qemu/include/block/block_int.h
<<
>>
Prefs
   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/aio-wait.h"
  30#include "qemu/queue.h"
  31#include "qemu/coroutine.h"
  32#include "qemu/stats64.h"
  33#include "qemu/timer.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_LAZY_REFCOUNTS   8
  40
  41#define BLOCK_OPT_SIZE              "size"
  42#define BLOCK_OPT_ENCRYPT           "encryption"
  43#define BLOCK_OPT_ENCRYPT_FORMAT    "encrypt.format"
  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#define BLOCK_OPT_DATA_FILE         "data_file"
  60#define BLOCK_OPT_DATA_FILE_RAW     "data_file_raw"
  61
  62#define BLOCK_PROBE_BUF_SIZE        512
  63
  64enum BdrvTrackedRequestType {
  65    BDRV_TRACKED_READ,
  66    BDRV_TRACKED_WRITE,
  67    BDRV_TRACKED_DISCARD,
  68    BDRV_TRACKED_TRUNCATE,
  69};
  70
  71typedef struct BdrvTrackedRequest {
  72    BlockDriverState *bs;
  73    int64_t offset;
  74    uint64_t bytes;
  75    enum BdrvTrackedRequestType type;
  76
  77    bool serialising;
  78    int64_t overlap_offset;
  79    uint64_t 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. Block filters pass
  93     * certain callbacks that refer to data (see block.c) to their bs->file if
  94     * the driver doesn't implement them. Drivers that do not wish to forward
  95     * must implement them and return -ENOTSUP.
  96     */
  97    bool is_filter;
  98    /* for snapshots block filter like Quorum can implement the
  99     * following recursive callback.
 100     * It's purpose is to recurse on the filter children while calling
 101     * bdrv_recurse_is_first_non_filter on them.
 102     * For a sample implementation look in the future Quorum block filter.
 103     */
 104    bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
 105                                             BlockDriverState *candidate);
 106
 107    int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
 108    int (*bdrv_probe_device)(const char *filename);
 109
 110    /* Any driver implementing this callback is expected to be able to handle
 111     * NULL file names in its .bdrv_open() implementation */
 112    void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
 113    /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
 114     * this field set to true, except ones that are defined only by their
 115     * child's bs.
 116     * An example of the last type will be the quorum block driver.
 117     */
 118    bool bdrv_needs_filename;
 119
 120    /* Set if a driver can support backing files */
 121    bool supports_backing;
 122
 123    /* For handling image reopen for split or non-split files */
 124    int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
 125                               BlockReopenQueue *queue, Error **errp);
 126    void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
 127    void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
 128    void (*bdrv_join_options)(QDict *options, QDict *old_options);
 129
 130    int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
 131                     Error **errp);
 132
 133    /* Protocol drivers should implement this instead of bdrv_open */
 134    int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
 135                          Error **errp);
 136    void (*bdrv_close)(BlockDriverState *bs);
 137    int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts,
 138                                       Error **errp);
 139    int coroutine_fn (*bdrv_co_create_opts)(const char *filename,
 140                                            QemuOpts *opts,
 141                                            Error **errp);
 142    int (*bdrv_make_empty)(BlockDriverState *bs);
 143
 144    /*
 145     * Refreshes the bs->exact_filename field. If that is impossible,
 146     * bs->exact_filename has to be left empty.
 147     */
 148    void (*bdrv_refresh_filename)(BlockDriverState *bs);
 149
 150    /*
 151     * Gathers the open options for all children into @target.
 152     * A simple format driver (without backing file support) might
 153     * implement this function like this:
 154     *
 155     *     QINCREF(bs->file->bs->full_open_options);
 156     *     qdict_put(target, "file", bs->file->bs->full_open_options);
 157     *
 158     * If not specified, the generic implementation will simply put
 159     * all children's options under their respective name.
 160     *
 161     * @backing_overridden is true when bs->backing seems not to be
 162     * the child that would result from opening bs->backing_file.
 163     * Therefore, if it is true, the backing child's options should be
 164     * gathered; otherwise, there is no need since the backing child
 165     * is the one implied by the image header.
 166     *
 167     * Note that ideally this function would not be needed.  Every
 168     * block driver which implements it is probably doing something
 169     * shady regarding its runtime option structure.
 170     */
 171    void (*bdrv_gather_child_options)(BlockDriverState *bs, QDict *target,
 172                                      bool backing_overridden);
 173
 174    /*
 175     * Returns an allocated string which is the directory name of this BDS: It
 176     * will be used to make relative filenames absolute by prepending this
 177     * function's return value to them.
 178     */
 179    char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp);
 180
 181    /* aio */
 182    BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
 183        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
 184        BlockCompletionFunc *cb, void *opaque);
 185    BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
 186        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
 187        BlockCompletionFunc *cb, void *opaque);
 188    BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 189        BlockCompletionFunc *cb, void *opaque);
 190    BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs,
 191        int64_t offset, int bytes,
 192        BlockCompletionFunc *cb, void *opaque);
 193
 194    int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 195        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 196
 197    /**
 198     * @offset: position in bytes to read at
 199     * @bytes: number of bytes to read
 200     * @qiov: the buffers to fill with read data
 201     * @flags: currently unused, always 0
 202     *
 203     * @offset and @bytes will be a multiple of 'request_alignment',
 204     * but the length of individual @qiov elements does not have to
 205     * be a multiple.
 206     *
 207     * @bytes will always equal the total size of @qiov, and will be
 208     * no larger than 'max_transfer'.
 209     *
 210     * The buffer in @qiov may point directly to guest memory.
