[Qemu-devel] [RFC PATCH 02/14] quorom: add a new read pattern

[Wen Congyang <wency@cn.fujitsu.com>]

To block replication, we only need to read from the first child.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 block/quorum.c       | 5 +++--
 qapi/block-core.json | 4 +++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/block/quorum.c b/block/quorum.c
index 437b122..5ed1ff8 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -286,9 +286,10 @@ static void quorum_aio_cb(void *opaque, int ret)
     BDRVQuorumState *s = acb->common.bs->opaque;
     bool rewrite = false;
 
-    if (acb->is_read && s->read_pattern == QUORUM_READ_PATTERN_FIFO) {
+    if (acb->is_read && s->read_pattern != QUORUM_READ_PATTERN_QUORUM) {
         /* We try to read next child in FIFO order if we fail to read */
-        if (ret < 0 && ++acb->child_iter < s->num_children) {
+        if (s->read_pattern == QUORUM_READ_PATTERN_FIFO &&
+            ret < 0 && ++acb->child_iter < s->num_children) {
             read_fifo_child(acb);
             return;
         }
diff --git a/qapi/block-core.json b/qapi/block-core.json
index a3fdaf0..d6382e9 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1618,9 +1618,11 @@
 #
 # @fifo: read only from the first child that has not failed
 #
+# @first: read only from the first child
+#
 # Since: 2.2
 ##
-{ 'enum': 'QuorumReadPattern', 'data': [ 'quorum', 'fifo' ] }
+{ 'enum': 'QuorumReadPattern', 'data': [ 'quorum', 'fifo', 'first' ] }
 
 ##
 # @BlockdevOptionsQuorum
-- 
2.1.0