Is it easier to write filesystem drivers in userspace than in kernel space?
- by Jack
I will use the Linux NTFS driver as an example.
The Linux kernel NTFS driver only has very limited write support in the kernel, and after 5 years it is still considered experimental.
The same development team creates the ntfsmount userspace driver, which has almost perfect write support.
Likewise, the NTFS-3G project which is written by a different team also has almost perfect write support.
Why has the kernel drive taken so much longer? Is it much harder to develop for?
Saying that there already exists a decent userspace application is not a reason why the kernel driver is not compelte.
NOTE: Do not migrate this to superuser.com. I want a programing heavy answer, from a programming perspective, not a practical use answer. If the question is not appropriate for SO, please advise me as to why so I can edit it so it is.