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
  71     /* if not defined external snapshots are allowed
  72      * future block filters will query their children to build the response
  73      */
  74     ExtSnapshotPerm (*bdrv_check_ext_snapshot)(BlockDriverState *bs);
  75
  76     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  77     int (*bdrv_probe_device)(const char *filename);
  78
  79     /* Any driver implementing this callback is expected to be able to handle
  80      * NULL file names in its .bdrv_open() implementation */
  81     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
  82     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
  83      * this field set to true, except ones that are defined only by their
  84      * child's bs.
  85      * An example of the last type will be the quorum block driver.
  86      */
  87     bool bdrv_needs_filename;
  88
  89     /* For handling image reopen for split or non-split files */
  90     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
  91                                BlockReopenQueue *queue, Error **errp);
  92     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
  93     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
  94
  95     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
  96                      Error **errp);
  97     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
  98                           Error **errp);
  99     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
 100                      uint8_t *buf, int nb_sectors);
 101     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
 102                       const uint8_t *buf, int nb_sectors);
 103     void (*bdrv_close)(BlockDriverState *bs);
 104     void (*bdrv_rebind)(BlockDriverState *bs);
 105     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options,
 106                        Error **errp);
 107     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 108     int (*bdrv_make_empty)(BlockDriverState *bs);
 109     /* aio */
 110     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 111         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 112         BlockDriverCompletionFunc *cb, void *opaque);
 113     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 114         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 115         BlockDriverCompletionFunc *cb, void *opaque);
 116     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 117         BlockDriverCompletionFunc *cb, void *opaque);
 118     BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 119         int64_t sector_num, int nb_sectors,
 120         BlockDriverCompletionFunc *cb, void *opaque);
 121
 122     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 123         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 124     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 125         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 126     /*
 127      * Efficiently zero a region of the disk image.  Typically an image format
 128      * would use a compact metadata representation to implement this.  This
 129      * function pointer may be NULL and .bdrv_co_writev() will be called
 130      * instead.
 131      */
 132     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 133         int64_t sector_num, int nb_sectors);
 134     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 135         int64_t sector_num, int nb_sectors);
 136     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
 137         int64_t sector_num, int nb_sectors, int *pnum);
 138
 139     /*
 140      * Invalidate any cached meta-data.
 141      */
 142     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 143
 144     /*
 145      * Flushes all data that was already written to the OS all the way down to
 146      * the disk (for example raw-posix calls fsync()).
 147      */
 148     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 149
 150     /*
 151      * Flushes all internal caches to the OS. The data may still sit in a
 152      * writeback cache of the host OS, but it will survive a crash of the qemu
 153      * process.
 154      */
 155     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 156
 157     const char *protocol_name;
 158     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 159
 160     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 161     bool has_variable_length;
 162     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 163
 164     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 165                                  const uint8_t *buf, int nb_sectors);
 166
 167     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 168                                 QEMUSnapshotInfo *sn_info);
 169     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 170                               const char *snapshot_id);
 171     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
 172                                 const char *snapshot_id,
 173                                 const char *name,
 174                                 Error **errp);
 175     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 176                               QEMUSnapshotInfo **psn_info);
 177     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 178                                   const char *snapshot_name);
 179     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 180     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
 181
 182     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
 183                              int64_t pos);
 184     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 185                              int64_t pos, int size);
 186
 187     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 188         const char *backing_file, const char *backing_fmt);
 189
 190     /* removable device specific */
 191     int (*bdrv_is_inserted)(BlockDriverState *bs);
 192     int (*bdrv_media_changed)(BlockDriverState *bs);
 193     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 194     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 195
 196     /* to control generic scsi devices */
 197     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 198     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 199         unsigned long int req, void *buf,
 200         BlockDriverCompletionFunc *cb, void *opaque);
 201
 202     /* List of options for creating images, terminated by name == NULL */
 203     QEMUOptionParameter *create_options;
 204
 205
 206     /*
 207      * Returns 0 for completed check, -errno for internal errors.
 208      * The check results are stored in result.
