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[PATCH v7 13/32] qcow2: Update get/set_l2_entry() and add get/set_l2_bit
From: |
Alberto Garcia |
Subject: |
[PATCH v7 13/32] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap() |
Date: |
Mon, 25 May 2020 20:08:38 +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>
Reviewed-by: Eric Blake <address@hidden>
---
block/qcow2.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/block/qcow2.h b/block/qcow2.h
index 95cc16a089..5c6bf48c7a 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;
--
2.20.1
- Re: [PATCH v7 28/32] qcow2: Add subcluster support to qcow2_co_pwrite_zeroes(), (continued)
- [PATCH v7 15/32] qcow2: Add qcow2_get_subcluster_range_type(), Alberto Garcia, 2020/05/25
- [PATCH v7 06/32] qcow2: Add get_l2_entry() and set_l2_entry(), Alberto Garcia, 2020/05/25
- [PATCH v7 09/32] qcow2: Add subcluster-related fields to BDRVQcow2State, Alberto Garcia, 2020/05/25
- [PATCH v7 23/32] qcow2: Add subcluster support to discard_in_l2_slice(), Alberto Garcia, 2020/05/25
- [PATCH v7 01/32] qcow2: Make Qcow2AioTask store the full host offset, Alberto Garcia, 2020/05/25
- [PATCH v7 22/32] qcow2: Add subcluster support to zero_in_l2_slice(), Alberto Garcia, 2020/05/25
- [PATCH v7 13/32] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(),
Alberto Garcia <=
- [PATCH v7 16/32] qcow2: Add qcow2_cluster_is_allocated(), Alberto Garcia, 2020/05/25
- [PATCH v7 04/32] qcow2: Split cluster_needs_cow() out of count_cow_clusters(), Alberto Garcia, 2020/05/25
- [PATCH v7 14/32] qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type(), Alberto Garcia, 2020/05/25
- [PATCH v7 08/32] qcow2: Add dummy has_subclusters() function, Alberto Garcia, 2020/05/25
- [PATCH v7 10/32] qcow2: Add offset_to_sc_index(), Alberto Garcia, 2020/05/25
- [PATCH v7 11/32] qcow2: Add offset_into_subcluster() and size_to_subclusters(), Alberto Garcia, 2020/05/25
- [PATCH v7 24/32] qcow2: Add subcluster support to check_refcounts_l2(), Alberto Garcia, 2020/05/25