[PATCH 03/10] scsi/scsi_bus: switch search direction in scsi_device_find

[Paolo Bonzini <pbonzini@redhat.com>]

From: Maxim Levitsky <mlevitsk@redhat.com>

This change will allow us to convert the bus children list to RCU,
while not changing the logic of this function

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200913160259.32145-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/scsi/scsi-bus.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index 94921c04b1..69d7c3f90c 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -1571,7 +1571,7 @@ SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
     BusChild *kid;
     SCSIDevice *target_dev = NULL;
 
-    QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, sibling) {
+    QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
         DeviceState *qdev = kid->child;
         SCSIDevice *dev = SCSI_DEVICE(qdev);
 
@@ -1579,7 +1579,15 @@ SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
             if (dev->lun == lun) {
                 return dev;
             }
-            target_dev = dev;
+
+            /*
+             * If we don't find exact match (channel/bus/lun),
+             * we will return the first device which matches channel/bus
+             */
+
+            if (!target_dev) {
+                target_dev = dev;
+            }
         }
     }
     return target_dev;
-- 
2.26.2