 209      */
 210     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 211         BdrvCheckMode fix);
 212
 213     int (*bdrv_amend_options)(BlockDriverState *bs,
 214         QEMUOptionParameter *options);
 215
 216     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 217
 218     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 219     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 220         const char *tag);
 221     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 222     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 223
 224     /*
 225      * Returns 1 if newly created images are guaranteed to contain only
 226      * zeros, 0 otherwise.
 227      */
 228     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 229
 230     QLIST_ENTRY(BlockDriver) list;
 231 };
 232
 233 /*
 234  * Note: the function bdrv_append() copies and swaps contents of
 235  * BlockDriverStates, so if you add new fields to this struct, please
 236  * inspect bdrv_append() to determine if the new fields need to be
 237  * copied as well.
 238  */
 239 struct BlockDriverState {
 240     int64_t total_sectors; /* if we are reading a disk image, give its
 241                               size in sectors */
 242     int read_only; /* if true, the media is read only */
 243     int open_flags; /* flags used to open the file, re-used for re-open */
 244     int encrypted; /* if true, the media is encrypted */
 245     int valid_key; /* if true, a valid encryption key has been set */
 246     int sg;        /* if true, the device is a /dev/sg* */
 247     int copy_on_read; /* if true, copy read backing sectors into image
 248                          note this is a reference count */
 249
 250     BlockDriver *drv; /* NULL means no media */
 251     void *opaque;
 252
 253     void *dev;                  /* attached device model, if any */
 254     /* TODO change to DeviceState when all users are qdevified */
 255     const BlockDevOps *dev_ops;
 256     void *dev_opaque;
 257
 258     char filename[1024];
 259     char backing_file[1024]; /* if non zero, the image is a diff of
 260                                 this file image */
 261     char backing_format[16]; /* if non-zero and backing_file exists */
 262     int is_temporary;
 263
 264     BlockDriverState *backing_hd;
 265     BlockDriverState *file;
 266
 267     NotifierList close_notifiers;
 268
 269     /* Callback before write request is processed */
 270     NotifierWithReturnList before_write_notifiers;
 271
 272     /* number of in-flight copy-on-read requests */
 273     unsigned int copy_on_read_in_flight;
 274
 275     /* I/O throttling */
 276     ThrottleState throttle_state;
 277     CoQueue      throttled_reqs[2];
 278     bool         io_limits_enabled;
 279
 280     /* I/O stats (display with "info blockstats"). */
 281     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 282     uint64_t nr_ops[BDRV_MAX_IOTYPE];
 283     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 284     uint64_t wr_highest_sector;
 285
 286     /* Whether the disk can expand beyond total_sectors */
 287     int growable;
 288
 289     /* Whether produces zeros when read beyond eof */
 290     bool zero_beyond_eof;
 291
 292     /* the memory alignment required for the buffers handled by this driver */
 293     int buffer_alignment;
 294
 295     /* do we need to tell the quest if we have a volatile write cache? */
 296     int enable_write_cache;
 297
 298     /* NOTE: the following infos are only hints for real hardware
 299        drivers. They are not used by the block driver */
 300     BlockdevOnError on_read_error, on_write_error;
 301     bool iostatus_enabled;
 302     BlockDeviceIoStatus iostatus;
 303     char device_name[32];
 304     HBitmap *dirty_bitmap;
 305     int refcnt;
 306     int in_use; /* users other than guest access, eg. block migration */
 307     QTAILQ_ENTRY(BlockDriverState) list;
 308
 309     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 310
 311     /* long-running background operation */
 312     BlockJob *job;
 313
 314     QDict *options;
 315 };
 316
 317 int get_tmp_filename(char *filename, int size);
 318
 319 void bdrv_set_io_limits(BlockDriverState *bs,
 320                         ThrottleConfig *cfg);
 321
 322
 323 /**
 324  * bdrv_add_before_write_notifier:
 325  *
 326  * Register a callback that is invoked before write requests are processed but
 327  * after any throttling or waiting for overlapping requests.
