include/block/block.h

   1 #ifndef BLOCK_H
   2 #define BLOCK_H
   3
   4 #include "block/aio.h"
   5 #include "qapi/qapi-types-block-core.h"
   6 #include "block/aio-wait.h"
   7 #include "qemu/iov.h"
   8 #include "qemu/coroutine.h"
   9 #include "block/accounting.h"
  10 #include "block/dirty-bitmap.h"
  11 #include "block/blockjob.h"
  12 #include "qemu/hbitmap.h"
  13
  14 /* block.c */
  15 typedef struct BlockDriver BlockDriver;
  16 typedef struct BdrvChild BdrvChild;
  17 typedef struct BdrvChildRole BdrvChildRole;
  18
  19 typedef struct BlockDriverInfo {
  20     /* in bytes, 0 if irrelevant */
  21     int cluster_size;
  22     /* offset at which the VM state can be saved (0 if not possible) */
  23     int64_t vm_state_offset;
  24     bool is_dirty;
  25     /*
  26      * True if unallocated blocks read back as zeroes. This is equivalent
  27      * to the LBPRZ flag in the SCSI logical block provisioning page.
  28      */
  29     bool unallocated_blocks_are_zero;
  30     /*
  31      * True if this block driver only supports compressed writes
  32      */
  33     bool needs_compressed_writes;
  34 } BlockDriverInfo;
  35
  36 typedef struct BlockFragInfo {
  37     uint64_t allocated_clusters;
  38     uint64_t total_clusters;
  39     uint64_t fragmented_clusters;
  40     uint64_t compressed_clusters;
  41 } BlockFragInfo;
  42
  43 typedef enum {
  44     BDRV_REQ_COPY_ON_READ       = 0x1,
  45     BDRV_REQ_ZERO_WRITE         = 0x2,
  46     /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
  47      * is allowed to optimize a write zeroes request by unmapping (discarding)
  48      * blocks if it is guaranteed that the result will read back as
  49      * zeroes. The flag is only passed to the driver if the block device is
  50      * opened with BDRV_O_UNMAP.
  51      */
  52     BDRV_REQ_MAY_UNMAP          = 0x4,
  53
  54     /*
  55      * The BDRV_REQ_NO_SERIALISING flag is only valid for reads and means that
  56      * we don't want wait_serialising_requests() during the read operation.
  57      *
  58      * This flag is used for backup copy-on-write operations, when we need to
  59      * read old data before write (write notifier triggered). It is okay since
  60      * we already waited for other serializing requests in the initiating write
  61      * (see bdrv_aligned_pwritev), and it is necessary if the initiating write
  62      * is already serializing (without the flag, the read would deadlock
  63      * waiting for the serialising write to complete).
  64      */
  65     BDRV_REQ_NO_SERIALISING     = 0x8,
  66     BDRV_REQ_FUA                = 0x10,
  67     BDRV_REQ_WRITE_COMPRESSED   = 0x20,
  68
  69     /* Signifies that this write request will not change the visible disk
  70      * content. */
  71     BDRV_REQ_WRITE_UNCHANGED    = 0x40,
  72
  73     /*
  74      * BDRV_REQ_SERIALISING forces request serialisation for writes.
  75      * It is used to ensure that writes to the backing file of a backup process
  76      * target cannot race with a read of the backup target that defers to the
  77      * backing file.
  78      *
  79      * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to
  80      * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be
  81      * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long.
  82      */
  83     BDRV_REQ_SERIALISING        = 0x80,
  84
  85     /* Mask of valid flags */
  86     BDRV_REQ_MASK               = 0xff,
  87 } BdrvRequestFlags;
  88
  89 typedef struct BlockSizes {
  90     uint32_t phys;
  91     uint32_t log;
  92 } BlockSizes;
  93
  94 typedef struct HDGeometry {
  95     uint32_t heads;
  96     uint32_t sectors;
  97     uint32_t cylinders;
  98 } HDGeometry;
  99
 100 #define BDRV_O_RDWR        0x0002
 101 #define BDRV_O_RESIZE      0x0004 /* request permission for resizing the node */
 102 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
 103 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
 104 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
 105 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
 106 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
 107 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
 108 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
 109 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
 110 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
 111 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
 112 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
 113 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
 114                                       select an appropriate protocol driver,
 115                                       ignoring the format layer */
 116 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
 117
 118 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
 119
 120
 121 /* Option names of options parsed by the block layer */
 122
 123 #define BDRV_OPT_CACHE_WB       "cache.writeback"
 124 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
 125 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
 126 #define BDRV_OPT_READ_ONLY      "read-only"
 127 #define BDRV_OPT_DISCARD        "discard"
 128 #define BDRV_OPT_FORCE_SHARE    "force-share"
 129
 130
 131 #define BDRV_SECTOR_BITS   9
 132 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 133 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 134
 135 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
 136                                      INT_MAX >> BDRV_SECTOR_BITS)
 137 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
 138
 139 /*
 140  * Allocation status flags for bdrv_block_status() and friends.
