blob: 5c39a9703715d200d07d89803e957241ace117e7 [file] [log] [blame]
/*
* Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <sched.h>
#include <sys/syscall.h>
#include <linux/aio_abi.h>
#include "os.h"
#include "helper.h"
#include "aio.h"
#include "init.h"
#include "user.h"
#include "mode.h"
struct aio_thread_req {
enum aio_type type;
int io_fd;
unsigned long long offset;
char *buf;
int len;
int reply_fd;
void *data;
};
static int aio_req_fd_r = -1;
static int aio_req_fd_w = -1;
#if defined(HAVE_AIO_ABI)
/* If we have the headers, we are going to build with AIO enabled.
* If we don't have aio in libc, we define the necessary stubs here.
*/
#if !defined(HAVE_AIO_LIBC)
#define __NR_io_setup 245
#define __NR_io_getevents 247
#define __NR_io_submit 248
static long io_setup(int n, aio_context_t *ctxp)
{
return(syscall(__NR_io_setup, n, ctxp));
}
static long io_submit(aio_context_t ctx, long nr, struct iocb **iocbpp)
{
return(syscall(__NR_io_submit, ctx, nr, iocbpp));
}
static long io_getevents(aio_context_t ctx_id, long min_nr, long nr,
struct io_event *events, struct timespec *timeout)
{
return(syscall(__NR_io_getevents, ctx_id, min_nr, nr, events, timeout));
}
#endif
/* The AIO_MMAP cases force the mmapped page into memory here
* rather than in whatever place first touches the data. I used
* to do this by touching the page, but that's delicate because
* gcc is prone to optimizing that away. So, what's done here
* is we read from the descriptor from which the page was
* mapped. The caller is required to pass an offset which is
* inside the page that was mapped. Thus, when the read
* returns, we know that the page is in the page cache, and
* that it now backs the mmapped area.
*/
static int do_aio(aio_context_t ctx, enum aio_type type, int fd, char *buf,
int len, unsigned long long offset, void *data)
{
struct iocb iocb, *iocbp = &iocb;
char c;
int err;
iocb = ((struct iocb) { .aio_data = (unsigned long) data,
.aio_reqprio = 0,
.aio_fildes = fd,
.aio_buf = (unsigned long) buf,
.aio_nbytes = len,
.aio_offset = offset,
.aio_reserved1 = 0,
.aio_reserved2 = 0,
.aio_reserved3 = 0 });
switch(type){
case AIO_READ:
iocb.aio_lio_opcode = IOCB_CMD_PREAD;
err = io_submit(ctx, 1, &iocbp);
break;
case AIO_WRITE:
iocb.aio_lio_opcode = IOCB_CMD_PWRITE;
err = io_submit(ctx, 1, &iocbp);
break;
case AIO_MMAP:
iocb.aio_lio_opcode = IOCB_CMD_PREAD;
iocb.aio_buf = (unsigned long) &c;
iocb.aio_nbytes = sizeof(c);
err = io_submit(ctx, 1, &iocbp);
break;
default:
printk("Bogus op in do_aio - %d\n", type);
err = -EINVAL;
break;
}
if(err > 0)
err = 0;
return(err);
}
static aio_context_t ctx = 0;
static int aio_thread(void *arg)
{
struct aio_thread_reply reply;
struct io_event event;
int err, n, reply_fd;
signal(SIGWINCH, SIG_IGN);
while(1){
n = io_getevents(ctx, 1, 1, &event, NULL);
if(n < 0){
if(errno == EINTR)
continue;
printk("aio_thread - io_getevents failed, "
"errno = %d\n", errno);
}
else {
reply = ((struct aio_thread_reply)
{ .data = (void *) event.data,
.err = event.res });
reply_fd =
((struct aio_context *) event.data)->reply_fd;
err = os_write_file(reply_fd, &reply, sizeof(reply));
if(err != sizeof(reply))
printk("not_aio_thread - write failed, "
"fd = %d, err = %d\n",
aio_req_fd_r, -err);
}
}
return(0);
}
#endif
static int do_not_aio(struct aio_thread_req *req)
{
char c;
int err;
switch(req->type){
case AIO_READ:
err = os_seek_file(req->io_fd, req->offset);
if(err)
goto out;
err = os_read_file(req->io_fd, req->buf, req->len);
