On Fri, 2013-01-11 at 13:54 -0500, Samuel Li wrote: +AD4- A simple question with NLM svid implementation with after 2.6.16 or later. +AD4- +AD4- In the old days when linux client request and NLM lock it submits a +AD4- svid with the content of the client pid. However this appears to have +AD4- changed a few year ago and I get an incremental number starting from 0. +AD4- +AD4- from the NLM server side we only report the content of svid. I am trying +AD4- to find a way to identify the end user application request. +AD4- +AD4- for example +AD4- +AD4- +AFs-sli+AEA-fed16-vm nfs3+AF0AIw- ./gwaiting +ACY- ./gwaiting +ACY- ./gwaiting +ACY- (excl lock +AD4- programs) +AD4- +AFs-2+AF0- 977 +ADw---pid +AD4- +AFs-3+AF0- 978 +AD4- +AFs-4+AF0- 979 +AD4- +AD4- tshark -i eth0 -R +ACI-nlm+ACI- -V +AHw- grep -i svid +AD4- OOPS: dissector table +ACI-sctp.ppi+ACI- doesn't exist +AD4- Protocol being registered is +ACI-Datagram Transport Layer Security+ACI- +AD4- Running as user +ACI-root+ACI- and group +ACI-root+ACI-. This could be dangerous. +AD4- Capturing on eth0 +AD4- svid: 4 +AD4- svid: 3 +AD4- svid: 5 +AD4- svid: 3 +AD4- svid: 4 +AD4- svid: 4 +AD4- svid: 4 +AD4- svid: 5 +AD4- svid: 5 +AD4- +AD4- How do I determine from the client side who owns these NLM processes? +AD4- +AD4- The file lock in question was +AD4- inode 4318756868 so I could determine the lock. +AD4- +AD4- cat /proc/locks +AD4- 1: POSIX ADVISORY WRITE 979 00:2a:4315692708 0 EOF +AD4- 1: -+AD4- ACCESS ADVISORY WRITE 978 00:2a:4315692708 0 EOF +AD4- 2: POSIX ADVISORY WRITE 1778 00:10:16424 0 EOF +AD4- 3: POSIX ADVISORY WRITE 1677 00:10:18376 0 EOF +AD4- +AD4- Now assume I did not have the output of /proc/locks and only +AD4- nlm+AF8-lockowner number how would I debug this? The POSIX lock inheritance rules under the clone() system call (where POSIX locks must follow the file descriptor table and +AF8-not+AF8- the pid inheritance rules) mean that the svid does not map naturally into a pid. So post-2.6.16 we no longer try to pretend that is the case. The bottom line is that you can use the svid as a debugging tool for figuring out which locks belong to the same lock owner, but you cannot map it to a pid. -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust+AEA-netapp.com www.netapp.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
