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