1 /* 2 * QEMU System Emulator block driver 3 * 4 * Copyright (c) 2003 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #ifndef BLOCK_INT_H 25 #define BLOCK_INT_H 26 27 #include "block/accounting.h" 28 #include "block/block.h" 29 #include "block/aio-wait.h" 30 #include "qemu/queue.h" 31 #include "qemu/coroutine.h" 32 #include "qemu/stats64.h" 33 #include "qemu/timer.h" 34 #include "qemu/hbitmap.h" 35 #include "block/snapshot.h" 36 #include "qemu/throttle.h" 37 38 #define BLOCK_FLAG_LAZY_REFCOUNTS 8 39 40 #define BLOCK_OPT_SIZE "size" 41 #define BLOCK_OPT_ENCRYPT "encryption" 42 #define BLOCK_OPT_ENCRYPT_FORMAT "encrypt.format" 43 #define BLOCK_OPT_COMPAT6 "compat6" 44 #define BLOCK_OPT_HWVERSION "hwversion" 45 #define BLOCK_OPT_BACKING_FILE "backing_file" 46 #define BLOCK_OPT_BACKING_FMT "backing_fmt" 47 #define BLOCK_OPT_CLUSTER_SIZE "cluster_size" 48 #define BLOCK_OPT_TABLE_SIZE "table_size" 49 #define BLOCK_OPT_PREALLOC "preallocation" 50 #define BLOCK_OPT_SUBFMT "subformat" 51 #define BLOCK_OPT_COMPAT_LEVEL "compat" 52 #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" 53 #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" 54 #define BLOCK_OPT_REDUNDANCY "redundancy" 55 #define BLOCK_OPT_NOCOW "nocow" 56 #define BLOCK_OPT_EXTENT_SIZE_HINT "extent_size_hint" 57 #define BLOCK_OPT_OBJECT_SIZE "object_size" 58 #define BLOCK_OPT_REFCOUNT_BITS "refcount_bits" 59 #define BLOCK_OPT_DATA_FILE "data_file" 60 #define BLOCK_OPT_DATA_FILE_RAW "data_file_raw" 61 #define BLOCK_OPT_COMPRESSION_TYPE "compression_type" 62 #define BLOCK_OPT_EXTL2 "extended_l2" 63 64 #define BLOCK_PROBE_BUF_SIZE 512 65 66 enum BdrvTrackedRequestType { 67 BDRV_TRACKED_READ, 68 BDRV_TRACKED_WRITE, 69 BDRV_TRACKED_DISCARD, 70 BDRV_TRACKED_TRUNCATE, 71 }; 72 73 typedef struct BdrvTrackedRequest { 74 BlockDriverState *bs; 75 int64_t offset; 76 uint64_t bytes; 77 enum BdrvTrackedRequestType type; 78 79 bool serialising; 80 int64_t overlap_offset; 81 uint64_t overlap_bytes; 82 83 QLIST_ENTRY(BdrvTrackedRequest) list; 84 Coroutine *co; /* owner, used for deadlock detection */ 85 CoQueue wait_queue; /* coroutines blocked on this request */ 86 87 struct BdrvTrackedRequest *waiting_for; 88 } BdrvTrackedRequest; 89 90 struct BlockDriver { 91 const char *format_name; 92 int instance_size; 93 94 /* set to true if the BlockDriver is a block filter. Block filters pass 95 * certain callbacks that refer to data (see block.c) to their bs->file 96 * or bs->backing (whichever one exists) if the driver doesn't implement 97 * them. Drivers that do not wish to forward must implement them and return 98 * -ENOTSUP. 99 * Note that filters are not allowed to modify data. 100 * 101 * Filters generally cannot have more than a single filtered child, 102 * because the data they present must at all times be the same as 103 * that on their filtered child. That would be impossible to 104 * achieve for multiple filtered children. 105 * (And this filtered child must then be bs->file or bs->backing.) 106 */ 107 bool is_filter; 108 /* 109 * Set to true if the BlockDriver is a format driver. Format nodes 110 * generally do not expect their children to be other format nodes 111 * (except for backing files), and so format probing is disabled 112 * on those children. 113 */ 114 bool is_format; 115 /* 116 * Return true if @to_replace can be replaced by a BDS with the 117 * same data as @bs without it affecting @bs's behavior (that is, 118 * without it being visible to @bs's parents). 119 */ 120 bool (*bdrv_recurse_can_replace)(BlockDriverState *bs, 121 BlockDriverState *to_replace); 122 123 int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename); 124 int (*bdrv_probe_device)(const char *filename); 125 126 /* Any driver implementing this callback is expected to be able to handle 127 * NULL file names in its .bdrv_open() implementation */ 128 void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp); 129 /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have 130 * this field set to true, except ones that are defined only by their 131 * child's bs. 132 * An example of the last type will be the quorum block driver. 133 */ 134 bool bdrv_needs_filename; 135 136 /* 137 * Set if a driver can support backing files. This also implies the 138 * following semantics: 139 * 140 * - Return status 0 of .bdrv_co_block_status means that corresponding 141 * blocks are not allocated in this layer of backing-chain 142 * - For such (unallocated) blocks, read will: 143 * - fill buffer with zeros if there is no backing file 144 * - read from the backing file otherwise, where the block layer 145 * takes care of reading zeros beyond EOF if backing file is short 146 */ 147 bool supports_backing; 148 149 /* For handling image reopen for split or non-split files */ 150 int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state, 151 BlockReopenQueue *queue, Error **errp); 152 void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state); 153 void (*bdrv_reopen_commit_post)(BDRVReopenState *reopen_state); 154 void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state); 155 void (*bdrv_join_options)(QDict *options, QDict *old_options); 156 157 int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags, 158 Error **errp); 159 160 /* Protocol drivers should implement this instead of bdrv_open */ 161 int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags, 162 Error **errp); 163 void (*bdrv_close)(BlockDriverState *bs); 164 165 166 int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts, 167 Error **errp); 168 int coroutine_fn (*bdrv_co_create_opts)(BlockDriver *drv, 169 const char *filename, 170 QemuOpts *opts, 171 Error **errp); 172 173 int coroutine_fn (*bdrv_co_amend)(BlockDriverState *bs, 174 BlockdevAmendOptions *opts, 175 bool force, 176 Error **errp); 177 178 int (*bdrv_amend_options)(BlockDriverState *bs, 179 QemuOpts *opts, 180 BlockDriverAmendStatusCB *status_cb, 181 void *cb_opaque, 182 bool force, 183 Error **errp); 184 185 int (*bdrv_make_empty)(BlockDriverState *bs); 186 187 /* 188 * Refreshes the bs->exact_filename field. If that is impossible, 189 * bs->exact_filename has to be left empty. 190 */ 191 void (*bdrv_refresh_filename)(BlockDriverState *bs); 192 193 /* 194 * Gathers the open options for all children into @target. 195 * A simple format driver (without backing file support) might 196 * implement this function like this: 197 * 198 * QINCREF(bs->file->bs->full_open_options); 199 * qdict_put(target, "file", bs->file->bs->full_open_options); 200 * 201 * If not specified, the generic implementation will simply put 202 * all children's options under their respective name. 203 * 204 * @backing_overridden is true when bs->backing seems not to be 205 * the child that would result from opening bs->backing_file. 206 * Therefore, if it is true, the backing child's options should be 207 * gathered; otherwise, there is no need since the backing child 208 * is the one implied by the image header. 