include/block/block.h

   1 #ifndef BLOCK_H
   2 #define BLOCK_H
   3
   4 #include "block/aio.h"
   5 #include "qemu/iov.h"
   6 #include "qemu/option.h"
   7 #include "qemu/coroutine.h"
   8 #include "block/accounting.h"
   9 #include "block/dirty-bitmap.h"
  10 #include "qapi/qmp/qobject.h"
  11 #include "qapi-types.h"
  12 #include "qemu/hbitmap.h"
  13
  14 /* block.c */
  15 typedef struct BlockDriver BlockDriver;
  16 typedef struct BlockJob BlockJob;
  17 typedef struct BdrvChild BdrvChild;
  18 typedef struct BdrvChildRole BdrvChildRole;
  19 typedef struct BlockJobTxn BlockJobTxn;
  20
  21 typedef struct BlockDriverInfo {
  22     /* in bytes, 0 if irrelevant */
  23     int cluster_size;
  24     /* offset at which the VM state can be saved (0 if not possible) */
  25     int64_t vm_state_offset;
  26     bool is_dirty;
  27     /*
  28      * True if unallocated blocks read back as zeroes. This is equivalent
  29      * to the LBPRZ flag in the SCSI logical block provisioning page.
  30      */
  31     bool unallocated_blocks_are_zero;
  32     /*
  33      * True if the driver can optimize writing zeroes by unmapping
  34      * sectors. This is equivalent to the BLKDISCARDZEROES ioctl in Linux
  35      * with the difference that in qemu a discard is allowed to silently
  36      * fail. Therefore we have to use bdrv_write_zeroes with the
  37      * BDRV_REQ_MAY_UNMAP flag for an optimized zero write with unmapping.
  38      * After this call the driver has to guarantee that the contents read
  39      * back as zero. It is additionally required that the block device is
  40      * opened with BDRV_O_UNMAP flag for this to work.
  41      */
  42     bool can_write_zeroes_with_unmap;
  43     /*
  44      * True if this block driver only supports compressed writes
  45      */
  46     bool needs_compressed_writes;
  47 } BlockDriverInfo;
  48
  49 typedef struct BlockFragInfo {
  50     uint64_t allocated_clusters;
  51     uint64_t total_clusters;
  52     uint64_t fragmented_clusters;
  53     uint64_t compressed_clusters;
  54 } BlockFragInfo;
  55
  56 typedef enum {
  57     BDRV_REQ_COPY_ON_READ       = 0x1,
  58     BDRV_REQ_ZERO_WRITE         = 0x2,
  59     /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
  60      * is allowed to optimize a write zeroes request by unmapping (discarding)
  61      * blocks if it is guaranteed that the result will read back as
  62      * zeroes. The flag is only passed to the driver if the block device is
  63      * opened with BDRV_O_UNMAP.
  64      */
  65     BDRV_REQ_MAY_UNMAP          = 0x4,
  66     BDRV_REQ_NO_SERIALISING     = 0x8,
  67 } BdrvRequestFlags;
  68
  69 typedef struct BlockSizes {
  70     uint32_t phys;
  71     uint32_t log;
  72 } BlockSizes;
  73
  74 typedef struct HDGeometry {
  75     uint32_t heads;
  76     uint32_t sectors;
  77     uint32_t cylinders;
  78 } HDGeometry;
  79
  80 #define BDRV_O_RDWR        0x0002
  81 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
  82 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
  83 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
  84 #define BDRV_O_CACHE_WB    0x0040 /* use write-back caching */
  85 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
  86 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
  87 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
  88 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
  89 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
  90 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
  91 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
  92 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
  93 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
  94                                       select an appropriate protocol driver,
  95                                       ignoring the format layer */
  96
  97 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
  98
  99
 100 /* Option names of options parsed by the block layer */
 101
 102 #define BDRV_OPT_CACHE_WB       "cache.writeback"
 103 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
 104 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
 105
 106
 107 #define BDRV_SECTOR_BITS   9
 108 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 109 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 110
 111 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
 112                                      INT_MAX >> BDRV_SECTOR_BITS)
 113
 114 /*
 115  * Allocation status flags
 116  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
 117  * BDRV_BLOCK_ZERO: sectors read as zero
 118  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
 119  *                          bdrv_get_block_status.
