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

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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: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Jeff Dike
2005-10-10 23:10:32 -04:00
committed by Linus Torvalds
parent da64c6ee6b
commit 91acb21f08
5 changed files with 486 additions and 376 deletions
Download Patch File Download Diff File Expand all files Collapse all files

207
arch/um/os-Linux/aio.c
View File

@@ -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");
submit_proc = submit_aio_26;
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;
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 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);
}
}