Commit graph

97 commits

Author SHA1 Message Date
Ilpo Järvinen b1721d2bb9 rpc/rdma: goto instead of copypaste
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-14 23:19:48 -08:00
Roel Kluin 5eaa65b240 net: Make static
Sparse asked whether these could be static.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-10 15:18:31 -08:00
Ingo Molnar ff0db0490a sunrpc: fix warning in net/sunrpc/xprtrdma/verbs.c
fix this warning:

  net/sunrpc/xprtrdma/verbs.c: In function ‘rpcrdma_conn_upcall’:
  net/sunrpc/xprtrdma/verbs.c:279: warning: unused variable ‘addr’

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 16:58:42 -08:00
Ingo Molnar ed72b9c6e0 sunrpc: fix warning in net/sunrpc/xprtrdma/svc_rdma_transport.c
this warning:

  net/sunrpc/xprtrdma/svc_rdma_transport.c: In function ‘svc_rdma_accept’:
  net/sunrpc/xprtrdma/svc_rdma_transport.c:830: warning: ‘dma_mr_acc’ may be used uninitialized in this function

triggers because GCC does not recognize the (correct) flow connection
between need_dma_mr and dma_mr_acc.

Annotate it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 16:49:37 -08:00
Harvey Harrison 21454aaad3 net: replace NIPQUAD() in net/*/
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31 00:54:56 -07:00
Trond Myklebust 6925bac120 Merge branch 'next' 2008-10-15 15:54:56 -04:00
Linus Torvalds 8acd3a60bc Merge branch 'for-2.6.28' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.28' of git://linux-nfs.org/~bfields/linux: (59 commits)
  svcrdma: Fix IRD/ORD polarity
  svcrdma: Update svc_rdma_send_error to use DMA LKEY
  svcrdma: Modify the RPC reply path to use FRMR when available
  svcrdma: Modify the RPC recv path to use FRMR when available
  svcrdma: Add support to svc_rdma_send to handle chained WR
  svcrdma: Modify post recv path to use local dma key
  svcrdma: Add a service to register a Fast Reg MR with the device
  svcrdma: Query device for Fast Reg support during connection setup
  svcrdma: Add FRMR get/put services
  NLM: Remove unused argument from svc_addsock() function
  NLM: Remove "proto" argument from lockd_up()
  NLM: Always start both UDP and TCP listeners
  lockd: Remove unused fields in the nlm_reboot structure
  lockd: Add helper to sanity check incoming NOTIFY requests
  lockd: change nlmclnt_grant() to take a "struct sockaddr *"
  lockd: Adjust nlmsvc_lookup_host() to accomodate AF_INET6 addresses
  lockd: Adjust nlmclnt_lookup_host() signature to accomodate non-AF_INET
  lockd: Support non-AF_INET addresses in nlm_lookup_host()
  NLM: Convert nlm_lookup_host() to use a single argument
  svcrdma: Add Fast Reg MR Data Types
  ...
2008-10-14 12:31:14 -07:00
Tom Talpey c055551e97 RPC/RDMA: ensure connection attempt is complete before signalling.
The RPC/RDMA connection logic could return early from reconnection
attempts, leading to additional spurious retries.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:15:06 -04:00
Tom Talpey 08ca0dce1e RPC/RDMA: correct the reconnect timer backoff
The RPC/RDMA code had a constant 5-second reconnect backoff, and
always performed it, even when re-establishing a connection to a
server after the RPC layer closed it due to being idle. Make it
an geometric backoff (up to 30 seconds), and don't delay idle
reconnect.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:15:02 -04:00
Tom Talpey b3cd8d45a7 RPC/RDMA: optionally emit useful transport info upon connect/disconnect.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:13:59 -04:00
Tom Talpey 5f37d561e0 RPC/RDMA: reformat a debug printk to keep lines together.
The send marshaling code split a particular dprintk across two
lines, which makes it hard to extract from logfiles.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:13:42 -04:00
Tom Talpey 5675add36e RPC/RDMA: harden connection logic against missing/late rdma_cm upcalls.
Add defensive timeouts to wait_for_completion() calls in RDMA
address resolution, and make them interruptible. Fix the timeout
units to milliseconds (formerly jiffies) and move to private header.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:13:31 -04:00
Tom Talpey 1a954051b0 RPC/RDMA: fix connect/reconnect resource leak.
The RPC/RDMA code can leak RDMA connection manager endpoints in
certain error cases on connect. Don't signal unwanted events,
and be certain to destroy any allocated qp.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:13:02 -04:00
Tom Talpey 926449ba66 RPC/RDMA: return a consistent error, when connect fails.
The xprt_connect call path does not expect such errors as ECONNREFUSED
to be returned from failed transport connection attempts, otherwise it
translates them to EIO and signals fatal errors. For example, mount.nfs
prints simply "internal error". Translate all such errors to ENOTCONN
from RPC/RDMA to match sockets behavior.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:12:44 -04:00
Tom Talpey 9191ca3b38 RPC/RDMA: adhere to protocol for unpadded client trailing write chunks.
The RPC/RDMA protocol allows clients and servers to avoid RDMA
operations for data which is purely the result of XDR padding.
On the client, automatically insert the necessary padding for
such server replies, and optionally don't marshal such chunks.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:12:33 -04:00
Tom Talpey fee08caf94 RPC/RDMA: avoid an oops due to disconnect racing with async upcalls.
RDMA disconnects yield an upcall from the RDMA connection manager,
which can race with rpc transport close, e.g. on ^C of a mount.
Ensure any rdma cm_id and qp are fully destroyed before continuing.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:11:40 -04:00
Tom Talpey ad0e9e01da RPC/RDMA: maintain the RPC task bytes-sent statistic.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:10:40 -04:00
Tom Talpey 575448bd36 RPC/RDMA: suppress retransmit on RPC/RDMA clients.
An RPC/RDMA client cannot retransmit on an unbroken connection,
doing so violates its flow control with the server.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:10:36 -04:00
Tom Tucker b334eaabf4 RPC/RDMA: fix connection IRD/ORD setting
This logic sets the connection parameter that configures the local device
and informs the remote peer how many concurrent incoming RDMA_READ
requests are supported. The original logic didn't really do what was
intended for two reasons:

