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_pwrite_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     BDRV_REQ_FUA                = 0x10,
  68
  69     /* Mask of valid flags */
  70     BDRV_REQ_MASK               = 0x1f,
  71 } BdrvRequestFlags;
  72
  73 typedef struct BlockSizes {
  74     uint32_t phys;
  75     uint32_t log;
  76 } BlockSizes;
  77
  78 typedef struct HDGeometry {
  79     uint32_t heads;
  80     uint32_t sectors;
  81     uint32_t cylinders;
  82 } HDGeometry;
  83
  84 #define BDRV_O_RDWR        0x0002
  85 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
  86 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
  87 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
  88 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
  89 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
  90 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
  91 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
  92 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
  93 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
  94 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
  95 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
  96 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
  97                                       select an appropriate protocol driver,
  98                                       ignoring the format layer */
  99 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
 100
 101 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
 102
 103
 104 /* Option names of options parsed by the block layer */
 105
 106 #define BDRV_OPT_CACHE_WB       "cache.writeback"
 107 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
 108 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
 109
 110
 111 #define BDRV_SECTOR_BITS   9
 112 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 113 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 114
 115 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
 116                                      INT_MAX >> BDRV_SECTOR_BITS)
 117
 118 /*
 119  * Allocation status flags
 120  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
 121  * BDRV_BLOCK_ZERO: sectors read as zero
 122  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
 123  *                          bdrv_get_block_status.
 124  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
 125  *                       layer (as opposed to the backing file)
 126  * BDRV_BLOCK_RAW: used internally to indicate that the request
 127  *                 was answered by the raw driver and that one
 128  *                 should look in bs->file directly.
 129  *
 130  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
 131  * bs->file where sector data can be read from as raw data.
 132  *
 133  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
 134  *
 135  * DATA ZERO OFFSET_VALID
 136  *  t    t        t       sectors read as zero, bs->file is zero at offset
 137  *  t    f        t       sectors read as valid from bs->file at offset
 138  *  f    t        t       sectors preallocated, read as zero, bs->file not
 139  *                        necessarily zero at offset
 140  *  f    f        t       sectors preallocated but read from backing_hd,
 141  *                        bs->file contains garbage at offset
 142  *  t    t        f       sectors preallocated, read as zero, unknown offset
 143  *  t    f        f       sectors read from unknown file or offset
 144  *  f    t        f       not allocated or unknown offset, read as zero
 145  *  f    f        f       not allocated or unknown offset, read from backing_hd
 146  */
 147 #define BDRV_BLOCK_DATA         0x01
 148 #define BDRV_BLOCK_ZERO         0x02
 149 #define BDRV_BLOCK_OFFSET_VALID 0x04
 150 #define BDRV_BLOCK_RAW          0x08
 151 #define BDRV_BLOCK_ALLOCATED    0x10
 152 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
 153
 154 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
 155
 156 typedef struct BDRVReopenState {
 157     BlockDriverState *bs;
 158     int flags;
 159     QDict *options;
 160     QDict *explicit_options;
 161     void *opaque;
 162 } BDRVReopenState;
 163
 164 /*
 165  * Block operation types
 166  */
 167 typedef enum BlockOpType {
 168     BLOCK_OP_TYPE_BACKUP_SOURCE,
 169     BLOCK_OP_TYPE_BACKUP_TARGET,
 170     BLOCK_OP_TYPE_CHANGE,
 171     BLOCK_OP_TYPE_COMMIT_SOURCE,
 172     BLOCK_OP_TYPE_COMMIT_TARGET,
 173     BLOCK_OP_TYPE_DATAPLANE,
 174     BLOCK_OP_TYPE_DRIVE_DEL,
 175     BLOCK_OP_TYPE_EJECT,
 176     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
 177     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
 178     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
 179     BLOCK_OP_TYPE_MIRROR_SOURCE,
 180     BLOCK_OP_TYPE_MIRROR_TARGET,
 181     BLOCK_OP_TYPE_RESIZE,
 182     BLOCK_OP_TYPE_STREAM,
 183     BLOCK_OP_TYPE_REPLACE,
 184     BLOCK_OP_TYPE_MAX,
 185 } BlockOpType;
 186
 187 void bdrv_info_print(Monitor *mon, const QObject *data);
 188 void bdrv_info(Monitor *mon, QObject **ret_data);
