[Qemu-devel] [PATCH 6/6] qcow2: Resize the cache upon image resizing

[Leonid Bloch <lbloch@janustech.com>]

The caches are now recalculated upon image resizing. This is done
because the new default behavior of assigning a sufficient L2 cache to
cover the entire image implies that the cache will still be sufficient
after image resizing. To put a limit on the cache, the options
cache-size and l2-cache-size can be used.

Signed-off-by: Leonid Bloch <lbloch@janustech.com>
---
 block/qcow2.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index 74f2cb10a4..06fac1bb8c 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3656,6 +3656,12 @@ static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset,
     }
 
     s->l1_vm_state_index = new_l1_size;
+    /* Update cache sizes */
+    QDict *options = qdict_clone_shallow(bs->options);
+    ret = qcow2_update_options(bs, options, s->flags, errp);
+    if (ret < 0) {
+        goto fail;
+    }
     ret = 0;
 fail:
     qemu_co_mutex_unlock(&s->lock);
-- 
2.17.1