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