qemu-e2k/block/raw-aio.h
Kevin Wolf 9d52aa3c38 raw-posix: Implement .bdrv_co_preadv/pwritev
The raw-posix block driver actually supports byte-aligned requests now
on non-O_DIRECT images, like it already (and previously incorrectly)
claimed in bs->request_alignment.

For some block drivers this means that a RMW cycle can be avoided when
they write sub-sector metadata e.g. for cluster allocation.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00

69 lines
2.4 KiB
C

/*
* Declarations for AIO in the raw protocol
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#ifndef QEMU_RAW_AIO_H
#define QEMU_RAW_AIO_H
#include "qemu/coroutine.h"
#include "qemu/iov.h"
/* AIO request types */
#define QEMU_AIO_READ 0x0001
#define QEMU_AIO_WRITE 0x0002
#define QEMU_AIO_IOCTL 0x0004
#define QEMU_AIO_FLUSH 0x0008
#define QEMU_AIO_DISCARD 0x0010
#define QEMU_AIO_WRITE_ZEROES 0x0020
#define QEMU_AIO_TYPE_MASK \
(QEMU_AIO_READ|QEMU_AIO_WRITE|QEMU_AIO_IOCTL|QEMU_AIO_FLUSH| \
QEMU_AIO_DISCARD|QEMU_AIO_WRITE_ZEROES)
/* AIO flags */
#define QEMU_AIO_MISALIGNED 0x1000
#define QEMU_AIO_BLKDEV 0x2000
/* linux-aio.c - Linux native implementation */
#ifdef CONFIG_LINUX_AIO
typedef struct LinuxAioState LinuxAioState;
LinuxAioState *laio_init(void);
void laio_cleanup(LinuxAioState *s);
int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
uint64_t offset, QEMUIOVector *qiov, int type);
BlockAIOCB *laio_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque, int type);
void laio_detach_aio_context(LinuxAioState *s, AioContext *old_context);
void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context);
void laio_io_plug(BlockDriverState *bs, LinuxAioState *s);
void laio_io_unplug(BlockDriverState *bs, LinuxAioState *s);
#endif
#ifdef _WIN32
typedef struct QEMUWin32AIOState QEMUWin32AIOState;
QEMUWin32AIOState *win32_aio_init(void);
void win32_aio_cleanup(QEMUWin32AIOState *aio);
int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile);
BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
QEMUWin32AIOState *aio, HANDLE hfile,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque, int type);
void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
AioContext *old_context);
void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
AioContext *new_context);
#endif
#endif /* QEMU_RAW_AIO_H */