On Apr 29, 2015, at 4:25 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > On Sat, Mar 28, 2015 at 11:46:35PM +0800, Kinglong Mee wrote: >> There are four macro defines for max tag length, >> in fs/nfs/nfs4xdr.c, >> /* NFSv4 COMPOUND tags are only wanted for debugging purposes */ >> #ifdef DEBUG >> #define NFS4_MAXTAGLEN 20 >> #else >> #define NFS4_MAXTAGLEN 0 >> #endif >> >> in fs/nfs/callback_xdr.c, >> #define CB_OP_TAGLEN_MAXSZ (512) >> >> in fs/nfsd/xdr4.h, >> #define NFSD4_MAX_TAGLEN 128 >> >> in fs/nfsd/xdr4cb.h, >> #define NFS4_MAXTAGLEN 20 >> >> But, according to rfc3530 and rfc5661, all the length should be >> limited by opaque limited. > > Neither server nor client really make any use of tags. The client at > least is never going Fwiw, Solaris clients send tags. > to send a tag. The server does echo back the tag > the client received. > > The one arguable bug here is that the spec doesn't appear to forbid the > server returning a non-zero-length tag when the client sent a > zero-length tag. And I don't think the client would handle that? > > If so, that might be better handled as a spec bug: if the most popular > client has never handled it then we know that no server's ever done it. > And it'd be annoying server behavior anyway, so, if it's de-facto > forbidden, great. > > In short, maybe best to just leave all this alone unless somebody's > actually seen this cause real-world problems.... > > --b. > >> >> The patch site defines a common macro named NFS4_MAXTAGLEN for >> all of them, limited to opaque limited. >> >> Kinglong Mee (4): >> nfs: define NFS4_MAXTAGLEN to OPAQUE limits >> nfs: use NFS4_MAXTAGLEN for cb_taglen checking >> nfsd: use NFS4_MAXTAGLEN for nfsd taglen checking >> nfsd: use NFS4_MAXTAGLEN defined in include/linux/nfs4.h >> >> fs/nfs/callback_xdr.c | 5 ++--- >> fs/nfs/nfs4xdr.c | 7 ------- >> fs/nfsd/nfs4xdr.c | 2 +- >> fs/nfsd/xdr4.h | 1 - >> fs/nfsd/xdr4cb.h | 3 ++- >> include/linux/nfs4.h | 1 + >> 6 files changed, 6 insertions(+), 13 deletions(-) >> >> -- >> 2.3.4 > -- > 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 -- Chuck Lever chuck[dot]lever[at]oracle[dot]com -- 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
