From a53e8b7202dd941c619a57a640389560214d1f70 Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Fri, 10 Jul 2020 18:12:52 +0200 Subject: [PATCH] qcow2: Add offset_to_sc_index() For a given offset, return the subcluster number within its cluster (i.e. with 32 subclusters per cluster it returns a number between 0 and 31). Signed-off-by: Alberto Garcia Reviewed-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <56e3e4ac0d827c6a2f5f259106c5ddb7c4ca2653.1594396418.git.berto@igalia.com> Signed-off-by: Max Reitz --- block/qcow2.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block/qcow2.h b/block/qcow2.h index eee4c8de9c..2503374677 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -581,6 +581,11 @@ static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset) return (offset >> s->cluster_bits) & (s->l2_slice_size - 1); } +static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset) +{ + return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1); +} + static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s) { return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);