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authorPaolo Bonzini <pbonzini@redhat.com>2013-03-06 18:02:01 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2013-03-15 16:07:50 +0100
commit381b487d54ba18c73df9db8452028a330058c505 (patch)
treeba501d114bd2f5010366e67c306ac08843186c77 /block
parent3647917919dfce5f731755f0ac5955a64bc12570 (diff)
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qcow2: make is_allocated return true for zero clusters
Otherwise, live migration of the top layer will miss zero clusters and let the backing file show through. This also matches what is done in qed. QCOW2_CLUSTER_ZERO clusters are invalid in v2 image files. Check this directly in qcow2_get_cluster_offset instead of replicating the test everywhere. Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/qcow2-cluster.c3
-rw-r--r--block/qcow2.c6
2 files changed, 4 insertions, 5 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index ff9ae18..d72d063 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -454,6 +454,9 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
*cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK;
break;
case QCOW2_CLUSTER_ZERO:
+ if (s->qcow_version < 3) {
+ return -EIO;
+ }
c = count_contiguous_clusters(nb_clusters, s->cluster_size,
&l2_table[l2_index], 0,
QCOW_OFLAG_COMPRESSED | QCOW_OFLAG_ZERO);
diff --git a/block/qcow2.c b/block/qcow2.c
index ad43a13..1f99866 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -621,7 +621,7 @@ static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs,
*pnum = 0;
}
- return (cluster_offset != 0);
+ return (cluster_offset != 0) || (ret == QCOW2_CLUSTER_ZERO);
}
/* handle reading after the end of the backing file */
@@ -702,10 +702,6 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num,
break;
case QCOW2_CLUSTER_ZERO:
- if (s->qcow_version < 3) {
- ret = -EIO;
- goto fail;
- }
qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
break;