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 57 typedef struct BdrvTrackedRequest { 58 BlockDriverState *bs; 59 int64_t sector_num; 60 int nb_sectors; 61 bool is_write; 62 QLIST_ENTRY(BdrvTrackedRequest) list; 63 Coroutine *co; /* owner, used for deadlock detection */ 64 CoQueue wait_queue; /* coroutines blocked on this request */ 65 } BdrvTrackedRequest; 66 67 struct BlockDriver { 68 const char *format_name; 69 int instance_size; 70 71 /* if not defined external snapshots are allowed 72 * future block filters will query their children to build the response 73 */ 74 ExtSnapshotPerm (*bdrv_check_ext_snapshot)(BlockDriverState *bs); 75 76 int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename); 77 int (*bdrv_probe_device)(const char *filename); 78 79 /* Any driver implementing this callback is expected to be able to handle 80 * NULL file names in its .bdrv_open() implementation */ 81 void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp); 82 /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have 83 * this field set to true, except ones that are defined only by their 84 * child's bs. 85 * An example of the last type will be the quorum block driver. 86 */ 87 bool bdrv_needs_filename; 88 89 /* For handling image reopen for split or non-split files */ 90 int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state, 91 BlockReopenQueue *queue, Error **errp); 92 void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state); 93 void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state); 94 95 int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags, 96 Error **errp); 97 int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags, 98 Error **errp); 99 int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num, 100 uint8_t *buf, int nb_sectors); 101 int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num, 102 const uint8_t *buf, int nb_sectors); 103 void (*bdrv_close)(BlockDriverState *bs); 104 void (*bdrv_rebind)(BlockDriverState *bs); 105 int (*bdrv_create)(const char *filename, QEMUOptionParameter *options, 106 Error **errp); 107 int (*bdrv_set_key)(BlockDriverState *bs, const char *key); 108 int (*bdrv_make_empty)(BlockDriverState *bs); 109 /* aio */ 110 BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, 111 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 112 BlockDriverCompletionFunc *cb, void *opaque); 113 BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs, 114 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 115 BlockDriverCompletionFunc *cb, void *opaque); 116 BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, 117 BlockDriverCompletionFunc *cb, void *opaque); 118 BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs, 119 int64_t sector_num, int nb_sectors, 120 BlockDriverCompletionFunc *cb, void *opaque); 121 122 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, 123 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 124 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, 125 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 126 /* 127 * Efficiently zero a region of the disk image. Typically an image format 128 * would use a compact metadata representation to implement this. This 129 * function pointer may be NULL and .bdrv_co_writev() will be called 130 * instead. 131 */ 132 int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs, 133 int64_t sector_num, int nb_sectors); 134 int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs, 135 int64_t sector_num, int nb_sectors); 136 int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs, 137 int64_t sector_num, int nb_sectors, int *pnum); 138 139 /* 140 * Invalidate any cached meta-data. 141 */ 142 void (*bdrv_invalidate_cache)(BlockDriverState *bs); 143 144 /* 145 * Flushes all data that was already written to the OS all the way down to 146 * the disk (for example raw-posix calls fsync()). 147 */ 148 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs); 149 150 /* 151 * Flushes all internal caches to the OS. The data may still sit in a 152 * writeback cache of the host OS, but it will survive a crash of the qemu 153 * process. 