qemu/include/block/block_int.h
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   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
  63enum BdrvTrackedRequestType {
  64    BDRV_TRACKED_READ,
  65    BDRV_TRACKED_WRITE,
  66    BDRV_TRACKED_FLUSH,
  67    BDRV_TRACKED_IOCTL,
  68    BDRV_TRACKED_DISCARD,
  69};
  70
  71typedef 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
  88struct 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    int coroutine_fn (*bdrv_co_writev_flags)(BlockDriverState *bs,
 159        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
 160
 161    int supported_write_flags;
 162
 163    /*
 164     * Efficiently zero a region of the disk image.  Typically an image format
 165     * would use a compact metadata representation to implement this.  This
 166     * function pointer may be NULL and .bdrv_co_writev() will be called
 167     * instead.
 168     */
 169    int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 170        int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
 171    int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 172        int64_t sector_num, int nb_sectors);
 173    int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
 174        int64_t sector_num, int nb_sectors, int *pnum,
 175        BlockDriverState **file);
 176
 177    /*
 178     * Invalidate any cached meta-data.
 179     */
 180    void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
 181    int (*bdrv_inactivate)(BlockDriverState *bs);
 182
 183    /*
 184     * Flushes all data for all layers by calling bdrv_co_flush for underlying
 185     * layers, if needed. This function is needed for deterministic
 186     * synchronization of the flush finishing callback.
 187     */
 188    int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
 189
 190    /*
 191     * Flushes all data that was already written to the OS all the way down to
 192     * the disk (for example raw-posix calls fsync()).
 193     */
 194    int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 195
 196    /*
 197     * Flushes all internal caches to the OS. The data may still sit in a
 198     * writeback cache of the host OS, but it will survive a crash of the qemu
 199     * process.
 200     */
 201    int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 202
 203    const char *protocol_name;
 204    int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 205
 206    int64_t (*bdrv_getlength)(BlockDriverState *bs);
 207    bool has_variable_length;
 208    int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 209
 210    int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 211                                 const uint8_t *buf, int nb_sectors);
 212
 213    int (*bdrv_snapshot_create)(BlockDriverState *bs,
 214                                QEMUSnapshotInfo *sn_info);
 215    int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 216                              const char *snapshot_id);
 217    int (*bdrv_snapshot_delete)(BlockDriverState *bs,
 218                                const char *snapshot_id,
 219                                const char *name,
 220                                Error **errp);
 221    int (*bdrv_snapshot_list)(BlockDriverState *bs,
 222                              QEMUSnapshotInfo **psn_info);
 223    int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 224                                  const char *snapshot_id,
 225                                  const char *name,
 226                                  Error **errp);
 227    int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 228    ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
 229
 230    int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
 231                             int64_t pos);
 232    int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 233                             int64_t pos, int size);
 234
 235    int (*bdrv_change_backing_file)(BlockDriverState *bs,
 236        const char *backing_file, const char *backing_fmt);
 237
 238    /* removable device specific */
 239    bool (*bdrv_is_inserted)(BlockDriverState *bs);
 240    int (*bdrv_media_changed)(BlockDriverState *bs);
 241    void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 242    void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 243
 244    /* to control generic scsi devices */
 245    BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 246        unsigned long int req, void *buf,
 247        BlockCompletionFunc *cb, void *opaque);
 248
 249    /* List of options for creating images, terminated by name == NULL */
 250    QemuOptsList *create_opts;
 251
 252    /*
 253     * Returns 0 for completed check, -errno for internal errors.
 254     * The check results are stored in result.
 255     */
 256    int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 257        BdrvCheckMode fix);
 258
 259    int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
 260                              BlockDriverAmendStatusCB *status_cb,
 261                              void *cb_opaque);
 262
 263    void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
 264
 265    /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 266    int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 267        const char *tag);
 268    int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
 269        const char *tag);
 270    int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 271    bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 272
 273    void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
 274
 275    /*
 276     * Returns 1 if newly created images are guaranteed to contain only
 277     * zeros, 0 otherwise.
 278     */
 279    int (*bdrv_has_zero_init)(BlockDriverState *bs);
 280
 281    /* Remove fd handlers, timers, and other event loop callbacks so the event
 282     * loop is no longer in use.  Called with no in-flight requests and in
 283     * depth-first traversal order with parents before child nodes.
