include/block/block_int.h

   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/accounting.h"
  28 #include "block/block.h"
  29 #include "block/throttle-groups.h"
  30 #include "qemu/option.h"
  31 #include "qemu/queue.h"
  32 #include "qemu/coroutine.h"
  33 #include "qemu/timer.h"
  34 #include "qapi-types.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 #define BLOCK_OPT_NOCOW             "nocow"
  58 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
  59 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
  60
  61 #define BLOCK_PROBE_BUF_SIZE        512
  62
  63 enum BdrvTrackedRequestType {
  64     BDRV_TRACKED_READ,
  65     BDRV_TRACKED_WRITE,
  66     BDRV_TRACKED_FLUSH,
  67     BDRV_TRACKED_IOCTL,
  68     BDRV_TRACKED_DISCARD,
  69 };
  70
  71 typedef struct BdrvTrackedRequest {
  72     BlockDriverState *bs;
  73     int64_t offset;
  74     unsigned int bytes;
  75     enum BdrvTrackedRequestType type;
  76
  77     bool serialising;
  78     int64_t overlap_offset;
  79     unsigned int overlap_bytes;
  80
  81     QLIST_ENTRY(BdrvTrackedRequest) list;
  82     Coroutine *co; /* owner, used for deadlock detection */
  83     CoQueue wait_queue; /* coroutines blocked on this request */
  84
  85     struct BdrvTrackedRequest *waiting_for;
  86 } BdrvTrackedRequest;
  87
  88 struct BlockDriver {
  89     const char *format_name;
  90     int instance_size;
  91
  92     /* set to true if the BlockDriver is a block filter */
  93     bool is_filter;
  94     /* for snapshots block filter like Quorum can implement the
  95      * following recursive callback.
  96      * It's purpose is to recurse on the filter children while calling
  97      * bdrv_recurse_is_first_non_filter on them.
  98      * For a sample implementation look in the future Quorum block filter.
  99      */
 100     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
 101                                              BlockDriverState *candidate);
 102
 103     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
 104     int (*bdrv_probe_device)(const char *filename);
 105
 106     /* Any driver implementing this callback is expected to be able to handle
 107      * NULL file names in its .bdrv_open() implementation */
 108     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
 109     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
 110      * this field set to true, except ones that are defined only by their
 111      * child's bs.
 112      * An example of the last type will be the quorum block driver.
 113      */
 114     bool bdrv_needs_filename;
 115
 116     /* Set if a driver can support backing files */
 117     bool supports_backing;
 118
 119     /* For handling image reopen for split or non-split files */
 120     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
 121                                BlockReopenQueue *queue, Error **errp);
 122     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
 123     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
 124
 125     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
 126                      Error **errp);
 127     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
 128                           Error **errp);
 129     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
 130                      uint8_t *buf, int nb_sectors);
 131     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
 132                       const uint8_t *buf, int nb_sectors);
 133     void (*bdrv_close)(BlockDriverState *bs);
 134     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
 135     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 136     int (*bdrv_make_empty)(BlockDriverState *bs);
 137
 138     void (*bdrv_refresh_filename)(BlockDriverState *bs);
 139
 140     /* aio */
 141     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 142         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 143         BlockCompletionFunc *cb, void *opaque);
 144     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 145         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 146         BlockCompletionFunc *cb, void *opaque);
 147     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 148         BlockCompletionFunc *cb, void *opaque);
 149     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 150         int64_t sector_num, int nb_sectors,
 151         BlockCompletionFunc *cb, void *opaque);
 152
 153     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 154         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 155     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 156         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 157     /*
 158      * Efficiently zero a region of the disk image.  Typically an image format
 159      * would use a compact metadata representation to implement this.  This
 160      * function pointer may be NULL and .bdrv_co_writev() will be called
 161      * instead.
 162      */
 163     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 164         int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
 165     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 166         int64_t sector_num, int nb_sectors);
 167     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
 168         int64_t sector_num, int nb_sectors, int *pnum);
 169
 170     /*
 171      * Invalidate any cached meta-data.
 172      */
 173     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
 174
 175     /*
 176      * Flushes all data that was already written to the OS all the way down to
 177      * the disk (for example raw-posix calls fsync()).
 178      */
 179     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 180
 181     /*
 182      * Flushes all internal caches to the OS. The data may still sit in a
 183      * writeback cache of the host OS, but it will survive a crash of the qemu
 184      * process.
