From 9b765486b7796bb775987dfbf5b99b9fdbc5e8ea Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Mon, 5 Feb 2018 16:33:28 +0200 Subject: qcow2: Read refcount before L2 table in expand_zero_clusters_in_l1() At the moment it doesn't really make a difference whether we call qcow2_get_refcount() before of after reading the L2 table, but if we want to support L2 slices we'll need to read the refcount first. This patch simply changes the order of those two operations to prepare for that. The patch with the actual semantic changes will be easier to read because of this. Signed-off-by: Alberto Garcia Reviewed-by: Eric Blake Reviewed-by: Max Reitz Message-id: 947a91d934053a2dbfef979aeb9568f57ef57c5d.1517840877.git.berto@igalia.com Signed-off-by: Max Reitz --- block/qcow2-cluster.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'block') diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index f440105f6c..1041dcb6dd 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1898,6 +1898,12 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, goto fail; } + ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, + &l2_refcount); + if (ret < 0) { + goto fail; + } + if (is_active_l1) { /* get active L2 tables from cache */ ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, @@ -1911,12 +1917,6 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, goto fail; } - ret = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits, - &l2_refcount); - if (ret < 0) { - goto fail; - } - for (j = 0; j < s->l2_size; j++) { uint64_t l2_entry = be64_to_cpu(l2_table[j]); int64_t offset = l2_entry & L2E_OFFSET_MASK; -- cgit v1.2.3