209 * 210 * Note that ideally this function would not be needed. Every 211 * block driver which implements it is probably doing something 212 * shady regarding its runtime option structure. 213 */ 214 void (*bdrv_gather_child_options)(BlockDriverState *bs, QDict *target, 215 bool backing_overridden); 216 217 /* 218 * Returns an allocated string which is the directory name of this BDS: It 219 * will be used to make relative filenames absolute by prepending this 220 * function's return value to them. 221 */ 222 char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp); 223 224 /* aio */ 225 BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs, 226 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags, 227 BlockCompletionFunc *cb, void *opaque); 228 BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs, 229 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags, 230 BlockCompletionFunc *cb, void *opaque); 231 BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, 232 BlockCompletionFunc *cb, void *opaque); 233 BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs, 234 int64_t offset, int bytes, 235 BlockCompletionFunc *cb, void *opaque); 236 237 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, 238 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 239 240 /** 241 * @offset: position in bytes to read at 242 * @bytes: number of bytes to read 243 * @qiov: the buffers to fill with read data 244 * @flags: currently unused, always 0 245 * 246 * @offset and @bytes will be a multiple of 'request_alignment', 247 * but the length of individual @qiov elements does not have to 248 * be a multiple. 249 * 250 * @bytes will always equal the total size of @qiov, and will be 251 * no larger than 'max_transfer'. 252 * 253 * The buffer in @qiov may point directly to guest memory. 254 */ 255 int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs, 256 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); 257 int coroutine_fn (*bdrv_co_preadv_part)(BlockDriverState *bs, 258 uint64_t offset, uint64_t bytes, 259 QEMUIOVector *qiov, size_t qiov_offset, int flags); 260 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, 261 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags); 262 /** 263 * @offset: position in bytes to write at 264 * @bytes: number of bytes to write 265 * @qiov: the buffers containing data to write 266 * @flags: zero or more bits allowed by 'supported_write_flags' 267 * 268 * @offset and @bytes will be a multiple of 'request_alignment', 269 * but the length of individual @qiov elements does not have to 270 * be a multiple. 271 * 272 * @bytes will always equal the total size of @qiov, and will be 273 * no larger than 'max_transfer'. 274 * 275 * The buffer in @qiov may point directly to guest memory. 276 */ 277 int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs, 278 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); 279 int coroutine_fn (*bdrv_co_pwritev_part)(BlockDriverState *bs, 280 uint64_t offset, uint64_t bytes, 281 QEMUIOVector *qiov, size_t qiov_offset, int flags); 282 283 /* 284 * Efficiently zero a region of the disk image. Typically an image format 285 * would use a compact metadata representation to implement this. This 286 * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev() 287 * will be called instead. 288 */ 289 int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs, 290 int64_t offset, int bytes, BdrvRequestFlags flags); 291 int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs, 292 int64_t offset, int bytes); 293 294 /* Map [offset, offset + nbytes) range onto a child of @bs to copy from, 295 * and invoke bdrv_co_copy_range_from(child, ...), or invoke 296 * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from. 297 * 298 * See the comment of bdrv_co_copy_range for the parameter and return value 299 * semantics. 300 */ 301 int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs, 302 BdrvChild *src, 303 uint64_t offset, 304 BdrvChild *dst, 305 uint64_t dst_offset, 306 uint64_t bytes, 307 BdrvRequestFlags read_flags, 308 BdrvRequestFlags write_flags); 309 310 /* Map [offset, offset + nbytes) range onto a child of bs to copy data to, 311 * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy 312 * operation if @bs is the leaf and @src has the same BlockDriver. Return 313 * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver. 314 * 315 * See the comment of bdrv_co_copy_range for the parameter and return value 316 * semantics. 317 */ 318 int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs, 319 BdrvChild *src, 320 uint64_t src_offset, 321 BdrvChild *dst, 322 uint64_t dst_offset, 323 uint64_t bytes, 324 BdrvRequestFlags read_flags, 325 BdrvRequestFlags write_flags); 326 327 /* 328 * Building block for bdrv_block_status[_above] and 329 * bdrv_is_allocated[_above]. The driver should answer only 330 * according to the current layer, and should only need to set 331 * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID, 332 * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing 333 * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See 334 * block.h for the overall meaning of the bits. As a hint, the 335 * flag want_zero is true if the caller cares more about precise 336 * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for 337 * overall allocation (favor larger *pnum, perhaps by reporting 338 * _DATA instead of _ZERO). The block layer guarantees input 339 * clamped to bdrv_getlength() and aligned to request_alignment, 340 * as well as non-NULL pnum, map, and file; in turn, the driver 341 * must return an error or set pnum to an aligned non-zero value. 342 */ 343 int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs, 344 bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, 345 int64_t *map, BlockDriverState **file); 346 347 /* 348 * Invalidate any cached meta-data. 349 */ 350 void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs, 351 Error **errp); 352 int (*bdrv_inactivate)(BlockDriverState *bs); 353 354 /* 355 * Flushes all data for all layers by calling bdrv_co_flush for underlying 356 * layers, if needed. This function is needed for deterministic 357 * synchronization of the flush finishing callback. 358 */ 359 int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs); 360 361 /* Delete a created file. */ 362 int coroutine_fn (*bdrv_co_delete_file)(BlockDriverState *bs, 363 Error **errp); 364 365 /* 366 * Flushes all data that was already written to the OS all the way down to 367 * the disk (for example file-posix.c calls fsync()). 368 */ 369 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs); 370 371 /* 372 * Flushes all internal caches to the OS. The data may still sit in a 373 * writeback cache of the host OS, but it will survive a crash of the qemu 374 * process. 