<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>That is depend of rpc type - is that RPC want to be return lock to caller or not, and is that rpc want to have special code to reconstruct in replay phase.</div><div>in general you need look to mdt/mdt_handler.c. mdt_get_info is good example of simple rpc processing - but it use new PtlRPC api.</div><div>that is API hide of low level request structures and provide api to access to message buffer by identifier.</div><div>to use that API you need define structure of own message in ptlrpc/layout.c, and own command in enum mds_cmd_t, adjust array with commands and write own handler.</div><div><br></div><div><br></div><div><div><div>On Oct 13, 2010, at 01:17, Vilobh Meshram wrote:</div><blockquote type="cite"><font color="#3333ff"><font size="2"><font face="times new roman,serif">Thanks <a href="http://Alexey.It">Alexey.It</a> was helpful.<br><br>I have one more question :-<br><br>If we want to add a new RPC with a new opcode are there any guidlines to be followed in the Lustre File System.<br>
<br>Also ,<br>1)How does the MDS process the ptlrpc_request i.e how does the MDS extract the buffer information from the ptlrpc_message.<br>2)For every new RPC is the message length which is to be sent on wire ( including the fixed header size + the buffer size) dependent on the number of buffers in the lustre request message i.e the count field in the ptlrpc_prep_req() or the size of the size[] array.<br>
<br><br clear="all"></font></font></font><font color="#3333ff"><font face="'times new roman', serif">Thanks,<br>Vilobh<br></font></font><i><font style="color: rgb(51, 51, 255);" size="2">Graduate Research Associate<br>
Department of Computer Science<br>The Ohio State University Columbus Ohio</font></i><br>
<br><br><div class="gmail_quote">On Tue, Oct 12, 2010 at 2:21 PM, Alexey Lyashkov <span dir="ltr"><<a href="mailto:alexey.lyashkov@clusterstor.com">alexey.lyashkov@clusterstor.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div style="word-wrap: break-word;">Hi Vilobh,<div><br></div><div>ldlm_cli_cancel_req is good example to use old PtlRPC API.</div><div>for first you need allocate request buffer via ptlrpc_prep_req</div><div>next is - allocate reply buffer via ptlrpc_req_set_repsize</div>
<div>next - call ptlrpc_queue_wait to send message and wait reply.</div><div><br></div><div>osc_getattr_async good example for new PtlRPC API and async RPC processing.</div><div><br></div><div>if that isn't help you - please show a yours code to find a error.</div>
<div><br><div><div><div></div><div class="h5"><div>On Oct 12, 2010, at 20:55, Vilobh Meshram wrote:</div><br></div></div><blockquote type="cite"><div><div></div><div class="h5"><font style="color: rgb(51, 51, 255);" size="2" color="#3333ff"><font face="times new roman,serif">I
want to understand the message encoding and decoding logic in lustre.I
am planning to send a request to the MDS and based on the reply from MDs want to populate the <br><br> struct lustre_msg *rq_repbuf; /* client only, buf may be bigger than msg */<br> struct lustre_msg *rq_repmsg;<br>
<br>I am trying this for a simple "Hello" message but not seeing the expected output.Sometime I even see Kernel Crash.<br>If you can please give me some insight on the way the Lustre File
system encodes decodes the messages sent accross nodes it would be
helpful.</font></font><font style="color: rgb(51, 51, 255);" size="2"><br><br clear="all"></font><font style="color: rgb(51, 51, 255);" size="2" color="#3333ff"><font face="'times new roman', serif">Thanks,<br>Vilobh<br>
</font></font><i><font style="color: rgb(51, 51, 255);" size="2">Graduate Research Associate<br>Department of Computer Science<br>The Ohio State University Columbus Ohio</font></i><br></div></div>
_______________________________________________<br>Lustre-devel mailing list<br><a href="mailto:Lustre-devel@lists.lustre.org" target="_blank">Lustre-devel@lists.lustre.org</a><br><a href="http://lists.lustre.org/mailman/listinfo/lustre-devel" target="_blank">http://lists.lustre.org/mailman/listinfo/lustre-devel</a><br>
</blockquote></div><br></div></div></blockquote></div><br>
</blockquote></div><br></div></div></body></html>