_is_writable(BlockDriverState *bs);
412 bool bdrv_is_sg(BlockDriverState *bs);
413 bool bdrv_is_inserted(BlockDriverState *bs);
414 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
415 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
416 const char *bdrv_get_format_name(BlockDriverState *bs);
417 BlockDriverState *bdrv_find_node(const char *node_name);
418 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
419 BlockDriverState *bdrv_lookup_bs(const char *device,
420 const char *node_name,
421 Error **errp);
422 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
423 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
424 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
425
426 typedef struct BdrvNextIterator {
427 enum {
428 BDRV_NEXT_BACKEND_ROOTS,
429 BDRV_NEXT_MONITOR_OWNED,
430 } phase;
431 BlockBackend *blk;
432 BlockDriverState *bs;
433 } BdrvNextIterator;
434
435 BlockDriverState *bdrv_first(BdrvNextIterator *it);
436 BlockDriverState *bdrv_next(BdrvNextIterator *it);
437 void bdrv_next_cleanup(BdrvNextIterator *it);
438
439 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
440 bool bdrv_is_encrypted(BlockDriverState *bs);
441 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
442 void *opaque);
443 const char *bdrv_get_node_name(const BlockDriverState *bs);
444 const char *bdrv_get_device_name(const BlockDriverState *bs);
445 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
446 int bdrv_get_flags(BlockDriverState *bs);
447 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
448 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
449 void bdrv_round_to_clusters(BlockDriverState *bs,
450 int64_t offset, int64_t bytes,
451 int64_t *cluster_offset,
452 int64_t *cluster_bytes);
453
454 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
455 void bdrv_get_backing_filename(BlockDriverState *bs,
456 char *filename, int filename_size);
457 void bdrv_get_full_backing_filename(BlockDriverState *bs,
458 char *dest, size_t sz, Error **errp);
459 void bdrv_get_full_backing_filename_from_filename(const char *backed,
460 const char *backing,
461 char *dest, size_t sz,
462 Error **errp);
463
464 int path_has_protocol(const char *path);
465 int path_is_absolute(const char *path);
466 void path_combine(char *dest, int dest_size,
467 const char *base_path,
468 const char *filename);
469
470 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
471 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
472 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
473 int64_t pos, int size);
474
475 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
476 int64_t pos, int size);
477
478 void bdrv_img_create(const char *filename, const char *fmt,
479 const char *base_filename, const char *base_fmt,
480 char *options, uint64_t img_size, int flags,
481 bool quiet, Error **errp);
482
483 /* Returns the alignment in bytes that is required so that no bounce buffer
484 * is required throughout the stack */
485 size_t bdrv_min_mem_align(BlockDriverState *bs);
486 /* Returns optimal alignment in bytes for bounce buffer */
487 size_t bdrv_opt_mem_align(BlockDriverState *bs);
488 void *qemu_blockalign(BlockDriverState *bs, size_t size);
489 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
490 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
491 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
492 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
493
494 void bdrv_enable_copy_on_read(BlockDriverState *bs);
495 void bdrv_disable_copy_on_read(BlockDriverState *bs);
496
497 void bdrv_ref(BlockDriverState *bs);
498 void bdrv_unref(BlockDriverState *bs);
499 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
500 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
501 BlockDriverState *child_bs,
502 const char *child_name,
503 const BdrvChildRole *child_role,
504 Error **errp);
505
506 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
507 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
508 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
509 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
510 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
511 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
512
513 #define BLKDBG_EVENT(child, evt) \
514 do { \
515 if (child) { \
516 bdrv_debug_event(child->bs, evt); \
517 } \
518 } while (0)
519
520 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
521
522 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
523 const char *tag);
524 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
525 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
526 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
527
528 /**
529 * bdrv_get_aio_context:
530 *
531 * Returns: the currently bound #AioContext
532 */
533 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
534
535 /**
536 * Transfer control to @co in the aio context of @bs
537 */
538 void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
539
540 /**
541 * bdrv_set_aio_context:
542 *
543 * Changes the #AioContext used for fd handlers, timers, and BHs by this
544 * BlockDriverState and all its children.
