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/block.h" 28 #include "qemu/option.h" 29 #include "qemu/queue.h" 30 #include "block/coroutine.h" 31 #include "qemu/timer.h" 32 #include "qapi-types.h" 33 #include "qapi/qmp/qerror.h" 34 #include "monitor/monitor.h" 35 #include "qemu/hbitmap.h" 36 #include "block/snapshot.h" 37 #include "qemu/main-loop.h" 38 #include "qemu/throttle.h" 39 40 #define BLOCK_FLAG_ENCRYPT 1 41 #define BLOCK_FLAG_COMPAT6 4 42 #define BLOCK_FLAG_LAZY_REFCOUNTS 8 43 44 #define BLOCK_OPT_SIZE "size" 45 #define BLOCK_OPT_ENCRYPT "encryption" 46 #define BLOCK_OPT_COMPAT6 "compat6" 47 #define BLOCK_OPT_BACKING_FILE "backing_file" 48 #define BLOCK_OPT_BACKING_FMT "backing_fmt" 49 #define BLOCK_OPT_CLUSTER_SIZE "cluster_size" 50 #define BLOCK_OPT_TABLE_SIZE "table_size" 51 #define BLOCK_OPT_PREALLOC "preallocation" 52 #define BLOCK_OPT_SUBFMT "subformat" 53 #define BLOCK_OPT_COMPAT_LEVEL "compat" 54 #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" 55 #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" 56 #define BLOCK_OPT_REDUNDANCY "redundancy" 57 58 typedef struct BdrvTrackedRequest { 59 BlockDriverState *bs; 60 int64_t offset; 61 unsigned int bytes; 62 bool is_write; 63 64 bool serialising; 65 int64_t overlap_offset; 66 unsigned int overlap_bytes; 67 68 QLIST_ENTRY(BdrvTrackedRequest) list; 69 Coroutine *co; /* owner, used for deadlock detection */ 70 CoQueue wait_queue; /* coroutines blocked on this request */ 71 72 struct BdrvTrackedRequest *waiting_for; 73 } BdrvTrackedRequest; 74 75 struct BlockDriver { 76 const char *format_name; 77 int instance_size; 78 79 /* set to true if the BlockDriver is a block filter */ 80 bool is_filter; 81 /* for snapshots block filter like Quorum can implement the 82 * following recursive callback. 83 * It's purpose is to recurse on the filter children while calling 84 * bdrv_recurse_is_first_non_filter on them. 85 * For a sample implementation look in the future Quorum block filter. 86 */ 87 bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs, 88 BlockDriverState *candidate); 89 90 int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename); 91 int (*bdrv_probe_device)(const char *filename); 92 93 /* Any driver implementing this callback is expected to be able to handle 94 * NULL file names in its .bdrv_open() implementation */ 95 void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp); 96 /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have 97 * this field set to true, except ones that are defined only by their 98 * child's bs. 99 * An example of the last type will be the quorum block driver. 100 */ 101 bool bdrv_needs_filename; 102 103 /* For handling image reopen for split or non-split files */ 104 int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state, 105 BlockReopenQueue *queue, Error **errp); 106 void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state); 107 void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state); 108 109 int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags, 110 Error **errp); 111 int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags, 112 Error **errp); 113 int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num, 114 uint8_t *buf, int nb_sectors); 115 int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num, 116 const uint8_t *buf, int nb_sectors); 117 void (*bdrv_close)(BlockDriverState *bs); 118 void (*bdrv_rebind)(BlockDriverState *bs); 119 int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp); 120 int (*bdrv_set_key)(BlockDriverState *bs, const char *key); 121 int (*bdrv_make_empty)(BlockDriverState *bs); 122 /* aio */ 123 BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, 124 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 125 BlockDriverCompletionFunc *cb, void *opaque); 126 BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs, 127 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 128 BlockDriverCompletionFunc *cb, void *opaque); 129 BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, 130 BlockDriverCompletionFunc *cb, void *opaque); 131 BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs, 132 int64_t sector_num, int nb_sectors, 133 BlockDriverCompletionFunc *cb, void *opaque); 134 135 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, 136 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 137 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, 138 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 139 /* 140 * Efficiently zero a region of the disk image. Typically an image format 141 * would use a compact metadata representation to implement this. This 142 * function pointer may be NULL and .bdrv_co_writev() will be called 143 * instead. 