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     /* Execute the request only if the operation can be offloaded or otherwise
  87      * be executed efficiently, but return an error instead of using a slow
  88      * fallback. */
  89     BDRV_REQ_NO_FALLBACK        = 0x100,
  90
  91     /* Mask of valid flags */
  92     BDRV_REQ_MASK               = 0x1ff,
  93 } BdrvRequestFlags;
  94
  95 typedef struct BlockSizes {
  96     uint32_t phys;
  97     uint32_t log;
  98 } BlockSizes;
  99
 100 typedef struct HDGeometry {
 101     uint32_t heads;
 102     uint32_t sectors;
 103     uint32_t cylinders;
 104 } HDGeometry;
 105
 106 #define BDRV_O_RDWR        0x0002
 107 #define BDRV_O_RESIZE      0x0004 /* request permission for resizing the node */
 108 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
 109 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
 110 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
 111 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
 112 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
 113 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
 114 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
 115 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
 116 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
 117 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
 118 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
 119 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
 120                                       select an appropriate protocol driver,
 121                                       ignoring the format layer */
 122 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
 123 #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
 124
 125 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
 126
 127
 128 /* Option names of options parsed by the block layer */
 129
 130 #define BDRV_OPT_CACHE_WB       "cache.writeback"
 131 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
 132 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
 133 #define BDRV_OPT_READ_ONLY      "read-only"
 134 #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
 135 #define BDRV_OPT_DISCARD        "discard"
 136 #define BDRV_OPT_FORCE_SHARE    "force-share"
 137
 138
 139 #define BDRV_SECTOR_BITS   9
 140 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 141 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 142
 143 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
 144                                      INT_MAX >> BDRV_SECTOR_BITS)
 145 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
 146
 147 /*
 148  * Allocation status flags for bdrv_block_status() and friends.
 149  *
 150  * Public flags:
 151  * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
 152  * BDRV_BLOCK_ZERO: offset reads as zero
 153  * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
 154  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
 155  *                       layer rather than any backing, set by block layer
 156  * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
 157  *                 layer, set by block layer
 158  *
 159  * Internal flags:
 160  * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
 161  *                 that the block layer recompute the answer from the returned
 162  *                 BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
 163  * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
 164  *                     zeroes in file child of current block node inside
 165  *                     returned region. Only valid together with both
 166  *                     BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
 167  *                     appear with BDRV_BLOCK_ZERO.
 168  *
 169  * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
 170  * host offset within the returned BDS that is allocated for the
 171  * corresponding raw guest data.  However, whether that offset
 172  * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
 173  *
 174  * DATA ZERO OFFSET_VALID
 175  *  t    t        t       sectors read as zero, returned file is zero at offset
 176  *  t    f        t       sectors read as valid from file at offset
 177  *  f    t        t       sectors preallocated, read as zero, returned file not
 178  *                        necessarily zero at offset
 179  *  f    f        t       sectors preallocated but read from backing_hd,
 180  *                        returned file contains garbage at offset
 181  *  t    t        f       sectors preallocated, read as zero, unknown offset
 182  *  t    f        f       sectors read from unknown file or offset
 183  *  f    t        f       not allocated or unknown offset, read as zero
 184  *  f    f        f       not allocated or unknown offset, read from backing_hd
 185  */
 186 #define BDRV_BLOCK_DATA         0x01
 187 #define BDRV_BLOCK_ZERO         0x02
 188 #define BDRV_BLOCK_OFFSET_VALID 0x04
 189 #define BDRV_BLOCK_RAW          0x08
 190 #define BDRV_BLOCK_ALLOCATED    0x10
 191 #define BDRV_BLOCK_EOF          0x20
 192 #define BDRV_BLOCK_RECURSE      0x40
 193 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
 194
 195 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
 196
 197 typedef struct BDRVReopenState {
 198     BlockDriverState *bs;
 199     int flags;
 200     BlockdevDetectZeroesOptions detect_zeroes;
 201     bool backing_missing;
 202     bool replace_backing_bs;  /* new_backing_bs is ignored if this is false */
 203     BlockDriverState *new_backing_bs; /* If NULL then detach the current bs */
 204     uint64_t perm, shared_perm;
 205     QDict *options;
 206     QDict *explicit_options;
 207     void *opaque;
 208 } BDRVReopenState;
 209
 210 /*
 211  * Block operation types
 212  */
 213 typedef enum BlockOpType {
 214     BLOCK_OP_TYPE_BACKUP_SOURCE,
 215     BLOCK_OP_TYPE_BACKUP_TARGET,
 216     BLOCK_OP_TYPE_CHANGE,
 217     BLOCK_OP_TYPE_COMMIT_SOURCE,
 218     BLOCK_OP_TYPE_COMMIT_TARGET,
 219     BLOCK_OP_TYPE_DATAPLANE,
 220     BLOCK_OP_TYPE_DRIVE_DEL,
 221     BLOCK_OP_TYPE_EJECT,
 222     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
 223     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
 224     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
 225     BLOCK_OP_TYPE_MIRROR_SOURCE,
 226     BLOCK_OP_TYPE_MIRROR_TARGET,
 227     BLOCK_OP_TYPE_RESIZE,
 228     BLOCK_OP_TYPE_STREAM,
 229     BLOCK_OP_TYPE_REPLACE,
 230     BLOCK_OP_TYPE_MAX,
 231 } BlockOpType;
 232
 233 /* Block node permission constants */
 234 enum {
 235     /**
 236      * A user that has the "permission" of consistent reads is guaranteed that
 237      * their view of the contents of the block device is complete and
 238      * self-consistent, representing the contents of a disk at a specific
 239      * point.
