Volume was not properly unmounted. Some data may be corrupt

在板子上运行程序，报错误

FAT-fs (mmcblk0p1): error, fat_get_cluster: invalid cluster chain (i_pos 141586439)

umount又 mount后报错误

FAT-fs (mmcblk0p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.

将T卡插到电脑上，用df命令查看挂载的路径， /dev/sdc1，运行 fsck

$ sudo fsck /dev/sdc1

根据提示，将corrupt的地方擦掉。