qemu-e2k/block.c
bellard 0849bf0821 allow read only images
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@299 c046a42c-6fe2-441c-8c8c-71466251a162
2003-06-30 23:17:31 +00:00

117 lines
3.0 KiB
C

/*
* QEMU System Emulator block driver
*
* Copyright (c) 2003 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 <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <getopt.h>
#include <inttypes.h>
#include <unistd.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <malloc.h>
#include <termios.h>
#include <sys/poll.h>
#include <errno.h>
#include <sys/wait.h>
#include "vl.h"
struct BlockDriverState {
int fd;
int64_t total_sectors;
int read_only;
};
BlockDriverState *bdrv_open(const char *filename)
{
BlockDriverState *bs;
int fd;
int64_t size;
bs = malloc(sizeof(BlockDriverState));
if(!bs)
return NULL;
bs->read_only = 0;
fd = open(filename, O_RDWR);
if (fd < 0) {
fd = open(filename, O_RDONLY);
if (fd < 0) {
close(fd);
free(bs);
return NULL;
}
bs->read_only = 1;
}
size = lseek64(fd, 0, SEEK_END);
bs->total_sectors = size / 512;
bs->fd = fd;
return bs;
}
void bdrv_close(BlockDriverState *bs)
{
close(bs->fd);
free(bs);
}
/* return -1 if error */
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
int ret;
lseek64(bs->fd, sector_num * 512, SEEK_SET);
ret = read(bs->fd, buf, nb_sectors * 512);
if (ret != nb_sectors * 512)
return -1;
else
return 0;
}
/* return -1 if error */
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
int ret;
if (bs->read_only)
return -1;
lseek64(bs->fd, sector_num * 512, SEEK_SET);
ret = write(bs->fd, buf, nb_sectors * 512);
if (ret != nb_sectors * 512)
return -1;
else
return 0;
}
void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
{
*nb_sectors_ptr = bs->total_sectors;
}