 240      *
 241      * For most block devices (including their backing files) this is true, but
 242      * the property cannot be maintained in a few situations like for
 243      * intermediate nodes of a commit block job.
 244      */
 245     BLK_PERM_CONSISTENT_READ    = 0x01,
 246
 247     /** This permission is required to change the visible disk contents. */
 248     BLK_PERM_WRITE              = 0x02,
 249
 250     /**
 251      * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
 252      * required for writes to the block node when the caller promises that
 253      * the visible disk content doesn't change.
 254      *
 255      * As the BLK_PERM_WRITE permission is strictly stronger, either is
 256      * sufficient to perform an unchanging write.
 257      */
 258     BLK_PERM_WRITE_UNCHANGED    = 0x04,
 259
 260     /** This permission is required to change the size of a block node. */
 261     BLK_PERM_RESIZE             = 0x08,
 262
 263     /**
 264      * This permission is required to change the node that this BdrvChild
 265      * points to.
 266      */
 267     BLK_PERM_GRAPH_MOD          = 0x10,
 268
 269     BLK_PERM_ALL                = 0x1f,
 270
 271     DEFAULT_PERM_PASSTHROUGH    = BLK_PERM_CONSISTENT_READ
 272                                  | BLK_PERM_WRITE
 273                                  | BLK_PERM_WRITE_UNCHANGED
 274                                  | BLK_PERM_RESIZE,
 275
 276     DEFAULT_PERM_UNCHANGED      = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH,
 277 };
 278
 279 char *bdrv_perm_names(uint64_t perm);
 280
 281 /* disk I/O throttling */
 282 void bdrv_init(void);
 283 void bdrv_init_with_whitelist(void);
 284 bool bdrv_uses_whitelist(void);
 285 int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
 286 BlockDriver *bdrv_find_protocol(const char *filename,
 287                                 bool allow_protocol_prefix,
 288                                 Error **errp);
 289 BlockDriver *bdrv_find_format(const char *format_name);
 290 int bdrv_create(BlockDriver *drv, const char* filename,
 291                 QemuOpts *opts, Error **errp);
 292 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
 293 BlockDriverState *bdrv_new(void);
 294 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
 295                  Error **errp);
 296 void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
 297                        Error **errp);
 298
 299 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
 300 int bdrv_parse_discard_flags(const char *mode, int *flags);
 301 BdrvChild *bdrv_open_child(const char *filename,
 302                            QDict *options, const char *bdref_key,
 303                            BlockDriverState* parent,
 304                            const BdrvChildRole *child_role,
 305                            bool allow_none, Error **errp);
 306 BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
 307 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
 308                          Error **errp);
 309 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
 310                            const char *bdref_key, Error **errp);
 311 BlockDriverState *bdrv_open(const char *filename, const char *reference,
 312                             QDict *options, int flags, Error **errp);
 313 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
 314                                        int flags, Error **errp);
 315 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
 316                                     BlockDriverState *bs, QDict *options,
 317                                     bool keep_old_opts);
 318 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
 319 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
 320                               Error **errp);
 321 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
 322                         BlockReopenQueue *queue, Error **errp);
 323 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
 324 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 325 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
 326                        int bytes, BdrvRequestFlags flags);
 327 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
 328 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
 329 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 330 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
 331 int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 332 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
 333                      const void *buf, int count);
 334 /*
 335  * Efficiently zero a region of the disk image.  Note that this is a regular
 336  * I/O request like read or write and should have a reasonable size.  This
 337  * function is not suitable for zeroing the entire image in a single request
 338  * because it may allocate memory for the entire region.