 141  *
 142  * Public flags:
 143  * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
 144  * BDRV_BLOCK_ZERO: offset reads as zero
 145  * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
 146  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
 147  *                       layer rather than any backing, set by block layer
 148  * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
 149  *                 layer, set by block layer
 150  *
 151  * Internal flag:
 152  * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
 153  *                 that the block layer recompute the answer from the returned
 154  *                 BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
 155  *
 156  * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
 157  * host offset within the returned BDS that is allocated for the
 158  * corresponding raw guest data.  However, whether that offset
 159  * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
 160  *
 161  * DATA ZERO OFFSET_VALID
 162  *  t    t        t       sectors read as zero, returned file is zero at offset
 163  *  t    f        t       sectors read as valid from file at offset
 164  *  f    t        t       sectors preallocated, read as zero, returned file not
 165  *                        necessarily zero at offset
 166  *  f    f        t       sectors preallocated but read from backing_hd,
 167  *                        returned file contains garbage at offset
 168  *  t    t        f       sectors preallocated, read as zero, unknown offset
 169  *  t    f        f       sectors read from unknown file or offset
 170  *  f    t        f       not allocated or unknown offset, read as zero
 171  *  f    f        f       not allocated or unknown offset, read from backing_hd
 172  */
 173 #define BDRV_BLOCK_DATA         0x01
 174 #define BDRV_BLOCK_ZERO         0x02
 175 #define BDRV_BLOCK_OFFSET_VALID 0x04
 176 #define BDRV_BLOCK_RAW          0x08
 177 #define BDRV_BLOCK_ALLOCATED    0x10
 178 #define BDRV_BLOCK_EOF          0x20
 179 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
 180
 181 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
 182
 183 typedef struct BDRVReopenState {
 184     BlockDriverState *bs;
 185     int flags;
 186     uint64_t perm, shared_perm;
 187     QDict *options;
 188     QDict *explicit_options;
 189     void *opaque;
 190 } BDRVReopenState;
 191
 192 /*
 193  * Block operation types
 194  */
 195 typedef enum BlockOpType {
 196     BLOCK_OP_TYPE_BACKUP_SOURCE,
 197     BLOCK_OP_TYPE_BACKUP_TARGET,
 198     BLOCK_OP_TYPE_CHANGE,
 199     BLOCK_OP_TYPE_COMMIT_SOURCE,
 200     BLOCK_OP_TYPE_COMMIT_TARGET,
 201     BLOCK_OP_TYPE_DATAPLANE,
 202     BLOCK_OP_TYPE_DRIVE_DEL,
 203     BLOCK_OP_TYPE_EJECT,
 204     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
 205     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
 206     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
 207     BLOCK_OP_TYPE_MIRROR_SOURCE,
 208     BLOCK_OP_TYPE_MIRROR_TARGET,
 209     BLOCK_OP_TYPE_RESIZE,
 210     BLOCK_OP_TYPE_STREAM,
 211     BLOCK_OP_TYPE_REPLACE,
 212     BLOCK_OP_TYPE_MAX,
 213 } BlockOpType;
 214
 215 /* Block node permission constants */
 216 enum {
 217     /**
 218      * A user that has the "permission" of consistent reads is guaranteed that
 219      * their view of the contents of the block device is complete and
 220      * self-consistent, representing the contents of a disk at a specific
 221      * point.
 222      *
 223      * For most block devices (including their backing files) this is true, but
 224      * the property cannot be maintained in a few situations like for
 225      * intermediate nodes of a commit block job.
