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 "qemu/option.h"
  30 #include "qemu/queue.h"
  31 #include "qemu/coroutine.h"
  32 #include "qemu/timer.h"
  33 #include "qapi-types.h"
  34 #include "qemu/hbitmap.h"
  35 #include "block/snapshot.h"
  36 #include "qemu/main-loop.h"
  37 #include "qemu/throttle.h"
  38
  39 #define BLOCK_FLAG_ENCRYPT          1
  40 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
  41
  42 #define BLOCK_OPT_SIZE              "size"
  43 #define BLOCK_OPT_ENCRYPT           "encryption"
  44 #define BLOCK_OPT_COMPAT6           "compat6"
  45 #define BLOCK_OPT_HWVERSION         "hwversion"
  46 #define BLOCK_OPT_BACKING_FILE      "backing_file"
  47 #define BLOCK_OPT_BACKING_FMT       "backing_fmt"
  48 #define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
  49 #define BLOCK_OPT_TABLE_SIZE        "table_size"
  50 #define BLOCK_OPT_PREALLOC          "preallocation"
  51 #define BLOCK_OPT_SUBFMT            "subformat"
  52 #define BLOCK_OPT_COMPAT_LEVEL      "compat"
  53 #define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
  54 #define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
  55 #define BLOCK_OPT_REDUNDANCY        "redundancy"
  56 #define BLOCK_OPT_NOCOW             "nocow"
  57 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
  58 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
  59
  60 #define BLOCK_PROBE_BUF_SIZE        512
  61
  62 enum BdrvTrackedRequestType {
  63     BDRV_TRACKED_READ,
  64     BDRV_TRACKED_WRITE,
  65     BDRV_TRACKED_FLUSH,
  66     BDRV_TRACKED_IOCTL,
  67     BDRV_TRACKED_DISCARD,
  68 };
  69
  70 typedef struct BdrvTrackedRequest {
  71     BlockDriverState *bs;
  72     int64_t offset;
  73     unsigned int bytes;
  74     enum BdrvTrackedRequestType type;
  75
  76     bool serialising;
  77     int64_t overlap_offset;
  78     unsigned int overlap_bytes;
  79
  80     QLIST_ENTRY(BdrvTrackedRequest) list;
  81     Coroutine *co; /* owner, used for deadlock detection */
  82     CoQueue wait_queue; /* coroutines blocked on this request */
  83
  84     struct BdrvTrackedRequest *waiting_for;
  85 } BdrvTrackedRequest;
  86
  87 struct BlockDriver {
  88     const char *format_name;
  89     int instance_size;
  90
  91     /* set to true if the BlockDriver is a block filter */
  92     bool is_filter;
  93     /* for snapshots block filter like Quorum can implement the
  94      * following recursive callback.
  95      * It's purpose is to recurse on the filter children while calling
  96      * bdrv_recurse_is_first_non_filter on them.
  97      * For a sample implementation look in the future Quorum block filter.
  98      */
  99     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
 100                                              BlockDriverState *candidate);
 101
 102     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
 103     int (*bdrv_probe_device)(const char *filename);
 104
 105     /* Any driver implementing this callback is expected to be able to handle
 106      * NULL file names in its .bdrv_open() implementation */
 107     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
 108     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
 109      * this field set to true, except ones that are defined only by their
 110      * child's bs.
 111      * An example of the last type will be the quorum block driver.
 112      */
 113     bool bdrv_needs_filename;
 114
 115     /* Set if a driver can support backing files */
 116     bool supports_backing;
 117
 118     /* For handling image reopen for split or non-split files */
 119     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
 120                                BlockReopenQueue *queue, Error **errp);
 121     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
 122     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
 123     void (*bdrv_join_options)(QDict *options, QDict *old_options);
 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     void (*bdrv_close)(BlockDriverState *bs);
 130     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
 131     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 132     int (*bdrv_make_empty)(BlockDriverState *bs);
 133
 134     void (*bdrv_refresh_filename)(BlockDriverState *bs, QDict *options);
 135
 136     /* aio */
 137     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 138         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 139         BlockCompletionFunc *cb, void *opaque);
 140     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 141         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 142         BlockCompletionFunc *cb, void *opaque);
 143     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 144         BlockCompletionFunc *cb, void *opaque);
 145     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 146         int64_t sector_num, int nb_sectors,
 147         BlockCompletionFunc *cb, void *opaque);
 148
 149     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 150         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 151     int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
 152         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
 153     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 154         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 155     int coroutine_fn (*bdrv_co_writev_flags)(BlockDriverState *bs,
 156         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
 157     int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
 158         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
 159
 160     /*
 161      * Efficiently zero a region of the disk image.  Typically an image format
 162      * would use a compact metadata representation to implement this.  This
 163      * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
 164      * will be called instead.