 211     */
 212    int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
 213        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
 214    int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 215        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
 216    /**
 217     * @offset: position in bytes to write at
 218     * @bytes: number of bytes to write
 219     * @qiov: the buffers containing data to write
 220     * @flags: zero or more bits allowed by 'supported_write_flags'
 221     *
 222     * @offset and @bytes will be a multiple of 'request_alignment',
 223     * but the length of individual @qiov elements does not have to
 224     * be a multiple.
 225     *
 226     * @bytes will always equal the total size of @qiov, and will be
 227     * no larger than 'max_transfer'.
 228     *
 229     * The buffer in @qiov may point directly to guest memory.
 230     */
 231    int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
 232        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
 233
 234    /*
 235     * Efficiently zero a region of the disk image.  Typically an image format
 236     * would use a compact metadata representation to implement this.  This
 237     * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
 238     * will be called instead.
 239     */
 240    int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
 241        int64_t offset, int bytes, BdrvRequestFlags flags);
 242    int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
 243        int64_t offset, int bytes);
 244
 245    /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
 246     * and invoke bdrv_co_copy_range_from(child, ...), or invoke
 247     * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
 248     *
 249     * See the comment of bdrv_co_copy_range for the parameter and return value
 250     * semantics.
 251     */
 252    int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs,
 253                                                BdrvChild *src,
 254                                                uint64_t offset,
 255                                                BdrvChild *dst,
 256                                                uint64_t dst_offset,
 257                                                uint64_t bytes,
 258                                                BdrvRequestFlags read_flags,
 259                                                BdrvRequestFlags write_flags);
 260
 261    /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
 262     * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
 263     * operation if @bs is the leaf and @src has the same BlockDriver.  Return
 264     * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
 265     *
 266     * See the comment of bdrv_co_copy_range for the parameter and return value
 267     * semantics.
 268     */
 269    int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs,
 270                                              BdrvChild *src,
 271                                              uint64_t src_offset,
 272                                              BdrvChild *dst,
 273                                              uint64_t dst_offset,
 274                                              uint64_t bytes,
 275                                              BdrvRequestFlags read_flags,
 276                                              BdrvRequestFlags write_flags);
 277
 278    /*
 279     * Building block for bdrv_block_status[_above] and
 280     * bdrv_is_allocated[_above].  The driver should answer only
 281     * according to the current layer, and should only need to set
 282     * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
 283     * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
 284     * layer, the result should be 0 (and not BDRV_BLOCK_ZERO).  See
 285     * block.h for the overall meaning of the bits.  As a hint, the
 286     * flag want_zero is true if the caller cares more about precise
 287     * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
 288     * overall allocation (favor larger *pnum, perhaps by reporting
 289     * _DATA instead of _ZERO).  The block layer guarantees input
 290     * clamped to bdrv_getlength() and aligned to request_alignment,
 291     * as well as non-NULL pnum, map, and file; in turn, the driver
 292     * must return an error or set pnum to an aligned non-zero value.
 293     */
 294    int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
 295        bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
 296        int64_t *map, BlockDriverState **file);
 297
 298    /*
 299     * Invalidate any cached meta-data.
 300     */
 301    void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs,
 302                                                  Error **errp);
 303    int (*bdrv_inactivate)(BlockDriverState *bs);
 304
 305    /*
 306     * Flushes all data for all layers by calling bdrv_co_flush for underlying
 307     * layers, if needed. This function is needed for deterministic
 308     * synchronization of the flush finishing callback.
 309     */
 310    int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
 311
 312    /*
 313     * Flushes all data that was already written to the OS all the way down to
 314     * the disk (for example file-posix.c calls fsync()).
 315     */
 316    int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 317
 318    /*
 319     * Flushes all internal caches to the OS. The data may still sit in a
 320     * writeback cache of the host OS, but it will survive a crash of the qemu
 321     * process.
 322     */
 323    int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 324
 325    /*
 326     * Drivers setting this field must be able to work with just a plain
 327     * filename with '<protocol_name>:' as a prefix, and no other options.
 328     * Options may be extracted from the filename by implementing
 329     * bdrv_parse_filename.
 330     */
 331    const char *protocol_name;
 332    int coroutine_fn (*bdrv_co_truncate)(BlockDriverState *bs, int64_t offset,
 333                                         PreallocMode prealloc, Error **errp);
 334
 335    int64_t (*bdrv_getlength)(BlockDriverState *bs);
 336    bool has_variable_length;
 337    int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 338    BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs,
 339                                      Error **errp);
 340
 341    int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs,
 342        uint64_t offset, uint64_t bytes, QEMUIOVector *qiov);
 343
 344    int (*bdrv_snapshot_create)(BlockDriverState *bs,
 345                                QEMUSnapshotInfo *sn_info);
 346    int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 347                              const char *snapshot_id);
 348    int (*bdrv_snapshot_delete)(BlockDriverState *bs,
 349                                const char *snapshot_id,
 350                                const char *name,
 351                                Error **errp);
 352    int (*bdrv_snapshot_list)(BlockDriverState *bs,
 353                              QEMUSnapshotInfo **psn_info);
 354    int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 355                                  const char *snapshot_id,
 356                                  const char *name,
 357                                  Error **errp);
 358    int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 359    ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
 360                                                 Error **errp);
 361
 362    int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
 363                                          QEMUIOVector *qiov,
 364                                          int64_t pos);
 365    int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
 366                                          QEMUIOVector *qiov,
 367                                          int64_t pos);
 368
 369    int (*bdrv_change_backing_file)(BlockDriverState *bs,
 370        const char *backing_file, const char *backing_fmt);
 371
 372    /* removable device specific */
 373    bool (*bdrv_is_inserted)(BlockDriverState *bs);
 374    void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 375    void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 376
 377    /* to control generic scsi devices */
 378    BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 379        unsigned long int req, void *buf,
 380        BlockCompletionFunc *cb, void *opaque);
 381    int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs,
 382                                      unsigned long int req, void *buf);
 383
 384    /* List of options for creating images, terminated by name == NULL */
 385    QemuOptsList *create_opts;
 386    /*
 387     * If this driver supports reopening images this contains a
 388     * NULL-terminated list of the runtime options that can be
 389     * modified. If an option in this list is unspecified during
 390     * reopen then it _must_ be reset to its default value or return
 391     * an error.
