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     BDRV_REQ_WRITE_COMPRESSED   = 0x20,
  69
  70     /* Mask of valid flags */
  71     BDRV_REQ_MASK               = 0x3f,
  72 } BdrvRequestFlags;
  73
  74 typedef struct BlockSizes {
  75     uint32_t phys;
  76     uint32_t log;
  77 } BlockSizes;
  78
  79 typedef struct HDGeometry {
  80     uint32_t heads;
  81     uint32_t sectors;
  82     uint32_t cylinders;
  83 } HDGeometry;
  84
  85 #define BDRV_O_RDWR        0x0002
  86 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
  87 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
  88 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
  89 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
  90 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
  91 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
  92 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
  93 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
  94 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
  95 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
  96 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
  97 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
  98                                       select an appropriate protocol driver,
  99                                       ignoring the format layer */
 100 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
 101
 102 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
 103
 104
 105 /* Option names of options parsed by the block layer */
 106
 107 #define BDRV_OPT_CACHE_WB       "cache.writeback"
 108 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
 109 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
 110
 111
 112 #define BDRV_SECTOR_BITS   9
 113 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 114 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 115
 116 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
 117                                      INT_MAX >> BDRV_SECTOR_BITS)
 118
 119 /*
 120  * Allocation status flags
 121  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
 122  * BDRV_BLOCK_ZERO: sectors read as zero
 123  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
 124  *                          bdrv_get_block_status.
 125  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
 126  *                       layer (as opposed to the backing file)
 127  * BDRV_BLOCK_RAW: used internally to indicate that the request
 128  *                 was answered by the raw driver and that one
 129  *                 should look in bs->file directly.
 130  *
 131  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
 132  * bs->file where sector data can be read from as raw data.
 133  *
 134  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
 135  *
 136  * DATA ZERO OFFSET_VALID
 137  *  t    t        t       sectors read as zero, bs->file is zero at offset
 138  *  t    f        t       sectors read as valid from bs->file at offset
 139  *  f    t        t       sectors preallocated, read as zero, bs->file not
 140  *                        necessarily zero at offset
 141  *  f    f        t       sectors preallocated but read from backing_hd,
 142  *                        bs->file contains garbage at offset
 143  *  t    t        f       sectors preallocated, read as zero, unknown offset
 144  *  t    f        f       sectors read from unknown file or offset
 145  *  f    t        f       not allocated or unknown offset, read as zero
 146  *  f    f        f       not allocated or unknown offset, read from backing_hd
 147  */
 148 #define BDRV_BLOCK_DATA         0x01
 149 #define BDRV_BLOCK_ZERO         0x02
 150 #define BDRV_BLOCK_OFFSET_VALID 0x04
 151 #define BDRV_BLOCK_RAW          0x08
 152 #define BDRV_BLOCK_ALLOCATED    0x10
 153 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
 154
 155 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
 156
 157 typedef struct BDRVReopenState {
 158     BlockDriverState *bs;
 159     int flags;
 160     QDict *options;
 161     QDict *explicit_options;
 162     void *opaque;
 163 } BDRVReopenState;
 164
 165 /*
 166  * Block operation types
 167  */
 168 typedef enum BlockOpType {
 169     BLOCK_OP_TYPE_BACKUP_SOURCE,
 170     BLOCK_OP_TYPE_BACKUP_TARGET,
 171     BLOCK_OP_TYPE_CHANGE,
 172     BLOCK_OP_TYPE_COMMIT_SOURCE,
 173     BLOCK_OP_TYPE_COMMIT_TARGET,
 174     BLOCK_OP_TYPE_DATAPLANE,
 175     BLOCK_OP_TYPE_DRIVE_DEL,
 176     BLOCK_OP_TYPE_EJECT,
 177     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
 178     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
 179     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
 180     BLOCK_OP_TYPE_MIRROR_SOURCE,
 181     BLOCK_OP_TYPE_MIRROR_TARGET,
 182     BLOCK_OP_TYPE_RESIZE,
 183     BLOCK_OP_TYPE_STREAM,
 184     BLOCK_OP_TYPE_REPLACE,
 185     BLOCK_OP_TYPE_MAX,
 186 } BlockOpType;
 187
 188 void bdrv_info_print(Monitor *mon, const QObject *data);
 189 void bdrv_info(Monitor *mon, QObject **ret_data);
 190 void bdrv_stats_print(Monitor *mon, const QObject *data);
 191 void bdrv_info_stats(Monitor *mon, QObject **ret_data);
 192
 193 /* disk I/O throttling */
 194 void bdrv_init(void);
 195 void bdrv_init_with_whitelist(void);
 196 bool bdrv_uses_whitelist(void);
 197 BlockDriver *bdrv_find_protocol(const char *filename,
 198                                 bool allow_protocol_prefix,