144 */ 145 int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs, 146 int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); 147 int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs, 148 int64_t sector_num, int nb_sectors); 149 int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs, 150 int64_t sector_num, int nb_sectors, int *pnum); 151 152 /* 153 * Invalidate any cached meta-data. 154 */ 155 void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp); 156 157 /* 158 * Flushes all data that was already written to the OS all the way down to 159 * the disk (for example raw-posix calls fsync()). 160 */ 161 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs); 162 163 /* 164 * Flushes all internal caches to the OS. The data may still sit in a 165 * writeback cache of the host OS, but it will survive a crash of the qemu 166 * process. 167 */ 168 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs); 169 170 const char *protocol_name; 171 int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset); 172 173 int64_t (*bdrv_getlength)(BlockDriverState *bs); 174 bool has_variable_length; 175 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); 176 177 int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num, 178 const uint8_t *buf, int nb_sectors); 179 180 int (*bdrv_snapshot_create)(BlockDriverState *bs, 181 QEMUSnapshotInfo *sn_info); 182 int (*bdrv_snapshot_goto)(BlockDriverState *bs, 183 const char *snapshot_id); 184 int (*bdrv_snapshot_delete)(BlockDriverState *bs, 185 const char *snapshot_id, 186 const char *name, 187 Error **errp); 188 int (*bdrv_snapshot_list)(BlockDriverState *bs, 189 QEMUSnapshotInfo **psn_info); 190 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, 191 const char *snapshot_id, 192 const char *name, 193 Error **errp); 194 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); 195 ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs); 196 197 int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov, 198 int64_t pos); 199 int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf, 200 int64_t pos, int size); 201 202 int (*bdrv_change_backing_file)(BlockDriverState *bs, 203 const char *backing_file, const char *backing_fmt); 204 205 /* removable device specific */ 206 int (*bdrv_is_inserted)(BlockDriverState *bs); 207 int (*bdrv_media_changed)(BlockDriverState *bs); 208 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); 209 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); 210 211 /* to control generic scsi devices */ 212 int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); 213 BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, 214 unsigned long int req, void *buf, 215 BlockDriverCompletionFunc *cb, void *opaque); 216 217 /* List of options for creating images, terminated by name == NULL */ 218 QemuOptsList *create_opts; 219 220 /* 221 * Returns 0 for completed check, -errno for internal errors. 222 * The check results are stored in result. 223 */ 224 int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result, 225 BdrvCheckMode fix); 226 227 int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts); 228 229 void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event); 230 231 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */ 232 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event, 233 const char *tag); 234 int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs, 235 const char *tag); 236 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag); 237 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag); 238 239 int (*bdrv_refresh_limits)(BlockDriverState *bs); 240 241 /* 242 * Returns 1 if newly created images are guaranteed to contain only 243 * zeros, 0 otherwise. 244 */ 245 int (*bdrv_has_zero_init)(BlockDriverState *bs); 246 247 /* Remove fd handlers, timers, and other event loop callbacks so the event 248 * loop is no longer in use. Called with no in-flight requests and in 249 * depth-first traversal order with parents before child nodes. 250 */ 251 void (*bdrv_detach_aio_context)(BlockDriverState *bs); 252 253 /* Add fd handlers, timers, and other event loop callbacks so I/O requests 254 * can be processed again. Called with no in-flight requests and in 255 * depth-first traversal order with child nodes before parent nodes. 