 392     */
 393    const char *const *mutable_opts;
 394
 395    /*
 396     * Returns 0 for completed check, -errno for internal errors.
 397     * The check results are stored in result.
 398     */
 399    int coroutine_fn (*bdrv_co_check)(BlockDriverState *bs,
 400                                      BdrvCheckResult *result,
 401                                      BdrvCheckMode fix);
 402
 403    int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
 404                              BlockDriverAmendStatusCB *status_cb,
 405                              void *cb_opaque,
 406                              Error **errp);
 407
 408    void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
 409
 410    /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 411    int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 412        const char *tag);
 413    int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
 414        const char *tag);
 415    int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 416    bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 417
 418    void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
 419
 420    /*
 421     * Returns 1 if newly created images are guaranteed to contain only
 422     * zeros, 0 otherwise.
 423     */
 424    int (*bdrv_has_zero_init)(BlockDriverState *bs);
 425
 426    /* Remove fd handlers, timers, and other event loop callbacks so the event
 427     * loop is no longer in use.  Called with no in-flight requests and in
 428     * depth-first traversal order with parents before child nodes.
 429     */
 430    void (*bdrv_detach_aio_context)(BlockDriverState *bs);
 431
 432    /* Add fd handlers, timers, and other event loop callbacks so I/O requests
 433     * can be processed again.  Called with no in-flight requests and in
 434     * depth-first traversal order with child nodes before parent nodes.
 435     */
 436    void (*bdrv_attach_aio_context)(BlockDriverState *bs,
 437                                    AioContext *new_context);
 438
 439    /* io queue for linux-aio */
 440    void (*bdrv_io_plug)(BlockDriverState *bs);
 441    void (*bdrv_io_unplug)(BlockDriverState *bs);
 442
 443    /**
 444     * Try to get @bs's logical and physical block size.
 445     * On success, store them in @bsz and return zero.
 446     * On failure, return negative errno.
 447     */
 448    int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
 449    /**
 450     * Try to get @bs's geometry (cyls, heads, sectors)
 451     * On success, store them in @geo and return 0.
 452     * On failure return -errno.
 453     * Only drivers that want to override guest geometry implement this
 454     * callback; see hd_geometry_guess().
 455     */
 456    int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
 457
 458    /**
 459     * bdrv_co_drain_begin is called if implemented in the beginning of a
 460     * drain operation to drain and stop any internal sources of requests in
 461     * the driver.
 462     * bdrv_co_drain_end is called if implemented at the end of the drain.
 463     *
 464     * They should be used by the driver to e.g. manage scheduled I/O
 465     * requests, or toggle an internal state. After the end of the drain new
 466     * requests will continue normally.
 467     */
 468    void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
 469    void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
 470
 471    void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
 472                           Error **errp);
 473    void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
 474                           Error **errp);
 475
 476    /**
 477     * Informs the block driver that a permission change is intended. The
 478     * driver checks whether the change is permissible and may take other
 479     * preparations for the change (e.g. get file system locks). This operation
 480     * is always followed either by a call to either .bdrv_set_perm or
 481     * .bdrv_abort_perm_update.
 482     *
 483     * Checks whether the requested set of cumulative permissions in @perm
 484     * can be granted for accessing @bs and whether no other users are using
 485     * permissions other than those given in @shared (both arguments take
 486     * BLK_PERM_* bitmasks).
 487     *
 488     * If both conditions are met, 0 is returned. Otherwise, -errno is returned
 489     * and errp is set to an error describing the conflict.
 490     */
 491    int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm,
 492                           uint64_t shared, Error **errp);
 493
 494    /**
 495     * Called to inform the driver that the set of cumulative set of used
 496     * permissions for @bs has changed to @perm, and the set of sharable
 497     * permission to @shared. The driver can use this to propagate changes to
 498     * its children (i.e. request permissions only if a parent actually needs
 499     * them).
 500     *
 501     * This function is only invoked after bdrv_check_perm(), so block drivers
 502     * may rely on preparations made in their .bdrv_check_perm implementation.
 503     */
 504    void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared);
 505
 506    /*
 507     * Called to inform the driver that after a previous bdrv_check_perm()
 508     * call, the permission update is not performed and any preparations made
 509     * for it (e.g. taken file locks) need to be undone.
 510     *
 511     * This function can be called even for nodes that never saw a
 512     * bdrv_check_perm() call. It is a no-op then.
 513     */
 514    void (*bdrv_abort_perm_update)(BlockDriverState *bs);
 515
 516    /**
 517     * Returns in @nperm and @nshared the permissions that the driver for @bs
 518     * needs on its child @c, based on the cumulative permissions requested by
 519     * the parents in @parent_perm and @parent_shared.
 520     *
 521     * If @c is NULL, return the permissions for attaching a new child for the
 522     * given @role.
 523     *
 524     * If @reopen_queue is non-NULL, don't return the currently needed
 525     * permissions, but those that will be needed after applying the
 526     * @reopen_queue.
 527     */
 528     void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
 529                             const BdrvChildRole *role,
 530                             BlockReopenQueue *reopen_queue,
 531                             uint64_t parent_perm, uint64_t parent_shared,
 532                             uint64_t *nperm, uint64_t *nshared);
 533
 534    /**
 535     * Bitmaps should be marked as 'IN_USE' in the image on reopening image
 536     * as rw. This handler should realize it. It also should unset readonly
 537     * field of BlockDirtyBitmap's in case of success.
