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[RFC PATCH v2 07/26] qcow2: Add subcluster-related fields to BDRVQcow2St
From: |
Alberto Garcia |
Subject: |
[RFC PATCH v2 07/26] qcow2: Add subcluster-related fields to BDRVQcow2State |
Date: |
Sun, 27 Oct 2019 00:25:09 +0300 |
This patch adds the following new fields to BDRVQcow2State:
- subclusters_per_cluster: Number of subclusters in a cluster
- subcluster_size: The size of each subcluster, in bytes
- subcluster_bits: No. of bits so 1 << subcluster_bits = subcluster_size
Images without subclusters are treated as if they had exactly one,
with subcluster_size = cluster_size.
Signed-off-by: Alberto Garcia <address@hidden>
---
block/qcow2.c | 5 +++++
block/qcow2.h | 5 +++++
2 files changed, 10 insertions(+)
diff --git a/block/qcow2.c b/block/qcow2.c
index 0bc69e6996..ed8b81c7b7 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1342,6 +1342,11 @@ static int coroutine_fn qcow2_do_open(BlockDriverState
*bs, QDict *options,
}
}
+ s->subclusters_per_cluster =
+ has_subclusters(s) ? QCOW_MAX_SUBCLUSTERS_PER_CLUSTER : 1;
+ s->subcluster_size = s->cluster_size / s->subclusters_per_cluster;
+ s->subcluster_bits = ctz32(s->subcluster_size);
+
/* Check support for various header values */
if (header.refcount_order > 6) {
error_setg(errp, "Reference count entry width too large; may not "
diff --git a/block/qcow2.h b/block/qcow2.h
index b3826b37c1..278ca41314 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -75,6 +75,8 @@
/* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1ULL << 0)
+#define QCOW_MAX_SUBCLUSTERS_PER_CLUSTER 32
+
#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21
@@ -277,6 +279,9 @@ typedef struct BDRVQcow2State {
int cluster_bits;
int cluster_size;
int l2_slice_size;
+ int subcluster_bits;
+ int subcluster_size;
+ int subclusters_per_cluster;
int l2_bits;
int l2_size;
int l1_size;
--
2.20.1
- [RFC PATCH v2 10/26] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(), (continued)
- [RFC PATCH v2 10/26] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 22/26] qcow2: Add subcluster support to handle_alloc_space(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 05/26] qcow2: Document the Extended L2 Entries feature, Alberto Garcia, 2019/10/26
- [RFC PATCH v2 14/26] qcow2: Add subcluster support to qcow2_get_cluster_offset(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 20/26] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 19/26] qcow2: Fix offset calculation in handle_dependencies(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 18/26] qcow2: Add subcluster support to expand_zero_clusters_in_l1(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 07/26] qcow2: Add subcluster-related fields to BDRVQcow2State,
Alberto Garcia <=
- [RFC PATCH v2 12/26] qcow2: Handle QCOW2_CLUSTER_UNALLOCATED_SUBCLUSTER, Alberto Garcia, 2019/10/26
- [RFC PATCH v2 23/26] qcow2: Restrict qcow2_co_pwrite_zeroes() to full clusters only, Alberto Garcia, 2019/10/26
- [RFC PATCH v2 09/26] qcow2: Add l2_entry_size(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 11/26] qcow2: Add qcow2_get_subcluster_type(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 15/26] qcow2: Add subcluster support to zero_in_l2_slice(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 17/26] qcow2: Add subcluster support to check_refcounts_l2(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 03/26] qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied(), Alberto Garcia, 2019/10/26
- [RFC PATCH v2 02/26] qcow2: Split cluster_needs_cow() out of count_cow_clusters(), Alberto Garcia, 2019/10/26