 120  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
 121  *                       layer (as opposed to the backing file)
 122  * BDRV_BLOCK_RAW: used internally to indicate that the request
 123  *                 was answered by the raw driver and that one
 124  *                 should look in bs->file directly.
 125  *
 126  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
 127  * bs->file where sector data can be read from as raw data.
 128  *
 129  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
 130  *
 131  * DATA ZERO OFFSET_VALID
 132  *  t    t        t       sectors read as zero, bs->file is zero at offset
 133  *  t    f        t       sectors read as valid from bs->file at offset
 134  *  f    t        t       sectors preallocated, read as zero, bs->file not
 135  *                        necessarily zero at offset
 136  *  f    f        t       sectors preallocated but read from backing_hd,
 137  *                        bs->file contains garbage at offset
 138  *  t    t        f       sectors preallocated, read as zero, unknown offset
 139  *  t    f        f       sectors read from unknown file or offset
 140  *  f    t        f       not allocated or unknown offset, read as zero
 141  *  f    f        f       not allocated or unknown offset, read from backing_hd
 142  */
 143 #define BDRV_BLOCK_DATA         0x01
 144 #define BDRV_BLOCK_ZERO         0x02
 145 #define BDRV_BLOCK_OFFSET_VALID 0x04
 146 #define BDRV_BLOCK_RAW          0x08
 147 #define BDRV_BLOCK_ALLOCATED    0x10
 148 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
 149
 150 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
 151
 152 typedef struct BDRVReopenState {
 153     BlockDriverState *bs;
 154     int flags;
 155     QDict *options;
 156     QDict *explicit_options;
 157     void *opaque;
 158 } BDRVReopenState;
 159
 160 /*
 161  * Block operation types
 162  */
 163 typedef enum BlockOpType {
 164     BLOCK_OP_TYPE_BACKUP_SOURCE,
 165     BLOCK_OP_TYPE_BACKUP_TARGET,
 166     BLOCK_OP_TYPE_CHANGE,
 167     BLOCK_OP_TYPE_COMMIT_SOURCE,
 168     BLOCK_OP_TYPE_COMMIT_TARGET,
 169     BLOCK_OP_TYPE_DATAPLANE,
 170     BLOCK_OP_TYPE_DRIVE_DEL,
 171     BLOCK_OP_TYPE_EJECT,
 172     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
 173     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
 174     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
 175     BLOCK_OP_TYPE_MIRROR_SOURCE,
 176     BLOCK_OP_TYPE_MIRROR_TARGET,
 177     BLOCK_OP_TYPE_RESIZE,
 178     BLOCK_OP_TYPE_STREAM,
 179     BLOCK_OP_TYPE_REPLACE,
 180     BLOCK_OP_TYPE_MAX,
 181 } BlockOpType;
 182
 183 void bdrv_info_print(Monitor *mon, const QObject *data);
 184 void bdrv_info(Monitor *mon, QObject **ret_data);
 185 void bdrv_stats_print(Monitor *mon, const QObject *data);
 186 void bdrv_info_stats(Monitor *mon, QObject **ret_data);
 187
 188 /* disk I/O throttling */
 189 void bdrv_io_limits_enable(BlockDriverState *bs, const char *group);
 190 void bdrv_io_limits_disable(BlockDriverState *bs);
 191 void bdrv_io_limits_update_group(BlockDriverState *bs, const char *group);
 192
 193 void bdrv_init(void);
 194 void bdrv_init_with_whitelist(void);
 195 BlockDriver *bdrv_find_protocol(const char *filename,
 196                                 bool allow_protocol_prefix,
 197                                 Error **errp);
 198 BlockDriver *bdrv_find_format(const char *format_name);
 199 int bdrv_create(BlockDriver *drv, const char* filename,
 200                 QemuOpts *opts, Error **errp);
 201 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
 202 BlockDriverState *bdrv_new_root(void);
 203 BlockDriverState *bdrv_new(void);
 204 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
 205 void bdrv_replace_in_backing_chain(BlockDriverState *old,
 206                                    BlockDriverState *new);
 207
 208 int bdrv_parse_cache_flags(const char *mode, int *flags);
 209 int bdrv_parse_discard_flags(const char *mode, int *flags);
 210 BdrvChild *bdrv_open_child(const char *filename,
 211                            QDict *options, const char *bdref_key,
 212                            BlockDriverState* parent,
 213                            const BdrvChildRole *child_role,
 214                            bool allow_none, Error **errp);
 215 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
 216 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
 217                            const char *bdref_key, Error **errp);
 218 int bdrv_open(BlockDriverState **pbs, const char *filename,
 219               const char *reference, QDict *options, int flags, Error **errp);
 220 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
 221                                     BlockDriverState *bs,
 222                                     QDict *options, int flags);
 223 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