545 *
546 * This function must be called with iothread lock held.
547 */
548 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
549 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
550 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
551
552 void bdrv_io_plug(BlockDriverState *bs);
553 void bdrv_io_unplug(BlockDriverState *bs);
554
555 /**
556 * bdrv_parent_drained_begin:
557 *
558 * Begin a quiesced section of all users of @bs. This is part of
559 * bdrv_drained_begin.
560 */
561 void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore,
562 bool ignore_bds_parents);
563
564 /**
565 * bdrv_parent_drained_end:
566 *
567 * End a quiesced section of all users of @bs. This is part of
568 * bdrv_drained_end.
569 */
570 void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore,
571 bool ignore_bds_parents);
572
573 /**
574 * bdrv_drain_poll:
575 *
576 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
577 * and if @recursive is true its children as well (used for subtree drain).
578 *
579 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
580 * ignore the drain request because they will be drained separately (used for
581 * drain_all).
582 *
583 * This is part of bdrv_drained_begin.
584 */
585 bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
586 BdrvChild *ignore_parent, bool ignore_bds_parents);
587
588 /**
589 * bdrv_drained_begin:
590 *
591 * Begin a quiesced section for exclusive access to the BDS, by disabling
592 * external request sources including NBD server and device model. Note that
593 * this doesn't block timers or coroutines from submitting more requests, which
594 * means block_job_pause is still necessary.
595 *
596 * This function can be recursive.
597 */
598 void bdrv_drained_begin(BlockDriverState *bs);
599
600 /**
601 * bdrv_do_drained_begin_quiesce:
602 *
603 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
604 * running requests to complete.
605 */
606 void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
607 BdrvChild *parent, bool ignore_bds_parents);
608
609 /**
610 * Like bdrv_drained_begin, but recursively begins a quiesced section for
611 * exclusive access to all child nodes as well.
612 */
613 void bdrv_subtree_drained_begin(BlockDriverState *bs);
614
615 /**
616 * bdrv_drained_end:
617 *
618 * End a quiescent section started by bdrv_drained_begin().
619 */
620 void bdrv_drained_end(BlockDriverState *bs);
621
622 /**
623 * End a quiescent section started by bdrv_subtree_drained_begin().
624 */
625 void bdrv_subtree_drained_end(BlockDriverState *bs);
626
627 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
628 Error **errp);
629 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
630
631 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
632 uint32_t granularity, Error **errp);
633 /**
634 *
635 * bdrv_register_buf/bdrv_unregister_buf:
636 *
637 * Register/unregister a buffer for I/O. For example, VFIO drivers are
638 * interested to know the memory areas that would later be used for I/O, so
639 * that they can prepare IOMMU mapping etc., to get better performance.
640 */
641 void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
642 void bdrv_unregister_buf(BlockDriverState *bs, void *host);
643
644 /**
645 *
646 * bdrv_co_copy_range:
647 *
648 * Do offloaded copy between two children. If the operation is not implemented
649 * by the driver, or if the backend storage doesn't support it, a negative
650 * error code will be returned.
651 *
652 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
653 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
654 * calling copy_file_range(2)) after the first error, thus it should fall back
655 * to a read+write path in the caller level.
656 *
657 * @src: Source child to copy data from
658 * @src_offset: offset in @src image to read data
659 * @dst: Destination child to copy data to
660 * @dst_offset: offset in @dst image to write data
661 * @bytes: number of bytes to copy
662 * @flags: request flags. Supported flags:
663 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
664 * write on @dst as if bdrv_co_pwrite_zeroes is
665 * called. Used to simplify caller code, or
666 * during BlockDriver.bdrv_co_copy_range_from()
667 * recursion.
668 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
669 * requests currently in flight.
670 *
671 * Returns: 0 if succeeded; negative error code if failed.
672 **/
673 int coroutine_fn bdrv_co_copy_range(BdrvChild *src, uint64_t src_offset,
674 BdrvChild *dst, uint64_t dst_offset,
675 uint64_t bytes, BdrvRequestFlags flags);
676 #endif