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 39 #define BLOCK_FLAG_ENCRYPT 1 40 #define BLOCK_FLAG_COMPAT6 4 41 #define BLOCK_FLAG_LAZY_REFCOUNTS 8 42 43 #define BLOCK_IO_LIMIT_READ 0 44 #define BLOCK_IO_LIMIT_WRITE 1 45 #define BLOCK_IO_LIMIT_TOTAL 2 46 47 #define BLOCK_IO_SLICE_TIME 100000000 48 #define NANOSECONDS_PER_SECOND 1000000000.0 49 50 #define BLOCK_OPT_SIZE "size" 51 #define BLOCK_OPT_ENCRYPT "encryption" 52 #define BLOCK_OPT_COMPAT6 "compat6" 53 #define BLOCK_OPT_BACKING_FILE "backing_file" 54 #define BLOCK_OPT_BACKING_FMT "backing_fmt" 55 #define BLOCK_OPT_CLUSTER_SIZE "cluster_size" 56 #define BLOCK_OPT_TABLE_SIZE "table_size" 57 #define BLOCK_OPT_PREALLOC "preallocation" 58 #define BLOCK_OPT_SUBFMT "subformat" 59 #define BLOCK_OPT_COMPAT_LEVEL "compat" 60 #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" 61 #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" 62 63 typedef struct BdrvTrackedRequest { 64 BlockDriverState *bs; 65 int64_t sector_num; 66 int nb_sectors; 67 bool is_write; 68 QLIST_ENTRY(BdrvTrackedRequest) list; 69 Coroutine *co; /* owner, used for deadlock detection */ 70 CoQueue wait_queue; /* coroutines blocked on this request */ 71 } BdrvTrackedRequest; 72 73 74 typedef struct BlockIOLimit { 75 int64_t bps[3]; 76 int64_t iops[3]; 77 } BlockIOLimit; 78 79 typedef struct BlockIOBaseValue { 80 uint64_t bytes[2]; 81 uint64_t ios[2]; 82 } BlockIOBaseValue; 83 84 struct BlockDriver { 85 const char *format_name; 86 int instance_size; 87 int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename); 88 int (*bdrv_probe_device)(const char *filename); 89 90 /* Any driver implementing this callback is expected to be able to handle 91 * NULL file names in its .bdrv_open() implementation */ 92 void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp); 93 94 /* For handling image reopen for split or non-split files */ 95 int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state, 96 BlockReopenQueue *queue, Error **errp); 97 void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state); 98 void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state); 99 100 int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags); 101 int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags); 102 int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num, 103 uint8_t *buf, int nb_sectors); 104 int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num, 105 const uint8_t *buf, int nb_sectors); 106 void (*bdrv_close)(BlockDriverState *bs); 107 void (*bdrv_rebind)(BlockDriverState *bs); 108 int (*bdrv_create)(const char *filename, QEMUOptionParameter *options); 109 int (*bdrv_set_key)(BlockDriverState *bs, const char *key); 110 int (*bdrv_make_empty)(BlockDriverState *bs); 111 /* aio */ 112 BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, 113 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 114 BlockDriverCompletionFunc *cb, void *opaque); 115 BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs, 116 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 117 BlockDriverCompletionFunc *cb, void *opaque); 118 BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, 119 BlockDriverCompletionFunc *cb, void *opaque); 120 BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs, 121 int64_t sector_num, int nb_sectors, 122 BlockDriverCompletionFunc *cb, void *opaque); 123 124 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, 125 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 126 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, 127 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); 128 /* 129 * Efficiently zero a region of the disk image. Typically an image format 130 * would use a compact metadata representation to implement this. This 131 * function pointer may be NULL and .bdrv_co_writev() will be called 132 * instead. 133 */ 134 int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs, 135 int64_t sector_num, int nb_sectors); 136 int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs, 137 int64_t sector_num, int nb_sectors); 138 int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs, 139 int64_t sector_num, int nb_sectors, int *pnum); 140 141 /* 142 * Invalidate any cached meta-data. 143 */ 144 void (*bdrv_invalidate_cache)(BlockDriverState *bs); 145 146 /* 147 * Flushes all data that was already written to the OS all the way down to 148 * the disk (for example raw-posix calls fsync()). 149 */ 150 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs); 151 152 /* 153 * Flushes all internal caches to the OS. The data may still sit in a 154 * writeback cache of the host OS, but it will survive a crash of the qemu 155 * process. 