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 38 #define BLOCK_FLAG_ENCRYPT 1 39 #define BLOCK_FLAG_COMPAT6 4 40 #define BLOCK_FLAG_LAZY_REFCOUNTS 8 41 42 #define BLOCK_IO_LIMIT_READ 0 43 #define BLOCK_IO_LIMIT_WRITE 1 44 #define BLOCK_IO_LIMIT_TOTAL 2 45 46 #define BLOCK_IO_SLICE_TIME 100000000 47 #define NANOSECONDS_PER_SECOND 1000000000.0 48 49 #define BLOCK_OPT_SIZE "size" 50 #define BLOCK_OPT_ENCRYPT "encryption" 51 #define BLOCK_OPT_COMPAT6 "compat6" 52 #define BLOCK_OPT_BACKING_FILE "backing_file" 53 #define BLOCK_OPT_BACKING_FMT "backing_fmt" 54 #define BLOCK_OPT_CLUSTER_SIZE "cluster_size" 55 #define BLOCK_OPT_TABLE_SIZE "table_size" 56 #define BLOCK_OPT_PREALLOC "preallocation" 57 #define BLOCK_OPT_SUBFMT "subformat" 58 #define BLOCK_OPT_COMPAT_LEVEL "compat" 59 #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" 60 #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" 61 62 typedef struct BdrvTrackedRequest { 63 BlockDriverState *bs; 64 int64_t sector_num; 65 int nb_sectors; 66 bool is_write; 67 QLIST_ENTRY(BdrvTrackedRequest) list; 68 Coroutine *co; /* owner, used for deadlock detection */ 69 CoQueue wait_queue; /* coroutines blocked on this request */ 70 } BdrvTrackedRequest; 71 72 73 typedef struct BlockIOLimit { 74 int64_t bps[3]; 75 int64_t iops[3]; 76 } BlockIOLimit; 77 78 typedef struct BlockIOBaseValue { 79 uint64_t bytes[2]; 80 uint64_t ios[2]; 81 } BlockIOBaseValue; 82 83 struct BlockDriver { 84 const char *format_name; 85 int instance_size; 86 int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename); 87 int (*bdrv_probe_device)(const char *filename); 88 89 /* Any driver implementing this callback is expected to be able to handle 90 * NULL file names in its .bdrv_open() implementation */ 91 void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp); 92 93 /* For handling image reopen for split or non-split files */ 94 int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state, 95 BlockReopenQueue *queue, Error **errp); 96 void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state); 97 void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state); 98 99 int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags); 100 int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags); 101 int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num, 102 uint8_t *buf, int nb_sectors); 103 int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num, 104 const uint8_t *buf, int nb_sectors); 105 void (*bdrv_close)(BlockDriverState *bs); 106 void (*bdrv_rebind)(BlockDriverState *bs); 107 int (*bdrv_create)(const char *filename, QEMUOptionParameter *options); 108 int (*bdrv_set_key)(BlockDriverState *bs, const char *key); 109 int (*bdrv_make_empty)(BlockDriverState *bs); 110 /* aio */ 111 BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, 112 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 113 BlockDriverCompletionFunc *cb, void *opaque); 114 BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs, 115 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 116 BlockDriverCompletionFunc *cb, void *opaque); 117 BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, 118 BlockDriverCompletionFunc *cb, void *opaque); 119 BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs, 120 int64_t sector_num, int nb_sectors, 121 BlockDriverCompletionFunc *cb, void *opaque); 122 123 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, 124 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 125 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, 126 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 127 /* 128 * Efficiently zero a region of the disk image. Typically an image format 129 * would use a compact metadata representation to implement this. This 130 * function pointer may be NULL and .bdrv_co_writev() will be called 131 * instead. 132 */ 133 int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs, 134 int64_t sector_num, int nb_sectors); 135 int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs, 136 int64_t sector_num, int nb_sectors); 137 int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs, 138 int64_t sector_num, int nb_sectors, int *pnum); 139 140 /* 141 * Invalidate any cached meta-data. 142 */ 143 void (*bdrv_invalidate_cache)(BlockDriverState *bs); 144 145 /* 146 * Flushes all data that was already written to the OS all the way down to 147 * the disk (for example raw-posix calls fsync()). 148 */ 149 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs); 150 151 /* 152 * Flushes all internal caches to the OS. The data may still sit in a 153 * writeback cache of the host OS, but it will survive a crash of the qemu 154 * process. 