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<p class="MsoNormal">I am interested in using a DLM for my user mode application and have been examining the ocfs2 DLM. I have been experimenting with the o2dlm_test code and have noticed an issue with the trylock command. When I start the o2dlm code with no
options, it is operating in classic mode and is using /dlm.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>On node 1 and node 2 I issue the command “register test”.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>On node 1 I issue the command “lock ex mylock” and the operation succeeds.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>On node 2 I issue the command “trylock ex mylock” and the operation fails as expected.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">4.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>On node 1, I then unlock by issuing the command “unlock mylock” and the operation succeeds.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="mso-list:Ignore">5.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>On node 2 I issue the command “trylock ex mylock” and the operation fails. This seems to be an error. The operation should succeed.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Note that if I try the same operations shown above with o2dlm_test invoked with the –u option which causes it to use fsdlm, I don’t see the error in step 5 above. Everything works as expected.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It is also my understanding from examining the code that when using /dlm (this mode is referred to as “classic” in the source code), blocking ASTs are supported, but when using fsdlm blocking operations are not supported. Is this a correct
understanding?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In the tests that I am running I am using the DLM with a two node ocfs2 cluster, but in my final design I want to remove the DLM code from the file system and use it in another application. Is this feasible?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Who is currently maintaining the DLM code?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">-jim<o:p></o:p></p>
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