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/block.h"
  28 #include "qemu/option.h"
  29 #include "qemu/queue.h"
  30 #include "block/coroutine.h"
  31 #include "qemu/timer.h"
  32 #include "qapi-types.h"
  33 #include "qapi/qmp/qerror.h"
  34 #include "monitor/monitor.h"
  35 #include "qemu/hbitmap.h"
  36 #include "block/snapshot.h"
  37
  38 #define BLOCK_FLAG_ENCRYPT          1
  39 #define BLOCK_FLAG_COMPAT6          4
  40 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
  41
  42 #define BLOCK_IO_LIMIT_READ     0
  43 #define BLOCK_IO_LIMIT_WRITE    1
  44 #define BLOCK_IO_LIMIT_TOTAL    2
  45
  46 #define BLOCK_IO_SLICE_TIME     100000000
  47 #define NANOSECONDS_PER_SECOND  1000000000.0
  48
  49 #define BLOCK_OPT_SIZE              "size"
  50 #define BLOCK_OPT_ENCRYPT           "encryption"
  51 #define BLOCK_OPT_COMPAT6           "compat6"
  52 #define BLOCK_OPT_BACKING_FILE      "backing_file"
  53 #define BLOCK_OPT_BACKING_FMT       "backing_fmt"
  54 #define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
  55 #define BLOCK_OPT_TABLE_SIZE        "table_size"
  56 #define BLOCK_OPT_PREALLOC          "preallocation"
  57 #define BLOCK_OPT_SUBFMT            "subformat"
  58 #define BLOCK_OPT_COMPAT_LEVEL      "compat"
  59 #define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
  60 #define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
  61
  62 typedef struct BdrvTrackedRequest {
  63     BlockDriverState *bs;
  64     int64_t sector_num;
  65     int nb_sectors;
  66     bool is_write;
  67     QLIST_ENTRY(BdrvTrackedRequest) list;
  68     Coroutine *co; /* owner, used for deadlock detection */
  69     CoQueue wait_queue; /* coroutines blocked on this request */
  70 } BdrvTrackedRequest;
  71
  72
  73 typedef struct BlockIOLimit {
  74     int64_t bps[3];
  75     int64_t iops[3];
  76 } BlockIOLimit;
  77
  78 typedef struct BlockIOBaseValue {
  79     uint64_t bytes[2];
  80     uint64_t ios[2];
  81 } BlockIOBaseValue;
  82
  83 struct BlockDriver {
  84     const char *format_name;
  85     int instance_size;
  86     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  87     int (*bdrv_probe_device)(const char *filename);
  88
  89     /* Any driver implementing this callback is expected to be able to handle
  90      * NULL file names in its .bdrv_open() implementation */
  91     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
  92
  93     /* For handling image reopen for split or non-split files */
  94     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
  95                                BlockReopenQueue *queue, Error **errp);
  96     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
  97     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
  98
  99     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags);
 100     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags);
 101     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
 102                      uint8_t *buf, int nb_sectors);
 103     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
 104                       const uint8_t *buf, int nb_sectors);
 105     void (*bdrv_close)(BlockDriverState *bs);
 106     void (*bdrv_rebind)(BlockDriverState *bs);
 107     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
 108     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 109     int (*bdrv_make_empty)(BlockDriverState *bs);
 110     /* aio */
 111     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 112         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 113         BlockDriverCompletionFunc *cb, void *opaque);
 114     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 115         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 116         BlockDriverCompletionFunc *cb, void *opaque);
 117     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 118         BlockDriverCompletionFunc *cb, void *opaque);
 119     BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 120         int64_t sector_num, int nb_sectors,
 121         BlockDriverCompletionFunc *cb, void *opaque);
 122
 123     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 124         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 125     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 126         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 127     /*
 128      * Efficiently zero a region of the disk image.  Typically an image format
 129      * would use a compact metadata representation to implement this.  This
 130      * function pointer may be NULL and .bdrv_co_writev() will be called
 131      * instead.
 132      */
 133     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 134         int64_t sector_num, int nb_sectors);
 135     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 136         int64_t sector_num, int nb_sectors);
 137     int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
 138         int64_t sector_num, int nb_sectors, int *pnum);
 139
 140     /*
 141      * Invalidate any cached meta-data.
 142      */
 143     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 144
 145     /*
 146      * Flushes all data that was already written to the OS all the way down to
 147      * the disk (for example raw-posix calls fsync()).
 148      */
 149     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 150
 151     /*
 152      * Flushes all internal caches to the OS. The data may still sit in a
 153      * writeback cache of the host OS, but it will survive a crash of the qemu
 154      * process.
