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); 704 705 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz); 706 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo); 707 708 void bdrv_io_plug(BlockDriverState *bs); 709 void bdrv_io_unplug(BlockDriverState *bs); 710 711 /** 712 * bdrv_parent_drained_begin_single: 713 * 714 * Begin a quiesced section for the parent of @c. If @poll is true, wait for 715 * any pending activity to cease. 716 */ 717 void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll); 718 719 /** 720 * bdrv_parent_drained_end_single: 721 * 722 * End a quiesced section for the parent of @c. 723 * 724 * This polls @bs's AioContext until all scheduled sub-drained_ends 725 * have settled, which may result in graph changes. 726 */ 727 void bdrv_parent_drained_end_single(BdrvChild *c); 728 729 /** 730 * bdrv_drain_poll: 731 * 732 * Poll for pending requests in @bs, its parents (except for @ignore_parent), 733 * and if @recursive is true its children as well (used for subtree drain). 734 * 735 * If @ignore_bds_parents is true, parents that are BlockDriverStates must 736 * ignore the drain request because they will be drained separately (used for 737 * drain_all). 738 * 739 * This is part of bdrv_drained_begin. 740 */ 741 bool bdrv_drain_poll(BlockDriverState *bs, bool recursive, 742 BdrvChild *ignore_parent, bool ignore_bds_parents); 743 744 /** 745 * bdrv_drained_begin: 746 * 747 * Begin a quiesced section for exclusive access to the BDS, by disabling 748 * external request sources including NBD server and device model. Note that 749 * this doesn't block timers or coroutines from submitting more requests, which 750 * means block_job_pause is still necessary. 751 * 752 * This function can be recursive. 753 */ 754 void bdrv_drained_begin(BlockDriverState *bs); 755 756 /** 757 * bdrv_do_drained_begin_quiesce: 758 * 759 * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already 760 * running requests to complete. 761 */ 762 void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, 763 BdrvChild *parent, bool ignore_bds_parents); 764 765 /** 766 * Like bdrv_drained_begin, but recursively begins a quiesced section for 767 * exclusive access to all child nodes as well. 768 */ 769 void bdrv_subtree_drained_begin(BlockDriverState *bs); 770 771 /** 772 * bdrv_drained_end: 773 * 774 * End a quiescent section started by bdrv_drained_begin(). 775 * 776 * This polls @bs's AioContext until all scheduled sub-drained_ends 777 * have settled. On one hand, that may result in graph changes. On 778 * the other, this requires that the caller either runs in the main 779 * loop; or that all involved nodes (@bs and all of its parents) are 780 * in the caller's AioContext. 781 */ 782 void bdrv_drained_end(BlockDriverState *bs); 783 784 /** 785 * bdrv_drained_end_no_poll: 786 * 787 * Same as bdrv_drained_end(), but do not poll for the subgraph to 788 * actually become unquiesced. Therefore, no graph changes will occur 789 * with this function. 790 * 791 * *drained_end_counter is incremented for every background operation 792 * that is scheduled, and will be decremented for every operation once 793 * it settles. The caller must poll until it reaches 0. The counter 794 * should be accessed using atomic operations only. 795 */ 796 void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter); 797 798 /** 799 * End a quiescent section started by bdrv_subtree_drained_begin(). 800 */ 801 void bdrv_subtree_drained_end(BlockDriverState *bs); 802 803 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, 804 Error **errp); 805 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); 806 807 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, 808 uint32_t granularity, Error **errp); 809 /** 810 * 811 * bdrv_register_buf/bdrv_unregister_buf: 812 * 813 * Register/unregister a buffer for I/O. For example, VFIO drivers are 814 * interested to know the memory areas that would later be used for I/O, so 815 * that they can prepare IOMMU mapping etc., to get better performance. 816 */ 817 void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size); 818 void bdrv_unregister_buf(BlockDriverState *bs, void *host); 819 820 /** 821 * 822 * bdrv_co_copy_range: 823 * 824 * Do offloaded copy between two children. If the operation is not implemented 825 * by the driver, or if the backend storage doesn't support it, a negative 826 * error code will be returned. 827 * 828 * Note: block layer doesn't emulate or fallback to a bounce buffer approach 829 * because usually the caller shouldn't attempt offloaded copy any more (e.g. 830 * calling copy_file_range(2)) after the first error, thus it should fall back 831 * to a read+write path in the caller level. 832 * 833 * @src: Source child to copy data from 834 * @src_offset: offset in @src image to read data 835 * @dst: Destination child to copy data to 836 * @dst_offset: offset in @dst image to write data 837 * @bytes: number of bytes to copy 838 * @flags: request flags. Supported flags: 839 * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero 840 * write on @dst as if bdrv_co_pwrite_zeroes is 841 * called. Used to simplify caller code, or 842 * during BlockDriver.bdrv_co_copy_range_from() 843 * recursion. 844 * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping 845 * requests currently in flight. 846 * 847 * Returns: 0 if succeeded; negative error code if failed. 848 **/ 849 int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset, 850 BdrvChild *dst, int64_t dst_offset, 851 int64_t bytes, BdrvRequestFlags read_flags, 852 BdrvRequestFlags write_flags); 853 854 void bdrv_cancel_in_flight(BlockDriverState *bs); 855 856 #endif 857