 199                                 Error **errp);
 200 BlockDriver *bdrv_find_format(const char *format_name);
 201 int bdrv_create(BlockDriver *drv, const char* filename,
 202                 QemuOpts *opts, Error **errp);
 203 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
 204 BlockDriverState *bdrv_new(void);
 205 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
 206 void bdrv_replace_in_backing_chain(BlockDriverState *old,
 207                                    BlockDriverState *new);
 208
 209 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
 210 int bdrv_parse_discard_flags(const char *mode, int *flags);
 211 BdrvChild *bdrv_open_child(const char *filename,
 212                            QDict *options, const char *bdref_key,
 213                            BlockDriverState* parent,
 214                            const BdrvChildRole *child_role,
 215                            bool allow_none, Error **errp);
 216 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
 217 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
 218                            const char *bdref_key, Error **errp);
 219 BlockDriverState *bdrv_open(const char *filename, const char *reference,
 220                             QDict *options, int flags, Error **errp);
 221 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
 222                                     BlockDriverState *bs,
 223                                     QDict *options, int flags);
 224 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
 225 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
 226 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
 227                         BlockReopenQueue *queue, Error **errp);
 228 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
 229 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 230 int bdrv_read(BdrvChild *child, int64_t sector_num,
 231               uint8_t *buf, int nb_sectors);
 232 int bdrv_write(BdrvChild *child, int64_t sector_num,
 233                const uint8_t *buf, int nb_sectors);
 234 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
 235                        int count, BdrvRequestFlags flags);
 236 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
 237 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
 238 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 239 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
 240 int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 241 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
 242                      const void *buf, int count);
 243 int coroutine_fn bdrv_co_readv(BdrvChild *child, int64_t sector_num,
 244                                int nb_sectors, QEMUIOVector *qiov);
 245 int coroutine_fn bdrv_co_writev(BdrvChild *child, int64_t sector_num,
 246                                int nb_sectors, QEMUIOVector *qiov);
 247 /*
 248  * Efficiently zero a region of the disk image.  Note that this is a regular
 249  * I/O request like read or write and should have a reasonable size.  This
 250  * function is not suitable for zeroing the entire image in a single request
 251  * because it may allocate memory for the entire region.
 252  */
 253 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
 254                                        int count, BdrvRequestFlags flags);
 255 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 256     const char *backing_file);
 257 int bdrv_get_backing_file_depth(BlockDriverState *bs);
 258 void bdrv_refresh_filename(BlockDriverState *bs);
 259 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
 260 int64_t bdrv_nb_sectors(BlockDriverState *bs);
 261 int64_t bdrv_getlength(BlockDriverState *bs);
 262 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 263 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 264 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 265 int bdrv_commit(BlockDriverState *bs);
 266 int bdrv_change_backing_file(BlockDriverState *bs,
 267     const char *backing_file, const char *backing_fmt);
 268 void bdrv_register(BlockDriver *bdrv);
 269 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
 270                            BlockDriverState *base,
 271                            const char *backing_file_str);
 272 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 273                                     BlockDriverState *bs);
 274 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 275
 276
 277 typedef struct BdrvCheckResult {
 278     int corruptions;
 279     int leaks;
 280     int check_errors;
 281     int corruptions_fixed;
 282     int leaks_fixed;
 283     int64_t image_end_offset;
 284     BlockFragInfo bfi;
 285 } BdrvCheckResult;
 286
 287 typedef enum {
 288     BDRV_FIX_LEAKS    = 1,
 289     BDRV_FIX_ERRORS   = 2,
 290 } BdrvCheckMode;
 291
 292 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 293
 294 /* The units of offset and total_work_size may be chosen arbitrarily by the
 295  * block driver; total_work_size may change during the course of the amendment
 296  * operation */
 297 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 298                                       int64_t total_work_size, void *opaque);
 299 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 300                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
 301
