-/*
+/*
* Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include <sched.h>
#include <sys/syscall.h>
#include "os.h"
-#include "helper.h"
#include "aio.h"
#include "init.h"
#include "user.h"
unsigned long long offset;
char *buf;
int len;
- int reply_fd;
- void *data;
+ struct aio_context *aio;
};
static int aio_req_fd_r = -1;
#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));
+ 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));
+ 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));
+ return syscall(__NR_io_getevents, ctx_id, min_nr, nr, events, timeout);
}
#endif
* 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
+ * 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
+ * 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)
+static int do_aio(aio_context_t ctx, enum aio_type type, int fd, char *buf,
+ int len, unsigned long long offset, struct aio_context *aio)
{
struct iocb iocb, *iocbp = &iocb;
char c;
int err;
- iocb = ((struct iocb) { .aio_data = (unsigned long) data,
+ iocb = ((struct iocb) { .aio_data = (unsigned long) aio,
.aio_reqprio = 0,
.aio_fildes = fd,
.aio_buf = (unsigned long) buf,
err = -EINVAL;
break;
}
+
if(err > 0)
err = 0;
+ else
+ err = -errno;
- return(err);
+ return err;
}
static aio_context_t ctx = 0;
"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;
+ reply = ((struct aio_thread_reply)
+ { .data = (void *) (long) event.data,
+ .err = event.res });
+ reply_fd = ((struct aio_context *) reply.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);
+ printk("aio_thread - write failed, fd = %d, "
+ "err = %d\n", aio_req_fd_r, -err);
}
}
- return(0);
+ return 0;
}
#endif
break;
}
- out:
- return(err);
+out:
+ return err;
}
static int not_aio_thread(void *arg)
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);
+ 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));
+ reply = ((struct aio_thread_reply) { .data = req.aio,
+ .err = err });
+ err = os_write_file(req.aio->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;
}
static int aio_pid = -1;
{
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,
+ 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:
+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);
+ aio_req_fd_r = -1;
+out:
+#ifndef HAVE_AIO_ABI
+ printk("/usr/include/linux/aio_abi.h not present during build\n");
+#endif
+ printk("2.6 host AIO support not used - falling back to I/O "
+ "thread\n");
+ return 0;
}
#ifdef HAVE_AIO_ABI
{
unsigned long stack;
int err;
-
+
if(io_setup(256, &ctx)){
+ err = -errno;
printk("aio_thread failed to initialize context, err = %d\n",
errno);
- return(-errno);
+ return err;
}
- err = run_helper_thread(aio_thread, NULL,
+ err = run_helper_thread(aio_thread, NULL,
CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
if(err < 0)
- return(-errno);
+ return err;
aio_pid = err;
- err = 0;
- out:
- return(err);
+
+ printk("Using 2.6 host AIO\n");
+ return 0;
}
-int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
- unsigned long long offset, int reply_fd, void *data)
+static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
+ unsigned long long offset, struct aio_context *aio)
{
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);
+ err = do_aio(ctx, type, io_fd, buf, len, offset, aio);
if(err){
- reply = ((struct aio_thread_reply) { .data = data,
- .err = err });
- err = os_write_file(reply_fd, &reply, sizeof(reply));
+ reply = ((struct aio_thread_reply) { .data = aio,
+ .err = err });
+ err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
if(err != sizeof(reply))
printk("submit_aio_26 - write failed, "
- "fd = %d, err = %d\n", reply_fd, -err);
+ "fd = %d, err = %d\n", aio->reply_fd, -err);
else err = 0;
}
- return(err);
+ return err;
}
#else
#define DEFAULT_24_AIO 1
static int init_aio_26(void)
{
- return(-ENOSYS);
+ return -ENOSYS;
}
-int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
- unsigned long long offset, int reply_fd, void *data)
+static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
+ unsigned long long offset, struct aio_context *aio)
{
- return(-ENOSYS);
+ return -ENOSYS;
}
#endif
static int __init set_aio_24(char *name, int *add)
{
aio_24 = 1;
- return(0);
+ return 0;
}
__uml_setup("aio=2.4", set_aio_24,
"aio=2.4\n"
" This is used to force UML to use 2.4-style AIO even when 2.6 AIO is\n"
" available. 2.4 AIO is a single thread that handles one request at a\n"
-" time, synchronously. 2.6 AIO is a thread which uses 2.5 AIO interface\n"
-" to handle an arbitrary number of pending requests. 2.6 AIO is not\n"
-" available in tt mode, on 2.4 hosts, or when UML is built with\n"
-" /usr/include/linux/aio_abi no available.\n\n"
+" time, synchronously. 2.6 AIO is a thread which uses the 2.6 AIO \n"
+" interface to handle an arbitrary number of pending requests. 2.6 AIO \n"
+" is not available in tt mode, on 2.4 hosts, or when UML is built with\n"
+" /usr/include/linux/aio_abi.h not available. Many distributions don't\n"
+" include aio_abi.h, so you will need to copy it from a kernel tree to\n"
+" your /usr/include/linux in order to build an AIO-capable UML\n\n"
);
static int init_aio(void)
{
int err;
- CHOOSE_MODE(({
- if(!aio_24){
- printk("Disabling 2.6 AIO in tt mode\n");
- aio_24 = 1;
- } }), (void) 0);
+ CHOOSE_MODE(({ if(!aio_24){
+ printk("Disabling 2.6 AIO in tt mode\n");
+ aio_24 = 1;
+ } }), (void) 0);
if(!aio_24){
err = init_aio_26();
"reverting to 2.4 AIO\n");
aio_24 = 1;
}
- else return(err);
+ else return err;
}
if(aio_24)
- return(init_aio_24());
+ return init_aio_24();
- return(0);
+ return 0;
}
+/* The reason for the __initcall/__uml_exitcall asymmetry is that init_aio
+ * needs to be called when the kernel is running because it calls run_helper,
+ * which needs get_free_page. exit_aio is a __uml_exitcall because the generic
+ * kernel does not run __exitcalls on shutdown, and can't because many of them
+ * break when called outside of module unloading.
+ */
__initcall(init_aio);
static void exit_aio(void)
__uml_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)
+static int submit_aio_24(enum aio_type type, int io_fd, char *buf, int len,
+ unsigned long long offset, struct aio_context *aio)
{
struct aio_thread_req req = { .type = type,
.io_fd = io_fd,
.offset = offset,
.buf = buf,
.len = len,
- .reply_fd = reply_fd,
- .data = data,
+ .aio = aio,
};
int err;
if(err == sizeof(req))
err = 0;
- return(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)
+int submit_aio(enum aio_type type, int io_fd, char *buf, int len,
+ unsigned long long offset, int reply_fd,
+ struct aio_context *aio)
{
+ aio->reply_fd = reply_fd;
if(aio_24)
- return(submit_aio_24(type, io_fd, buf, len, offset, reply_fd,
- data));
+ return submit_aio_24(type, io_fd, buf, len, offset, aio);
else {
- return(submit_aio_26(type, io_fd, buf, len, offset, reply_fd,
- data));
+ return submit_aio_26(type, io_fd, buf, len, offset, aio);
}
}
-
-/*
- * 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:
- */
git://git.onelab.eu / linux-2.6.git / blobdiff