- The max number supported by the device is typically smaller than
any one factor in the calculation used, and

- The field in the connection parameter structure where the value is
stored is a u8 and always overflows for the default settings.

So what really happens is the value requested for responder resources
is the left over 8 bits from the "desired value". If the desired value
happened to be a multiple of 256, the result was zero and it wouldn't
connect at all.

Given the above and the fact that max_requests is almost always larger
than the max responder resources supported by the adapter, this patch
simplifies this logic and simply requests the max supported by the device,
subject to a reasonable limit.

This bug was found by Jim Schutt at Sandia.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:09:56 -04:00
Tom Talpey 3197d309f5 RPC/RDMA: support FRMR client memory registration.
Configure, detect and use "fastreg" support from IB/iWARP verbs
layer to perform RPC/RDMA memory registration.

Make FRMR the default memreg mode (will fall back if not supported
by the selected RDMA adapter).

This allows full and optimal operation over the cxgb3 adapter, and others.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:09:34 -04:00
Tom Talpey bd7ed1d133 RPC/RDMA: check selected memory registration mode at runtime.
At transport creation, check for, and use, any local dma lkey.
Then, check that the selected memory registration mode is in fact
supported by the RDMA adapter selected for the mount. Fall back
to best alternative if not.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:09:26 -04:00
Tom Talpey fe9053b30b RPC/RDMA: add data types and new FRMR memory registration enum.
Internal RPC/RDMA structure updates in preparation for FRMR support.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:09:24 -04:00
Tom Talpey 8d4ba0347c RPC/RDMA: refactor the inline memory registration code.
Refactor the memory registration and deregistration routines.
This saves stack space, makes the code more readable and prepares
to add the new FRMR registration methods.

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-10 15:09:16 -04:00
Tom Tucker 67080c8236 svcrdma: Fix IRD/ORD polarity
The inititator/responder resources in the event have been swapped. They
no represent what the local peer would set their values to in order to
match the peer. Note that iWARP does not exchange these on the wire and
the provider is simply putting in the local device max.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:46:13 -05:00
Tom Tucker 04911b539c svcrdma: Update svc_rdma_send_error to use DMA LKEY
Update the svc_rdma_send_error code to use the DMA LKEY which is valid
regardless of the memory registration strategy in use.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:46:08 -05:00
Tom Tucker afd566ea08 svcrdma: Modify the RPC reply path to use FRMR when available
Use FRMR to map local RPC reply data. This allows RDMA_WRITE to send reply
data using a single WR. The FRMR is invalidated by linking the LOCAL_INV WR
to the RDMA_SEND message used to complete the reply.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:46:05 -05:00
Tom Tucker 146b6df6a5 svcrdma: Modify the RPC recv path to use FRMR when available
RPCRDMA requests that specify a read-list are fetched with RDMA_READ. Using
an FRMR to map the data sink improves NFSRDMA security on transports that
place the RDMA_READ data sink LKEY on the wire because the valid lifetime
of the MR is only the duration of the RDMA_READ. The LKEY is invalidated
when the last RDMA_READ WR completes.

