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