[linux-pm] Freezer: Don't count threads waiting for frozen filesystems.

[Miklos Szeredi]

On Thu, 30 Oct 2008, Alan Stern wrote:
> Okay.  Don't forget things like ioctl for sockets -- they often involve 
> doing I/O directly to the network interface device.

Yeah, ioctls should probably just always be protected (at least
initially), regardless of what type of file they are done on.

> What happens to a task accessing a non-regular file on a fuse 
> filesystem?  :-)

The same as on any other filesystem, i.e. the fs is only involved as
far as calling init_special_inode(), the rest is taken care of by the
VFS.

Tejun Heo recently posted patches to fuse which enable emulating a
char device from userspace.  That is another matter, obviously we'd
want to keep the "allow suspend during I/O" property of fuse in that
case, even though there's a char device involved (but no hardware, at
least not on that level).

Miklos