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