 284     */
 285    void (*bdrv_detach_aio_context)(BlockDriverState *bs);
 286
 287    /* Add fd handlers, timers, and other event loop callbacks so I/O requests
 288     * can be processed again.  Called with no in-flight requests and in
 289     * depth-first traversal order with child nodes before parent nodes.
 290     */
 291    void (*bdrv_attach_aio_context)(BlockDriverState *bs,
 292                                    AioContext *new_context);
 293
 294    /* io queue for linux-aio */
 295    void (*bdrv_io_plug)(BlockDriverState *bs);
 296    void (*bdrv_io_unplug)(BlockDriverState *bs);
 297    void (*bdrv_flush_io_queue)(BlockDriverState *bs);
 298
 299    /**
 300     * Try to get @bs's logical and physical block size.
 301     * On success, store them in @bsz and return zero.
 302     * On failure, return negative errno.
 303     */
 304    int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
 305    /**
 306     * Try to get @bs's geometry (cyls, heads, sectors)
 307     * On success, store them in @geo and return 0.
 308     * On failure return -errno.
 309     * Only drivers that want to override guest geometry implement this
 310     * callback; see hd_geometry_guess().
 311     */
 312    int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
 313
 314    /**
 315     * Drain and stop any internal sources of requests in the driver, and
 316     * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
 317     */
 318    void (*bdrv_drain)(BlockDriverState *bs);
 319
 320    QLIST_ENTRY(BlockDriver) list;
 321};
 322
 323typedef struct BlockLimits {
 324    /* maximum number of sectors that can be discarded at once */
 325    int max_discard;
 326
 327    /* optimal alignment for discard requests in sectors */
 328    int64_t discard_alignment;
 329
 330    /* maximum number of sectors that can zeroized at once */
 331    int max_write_zeroes;
 332
 333    /* optimal alignment for write zeroes requests in sectors */
 334    int64_t write_zeroes_alignment;
 335
 336    /* optimal transfer length in sectors */
 337    int opt_transfer_length;
 338
 339    /* maximal transfer length in sectors */
 340    int max_transfer_length;
 341
 342    /* memory alignment so that no bounce buffer is needed */
 343    size_t min_mem_alignment;
 344
 345    /* memory alignment for bounce buffer */
 346    size_t opt_mem_alignment;
 347
 348    /* maximum number of iovec elements */
 349    int max_iov;
 350} BlockLimits;
 351
 352typedef struct BdrvOpBlocker BdrvOpBlocker;
 353
 354typedef struct BdrvAioNotifier {
 355    void (*attached_aio_context)(AioContext *new_context, void *opaque);
 356    void (*detach_aio_context)(void *opaque);
 357
 358    void *opaque;
 359
 360    QLIST_ENTRY(BdrvAioNotifier) list;
 361} BdrvAioNotifier;
 362
 363struct BdrvChildRole {
 364    void (*inherit_options)(int *child_flags, QDict *child_options,
 365                            int parent_flags, QDict *parent_options);
 366};
 367
 368extern const BdrvChildRole child_file;
 369extern const BdrvChildRole child_format;
 370
 371struct BdrvChild {
 372    BlockDriverState *bs;
 373    char *name;
 374    const BdrvChildRole *role;
 375    QLIST_ENTRY(BdrvChild) next;
 376    QLIST_ENTRY(BdrvChild) next_parent;
 377};
 378
 379/*
 380 * Note: the function bdrv_append() copies and swaps contents of
 381 * BlockDriverStates, so if you add new fields to this struct, please
 382 * inspect bdrv_append() to determine if the new fields need to be
 383 * copied as well.