 189 void bdrv_stats_print(Monitor *mon, const QObject *data);
 190 void bdrv_info_stats(Monitor *mon, QObject **ret_data);
 191
 192 /* disk I/O throttling */
 193 void bdrv_init(void);
 194 void bdrv_init_with_whitelist(void);
 195 bool bdrv_uses_whitelist(void);
 196 BlockDriver *bdrv_find_protocol(const char *filename,
 197                                 bool allow_protocol_prefix,
 198                                 Error **errp);
 199 BlockDriver *bdrv_find_format(const char *format_name);
 200 int bdrv_create(BlockDriver *drv, const char* filename,
 201                 QemuOpts *opts, Error **errp);
 202 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
 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_mode(const char *mode, int *flags, bool *writethrough);
 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 BlockDriverState *bdrv_open(const char *filename, const char *reference,
 219                             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_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
 234                        int count, BdrvRequestFlags flags);
 235 int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags);
 236 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 237                void *buf, int count);
 238 int bdrv_preadv(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
 239 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 240                 const void *buf, int count);
 241 int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
 242 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
 243     const void *buf, int count);
 244 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
 245     int nb_sectors, QEMUIOVector *qiov);
 246 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
 247     int nb_sectors, QEMUIOVector *qiov);
 248 /*
 249  * Efficiently zero a region of the disk image.  Note that this is a regular
 250  * I/O request like read or write and should have a reasonable size.  This
 251  * function is not suitable for zeroing the entire image in a single request
 252  * because it may allocate memory for the entire region.
 253  */
 254 int coroutine_fn bdrv_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
 255     int count, BdrvRequestFlags flags);
 256 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 257     const char *backing_file);
 258 int bdrv_get_backing_file_depth(BlockDriverState *bs);
 259 void bdrv_refresh_filename(BlockDriverState *bs);
 260 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
 261 int64_t bdrv_nb_sectors(BlockDriverState *bs);
 262 int64_t bdrv_getlength(BlockDriverState *bs);
 263 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 264 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 265 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 266 int bdrv_commit(BlockDriverState *bs);
 267 int bdrv_change_backing_file(BlockDriverState *bs,
 268     const char *backing_file, const char *backing_fmt);
 269 void bdrv_register(BlockDriver *bdrv);
 270 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
 271                            BlockDriverState *base,
 272                            const char *backing_file_str);
 273 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 274                                     BlockDriverState *bs);
 275 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 276
 277
 278 typedef struct BdrvCheckResult {
 279     int corruptions;
 280     int leaks;
 281     int check_errors;
 282     int corruptions_fixed;
 283     int leaks_fixed;
 284     int64_t image_end_offset;
 285     BlockFragInfo bfi;
 286 } BdrvCheckResult;
 287
 288 typedef enum {
 289     BDRV_FIX_LEAKS    = 1,
 290     BDRV_FIX_ERRORS   = 2,
 291 } BdrvCheckMode;
 292
 293 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 294
 295 /* The units of offset and total_work_size may be chosen arbitrarily by the
 296  * block driver; total_work_size may change during the course of the amendment
 297  * operation */
 298 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 299                                       int64_t total_work_size, void *opaque);
 300 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 301                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
 302
 303 /* external snapshots */
 304 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
 305                                       BlockDriverState *candidate);
 306 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
 307
 308 /* check if a named node can be replaced when doing drive-mirror */
 309 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 310                                         const char *node_name, Error **errp);
 311
 312 /* async block I/O */
 313 BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
 314                            QEMUIOVector *iov, int nb_sectors,
 315                            BlockCompletionFunc *cb, void *opaque);
 316 BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