 185      */
 186     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 187
 188     const char *protocol_name;
 189     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 190
 191     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 192     bool has_variable_length;
 193     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 194
 195     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 196                                  const uint8_t *buf, int nb_sectors);
 197
 198     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 199                                 QEMUSnapshotInfo *sn_info);
 200     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 201                               const char *snapshot_id);
 202     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
 203                                 const char *snapshot_id,
 204                                 const char *name,
 205                                 Error **errp);
 206     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 207                               QEMUSnapshotInfo **psn_info);
 208     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 209                                   const char *snapshot_id,
 210                                   const char *name,
 211                                   Error **errp);
 212     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 213     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
 214
 215     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
 216                              int64_t pos);
 217     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 218                              int64_t pos, int size);
 219
 220     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 221         const char *backing_file, const char *backing_fmt);
 222
 223     /* removable device specific */
 224     bool (*bdrv_is_inserted)(BlockDriverState *bs);
 225     int (*bdrv_media_changed)(BlockDriverState *bs);
 226     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 227     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 228
 229     /* to control generic scsi devices */
 230     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 231         unsigned long int req, void *buf,
 232         BlockCompletionFunc *cb, void *opaque);
 233
 234     /* List of options for creating images, terminated by name == NULL */
 235     QemuOptsList *create_opts;
 236
 237     /*
 238      * Returns 0 for completed check, -errno for internal errors.
 239      * The check results are stored in result.
 240      */
 241     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 242         BdrvCheckMode fix);
 243
 244     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
 245                               BlockDriverAmendStatusCB *status_cb);
 246
 247     void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
 248
 249     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 250     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 251         const char *tag);
 252     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
 253         const char *tag);
 254     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 255     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 256
 257     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
 258
 259     /*
 260      * Returns 1 if newly created images are guaranteed to contain only
 261      * zeros, 0 otherwise.
 262      */
 263     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 264
 265     /* Remove fd handlers, timers, and other event loop callbacks so the event
 266      * loop is no longer in use.  Called with no in-flight requests and in
 267      * depth-first traversal order with parents before child nodes.
 268      */
 269     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
 270
 271     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
 272      * can be processed again.  Called with no in-flight requests and in
 273      * depth-first traversal order with child nodes before parent nodes.
 274      */
 275     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
 276                                     AioContext *new_context);
 277
 278     /* io queue for linux-aio */
 279     void (*bdrv_io_plug)(BlockDriverState *bs);
 280     void (*bdrv_io_unplug)(BlockDriverState *bs);
 281     void (*bdrv_flush_io_queue)(BlockDriverState *bs);
 282
 283     /**
 284      * Try to get @bs's logical and physical block size.
 285      * On success, store them in @bsz and return zero.
 286      * On failure, return negative errno.
 287      */
 288     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
 289     /**
 290      * Try to get @bs's geometry (cyls, heads, sectors)
 291      * On success, store them in @geo and return 0.
 292      * On failure return -errno.
 293      * Only drivers that want to override guest geometry implement this
 294      * callback; see hd_geometry_guess().
 295      */
 296     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
 297
 298     /**
 299      * Drain and stop any internal sources of requests in the driver, and
 300      * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
 301      */
 302     void (*bdrv_drain)(BlockDriverState *bs);
 303
 304     QLIST_ENTRY(BlockDriver) list;
 305 };
 306
 307 typedef struct BlockLimits {
 308     /* maximum number of sectors that can be discarded at once */
 309     int max_discard;
 310
 311     /* optimal alignment for discard requests in sectors */
 312     int64_t discard_alignment;
 313
 314     /* maximum number of sectors that can zeroized at once */
 315     int max_write_zeroes;
 316
 317     /* optimal alignment for write zeroes requests in sectors */
 318     int64_t write_zeroes_alignment;
 319
 320     /* optimal transfer length in sectors */
 321     int opt_transfer_length;
 322
 323     /* maximal transfer length in sectors */
 324     int max_transfer_length;
 325
 326     /* memory alignment so that no bounce buffer is needed */
 327     size_t min_mem_alignment;
 328
 329     /* memory alignment for bounce buffer */
 330     size_t opt_mem_alignment;
 331 } BlockLimits;
 332
 333 typedef struct BdrvOpBlocker BdrvOpBlocker;
 334
 335 typedef struct BdrvAioNotifier {
 336     void (*attached_aio_context)(AioContext *new_context, void *opaque);
 337     void (*detach_aio_context)(void *opaque);
 338
 339     void *opaque;
 340
 341     QLIST_ENTRY(BdrvAioNotifier) list;
 342 } BdrvAioNotifier;
 343
 344 struct BdrvChildRole {
 345     int (*inherit_flags)(int parent_flags);
 346 };
 347
 348 extern const BdrvChildRole child_file;
 349 extern const BdrvChildRole child_format;
 350
 351 struct BdrvChild {
 352     BlockDriverState *bs;
 353     const BdrvChildRole *role;
 354     QLIST_ENTRY(BdrvChild) next;
 355     QLIST_ENTRY(BdrvChild) next_parent;
 356 };
 357
 358 /*
 359  * Note: the function bdrv_append() copies and swaps contents of
 360  * BlockDriverStates, so if you add new fields to this struct, please
 361  * inspect bdrv_append() to determine if the new fields need to be
 362  * copied as well.
