On Tue, Aug 19, 2014 at 6:38 PM, Loris Degioanni [off-list ref] wrote:

(resending making sure this is not part of another thread)

I'm looking for an efficient way to determine the type of an fd (file,
socket...) given its number, from a kernel module.
The closest thing I found by looking at the kernel sources is
sockfd_lookup(), which works but is limited to telling me if the fd is a
socket or not.

Is there something else I can look at?

https://www.kernel.org/doc/Documentation/filesystems/files.txt

See point 4.

Daniel.