 226      */
 227     BLK_PERM_CONSISTENT_READ    = 0x01,
 228
 229     /** This permission is required to change the visible disk contents. */
 230     BLK_PERM_WRITE              = 0x02,
 231
 232     /**
 233      * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
 234      * required for writes to the block node when the caller promises that
 235      * the visible disk content doesn't change.
 236      *
 237      * As the BLK_PERM_WRITE permission is strictly stronger, either is
 238      * sufficient to perform an unchanging write.
 239      */
 240     BLK_PERM_WRITE_UNCHANGED    = 0x04,
 241
 242     /** This permission is required to change the size of a block node. */
 243     BLK_PERM_RESIZE             = 0x08,
 244
 245     /**
 246      * This permission is required to change the node that this BdrvChild
 247      * points to.
 248      */
 249     BLK_PERM_GRAPH_MOD          = 0x10,
 250
 251     BLK_PERM_ALL                = 0x1f,
 252
 253     DEFAULT_PERM_PASSTHROUGH    = BLK_PERM_CONSISTENT_READ
 254                                  | BLK_PERM_WRITE
 255                                  | BLK_PERM_WRITE_UNCHANGED
 256                                  | BLK_PERM_RESIZE,
 257
 258     DEFAULT_PERM_UNCHANGED      = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH,
 259 };
 260
 261 char *bdrv_perm_names(uint64_t perm);
 262
 263 /* disk I/O throttling */
 264 void bdrv_init(void);
 265 void bdrv_init_with_whitelist(void);
 266 bool bdrv_uses_whitelist(void);
 267 int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
 268 BlockDriver *bdrv_find_protocol(const char *filename,
 269                                 bool allow_protocol_prefix,
 270                                 Error **errp);
 271 BlockDriver *bdrv_find_format(const char *format_name);
 272 int bdrv_create(BlockDriver *drv, const char* filename,
 273                 QemuOpts *opts, Error **errp);
 274 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
 275 BlockDriverState *bdrv_new(void);
 276 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
 277                  Error **errp);
 278 void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
 279                        Error **errp);
 280
 281 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
 282 int bdrv_parse_discard_flags(const char *mode, int *flags);
 283 BdrvChild *bdrv_open_child(const char *filename,
 284                            QDict *options, const char *bdref_key,
 285                            BlockDriverState* parent,
 286                            const BdrvChildRole *child_role,
 287                            bool allow_none, Error **errp);
 288 BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
 289 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
 290                          Error **errp);
 291 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
 292                            const char *bdref_key, Error **errp);
 293 BlockDriverState *bdrv_open(const char *filename, const char *reference,
 294                             QDict *options, int flags, Error **errp);
 295 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
 296                                        int flags, Error **errp);
 297 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
 298                                     BlockDriverState *bs,
 299                                     QDict *options, int flags);
 300 int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp);
 301 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
 302 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
 303                         BlockReopenQueue *queue, Error **errp);
 304 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
 305 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 306 int bdrv_read(BdrvChild *child, int64_t sector_num,
 307               uint8_t *buf, int nb_sectors);
 308 int bdrv_write(BdrvChild *child, int64_t sector_num,
 309                const uint8_t *buf, int nb_sectors);
 310 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
 311                        int bytes, BdrvRequestFlags flags);
 312 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
 313 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
 314 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 315 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
 316 int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 317 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
 318                      const void *buf, int count);
 319 /*
 320  * Efficiently zero a region of the disk image.  Note that this is a regular
 321  * I/O request like read or write and should have a reasonable size.  This
 322  * function is not suitable for zeroing the entire image in a single request
 323  * because it may allocate memory for the entire region.
