It was introduced by d1d5e05ffd ("hugetlbfs: return error code when
initializing module") but as Al pointed out, is a bad idea.
Quoted comments from Al:
"Note that unregister_filesystem() in module init is *always* wrong;
it's not an issue here (it's done too early to care about and
realistically the box is not going anywhere - it'll panic when attempt
to exec /sbin/init fails, if not earlier), but it's a damn bad
example.
Consider a normal fs module. Somebody loads it and in parallel with
that we get a mount attempt on that fs type. It comes between
register and failure exits that causes unregister; at that point we
are screwed since grabbing a reference to module as done by mount is
enough to prevent exit, but not to prevent the failure of init. As
the result, module will get freed when init fails, mounted fs of that
type be damned."
So remove it.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hillf Danton
7563ec4c21