 165      */
 166     int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
 167         int64_t offset, int count, BdrvRequestFlags flags);
 168     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 169         int64_t sector_num, int nb_sectors);
 170     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
 171         int64_t sector_num, int nb_sectors, int *pnum,
 172         BlockDriverState **file);
 173
 174     /*
 175      * Invalidate any cached meta-data.
 176      */
 177     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
 178     int (*bdrv_inactivate)(BlockDriverState *bs);
 179
 180     /*
 181      * Flushes all data for all layers by calling bdrv_co_flush for underlying
 182      * layers, if needed. This function is needed for deterministic
 183      * synchronization of the flush finishing callback.
 184      */
 185     int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
 186
 187     /*
 188      * Flushes all data that was already written to the OS all the way down to
 189      * the disk (for example raw-posix calls fsync()).
 190      */
 191     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 192
 193     /*
 194      * Flushes all internal caches to the OS. The data may still sit in a
 195      * writeback cache of the host OS, but it will survive a crash of the qemu
 196      * process.
 197      */
 198     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 199
 200     const char *protocol_name;
 201     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 202
 203     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 204     bool has_variable_length;
 205     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 206
 207     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 208                                  const uint8_t *buf, int nb_sectors);
 209
 210     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 211                                 QEMUSnapshotInfo *sn_info);
 212     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 213                               const char *snapshot_id);
 214     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
 215                                 const char *snapshot_id,
 216                                 const char *name,
 217                                 Error **errp);
 218     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 219                               QEMUSnapshotInfo **psn_info);
 220     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 221                                   const char *snapshot_id,
 222                                   const char *name,
 223                                   Error **errp);
 224     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 225     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
 226
 227     int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
 228                                           QEMUIOVector *qiov,
 229                                           int64_t pos);
 230     int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
 231                                           QEMUIOVector *qiov,
 232                                           int64_t pos);
 233
 234     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 235         const char *backing_file, const char *backing_fmt);
 236
 237     /* removable device specific */
 238     bool (*bdrv_is_inserted)(BlockDriverState *bs);
 239     int (*bdrv_media_changed)(BlockDriverState *bs);
 240     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 241     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 242
 243     /* to control generic scsi devices */
 244     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 245         unsigned long int req, void *buf,
 246         BlockCompletionFunc *cb, void *opaque);
 247
 248     /* List of options for creating images, terminated by name == NULL */
 249     QemuOptsList *create_opts;
 250
 251     /*
 252      * Returns 0 for completed check, -errno for internal errors.
 253      * The check results are stored in result.
 254      */
 255     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 256         BdrvCheckMode fix);
 257
 258     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
 259                               BlockDriverAmendStatusCB *status_cb,
 260                               void *cb_opaque);
 261
 262     void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
 263
 264     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 265     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 266         const char *tag);
 267     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
 268         const char *tag);
 269     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 270     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 271
 272     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
 273
 274     /*
 275      * Returns 1 if newly created images are guaranteed to contain only
 276      * zeros, 0 otherwise.
 277      */
 278     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 279
 280     /* Remove fd handlers, timers, and other event loop callbacks so the event
 281      * loop is no longer in use.  Called with no in-flight requests and in
 282      * depth-first traversal order with parents before child nodes.
 283      */
 284     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
 285
 286     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
 287      * can be processed again.  Called with no in-flight requests and in
 288      * depth-first traversal order with child nodes before parent nodes.
 289      */
 290     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
 291                                     AioContext *new_context);
 292
 293     /* io queue for linux-aio */
 294     void (*bdrv_io_plug)(BlockDriverState *bs);
 295     void (*bdrv_io_unplug)(BlockDriverState *bs);
 296
 297     /**
 298      * Try to get @bs's logical and physical block size.
 299      * On success, store them in @bsz and return zero.
 300      * On failure, return negative errno.
 301      */
 302     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
 303     /**
 304      * Try to get @bs's geometry (cyls, heads, sectors)
 305      * On success, store them in @geo and return 0.
 306      * On failure return -errno.
