block.h (35661B)
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 */ 25typedef struct BlockDriver BlockDriver; 26typedef struct BdrvChild BdrvChild; 27typedef struct BdrvChildClass BdrvChildClass; 28 29typedef 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 41typedef 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 48typedef 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 94typedef struct BlockSizes { 95 uint32_t phys; 96 uint32_t log; 97} BlockSizes; 98 99typedef 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 204typedef QTAILQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue; 205 206typedef struct BDRVReopenState { 207 BlockDriverState *bs; 208 int flags; 209 BlockdevDetectZeroesOptions detect_zeroes; 210 bool backing_missing; 211 BlockDriverState *old_backing_bs; /* keep pointer for permissions update */ 212 BlockDriverState *old_file_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 */ 221typedef 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 */ 242enum { 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 */ 294enum 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 */ 341typedef unsigned int BdrvChildRole; 342 343char *bdrv_perm_names(uint64_t perm); 344uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm); 345 346/* disk I/O throttling */ 347void bdrv_init(void); 348void bdrv_init_with_whitelist(void); 349bool bdrv_uses_whitelist(void); 350int bdrv_is_whitelisted(BlockDriver *drv, bool read_only); 351BlockDriver *bdrv_find_protocol(const char *filename, 352 bool allow_protocol_prefix, 353 Error **errp); 354BlockDriver *bdrv_find_format(const char *format_name); 355int bdrv_create(BlockDriver *drv, const char* filename, 356 QemuOpts *opts, Error **errp); 357int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp); 358 359BlockDriverState *bdrv_new(void); 360int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, 361 Error **errp); 362int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, 363 Error **errp); 364int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs, 365 Error **errp); 366BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options, 367 int flags, Error **errp); 368int bdrv_drop_filter(BlockDriverState *bs, Error **errp); 369 370int bdrv_parse_aio(const char *mode, int *flags); 371int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough); 372int bdrv_parse_discard_flags(const char *mode, int *flags); 373BdrvChild *bdrv_open_child(const char *filename, 374 QDict *options, const char *bdref_key, 375 BlockDriverState* parent, 376 const BdrvChildClass *child_class, 377 BdrvChildRole child_role, 378 bool allow_none, Error **errp); 379BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp); 380int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, 381 Error **errp); 382int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, 383 const char *bdref_key, Error **errp); 384BlockDriverState *bdrv_open(const char *filename, const char *reference, 385 QDict *options, int flags, Error **errp); 386BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv, 387 const char *node_name, 388 QDict *options, int flags, 389 Error **errp); 390BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, 391 int flags, Error **errp); 392BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, 393 BlockDriverState *bs, QDict *options, 394 bool keep_old_opts); 395void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue); 396int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp); 397int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts, 398 Error **errp); 399int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, 400 Error **errp); 401int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, 402 int64_t bytes, BdrvRequestFlags flags); 403int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags); 404int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes); 405int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, 406 int64_t bytes); 407int bdrv_pwrite_sync(BdrvChild *child, int64_t offset, 408 const void *buf, int64_t bytes); 409/* 410 * Efficiently zero a region of the disk image. Note that this is a regular 411 * I/O request like read or write and should have a reasonable size. This 412 * function is not suitable for zeroing the entire image in a single request 413 * because it may allocate memory for the entire region. 414 */ 415int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, 416 int64_t bytes, BdrvRequestFlags flags); 417BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, 418 const char *backing_file); 419void bdrv_refresh_filename(BlockDriverState *bs); 420 421int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact, 422 PreallocMode prealloc, BdrvRequestFlags flags, 423 Error **errp); 424int generated_co_wrapper 425bdrv_truncate(BdrvChild *child, int64_t offset, bool exact, 426 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); 427 428int64_t bdrv_nb_sectors(BlockDriverState *bs); 429int64_t bdrv_getlength(BlockDriverState *bs); 430int64_t bdrv_get_allocated_file_size(BlockDriverState *bs); 431BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, 432 BlockDriverState *in_bs, Error **errp); 433void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr); 434void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp); 435int bdrv_commit(BlockDriverState *bs); 436int bdrv_make_empty(BdrvChild *c, Error **errp); 437int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file, 