Skip to content

L
linux-davinci
Commit 91acb21f authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files
Options

[PATCH] uml: revert block driver use of host AIO 

The patch to use host AIO support that I submitted early after 2.6.13 exposed
some problems in the block driver.  I have fixes for these, but am not
comfortable putting them into 2.6.14 at this late date.  So, this patch reverts
the use of host AIO.

I will resubmit the original patch, plus fixes to the driver after 2.6.14
in order to get a reasonable amount of testing before they're exposed to
the general public.
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent da64c6ee
Hide whitespace changes
Inline Side-by-side
Showing with 483 additions and 373 deletions
arch/um/drivers/Makefile
View file @ 91acb21f
......@@ -13,7 +13,7 @@ mcast-objs := mcast_kern.o mcast_user.o
net-objs := net_kern.o net_user.o
mconsole-objs := mconsole_kern.o mconsole_user.o
hostaudio-objs := hostaudio_kern.o
ubd-objs := ubd_kern.o
ubd-objs := ubd_kern.o ubd_user.o
port-objs := port_kern.o port_user.o
harddog-objs := harddog_kern.o harddog_user.o
......
arch/um/drivers/ubd_kern.c
View file @ 91acb21f
......@@ -35,7 +35,6 @@
#include "linux/blkpg.h"
#include "linux/genhd.h"
#include "linux/spinlock.h"
#include "asm/atomic.h"
#include "asm/segment.h"
#include "asm/uaccess.h"
#include "asm/irq.h"
......@@ -54,21 +53,20 @@
#include "mem.h"
#include "mem_kern.h"
#include "cow.h"
#include "aio.h"
enum ubd_req { UBD_READ, UBD_WRITE };
struct io_thread_req {
enum aio_type op;
enum ubd_req op;
int fds[2];
unsigned long offsets[2];
unsigned long long offset;
unsigned long length;
char *buffer;
int sectorsize;
int bitmap_offset;
long bitmap_start;
long bitmap_end;
unsigned long sector_mask;
unsigned long long cow_offset;
unsigned long bitmap_words[2];
int error;
};
......@@ -82,31 +80,28 @@ extern int create_cow_file(char *cow_file, char *backing_file,
unsigned long *bitmap_len_out,
int *data_offset_out);
extern int read_cow_bitmap(int fd, void *buf, int offset, int len);
extern void do_io(struct io_thread_req *req, struct request *r,
unsigned long *bitmap);
extern void do_io(struct io_thread_req *req);
static inline int ubd_test_bit(__u64 bit, void *data)
static inline int ubd_test_bit(__u64 bit, unsigned char *data)
{
unsigned char *buffer = data;
__u64 n;
int bits, off;
bits = sizeof(buffer[0]) * 8;
bits = sizeof(data[0]) * 8;
n = bit / bits;
off = bit % bits;
return((buffer[n] & (1 << off)) != 0);
return((data[n] & (1 << off)) != 0);
}
static inline void ubd_set_bit(__u64 bit, void *data)
static inline void ubd_set_bit(__u64 bit, unsigned char *data)
{
unsigned char *buffer = data;
__u64 n;
int bits, off;
bits = sizeof(buffer[0]) * 8;
bits = sizeof(data[0]) * 8;
n = bit / bits;
off = bit % bits;
buffer[n] |= (1 << off);
data[n] |= (1 << off);
}
/*End stuff from ubd_user.h*/
......@@ -115,6 +110,8 @@ static inline void ubd_set_bit(__u64 bit, void *data)
static DEFINE_SPINLOCK(ubd_io_lock);
static DEFINE_SPINLOCK(ubd_lock);
static void (*do_ubd)(void);
static int ubd_open(struct inode * inode, struct file * filp);
static int ubd_release(struct inode * inode, struct file * file);
static int ubd_ioctl(struct inode * inode, struct file * file,
......@@ -161,8 +158,6 @@ struct cow {
int data_offset;
};
#define MAX_SG 64
struct ubd {
char *file;
int count;
......@@ -173,7 +168,6 @@ struct ubd {
int no_cow;
struct cow cow;
struct platform_device pdev;
struct scatterlist sg[MAX_SG];
};
#define DEFAULT_COW { \
......@@ -466,114 +460,81 @@ __uml_help(fakehd,
);
static void do_ubd_request(request_queue_t * q);
static int in_ubd;
/* Only changed by ubd_init, which is an initcall. */
int thread_fd = -1;
/* Changed by ubd_handler, which is serialized because interrupts only
* happen on CPU 0.
