Merge remote-tracking branch 'remotes/jasowang/tags/net-pull-request' into staging
[qemu.git] / include / block / block.h
1 #ifndef BLOCK_H
2 #define BLOCK_H
3
4 #include "block/aio.h"
5 #include "block/aio-wait.h"
6 #include "qemu/iov.h"
7 #include "qemu/coroutine.h"
8 #include "block/accounting.h"
9 #include "block/dirty-bitmap.h"
10 #include "block/blockjob.h"
11 #include "qemu/hbitmap.h"
12 #include "qemu/transactions.h"
13
14 /*
15 * generated_co_wrapper
16 *
17 * Function specifier, which does nothing but mark functions to be
18 * generated by scripts/block-coroutine-wrapper.py
19 *
20 * Read more in docs/devel/block-coroutine-wrapper.rst
21 */
22 #define generated_co_wrapper
23
24 /* block.c */
25 typedef struct BlockDriver BlockDriver;
26 typedef struct BdrvChild BdrvChild;
27 typedef struct BdrvChildClass BdrvChildClass;
28
29 typedef struct BlockDriverInfo {
30 /* in bytes, 0 if irrelevant */
31 int cluster_size;
32 /* offset at which the VM state can be saved (0 if not possible) */
33 int64_t vm_state_offset;
34 bool is_dirty;
35 /*
36 * True if this block driver only supports compressed writes
37 */
38 bool needs_compressed_writes;
39 } BlockDriverInfo;
40
41 typedef struct BlockFragInfo {
42 uint64_t allocated_clusters;
43 uint64_t total_clusters;
44 uint64_t fragmented_clusters;
45 uint64_t compressed_clusters;
46 } BlockFragInfo;
47
48 typedef enum {
49 BDRV_REQ_COPY_ON_READ = 0x1,
50 BDRV_REQ_ZERO_WRITE = 0x2,
51
52 /*
53 * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
54 * that the block driver should unmap (discard) blocks if it is guaranteed
55 * that the result will read back as zeroes. The flag is only passed to the
56 * driver if the block device is opened with BDRV_O_UNMAP.
57 */
58 BDRV_REQ_MAY_UNMAP = 0x4,
59
60 BDRV_REQ_FUA = 0x10,
61 BDRV_REQ_WRITE_COMPRESSED = 0x20,
62
63 /* Signifies that this write request will not change the visible disk
64 * content. */
65 BDRV_REQ_WRITE_UNCHANGED = 0x40,
66
67 /* Forces request serialisation. Use only with write requests. */
68 BDRV_REQ_SERIALISING = 0x80,
69
70 /* Execute the request only if the operation can be offloaded or otherwise
71 * be executed efficiently, but return an error instead of using a slow
72 * fallback. */
73 BDRV_REQ_NO_FALLBACK = 0x100,
74
75 /*
76 * BDRV_REQ_PREFETCH makes sense only in the context of copy-on-read
77 * (i.e., together with the BDRV_REQ_COPY_ON_READ flag or when a COR
78 * filter is involved), in which case it signals that the COR operation
79 * need not read the data into memory (qiov) but only ensure they are
80 * copied to the top layer (i.e., that COR operation is done).
81 */
82 BDRV_REQ_PREFETCH = 0x200,
83
84 /*
85 * If we need to wait for other requests, just fail immediately. Used
86 * only together with BDRV_REQ_SERIALISING.
