Re: [libvirt] Use flock() instead of fcntl()

Am Freitag, 26. Juli 2013, 10:14:59 schrieb Daniel P. Berrange: > On Fri, Jul 26, 2013 at 10:44:24AM +0200, David Weber wrote: > > > Looking again at flock() I see it cannot support locking of ranges, only > > > the entire file. This makes it unsuitable as a replacement for libvirt's > > > use of fcntl() I'm afraid. I can only sugggest you configure OCFS2 so > > > that it supports fcntl(), or setup virtlockd to use separate indirect > > > leases on a diffrent shared filesystem, or perhaps try sanlock instead > > > which doesn't require any special filesystem support. > > > > It's true that flock() doesn't support locking of ranges but I can't see > > how this is necessary. > > The code may not currently use ranges, but that doesn't mean it'll stay > that way. By adding support for flock() we're preventing us from making > use of this feature in the future, and I don't want to see that. Just curious, what would be a possible feature which would require range based locking? I would really like to see flock() support in virtlockd because all other solutions have major drawbacks for me.