On Mon, Mar 21, 2011 at 08:07:06PM +0900, Ryusuke Konishi wrote: > > So IMHO the .nilfs file is a hack in itself :-D > > The ".nilfs" file is used for two purposes: > > 1) As the file on which the nilfs library issues ioctls. > > 2) For advisory locks (i.e. fcntl(F_GETLK/F_SETLK/FSETLKW)). This > works as a mutex between the cleaner and other nilfs-tools. > > Note that the nilfs2 kernel code never uses the .nilfs file; it's just > a regular file for nilfs2. > > As for the item (1), we can use the root directory of each filesystem > instead. And for (2), a Posix semaphore or other lock primitives may > be available.
In NetBSD this is normally resolved by looking up the device the directory is residing and then opening/locking the device file etc. I think this is a better way of operating! It also doesn't allow two cleanerds to be started on one device; otherwise one could be started on the head and the other on a snapshot, or not? With regards, Reinoud -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
