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[PATCH v11 04/34] qcow2: Split cluster_needs_cow() out of count_cow_clus
From: |
Alberto Garcia |
Subject: |
[PATCH v11 04/34] qcow2: Split cluster_needs_cow() out of count_cow_clusters() |
Date: |
Fri, 10 Jul 2020 18:12:46 +0200 |
We are going to need it in other places.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
block/qcow2-cluster.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 360da3f6b2..543f515c81 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1088,6 +1088,24 @@ static void calculate_l2_meta(BlockDriverState *bs,
QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight);
}
+/* Returns true if writing to a cluster requires COW */
+static bool cluster_needs_cow(BlockDriverState *bs, uint64_t l2_entry)
+{
+ switch (qcow2_get_cluster_type(bs, l2_entry)) {
+ case QCOW2_CLUSTER_NORMAL:
+ if (l2_entry & QCOW_OFLAG_COPIED) {
+ return false;
+ }
+ case QCOW2_CLUSTER_UNALLOCATED:
+ case QCOW2_CLUSTER_COMPRESSED:
+ case QCOW2_CLUSTER_ZERO_PLAIN:
+ case QCOW2_CLUSTER_ZERO_ALLOC:
+ return true;
+ default:
+ abort();
+ }
+}
+
/*
* Returns the number of contiguous clusters that can be used for an allocating
* write, but require COW to be performed (this includes yet unallocated space,
@@ -1100,25 +1118,11 @@ static int count_cow_clusters(BlockDriverState *bs, int
nb_clusters,
for (i = 0; i < nb_clusters; i++) {
uint64_t l2_entry = be64_to_cpu(l2_slice[l2_index + i]);
- QCow2ClusterType cluster_type = qcow2_get_cluster_type(bs, l2_entry);
-
- switch(cluster_type) {
- case QCOW2_CLUSTER_NORMAL:
- if (l2_entry & QCOW_OFLAG_COPIED) {
- goto out;
- }
+ if (!cluster_needs_cow(bs, l2_entry)) {
break;
- case QCOW2_CLUSTER_UNALLOCATED:
- case QCOW2_CLUSTER_COMPRESSED:
- case QCOW2_CLUSTER_ZERO_PLAIN:
- case QCOW2_CLUSTER_ZERO_ALLOC:
- break;
- default:
- abort();
}
}
-out:
assert(i <= nb_clusters);
return i;
}
--
2.20.1
- [PATCH v11 00/34] Add subcluster allocation to qcow2, Alberto Garcia, 2020/07/10
- [PATCH v11 08/34] qcow2: Add dummy has_subclusters() function, Alberto Garcia, 2020/07/10
- [PATCH v11 03/34] qcow2: Add calculate_l2_meta(), Alberto Garcia, 2020/07/10
- [PATCH v11 01/34] qcow2: Make Qcow2AioTask store the full host offset, Alberto Garcia, 2020/07/10
- [PATCH v11 02/34] qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset(), Alberto Garcia, 2020/07/10
- [PATCH v11 06/34] qcow2: Add get_l2_entry() and set_l2_entry(), Alberto Garcia, 2020/07/10
- [PATCH v11 04/34] qcow2: Split cluster_needs_cow() out of count_cow_clusters(),
Alberto Garcia <=
- [PATCH v11 07/34] qcow2: Document the Extended L2 Entries feature, Alberto Garcia, 2020/07/10
- [PATCH v11 05/34] qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied(), Alberto Garcia, 2020/07/10
- [PATCH v11 13/34] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(), Alberto Garcia, 2020/07/10
- [PATCH v11 15/34] qcow2: Add qcow2_get_subcluster_range_type(), Alberto Garcia, 2020/07/10
- [PATCH v11 19/34] qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC, Alberto Garcia, 2020/07/10
- [PATCH v11 09/34] qcow2: Add subcluster-related fields to BDRVQcow2State, Alberto Garcia, 2020/07/10
- [PATCH v11 20/34] qcow2: Add subcluster support to calculate_l2_meta(), Alberto Garcia, 2020/07/10
- [PATCH v11 18/34] qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*, Alberto Garcia, 2020/07/10
- [PATCH v11 22/34] qcow2: Add subcluster support to zero_in_l2_slice(), Alberto Garcia, 2020/07/10
- [PATCH v11 24/34] qcow2: Add subcluster support to check_refcounts_l2(), Alberto Garcia, 2020/07/10