On Mon, 2010-03-15 at 17:39 -0400, Jeff Layton wrote: > When a file is opened with O_TRUNC, the truncate processing is handled > by handle_truncate(). This function however doesn't receive any info > about the newly instantiated filp, and therefore can't pass that info > along so that the setattr can use it. > > This makes NFSv4 misbehave. The client does an open and gets a valid > stateid, and then doesn't use that stateid on the subsequent truncate. > It uses the zero-stateid instead. Most servers ignore this fact and > just do the truncate anyway, but some don't like it (notably, RHEL4). > > It seems more correct that since we have a fully instantiated file at > the time that handle_truncate is called, that we pass that along so > that the truncate operation can properly use it. At least in the O_CREAT|O_TRUNC case, we really should modify nfs4_opendata_alloc() to set the attrs.ia_size to zero, so that the server does an atomic open(O_CREAT|O_TRUNC) for us (see the DESCRIPTION paragraph in RFC3530 section 14.2.16). There shouldn't be any need for an extra truncate RPC call. Plain open(O_TRUNC) probably does need something along the lines of what you propose, however. Cheers 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
