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[PULL 13/34] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(
From: |
Max Reitz |
Subject: |
[PULL 13/34] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap() |
Date: |
Tue, 25 Aug 2020 10:32:50 +0200 |
From: Alberto Garcia <berto@igalia.com>
Extended L2 entries are 128-bit wide: 64 bits for the entry itself and
64 bits for the subcluster allocation bitmap.
In order to support them correctly get/set_l2_entry() need to be
updated so they take the entry width into account in order to
calculate the correct offset.
This patch also adds the get/set_l2_bitmap() functions that are
used to access the bitmaps. For convenience we allow calling
get_l2_bitmap() on images without subclusters. In this case the
returned value is always 0 and has no meaning.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id:
<6ee0f81ae3329c991de125618b3675e1e46acdbb.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
block/qcow2.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/block/qcow2.h b/block/qcow2.h
index 46b351229a..82b86f6cec 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -533,15 +533,36 @@ static inline size_t l2_entry_size(BDRVQcow2State *s)
static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
int idx)
{
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
return be64_to_cpu(l2_slice[idx]);
}
+static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
+ int idx)
+{
+ if (has_subclusters(s)) {
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
+ return be64_to_cpu(l2_slice[idx + 1]);
+ } else {
+ return 0; /* For convenience only; this value has no meaning. */
+ }
+}
+
static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
int idx, uint64_t entry)
{
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
l2_slice[idx] = cpu_to_be64(entry);
}
+static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
+ int idx, uint64_t bitmap)
+{
+ assert(has_subclusters(s));
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
+ l2_slice[idx + 1] = cpu_to_be64(bitmap);
+}
+
static inline bool has_data_file(BlockDriverState *bs)
{
BDRVQcow2State *s = bs->opaque;
--
2.26.2
- [PULL 02/34] qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset(), (continued)
- [PULL 02/34] qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset(), Max Reitz, 2020/08/25
- [PULL 03/34] qcow2: Add calculate_l2_meta(), Max Reitz, 2020/08/25
- [PULL 04/34] qcow2: Split cluster_needs_cow() out of count_cow_clusters(), Max Reitz, 2020/08/25
- [PULL 05/34] qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied(), Max Reitz, 2020/08/25
- [PULL 06/34] qcow2: Add get_l2_entry() and set_l2_entry(), Max Reitz, 2020/08/25
- [PULL 07/34] qcow2: Document the Extended L2 Entries feature, Max Reitz, 2020/08/25
- [PULL 09/34] qcow2: Add subcluster-related fields to BDRVQcow2State, Max Reitz, 2020/08/25
- [PULL 10/34] qcow2: Add offset_to_sc_index(), Max Reitz, 2020/08/25
- [PULL 11/34] qcow2: Add offset_into_subcluster() and size_to_subclusters(), Max Reitz, 2020/08/25
- [PULL 12/34] qcow2: Add l2_entry_size(), Max Reitz, 2020/08/25
- [PULL 13/34] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(),
Max Reitz <=
- [PULL 08/34] qcow2: Add dummy has_subclusters() function, Max Reitz, 2020/08/25
- [PULL 15/34] qcow2: Add qcow2_get_subcluster_range_type(), Max Reitz, 2020/08/25
- [PULL 14/34] qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type(), Max Reitz, 2020/08/25
- [PULL 16/34] qcow2: Add qcow2_cluster_is_allocated(), Max Reitz, 2020/08/25
- [PULL 18/34] qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*, Max Reitz, 2020/08/25
- [PULL 19/34] qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC, Max Reitz, 2020/08/25
- [PULL 22/34] qcow2: Add subcluster support to zero_in_l2_slice(), Max Reitz, 2020/08/25
- [PULL 21/34] qcow2: Add subcluster support to qcow2_get_host_offset(), Max Reitz, 2020/08/25
- [PULL 23/34] qcow2: Add subcluster support to discard_in_l2_slice(), Max Reitz, 2020/08/25
- [PULL 20/34] qcow2: Add subcluster support to calculate_l2_meta(), Max Reitz, 2020/08/25