375 */ 376 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs); 377 378 /* 379 * Drivers setting this field must be able to work with just a plain 380 * filename with '<protocol_name>:' as a prefix, and no other options. 381 * Options may be extracted from the filename by implementing 382 * bdrv_parse_filename. 383 */ 384 const char *protocol_name; 385 386 /* 387 * Truncate @bs to @offset bytes using the given @prealloc mode 388 * when growing. Modes other than PREALLOC_MODE_OFF should be 389 * rejected when shrinking @bs. 390 * 391 * If @exact is true, @bs must be resized to exactly @offset. 392 * Otherwise, it is sufficient for @bs (if it is a host block 393 * device and thus there is no way to resize it) to be at least 394 * @offset bytes in length. 395 * 396 * If @exact is true and this function fails but would succeed 397 * with @exact = false, it should return -ENOTSUP. 398 */ 399 int coroutine_fn (*bdrv_co_truncate)(BlockDriverState *bs, int64_t offset, 400 bool exact, PreallocMode prealloc, 401 BdrvRequestFlags flags, Error **errp); 402 403 int64_t (*bdrv_getlength)(BlockDriverState *bs); 404 bool has_variable_length; 405 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); 406 BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs, 407 Error **errp); 408 409 int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs, 410 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov); 411 int coroutine_fn (*bdrv_co_pwritev_compressed_part)(BlockDriverState *bs, 412 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, 413 size_t qiov_offset); 414 415 int (*bdrv_snapshot_create)(BlockDriverState *bs, 416 QEMUSnapshotInfo *sn_info); 417 int (*bdrv_snapshot_goto)(BlockDriverState *bs, 418 const char *snapshot_id); 419 int (*bdrv_snapshot_delete)(BlockDriverState *bs, 420 const char *snapshot_id, 421 const char *name, 422 Error **errp); 423 int (*bdrv_snapshot_list)(BlockDriverState *bs, 424 QEMUSnapshotInfo **psn_info); 425 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, 426 const char *snapshot_id, 427 const char *name, 428 Error **errp); 429 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); 430 ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs, 431 Error **errp); 432 BlockStatsSpecific *(*bdrv_get_specific_stats)(BlockDriverState *bs); 433 434 int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs, 435 QEMUIOVector *qiov, 436 int64_t pos); 437 int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs, 438 QEMUIOVector *qiov, 439 int64_t pos); 440 441 int (*bdrv_change_backing_file)(BlockDriverState *bs, 442 const char *backing_file, const char *backing_fmt); 443 444 /* removable device specific */ 445 bool (*bdrv_is_inserted)(BlockDriverState *bs); 446 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); 447 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); 448 449 /* to control generic scsi devices */ 450 BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, 451 unsigned long int req, void *buf, 452 BlockCompletionFunc *cb, void *opaque); 453 int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs, 454 unsigned long int req, void *buf); 455 456 /* List of options for creating images, terminated by name == NULL */ 457 QemuOptsList *create_opts; 458 459 /* List of options for image amend */ 460 QemuOptsList *amend_opts; 461 462 /* 463 * If this driver supports reopening images this contains a 464 * NULL-terminated list of the runtime options that can be 465 * modified. If an option in this list is unspecified during 466 * reopen then it _must_ be reset to its default value or return 467 * an error. 468 */ 469 const char *const *mutable_opts; 470 471 /* 472 * Returns 0 for completed check, -errno for internal errors. 473 * The check results are stored in result. 474 */ 475 int coroutine_fn (*bdrv_co_check)(BlockDriverState *bs, 476 BdrvCheckResult *result, 477 BdrvCheckMode fix); 478 479 void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event); 480 481 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */ 482 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event, 483 const char *tag); 484 int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs, 485 const char *tag); 486 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag); 487 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag); 488 489 void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp); 490 491 /* 492 * Returns 1 if newly created images are guaranteed to contain only 493 * zeros, 0 otherwise. 494 */ 495 int (*bdrv_has_zero_init)(BlockDriverState *bs); 496 497 /* Remove fd handlers, timers, and other event loop callbacks so the event 498 * loop is no longer in use. Called with no in-flight requests and in 499 * depth-first traversal order with parents before child nodes. 500 */ 501 void (*bdrv_detach_aio_context)(BlockDriverState *bs); 502 503 /* Add fd handlers, timers, and other event loop callbacks so I/O requests 504 * can be processed again. Called with no in-flight requests and in 505 * depth-first traversal order with child nodes before parent nodes. 506 */ 507 void (*bdrv_attach_aio_context)(BlockDriverState *bs, 508 AioContext *new_context); 509 510 /* io queue for linux-aio */ 511 void (*bdrv_io_plug)(BlockDriverState *bs); 512 void (*bdrv_io_unplug)(BlockDriverState *bs); 513 514 /** 515 * Try to get @bs's logical and physical block size. 516 * On success, store them in @bsz and return zero. 517 * On failure, return negative errno. 518 */ 519 int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz); 520 /** 521 * Try to get @bs's geometry (cyls, heads, sectors) 522 * On success, store them in @geo and return 0. 523 * On failure return -errno. 524 * Only drivers that want to override guest geometry implement this 525 * callback; see hd_geometry_guess(). 526 */ 527 int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo); 528 529 /** 530 * bdrv_co_drain_begin is called if implemented in the beginning of a 531 * drain operation to drain and stop any internal sources of requests in 532 * the driver. 533 * bdrv_co_drain_end is called if implemented at the end of the drain. 534 * 535 * They should be used by the driver to e.g. manage scheduled I/O 536 * requests, or toggle an internal state. After the end of the drain new 537 * requests will continue normally. 538 */ 539 void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs); 540 void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs); 541 542 void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child, 543 Error **errp); 544 void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child, 545 Error **errp); 546 547 /** 548 * Informs the block driver that a permission change is intended. The 549 * driver checks whether the change is permissible and may take other 550 * preparations for the change (e.g. get file system locks). This operation 551 * is always followed either by a call to either .bdrv_set_perm or 552 * .bdrv_abort_perm_update. 