Re: cvs commit: src/sys/kern vfs_cache.c vfs_syscalls.c vfs_vnops.c vfs_vopops.c src/sys/sys namecache.h stat.h

[Hiten Pandya <hmp@xxxxxxxxxxxxx>]

Joerg, the kqueue interface is not only un-suitable but it is a lot higher 
than FSMIDs (which are at namecache level) to be of any use.  Kqueue is 
too generic and does not even come close to solving the journaling and 
transactional requirements that FSMIDs are meant to solve.

The whole reason why FSMIDs are implemented within the namecache is 
because it makes it easier to manipulate the topology.  Even though the 
current FSMID framework has its issues, they are not exactly unsolvable.

				Hiten Pandya
				hmp@xxxxxxxxxxxxx

Joerg Sonnenberger wrote:
> That's not so much a problem of softupdates, but of any filesystem without very
> strong data journaling. ZFS is said to do something in that area, but it
> can't really solve interactions which cross filesystems. The very same
> problem exists for FSMIDs. This is something where a transactional database
> and a normal filesystem differ: filesystems almost never have full
> write-ahead log files, because it makes them awefully slow. The most
> important reason is that applications have no means to specify explicit
> transaction borders, so you have to assume an autocommit style usage
> always.
>
> Joerg