154 */ 155 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs); 156 157 const char *protocol_name; 158 int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset); 159 160 int64_t (*bdrv_getlength)(BlockDriverState *bs); 161 bool has_variable_length; 162 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); 163 164 int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num, 165 const uint8_t *buf, int nb_sectors); 166 167 int (*bdrv_snapshot_create)(BlockDriverState *bs, 168 QEMUSnapshotInfo *sn_info); 169 int (*bdrv_snapshot_goto)(BlockDriverState *bs, 170 const char *snapshot_id); 171 int (*bdrv_snapshot_delete)(BlockDriverState *bs, 172 const char *snapshot_id, 173 const char *name, 174 Error **errp); 175 int (*bdrv_snapshot_list)(BlockDriverState *bs, 176 QEMUSnapshotInfo **psn_info); 177 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, 178 const char *snapshot_name); 179 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); 180 ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs); 181 182 int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov, 183 int64_t pos); 184 int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf, 185 int64_t pos, int size); 186 187 int (*bdrv_change_backing_file)(BlockDriverState *bs, 188 const char *backing_file, const char *backing_fmt); 189 190 /* removable device specific */ 191 int (*bdrv_is_inserted)(BlockDriverState *bs); 192 int (*bdrv_media_changed)(BlockDriverState *bs); 193 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); 194 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); 195 196 /* to control generic scsi devices */ 197 int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); 198 BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, 199 unsigned long int req, void *buf, 200 BlockDriverCompletionFunc *cb, void *opaque); 201 202 /* List of options for creating images, terminated by name == NULL */ 203 QEMUOptionParameter *create_options; 204 205 206 /* 207 * Returns 0 for completed check, -errno for internal errors. 208 * The check results are stored in result. 209 */ 210 int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result, 211 BdrvCheckMode fix); 212 213 int (*bdrv_amend_options)(BlockDriverState *bs, 214 QEMUOptionParameter *options); 215 216 void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event); 217 218 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */ 219 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event, 220 const char *tag); 221 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag); 222 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag); 223 224 /* 225 * Returns 1 if newly created images are guaranteed to contain only 226 * zeros, 0 otherwise. 227 */ 228 int (*bdrv_has_zero_init)(BlockDriverState *bs); 229 230 QLIST_ENTRY(BlockDriver) list; 231 }; 232 233 /* 234 * Note: the function bdrv_append() copies and swaps contents of 235 * BlockDriverStates, so if you add new fields to this struct, please 236 * inspect bdrv_append() to determine if the new fields need to be 237 * copied as well. 238 */ 239 struct BlockDriverState { 240 int64_t total_sectors; /* if we are reading a disk image, give its 241 size in sectors */ 242 int read_only; /* if true, the media is read only */ 243 int open_flags; /* flags used to open the file, re-used for re-open */ 244 int encrypted; /* if true, the media is encrypted */ 245 int valid_key; /* if true, a valid encryption key has been set */ 246 int sg; /* if true, the device is a /dev/sg* */ 247 int copy_on_read; /* if true, copy read backing sectors into image 248 note this is a reference count */ 249 250 BlockDriver *drv; /* NULL means no media */ 251 void *opaque; 252 253 void *dev; /* attached device model, if any */ 254 /* TODO change to DeviceState when all users are qdevified */ 255 const BlockDevOps *dev_ops; 256 void *dev_opaque; 257 258 char filename[1024]; 259 char backing_file[1024]; /* if non zero, the image is a diff of 260 this file image */ 261 char backing_format[16]; /* if non-zero and backing_file exists */ 262 int is_temporary; 263 264 BlockDriverState *backing_hd; 265 BlockDriverState *file; 266 267 NotifierList close_notifiers; 268 269 /* Callback before write request is processed */ 270 NotifierWithReturnList before_write_notifiers; 271 272 /* number of in-flight copy-on-read requests */ 273 unsigned int copy_on_read_in_flight; 274 275 /* I/O throttling */ 276 ThrottleState throttle_state; 277 CoQueue throttled_reqs[2]; 278 bool io_limits_enabled; 279 280 /* I/O stats (display with "info blockstats"). */ 281 uint64_t nr_bytes[BDRV_MAX_IOTYPE]; 282 uint64_t nr_ops[BDRV_MAX_IOTYPE]; 283 uint64_t total_time_ns[BDRV_MAX_IOTYPE]; 284 uint64_t wr_highest_sector; 285 286 /* Whether the disk can expand beyond total_sectors */ 287 int growable; 288 289 /* Whether produces zeros when read beyond eof */ 290 bool zero_beyond_eof; 291 292 /* the memory alignment required for the buffers handled by this driver */ 293 int buffer_alignment; 294 295 /* do we need to tell the quest if we have a volatile write cache? */ 296 int enable_write_cache; 297 298 /* NOTE: the following infos are only hints for real hardware 299 drivers. They are not used by the block driver */ 300 BlockdevOnError on_read_error, on_write_error; 301 bool iostatus_enabled; 302 BlockDeviceIoStatus iostatus; 303 char device_name[32]; 304 HBitmap *dirty_bitmap; 305 int refcnt; 306 int in_use; /* users other than guest access, eg. block migration */ 307 QTAILQ_ENTRY(BlockDriverState) list; 308 309 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; 310 311 /* long-running background operation */ 312 BlockJob *job; 313 314 QDict *options; 315 }; 316 317 int get_tmp_filename(char *filename, int size); 318 319 void bdrv_set_io_limits(BlockDriverState *bs, 320 ThrottleConfig *cfg); 321 322 323 /** 324 * bdrv_add_before_write_notifier: 325 * 326 * Register a callback that is invoked before write requests are processed but 327 * after any throttling or waiting for overlapping requests. 