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     void (*bdrv_join_options)(QDict *options, QDict *old_options);
 125
 126     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
 127                      Error **errp);
 128     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
 129                           Error **errp);
 130     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
 131                      uint8_t *buf, int nb_sectors);
 132     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
 133                       const uint8_t *buf, int nb_sectors);
 134     void (*bdrv_close)(BlockDriverState *bs);
 135     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
 136     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 137     int (*bdrv_make_empty)(BlockDriverState *bs);
 138
 139     void (*bdrv_refresh_filename)(BlockDriverState *bs, QDict *options);
 140
 141     /* aio */
 142     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 143         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 144         BlockCompletionFunc *cb, void *opaque);
 145     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 146         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 147         BlockCompletionFunc *cb, void *opaque);
 148     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 149         BlockCompletionFunc *cb, void *opaque);
 150     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 151         int64_t sector_num, int nb_sectors,
 152         BlockCompletionFunc *cb, void *opaque);
 153
 154     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 155         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 156     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 157         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 158     /*
 159      * Efficiently zero a region of the disk image.  Typically an image format
 160      * would use a compact metadata representation to implement this.  This
 161      * function pointer may be NULL and .bdrv_co_writev() will be called
 162      * instead.
 163      */
 164     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 165         int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
 166     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 167         int64_t sector_num, int nb_sectors);
 168     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
 169         int64_t sector_num, int nb_sectors, int *pnum);
 170
 171     /*
 172      * Invalidate any cached meta-data.
 173      */
 174     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
 175
 176     /*
 177      * Flushes all data that was already written to the OS all the way down to
 178      * the disk (for example raw-posix calls fsync()).
 179      */
 180     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 181
 182     /*
 183      * Flushes all internal caches to the OS. The data may still sit in a
 184      * writeback cache of the host OS, but it will survive a crash of the qemu
 185      * process.
 186      */
 187     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 188
 189     const char *protocol_name;
 190     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 191
 192     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 193     bool has_variable_length;
 194     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 195
 196     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 197                                  const uint8_t *buf, int nb_sectors);
 198
 199     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 200                                 QEMUSnapshotInfo *sn_info);
 201     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 202                               const char *snapshot_id);
 203     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
 204                                 const char *snapshot_id,
 205                                 const char *name,
 206                                 Error **errp);
 207     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 208                               QEMUSnapshotInfo **psn_info);
 209     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 210                                   const char *snapshot_id,
 211                                   const char *name,
 212                                   Error **errp);
 213     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 214     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
 215
 216     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
 217                              int64_t pos);
 218     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 219                              int64_t pos, int size);
 220
 221     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 222         const char *backing_file, const char *backing_fmt);
 223
 224     /* removable device specific */
 225     bool (*bdrv_is_inserted)(BlockDriverState *bs);
 226     int (*bdrv_media_changed)(BlockDriverState *bs);
 227     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 228     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 229
 230     /* to control generic scsi devices */
 231     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 232         unsigned long int req, void *buf,
 233         BlockCompletionFunc *cb, void *opaque);
 234
 235     /* List of options for creating images, terminated by name == NULL */
 236     QemuOptsList *create_opts;
 237
 238     /*
 239      * Returns 0 for completed check, -errno for internal errors.
 240      * The check results are stored in result.
 241      */
 242     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 243         BdrvCheckMode fix);
 244
 245     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
 246                               BlockDriverAmendStatusCB *status_cb,
 247                               void *cb_opaque);
 248
 249     void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
 250
 251     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 252     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 253         const char *tag);
 254     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
 255         const char *tag);
 256     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 257     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 258
 259     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
 260
 261     /*
 262      * Returns 1 if newly created images are guaranteed to contain only
 263      * zeros, 0 otherwise.
 264      */
 265     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 266
 267     /* Remove fd handlers, timers, and other event loop callbacks so the event
 268      * loop is no longer in use.  Called with no in-flight requests and in
 269      * depth-first traversal order with parents before child nodes.
 270      */
 271     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
 272
 273     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
 274      * can be processed again.  Called with no in-flight requests and in
 275      * depth-first traversal order with child nodes before parent nodes.
