qemu-e2k/include/sysemu/block-backend-io.h
Stefan Hajnoczi 41abca8c39 block: add blk_io_plug_call() API
Introduce a new API for thread-local blk_io_plug() that does not
traverse the block graph. The goal is to make blk_io_plug() multi-queue
friendly.

Instead of having block drivers track whether or not we're in a plugged
section, provide an API that allows them to defer a function call until
we're unplugged: blk_io_plug_call(fn, opaque). If blk_io_plug_call() is
called multiple times with the same fn/opaque pair, then fn() is only
called once at the end of the function - resulting in batching.

This patch introduces the API and changes blk_io_plug()/blk_io_unplug().
blk_io_plug()/blk_io_unplug() no longer require a BlockBackend argument
because the plug state is now thread-local.

Later patches convert block drivers to blk_io_plug_call() and then we
can finally remove .bdrv_co_io_plug() once all block drivers have been
converted.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20230530180959.1108766-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-06-01 07:34:03 -04:00

235 lines
11 KiB
C

/*
* QEMU Block backends
*
* Copyright (C) 2014-2016 Red Hat, Inc.
*
* Authors:
* Markus Armbruster <armbru@redhat.com>,
*
* This work is licensed under the terms of the GNU LGPL, version 2.1
* or later. See the COPYING.LIB file in the top-level directory.
*/
#ifndef BLOCK_BACKEND_IO_H
#define BLOCK_BACKEND_IO_H
#include "block-backend-common.h"
#include "block/accounting.h"
/*
* I/O API functions. These functions are thread-safe.
*
* See include/block/block-io.h for more information about
* the I/O API.
*/
const char *blk_name(const BlockBackend *blk);
BlockDriverState *blk_bs(BlockBackend *blk);
void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
bool blk_iostatus_is_enabled(const BlockBackend *blk);
char *blk_get_attached_dev_id(BlockBackend *blk);
BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
int64_t bytes, BdrvRequestFlags flags,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
QEMUIOVector *qiov, BdrvRequestFlags flags,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
QEMUIOVector *qiov, BdrvRequestFlags flags,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_flush(BlockBackend *blk,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_zone_report(BlockBackend *blk, int64_t offset,
unsigned int *nr_zones,
BlockZoneDescriptor *zones,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_zone_mgmt(BlockBackend *blk, BlockZoneOp op,
int64_t offset, int64_t len,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_zone_append(BlockBackend *blk, int64_t *offset,
QEMUIOVector *qiov, BdrvRequestFlags flags,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes,
BlockCompletionFunc *cb, void *opaque);
void blk_aio_cancel_async(BlockAIOCB *acb);
BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
BlockCompletionFunc *cb, void *opaque);
void blk_inc_in_flight(BlockBackend *blk);
void blk_dec_in_flight(BlockBackend *blk);
bool coroutine_fn GRAPH_RDLOCK blk_co_is_inserted(BlockBackend *blk);
bool co_wrapper_mixed_bdrv_rdlock blk_is_inserted(BlockBackend *blk);
bool coroutine_fn GRAPH_RDLOCK blk_co_is_available(BlockBackend *blk);
bool co_wrapper_mixed_bdrv_rdlock blk_is_available(BlockBackend *blk);
void coroutine_fn blk_co_lock_medium(BlockBackend *blk, bool locked);
void co_wrapper blk_lock_medium(BlockBackend *blk, bool locked);
void coroutine_fn blk_co_eject(BlockBackend *blk, bool eject_flag);
void co_wrapper blk_eject(BlockBackend *blk, bool eject_flag);
int64_t coroutine_fn blk_co_getlength(BlockBackend *blk);
int64_t co_wrapper_mixed blk_getlength(BlockBackend *blk);
void coroutine_fn blk_co_get_geometry(BlockBackend *blk,
uint64_t *nb_sectors_ptr);
void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
int64_t coroutine_fn blk_co_nb_sectors(BlockBackend *blk);
int64_t blk_nb_sectors(BlockBackend *blk);
void *blk_try_blockalign(BlockBackend *blk, size_t size);
void *blk_blockalign(BlockBackend *blk, size_t size);
bool blk_is_writable(BlockBackend *blk);
bool blk_enable_write_cache(BlockBackend *blk);
BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
int error);
void blk_error_action(BlockBackend *blk, BlockErrorAction action,
bool is_read, int error);
void blk_iostatus_set_err(BlockBackend *blk, int error);
int blk_get_max_iov(BlockBackend *blk);
int blk_get_max_hw_iov(BlockBackend *blk);
