diff mbox series

[RFC,22/23] qcow2: Restrict qcow2_co_pwrite_zeroes() to full clusters only

Message ID a0098a6a28b64c709bd06c02e7603426b6a2992f.1571152571.git.berto@igalia.com (mailing list archive)
State New, archived
Headers show
Series Add subcluster allocation to qcow2 | expand

Commit Message

Alberto Garcia Oct. 15, 2019, 3:23 p.m. UTC 
Ideally it should be possible to zero individual subclusters using
this function, but this is currently not implemented.

Signed-off-by: Alberto Garcia <berto@igalia.com>
---
 block/qcow2.c | 6 ++++++
 1 file changed, 6 insertions(+)
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Patch

diff --git a/block/qcow2.c b/block/qcow2.c
index c54278ab0b..2eb032aed7 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3544,6 +3544,12 @@  static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
         bytes = s->cluster_size;
         nr = s->cluster_size;
         ret = qcow2_get_cluster_offset(bs, offset, &nr, &off);
+        /* TODO: allow zeroing separate subclusters, we only allow
+         * zeroing full clusters at the moment. */
+        if (nr != bytes) {
+            qemu_co_mutex_unlock(&s->lock);
+            return -ENOTSUP;
+        }
         if (ret != QCOW2_CLUSTER_UNALLOCATED &&
             ret != QCOW2_CLUSTER_UNALLOCATED_SUBCLUSTER &&
             ret != QCOW2_CLUSTER_ZERO_PLAIN &&