include/block/block.h

   1 #ifndef BLOCK_H
   2 #define BLOCK_H
   3
   4 #include "block/aio.h"
   5 #include "qemu/iov.h"
   6 #include "qemu/option.h"
   7 #include "qemu/coroutine.h"
   8 #include "block/accounting.h"
   9 #include "block/dirty-bitmap.h"
  10 #include "block/blockjob.h"
  11 #include "qapi/qmp/qobject.h"
  12 #include "qapi-types.h"
  13 #include "qemu/hbitmap.h"
  14
  15 /* block.c */
  16 typedef struct BlockDriver BlockDriver;
  17 typedef struct BdrvChild BdrvChild;
  18 typedef struct BdrvChildRole BdrvChildRole;
  19
  20 typedef struct BlockDriverInfo {
  21     /* in bytes, 0 if irrelevant */
  22     int cluster_size;
  23     /* offset at which the VM state can be saved (0 if not possible) */
  24     int64_t vm_state_offset;
  25     bool is_dirty;
  26     /*
  27      * True if unallocated blocks read back as zeroes. This is equivalent
  28      * to the LBPRZ flag in the SCSI logical block provisioning page.
  29      */
  30     bool unallocated_blocks_are_zero;
  31     /*
  32      * True if the driver can optimize writing zeroes by unmapping
  33      * sectors. This is equivalent to the BLKDISCARDZEROES ioctl in Linux
  34      * with the difference that in qemu a discard is allowed to silently
  35      * fail. Therefore we have to use bdrv_pwrite_zeroes with the
  36      * BDRV_REQ_MAY_UNMAP flag for an optimized zero write with unmapping.
  37      * After this call the driver has to guarantee that the contents read
  38      * back as zero. It is additionally required that the block device is
  39      * opened with BDRV_O_UNMAP flag for this to work.
  40      */
  41     bool can_write_zeroes_with_unmap;
  42     /*
  43      * True if this block driver only supports compressed writes
  44      */
  45     bool needs_compressed_writes;
  46 } BlockDriverInfo;
  47
  48 typedef struct BlockFragInfo {
  49     uint64_t allocated_clusters;
  50     uint64_t total_clusters;
  51     uint64_t fragmented_clusters;
  52     uint64_t compressed_clusters;
  53 } BlockFragInfo;
  54
  55 typedef enum {
  56     BDRV_REQ_COPY_ON_READ       = 0x1,
  57     BDRV_REQ_ZERO_WRITE         = 0x2,
  58     /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
  59      * is allowed to optimize a write zeroes request by unmapping (discarding)
  60      * blocks if it is guaranteed that the result will read back as
  61      * zeroes. The flag is only passed to the driver if the block device is
  62      * opened with BDRV_O_UNMAP.
  63      */
  64     BDRV_REQ_MAY_UNMAP          = 0x4,
  65     BDRV_REQ_NO_SERIALISING     = 0x8,
  66     BDRV_REQ_FUA                = 0x10,
  67     BDRV_REQ_WRITE_COMPRESSED   = 0x20,
  68
  69     /* Mask of valid flags */
  70     BDRV_REQ_MASK               = 0x3f,
  71 } BdrvRequestFlags;
  72
  73 typedef struct BlockSizes {
  74     uint32_t phys;
  75     uint32_t log;
  76 } BlockSizes;
  77
  78 typedef struct HDGeometry {
  79     uint32_t heads;
  80     uint32_t sectors;
  81     uint32_t cylinders;
  82 } HDGeometry;
  83
  84 #define BDRV_O_RDWR        0x0002
  85 #define BDRV_O_RESIZE      0x0004 /* request permission for resizing the node */
  86 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
  87 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
  88 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
  89 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
  90 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
  91 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
  92 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
  93 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
  94 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
  95 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
  96 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
  97 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
  98                                       select an appropriate protocol driver,
  99                                       ignoring the format layer */
 100 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
 101
 102 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
 103
 104
 105 /* Option names of options parsed by the block layer */
 106
 107 #define BDRV_OPT_CACHE_WB       "cache.writeback"
 108 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
 109 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
 110 #define BDRV_OPT_READ_ONLY      "read-only"
 111 #define BDRV_OPT_DISCARD        "discard"
 112
 113
 114 #define BDRV_SECTOR_BITS   9
 115 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 116 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 117
 118 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
 119                                      INT_MAX >> BDRV_SECTOR_BITS)
 120 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
 121
 122 /*
 123  * Allocation status flags
 124  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
 125  * BDRV_BLOCK_ZERO: sectors read as zero
 126  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
 127  *                          bdrv_get_block_status.
