#ifndef BLOCK_H #define BLOCK_H #include "block/aio.h" #include "block/aio-wait.h" #include "qemu/iov.h" #include "qemu/coroutine.h" #include "block/accounting.h" #include "block/dirty-bitmap.h" #include "block/blockjob.h" #include "qemu/hbitmap.h" /* * generated_co_wrapper * * Function specifier, which does nothing but mark functions to be * generated by scripts/block-coroutine-wrapper.py * * Read more in docs/devel/block-coroutine-wrapper.rst */ #define generated_co_wrapper /* block.c */ typedef struct BlockDriver BlockDriver; typedef struct BdrvChild BdrvChild; typedef struct BdrvChildClass BdrvChildClass; typedef struct BlockDriverInfo { /* in bytes, 0 if irrelevant */ int cluster_size; /* offset at which the VM state can be saved (0 if not possible) */ int64_t vm_state_offset; bool is_dirty; /* * True if this block driver only supports compressed writes */ bool needs_compressed_writes; } BlockDriverInfo; typedef struct BlockFragInfo { uint64_t allocated_clusters; uint64_t total_clusters; uint64_t fragmented_clusters; uint64_t compressed_clusters; } BlockFragInfo; typedef enum { BDRV_REQ_COPY_ON_READ = 0x1, BDRV_REQ_ZERO_WRITE = 0x2, /* * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate * that the block driver should unmap (discard) blocks if it is guaranteed * that the result will read back as zeroes. The flag is only passed to the * driver if the block device is opened with BDRV_O_UNMAP. */ BDRV_REQ_MAY_UNMAP = 0x4, BDRV_REQ_FUA = 0x10, BDRV_REQ_WRITE_COMPRESSED = 0x20, /* Signifies that this write request will not change the visible disk * content. */ BDRV_REQ_WRITE_UNCHANGED = 0x40, /* * BDRV_REQ_SERIALISING forces request serialisation for writes. * It is used to ensure that writes to the backing file of a backup process * target cannot race with a read of the backup target that defers to the * backing file. * * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long. */ BDRV_REQ_SERIALISING = 0x80, /* Execute the request only if the operation can be offloaded or otherwise * be executed efficiently, but return an error instead of using a slow * fallback. */ BDRV_REQ_NO_FALLBACK = 0x100, /* * BDRV_REQ_PREFETCH may be used only together with BDRV_REQ_COPY_ON_READ * on read request and means that caller doesn't really need data to be * written to qiov parameter which may be NULL. */ BDRV_REQ_PREFETCH = 0x200, /* Mask of valid flags */ BDRV_REQ_MASK = 0x3ff, } BdrvRequestFlags; typedef struct BlockSizes { uint32_t phys; uint32_t log; } BlockSizes; typedef struct HDGeometry { uint32_t heads; uint32_t sectors; uint32_t cylinders; } HDGeometry; #define BDRV_O_RDWR 0x0002 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */ #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */ #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */ #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */ #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */ #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */ #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */ #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */ #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */ #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */ #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */ #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */ #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given: select an appropriate protocol driver, ignoring the format layer */ #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */ #define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */ #define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */ #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH) /* Option names of options parsed by the block layer */ #define BDRV_OPT_CACHE_WB "cache.writeback" #define BDRV_OPT_CACHE_DIRECT "cache.direct" #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush" #define BDRV_OPT_READ_ONLY "read-only" #define BDRV_OPT_AUTO_READ_ONLY "auto-read-only" #define BDRV_OPT_DISCARD "discard" #define BDRV_OPT_FORCE_SHARE "force-share" #define BDRV_SECTOR_BITS 9 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS) #define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \ INT_MAX >> BDRV_SECTOR_BITS) #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) /* * Allocation status flags for bdrv_block_status() and friends. * * Public flags: * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer * BDRV_BLOCK_ZERO: offset reads as zero * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this * layer rather than any backing, set by block layer * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this * layer, set by block layer * * Internal flags: * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request * that the block layer recompute the answer from the returned * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID. * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for * zeroes in file child of current block node inside * returned region. Only valid together with both * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not * appear with BDRV_BLOCK_ZERO. * * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the * host offset within the returned BDS that is allocated for the * corresponding raw guest data. However, whether that offset * actually contains data also depends on BDRV_BLOCK_DATA, as follows: * * DATA ZERO OFFSET_VALID * t t t sectors read as zero, returned file is zero at offset * t f t sectors read as valid from file at offset * f t t sectors preallocated, read as zero, returned file not * necessarily zero at offset * f f t sectors preallocated but read from backing_hd, * returned file contains garbage at offset * t t f sectors preallocated, read as zero, unknown offset * t f f sectors read from unknown file or offset * f t f not allocated or unknown offset, read as zero * f f f not allocated or unknown offset, read from backing_hd */ #define BDRV_BLOCK_DATA 0x01 #define BDRV_BLOCK_ZERO 0x02 #define BDRV_BLOCK_OFFSET_VALID 0x04 #define BDRV_BLOCK_RAW 0x08 #define BDRV_BLOCK_ALLOCATED 0x10 #define BDRV_BLOCK_EOF 0x20 #define BDRV_BLOCK_RECURSE 0x40 typedef QTAILQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue; typedef struct BDRVReopenState { BlockDriverState *bs; int flags; BlockdevDetectZeroesOptions detect_zeroes; bool backing_missing; bool replace_backing_bs; /* new_backing_bs is ignored if this is false */ BlockDriverState *new_backing_bs; /* If NULL then detach the current bs */ uint64_t perm, shared_perm; QDict *options; QDict *explicit_options; void *opaque; } BDRVReopenState; /* * Block operation types */ typedef enum BlockOpType { BLOCK_OP_TYPE_BACKUP_SOURCE, BLOCK_OP_TYPE_BACKUP_TARGET, BLOCK_OP_TYPE_CHANGE, BLOCK_OP_TYPE_COMMIT_SOURCE, BLOCK_OP_TYPE_COMMIT_TARGET, BLOCK_OP_TYPE_DATAPLANE, BLOCK_OP_TYPE_DRIVE_DEL, BLOCK_OP_TYPE_EJECT, BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, BLOCK_OP_TYPE_MIRROR_SOURCE, BLOCK_OP_TYPE_MIRROR_TARGET, BLOCK_OP_TYPE_RESIZE, BLOCK_OP_TYPE_STREAM, BLOCK_OP_TYPE_REPLACE, BLOCK_OP_TYPE_MAX, } BlockOpType; /* Block node permission constants */ enum { /** * A user that has the "permission" of consistent reads is guaranteed that * their view of the contents of the block device is complete and * self-consistent, representing the contents of a disk at a specific * point. * * For most block devices (including their backing files) this is true, but * the property cannot be maintained in a few situations like for * intermediate nodes of a commit block job. */ BLK_PERM_CONSISTENT_READ = 0x01, /** This permission is required to change the visible disk contents. */ BLK_PERM_WRITE = 0x02, /** * This permission (which is weaker than BLK_PERM_WRITE) is both enough and * required for writes to the block node when the caller promises that * the visible disk content doesn't change. * * As the BLK_PERM_WRITE permission is strictly stronger, either is * sufficient to perform an unchanging write. */ BLK_PERM_WRITE_UNCHANGED = 0x04, /** This permission is required to change the size of a block node. */ BLK_PERM_RESIZE = 0x08, /** * This permission is required to change the node that this BdrvChild * points to. */ BLK_PERM_GRAPH_MOD = 0x10, BLK_PERM_ALL = 0x1f, DEFAULT_PERM_PASSTHROUGH = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED | BLK_PERM_RESIZE, DEFAULT_PERM_UNCHANGED = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH, }; /* * Flags that parent nodes assign to child nodes to specify what kind of * role(s) they take. * * At least one of DATA, METADATA, FILTERED, or COW must be set for * every child. */ enum BdrvChildRoleBits { /* * This child stores data. * Any node may have an arbitrary number of such children. */ BDRV_CHILD_DATA = (1 << 0), /* * This child stores metadata. * Any node may have an arbitrary number of metadata-storing * children. */ BDRV_CHILD_METADATA = (1 << 1), /* * A child that always presents exactly the same visible data as * the parent, e.g. by virtue of the parent forwarding all reads * and writes. * This flag is mutually exclusive with DATA, METADATA, and COW. * Any node may have at most one filtered child at a time. */ BDRV_CHILD_FILTERED = (1 << 2), /* * Child from which to read all data that isn't allocated in the * parent (i.e., the backing child); such data is copied to the * parent through COW (and optionally COR). * This field is mutually exclusive