 224 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
 225 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
 226                         BlockReopenQueue *queue, Error **errp);
 227 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
 228 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 229 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 230               uint8_t *buf, int nb_sectors);
 231 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 232                const uint8_t *buf, int nb_sectors);
 233 int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
 234                int nb_sectors, BdrvRequestFlags flags);
 235 BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, int64_t sector_num,
 236                                   int nb_sectors, BdrvRequestFlags flags,
 237                                   BlockCompletionFunc *cb, void *opaque);
 238 int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags);
 239 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 240                void *buf, int count);
 241 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 242                 const void *buf, int count);
 243 int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
 244 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
 245     const void *buf, int count);
 246 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
 247     int nb_sectors, QEMUIOVector *qiov);
 248 int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
 249     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 250 int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs,
 251     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 252 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
 253     int nb_sectors, QEMUIOVector *qiov);
 254 /*
 255  * Efficiently zero a region of the disk image.  Note that this is a regular
 256  * I/O request like read or write and should have a reasonable size.  This
 257  * function is not suitable for zeroing the entire image in a single request
 258  * because it may allocate memory for the entire region.
 259  */
 260 int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
 261     int nb_sectors, BdrvRequestFlags flags);
 262 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 263     const char *backing_file);
 264 int bdrv_get_backing_file_depth(BlockDriverState *bs);
 265 void bdrv_refresh_filename(BlockDriverState *bs);
 266 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
 267 int64_t bdrv_nb_sectors(BlockDriverState *bs);
 268 int64_t bdrv_getlength(BlockDriverState *bs);
 269 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 270 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 271 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 272 int bdrv_commit(BlockDriverState *bs);
 273 int bdrv_change_backing_file(BlockDriverState *bs,
 274     const char *backing_file, const char *backing_fmt);
 275 void bdrv_register(BlockDriver *bdrv);
 276 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
 277                            BlockDriverState *base,
 278                            const char *backing_file_str);
 279 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 280                                     BlockDriverState *bs);
 281 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 282
 283
 284 typedef struct BdrvCheckResult {
 285     int corruptions;
 286     int leaks;
 287     int check_errors;
 288     int corruptions_fixed;
 289     int leaks_fixed;
 290     int64_t image_end_offset;
 291     BlockFragInfo bfi;
 292 } BdrvCheckResult;
 293
 294 typedef enum {
 295     BDRV_FIX_LEAKS    = 1,
 296     BDRV_FIX_ERRORS   = 2,
 297 } BdrvCheckMode;
 298
 299 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 300
 301 /* The units of offset and total_work_size may be chosen arbitrarily by the
 302  * block driver; total_work_size may change during the course of the amendment
 303  * operation */
 304 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 305                                       int64_t total_work_size, void *opaque);
 306 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 307                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
 308
 309 /* external snapshots */
 310 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
 311                                       BlockDriverState *candidate);
 312 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
 313
 314 /* check if a named node can be replaced when doing drive-mirror */
 315 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 316                                         const char *node_name, Error **errp);
 317
 318 /* async block I/O */
 319 BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
 320                            QEMUIOVector *iov, int nb_sectors,
 321                            BlockCompletionFunc *cb, void *opaque);
