On Tue, 2010-08-31 at 15:18 -0400, Valerie Aurora wrote: > On Mon, Aug 30, 2010 at 02:20:47PM +0200, Miklos Szeredi wrote: > > On Mon, 30 Aug 2010, Neil Brown wrote: > > > > > Val has been following that approach and asking if it is possible to make an > > > NFS filesystem really-truly read-only. i.e. no changes. > > > I don't believe it is. > > > > Perhaps it doesn't matter. The nasty cases can be prevented by just > > disallowing local modification. For the rest NFS will return ESTALE: > > "though luck, why didn't you follow the rules?" > > I agree: Ask the server to keep it read-only, but also detect if it > lied to prevent kernel bugs on the client. > > Is detecting ESTALE and failing the mount sufficient to detect all > cases of a cached directory being altered? No. Files can be altered without being unlinked. > I keep trying to trap an > NFS developer and beat the answer out of him but they usually get hung > up on the impossibility of 100% enforcement of the read-only server > option. (Agreed, impossible, just give the sysadmin a mount option so > that it doesn't happen accidentally.) Remind me again why mounting the filesystem '-oro' on the server (and possibly exporting it 'ro') isn't an option? Trond -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
