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