 324  */
 325 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
 326                                        int bytes, BdrvRequestFlags flags);
 327 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 328     const char *backing_file);
 329 void bdrv_refresh_filename(BlockDriverState *bs);
 330
 331 int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset,
 332                                   PreallocMode prealloc, Error **errp);
 333 int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
 334                   Error **errp);
 335
 336 int64_t bdrv_nb_sectors(BlockDriverState *bs);
 337 int64_t bdrv_getlength(BlockDriverState *bs);
 338 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 339 BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
 340                                BlockDriverState *in_bs, Error **errp);
 341 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 342 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 343 int bdrv_commit(BlockDriverState *bs);
 344 int bdrv_change_backing_file(BlockDriverState *bs,
 345     const char *backing_file, const char *backing_fmt);
 346 void bdrv_register(BlockDriver *bdrv);
 347 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
 348                            const char *backing_file_str);
 349 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 350                                     BlockDriverState *bs);
 351 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 352
 353
 354 typedef struct BdrvCheckResult {
 355     int corruptions;
 356     int leaks;
 357     int check_errors;
 358     int corruptions_fixed;
 359     int leaks_fixed;
 360     int64_t image_end_offset;
 361     BlockFragInfo bfi;
 362 } BdrvCheckResult;
 363
 364 typedef enum {
 365     BDRV_FIX_LEAKS    = 1,
 366     BDRV_FIX_ERRORS   = 2,
 367 } BdrvCheckMode;
 368
 369 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 370
 371 /* The units of offset and total_work_size may be chosen arbitrarily by the
 372  * block driver; total_work_size may change during the course of the amendment
 373  * operation */
 374 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 375                                       int64_t total_work_size, void *opaque);
 376 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 377                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
 378                        Error **errp);
 379
 380 /* external snapshots */
 381 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
 382                                       BlockDriverState *candidate);
 383 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
 384
 385 /* check if a named node can be replaced when doing drive-mirror */
 386 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 387                                         const char *node_name, Error **errp);
 388
 389 /* async block I/O */
 390 void bdrv_aio_cancel(BlockAIOCB *acb);
 391 void bdrv_aio_cancel_async(BlockAIOCB *acb);
 392
 393 /* sg packet commands */
 394 int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
 395
 396 /* Invalidate any cached metadata used by image formats */
 397 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
 398 void bdrv_invalidate_cache_all(Error **errp);
 399 int bdrv_inactivate_all(void);
 400
 401 /* Ensure contents are flushed to disk.  */
 402 int bdrv_flush(BlockDriverState *bs);
 403 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
 404 int bdrv_flush_all(void);
 405 void bdrv_close_all(void);
 406 void bdrv_drain(BlockDriverState *bs);
 407 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
 408 void bdrv_drain_all_begin(void);
 409 void bdrv_drain_all_end(void);
 410 void bdrv_drain_all(void);
 411
 412 /* Returns NULL when bs == NULL */
 413 AioWait *bdrv_get_aio_wait(BlockDriverState *bs);
 414
 415 #define BDRV_POLL_WHILE(bs, cond) ({                       \
 416     BlockDriverState *bs_ = (bs);                          \
 417     AIO_WAIT_WHILE(bdrv_get_aio_wait(bs_),                 \
 418                    bdrv_get_aio_context(bs_),              \
 419                    cond); })
 420
 421 int bdrv_pdiscard(BdrvChild *child, int64_t offset, int bytes);
 422 int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int bytes);
 423 int bdrv_has_zero_init_1(BlockDriverState *bs);
 424 int bdrv_has_zero_init(BlockDriverState *bs);
 425 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 426 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 427 int bdrv_block_status(BlockDriverState *bs, int64_t offset,
 428                       int64_t bytes, int64_t *pnum, int64_t *map,
 429                       BlockDriverState **file);
 430 int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
 431                             int64_t offset, int64_t bytes, int64_t *pnum,
 432                             int64_t *map, BlockDriverState **file);
 433 int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
 434                       int64_t *pnum);
 435 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
 436                             int64_t offset, int64_t bytes, int64_t *pnum);
 437
 438 bool bdrv_is_read_only(BlockDriverState *bs);
 439 int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
 440                            bool ignore_allow_rdw, Error **errp);
 441 int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp);
 442 bool bdrv_is_writable(BlockDriverState *bs);
 443 bool bdrv_is_sg(BlockDriverState *bs);
 444 bool bdrv_is_inserted(BlockDriverState *bs);
 445 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
 446 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
 447 const char *bdrv_get_format_name(BlockDriverState *bs);
 448 BlockDriverState *bdrv_find_node(const char *node_name);
 449 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
 450 BlockDriverState *bdrv_lookup_bs(const char *device,
 451                                  const char *node_name,
 452                                  Error **errp);
 453 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 454 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 455 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