with DATA, METADATA, and * FILTERED. * Any node may have at most one such backing child at a time. */ BDRV_CHILD_COW = (1 << 3), /* * The primary child. For most drivers, this is the child whose * filename applies best to the parent node. * Any node may have at most one primary child at a time. */ BDRV_CHILD_PRIMARY = (1 << 4), /* Useful combination of flags */ BDRV_CHILD_IMAGE = BDRV_CHILD_DATA | BDRV_CHILD_METADATA | BDRV_CHILD_PRIMARY, }; /* Mask of BdrvChildRoleBits values */ typedef unsigned int BdrvChildRole; char *bdrv_perm_names(uint64_t perm); uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm); /* disk I/O throttling */ void bdrv_init(void); void bdrv_init_with_whitelist(void); bool bdrv_uses_whitelist(void); int bdrv_is_whitelisted(BlockDriver *drv, bool read_only); BlockDriver *bdrv_find_protocol(const char *filename, bool allow_protocol_prefix, Error **errp); BlockDriver *bdrv_find_format(const char *format_name); int bdrv_create(BlockDriver *drv, const char* filename, QemuOpts *opts, Error **errp); int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp); BlockDriverState *bdrv_new(void); void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, Error **errp); void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, Error **errp); int bdrv_parse_aio(const char *mode, int *flags); int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough); int bdrv_parse_discard_flags(const char *mode, int *flags); BdrvChild *bdrv_open_child(const char *filename, QDict *options, const char *bdref_key, BlockDriverState* parent, const BdrvChildClass *child_class, BdrvChildRole child_role, bool allow_none, Error **errp); BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp); void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, Error **errp); int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, const char *bdref_key, Error **errp); BlockDriverState *bdrv_open(const char *filename, const char *reference, QDict *options, int flags, Error **errp); BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, int flags, Error **errp); BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, BlockDriverState *bs, QDict *options, bool keep_old_opts); int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp); int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, Error **errp); int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, Error **errp); void bdrv_reopen_commit(BDRVReopenState *reopen_state); void bdrv_reopen_abort(BDRVReopenState *reopen_state); int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, int bytes, BdrvRequestFlags flags); int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags); int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes); int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes); int bdrv_pwrite_sync(BdrvChild *child, int64_t offset, const void *buf, int count); /* * Efficiently zero a region of the disk image. Note that this is a regular * I/O request like read or write and should have a reasonable size. This * function is not suitable for zeroing the entire image in a single request * because it may allocate memory for the entire region. */ int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, int bytes, BdrvRequestFlags flags); BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, const char *backing_file); void bdrv_refresh_filename(BlockDriverState *bs); int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact, PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); int generated_co_wrapper bdrv_truncate(BdrvChild *child, int64_t offset, bool exact, PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); int64_t bdrv_nb_sectors(BlockDriverState *bs); int64_t bdrv_getlength(BlockDriverState *bs); int64_t bdrv_get_allocated_file_size(BlockDriverState *bs); BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, BlockDriverState *in_bs, Error **errp); void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr); void bdrv_refresh_limits(BlockDriverState *bs, Error **errp); int bdrv_commit(BlockDriverState *bs); int bdrv_make_empty(BdrvChild *c, Error **errp); int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file, const char *backing_fmt, bool warn); void bdrv_register(BlockDriver *bdrv); int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, const char *backing_file_str); BlockDriverState *bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs); BlockDriverState *bdrv_find_base(BlockDriverState *bs); bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base, Error **errp); int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, Error **errp); void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base); int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp); typedef