:On Mon, 2 Aug 1999, Alfred Perlstein wrote:
:
:>              } \
:>              if (fhlen != 0) { \
:>                      nfsm_dissect(tl, u_int32_t *, NFSX_V3FH); \
:>                      bcopy((caddr_t)tl, (caddr_t)(f), NFSX_V3FH); \
:>                      if ((nfsd->nd_flag & ND_NFSV3) == 0) \
:>                              nfsm_adv(NFSX_V2FH - NFSX_V3FH); \
:>              } \
:>      }
:
:...
:
:> it then rewinds the mbuf pointers (i think) because of the
:>   over "dissection" above.
:> ---
:> 
:> why does it do the copy, then rewind it, it seems like it knows
:> it's doing something wrong and instead of fixing it, it just 
:> compensates after the fact.
:
:yes, replying to my own message.
:
:the only thing i can think of is that the extra data is safely
:ignored because the routines that use these macros seem to
:pass the version of NFS to all the function that they call...
:
:however unless i'm wrong (which i probably am) nfsV2 stuff
:could be made faster if it was correctly noted and less data
:was copied.  It would also DTRT and not access data it isn't
:supposed to :)
:
:it seems like all of the V3 handles are the same length so
:there isn't much to do there...
:
:-Alfred
    
    Well, I must say that it certainly looks like a bug.  It is not going
    to blow anything up since the nfsm_dissect() will break out if it runs
    out of buffer space, but it certainly seems inefficient.  I am somewhat 
    loath to fix anything in NFS that does not create a demonstrateable
    problem for fear of creating new problems, though, it is quite possible
    that the server code depends on the extra junk in the file handle for
    V2 mounts - A full audit of nfs_nqlease.c and nfs_serv.c would be
    necessary before this could be fixed.

                                        -Matt
                                        Matthew Dillon 
                                        <[email protected]>


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