 128  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
 129  *                       layer (as opposed to the backing file)
 130  * BDRV_BLOCK_RAW: used internally to indicate that the request
 131  *                 was answered by the raw driver and that one
 132  *                 should look in bs->file directly.
 133  *
 134  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
 135  * bs->file where sector data can be read from as raw data.
 136  *
 137  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
 138  *
 139  * DATA ZERO OFFSET_VALID
 140  *  t    t        t       sectors read as zero, bs->file is zero at offset
 141  *  t    f        t       sectors read as valid from bs->file at offset
 142  *  f    t        t       sectors preallocated, read as zero, bs->file not
 143  *                        necessarily zero at offset
 144  *  f    f        t       sectors preallocated but read from backing_hd,
 145  *                        bs->file contains garbage at offset
 146  *  t    t        f       sectors preallocated, read as zero, unknown offset
 147  *  t    f        f       sectors read from unknown file or offset
 148  *  f    t        f       not allocated or unknown offset, read as zero
 149  *  f    f        f       not allocated or unknown offset, read from backing_hd
 150  */
 151 #define BDRV_BLOCK_DATA         0x01
 152 #define BDRV_BLOCK_ZERO         0x02
 153 #define BDRV_BLOCK_OFFSET_VALID 0x04
 154 #define BDRV_BLOCK_RAW          0x08
 155 #define BDRV_BLOCK_ALLOCATED    0x10
 156 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
 157
 158 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
 159
 160 typedef struct BDRVReopenState {
 161     BlockDriverState *bs;
 162     int flags;
 163     QDict *options;
 164     QDict *explicit_options;
 165     void *opaque;
 166 } BDRVReopenState;
 167
 168 /*
 169  * Block operation types
 170  */
 171 typedef enum BlockOpType {
 172     BLOCK_OP_TYPE_BACKUP_SOURCE,
 173     BLOCK_OP_TYPE_BACKUP_TARGET,
 174     BLOCK_OP_TYPE_CHANGE,
 175     BLOCK_OP_TYPE_COMMIT_SOURCE,
 176     BLOCK_OP_TYPE_COMMIT_TARGET,
 177     BLOCK_OP_TYPE_DATAPLANE,
 178     BLOCK_OP_TYPE_DRIVE_DEL,
 179     BLOCK_OP_TYPE_EJECT,
 180     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
 181     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
 182     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
 183     BLOCK_OP_TYPE_MIRROR_SOURCE,
 184     BLOCK_OP_TYPE_MIRROR_TARGET,
 185     BLOCK_OP_TYPE_RESIZE,
 186     BLOCK_OP_TYPE_STREAM,
 187     BLOCK_OP_TYPE_REPLACE,
 188     BLOCK_OP_TYPE_MAX,
 189 } BlockOpType;
 190
 191 /* Block node permission constants */
 192 enum {
 193     /**
 194      * A user that has the "permission" of consistent reads is guaranteed that
 195      * their view of the contents of the block device is complete and
 196      * self-consistent, representing the contents of a disk at a specific
 197      * point.
 198      *
 199      * For most block devices (including their backing files) this is true, but
 200      * the property cannot be maintained in a few situations like for
 201      * intermediate nodes of a commit block job.
 202      */
 203     BLK_PERM_CONSISTENT_READ    = 0x01,
 204
 205     /** This permission is required to change the visible disk contents. */
 206     BLK_PERM_WRITE              = 0x02,
 207
 208     /**
 209      * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
 210      * required for writes to the block node when the caller promises that
 211      * the visible disk content doesn't change.
 212      */
 213     BLK_PERM_WRITE_UNCHANGED    = 0x04,
 214
 215     /** This permission is required to change the size of a block node. */
 216     BLK_PERM_RESIZE             = 0x08,
 217
 218     /**
 219      * This permission is required to change the node that this BdrvChild
 220      * points to.