 155      */
 156     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 157
 158     const char *protocol_name;
 159     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 160     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 161     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 162     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 163                                  const uint8_t *buf, int nb_sectors);
 164
 165     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 166                                 QEMUSnapshotInfo *sn_info);
 167     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 168                               const char *snapshot_id);
 169     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
 170     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 171                               QEMUSnapshotInfo **psn_info);
 172     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 173                                   const char *snapshot_name);
 174     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 175
 176     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
 177                              int64_t pos);
 178     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 179                              int64_t pos, int size);
 180
 181     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 182         const char *backing_file, const char *backing_fmt);
 183
 184     /* removable device specific */
 185     int (*bdrv_is_inserted)(BlockDriverState *bs);
 186     int (*bdrv_media_changed)(BlockDriverState *bs);
 187     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 188     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 189
 190     /* to control generic scsi devices */
 191     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 192     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 193         unsigned long int req, void *buf,
 194         BlockDriverCompletionFunc *cb, void *opaque);
 195
 196     /* List of options for creating images, terminated by name == NULL */
 197     QEMUOptionParameter *create_options;
 198
 199
 200     /*
 201      * Returns 0 for completed check, -errno for internal errors.
 202      * The check results are stored in result.
 203      */
 204     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 205         BdrvCheckMode fix);
 206
 207     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 208
 209     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 210     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 211         const char *tag);
 212     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 213     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 214
 215     /*
 216      * Returns 1 if newly created images are guaranteed to contain only
 217      * zeros, 0 otherwise.
 218      */
 219     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 220
 221     QLIST_ENTRY(BlockDriver) list;
 222 };
 223
 224 /*
 225  * Note: the function bdrv_append() copies and swaps contents of
 226  * BlockDriverStates, so if you add new fields to this struct, please
 227  * inspect bdrv_append() to determine if the new fields need to be
 228  * copied as well.
 229  */
 230 struct BlockDriverState {
 231     int64_t total_sectors; /* if we are reading a disk image, give its
 232                               size in sectors */
 233     int read_only; /* if true, the media is read only */
 234     int open_flags; /* flags used to open the file, re-used for re-open */
 235     int encrypted; /* if true, the media is encrypted */
 236     int valid_key; /* if true, a valid encryption key has been set */
 237     int sg;        /* if true, the device is a /dev/sg* */
 238     int copy_on_read; /* if true, copy read backing sectors into image
 239                          note this is a reference count */
 240
 241     BlockDriver *drv; /* NULL means no media */
 242     void *opaque;
 243
 244     void *dev;                  /* attached device model, if any */
 245     /* TODO change to DeviceState when all users are qdevified */
 246     const BlockDevOps *dev_ops;
 247     void *dev_opaque;
 248
 249     char filename[1024];
 250     char backing_file[1024]; /* if non zero, the image is a diff of
 251                                 this file image */
 252     char backing_format[16]; /* if non-zero and backing_file exists */
 253     int is_temporary;
 254
 255     BlockDriverState *backing_hd;
 256     BlockDriverState *file;
 257
 258     NotifierList close_notifiers;
 259
 260     /* Callback before write request is processed */
 261     NotifierWithReturnList before_write_notifiers;
 262
 263     /* number of in-flight copy-on-read requests */
 264     unsigned int copy_on_read_in_flight;
 265
 266     /* the time for latest disk I/O */
 267     int64_t slice_start;
 268     int64_t slice_end;
 269     BlockIOLimit io_limits;
 270     BlockIOBaseValue slice_submitted;
 271     CoQueue      throttled_reqs;
 272     QEMUTimer    *block_timer;
 273     bool         io_limits_enabled;
 274
 275     /* I/O stats (display with "info blockstats"). */
 276     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 277     uint64_t nr_ops[BDRV_MAX_IOTYPE];
 278     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 279     uint64_t wr_highest_sector;
 280
 281     /* Whether the disk can expand beyond total_sectors */
 282     int growable;
 283
 284     /* the memory alignment required for the buffers handled by this driver */
 285     int buffer_alignment;
 286
 287     /* do we need to tell the quest if we have a volatile write cache? */
 288     int enable_write_cache;
 289
 290     /* NOTE: the following infos are only hints for real hardware
 291        drivers. They are not used by the block driver */
 292     BlockdevOnError on_read_error, on_write_error;
 293     bool iostatus_enabled;
 294     BlockDeviceIoStatus iostatus;
 295     char device_name[32];
 296     HBitmap *dirty_bitmap;
 297     int in_use; /* users other than guest access, eg. block migration */
 298     QTAILQ_ENTRY(BlockDriverState) list;
 299
 300     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 301
 302     /* long-running background operation */
 303     BlockJob *job;
 304
 305     QDict *options;
 306 };
 307
 308 int get_tmp_filename(char *filename, int size);
 309
 310 void bdrv_set_io_limits(BlockDriverState *bs,
 311                         BlockIOLimit *io_limits);
 312
 313 /**
 314  * bdrv_add_before_write_notifier:
 315  *
 316  * Register a callback that is invoked before write requests are processed but
 317  * after any throttling or waiting for overlapping requests.