 538     */
 539    int (*bdrv_reopen_bitmaps_rw)(BlockDriverState *bs, Error **errp);
 540    bool (*bdrv_can_store_new_dirty_bitmap)(BlockDriverState *bs,
 541                                            const char *name,
 542                                            uint32_t granularity,
 543                                            Error **errp);
 544    void (*bdrv_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
 545                                                const char *name,
 546                                                Error **errp);
 547
 548    /**
 549     * Register/unregister a buffer for I/O. For example, when the driver is
 550     * interested to know the memory areas that will later be used in iovs, so
 551     * that it can do IOMMU mapping with VFIO etc., in order to get better
 552     * performance. In the case of VFIO drivers, this callback is used to do
 553     * DMA mapping for hot buffers.
 554     */
 555    void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
 556    void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
 557    QLIST_ENTRY(BlockDriver) list;
 558
 559    /* Pointer to a NULL-terminated array of names of strong options
 560     * that can be specified for bdrv_open(). A strong option is one
 561     * that changes the data of a BDS.
 562     * If this pointer is NULL, the array is considered empty.
 563     * "filename" and "driver" are always considered strong. */
 564    const char *const *strong_runtime_opts;
 565};
 566
 567typedef struct BlockLimits {
 568    /* Alignment requirement, in bytes, for offset/length of I/O
 569     * requests. Must be a power of 2 less than INT_MAX; defaults to
 570     * 1 for drivers with modern byte interfaces, and to 512
 571     * otherwise. */
 572    uint32_t request_alignment;
 573
 574    /* Maximum number of bytes that can be discarded at once (since it
 575     * is signed, it must be < 2G, if set). Must be multiple of
 576     * pdiscard_alignment, but need not be power of 2. May be 0 if no
 577     * inherent 32-bit limit */
 578    int32_t max_pdiscard;
 579
 580    /* Optimal alignment for discard requests in bytes. A power of 2
 581     * is best but not mandatory.  Must be a multiple of
 582     * bl.request_alignment, and must be less than max_pdiscard if
 583     * that is set. May be 0 if bl.request_alignment is good enough */
 584    uint32_t pdiscard_alignment;
 585
 586    /* Maximum number of bytes that can zeroized at once (since it is
 587     * signed, it must be < 2G, if set). Must be multiple of
 588     * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
 589    int32_t max_pwrite_zeroes;
 590
 591    /* Optimal alignment for write zeroes requests in bytes. A power
 592     * of 2 is best but not mandatory.  Must be a multiple of
 593     * bl.request_alignment, and must be less than max_pwrite_zeroes
 594     * if that is set. May be 0 if bl.request_alignment is good
 595     * enough */
 596    uint32_t pwrite_zeroes_alignment;
 597
 598    /* Optimal transfer length in bytes.  A power of 2 is best but not
 599     * mandatory.  Must be a multiple of bl.request_alignment, or 0 if
 600     * no preferred size */
 601    uint32_t opt_transfer;
 602
 603    /* Maximal transfer length in bytes.  Need not be power of 2, but
 604     * must be multiple of opt_transfer and bl.request_alignment, or 0
 605     * for no 32-bit limit.  For now, anything larger than INT_MAX is
 606     * clamped down. */
 607    uint32_t max_transfer;
 608
 609    /* memory alignment, in bytes so that no bounce buffer is needed */
 610    size_t min_mem_alignment;
 611
 612    /* memory alignment, in bytes, for bounce buffer */
 613    size_t opt_mem_alignment;
 614
 615    /* maximum number of iovec elements */
 616    int max_iov;
 617} BlockLimits;
 618
 619typedef struct BdrvOpBlocker BdrvOpBlocker;
 620
 621typedef struct BdrvAioNotifier {
 622    void (*attached_aio_context)(AioContext *new_context, void *opaque);
 623    void (*detach_aio_context)(void *opaque);
 624
 625    void *opaque;
 626    bool deleted;
 627
 628    QLIST_ENTRY(BdrvAioNotifier) list;
 629} BdrvAioNotifier;
 630
 631struct BdrvChildRole {
 632    /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
 633     * points to. */
 634    bool stay_at_node;
 635
 636    /* If true, the parent is a BlockDriverState and bdrv_next_all_states()
 637     * will return it. This information is used for drain_all, where every node
 638     * will be drained separately, so the drain only needs to be propagated to
 639     * non-BDS parents. */
 640    bool parent_is_bds;
 641
 642    void (*inherit_options)(int *child_flags, QDict *child_options,
 643                            int parent_flags, QDict *parent_options);
 644
 645    void (*change_media)(BdrvChild *child, bool load);
 646    void (*resize)(BdrvChild *child);
 647
 648    /* Returns a name that is supposedly more useful for human users than the
 649     * node name for identifying the node in question (in particular, a BB
 650     * name), or NULL if the parent can't provide a better name. */
 651    const char *(*get_name)(BdrvChild *child);
 652
 653    /* Returns a malloced string that describes the parent of the child for a
 654     * human reader. This could be a node-name, BlockBackend name, qdev ID or
 655     * QOM path of the device owning the BlockBackend, job type and ID etc. The
 656     * caller is responsible for freeing the memory. */
 657    char *(*get_parent_desc)(BdrvChild *child);
 658
 659    /*
 660     * If this pair of functions is implemented, the parent doesn't issue new
 661     * requests after returning from .drained_begin() until .drained_end() is
 662     * called.
 663     *
 664     * These functions must not change the graph (and therefore also must not
 665     * call aio_poll(), which could change the graph indirectly).
 666     *
 667     * Note that this can be nested. If drained_begin() was called twice, new
 668     * I/O is allowed only after drained_end() was called twice, too.