 317                             QEMUIOVector *iov, int nb_sectors,
 318                             BlockCompletionFunc *cb, void *opaque);
 319 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
 320                            BlockCompletionFunc *cb, void *opaque);
 321 BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
 322                              int64_t sector_num, int nb_sectors,
 323                              BlockCompletionFunc *cb, void *opaque);
 324 void bdrv_aio_cancel(BlockAIOCB *acb);
 325 void bdrv_aio_cancel_async(BlockAIOCB *acb);
 326
 327 /* sg packet commands */
 328 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
 329 BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
 330         unsigned long int req, void *buf,
 331         BlockCompletionFunc *cb, void *opaque);
 332
 333 /* Invalidate any cached metadata used by image formats */
 334 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
 335 void bdrv_invalidate_cache_all(Error **errp);
 336 int bdrv_inactivate_all(void);
 337
 338 /* Ensure contents are flushed to disk.  */
 339 int bdrv_flush(BlockDriverState *bs);
 340 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
 341 void bdrv_close_all(void);
 342 void bdrv_drain(BlockDriverState *bs);
 343 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
 344 void bdrv_drain_all(void);
 345
 346 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 347 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 348 int bdrv_has_zero_init_1(BlockDriverState *bs);
 349 int bdrv_has_zero_init(BlockDriverState *bs);
 350 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 351 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 352 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
 353                               int nb_sectors, int *pnum,
 354                               BlockDriverState **file);
 355 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
 356                                     BlockDriverState *base,
 357                                     int64_t sector_num,
 358                                     int nb_sectors, int *pnum,
 359                                     BlockDriverState **file);
 360 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 361                       int *pnum);
 362 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
 363                             int64_t sector_num, int nb_sectors, int *pnum);
 364
 365 int bdrv_is_read_only(BlockDriverState *bs);
 366 int bdrv_is_sg(BlockDriverState *bs);
 367 bool bdrv_is_inserted(BlockDriverState *bs);
 368 int bdrv_media_changed(BlockDriverState *bs);
 369 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
 370 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
 371 const char *bdrv_get_format_name(BlockDriverState *bs);
 372 BlockDriverState *bdrv_find_node(const char *node_name);
 373 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
 374 BlockDriverState *bdrv_lookup_bs(const char *device,
 375                                  const char *node_name,
 376                                  Error **errp);
 377 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 378 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 379
 380 typedef struct BdrvNextIterator {
 381     enum {
 382         BDRV_NEXT_BACKEND_ROOTS,
 383         BDRV_NEXT_MONITOR_OWNED,
 384     } phase;
 385     BlockBackend *blk;
 386     BlockDriverState *bs;
 387 } BdrvNextIterator;
 388
 389 BlockDriverState *bdrv_first(BdrvNextIterator *it);
 390 BlockDriverState *bdrv_next(BdrvNextIterator *it);
 391
 392 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 393 int bdrv_is_encrypted(BlockDriverState *bs);
 394 int bdrv_key_required(BlockDriverState *bs);
 395 int bdrv_set_key(BlockDriverState *bs, const char *key);
 396 void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
 397 int bdrv_query_missing_keys(void);
 398 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 399                          void *opaque);
 400 const char *bdrv_get_node_name(const BlockDriverState *bs);
 401 const char *bdrv_get_device_name(const BlockDriverState *bs);
 402 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 403 int bdrv_get_flags(BlockDriverState *bs);
 404 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
 405                           const uint8_t *buf, int nb_sectors);
 406 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 407 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
 408 void bdrv_round_sectors_to_clusters(BlockDriverState *bs,
 409                                     int64_t sector_num, int nb_sectors,
 410                                     int64_t *cluster_sector_num,
 411                                     int *cluster_nb_sectors);
 412 void bdrv_round_to_clusters(BlockDriverState *bs,
 413                             int64_t offset, unsigned int bytes,
 414                             int64_t *cluster_offset,
 415                             unsigned int *cluster_bytes);
 416
 417 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