 221      */
 222     BLK_PERM_GRAPH_MOD          = 0x10,
 223
 224     BLK_PERM_ALL                = 0x1f,
 225 };
 226
 227 /* disk I/O throttling */
 228 void bdrv_init(void);
 229 void bdrv_init_with_whitelist(void);
 230 bool bdrv_uses_whitelist(void);
 231 BlockDriver *bdrv_find_protocol(const char *filename,
 232                                 bool allow_protocol_prefix,
 233                                 Error **errp);
 234 BlockDriver *bdrv_find_format(const char *format_name);
 235 int bdrv_create(BlockDriver *drv, const char* filename,
 236                 QemuOpts *opts, Error **errp);
 237 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
 238 BlockDriverState *bdrv_new(void);
 239 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
 240                  Error **errp);
 241 void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
 242                        Error **errp);
 243
 244 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
 245 int bdrv_parse_discard_flags(const char *mode, int *flags);
 246 BdrvChild *bdrv_open_child(const char *filename,
 247                            QDict *options, const char *bdref_key,
 248                            BlockDriverState* parent,
 249                            const BdrvChildRole *child_role,
 250                            bool allow_none, Error **errp);
 251 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
 252                          Error **errp);
 253 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
 254                            const char *bdref_key, Error **errp);
 255 BlockDriverState *bdrv_open(const char *filename, const char *reference,
 256                             QDict *options, int flags, Error **errp);
 257 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
 258                                        int flags, Error **errp);
 259 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
 260                                     BlockDriverState *bs,
 261                                     QDict *options, int flags);
 262 int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp);
 263 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
 264 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
 265                         BlockReopenQueue *queue, Error **errp);
 266 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
 267 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 268 int bdrv_read(BdrvChild *child, int64_t sector_num,
 269               uint8_t *buf, int nb_sectors);
 270 int bdrv_write(BdrvChild *child, int64_t sector_num,
 271                const uint8_t *buf, int nb_sectors);
 272 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
 273                        int count, BdrvRequestFlags flags);
 274 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
 275 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
 276 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 277 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
 278 int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
 279 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
 280                      const void *buf, int count);
 281 int coroutine_fn bdrv_co_readv(BdrvChild *child, int64_t sector_num,
 282                                int nb_sectors, QEMUIOVector *qiov);
 283 int coroutine_fn bdrv_co_writev(BdrvChild *child, int64_t sector_num,
 284                                int nb_sectors, QEMUIOVector *qiov);
 285 /*
 286  * Efficiently zero a region of the disk image.  Note that this is a regular
 287  * I/O request like read or write and should have a reasonable size.  This
 288  * function is not suitable for zeroing the entire image in a single request
 289  * because it may allocate memory for the entire region.
 290  */
 291 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
 292                                        int count, BdrvRequestFlags flags);
 293 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 294     const char *backing_file);
 295 void bdrv_refresh_filename(BlockDriverState *bs);
 296 int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp);
 297 int64_t bdrv_nb_sectors(BlockDriverState *bs);
 298 int64_t bdrv_getlength(BlockDriverState *bs);
 299 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 300 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 301 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 302 int bdrv_commit(BlockDriverState *bs);
 303 int bdrv_change_backing_file(BlockDriverState *bs,
 304     const char *backing_file, const char *backing_fmt);
 305 void bdrv_register(BlockDriver *bdrv);
 306 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
 307                            BlockDriverState *base,
 308                            const char *backing_file_str);
 309 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 310                                     BlockDriverState *bs);
 311 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 312
 313
 314 typedef struct BdrvCheckResult {
 315     int corruptions;
 316     int leaks;
 317     int check_errors;
 318     int corruptions_fixed;
 319     int leaks_fixed;
 320     int64_t image_end_offset;
 321     BlockFragInfo bfi;
 322 } BdrvCheckResult;
 323
 324 typedef enum {
 325     BDRV_FIX_LEAKS    = 1,
 326     BDRV_FIX_ERRORS   = 2,
 327 } BdrvCheckMode;
 328
 329 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
 330
 331 /* The units of offset and total_work_size may be chosen arbitrarily by the
 332  * block driver; total_work_size may change during the course of the amendment
 333  * operation */
 334 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 335                                       int64_t total_work_size, void *opaque);
 336 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 337                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
 338
 339 /* external snapshots */
 340 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
 341                                       BlockDriverState *candidate);
 342 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
 343
 344 /* check if a named node can be replaced when doing drive-mirror */
 345 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 346                                         const char *node_name, Error **errp);
 347
 348 /* async block I/O */