 307      * Only drivers that want to override guest geometry implement this
 308      * callback; see hd_geometry_guess().
 309      */
 310     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
 311
 312     /**
 313      * Drain and stop any internal sources of requests in the driver, and
 314      * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
 315      */
 316     void (*bdrv_drain)(BlockDriverState *bs);
 317
 318     void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
 319                            Error **errp);
 320     void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
 321                            Error **errp);
 322
 323     QLIST_ENTRY(BlockDriver) list;
 324 };
 325
 326 typedef struct BlockLimits {
 327     /* maximum number of sectors that can be discarded at once */
 328     int max_discard;
 329
 330     /* optimal alignment for discard requests in sectors */
 331     int64_t discard_alignment;
 332
 333     /* maximum number of bytes that can zeroized at once (since it is
 334      * signed, it must be < 2G, if set) */
 335     int32_t max_pwrite_zeroes;
 336
 337     /* optimal alignment for write zeroes requests in bytes, must be
 338      * power of 2, and less than max_pwrite_zeroes if that is set */
 339     uint32_t pwrite_zeroes_alignment;
 340
 341     /* optimal transfer length in sectors */
 342     int opt_transfer_length;
 343
 344     /* maximal transfer length in sectors */
 345     int max_transfer_length;
 346
 347     /* memory alignment so that no bounce buffer is needed */
 348     size_t min_mem_alignment;
 349
 350     /* memory alignment for bounce buffer */
 351     size_t opt_mem_alignment;
 352
 353     /* maximum number of iovec elements */
 354     int max_iov;
 355 } BlockLimits;
 356
 357 typedef struct BdrvOpBlocker BdrvOpBlocker;
 358
 359 typedef struct BdrvAioNotifier {
 360     void (*attached_aio_context)(AioContext *new_context, void *opaque);
 361     void (*detach_aio_context)(void *opaque);
 362
 363     void *opaque;
 364
 365     QLIST_ENTRY(BdrvAioNotifier) list;
 366 } BdrvAioNotifier;
 367
 368 struct BdrvChildRole {
 369     void (*inherit_options)(int *child_flags, QDict *child_options,
 370                             int parent_flags, QDict *parent_options);
 371
 372     void (*change_media)(BdrvChild *child, bool load);
 373     void (*resize)(BdrvChild *child);
 374
 375     /* Returns a name that is supposedly more useful for human users than the
 376      * node name for identifying the node in question (in particular, a BB
 377      * name), or NULL if the parent can't provide a better name. */
 378     const char* (*get_name)(BdrvChild *child);
 379
 380     /*
 381      * If this pair of functions is implemented, the parent doesn't issue new
 382      * requests after returning from .drained_begin() until .drained_end() is
 383      * called.
 384      *
 385      * Note that this can be nested. If drained_begin() was called twice, new
 386      * I/O is allowed only after drained_end() was called twice, too.
 387      */
 388     void (*drained_begin)(BdrvChild *child);
 389     void (*drained_end)(BdrvChild *child);
 390 };
 391
 392 extern const BdrvChildRole child_file;
 393 extern const BdrvChildRole child_format;
 394
 395 struct BdrvChild {
 396     BlockDriverState *bs;
 397     char *name;
 398     const BdrvChildRole *role;
 399     void *opaque;
 400     QLIST_ENTRY(BdrvChild) next;
 401     QLIST_ENTRY(BdrvChild) next_parent;
 402 };
 403
 404 /*
 405  * Note: the function bdrv_append() copies and swaps contents of
 406  * BlockDriverStates, so if you add new fields to this struct, please
 407  * inspect bdrv_append() to determine if the new fields need to be
 408  * copied as well.