553 * 554 * Checks whether the requested set of cumulative permissions in @perm 555 * can be granted for accessing @bs and whether no other users are using 556 * permissions other than those given in @shared (both arguments take 557 * BLK_PERM_* bitmasks). 558 * 559 * If both conditions are met, 0 is returned. Otherwise, -errno is returned 560 * and errp is set to an error describing the conflict. 561 */ 562 int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm, 563 uint64_t shared, Error **errp); 564 565 /** 566 * Called to inform the driver that the set of cumulative set of used 567 * permissions for @bs has changed to @perm, and the set of sharable 568 * permission to @shared. The driver can use this to propagate changes to 569 * its children (i.e. request permissions only if a parent actually needs 570 * them). 571 * 572 * This function is only invoked after bdrv_check_perm(), so block drivers 573 * may rely on preparations made in their .bdrv_check_perm implementation. 574 */ 575 void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared); 576 577 /* 578 * Called to inform the driver that after a previous bdrv_check_perm() 579 * call, the permission update is not performed and any preparations made 580 * for it (e.g. taken file locks) need to be undone. 581 * 582 * This function can be called even for nodes that never saw a 583 * bdrv_check_perm() call. It is a no-op then. 584 */ 585 void (*bdrv_abort_perm_update)(BlockDriverState *bs); 586 587 /** 588 * Returns in @nperm and @nshared the permissions that the driver for @bs 589 * needs on its child @c, based on the cumulative permissions requested by 590 * the parents in @parent_perm and @parent_shared. 591 * 592 * If @c is NULL, return the permissions for attaching a new child for the 593 * given @child_class and @role. 594 * 595 * If @reopen_queue is non-NULL, don't return the currently needed 596 * permissions, but those that will be needed after applying the 597 * @reopen_queue. 598 */ 599 void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c, 600 BdrvChildRole role, 601 BlockReopenQueue *reopen_queue, 602 uint64_t parent_perm, uint64_t parent_shared, 603 uint64_t *nperm, uint64_t *nshared); 604 605 bool (*bdrv_supports_persistent_dirty_bitmap)(BlockDriverState *bs); 606 bool (*bdrv_co_can_store_new_dirty_bitmap)(BlockDriverState *bs, 607 const char *name, 608 uint32_t granularity, 609 Error **errp); 610 int (*bdrv_co_remove_persistent_dirty_bitmap)(BlockDriverState *bs, 611 const char *name, 612 Error **errp); 613 614 /** 615 * Register/unregister a buffer for I/O. For example, when the driver is 616 * interested to know the memory areas that will later be used in iovs, so 617 * that it can do IOMMU mapping with VFIO etc., in order to get better 618 * performance. In the case of VFIO drivers, this callback is used to do 619 * DMA mapping for hot buffers. 620 */ 621 void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size); 622 void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host); 623 QLIST_ENTRY(BlockDriver) list; 624 625 /* Pointer to a NULL-terminated array of names of strong options 626 * that can be specified for bdrv_open(). A strong option is one 627 * that changes the data of a BDS. 628 * If this pointer is NULL, the array is considered empty. 629 * "filename" and "driver" are always considered strong. */ 630 const char *const *strong_runtime_opts; 631 }; 632 633 static inline bool block_driver_can_compress(BlockDriver *drv) 634 { 635 return drv->bdrv_co_pwritev_compressed || 636 drv->bdrv_co_pwritev_compressed_part; 637 } 638 639 typedef struct BlockLimits { 640 /* Alignment requirement, in bytes, for offset/length of I/O 641 * requests. Must be a power of 2 less than INT_MAX; defaults to 642 * 1 for drivers with modern byte interfaces, and to 512 643 * otherwise. */ 644 uint32_t request_alignment; 645 646 /* Maximum number of bytes that can be discarded at once (since it 647 * is signed, it must be < 2G, if set). Must be multiple of 648 * pdiscard_alignment, but need not be power of 2. May be 0 if no 649 * inherent 32-bit limit */ 650 int32_t max_pdiscard; 651 652 /* Optimal alignment for discard requests in bytes. A power of 2 653 * is best but not mandatory. Must be a multiple of 654 * bl.request_alignment, and must be less than max_pdiscard if 655 * that is set. May be 0 if bl.request_alignment is good enough */ 656 uint32_t pdiscard_alignment; 657 658 /* Maximum number of bytes that can zeroized at once (since it is 659 * signed, it must be < 2G, if set). Must be multiple of 660 * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */ 661 int32_t max_pwrite_zeroes; 662 663 /* Optimal alignment for write zeroes requests in bytes. A power 664 * of 2 is best but not mandatory. Must be a multiple of 665 * bl.request_alignment, and must be less than max_pwrite_zeroes 666 * if that is set. May be 0 if bl.request_alignment is good 667 * enough */ 668 uint32_t pwrite_zeroes_alignment; 669 670 /* Optimal transfer length in bytes. A power of 2 is best but not 671 * mandatory. Must be a multiple of bl.request_alignment, or 0 if 672 * no preferred size */ 673 uint32_t opt_transfer; 674 675 /* Maximal transfer length in bytes. Need not be power of 2, but 676 * must be multiple of opt_transfer and bl.request_alignment, or 0 677 * for no 32-bit limit. For now, anything larger than INT_MAX is 678 * clamped down. */ 679 uint32_t max_transfer; 680 681 /* memory alignment, in bytes so that no bounce buffer is needed */ 682 size_t min_mem_alignment; 683 684 /* memory alignment, in bytes, for bounce buffer */ 685 size_t opt_mem_alignment; 686 687 /* maximum number of iovec elements */ 688 int max_iov; 689 } BlockLimits; 690 691 typedef struct BdrvOpBlocker BdrvOpBlocker; 692 693 typedef struct BdrvAioNotifier { 694 void (*attached_aio_context)(AioContext *new_context, void *opaque); 695 void (*detach_aio_context)(void *opaque); 696 697 void *opaque; 698 bool deleted; 699 700 QLIST_ENTRY(BdrvAioNotifier) list; 701 } BdrvAioNotifier; 702 703 struct BdrvChildClass { 704 /* If true, bdrv_replace_node() doesn't change the node this BdrvChild 705 * points to. */ 706 bool stay_at_node; 707 708 /* If true, the parent is a BlockDriverState and bdrv_next_all_states() 709 * will return it. This information is used for drain_all, where every node 710 * will be drained separately, so the drain only needs to be propagated to 711 * non-BDS parents. */ 712 bool parent_is_bds; 713 714 void (*inherit_options)(BdrvChildRole role, bool parent_is_format, 715 int *child_flags, QDict *child_options, 716 int parent_flags, QDict *parent_options); 717 718 void (*change_media)(BdrvChild *child, bool load); 719 void (*resize)(BdrvChild *child); 720 721 /* Returns a name that is supposedly more useful for human users than the 722 * node name for identifying the node in question (in particular, a BB 723 * name), or NULL if the parent can't provide a better name. */ 724 const char *(*get_name)(BdrvChild *child); 725 726 /* Returns a malloced string that describes the parent of the child for a 727 * human reader. This could be a node-name, BlockBackend name, qdev ID or 728 * QOM path of the device owning the BlockBackend, job type and ID etc. The 729 * caller is responsible for freeing the memory. */ 730 char *(*get_parent_desc)(BdrvChild *child); 731 732 /* 733 * If this pair of functions is implemented, the parent doesn't issue new 734 * requests after returning from .drained_begin() until .drained_end() is 735 * called. 