*/
int intr_count = 0;
static void ubd_end_request(struct request *req, int bytes, int uptodate)
/* call ubd_finish if you need to serialize */
static void __ubd_finish(struct request *req, int error)
{
if (!end_that_request_first(req, uptodate, bytes >> 9)) {
add_disk_randomness(req->rq_disk);
end_that_request_last(req);
int nsect;
if(error){
end_request(req, 0);
return;
}
nsect = req->current_nr_sectors;
req->sector += nsect;
req->buffer += nsect << 9;
req->errors = 0;
req->nr_sectors -= nsect;
req->current_nr_sectors = 0;
end_request(req, 1);
}
/* call ubd_finish if you need to serialize */
static void __ubd_finish(struct request *req, int bytes)
static inline void ubd_finish(struct request *req, int error)
{
if(bytes < 0){
ubd_end_request(req, 0, 0);
return;
}
ubd_end_request(req, bytes, 1);
spin_lock(&ubd_io_lock);
__ubd_finish(req, error);
spin_unlock(&ubd_io_lock);
}
static inline void ubd_finish(struct request *req, int bytes)
/* Called without ubd_io_lock held */
static void ubd_handler(void)
{
spin_lock(&ubd_io_lock);
__ubd_finish(req, bytes);
spin_unlock(&ubd_io_lock);
struct io_thread_req req;
struct request *rq = elv_next_request(ubd_queue);
int n;
do_ubd = NULL;
intr_count++;
n = os_read_file(thread_fd, &req, sizeof(req));
if(n != sizeof(req)){
printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, "
"err = %d\n", os_getpid(), -n);
spin_lock(&ubd_io_lock);
end_request(rq, 0);
spin_unlock(&ubd_io_lock);
return;
}
ubd_finish(rq, req.error);
reactivate_fd(thread_fd, UBD_IRQ);
do_ubd_request(ubd_queue);
}
struct bitmap_io {
atomic_t count;
struct aio_context aio;
};
struct ubd_aio {
struct aio_context aio;
struct request *req;
int len;
struct bitmap_io *bitmap;
void *bitmap_buf;
};
static int ubd_reply_fd = -1;
static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused)
{
struct aio_thread_reply reply;
struct ubd_aio *aio;
struct request *req;
int err, n, fd = (int) (long) dev;
while(1){
err = os_read_file(fd, &reply, sizeof(reply));
if(err == -EAGAIN)
break;
if(err < 0){
printk("ubd_aio_handler - read returned err %d\n",
-err);
break;
}
aio = container_of(reply.data, struct ubd_aio, aio);
n = reply.err;
if(n == 0){
req = aio->req;
req->nr_sectors -= aio->len >> 9;
if((aio->bitmap != NULL) &&
(atomic_dec_and_test(&aio->bitmap->count))){
aio->aio = aio->bitmap->aio;
aio->len = 0;
kfree(aio->bitmap);
aio->bitmap = NULL;
submit_aio(&aio->aio);
}
else {
if((req->nr_sectors == 0) &&
(aio->bitmap == NULL)){
int len = req->hard_nr_sectors << 9;
ubd_finish(req, len);
}
if(aio->bitmap_buf != NULL)
kfree(aio->bitmap_buf);
kfree(aio);
}
}
else if(n < 0){
ubd_finish(aio->req, n);
if(aio->bitmap != NULL)
kfree(aio->bitmap);
if(aio->bitmap_buf != NULL)
kfree(aio->bitmap_buf);
kfree(aio);
}
}
reactivate_fd(fd, UBD_IRQ);
ubd_handler();
return(IRQ_HANDLED);
}
do_ubd_request(ubd_queue);
/* Only changed by ubd_init, which is an initcall. */
static int io_pid = -1;
return(IRQ_HANDLED);
void kill_io_thread(void)
{
if(io_pid != -1)
os_kill_process(io_pid, 1);
}