 409  */
 410 struct BlockDriverState {
 411     int64_t total_sectors; /* if we are reading a disk image, give its
 412                               size in sectors */
 413     int read_only; /* if true, the media is read only */
 414     int open_flags; /* flags used to open the file, re-used for re-open */
 415     int encrypted; /* if true, the media is encrypted */
 416     int valid_key; /* if true, a valid encryption key has been set */
 417     int sg;        /* if true, the device is a /dev/sg* */
 418     int copy_on_read; /* if true, copy read backing sectors into image
 419                          note this is a reference count */
 420     bool probed;
 421
 422     BlockDriver *drv; /* NULL means no media */
 423     void *opaque;
 424
 425     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
 426     /* long-running tasks intended to always use the same AioContext as this
 427      * BDS may register themselves in this list to be notified of changes
 428      * regarding this BDS's context */
 429     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
 430
 431     char filename[PATH_MAX];
 432     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
 433                                     this file image */
 434     char backing_format[16]; /* if non-zero and backing_file exists */
 435
 436     QDict *full_open_options;
 437     char exact_filename[PATH_MAX];
 438
 439     BdrvChild *backing;
 440     BdrvChild *file;
 441
 442     /* Callback before write request is processed */
 443     NotifierWithReturnList before_write_notifiers;
 444
 445     /* number of in-flight serialising requests */
 446     unsigned int serialising_in_flight;
 447
 448     /* Offset after the highest byte written to */
 449     uint64_t wr_highest_offset;
 450
 451     /* I/O Limits */
 452     BlockLimits bl;
 453
 454     /* Alignment requirement for offset/length of I/O requests */
 455     unsigned int request_alignment;
 456     /* Flags honored during pwrite (so far: BDRV_REQ_FUA) */
 457     unsigned int supported_write_flags;
 458     /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
 459      * BDRV_REQ_MAY_UNMAP) */
 460     unsigned int supported_zero_flags;
 461
 462     /* the following member gives a name to every node on the bs graph. */
 463     char node_name[32];
 464     /* element of the list of named nodes building the graph */
 465     QTAILQ_ENTRY(BlockDriverState) node_list;
 466     /* element of the list of all BlockDriverStates (all_bdrv_states) */
 467     QTAILQ_ENTRY(BlockDriverState) bs_list;
 468     /* element of the list of monitor-owned BDS */
 469     QTAILQ_ENTRY(BlockDriverState) monitor_list;
 470     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
 471     int refcnt;
 472
 473     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 474
 475     /* operation blockers */
 476     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
 477
 478     /* long-running background operation */
 479     BlockJob *job;
 480
 481     /* The node that this node inherited default options from (and a reopen on
 482      * which can affect this node by changing these defaults). This is always a
 483      * parent node of this node. */
 484     BlockDriverState *inherits_from;
 485     QLIST_HEAD(, BdrvChild) children;
 486     QLIST_HEAD(, BdrvChild) parents;
 487
 488     QDict *options;
 489     QDict *explicit_options;
 490     BlockdevDetectZeroesOptions detect_zeroes;
 491
 492     /* The error object in use for blocking operations on backing_hd */
 493     Error *backing_blocker;
 494
 495     /* threshold limit for writes, in bytes. "High water mark". */
 496     uint64_t write_threshold_offset;
 497     NotifierWithReturn write_threshold_notifier;
 498
 499     /* counters for nested bdrv_io_plug and bdrv_io_unplugged_begin */
 500     unsigned io_plugged;
 501     unsigned io_plug_disabled;
 502
 503     int quiesce_counter;
 504 };
 505
 506 struct BlockBackendRootState {
 507     int open_flags;
 508     bool read_only;
 509     BlockdevDetectZeroesOptions detect_zeroes;
 510 };
 511
 512 typedef enum BlockMirrorBackingMode {
 513     /* Reuse the existing backing chain from the source for the target.
 514      * - sync=full: Set backing BDS to NULL.
 515      * - sync=top:  Use source's backing BDS.
 516      * - sync=none: Use source as the backing BDS. */
 517     MIRROR_SOURCE_BACKING_CHAIN,
 518
 519     /* Open the target's backing chain completely anew */
 520     MIRROR_OPEN_BACKING_CHAIN,
 521
 522     /* Do not change the target's backing BDS after job completion */
 523     MIRROR_LEAVE_BACKING_CHAIN,
 524 } BlockMirrorBackingMode;
 525
 526 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
 527 {
 528     return bs->backing ? bs->backing->bs : NULL;
 529 }
 530
 531
 532 /* Essential block drivers which must always be statically linked into qemu, and
 533  * which therefore can be accessed without using bdrv_find_format() */
 534 extern BlockDriver bdrv_file;
 535 extern BlockDriver bdrv_raw;
 536 extern BlockDriver bdrv_qcow2;
 537
 538 /**
 539  * bdrv_setup_io_funcs:
 540  *
 541  * Prepare a #BlockDriver for I/O request processing by populating
 542  * unimplemented coroutine and AIO interfaces with generic wrapper functions
 543  * that fall back to implemented interfaces.
