Allover Stripes <[EMAIL PROTECTED]> writes: > > If you look at the implementation of the NFS lookup call in the Hurd > > nfsd (hurd/nfsd/ops.c:op_lookup) you will see that the server uses > > O_NOTRANS to prevent such activation.
> Hmmm. Is this really a good idea? Won't this cause problems if, for > example, there's a "mount point" in the filesystem being served? What > if the server really does want to run translators? Well, this is the current behavior of Sun NFS and most others; it would have to be a configuration option for the server which way you wanted it to run. > Say, it wants to export via NFS its BSD filesystem; would it then > send raw disk blocks across the network for the client to translate? I can't understand at all what you mean. Why does the fact that it's a BSD filesystem have anything to do with it? The point is that the nfsd doesn't ever cross translator linkages (== mount points). > That wasn't very clear. Suppose I have the following: antelope is > running an NFS server. It exports /visible and everything under it. > caribou is running an NFS client, importing the tree as /nfs. Now > suppose the following occur: antelope:/visible/bsd has a translator > set to "/bin/ufs /dev/hd0s3". Then if caribou tries to read and write > caribou:/nfs/bsd, it starts a translator trying to read and write > caribou's /dev/hd0s3. Yes, that's right. This is thus a little more live than the Sun NFS (for which the client doesn't see a mount at all). A server option could usefully set whether the client ever sees a translator. > At best it returns an error message; at worst severe lossage occurs. > Alternatively, suppose antelope:/visible/foo has its translator set > as /visible/bar. Then caribou:/nfs/foo apparently has its translator > set to teh nonexistent /visible/bar. If you then set > caribou:/nfs/foo's translator to /nfs/bar, reading the file works on > caribou but not on antelope. Yep, that's right. > Some nightmares are to be expected when using NFS; but is this really > the Right Thing? Possibly not. NFS handles mount points poorly, and the flexibility of translators makes it even harder to decide just what the Right Thing is. The best I can think of is a plethora of server options so users can pick which form of confusion they prefer. Thomas