 276      */
 277     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
 278                                     AioContext *new_context);
 279
 280     /* io queue for linux-aio */
 281     void (*bdrv_io_plug)(BlockDriverState *bs);
 282     void (*bdrv_io_unplug)(BlockDriverState *bs);
 283     void (*bdrv_flush_io_queue)(BlockDriverState *bs);
 284
 285     /**
 286      * Try to get @bs's logical and physical block size.
 287      * On success, store them in @bsz and return zero.
 288      * On failure, return negative errno.
 289      */
 290     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
 291     /**
 292      * Try to get @bs's geometry (cyls, heads, sectors)
 293      * On success, store them in @geo and return 0.
 294      * On failure return -errno.
 295      * Only drivers that want to override guest geometry implement this
 296      * callback; see hd_geometry_guess().
 297      */
 298     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
 299
 300     /**
 301      * Drain and stop any internal sources of requests in the driver, and
 302      * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
 303      */
 304     void (*bdrv_drain)(BlockDriverState *bs);
 305
 306     QLIST_ENTRY(BlockDriver) list;
 307 };
 308
 309 typedef struct BlockLimits {
 310     /* maximum number of sectors that can be discarded at once */
 311     int max_discard;
 312
 313     /* optimal alignment for discard requests in sectors */
 314     int64_t discard_alignment;
 315
 316     /* maximum number of sectors that can zeroized at once */
 317     int max_write_zeroes;
 318
 319     /* optimal alignment for write zeroes requests in sectors */
 320     int64_t write_zeroes_alignment;
 321
 322     /* optimal transfer length in sectors */
 323     int opt_transfer_length;
 324
 325     /* maximal transfer length in sectors */
 326     int max_transfer_length;
 327
 328     /* memory alignment so that no bounce buffer is needed */
 329     size_t min_mem_alignment;
 330
 331     /* memory alignment for bounce buffer */
 332     size_t opt_mem_alignment;
 333
 334     /* maximum number of iovec elements */
 335     int max_iov;
 336 } BlockLimits;
 337
 338 typedef struct BdrvOpBlocker BdrvOpBlocker;
 339
 340 typedef struct BdrvAioNotifier {
 341     void (*attached_aio_context)(AioContext *new_context, void *opaque);
 342     void (*detach_aio_context)(void *opaque);
 343
 344     void *opaque;
 345
 346     QLIST_ENTRY(BdrvAioNotifier) list;
 347 } BdrvAioNotifier;
 348
 349 struct BdrvChildRole {
 350     void (*inherit_options)(int *child_flags, QDict *child_options,
 351                             int parent_flags, QDict *parent_options);
 352 };
 353
 354 extern const BdrvChildRole child_file;
 355 extern const BdrvChildRole child_format;
 356
 357 struct BdrvChild {
 358     BlockDriverState *bs;
 359     char *name;
 360     const BdrvChildRole *role;
 361     QLIST_ENTRY(BdrvChild) next;
 362     QLIST_ENTRY(BdrvChild) next_parent;
 363 };
 364
 365 /*
 366  * Note: the function bdrv_append() copies and swaps contents of
 367  * BlockDriverStates, so if you add new fields to this struct, please
 368  * inspect bdrv_append() to determine if the new fields need to be
 369  * copied as well.
 370  */
 371 struct BlockDriverState {
 372     int64_t total_sectors; /* if we are reading a disk image, give its
 373                               size in sectors */
 374     int read_only; /* if true, the media is read only */
 375     int open_flags; /* flags used to open the file, re-used for re-open */
 376     int encrypted; /* if true, the media is encrypted */
 377     int valid_key; /* if true, a valid encryption key has been set */
 378     int sg;        /* if true, the device is a /dev/sg* */
 379     int copy_on_read; /* if true, copy read backing sectors into image
 380                          note this is a reference count */
 381     bool probed;
 382
 383     BlockDriver *drv; /* NULL means no media */
 384     void *opaque;
 385
 386     BlockBackend *blk;          /* owning backend, if any */
 387
 388     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
 389     /* long-running tasks intended to always use the same AioContext as this
 390      * BDS may register themselves in this list to be notified of changes
 391      * regarding this BDS's context */
 392     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
 393
 394     char filename[PATH_MAX];
 395     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
 396                                     this file image */
 397     char backing_format[16]; /* if non-zero and backing_file exists */
 398
 399     QDict *full_open_options;
 400     char exact_filename[PATH_MAX];
 401
 402     BdrvChild *backing;
 403     BdrvChild *file;
 404
 405     NotifierList close_notifiers;
 406
 407     /* Callback before write request is processed */
 408     NotifierWithReturnList before_write_notifiers;
 409
 410     /* number of in-flight serialising requests */
 411     unsigned int serialising_in_flight;
 412
 413     /* I/O throttling.