256 */ 257 void (*bdrv_attach_aio_context)(BlockDriverState *bs, 258 AioContext *new_context); 259 260 QLIST_ENTRY(BlockDriver) list; 261 }; 262 263 typedef struct BlockLimits { 264 /* maximum number of sectors that can be discarded at once */ 265 int max_discard; 266 267 /* optimal alignment for discard requests in sectors */ 268 int64_t discard_alignment; 269 270 /* maximum number of sectors that can zeroized at once */ 271 int max_write_zeroes; 272 273 /* optimal alignment for write zeroes requests in sectors */ 274 int64_t write_zeroes_alignment; 275 276 /* optimal transfer length in sectors */ 277 int opt_transfer_length; 278 279 /* memory alignment so that no bounce buffer is needed */ 280 size_t opt_mem_alignment; 281 } BlockLimits; 282 283 typedef struct BdrvOpBlocker BdrvOpBlocker; 284 285 /* 286 * Note: the function bdrv_append() copies and swaps contents of 287 * BlockDriverStates, so if you add new fields to this struct, please 288 * inspect bdrv_append() to determine if the new fields need to be 289 * copied as well. 290 */ 291 struct BlockDriverState { 292 int64_t total_sectors; /* if we are reading a disk image, give its 293 size in sectors */ 294 int read_only; /* if true, the media is read only */ 295 int open_flags; /* flags used to open the file, re-used for re-open */ 296 int encrypted; /* if true, the media is encrypted */ 297 int valid_key; /* if true, a valid encryption key has been set */ 298 int sg; /* if true, the device is a /dev/sg* */ 299 int copy_on_read; /* if true, copy read backing sectors into image 300 note this is a reference count */ 301 302 BlockDriver *drv; /* NULL means no media */ 303 void *opaque; 304 305 void *dev; /* attached device model, if any */ 306 /* TODO change to DeviceState when all users are qdevified */ 307 const BlockDevOps *dev_ops; 308 void *dev_opaque; 309 310 AioContext *aio_context; /* event loop used for fd handlers, timers, etc */ 311 312 char filename[1024]; 313 char backing_file[1024]; /* if non zero, the image is a diff of 314 this file image */ 315 char backing_format[16]; /* if non-zero and backing_file exists */ 316 317 BlockDriverState *backing_hd; 318 BlockDriverState *file; 319 320 NotifierList close_notifiers; 321 322 /* Callback before write request is processed */ 323 NotifierWithReturnList before_write_notifiers; 324 325 /* number of in-flight serialising requests */ 326 unsigned int serialising_in_flight; 327 328 /* I/O throttling */ 329 ThrottleState throttle_state; 330 CoQueue throttled_reqs[2]; 331 bool io_limits_enabled; 332 333 /* I/O stats (display with "info blockstats"). */ 334 uint64_t nr_bytes[BDRV_MAX_IOTYPE]; 335 uint64_t nr_ops[BDRV_MAX_IOTYPE]; 336 uint64_t total_time_ns[BDRV_MAX_IOTYPE]; 337 uint64_t wr_highest_sector; 338 339 /* I/O Limits */ 340 BlockLimits bl; 341 342 /* Whether the disk can expand beyond total_sectors */ 343 int growable; 344 345 /* Whether produces zeros when read beyond eof */ 346 bool zero_beyond_eof; 347 348 /* Alignment requirement for offset/length of I/O requests */ 349 unsigned int request_alignment; 350 351 /* the block size for which the guest device expects atomicity */ 352 int guest_block_size; 353 354 /* do we need to tell the quest if we have a volatile write cache? */ 355 int enable_write_cache; 356 357 /* NOTE: the following infos are only hints for real hardware 358 drivers. They are not used by the block driver */ 359 BlockdevOnError on_read_error, on_write_error; 360 bool iostatus_enabled; 361 BlockDeviceIoStatus iostatus; 362 363 /* the following member gives a name to every node on the bs graph. */ 364 char node_name[32]; 365 /* element of the list of named nodes building the graph */ 366 QTAILQ_ENTRY(BlockDriverState) node_list; 367 /* Device name is the name associated with the "drive" the guest sees */ 368 char device_name[32]; 369 /* element of the list of "drives" the guest sees */ 370 QTAILQ_ENTRY(BlockDriverState) device_list; 371 QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps; 372 int refcnt; 373 374 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; 375 376 /* operation blockers */ 377 QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX]; 378 379 /* long-running background operation */ 380 BlockJob *job; 381 382 QDict *options; 383 BlockdevDetectZeroesOptions detect_zeroes; 384 385 /* The error object in use for blocking operations on backing_hd */ 386 Error *backing_blocker; 387 }; 388 389 int get_tmp_filename(char *filename, int size); 390 391 void bdrv_set_io_limits(BlockDriverState *bs, 392 ThrottleConfig *cfg); 393 394 395 /** 396 * bdrv_add_before_write_notifier: 397 * 398 * Register a callback that is invoked before write requests are processed but 399 * after any throttling or waiting for overlapping requests. 400 */ 401 void bdrv_add_before_write_notifier(BlockDriverState *bs, 402 NotifierWithReturn *notifier); 403 404 /** 405 * bdrv_detach_aio_context: 406 * 407 * May be called from .bdrv_detach_aio_context() to detach children from the 408 * current #AioContext. This is only needed by block drivers that manage their 409 * own children. Both ->file and ->backing_hd are automatically handled and 410 * block drivers should not call this function on them explicitly. 411 */ 412 void bdrv_detach_aio_context(BlockDriverState *bs); 413 414 /** 415 * bdrv_attach_aio_context: 416 * 417 * May be called from .bdrv_attach_aio_context() to attach children to the new 418 * #AioContext. This is only needed by block drivers that manage their own 419 * children. Both ->file and ->backing_hd are automatically handled and block 420 * drivers should not call this function on them explicitly. 