__uml_exitcall(kill_io_thread);
static int ubd_file_size(struct ubd *dev, __u64 *size_out)
{
char *file;
......@@ -608,7 +569,7 @@ static int ubd_open_dev(struct ubd *dev)
&dev->cow.data_offset, create_ptr);
if((dev->fd == -ENOENT) && create_cow){
dev->fd = create_cow_file(dev->file, dev->cow.file,
dev->fd = create_cow_file(dev->file, dev->cow.file,
dev->openflags, 1 << 9, PAGE_SIZE,
&dev->cow.bitmap_offset,
&dev->cow.bitmap_len,
......@@ -870,10 +831,6 @@ int ubd_init(void)
{
int i;
ubd_reply_fd = init_aio_irq(UBD_IRQ, "ubd", ubd_intr);
if(ubd_reply_fd < 0)
printk("Setting up ubd AIO failed, err = %d\n", ubd_reply_fd);
devfs_mk_dir("ubd");
if (register_blkdev(MAJOR_NR, "ubd"))
return -1;
......@@ -884,7 +841,6 @@ int ubd_init(void)
return -1;
}
blk_queue_max_hw_segments(ubd_queue, MAX_SG);
if (fake_major != MAJOR_NR) {
char name[sizeof("ubd_nnn\0")];
......@@ -896,12 +852,40 @@ int ubd_init(void)
driver_register(&ubd_driver);
for (i = 0; i < MAX_DEV; i++)
ubd_add(i);
return 0;
}
late_initcall(ubd_init);
int ubd_driver_init(void){
unsigned long stack;
int err;
/* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
if(global_openflags.s){
printk(KERN_INFO "ubd: Synchronous mode\n");
/* Letting ubd=sync be like using ubd#s= instead of ubd#= is
* enough. So use anyway the io thread. */
}
stack = alloc_stack(0, 0);
io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
&thread_fd);
if(io_pid < 0){
printk(KERN_ERR
"ubd : Failed to start I/O thread (errno = %d) - "
"falling back to synchronous I/O\n", -io_pid);
io_pid = -1;
return(0);
}
err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
SA_INTERRUPT, "ubd", ubd_dev);
if(err != 0)
printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
return(err);
}
device_initcall(ubd_driver_init);
static int ubd_open(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
......@@ -939,55 +923,105 @@ static int ubd_release(struct inode * inode, struct file * file)
return(0);
}
static void cowify_bitmap(struct io_thread_req *req, unsigned long *bitmap)
static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
__u64 *cow_offset, unsigned long *bitmap,
__u64 bitmap_offset, unsigned long *bitmap_words,
__u64 bitmap_len)
{
__u64 sector = req->offset / req->sectorsize;
int i;
__u64 sector = io_offset >> 9;
int i, update_bitmap = 0;
for(i = 0; i < length >> 9; i++){
if(cow_mask != NULL)
ubd_set_bit(i, (unsigned char *) cow_mask);
if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
continue;
for(i = 0; i < req->length / req->sectorsize; i++){
if(ubd_test_bit(sector + i, bitmap))
continue;
update_bitmap = 1;
ubd_set_bit(sector + i, (unsigned char *) bitmap);
}
if(!update_bitmap)
return;
if(req->bitmap_start == -1)
req->bitmap_start = sector + i;
req->bitmap_end = sector + i + 1;
*cow_offset = sector / (sizeof(unsigned long) * 8);
ubd_set_bit(sector + i, bitmap);
}
/* This takes care of the case where we're exactly at the end of the
* device, and *cow_offset + 1 is off the end. So, just back it up
* by one word. Thanks to Lynn Kerby for the fix and James McMechan
* for the original diagnosis.
