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authorKevin Wolf <kwolf@redhat.com>2013-03-26 17:50:11 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2013-03-28 11:52:44 +0100
commit88c6588c5165da1526f735ed850861c5b74670bd (patch)
tree9ad34c64a0ead016b0c384a319e9721837d7f81a /block/qcow2-cluster.c
parent710c2496d8cecc92568d439a3cf9d5874b3a55e2 (diff)
downloadqemu-88c6588c5165da1526f735ed850861c5b74670bd.tar.gz
qcow2: Allow requests with multiple l2metas
Instead of expecting a single l2meta, have a list of them. This allows to still have a single I/O request for the guest data, even though multiple l2meta may be needed in order to describe both a COW overwrite and a new cluster allocation (typical sequential write case). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/qcow2-cluster.c')
-rw-r--r--block/qcow2-cluster.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 78e7db9b28..6dc7f7f36b 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1069,10 +1069,13 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
int alloc_n_start = offset_into_cluster(s, guest_offset)
>> BDRV_SECTOR_BITS;
int nb_sectors = MIN(requested_sectors, avail_sectors);
+ QCowL2Meta *old_m = *m;
*m = g_malloc0(sizeof(**m));
**m = (QCowL2Meta) {
+ .next = old_m,
+
.alloc_offset = alloc_cluster_offset,
.offset = start_of_cluster(s, guest_offset),
.nb_clusters = nb_clusters,