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
13/* block.c */
14typedef struct BlockDriver BlockDriver;
15typedef struct BdrvChild BdrvChild;
16typedef struct BdrvChildRole BdrvChildRole;
17
18typedef struct BlockDriverInfo {
19 /* in bytes, 0 if irrelevant */
20 int cluster_size;
21 /* offset at which the VM state can be saved (0 if not possible) */
22 int64_t vm_state_offset;
23 bool is_dirty;
24 /*
25 * True if unallocated blocks read back as zeroes. This is equivalent
26 * to the LBPRZ flag in the SCSI logical block provisioning page.
27 */
28 bool unallocated_blocks_are_zero;
29 /*
30 * True if this block driver only supports compressed writes
31 */
32 bool needs_compressed_writes;
33} BlockDriverInfo;
34
35typedef struct BlockFragInfo {
36 uint64_t allocated_clusters;
37 uint64_t total_clusters;
38 uint64_t fragmented_clusters;
39 uint64_t compressed_clusters;
40} BlockFragInfo;
41
42typedef enum {
43 BDRV_REQ_COPY_ON_READ = 0x1,
44 BDRV_REQ_ZERO_WRITE = 0x2,
45
46 /*
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.
51 */
52 BDRV_REQ_MAY_UNMAP = 0x4,
53
54 /*
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.
57 *
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).
64 */
65 BDRV_REQ_NO_SERIALISING = 0x8,
66 BDRV_REQ_FUA = 0x10,
67 BDRV_REQ_WRITE_COMPRESSED = 0x20,
68
69 /* Signifies that this write request will not change the visible disk
70 * content. */
71 BDRV_REQ_WRITE_UNCHANGED = 0x40,
72
73 /*
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
77 * backing file.
78 *
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.
82 */
83 BDRV_REQ_SERIALISING = 0x80,
84
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
87 * fallback. */
88 BDRV_REQ_NO_FALLBACK = 0x100,
89
90 /*
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.
94 */
95 BDRV_REQ_PREFETCH = 0x200,
96 /* Mask of valid flags */
97 BDRV_REQ_MASK = 0x3ff,
98} BdrvRequestFlags;
99
100typedef struct BlockSizes {
101 uint32_t phys;
102 uint32_t log;
103} BlockSizes;
104
105typedef struct HDGeometry {
106 uint32_t heads;
107 uint32_t sectors;
108 uint32_t cylinders;
109} HDGeometry;
110
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 */
129
130#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
131
132
133/* Option names of options parsed by the block layer */
134
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"
142
143
144#define BDRV_SECTOR_BITS 9
145#define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
146#define BDRV_SECTOR_MASK ~(BDRV_SECTOR_SIZE - 1)
147
148#define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
149 INT_MAX >> BDRV_SECTOR_BITS)
150#define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
151
152/*
153 * Allocation status flags for bdrv_block_status() and friends.
154 *
155 * Public flags:
156 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
157 * BDRV_BLOCK_ZERO: offset reads as zero
158 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
159 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
160 * layer rather than any backing, set by block layer
161 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
162 * layer, set by block layer
163 *
164 * Internal flags:
165 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
166 * that the block layer recompute the answer from the returned
167 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
168 * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
169 * zeroes in file child of current block node inside
170 * returned region. Only valid together with both
171 * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
172 * appear with BDRV_BLOCK_ZERO.
