Lab 8 QA

Q1

Explain how an OS supports automatically mounting file systems after plug in a USB flash drive into a computer.

keyword: hotplug, uevent, udev, udevd

• 熱插拔事件
• 拿到設備資料 (e.g. sysfs)
• 用 mknod 建立 device file
• 透過 USB Controller driver 讀寫 device file
• 透過 MBR/GPT 建立 partition 相關的 kernel object
• 透過 filesystem driver 讀寫對應的 partition

Q2

How to implement a component cache mechanism if a file has multiple names (because of hard links)

兩個 directory entry 指向同一個 cluster

Q3

Does tmpfs need sync method?

No.