The Friday 29 Aug 2014 à 23:45:26 (+0200), Max Reitz wrote :
> With BDRVQcowState.refcount_block_bits, we don't need REFCOUNT_SHIFT
> anymore.
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> ---
> 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
>
>
Putting Jun Li in copy because he just wrote a patch using it.