438 const char *backing_fmt, bool warn); 439void bdrv_register(BlockDriver *bdrv); 440int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, 441 const char *backing_file_str); 442BlockDriverState *bdrv_find_overlay(BlockDriverState *active, 443 BlockDriverState *bs); 444BlockDriverState *bdrv_find_base(BlockDriverState *bs); 445bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base, 446 Error **errp); 447int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, 448 Error **errp); 449void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base); 450int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp); 451void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs); 452 453 454typedef struct BdrvCheckResult { 455 int corruptions; 456 int leaks; 457 int check_errors; 458 int corruptions_fixed; 459 int leaks_fixed; 460 int64_t image_end_offset; 461 BlockFragInfo bfi; 462} BdrvCheckResult; 463 464typedef enum { 465 BDRV_FIX_LEAKS = 1, 466 BDRV_FIX_ERRORS = 2, 467} BdrvCheckMode; 468 469int generated_co_wrapper bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, 470 BdrvCheckMode fix); 471 472/* The units of offset and total_work_size may be chosen arbitrarily by the 473 * block driver; total_work_size may change during the course of the amendment 474 * operation */ 475typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset, 476 int64_t total_work_size, void *opaque); 477int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts, 478 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 479 bool force, 480 Error **errp); 481 482/* check if a named node can be replaced when doing drive-mirror */ 483BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, 484 const char *node_name, Error **errp); 485 486/* async block I/O */ 487void bdrv_aio_cancel(BlockAIOCB *acb); 488void bdrv_aio_cancel_async(BlockAIOCB *acb); 489 490/* sg packet commands */ 491int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf); 492 493/* Invalidate any cached metadata used by image formats */ 494int generated_co_wrapper bdrv_invalidate_cache(BlockDriverState *bs, 495 Error **errp); 496void bdrv_invalidate_cache_all(Error **errp); 497int bdrv_inactivate_all(void); 498 499/* Ensure contents are flushed to disk. */ 500int generated_co_wrapper bdrv_flush(BlockDriverState *bs); 501int coroutine_fn bdrv_co_flush(BlockDriverState *bs); 502int bdrv_flush_all(void); 503void bdrv_close_all(void); 504void bdrv_drain(BlockDriverState *bs); 505void coroutine_fn bdrv_co_drain(BlockDriverState *bs); 506void bdrv_drain_all_begin(void); 507void bdrv_drain_all_end(void); 508void bdrv_drain_all(void); 509 510#define BDRV_POLL_WHILE(bs, cond) ({ \ 511 BlockDriverState *bs_ = (bs); \ 512 AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \ 513 cond); }) 514 515int generated_co_wrapper bdrv_pdiscard(BdrvChild *child, int64_t offset, 516 int64_t bytes); 517int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes); 518int bdrv_has_zero_init_1(BlockDriverState *bs); 519int bdrv_has_zero_init(BlockDriverState *bs); 520bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs); 521int bdrv_block_status(BlockDriverState *bs, int64_t offset, 522 int64_t bytes, int64_t *pnum, int64_t *map, 523 BlockDriverState **file); 524int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, 525 int64_t offset, int64_t bytes, int64_t *pnum, 526 int64_t *map, BlockDriverState **file); 527int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes, 528 int64_t *pnum); 529int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, 530 bool include_base, int64_t offset, int64_t bytes, 531 int64_t *pnum); 532int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset, 533 int64_t bytes); 534 535bool bdrv_is_read_only(BlockDriverState *bs); 536int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, 537 bool ignore_allow_rdw, Error **errp); 538int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg, 539 Error **errp); 540bool bdrv_is_writable(BlockDriverState *bs); 541bool bdrv_is_sg(BlockDriverState *bs); 542bool bdrv_is_inserted(BlockDriverState *bs); 543void bdrv_lock_medium(BlockDriverState *bs, bool locked); 544void bdrv_eject(BlockDriverState *bs, bool eject_flag); 545const char *bdrv_get_format_name(BlockDriverState *bs); 546BlockDriverState *bdrv_find_node(const char *node_name); 547BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp); 548XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp); 549BlockDriverState *bdrv_lookup_bs(const char *device, 550 const char *node_name, 551 Error **errp); 552bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base); 553BlockDriverState *bdrv_next_node(BlockDriverState *bs); 554BlockDriverState *bdrv_next_all_states(BlockDriverState *bs); 555 556typedef struct BdrvNextIterator { 557 enum { 558 BDRV_NEXT_BACKEND_ROOTS, 559 BDRV_NEXT_MONITOR_OWNED, 560 } phase; 561 BlockBackend *blk; 562 BlockDriverState *bs; 563} BdrvNextIterator; 564 565BlockDriverState *bdrv_first(BdrvNextIterator *it); 566BlockDriverState *bdrv_next(BdrvNextIterator *it); 567void bdrv_next_cleanup(BdrvNextIterator *it); 568 569BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs); 570bool bdrv_supports_compressed_writes(BlockDriverState *bs); 571void bdrv_iterate_format(void (*it)(void *opaque, const char *name), 572 void *opaque, bool read_only); 573const char *bdrv_get_node_name(const BlockDriverState *bs); 574const char *bdrv_get_device_name(const BlockDriverState *bs); 575const char *bdrv_get_device_or_node_name(const BlockDriverState *bs); 576int bdrv_get_flags(BlockDriverState *bs); 577int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi); 578ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs, 579 Error **errp); 580BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs); 581void bdrv_round_to_clusters(BlockDriverState *bs, 582 int64_t offset, int64_t bytes, 583 int64_t *cluster_offset, 584 int64_t *cluster_bytes); 585 586void bdrv_get_backing_filename(BlockDriverState *bs, 587 char *filename, int filename_size); 588char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp); 589char *bdrv_get_full_backing_filename_from_filename(const char *backed, 590 const char *backing, 591 Error **errp); 592char *bdrv_dirname(BlockDriverState *bs, Error **errp); 593 594int path_has_protocol(const char *path); 595int path_is_absolute(const char *path); 596char *path_combine(const char *base_path, const char *filename); 597 598int generated_co_wrapper 599bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); 600int generated_co_wrapper 601bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); 602int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, 603 int64_t pos, int size); 604 605int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, 606 int64_t pos, int size); 607 608void bdrv_img_create(const char *filename, const char *fmt, 609 const char *base_filename, const char *base_fmt, 610 char *options, uint64_t img_size, int flags, 611 bool quiet, Error **errp); 612 613/* Returns the alignment in bytes that is required so that no bounce buffer 614 * is required throughout the stack */ 615size_t bdrv_min_mem_align(BlockDriverState *bs); 616/* Returns optimal alignment in bytes for bounce buffer */ 617size_t bdrv_opt_mem_align(BlockDriverState *bs); 618void *qemu_blockalign(BlockDriverState *bs, size_t size); 619void *qemu_blockalign0(BlockDriverState *bs, size_t size); 620void *qemu_try_blockalign(BlockDriverState *bs, size_t size); 621void *qemu_try_blockalign0(BlockDriverState *bs, size_t size); 622bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov); 623 624void bdrv_enable_copy_on_read(BlockDriverState *bs); 625void bdrv_disable_copy_on_read(BlockDriverState *bs); 626 627void bdrv_ref(BlockDriverState *bs); 628void bdrv_unref(BlockDriverState *bs); 629void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); 630BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, 631 BlockDriverState *child_bs, 632 const char *child_name, 633 const BdrvChildClass *child_class, 634 BdrvChildRole child_role, 635 Error **errp); 636 637bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); 638void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason); 639void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason); 640void bdrv_op_block_all(BlockDriverState *bs, Error *reason); 641void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason); 642bool bdrv_op_blocker_is_empty(BlockDriverState *bs); 643 644#define BLKDBG_EVENT(child, evt) \ 645 do { \ 646 if (child) { \ 647 bdrv_debug_event(child->bs, evt); \ 648 } \ 649 } while (0) 650 651void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event); 652 653int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, 654 const char *tag); 655int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag); 656int bdrv_debug_resume(BlockDriverState *bs, const char *tag); 657bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); 658 659/** 660 * bdrv_get_aio_context: 661 * 662 * Returns: the currently bound #AioContext 663 */ 664AioContext *bdrv_get_aio_context(BlockDriverState *bs); 665 666/** 667 * Move the current coroutine to the AioContext of @bs and return the old 668 * AioContext of the coroutine. Increase bs->in_flight so that draining @bs 669 * will wait for the operation to proceed until the corresponding 670 * bdrv_co_leave(). 671 * 672 * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as 673 * this will deadlock. 674 */ 675AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs); 676 677/** 678 * Ends a section started by bdrv_co_enter(). Move the current coroutine back 679 * to old_ctx and decrease bs->in_flight again. 680 */ 681void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx); 682 683/** 684 * Locks the AioContext of @bs if it's not the current AioContext. This avoids 685 * double locking which could lead to deadlocks: This is a coroutine_fn, so we 686 * know we already own the lock of the current AioContext. 687 * 688 * May only be called in the main thread. 689 */ 690void coroutine_fn bdrv_co_lock(BlockDriverState *bs); 691 692/** 693 * Unlocks the AioContext of @bs if it's not the current AioContext. 694 */ 695void coroutine_fn bdrv_co_unlock(BlockDriverState *bs); 696 697/** 698 * Transfer control to @co in the aio context of @bs 699 */ 700void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co); 701 702void bdrv_set_aio_context_ignore(BlockDriverState *bs, 703 AioContext *new_context, GSList **ignore); 704int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx, 705 Error **errp); 706int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx, 707 BdrvChild *ignore_child, Error **errp); 708bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx, 709 GSList **ignore, Error **errp); 710bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx, 711 GSList **ignore, Error **errp); 712AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c); 713AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c); 714 715int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz); 716int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo); 717 718void bdrv_io_plug(BlockDriverState *bs); 719void bdrv_io_unplug(BlockDriverState *bs); 720 721/** 722 * bdrv_parent_drained_begin_single: 723 * 724 * Begin a quiesced section for the parent of @c. If @poll is true, wait for 725 * any pending activity to cease. 