 669     */
 670    void (*drained_begin)(BdrvChild *child);
 671    void (*drained_end)(BdrvChild *child);
 672
 673    /*
 674     * Returns whether the parent has pending requests for the child. This
 675     * callback is polled after .drained_begin() has been called until all
 676     * activity on the child has stopped.
 677     */
 678    bool (*drained_poll)(BdrvChild *child);
 679
 680    /* Notifies the parent that the child has been activated/inactivated (e.g.
 681     * when migration is completing) and it can start/stop requesting
 682     * permissions and doing I/O on it. */
 683    void (*activate)(BdrvChild *child, Error **errp);
 684    int (*inactivate)(BdrvChild *child);
 685
 686    void (*attach)(BdrvChild *child);
 687    void (*detach)(BdrvChild *child);
 688
 689    /* Notifies the parent that the filename of its child has changed (e.g.
 690     * because the direct child was removed from the backing chain), so that it
 691     * can update its reference. */
 692    int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
 693                           const char *filename, Error **errp);
 694};
 695
 696extern const BdrvChildRole child_file;
 697extern const BdrvChildRole child_format;
 698extern const BdrvChildRole child_backing;
 699
 700struct BdrvChild {
 701    BlockDriverState *bs;
 702    char *name;
 703    const BdrvChildRole *role;
 704    void *opaque;
 705
 706    /**
 707     * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
 708     */
 709    uint64_t perm;
 710
 711    /**
 712     * Permissions that can still be granted to other users of @bs while this
 713     * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
 714     */
 715    uint64_t shared_perm;
 716
 717    /* backup of permissions during permission update procedure */
 718    bool has_backup_perm;
 719    uint64_t backup_perm;
 720    uint64_t backup_shared_perm;
 721
 722    /*
 723     * This link is frozen: the child can neither be replaced nor
 724     * detached from the parent.
 725     */
 726    bool frozen;
 727
 728    QLIST_ENTRY(BdrvChild) next;
 729    QLIST_ENTRY(BdrvChild) next_parent;
 730};
 731
 732/*
 733 * Note: the function bdrv_append() copies and swaps contents of
 734 * BlockDriverStates, so if you add new fields to this struct, please
 735 * inspect bdrv_append() to determine if the new fields need to be
 736 * copied as well.
 737 */
 738struct BlockDriverState {
 739    /* Protected by big QEMU lock or read-only after opening.  No special
 740     * locking needed during I/O...
 741     */
 742    int open_flags; /* flags used to open the file, re-used for re-open */
 743    bool read_only; /* if true, the media is read only */
 744    bool encrypted; /* if true, the media is encrypted */
 745    bool sg;        /* if true, the device is a /dev/sg* */
 746    bool probed;    /* if true, format was probed rather than specified */
 747    bool force_share; /* if true, always allow all shared permissions */
 748    bool implicit;  /* if true, this filter node was automatically inserted */
 749
 750    BlockDriver *drv; /* NULL means no media */
 751    void *opaque;
 752
 753    AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
 754    /* long-running tasks intended to always use the same AioContext as this
 755     * BDS may register themselves in this list to be notified of changes
 756     * regarding this BDS's context */
 757    QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
 758    bool walking_aio_notifiers; /* to make removal during iteration safe */
 759
 760    char filename[PATH_MAX];
 761    char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
 762                                    this file image */
 763    /* The backing filename indicated by the image header; if we ever
 764     * open this file, then this is replaced by the resulting BDS's
 765     * filename (i.e. after a bdrv_refresh_filename() run). */
 766    char auto_backing_file[PATH_MAX];
 767    char backing_format[16]; /* if non-zero and backing_file exists */
 768
 769    QDict *full_open_options;
 770    char exact_filename[PATH_MAX];
 771
 772    BdrvChild *backing;
 773    BdrvChild *file;
 774
 775    /* I/O Limits */
 776    BlockLimits bl;
 777
 778    /* Flags honored during pwrite (so far: BDRV_REQ_FUA,
 779     * BDRV_REQ_WRITE_UNCHANGED).
 780     * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
 781     * writes will be issued as normal writes without the flag set.
 782     * This is important to note for drivers that do not explicitly
 783     * request a WRITE permission for their children and instead take
 784     * the same permissions as their parent did (this is commonly what
 785     * block filters do).  Such drivers have to be aware that the
 786     * parent may have taken a WRITE_UNCHANGED permission only and is
 787     * issuing such requests.  Drivers either must make sure that
 788     * these requests do not result in plain WRITE accesses (usually
 789     * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
 790     * every incoming write request as-is, including potentially that
 791     * flag), or they have to explicitly take the WRITE permission for
 792     * their children. */
 793    unsigned int supported_write_flags;
 794    /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
 795     * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */
 796    unsigned int supported_zero_flags;
 797
 798    /* the following member gives a name to every node on the bs graph. */
 799    char node_name[32];
 800    /* element of the list of named nodes building the graph */
 801    QTAILQ_ENTRY(BlockDriverState) node_list;
 802    /* element of the list of all BlockDriverStates (all_bdrv_states) */
 803    QTAILQ_ENTRY(BlockDriverState) bs_list;
 804    /* element of the list of monitor-owned BDS */
 805    QTAILQ_ENTRY(BlockDriverState) monitor_list;
 806    int refcnt;
 807
 808    /* operation blockers */
 809    QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
 810
 811    /* long-running background operation */
 812    BlockJob *job;
 813
 814    /* The node that this node inherited default options from (and a reopen on
 815     * which can affect this node by changing these defaults). This is always a
 816     * parent node of this node. */
 817    BlockDriverState *inherits_from;
 818    QLIST_HEAD(, BdrvChild) children;
 819    QLIST_HEAD(, BdrvChild) parents;
 820
 821    QDict *options;
 822    QDict *explicit_options;
 823    BlockdevDetectZeroesOptions detect_zeroes;
 824
 825    /* The error object in use for blocking operations on backing_hd */
 826    Error *backing_blocker;
 827
 828    /* Protected by AioContext lock */
 829
 830    /* If we are reading a disk image, give its size in sectors.
