qemu-patch-raspberry4/block/raw-win32.c
Christoph Hellwig 84a12e6648 block: separate raw images from the file protocol
We're running into various problems because the "raw" file access, which
is used internally by the various image formats is entangled with the
"raw" image format, which maps the VM view 1:1 to a file system.

This patch renames the raw file backends to the file protocol which
is treated like other protocols (e.g. nbd and http) and adds a new
"raw" image format which is just a wrapper around calls to the underlying
protocol.

The patch is surprisingly simple, besides changing the probing logical
in block.c to only look for image formats when using bdrv_open and
renaming of the old raw protocols to file there's almost nothing in there.

For creating images, a new bdrv_create_file is introduced which guesses the
protocol to use. This allows using qemu-img create -f raw (or just using the
default) for both files and host devices. Converting the other format drivers
to use this function to create their images is left for later patches.

The only issues still open are in the handling of the host devices.
Firstly in current qemu we can specifiy the host* format names
on various command line acceping images, but the new code can't
do that without adding some translation.  Second the layering breaks
the no_zero_init flag in the BlockDriver used by qemu-img.  I'm not
happy how this is done per-driver instead of per-state so I'll
prepare a separate patch to clean this up.

There's some more cleanup opportunity after this patch, e.g. using
separate lists and registration functions for image formats vs
protocols and maybe even host drivers, but this can be done at a
later stage.

Also there's a check for protocol in bdrv_open for the BDRV_O_SNAPSHOT
case that I don't quite understand, but which I fear won't work as
expected - possibly even before this patch.

Note that this patch requires various recent block patches from Kevin
and me, which should all be in his block queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03 10:07:30 +02:00

418 lines
11 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 "module.h"
#include <windows.h>
#include <winioctl.h>
#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;
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;
DWORD overlapped;
s->type = FTYPE_FILE;
if (flags & BDRV_O_RDWR) {
access_flags = GENERIC_READ | GENERIC_WRITE;
} else {
access_flags = GENERIC_READ;
}
overlapped = FILE_ATTRIBUTE_NORMAL;
if ((flags & BDRV_O_NOCACHE))
overlapped |= FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
else if (!(flags & BDRV_O_CACHE_WB))
overlapped |= FILE_FLAG_WRITE_THROUGH;
s->hfile = CreateFile(filename, access_flags,
FILE_SHARE_READ, NULL,
OPEN_EXISTING, 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_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BDRVRawState *s = bs->opaque;
OVERLAPPED ov;
DWORD ret_count;
int ret;
int64_t offset = sector_num * 512;
int count = nb_sectors * 512;
memset(&ov, 0, sizeof(ov));
ov.Offset = offset;
ov.OffsetHigh = offset >> 32;
ret = ReadFile(s->hfile, buf, count, &ret_count, &ov);
if (!ret)
return ret_count;
if (ret_count == count)
ret_count = 0;
return ret_count;
}
static int raw_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
BDRVRawState *s = bs->opaque;
OVERLAPPED ov;
DWORD ret_count;
int ret;
int64_t offset = sector_num * 512;
int count = nb_sectors * 512;
memset(&ov, 0, sizeof(ov));
ov.Offset = offset;
ov.OffsetHigh = offset >> 32;
ret = WriteFile(s->hfile, buf, count, &ret_count, &ov);
if (!ret)
return ret_count;
if (ret_count == count)
ret_count = 0;
return ret_count;
}
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;
LONG 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, (PDWORD)&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, QEMUOptionParameter *options)
{
int fd;
int64_t total_size = 0;
/* Read out options */
while (options && options->name) {
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
total_size = options->value.n / 512;
}
options++;
}
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;
}
static QEMUOptionParameter raw_create_options[] = {
{
.name = BLOCK_OPT_SIZE,
.type = OPT_SIZE,
.help = "Virtual disk size"
},
{ NULL }
};
static BlockDriver bdrv_file = {
.format_name = "file",
.protocol_name = "file",
.instance_size = sizeof(BDRVRawState),
.bdrv_open = raw_open,
.bdrv_close = raw_close,
.bdrv_create = raw_create,
.bdrv_flush = raw_flush,
.bdrv_read = raw_read,
.bdrv_write = raw_write,
.bdrv_truncate = raw_truncate,
.bdrv_getlength = raw_getlength,
.create_options = raw_create_options,
};
/***********************************************/
/* 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);
switch (type) {
case DRIVE_REMOVABLE:
case DRIVE_FIXED:
return FTYPE_HARDDISK;
case DRIVE_CDROM:
return FTYPE_CD;
default:
return FTYPE_FILE;
}
} else {
return FTYPE_FILE;
}
}
static int hdev_probe_device(const char *filename)
{
if (strstart(filename, "/dev/cdrom", NULL))
return 100;
if (is_windows_drive(filename))
return 100;
return 0;
}
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_RDWR) {
access_flags = GENERIC_READ | GENERIC_WRITE;
} else {
access_flags = GENERIC_READ;
}
create_flags = OPEN_EXISTING;
overlapped = FILE_ATTRIBUTE_NORMAL;
if ((flags & BDRV_O_NOCACHE))
overlapped |= FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
else if (!(flags & BDRV_O_CACHE_WB))
overlapped |= 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
static BlockDriver bdrv_host_device = {
.format_name = "host_device",
.protocol_name = "host_device",
.instance_size = sizeof(BDRVRawState),
.bdrv_probe_device = hdev_probe_device,
.bdrv_open = hdev_open,
.bdrv_close = raw_close,
.bdrv_flush = raw_flush,
.bdrv_read = raw_read,
.bdrv_write = raw_write,
.bdrv_getlength = raw_getlength,
};
static void bdrv_file_init(void)
{
bdrv_register(&bdrv_file);
bdrv_register(&bdrv_host_device);
}
block_init(bdrv_file_init);