 322 BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
 323                             QEMUIOVector *iov, int nb_sectors,
 324                             BlockCompletionFunc *cb, void *opaque);
 325 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
 326                            BlockCompletionFunc *cb, void *opaque);
 327 BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
 328                              int64_t sector_num, int nb_sectors,
 329                              BlockCompletionFunc *cb, void *opaque);
 330 void bdrv_aio_cancel(BlockAIOCB *acb);
 331 void bdrv_aio_cancel_async(BlockAIOCB *acb);
 332
 333 typedef struct BlockRequest {
 334     /* Fields to be filled by multiwrite caller */
 335     union {
 336         struct {
 337             int64_t sector;
 338             int nb_sectors;
 339             int flags;
 340             QEMUIOVector *qiov;
 341         };
 342         struct {
 343             int req;
 344             void *buf;
 345         };
 346     };
 347     BlockCompletionFunc *cb;
 348     void *opaque;
 349
 350     /* Filled by multiwrite implementation */
 351     int error;
 352 } BlockRequest;
 353
 354 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs,
 355     int num_reqs);
 356
 357 /* sg packet commands */
 358 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
 359 BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
 360         unsigned long int req, void *buf,
 361         BlockCompletionFunc *cb, void *opaque);
 362
 363 /* Invalidate any cached metadata used by image formats */
 364 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
 365 void bdrv_invalidate_cache_all(Error **errp);
 366 int bdrv_inactivate_all(void);
 367
 368 /* Ensure contents are flushed to disk.  */
 369 int bdrv_flush(BlockDriverState *bs);
 370 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
 371 void bdrv_close_all(void);
 372 void bdrv_drain(BlockDriverState *bs);
 373 void bdrv_drain_all(void);
 374
 375 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 376 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 377 int bdrv_has_zero_init_1(BlockDriverState *bs);
 378 int bdrv_has_zero_init(BlockDriverState *bs);
 379 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 380 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 381 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
 382                               int nb_sectors, int *pnum,
 383                               BlockDriverState **file);
 384 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
 385                                     BlockDriverState *base,
 386                                     int64_t sector_num,
 387                                     int nb_sectors, int *pnum,
 388                                     BlockDriverState **file);
 389 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 390                       int *pnum);
 391 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
 392                             int64_t sector_num, int nb_sectors, int *pnum);
 393
 394 int bdrv_is_read_only(BlockDriverState *bs);
 395 int bdrv_is_sg(BlockDriverState *bs);
 396 int bdrv_enable_write_cache(BlockDriverState *bs);
 397 void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce);
 398 bool bdrv_is_inserted(BlockDriverState *bs);
 399 int bdrv_media_changed(BlockDriverState *bs);
 400 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
 401 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
 402 const char *bdrv_get_format_name(BlockDriverState *bs);
 403 BlockDriverState *bdrv_find_node(const char *node_name);
 404 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
 405 BlockDriverState *bdrv_lookup_bs(const char *device,
 406                                  const char *node_name,
 407                                  Error **errp);
 408 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 409 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 410 BlockDriverState *bdrv_next(BlockDriverState *bs);
 411 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 412 int bdrv_is_encrypted(BlockDriverState *bs);
 413 int bdrv_key_required(BlockDriverState *bs);
 414 int bdrv_set_key(BlockDriverState *bs, const char *key);
 415 void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
 416 int bdrv_query_missing_keys(void);
 417 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 418                          void *opaque);
 419 const char *bdrv_get_node_name(const BlockDriverState *bs);
 420 const char *bdrv_get_device_name(const BlockDriverState *bs);
 421 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 422 int bdrv_get_flags(BlockDriverState *bs);
 423 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
 424                           const uint8_t *buf, int nb_sectors);
 425 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 426 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
