diff options
Diffstat (limited to 'include/block/block.h')
| -rw-r--r-- | include/block/block.h | 864 |
1 files changed, 864 insertions, 0 deletions
diff --git a/include/block/block.h b/include/block/block.h new file mode 100644 index 000000000..e5dd22b03 --- /dev/null +++ b/include/block/block.h @@ -0,0 +1,864 @@ +#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" +#include "qemu/transactions.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, + + /* Forces request serialisation. Use only with write requests. */ + 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 makes sense only in the context of copy-on-read + * (i.e., together with the BDRV_REQ_COPY_ON_READ flag or when a COR + * filter is involved), in which case it signals that the COR operation + * need not read the data into memory (qiov) but only ensure they are + * copied to the top layer (i.e., that COR operation is done). + */ + BDRV_REQ_PREFETCH = 0x200, + + /* + * If we need to wait for other requests, just fail immediately. Used + * only together with BDRV_REQ_SERIALISING. + */ + BDRV_REQ_NO_WAIT = 0x400, + + /* Mask of valid flags */ + BDRV_REQ_MASK = 0x7ff, +} 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_NO_SHARE 0x0001 /* don't share permissions */ +#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) + +/* + * We want allow aligning requests and disk length up to any 32bit alignment + * and don't afraid of overflow. + * To achieve it, and in the same time use some pretty number as maximum disk + * size, let's define maximum "length" (a limit for any offset/bytes request and + * for disk size) to be the greatest power of 2 less than INT64_MAX. + */ +#define BDRV_MAX_ALIGNMENT (1L << 30) +#define BDRV_MAX_LENGTH (QEMU_ALIGN_DOWN(INT64_MAX, BDRV_MAX_ALIGNMENT)) + +/* + * 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; + BlockDriverState *old_backing_bs; /* keep pointer for permissions update */ + BlockDriverState *old_file_bs; /* keep pointer for permissions update */ + 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); +int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, + Error **errp); +int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, + Error **errp); +int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs, + Error **errp); +BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options, + int flags, Error **errp); +int bdrv_drop_filter(BlockDriverState *bs, 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); +int 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_opts(BlockDriver *drv, + const char *node_name, + 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); +void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue); +int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp); +int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts, + Error **errp); +int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, + Error **errp); +int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, + int64_t bytes, BdrvRequestFlags flags); +int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags); +int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes); +int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, + int64_t bytes); +int bdrv_pwrite_sync(BdrvChild *child, int64_t offset, + const void *buf, int64_t bytes); +/* + * 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, + int64_t 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, Transaction *tran, 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); +void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs); + + +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); +AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c); +AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c); + +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, block jobs, and device model. + * + * 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 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, int64_t src_offset, + BdrvChild *dst, int64_t dst_offset, + int64_t bytes, BdrvRequestFlags read_flags, + BdrvRequestFlags write_flags); + +void bdrv_cancel_in_flight(BlockDriverState *bs); + +#endif |