[PATCH v4 2/5] migration: Fix missing rcu_read_unlock

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Use the automatic rcu_read unlocker to fix a missing unlock.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
 migration/ram.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 22423f08cd..484d66379a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3373,24 +3373,23 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
     }
     (*rsp)->f = f;
 
-    rcu_read_lock();
-
-    qemu_put_be64(f, ram_bytes_total_common(true) | RAM_SAVE_FLAG_MEM_SIZE);
+    WITH_RCU_READ_LOCK_GUARD() {
+        qemu_put_be64(f, ram_bytes_total_common(true) | RAM_SAVE_FLAG_MEM_SIZE);
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
-        qemu_put_byte(f, strlen(block->idstr));
-        qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
-        qemu_put_be64(f, block->used_length);
-        if (migrate_postcopy_ram() && block->page_size != qemu_host_page_size) {
-            qemu_put_be64(f, block->page_size);
-        }
-        if (migrate_ignore_shared()) {
-            qemu_put_be64(f, block->mr->addr);
+        RAMBLOCK_FOREACH_MIGRATABLE(block) {
+            qemu_put_byte(f, strlen(block->idstr));
+            qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
+            qemu_put_be64(f, block->used_length);
+            if (migrate_postcopy_ram() && block->page_size !=
+                                          qemu_host_page_size) {
+                qemu_put_be64(f, block->page_size);
+            }
+            if (migrate_ignore_shared()) {
+                qemu_put_be64(f, block->mr->addr);
+            }
         }
     }
 
-    rcu_read_unlock();
-
     ram_control_before_iterate(f, RAM_CONTROL_SETUP);
     ram_control_after_iterate(f, RAM_CONTROL_SETUP);
 
-- 
2.23.0