736 * 737 * These functions must not change the graph (and therefore also must not 738 * call aio_poll(), which could change the graph indirectly). 739 * 740 * If drained_end() schedules background operations, it must atomically 741 * increment *drained_end_counter for each such operation and atomically 742 * decrement it once the operation has settled. 743 * 744 * Note that this can be nested. If drained_begin() was called twice, new 745 * I/O is allowed only after drained_end() was called twice, too. 746 */ 747 void (*drained_begin)(BdrvChild *child); 748 void (*drained_end)(BdrvChild *child, int *drained_end_counter); 749 750 /* 751 * Returns whether the parent has pending requests for the child. This 752 * callback is polled after .drained_begin() has been called until all 753 * activity on the child has stopped. 754 */ 755 bool (*drained_poll)(BdrvChild *child); 756 757 /* Notifies the parent that the child has been activated/inactivated (e.g. 758 * when migration is completing) and it can start/stop requesting 759 * permissions and doing I/O on it. */ 760 void (*activate)(BdrvChild *child, Error **errp); 761 int (*inactivate)(BdrvChild *child); 762 763 void (*attach)(BdrvChild *child); 764 void (*detach)(BdrvChild *child); 765 766 /* Notifies the parent that the filename of its child has changed (e.g. 767 * because the direct child was removed from the backing chain), so that it 768 * can update its reference. */ 769 int (*update_filename)(BdrvChild *child, BlockDriverState *new_base, 770 const char *filename, Error **errp); 771 772 bool (*can_set_aio_ctx)(BdrvChild *child, AioContext *ctx, 773 GSList **ignore, Error **errp); 774 void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore); 775 }; 776 777 extern const BdrvChildClass child_of_bds; 778 779 struct BdrvChild { 780 BlockDriverState *bs; 781 char *name; 782 const BdrvChildClass *klass; 783 BdrvChildRole role; 784 void *opaque; 785 786 /** 787 * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask) 788 */ 789 uint64_t perm; 790 791 /** 792 * Permissions that can still be granted to other users of @bs while this 793 * BdrvChild is still attached to it. (BLK_PERM_* bitmask) 794 */ 795 uint64_t shared_perm; 796 797 /* backup of permissions during permission update procedure */ 798 bool has_backup_perm; 799 uint64_t backup_perm; 800 uint64_t backup_shared_perm; 801 802 /* 803 * This link is frozen: the child can neither be replaced nor 804 * detached from the parent. 805 */ 806 bool frozen; 807 808 /* 809 * How many times the parent of this child has been drained 810 * (through klass->drained_*). 811 * Usually, this is equal to bs->quiesce_counter (potentially 812 * reduced by bdrv_drain_all_count). It may differ while the 813 * child is entering or leaving a drained section. 814 */ 815 int parent_quiesce_counter; 816 817 QLIST_ENTRY(BdrvChild) next; 818 QLIST_ENTRY(BdrvChild) next_parent; 819 }; 820 821 /* 822 * Note: the function bdrv_append() copies and swaps contents of 823 * BlockDriverStates, so if you add new fields to this struct, please 824 * inspect bdrv_append() to determine if the new fields need to be 825 * copied as well. 826 */ 827 struct BlockDriverState { 828 /* Protected by big QEMU lock or read-only after opening. No special 829 * locking needed during I/O... 830 */ 831 int open_flags; /* flags used to open the file, re-used for re-open */ 832 bool read_only; /* if true, the media is read only */ 833 bool encrypted; /* if true, the media is encrypted */ 834 bool sg; /* if true, the device is a /dev/sg* */ 835 bool probed; /* if true, format was probed rather than specified */ 836 bool force_share; /* if true, always allow all shared permissions */ 837 bool implicit; /* if true, this filter node was automatically inserted */ 838 839 BlockDriver *drv; /* NULL means no media */ 840 void *opaque; 841 842 AioContext *aio_context; /* event loop used for fd handlers, timers, etc */ 843 /* long-running tasks intended to always use the same AioContext as this 844 * BDS may register themselves in this list to be notified of changes 845 * regarding this BDS's context */ 846 QLIST_HEAD(, BdrvAioNotifier) aio_notifiers; 847 bool walking_aio_notifiers; /* to make removal during iteration safe */ 848 849 char filename[PATH_MAX]; 850 /* 851 * If not empty, this image is a diff in relation to backing_file. 852 * Note that this is the name given in the image header and 853 * therefore may or may not be equal to .backing->bs->filename. 854 * If this field contains a relative path, it is to be resolved 855 * relatively to the overlay's location. 856 */ 857 char backing_file[PATH_MAX]; 858 /* 859 * The backing filename indicated by the image header. Contrary 860 * to backing_file, if we ever open this file, auto_backing_file 861 * is replaced by the resulting BDS's filename (i.e. after a 862 * bdrv_refresh_filename() run). 863 */ 864 char auto_backing_file[PATH_MAX]; 865 char backing_format[16]; /* if non-zero and backing_file exists */ 866 867 QDict *full_open_options; 868 char exact_filename[PATH_MAX]; 869 870 BdrvChild *backing; 871 BdrvChild *file; 872 873 /* I/O Limits */ 874 BlockLimits bl; 875 876 /* Flags honored during pwrite (so far: BDRV_REQ_FUA, 877 * BDRV_REQ_WRITE_UNCHANGED). 878 * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those 879 * writes will be issued as normal writes without the flag set. 880 * This is important to note for drivers that do not explicitly 881 * request a WRITE permission for their children and instead take 882 * the same permissions as their parent did (this is commonly what 883 * block filters do). Such drivers have to be aware that the 884 * parent may have taken a WRITE_UNCHANGED permission only and is 885 * issuing such requests. Drivers either must make sure that 886 * these requests do not result in plain WRITE accesses (usually 887 * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding 888 * every incoming write request as-is, including potentially that 889 * flag), or they have to explicitly take the WRITE permission for 890 * their children. */ 891 unsigned int supported_write_flags; 892 /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA, 893 * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */ 894 unsigned int supported_zero_flags; 895 /* 896 * Flags honoured during truncate (so far: BDRV_REQ_ZERO_WRITE). 