87 */
88 BDRV_REQ_NO_WAIT = 0x400,
89
90 /* Mask of valid flags */
91 BDRV_REQ_MASK = 0x7ff,
92 } BdrvRequestFlags;
93
94 typedef struct BlockSizes {
95 uint32_t phys;
96 uint32_t log;
97 } BlockSizes;
98
99 typedef struct HDGeometry {
100 uint32_t heads;
101 uint32_t sectors;
102 uint32_t cylinders;
103 } HDGeometry;
104
105 #define BDRV_O_NO_SHARE 0x0001 /* don't share permissions */
106 #define BDRV_O_RDWR 0x0002
107 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
108 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
109 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
110 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
111 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
112 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
113 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
114 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
115 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
116 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
117 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
118 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
119 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
120 select an appropriate protocol driver,
121 ignoring the format layer */
122 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
123 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
124 #define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
125
126 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
127
128
129 /* Option names of options parsed by the block layer */
130
131 #define BDRV_OPT_CACHE_WB "cache.writeback"
132 #define BDRV_OPT_CACHE_DIRECT "cache.direct"
133 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
134 #define BDRV_OPT_READ_ONLY "read-only"
135 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
136 #define BDRV_OPT_DISCARD "discard"
137 #define BDRV_OPT_FORCE_SHARE "force-share"
138
139
140 #define BDRV_SECTOR_BITS 9
141 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
142
143 #define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \
144 INT_MAX >> BDRV_SECTOR_BITS)
145 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
146
147 /*
148 * We want allow aligning requests and disk length up to any 32bit alignment
149 * and don't afraid of overflow.
150 * To achieve it, and in the same time use some pretty number as maximum disk
151 * size, let's define maximum "length" (a limit for any offset/bytes request and
152 * for disk size) to be the greatest power of 2 less than INT64_MAX.
153 */
154 #define BDRV_MAX_ALIGNMENT (1L << 30)
155 #define BDRV_MAX_LENGTH (QEMU_ALIGN_DOWN(INT64_MAX, BDRV_MAX_ALIGNMENT))
156
157 /*
158 * Allocation status flags for bdrv_block_status() and friends.
159 *
160 * Public flags:
161 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
162 * BDRV_BLOCK_ZERO: offset reads as zero
163 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
164 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
165 * layer rather than any backing, set by block layer
166 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
167 * layer, set by block layer
168 *
169 * Internal flags:
170 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
171 * that the block layer recompute the answer from the returned
172 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
173 * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
174 * zeroes in file child of current block node inside
175 * returned region. Only valid together with both
176 * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
177 * appear with BDRV_BLOCK_ZERO.
178 *
179 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
180 * host offset within the returned BDS that is allocated for the
181 * corresponding raw guest data. However, whether that offset
182 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
183 *
184 * DATA ZERO OFFSET_VALID
185 * t t t sectors read as zero, returned file is zero at offset
186 * t f t sectors read as valid from file at offset
187 * f t t sectors preallocated, read as zero, returned file not
188 * necessarily zero at offset
189 * f f t sectors preallocated but read from backing_hd,
190 * returned file contains garbage at offset
191 * t t f sectors preallocated, read as zero, unknown offset
192 * t f f sectors read from unknown file or offset
193 * f t f not allocated or unknown offset, read as zero
194 * f f f not allocated or unknown offset, read from backing_hd
195 */
196 #define BDRV_BLOCK_DATA 0x01
197 #define BDRV_BLOCK_ZERO 0x02
198 #define BDRV_BLOCK_OFFSET_VALID 0x04
199 #define BDRV_BLOCK_RAW 0x08
200 #define BDRV_BLOCK_ALLOCATED 0x10
201 #define BDRV_BLOCK_EOF 0x20
202 #define BDRV_BLOCK_RECURSE 0x40
203
204 typedef QTAILQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
205
206 typedef struct BDRVReopenState {
207 BlockDriverState *bs;
208 int flags;
209 BlockdevDetectZeroesOptions detect_zeroes;
210 bool backing_missing;
211 bool replace_backing_bs; /* new_backing_bs is ignored if this is false */
212 BlockDriverState *old_backing_bs; /* keep pointer for permissions update */
213 QDict *options;
214 QDict *explicit_options;
215 void *opaque;
216 } BDRVReopenState;
217
218 /*
219 * Block operation types
220 */
221 typedef enum BlockOpType {
222 BLOCK_OP_TYPE_BACKUP_SOURCE,
223 BLOCK_OP_TYPE_BACKUP_TARGET,
224 BLOCK_OP_TYPE_CHANGE,
225 BLOCK_OP_TYPE_COMMIT_SOURCE,
226 BLOCK_OP_TYPE_COMMIT_TARGET,
227 BLOCK_OP_TYPE_DATAPLANE,
228 BLOCK_OP_TYPE_DRIVE_DEL,
229 BLOCK_OP_TYPE_EJECT,
230 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
231 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
232 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
233 BLOCK_OP_TYPE_MIRROR_SOURCE,
234 BLOCK_OP_TYPE_MIRROR_TARGET,
235 BLOCK_OP_TYPE_RESIZE,
236 BLOCK_OP_TYPE_STREAM,
237 BLOCK_OP_TYPE_REPLACE,
238 BLOCK_OP_TYPE_MAX,
239 } BlockOpType;
240
241 /* Block node permission constants */
242 enum {
243 /**
244 * A user that has the "permission" of consistent reads is guaranteed that
245 * their view of the contents of the block device is complete and
246 * self-consistent, representing the contents of a disk at a specific
247 * point.