155 */ 156 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs); 157 158 const char *protocol_name; 159 int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset); 160 int64_t (*bdrv_getlength)(BlockDriverState *bs); 161 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); 162 int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num, 163 const uint8_t *buf, int nb_sectors); 164 165 int (*bdrv_snapshot_create)(BlockDriverState *bs, 166 QEMUSnapshotInfo *sn_info); 167 int (*bdrv_snapshot_goto)(BlockDriverState *bs, 168 const char *snapshot_id); 169 int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id); 170 int (*bdrv_snapshot_list)(BlockDriverState *bs, 171 QEMUSnapshotInfo **psn_info); 172 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, 173 const char *snapshot_name); 174 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); 175 176 int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov, 177 int64_t pos); 178 int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf, 179 int64_t pos, int size); 180 181 int (*bdrv_change_backing_file)(BlockDriverState *bs, 182 const char *backing_file, const char *backing_fmt); 183 184 /* removable device specific */ 185 int (*bdrv_is_inserted)(BlockDriverState *bs); 186 int (*bdrv_media_changed)(BlockDriverState *bs); 187 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); 188 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); 189 190 /* to control generic scsi devices */ 191 int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); 192 BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, 193 unsigned long int req, void *buf, 194 BlockDriverCompletionFunc *cb, void *opaque); 195 196 /* List of options for creating images, terminated by name == NULL */ 197 QEMUOptionParameter *create_options; 198 199 200 /* 201 * Returns 0 for completed check, -errno for internal errors. 202 * The check results are stored in result. 203 */ 204 int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result, 205 BdrvCheckMode fix); 206 207 void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event); 208 209 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */ 210 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event, 211 const char *tag); 212 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag); 213 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag); 214 215 /* 216 * Returns 1 if newly created images are guaranteed to contain only 217 * zeros, 0 otherwise. 218 */ 219 int (*bdrv_has_zero_init)(BlockDriverState *bs); 220 221 QLIST_ENTRY(BlockDriver) list; 222 }; 223 224 /* 225 * Note: the function bdrv_append() copies and swaps contents of 226 * BlockDriverStates, so if you add new fields to this struct, please 227 * inspect bdrv_append() to determine if the new fields need to be 228 * copied as well. 229 */ 230 struct BlockDriverState { 231 int64_t total_sectors; /* if we are reading a disk image, give its 232 size in sectors */ 233 int read_only; /* if true, the media is read only */ 234 int open_flags; /* flags used to open the file, re-used for re-open */ 235 int encrypted; /* if true, the media is encrypted */ 236 int valid_key; /* if true, a valid encryption key has been set */ 237 int sg; /* if true, the device is a /dev/sg* */ 238 int copy_on_read; /* if true, copy read backing sectors into image 239 note this is a reference count */ 240 241 BlockDriver *drv; /* NULL means no media */ 242 void *opaque; 243 244 void *dev; /* attached device model, if any */ 245 /* TODO change to DeviceState when all users are qdevified */ 246 const BlockDevOps *dev_ops; 247 void *dev_opaque; 248 249 char filename[1024]; 250 char backing_file[1024]; /* if non zero, the image is a diff of 251 this file image */ 252 char backing_format[16]; /* if non-zero and backing_file exists */ 253 int is_temporary; 254 255 BlockDriverState *backing_hd; 256 BlockDriverState *file; 257 258 NotifierList close_notifiers; 259 260 /* Callback before write request is processed */ 261 NotifierWithReturnList before_write_notifiers; 262 263 /* number of in-flight copy-on-read requests */ 264 unsigned int copy_on_read_in_flight; 265 266 /* the time for latest disk I/O */ 267 int64_t slice_start; 268 int64_t slice_end; 269 BlockIOLimit io_limits; 270 BlockIOBaseValue slice_submitted; 271 CoQueue throttled_reqs; 272 QEMUTimer *block_timer; 273 bool io_limits_enabled; 274 275 /* I/O stats (display with "info blockstats"). */ 276 uint64_t nr_bytes[BDRV_MAX_IOTYPE]; 277 uint64_t nr_ops[BDRV_MAX_IOTYPE]; 278 uint64_t total_time_ns[BDRV_MAX_IOTYPE]; 279 uint64_t wr_highest_sector; 280 281 /* Whether the disk can expand beyond total_sectors */ 282 int growable; 283 284 /* the memory alignment required for the buffers handled by this driver */ 285 int buffer_alignment; 286 287 /* do we need to tell the quest if we have a volatile write cache? */ 288 int enable_write_cache; 289 290 /* NOTE: the following infos are only hints for real hardware 291 drivers. They are not used by the block driver */ 292 BlockdevOnError on_read_error, on_write_error; 293 bool iostatus_enabled; 294 BlockDeviceIoStatus iostatus; 295 char device_name[32]; 296 HBitmap *dirty_bitmap; 297 int in_use; /* users other than guest access, eg. block migration */ 298 QTAILQ_ENTRY(BlockDriverState) list; 299 300 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; 301 302 /* long-running background operation */ 303 BlockJob *job; 304 305 QDict *options; 306 }; 307 308 int get_tmp_filename(char *filename, int size); 309 310 void bdrv_set_io_limits(BlockDriverState *bs, 311 BlockIOLimit *io_limits); 312 313 /** 314 * bdrv_add_before_write_notifier: 315 * 316 * Register a callback that is invoked before write requests are processed but 317 * after any throttling or waiting for overlapping requests. 