From ab94db6f7609e562b5f68cc71807d5d50e24e224 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 25 Sep 2017 09:55:23 -0500 Subject: [PATCH] qcow2: Switch load_bitmap_data() to byte-based iteration Now that we have adjusted the majority of the calls this function makes to be byte-based, it is easier to read the code if it makes passes over the image using bytes rather than sectors. Signed-off-by: Eric Blake Reviewed-by: John Snow Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Kevin Wolf Reviewed-by: Fam Zheng Signed-off-by: Kevin Wolf --- block/qcow2-bitmap.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 2d8dcba3e8..02512a21f2 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -291,9 +291,8 @@ static int load_bitmap_data(BlockDriverState *bs, { int ret = 0; BDRVQcow2State *s = bs->opaque; - uint64_t sector, limit, sbc; + uint64_t offset, limit; uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); - uint64_t bm_sectors = DIV_ROUND_UP(bm_size, BDRV_SECTOR_SIZE); uint8_t *buf = NULL; uint64_t i, tab_size = size_to_clusters(s, @@ -305,32 +304,27 @@ static int load_bitmap_data(BlockDriverState *bs, buf = g_malloc(s->cluster_size); limit = bytes_covered_by_bitmap_cluster(s, bitmap); - sbc = limit >> BDRV_SECTOR_BITS; - for (i = 0, sector = 0; i < tab_size; ++i, sector += sbc) { - uint64_t count = MIN(bm_sectors - sector, sbc); + for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) { + uint64_t count = MIN(bm_size - offset, limit); uint64_t entry = bitmap_table[i]; - uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; + uint64_t data_offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; assert(check_table_entry(entry, s->cluster_size) == 0); - if (offset == 0) { + if (data_offset == 0) { if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) { - bdrv_dirty_bitmap_deserialize_ones(bitmap, - sector * BDRV_SECTOR_SIZE, - count * BDRV_SECTOR_SIZE, + bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count, false); } else { /* No need to deserialize zeros because the dirty bitmap is * already cleared */ } } else { - ret = bdrv_pread(bs->file, offset, buf, s->cluster_size); + ret = bdrv_pread(bs->file, data_offset, buf, s->cluster_size); if (ret < 0) { goto finish; } - bdrv_dirty_bitmap_deserialize_part(bitmap, buf, - sector * BDRV_SECTOR_SIZE, - count * BDRV_SECTOR_SIZE, + bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count, false); } }