[Linux-cluster] What is the order of processing a lock request?

[Ja S]

Hi, All:


When an application on a cluster node A needs to
access a file on a SAN storage, how DLM process the
lock request? 

Should DLM firstly determine whether there already
exists a lock resource mapped to the file, by doing
the following things in the order 1) looking at the
master lock resources on the node A, 2) searching the
local copies of lock resources on the node A, 3)
searching the lock directory on the node A to find out
whether a master lock resource assosicated with the
file exists on another node, 4) sending messages to
other nodes in the cluster for the location of the
master lock resource? 

I ask this question because from some online articles,
it seems that DLM will always search the cluster-wide
lock directory across the whole cluster first  to find
the location of the master lock resource. 

Can anyone kindly confirm the order of processes that
DLM does?

Many thanks in advance.

Jas



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