This file implements the RDMA transport sendto function. A RPC reply
on an RDMA transport consists of some number of RDMA_WRITE requests
followed by an RDMA_SEND request. The sendto function parses the
ONCRPC RDMA reply header to determine how to send the reply back to
the client. The send queue is sized so as to be able to send complete
replies for requests in most cases.  In the event that there are not
enough SQ WR slots to reply, e.g.  big data, the send will block the
NFSD thread. The I/O callback functions in svc_rdma_transport.c that
reap WR completions wake any waiters blocked on the SQ. In general,
the goal is not to block NFSD threads and the has_wspace method
stall requests when the SQ is nearly full.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This file implements the RDMA transport recvfrom function. The function
dequeues work reqeust completion contexts from an I/O list that it shares
with the I/O tasklet in svc_rdma_transport.c. For ONCRPC RDMA, an RPC may
not be complete when it is received. Instead, the RDMA header that precedes
the RPC message informs the transport where to get the RPC data from on
the client and where to place it in the RPC message before it is delivered
to the server. The svc_rdma_recvfrom function therefore, parses this RDMA
header and issues any necessary RDMA operations to fetch the remainder of
the RPC from the client.

Special handling is required when the request involves an RDMA_READ.
In this case, recvfrom submits the RDMA_READ requests to the underlying
transport driver and then returns 0. When the transport
completes the last RDMA_READ for the request, it enqueues it on a
read completion queue and enqueues the transport. The recvfrom code
favors this queue over the regular DTO queue when satisfying reads.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This file implements the core transport data management and I/O
path. The I/O path for RDMA involves receiving callbacks on interrupt
context. Since all the svc transport locks are _bh locks we enqueue the
transport on a list, schedule a tasklet to dequeue data indications from
the RDMA completion queue. The tasklet in turn takes _bh locks to
enqueue receive data indications on a list for the transport. The
svc_rdma_recvfrom transport function dequeues data from this list in an
NFSD thread context.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This file implements the RDMA transport module initialization and
termination logic and registers the transport sysctl variables.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This file defines the data types used by the SVCRDMA transport module.
The principle data structure is the transport specific extension to
the svcxprt structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Create a transport independent version of the svc_sock_names function.

The toclose capability of the svc_sock_names service can be implemented
using the svc_xprt_find and svc_xprt_close services.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Update the write handler for the portlist file to allow creating new
listening endpoints on a transport. The general form of the string is:

<transport_name><space><port number>

For example:

echo "tcp 2049" > /proc/fs/nfsd/portlist

This is intended to support the creation of a listening endpoint for
RDMA transports without adding #ifdef code to the nfssvc.c file.

Transports can also be removed as follows:

'-'<transport_name><space><port number>

For example:

echo "-tcp 2049" > /proc/fs/nfsd/portlist

Attempting to add a listener with an invalid transport string results
in EPROTONOSUPPORT and a perror string of "Protocol not supported".

Attempting to remove an non-existent listener (.e.g. bad proto or port)
results in ENOTCONN and a perror string of
"Transport endpoint is not connected"
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Add a new svc function that allows a service to query whether a
transport instance has already been created. This is used in lockd
to determine whether or not a transport needs to be created when
a lockd instance is brought up.

Specifying 0 for the address family or port is effectively a wild-card,
and will result in matching the first transport in the service's list
that has a matching class name.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Add a file that when read lists the set of registered svc
transports.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Some transports have a header in front of the RPC header. The current
defer/revisit processing considers only the iov_len and arg_len to
determine how much to back up when saving the original request
to revisit. Add a field to the rqstp structure to save the size
of the transport header so svc_defer can correctly compute
the start of a request.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This functionally trivial patch moves all of the transport independent
functions from the svcsock.c file to the transport independent svc_xprt.c
file.

In addition the following formatting changes were made:
- White space cleanup
- Function signatures on single line
- The inline directive was removed
- Lines over 80 columns were reformatted
- The term 'socket' was changed to 'transport' in comments
- The SMP comment was moved and updated.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The svc_check_conn_limits function only manipulates xprt fields. Change references
to svc_sock->sk_xprt to svc_xprt directly.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This functionally empty patch removes rq_sock and unamed union
from rqstp structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move the svc transport list logic into common transport creation code.
Refactor this code path to make the flow of control easier to read.

Move the setting and clearing of the BUSY_BIT during transport creation
to common code.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This function is transport independent. Change it to use svc_xprt directly
and change it's name to reflect this.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

All of the transport field and functions used by svc_recv are now
transport independent. Change the svc_recv function to use the svc_xprt
structure directly instead of the transport specific svc_sock structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The svc_sock_release function only touches transport independent fields.
Change the function to manipulate svc_xprt directly instead of the transport
dependent svc_sock structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This patch moves the transport sockaddr to the svc_xprt
structure.  Convenience functions are added to set and
get the local and remote addresses of a transport from
the transport provider as well as determine the length
of a sockaddr.

A transport is responsible for setting the xpt_local
and xpt_remote addresses in the svc_xprt structure as
part of transport creation and xpo_accept processing. This
cannot be done in a generic way and in fact varies
between TCP, UDP and RDMA. A set of xpo_ functions
(e.g. getlocalname, getremotename) could have been
added but this would have resulted in additional
caching and copying of the addresses around.  Note that
the xpt_local address should also be set on listening
endpoints; for TCP/RDMA this is done as part of
endpoint creation.