struct BdrvCheckResult { int corruptions; int leaks; int check_errors; int corruptions_fixed; int leaks_fixed; int64_t image_end_offset; BlockFragInfo bfi; } BdrvCheckResult; typedef enum { BDRV_FIX_LEAKS = 1, BDRV_FIX_ERRORS = 2, } BdrvCheckMode; int generated_co_wrapper bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix); /* The units of offset and total_work_size may be chosen arbitrarily by the * block driver; total_work_size may change during the course of the amendment * operation */ typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset, int64_t total_work_size, void *opaque); int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts, BlockDriverAmendStatusCB *status_cb, void *cb_opaque, bool force, Error **errp); /* check if a named node can be replaced when doing drive-mirror */ BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, const char *node_name, Error **errp); /* async block I/O */ void bdrv_aio_cancel(BlockAIOCB *acb); void bdrv_aio_cancel_async(BlockAIOCB *acb); /* sg packet commands */ int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf); /* Invalidate any cached metadata used by image formats */ int generated_co_wrapper bdrv_invalidate_cache(BlockDriverState *bs, Error **errp); void bdrv_invalidate_cache_all(Error **errp); int bdrv_inactivate_all(void); /* Ensure contents are flushed to disk. */ int generated_co_wrapper bdrv_flush(BlockDriverState *bs); int coroutine_fn bdrv_co_flush(BlockDriverState *bs); int bdrv_flush_all(void); void bdrv_close_all(void); void bdrv_drain(BlockDriverState *bs); void coroutine_fn bdrv_co_drain(BlockDriverState *bs); void bdrv_drain_all_begin(void); void bdrv_drain_all_end(void); void bdrv_drain_all(void); #define BDRV_POLL_WHILE(bs, cond) ({ \ BlockDriverState *bs_ = (bs); \ AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \ cond); }) int generated_co_wrapper bdrv_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes); int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes); int bdrv_has_zero_init_1(BlockDriverState *bs); int bdrv_has_zero_init(BlockDriverState *bs); bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs); int bdrv_block_status(BlockDriverState *bs, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file); int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file); int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes, int64_t *pnum); int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, bool include_base, int64_t offset, int64_t bytes, int64_t *pnum); int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset, int64_t bytes); bool bdrv_is_read_only(BlockDriverState *bs); int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, bool ignore_allow_rdw, Error **errp); int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg, Error **errp); bool bdrv_is_writable(BlockDriverState *bs); bool bdrv_is_sg(BlockDriverState *bs); bool bdrv_is_inserted(BlockDriverState *bs); void bdrv_lock_medium(BlockDriverState *bs, bool locked); void bdrv_eject(BlockDriverState *bs, bool eject_flag); const char *bdrv_get_format_name(BlockDriverState *bs); BlockDriverState *bdrv_find_node(const char *node_name); BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp); XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp); BlockDriverState *bdrv_lookup_bs(const char *device, const char *node_name, Error **errp); bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base); BlockDriverState *bdrv_next_node(BlockDriverState *bs); BlockDriverState *bdrv_next_all_states(BlockDriverState *bs); typedef struct BdrvNextIterator { enum { BDRV_NEXT_BACKEND_ROOTS, BDRV_NEXT_MONITOR_OWNED, } phase; BlockBackend *blk; BlockDriverState *bs; } BdrvNextIterator; BlockDriverState *bdrv_first(BdrvNextIterator *it); BlockDriverState *bdrv_next(BdrvNextIterator *it); void bdrv_next_cleanup(BdrvNextIterator *it); BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs); bool bdrv_supports_compressed_writes(BlockDriverState *bs); void bdrv_iterate_format(void (*it)(void *opaque, const char *name), void *opaque, bool read_only); const char *bdrv_get_node_name(const BlockDriverState *bs); const char *bdrv_get_device_name(const BlockDriverState *bs); const char *bdrv_get_device_or_node_name(const BlockDriverState *bs); int bdrv_get_flags(BlockDriverState *bs); int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi); ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs, Error **errp); BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs); void bdrv_round_to_clusters(BlockDriverState *bs, int64_t offset, int64_t bytes, int64_t *cluster_offset, int64_t *cluster_bytes); void