[Qemu-devel] [PATCH v2 3/5] 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 an image resizing.

Signed-off-by: Leonid Bloch <lbloch@janustech.com>
---
 block/qcow2.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index 98cb96aaca..f60cb92169 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3639,6 +3639,8 @@ static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset,
         }
     }
 
+    bs->total_sectors = offset / BDRV_SECTOR_SIZE;
+
     /* write updated header.size */
     offset = cpu_to_be64(offset);
     ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
@@ -3649,6 +3651,12 @@ 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