318 */ 319 void bdrv_add_before_write_notifier(BlockDriverState *bs, 320 NotifierWithReturn *notifier); 321 322 /** 323 * bdrv_get_aio_context: 324 * 325 * Returns: the currently bound #AioContext 326 */ 327 AioContext *bdrv_get_aio_context(BlockDriverState *bs); 328 329 #ifdef _WIN32 330 int is_windows_drive(const char *filename); 331 #endif 332 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, 333 enum MonitorEvent ev, 334 BlockErrorAction action, bool is_read); 335 336 /** 337 * stream_start: 338 * @bs: Block device to operate on. 339 * @base: Block device that will become the new base, or %NULL to 340 * flatten the whole backing file chain onto @bs. 341 * @base_id: The file name that will be written to @bs as the new 342 * backing file if the job completes. Ignored if @base is %NULL. 343 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 344 * @on_error: The action to take upon error. 345 * @cb: Completion function for the job. 346 * @opaque: Opaque pointer value passed to @cb. 347 * @errp: Error object. 348 * 349 * Start a streaming operation on @bs. Clusters that are unallocated 350 * in @bs, but allocated in any image between @base and @bs (both 351 * exclusive) will be written to @bs. At the end of a successful 352 * streaming job, the backing file of @bs will be changed to 353 * @base_id in the written image and to @base in the live BlockDriverState. 354 */ 355 void stream_start(BlockDriverState *bs, BlockDriverState *base, 356 const char *base_id, int64_t speed, BlockdevOnError on_error, 357 BlockDriverCompletionFunc *cb, 358 void *opaque, Error **errp); 359 360 /** 361 * commit_start: 362 * @bs: Top Block device 363 * @base: Block device that will be written into, and become the new top 364 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 365 * @on_error: The action to take upon error. 366 * @cb: Completion function for the job. 367 * @opaque: Opaque pointer value passed to @cb. 368 * @errp: Error object. 369 * 370 */ 371 void commit_start(BlockDriverState *bs, BlockDriverState *base, 372 BlockDriverState *top, int64_t speed, 373 BlockdevOnError on_error, BlockDriverCompletionFunc *cb, 374 void *opaque, Error **errp); 375 376 /* 377 * mirror_start: 378 * @bs: Block device to operate on. 379 * @target: Block device to write to. 380 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 381 * @granularity: The chosen granularity for the dirty bitmap. 382 * @buf_size: The amount of data that can be in flight at one time. 383 * @mode: Whether to collapse all images in the chain to the target. 384 * @on_source_error: The action to take upon error reading from the source. 385 * @on_target_error: The action to take upon error writing to the target. 386 * @cb: Completion function for the job. 387 * @opaque: Opaque pointer value passed to @cb. 388 * @errp: Error object. 389 * 390 * Start a mirroring operation on @bs. Clusters that are allocated 391 * in @bs will be written to @bs until the job is cancelled or 392 * manually completed. At the end of a successful mirroring job, 393 * @bs will be switched to read from @target. 394 */ 395 void mirror_start(BlockDriverState *bs, BlockDriverState *target, 396 int64_t speed, int64_t granularity, int64_t buf_size, 397 MirrorSyncMode mode, BlockdevOnError on_source_error, 398 BlockdevOnError on_target_error, 399 BlockDriverCompletionFunc *cb, 400 void *opaque, Error **errp); 401 402 /* 403 * backup_start: 404 * @bs: Block device to operate on. 405 * @target: Block device to write to. 406 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 407 * @on_source_error: The action to take upon error reading from the source. 408 * @on_target_error: The action to take upon error writing to the target. 409 * @cb: Completion function for the job. 410 * @opaque: Opaque pointer value passed to @cb. 411 * 412 * Start a backup operation on @bs. Clusters in @bs are written to @target 413 * until the job is cancelled or manually completed. 414 */ 415 void backup_start(BlockDriverState *bs, BlockDriverState *target, 416 int64_t speed, BlockdevOnError on_source_error, 417 BlockdevOnError on_target_error, 418 BlockDriverCompletionFunc *cb, void *opaque, 419 Error **errp); 420 421 #endif /* BLOCK_INT_H */ 422