*/
if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) /
sizeof(unsigned long) - 1))
(*cow_offset)--;
bitmap_words[0] = bitmap[*cow_offset];
bitmap_words[1] = bitmap[*cow_offset + 1];
*cow_offset *= sizeof(unsigned long);
*cow_offset += bitmap_offset;
}
static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
__u64 bitmap_offset, __u64 bitmap_len)
{
__u64 sector = req->offset >> 9;
int i;
if(req->length > (sizeof(req->sector_mask) * 8) << 9)
panic("Operation too long");
if(req->op == UBD_READ) {
for(i = 0; i < req->length >> 9; i++){
if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
ubd_set_bit(i, (unsigned char *)
&req->sector_mask);
}
}
else cowify_bitmap(req->offset, req->length, &req->sector_mask,
&req->cow_offset, bitmap, bitmap_offset,
req->bitmap_words, bitmap_len);
}
/* Called with ubd_io_lock held */
static int prepare_request(struct request *req, struct io_thread_req *io_req,
unsigned long long offset, int page_offset,
int len, struct page *page)
static int prepare_request(struct request *req, struct io_thread_req *io_req)
{
struct gendisk *disk = req->rq_disk;
struct ubd *dev = disk->private_data;
__u64 offset;
int len;
if(req->rq_status == RQ_INACTIVE) return(1);
/* This should be impossible now */
if((rq_data_dir(req) == WRITE) && !dev->openflags.w){
printk("Write attempted on readonly ubd device %s\n",
disk->disk_name);
ubd_end_request(req, 0, 0);
end_request(req, 0);
return(1);
}
offset = ((__u64) req->sector) << 9;
len = req->current_nr_sectors << 9;
io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd;
io_req->fds[1] = dev->fd;
io_req->cow_offset = -1;
io_req->offset = offset;
io_req->length = len;
io_req->error = 0;
io_req->op = (rq_data_dir(req) == READ) ? AIO_READ : AIO_WRITE;
io_req->sector_mask = 0;
io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
io_req->offsets[0] = 0;
io_req->offsets[1] = dev->cow.data_offset;
io_req->buffer = page_address(page) + page_offset;
io_req->buffer = req->buffer;
io_req->sectorsize = 1 << 9;
io_req->bitmap_offset = dev->cow.bitmap_offset;
io_req->bitmap_start = -1;
io_req->bitmap_end = -1;
if((dev->cow.file != NULL) && (io_req->op == UBD_WRITE))
cowify_bitmap(io_req, dev->cow.bitmap);
if(dev->cow.file != NULL)
cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset,
dev->cow.bitmap_len);
return(0);
}
......@@ -996,36 +1030,30 @@ static void do_ubd_request(request_queue_t *q)
{
struct io_thread_req io_req;
struct request *req;
__u64 sector;
int err;
if(in_ubd)
return;
in_ubd = 1;
while((req = elv_next_request(q)) != NULL){
struct gendisk *disk = req->rq_disk;
struct ubd *dev = disk->private_data;
int n, i;
blkdev_dequeue_request(req);
sector = req->sector;
n = blk_rq_map_sg(q, req, dev->sg);
for(i = 0; i < n; i++){
struct scatterlist *sg = &dev->sg[i];
err = prepare_request(req, &io_req, sector << 9,
sg->offset, sg->length,
sg->page);
if(err)
continue;
sector += sg->length >> 9;
do_io(&io_req, req, dev->cow.bitmap);
int err, n;
if(thread_fd == -1){
while((req = elv_next_request(q)) != NULL){
err = prepare_request(req, &io_req);
if(!err){
do_io(&io_req);
__ubd_finish(req, io_req.error);
}
}
}
else {
if(do_ubd || (req = elv_next_request(q)) == NULL)
return;
err = prepare_request(req, &io_req);
if(!err){
do_ubd = ubd_handler;
n = os_write_file(thread_fd, (char *) &io_req,
sizeof(io_req));
if(n != sizeof(io_req))
printk("write to io thread failed, "
"errno = %d\n", -n);
}
}
in_ubd = 0;
}