248 *
249 * For most block devices (including their backing files) this is true, but
250 * the property cannot be maintained in a few situations like for
251 * intermediate nodes of a commit block job.
252 */
253 BLK_PERM_CONSISTENT_READ = 0x01,
254
255 /** This permission is required to change the visible disk contents. */
256 BLK_PERM_WRITE = 0x02,
257
258 /**
259 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
260 * required for writes to the block node when the caller promises that
261 * the visible disk content doesn't change.
262 *
263 * As the BLK_PERM_WRITE permission is strictly stronger, either is
264 * sufficient to perform an unchanging write.
265 */
266 BLK_PERM_WRITE_UNCHANGED = 0x04,
267
268 /** This permission is required to change the size of a block node. */
269 BLK_PERM_RESIZE = 0x08,
270
271 /**
272 * This permission is required to change the node that this BdrvChild
273 * points to.
274 */
275 BLK_PERM_GRAPH_MOD = 0x10,
276
277 BLK_PERM_ALL = 0x1f,
278
279 DEFAULT_PERM_PASSTHROUGH = BLK_PERM_CONSISTENT_READ
280 | BLK_PERM_WRITE
281 | BLK_PERM_WRITE_UNCHANGED
282 | BLK_PERM_RESIZE,
283
284 DEFAULT_PERM_UNCHANGED = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH,
285 };
286
287 /*
288 * Flags that parent nodes assign to child nodes to specify what kind of
289 * role(s) they take.
290 *
291 * At least one of DATA, METADATA, FILTERED, or COW must be set for
292 * every child.
293 */
294 enum BdrvChildRoleBits {
295 /*
296 * This child stores data.
297 * Any node may have an arbitrary number of such children.
298 */
299 BDRV_CHILD_DATA = (1 << 0),
300
301 /*
302 * This child stores metadata.
303 * Any node may have an arbitrary number of metadata-storing
304 * children.
305 */
306 BDRV_CHILD_METADATA = (1 << 1),
307
308 /*
309 * A child that always presents exactly the same visible data as
310 * the parent, e.g. by virtue of the parent forwarding all reads
311 * and writes.
312 * This flag is mutually exclusive with DATA, METADATA, and COW.
313 * Any node may have at most one filtered child at a time.
314 */
315 BDRV_CHILD_FILTERED = (1 << 2),
316
317 /*
318 * Child from which to read all data that isn't allocated in the
319 * parent (i.e., the backing child); such data is copied to the
320 * parent through COW (and optionally COR).
321 * This field is mutually exclusive with DATA, METADATA, and
322 * FILTERED.
323 * Any node may have at most one such backing child at a time.
324 */
325 BDRV_CHILD_COW = (1 << 3),
326
327 /*
328 * The primary child. For most drivers, this is the child whose
329 * filename applies best to the parent node.
330 * Any node may have at most one primary child at a time.
