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