 363  */
 364 struct BlockDriverState {
 365     int64_t total_sectors; /* if we are reading a disk image, give its
 366                               size in sectors */
 367     int read_only; /* if true, the media is read only */
 368     int open_flags; /* flags used to open the file, re-used for re-open */
 369     int encrypted; /* if true, the media is encrypted */
 370     int valid_key; /* if true, a valid encryption key has been set */
 371     int sg;        /* if true, the device is a /dev/sg* */
 372     int copy_on_read; /* if true, copy read backing sectors into image
 373                          note this is a reference count */
 374     bool probed;
 375
 376     BlockDriver *drv; /* NULL means no media */
 377     void *opaque;
 378
 379     BlockBackend *blk;          /* owning backend, if any */
 380
 381     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
 382     /* long-running tasks intended to always use the same AioContext as this
 383      * BDS may register themselves in this list to be notified of changes
 384      * regarding this BDS's context */
 385     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
 386
 387     char filename[PATH_MAX];
 388     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
 389                                     this file image */
 390     char backing_format[16]; /* if non-zero and backing_file exists */
 391
 392     QDict *full_open_options;
 393     char exact_filename[PATH_MAX];
 394
 395     BdrvChild *backing;
 396     BdrvChild *file;
 397
 398     NotifierList close_notifiers;
 399
 400     /* Callback before write request is processed */
 401     NotifierWithReturnList before_write_notifiers;
 402
 403     /* number of in-flight serialising requests */
 404     unsigned int serialising_in_flight;
 405
 406     /* I/O throttling.
 407      * throttle_state tells us if this BDS has I/O limits configured.
 408      * io_limits_enabled tells us if they are currently being
 409      * enforced, but it can be temporarily set to false */
 410     CoQueue      throttled_reqs[2];
 411     bool         io_limits_enabled;
 412     /* The following fields are protected by the ThrottleGroup lock.
 413      * See the ThrottleGroup documentation for details. */
 414     ThrottleState *throttle_state;
 415     ThrottleTimers throttle_timers;
 416     unsigned       pending_reqs[2];
 417     QLIST_ENTRY(BlockDriverState) round_robin;
 418
 419     /* Offset after the highest byte written to */
 420     uint64_t wr_highest_offset;
 421
 422     /* I/O Limits */
 423     BlockLimits bl;
 424
 425     /* Whether produces zeros when read beyond eof */
 426     bool zero_beyond_eof;
 427
 428     /* Alignment requirement for offset/length of I/O requests */
 429     unsigned int request_alignment;
 430
 431     /* do we need to tell the quest if we have a volatile write cache? */
 432     int enable_write_cache;
 433
 434     /* the following member gives a name to every node on the bs graph. */
 435     char node_name[32];
 436     /* element of the list of named nodes building the graph */
 437     QTAILQ_ENTRY(BlockDriverState) node_list;
 438     /* element of the list of "drives" the guest sees */
 439     QTAILQ_ENTRY(BlockDriverState) device_list;
 440     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
 441     int refcnt;
 442
 443     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 444
 445     /* operation blockers */
 446     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
 447
 448     /* long-running background operation */
 449     BlockJob *job;
 450
 451     /* The node that this node inherited default options from (and a reopen on
 452      * which can affect this node by changing these defaults). This is always a
 453      * parent node of this node. */
 454     BlockDriverState *inherits_from;
 455     QLIST_HEAD(, BdrvChild) children;
 456     QLIST_HEAD(, BdrvChild) parents;
 457
 458     QDict *options;
 459     BlockdevDetectZeroesOptions detect_zeroes;
 460
 461     /* The error object in use for blocking operations on backing_hd */
 462     Error *backing_blocker;
 463
 464     /* threshold limit for writes, in bytes. "High water mark". */
 465     uint64_t write_threshold_offset;
 466     NotifierWithReturn write_threshold_notifier;
 467
 468     int quiesce_counter;
 469 };
 470
 471 struct BlockBackendRootState {
 472     int open_flags;
 473     bool read_only;
 474     BlockdevDetectZeroesOptions detect_zeroes;
 475
 476     char *throttle_group;
 477     ThrottleState *throttle_state;
 478 };
 479
 480 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
 481 {
 482     return bs->backing ? bs->backing->bs : NULL;
 483 }
 484
 485
 486 /* Essential block drivers which must always be statically linked into qemu, and
 487  * which therefore can be accessed without using bdrv_find_format() */
 488 extern BlockDriver bdrv_file;
 489 extern BlockDriver bdrv_raw;
 490 extern BlockDriver bdrv_qcow2;
 491
 492 extern QTAILQ_HEAD(BdrvStates, BlockDriverState) bdrv_states;
 493
 494 /**
 495  * bdrv_setup_io_funcs:
 496  *
 497  * Prepare a #BlockDriver for I/O request processing by populating
 498  * unimplemented coroutine and AIO interfaces with generic wrapper functions
 499  * that fall back to implemented interfaces.