static int ubd_ioctl(struct inode * inode, struct file * file,
......@@ -1241,95 +1269,131 @@ int create_cow_file(char *cow_file, char *backing_file, struct openflags flags,
return(err);
}
void do_io(struct io_thread_req *req, struct request *r, unsigned long *bitmap)
static int update_bitmap(struct io_thread_req *req)
{
struct ubd_aio *aio;
struct bitmap_io *bitmap_io = NULL;
char *buf;
void *bitmap_buf = NULL;
unsigned long len, sector;
int nsectors, start, end, bit, err;
__u64 off;
if(req->bitmap_start != -1){
/* Round up to the nearest word */
int round = sizeof(unsigned long);
len = (req->bitmap_end - req->bitmap_start +
round * 8 - 1) / (round * 8);
len *= round;
off = req->bitmap_start / (8 * round);
off *= round;
bitmap_io = kmalloc(sizeof(*bitmap_io), GFP_KERNEL);
if(bitmap_io == NULL){
printk("Failed to kmalloc bitmap IO\n");
req->error = 1;
return;
}
int n;
bitmap_buf = kmalloc(len, GFP_KERNEL);
if(bitmap_buf == NULL){
printk("do_io : kmalloc of bitmap chunk "
"failed\n");
kfree(bitmap_io);
req->error = 1;
return;
}
memcpy(bitmap_buf, &bitmap[off / sizeof(bitmap[0])], len);
*bitmap_io = ((struct bitmap_io)
{ .count = ATOMIC_INIT(0),
.aio = INIT_AIO(AIO_WRITE, req->fds[1],
bitmap_buf, len,
req->bitmap_offset + off,
ubd_reply_fd) } );
}
if(req->cow_offset == -1)
return(0);
nsectors = req->length / req->sectorsize;
start = 0;
end = nsectors;
bit = 0;
do {
if(bitmap != NULL){
sector = req->offset / req->sectorsize;
bit = ubd_test_bit(sector + start, bitmap);
end = start;
while((end < nsectors) &&
(ubd_test_bit(sector + end, bitmap) == bit))
end++;
}
n = os_seek_file(req->fds[1], req->cow_offset);
if(n < 0){
printk("do_io - bitmap lseek failed : err = %d\n", -n);
return(1);
}
off = req->offsets[bit] + req->offset +
start * req->sectorsize;
len = (end - start) * req->sectorsize;
buf = &req->buffer[start * req->sectorsize];
n = os_write_file(req->fds[1], &req->bitmap_words,
sizeof(req->bitmap_words));
if(n != sizeof(req->bitmap_words)){
printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
req->fds[1]);
return(1);
}
aio = kmalloc(sizeof(*aio), GFP_KERNEL);
if(aio == NULL){
req->error = 1;
return;
}
return(0);
}
*aio = ((struct ubd_aio)
{ .aio = INIT_AIO(req->op, req->fds[bit], buf,
len, off, ubd_reply_fd),
.len = len,
.req = r,
.bitmap = bitmap_io,
.bitmap_buf = bitmap_buf });
if(aio->bitmap != NULL)
atomic_inc(&aio->bitmap->count);
err = submit_aio(&aio->aio);
if(err){
printk("do_io - submit_aio failed, "
"err = %d\n", err);
req->error = 1;
return;
}
void do_io(struct io_thread_req *req)
{
char *buf;
unsigned long len;
int n, nsectors, start, end, bit;
int err;
__u64 off;
nsectors = req->length / req->sectorsize;
start = 0;
do {
bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
end = start;
while((end < nsectors) &&
(ubd_test_bit(end, (unsigned char *)
&req->sector_mask) == bit))
end++;
off = req->offset + req->offsets[bit] +
start * req->sectorsize;
len = (end - start) * req->sectorsize;
buf = &req->buffer[start * req->sectorsize];
err = os_seek_file(req->fds[bit], off);
if(err < 0){
printk("do_io - lseek failed : err = %d\n", -err);
req->error = 1;
return;
}
if(req->op == UBD_READ){
n = 0;
do {
buf = &buf[n];
len -= n;
n = os_read_file(req->fds[bit], buf, len);
if (n < 0) {
printk("do_io - read failed, err = %d "
"fd = %d\n", -n, req->fds[bit]);
req->error = 1;
return;
}
} while((n < len) && (n != 0));
if (n < len) memset(&buf[n], 0, len - n);
} else {
n = os_write_file(req->fds[bit], buf, len);
if(n != len){
