Make sure the data is flushed to disk before closing file
channels. This is to ensure data is on disk and not lost in the event
of a host crash.

This is currently being implemented to affect the migration code when
migrating to a file, but all QIOChannelFile users should benefit from
the change.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 io/channel-file.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/io/channel-file.c b/io/channel-file.c
index a6ad7770c6..d4706fa592 100644
--- a/io/channel-file.c
+++ b/io/channel-file.c
@@ -242,6 +242,11 @@ static int qio_channel_file_close(QIOChannel *ioc,
 {
     QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
 
+    if (qemu_fdatasync(fioc->fd) < 0) {
+        error_setg_errno(errp, errno,
+                         "Unable to synchronize file data with storage device");
+        return -1;
+    }
     if (qemu_close(fioc->fd) < 0) {
         error_setg_errno(errp, errno,
                          "Unable to close file");
-- 
2.35.3