 831     * Generally read-only; it is written to by load_snapshot and
 832     * save_snaphost, but the block layer is quiescent during those.
 833     */
 834    int64_t total_sectors;
 835
 836    /* Callback before write request is processed */
 837    NotifierWithReturnList before_write_notifiers;
 838
 839    /* threshold limit for writes, in bytes. "High water mark". */
 840    uint64_t write_threshold_offset;
 841    NotifierWithReturn write_threshold_notifier;
 842
 843    /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
 844     * Reading from the list can be done with either the BQL or the
 845     * dirty_bitmap_mutex.  Modifying a bitmap only requires
 846     * dirty_bitmap_mutex.  */
 847    QemuMutex dirty_bitmap_mutex;
 848    QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
 849
 850    /* Offset after the highest byte written to */
 851    Stat64 wr_highest_offset;
 852
 853    /* If true, copy read backing sectors into image.  Can be >1 if more
 854     * than one client has requested copy-on-read.  Accessed with atomic
 855     * ops.
 856     */
 857    int copy_on_read;
 858
 859    /* number of in-flight requests; overall and serialising.
 860     * Accessed with atomic ops.
 861     */
 862    unsigned int in_flight;
 863    unsigned int serialising_in_flight;
 864
 865    /* counter for nested bdrv_io_plug.
 866     * Accessed with atomic ops.
 867    */
 868    unsigned io_plugged;
 869
 870    /* do we need to tell the quest if we have a volatile write cache? */
 871    int enable_write_cache;
 872
 873    /* Accessed with atomic ops.  */
 874    int quiesce_counter;
 875    int recursive_quiesce_counter;
 876
 877    unsigned int write_gen;               /* Current data generation */
 878
 879    /* Protected by reqs_lock.  */
 880    CoMutex reqs_lock;
 881    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 882    CoQueue flush_queue;                  /* Serializing flush queue */
 883    bool active_flush_req;                /* Flush request in flight? */
 884
 885    /* Only read/written by whoever has set active_flush_req to true.  */
 886    unsigned int flushed_gen;             /* Flushed write generation */
 887};
 888
 889struct BlockBackendRootState {
 890    int open_flags;
 891    bool read_only;
 892    BlockdevDetectZeroesOptions detect_zeroes;
 893};
 894
 895typedef enum BlockMirrorBackingMode {
 896    /* Reuse the existing backing chain from the source for the target.
 897     * - sync=full: Set backing BDS to NULL.
 898     * - sync=top:  Use source's backing BDS.
 899     * - sync=none: Use source as the backing BDS. */
 900    MIRROR_SOURCE_BACKING_CHAIN,
 901
 902    /* Open the target's backing chain completely anew */
 903    MIRROR_OPEN_BACKING_CHAIN,
 904
 905    /* Do not change the target's backing BDS after job completion */
 906    MIRROR_LEAVE_BACKING_CHAIN,
 907} BlockMirrorBackingMode;
 908
 909static inline BlockDriverState *backing_bs(BlockDriverState *bs)
 910{
 911    return bs->backing ? bs->backing->bs : NULL;
 912}
 913
 914
 915/* Essential block drivers which must always be statically linked into qemu, and
 916 * which therefore can be accessed without using bdrv_find_format() */
 917extern BlockDriver bdrv_file;
 918extern BlockDriver bdrv_raw;
 919extern BlockDriver bdrv_qcow2;
 920
 921int coroutine_fn bdrv_co_preadv(BdrvChild *child,
 922    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
 923    BdrvRequestFlags flags);
 924int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
 925    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
 926    BdrvRequestFlags flags);
 927
 928extern unsigned int bdrv_drain_all_count;
 929void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
 930void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
 931
 932int get_tmp_filename(char *filename, int size);
 933BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
 934                            const char *filename);
 935
 936void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
 937                                      QDict *options);
 938
 939
 940/**
 941 * bdrv_add_before_write_notifier:
 942 *
 943 * Register a callback that is invoked before write requests are processed but
 944 * after any throttling or waiting for overlapping requests.
 945 */
 946void bdrv_add_before_write_notifier(BlockDriverState *bs,
 947                                    NotifierWithReturn *notifier);
 948
 949/**
 950 * bdrv_detach_aio_context:
 951 *
 952 * May be called from .bdrv_detach_aio_context() to detach children from the
 953 * current #AioContext.  This is only needed by block drivers that manage their
 954 * own children.  Both ->file and ->backing are automatically handled and
 955 * block drivers should not call this function on them explicitly.
 956 */
 957void bdrv_detach_aio_context(BlockDriverState *bs);
 958
 959/**
 960 * bdrv_attach_aio_context:
 961 *
 962 * May be called from .bdrv_attach_aio_context() to attach children to the new
 963 * #AioContext.  This is only needed by block drivers that manage their own
 964 * children.  Both ->file and ->backing are automatically handled and block
 965 * drivers should not call this function on them explicitly.
 966 */
 967void bdrv_attach_aio_context(BlockDriverState *bs,
 968                             AioContext *new_context);
 969
 970/**
 971 * bdrv_add_aio_context_notifier:
 972 *
 973 * If a long-running job intends to be always run in the same AioContext as a
 974 * certain BDS, it may use this function to be notified of changes regarding the
 975 * association of the BDS to an AioContext.
 976 *
 977 * attached_aio_context() is called after the target BDS has been attached to a
 978 * new AioContext; detach_aio_context() is called before the target BDS is being
 979 * detached from its old AioContext.