331 */
332 BDRV_CHILD_PRIMARY = (1 << 4),
333
334 /* Useful combination of flags */
335 BDRV_CHILD_IMAGE = BDRV_CHILD_DATA
336 | BDRV_CHILD_METADATA
337 | BDRV_CHILD_PRIMARY,
338 };
339
340 /* Mask of BdrvChildRoleBits values */
341 typedef unsigned int BdrvChildRole;
342
343 char *bdrv_perm_names(uint64_t perm);
344 uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm);
345
346 /* disk I/O throttling */
347 void bdrv_init(void);
348 void bdrv_init_with_whitelist(void);
349 bool bdrv_uses_whitelist(void);
350 int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
351 BlockDriver *bdrv_find_protocol(const char *filename,
352 bool allow_protocol_prefix,
353 Error **errp);
354 BlockDriver *bdrv_find_format(const char *format_name);
355 int bdrv_create(BlockDriver *drv, const char* filename,
356 QemuOpts *opts, Error **errp);
357 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
358
359 BlockDriverState *bdrv_new(void);
360 int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
361 Error **errp);
362 int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
363 Error **errp);
364 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
365 int flags, Error **errp);
366 int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
367
368 int bdrv_parse_aio(const char *mode, int *flags);
369 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
370 int bdrv_parse_discard_flags(const char *mode, int *flags);
371 BdrvChild *bdrv_open_child(const char *filename,
372 QDict *options, const char *bdref_key,
373 BlockDriverState* parent,
374 const BdrvChildClass *child_class,
375 BdrvChildRole child_role,
376 bool allow_none, Error **errp);
377 BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
378 int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
379 Error **errp);
380 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
381 const char *bdref_key, Error **errp);
382 BlockDriverState *bdrv_open(const char *filename, const char *reference,
383 QDict *options, int flags, Error **errp);
384 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
385 int flags, Error **errp);
386 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
387 BlockDriverState *bs, QDict *options,
388 bool keep_old_opts);
389 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
390 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
391 Error **errp);
392 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
393 int64_t bytes, BdrvRequestFlags flags);
394 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
395 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes);
396 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf,
397 int64_t bytes);
398 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
399 const void *buf, int64_t bytes);
400 /*
401 * Efficiently zero a region of the disk image. Note that this is a regular
402 * I/O request like read or write and should have a reasonable size. This
403 * function is not suitable for zeroing the entire image in a single request
404 * because it may allocate memory for the entire region.
405 */
406 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
407 int64_t bytes, BdrvRequestFlags flags);
408 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
409 const char *backing_file);
410 void bdrv_refresh_filename(BlockDriverState *bs);
411
412 int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact,
413 PreallocMode prealloc, BdrvRequestFlags flags,
414 Error **errp);
415 int generated_co_wrapper
416 bdrv_truncate(BdrvChild *child, int64_t offset, bool exact,
417 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
418
419 int64_t bdrv_nb_sectors(BlockDriverState *bs);
420 int64_t bdrv_getlength(BlockDriverState *bs);
421 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
422 BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
423 BlockDriverState *in_bs, Error **errp);
424 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
425 void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
426 int bdrv_commit(BlockDriverState *bs);
427 int bdrv_make_empty(BdrvChild *c, Error **errp);
428 int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
429 const char *backing_fmt, bool warn);
430 void bdrv_register(BlockDriver *bdrv);
431 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
432 const char *backing_file_str);
433 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
434 BlockDriverState *bs);
435 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
436 bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
437 Error **errp);
438 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
439 Error **errp);
440 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
441 int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp);
442 void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs);
443
444
445 typedef struct BdrvCheckResult {
446 int corruptions;
447 int leaks;
448 int check_errors;
449 int corruptions_fixed;
450 int leaks_fixed;
451 int64_t image_end_offset;
452 BlockFragInfo bfi;
453 } BdrvCheckResult;
454
455 typedef enum {
456 BDRV_FIX_LEAKS = 1,
457 BDRV_FIX_ERRORS = 2,
458 } BdrvCheckMode;
459
460 int generated_co_wrapper bdrv_check(BlockDriverState *bs, BdrvCheckResult *res,
461 BdrvCheckMode fix);
462
463 /* The units of offset and total_work_size may be chosen arbitrarily by the
