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[PATCH v6 25/32] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2(
From: |
Alberto Garcia |
Subject: |
[PATCH v6 25/32] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2() |
Date: |
Sun, 24 May 2020 16:51:45 +0200 |
The L2 bitmap needs to be updated after each write to indicate what
new subclusters are now allocated. This needs to happen even if the
cluster was already allocated and the L2 entry was otherwise valid.
In some cases however a write operation doesn't need change the L2
bitmap (because all affected subclusters were already allocated). This
is detected in calculate_l2_meta(), and qcow2_alloc_cluster_link_l2()
is never called in those cases.
Signed-off-by: Alberto Garcia <address@hidden>
---
block/qcow2-cluster.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 5e70b76c21..c8d6e16237 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1061,6 +1061,24 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs,
QCowL2Meta *m)
assert((offset & L2E_OFFSET_MASK) == offset);
set_l2_entry(s, l2_slice, l2_index + i, offset | QCOW_OFLAG_COPIED);
+
+ /* Update bitmap with the subclusters that were just written */
+ if (has_subclusters(s)) {
+ uint64_t l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index + i);
+ unsigned written_from = m->cow_start.offset;
+ unsigned written_to = m->cow_end.offset + m->cow_end.nb_bytes ?:
+ m->nb_clusters << s->cluster_bits;
+ int first_sc, last_sc;
+ /* Narrow written_from and written_to down to the current cluster
*/
+ written_from = MAX(written_from, i << s->cluster_bits);
+ written_to = MIN(written_to, (i + 1) << s->cluster_bits);
+ assert(written_from < written_to);
+ first_sc = offset_to_sc_index(s, written_from);
+ last_sc = offset_to_sc_index(s, written_to - 1);
+ l2_bitmap |= QCOW_OFLAG_SUB_ALLOC_RANGE(first_sc, last_sc + 1);
+ l2_bitmap &= ~QCOW_OFLAG_SUB_ZERO_RANGE(first_sc, last_sc + 1);
+ set_l2_bitmap(s, l2_slice, l2_index + i, l2_bitmap);
+ }
}
--
2.20.1
- [PATCH v6 16/32] qcow2: Add qcow2_cluster_is_allocated(), (continued)
- [PATCH v6 16/32] qcow2: Add qcow2_cluster_is_allocated(), Alberto Garcia, 2020/05/24
- [PATCH v6 09/32] qcow2: Add subcluster-related fields to BDRVQcow2State, Alberto Garcia, 2020/05/24
- [PATCH v6 02/32] qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset(), Alberto Garcia, 2020/05/24
- [PATCH v6 22/32] qcow2: Add subcluster support to zero_in_l2_slice(), Alberto Garcia, 2020/05/24
- [PATCH v6 17/32] qcow2: Add cluster type parameter to qcow2_get_host_offset(), Alberto Garcia, 2020/05/24
- [PATCH v6 24/32] qcow2: Add subcluster support to check_refcounts_l2(), Alberto Garcia, 2020/05/24
- [PATCH v6 26/32] qcow2: Clear the L2 bitmap when allocating a compressed cluster, Alberto Garcia, 2020/05/24
- [PATCH v6 28/32] qcow2: Add subcluster support to qcow2_co_pwrite_zeroes(), Alberto Garcia, 2020/05/24
- [PATCH v6 27/32] qcow2: Add subcluster support to handle_alloc_space(), Alberto Garcia, 2020/05/24
- [PATCH v6 19/32] qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC, Alberto Garcia, 2020/05/24
- [PATCH v6 25/32] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2(),
Alberto Garcia <=
- [PATCH v6 11/32] qcow2: Add offset_into_subcluster() and size_to_subclusters(), Alberto Garcia, 2020/05/24
- [PATCH v6 15/32] qcow2: Add qcow2_get_subcluster_range_type(), Alberto Garcia, 2020/05/24
- [PATCH v6 07/32] qcow2: Document the Extended L2 Entries feature, Alberto Garcia, 2020/05/24
- [PATCH v6 13/32] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap(), Alberto Garcia, 2020/05/24
- [PATCH v6 04/32] qcow2: Split cluster_needs_cow() out of count_cow_clusters(), Alberto Garcia, 2020/05/24
- [PATCH v6 31/32] qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters, Alberto Garcia, 2020/05/24
- [PATCH v6 32/32] iotests: Add tests for qcow2 images with extended L2 entries, Alberto Garcia, 2020/05/24
- [PATCH v6 08/32] qcow2: Add dummy has_subclusters() function, Alberto Garcia, 2020/05/24
- [PATCH v6 18/32] qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*, Alberto Garcia, 2020/05/24