 500  */
 501 void bdrv_setup_io_funcs(BlockDriver *bdrv);
 502
 503 int get_tmp_filename(char *filename, int size);
 504 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
 505                             const char *filename);
 506
 507 void bdrv_set_io_limits(BlockDriverState *bs,
 508                         ThrottleConfig *cfg);
 509
 510
 511 /**
 512  * bdrv_add_before_write_notifier:
 513  *
 514  * Register a callback that is invoked before write requests are processed but
 515  * after any throttling or waiting for overlapping requests.
 516  */
 517 void bdrv_add_before_write_notifier(BlockDriverState *bs,
 518                                     NotifierWithReturn *notifier);
 519
 520 /**
 521  * bdrv_detach_aio_context:
 522  *
 523  * May be called from .bdrv_detach_aio_context() to detach children from the
 524  * current #AioContext.  This is only needed by block drivers that manage their
 525  * own children.  Both ->file and ->backing are automatically handled and
 526  * block drivers should not call this function on them explicitly.
 527  */
 528 void bdrv_detach_aio_context(BlockDriverState *bs);
 529
 530 /**
 531  * bdrv_attach_aio_context:
 532  *
 533  * May be called from .bdrv_attach_aio_context() to attach children to the new
 534  * #AioContext.  This is only needed by block drivers that manage their own
 535  * children.  Both ->file and ->backing are automatically handled and block
 536  * drivers should not call this function on them explicitly.
 537  */
 538 void bdrv_attach_aio_context(BlockDriverState *bs,
 539                              AioContext *new_context);
 540
 541 /**
 542  * bdrv_add_aio_context_notifier:
 543  *
 544  * If a long-running job intends to be always run in the same AioContext as a
 545  * certain BDS, it may use this function to be notified of changes regarding the
 546  * association of the BDS to an AioContext.
 547  *
 548  * attached_aio_context() is called after the target BDS has been attached to a
 549  * new AioContext; detach_aio_context() is called before the target BDS is being
 550  * detached from its old AioContext.
 551  */
 552 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
 553         void (*attached_aio_context)(AioContext *new_context, void *opaque),
 554         void (*detach_aio_context)(void *opaque), void *opaque);
 555
 556 /**
 557  * bdrv_remove_aio_context_notifier:
 558  *
 559  * Unsubscribe of change notifications regarding the BDS's AioContext. The
 560  * parameters given here have to be the same as those given to
 561  * bdrv_add_aio_context_notifier().
 562  */
 563 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
 564                                       void (*aio_context_attached)(AioContext *,
 565                                                                    void *),
 566                                       void (*aio_context_detached)(void *),
 567                                       void *opaque);
 568
 569 #ifdef _WIN32
 570 int is_windows_drive(const char *filename);
 571 #endif
 572
 573 /**
 574  * stream_start:
 575  * @bs: Block device to operate on.
 576  * @base: Block device that will become the new base, or %NULL to
 577  * flatten the whole backing file chain onto @bs.
 578  * @base_id: The file name that will be written to @bs as the new
 579  * backing file if the job completes.  Ignored if @base is %NULL.
 580  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 581  * @on_error: The action to take upon error.
 582  * @cb: Completion function for the job.
 583  * @opaque: Opaque pointer value passed to @cb.
 584  * @errp: Error object.
 585  *
 586  * Start a streaming operation on @bs.  Clusters that are unallocated
 587  * in @bs, but allocated in any image between @base and @bs (both
 588  * exclusive) will be written to @bs.  At the end of a successful
 589  * streaming job, the backing file of @bs will be changed to
 590  * @base_id in the written image and to @base in the live BlockDriverState.