 456
 457 typedef struct BdrvNextIterator {
 458     enum {
 459         BDRV_NEXT_BACKEND_ROOTS,
 460         BDRV_NEXT_MONITOR_OWNED,
 461     } phase;
 462     BlockBackend *blk;
 463     BlockDriverState *bs;
 464 } BdrvNextIterator;
 465
 466 BlockDriverState *bdrv_first(BdrvNextIterator *it);
 467 BlockDriverState *bdrv_next(BdrvNextIterator *it);
 468 void bdrv_next_cleanup(BdrvNextIterator *it);
 469
 470 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 471 bool bdrv_is_encrypted(BlockDriverState *bs);
 472 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 473                          void *opaque);
 474 const char *bdrv_get_node_name(const BlockDriverState *bs);
 475 const char *bdrv_get_device_name(const BlockDriverState *bs);
 476 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 477 int bdrv_get_flags(BlockDriverState *bs);
 478 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 479 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
 480 void bdrv_round_to_clusters(BlockDriverState *bs,
 481                             int64_t offset, int64_t bytes,
 482                             int64_t *cluster_offset,
 483                             int64_t *cluster_bytes);
 484
 485 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
 486 void bdrv_get_backing_filename(BlockDriverState *bs,
 487                                char *filename, int filename_size);
 488 void bdrv_get_full_backing_filename(BlockDriverState *bs,
 489                                     char *dest, size_t sz, Error **errp);
 490 void bdrv_get_full_backing_filename_from_filename(const char *backed,
 491                                                   const char *backing,
 492                                                   char *dest, size_t sz,
 493                                                   Error **errp);
 494
 495 int path_has_protocol(const char *path);
 496 int path_is_absolute(const char *path);
 497 void path_combine(char *dest, int dest_size,
 498                   const char *base_path,
 499                   const char *filename);
 500
 501 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 502 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 503 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 504                       int64_t pos, int size);
 505
 506 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 507                       int64_t pos, int size);
 508
 509 void bdrv_img_create(const char *filename, const char *fmt,
 510                      const char *base_filename, const char *base_fmt,
 511                      char *options, uint64_t img_size, int flags,
 512                      bool quiet, Error **errp);
 513
 514 /* Returns the alignment in bytes that is required so that no bounce buffer
 515  * is required throughout the stack */
 516 size_t bdrv_min_mem_align(BlockDriverState *bs);
 517 /* Returns optimal alignment in bytes for bounce buffer */
 518 size_t bdrv_opt_mem_align(BlockDriverState *bs);
 519 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 520 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
 521 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
 522 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 523 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 524
 525 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 526 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 527
 528 void bdrv_ref(BlockDriverState *bs);
 529 void bdrv_unref(BlockDriverState *bs);
 530 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 531 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
 532                              BlockDriverState *child_bs,
 533                              const char *child_name,
 534                              const BdrvChildRole *child_role,
 535                              Error **errp);
 536
 537 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 538 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 539 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 540 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 541 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 542 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 543
 544 #define BLKDBG_EVENT(child, evt) \
 545     do { \
 546         if (child) { \
 547             bdrv_debug_event(child->bs, evt); \
 548         } \
 549     } while (0)
 550
 551 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
 552
 553 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 554                            const char *tag);
 555 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 556 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 557 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 558
 559 /**
 560  * bdrv_get_aio_context:
 561  *
 562  * Returns: the currently bound #AioContext
 563  */
 564 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 565
 566 /**
 567  * Transfer control to @co in the aio context of @bs
 568  */
 569 void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
 570
 571 /**
 572  * bdrv_set_aio_context:
 573  *
 574  * Changes the #AioContext used for fd handlers, timers, and BHs by this
 575  * BlockDriverState and all its children.
 576  *
 577  * This function must be called with iothread lock held.
 578  */
 579 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
 580 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 581 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 582
 583 void bdrv_io_plug(BlockDriverState *bs);
 584 void bdrv_io_unplug(BlockDriverState *bs);
 585
 586 /**
 587  * bdrv_parent_drained_begin:
 588  *
 589  * Begin a quiesced section of all users of @bs. This is part of
 590  * bdrv_drained_begin.
 591  */
 592 void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore,
 593                                bool ignore_bds_parents);
 594
 595 /**
 596  * bdrv_parent_drained_begin_single:
 597  *
 598  * Begin a quiesced section for the parent of @c. If @poll is true, wait for
 599  * any pending activity to cease.
