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