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, QEMUOptionParameter *options, 120 Error **errp); 121 int (*bdrv_set_key)(BlockDriverState *bs, const char *key); 122 int (*bdrv_make_empty)(BlockDriverState *bs); 123 /* aio */ 124 BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, 125 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 126 BlockDriverCompletionFunc *cb, void *opaque); 127 BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs, 128 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 129 BlockDriverCompletionFunc *cb, void *opaque); 130 BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, 131 BlockDriverCompletionFunc *cb, void *opaque); 132 BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs, 133 int64_t sector_num, int nb_sectors, 134 BlockDriverCompletionFunc *cb, void *opaque); 135 136 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, 137 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 138 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, 139 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 140 /* 141 * Efficiently zero a region of the disk image. Typically an image format 142 * would use a compact metadata representation to implement this. This 143 * function pointer may be NULL and .bdrv_co_writev() will be called 144 * instead. 145 */ 146 int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs, 147 int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); 148 int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs, 149 int64_t sector_num, int nb_sectors); 150 int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs, 151 int64_t sector_num, int nb_sectors, int *pnum); 152 153 /* 154 * Invalidate any cached meta-data. 155 */ 156 void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp); 157 158 /* 159 * Flushes all data that was already written to the OS all the way down to 160 * the disk (for example raw-posix calls fsync()). 161 */ 162 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs); 163 164 /* 165 * Flushes all internal caches to the OS. The data may still sit in a 166 * writeback cache of the host OS, but it will survive a crash of the qemu 167 * process. 168 */ 169 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs); 170 171 const char *protocol_name; 172 int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset); 173 174 int64_t (*bdrv_getlength)(BlockDriverState *bs); 175 bool has_variable_length; 176 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); 177 178 int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num, 179 const uint8_t *buf, int nb_sectors); 180 181 int (*bdrv_snapshot_create)(BlockDriverState *bs, 182 QEMUSnapshotInfo *sn_info); 183 int (*bdrv_snapshot_goto)(BlockDriverState *bs, 184 const char *snapshot_id); 185 int (*bdrv_snapshot_delete)(BlockDriverState *bs, 186 const char *snapshot_id, 187 const char *name, 188 Error **errp); 189 int (*bdrv_snapshot_list)(BlockDriverState *bs, 190 QEMUSnapshotInfo **psn_info); 191 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, 192 const char *snapshot_id, 193 const char *name, 194 Error **errp); 195 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); 196 ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs); 197 198 int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov, 199 int64_t pos); 200 int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf, 201 int64_t pos, int size); 202 203 int (*bdrv_change_backing_file)(BlockDriverState *bs, 204 const char *backing_file, const char *backing_fmt); 205 206 /* removable device specific */ 207 int (*bdrv_is_inserted)(BlockDriverState *bs); 208 int (*bdrv_media_changed)(BlockDriverState *bs); 209 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); 210 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); 211 212 /* to control generic scsi devices */ 213 int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); 214 BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, 215 unsigned long int req, void *buf, 216 BlockDriverCompletionFunc *cb, void *opaque); 217 218 /* List of options for creating images, terminated by name == NULL */ 219 QEMUOptionParameter *create_options; 220 221 222 /* 223 * Returns 0 for completed check, -errno for internal errors. 224 * The check results are stored in result. 225 */ 226 int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result, 227 BdrvCheckMode fix); 228 229 int (*bdrv_amend_options)(BlockDriverState *bs, 230 QEMUOptionParameter *options); 231 232 void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event); 233 234 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */ 235 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event, 236 const char *tag); 237 int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs, 238 const char *tag); 239 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag); 240 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag); 241 242 int (*bdrv_refresh_limits)(BlockDriverState *bs); 243 244 /* 245 * Returns 1 if newly created images are guaranteed to contain only 246 * zeros, 0 otherwise. 