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[Qemu-devel] [PATCH 1/2] qcow2: Drop REFCOUNT_SHIFT
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH 1/2] qcow2: Drop REFCOUNT_SHIFT |
Date: |
Fri, 29 Aug 2014 23:45:26 +0200 |
With BDRVQcowState.refcount_block_bits, we don't need REFCOUNT_SHIFT
anymore.
Signed-off-by: Max Reitz <address@hidden>
---
block/qcow2-refcount.c | 32 ++++++++++++++------------------
block/qcow2.c | 2 +-
block/qcow2.h | 2 --
3 files changed, 15 insertions(+), 21 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 29136ee..cd6f5a0 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -102,7 +102,7 @@ static int get_refcount(BlockDriverState *bs, int64_t
cluster_index)
uint16_t *refcount_block;
uint16_t refcount;
- refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
+ refcount_table_index = cluster_index >> s->refcount_block_bits;
if (refcount_table_index >= s->refcount_table_size)
return 0;
refcount_block_offset =
@@ -116,8 +116,7 @@ static int get_refcount(BlockDriverState *bs, int64_t
cluster_index)
return ret;
}
- block_index = cluster_index &
- ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
+ block_index = cluster_index & (s->refcount_block_size - 1);
refcount = be16_to_cpu(refcount_block[block_index]);
ret = qcow2_cache_put(bs, s->refcount_block_cache,
@@ -152,8 +151,8 @@ static unsigned int next_refcount_table_size(BDRVQcowState
*s,
static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a,
uint64_t offset_b)
{
- uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
- uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
+ uint64_t block_a = offset_a >> (s->cluster_bits + s->refcount_block_bits);
+ uint64_t block_b = offset_b >> (s->cluster_bits + s->refcount_block_bits);
return (block_a == block_b);
}
@@ -174,7 +173,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC);
/* Find the refcount block for the given cluster */
- refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
+ refcount_table_index = cluster_index >> s->refcount_block_bits;
if (refcount_table_index < s->refcount_table_size) {
@@ -243,7 +242,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
/* The block describes itself, need to update the cache */
int block_index = (new_block >> s->cluster_bits) &
- ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
+ (s->refcount_block_size - 1);
(*refcount_block)[block_index] = cpu_to_be16(1);
} else {
/* Described somewhere else. This can recurse at most twice before we
@@ -315,8 +314,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW);
/* Calculate the number of refcount blocks needed so far */
- uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT);
- uint64_t blocks_used = DIV_ROUND_UP(cluster_index,
refcount_block_clusters);
+ uint64_t blocks_used = DIV_ROUND_UP(cluster_index, s->refcount_block_size);
if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) {
return -EFBIG;
@@ -330,14 +328,14 @@ static int alloc_refcount_block(BlockDriverState *bs,
uint64_t table_clusters =
size_to_clusters(s, table_size * sizeof(uint64_t));
blocks_clusters = 1 +
- ((table_clusters + refcount_block_clusters - 1)
- / refcount_block_clusters);
+ ((table_clusters + s->refcount_block_size - 1)
+ / s->refcount_block_size);
uint64_t meta_clusters = table_clusters + blocks_clusters;
last_table_size = table_size;
table_size = next_refcount_table_size(s, blocks_used +
- ((meta_clusters + refcount_block_clusters - 1)
- / refcount_block_clusters));
+ ((meta_clusters + s->refcount_block_size - 1)
+ / s->refcount_block_size));
} while (last_table_size != table_size);
@@ -347,7 +345,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
#endif
/* Create the new refcount table and blocks */
- uint64_t meta_offset = (blocks_used * refcount_block_clusters) *
+ uint64_t meta_offset = (blocks_used * s->refcount_block_size) *
s->cluster_size;
uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size;
uint64_t *new_table = g_try_new0(uint64_t, table_size);
@@ -546,8 +544,7 @@ static int QEMU_WARN_UNUSED_RESULT
update_refcount(BlockDriverState *bs,
{
int block_index, refcount;
int64_t cluster_index = cluster_offset >> s->cluster_bits;
- int64_t table_index =
- cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
+ int64_t table_index = cluster_index >> s->refcount_block_bits;
/* Load the refcount block and allocate it if needed */
if (table_index != old_table_index) {
@@ -569,8 +566,7 @@ static int QEMU_WARN_UNUSED_RESULT
update_refcount(BlockDriverState *bs,
qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block);
/* we can update the count and save it */
- block_index = cluster_index &
- ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
+ block_index = cluster_index & (s->refcount_block_size - 1);
refcount = be16_to_cpu(refcount_block[block_index]);
refcount += addend;
diff --git a/block/qcow2.c b/block/qcow2.c
index 82bca88..cdbcb81 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1799,7 +1799,7 @@ static int qcow2_create2(const char *filename, int64_t
total_size,
.l1_size = cpu_to_be32(0),
.refcount_table_offset = cpu_to_be64(cluster_size),
.refcount_table_clusters = cpu_to_be32(1),
- .refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT),
+ .refcount_order = cpu_to_be32(4),
.header_length = cpu_to_be32(sizeof(*header)),
};
diff --git a/block/qcow2.h b/block/qcow2.h
index 7c01fb7..5b099cb 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -59,8 +59,6 @@
/* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1ULL << 0)
-#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
-
#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21
--
2.1.0