 414      * throttle_state tells us if this BDS has I/O limits configured.
 415      * io_limits_enabled tells us if they are currently being
 416      * enforced, but it can be temporarily set to false */
 417     CoQueue      throttled_reqs[2];
 418     bool         io_limits_enabled;
 419     /* The following fields are protected by the ThrottleGroup lock.
 420      * See the ThrottleGroup documentation for details. */
 421     ThrottleState *throttle_state;
 422     ThrottleTimers throttle_timers;
 423     unsigned       pending_reqs[2];
 424     QLIST_ENTRY(BlockDriverState) round_robin;
 425
 426     /* Offset after the highest byte written to */
 427     uint64_t wr_highest_offset;
 428
 429     /* I/O Limits */
 430     BlockLimits bl;
 431
 432     /* Whether produces zeros when read beyond eof */
 433     bool zero_beyond_eof;
 434
 435     /* Alignment requirement for offset/length of I/O requests */
 436     unsigned int request_alignment;
 437
 438     /* do we need to tell the quest if we have a volatile write cache? */
 439     int enable_write_cache;
 440
 441     /* the following member gives a name to every node on the bs graph. */
 442     char node_name[32];
 443     /* element of the list of named nodes building the graph */
 444     QTAILQ_ENTRY(BlockDriverState) node_list;
 445     /* element of the list of "drives" the guest sees */
 446     QTAILQ_ENTRY(BlockDriverState) device_list;
 447     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
 448     int refcnt;
 449
 450     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 451
 452     /* operation blockers */
 453     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
 454
 455     /* long-running background operation */
 456     BlockJob *job;
 457
 458     /* The node that this node inherited default options from (and a reopen on
 459      * which can affect this node by changing these defaults). This is always a
 460      * parent node of this node. */
 461     BlockDriverState *inherits_from;
 462     QLIST_HEAD(, BdrvChild) children;
 463     QLIST_HEAD(, BdrvChild) parents;
 464
 465     QDict *options;
 466     QDict *explicit_options;
 467     BlockdevDetectZeroesOptions detect_zeroes;
 468
 469     /* The error object in use for blocking operations on backing_hd */
 470     Error *backing_blocker;
 471
 472     /* threshold limit for writes, in bytes. "High water mark". */
 473     uint64_t write_threshold_offset;
 474     NotifierWithReturn write_threshold_notifier;
 475
 476     int quiesce_counter;
 477 };
 478
 479 struct BlockBackendRootState {
 480     int open_flags;
 481     bool read_only;
 482     BlockdevDetectZeroesOptions detect_zeroes;
 483
 484     char *throttle_group;
 485     ThrottleState *throttle_state;
 486 };
 487
 488 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
 489 {
 490     return bs->backing ? bs->backing->bs : NULL;
 491 }
 492
 493
 494 /* Essential block drivers which must always be statically linked into qemu, and
 495  * which therefore can be accessed without using bdrv_find_format() */
 496 extern BlockDriver bdrv_file;
 497 extern BlockDriver bdrv_raw;
 498 extern BlockDriver bdrv_qcow2;
 499
 500 extern QTAILQ_HEAD(BdrvStates, BlockDriverState) bdrv_states;
 501
 502 /**
 503  * bdrv_setup_io_funcs:
 504  *
 505  * Prepare a #BlockDriver for I/O request processing by populating
 506  * unimplemented coroutine and AIO interfaces with generic wrapper functions
 507  * that fall back to implemented interfaces.
