From: Trond Myklebust Subject: Re: [NFS] question about file identifier in NFS trace data Date: Mon, 28 Aug 2006 23:58:15 -0400 Message-ID: <1156823895.5609.3.camel@localhost> References: Mime-Version: 1.0 Content-Type: text/plain Cc: systemtap@sourceware.org, nfs@lists.sourceforge.net, tony.reix@bull.net, chucklever@gmail.com Return-path: To: Xue Peng Li In-Reply-To: List-Unsubscribe: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org List-ID: On Tue, 2006-08-29 at 11:12 +0800, Xue Peng Li wrote: > 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 See what we use for dprintk(): use dentries whenever possible, else use the combination sb->s_id + fileid. Cheers, Trond