For connected transports like TCP and RDMA, the addresses
never change and can be set once and copied into the
rqstp structure for each request. For UDP, however, the
local and remote addresses may change for each request. In
this case, the address information is obtained from the
UDP recvmsg info and copied into the rqstp structure from
there.

A svc_xprt_local_port function was also added that returns
the local port given a transport. This is used by
svc_create_xprt when returning the port associated with
a newly created transport, and later when creating a
generic find transport service to check if a service is
already listening on a given port.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This patch moves the transport independent sk_deferred list to the svc_xprt
structure and updates the svc_deferred_req structure to keep pointers to
svc_xprt's directly. The deferral processing code is also moved out of the
transport dependent recvfrom functions and into the generic svc_recv path.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move the authinfo cache to svc_xprt. This allows both the TCP and RDMA
transports to share this logic. A flag bit is used to determine if
auth information is to be cached or not. Previously, this code looked
at the transport protocol.

I've also changed the spin_lock/unlock logic so that a lock is not taken for
transports that are not caching auth info.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

With the implementation of the new mark and sweep algorithm for shutting
down old connections, the sk_lastrecv field is no longer needed.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Now that the svc_xprt_received function handles transports, the call
to svc_xprt_received in the xpo_tcp_accept function can be moved to
common code.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

All fields touched by svc_sock_received are now transport independent.
Change it to use svc_xprt directly. This function is called from
transport dependent code, so export it.

Update the comment to clearly state the rules for calling this function.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move the sk_mutex field to the transport independent svc_xprt structure.
Now all the fields that svc_send touches are transport neutral. Change the
svc_send function to use the transport independent svc_xprt directly instead
of the transport dependent svc_sock structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The svc_sock_enqueue function is now transport independent since all of
the fields it touches have been moved to the transport independent svc_xprt
structure. Change the function to use the svc_xprt structure directly
instead of the transport specific svc_sock structure.

Transport specific data-ready handlers need to call this function, so
export it.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This functionally trivial patch moves the sk_reserved field to the
transport independent svc_xprt structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move sk_list and sk_ready to svc_xprt. This involves close because these
lists are walked by svcs when closing all their transports. So I combined
the moving of these lists to svc_xprt with making close transport independent.

The svc_force_sock_close has been changed to svc_close_all and takes a list
as an argument. This removes some svc internals knowledge from the svcs.

This code races with module removal and transport addition.

Thanks to Simon Holm Thøgersen for a compile fix.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Simon Holm Thøgersen <odie@cs.aau.dk>

This is another incremental change that moves transport independent
fields from svc_sock to the svc_xprt structure. The changes
should be functionally null.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This functionally trivial change moves the transport independent sk_flags
field to the transport independent svc_xprt structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Change the atomic_t reference count to a kref and move it to the
transport indepenent svc_xprt structure. Change the reference count
wrapper names to be generic.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Modify the various kernel RPC svcs to use the svc_create_xprt service.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The svc_create_xprt function is a transport independent version
of the svc_makesock function.

Since transport instance creation contains transport dependent and
independent components, add an xpo_create transport function. The
transport implementation of this function allocates the memory for the
endpoint, implements the transport dependent initialization logic, and
calls svc_xprt_init to initialize the transport independent field (svc_xprt)
in it's data structure.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move the code that poaches connections when the connection limit is hit
to a subroutine to make the accept logic path easier to follow. Since this
is in the new connection path, it should not be a performance issue.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The svc_tcp_accept function calls svc_sock_enqueue after setting the
SK_CONN bit. This doesn't actually do anything because the SK_BUSY bit
is still set. The call is unnecessary anyway because the generic code in
svc_recv calls svc_sock_received after calling the accept function.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Previously, the accept logic looked into the socket state to determine
whether to call accept or recv when data-ready was indicated on an endpoint.
Since some transports don't use sockets, this logic now uses a flag
bit (SK_LISTENER) to identify listening endpoints. A transport function
(xpo_accept) allows each transport to define its own accept processing.
A transport's initialization logic is reponsible for setting the
SK_LISTENER bit. I didn't see any way to do this in transport independent
logic since the passive side of a UDP connection doesn't listen and
always recv's.

In the svc_recv function, if the SK_LISTENER bit is set, the transport
xpo_accept function is called to handle accept processing.

Note that all functions are defined even if they don't make sense
for a given transport. For example, accept doesn't mean anything for
UDP. The function is defined anyway and bug checks if called. The
UDP transport should never set the SK_LISTENER bit.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Close handling was duplicated in the UDP and TCP recvfrom
methods. This code has been moved to the transport independent
svc_recv function.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

In order to avoid blocking a service thread, the receive side checks
to see if there is sufficient write space to reply to the request.
Each transport has a different mechanism for determining if there is
enough write space to reply.

The code that checked for write space was coupled with code that
checked for CLOSE and CONN. These checks have been broken out into
separate statements to make the code easier to read.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Some transports add fields to the RPC header for replies, e.g. the TCP
record length. This function is called when preparing the reply header
to allow each transport to add whatever fields it requires.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Add transport specific xpo_detach and xpo_free functions. The xpo_detach
function causes the transport to stop delivering data-ready events
and enqueing the transport for I/O.

The xpo_free function frees all resources associated with the particular
transport instance.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The svc_sock_release function releases pages allocated to a thread. For
UDP this frees the receive skb. For RDMA it will post a receive WR
and bump the client credit count.
Signed-off-by: NTom Tucker <tom@opengridcomputing.com>
Acked-by: NNeil Brown <neilb@suse.de>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>