897 * 898 * If BDRV_REQ_ZERO_WRITE is given, the truncate operation must make sure 899 * that any added space reads as all zeros. If this can't be guaranteed, 900 * the operation must fail. 901 */ 902 unsigned int supported_truncate_flags; 903 904 /* the following member gives a name to every node on the bs graph. */ 905 char node_name[32]; 906 /* element of the list of named nodes building the graph */ 907 QTAILQ_ENTRY(BlockDriverState) node_list; 908 /* element of the list of all BlockDriverStates (all_bdrv_states) */ 909 QTAILQ_ENTRY(BlockDriverState) bs_list; 910 /* element of the list of monitor-owned BDS */ 911 QTAILQ_ENTRY(BlockDriverState) monitor_list; 912 int refcnt; 913 914 /* operation blockers */ 915 QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX]; 916 917 /* The node that this node inherited default options from (and a reopen on 918 * which can affect this node by changing these defaults). This is always a 919 * parent node of this node. */ 920 BlockDriverState *inherits_from; 921 QLIST_HEAD(, BdrvChild) children; 922 QLIST_HEAD(, BdrvChild) parents; 923 924 QDict *options; 925 QDict *explicit_options; 926 BlockdevDetectZeroesOptions detect_zeroes; 927 928 /* The error object in use for blocking operations on backing_hd */ 929 Error *backing_blocker; 930 931 /* Protected by AioContext lock */ 932 933 /* If we are reading a disk image, give its size in sectors. 934 * Generally read-only; it is written to by load_snapshot and 935 * save_snaphost, but the block layer is quiescent during those. 936 */ 937 int64_t total_sectors; 938 939 /* Callback before write request is processed */ 940 NotifierWithReturnList before_write_notifiers; 941 942 /* threshold limit for writes, in bytes. "High water mark". */ 943 uint64_t write_threshold_offset; 944 NotifierWithReturn write_threshold_notifier; 945 946 /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex. 947 * Reading from the list can be done with either the BQL or the 948 * dirty_bitmap_mutex. Modifying a bitmap only requires 949 * dirty_bitmap_mutex. */ 950 QemuMutex dirty_bitmap_mutex; 951 QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps; 952 953 /* Offset after the highest byte written to */ 954 Stat64 wr_highest_offset; 955 956 /* If true, copy read backing sectors into image. Can be >1 if more 957 * than one client has requested copy-on-read. Accessed with atomic 958 * ops. 959 */ 960 int copy_on_read; 961 962 /* number of in-flight requests; overall and serialising. 963 * Accessed with atomic ops. 964 */ 965 unsigned int in_flight; 966 unsigned int serialising_in_flight; 967 968 /* counter for nested bdrv_io_plug. 969 * Accessed with atomic ops. 970 */ 971 unsigned io_plugged; 972 973 /* do we need to tell the quest if we have a volatile write cache? */ 974 int enable_write_cache; 975 976 /* Accessed with atomic ops. */ 977 int quiesce_counter; 978 int recursive_quiesce_counter; 979 980 unsigned int write_gen; /* Current data generation */ 981 982 /* Protected by reqs_lock. */ 983 CoMutex reqs_lock; 984 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; 985 CoQueue flush_queue; /* Serializing flush queue */ 986 bool active_flush_req; /* Flush request in flight? */ 987 988 /* Only read/written by whoever has set active_flush_req to true. */ 989 unsigned int flushed_gen; /* Flushed write generation */ 990 991 /* BdrvChild links to this node may never be frozen */ 992 bool never_freeze; 993 }; 994 995 struct BlockBackendRootState { 996 int open_flags; 997 bool read_only; 998 BlockdevDetectZeroesOptions detect_zeroes; 999 }; 1000 1001 typedef enum BlockMirrorBackingMode { 1002 /* Reuse the existing backing chain from the source for the target. 1003 * - sync=full: Set backing BDS to NULL. 1004 * - sync=top: Use source's backing BDS. 1005 * - sync=none: Use source as the backing BDS. */ 1006 MIRROR_SOURCE_BACKING_CHAIN, 1007 1008 /* Open the target's backing chain completely anew */ 1009 MIRROR_OPEN_BACKING_CHAIN, 1010 1011 /* Do not change the target's backing BDS after job completion */ 1012 MIRROR_LEAVE_BACKING_CHAIN, 1013 } BlockMirrorBackingMode; 1014 1015 1016 /* Essential block drivers which must always be statically linked into qemu, and 1017 * which therefore can be accessed without using bdrv_find_format() */ 1018 extern BlockDriver bdrv_file; 1019 extern BlockDriver bdrv_raw; 1020 extern BlockDriver bdrv_qcow2; 1021 1022 int coroutine_fn bdrv_co_preadv(BdrvChild *child, 1023 int64_t offset, unsigned int bytes, QEMUIOVector *qiov, 1024 BdrvRequestFlags flags); 1025 int coroutine_fn bdrv_co_preadv_part(BdrvChild *child, 1026 int64_t offset, unsigned int bytes, 1027 QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags); 1028 int coroutine_fn bdrv_co_pwritev(BdrvChild *child, 1029 int64_t offset, unsigned int bytes, QEMUIOVector *qiov, 1030 BdrvRequestFlags flags); 1031 int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child, 1032 int64_t offset, unsigned int bytes, 1033 QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags); 1034 1035 static inline int coroutine_fn bdrv_co_pread(BdrvChild *child, 1036 int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags) 1037 { 1038 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); 1039 1040 return bdrv_co_preadv(child, offset, bytes, &qiov, flags); 1041 } 1042 1043 static inline int coroutine_fn bdrv_co_pwrite(BdrvChild *child, 1044 int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags) 1045 { 1046 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); 1047 1048 return bdrv_co_pwritev(child, offset, bytes, &qiov, flags); 1049 } 1050 1051 extern unsigned int bdrv_drain_all_count; 1052 void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent); 1053 void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent); 1054 1055 bool coroutine_fn bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align); 1056 BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs); 1057 1058 int get_tmp_filename(char *filename, int size); 1059 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, 1060 const char *filename); 1061 1062 void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix, 1063 QDict *options); 1064 1065 bool bdrv_backing_overridden(BlockDriverState *bs); 1066 1067 1068 /** 1069 * bdrv_add_before_write_notifier: 1070 * 1071 * Register a callback that is invoked before write requests are processed but 1072 * after any throttling or waiting for overlapping requests. 1073 */ 1074 void bdrv_add_before_write_notifier(BlockDriverState *bs, 1075 NotifierWithReturn *notifier); 1076 1077 /** 1078 * bdrv_add_aio_context_notifier: 1079 * 1080 * If a long-running job intends to be always run in the same AioContext as a 1081 * certain BDS, it may use this function to be notified of changes regarding the 1082 * association of the BDS to an AioContext. 