• NeilBrown's avatar
    [PATCH] knfsd: fix hash function for IP addresses on 64bit little-endian machines. · 1f1e030b
    NeilBrown authored
    The hash.h hash_long function, when used on a 64 bit machine, ignores many
    of the middle-order bits.  (The prime chosen it too bit-sparse).
    
    IP addresses for clients of an NFS server are very likely to differ only in
    the low-order bits.  As addresses are stored in network-byte-order, these
    bits become middle-order bits in a little-endian 64bit 'long', and so do
    not contribute to the hash.  Thus you can have the situation where all
    clients appear on one hash chain.
    
    So, until hash_long is fixed (or maybe forever), us a hash function that
    works well on IP addresses - xor the bytes together.
    
    Thanks to "Iozone" <capps@iozone.org> for identifying this problem.
    
    Cc: "Iozone" <capps@iozone.org>
    Signed-off-by: default avatarNeil Brown <neilb@suse.de>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    1f1e030b
svcauth_unix.c 11.4 KB