Mapping the data sink also allows for very large amounts to data to be
fetched with a single WR, so if the client is also using FRMR, the entire
RPC read-list can be fetched with a single WR.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:46:01 -05:00
Tom Tucker 5b180a9a64 svcrdma: Add support to svc_rdma_send to handle chained WR
WR can be submitted as linked lists of WR. Update the svc_rdma_send
routine to handle WR chains. This will be used to submit a WR that
uses an FRMR with another WR that invalidates the FRMR.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:45:56 -05:00
Tom Tucker a5abf4e815 svcrdma: Modify post recv path to use local dma key
Update the svc_rdma_post_recv routine to use the adapter's global LKEY
instead of sc_phys_mr which is only valid when using a DMA MR.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:45:52 -05:00
Tom Tucker e118321062 svcrdma: Add a service to register a Fast Reg MR with the device
Fast Reg MR introduces a new WR type. Add a service to register the
region with the adapter and update the completion handling to support
completions with a NULL WR context.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:45:49 -05:00
Tom Tucker 3a5c63803d svcrdma: Query device for Fast Reg support during connection setup
Query the device capabilities in the svc_rdma_accept function to determine
what advanced memory management capabilities are supported by the device.
Based on the query, select the most secure model available given the
requirements of the transport and capabilities of the adapter.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:45:45 -05:00
Tom Tucker 64be8608c1 svcrdma: Add FRMR get/put services
Add services for the allocating, freeing, and unmapping Fast Reg MR. These
services will be used by the transport connection setup, send and receive
routines.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-10-06 14:45:18 -05:00
Arnaldo Carvalho de Melo 6067804047 net: Use hton[sl]() instead of __constant_hton[sl]() where applicable
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-20 22:20:49 -07:00
Tom Tucker 24b8b44780 svcrdma: Fix race between svc_rdma_recvfrom thread and the dto_tasklet
RDMA_READ completions are kept on a separate queue from the general
I/O request queue. Since a separate lock is used to protect the RDMA_READ
completion queue, a race exists between the dto_tasklet and the
svc_rdma_recvfrom thread where the dto_tasklet sets the XPT_DATA
bit and adds I/O to the read-completion queue. Concurrently, the
recvfrom thread checks the generic queue, finds it empty and resets
the XPT_DATA bit. A subsequent svc_xprt_enqueue will fail to enqueue
the transport for I/O and cause the transport to "stall".

The fix is to protect both lists with the same lock and set the XPT_DATA
bit with this lock held.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-08-13 16:57:31 -04:00
FUJITA Tomonori 8d8bb39b9e dma-mapping: add the device argument to dma_mapping_error()
Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER
architecture does:

This enables us to cleanly fix the Calgary IOMMU issue that some devices
are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423).

I think that per-device dma_mapping_ops support would be also helpful for
KVM people to support PCI passthrough but Andi thinks that this makes it
difficult to support the PCI passthrough (see the above thread).  So I
CC'ed this to KVM camp.  Comments are appreciated.

A pointer to dma_mapping_ops to struct dev_archdata is added.  If the
pointer is non NULL, DMA operations in asm/dma-mapping.h use it.  If it's
NULL, the system-wide dma_ops pointer is used as before.

If it's useful for KVM people, I plan to implement a mechanism to register
a hook called when a new pci (or dma capable) device is created (it works
with hot plugging).  It enables IOMMUs to set up an appropriate
dma_mapping_ops per device.

The major obstacle is that dma_mapping_error doesn't take a pointer to the
device unlike other DMA operations.  So x86 can't have dma_mapping_ops per
device.  Note all the POWER IOMMUs use the same dma_mapping_error function
so this is not a problem for POWER but x86 IOMMUs use different
dma_mapping_error functions.

The first patch adds the device argument to dma_mapping_error.  The patch
is trivial but large since it touches lots of drivers and dma-mapping.h in
all the architecture.

This patch:

dma_mapping_error() doesn't take a pointer to the device unlike other DMA
operations.  So we can't have dma_mapping_ops per device.

Note that POWER already has dma_mapping_ops per device but all the POWER
IOMMUs use the same dma_mapping_error function.  x86 IOMMUs use device
argument.