 384 */
 385struct BlockDriverState {
 386    int64_t total_sectors; /* if we are reading a disk image, give its
 387                              size in sectors */
 388    int read_only; /* if true, the media is read only */
 389    int open_flags; /* flags used to open the file, re-used for re-open */
 390    int encrypted; /* if true, the media is encrypted */
 391    int valid_key; /* if true, a valid encryption key has been set */
 392    int sg;        /* if true, the device is a /dev/sg* */
 393    int copy_on_read; /* if true, copy read backing sectors into image
 394                         note this is a reference count */
 395    bool probed;
 396
 397    BlockDriver *drv; /* NULL means no media */
 398    void *opaque;
 399
 400    BlockBackend *blk;          /* owning backend, if any */
 401
 402    AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
 403    /* long-running tasks intended to always use the same AioContext as this
 404     * BDS may register themselves in this list to be notified of changes
 405     * regarding this BDS's context */
 406    QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
 407
 408    char filename[PATH_MAX];
 409    char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
 410                                    this file image */
 411    char backing_format[16]; /* if non-zero and backing_file exists */
 412
 413    QDict *full_open_options;
 414    char exact_filename[PATH_MAX];
 415
 416    BdrvChild *backing;
 417    BdrvChild *file;
 418
 419    /* Callback before write request is processed */
 420    NotifierWithReturnList before_write_notifiers;
 421
 422    /* number of in-flight serialising requests */
 423    unsigned int serialising_in_flight;
 424
 425    /* I/O throttling.
 426     * throttle_state tells us if this BDS has I/O limits configured.
 427     * io_limits_enabled tells us if they are currently being
 428     * enforced, but it can be temporarily set to false */
 429    CoQueue      throttled_reqs[2];
 430    bool         io_limits_enabled;
 431    /* The following fields are protected by the ThrottleGroup lock.
 432     * See the ThrottleGroup documentation for details. */
 433    ThrottleState *throttle_state;
 434    ThrottleTimers throttle_timers;
 435    unsigned       pending_reqs[2];
 436    QLIST_ENTRY(BlockDriverState) round_robin;
 437
 438    /* Offset after the highest byte written to */
 439    uint64_t wr_highest_offset;
 440
 441    /* I/O Limits */
 442    BlockLimits bl;
 443
 444    /* Whether produces zeros when read beyond eof */
 445    bool zero_beyond_eof;
 446
 447    /* Alignment requirement for offset/length of I/O requests */
 448    unsigned int request_alignment;
 449
 450    /* the following member gives a name to every node on the bs graph. */
 451    char node_name[32];
 452    /* element of the list of named nodes building the graph */
 453    QTAILQ_ENTRY(BlockDriverState) node_list;
 454    /* element of the list of all BlockDriverStates (all_bdrv_states) */
 455    QTAILQ_ENTRY(BlockDriverState) bs_list;
 456    /* element of the list of monitor-owned BDS */
 457    QTAILQ_ENTRY(BlockDriverState) monitor_list;
 458    QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
 459    int refcnt;
 460
 461    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 462
 463    /* operation blockers */
 464    QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
 465
 466    /* long-running background operation */
 467    BlockJob *job;
 468
 469    /* The node that this node inherited default options from (and a reopen on
 470     * which can affect this node by changing these defaults). This is always a
 471     * parent node of this node. */
 472    BlockDriverState *inherits_from;
 473    QLIST_HEAD(, BdrvChild) children;
 474    QLIST_HEAD(, BdrvChild) parents;
 475
 476    QDict *options;
 477    QDict *explicit_options;
 478    BlockdevDetectZeroesOptions detect_zeroes;
 479
 480    /* The error object in use for blocking operations on backing_hd */
 481    Error *backing_blocker;
 482
 483    /* threshold limit for writes, in bytes. "High water mark". */
 484    uint64_t write_threshold_offset;
 485    NotifierWithReturn write_threshold_notifier;
 486
 487    int quiesce_counter;
 488};
 489
 490struct BlockBackendRootState {
 491    int open_flags;
 492    bool read_only;
 493    BlockdevDetectZeroesOptions detect_zeroes;
 494
 495    char *throttle_group;
 496    ThrottleState *throttle_state;
 497};
 498
 499static inline BlockDriverState *backing_bs(BlockDriverState *bs)
 500{
 501    return bs->backing ? bs->backing->bs : NULL;
 502}
 503
 504
 505/* Essential block drivers which must always be statically linked into qemu, and
 506 * which therefore can be accessed without using bdrv_find_format() */
 507extern BlockDriver bdrv_file;
 508extern BlockDriver bdrv_raw;
 509extern BlockDriver bdrv_qcow2;
 510
 511/**
 512 * bdrv_setup_io_funcs:
 513 *
 514 * Prepare a #BlockDriver for I/O request processing by populating
 515 * unimplemented coroutine and AIO interfaces with generic wrapper functions
 516 * that fall back to implemented interfaces.
