Reserved file structs

Fri, 26 Apr 96 09:36:53 +0100


I noticed last night that are no 'struct file's reserved for the
super-user. When max_files is reached the system becomes unusable as
no new processes can be started - ie. root cannot login to correct
the problem.
This can easily happen with a run-away process (or malicious(sp?)
user process); opening files, spawning, opening more files....

Is 'max_files' intended to be an absolute hard limit? In which case
the last few, say 5, should be reserved for root. If 'max_files'
is considered as a soft limit, then a request for a file ptr by
root should cause this limit to grow.

Havn't checked up, but I fairly sure get_empty_filp() is always
called in the context of the user-process which needs the structure.