 339  */
 340 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
 341                                        int bytes, BdrvRequestFlags flags);
 342 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 343     const char *backing_file);
 344 void bdrv_refresh_filename(BlockDriverState *bs);
 345
 346 int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset,
 347                                   PreallocMode prealloc, Error **errp);
 348 int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
 349                   Error **errp);
 350
 351 int64_t bdrv_nb_sectors(BlockDriverState *bs);
 352 int64_t bdrv_getlength(BlockDriverState *bs);
 353 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 354 BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
 355                                BlockDriverState *in_bs, Error **errp);
 356 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 357 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 358 int bdrv_commit(BlockDriverState *bs);
 359 int bdrv_change_backing_file(BlockDriverState *bs,
 360     const char *backing_file, const char *backing_fmt);
 361 void bdrv_register(BlockDriver *bdrv);
 362 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
 363                            const char *backing_file_str);
 364 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 365                                     BlockDriverState *bs);
 366 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 367 bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
 368                                   Error **errp);
 369 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
 370                               Error **errp);
 371 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
 372
 373
 374 typedef struct BdrvCheckResult {
 375     int corruptions;
 376     int leaks;
 377     int check_errors;
 378     int corruptions_fixed;
 379     int leaks_fixed;
 380     int64_t image_end_offset;
 381     BlockFragInfo bfi;
 382 } BdrvCheckResult;
 383
 384 typedef enum {
 385     BDRV_FIX_LEAKS    = 1,
 386     BDRV_FIX_ERRORS   = 2,
 387 } BdrvCheckMode;
 388
 389 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 390
 391 /* The units of offset and total_work_size may be chosen arbitrarily by the
 392  * block driver; total_work_size may change during the course of the amendment
 393  * operation */
 394 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 395                                       int64_t total_work_size, void *opaque);
 396 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 397                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
 398                        Error **errp);
 399
 400 /* external snapshots */
 401 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
 402                                       BlockDriverState *candidate);
 403 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
 404
 405 /* check if a named node can be replaced when doing drive-mirror */
 406 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 407                                         const char *node_name, Error **errp);
 408
 409 /* async block I/O */
 410 void bdrv_aio_cancel(BlockAIOCB *acb);
 411 void bdrv_aio_cancel_async(BlockAIOCB *acb);
 412
 413 /* sg packet commands */
 414 int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
 415
 416 /* Invalidate any cached metadata used by image formats */
 417 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
 418 void bdrv_invalidate_cache_all(Error **errp);
 419 int bdrv_inactivate_all(void);
 420
 421 /* Ensure contents are flushed to disk.  */
 422 int bdrv_flush(BlockDriverState *bs);
 423 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
 424 int bdrv_flush_all(void);
 425 void bdrv_close_all(void);
 426 void bdrv_drain(BlockDriverState *bs);
 427 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
 428 void bdrv_drain_all_begin(void);
 429 void bdrv_drain_all_end(void);
 430 void bdrv_drain_all(void);
 431
 432 #define BDRV_POLL_WHILE(bs, cond) ({                       \
 433     BlockDriverState *bs_ = (bs);                          \
 434     AIO_WAIT_WHILE(bdrv_get_aio_context(bs_),              \
 435                    cond); })
 436
 437 int bdrv_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
 438 int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
 439 int bdrv_has_zero_init_1(BlockDriverState *bs);
 440 int bdrv_has_zero_init(BlockDriverState *bs);
 441 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 442 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 443 int bdrv_block_status(BlockDriverState *bs, int64_t offset,
 444                       int64_t bytes, int64_t *pnum, int64_t *map,
 445                       BlockDriverState **file);
 446 int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
 447                             int64_t offset, int64_t bytes, int64_t *pnum,
 448                             int64_t *map, BlockDriverState **file);
 449 int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
 450                       int64_t *pnum);
 451 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
 452                             bool include_base, int64_t offset, int64_t bytes,
 453                             int64_t *pnum);
 454
 455 bool bdrv_is_read_only(BlockDriverState *bs);
 456 int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
 457                            bool ignore_allow_rdw, Error **errp);
 458 int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
 459                               Error **errp);
 460 bool bdrv_is_writable(BlockDriverState *bs);
 461 bool bdrv_is_sg(BlockDriverState *bs);
 462 bool bdrv_is_inserted(BlockDriverState *bs);
 463 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
 464 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
 465 const char *bdrv_get_format_name(BlockDriverState *bs);
 466 BlockDriverState *bdrv_find_node(const char *node_name);
 467 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
 468 XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
 469 BlockDriverState *bdrv_lookup_bs(const char *device,
 470                                  const char *node_name,