 980 */
 981void bdrv_add_aio_context_notifier(BlockDriverState *bs,
 982        void (*attached_aio_context)(AioContext *new_context, void *opaque),
 983        void (*detach_aio_context)(void *opaque), void *opaque);
 984
 985/**
 986 * bdrv_remove_aio_context_notifier:
 987 *
 988 * Unsubscribe of change notifications regarding the BDS's AioContext. The
 989 * parameters given here have to be the same as those given to
 990 * bdrv_add_aio_context_notifier().
 991 */
 992void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
 993                                      void (*aio_context_attached)(AioContext *,
 994                                                                   void *),
 995                                      void (*aio_context_detached)(void *),
 996                                      void *opaque);
 997
 998/**
 999 * bdrv_wakeup:
1000 * @bs: The BlockDriverState for which an I/O operation has been completed.
1001 *
1002 * Wake up the main thread if it is waiting on BDRV_POLL_WHILE.  During
1003 * synchronous I/O on a BlockDriverState that is attached to another
1004 * I/O thread, the main thread lets the I/O thread's event loop run,
1005 * waiting for the I/O operation to complete.  A bdrv_wakeup will wake
1006 * up the main thread if necessary.
1007 *
1008 * Manual calls to bdrv_wakeup are rarely necessary, because
1009 * bdrv_dec_in_flight already calls it.
1010 */
1011void bdrv_wakeup(BlockDriverState *bs);
1012
1013#ifdef _WIN32
1014int is_windows_drive(const char *filename);
1015#endif
1016
1017/**
1018 * stream_start:
1019 * @job_id: The id of the newly-created job, or %NULL to use the
1020 * device name of @bs.
1021 * @bs: Block device to operate on.
1022 * @base: Block device that will become the new base, or %NULL to
1023 * flatten the whole backing file chain onto @bs.
1024 * @backing_file_str: The file name that will be written to @bs as the
1025 * the new backing file if the job completes. Ignored if @base is %NULL.
1026 * @creation_flags: Flags that control the behavior of the Job lifetime.
1027 *                  See @BlockJobCreateFlags
1028 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1029 * @on_error: The action to take upon error.
1030 * @errp: Error object.
1031 *
1032 * Start a streaming operation on @bs.  Clusters that are unallocated
1033 * in @bs, but allocated in any image between @base and @bs (both
1034 * exclusive) will be written to @bs.  At the end of a successful
1035 * streaming job, the backing file of @bs will be changed to
1036 * @backing_file_str in the written image and to @base in the live
1037 * BlockDriverState.
1038 */
1039void stream_start(const char *job_id, BlockDriverState *bs,
1040                  BlockDriverState *base, const char *backing_file_str,
1041                  int creation_flags, int64_t speed,
1042                  BlockdevOnError on_error, Error **errp);
1043
1044/**
1045 * commit_start:
1046 * @job_id: The id of the newly-created job, or %NULL to use the
1047 * device name of @bs.
1048 * @bs: Active block device.
1049 * @top: Top block device to be committed.
1050 * @base: Block device that will be written into, and become the new top.
1051 * @creation_flags: Flags that control the behavior of the Job lifetime.
1052 *                  See @BlockJobCreateFlags
1053 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1054 * @on_error: The action to take upon error.
1055 * @backing_file_str: String to use as the backing file in @top's overlay
1056 * @filter_node_name: The node name that should be assigned to the filter
1057 * driver that the commit job inserts into the graph above @top. NULL means
1058 * that a node name should be autogenerated.
1059 * @errp: Error object.
1060 *
1061 */
1062void commit_start(const char *job_id, BlockDriverState *bs,
1063                  BlockDriverState *base, BlockDriverState *top,
1064                  int creation_flags, int64_t speed,
1065                  BlockdevOnError on_error, const char *backing_file_str,
1066                  const char *filter_node_name, Error **errp);
1067/**
1068 * commit_active_start:
1069 * @job_id: The id of the newly-created job, or %NULL to use the
1070 * device name of @bs.
1071 * @bs: Active block device to be committed.
1072 * @base: Block device that will be written into, and become the new top.
1073 * @creation_flags: Flags that control the behavior of the Job lifetime.
1074 *                  See @BlockJobCreateFlags
1075 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1076 * @on_error: The action to take upon error.
1077 * @filter_node_name: The node name that should be assigned to the filter
1078 * driver that the commit job inserts into the graph above @bs. NULL means that
1079 * a node name should be autogenerated.
1080 * @cb: Completion function for the job.
1081 * @opaque: Opaque pointer value passed to @cb.
1082 * @auto_complete: Auto complete the job.
1083 * @errp: Error object.
1084 *
1085 */
1086void commit_active_start(const char *job_id, BlockDriverState *bs,
1087                         BlockDriverState *base, int creation_flags,
1088                         int64_t speed, BlockdevOnError on_error,
1089                         const char *filter_node_name,
1090                         BlockCompletionFunc *cb, void *opaque,
1091                         bool auto_complete, Error **errp);
1092/*
1093 * mirror_start:
1094 * @job_id: The id of the newly-created job, or %NULL to use the
1095 * device name of @bs.
1096 * @bs: Block device to operate on.
1097 * @target: Block device to write to.
1098 * @replaces: Block graph node name to replace once the mirror is done. Can
1099 *            only be used when full mirroring is selected.
1100 * @creation_flags: Flags that control the behavior of the Job lifetime.
1101 *                  See @BlockJobCreateFlags
1102 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1103 * @granularity: The chosen granularity for the dirty bitmap.
1104 * @buf_size: The amount of data that can be in flight at one time.
1105 * @mode: Whether to collapse all images in the chain to the target.
1106 * @backing_mode: How to establish the target's backing chain after completion.
1107 * @on_source_error: The action to take upon error reading from the source.
1108 * @on_target_error: The action to take upon error writing to the target.
