vmdk: Allow reading variable size descriptor files

the hard-coded 2k buffer on the stack won't allow reading big descriptor
files which can be generated when storing big images. For example 500G
vmdk splitted to 2G chunks.

Signed-off-by: Evgeny Budilovsky <evgeny.budilovsky@ravellosystems.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Evgeny Budilovsky 2013-06-12 14:06:30 +03:00 committed by Kevin Wolf
parent f3c507adcd
commit 0bed087df2

View File

@ -722,27 +722,40 @@ static int vmdk_open_desc_file(BlockDriverState *bs, int flags,
int64_t desc_offset)
{
int ret;
char buf[2048];
char *buf = NULL;
char ct[128];
BDRVVmdkState *s = bs->opaque;
int64_t size;
ret = bdrv_pread(bs->file, desc_offset, buf, sizeof(buf));
if (ret < 0) {
return ret;
size = bdrv_getlength(bs->file);
if (size < 0) {
return -EINVAL;
}
size = MIN(size, 1 << 20); /* avoid unbounded allocation */
buf = g_malloc0(size + 1);
ret = bdrv_pread(bs->file, desc_offset, buf, size);
if (ret < 0) {
goto exit;
}
buf[2047] = '\0';
if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) {
return -EMEDIUMTYPE;
ret = -EMEDIUMTYPE;
goto exit;
}
if (strcmp(ct, "monolithicFlat") &&
strcmp(ct, "twoGbMaxExtentSparse") &&
strcmp(ct, "twoGbMaxExtentFlat")) {
fprintf(stderr,
"VMDK: Not supported image type \"%s\""".\n", ct);
return -ENOTSUP;
ret = -ENOTSUP;
goto exit;
}
s->desc_offset = 0;
return vmdk_parse_extents(buf, bs, bs->file->filename);
ret = vmdk_parse_extents(buf, bs, bs->file->filename);
exit:
g_free(buf);
return ret;
}
static int vmdk_open(BlockDriverState *bs, QDict *options, int flags)