--- fs/nfs/super.c

+++ fs/nfs/super.c

@@ -1925,6 +1925,15 @@ nfs_remount(struct super_block *sb, int

if (error < 0)

goto out;

+ /*

+ * noac is a special case. It implies -o sync, but that's not

+ * necessarily reflected in the mtab options. do_remount_sb

+ * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the

+ * remount options, so we have to explicitly reset it.

+ */

+ if (data->flags & NFS_MOUNT_NOAC)

+ *flags |= MS_SYNCHRONOUS;

+

/* compare new mount options with old ones */

error = nfs_compare_remount_data(nfss, data);

out: