qemu-e2k/block-raw-win32.c
aliguori a76bab4952 Refactor AIO to allow multiple AIO implementations
This patch refactors the AIO layer to allow multiple AIO implementations.  It's
only possible because of the recent signalfd() patch.  

Right now, the AIO infrastructure is pretty specific to the block raw backend.
For other block devices to implement AIO, the qemu_aio_wait function must
support registration.  This patch introduces a new function,
qemu_aio_set_fd_handler, which can be used to register a file descriptor to be
called back.  qemu_aio_wait() now polls a set of file descriptors registered
with this function until one becomes readable or writable.

This patch should allow the implementation of alternative AIO backends (via a
thread pool or linux-aio) and AIO backends in non-traditional block devices
(like NBD).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5297 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-22 19:17:18 +00:00

514 lines
13 KiB
C

/*
* Block driver for RAW files (win32)
*
* Copyright (c) 2006 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "qemu-timer.h"
#include "block_int.h"
#include <assert.h>
#include <winioctl.h>
//#define WIN32_AIO
#define FTYPE_FILE 0
#define FTYPE_CD 1
#define FTYPE_HARDDISK 2
typedef struct BDRVRawState {
HANDLE hfile;
int type;
char drive_path[16]; /* format: "d:\" */
} BDRVRawState;
typedef struct RawAIOCB {
BlockDriverAIOCB common;
HANDLE hEvent;
OVERLAPPED ov;
int count;
} RawAIOCB;
int qemu_ftruncate64(int fd, int64_t length)
{
LARGE_INTEGER li;
LONG high;
HANDLE h;
BOOL res;
if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
return -1;
h = (HANDLE)_get_osfhandle(fd);
/* get current position, ftruncate do not change position */
li.HighPart = 0;
li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
if (li.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
return -1;
high = length >> 32;
if (!SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN))
return -1;
res = SetEndOfFile(h);
/* back to old position */
SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
return res ? 0 : -1;
}
static int set_sparse(int fd)
{
DWORD returned;
return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
NULL, 0, NULL, 0, &returned, NULL);
}
static int raw_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVRawState *s = bs->opaque;
int access_flags, create_flags;
DWORD overlapped;
s->type = FTYPE_FILE;
if ((flags & BDRV_O_ACCESS) == O_RDWR) {
access_flags = GENERIC_READ | GENERIC_WRITE;
} else {
access_flags = GENERIC_READ;
}
if (flags & BDRV_O_CREAT) {
create_flags = CREATE_ALWAYS;
} else {
create_flags = OPEN_EXISTING;
}
#ifdef WIN32_AIO
overlapped = FILE_FLAG_OVERLAPPED;
#else
overlapped = FILE_ATTRIBUTE_NORMAL;
#endif
if (flags & BDRV_O_DIRECT)
overlapped |= FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
s->hfile = CreateFile(filename, access_flags,
FILE_SHARE_READ, NULL,
create_flags, overlapped, NULL);
if (s->hfile == INVALID_HANDLE_VALUE) {
int err = GetLastError();
if (err == ERROR_ACCESS_DENIED)
return -EACCES;
return -1;
}
return 0;
}
static int raw_pread(BlockDriverState *bs, int64_t offset,
uint8_t *buf, int count)
{
BDRVRawState *s = bs->opaque;
OVERLAPPED ov;
DWORD ret_count;
int ret;
memset(&ov, 0, sizeof(ov));
ov.Offset = offset;
ov.OffsetHigh = offset >> 32;
ret = ReadFile(s->hfile, buf, count, &ret_count, &ov);
if (!ret) {
#ifdef WIN32_AIO
ret = GetOverlappedResult(s->hfile, &ov, &ret_count, TRUE);
if (!ret)
return -EIO;
else
#endif
return ret_count;
}
return ret_count;
}
static int raw_pwrite(BlockDriverState *bs, int64_t offset,
const uint8_t *buf, int count)
{
BDRVRawState *s = bs->opaque;
OVERLAPPED ov;
DWORD ret_count;
int ret;