 508  */
 509 void bdrv_setup_io_funcs(BlockDriver *bdrv);
 510
 511 int get_tmp_filename(char *filename, int size);
 512 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
 513                             const char *filename);
 514
 515 void bdrv_set_io_limits(BlockDriverState *bs,
 516                         ThrottleConfig *cfg);
 517
 518
 519 /**
 520  * bdrv_add_before_write_notifier:
 521  *
 522  * Register a callback that is invoked before write requests are processed but
 523  * after any throttling or waiting for overlapping requests.
 524  */
 525 void bdrv_add_before_write_notifier(BlockDriverState *bs,
 526                                     NotifierWithReturn *notifier);
 527
 528 /**
 529  * bdrv_detach_aio_context:
 530  *
 531  * May be called from .bdrv_detach_aio_context() to detach children from the
 532  * current #AioContext.  This is only needed by block drivers that manage their
 533  * own children.  Both ->file and ->backing are automatically handled and
 534  * block drivers should not call this function on them explicitly.
 535  */
 536 void bdrv_detach_aio_context(BlockDriverState *bs);
 537
 538 /**
 539  * bdrv_attach_aio_context:
 540  *
 541  * May be called from .bdrv_attach_aio_context() to attach children to the new
 542  * #AioContext.  This is only needed by block drivers that manage their own
 543  * children.  Both ->file and ->backing are automatically handled and block
 544  * drivers should not call this function on them explicitly.
 545  */
 546 void bdrv_attach_aio_context(BlockDriverState *bs,
 547                              AioContext *new_context);
 548
 549 /**
 550  * bdrv_add_aio_context_notifier:
 551  *
 552  * If a long-running job intends to be always run in the same AioContext as a
 553  * certain BDS, it may use this function to be notified of changes regarding the
 554  * association of the BDS to an AioContext.
 555  *
 556  * attached_aio_context() is called after the target BDS has been attached to a
 557  * new AioContext; detach_aio_context() is called before the target BDS is being
 558  * detached from its old AioContext.
 559  */
 560 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
 561         void (*attached_aio_context)(AioContext *new_context, void *opaque),
 562         void (*detach_aio_context)(void *opaque), void *opaque);
 563
 564 /**
 565  * bdrv_remove_aio_context_notifier:
 566  *
 567  * Unsubscribe of change notifications regarding the BDS's AioContext. The
 568  * parameters given here have to be the same as those given to
 569  * bdrv_add_aio_context_notifier().
 570  */
 571 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
 572                                       void (*aio_context_attached)(AioContext *,
 573                                                                    void *),
 574                                       void (*aio_context_detached)(void *),
 575                                       void *opaque);
 576
 577 #ifdef _WIN32
 578 int is_windows_drive(const char *filename);
 579 #endif
 580
 581 /**
 582  * stream_start:
 583  * @bs: Block device to operate on.
 584  * @base: Block device that will become the new base, or %NULL to
 585  * flatten the whole backing file chain onto @bs.
 586  * @base_id: The file name that will be written to @bs as the new
 587  * backing file if the job completes.  Ignored if @base is %NULL.
 588  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 589  * @on_error: The action to take upon error.
 590  * @cb: Completion function for the job.
 591  * @opaque: Opaque pointer value passed to @cb.
 592  * @errp: Error object.
 593  *
 594  * Start a streaming operation on @bs.  Clusters that are unallocated
 595  * in @bs, but allocated in any image between @base and @bs (both
 596  * exclusive) will be written to @bs.  At the end of a successful
 597  * streaming job, the backing file of @bs will be changed to
 598  * @base_id in the written image and to @base in the live BlockDriverState.
 599  */
 600 void stream_start(BlockDriverState *bs, BlockDriverState *base,
 601                   const char *base_id, int64_t speed, BlockdevOnError on_error,
 602                   BlockCompletionFunc *cb,
 603                   void *opaque, Error **errp);
 604
 605 /**
 606  * commit_start:
 607  * @bs: Active block device.
 608  * @top: Top block device to be committed.
 609  * @base: Block device that will be written into, and become the new top.
 610  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 611  * @on_error: The action to take upon error.
 612  * @cb: Completion function for the job.
