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block-vpc: Use the qemu block layer (Kevin Wolf) 

Instead of accessing the file directly, use the qemu block layer.

Signed-off-by: Kevin Wolf <kwolf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6457 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aliguori 2009-01-26 20:26:58 +00:00
parent 1fa792286c
commit b71d1c2e11
1 changed files with 32 additions and 27 deletions
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59
block-vpc.c
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@ -105,7 +105,7 @@ struct vhd_dyndisk_header {
};
typedef struct BDRVVPCState {
int fd;
BlockDriverState *hd;
int max_table_entries;
uint32_t *pagetable;
@ -130,20 +130,18 @@ static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVVPCState *s = bs->opaque;
int fd, i;
int ret, i;
struct vhd_footer* footer;
struct vhd_dyndisk_header* dyndisk_header;
uint8_t buf[HEADER_SIZE];
fd = open(filename, O_RDONLY | O_BINARY);
if (fd < 0)
return -1;
bs->read_only = 1; // no write support yet
s->fd = fd;
ret = bdrv_file_open(&s->hd, filename, flags);
if (ret < 0)
return ret;
if (read(fd, buf, HEADER_SIZE) != HEADER_SIZE)
if (bdrv_pread(s->hd, 0, buf, HEADER_SIZE) != HEADER_SIZE)
goto fail;
footer = (struct vhd_footer*) buf;
@ -156,8 +154,8 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
bs->total_sectors = (int64_t)
be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
lseek(s->fd, be64_to_cpu(footer->data_offset), SEEK_SET);
if (read(fd, buf, HEADER_SIZE) != HEADER_SIZE)
if (bdrv_pread(s->hd, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE)
!= HEADER_SIZE)
goto fail;
footer = NULL;
@ -166,15 +164,16 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
if (strncmp(dyndisk_header->magic, "cxsparse", 8))
goto fail;
lseek(s->fd, be64_to_cpu(dyndisk_header->table_offset), SEEK_SET);
s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries);
s->pagetable = qemu_malloc(s->max_table_entries * 4);
if (!s->pagetable)
goto fail;
if (read(s->fd, s->pagetable, s->max_table_entries * 4) !=
s->max_table_entries * 4)
goto fail;
goto fail;
if (bdrv_pread(s->hd, be64_to_cpu(dyndisk_header->table_offset),
s->pagetable, s->max_table_entries * 4) != s->max_table_entries * 4)
goto fail;
for (i = 0; i < s->max_table_entries; i++)
be32_to_cpus(&s->pagetable[i]);
@ -190,11 +189,15 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
return 0;
fail:
close(fd);
bdrv_delete(s->hd);
return -1;
}
static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
/*
* Returns the absolute byte offset of the given sector in the image file.
* If the sector is not allocated, -1 is returned instead.
*/
static inline int64_t get_sector_offset(BlockDriverState *bs, int64_t sector_num)
{
BDRVVPCState *s = bs->opaque;
uint64_t offset = sector_num * 512;
@ -241,9 +244,8 @@ static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
return -1; // not allocated
#endif
#endif
lseek(s->fd, block_offset, SEEK_SET);
return 0;
return block_offset;
}
static int vpc_read(BlockDriverState *bs, int64_t sector_num,
@ -251,16 +253,19 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num,
{
BDRVVPCState *s = bs->opaque;
int ret;
int64_t offset;
while (nb_sectors > 0) {
if (!seek_to_sector(bs, sector_num))
{
ret = read(s->fd, buf, 512);
if (ret != 512)
return -1;
}
else
offset = get_sector_offset(bs, sector_num);
if (offset == -1) {
memset(buf, 0, 512);
} else {
ret = bdrv_pread(s->hd, offset, buf, 512);
if (ret != 512)
return -1;
}
nb_sectors--;
sector_num++;
buf += 512;
@ -275,7 +280,7 @@ static void vpc_close(BlockDriverState *bs)
#ifdef CACHE
qemu_free(s->pageentry_u8);
#endif
close(s->fd);
bdrv_delete(s->hd);
}
BlockDriver bdrv_vpc = {