memset(&ov, 0, sizeof(ov));
ov.Offset = offset;
ov.OffsetHigh = offset >> 32;
ret = WriteFile(s->hfile, buf, count, &ret_count, &ov);
if (!ret) {
#ifdef WIN32_AIO
ret = GetOverlappedResult(s->hfile, &ov, &ret_count, TRUE);
if (!ret)
return -EIO;
else
#endif
return ret_count;
}
return ret_count;
}
#ifdef WIN32_AIO
static void raw_aio_cb(void *opaque)
{
RawAIOCB *acb = opaque;
BlockDriverState *bs = acb->common.bs;
BDRVRawState *s = bs->opaque;
DWORD ret_count;
int ret;
ret = GetOverlappedResult(s->hfile, &acb->ov, &ret_count, TRUE);
if (!ret || ret_count != acb->count) {
acb->common.cb(acb->common.opaque, -EIO);
} else {
acb->common.cb(acb->common.opaque, 0);
}
}
static RawAIOCB *raw_aio_setup(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
RawAIOCB *acb;
int64_t offset;
acb = qemu_aio_get(bs, cb, opaque);
if (acb->hEvent) {
acb->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!acb->hEvent) {
qemu_aio_release(acb);
return NULL;
}
}
memset(&acb->ov, 0, sizeof(acb->ov));
offset = sector_num * 512;
acb->ov.Offset = offset;
acb->ov.OffsetHigh = offset >> 32;
acb->ov.hEvent = acb->hEvent;
acb->count = nb_sectors * 512;
qemu_add_wait_object(acb->ov.hEvent, raw_aio_cb, acb);
return acb;
}
static BlockDriverAIOCB *raw_aio_read(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
RawAIOCB *acb;
int ret;
acb = raw_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
if (!acb)
return NULL;
ret = ReadFile(s->hfile, buf, acb->count, NULL, &acb->ov);
if (!ret) {
qemu_aio_release(acb);
return NULL;
}
qemu_aio_release(acb);
return (BlockDriverAIOCB *)acb;
}
static BlockDriverAIOCB *raw_aio_write(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVRawState *s = bs->opaque;
RawAIOCB *acb;
int ret;
acb = raw_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
if (!acb)
return NULL;
ret = WriteFile(s->hfile, buf, acb->count, NULL, &acb->ov);
if (!ret) {
qemu_aio_release(acb);
return NULL;
}
qemu_aio_release(acb);
return (BlockDriverAIOCB *)acb;
}
static void raw_aio_cancel(BlockDriverAIOCB *blockacb)
{
RawAIOCB *acb = (RawAIOCB *)blockacb;
BlockDriverState *bs = acb->common.bs;
BDRVRawState *s = bs->opaque;
qemu_del_wait_object(acb->ov.hEvent, raw_aio_cb, acb);
/* XXX: if more than one async I/O it is not correct */
CancelIo(s->hfile);
qemu_aio_release(acb);
}
#endif /* #if WIN32_AIO */
static void raw_flush(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
FlushFileBuffers(s->hfile);
}
static void raw_close(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
CloseHandle(s->hfile);
}
static int raw_truncate(BlockDriverState *bs, int64_t offset)
{
BDRVRawState *s = bs->opaque;
DWORD low, high;
low = offset;
high = offset >> 32;
if (!SetFilePointer(s->hfile, low, &high, FILE_BEGIN))
return -EIO;
if (!SetEndOfFile(s->hfile))
return -EIO;
return 0;
}
static int64_t raw_getlength(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
LARGE_INTEGER l;
ULARGE_INTEGER available, total, total_free;
DISK_GEOMETRY_EX dg;
DWORD count;
BOOL status;
switch(s->type) {
case FTYPE_FILE:
l.LowPart = GetFileSize(s->hfile, &l.HighPart);
if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
return -EIO;
break;
case FTYPE_CD:
if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
return -EIO;
l.QuadPart = total.QuadPart;
break;
case FTYPE_HARDDISK:
status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
NULL, 0, &dg, sizeof(dg), &count, NULL);
if (status != 0) {
l = dg.DiskSize;
}
break;
default:
return -EIO;
}
return l.QuadPart;
}
static int raw_create(const char *filename, int64_t total_size,
const char *backing_file, int flags)
{
int fd;
if (flags || backing_file)
return -ENOTSUP;
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
0644);
if (fd < 0)
return -EIO;