 544  */
 545 void bdrv_setup_io_funcs(BlockDriver *bdrv);
 546
 547 int coroutine_fn bdrv_co_preadv(BlockDriverState *bs,
 548     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
 549     BdrvRequestFlags flags);
 550 int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs,
 551     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
 552     BdrvRequestFlags flags);
 553
 554 int get_tmp_filename(char *filename, int size);
 555 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
 556                             const char *filename);
 557
 558
 559 /**
 560  * bdrv_add_before_write_notifier:
 561  *
 562  * Register a callback that is invoked before write requests are processed but
 563  * after any throttling or waiting for overlapping requests.
 564  */
 565 void bdrv_add_before_write_notifier(BlockDriverState *bs,
 566                                     NotifierWithReturn *notifier);
 567
 568 /**
 569  * bdrv_detach_aio_context:
 570  *
 571  * May be called from .bdrv_detach_aio_context() to detach children from the
 572  * current #AioContext.  This is only needed by block drivers that manage their
 573  * own children.  Both ->file and ->backing are automatically handled and
 574  * block drivers should not call this function on them explicitly.
 575  */
 576 void bdrv_detach_aio_context(BlockDriverState *bs);
 577
 578 /**
 579  * bdrv_attach_aio_context:
 580  *
 581  * May be called from .bdrv_attach_aio_context() to attach children to the new
 582  * #AioContext.  This is only needed by block drivers that manage their own
 583  * children.  Both ->file and ->backing are automatically handled and block
 584  * drivers should not call this function on them explicitly.
 585  */
 586 void bdrv_attach_aio_context(BlockDriverState *bs,
 587                              AioContext *new_context);
 588
 589 /**
 590  * bdrv_add_aio_context_notifier:
 591  *
 592  * If a long-running job intends to be always run in the same AioContext as a
 593  * certain BDS, it may use this function to be notified of changes regarding the
 594  * association of the BDS to an AioContext.
 595  *
 596  * attached_aio_context() is called after the target BDS has been attached to a
 597  * new AioContext; detach_aio_context() is called before the target BDS is being
 598  * detached from its old AioContext.
 599  */
 600 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
 601         void (*attached_aio_context)(AioContext *new_context, void *opaque),
 602         void (*detach_aio_context)(void *opaque), void *opaque);
 603
 604 /**
 605  * bdrv_remove_aio_context_notifier:
 606  *
 607  * Unsubscribe of change notifications regarding the BDS's AioContext. The
 608  * parameters given here have to be the same as those given to
 609  * bdrv_add_aio_context_notifier().
 610  */
 611 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
 612                                       void (*aio_context_attached)(AioContext *,
 613                                                                    void *),
 614                                       void (*aio_context_detached)(void *),
 615                                       void *opaque);
 616
 617 #ifdef _WIN32
 618 int is_windows_drive(const char *filename);
 619 #endif
 620
 621 /**
 622  * stream_start:
 623  * @bs: Block device to operate on.
 624  * @base: Block device that will become the new base, or %NULL to
 625  * flatten the whole backing file chain onto @bs.
 626  * @base_id: The file name that will be written to @bs as the new
 627  * backing file if the job completes.  Ignored if @base is %NULL.
 628  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 629  * @on_error: The action to take upon error.
 630  * @cb: Completion function for the job.
 631  * @opaque: Opaque pointer value passed to @cb.
 632  * @errp: Error object.
 633  *
 634  * Start a streaming operation on @bs.  Clusters that are unallocated
 635  * in @bs, but allocated in any image between @base and @bs (both
 636  * exclusive) will be written to @bs.  At the end of a successful
 637  * streaming job, the backing file of @bs will be changed to
 638  * @base_id in the written image and to @base in the live BlockDriverState.
 639  */
 640 void stream_start(BlockDriverState *bs, BlockDriverState *base,
 641                   const char *base_id, int64_t speed, BlockdevOnError on_error,
 642                   BlockCompletionFunc *cb,
 643                   void *opaque, Error **errp);
 644
 645 /**
 646  * commit_start:
 647  * @bs: Active block device.
 648  * @top: Top block device to be committed.
 649  * @base: Block device that will be written into, and become the new top.
 650  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 651  * @on_error: The action to take upon error.
 652  * @cb: Completion function for the job.
 653  * @opaque: Opaque pointer value passed to @cb.
 654  * @backing_file_str: String to use as the backing file in @top's overlay
 655  * @errp: Error object.