173 *
174 * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
175 * host offset within the returned BDS that is allocated for the
176 * corresponding raw guest data. However, whether that offset
177 * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
178 *
179 * DATA ZERO OFFSET_VALID
180 * t t t sectors read as zero, returned file is zero at offset
181 * t f t sectors read as valid from file at offset
182 * f t t sectors preallocated, read as zero, returned file not
183 * necessarily zero at offset
184 * f f t sectors preallocated but read from backing_hd,
185 * returned file contains garbage at offset
186 * t t f sectors preallocated, read as zero, unknown offset
187 * t f f sectors read from unknown file or offset
188 * f t f not allocated or unknown offset, read as zero
189 * f f f not allocated or unknown offset, read from backing_hd
190 */
191#define BDRV_BLOCK_DATA 0x01
192#define BDRV_BLOCK_ZERO 0x02
193#define BDRV_BLOCK_OFFSET_VALID 0x04
194#define BDRV_BLOCK_RAW 0x08
195#define BDRV_BLOCK_ALLOCATED 0x10
196#define BDRV_BLOCK_EOF 0x20
197#define BDRV_BLOCK_RECURSE 0x40
198#define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK
199
200typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
201
202typedef struct BDRVReopenState {
203 BlockDriverState *bs;
204 int flags;
205 BlockdevDetectZeroesOptions detect_zeroes;
206 bool backing_missing;
207 bool replace_backing_bs; /* new_backing_bs is ignored if this is false */
208 BlockDriverState *new_backing_bs; /* If NULL then detach the current bs */
209 uint64_t perm, shared_perm;
210 QDict *options;
211 QDict *explicit_options;
212 void *opaque;
213} BDRVReopenState;
214
215/*
216 * Block operation types
217 */
218typedef enum BlockOpType {
219 BLOCK_OP_TYPE_BACKUP_SOURCE,
220 BLOCK_OP_TYPE_BACKUP_TARGET,
221 BLOCK_OP_TYPE_CHANGE,
222 BLOCK_OP_TYPE_COMMIT_SOURCE,
223 BLOCK_OP_TYPE_COMMIT_TARGET,
224 BLOCK_OP_TYPE_DATAPLANE,
225 BLOCK_OP_TYPE_DRIVE_DEL,
226 BLOCK_OP_TYPE_EJECT,
227 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
228 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
229 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
230 BLOCK_OP_TYPE_MIRROR_SOURCE,
231 BLOCK_OP_TYPE_MIRROR_TARGET,
232 BLOCK_OP_TYPE_RESIZE,
233 BLOCK_OP_TYPE_STREAM,
234 BLOCK_OP_TYPE_REPLACE,
235 BLOCK_OP_TYPE_MAX,
236} BlockOpType;
237
238/* Block node permission constants */
239enum {
240 /**
241 * A user that has the "permission" of consistent reads is guaranteed that
242 * their view of the contents of the block device is complete and
243 * self-consistent, representing the contents of a disk at a specific
244 * point.
245 *
246 * For most block devices (including their backing files) this is true, but
247 * the property cannot be maintained in a few situations like for
248 * intermediate nodes of a commit block job.
249 */
250 BLK_PERM_CONSISTENT_READ = 0x01,
251
252 /** This permission is required to change the visible disk contents. */
253 BLK_PERM_WRITE = 0x02,
254
255 /**
256 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
257 * required for writes to the block node when the caller promises that
258 * the visible disk content doesn't change.
259 *
260 * As the BLK_PERM_WRITE permission is strictly stronger, either is
261 * sufficient to perform an unchanging write.
262 */
263 BLK_PERM_WRITE_UNCHANGED = 0x04,
264
265 /** This permission is required to change the size of a block node. */
266 BLK_PERM_RESIZE = 0x08,
267
268 /**
269 * This permission is required to change the node that this BdrvChild
270 * points to.
