[PATCH 4/7] migration: Deliver return path file error to migrate state too

[Peter Xu <peterx@redhat.com>]

We've already did this for most of the return path thread errors, but not
yet for the IO errors happened on the return path qemufile.  Do that too.

Remember to reset "err" always, because the ownership is not us anymore,
otherwise we're prone to use-after-free later after recovered.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/migration.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/migration/migration.c b/migration/migration.c
index f8c41c4d98..234dd3601d 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1992,6 +1992,13 @@ out:
 
     res = qemu_file_get_error(rp);
     if (res) {
+        /* We have forwarded any error in "err" already, reuse "error" */
+        assert(err == NULL);
+        /* Try to deliver this file error to migration state */
+        qemu_file_get_error_obj(rp, &err);
+        migrate_set_error(ms, err);
+        err = NULL;
+
         if (res && migration_in_postcopy()) {
             /*
              * Maybe there is something we can do: it looks like a
-- 
2.41.0