 427 void bdrv_round_to_clusters(BlockDriverState *bs,
 428                             int64_t sector_num, int nb_sectors,
 429                             int64_t *cluster_sector_num,
 430                             int *cluster_nb_sectors);
 431
 432 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
 433 void bdrv_get_backing_filename(BlockDriverState *bs,
 434                                char *filename, int filename_size);
 435 void bdrv_get_full_backing_filename(BlockDriverState *bs,
 436                                     char *dest, size_t sz, Error **errp);
 437 void bdrv_get_full_backing_filename_from_filename(const char *backed,
 438                                                   const char *backing,
 439                                                   char *dest, size_t sz,
 440                                                   Error **errp);
 441 int bdrv_is_snapshot(BlockDriverState *bs);
 442
 443 int path_has_protocol(const char *path);
 444 int path_is_absolute(const char *path);
 445 void path_combine(char *dest, int dest_size,
 446                   const char *base_path,
 447                   const char *filename);
 448
 449 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 450 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 451                       int64_t pos, int size);
 452
 453 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 454                       int64_t pos, int size);
 455
 456 void bdrv_img_create(const char *filename, const char *fmt,
 457                      const char *base_filename, const char *base_fmt,
 458                      char *options, uint64_t img_size, int flags,
 459                      Error **errp, bool quiet);
 460
 461 /* Returns the alignment in bytes that is required so that no bounce buffer
 462  * is required throughout the stack */
 463 size_t bdrv_min_mem_align(BlockDriverState *bs);
 464 /* Returns optimal alignment in bytes for bounce buffer */
 465 size_t bdrv_opt_mem_align(BlockDriverState *bs);
 466 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 467 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
 468 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
 469 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 470 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 471
 472 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 473 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 474
 475 void bdrv_ref(BlockDriverState *bs);
 476 void bdrv_unref(BlockDriverState *bs);
 477 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 478
 479 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 480 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 481 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 482 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 483 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 484 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 485
 486 #define BLKDBG_EVENT(child, evt) \
 487     do { \
 488         if (child) { \
 489             bdrv_debug_event(child->bs, evt); \
 490         } \
 491     } while (0)
 492
 493 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
 494
 495 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 496                            const char *tag);
 497 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 498 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 499 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 500
 501 /**
 502  * bdrv_get_aio_context:
 503  *
 504  * Returns: the currently bound #AioContext
 505  */
 506 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 507
 508 /**
 509  * bdrv_set_aio_context:
 510  *
 511  * Changes the #AioContext used for fd handlers, timers, and BHs by this
 512  * BlockDriverState and all its children.
 513  *
 514  * This function must be called with iothread lock held.
 515  */
 516 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
 517 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 518 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 519
 520 void bdrv_io_plug(BlockDriverState *bs);
 521 void bdrv_io_unplug(BlockDriverState *bs);
 522 void bdrv_flush_io_queue(BlockDriverState *bs);
 523
 524 /**
 525  * bdrv_drained_begin:
 526  *
 527  * Begin a quiesced section for exclusive access to the BDS, by disabling
 528  * external request sources including NBD server and device model. Note that
 529  * this doesn't block timers or coroutines from submitting more requests, which
 530  * means block_job_pause is still necessary.
 531  *
 532  * This function can be recursive.
 533  */
 534 void bdrv_drained_begin(BlockDriverState *bs);
 535
 536 /**
 537  * bdrv_drained_end:
 538  *
 539  * End a quiescent section started by bdrv_drained_begin().
 540  */
 541 void bdrv_drained_end(BlockDriverState *bs);
 542
 543 #endif