271 */
272 BLK_PERM_GRAPH_MOD = 0x10,
273
274 BLK_PERM_ALL = 0x1f,
275
276 DEFAULT_PERM_PASSTHROUGH = BLK_PERM_CONSISTENT_READ
277 | BLK_PERM_WRITE
278 | BLK_PERM_WRITE_UNCHANGED
279 | BLK_PERM_RESIZE,
280
281 DEFAULT_PERM_UNCHANGED = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH,
282};
283
284char *bdrv_perm_names(uint64_t perm);
285
286/* disk I/O throttling */
287void bdrv_init(void);
288void bdrv_init_with_whitelist(void);
289bool bdrv_uses_whitelist(void);
290int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
291BlockDriver *bdrv_find_protocol(const char *filename,
292 bool allow_protocol_prefix,
293 Error **errp);
294BlockDriver *bdrv_find_format(const char *format_name);
295int bdrv_create(BlockDriver *drv, const char* filename,
296 QemuOpts *opts, Error **errp);
297int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
298BlockDriverState *bdrv_new(void);
299void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
300 Error **errp);
301void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
302 Error **errp);
303
304int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
305int bdrv_parse_discard_flags(const char *mode, int *flags);
306BdrvChild *bdrv_open_child(const char *filename,
307 QDict *options, const char *bdref_key,
308 BlockDriverState* parent,
309 const BdrvChildRole *child_role,
310 bool allow_none, Error **errp);
311BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
312void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
313 Error **errp);
314int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
315 const char *bdref_key, Error **errp);
316BlockDriverState *bdrv_open(const char *filename, const char *reference,
317 QDict *options, int flags, Error **errp);
318BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
319 int flags, Error **errp);
320BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
321 BlockDriverState *bs, QDict *options,
322 bool keep_old_opts);
323int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
324int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
325 Error **errp);
326int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
327 BlockReopenQueue *queue, Error **errp);
328void bdrv_reopen_commit(BDRVReopenState *reopen_state);
329void bdrv_reopen_abort(BDRVReopenState *reopen_state);
330int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
331 int bytes, BdrvRequestFlags flags);
332int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
333int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
334int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
335int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
336int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
337int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
338 const void *buf, int count);
339/*
340 * Efficiently zero a region of the disk image. Note that this is a regular
341 * I/O request like read or write and should have a reasonable size. This
342 * function is not suitable for zeroing the entire image in a single request
343 * because it may allocate memory for the entire region.
344 */
345int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
346 int bytes, BdrvRequestFlags flags);
347BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
348 const char *backing_file);
349void bdrv_refresh_filename(BlockDriverState *bs);
350
351int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset,
352 PreallocMode prealloc, Error **errp);
353int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
354 Error **errp);
355
356int64_t bdrv_nb_sectors(BlockDriverState *bs);
357int64_t bdrv_getlength(BlockDriverState *bs);
358int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
359BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
360 BlockDriverState *in_bs, Error **errp);
361void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
362void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
363int bdrv_commit(BlockDriverState *bs);
364int bdrv_change_backing_file(BlockDriverState *bs,
365 const char *backing_file, const char *backing_fmt);
366void bdrv_register(BlockDriver *bdrv);
367int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
368 const char *backing_file_str);
369BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
370 BlockDriverState *bs);
371BlockDriverState *bdrv_find_base(BlockDriverState *bs);
372bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
373 Error **errp);
374int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
375 Error **errp);
376void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
377
378
379typedef struct BdrvCheckResult {
380 int corruptions;
381 int leaks;
382 int check_errors;
383 int corruptions_fixed;
384 int leaks_fixed;
385 int64_t image_end_offset;
386 BlockFragInfo bfi;
387} BdrvCheckResult;
388
389typedef enum {
390 BDRV_FIX_LEAKS = 1,
391 BDRV_FIX_ERRORS = 2,
392} BdrvCheckMode;
393
394int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
395
396/* The units of offset and total_work_size may be chosen arbitrarily by the
397 * block driver; total_work_size may change during the course of the amendment
398 * operation */
399typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
400 int64_t total_work_size, void *opaque);
401int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
402 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
403 Error **errp);
404
405/* external snapshots */
406bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
407 BlockDriverState *candidate);