 349 BlockAIOCB *bdrv_aio_readv(BdrvChild *child, int64_t sector_num,
 350                            QEMUIOVector *iov, int nb_sectors,
 351                            BlockCompletionFunc *cb, void *opaque);
 352 BlockAIOCB *bdrv_aio_writev(BdrvChild *child, int64_t sector_num,
 353                             QEMUIOVector *iov, int nb_sectors,
 354                             BlockCompletionFunc *cb, void *opaque);
 355 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
 356                            BlockCompletionFunc *cb, void *opaque);
 357 void bdrv_aio_cancel(BlockAIOCB *acb);
 358 void bdrv_aio_cancel_async(BlockAIOCB *acb);
 359
 360 /* sg packet commands */
 361 int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
 362
 363 /* Invalidate any cached metadata used by image formats */
 364 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
 365 void bdrv_invalidate_cache_all(Error **errp);
 366 int bdrv_inactivate_all(void);
 367
 368 void blk_resume_after_migration(Error **errp);
 369
 370 /* Ensure contents are flushed to disk.  */
 371 int bdrv_flush(BlockDriverState *bs);
 372 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
 373 int bdrv_flush_all(void);
 374 void bdrv_close_all(void);
 375 void bdrv_drain(BlockDriverState *bs);
 376 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
 377 void bdrv_drain_all_begin(void);
 378 void bdrv_drain_all_end(void);
 379 void bdrv_drain_all(void);
 380
 381 #define BDRV_POLL_WHILE(bs, cond) ({                       \
 382     bool waited_ = false;                                  \
 383     bool busy_ = true;                                     \
 384     BlockDriverState *bs_ = (bs);                          \
 385     AioContext *ctx_ = bdrv_get_aio_context(bs_);          \
 386     if (aio_context_in_iothread(ctx_)) {                   \
 387         while ((cond) || busy_) {                          \
 388             busy_ = aio_poll(ctx_, (cond));                \
 389             waited_ |= !!(cond) | busy_;                   \
 390         }                                                  \
 391     } else {                                               \
 392         assert(qemu_get_current_aio_context() ==           \
 393                qemu_get_aio_context());                    \
 394         /* Ask bdrv_dec_in_flight to wake up the main      \
 395          * QEMU AioContext.  Extra I/O threads never take  \
 396          * other I/O threads' AioContexts (see for example \
 397          * block_job_defer_to_main_loop for how to do it). \
 398          */                                                \
 399         assert(!bs_->wakeup);                              \
 400         bs_->wakeup = true;                                \
 401         while (busy_) {                                    \
 402             if ((cond)) {                                  \
 403                 waited_ = busy_ = true;                    \
 404                 aio_context_release(ctx_);                 \
 405                 aio_poll(qemu_get_aio_context(), true);    \
 406                 aio_context_acquire(ctx_);                 \
 407             } else {                                       \
 408                 busy_ = aio_poll(ctx_, false);             \
 409                 waited_ |= busy_;                          \
 410             }                                              \
 411         }                                                  \
 412         bs_->wakeup = false;                               \
 413     }                                                      \
 414     waited_; })
 415
 416 int bdrv_pdiscard(BlockDriverState *bs, int64_t offset, int count);
 417 int bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, int count);
 418 int bdrv_has_zero_init_1(BlockDriverState *bs);
 419 int bdrv_has_zero_init(BlockDriverState *bs);
 420 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 421 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 422 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
 423                               int nb_sectors, int *pnum,
 424                               BlockDriverState **file);
 425 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
 426                                     BlockDriverState *base,
 427                                     int64_t sector_num,
 428                                     int nb_sectors, int *pnum,
 429                                     BlockDriverState **file);
 430 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 431                       int *pnum);
 432 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
 433                             int64_t sector_num, int nb_sectors, int *pnum);
 434
 435 bool bdrv_is_read_only(BlockDriverState *bs);
 436 bool bdrv_is_sg(BlockDriverState *bs);
 437 bool bdrv_is_inserted(BlockDriverState *bs);
 438 int bdrv_media_changed(BlockDriverState *bs);
 439 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
 440 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
 441 const char *bdrv_get_format_name(BlockDriverState *bs);
 442 BlockDriverState *bdrv_find_node(const char *node_name);
 443 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
 444 BlockDriverState *bdrv_lookup_bs(const char *device,
 445                                  const char *node_name,
 446                                  Error **errp);
 447 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 448 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 449
 450 typedef struct BdrvNextIterator {
 451     enum {
 452         BDRV_NEXT_BACKEND_ROOTS,
 453         BDRV_NEXT_MONITOR_OWNED,
 454     } phase;
 455     BlockBackend *blk;
 456     BlockDriverState *bs;
 457 } BdrvNextIterator;
 458
 459 BlockDriverState *bdrv_first(BdrvNextIterator *it);
 460 BlockDriverState *bdrv_next(BdrvNextIterator *it);
 461
 462 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 463 bool bdrv_is_encrypted(BlockDriverState *bs);
 464 bool bdrv_key_required(BlockDriverState *bs);
 465 int bdrv_set_key(BlockDriverState *bs, const char *key);
 466 void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
 467 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 468                          void *opaque);
 469 const char *bdrv_get_node_name(const BlockDriverState *bs);
 470 const char *bdrv_get_device_name(const BlockDriverState *bs);