726 */ 727void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll); 728 729/** 730 * bdrv_parent_drained_end_single: 731 * 732 * End a quiesced section for the parent of @c. 733 * 734 * This polls @bs's AioContext until all scheduled sub-drained_ends 735 * have settled, which may result in graph changes. 736 */ 737void bdrv_parent_drained_end_single(BdrvChild *c); 738 739/** 740 * bdrv_drain_poll: 741 * 742 * Poll for pending requests in @bs, its parents (except for @ignore_parent), 743 * and if @recursive is true its children as well (used for subtree drain). 744 * 745 * If @ignore_bds_parents is true, parents that are BlockDriverStates must 746 * ignore the drain request because they will be drained separately (used for 747 * drain_all). 748 * 749 * This is part of bdrv_drained_begin. 750 */ 751bool bdrv_drain_poll(BlockDriverState *bs, bool recursive, 752 BdrvChild *ignore_parent, bool ignore_bds_parents); 753 754/** 755 * bdrv_drained_begin: 756 * 757 * Begin a quiesced section for exclusive access to the BDS, by disabling 758 * external request sources including NBD server, block jobs, and device model. 759 * 760 * This function can be recursive. 761 */ 762void bdrv_drained_begin(BlockDriverState *bs); 763 764/** 765 * bdrv_do_drained_begin_quiesce: 766 * 767 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already 768 * running requests to complete. 769 */ 770void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, 771 BdrvChild *parent, bool ignore_bds_parents); 772 773/** 774 * Like bdrv_drained_begin, but recursively begins a quiesced section for 775 * exclusive access to all child nodes as well. 776 */ 777void bdrv_subtree_drained_begin(BlockDriverState *bs); 778 779/** 780 * bdrv_drained_end: 781 * 782 * End a quiescent section started by bdrv_drained_begin(). 783 * 784 * This polls @bs's AioContext until all scheduled sub-drained_ends 785 * have settled. On one hand, that may result in graph changes. On 786 * the other, this requires that the caller either runs in the main 787 * loop; or that all involved nodes (@bs and all of its parents) are 788 * in the caller's AioContext. 789 */ 790void bdrv_drained_end(BlockDriverState *bs); 791 792/** 793 * bdrv_drained_end_no_poll: 794 * 795 * Same as bdrv_drained_end(), but do not poll for the subgraph to 796 * actually become unquiesced. Therefore, no graph changes will occur 797 * with this function. 798 * 799 * *drained_end_counter is incremented for every background operation 800 * that is scheduled, and will be decremented for every operation once 801 * it settles. The caller must poll until it reaches 0. The counter 802 * should be accessed using atomic operations only. 803 */ 804void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter); 805 806/** 807 * End a quiescent section started by bdrv_subtree_drained_begin(). 808 */ 809void bdrv_subtree_drained_end(BlockDriverState *bs); 810 811void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, 812 Error **errp); 813void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); 814 815bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, 816 uint32_t granularity, Error **errp); 817/** 818 * 819 * bdrv_register_buf/bdrv_unregister_buf: 820 * 821 * Register/unregister a buffer for I/O. For example, VFIO drivers are 822 * interested to know the memory areas that would later be used for I/O, so 823 * that they can prepare IOMMU mapping etc., to get better performance. 824 */ 825void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size); 826void bdrv_unregister_buf(BlockDriverState *bs, void *host); 827 828/** 829 * 830 * bdrv_co_copy_range: 831 * 832 * Do offloaded copy between two children. If the operation is not implemented 833 * by the driver, or if the backend storage doesn't support it, a negative 834 * error code will be returned. 835 * 836 * Note: block layer doesn't emulate or fallback to a bounce buffer approach 837 * because usually the caller shouldn't attempt offloaded copy any more (e.g. 838 * calling copy_file_range(2)) after the first error, thus it should fall back 839 * to a read+write path in the caller level. 840 * 841 * @src: Source child to copy data from 842 * @src_offset: offset in @src image to read data 843 * @dst: Destination child to copy data to 844 * @dst_offset: offset in @dst image to write data 845 * @bytes: number of bytes to copy 846 * @flags: request flags. Supported flags: 847 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero 848 * write on @dst as if bdrv_co_pwrite_zeroes is 849 * called. Used to simplify caller code, or 850 * during BlockDriver.bdrv_co_copy_range_from() 851 * recursion. 852 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping 853 * requests currently in flight. 854 * 855 * Returns: 0 if succeeded; negative error code if failed. 856 **/ 857int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset, 858 BdrvChild *dst, int64_t dst_offset, 859 int64_t bytes, BdrvRequestFlags read_flags, 860 BdrvRequestFlags write_flags); 861 862void bdrv_cancel_in_flight(BlockDriverState *bs); 863 864#endif