void blk_io_plug(void);
void blk_io_unplug(void);
void blk_io_plug_call(void (*fn)(void *), void *opaque);
AioContext *blk_get_aio_context(BlockBackend *blk);
BlockAcctStats *blk_get_stats(BlockBackend *blk);
void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
BlockCompletionFunc *cb,
void *opaque, int ret);
uint32_t blk_get_request_alignment(BlockBackend *blk);
uint32_t blk_get_max_transfer(BlockBackend *blk);
uint64_t blk_get_max_hw_transfer(BlockBackend *blk);
int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
BlockBackend *blk_out, int64_t off_out,
int64_t bytes, BdrvRequestFlags read_flags,
BdrvRequestFlags write_flags);
int coroutine_fn blk_co_block_status_above(BlockBackend *blk,
BlockDriverState *base,
int64_t offset, int64_t bytes,
int64_t *pnum, int64_t *map,
BlockDriverState **file);
int coroutine_fn blk_co_is_allocated_above(BlockBackend *blk,
BlockDriverState *base,
bool include_base, int64_t offset,
int64_t bytes, int64_t *pnum);
/*
* "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.
*/
int co_wrapper_mixed blk_pread(BlockBackend *blk, int64_t offset,
int64_t bytes, void *buf,
BdrvRequestFlags flags);
int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset, int64_t bytes,
void *buf, BdrvRequestFlags flags);
int co_wrapper_mixed blk_preadv(BlockBackend *blk, int64_t offset,
int64_t bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
int64_t bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
int co_wrapper_mixed blk_preadv_part(BlockBackend *blk, int64_t offset,
int64_t bytes, QEMUIOVector *qiov,
size_t qiov_offset,
BdrvRequestFlags flags);
int coroutine_fn blk_co_preadv_part(BlockBackend *blk, int64_t offset,
int64_t bytes, QEMUIOVector *qiov,
size_t qiov_offset, BdrvRequestFlags flags);
int co_wrapper_mixed blk_pwrite(BlockBackend *blk, int64_t offset,
int64_t bytes, const void *buf,
BdrvRequestFlags flags);
int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset, int64_t bytes,
const void *buf, BdrvRequestFlags flags);
int co_wrapper_mixed blk_pwritev(BlockBackend *blk, int64_t offset,
int64_t bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
int64_t bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags);
int co_wrapper_mixed blk_pwritev_part(BlockBackend *blk, int64_t offset,
int64_t bytes, QEMUIOVector *qiov,
size_t qiov_offset,
BdrvRequestFlags flags);
int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
int64_t bytes,
QEMUIOVector *qiov, size_t qiov_offset,
BdrvRequestFlags flags);
int co_wrapper_mixed blk_pwrite_compressed(BlockBackend *blk,
int64_t offset, int64_t bytes,
const void *buf);
int coroutine_fn blk_co_pwrite_compressed(BlockBackend *blk, int64_t offset,
int64_t bytes, const void *buf);
int co_wrapper_mixed blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
int64_t bytes,
BdrvRequestFlags flags);
int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
int64_t bytes, BdrvRequestFlags flags);
int coroutine_fn blk_co_zone_report(BlockBackend *blk, int64_t offset,
unsigned int *nr_zones,
BlockZoneDescriptor *zones);
int co_wrapper_mixed blk_zone_report(BlockBackend *blk, int64_t offset,
unsigned int *nr_zones,
BlockZoneDescriptor *zones);
int coroutine_fn blk_co_zone_mgmt(BlockBackend *blk, BlockZoneOp op,
int64_t offset, int64_t len);
int co_wrapper_mixed blk_zone_mgmt(BlockBackend *blk, BlockZoneOp op,
int64_t offset, int64_t len);
int coroutine_fn blk_co_zone_append(BlockBackend *blk, int64_t *offset,
QEMUIOVector *qiov,
BdrvRequestFlags flags);
int co_wrapper_mixed blk_zone_append(BlockBackend *blk, int64_t *offset,
QEMUIOVector *qiov,
BdrvRequestFlags flags);
int co_wrapper_mixed blk_pdiscard(BlockBackend *blk, int64_t offset,
int64_t bytes);
int coroutine_fn blk_co_pdiscard(BlockBackend *blk, int64_t offset,
int64_t bytes);
int co_wrapper_mixed blk_flush(BlockBackend *blk);
int coroutine_fn blk_co_flush(BlockBackend *blk);
int co_wrapper_mixed blk_ioctl(BlockBackend *blk, unsigned long int req,
void *buf);
int coroutine_fn blk_co_ioctl(BlockBackend *blk, unsigned long int req,
void *buf);
int co_wrapper_mixed blk_truncate(BlockBackend *blk, int64_t offset,
bool exact, PreallocMode prealloc,
BdrvRequestFlags flags, Error **errp);
int coroutine_fn blk_co_truncate(BlockBackend *blk, int64_t offset, bool exact,
PreallocMode prealloc, BdrvRequestFlags flags,
Error **errp);
#endif /* BLOCK_BACKEND_IO_H */