break;
case AIO_WRITE:
err = os_seek_file(req->io_fd, req->offset);
if(err)
goto out;
err = os_write_file(req->io_fd, req->buf, req->len);
break;
case AIO_MMAP:
err = os_seek_file(req->io_fd, req->offset);
if(err)
goto out;
err = os_read_file(req->io_fd, &c, sizeof(c));
break;
default:
printk("do_aio - bad request type : %d\n", req->type);
err = -EINVAL;
break;
}
out:
return(err);
}
static int not_aio_thread(void *arg)
{
struct aio_thread_req req;
struct aio_thread_reply reply;
int err;
signal(SIGWINCH, SIG_IGN);
while(1){
err = os_read_file(aio_req_fd_r, &req, sizeof(req));
if(err != sizeof(req)){
if(err < 0)
printk("not_aio_thread - read failed, fd = %d, "
"err = %d\n", aio_req_fd_r, -err);
else {
printk("not_aio_thread - short read, fd = %d, "
"length = %d\n", aio_req_fd_r, err);
}
continue;
}
err = do_not_aio(&req);
reply = ((struct aio_thread_reply) { .data = req.data,
.err = err });
err = os_write_file(req.reply_fd, &reply, sizeof(reply));
if(err != sizeof(reply))
printk("not_aio_thread - write failed, fd = %d, "
"err = %d\n", aio_req_fd_r, -err);
}
}
static int aio_pid = -1;
static int init_aio_24(void)
{
unsigned long stack;
int fds[2], err;
err = os_pipe(fds, 1, 1);
if(err)
goto out;
aio_req_fd_w = fds[0];
aio_req_fd_r = fds[1];
err = run_helper_thread(not_aio_thread, NULL,
CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
if(err < 0)
goto out_close_pipe;
aio_pid = err;
goto out;
out_close_pipe:
os_close_file(fds[0]);
os_close_file(fds[1]);
aio_req_fd_w = -1;
aio_req_fd_r = -1;
out:
return(0);
}
static int init_aio_26(void)
{
unsigned long stack;
int err;
err = io_setup(256, &ctx);
if(err){
printk("aio_thread failed to initialize context, err = %d\n",
errno);
goto out;
}
err = run_helper_thread(aio_thread, NULL,
CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
if(err < 0)
goto out;
aio_pid = err;
err = 0;
out:
return(err);
}
static int aio_24 = 0;
static int init_aio(void)
{
CHOOSE_MODE(({
if(!aio_24){
printk("Disabling 2.6 AIO in tt mode\n");
aio_24 = 1;
} }), (void) 0);
if(aio_24)
return(init_aio_24());
else return(init_aio_26());
}
__initcall(init_aio);
static void exit_aio(void)
{
if(aio_pid != -1)
os_kill_process(aio_pid, 1);
}
__exitcall(exit_aio);
int submit_aio_24(enum aio_type type, int io_fd, char *buf, int len,
unsigned long long offset, int reply_fd, void *data)
{
struct aio_thread_req req = { .type = type,
.io_fd = io_fd,
.offset = offset,
.buf = buf,
.len = len,
.reply_fd = reply_fd,
.data = data,
};
int err;
err = os_write_file(aio_req_fd_w, &req, sizeof(req));
if(err == sizeof(req))
err = 0;
return(err);
}
int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
unsigned long long offset, int reply_fd, void *data)
{
struct aio_thread_reply reply;
int err;
((struct aio_context *) data)->reply_fd = reply_fd;
err = do_aio(ctx, type, io_fd, buf, len, offset, data);
if(err){
reply = ((struct aio_thread_reply) { .data = data,
.err = err });
err = os_write_file(reply_fd, &reply, sizeof(reply));
if(err != sizeof(reply))
printk("submit_aio_26 - write failed, "
"fd = %d, err = %d\n", reply_fd, -err);
}
return(err);
}
int submit_aio(enum aio_type type, int io_fd, char *buf, int len,
unsigned long long offset, int reply_fd, void *data)
{
if(aio_24)
return(submit_aio_24(type, io_fd, buf, len, offset, reply_fd,
data));
else {
return(submit_aio_26(type, io_fd, buf, len, offset, reply_fd,
data));
}
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/