On Wed, Feb 13, 2013 at 04:43:05PM +0000, Myklebust, Trond wrote: > On Wed, 2013-02-13 at 11:20 -0500, J. Bruce Fields wrote: > > Oops, probably should have cc'd linux-nfs. > > > > On Wed, Feb 13, 2013 at 10:36:54AM -0500, Theodore Ts'o wrote: > > > The other thing that I'd note is that the readdir cookie has been > > > 64-bit since NFSv3, which was released in June ***1995***. And the > > > explicit, stated purpose of making it be a 64-bit value (as stated in > > > RFC 1813) was to reduce interoperability problems. If that were the > > > case, are you telling me that Sun (who has traditionally been pretty > > > good worrying about interoperability concerns, and in fact employed > > > the editors of RFC 1813) didn't get this right? This seems > > > quite.... surprising to me. > > > > > > I thought this was the whole point of the various NFS interoperability > > > testing done at Connectathon, for which Sun was a major sponsor?!? No > > > one noticed?!? > > > > Beats me. But it's not necessarily easy to replace clients running > > legacy applications, so we're stuck working with the clients we have.... > > > > The linux client does remap the server-provided cookies to small > > integers, I believe exactly because older applications had trouble with > > servers returning "large" cookies. So presumably ext4-exporting-Linux > > servers aren't the first to do this. > > > > I don't know which client versions are affected--Connectathon's next > > week and I'll talk to people and make sure there's an ext4 export with > > this turned on to test against. > > Actually, one of the main reasons for the Linux client not exporting raw > readdir cookies is because the glibc-2 folks in their infinite wisdom > declared that telldir()/seekdir() use an off_t. They then went yet one > further and decided to declare negative offsets to be illegal so that > they could use the negative values internally in their syscall wrappers. > > The POSIX definition has none of the above rubbish > (http://pubs.opengroup.org/onlinepubs/009695399/functions/telldir.html) > and so glibc brilliantly saddled Linux with a crippled readdir > implementation that is _not_ POSIX compatible. > > No, I'm not at all bitter... Oh, right, I knew I'd forgotten part of the story.... But then you must have actually been testing against servers that were using that 32nd bit? I think ext4 actually only uses 31 bits even in the 32-bit case. And for a server that was literally using an offset inside a directory file, that would be a colossal directory. So I'm wondering how you ran across it. Partly just pure curiosity. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