156 */ 157 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs); 158 159 const char *protocol_name; 160 int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset); 161 int64_t (*bdrv_getlength)(BlockDriverState *bs); 162 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); 163 int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num, 164 const uint8_t *buf, int nb_sectors); 165 166 int (*bdrv_snapshot_create)(BlockDriverState *bs, 167 QEMUSnapshotInfo *sn_info); 168 int (*bdrv_snapshot_goto)(BlockDriverState *bs, 169 const char *snapshot_id); 170 int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id); 171 int (*bdrv_snapshot_list)(BlockDriverState *bs, 172 QEMUSnapshotInfo **psn_info); 173 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, 174 const char *snapshot_name); 175 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); 176 177 int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov, 178 int64_t pos); 179 int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf, 180 int64_t pos, int size); 181 182 int (*bdrv_change_backing_file)(BlockDriverState *bs, 183 const char *backing_file, const char *backing_fmt); 184 185 /* removable device specific */ 186 int (*bdrv_is_inserted)(BlockDriverState *bs); 187 int (*bdrv_media_changed)(BlockDriverState *bs); 188 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); 189 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); 190 191 /* to control generic scsi devices */ 192 int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); 193 BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, 194 unsigned long int req, void *buf, 195 BlockDriverCompletionFunc *cb, void *opaque); 196 197 /* List of options for creating images, terminated by name == NULL */ 198 QEMUOptionParameter *create_options; 199 200 201 /* 202 * Returns 0 for completed check, -errno for internal errors. 203 * The check results are stored in result. 204 */ 205 int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result, 206 BdrvCheckMode fix); 207 208 void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event); 209 210 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */ 211 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event, 212 const char *tag); 213 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag); 214 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag); 215 216 /* 217 * Returns 1 if newly created images are guaranteed to contain only 218 * zeros, 0 otherwise. 219 */ 220 int (*bdrv_has_zero_init)(BlockDriverState *bs); 221 222 QLIST_ENTRY(BlockDriver) list; 223 }; 224 225 /* 226 * Note: the function bdrv_append() copies and swaps contents of 227 * BlockDriverStates, so if you add new fields to this struct, please 228 * inspect bdrv_append() to determine if the new fields need to be 229 * copied as well. 230 */ 231 struct BlockDriverState { 232 int64_t total_sectors; /* if we are reading a disk image, give its 233 size in sectors */ 234 int read_only; /* if true, the media is read only */ 235 int open_flags; /* flags used to open the file, re-used for re-open */ 236 int encrypted; /* if true, the media is encrypted */ 237 int valid_key; /* if true, a valid encryption key has been set */ 238 int sg; /* if true, the device is a /dev/sg* */ 239 int copy_on_read; /* if true, copy read backing sectors into image 240 note this is a reference count */ 241 242 BlockDriver *drv; /* NULL means no media */ 243 void *opaque; 244 245 void *dev; /* attached device model, if any */ 246 /* TODO change to DeviceState when all users are qdevified */ 247 const BlockDevOps *dev_ops; 248 void *dev_opaque; 249 250 char filename[1024]; 251 char backing_file[1024]; /* if non zero, the image is a diff of 252 this file image */ 253 char backing_format[16]; /* if non-zero and backing_file exists */ 254 int is_temporary; 255 256 BlockDriverState *backing_hd; 257 BlockDriverState *file; 258 259 NotifierList close_notifiers; 260 261 /* Callback before write request is processed */ 262 NotifierWithReturnList before_write_notifiers; 263 264 /* number of in-flight copy-on-read requests */ 265 unsigned int copy_on_read_in_flight; 266 267 /* the time for latest disk I/O */ 268 int64_t slice_start; 269 int64_t slice_end; 270 BlockIOLimit io_limits; 271 BlockIOBaseValue slice_submitted; 272 CoQueue throttled_reqs; 273 QEMUTimer *block_timer; 274 bool io_limits_enabled; 275 276 /* I/O stats (display with "info blockstats"). */ 277 uint64_t nr_bytes[BDRV_MAX_IOTYPE]; 278 uint64_t nr_ops[BDRV_MAX_IOTYPE]; 279 uint64_t total_time_ns[BDRV_MAX_IOTYPE]; 280 uint64_t wr_highest_sector; 281 282 /* Whether the disk can expand beyond total_sectors */ 283 int growable; 284 285 /* Whether produces zeros when read beyond eof */ 286 bool zero_beyond_eof; 287 288 /* the memory alignment required for the buffers handled by this driver */ 289 int buffer_alignment; 290 291 /* do we need to tell the quest if we have a volatile write cache? */ 292 int enable_write_cache; 293 294 /* NOTE: the following infos are only hints for real hardware 295 drivers. They are not used by the block driver */ 296 BlockdevOnError on_read_error, on_write_error; 297 bool iostatus_enabled; 298 BlockDeviceIoStatus iostatus; 299 char device_name[32]; 300 HBitmap *dirty_bitmap; 301 int in_use; /* users other than guest access, eg. block migration */ 302 QTAILQ_ENTRY(BlockDriverState) list; 303 304 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; 305 306 /* long-running background operation */ 307 BlockJob *job; 308 309 QDict *options; 310 }; 311 312 int get_tmp_filename(char *filename, int size); 313 314 void bdrv_set_io_limits(BlockDriverState *bs, 315 BlockIOLimit *io_limits); 316 317 /** 318 * bdrv_add_before_write_notifier: 319 * 320 * Register a callback that is invoked before write requests are processed but 321 * after any throttling or waiting for overlapping requests. 