 302 /* external snapshots */
 303 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
 304                                       BlockDriverState *candidate);
 305 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
 306
 307 /* check if a named node can be replaced when doing drive-mirror */
 308 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 309                                         const char *node_name, Error **errp);
 310
 311 /* async block I/O */
 312 BlockAIOCB *bdrv_aio_readv(BdrvChild *child, int64_t sector_num,
 313                            QEMUIOVector *iov, int nb_sectors,
 314                            BlockCompletionFunc *cb, void *opaque);
 315 BlockAIOCB *bdrv_aio_writev(BdrvChild *child, int64_t sector_num,
 316                             QEMUIOVector *iov, int nb_sectors,
 317                             BlockCompletionFunc *cb, void *opaque);
 318 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
 319                            BlockCompletionFunc *cb, void *opaque);
 320 BlockAIOCB *bdrv_aio_pdiscard(BlockDriverState *bs,
 321                               int64_t offset, int count,
 322                               BlockCompletionFunc *cb, void *opaque);
 323 void bdrv_aio_cancel(BlockAIOCB *acb);
 324 void bdrv_aio_cancel_async(BlockAIOCB *acb);
 325
 326 /* sg packet commands */
 327 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
 328 BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
 329         unsigned long int req, void *buf,
 330         BlockCompletionFunc *cb, void *opaque);
 331
 332 /* Invalidate any cached metadata used by image formats */
 333 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
 334 void bdrv_invalidate_cache_all(Error **errp);
 335 int bdrv_inactivate_all(void);
 336
 337 /* Ensure contents are flushed to disk.  */
 338 int bdrv_flush(BlockDriverState *bs);
 339 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
 340 void bdrv_close_all(void);
 341 void bdrv_drain(BlockDriverState *bs);
 342 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
 343 void bdrv_drain_all(void);
 344
 345 int bdrv_pdiscard(BlockDriverState *bs, int64_t offset, int count);
 346 int bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, int count);
 347 int bdrv_has_zero_init_1(BlockDriverState *bs);
 348 int bdrv_has_zero_init(BlockDriverState *bs);
 349 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 350 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 351 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
 352                               int nb_sectors, int *pnum,
 353                               BlockDriverState **file);
 354 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
 355                                     BlockDriverState *base,
 356                                     int64_t sector_num,
 357                                     int nb_sectors, int *pnum,
 358                                     BlockDriverState **file);
 359 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 360                       int *pnum);
 361 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
 362                             int64_t sector_num, int nb_sectors, int *pnum);
 363
 364 bool bdrv_is_read_only(BlockDriverState *bs);
 365 bool bdrv_is_sg(BlockDriverState *bs);
 366 bool bdrv_is_inserted(BlockDriverState *bs);
 367 int bdrv_media_changed(BlockDriverState *bs);
 368 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
 369 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
 370 const char *bdrv_get_format_name(BlockDriverState *bs);
 371 BlockDriverState *bdrv_find_node(const char *node_name);
 372 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
 373 BlockDriverState *bdrv_lookup_bs(const char *device,
 374                                  const char *node_name,
 375                                  Error **errp);
 376 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 377 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 378
 379 typedef struct BdrvNextIterator {
 380     enum {
 381         BDRV_NEXT_BACKEND_ROOTS,
 382         BDRV_NEXT_MONITOR_OWNED,
 383     } phase;
 384     BlockBackend *blk;
 385     BlockDriverState *bs;
 386 } BdrvNextIterator;
 387
 388 BlockDriverState *bdrv_first(BdrvNextIterator *it);
 389 BlockDriverState *bdrv_next(BdrvNextIterator *it);
 390
 391 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 392 bool bdrv_is_encrypted(BlockDriverState *bs);
 393 bool bdrv_key_required(BlockDriverState *bs);
 394 int bdrv_set_key(BlockDriverState *bs, const char *key);
 395 void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
 396 int bdrv_query_missing_keys(void);
 397 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 398                          void *opaque);
 399 const char *bdrv_get_node_name(const BlockDriverState *bs);
 400 const char *bdrv_get_device_name(const BlockDriverState *bs);
 401 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 402 int bdrv_get_flags(BlockDriverState *bs);
 403 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 404 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
 405 void bdrv_round_sectors_to_clusters(BlockDriverState *bs,
 406                                     int64_t sector_num, int nb_sectors,
 407                                     int64_t *cluster_sector_num,
 408                                     int *cluster_nb_sectors);
