ENOENT as an ioctl return code

[Thomas Hellstrom]

Hi,

By concidence I ran across this lkml message

http://marc.info/?l=linux-kernel&m=135628421403144&w=2

with an important part in the middle: (this is not a drm commit)

To make matters worse, commit f0ed2ce840b3 is clearly total and utter
CRAP even if it didn't break applications. ENOENT is not a valid error
return from an ioctl. Never has been, never will be. ENOENT means "No
such file and directory", and is for path operations. ioctl's are done
on files that have already been opened, there's no way in hell that
ENOENT would ever be valid.

Perhaps we should rethink the use of ENOENT when not finding mode objects?

Thanks,
Thomas