1083 * 1084 * attached_aio_context() is called after the target BDS has been attached to a 1085 * new AioContext; detach_aio_context() is called before the target BDS is being 1086 * detached from its old AioContext. 1087 */ 1088 void bdrv_add_aio_context_notifier(BlockDriverState *bs, 1089 void (*attached_aio_context)(AioContext *new_context, void *opaque), 1090 void (*detach_aio_context)(void *opaque), void *opaque); 1091 1092 /** 1093 * bdrv_remove_aio_context_notifier: 1094 * 1095 * Unsubscribe of change notifications regarding the BDS's AioContext. The 1096 * parameters given here have to be the same as those given to 1097 * bdrv_add_aio_context_notifier(). 1098 */ 1099 void bdrv_remove_aio_context_notifier(BlockDriverState *bs, 1100 void (*aio_context_attached)(AioContext *, 1101 void *), 1102 void (*aio_context_detached)(void *), 1103 void *opaque); 1104 1105 /** 1106 * bdrv_wakeup: 1107 * @bs: The BlockDriverState for which an I/O operation has been completed. 1108 * 1109 * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During 1110 * synchronous I/O on a BlockDriverState that is attached to another 1111 * I/O thread, the main thread lets the I/O thread's event loop run, 1112 * waiting for the I/O operation to complete. A bdrv_wakeup will wake 1113 * up the main thread if necessary. 1114 * 1115 * Manual calls to bdrv_wakeup are rarely necessary, because 1116 * bdrv_dec_in_flight already calls it. 1117 */ 1118 void bdrv_wakeup(BlockDriverState *bs); 1119 1120 #ifdef _WIN32 1121 int is_windows_drive(const char *filename); 1122 #endif 1123 1124 /** 1125 * stream_start: 1126 * @job_id: The id of the newly-created job, or %NULL to use the 1127 * device name of @bs. 1128 * @bs: Block device to operate on. 1129 * @base: Block device that will become the new base, or %NULL to 1130 * flatten the whole backing file chain onto @bs. 1131 * @backing_file_str: The file name that will be written to @bs as the 1132 * the new backing file if the job completes. Ignored if @base is %NULL. 1133 * @creation_flags: Flags that control the behavior of the Job lifetime. 1134 * See @BlockJobCreateFlags 1135 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 1136 * @on_error: The action to take upon error. 1137 * @errp: Error object. 1138 * 1139 * Start a streaming operation on @bs. Clusters that are unallocated 1140 * in @bs, but allocated in any image between @base and @bs (both 1141 * exclusive) will be written to @bs. At the end of a successful 1142 * streaming job, the backing file of @bs will be changed to 1143 * @backing_file_str in the written image and to @base in the live 1144 * BlockDriverState. 1145 */ 1146 void stream_start(const char *job_id, BlockDriverState *bs, 1147 BlockDriverState *base, const char *backing_file_str, 1148 int creation_flags, int64_t speed, 1149 BlockdevOnError on_error, Error **errp); 1150 1151 /** 1152 * commit_start: 1153 * @job_id: The id of the newly-created job, or %NULL to use the 1154 * device name of @bs. 1155 * @bs: Active block device. 1156 * @top: Top block device to be committed. 1157 * @base: Block device that will be written into, and become the new top. 1158 * @creation_flags: Flags that control the behavior of the Job lifetime. 1159 * See @BlockJobCreateFlags 1160 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 1161 * @on_error: The action to take upon error. 1162 * @backing_file_str: String to use as the backing file in @top's overlay 1163 * @filter_node_name: The node name that should be assigned to the filter 1164 * driver that the commit job inserts into the graph above @top. NULL means 1165 * that a node name should be autogenerated. 1166 * @errp: Error object. 1167 * 1168 */ 1169 void commit_start(const char *job_id, BlockDriverState *bs, 1170 BlockDriverState *base, BlockDriverState *top, 1171 int creation_flags, int64_t speed, 1172 BlockdevOnError on_error, const char *backing_file_str, 1173 const char *filter_node_name, Error **errp); 1174 /** 1175 * commit_active_start: 1176 * @job_id: The id of the newly-created job, or %NULL to use the 1177 * device name of @bs. 1178 * @bs: Active block device to be committed. 1179 * @base: Block device that will be written into, and become the new top. 1180 * @creation_flags: Flags that control the behavior of the Job lifetime. 1181 * See @BlockJobCreateFlags 1182 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 1183 * @on_error: The action to take upon error. 1184 * @filter_node_name: The node name that should be assigned to the filter 1185 * driver that the commit job inserts into the graph above @bs. NULL means that 1186 * a node name should be autogenerated. 1187 * @cb: Completion function for the job. 1188 * @opaque: Opaque pointer value passed to @cb. 1189 * @auto_complete: Auto complete the job. 1190 * @errp: Error object. 1191 * 1192 */ 1193 BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs, 1194 BlockDriverState *base, int creation_flags, 1195 int64_t speed, BlockdevOnError on_error, 1196 const char *filter_node_name, 1197 BlockCompletionFunc *cb, void *opaque, 1198 bool auto_complete, Error **errp); 1199 /* 1200 * mirror_start: 1201 * @job_id: The id of the newly-created job, or %NULL to use the 1202 * device name of @bs. 1203 * @bs: Block device to operate on. 1204 * @target: Block device to write to. 1205 * @replaces: Block graph node name to replace once the mirror is done. Can 1206 * only be used when full mirroring is selected. 1207 * @creation_flags: Flags that control the behavior of the Job lifetime. 1208 * See @BlockJobCreateFlags 1209 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 1210 * @granularity: The chosen granularity for the dirty bitmap. 1211 * @buf_size: The amount of data that can be in flight at one time. 1212 * @mode: Whether to collapse all images in the chain to the target. 1213 * @backing_mode: How to establish the target's backing chain after completion. 1214 * @zero_target: Whether the target should be explicitly zero-initialized 1215 * @on_source_error: The action to take upon error reading from the source. 1216 * @on_target_error: The action to take upon error writing to the target. 1217 * @unmap: Whether to unmap target where source sectors only contain zeroes. 1218 * @filter_node_name: The node name that should be assigned to the filter 1219 * driver that the mirror job inserts into the graph above @bs. NULL means that 1220 * a node name should be autogenerated. 1221 * @copy_mode: When to trigger writes to the target. 1222 * @errp: Error object. 1223 * 1224 * Start a mirroring operation on @bs. Clusters that are allocated 1225 * in @bs will be written to @target until the job is cancelled or 1226 * manually completed. At the end of a successful mirroring job, 1227 * @bs will be switched to read from @target. 