 409 void bdrv_round_to_clusters(BlockDriverState *bs,
 410                             int64_t offset, unsigned int bytes,
 411                             int64_t *cluster_offset,
 412                             unsigned int *cluster_bytes);
 413
 414 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
 415 void bdrv_get_backing_filename(BlockDriverState *bs,
 416                                char *filename, int filename_size);
 417 void bdrv_get_full_backing_filename(BlockDriverState *bs,
 418                                     char *dest, size_t sz, Error **errp);
 419 void bdrv_get_full_backing_filename_from_filename(const char *backed,
 420                                                   const char *backing,
 421                                                   char *dest, size_t sz,
 422                                                   Error **errp);
 423 int bdrv_is_snapshot(BlockDriverState *bs);
 424
 425 int path_has_protocol(const char *path);
 426 int path_is_absolute(const char *path);
 427 void path_combine(char *dest, int dest_size,
 428                   const char *base_path,
 429                   const char *filename);
 430
 431 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 432 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 433 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 434                       int64_t pos, int size);
 435
 436 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 437                       int64_t pos, int size);
 438
 439 void bdrv_img_create(const char *filename, const char *fmt,
 440                      const char *base_filename, const char *base_fmt,
 441                      char *options, uint64_t img_size, int flags,
 442                      Error **errp, bool quiet);
 443
 444 /* Returns the alignment in bytes that is required so that no bounce buffer
 445  * is required throughout the stack */
 446 size_t bdrv_min_mem_align(BlockDriverState *bs);
 447 /* Returns optimal alignment in bytes for bounce buffer */
 448 size_t bdrv_opt_mem_align(BlockDriverState *bs);
 449 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 450 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
 451 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
 452 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 453 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 454
 455 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 456 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 457
 458 void bdrv_ref(BlockDriverState *bs);
 459 void bdrv_unref(BlockDriverState *bs);
 460 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 461 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
 462                              BlockDriverState *child_bs,
 463                              const char *child_name,
 464                              const BdrvChildRole *child_role);
 465
 466 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 467 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 468 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 469 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 470 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 471 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 472
 473 #define BLKDBG_EVENT(child, evt) \
 474     do { \
 475         if (child) { \
 476             bdrv_debug_event(child->bs, evt); \
 477         } \
 478     } while (0)
 479
 480 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
 481
 482 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 483                            const char *tag);
 484 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 485 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 486 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 487
 488 /**
 489  * bdrv_get_aio_context:
 490  *
 491  * Returns: the currently bound #AioContext
 492  */
 493 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 494
 495 /**
 496  * bdrv_set_aio_context:
 497  *
 498  * Changes the #AioContext used for fd handlers, timers, and BHs by this
 499  * BlockDriverState and all its children.
 500  *
 501  * This function must be called with iothread lock held.
 502  */
 503 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
 504 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 505 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 506
 507 void bdrv_io_plug(BlockDriverState *bs);
 508 void bdrv_io_unplug(BlockDriverState *bs);
 509 void bdrv_io_unplugged_begin(BlockDriverState *bs);
 510 void bdrv_io_unplugged_end(BlockDriverState *bs);
 511
 512 /**
 513  * bdrv_drained_begin:
 514  *
 515  * Begin a quiesced section for exclusive access to the BDS, by disabling
 516  * external request sources including NBD server and device model. Note that
 517  * this doesn't block timers or coroutines from submitting more requests, which
 518  * means block_job_pause is still necessary.
 519  *
 520  * This function can be recursive.
 521  */
 522 void bdrv_drained_begin(BlockDriverState *bs);
 523
 524 /**
 525  * bdrv_drained_end:
 526  *
 527  * End a quiescent section started by bdrv_drained_begin().
 528  */
 529 void bdrv_drained_end(BlockDriverState *bs);
 530
 531 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
 532                     Error **errp);
 533 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 534
 535 #endif