[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v7 25/32] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2(
From: |
Alberto Garcia |
Subject: |
[PATCH v7 25/32] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2() |
Date: |
Mon, 25 May 2020 20:08:50 +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 edfc8ea91c..2276cee6d6 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
- Re: [PATCH v7 14/32] qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type(), (continued)
[PATCH v7 08/32] qcow2: Add dummy has_subclusters() function, Alberto Garcia, 2020/05/25
[PATCH v7 27/32] qcow2: Add subcluster support to handle_alloc_space(), Alberto Garcia, 2020/05/25
[PATCH v7 24/32] qcow2: Add subcluster support to check_refcounts_l2(), Alberto Garcia, 2020/05/25
[PATCH v7 11/32] qcow2: Add offset_into_subcluster() and size_to_subclusters(), Alberto Garcia, 2020/05/25
[PATCH v7 10/32] qcow2: Add offset_to_sc_index(), Alberto Garcia, 2020/05/25
[PATCH v7 29/32] qcow2: Add subcluster support to qcow2_measure(), Alberto Garcia, 2020/05/25
[PATCH v7 04/32] qcow2: Split cluster_needs_cow() out of count_cow_clusters(), Alberto Garcia, 2020/05/25
[PATCH v7 31/32] qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters, Alberto Garcia, 2020/05/25
[PATCH v7 25/32] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2(),
Alberto Garcia <=
[PATCH v7 18/32] qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*, Alberto Garcia, 2020/05/25
[PATCH v7 19/32] qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC, Alberto Garcia, 2020/05/25
[PATCH v7 03/32] qcow2: Add calculate_l2_meta(), Alberto Garcia, 2020/05/25
[PATCH v7 26/32] qcow2: Clear the L2 bitmap when allocating a compressed cluster, Alberto Garcia, 2020/05/25
[PATCH v7 21/32] qcow2: Add subcluster support to qcow2_get_host_offset(), Alberto Garcia, 2020/05/25
[PATCH v7 32/32] iotests: Add tests for qcow2 images with extended L2 entries, Alberto Garcia, 2020/05/25