On 5/12/25 14:28, Hanna Czenczek wrote:
On 29.04.25 12:31, Jean-Louis Dupond wrote:
When discard-no-unref is enabled, discards are not queued like it
should.
This was broken since discard-no-unref was added.
Add some helper function qcow2_discard_cluster which handles some common
checks and calls the queue_discards function if needed to add the
discard request to the queue.
Signed-off-by: Jean-Louis Dupond <jean-lo...@dupond.be>
---
block/qcow2-cluster.c | 16 ++++++----------
block/qcow2-refcount.c | 19 ++++++++++++++++++-
block/qcow2.h | 4 ++++
3 files changed, 28 insertions(+), 11 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index ce8c0076b3..c655bf6df4 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1978,12 +1978,10 @@ discard_in_l2_slice(BlockDriverState *bs,
uint64_t offset, uint64_t nb_clusters,
if (!keep_reference) {
/* Then decrease the refcount */
qcow2_free_any_cluster(bs, old_l2_entry, type);
- } else if (s->discard_passthrough[type] &&
- (cluster_type == QCOW2_CLUSTER_NORMAL ||
- cluster_type == QCOW2_CLUSTER_ZERO_ALLOC)) {
+ } else {
/* If we keep the reference, pass on the discard still */
- bdrv_pdiscard(s->data_file, old_l2_entry & L2E_OFFSET_MASK,
- s->cluster_size);
+ qcow2_discard_cluster(bs, old_l2_entry & L2E_OFFSET_MASK,
+ s->cluster_size, cluster_type, type);
}
}
@@ -2092,12 +2090,10 @@ zero_in_l2_slice(BlockDriverState *bs,
uint64_t offset,
if (!keep_reference) {
/* Then decrease the refcount */
qcow2_free_any_cluster(bs, old_l2_entry,
QCOW2_DISCARD_REQUEST);
- } else if (s->discard_passthrough[QCOW2_DISCARD_REQUEST] &&
- (type == QCOW2_CLUSTER_NORMAL ||
- type == QCOW2_CLUSTER_ZERO_ALLOC)) {
+ } else {
/* If we keep the reference, pass on the discard
still */
- bdrv_pdiscard(s->data_file, old_l2_entry &
L2E_OFFSET_MASK,
- s->cluster_size);
+ qcow2_discard_cluster(bs, old_l2_entry &
L2E_OFFSET_MASK,
+ s->cluster_size, type,
QCOW2_DISCARD_REQUEST);
}
}
}
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index d796018970..e1f830504d 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1205,6 +1205,23 @@ void qcow2_free_any_cluster(BlockDriverState
*bs, uint64_t l2_entry,
}
}
+void qcow2_discard_cluster(BlockDriverState *bs, uint64_t offset,
+ uint64_t length, QCow2ClusterType ctype,
+ enum qcow2_discard_type dtype) {
+
QEMU coding style requires putting the { on a separate line.
Fixed
+ BDRVQcow2State *s = bs->opaque;
+
+ if (s->discard_passthrough[dtype] &&
+ (ctype == QCOW2_CLUSTER_NORMAL ||
+ ctype == QCOW2_CLUSTER_ZERO_ALLOC)) {
+ if (has_data_file(bs)) {
+ bdrv_pdiscard(s->data_file, offset, length);
+ } else {
+ queue_discard(bs, offset, length);
+ }
+ }
+}
+
int qcow2_write_caches(BlockDriverState *bs)
{
BDRVQcow2State *s = bs->opaque;
@@ -3619,7 +3636,7 @@ qcow2_discard_refcount_block(BlockDriverState
*bs, uint64_t discard_block_offs)
/* discard refblock from the cache if refblock is cached */
qcow2_cache_discard(s->refcount_block_cache, refblock);
}
- update_refcount_discard(bs, discard_block_offs, s->cluster_size);
+ queue_discard(bs, discard_block_offs, s->cluster_size);
return 0;
}
This hunk should go into the previous patch.
Fixed
diff --git a/block/qcow2.h b/block/qcow2.h
index a9e3481c6e..547bb2b814 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -880,6 +880,10 @@ void GRAPH_RDLOCK
qcow2_free_clusters(BlockDriverState *bs,
void GRAPH_RDLOCK
qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
enum qcow2_discard_type type);
+void GRAPH_RDLOCK
+qcow2_discard_cluster(BlockDriverState *bs, uint64_t offset,
+ uint64_t length, QCow2ClusterType ctype,
+ enum qcow2_discard_type dtype);
int GRAPH_RDLOCK
qcow2_update_snapshot_refcount(BlockDriverState *bs, int64_t
l1_table_offset,
With the above done, for both patch 1 and 2:
Reviewed-by: Hanna Czenczek <hre...@redhat.com>
Send v2 patch with comments addressed.
Thanks
Jean-Louis