 471                                  Error **errp);
 472 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 473 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 474 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
 475
 476 typedef struct BdrvNextIterator {
 477     enum {
 478         BDRV_NEXT_BACKEND_ROOTS,
 479         BDRV_NEXT_MONITOR_OWNED,
 480     } phase;
 481     BlockBackend *blk;
 482     BlockDriverState *bs;
 483 } BdrvNextIterator;
 484
 485 BlockDriverState *bdrv_first(BdrvNextIterator *it);
 486 BlockDriverState *bdrv_next(BdrvNextIterator *it);
 487 void bdrv_next_cleanup(BdrvNextIterator *it);
 488
 489 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 490 bool bdrv_is_encrypted(BlockDriverState *bs);
 491 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 492                          void *opaque, bool read_only);
 493 const char *bdrv_get_node_name(const BlockDriverState *bs);
 494 const char *bdrv_get_device_name(const BlockDriverState *bs);
 495 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 496 int bdrv_get_flags(BlockDriverState *bs);
 497 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 498 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
 499                                           Error **errp);
 500 void bdrv_round_to_clusters(BlockDriverState *bs,
 501                             int64_t offset, int64_t bytes,
 502                             int64_t *cluster_offset,
 503                             int64_t *cluster_bytes);
 504
 505 void bdrv_get_backing_filename(BlockDriverState *bs,
 506                                char *filename, int filename_size);
 507 char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
 508 char *bdrv_get_full_backing_filename_from_filename(const char *backed,
 509                                                    const char *backing,
 510                                                    Error **errp);
 511 char *bdrv_dirname(BlockDriverState *bs, Error **errp);
 512
 513 int path_has_protocol(const char *path);
 514 int path_is_absolute(const char *path);
 515 char *path_combine(const char *base_path, const char *filename);
 516
 517 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 518 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 519 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 520                       int64_t pos, int size);
 521
 522 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 523                       int64_t pos, int size);
 524
 525 void bdrv_img_create(const char *filename, const char *fmt,
 526                      const char *base_filename, const char *base_fmt,
 527                      char *options, uint64_t img_size, int flags,
 528                      bool quiet, Error **errp);
 529
 530 /* Returns the alignment in bytes that is required so that no bounce buffer
 531  * is required throughout the stack */
 532 size_t bdrv_min_mem_align(BlockDriverState *bs);
 533 /* Returns optimal alignment in bytes for bounce buffer */
 534 size_t bdrv_opt_mem_align(BlockDriverState *bs);
 535 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 536 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
 537 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
 538 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 539 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 540
 541 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 542 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 543
 544 void bdrv_ref(BlockDriverState *bs);
 545 void bdrv_unref(BlockDriverState *bs);
 546 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 547 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
 548                              BlockDriverState *child_bs,
 549                              const char *child_name,
 550                              const BdrvChildRole *child_role,
 551                              Error **errp);
 552
 553 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 554 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 555 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 556 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 557 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 558 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 559
 560 #define BLKDBG_EVENT(child, evt) \
 561     do { \
 562         if (child) { \
 563             bdrv_debug_event(child->bs, evt); \
 564         } \
 565     } while (0)
 566
 567 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
 568
 569 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 570                            const char *tag);
 571 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 572 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 573 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 574
 575 /**
 576  * bdrv_get_aio_context:
 577  *
 578  * Returns: the currently bound #AioContext
 579  */
 580 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 581
 582 /**
 583  * Transfer control to @co in the aio context of @bs
 584  */
 585 void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
 586
 587 void bdrv_set_aio_context_ignore(BlockDriverState *bs,
 588                                  AioContext *new_context, GSList **ignore);
 589 int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
 590                              Error **errp);
 591 int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
 592                                    BdrvChild *ignore_child, Error **errp);
 593 bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
 594                                     GSList **ignore, Error **errp);
 595 bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
 596                               GSList **ignore, Error **errp);
 597 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 598 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 599
 600 void bdrv_io_plug(BlockDriverState *bs);
 601 void bdrv_io_unplug(BlockDriverState *bs);
 602
 603 /**
 604  * bdrv_parent_drained_begin:
 605  *
 606  * Begin a quiesced section of all users of @bs. This is part of
 607  * bdrv_drained_begin.
