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-rw-r--r--block/qcow2.c31
-rw-r--r--block/qcow2.h4
-rw-r--r--tests/qemu-iotests/137.out2
3 files changed, 20 insertions, 17 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 2f36e632f9..6d532470a8 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -802,23 +802,30 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
} else if (refcount_cache_size_set) {
*l2_cache_size = combined_cache_size - *refcount_cache_size;
} else {
- *refcount_cache_size = combined_cache_size
- / (DEFAULT_L2_REFCOUNT_SIZE_RATIO + 1);
- *l2_cache_size = combined_cache_size - *refcount_cache_size;
+ uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE;
+ uint64_t max_l2_cache = virtual_disk_size / (s->cluster_size / 8);
+ uint64_t min_refcount_cache =
+ (uint64_t) MIN_REFCOUNT_CACHE_SIZE * s->cluster_size;
+
+ /* Assign as much memory as possible to the L2 cache, and
+ * use the remainder for the refcount cache */
+ if (combined_cache_size >= max_l2_cache + min_refcount_cache) {
+ *l2_cache_size = max_l2_cache;
+ *refcount_cache_size = combined_cache_size - *l2_cache_size;
+ } else {
+ *refcount_cache_size =
+ MIN(combined_cache_size, min_refcount_cache);
+ *l2_cache_size = combined_cache_size - *refcount_cache_size;
+ }
}
} else {
- if (!l2_cache_size_set && !refcount_cache_size_set) {
+ if (!l2_cache_size_set) {
*l2_cache_size = MAX(DEFAULT_L2_CACHE_BYTE_SIZE,
(uint64_t)DEFAULT_L2_CACHE_CLUSTERS
* s->cluster_size);
- *refcount_cache_size = *l2_cache_size
- / DEFAULT_L2_REFCOUNT_SIZE_RATIO;
- } else if (!l2_cache_size_set) {
- *l2_cache_size = *refcount_cache_size
- * DEFAULT_L2_REFCOUNT_SIZE_RATIO;
- } else if (!refcount_cache_size_set) {
- *refcount_cache_size = *l2_cache_size
- / DEFAULT_L2_REFCOUNT_SIZE_RATIO;
+ }
+ if (!refcount_cache_size_set) {
+ *refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size;
}
}
diff --git a/block/qcow2.h b/block/qcow2.h
index adf5c3950f..01b5250415 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -77,10 +77,6 @@
#define DEFAULT_L2_CACHE_CLUSTERS 8 /* clusters */
#define DEFAULT_L2_CACHE_BYTE_SIZE 1048576 /* bytes */
-/* The refblock cache needs only a fourth of the L2 cache size to cover as many
- * clusters */
-#define DEFAULT_L2_REFCOUNT_SIZE_RATIO 4
-
#define DEFAULT_CLUSTER_SIZE 65536
diff --git a/tests/qemu-iotests/137.out b/tests/qemu-iotests/137.out
index e28e1eadba..96724a6c33 100644
--- a/tests/qemu-iotests/137.out
+++ b/tests/qemu-iotests/137.out
@@ -22,7 +22,7 @@ refcount-cache-size may not exceed cache-size
L2 cache size too big
L2 cache entry size must be a power of two between 512 and the cluster size (65536)
L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-L2 cache size too big
+Refcount cache size too big
Conflicting values for qcow2 options 'overlap-check' ('constant') and 'overlap-check.template' ('all')
Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all