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 #include "qemu/main-loop.h"
  38 #include "qemu/throttle.h"
  39
  40 #define BLOCK_FLAG_ENCRYPT          1
  41 #define BLOCK_FLAG_COMPAT6          4
  42 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
  43
  44 #define BLOCK_OPT_SIZE              "size"
  45 #define BLOCK_OPT_ENCRYPT           "encryption"
  46 #define BLOCK_OPT_COMPAT6           "compat6"
  47 #define BLOCK_OPT_BACKING_FILE      "backing_file"
  48 #define BLOCK_OPT_BACKING_FMT       "backing_fmt"
  49 #define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
  50 #define BLOCK_OPT_TABLE_SIZE        "table_size"
  51 #define BLOCK_OPT_PREALLOC          "preallocation"
  52 #define BLOCK_OPT_SUBFMT            "subformat"
  53 #define BLOCK_OPT_COMPAT_LEVEL      "compat"
  54 #define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
  55 #define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
  56
  57 typedef struct BdrvTrackedRequest {
  58     BlockDriverState *bs;
  59     int64_t sector_num;
  60     int nb_sectors;
  61     bool is_write;
  62     QLIST_ENTRY(BdrvTrackedRequest) list;
  63     Coroutine *co; /* owner, used for deadlock detection */
  64     CoQueue wait_queue; /* coroutines blocked on this request */
  65 } BdrvTrackedRequest;
  66
  67 struct BlockDriver {
  68     const char *format_name;
  69     int instance_size;
  70     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  71     int (*bdrv_probe_device)(const char *filename);
  72
  73     /* Any driver implementing this callback is expected to be able to handle
  74      * NULL file names in its .bdrv_open() implementation */
  75     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
  76     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
  77      * this field set to true, except ones that are defined only by their
  78      * child's bs.
  79      * An example of the last type will be the quorum block driver.
  80      */
  81     bool bdrv_needs_filename;
  82
  83     /* For handling image reopen for split or non-split files */
  84     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
  85                                BlockReopenQueue *queue, Error **errp);
  86     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
  87     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
  88
  89     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
  90                      Error **errp);
  91     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
  92                           Error **errp);
  93     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
  94                      uint8_t *buf, int nb_sectors);
  95     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
  96                       const uint8_t *buf, int nb_sectors);
  97     void (*bdrv_close)(BlockDriverState *bs);
  98     void (*bdrv_rebind)(BlockDriverState *bs);
  99     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options,
 100                        Error **errp);
 101     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 102     int (*bdrv_make_empty)(BlockDriverState *bs);
 103     /* aio */
 104     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 105         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 106         BlockDriverCompletionFunc *cb, void *opaque);
 107     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 108         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 109         BlockDriverCompletionFunc *cb, void *opaque);
 110     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 111         BlockDriverCompletionFunc *cb, void *opaque);
 112     BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 113         int64_t sector_num, int nb_sectors,
 114         BlockDriverCompletionFunc *cb, void *opaque);
 115
 116     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 117         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 118     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 119         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 120     /*
 121      * Efficiently zero a region of the disk image.  Typically an image format
 122      * would use a compact metadata representation to implement this.  This
 123      * function pointer may be NULL and .bdrv_co_writev() will be called
 124      * instead.
 125      */
 126     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 127         int64_t sector_num, int nb_sectors);
 128     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 129         int64_t sector_num, int nb_sectors);
 130     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
 131         int64_t sector_num, int nb_sectors, int *pnum);
 132
 133     /*
 134      * Invalidate any cached meta-data.
 135      */
 136     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 137
 138     /*
 139      * Flushes all data that was already written to the OS all the way down to
 140      * the disk (for example raw-posix calls fsync()).
 141      */
 142     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 143
 144     /*
 145      * Flushes all internal caches to the OS. The data may still sit in a
 146      * writeback cache of the host OS, but it will survive a crash of the qemu
 147      * process.
 148      */
 149     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 150
 151     const char *protocol_name;
 152     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 153     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 154     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 155     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 156                                  const uint8_t *buf, int nb_sectors);
 157
 158     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 159                                 QEMUSnapshotInfo *sn_info);
 160     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 161                               const char *snapshot_id);
 162     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
 163                                 const char *snapshot_id,
 164                                 const char *name,
 165                                 Error **errp);
 166     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 167                               QEMUSnapshotInfo **psn_info);
 168     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 169                                   const char *snapshot_name);
 170     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 171     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
 172
 173     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
 174                              int64_t pos);
 175     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 176                              int64_t pos, int size);
 177
 178     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 179         const char *backing_file, const char *backing_fmt);
 180
 181     /* removable device specific */
 182     int (*bdrv_is_inserted)(BlockDriverState *bs);
 183     int (*bdrv_media_changed)(BlockDriverState *bs);
 184     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 185     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 186
 187     /* to control generic scsi devices */
 188     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 189     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 190         unsigned long int req, void *buf,
 191         BlockDriverCompletionFunc *cb, void *opaque);
 192
 193     /* List of options for creating images, terminated by name == NULL */
 194     QEMUOptionParameter *create_options;
 195
 196
 197     /*
 198      * Returns 0 for completed check, -errno for internal errors.
 199      * The check results are stored in result.