 656  *
 657  */
 658 void commit_start(BlockDriverState *bs, BlockDriverState *base,
 659                  BlockDriverState *top, int64_t speed,
 660                  BlockdevOnError on_error, BlockCompletionFunc *cb,
 661                  void *opaque, const char *backing_file_str, Error **errp);
 662 /**
 663  * commit_active_start:
 664  * @bs: Active block device to be committed.
 665  * @base: Block device that will be written into, and become the new top.
 666  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 667  * @on_error: The action to take upon error.
 668  * @cb: Completion function for the job.
 669  * @opaque: Opaque pointer value passed to @cb.
 670  * @errp: Error object.
 671  *
 672  */
 673 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
 674                          int64_t speed,
 675                          BlockdevOnError on_error,
 676                          BlockCompletionFunc *cb,
 677                          void *opaque, Error **errp);
 678 /*
 679  * mirror_start:
 680  * @bs: Block device to operate on.
 681  * @target: Block device to write to.
 682  * @replaces: Block graph node name to replace once the mirror is done. Can
 683  *            only be used when full mirroring is selected.
 684  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 685  * @granularity: The chosen granularity for the dirty bitmap.
 686  * @buf_size: The amount of data that can be in flight at one time.
 687  * @mode: Whether to collapse all images in the chain to the target.
 688  * @backing_mode: How to establish the target's backing chain after completion.
 689  * @on_source_error: The action to take upon error reading from the source.
 690  * @on_target_error: The action to take upon error writing to the target.
 691  * @unmap: Whether to unmap target where source sectors only contain zeroes.
 692  * @cb: Completion function for the job.
 693  * @opaque: Opaque pointer value passed to @cb.
 694  * @errp: Error object.
 695  *
 696  * Start a mirroring operation on @bs.  Clusters that are allocated
 697  * in @bs will be written to @bs until the job is cancelled or
 698  * manually completed.  At the end of a successful mirroring job,
 699  * @bs will be switched to read from @target.
 700  */
 701 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 702                   const char *replaces,
 703                   int64_t speed, uint32_t granularity, int64_t buf_size,
 704                   MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
 705                   BlockdevOnError on_source_error,
 706                   BlockdevOnError on_target_error,
 707                   bool unmap,
 708                   BlockCompletionFunc *cb,
 709                   void *opaque, Error **errp);
 710
 711 /*
 712  * backup_start:
 713  * @bs: Block device to operate on.
 714  * @target: Block device to write to.
 715  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 716  * @sync_mode: What parts of the disk image should be copied to the destination.
 717  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
 718  * @on_source_error: The action to take upon error reading from the source.
 719  * @on_target_error: The action to take upon error writing to the target.
 720  * @cb: Completion function for the job.
 721  * @opaque: Opaque pointer value passed to @cb.
 722  * @txn: Transaction that this job is part of (may be NULL).
 723  *
 724  * Start a backup operation on @bs.  Clusters in @bs are written to @target
 725  * until the job is cancelled or manually completed.
 726  */
 727 void backup_start(BlockDriverState *bs, BlockDriverState *target,
 728                   int64_t speed, MirrorSyncMode sync_mode,
 729                   BdrvDirtyBitmap *sync_bitmap,
 730                   BlockdevOnError on_source_error,
 731                   BlockdevOnError on_target_error,
 732                   BlockCompletionFunc *cb, void *opaque,
 733                   BlockJobTxn *txn, Error **errp);
 734
 735 void hmp_drive_add_node(Monitor *mon, const char *optstr);
 736
 737 BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
 738                                   const char *child_name,
 739                                   const BdrvChildRole *child_role,
 740                                   void *opaque);
 741 void bdrv_root_unref_child(BdrvChild *child);
 742
 743 const char *bdrv_get_parent_name(const BlockDriverState *bs);
 744 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
 745 bool blk_dev_has_removable_media(BlockBackend *blk);
 746 bool blk_dev_has_tray(BlockBackend *blk);
 747 void blk_dev_eject_request(BlockBackend *blk, bool force);
 748 bool blk_dev_is_tray_open(BlockBackend *blk);
 749 bool blk_dev_is_medium_locked(BlockBackend *blk);
 750
 751 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
 752 bool bdrv_requests_pending(BlockDriverState *bs);
 753
 754 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
 755 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
 756
 757 void blockdev_close_all_bdrv_states(void);
 758
 759 #endif /* BLOCK_INT_H */