On Fri, Dec 05, 2008 at 09:51:45AM +0000, Steven Whitehouse wrote: > In that case gfs2 should be able to generate the id itself from the > fsname and it still doesn't need it passed in, even if it continues to > expose the id in sysfs. > > Perhaps better still, it should be possible for David to generate the id > directly if he really needs it from the fsname.
It's not actually a crc of the fsname, but a crc of the cpg name gfs_controld creates for the mountgroup, which is "gfs:mount:<fsname>". Also, we may at some point want to allow that generated id to be overriden by one that's set explicitly. > worry about!), and I don't see that netlink should have any more > overhead than any other method of sending messages. netlink is painful compared to uevents, look at dlm_controld/netlink.c which uses the "generic netlink" interface to transfer a data structure from the kernel to userspace. A library would help, but there didn't seem to be a de facto netlink lib when I needed it, maybe that's changed.
