qcow2: Update get_cluster_table() to support L2 slices

This patch updates get_cluster_table() to return L2 slices instead of
full L2 tables.

The code itself needs almost no changes, it only needs to call
offset_to_l2_slice_index() instead of offset_to_l2_index(). This patch
also renames all the relevant variables and the documentation.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 64cf064c0021ba315d3f3032da0f95db1b615f33.1517840877.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Alberto Garcia 2018-02-05 16:33:19 +02:00 committed by Max Reitz
parent 05f9ee4689
commit c03bfc5bba

View File

@ -659,20 +659,20 @@ fail:
* get_cluster_table
*
* for a given disk offset, load (and allocate if needed)
* the l2 table.
* the appropriate slice of its l2 table.
*
* the cluster index in the l2 table is given to the caller.
* the cluster index in the l2 slice is given to the caller.
*
* Returns 0 on success, -errno in failure case
*/
static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
uint64_t **new_l2_table,
uint64_t **new_l2_slice,
int *new_l2_index)
{
BDRVQcow2State *s = bs->opaque;
unsigned int l2_index;
uint64_t l1_index, l2_offset;
uint64_t *l2_table = NULL;
uint64_t *l2_slice = NULL;
int ret;
/* seek to the l2 offset in the l1 table */
@ -712,17 +712,17 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
assert(offset_into_cluster(s, l2_offset) == 0);
}
/* load the l2 table in memory */
ret = l2_load(bs, offset, l2_offset, &l2_table);
/* load the l2 slice in memory */
ret = l2_load(bs, offset, l2_offset, &l2_slice);
if (ret < 0) {
return ret;
}
/* find the cluster offset for the given disk offset */
l2_index = offset_to_l2_index(s, offset);
l2_index = offset_to_l2_slice_index(s, offset);
*new_l2_table = l2_table;
*new_l2_slice = l2_slice;
*new_l2_index = l2_index;
return 0;