printk("do_io - write failed err = %d "
"fd = %d\n", -n, req->fds[bit]);
req->error = 1;
return;
}
}
start = end;
} while(start < nsectors);
start = end;
} while(start < nsectors);
req->error = update_bitmap(req);
}
/* Changed in start_io_thread, which is serialized by being called only
* from ubd_init, which is an initcall.
*/
int kernel_fd = -1;
/* Only changed by the io thread */
int io_count = 0;
int io_thread(void *arg)
{
struct io_thread_req req;
int n;
ignore_sigwinch_sig();
while(1){
n = os_read_file(kernel_fd, &req, sizeof(req));
if(n != sizeof(req)){
if(n < 0)
printk("io_thread - read failed, fd = %d, "
"err = %d\n", kernel_fd, -n);
else {
printk("io_thread - short read, fd = %d, "
"length = %d\n", kernel_fd, n);
}
continue;
}
io_count++;
do_io(&req);
n = os_write_file(kernel_fd, &req, sizeof(req));
if(n != sizeof(req))
printk("io_thread - write failed, fd = %d, err = %d\n",
kernel_fd, -n);
}
}
/*
* 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:
*/
arch/um/drivers/ubd_user.c 0 → 100644
View file @ 91acb21f
/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
* Licensed under the GPL
*/
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <sched.h>
#include <signal.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/mman.h>
#include <sys/param.h>
#include "asm/types.h"
#include "user_util.h"
#include "kern_util.h"
#include "user.h"
#include "ubd_user.h"
#include "os.h"
#include "cow.h"
#include <endian.h>
#include <byteswap.h>
void ignore_sigwinch_sig(void)
{
signal(SIGWINCH, SIG_IGN);
}
int start_io_thread(unsigned long sp, int *fd_out)
{
int pid, fds[2], err;
err = os_pipe(fds, 1, 1);
if(err < 0){
printk("start_io_thread - os_pipe failed, err = %d\n", -err);
goto out;
}
kernel_fd = fds[0];
*fd_out = fds[1];
pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM | SIGCHLD,
NULL);
if(pid < 0){
printk("start_io_thread - clone failed : errno = %d\n", errno);
err = -errno;
goto out_close;
}
return(pid);
out_close:
os_close_file(fds[0]);
os_close_file(fds[1]);
kernel_fd = -1;
*fd_out = -1;
out:
return(err);
}
/*
* 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:
*/
arch/um/include/aio.h
View file @ 91acb21f
......@@ -14,27 +14,15 @@ struct aio_thread_reply {
};
struct aio_context {
enum aio_type type;
int fd;
void *data;
int len;
unsigned long long offset;
int reply_fd;
struct aio_context *next;
};
#define INIT_AIO(aio_type, aio_fd, aio_data, aio_len, aio_offset, \
aio_reply_fd) \
{ .type = aio_type, \
.fd = aio_fd, \
.data = aio_data, \
.len = aio_len, \
.offset = aio_offset, \
.reply_fd = aio_reply_fd }
#define INIT_AIO_CONTEXT { .reply_fd = -1, \
.next = NULL }
extern int submit_aio(struct aio_context *aio);
extern int submit_aio(enum aio_type type, int fd, char *buf, int len,
unsigned long long offset, int reply_fd,
struct aio_context *aio);
#endif
arch/um/os-Linux/aio.c
View file @ 91acb21f
......@@ -6,7 +6,6 @@
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#include <sched.h>
#include <sys/syscall.h>
......@@ -17,31 +16,18 @@
#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;
struct aio_context *aio;
};
static int aio_req_fd_r = -1;
static int aio_req_fd_w = -1;
static int update_aio(struct aio_context *aio, int res)
{
if(res < 0)
aio->len = res;
else if((res == 0) && (aio->type == AIO_READ)){
/* This is the EOF case - we have hit the end of the file
* and it ends in a partial block, so we fill the end of
* the block with zeros and claim success.
