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bfe4037e72
Simple one-shot poll through the io_submit() interface. To poll for a file descriptor the application should submit an iocb of type IOCB_CMD_POLL. It will poll the fd for the events specified in the the first 32 bits of the aio_buf field of the iocb. Unlike poll or epoll without EPOLLONESHOT this interface always works in one shot mode, that is once the iocb is completed, it will have to be resubmitted. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Avi Kivity <avi@scylladb.com>
112 lines
3.2 KiB
C
112 lines
3.2 KiB
C
/* include/linux/aio_abi.h
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*
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* Copyright 2000,2001,2002 Red Hat.
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*
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* Written by Benjamin LaHaise <bcrl@kvack.org>
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*
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* Distribute under the terms of the GPLv2 (see ../../COPYING) or under
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* the following terms.
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*
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* Permission to use, copy, modify, and distribute this software and its
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* documentation is hereby granted, provided that the above copyright
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* notice appears in all copies. This software is provided without any
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* warranty, express or implied. Red Hat makes no representations about
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* the suitability of this software for any purpose.
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*
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* IN NO EVENT SHALL RED HAT BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
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* SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF
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* THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF RED HAT HAS BEEN ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* RED HAT DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND
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* RED HAT HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
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* ENHANCEMENTS, OR MODIFICATIONS.
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*/
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#ifndef __LINUX__AIO_ABI_H
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#define __LINUX__AIO_ABI_H
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#include <linux/types.h>
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#include <linux/fs.h>
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#include <asm/byteorder.h>
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typedef __kernel_ulong_t aio_context_t;
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enum {
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IOCB_CMD_PREAD = 0,
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IOCB_CMD_PWRITE = 1,
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IOCB_CMD_FSYNC = 2,
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IOCB_CMD_FDSYNC = 3,
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/* 4 was the experimental IOCB_CMD_PREADX */
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IOCB_CMD_POLL = 5,
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IOCB_CMD_NOOP = 6,
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IOCB_CMD_PREADV = 7,
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IOCB_CMD_PWRITEV = 8,
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};
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/*
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* Valid flags for the "aio_flags" member of the "struct iocb".
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*
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* IOCB_FLAG_RESFD - Set if the "aio_resfd" member of the "struct iocb"
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* is valid.
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*/
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#define IOCB_FLAG_RESFD (1 << 0)
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#define IOCB_FLAG_IOPRIO (1 << 1)
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/* read() from /dev/aio returns these structures. */
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struct io_event {
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__u64 data; /* the data field from the iocb */
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__u64 obj; /* what iocb this event came from */
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__s64 res; /* result code for this event */
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__s64 res2; /* secondary result */
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};
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/*
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* we always use a 64bit off_t when communicating
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* with userland. its up to libraries to do the
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* proper padding and aio_error abstraction
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*/
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struct iocb {
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/* these are internal to the kernel/libc. */
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__u64 aio_data; /* data to be returned in event's data */
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#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
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__u32 aio_key; /* the kernel sets aio_key to the req # */
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__kernel_rwf_t aio_rw_flags; /* RWF_* flags */
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#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
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__kernel_rwf_t aio_rw_flags; /* RWF_* flags */
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__u32 aio_key; /* the kernel sets aio_key to the req # */
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#else
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#error edit for your odd byteorder.
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#endif
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/* common fields */
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__u16 aio_lio_opcode; /* see IOCB_CMD_ above */
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__s16 aio_reqprio;
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__u32 aio_fildes;
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__u64 aio_buf;
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__u64 aio_nbytes;
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__s64 aio_offset;
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/* extra parameters */
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__u64 aio_reserved2; /* TODO: use this for a (struct sigevent *) */
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/* flags for the "struct iocb" */
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__u32 aio_flags;
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/*
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* if the IOCB_FLAG_RESFD flag of "aio_flags" is set, this is an
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* eventfd to signal AIO readiness to
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*/
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__u32 aio_resfd;
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}; /* 64 bytes */
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#undef IFBIG
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#undef IFLITTLE
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#endif /* __LINUX__AIO_ABI_H */
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