question about file identifier in NFS trace data

[Xue Peng Li]

Hi,
    I am now working on NFS trace hooks of LKET. I want to know what file 
is being operated for both client side and server 
side NFS functions. On client side, two kinds of data can be used to 
identify files, i.e. i_ino field of the inode object
which can identify the filesystem inode on disk, and the other is NFS file 
handler which is used to identify files between 
client and server.On server side ,only NFS file handler received from 
client can be used to identify file(It's very 
complicated to convert it to inode object at nfsd_* probe point).
 
    I am not sure which one should be traced. If file handler is traced 
,there is another problem , the total length of
file handler is 128 bytes,and for NFSV3 the length is variable. I am not 
sure how many bytes should be traced, if 128 bytes
are traced ,it's will so long for performance penalty, usually we only 
trace serval bytes for one data.

   Could anyone give me some suggestions? Thanks in advance

Thanks.

Best Regards,
Li Xuepeng  (李雪鹏)

Linux Performance, China Systems & Technology Lab
China Development Labs, Beijing
Email: xuepengl@cn.ibm.com