322 */ 323 void bdrv_add_before_write_notifier(BlockDriverState *bs, 324 NotifierWithReturn *notifier); 325 326 /** 327 * bdrv_get_aio_context: 328 * 329 * Returns: the currently bound #AioContext 330 */ 331 AioContext *bdrv_get_aio_context(BlockDriverState *bs); 332 333 #ifdef _WIN32 334 int is_windows_drive(const char *filename); 335 #endif 336 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, 337 enum MonitorEvent ev, 338 BlockErrorAction action, bool is_read); 339 340 /** 341 * stream_start: 342 * @bs: Block device to operate on. 343 * @base: Block device that will become the new base, or %NULL to 344 * flatten the whole backing file chain onto @bs. 345 * @base_id: The file name that will be written to @bs as the new 346 * backing file if the job completes. Ignored if @base is %NULL. 347 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 348 * @on_error: The action to take upon error. 349 * @cb: Completion function for the job. 350 * @opaque: Opaque pointer value passed to @cb. 351 * @errp: Error object. 352 * 353 * Start a streaming operation on @bs. Clusters that are unallocated 354 * in @bs, but allocated in any image between @base and @bs (both 355 * exclusive) will be written to @bs. At the end of a successful 356 * streaming job, the backing file of @bs will be changed to 357 * @base_id in the written image and to @base in the live BlockDriverState. 358 */ 359 void stream_start(BlockDriverState *bs, BlockDriverState *base, 360 const char *base_id, int64_t speed, BlockdevOnError on_error, 361 BlockDriverCompletionFunc *cb, 362 void *opaque, Error **errp); 363 364 /** 365 * commit_start: 366 * @bs: Top Block device 367 * @base: Block device that will be written into, and become the new top 368 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 369 * @on_error: The action to take upon error. 370 * @cb: Completion function for the job. 371 * @opaque: Opaque pointer value passed to @cb. 372 * @errp: Error object. 373 * 374 */ 375 void commit_start(BlockDriverState *bs, BlockDriverState *base, 376 BlockDriverState *top, int64_t speed, 377 BlockdevOnError on_error, BlockDriverCompletionFunc *cb, 378 void *opaque, Error **errp); 379 380 /* 381 * mirror_start: 382 * @bs: Block device to operate on. 383 * @target: Block device to write to. 384 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 385 * @granularity: The chosen granularity for the dirty bitmap. 386 * @buf_size: The amount of data that can be in flight at one time. 387 * @mode: Whether to collapse all images in the chain to the target. 388 * @on_source_error: The action to take upon error reading from the source. 389 * @on_target_error: The action to take upon error writing to the target. 390 * @cb: Completion function for the job. 391 * @opaque: Opaque pointer value passed to @cb. 392 * @errp: Error object. 393 * 394 * Start a mirroring operation on @bs. Clusters that are allocated 395 * in @bs will be written to @bs until the job is cancelled or 396 * manually completed. At the end of a successful mirroring job, 397 * @bs will be switched to read from @target. 398 */ 399 void mirror_start(BlockDriverState *bs, BlockDriverState *target, 400 int64_t speed, int64_t granularity, int64_t buf_size, 401 MirrorSyncMode mode, BlockdevOnError on_source_error, 402 BlockdevOnError on_target_error, 403 BlockDriverCompletionFunc *cb, 404 void *opaque, Error **errp); 405 406 /* 407 * backup_start: 408 * @bs: Block device to operate on. 409 * @target: Block device to write to. 410 * @speed: The maximum speed, in bytes per second, or 0 for unlimited. 411 * @sync_mode: What parts of the disk image should be copied to the destination. 412 * @on_source_error: The action to take upon error reading from the source. 413 * @on_target_error: The action to take upon error writing to the target. 414 * @cb: Completion function for the job. 415 * @opaque: Opaque pointer value passed to @cb. 416 * 417 * Start a backup operation on @bs. Clusters in @bs are written to @target 418 * until the job is cancelled or manually completed. 419 */ 420 void backup_start(BlockDriverState *bs, BlockDriverState *target, 421 int64_t speed, MirrorSyncMode sync_mode, 422 BlockdevOnError on_source_error, 423 BlockdevOnError on_target_error, 424 BlockDriverCompletionFunc *cb, void *opaque, 425 Error **errp); 426 427 #endif /* BLOCK_INT_H */ 428