 613  * @opaque: Opaque pointer value passed to @cb.
 614  * @backing_file_str: String to use as the backing file in @top's overlay
 615  * @errp: Error object.
 616  *
 617  */
 618 void commit_start(BlockDriverState *bs, BlockDriverState *base,
 619                  BlockDriverState *top, int64_t speed,
 620                  BlockdevOnError on_error, BlockCompletionFunc *cb,
 621                  void *opaque, const char *backing_file_str, Error **errp);
 622 /**
 623  * commit_active_start:
 624  * @bs: Active block device to be committed.
 625  * @base: Block device that will be written into, and become the new top.
 626  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 627  * @on_error: The action to take upon error.
 628  * @cb: Completion function for the job.
 629  * @opaque: Opaque pointer value passed to @cb.
 630  * @errp: Error object.
 631  *
 632  */
 633 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
 634                          int64_t speed,
 635                          BlockdevOnError on_error,
 636                          BlockCompletionFunc *cb,
 637                          void *opaque, Error **errp);
 638 /*
 639  * mirror_start:
 640  * @bs: Block device to operate on.
 641  * @target: Block device to write to.
 642  * @replaces: Block graph node name to replace once the mirror is done. Can
 643  *            only be used when full mirroring is selected.
 644  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 645  * @granularity: The chosen granularity for the dirty bitmap.
 646  * @buf_size: The amount of data that can be in flight at one time.
 647  * @mode: Whether to collapse all images in the chain to the target.
 648  * @on_source_error: The action to take upon error reading from the source.
 649  * @on_target_error: The action to take upon error writing to the target.
 650  * @unmap: Whether to unmap target where source sectors only contain zeroes.
 651  * @cb: Completion function for the job.
 652  * @opaque: Opaque pointer value passed to @cb.
 653  * @errp: Error object.
 654  *
 655  * Start a mirroring operation on @bs.  Clusters that are allocated
 656  * in @bs will be written to @bs until the job is cancelled or
 657  * manually completed.  At the end of a successful mirroring job,
 658  * @bs will be switched to read from @target.
 659  */
 660 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 661                   const char *replaces,
 662                   int64_t speed, uint32_t granularity, int64_t buf_size,
 663                   MirrorSyncMode mode, BlockdevOnError on_source_error,
 664                   BlockdevOnError on_target_error,
 665                   bool unmap,
 666                   BlockCompletionFunc *cb,
 667                   void *opaque, Error **errp);
 668
 669 /*
 670  * backup_start:
 671  * @bs: Block device to operate on.
 672  * @target: Block device to write to.
 673  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 674  * @sync_mode: What parts of the disk image should be copied to the destination.
 675  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
 676  * @on_source_error: The action to take upon error reading from the source.
 677  * @on_target_error: The action to take upon error writing to the target.
 678  * @cb: Completion function for the job.
 679  * @opaque: Opaque pointer value passed to @cb.
 680  * @txn: Transaction that this job is part of (may be NULL).
 681  *
 682  * Start a backup operation on @bs.  Clusters in @bs are written to @target
 683  * until the job is cancelled or manually completed.
 684  */
 685 void backup_start(BlockDriverState *bs, BlockDriverState *target,
 686                   int64_t speed, MirrorSyncMode sync_mode,
 687                   BdrvDirtyBitmap *sync_bitmap,
 688                   BlockdevOnError on_source_error,
 689                   BlockdevOnError on_target_error,
 690                   BlockCompletionFunc *cb, void *opaque,
 691                   BlockJobTxn *txn, Error **errp);
 692
 693 void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
 694
 695 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
 696 bool blk_dev_has_removable_media(BlockBackend *blk);
 697 void blk_dev_eject_request(BlockBackend *blk, bool force);
 698 bool blk_dev_is_tray_open(BlockBackend *blk);
 699 bool blk_dev_is_medium_locked(BlockBackend *blk);
 700 void blk_dev_resize_cb(BlockBackend *blk);
 701
 702 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
 703 bool bdrv_requests_pending(BlockDriverState *bs);
 704
 705 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
 706 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
 707
 708 #endif /* BLOCK_INT_H */