 418 void bdrv_get_backing_filename(BlockDriverState *bs,
 419                                char *filename, int filename_size);
 420 void bdrv_get_full_backing_filename(BlockDriverState *bs,
 421                                     char *dest, size_t sz, Error **errp);
 422 void bdrv_get_full_backing_filename_from_filename(const char *backed,
 423                                                   const char *backing,
 424                                                   char *dest, size_t sz,
 425                                                   Error **errp);
 426 int bdrv_is_snapshot(BlockDriverState *bs);
 427
 428 int path_has_protocol(const char *path);
 429 int path_is_absolute(const char *path);
 430 void path_combine(char *dest, int dest_size,
 431                   const char *base_path,
 432                   const char *filename);
 433
 434 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 435 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 436 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 437                       int64_t pos, int size);
 438
 439 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 440                       int64_t pos, int size);
 441
 442 void bdrv_img_create(const char *filename, const char *fmt,
 443                      const char *base_filename, const char *base_fmt,
 444                      char *options, uint64_t img_size, int flags,
 445                      Error **errp, bool quiet);
 446
 447 /* Returns the alignment in bytes that is required so that no bounce buffer
 448  * is required throughout the stack */
 449 size_t bdrv_min_mem_align(BlockDriverState *bs);
 450 /* Returns optimal alignment in bytes for bounce buffer */
 451 size_t bdrv_opt_mem_align(BlockDriverState *bs);
 452 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 453 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
 454 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
 455 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 456 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 457
 458 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 459 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 460
 461 void bdrv_ref(BlockDriverState *bs);
 462 void bdrv_unref(BlockDriverState *bs);
 463 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 464 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
 465                              BlockDriverState *child_bs,
 466                              const char *child_name,
 467                              const BdrvChildRole *child_role);
 468
 469 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 470 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 471 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 472 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 473 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 474 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 475
 476 #define BLKDBG_EVENT(child, evt) \
 477     do { \
 478         if (child) { \
 479             bdrv_debug_event(child->bs, evt); \
 480         } \
 481     } while (0)
 482
 483 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
 484
 485 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 486                            const char *tag);
 487 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 488 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 489 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 490
 491 /**
 492  * bdrv_get_aio_context:
 493  *
 494  * Returns: the currently bound #AioContext
 495  */
 496 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 497
 498 /**
 499  * bdrv_set_aio_context:
 500  *
 501  * Changes the #AioContext used for fd handlers, timers, and BHs by this
 502  * BlockDriverState and all its children.
 503  *
 504  * This function must be called with iothread lock held.
 505  */
 506 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
 507 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 508 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 509
 510 void bdrv_io_plug(BlockDriverState *bs);
 511 void bdrv_io_unplug(BlockDriverState *bs);
 512 void bdrv_io_unplugged_begin(BlockDriverState *bs);
 513 void bdrv_io_unplugged_end(BlockDriverState *bs);
 514
 515 /**
 516  * bdrv_drained_begin:
 517  *
 518  * Begin a quiesced section for exclusive access to the BDS, by disabling
 519  * external request sources including NBD server and device model. Note that
 520  * this doesn't block timers or coroutines from submitting more requests, which
 521  * means block_job_pause is still necessary.
 522  *
 523  * This function can be recursive.
 524  */
 525 void bdrv_drained_begin(BlockDriverState *bs);
 526
 527 /**
 528  * bdrv_drained_end:
 529  *
 530  * End a quiescent section started by bdrv_drained_begin().
 531  */
 532 void bdrv_drained_end(BlockDriverState *bs);
 533
 534 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
 535                     Error **errp);
 536 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 537
 538 #endif