qemu-e2k/include/block/block_int-io.h
Vladimir Sementsov-Ogievskiy ce14f3b407 block/io: introduce block driver snapshot-access API
Add new block driver handlers and corresponding generic wrappers.
It will be used to allow copy-before-write filter to provide
reach fleecing interface in further commit.

In future this approach may be used to allow reading qcow2 internal
snapshots, for example to export them through NBD.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220303194349.2304213-11-vsementsov@virtuozzo.com>
[hreitz: Rebased on block GS/IO split]
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-07 09:33:31 +01:00

195 lines
7.1 KiB
C

/*
* QEMU System Emulator block driver
*
* Copyright (c) 2003 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef BLOCK_INT_IO_H
#define BLOCK_INT_IO_H
#include "block_int-common.h"
/*
* I/O API functions. These functions are thread-safe.
*
* See include/block/block-io.h for more information about
* the I/O API.
*/
int coroutine_fn bdrv_co_preadv_snapshot(BdrvChild *child,
int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset);
int coroutine_fn bdrv_co_snapshot_block_status(BlockDriverState *bs,
bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
int64_t *map, BlockDriverState **file);
int coroutine_fn bdrv_co_pdiscard_snapshot(BlockDriverState *bs,
int64_t offset, int64_t bytes);
int coroutine_fn bdrv_co_preadv(BdrvChild *child,
int64_t offset, int64_t bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
int64_t offset, int64_t bytes,
QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
int64_t offset, int64_t bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
int64_t offset, int64_t bytes,
QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,
int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
{
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
IO_CODE();
return bdrv_co_preadv(child, offset, bytes, &qiov, flags);
}
static inline int coroutine_fn bdrv_co_pwrite(BdrvChild *child,
int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
{
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
IO_CODE();
return bdrv_co_pwritev(child, offset, bytes, &qiov, flags);
}
bool coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req,
uint64_t align);
BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
const char *filename);
/**
* bdrv_wakeup:
* @bs: The BlockDriverState for which an I/O operation has been completed.
*
* Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During
* synchronous I/O on a BlockDriverState that is attached to another
* I/O thread, the main thread lets the I/O thread's event loop run,
* waiting for the I/O operation to complete. A bdrv_wakeup will wake
* up the main thread if necessary.
*
* Manual calls to bdrv_wakeup are rarely necessary, because
* bdrv_dec_in_flight already calls it.
*/
void bdrv_wakeup(BlockDriverState *bs);
const char *bdrv_get_parent_name(const BlockDriverState *bs);
bool blk_dev_has_tray(BlockBackend *blk);
bool blk_dev_is_tray_open(BlockBackend *blk);
void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
const BdrvDirtyBitmap *src,
HBitmap **backup, bool lock);
void bdrv_inc_in_flight(BlockDriverState *bs);
void bdrv_dec_in_flight(BlockDriverState *bs);
int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, int64_t src_offset,
BdrvChild *dst, int64_t dst_offset,
int64_t bytes,
BdrvRequestFlags read_flags,
BdrvRequestFlags write_flags);
int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, int64_t src_offset,
BdrvChild *dst, int64_t dst_offset,
int64_t bytes,
BdrvRequestFlags read_flags,
BdrvRequestFlags write_flags);
int refresh_total_sectors(BlockDriverState *bs, int64_t hint);
BdrvChild *bdrv_cow_child(BlockDriverState *bs);
BdrvChild *bdrv_filter_child(BlockDriverState *bs);
BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs);
BdrvChild *bdrv_primary_child(BlockDriverState *bs);
BlockDriverState *bdrv_skip_filters(BlockDriverState *bs);
BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs);
static inline BlockDriverState *bdrv_cow_bs(BlockDriverState *bs)
{
IO_CODE();
return child_bs(bdrv_cow_child(bs));
}
static inline BlockDriverState *bdrv_filter_bs(BlockDriverState *bs)
{
IO_CODE();
return child_bs(bdrv_filter_child(bs));
}
static inline BlockDriverState *bdrv_filter_or_cow_bs(BlockDriverState *bs)
{
IO_CODE();
return child_bs(bdrv_filter_or_cow_child(bs));
}
static inline BlockDriverState *bdrv_primary_bs(BlockDriverState *bs)
{
IO_CODE();
return child_bs(bdrv_primary_child(bs));
}
/**
* Check whether the given offset is in the cached block-status data
* region.
*
* If it is, and @pnum is not NULL, *pnum is set to
* `bsc.data_end - offset`, i.e. how many bytes, starting from
* @offset, are data (according to the cache).
* Otherwise, *pnum is not touched.
*/
bool bdrv_bsc_is_data(BlockDriverState *bs, int64_t offset, int64_t *pnum);
/**
* If [offset, offset + bytes) overlaps with the currently cached
* block-status region, invalidate the cache.
*
* (To be used by I/O paths that cause data regions to be zero or
* holes.)
*/
void bdrv_bsc_invalidate_range(BlockDriverState *bs,
int64_t offset, int64_t bytes);
/**
* Mark the range [offset, offset + bytes) as a data region.
*/
void bdrv_bsc_fill(BlockDriverState *bs, int64_t offset, int64_t bytes);
/*
* "I/O or GS" API functions. These functions can run without
* the BQL, but only in one specific iothread/main loop.
*
* See include/block/block-io.h for more information about
* the "I/O or GS" API.
*/
void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
#endif /* BLOCK_INT_IO_H */