 471 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
 472 int bdrv_get_flags(BlockDriverState *bs);
 473 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 474 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
 475 void bdrv_round_sectors_to_clusters(BlockDriverState *bs,
 476                                     int64_t sector_num, int nb_sectors,
 477                                     int64_t *cluster_sector_num,
 478                                     int *cluster_nb_sectors);
 479 void bdrv_round_to_clusters(BlockDriverState *bs,
 480                             int64_t offset, unsigned int bytes,
 481                             int64_t *cluster_offset,
 482                             unsigned int *cluster_bytes);
 483
 484 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
 485 void bdrv_get_backing_filename(BlockDriverState *bs,
 486                                char *filename, int filename_size);
 487 void bdrv_get_full_backing_filename(BlockDriverState *bs,
 488                                     char *dest, size_t sz, Error **errp);
 489 void bdrv_get_full_backing_filename_from_filename(const char *backed,
 490                                                   const char *backing,
 491                                                   char *dest, size_t sz,
 492                                                   Error **errp);
 493
 494 int path_has_protocol(const char *path);
 495 int path_is_absolute(const char *path);
 496 void path_combine(char *dest, int dest_size,
 497                   const char *base_path,
 498                   const char *filename);
 499
 500 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 501 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 502 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 503                       int64_t pos, int size);
 504
 505 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 506                       int64_t pos, int size);
 507
 508 void bdrv_img_create(const char *filename, const char *fmt,
 509                      const char *base_filename, const char *base_fmt,
 510                      char *options, uint64_t img_size, int flags,
 511                      Error **errp, bool quiet);
 512
 513 /* Returns the alignment in bytes that is required so that no bounce buffer
 514  * is required throughout the stack */
 515 size_t bdrv_min_mem_align(BlockDriverState *bs);
 516 /* Returns optimal alignment in bytes for bounce buffer */
 517 size_t bdrv_opt_mem_align(BlockDriverState *bs);
 518 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 519 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
 520 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
 521 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 522 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 523
 524 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 525 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 526
 527 void bdrv_ref(BlockDriverState *bs);
 528 void bdrv_unref(BlockDriverState *bs);
 529 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 530 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
 531                              BlockDriverState *child_bs,
 532                              const char *child_name,
 533                              const BdrvChildRole *child_role,
 534                              Error **errp);
 535
 536 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 537 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 538 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 539 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 540 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 541 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 542
 543 #define BLKDBG_EVENT(child, evt) \
 544     do { \
 545         if (child) { \
 546             bdrv_debug_event(child->bs, evt); \
 547         } \
 548     } while (0)
 549
 550 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
 551
 552 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 553                            const char *tag);
 554 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 555 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 556 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 557
 558 /**
 559  * bdrv_get_aio_context:
 560  *
 561  * Returns: the currently bound #AioContext
 562  */
 563 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 564
 565 /**
 566  * Transfer control to @co in the aio context of @bs
 567  */
 568 void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
 569
 570 /**
 571  * bdrv_set_aio_context:
 572  *
 573  * Changes the #AioContext used for fd handlers, timers, and BHs by this
 574  * BlockDriverState and all its children.
 575  *
 576  * This function must be called with iothread lock held.
 577  */
 578 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
 579 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 580 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 581
 582 void bdrv_io_plug(BlockDriverState *bs);
 583 void bdrv_io_unplug(BlockDriverState *bs);
 584
 585 /**
 586  * bdrv_parent_drained_begin:
 587  *
 588  * Begin a quiesced section of all users of @bs. This is part of
 589  * bdrv_drained_begin.
 590  */
 591 void bdrv_parent_drained_begin(BlockDriverState *bs);
 592
 593 /**
 594  * bdrv_parent_drained_end:
 595  *
 596  * End a quiesced section of all users of @bs. This is part of
 597  * bdrv_drained_end.
 598  */
 599 void bdrv_parent_drained_end(BlockDriverState *bs);
 600
 601 /**
 602  * bdrv_drained_begin:
 603  *
 604  * Begin a quiesced section for exclusive access to the BDS, by disabling
 605  * external request sources including NBD server and device model. Note that
 606  * this doesn't block timers or coroutines from submitting more requests, which
 607  * means block_job_pause is still necessary.
 608  *
 609  * This function can be recursive.
 610  */
 611 void bdrv_drained_begin(BlockDriverState *bs);
 612
 613 /**
 614  * bdrv_drained_end:
 615  *
 616  * End a quiescent section started by bdrv_drained_begin().
 617  */
 618 void bdrv_drained_end(BlockDriverState *bs);
 619
 620 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
 621                     Error **errp);
 622 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 623
 624 #endif