zfs-builds-mm/zfs-2.0.0-rc5/lib/libspl/include/sys/uio.h
2020-11-03 21:32:00 +01:00

153 lines
4.1 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
#ifndef _LIBSPL_SYS_UIO_H
#define _LIBSPL_SYS_UIO_H
#include <sys/types.h>
#include_next <sys/uio.h>
#ifdef __APPLE__
#include <sys/_types/_iovec_t.h>
#endif
#include <stdint.h>
typedef struct iovec iovec_t;
#if defined(__linux__) || defined(__APPLE__)
typedef enum uio_rw {
UIO_READ = 0,
UIO_WRITE = 1,
} uio_rw_t;
typedef enum uio_seg {
UIO_USERSPACE = 0,
UIO_SYSSPACE = 1,
UIO_USERISPACE = 2,
} uio_seg_t;
#elif defined(__FreeBSD__)
typedef enum uio_seg uio_seg_t;
#endif
typedef struct uio {
struct iovec *uio_iov; /* pointer to array of iovecs */
int uio_iovcnt; /* number of iovecs */
offset_t uio_loffset; /* file offset */
uio_seg_t uio_segflg; /* address space (kernel or user) */
uint16_t uio_fmode; /* file mode flags */
uint16_t uio_extflg; /* extended flags */
offset_t uio_limit; /* u-limit (maximum byte offset) */
ssize_t uio_resid; /* residual count */
} uio_t;
typedef enum xuio_type {
UIOTYPE_ASYNCIO,
UIOTYPE_ZEROCOPY,
} xuio_type_t;
#define UIOA_IOV_MAX 16
typedef struct uioa_page_s { /* locked uio_iov state */
int uioa_pfncnt; /* count of pfn_t(s) in *uioa_ppp */
void **uioa_ppp; /* page_t or pfn_t array */
caddr_t uioa_base; /* address base */
size_t uioa_len; /* span length */
} uioa_page_t;
typedef struct xuio {
uio_t xu_uio; /* embedded UIO structure */
/* Extended uio fields */
enum xuio_type xu_type; /* uio type */
union {
struct {
uint32_t xu_a_state; /* state of async i/o */
ssize_t xu_a_mbytes; /* bytes moved */
uioa_page_t *xu_a_lcur; /* uioa_locked[] pointer */
void **xu_a_lppp; /* lcur->uioa_pppp[] pointer */
void *xu_a_hwst[4]; /* opaque hardware state */
uioa_page_t xu_a_locked[UIOA_IOV_MAX];
} xu_aio;
struct {
int xu_zc_rw; /* read or write buffer */
void *xu_zc_priv; /* fs specific */
} xu_zc;
} xu_ext;
} xuio_t;
#define XUIO_XUZC_PRIV(xuio) xuio->xu_ext.xu_zc.xu_zc_priv
#define XUIO_XUZC_RW(xuio) xuio->xu_ext.xu_zc.xu_zc_rw
#define uio_segflg(uio) (uio)->uio_segflg
#define uio_offset(uio) (uio)->uio_loffset
#define uio_resid(uio) (uio)->uio_resid
#define uio_iovcnt(uio) (uio)->uio_iovcnt
#define uio_iovlen(uio, idx) (uio)->uio_iov[(idx)].iov_len
#define uio_iovbase(uio, idx) (uio)->uio_iov[(idx)].iov_base
static inline void
uio_iov_at_index(uio_t *uio, uint_t idx, void **base, uint64_t *len)
{
*base = uio_iovbase(uio, idx);
*len = uio_iovlen(uio, idx);
}
static inline void
uio_advance(uio_t *uio, size_t size)
{
uio->uio_resid -= size;
uio->uio_loffset += size;
}
static inline offset_t
uio_index_at_offset(uio_t *uio, offset_t off, uint_t *vec_idx)
{
*vec_idx = 0;
while (*vec_idx < (uint_t)uio_iovcnt(uio) &&
off >= (offset_t)uio_iovlen(uio, *vec_idx)) {
off -= uio_iovlen(uio, *vec_idx);
(*vec_idx)++;
}
return (off);
}
#endif /* _SYS_UIO_H */