[akpm@linux-foundation.org: fix sge]
[akpm@linux-foundation.org: fix svc_rdma]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix bnx2x]
[akpm@linux-foundation.org: fix s2io]
[akpm@linux-foundation.org: fix pasemi_mac]
[akpm@linux-foundation.org: fix sdhci]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc]
[akpm@linux-foundation.org: fix ibmvscsi]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:03 -07:00
Tom Tucker 8948896c9e svcrdma: Change WR context get/put to use the kmem cache
Change the WR context pool to be shared across mount points. This
reduces the RDMA transport memory footprint significantly since
idle mounts don't consume WR context memory.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:02:02 -05:00
Tom Tucker bf5927d84e svcrdma: Create a kmem cache for the WR contexts
Create a kmem cache to hold WR contexts. Next we will convert
the WR context get and put services to use this kmem cache.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:02:01 -05:00
Tom Tucker 902a94e088 svcrdma: Add flush_scheduled_work to module exit function
Make certain all transports pending free are flushed from the wq
before unloading the module.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:02:00 -05:00
Tom Tucker 36ef25e464 svcrdma: Limit ORD based on client's advertised IRD
When adapters have differing IRD limits, the RDMA transport will fail to
connect properly. The RDMA transport should use the client's advertised
inbound read limit when computing its outbound read limit. For iWARP
transports, there is currently no standard for exchanging IRD/ORD
during connection establishment so the 'responder_resources' field in the
connect event is the local device's limit. The RDMA transport can be
configured to use a smaller ORD by writing the desired number to the
/proc/sys/sunrpc/svc_rdma/max_outbound_read_requests file.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:01:59 -05:00
Tom Tucker 94dba4918d svcrdma: Remove unneeded spin locks from __svc_rdma_free
At the time __svc_rdma_free is called, we are guaranteed that all references
to this transport are gone. There is, therefore, no need to protect the
resource lists with a spin lock.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:01:57 -05:00
Tom Tucker 87295b6c5c svcrdma: Add dma map count and WARN_ON
Add a dma map count in order to verify that all DMA mapping resources
have been freed when the transport is closed.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:01:56 -05:00
Tom Tucker e6ab914371 svcrdma: Move the DMA unmap logic to the CQ handler
Separate DMA unmap from context destruction and perform DMA unmapping
in the SQ/RQ CQ reap functions. This is necessary to support software
based RDMA implementations that actually copy the data in their
ib_dma_unmap callback functions and architectures that don't have
cache coherent I/O busses.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:01:55 -05:00
Tom Tucker f820c57ebf svcrdma: Use reply and chunk map for RDMA_READ processing
Modify the RDMA_READ processing to use the reply and chunk list mapping data
types. Also add a special purpose 'hdr_count' field in in the context to hold
the header page count instead of overloading the SGE length field and
corrupting the DMA map length.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:01:55 -05:00
Tom Tucker 34d16e42a6 svcrdma: Use RPC reply map for RDMA_WRITE processing
Use the new svc_rdma_req_map data type for mapping the client side memory
to the server side memory. Move the DMA mapping to the context pointed to
by each WR individually so that it is unmapped after the WR completes.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:01:54 -05:00
Tom Tucker ab96dddbed svcrdma: Add a type for keeping NFS RPC mapping
Create a new data structure to hold the remote client address space
to local server address space mapping.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-07-02 15:01:53 -05:00
Tom Tucker a6f911c04e svcrdma: Verify read-list fits within RPCSVC_MAXPAGES
A RDMA read-list cannot contain more elements than RPCSVC_MAXPAGES or
it will overflow the DTO context. Verify this when processing the
protocol header.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-05-19 07:34:02 -05:00
Tom Tucker 008fdbc571 svcrdma: Change svc_rdma_send_error return type to void
The svc_rdma_send_error function is called when an RPCRDMA protocol
error is detected. This function attempts to post an error reply message.
Since an error posting to a transport in error is ignored, change
the return type to void.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-05-19 07:34:01 -05:00
Tom Tucker af261af4db svcrdma: Copy transport address and arm CQ before calling rdma_accept
This race was found by inspection. Messages can be received from the peer
immediately following the rdma_accept call, however, the CQ have not yet
been armed and the transport address has not yet been set.

Set the transport address in the connect request handler and arm the CQ
prior to calling rdma_accept.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-05-19 07:34:00 -05:00
Tom Tucker 69500c43b4 svcrdma: Set rqstp transport address in rdma_read_complete function
The rdma_read_complete function needs to copy the rqstp transport address
from the transport. Failure to do so can result in using the wrong
authentication method for the RPC or bug checking if the rqstp address
is not valid.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-05-19 07:33:59 -05:00
Tom Tucker 97a3df382e svcrdma: Use ib verbs version of dma_unmap
Use the ib_verbs version of the dma_unmap service in the
svc_rdma_put_context function. This should support providers
using software rdma.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
2008-05-19 07:33:58 -05:00