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qcow2: Drop REFCOUNT_SHIFT

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With BDRVQcowState.refcount_block_bits, we don't need REFCOUNT_SHIFT
anymore.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2014-09-03 00:25:07 +02:00 committed by Kevin Wolf
parent 234764eed1
commit 17bd5f4727
3 changed files with 15 additions and 21 deletions
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32
block/qcow2-refcount.c
View File

@ -100,7 +100,7 @@ static int get_refcount(BlockDriverState *bs, int64_t cluster_index)
uint16_t *refcount_block; uint16_t *refcount_block;
uint16_t refcount; 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) if (refcount_table_index >= s->refcount_table_size)
return 0; return 0;
refcount_block_offset = refcount_block_offset =
@ -121,8 +121,7 @@ static int get_refcount(BlockDriverState *bs, int64_t cluster_index)
return ret; return ret;
} }
block_index = cluster_index & block_index = cluster_index & (s->refcount_block_size - 1);
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
refcount = be16_to_cpu(refcount_block[block_index]); refcount = be16_to_cpu(refcount_block[block_index]);
ret = qcow2_cache_put(bs, s->refcount_block_cache, ret = qcow2_cache_put(bs, s->refcount_block_cache,
@ -157,8 +156,8 @@ static unsigned int next_refcount_table_size(BDRVQcowState *s,
static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a,
uint64_t offset_b) uint64_t offset_b)
{ {
uint64_t block_a = offset_a >> (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 >> (2 * s->cluster_bits - REFCOUNT_SHIFT); uint64_t block_b = offset_b >> (s->cluster_bits + s->refcount_block_bits);
return (block_a == block_b); return (block_a == block_b);
} }
@ -179,7 +178,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC);
/* Find the refcount block for the given cluster */ /* 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) { if (refcount_table_index < s->refcount_table_size) {
@ -256,7 +255,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
/* The block describes itself, need to update the cache */ /* The block describes itself, need to update the cache */
int block_index = (new_block >> s->cluster_bits) & 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); (*refcount_block)[block_index] = cpu_to_be16(1);
} else { } else {
/* Described somewhere else. This can recurse at most twice before we /* Described somewhere else. This can recurse at most twice before we
@ -328,8 +327,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW);
/* Calculate the number of refcount blocks needed so far */ /* 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, s->refcount_block_size);
uint64_t blocks_used = DIV_ROUND_UP(cluster_index, refcount_block_clusters);
if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) { if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) {
return -EFBIG; return -EFBIG;
@ -343,14 +341,14 @@ static int alloc_refcount_block(BlockDriverState *bs,
uint64_t table_clusters = uint64_t table_clusters =
size_to_clusters(s, table_size * sizeof(uint64_t)); size_to_clusters(s, table_size * sizeof(uint64_t));
blocks_clusters = 1 + blocks_clusters = 1 +
((table_clusters + refcount_block_clusters - 1) ((table_clusters + s->refcount_block_size - 1)
/ refcount_block_clusters); / s->refcount_block_size);
uint64_t meta_clusters = table_clusters + blocks_clusters; uint64_t meta_clusters = table_clusters + blocks_clusters;
last_table_size = table_size; last_table_size = table_size;
table_size = next_refcount_table_size(s, blocks_used + table_size = next_refcount_table_size(s, blocks_used +
((meta_clusters + refcount_block_clusters - 1) ((meta_clusters + s->refcount_block_size - 1)
/ refcount_block_clusters)); / s->refcount_block_size));
} while (last_table_size != table_size); } while (last_table_size != table_size);
@ -360,7 +358,7 @@ static int alloc_refcount_block(BlockDriverState *bs,
#endif #endif
/* Create the new refcount table and blocks */ /* 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; s->cluster_size;
uint64_t table_offset = meta_offset + blocks_clusters * 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); uint64_t *new_table = g_try_new0(uint64_t, table_size);
@ -560,8 +558,7 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
{ {
int block_index, refcount; int block_index, refcount;
int64_t cluster_index = cluster_offset >> s->cluster_bits; int64_t cluster_index = cluster_offset >> s->cluster_bits;
int64_t table_index = int64_t table_index = cluster_index >> s->refcount_block_bits;
cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
/* Load the refcount block and allocate it if needed */ /* Load the refcount block and allocate it if needed */
if (table_index != old_table_index) { if (table_index != old_table_index) {
@ -583,8 +580,7 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block);
/* we can update the count and save it */ /* we can update the count and save it */
block_index = cluster_index & block_index = cluster_index & (s->refcount_block_size - 1);
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
refcount = be16_to_cpu(refcount_block[block_index]); refcount = be16_to_cpu(refcount_block[block_index]);
refcount += addend; refcount += addend;

2
block/qcow2.c
View File

@ -1874,7 +1874,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
.l1_size = cpu_to_be32(0), .l1_size = cpu_to_be32(0),
.refcount_table_offset = cpu_to_be64(cluster_size), .refcount_table_offset = cpu_to_be64(cluster_size),
.refcount_table_clusters = cpu_to_be32(1), .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)), .header_length = cpu_to_be32(sizeof(*header)),
}; };

2
block/qcow2.h
View File

@ -59,8 +59,6 @@
/* The cluster reads as all zeros */ /* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1ULL << 0) #define QCOW_OFLAG_ZERO (1ULL << 0)
#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
#define MIN_CLUSTER_BITS 9 #define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21 #define MAX_CLUSTER_BITS 21