add-server-req

Steps in adding a request to the server:

1) select a request name and number
		src/proto/pvfs2-req-proto.h

2) add a request and response struct
		src/proto/pvfs2-req-proto.h
		add entry to unions: PVFS_server_req and PVFS_server_resp

2a) add endecode functions if needed
		src/proto/endecode-funcs.h
			for each of these you add or modify you must also
			add a stub in include/pvfs2-encode-stubs.h

2b) update the protocol version number
		src/proto/pvfs2-req-proto.h
			increment PVFS2_PROTO_MINOR, assuming that the
			addition of this new request does not break backwards
			compatibility for other request types
       
3) add entries to decode/encode functions
		src/proto/PINT-le-bytefield.c
			lebf_initialize() - need code here to set up a request so it
				can be encoded and expression for extra message size if any
			lebf_encode_req()
			lebf_encode_resp()
			lebf_decode_req()
			lebf_decode_resp()
			lebf_decode_rel() (2 places)
				In this last entry, we free any resources allocated during
				decode - specifically array items
				This does not free resources allocated by SM code

4) add request specific scratch space to PINT_server_op
		src/server/pvfs2-server.h
			PINT_server_op  -- only if required

5) write state machine -- see details below
		src/server/<reqname>.sm
			each state machine added must have a delcaration in
				src/server/pvfs2-server.h

6) update src/server/pvfs2-server-req.c
                add new entry to PINT_server_req_table[]
                reference the params structure from the state machine


Writing State Machines

Every state machine passes a PINT_server_op in to each state function.
	state machine initialized in src/server/pvfs2-server.c
		server_state_machine_start
			gets the s_op set up
			decodes request message
			sets s_op->req, s_op->resp

Each state machine must first run the pvfs2_prelude_sm
	reads the attribs of the target object, if appropriate to s_op->attr
	does basic permission checking
	posts request to the scheduler

State machines typically submit jobs, defined in
	src/io/job/job.h

Each state machine must run the pvfs2_final_response_sm
	releases request from the scheduler
	sends response to the client
		s_op->resp must be filled in
		return status in js_p->error_code

Cleanup must free any memory allocated by SM code

State functions return 0 or 1 on error-free completion,
	0 indicates an asynchronous call has been made and must be waited for
	1 indicates no async call was made and should proceed to next state
	<0 indicates an error - use PVFS_EXXX codes defined in
		include/pvfs2-types.h