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