*/
memset(aio->data, 0, aio->len);
aio->len = 0;
}
else if(res > 0){
aio->len -= res;
aio->data += res;
aio->offset += res;
return aio->len;
}
return 0;
}
#if defined(HAVE_AIO_ABI)
#include <linux/aio_abi.h>
......@@ -80,7 +66,8 @@ static long io_getevents(aio_context_t ctx_id, long min_nr, long nr,
* that it now backs the mmapped area.
*/
static int do_aio(aio_context_t ctx, struct aio_context *aio)
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;
......@@ -88,39 +75,40 @@ static int do_aio(aio_context_t ctx, struct aio_context *aio)
iocb = ((struct iocb) { .aio_data = (unsigned long) aio,
.aio_reqprio = 0,
.aio_fildes = aio->fd,
.aio_buf = (unsigned long) aio->data,
.aio_nbytes = aio->len,
.aio_offset = aio->offset,
.aio_fildes = fd,
.aio_buf = (unsigned long) buf,
.aio_nbytes = len,
.aio_offset = offset,
.aio_reserved1 = 0,
.aio_reserved2 = 0,
.aio_reserved3 = 0 });
switch(aio->type){
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", aio->type);
printk("Bogus op in do_aio - %d\n", type);
err = -EINVAL;
goto out;
break;
}
err = io_submit(ctx, 1, &iocbp);
if(err > 0)
err = 0;
else
err = -errno;
out:
return err;
}
......@@ -129,9 +117,8 @@ static aio_context_t ctx = 0;
static int aio_thread(void *arg)
{
struct aio_thread_reply reply;
struct aio_context *aio;
struct io_event event;
int err, n;
int err, n, reply_fd;
signal(SIGWINCH, SIG_IGN);
......@@ -144,22 +131,14 @@ static int aio_thread(void *arg)
"errno = %d\n", errno);
}
else {
/* This is safe as we've just a pointer here. */
aio = (struct aio_context *) (long) event.data;
if(update_aio(aio, event.res)){
do_aio(ctx, aio);
continue;
}
reply = ((struct aio_thread_reply)
{ .data = aio,
.err = aio->len });
err = os_write_file(aio->reply_fd, &reply,
sizeof(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("aio_thread - write failed, "
"fd = %d, err = %d\n", aio->reply_fd,
-err);
printk("aio_thread - write failed, fd = %d, "
"err = %d\n", aio_req_fd_r, -err);
}
}
return 0;
......@@ -167,35 +146,35 @@ static int aio_thread(void *arg)
#endif
static int do_not_aio(struct aio_context *aio)
static int do_not_aio(struct aio_thread_req *req)
{
char c;
int err;
switch(aio->type){
switch(req->type){
case AIO_READ:
err = os_seek_file(aio->fd, aio->offset);
err = os_seek_file(req->io_fd, req->offset);
if(err)
goto out;
err = os_read_file(aio->fd, aio->data, aio->len);
err = os_read_file(req->io_fd, req->buf, req->len);
break;
case AIO_WRITE:
err = os_seek_file(aio->fd, aio->offset);
err = os_seek_file(req->io_fd, req->offset);
if(err)
goto out;
err = os_write_file(aio->fd, aio->data, aio->len);
err = os_write_file(req->io_fd, req->buf, req->len);
break;
case AIO_MMAP:
err = os_seek_file(aio->fd, aio->offset);
err = os_seek_file(req->io_fd, req->offset);
if(err)
goto out;
err = os_read_file(aio->fd, &c, sizeof(c));
err = os_read_file(req->io_fd, &c, sizeof(c));
break;
default:
printk("do_not_aio - bad request type : %d\n", aio->type);