 200      */
 201     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 202         BdrvCheckMode fix);
 203
 204     int (*bdrv_amend_options)(BlockDriverState *bs,
 205         QEMUOptionParameter *options);
 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     /* I/O throttling */
 267     ThrottleState throttle_state;
 268     CoQueue      throttled_reqs[2];
 269     bool         io_limits_enabled;
 270
 271     /* I/O stats (display with "info blockstats"). */
 272     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 273     uint64_t nr_ops[BDRV_MAX_IOTYPE];
 274     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 275     uint64_t wr_highest_sector;
 276
 277     /* Whether the disk can expand beyond total_sectors */
 278     int growable;
 279
 280     /* Whether produces zeros when read beyond eof */
 281     bool zero_beyond_eof;
 282
 283     /* the memory alignment required for the buffers handled by this driver */
 284     int buffer_alignment;
 285
 286     /* do we need to tell the quest if we have a volatile write cache? */
 287     int enable_write_cache;
 288
 289     /* NOTE: the following infos are only hints for real hardware
 290        drivers. They are not used by the block driver */
 291     BlockdevOnError on_read_error, on_write_error;
 292     bool iostatus_enabled;
 293     BlockDeviceIoStatus iostatus;
 294     char device_name[32];
 295     HBitmap *dirty_bitmap;
 296     int refcnt;
 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                         ThrottleConfig *cfg);
 312
 313
 314 /**
 315  * bdrv_add_before_write_notifier:
 316  *
 317  * Register a callback that is invoked before write requests are processed but
 318  * after any throttling or waiting for overlapping requests.
 319  */
 320 void bdrv_add_before_write_notifier(BlockDriverState *bs,
 321                                     NotifierWithReturn *notifier);
 322
 323 /**
 324  * bdrv_get_aio_context:
 325  *
 326  * Returns: the currently bound #AioContext
 327  */
 328 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 329
 330 #ifdef _WIN32
 331 int is_windows_drive(const char *filename);
 332 #endif
 333 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
 334                                enum MonitorEvent ev,
 335                                BlockErrorAction action, bool is_read);
 336
 337 /**
 338  * stream_start:
 339  * @bs: Block device to operate on.
 340  * @base: Block device that will become the new base, or %NULL to
 341  * flatten the whole backing file chain onto @bs.
 342  * @base_id: The file name that will be written to @bs as the new
 343  * backing file if the job completes.  Ignored if @base is %NULL.
 344  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 345  * @on_error: The action to take upon error.
 346  * @cb: Completion function for the job.
 347  * @opaque: Opaque pointer value passed to @cb.
 348  * @errp: Error object.
 349  *
 350  * Start a streaming operation on @bs.  Clusters that are unallocated
 351  * in @bs, but allocated in any image between @base and @bs (both
 352  * exclusive) will be written to @bs.  At the end of a successful
 353  * streaming job, the backing file of @bs will be changed to
 354  * @base_id in the written image and to @base in the live BlockDriverState.
 355  */
 356 void stream_start(BlockDriverState *bs, BlockDriverState *base,
 357                   const char *base_id, int64_t speed, BlockdevOnError on_error,
 358                   BlockDriverCompletionFunc *cb,
 359                   void *opaque, Error **errp);
 360
 361 /**
 362  * commit_start:
 363  * @bs: Top Block device
 364  * @base: Block device that will be written into, and become the new top
 365  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 366  * @on_error: The action to take upon error.
 367  * @cb: Completion function for the job.
 368  * @opaque: Opaque pointer value passed to @cb.
 369  * @errp: Error object.
 370  *
 371  */
 372 void commit_start(BlockDriverState *bs, BlockDriverState *base,
 373                  BlockDriverState *top, int64_t speed,
 374                  BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
 375                  void *opaque, Error **errp);
 376
 377 /*
 378  * mirror_start:
 379  * @bs: Block device to operate on.
 380  * @target: Block device to write to.
 381  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 382  * @granularity: The chosen granularity for the dirty bitmap.
 383  * @buf_size: The amount of data that can be in flight at one time.
 384  * @mode: Whether to collapse all images in the chain to the target.
 385  * @on_source_error: The action to take upon error reading from the source.
 386  * @on_target_error: The action to take upon error writing to the target.
 387  * @cb: Completion function for the job.
 388  * @opaque: Opaque pointer value passed to @cb.
 389  * @errp: Error object.
 390  *
 391  * Start a mirroring operation on @bs.  Clusters that are allocated
 392  * in @bs will be written to @bs until the job is cancelled or
 393  * manually completed.  At the end of a successful mirroring job,
 394  * @bs will be switched to read from @target.
 395  */
 396 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 397                   int64_t speed, int64_t granularity, int64_t buf_size,
 398                   MirrorSyncMode mode, BlockdevOnError on_source_error,
 399                   BlockdevOnError on_target_error,
 400                   BlockDriverCompletionFunc *cb,
 401                   void *opaque, Error **errp);
 402
 403 /*
 404  * backup_start:
 405  * @bs: Block device to operate on.
 406  * @target: Block device to write to.
 407  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 408  * @sync_mode: What parts of the disk image should be copied to the destination.
 409  * @on_source_error: The action to take upon error reading from the source.
 410  * @on_target_error: The action to take upon error writing to the target.
 411  * @cb: Completion function for the job.
 412  * @opaque: Opaque pointer value passed to @cb.
 413  *
 414  * Start a backup operation on @bs.  Clusters in @bs are written to @target
 415  * until the job is cancelled or manually completed.
 416  */
 417 void backup_start(BlockDriverState *bs, BlockDriverState *target,
 418                   int64_t speed, MirrorSyncMode sync_mode,
 419                   BlockdevOnError on_source_error,
 420                   BlockdevOnError on_target_error,
 421                   BlockDriverCompletionFunc *cb, void *opaque,
 422                   Error **errp);
 423
 424 #endif /* BLOCK_INT_H */