 328  */
 329 void bdrv_add_before_write_notifier(BlockDriverState *bs,
 330                                     NotifierWithReturn *notifier);
 331
 332 /**
 333  * bdrv_get_aio_context:
 334  *
 335  * Returns: the currently bound #AioContext
 336  */
 337 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 338
 339 #ifdef _WIN32
 340 int is_windows_drive(const char *filename);
 341 #endif
 342 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
 343                                enum MonitorEvent ev,
 344                                BlockErrorAction action, bool is_read);
 345
 346 /**
 347  * stream_start:
 348  * @bs: Block device to operate on.
 349  * @base: Block device that will become the new base, or %NULL to
 350  * flatten the whole backing file chain onto @bs.
 351  * @base_id: The file name that will be written to @bs as the new
 352  * backing file if the job completes.  Ignored if @base is %NULL.
 353  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 354  * @on_error: The action to take upon error.
 355  * @cb: Completion function for the job.
 356  * @opaque: Opaque pointer value passed to @cb.
 357  * @errp: Error object.
 358  *
 359  * Start a streaming operation on @bs.  Clusters that are unallocated
 360  * in @bs, but allocated in any image between @base and @bs (both
 361  * exclusive) will be written to @bs.  At the end of a successful
 362  * streaming job, the backing file of @bs will be changed to
 363  * @base_id in the written image and to @base in the live BlockDriverState.
 364  */
 365 void stream_start(BlockDriverState *bs, BlockDriverState *base,
 366                   const char *base_id, int64_t speed, BlockdevOnError on_error,
 367                   BlockDriverCompletionFunc *cb,
 368                   void *opaque, Error **errp);
 369
 370 /**
 371  * commit_start:
 372  * @bs: Top Block device
 373  * @base: Block device that will be written into, and become the new top
 374  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 375  * @on_error: The action to take upon error.
 376  * @cb: Completion function for the job.
 377  * @opaque: Opaque pointer value passed to @cb.
 378  * @errp: Error object.
 379  *
 380  */
 381 void commit_start(BlockDriverState *bs, BlockDriverState *base,
 382                  BlockDriverState *top, int64_t speed,
 383                  BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
 384                  void *opaque, Error **errp);
 385
 386 /*
 387  * mirror_start:
 388  * @bs: Block device to operate on.
 389  * @target: Block device to write to.
 390  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 391  * @granularity: The chosen granularity for the dirty bitmap.
 392  * @buf_size: The amount of data that can be in flight at one time.
 393  * @mode: Whether to collapse all images in the chain to the target.
 394  * @on_source_error: The action to take upon error reading from the source.
 395  * @on_target_error: The action to take upon error writing to the target.
 396  * @cb: Completion function for the job.
 397  * @opaque: Opaque pointer value passed to @cb.
 398  * @errp: Error object.
 399  *
 400  * Start a mirroring operation on @bs.  Clusters that are allocated
 401  * in @bs will be written to @bs until the job is cancelled or
 402  * manually completed.  At the end of a successful mirroring job,
 403  * @bs will be switched to read from @target.
 404  */
 405 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 406                   int64_t speed, int64_t granularity, int64_t buf_size,
 407                   MirrorSyncMode mode, BlockdevOnError on_source_error,
 408                   BlockdevOnError on_target_error,
 409                   BlockDriverCompletionFunc *cb,
 410                   void *opaque, Error **errp);
 411
 412 /*
 413  * backup_start:
 414  * @bs: Block device to operate on.
 415  * @target: Block device to write to.
 416  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 417  * @sync_mode: What parts of the disk image should be copied to the destination.
 418  * @on_source_error: The action to take upon error reading from the source.
 419  * @on_target_error: The action to take upon error writing to the target.
 420  * @cb: Completion function for the job.
 421  * @opaque: Opaque pointer value passed to @cb.
 422  *
 423  * Start a backup operation on @bs.  Clusters in @bs are written to @target
 424  * until the job is cancelled or manually completed.
 425  */
 426 void backup_start(BlockDriverState *bs, BlockDriverState *target,
 427                   int64_t speed, MirrorSyncMode sync_mode,
 428                   BlockdevOnError on_source_error,
 429                   BlockdevOnError on_target_error,
 430                   BlockDriverCompletionFunc *cb, void *opaque,
 431                   Error **errp);
 432
 433 #endif /* BLOCK_INT_H */