VMDK: add field BDRVVmdkState.desc_offset

There are several occurrence of magic number 0x200 as the descriptor
offset within mono sparse image file. This is not the case for images
with separate descriptor file. So a field is added to BDRVVmdkState to
hold the correct value.

Signed-off-by: Fam Zheng <famcool@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2011-07-12 19:56:32 +08:00 committed by Kevin Wolf
parent b4b3ab146c
commit e1da9b2433

View File

@ -81,6 +81,7 @@ typedef struct VmdkExtent {
} VmdkExtent;
typedef struct BDRVVmdkState {
int desc_offset;
uint32_t parent_cid;
int num_extents;
/* Extent array with num_extents entries, ascend ordered by address */
@ -175,10 +176,11 @@ static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
uint32_t cid;
const char *p_name, *cid_str;
size_t cid_str_size;
BDRVVmdkState *s = bs->opaque;
/* the descriptor offset = 0x200 */
if (bdrv_pread(bs->file, 0x200, desc, DESC_SIZE) != DESC_SIZE)
if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
return 0;
}
if (parent) {
cid_str = "parentCID";
@ -200,10 +202,12 @@ static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
{
char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
char *p_name, *tmp_str;
BDRVVmdkState *s = bs->opaque;
/* the descriptor offset = 0x200 */
if (bdrv_pread(bs->file, 0x200, desc, DESC_SIZE) != DESC_SIZE)
return -1;
memset(desc, 0, sizeof(desc));
if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
return -EIO;
}
tmp_str = strstr(desc,"parentCID");
pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str);
@ -213,8 +217,9 @@ static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
pstrcat(desc, sizeof(desc), tmp_desc);
}
if (bdrv_pwrite_sync(bs->file, 0x200, desc, DESC_SIZE) < 0)
return -1;
if (bdrv_pwrite_sync(bs->file, s->desc_offset, desc, DESC_SIZE) < 0) {
return -EIO;
}
return 0;
}
@ -402,10 +407,11 @@ static int vmdk_parent_open(BlockDriverState *bs)
{
char *p_name;
char desc[DESC_SIZE];
BDRVVmdkState *s = bs->opaque;
/* the descriptor offset = 0x200 */
if (bdrv_pread(bs->file, 0x200, desc, DESC_SIZE) != DESC_SIZE)
if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
return -1;
}
if ((p_name = strstr(desc,"parentFileNameHint")) != NULL) {
char *end_name;
@ -506,8 +512,10 @@ static int vmdk_open_vmdk3(BlockDriverState *bs, int flags)
int ret;
uint32_t magic;
VMDK3Header header;
BDRVVmdkState *s = bs->opaque;
VmdkExtent *extent;
s->desc_offset = 0x200;
ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
if (ret < 0) {
goto fail;
@ -539,6 +547,7 @@ static int vmdk_open_vmdk4(BlockDriverState *bs, int flags)
BDRVVmdkState *s = bs->opaque;
VmdkExtent *extent;
s->desc_offset = 0x200;
ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
if (ret < 0) {
goto fail;