 608  */
 609 void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore,
 610                                bool ignore_bds_parents);
 611
 612 /**
 613  * bdrv_parent_drained_begin_single:
 614  *
 615  * Begin a quiesced section for the parent of @c. If @poll is true, wait for
 616  * any pending activity to cease.
 617  */
 618 void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
 619
 620 /**
 621  * bdrv_parent_drained_end:
 622  *
 623  * End a quiesced section of all users of @bs. This is part of
 624  * bdrv_drained_end.
 625  */
 626 void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore,
 627                              bool ignore_bds_parents);
 628
 629 /**
 630  * bdrv_drain_poll:
 631  *
 632  * Poll for pending requests in @bs, its parents (except for @ignore_parent),
 633  * and if @recursive is true its children as well (used for subtree drain).
 634  *
 635  * If @ignore_bds_parents is true, parents that are BlockDriverStates must
 636  * ignore the drain request because they will be drained separately (used for
 637  * drain_all).
 638  *
 639  * This is part of bdrv_drained_begin.
 640  */
 641 bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
 642                      BdrvChild *ignore_parent, bool ignore_bds_parents);
 643
 644 /**
 645  * bdrv_drained_begin:
 646  *
 647  * Begin a quiesced section for exclusive access to the BDS, by disabling
 648  * external request sources including NBD server and device model. Note that
 649  * this doesn't block timers or coroutines from submitting more requests, which
 650  * means block_job_pause is still necessary.
 651  *
 652  * This function can be recursive.
 653  */
 654 void bdrv_drained_begin(BlockDriverState *bs);
 655
 656 /**
 657  * bdrv_do_drained_begin_quiesce:
 658  *
 659  * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
 660  * running requests to complete.
 661  */
 662 void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
 663                                    BdrvChild *parent, bool ignore_bds_parents);
 664
 665 /**
 666  * Like bdrv_drained_begin, but recursively begins a quiesced section for
 667  * exclusive access to all child nodes as well.
 668  */
 669 void bdrv_subtree_drained_begin(BlockDriverState *bs);
 670
 671 /**
 672  * bdrv_drained_end:
 673  *
 674  * End a quiescent section started by bdrv_drained_begin().
 675  */
 676 void bdrv_drained_end(BlockDriverState *bs);
 677
 678 /**
 679  * End a quiescent section started by bdrv_subtree_drained_begin().
 680  */
 681 void bdrv_subtree_drained_end(BlockDriverState *bs);
 682
 683 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
 684                     Error **errp);
 685 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 686
 687 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
 688                                      uint32_t granularity, Error **errp);
 689 /**
 690  *
 691  * bdrv_register_buf/bdrv_unregister_buf:
 692  *
 693  * Register/unregister a buffer for I/O. For example, VFIO drivers are
 694  * interested to know the memory areas that would later be used for I/O, so
 695  * that they can prepare IOMMU mapping etc., to get better performance.
 696  */
 697 void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
 698 void bdrv_unregister_buf(BlockDriverState *bs, void *host);
 699
 700 /**
 701  *
 702  * bdrv_co_copy_range:
 703  *
 704  * Do offloaded copy between two children. If the operation is not implemented
 705  * by the driver, or if the backend storage doesn't support it, a negative
 706  * error code will be returned.
 707  *
 708  * Note: block layer doesn't emulate or fallback to a bounce buffer approach
 709  * because usually the caller shouldn't attempt offloaded copy any more (e.g.
 710  * calling copy_file_range(2)) after the first error, thus it should fall back
 711  * to a read+write path in the caller level.
 712  *
 713  * @src: Source child to copy data from
 714  * @src_offset: offset in @src image to read data
 715  * @dst: Destination child to copy data to
 716  * @dst_offset: offset in @dst image to write data
 717  * @bytes: number of bytes to copy
 718  * @flags: request flags. Supported flags:
 719  *         BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
 720  *                               write on @dst as if bdrv_co_pwrite_zeroes is
 721  *                               called. Used to simplify caller code, or
 722  *                               during BlockDriver.bdrv_co_copy_range_from()
 723  *                               recursion.
 724  *         BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
 725  *                                   requests currently in flight.
 726  *
 727  * Returns: 0 if succeeded; negative error code if failed.
 728  **/
 729 int coroutine_fn bdrv_co_copy_range(BdrvChild *src, uint64_t src_offset,
 730                                     BdrvChild *dst, uint64_t dst_offset,
 731                                     uint64_t bytes, BdrvRequestFlags read_flags,
 732                                     BdrvRequestFlags write_flags);
 733 #endif