464 * block driver; total_work_size may change during the course of the amendment
465 * operation */
466 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
467 int64_t total_work_size, void *opaque);
468 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
469 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
470 bool force,
471 Error **errp);
472
473 /* check if a named node can be replaced when doing drive-mirror */
474 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
475 const char *node_name, Error **errp);
476
477 /* async block I/O */
478 void bdrv_aio_cancel(BlockAIOCB *acb);
479 void bdrv_aio_cancel_async(BlockAIOCB *acb);
480
481 /* sg packet commands */
482 int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
483
484 /* Invalidate any cached metadata used by image formats */
485 int generated_co_wrapper bdrv_invalidate_cache(BlockDriverState *bs,
486 Error **errp);
487 void bdrv_invalidate_cache_all(Error **errp);
488 int bdrv_inactivate_all(void);
489
490 /* Ensure contents are flushed to disk. */
491 int generated_co_wrapper bdrv_flush(BlockDriverState *bs);
492 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
493 int bdrv_flush_all(void);
494 void bdrv_close_all(void);
495 void bdrv_drain(BlockDriverState *bs);
496 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
497 void bdrv_drain_all_begin(void);
498 void bdrv_drain_all_end(void);
499 void bdrv_drain_all(void);
500
501 #define BDRV_POLL_WHILE(bs, cond) ({ \
502 BlockDriverState *bs_ = (bs); \
503 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
504 cond); })
505
506 int generated_co_wrapper bdrv_pdiscard(BdrvChild *child, int64_t offset,
507 int64_t bytes);
508 int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
509 int bdrv_has_zero_init_1(BlockDriverState *bs);
510 int bdrv_has_zero_init(BlockDriverState *bs);
511 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
512 int bdrv_block_status(BlockDriverState *bs, int64_t offset,
513 int64_t bytes, int64_t *pnum, int64_t *map,
514 BlockDriverState **file);
515 int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
516 int64_t offset, int64_t bytes, int64_t *pnum,
517 int64_t *map, BlockDriverState **file);
518 int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
519 int64_t *pnum);
520 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
521 bool include_base, int64_t offset, int64_t bytes,
522 int64_t *pnum);
523 int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset,
524 int64_t bytes);
525
526 bool bdrv_is_read_only(BlockDriverState *bs);
527 int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
528 bool ignore_allow_rdw, Error **errp);
529 int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
530 Error **errp);
531 bool bdrv_is_writable(BlockDriverState *bs);
532 bool bdrv_is_sg(BlockDriverState *bs);
533 bool bdrv_is_inserted(BlockDriverState *bs);
534 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
535 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
536 const char *bdrv_get_format_name(BlockDriverState *bs);
537 BlockDriverState *bdrv_find_node(const char *node_name);
538 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
539 XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
540 BlockDriverState *bdrv_lookup_bs(const char *device,
541 const char *node_name,
542 Error **errp);
543 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
544 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
545 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
546
547 typedef struct BdrvNextIterator {
548 enum {
549 BDRV_NEXT_BACKEND_ROOTS,
550 BDRV_NEXT_MONITOR_OWNED,
551 } phase;
552 BlockBackend *blk;
553 BlockDriverState *bs;
554 } BdrvNextIterator;
555
556 BlockDriverState *bdrv_first(BdrvNextIterator *it);
557 BlockDriverState *bdrv_next(BdrvNextIterator *it);
558 void bdrv_next_cleanup(BdrvNextIterator *it);
559
560 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
561 bool bdrv_supports_compressed_writes(BlockDriverState *bs);
562 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
563 void *opaque, bool read_only);
564 const char *bdrv_get_node_name(const BlockDriverState *bs);
565 const char *bdrv_get_device_name(const BlockDriverState *bs);
566 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
567 int bdrv_get_flags(BlockDriverState *bs);
568 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
569 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
570 Error **errp);
571 BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs);
572 void bdrv_round_to_clusters(BlockDriverState *bs,
573 int64_t offset, int64_t bytes,
574 int64_t *cluster_offset,
575 int64_t *cluster_bytes);
576
577 void bdrv_get_backing_filename(BlockDriverState *bs,
578 char *filename, int filename_size);
579 char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
580 char *bdrv_get_full_backing_filename_from_filename(const char *backed,
581 const char *backing,
582 Error **errp);
583 char *bdrv_dirname(BlockDriverState *bs, Error **errp);
584
585 int path_has_protocol(const char *path);
586 int path_is_absolute(const char *path);
587 char *path_combine(const char *base_path, const char *filename);
588
589 int generated_co_wrapper
590 bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
591 int generated_co_wrapper
592 bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
593 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