421 */ 422 void bdrv_attach_aio_context(BlockDriverState *bs, 423 AioContext *new_context); 424 425 #ifdef _WIN32 426 int is_windows_drive(const char *filename); 427 #endif 428 429 /** 430 * stream_start: 431 * @bs: Block device to operate on. 432 * @base: Block device that will become the new base, or %NULL to 433 * flatten the whole backing file chain onto @bs. 434 * @base_id: The file name that will be written to @bs as the new 435 * backing file if the job completes. Ignored if @base is %NULL. 436 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 437 * @on_error: The action to take upon error. 438 * @cb: Completion function for the job. 439 * @opaque: Opaque pointer value passed to @cb. 440 * @errp: Error object. 441 * 442 * Start a streaming operation on @bs. Clusters that are unallocated 443 * in @bs, but allocated in any image between @base and @bs (both 444 * exclusive) will be written to @bs. At the end of a successful 445 * streaming job, the backing file of @bs will be changed to 446 * @base_id in the written image and to @base in the live BlockDriverState. 447 */ 448 void stream_start(BlockDriverState *bs, BlockDriverState *base, 449 const char *base_id, int64_t speed, BlockdevOnError on_error, 450 BlockDriverCompletionFunc *cb, 451 void *opaque, Error **errp); 452 453 /** 454 * commit_start: 455 * @bs: Active block device. 456 * @top: Top block device to be committed. 457 * @base: Block device that will be written into, and become the new top. 458 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 459 * @on_error: The action to take upon error. 460 * @cb: Completion function for the job. 461 * @opaque: Opaque pointer value passed to @cb. 462 * @errp: Error object. 463 * 464 */ 465 void commit_start(BlockDriverState *bs, BlockDriverState *base, 466 BlockDriverState *top, int64_t speed, 467 BlockdevOnError on_error, BlockDriverCompletionFunc *cb, 468 void *opaque, Error **errp); 469 /** 470 * commit_active_start: 471 * @bs: Active block device to be committed. 472 * @base: Block device that will be written into, and become the new top. 473 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 474 * @on_error: The action to take upon error. 475 * @cb: Completion function for the job. 476 * @opaque: Opaque pointer value passed to @cb. 477 * @errp: Error object. 478 * 479 */ 480 void commit_active_start(BlockDriverState *bs, BlockDriverState *base, 481 int64_t speed, 482 BlockdevOnError on_error, 483 BlockDriverCompletionFunc *cb, 484 void *opaque, Error **errp); 485 /* 486 * mirror_start: 487 * @bs: Block device to operate on. 488 * @target: Block device to write to. 489 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 490 * @granularity: The chosen granularity for the dirty bitmap. 491 * @buf_size: The amount of data that can be in flight at one time. 492 * @mode: Whether to collapse all images in the chain to the target. 493 * @on_source_error: The action to take upon error reading from the source. 494 * @on_target_error: The action to take upon error writing to the target. 495 * @cb: Completion function for the job. 496 * @opaque: Opaque pointer value passed to @cb. 497 * @errp: Error object. 498 * 499 * Start a mirroring operation on @bs. Clusters that are allocated 500 * in @bs will be written to @bs until the job is cancelled or 501 * manually completed. At the end of a successful mirroring job, 502 * @bs will be switched to read from @target. 503 */ 504 void mirror_start(BlockDriverState *bs, BlockDriverState *target, 505 int64_t speed, int64_t granularity, int64_t buf_size, 506 MirrorSyncMode mode, BlockdevOnError on_source_error, 507 BlockdevOnError on_target_error, 508 BlockDriverCompletionFunc *cb, 509 void *opaque, Error **errp); 510 511 /* 512 * backup_start: 513 * @bs: Block device to operate on. 514 * @target: Block device to write to. 515 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 516 * @sync_mode: What parts of the disk image should be copied to the destination. 517 * @on_source_error: The action to take upon error reading from the source. 518 * @on_target_error: The action to take upon error writing to the target. 519 * @cb: Completion function for the job. 520 * @opaque: Opaque pointer value passed to @cb. 521 * 522 * Start a backup operation on @bs. Clusters in @bs are written to @target 523 * until the job is cancelled or manually completed. 524 */ 525 void backup_start(BlockDriverState *bs, BlockDriverState *target, 526 int64_t speed, MirrorSyncMode sync_mode, 527 BlockdevOnError on_source_error, 528 BlockdevOnError on_target_error, 529 BlockDriverCompletionFunc *cb, void *opaque, 530 Error **errp); 531 532 #endif /* BLOCK_INT_H */ 533