1109 * @unmap: Whether to unmap target where source sectors only contain zeroes.
1110 * @filter_node_name: The node name that should be assigned to the filter
1111 * driver that the mirror job inserts into the graph above @bs. NULL means that
1112 * a node name should be autogenerated.
1113 * @copy_mode: When to trigger writes to the target.
1114 * @errp: Error object.
1115 *
1116 * Start a mirroring operation on @bs.  Clusters that are allocated
1117 * in @bs will be written to @target until the job is cancelled or
1118 * manually completed.  At the end of a successful mirroring job,
1119 * @bs will be switched to read from @target.
1120 */
1121void mirror_start(const char *job_id, BlockDriverState *bs,
1122                  BlockDriverState *target, const char *replaces,
1123                  int creation_flags, int64_t speed,
1124                  uint32_t granularity, int64_t buf_size,
1125                  MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
1126                  BlockdevOnError on_source_error,
1127                  BlockdevOnError on_target_error,
1128                  bool unmap, const char *filter_node_name,
1129                  MirrorCopyMode copy_mode, Error **errp);
1130
1131/*
1132 * backup_job_create:
1133 * @job_id: The id of the newly-created job, or %NULL to use the
1134 * device name of @bs.
1135 * @bs: Block device to operate on.
1136 * @target: Block device to write to.
1137 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1138 * @sync_mode: What parts of the disk image should be copied to the destination.
1139 * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
1140 * @on_source_error: The action to take upon error reading from the source.
1141 * @on_target_error: The action to take upon error writing to the target.
1142 * @creation_flags: Flags that control the behavior of the Job lifetime.
1143 *                  See @BlockJobCreateFlags
1144 * @cb: Completion function for the job.
1145 * @opaque: Opaque pointer value passed to @cb.
1146 * @txn: Transaction that this job is part of (may be NULL).
1147 *
1148 * Create a backup operation on @bs.  Clusters in @bs are written to @target
1149 * until the job is cancelled or manually completed.
1150 */
1151BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
1152                            BlockDriverState *target, int64_t speed,
1153                            MirrorSyncMode sync_mode,
1154                            BdrvDirtyBitmap *sync_bitmap,
1155                            bool compress,
1156                            BlockdevOnError on_source_error,
1157                            BlockdevOnError on_target_error,
1158                            int creation_flags,
1159                            BlockCompletionFunc *cb, void *opaque,
1160                            JobTxn *txn, Error **errp);
1161
1162void hmp_drive_add_node(Monitor *mon, const char *optstr);
1163
1164BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
1165                                  const char *child_name,
1166                                  const BdrvChildRole *child_role,
1167                                  uint64_t perm, uint64_t shared_perm,
1168                                  void *opaque, Error **errp);
1169void bdrv_root_unref_child(BdrvChild *child);
1170
1171int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
1172                            Error **errp);
1173
1174/* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1175 * block filters: Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED and RESIZE to
1176 * all children */
1177void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
1178                               const BdrvChildRole *role,
1179                               BlockReopenQueue *reopen_queue,
1180                               uint64_t perm, uint64_t shared,
1181                               uint64_t *nperm, uint64_t *nshared);
1182
1183/* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1184 * (non-raw) image formats: Like above for bs->backing, but for bs->file it
1185 * requires WRITE | RESIZE for read-write images, always requires
1186 * CONSISTENT_READ and doesn't share WRITE. */
1187void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
1188                               const BdrvChildRole *role,
1189                               BlockReopenQueue *reopen_queue,
1190                               uint64_t perm, uint64_t shared,
1191                               uint64_t *nperm, uint64_t *nshared);
1192
1193/*
1194 * Default implementation for drivers to pass bdrv_co_block_status() to
1195 * their file.
1196 */
1197int coroutine_fn bdrv_co_block_status_from_file(BlockDriverState *bs,
1198                                                bool want_zero,
1199                                                int64_t offset,
1200                                                int64_t bytes,
1201                                                int64_t *pnum,
1202                                                int64_t *map,
1203                                                BlockDriverState **file);
1204/*
1205 * Default implementation for drivers to pass bdrv_co_block_status() to
1206 * their backing file.
1207 */
1208int coroutine_fn bdrv_co_block_status_from_backing(BlockDriverState *bs,
1209                                                   bool want_zero,
1210                                                   int64_t offset,
1211                                                   int64_t bytes,
1212                                                   int64_t *pnum,
1213                                                   int64_t *map,
1214                                                   BlockDriverState **file);
1215const char *bdrv_get_parent_name(const BlockDriverState *bs);
1216void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
1217bool blk_dev_has_removable_media(BlockBackend *blk);
1218bool blk_dev_has_tray(BlockBackend *blk);
1219void blk_dev_eject_request(BlockBackend *blk, bool force);
1220bool blk_dev_is_tray_open(BlockBackend *blk);
1221bool blk_dev_is_medium_locked(BlockBackend *blk);
1222
1223void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
1224
1225void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
1226void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup);
1227
1228void bdrv_inc_in_flight(BlockDriverState *bs);
1229void bdrv_dec_in_flight(BlockDriverState *bs);
1230
1231void blockdev_close_all_bdrv_states(void);
1232
1233int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset,
1234                                         BdrvChild *dst, uint64_t dst_offset,
1235                                         uint64_t bytes,
1236                                         BdrvRequestFlags read_flags,
1237                                         BdrvRequestFlags write_flags);
1238int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset,
1239                                       BdrvChild *dst, uint64_t dst_offset,
1240                                       uint64_t bytes,
1241                                       BdrvRequestFlags read_flags,
1242                                       BdrvRequestFlags write_flags);
1243
1244int refresh_total_sectors(BlockDriverState *bs, int64_t hint);
1245
1246#endif /* BLOCK_INT_H */
1247