printk("do_not_aio - bad request type : %d\n", req->type);
err = -EINVAL;
break;
}
......@@ -206,14 +185,14 @@ static int do_not_aio(struct aio_context *aio)
static int not_aio_thread(void *arg)
{
struct aio_context *aio;
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, &aio, sizeof(aio));
if(err != sizeof(aio)){
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,
......@@ -224,34 +203,17 @@ static int not_aio_thread(void *arg)
}
continue;
}
again:
err = do_not_aio(aio);
if(update_aio(aio, err))
goto again;
reply = ((struct aio_thread_reply) { .data = aio,
.err = aio->len });
err = os_write_file(aio->reply_fd, &reply, sizeof(reply));
err = do_not_aio(&req);
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);
}
}
static int submit_aio_24(struct aio_context *aio)
{
int err;
err = os_write_file(aio_req_fd_w, &aio, sizeof(aio));
if(err == sizeof(aio))
err = 0;
return err;
}
static int aio_pid = -1;
static int (*submit_proc)(struct aio_context *aio);
static int init_aio_24(void)
{
......@@ -283,33 +245,11 @@ static int init_aio_24(void)
#endif
printk("2.6 host AIO support not used - falling back to I/O "
"thread\n");
submit_proc = submit_aio_24;
return 0;
}
#ifdef HAVE_AIO_ABI
#define DEFAULT_24_AIO 0
static int submit_aio_26(struct aio_context *aio)
{
struct aio_thread_reply reply;
int err;
err = do_aio(ctx, aio);
if(err){
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", aio->reply_fd, -err);
else err = 0;
}
return err;
}
static int init_aio_26(void)
{
unsigned long stack;
......@@ -330,22 +270,39 @@ static int init_aio_26(void)
aio_pid = err;
printk("Using 2.6 host AIO\n");
return 0;
}
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;
submit_proc = submit_aio_26;
err = do_aio(ctx, type, io_fd, buf, len, offset, aio);
if(err){
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", aio->reply_fd, -err);
else err = 0;
}
return 0;
return err;
}
#else
#define DEFAULT_24_AIO 1
static int submit_aio_26(struct aio_context *aio)
static int init_aio_26(void)
{
return -ENOSYS;
}
static int init_aio_26(void)
static int submit_aio_26(enum aio_type type, int io_fd, char *buf, int len,
unsigned long long offset, struct aio_context *aio)
{
submit_proc = submit_aio_26;
return -ENOSYS;
}
#endif
......@@ -412,7 +369,33 @@ static void exit_aio(void)
__uml_exitcall(exit_aio);
int submit_aio(struct aio_context *aio)
static int submit_aio_24(enum aio_type type, int io_fd, char *buf, int len,
unsigned long long offset, struct aio_context *aio)
{
return (*submit_proc)(aio);
struct aio_thread_req req = { .type = type,
.io_fd = io_fd,
.offset = offset,
.buf = buf,
.len = len,
.aio = aio,
};
int err;
err = os_write_file(aio_req_fd_w, &req, sizeof(req));
if(err == sizeof(req))
err = 0;
return err;
}
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, aio);
else {
return submit_aio_26(type, io_fd, buf, len, offset, aio);
}
}
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment