qemu/block_int.h
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   1/*
   2 * QEMU System Emulator block driver
   3 *
   4 * Copyright (c) 2003 Fabrice Bellard
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24#ifndef BLOCK_INT_H
  25#define BLOCK_INT_H
  26
  27#include "block.h"
  28#include "qemu-option.h"
  29#include "qemu-queue.h"
  30#include "qemu-coroutine.h"
  31#include "qemu-timer.h"
  32#include "qapi-types.h"
  33#include "qerror.h"
  34#include "monitor.h"
  35
  36#define BLOCK_FLAG_ENCRYPT          1
  37#define BLOCK_FLAG_COMPAT6          4
  38#define BLOCK_FLAG_LAZY_REFCOUNTS   8
  39
  40#define BLOCK_IO_LIMIT_READ     0
  41#define BLOCK_IO_LIMIT_WRITE    1
  42#define BLOCK_IO_LIMIT_TOTAL    2
  43
  44#define BLOCK_IO_SLICE_TIME     100000000
  45#define NANOSECONDS_PER_SECOND  1000000000.0
  46
  47#define BLOCK_OPT_SIZE              "size"
  48#define BLOCK_OPT_ENCRYPT           "encryption"
  49#define BLOCK_OPT_COMPAT6           "compat6"
  50#define BLOCK_OPT_BACKING_FILE      "backing_file"
  51#define BLOCK_OPT_BACKING_FMT       "backing_fmt"
  52#define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
  53#define BLOCK_OPT_TABLE_SIZE        "table_size"
  54#define BLOCK_OPT_PREALLOC          "preallocation"
  55#define BLOCK_OPT_SUBFMT            "subformat"
  56#define BLOCK_OPT_COMPAT_LEVEL      "compat"
  57#define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
  58
  59typedef struct BdrvTrackedRequest BdrvTrackedRequest;
  60
  61typedef struct BlockIOLimit {
  62    int64_t bps[3];
  63    int64_t iops[3];
  64} BlockIOLimit;
  65
  66typedef struct BlockIOBaseValue {
  67    uint64_t bytes[2];
  68    uint64_t ios[2];
  69} BlockIOBaseValue;
  70
  71struct BlockDriver {
  72    const char *format_name;
  73    int instance_size;
  74    int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  75    int (*bdrv_probe_device)(const char *filename);
  76
  77    /* For handling image reopen for split or non-split files */
  78    int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
  79                               BlockReopenQueue *queue, Error **errp);
  80    void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
  81    void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
  82
  83    int (*bdrv_open)(BlockDriverState *bs, int flags);
  84    int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
  85    int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
  86                     uint8_t *buf, int nb_sectors);
  87    int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
  88                      const uint8_t *buf, int nb_sectors);
  89    void (*bdrv_close)(BlockDriverState *bs);
  90    void (*bdrv_rebind)(BlockDriverState *bs);
  91    int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
  92    int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
  93    int (*bdrv_make_empty)(BlockDriverState *bs);
  94    /* aio */
  95    BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
  96        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
  97        BlockDriverCompletionFunc *cb, void *opaque);
  98    BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
  99        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 100        BlockDriverCompletionFunc *cb, void *opaque);
 101    BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 102        BlockDriverCompletionFunc *cb, void *opaque);
 103    BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 104        int64_t sector_num, int nb_sectors,
 105        BlockDriverCompletionFunc *cb, void *opaque);
 106
 107    int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 108        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 109    int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 110        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 111    /*
 112     * Efficiently zero a region of the disk image.  Typically an image format
 113     * would use a compact metadata representation to implement this.  This
 114     * function pointer may be NULL and .bdrv_co_writev() will be called
 115     * instead.
 116     */
 117    int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 118        int64_t sector_num, int nb_sectors);
 119    int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 120        int64_t sector_num, int nb_sectors);
 121    int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
 122        int64_t sector_num, int nb_sectors, int *pnum);
 123
 124    /*
 125     * Invalidate any cached meta-data.
 126     */
 127    void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 128
 129    /*
 130     * Flushes all data that was already written to the OS all the way down to
 131     * the disk (for example raw-posix calls fsync()).
 132     */
 133    int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 134
 135    /*
 136     * Flushes all internal caches to the OS. The data may still sit in a
 137     * writeback cache of the host OS, but it will survive a crash of the qemu
 138     * process.
 139     */
 140    int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 141
 142    const char *protocol_name;
 143    int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 144    int64_t (*bdrv_getlength)(BlockDriverState *bs);
 145    int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 146    int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 147                                 const uint8_t *buf, int nb_sectors);
 148
 149    int (*bdrv_snapshot_create)(BlockDriverState *bs,
 150                                QEMUSnapshotInfo *sn_info);
 151    int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 152                              const char *snapshot_id);
 153    int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
 154    int (*bdrv_snapshot_list)(BlockDriverState *bs,
 155                              QEMUSnapshotInfo **psn_info);
 156    int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 157                                  const char *snapshot_name);
 158    int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 159
 160    int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
 161                             int64_t pos, int size);
 162    int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 163                             int64_t pos, int size);
 164
 165    int (*bdrv_change_backing_file)(BlockDriverState *bs,
 166        const char *backing_file, const char *backing_fmt);
 167
 168    /* removable device specific */
 169    int (*bdrv_is_inserted)(BlockDriverState *bs);
 170    int (*bdrv_media_changed)(BlockDriverState *bs);
 171    void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 172    void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 173
 174    /* to control generic scsi devices */
 175    int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 176    BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 177        unsigned long int req, void *buf,
 178        BlockDriverCompletionFunc *cb, void *opaque);
 179
 180    /* List of options for creating images, terminated by name == NULL */
 181    QEMUOptionParameter *create_options;
 182
 183
 184    /*
 185     * Returns 0 for completed check, -errno for internal errors.
 186     * The check results are stored in result.
 187     */
 188    int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 189        BdrvCheckMode fix);
 190
 191    void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 192
 193    /*
 194     * Returns 1 if newly created images are guaranteed to contain only
 195     * zeros, 0 otherwise.
 196     */
 197    int (*bdrv_has_zero_init)(BlockDriverState *bs);
 198
 199    QLIST_ENTRY(BlockDriver) list;
 200};
 201
 202/*
 203 * Note: the function bdrv_append() copies and swaps contents of
 204 * BlockDriverStates, so if you add new fields to this struct, please
 205 * inspect bdrv_append() to determine if the new fields need to be
 206 * copied as well.
 207 */
 208struct BlockDriverState {
 209    int64_t total_sectors; /* if we are reading a disk image, give its
 210                              size in sectors */
 211    int read_only; /* if true, the media is read only */
 212    int open_flags; /* flags used to open the file, re-used for re-open */
 213    int encrypted; /* if true, the media is encrypted */
 214    int valid_key; /* if true, a valid encryption key has been set */
 215    int sg;        /* if true, the device is a /dev/sg* */
 216    int copy_on_read; /* if true, copy read backing sectors into image
 217                         note this is a reference count */
 218
 219    BlockDriver *drv; /* NULL means no media */
 220    void *opaque;
 221
 222    void *dev;                  /* attached device model, if any */
 223    /* TODO change to DeviceState when all users are qdevified */
 224    const BlockDevOps *dev_ops;
 225    void *dev_opaque;
 226
 227    char filename[1024];
 228    char backing_file[1024]; /* if non zero, the image is a diff of
 229                                this file image */
 230    char backing_format[16]; /* if non-zero and backing_file exists */
 231    int is_temporary;
 232
 233    BlockDriverState *backing_hd;
 234    BlockDriverState *file;
 235
 236    NotifierList close_notifiers;
 237
 238    /* number of in-flight copy-on-read requests */
 239    unsigned int copy_on_read_in_flight;
 240
 241    /* the time for latest disk I/O */
 242    int64_t slice_time;
 243    int64_t slice_start;
 244    int64_t slice_end;
 245    BlockIOLimit io_limits;
 246    BlockIOBaseValue  io_base;
 247    CoQueue      throttled_reqs;
 248    QEMUTimer    *block_timer;
 249    bool         io_limits_enabled;
 250
 251    /* I/O stats (display with "info blockstats"). */
 252    uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 253    uint64_t nr_ops[BDRV_MAX_IOTYPE];
 254    uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 255    uint64_t wr_highest_sector;
 256
 257    /* Whether the disk can expand beyond total_sectors */
 258    int growable;
 259
 260    /* the memory alignment required for the buffers handled by this driver */
 261    int buffer_alignment;
 262
 263    /* do we need to tell the quest if we have a volatile write cache? */
 264    int enable_write_cache;
 265
 266    /* NOTE: the following infos are only hints for real hardware
 267       drivers. They are not used by the block driver */
 268    BlockdevOnError on_read_error, on_write_error;
 269    bool iostatus_enabled;
 270    BlockDeviceIoStatus iostatus;
 271    char device_name[32];
 272    unsigned long *dirty_bitmap;
 273    int64_t dirty_count;
 274    int in_use; /* users other than guest access, eg. block migration */
 275    QTAILQ_ENTRY(BlockDriverState) list;
 276
 277    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 278
 279    /* long-running background operation */
 280    BlockJob *job;
 281
 282};
 283
 284int get_tmp_filename(char *filename, int size);
 285
 286void bdrv_set_io_limits(BlockDriverState *bs,
 287                        BlockIOLimit *io_limits);
 288
 289#ifdef _WIN32
 290int is_windows_drive(const char *filename);
 291#endif
 292void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
 293                               enum MonitorEvent ev,
 294                               BlockErrorAction action, bool is_read);
 295
 296/**
 297 * stream_start:
 298 * @bs: Block device to operate on.
 299 * @base: Block device that will become the new base, or %NULL to
 300 * flatten the whole backing file chain onto @bs.
 301 * @base_id: The file name that will be written to @bs as the new
 302 * backing file if the job completes.  Ignored if @base is %NULL.
 303 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 304 * @on_error: The action to take upon error.
 305 * @cb: Completion function for the job.
 306 * @opaque: Opaque pointer value passed to @cb.
 307 * @errp: Error object.
 308 *
 309 * Start a streaming operation on @bs.  Clusters that are unallocated
 310 * in @bs, but allocated in any image between @base and @bs (both
 311 * exclusive) will be written to @bs.  At the end of a successful
 312 * streaming job, the backing file of @bs will be changed to
 313 * @base_id in the written image and to @base in the live BlockDriverState.
 314 */
 315void stream_start(BlockDriverState *bs, BlockDriverState *base,
 316                  const char *base_id, int64_t speed, BlockdevOnError on_error,
 317                  BlockDriverCompletionFunc *cb,
 318                  void *opaque, Error **errp);
 319
 320/**
 321 * commit_start:
 322 * @bs: Top Block device
 323 * @base: Block device that will be written into, and become the new top
 324 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 325 * @on_error: The action to take upon error.
 326 * @cb: Completion function for the job.
 327 * @opaque: Opaque pointer value passed to @cb.
 328 * @errp: Error object.
 329 *
 330 */
 331void commit_start(BlockDriverState *bs, BlockDriverState *base,
 332                 BlockDriverState *top, int64_t speed,
 333                 BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
 334                 void *opaque, Error **errp);
 335
 336/*
 337 * mirror_start:
 338 * @bs: Block device to operate on.
 339 * @target: Block device to write to.
 340 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 341 * @mode: Whether to collapse all images in the chain to the target.
 342 * @on_source_error: The action to take upon error reading from the source.
 343 * @on_target_error: The action to take upon error writing to the target.
 344 * @cb: Completion function for the job.
 345 * @opaque: Opaque pointer value passed to @cb.
 346 * @errp: Error object.
 347 *
 348 * Start a mirroring operation on @bs.  Clusters that are allocated
 349 * in @bs will be written to @bs until the job is cancelled or
 350 * manually completed.  At the end of a successful mirroring job,
 351 * @bs will be switched to read from @target.
 352 */
 353void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 354                  int64_t speed, MirrorSyncMode mode,
 355                  BlockdevOnError on_source_error,
 356                  BlockdevOnError on_target_error,
 357                  BlockDriverCompletionFunc *cb,
 358                  void *opaque, Error **errp);
 359
 360#endif /* BLOCK_INT_H */
 361