Messages in this thread | | | Date | Fri, 14 Sep 2007 12:01:03 -0400 | From | Jeff Layton <> | Subject | Re: [NFS] [PATCH 2/7] NFS: if ATTR_KILL_S*ID bits are set, then skip mode change |
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On Sat, 15 Sep 2007 01:43:45 +1000 Greg Banks <gnb@sgi.com> wrote:
> On Fri, Sep 14, 2007 at 10:58:38AM -0400, Jeff Layton wrote: > > On Sat, 15 Sep 2007 00:40:33 +1000 > > Greg Banks <gnb@sgi.com> wrote: > > > > > > > Ok, you convinced me. > > > > Right. When I was first looking at this, I considered some similar > > approaches, but hit roadblocks with all of them. The only real option > > seems to be to leave this to the server, but that does assume that the > > server handles this properly. > > > > Servers that don't are broken, IMO. > > According to what spec? A quick trip around the machine room shows > that neither Solaris 10 nor Darwin 7.9.0 clobber setuid on write > either. >
Hmm, last time I checked Solaris, I thought it did, but that was Solaris 11. I'll plan to fire up my solaris qemu image and test it again...
> > If Irix isn't clearing these bits > > on a write then it might be good to see if they can fix that... > > I think first you'd have to mount a serious argument that it's broken, > more serious than "it works differently from Linux". >
Good point. POSIX is frustratingly ambiguous on this:
Upon successful completion, where nbyte is greater than 0, write() shall mark for update the st_ctime and st_mtime fields of the file, and if the file is a regular file, the S_ISUID and S_ISGID bits of the file mode may be cleared.
...the "may" in that last sentence makes it optional, I suppose. Even if it weren't then I guess there's also an argument that a write that comes in via a nfs server may not be subject to the same semantics as the write() syscall.
In any case, "broken" is probably too strong a term :-)
-- Jeff Layton <jlayton@redhat.com> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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