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