594 int64_t pos, int size);
595
596 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
597 int64_t pos, int size);
598
599 void bdrv_img_create(const char *filename, const char *fmt,
600 const char *base_filename, const char *base_fmt,
601 char *options, uint64_t img_size, int flags,
602 bool quiet, Error **errp);
603
604 /* Returns the alignment in bytes that is required so that no bounce buffer
605 * is required throughout the stack */
606 size_t bdrv_min_mem_align(BlockDriverState *bs);
607 /* Returns optimal alignment in bytes for bounce buffer */
608 size_t bdrv_opt_mem_align(BlockDriverState *bs);
609 void *qemu_blockalign(BlockDriverState *bs, size_t size);
610 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
611 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
612 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
613 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
614
615 void bdrv_enable_copy_on_read(BlockDriverState *bs);
616 void bdrv_disable_copy_on_read(BlockDriverState *bs);
617
618 void bdrv_ref(BlockDriverState *bs);
619 void bdrv_unref(BlockDriverState *bs);
620 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
621 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
622 BlockDriverState *child_bs,
623 const char *child_name,
624 const BdrvChildClass *child_class,
625 BdrvChildRole child_role,
626 Error **errp);
627
628 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
629 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
630 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
631 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
632 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
633 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
634
635 #define BLKDBG_EVENT(child, evt) \
636 do { \
637 if (child) { \
638 bdrv_debug_event(child->bs, evt); \
639 } \
640 } while (0)
641
642 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
643
644 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
645 const char *tag);
646 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
647 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
648 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
649
650 /**
651 * bdrv_get_aio_context:
652 *
653 * Returns: the currently bound #AioContext
654 */
655 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
656
657 /**
658 * Move the current coroutine to the AioContext of @bs and return the old
659 * AioContext of the coroutine. Increase bs->in_flight so that draining @bs
660 * will wait for the operation to proceed until the corresponding
661 * bdrv_co_leave().
662 *
663 * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as
664 * this will deadlock.
665 */
666 AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs);
667
668 /**
669 * Ends a section started by bdrv_co_enter(). Move the current coroutine back
670 * to old_ctx and decrease bs->in_flight again.
671 */
672 void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx);
673
674 /**
675 * Locks the AioContext of @bs if it's not the current AioContext. This avoids
676 * double locking which could lead to deadlocks: This is a coroutine_fn, so we
677 * know we already own the lock of the current AioContext.
678 *
679 * May only be called in the main thread.
680 */
681 void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
682
683 /**
684 * Unlocks the AioContext of @bs if it's not the current AioContext.
685 */
686 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
687
688 /**
689 * Transfer control to @co in the aio context of @bs
690 */
691 void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
692
693 void bdrv_set_aio_context_ignore(BlockDriverState *bs,
694 AioContext *new_context, GSList **ignore);
695 int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
696 Error **errp);
697 int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
698 BdrvChild *ignore_child, Error **errp);
699 bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
700 GSList **ignore, Error **errp);
701 bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
702 GSList **ignore, Error **errp);
703 AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c);
704 AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c);
705
706 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
707 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
708
709 void bdrv_io_plug(BlockDriverState *bs);
710 void bdrv_io_unplug(BlockDriverState *bs);
711
712 /**
713 * bdrv_parent_drained_begin_single:
714 *
715 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
716 * any pending activity to cease.
717 */
718 void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
719
720 /**
721 * bdrv_parent_drained_end_single:
722 *
723 * End a quiesced section for the parent of @c.
724 *
725 * This polls @bs's AioContext until all scheduled sub-drained_ends
726 * have settled, which may result in graph changes.
727 */
728 void bdrv_parent_drained_end_single(BdrvChild *c);
729
730 /**
731 * bdrv_drain_poll:
732 *
733 * Poll for pending requests in @bs, its parents (except for @ignore_parent),
734 * and if @recursive is true its children as well (used for subtree drain).
735 *
736 * If @ignore_bds_parents is true, parents that are BlockDriverStates must
737 * ignore the drain request because they will be drained separately (used for
738 * drain_all).