247 */ 248 int (*bdrv_has_zero_init)(BlockDriverState *bs); 249 250 QLIST_ENTRY(BlockDriver) list; 251 }; 252 253 typedef struct BlockLimits { 254 /* maximum number of sectors that can be discarded at once */ 255 int max_discard; 256 257 /* optimal alignment for discard requests in sectors */ 258 int64_t discard_alignment; 259 260 /* maximum number of sectors that can zeroized at once */ 261 int max_write_zeroes; 262 263 /* optimal alignment for write zeroes requests in sectors */ 264 int64_t write_zeroes_alignment; 265 266 /* optimal transfer length in sectors */ 267 int opt_transfer_length; 268 269 /* memory alignment so that no bounce buffer is needed */ 270 size_t opt_mem_alignment; 271 } BlockLimits; 272 273 /* 274 * Note: the function bdrv_append() copies and swaps contents of 275 * BlockDriverStates, so if you add new fields to this struct, please 276 * inspect bdrv_append() to determine if the new fields need to be 277 * copied as well. 278 */ 279 struct BlockDriverState { 280 int64_t total_sectors; /* if we are reading a disk image, give its 281 size in sectors */ 282 int read_only; /* if true, the media is read only */ 283 int open_flags; /* flags used to open the file, re-used for re-open */ 284 int encrypted; /* if true, the media is encrypted */ 285 int valid_key; /* if true, a valid encryption key has been set */ 286 int sg; /* if true, the device is a /dev/sg* */ 287 int copy_on_read; /* if true, copy read backing sectors into image 288 note this is a reference count */ 289 290 BlockDriver *drv; /* NULL means no media */ 291 void *opaque; 292 293 void *dev; /* attached device model, if any */ 294 /* TODO change to DeviceState when all users are qdevified */ 295 const BlockDevOps *dev_ops; 296 void *dev_opaque; 297 298 char filename[1024]; 299 char backing_file[1024]; /* if non zero, the image is a diff of 300 this file image */ 301 char backing_format[16]; /* if non-zero and backing_file exists */ 302 303 BlockDriverState *backing_hd; 304 BlockDriverState *file; 305 306 NotifierList close_notifiers; 307 308 /* Callback before write request is processed */ 309 NotifierWithReturnList before_write_notifiers; 310 311 /* number of in-flight serialising requests */ 312 unsigned int serialising_in_flight; 313 314 /* I/O throttling */ 315 ThrottleState throttle_state; 316 CoQueue throttled_reqs[2]; 317 bool io_limits_enabled; 318 319 /* I/O stats (display with "info blockstats"). */ 320 uint64_t nr_bytes[BDRV_MAX_IOTYPE]; 321 uint64_t nr_ops[BDRV_MAX_IOTYPE]; 322 uint64_t total_time_ns[BDRV_MAX_IOTYPE]; 323 uint64_t wr_highest_sector; 324 325 /* I/O Limits */ 326 BlockLimits bl; 327 328 /* Whether the disk can expand beyond total_sectors */ 329 int growable; 330 331 /* Whether produces zeros when read beyond eof */ 332 bool zero_beyond_eof; 333 334 /* Alignment requirement for offset/length of I/O requests */ 335 unsigned int request_alignment; 336 337 /* the block size for which the guest device expects atomicity */ 338 int guest_block_size; 339 340 /* do we need to tell the quest if we have a volatile write cache? */ 341 int enable_write_cache; 342 343 /* NOTE: the following infos are only hints for real hardware 344 drivers. They are not used by the block driver */ 345 BlockdevOnError on_read_error, on_write_error; 346 bool iostatus_enabled; 347 BlockDeviceIoStatus iostatus; 348 349 /* the following member gives a name to every node on the bs graph. */ 350 char node_name[32]; 351 /* element of the list of named nodes building the graph */ 352 QTAILQ_ENTRY(BlockDriverState) node_list; 353 /* Device name is the name associated with the "drive" the guest sees */ 354 char device_name[32]; 355 /* element of the list of "drives" the guest sees */ 356 QTAILQ_ENTRY(BlockDriverState) device_list; 357 QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps; 358 int refcnt; 359 int in_use; /* users other than guest access, eg. block migration */ 360 361 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; 362 363 /* long-running background operation */ 364 BlockJob *job; 365 366 QDict *options; 367 }; 368 369 int get_tmp_filename(char *filename, int size); 370 371 void bdrv_set_io_limits(BlockDriverState *bs, 372 ThrottleConfig *cfg); 373 374 375 /** 376 * bdrv_add_before_write_notifier: 377 * 378 * Register a callback that is invoked before write requests are processed but 379 * after any throttling or waiting for overlapping requests. 