1228 */ 1229 void mirror_start(const char *job_id, BlockDriverState *bs, 1230 BlockDriverState *target, const char *replaces, 1231 int creation_flags, int64_t speed, 1232 uint32_t granularity, int64_t buf_size, 1233 MirrorSyncMode mode, BlockMirrorBackingMode backing_mode, 1234 bool zero_target, 1235 BlockdevOnError on_source_error, 1236 BlockdevOnError on_target_error, 1237 bool unmap, const char *filter_node_name, 1238 MirrorCopyMode copy_mode, Error **errp); 1239 1240 /* 1241 * backup_job_create: 1242 * @job_id: The id of the newly-created job, or %NULL to use the 1243 * device name of @bs. 1244 * @bs: Block device to operate on. 1245 * @target: Block device to write to. 1246 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 1247 * @sync_mode: What parts of the disk image should be copied to the destination. 1248 * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental' 1249 * @bitmap_mode: The bitmap synchronization policy to use. 1250 * @on_source_error: The action to take upon error reading from the source. 1251 * @on_target_error: The action to take upon error writing to the target. 1252 * @creation_flags: Flags that control the behavior of the Job lifetime. 1253 * See @BlockJobCreateFlags 1254 * @cb: Completion function for the job. 1255 * @opaque: Opaque pointer value passed to @cb. 1256 * @txn: Transaction that this job is part of (may be NULL). 1257 * 1258 * Create a backup operation on @bs. Clusters in @bs are written to @target 1259 * until the job is cancelled or manually completed. 1260 */ 1261 BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, 1262 BlockDriverState *target, int64_t speed, 1263 MirrorSyncMode sync_mode, 1264 BdrvDirtyBitmap *sync_bitmap, 1265 BitmapSyncMode bitmap_mode, 1266 bool compress, 1267 const char *filter_node_name, 1268 BlockdevOnError on_source_error, 1269 BlockdevOnError on_target_error, 1270 int creation_flags, 1271 BlockCompletionFunc *cb, void *opaque, 1272 JobTxn *txn, Error **errp); 1273 1274 BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, 1275 const char *child_name, 1276 const BdrvChildClass *child_class, 1277 BdrvChildRole child_role, 1278 AioContext *ctx, 1279 uint64_t perm, uint64_t shared_perm, 1280 void *opaque, Error **errp); 1281 void bdrv_root_unref_child(BdrvChild *child); 1282 1283 void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, 1284 uint64_t *shared_perm); 1285 1286 /** 1287 * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use 1288 * bdrv_child_refresh_perms() instead and make the parent's 1289 * .bdrv_child_perm() implementation return the correct values. 1290 */ 1291 int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, 1292 Error **errp); 1293 1294 /** 1295 * Calls bs->drv->bdrv_child_perm() and updates the child's permission 1296 * masks with the result. 1297 * Drivers should invoke this function whenever an event occurs that 1298 * makes their .bdrv_child_perm() implementation return different 1299 * values than before, but which will not result in the block layer 1300 * automatically refreshing the permissions. 1301 */ 1302 int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp); 1303 1304 bool bdrv_recurse_can_replace(BlockDriverState *bs, 1305 BlockDriverState *to_replace); 1306 1307 /* 1308 * Default implementation for BlockDriver.bdrv_child_perm() that can 1309 * be used by block filters and image formats, as long as they use the 1310 * child_of_bds child class and set an appropriate BdrvChildRole. 1311 */ 1312 void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c, 1313 BdrvChildRole role, BlockReopenQueue *reopen_queue, 1314 uint64_t perm, uint64_t shared, 1315 uint64_t *nperm, uint64_t *nshared); 1316 1317 const char *bdrv_get_parent_name(const BlockDriverState *bs); 1318 void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp); 1319 bool blk_dev_has_removable_media(BlockBackend *blk); 1320 bool blk_dev_has_tray(BlockBackend *blk); 1321 void blk_dev_eject_request(BlockBackend *blk, bool force); 1322 bool blk_dev_is_tray_open(BlockBackend *blk); 1323 bool blk_dev_is_medium_locked(BlockBackend *blk); 1324 1325 void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes); 1326 1327 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out); 1328 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup); 1329 bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest, 1330 const BdrvDirtyBitmap *src, 1331 HBitmap **backup, bool lock); 1332 1333 void bdrv_inc_in_flight(BlockDriverState *bs); 1334 void bdrv_dec_in_flight(BlockDriverState *bs); 1335 1336 void blockdev_close_all_bdrv_states(void); 1337 1338 int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset, 1339 BdrvChild *dst, uint64_t dst_offset, 1340 uint64_t bytes, 1341 BdrvRequestFlags read_flags, 1342 BdrvRequestFlags write_flags); 1343 int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset, 1344 BdrvChild *dst, uint64_t dst_offset, 1345 uint64_t bytes, 1346 BdrvRequestFlags read_flags, 1347 BdrvRequestFlags write_flags); 1348 1349 int refresh_total_sectors(BlockDriverState *bs, int64_t hint); 1350 1351 void bdrv_set_monitor_owned(BlockDriverState *bs); 1352 BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp); 1353 1354 /** 1355 * Simple implementation of bdrv_co_create_opts for protocol drivers 1356 * which only support creation via opening a file 1357 * (usually existing raw storage device) 1358 */ 1359 int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv, 1360 const char *filename, 1361 QemuOpts *opts, 1362 Error **errp); 1363 extern QemuOptsList bdrv_create_opts_simple; 1364 1365 BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node, 1366 const char *name, 1367 BlockDriverState **pbs, 1368 Error **errp); 1369 BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target, 1370 BlockDirtyBitmapMergeSourceList *bms, 1371 HBitmap **backup, Error **errp); 1372 BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name, 1373 bool release, 1374 BlockDriverState **bitmap_bs, 1375 Error **errp); 1376 1377 BdrvChild *bdrv_cow_child(BlockDriverState *bs); 1378 BdrvChild *bdrv_filter_child(BlockDriverState *bs); 1379 BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs); 1380 BdrvChild *bdrv_primary_child(BlockDriverState *bs); 1381 BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs); 1382 BlockDriverState *bdrv_skip_filters(BlockDriverState *bs); 1383 BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs); 1384 1385 static inline BlockDriverState *child_bs(BdrvChild *child) 1386 { 1387 return child ? child->bs : NULL; 1388 } 1389 1390 static inline BlockDriverState *bdrv_cow_bs(BlockDriverState *bs) 1391 { 1392 return child_bs(bdrv_cow_child(bs)); 1393 } 1394 1395 static inline BlockDriverState *bdrv_filter_bs(BlockDriverState *bs) 1396 { 1397 return child_bs(bdrv_filter_child(bs)); 1398 } 1399 1400 static inline BlockDriverState *bdrv_filter_or_cow_bs(BlockDriverState *bs) 1401 { 1402 return child_bs(bdrv_filter_or_cow_child(bs)); 1403 } 1404 1405 static inline BlockDriverState *bdrv_primary_bs(BlockDriverState *bs) 1406 { 1407 return child_bs(bdrv_primary_child(bs)); 1408 } 1409 1410 #endif /* BLOCK_INT_H */ 1411