739 *
740 * This is part of bdrv_drained_begin.
741 */
742 bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
743 BdrvChild *ignore_parent, bool ignore_bds_parents);
744
745 /**
746 * bdrv_drained_begin:
747 *
748 * Begin a quiesced section for exclusive access to the BDS, by disabling
749 * external request sources including NBD server and device model. Note that
750 * this doesn't block timers or coroutines from submitting more requests, which
751 * means block_job_pause is still necessary.
752 *
753 * This function can be recursive.
754 */
755 void bdrv_drained_begin(BlockDriverState *bs);
756
757 /**
758 * bdrv_do_drained_begin_quiesce:
759 *
760 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
761 * running requests to complete.
762 */
763 void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
764 BdrvChild *parent, bool ignore_bds_parents);
765
766 /**
767 * Like bdrv_drained_begin, but recursively begins a quiesced section for
768 * exclusive access to all child nodes as well.
769 */
770 void bdrv_subtree_drained_begin(BlockDriverState *bs);
771
772 /**
773 * bdrv_drained_end:
774 *
775 * End a quiescent section started by bdrv_drained_begin().
776 *
777 * This polls @bs's AioContext until all scheduled sub-drained_ends
778 * have settled. On one hand, that may result in graph changes. On
779 * the other, this requires that the caller either runs in the main
780 * loop; or that all involved nodes (@bs and all of its parents) are
781 * in the caller's AioContext.
782 */
783 void bdrv_drained_end(BlockDriverState *bs);
784
785 /**
786 * bdrv_drained_end_no_poll:
787 *
788 * Same as bdrv_drained_end(), but do not poll for the subgraph to
789 * actually become unquiesced. Therefore, no graph changes will occur
790 * with this function.
791 *
792 * *drained_end_counter is incremented for every background operation
793 * that is scheduled, and will be decremented for every operation once
794 * it settles. The caller must poll until it reaches 0. The counter
795 * should be accessed using atomic operations only.
796 */
797 void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter);
798
799 /**
800 * End a quiescent section started by bdrv_subtree_drained_begin().
801 */
802 void bdrv_subtree_drained_end(BlockDriverState *bs);
803
804 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
805 Error **errp);
806 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
807
808 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
809 uint32_t granularity, Error **errp);
810 /**
811 *
812 * bdrv_register_buf/bdrv_unregister_buf:
813 *
814 * Register/unregister a buffer for I/O. For example, VFIO drivers are
815 * interested to know the memory areas that would later be used for I/O, so
816 * that they can prepare IOMMU mapping etc., to get better performance.
817 */
818 void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
819 void bdrv_unregister_buf(BlockDriverState *bs, void *host);
820
821 /**
822 *
823 * bdrv_co_copy_range:
824 *
825 * Do offloaded copy between two children. If the operation is not implemented
826 * by the driver, or if the backend storage doesn't support it, a negative
827 * error code will be returned.
828 *
829 * Note: block layer doesn't emulate or fallback to a bounce buffer approach
830 * because usually the caller shouldn't attempt offloaded copy any more (e.g.
831 * calling copy_file_range(2)) after the first error, thus it should fall back
832 * to a read+write path in the caller level.
833 *
834 * @src: Source child to copy data from
835 * @src_offset: offset in @src image to read data
836 * @dst: Destination child to copy data to
837 * @dst_offset: offset in @dst image to write data
838 * @bytes: number of bytes to copy
839 * @flags: request flags. Supported flags:
840 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
841 * write on @dst as if bdrv_co_pwrite_zeroes is
842 * called. Used to simplify caller code, or
843 * during BlockDriver.bdrv_co_copy_range_from()
844 * recursion.
845 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
846 * requests currently in flight.
847 *
848 * Returns: 0 if succeeded; negative error code if failed.
849 **/
850 int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset,
851 BdrvChild *dst, int64_t dst_offset,
852 int64_t bytes, BdrvRequestFlags read_flags,
853 BdrvRequestFlags write_flags);
854
855 void bdrv_cancel_in_flight(BlockDriverState *bs);
856
857 #endif