 318  */
 319 void bdrv_add_before_write_notifier(BlockDriverState *bs,
 320                                     NotifierWithReturn *notifier);
 321
 322 /**
 323  * bdrv_get_aio_context:
 324  *
 325  * Returns: the currently bound #AioContext
 326  */
 327 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 328
 329 #ifdef _WIN32
 330 int is_windows_drive(const char *filename);
 331 #endif
 332 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
 333                                enum MonitorEvent ev,
 334                                BlockErrorAction action, bool is_read);
 335
 336 /**
 337  * stream_start:
 338  * @bs: Block device to operate on.
 339  * @base: Block device that will become the new base, or %NULL to
 340  * flatten the whole backing file chain onto @bs.
 341  * @base_id: The file name that will be written to @bs as the new
 342  * backing file if the job completes.  Ignored if @base is %NULL.
 343  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 344  * @on_error: The action to take upon error.
 345  * @cb: Completion function for the job.
 346  * @opaque: Opaque pointer value passed to @cb.
 347  * @errp: Error object.
 348  *
 349  * Start a streaming operation on @bs.  Clusters that are unallocated
 350  * in @bs, but allocated in any image between @base and @bs (both
 351  * exclusive) will be written to @bs.  At the end of a successful
 352  * streaming job, the backing file of @bs will be changed to
 353  * @base_id in the written image and to @base in the live BlockDriverState.
 354  */
 355 void stream_start(BlockDriverState *bs, BlockDriverState *base,
 356                   const char *base_id, int64_t speed, BlockdevOnError on_error,
 357                   BlockDriverCompletionFunc *cb,
 358                   void *opaque, Error **errp);
 359
 360 /**
 361  * commit_start:
 362  * @bs: Top Block device
 363  * @base: Block device that will be written into, and become the new top
 364  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 365  * @on_error: The action to take upon error.
 366  * @cb: Completion function for the job.
 367  * @opaque: Opaque pointer value passed to @cb.
 368  * @errp: Error object.
 369  *
 370  */
 371 void commit_start(BlockDriverState *bs, BlockDriverState *base,
 372                  BlockDriverState *top, int64_t speed,
 373                  BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
 374                  void *opaque, Error **errp);
 375
 376 /*
 377  * mirror_start:
 378  * @bs: Block device to operate on.
 379  * @target: Block device to write to.
 380  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 381  * @granularity: The chosen granularity for the dirty bitmap.
 382  * @buf_size: The amount of data that can be in flight at one time.
 383  * @mode: Whether to collapse all images in the chain to the target.
 384  * @on_source_error: The action to take upon error reading from the source.
 385  * @on_target_error: The action to take upon error writing to the target.
 386  * @cb: Completion function for the job.
 387  * @opaque: Opaque pointer value passed to @cb.
 388  * @errp: Error object.
 389  *
 390  * Start a mirroring operation on @bs.  Clusters that are allocated
 391  * in @bs will be written to @bs until the job is cancelled or
 392  * manually completed.  At the end of a successful mirroring job,
 393  * @bs will be switched to read from @target.
 394  */
 395 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 396                   int64_t speed, int64_t granularity, int64_t buf_size,
 397                   MirrorSyncMode mode, BlockdevOnError on_source_error,
 398                   BlockdevOnError on_target_error,
 399                   BlockDriverCompletionFunc *cb,
 400                   void *opaque, Error **errp);
 401
 402 /*
 403  * backup_start:
 404  * @bs: Block device to operate on.
 405  * @target: Block device to write to.
 406  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 407  * @sync_mode: What parts of the disk image should be copied to the destination.
 408  * @on_source_error: The action to take upon error reading from the source.
 409  * @on_target_error: The action to take upon error writing to the target.
 410  * @cb: Completion function for the job.
 411  * @opaque: Opaque pointer value passed to @cb.
 412  *
 413  * Start a backup operation on @bs.  Clusters in @bs are written to @target
 414  * until the job is cancelled or manually completed.
 415  */
 416 void backup_start(BlockDriverState *bs, BlockDriverState *target,
 417                   int64_t speed, MirrorSyncMode sync_mode,
 418                   BlockdevOnError on_source_error,
 419                   BlockdevOnError on_target_error,
 420                   BlockDriverCompletionFunc *cb, void *opaque,
 421                   Error **errp);
 422
 423 #endif /* BLOCK_INT_H */