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qemu/include/block/block.h
Andrey Shinkevich e275458b29 copy-on-read: skip non-guest reads if no copy needed 
If the flag BDRV_REQ_PREFETCH was set, skip idling read/write
operations in COR-driver. It can be taken into account for the
COR-algorithms optimization. That check is being made during the
block stream job by the moment.

Add the BDRV_REQ_PREFETCH flag to the supported_read_flags of the
COR-filter.

block: Modify the comment for the flag BDRV_REQ_PREFETCH as we are
going to use it alone and pass it to the COR-filter driver for further
processing.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201216061703.70908-9-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2021-01-26 14:36:37 +01:00

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#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,
/* 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_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;
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);
BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
int flags, 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 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
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