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