bdrv_get_backing_filename(BlockDriverState *bs, char *filename, int filename_size); char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp); char *bdrv_get_full_backing_filename_from_filename(const char *backed, const char *backing, Error **errp); char *bdrv_dirname(BlockDriverState *bs, Error **errp); int path_has_protocol(const char *path); int path_is_absolute(const char *path); char *path_combine(const char *base_path, const char *filename); int generated_co_wrapper bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); int generated_co_wrapper bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, int64_t pos, int size); int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size); void bdrv_img_create(const char *filename, const char *fmt, const char *base_filename, const char *base_fmt, char *options, uint64_t img_size, int flags, bool quiet, Error **errp); /* Returns the alignment in bytes that is required so that no bounce buffer * is required throughout the stack */ size_t bdrv_min_mem_align(BlockDriverState *bs); /* Returns optimal alignment in bytes for bounce buffer */ size_t bdrv_opt_mem_align(BlockDriverState *bs); void *qemu_blockalign(BlockDriverState *bs, size_t size); void *qemu_blockalign0(BlockDriverState *bs, size_t size); void *qemu_try_blockalign(BlockDriverState *bs, size_t size); void *qemu_try_blockalign0(BlockDriverState *bs, size_t size); bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov); void bdrv_enable_copy_on_read(BlockDriverState *bs); void bdrv_disable_copy_on_read(BlockDriverState *bs); void bdrv_ref(BlockDriverState *bs); void bdrv_unref(BlockDriverState *bs); void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, const char *child_name, const BdrvChildClass *child_class, BdrvChildRole child_role, Error **errp); bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason); void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason); void bdrv_op_block_all(BlockDriverState *bs, Error *reason); void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason); bool bdrv_op_blocker_is_empty(BlockDriverState *bs); #define BLKDBG_EVENT(child, evt) \ do { \ if (child) { \ bdrv_debug_event(child->bs, evt); \ } \ } while (0) void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event); int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, const char *tag); int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag); int bdrv_debug_resume(BlockDriverState *bs, const char *tag); bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); /** * bdrv_get_aio_context: * * Returns: the currently bound #AioContext */ AioContext *bdrv_get_aio_context(BlockDriverState *bs); /** * Move the current coroutine to the AioContext of @bs and return the old * AioContext of the coroutine. Increase bs->in_flight so that draining @bs * will wait for the operation to proceed until the corresponding * bdrv_co_leave(). * * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as * this will deadlock. */ AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs); /** * Ends a section started by bdrv_co_enter(). Move the current coroutine back * to old_ctx and decrease bs->in_flight again. */ void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx); /** * Locks the AioContext of @bs if it's not the current AioContext. This avoids * double locking which could lead to deadlocks: This is a coroutine_fn, so we * know we already own the lock of the current AioContext. * * May only be called in the main thread. */ void coroutine_fn bdrv_co_lock(BlockDriverState *bs); /** * Unlocks the AioContext of @bs if it's not the current AioContext. */ void coroutine_fn bdrv_co_unlock(BlockDriverState *bs); /** * Transfer control to @co in the aio context of @bs */ void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co); void bdrv_set_aio_context_ignore(BlockDriverState *bs, AioContext *new_context, GSList **ignore); int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx, Error **errp); int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx, BdrvChild *ignore_child, Error **errp); bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx, GSList **ignore, Error **errp); bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx, GSList **ignore, Error **errp); int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz); int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo); void bdrv_io_plug(BlockDriverState *bs); void bdrv_io_unplug(BlockDriverState *bs); /** * bdrv_parent_drained_begin_single: * * Begin a quiesced section for the parent of @c. If @poll is true, wait for * any pending activity to cease. */ void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll); /** * bdrv_parent_drained_end_single: * * End a quiesced section for the parent of @c. * * This polls @bs's AioContext until all scheduled sub-drained_ends * have settled, which may result in graph changes. */ void bdrv_parent_drained_end_single(BdrvChild *c); /** * bdrv_drain_poll: * * Poll for pending requests in @bs, its parents (except for @ignore_parent), * and if @recursive is true its children as well (used for subtree drain). * * If @ignore_bds_parents is true, parents that are BlockDriverStates must * ignore the drain request because they will be drained separately (used for * drain_all). * * This is part of bdrv_drained_begin. */ bool bdrv_drain_poll(BlockDriverState *bs, bool recursive, BdrvChild *ignore_parent, bool ignore_bds_parents); /** * bdrv_drained_begin: * * Begin a quiesced section for exclusive access to the BDS, by disabling * external request sources including NBD server and device model. Note that * this doesn't block timers or coroutines from submitting more requests, which * means block_job_pause is still necessary. * * This function can be recursive. */ void bdrv_drained_begin(BlockDriverState *bs); /** * bdrv_do_drained_begin_quiesce: * * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already * running requests to complete. */ void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, BdrvChild *parent, bool ignore_bds_parents); /** * Like bdrv_drained_begin, but recursively begins a quiesced section for * exclusive access to all child nodes as well. */ void bdrv_subtree_drained_begin(BlockDriverState *bs); /** * bdrv_drained_end: * * End a quiescent section started by bdrv_drained_begin(). * * This polls @bs's AioContext until all scheduled sub-drained_ends * have settled. On one hand, that may result in graph changes. On * the other, this requires that the caller either runs in the main * loop; or that all involved nodes (@bs and all of its parents) are * in the caller's AioContext. */ void bdrv_drained_end(BlockDriverState *bs); /** * bdrv_drained_end_no_poll: * * Same as bdrv_drained_end(), but do not poll for the subgraph to * actually become unquiesced. Therefore, no graph changes will occur * with this function. * * *drained_end_counter is incremented for every background operation * that is scheduled, and will be decremented for every operation once * it settles. The caller must poll until it reaches 0. The counter * should be accessed using atomic operations only. */ void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter); /** * End all quiescent sections started by bdrv_drain_all_begin(). This is * only needed when deleting a BDS before bdrv_drain_all_end() is called. */ void bdrv_drain_all_end_quiesce(BlockDriverState *bs); /** * End a quiescent section started by bdrv_subtree_drained_begin(). */ void bdrv_subtree_drained_end(BlockDriverState *bs); void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, Error **errp); void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, uint32_t granularity, Error **errp); /** * * bdrv_register_buf/bdrv_unregister_buf: * * Register/unregister a buffer for I/O. For example, VFIO drivers are * interested to know the memory areas that would later be used for I/O, so * that they can prepare IOMMU mapping etc., to get better performance. */ void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size); void bdrv_unregister_buf(BlockDriverState *bs, void *host); /** * * bdrv_co_copy_range: * * Do offloaded copy between two children. If the operation is not implemented * by the driver, or if the backend storage doesn't support it, a negative * error code will be returned. * * Note: block layer doesn't emulate or fallback to a bounce buffer approach * because usually the caller shouldn't attempt offloaded copy any more (e.g. * calling copy_file_range(2)) after the first error, thus it should fall back * to a read+write path in the caller level. * * @src: Source child to copy data from * @src_offset: offset in @src image to read data * @dst: Destination child to copy data to * @dst_offset: offset in @dst image to write data * @bytes: number of bytes to copy * @flags: request flags. Supported flags: * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero * write on @dst as if bdrv_co_pwrite_zeroes is * called. Used to simplify caller code, or * during BlockDriver.bdrv_co_copy_range_from() * recursion. * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping * requests currently in flight. * * Returns: 0 if succeeded; negative error code if failed. **/ int coroutine_fn bdrv_co_copy_range(BdrvChild *src, uint64_t src_offset, BdrvChild *dst, uint64_t dst_offset, uint64_t bytes, BdrvRequestFlags read_flags, BdrvRequestFlags write_flags); #endif