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[Qemu-devel] [PATCH v8 02/17] qcow2: Calculate refcount block entry coun
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH v8 02/17] qcow2: Calculate refcount block entry count |
Date: |
Wed, 22 Oct 2014 14:09:28 +0200 |
The size of a refblock entry is (in theory) variable; calculate
therefore the number of entries per refblock and the according bit shift
(1 << x == entry count) when opening an image.
Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
---
block/qcow2.c | 3 +++
block/qcow2.h | 2 ++
2 files changed, 5 insertions(+)
diff --git a/block/qcow2.c b/block/qcow2.c
index 156a219..3c8b881 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -698,6 +698,9 @@ static int qcow2_open(BlockDriverState *bs, QDict *options,
int flags,
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
s->l2_size = 1 << s->l2_bits;
+ /* 2^(s->refcount_order - 3) is the refcount width in bytes */
+ s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3);
+ s->refcount_block_size = 1 << s->refcount_block_bits;
bs->total_sectors = header.size / 512;
s->csize_shift = (62 - (s->cluster_bits - 8));
s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
diff --git a/block/qcow2.h b/block/qcow2.h
index 7d61e61..47cd4b3 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -223,6 +223,8 @@ typedef struct BDRVQcowState {
int l2_size;
int l1_size;
int l1_vm_state_index;
+ int refcount_block_bits;
+ int refcount_block_size;
int csize_shift;
int csize_mask;
uint64_t cluster_offset_mask;
--
1.9.3
- [Qemu-devel] [PATCH v8 00/17] qcow2: Fix image repairing, Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 02/17] qcow2: Calculate refcount block entry count,
Max Reitz <=
- [Qemu-devel] [PATCH v8 04/17] qcow2: Split qcow2_check_refcounts(), Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 01/17] block: Add qemu_{, try_}blockalign0(), Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 06/17] qcow2: Pull check_refblocks() up, Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 03/17] qcow2: Fix leaks in dirty images, Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 05/17] qcow2: Use sizeof(**refcount_table), Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 07/17] qcow2: Use int64_t for in-memory reftable size, Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 08/17] qcow2: Split fail code in L1 and L2 checks, Max Reitz, 2014/10/22
- [Qemu-devel] [PATCH v8 09/17] qcow2: Let inc_refcounts() return -errno, Max Reitz, 2014/10/22