set_sparse(fd);
ftruncate(fd, total_size * 512);
close(fd);
return 0;
}
BlockDriver bdrv_raw = {
"raw",
sizeof(BDRVRawState),
NULL, /* no probe for protocols */
raw_open,
NULL,
NULL,
raw_close,
raw_create,
raw_flush,
#ifdef WIN32_AIO
.bdrv_aio_read = raw_aio_read,
.bdrv_aio_write = raw_aio_write,
.bdrv_aio_cancel = raw_aio_cancel,
.aiocb_size = sizeof(RawAIOCB);
#endif
.bdrv_pread = raw_pread,
.bdrv_pwrite = raw_pwrite,
.bdrv_truncate = raw_truncate,
.bdrv_getlength = raw_getlength,
};
/***********************************************/
/* host device */
static int find_cdrom(char *cdrom_name, int cdrom_name_size)
{
char drives[256], *pdrv = drives;
UINT type;
memset(drives, 0, sizeof(drives));
GetLogicalDriveStrings(sizeof(drives), drives);
while(pdrv[0] != '\0') {
type = GetDriveType(pdrv);
switch(type) {
case DRIVE_CDROM:
snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
return 0;
break;
}
pdrv += lstrlen(pdrv) + 1;
}
return -1;
}
static int find_device_type(BlockDriverState *bs, const char *filename)
{
BDRVRawState *s = bs->opaque;
UINT type;
const char *p;
if (strstart(filename, "\\\\.\\", &p) ||
strstart(filename, "//./", &p)) {
if (stristart(p, "PhysicalDrive", NULL))
return FTYPE_HARDDISK;
snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
type = GetDriveType(s->drive_path);
if (type == DRIVE_CDROM)
return FTYPE_CD;
else
return FTYPE_FILE;
} else {
return FTYPE_FILE;
}
}
static int hdev_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVRawState *s = bs->opaque;
int access_flags, create_flags;
DWORD overlapped;
char device_name[64];
if (strstart(filename, "/dev/cdrom", NULL)) {
if (find_cdrom(device_name, sizeof(device_name)) < 0)
return -ENOENT;
filename = device_name;
} else {
/* transform drive letters into device name */
if (((filename[0] >= 'a' && filename[0] <= 'z') ||
(filename[0] >= 'A' && filename[0] <= 'Z')) &&
filename[1] == ':' && filename[2] == '\0') {
snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
filename = device_name;
}
}
s->type = find_device_type(bs, filename);
if ((flags & BDRV_O_ACCESS) == O_RDWR) {
access_flags = GENERIC_READ | GENERIC_WRITE;
} else {
access_flags = GENERIC_READ;
}
create_flags = OPEN_EXISTING;
#ifdef WIN32_AIO
overlapped = FILE_FLAG_OVERLAPPED;
#else
overlapped = FILE_ATTRIBUTE_NORMAL;
#endif
if (flags & BDRV_O_DIRECT)
overlapped |= FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
s->hfile = CreateFile(filename, access_flags,
FILE_SHARE_READ, NULL,
create_flags, overlapped, NULL);
if (s->hfile == INVALID_HANDLE_VALUE) {
int err = GetLastError();
if (err == ERROR_ACCESS_DENIED)
return -EACCES;
return -1;
}
return 0;
}
#if 0
/***********************************************/
/* removable device additional commands */
static int raw_is_inserted(BlockDriverState *bs)
{
return 1;
}
static int raw_media_changed(BlockDriverState *bs)
{
return -ENOTSUP;
}
static int raw_eject(BlockDriverState *bs, int eject_flag)
{
DWORD ret_count;
if (s->type == FTYPE_FILE)
return -ENOTSUP;
if (eject_flag) {
DeviceIoControl(s->hfile, IOCTL_STORAGE_EJECT_MEDIA,
NULL, 0, NULL, 0, &lpBytesReturned, NULL);
} else {
DeviceIoControl(s->hfile, IOCTL_STORAGE_LOAD_MEDIA,
NULL, 0, NULL, 0, &lpBytesReturned, NULL);
}
}
static int raw_set_locked(BlockDriverState *bs, int locked)
{
return -ENOTSUP;
}
#endif
BlockDriver bdrv_host_device = {
"host_device",
sizeof(BDRVRawState),
NULL, /* no probe for protocols */
hdev_open,
NULL,
NULL,
raw_close,
NULL,
raw_flush,
#ifdef WIN32_AIO
.bdrv_aio_read = raw_aio_read,
.bdrv_aio_write = raw_aio_write,
.bdrv_aio_cancel = raw_aio_cancel,
.aiocb_size = sizeof(RawAIOCB);
#endif
.bdrv_pread = raw_pread,
.bdrv_pwrite = raw_pwrite,
.bdrv_getlength = raw_getlength,
};