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