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[PATCH v5 13/31] qcow2: Update get/set_l2_entry() and add get/set_l2_bit
From: |
Alberto Garcia |
Subject: |
[PATCH v5 13/31] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap() |
Date: |
Tue, 5 May 2020 19:38:13 +0200 |
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 <address@hidden>
---
block/qcow2.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/block/qcow2.h b/block/qcow2.h
index 80ceb352c9..4ad93772b9 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -515,15 +515,36 @@ 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;
--
2.20.1
- [PATCH v5 25/31] qcow2: Clear the L2 bitmap when allocating a compressed cluster, (continued)
- [PATCH v5 25/31] qcow2: Clear the L2 bitmap when allocating a compressed cluster, Alberto Garcia, 2020/05/05
- [PATCH v5 28/31] qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit, Alberto Garcia, 2020/05/05
- [PATCH v5 05/31] qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied(), Alberto Garcia, 2020/05/05
- [PATCH v5 26/31] qcow2: Add subcluster support to handle_alloc_space(), Alberto Garcia, 2020/05/05
- [PATCH v5 20/31] qcow2: Add subcluster support to qcow2_get_host_offset(), Alberto Garcia, 2020/05/05
- [PATCH v5 13/31] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(),
Alberto Garcia <=
- [PATCH v5 16/31] qcow2: Add cluster type parameter to qcow2_get_host_offset(), Alberto Garcia, 2020/05/05
- Re: [PATCH v5 00/31] Add subcluster allocation to qcow2, Derek Su, 2020/05/20