408bool bdrv_is_first_non_filter(BlockDriverState *candidate);
409
410/* check if a named node can be replaced when doing drive-mirror */
411BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
412 const char *node_name, Error **errp);
413
414/* async block I/O */
415void bdrv_aio_cancel(BlockAIOCB *acb);
416void bdrv_aio_cancel_async(BlockAIOCB *acb);
417
418/* sg packet commands */
419int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
420
421/* Invalidate any cached metadata used by image formats */
422void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
423void bdrv_invalidate_cache_all(Error **errp);
424int bdrv_inactivate_all(void);
425
426/* Ensure contents are flushed to disk. */
427int bdrv_flush(BlockDriverState *bs);
428int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
429int bdrv_flush_all(void);
430void bdrv_close_all(void);
431void bdrv_drain(BlockDriverState *bs);
432void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
433void bdrv_drain_all_begin(void);
434void bdrv_drain_all_end(void);
435void bdrv_drain_all(void);
436
437#define BDRV_POLL_WHILE(bs, cond) ({ \
438 BlockDriverState *bs_ = (bs); \
439 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
440 cond); })
441
442int bdrv_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
443int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
444int bdrv_has_zero_init_1(BlockDriverState *bs);
445int bdrv_has_zero_init(BlockDriverState *bs);
446int bdrv_has_zero_init_truncate(BlockDriverState *bs);
447bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
448bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
449int bdrv_block_status(BlockDriverState *bs, int64_t offset,
450 int64_t bytes, int64_t *pnum, int64_t *map,
451 BlockDriverState **file);
452int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
453 int64_t offset, int64_t bytes, int64_t *pnum,
454 int64_t *map, BlockDriverState **file);
455int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
456 int64_t *pnum);
457int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
458 bool include_base, int64_t offset, int64_t bytes,
459 int64_t *pnum);
460
461bool bdrv_is_read_only(BlockDriverState *bs);
462int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
463 bool ignore_allow_rdw, Error **errp);
464int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
465 Error **errp);
466bool bdrv_is_writable(BlockDriverState *bs);
467bool bdrv_is_sg(BlockDriverState *bs);
468bool bdrv_is_inserted(BlockDriverState *bs);
469void bdrv_lock_medium(BlockDriverState *bs, bool locked);
470void bdrv_eject(BlockDriverState *bs, bool eject_flag);
471const char *bdrv_get_format_name(BlockDriverState *bs);
472BlockDriverState *bdrv_find_node(const char *node_name);
473BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
474XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
475BlockDriverState *bdrv_lookup_bs(const char *device,
476 const char *node_name,
477 Error **errp);
478bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
479BlockDriverState *bdrv_next_node(BlockDriverState *bs);
480BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
481
482typedef struct BdrvNextIterator {
483 enum {
484 BDRV_NEXT_BACKEND_ROOTS,
485 BDRV_NEXT_MONITOR_OWNED,
486 } phase;
487 BlockBackend *blk;
488 BlockDriverState *bs;
489} BdrvNextIterator;
490
491BlockDriverState *bdrv_first(BdrvNextIterator *it);
492BlockDriverState *bdrv_next(BdrvNextIterator *it);
493void bdrv_next_cleanup(BdrvNextIterator *it);
494
495BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
496bool bdrv_is_encrypted(BlockDriverState *bs);
497void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
498 void *opaque, bool read_only);
499const char *bdrv_get_node_name(const BlockDriverState *bs);
500const char *bdrv_get_device_name(const BlockDriverState *bs);
501const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
502int bdrv_get_flags(BlockDriverState *bs);
503int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
504ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
505 Error **errp);
506void bdrv_round_to_clusters(BlockDriverState *bs,
507 int64_t offset, int64_t bytes,
508 int64_t *cluster_offset,
509 int64_t *cluster_bytes);
510
511void bdrv_get_backing_filename(BlockDriverState *bs,
512 char *filename, int filename_size);
513char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
514char *bdrv_get_full_backing_filename_from_filename(const char *backed,
515 const char *backing,
516 Error **errp);
517char *bdrv_dirname(BlockDriverState *bs, Error **errp);
518
519int path_has_protocol(const char *path);
520int path_is_absolute(const char *path);
521char *path_combine(const char *base_path, const char *filename);
522
523int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
524int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
525int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
526 int64_t pos, int size);
527
528int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
529 int64_t pos, int size);
530
531void 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);
535
536/* Returns the alignment in bytes that is required so that no bounce buffer
537 * is required throughout the stack */
538size_t bdrv_min_mem_align(BlockDriverState *bs);
539/* Returns optimal alignment in bytes for bounce buffer */
540size_t bdrv_opt_mem_align(BlockDriverState *bs);
541void *qemu_blockalign(BlockDriverState *bs, size_t size);
542void *qemu_blockalign0(BlockDriverState *bs, size_t size);
543void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