 517 */
 518void bdrv_setup_io_funcs(BlockDriver *bdrv);
 519
 520int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
 521    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
 522    BdrvRequestFlags flags);
 523int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
 524    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
 525    BdrvRequestFlags flags);
 526
 527int get_tmp_filename(char *filename, int size);
 528BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
 529                            const char *filename);
 530
 531void bdrv_set_io_limits(BlockDriverState *bs,
 532                        ThrottleConfig *cfg);
 533
 534
 535/**
 536 * bdrv_add_before_write_notifier:
 537 *
 538 * Register a callback that is invoked before write requests are processed but
 539 * after any throttling or waiting for overlapping requests.
 540 */
 541void bdrv_add_before_write_notifier(BlockDriverState *bs,
 542                                    NotifierWithReturn *notifier);
 543
 544/**
 545 * bdrv_detach_aio_context:
 546 *
 547 * May be called from .bdrv_detach_aio_context() to detach children from the
 548 * current #AioContext.  This is only needed by block drivers that manage their
 549 * own children.  Both ->file and ->backing are automatically handled and
 550 * block drivers should not call this function on them explicitly.
 551 */
 552void bdrv_detach_aio_context(BlockDriverState *bs);
 553
 554/**
 555 * bdrv_attach_aio_context:
 556 *
 557 * May be called from .bdrv_attach_aio_context() to attach children to the new
 558 * #AioContext.  This is only needed by block drivers that manage their own
 559 * children.  Both ->file and ->backing are automatically handled and block
 560 * drivers should not call this function on them explicitly.
 561 */
 562void bdrv_attach_aio_context(BlockDriverState *bs,
 563                             AioContext *new_context);
 564
 565/**
 566 * bdrv_add_aio_context_notifier:
 567 *
 568 * If a long-running job intends to be always run in the same AioContext as a
 569 * certain BDS, it may use this function to be notified of changes regarding the
 570 * association of the BDS to an AioContext.
 571 *
 572 * attached_aio_context() is called after the target BDS has been attached to a
 573 * new AioContext; detach_aio_context() is called before the target BDS is being
 574 * detached from its old AioContext.
 575 */
 576void bdrv_add_aio_context_notifier(BlockDriverState *bs,
 577        void (*attached_aio_context)(AioContext *new_context, void *opaque),
 578        void (*detach_aio_context)(void *opaque), void *opaque);
 579
 580/**
 581 * bdrv_remove_aio_context_notifier:
 582 *
 583 * Unsubscribe of change notifications regarding the BDS's AioContext. The
 584 * parameters given here have to be the same as those given to
 585 * bdrv_add_aio_context_notifier().
 586 */
 587void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
 588                                      void (*aio_context_attached)(AioContext *,
 589                                                                   void *),
 590                                      void (*aio_context_detached)(void *),
 591                                      void *opaque);
 592
 593#ifdef _WIN32
 594int is_windows_drive(const char *filename);
 595#endif
 596
 597/**
 598 * stream_start:
 599 * @bs: Block device to operate on.
 600 * @base: Block device that will become the new base, or %NULL to
 601 * flatten the whole backing file chain onto @bs.
 602 * @base_id: The file name that will be written to @bs as the new
 603 * backing file if the job completes.  Ignored if @base is %NULL.
 604 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 605 * @on_error: The action to take upon error.
 606 * @cb: Completion function for the job.
 607 * @opaque: Opaque pointer value passed to @cb.
 608 * @errp: Error object.
 609 *
 610 * Start a streaming operation on @bs.  Clusters that are unallocated
 611 * in @bs, but allocated in any image between @base and @bs (both
 612 * exclusive) will be written to @bs.  At the end of a successful
 613 * streaming job, the backing file of @bs will be changed to
 614 * @base_id in the written image and to @base in the live BlockDriverState.
 615 */
 616void stream_start(BlockDriverState *bs, BlockDriverState *base,
 617                  const char *base_id, int64_t speed, BlockdevOnError on_error,
 618                  BlockCompletionFunc *cb,
 619                  void *opaque, Error **errp);
 620
 621/**
 622 * commit_start:
 623 * @bs: Active block device.
 624 * @top: Top 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 * @backing_file_str: String to use as the backing file in @top's overlay
 631 * @errp: Error object.