380 */ 381 void bdrv_add_before_write_notifier(BlockDriverState *bs, 382 NotifierWithReturn *notifier); 383 384 /** 385 * bdrv_get_aio_context: 386 * 387 * Returns: the currently bound #AioContext 388 */ 389 AioContext *bdrv_get_aio_context(BlockDriverState *bs); 390 391 #ifdef _WIN32 392 int is_windows_drive(const char *filename); 393 #endif 394 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, 395 enum MonitorEvent ev, 396 BlockErrorAction action, bool is_read); 397 398 /** 399 * stream_start: 400 * @bs: Block device to operate on. 401 * @base: Block device that will become the new base, or %NULL to 402 * flatten the whole backing file chain onto @bs. 403 * @base_id: The file name that will be written to @bs as the new 404 * backing file if the job completes. Ignored if @base is %NULL. 405 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 406 * @on_error: The action to take upon error. 407 * @cb: Completion function for the job. 408 * @opaque: Opaque pointer value passed to @cb. 409 * @errp: Error object. 410 * 411 * Start a streaming operation on @bs. Clusters that are unallocated 412 * in @bs, but allocated in any image between @base and @bs (both 413 * exclusive) will be written to @bs. At the end of a successful 414 * streaming job, the backing file of @bs will be changed to 415 * @base_id in the written image and to @base in the live BlockDriverState. 416 */ 417 void stream_start(BlockDriverState *bs, BlockDriverState *base, 418 const char *base_id, int64_t speed, BlockdevOnError on_error, 419 BlockDriverCompletionFunc *cb, 420 void *opaque, Error **errp); 421 422 /** 423 * commit_start: 424 * @bs: Active block device. 425 * @top: Top block device to be committed. 426 * @base: Block device that will be written into, and become the new top. 427 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 428 * @on_error: The action to take upon error. 429 * @cb: Completion function for the job. 430 * @opaque: Opaque pointer value passed to @cb. 431 * @errp: Error object. 432 * 433 */ 434 void commit_start(BlockDriverState *bs, BlockDriverState *base, 435 BlockDriverState *top, int64_t speed, 436 BlockdevOnError on_error, BlockDriverCompletionFunc *cb, 437 void *opaque, Error **errp); 438 /** 439 * commit_active_start: 440 * @bs: Active block device to be committed. 441 * @base: Block device that will be written into, and become the new top. 442 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 443 * @on_error: The action to take upon error. 444 * @cb: Completion function for the job. 445 * @opaque: Opaque pointer value passed to @cb. 446 * @errp: Error object. 447 * 448 */ 449 void commit_active_start(BlockDriverState *bs, BlockDriverState *base, 450 int64_t speed, 451 BlockdevOnError on_error, 452 BlockDriverCompletionFunc *cb, 453 void *opaque, Error **errp); 454 /* 455 * mirror_start: 456 * @bs: Block device to operate on. 457 * @target: Block device to write to. 458 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 459 * @granularity: The chosen granularity for the dirty bitmap. 460 * @buf_size: The amount of data that can be in flight at one time. 461 * @mode: Whether to collapse all images in the chain to the target. 462 * @on_source_error: The action to take upon error reading from the source. 463 * @on_target_error: The action to take upon error writing to the target. 464 * @cb: Completion function for the job. 465 * @opaque: Opaque pointer value passed to @cb. 466 * @errp: Error object. 467 * 468 * Start a mirroring operation on @bs. Clusters that are allocated 469 * in @bs will be written to @bs until the job is cancelled or 470 * manually completed. At the end of a successful mirroring job, 471 * @bs will be switched to read from @target. 472 */ 473 void mirror_start(BlockDriverState *bs, BlockDriverState *target, 474 int64_t speed, int64_t granularity, int64_t buf_size, 475 MirrorSyncMode mode, BlockdevOnError on_source_error, 476 BlockdevOnError on_target_error, 477 BlockDriverCompletionFunc *cb, 478 void *opaque, Error **errp); 479 480 /* 481 * backup_start: 482 * @bs: Block device to operate on. 483 * @target: Block device to write to. 484 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 485 * @sync_mode: What parts of the disk image should be copied to the destination. 486 * @on_source_error: The action to take upon error reading from the source. 487 * @on_target_error: The action to take upon error writing to the target. 488 * @cb: Completion function for the job. 489 * @opaque: Opaque pointer value passed to @cb. 490 * 491 * Start a backup operation on @bs. Clusters in @bs are written to @target 492 * until the job is cancelled or manually completed. 493 */ 494 void backup_start(BlockDriverState *bs, BlockDriverState *target, 495 int64_t speed, MirrorSyncMode sync_mode, 496 BlockdevOnError on_source_error, 497 BlockdevOnError on_target_error, 498 BlockDriverCompletionFunc *cb, void *opaque, 499 Error **errp); 500 501 #endif /* BLOCK_INT_H */ 502