> -----Original Message----- > From: linux-nfs-owner@xxxxxxxxxxxxxxx [mailto:linux-nfs- > owner@xxxxxxxxxxxxxxx] On Behalf Of NeilBrown > Sent: Sunday, September 16, 2012 7:06 PM > To: linux-nfs@xxxxxxxxxxxxxxx > Subject: What is NFSv4 READDIR doesn't return a filehandle.... > > > In NFSv4, the server can report which attributes it chose to return in a > READDIR reply. > > A customer has come across a server which does not return the filehandle > information (is that allowed?). The filehandle attribute is a mandatory attribute according to RFC3530, so I believe that the answer is "no". > A consequence of this is that Linux/NFS gets confused. > nfs_readdir_page_filler calls nfs_prime_dcache() (because it was a readdir > plus request that was sent) and nfs_prime_dcache goes ahead and creates > an inode based on the filehandle that it has. > However decode_attr_filehandle() had happily decoded nothing as the > FATTR4_WORD0_FILEHANDLE bit wasn't set. > So the inode gets created with a zero-length filehandle and when this gets > sent back to the server to act on the inode, it gets NFS4ERR_BADHANDLE to > the PUTFH op. > > So should nfs_prime_dcache() abort if the filehandle doesn't exist (patch > below) or should nfs_fhget() return an error if the filehandle is empty? > > Or maybe this behaviour should be detected and readdir should be disabled > for that server? > I don't want to have to code the client to deal with broken servers. If we start down that path, then we'll end up doing nothing else. I can, however, see a case for extending the "nordirplus" mount option to cover NFSv4. Currently it only acts on NFSv3 mounts... Cheers Trond -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