 600  */
 601 void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
 602
 603 /**
 604  * bdrv_parent_drained_end:
 605  *
 606  * End a quiesced section of all users of @bs. This is part of
 607  * bdrv_drained_end.
 608  */
 609 void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore,
 610                              bool ignore_bds_parents);
 611
 612 /**
 613  * bdrv_drain_poll:
 614  *
 615  * Poll for pending requests in @bs, its parents (except for @ignore_parent),
 616  * and if @recursive is true its children as well (used for subtree drain).
 617  *
 618  * If @ignore_bds_parents is true, parents that are BlockDriverStates must
 619  * ignore the drain request because they will be drained separately (used for
 620  * drain_all).
 621  *
 622  * This is part of bdrv_drained_begin.
 623  */
 624 bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
 625                      BdrvChild *ignore_parent, bool ignore_bds_parents);
 626
 627 /**
 628  * bdrv_drained_begin:
 629  *
 630  * Begin a quiesced section for exclusive access to the BDS, by disabling
 631  * external request sources including NBD server and device model. Note that
 632  * this doesn't block timers or coroutines from submitting more requests, which
 633  * means block_job_pause is still necessary.
 634  *
 635  * This function can be recursive.
 636  */
 637 void bdrv_drained_begin(BlockDriverState *bs);
 638
 639 /**
 640  * bdrv_do_drained_begin_quiesce:
 641  *
 642  * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
 643  * running requests to complete.
 644  */
 645 void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
 646                                    BdrvChild *parent, bool ignore_bds_parents);
 647
 648 /**
 649  * Like bdrv_drained_begin, but recursively begins a quiesced section for
 650  * exclusive access to all child nodes as well.
 651  */
 652 void bdrv_subtree_drained_begin(BlockDriverState *bs);
 653
 654 /**
 655  * bdrv_drained_end:
 656  *
 657  * End a quiescent section started by bdrv_drained_begin().
 658  */
 659 void bdrv_drained_end(BlockDriverState *bs);
 660
 661 /**
 662  * End a quiescent section started by bdrv_subtree_drained_begin().
 663  */
 664 void bdrv_subtree_drained_end(BlockDriverState *bs);
 665
 666 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
 667                     Error **errp);
 668 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 669
 670 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
 671                                      uint32_t granularity, Error **errp);
 672 /**
 673  *
 674  * bdrv_register_buf/bdrv_unregister_buf:
 675  *
 676  * Register/unregister a buffer for I/O. For example, VFIO drivers are
 677  * interested to know the memory areas that would later be used for I/O, so
 678  * that they can prepare IOMMU mapping etc., to get better performance.
 679  */
 680 void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
 681 void bdrv_unregister_buf(BlockDriverState *bs, void *host);
 682
 683 /**
 684  *
 685  * bdrv_co_copy_range:
 686  *
 687  * Do offloaded copy between two children. If the operation is not implemented
 688  * by the driver, or if the backend storage doesn't support it, a negative
 689  * error code will be returned.
 690  *
 691  * Note: block layer doesn't emulate or fallback to a bounce buffer approach
 692  * because usually the caller shouldn't attempt offloaded copy any more (e.g.
 693  * calling copy_file_range(2)) after the first error, thus it should fall back
 694  * to a read+write path in the caller level.
 695  *
 696  * @src: Source child to copy data from
 697  * @src_offset: offset in @src image to read data
 698  * @dst: Destination child to copy data to
 699  * @dst_offset: offset in @dst image to write data
 700  * @bytes: number of bytes to copy
 701  * @flags: request flags. Supported flags:
 702  *         BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
 703  *                               write on @dst as if bdrv_co_pwrite_zeroes is
 704  *                               called. Used to simplify caller code, or
 705  *                               during BlockDriver.bdrv_co_copy_range_from()
 706  *                               recursion.
 707  *         BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
 708  *                                   requests currently in flight.
 709  *
 710  * Returns: 0 if succeeded; negative error code if failed.
 711  **/
 712 int coroutine_fn bdrv_co_copy_range(BdrvChild *src, uint64_t src_offset,
 713                                     BdrvChild *dst, uint64_t dst_offset,
 714                                     uint64_t bytes, BdrvRequestFlags read_flags,
 715                                     BdrvRequestFlags write_flags);
 716 #endif