 632 *
 633 */
 634void commit_start(BlockDriverState *bs, BlockDriverState *base,
 635                 BlockDriverState *top, int64_t speed,
 636                 BlockdevOnError on_error, BlockCompletionFunc *cb,
 637                 void *opaque, const char *backing_file_str, Error **errp);
 638/**
 639 * commit_active_start:
 640 * @bs: Active block device to be committed.
 641 * @base: Block device that will be written into, and become the new top.
 642 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 643 * @on_error: The action to take upon error.
 644 * @cb: Completion function for the job.
 645 * @opaque: Opaque pointer value passed to @cb.
 646 * @errp: Error object.
 647 *
 648 */
 649void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
 650                         int64_t speed,
 651                         BlockdevOnError on_error,
 652                         BlockCompletionFunc *cb,
 653                         void *opaque, Error **errp);
 654/*
 655 * mirror_start:
 656 * @bs: Block device to operate on.
 657 * @target: Block device to write to.
 658 * @replaces: Block graph node name to replace once the mirror is done. Can
 659 *            only be used when full mirroring is selected.
 660 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 661 * @granularity: The chosen granularity for the dirty bitmap.
 662 * @buf_size: The amount of data that can be in flight at one time.
 663 * @mode: Whether to collapse all images in the chain to the target.
 664 * @on_source_error: The action to take upon error reading from the source.
 665 * @on_target_error: The action to take upon error writing to the target.
 666 * @unmap: Whether to unmap target where source sectors only contain zeroes.
 667 * @cb: Completion function for the job.
 668 * @opaque: Opaque pointer value passed to @cb.
 669 * @errp: Error object.
 670 *
 671 * Start a mirroring operation on @bs.  Clusters that are allocated
 672 * in @bs will be written to @bs until the job is cancelled or
 673 * manually completed.  At the end of a successful mirroring job,
 674 * @bs will be switched to read from @target.
 675 */
 676void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 677                  const char *replaces,
 678                  int64_t speed, uint32_t granularity, int64_t buf_size,
 679                  MirrorSyncMode mode, BlockdevOnError on_source_error,
 680                  BlockdevOnError on_target_error,
 681                  bool unmap,
 682                  BlockCompletionFunc *cb,
 683                  void *opaque, Error **errp);
 684
 685/*
 686 * backup_start:
 687 * @bs: Block device to operate on.
 688 * @target: Block device to write to.
 689 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 690 * @sync_mode: What parts of the disk image should be copied to the destination.
 691 * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
 692 * @on_source_error: The action to take upon error reading from the source.
 693 * @on_target_error: The action to take upon error writing to the target.
 694 * @cb: Completion function for the job.
 695 * @opaque: Opaque pointer value passed to @cb.
 696 * @txn: Transaction that this job is part of (may be NULL).
 697 *
 698 * Start a backup operation on @bs.  Clusters in @bs are written to @target
 699 * until the job is cancelled or manually completed.
 700 */
 701void backup_start(BlockDriverState *bs, BlockDriverState *target,
 702                  int64_t speed, MirrorSyncMode sync_mode,
 703                  BdrvDirtyBitmap *sync_bitmap,
 704                  BlockdevOnError on_source_error,
 705                  BlockdevOnError on_target_error,
 706                  BlockCompletionFunc *cb, void *opaque,
 707                  BlockJobTxn *txn, Error **errp);
 708
 709void hmp_drive_add_node(Monitor *mon, const char *optstr);
 710
 711BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
 712                                  const char *child_name,
 713                                  const BdrvChildRole *child_role);
 714void bdrv_root_unref_child(BdrvChild *child);
 715
 716void blk_dev_change_media_cb(BlockBackend *blk, bool load);
 717bool blk_dev_has_removable_media(BlockBackend *blk);
 718bool blk_dev_has_tray(BlockBackend *blk);
 719void blk_dev_eject_request(BlockBackend *blk, bool force);
 720bool blk_dev_is_tray_open(BlockBackend *blk);
 721bool blk_dev_is_medium_locked(BlockBackend *blk);
 722void blk_dev_resize_cb(BlockBackend *blk);
 723
 724void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
 725bool bdrv_requests_pending(BlockDriverState *bs);
 726
 727void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
 728void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
 729
 730void blockdev_close_all_bdrv_states(void);
 731
 732#endif /* BLOCK_INT_H */
 733