mirror of
https://github.com/schoebel/mars
synced 2024-12-18 04:34:48 +00:00
99 lines
2.9 KiB
C
99 lines
2.9 KiB
C
/*
|
|
* MARS Long Distance Replication Software
|
|
*
|
|
* This file is part of MARS project: http://schoebel.github.io/mars/
|
|
*
|
|
* Copyright (C) 2010-2022 Thomas Schoebel-Theuer
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#ifndef MARS_LIB_QIO_RW_H
|
|
#define MARS_LIB_QIO_RW_H
|
|
|
|
#include "brick.h"
|
|
#include "lamport.h"
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/uio.h>
|
|
#include <linux/pagemap.h>
|
|
|
|
/* Minor abstraction to/from the kernel IO interface.
|
|
* (a) hopefully this interface will remain stable until MARS
|
|
* can go upstream. Only the implementation in lib_qio_rw.c
|
|
* should need to cope with kernel versions.
|
|
* (b) keep the door open for alternative kernel adaptors, maybe even
|
|
* more direct access to the page cache, or some future developments.
|
|
*
|
|
* Architectural differences to kernel_{read,write}():
|
|
* (1) The interface is as similar as possible, for long-term
|
|
* code maintenance.
|
|
* (2) Submission should work as non-blocking as possible ;)
|
|
* (3) *_wait() operations are supposed to block any (separate)
|
|
* kernel threads.
|
|
* Any information transfer between submission and (internal)
|
|
* completion path(s) goes via *private, which should always
|
|
* start with prefix "struct qio_rw_...", but may append further
|
|
* external items.
|
|
*/
|
|
|
|
enum qio_rw_phase {
|
|
QIO_RW_NOTSTARTED,
|
|
QIO_RW_RD_STARTED,
|
|
QIO_RW_WR_STARTED,
|
|
QIO_RW_WAITING,
|
|
QIO_RW_COMPLETED,
|
|
};
|
|
|
|
struct qio_rw {
|
|
union {
|
|
struct {
|
|
/* from general kernel infrastructure */
|
|
struct kiocb kiocb;
|
|
struct iov_iter from_to;
|
|
/* from io_uring */
|
|
/* currently unused: struct io_async_rw rw; */
|
|
/* private */
|
|
ssize_t submission_ret;
|
|
ssize_t completion_ret;
|
|
enum qio_rw_phase qio_phase;
|
|
};
|
|
};
|
|
};
|
|
|
|
struct qio_rw_operations {
|
|
ssize_t (*qio_read_start)(struct file *file,
|
|
void *buf, size_t count,
|
|
loff_t *pos,
|
|
void *private,
|
|
bool nowait);
|
|
ssize_t (*qio_write_start)(struct file *file,
|
|
void *buf, size_t count,
|
|
loff_t *pos,
|
|
void *private,
|
|
bool wait_for_sync);
|
|
ssize_t (*qio_rw_wait)(struct file *file,
|
|
bool is_write,
|
|
bool needs_write_sync,
|
|
void *private);
|
|
};
|
|
|
|
extern const struct qio_rw_operations qio_rw_operations;
|
|
|
|
extern void init_qio_rw(struct qio_rw *qio_rw);
|
|
extern void exit_qio_rw(struct qio_rw *qio_rw);
|
|
|
|
#endif
|