328 */ 329 void bdrv_add_before_write_notifier(BlockDriverState *bs, 330 NotifierWithReturn *notifier); 331 332 /** 333 * bdrv_get_aio_context: 334 * 335 * Returns: the currently bound #AioContext 336 */ 337 AioContext *bdrv_get_aio_context(BlockDriverState *bs); 338 339 #ifdef _WIN32 340 int is_windows_drive(const char *filename); 341 #endif 342 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, 343 enum MonitorEvent ev, 344 BlockErrorAction action, bool is_read); 345 346 /** 347 * stream_start: 348 * @bs: Block device to operate on. 349 * @base: Block device that will become the new base, or %NULL to 350 * flatten the whole backing file chain onto @bs. 351 * @base_id: The file name that will be written to @bs as the new 352 * backing file if the job completes. Ignored if @base is %NULL. 353 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 354 * @on_error: The action to take upon error. 355 * @cb: Completion function for the job. 356 * @opaque: Opaque pointer value passed to @cb. 357 * @errp: Error object. 358 * 359 * Start a streaming operation on @bs. Clusters that are unallocated 360 * in @bs, but allocated in any image between @base and @bs (both 361 * exclusive) will be written to @bs. At the end of a successful 362 * streaming job, the backing file of @bs will be changed to 363 * @base_id in the written image and to @base in the live BlockDriverState. 364 */ 365 void stream_start(BlockDriverState *bs, BlockDriverState *base, 366 const char *base_id, int64_t speed, BlockdevOnError on_error, 367 BlockDriverCompletionFunc *cb, 368 void *opaque, Error **errp); 369 370 /** 371 * commit_start: 372 * @bs: Top Block device 373 * @base: Block device that will be written into, and become the new top 374 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 375 * @on_error: The action to take upon error. 376 * @cb: Completion function for the job. 377 * @opaque: Opaque pointer value passed to @cb. 378 * @errp: Error object. 379 * 380 */ 381 void commit_start(BlockDriverState *bs, BlockDriverState *base, 382 BlockDriverState *top, int64_t speed, 383 BlockdevOnError on_error, BlockDriverCompletionFunc *cb, 384 void *opaque, Error **errp); 385 386 /* 387 * mirror_start: 388 * @bs: Block device to operate on. 389 * @target: Block device to write to. 390 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 391 * @granularity: The chosen granularity for the dirty bitmap. 392 * @buf_size: The amount of data that can be in flight at one time. 393 * @mode: Whether to collapse all images in the chain to the target. 394 * @on_source_error: The action to take upon error reading from the source. 395 * @on_target_error: The action to take upon error writing to the target. 396 * @cb: Completion function for the job. 397 * @opaque: Opaque pointer value passed to @cb. 398 * @errp: Error object. 399 * 400 * Start a mirroring operation on @bs. Clusters that are allocated 401 * in @bs will be written to @bs until the job is cancelled or 402 * manually completed. At the end of a successful mirroring job, 403 * @bs will be switched to read from @target. 404 */ 405 void mirror_start(BlockDriverState *bs, BlockDriverState *target, 406 int64_t speed, int64_t granularity, int64_t buf_size, 407 MirrorSyncMode mode, BlockdevOnError on_source_error, 408 BlockdevOnError on_target_error, 409 BlockDriverCompletionFunc *cb, 410 void *opaque, Error **errp); 411 412 /* 413 * backup_start: 414 * @bs: Block device to operate on. 415 * @target: Block device to write to. 416 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 417 * @sync_mode: What parts of the disk image should be copied to the destination. 418 * @on_source_error: The action to take upon error reading from the source. 419 * @on_target_error: The action to take upon error writing to the target. 420 * @cb: Completion function for the job. 421 * @opaque: Opaque pointer value passed to @cb. 422 * 423 * Start a backup operation on @bs. Clusters in @bs are written to @target 424 * until the job is cancelled or manually completed. 425 */ 426 void backup_start(BlockDriverState *bs, BlockDriverState *target, 427 int64_t speed, MirrorSyncMode sync_mode, 428 BlockdevOnError on_source_error, 429 BlockdevOnError on_target_error, 430 BlockDriverCompletionFunc *cb, void *opaque, 431 Error **errp); 432 433 #endif /* BLOCK_INT_H */ 434