When every item of refcount block is NULL, free refcount block and reset the
corresponding item of refcount table with NULL.
Signed-off-by: Jun Li <junm...@gmail.com>
---
block/qcow2-refcount.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 43665b8..b53a000 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -586,6 +586,37 @@ static int QEMU_WARN_UNUSED_RESULT
update_refcount(BlockDriverState *bs,
if (refcount == 0 && s->discard_passthrough[type]) {
update_refcount_discard(bs, cluster_offset, s->cluster_size);
}
+
+ /* When refcount block is NULL, update refcount table */
+ if (block_index == 0) {
+ int k = block_index;
+ int refcount_block_entries = s->cluster_size / sizeof(uint16_t);
+ for (k = 1; k < refcount_block_entries; k++) {
+ if (refcount_block[++k] != cpu_to_be16(refcount)) {
+ break;
+ }
+ }
+
+ if (k == refcount_block_entries) {
+ qemu_vfree(refcount_block);
+ /* update refcount table */
+ unsigned int refcount_table_index;
+ uint64_t data64 = cpu_to_be64(0);
+ refcount_table_index = cluster_index >> (s->cluster_bits -
+ REFCOUNT_SHIFT);
+ ret = bdrv_pwrite_sync(bs->file,
+ s->refcount_table_offset +
+ refcount_table_index *
+ sizeof(uint64_t),
+ &data64, sizeof(data64));
+ if (ret < 0) {
+ goto fail;
+ }
+
+ s->refcount_table[refcount_table_index] = data64;
+
+ }
+ }
}
ret = 0;
--
1.9.3