 591  */
 592 void stream_start(BlockDriverState *bs, BlockDriverState *base,
 593                   const char *base_id, int64_t speed, BlockdevOnError on_error,
 594                   BlockCompletionFunc *cb,
 595                   void *opaque, Error **errp);
 596
 597 /**
 598  * commit_start:
 599  * @bs: Active block device.
 600  * @top: Top block device to be committed.
 601  * @base: Block device that will be written into, and become the new top.
 602  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 603  * @on_error: The action to take upon error.
 604  * @cb: Completion function for the job.
 605  * @opaque: Opaque pointer value passed to @cb.
 606  * @backing_file_str: String to use as the backing file in @top's overlay
 607  * @errp: Error object.
 608  *
 609  */
 610 void commit_start(BlockDriverState *bs, BlockDriverState *base,
 611                  BlockDriverState *top, int64_t speed,
 612                  BlockdevOnError on_error, BlockCompletionFunc *cb,
 613                  void *opaque, const char *backing_file_str, Error **errp);
 614 /**
 615  * commit_active_start:
 616  * @bs: Active block device to be committed.
 617  * @base: Block device that will be written into, and become the new top.
 618  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 619  * @on_error: The action to take upon error.
 620  * @cb: Completion function for the job.
 621  * @opaque: Opaque pointer value passed to @cb.
 622  * @errp: Error object.
 623  *
 624  */
 625 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
 626                          int64_t speed,
 627                          BlockdevOnError on_error,
 628                          BlockCompletionFunc *cb,
 629                          void *opaque, Error **errp);
 630 /*
 631  * mirror_start:
 632  * @bs: Block device to operate on.
 633  * @target: Block device to write to.
 634  * @replaces: Block graph node name to replace once the mirror is done. Can
 635  *            only be used when full mirroring is selected.
 636  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 637  * @granularity: The chosen granularity for the dirty bitmap.
 638  * @buf_size: The amount of data that can be in flight at one time.
 639  * @mode: Whether to collapse all images in the chain to the target.
 640  * @on_source_error: The action to take upon error reading from the source.
 641  * @on_target_error: The action to take upon error writing to the target.
 642  * @unmap: Whether to unmap target where source sectors only contain zeroes.
 643  * @cb: Completion function for the job.
 644  * @opaque: Opaque pointer value passed to @cb.
 645  * @errp: Error object.
 646  *
 647  * Start a mirroring operation on @bs.  Clusters that are allocated
 648  * in @bs will be written to @bs until the job is cancelled or
 649  * manually completed.  At the end of a successful mirroring job,
 650  * @bs will be switched to read from @target.
 651  */
 652 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 653                   const char *replaces,
 654                   int64_t speed, uint32_t granularity, int64_t buf_size,
 655                   MirrorSyncMode mode, BlockdevOnError on_source_error,
 656                   BlockdevOnError on_target_error,
 657                   bool unmap,
 658                   BlockCompletionFunc *cb,
 659                   void *opaque, Error **errp);
 660
 661 /*
 662  * backup_start:
 663  * @bs: Block device to operate on.
 664  * @target: Block device to write to.
 665  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 666  * @sync_mode: What parts of the disk image should be copied to the destination.
 667  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
 668  * @on_source_error: The action to take upon error reading from the source.
 669  * @on_target_error: The action to take upon error writing to the target.
 670  * @cb: Completion function for the job.
 671  * @opaque: Opaque pointer value passed to @cb.
 672  * @txn: Transaction that this job is part of (may be NULL).
 673  *
 674  * Start a backup operation on @bs.  Clusters in @bs are written to @target
 675  * until the job is cancelled or manually completed.
 676  */
 677 void backup_start(BlockDriverState *bs, BlockDriverState *target,
 678                   int64_t speed, MirrorSyncMode sync_mode,
 679                   BdrvDirtyBitmap *sync_bitmap,
 680                   BlockdevOnError on_source_error,
 681                   BlockdevOnError on_target_error,
 682                   BlockCompletionFunc *cb, void *opaque,
 683                   BlockJobTxn *txn, Error **errp);
 684
 685 void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
 686
 687 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
 688 bool blk_dev_has_removable_media(BlockBackend *blk);
 689 void blk_dev_eject_request(BlockBackend *blk, bool force);
 690 bool blk_dev_is_tray_open(BlockBackend *blk);
 691 bool blk_dev_is_medium_locked(BlockBackend *blk);
 692 void blk_dev_resize_cb(BlockBackend *blk);
 693
 694 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
 695 bool bdrv_requests_pending(BlockDriverState *bs);
 696
 697 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
 698 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
 699
 700 #endif /* BLOCK_INT_H */