544void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
545bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
546
547void bdrv_enable_copy_on_read(BlockDriverState *bs);
548void bdrv_disable_copy_on_read(BlockDriverState *bs);
549
550void bdrv_ref(BlockDriverState *bs);
551void bdrv_unref(BlockDriverState *bs);
552void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
553BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
554 BlockDriverState *child_bs,
555 const char *child_name,
556 const BdrvChildRole *child_role,
557 Error **errp);
558
559bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
560void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
561void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
562void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
563void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
564bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
565
566#define BLKDBG_EVENT(child, evt) \
567 do { \
568 if (child) { \
569 bdrv_debug_event(child->bs, evt); \
570 } \
571 } while (0)
572
573void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
574
575int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
576 const char *tag);
577int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
578int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
579bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
580
581/**
582 * bdrv_get_aio_context:
583 *
584 * Returns: the currently bound #AioContext
585 */
586AioContext *bdrv_get_aio_context(BlockDriverState *bs);
587
588/**
589 * Transfer control to @co in the aio context of @bs
590 */
591void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
592
593void bdrv_set_aio_context_ignore(BlockDriverState *bs,
594 AioContext *new_context, GSList **ignore);
595int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
596 Error **errp);
597int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
598 BdrvChild *ignore_child, Error **errp);
599bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
600 GSList **ignore, Error **errp);
601bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
602 GSList **ignore, Error **errp);
603int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
604int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
605
606void bdrv_io_plug(BlockDriverState *bs);
607void bdrv_io_unplug(BlockDriverState *bs);
608
609/**
610 * bdrv_parent_drained_begin_single:
611 *
612 * Begin a quiesced section for the parent of @c. If @poll is true, wait for
613 * any pending activity to cease.
614 */
615void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
616
617/**
618 * bdrv_parent_drained_end_single:
619 *
620 * End a quiesced section for the parent of @c.
621 *
622 * This polls @bs's AioContext until all scheduled sub-drained_ends
623 * have settled, which may result in graph changes.
624 */
625void bdrv_parent_drained_end_single(BdrvChild *c);
626
627/**
628 * bdrv_drain_poll:
629 *
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).
632 *
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
635 * drain_all).
636 *
637 * This is part of bdrv_drained_begin.
638 */
639bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
640 BdrvChild *ignore_parent, bool ignore_bds_parents);
641
642/**
643 * bdrv_drained_begin:
644 *
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.
649 *
650 * This function can be recursive.
651 */
652void bdrv_drained_begin(BlockDriverState *bs);
653
654/**
655 * bdrv_do_drained_begin_quiesce:
656 *
657 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
658 * running requests to complete.
659 */
660void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
661 BdrvChild *parent, bool ignore_bds_parents);
662
663/**
664 * Like bdrv_drained_begin, but recursively begins a quiesced section for
665 * exclusive access to all child nodes as well.
666 */
667void bdrv_subtree_drained_begin(BlockDriverState *bs);
668
669/**
670 * bdrv_drained_end:
671 *
672 * End a quiescent section started by bdrv_drained_begin().
673 *
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.
679 */
680void bdrv_drained_end(BlockDriverState *bs);
681
682/**
683 * bdrv_drained_end_no_poll:
684 *
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.
688 *
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.
693 */
694void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter);
695
696/**
697 * End a quiescent section started by bdrv_subtree_drained_begin().
698 */
699void bdrv_subtree_drained_end(BlockDriverState *bs);
700
701void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
702 Error **errp);
703void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
704
705bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
706 uint32_t granularity, Error **errp);
707/**
708 *
709 * bdrv_register_buf/bdrv_unregister_buf:
710 *
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.
714 */
715void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
716void bdrv_unregister_buf(BlockDriverState *bs, void *host);
717
718/**
719 *
720 * bdrv_co_copy_range:
721 *
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.
725 *
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.
730 *
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()
741 * recursion.
742 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
743 * requests currently in flight.
744 *
745 * Returns: 0 if succeeded; negative error code if failed.
746 **/
747int 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);
751#endif
752