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| author | Alberto Garcia <berto@igalia.com> | 2020-07-10 18:12:51 +0200 |
|---|---|---|
| committer | Max Reitz <mreitz@redhat.com> | 2020-08-25 08:33:20 +0200 |
| commit | d0346b5591825bab4d4b35aefb0ab0d7650e3641 (patch) | |
| tree | d4c0f80f2702fdc2544526fcb3b9474eb338a525 /block/qcow2.c | |
| parent | a3c7d9162513c2bea742f4278a58e401c6f37d0c (diff) | |
qcow2: Add subcluster-related fields to BDRVQcow2State
This patch adds the following new fields to BDRVQcow2State:
- subclusters_per_cluster: Number of subclusters in a cluster
- subcluster_size: The size of each subcluster, in bytes
- subcluster_bits: No. of bits so 1 << subcluster_bits = subcluster_size
Images without subclusters are treated as if they had exactly one
subcluster per cluster (i.e. subcluster_size = cluster_size).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <55bfeac86b092fa2c9d182a95cbeb479ff7eca4f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/qcow2.c')
| -rw-r--r-- | block/qcow2.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 6738daa247..fb4584d3ee 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1444,6 +1444,11 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, } } + s->subclusters_per_cluster = + has_subclusters(s) ? QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER : 1; + s->subcluster_size = s->cluster_size / s->subclusters_per_cluster; + s->subcluster_bits = ctz32(s->subcluster_size); + /* Check support for various header values */ if (header.refcount_order > 6) { error_setg(errp, "Reference count entry width too large; may not " |