报错解决transmission: Error: Input/Output error和ls: reading directory '': Input/output error

transmission: Error: Input/Output error

晚上想用transmission下载新的种子时报错：Error: Input/Output error。
我很奇怪，先运行命令：

-> # df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       874G  246G  582G  30% /media/pi/hdd

看到移动硬盘还挂载在那里，没有掉，然后奇怪的事情发生了：

-> # ls /media/pi/hdd 
ls: reading directory '/media/pi/hdd': Input/output error

运行如下命令查看出现什么问题：

-> # dmesg
[3914473.433059] EXT4-fs error (device sda1): ext4_find_entry:1436: inode #2: comm git: reading directory lblock 0
[3914473.486596] blk_partition_remap: fail for partition 1
[3914473.486615] EXT4-fs error (device sda1): ext4_find_entry:1436: inode #2: comm git: reading directory lblock 0
[3914483.904501] Voltage normalised (0x00000000)
[3914491.968540] Under-voltage detected! (0x00050005)
[3914496.032550] Voltage normalised (0x00000000)

我这里的问题是电压过低，重新连接即可