Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Tested-by: NDevesh Sharma <Devesh.Sharma@Emulex.Com>
Tested-by: NMeghana Cheripady <Meghana.Cheripady@Emulex.Com>
Tested-by: NVeeresh U. Kokatnur <veereshuk@chelsio.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

rpcrdma_{de}register_internal() are used only in verbs.c now.

MAX_RPCRDMAHDR is no longer used and can be removed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Use the new rpcrdma_alloc_regbuf() API to shrink the amount of
contiguous memory needed for a buffer pool by moving the zero
pad buffer into a regbuf.

This is for consistency with the other uses of internally
registered memory.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The rr_base field is currently the buffer where RPC replies land.

An RPC/RDMA reply header lands in this buffer. In some cases an RPC
reply header also lands in this buffer, just after the RPC/RDMA
header.

The inline threshold is an agreed-on size limit for RDMA SEND
operations that pass from server and client. The sum of the
RPC/RDMA reply header size and the RPC reply header size must be
less than this threshold.

The largest RDMA RECV that the client should have to handle is the
size of the inline threshold. The receive buffer should thus be the
size of the inline threshold, and not related to RPCRDMA_MAX_SEGS.

RPC replies received via RDMA WRITE (long replies) are caught in
rq_rcv_buf, which is the second half of the RPC send buffer. Ie,
such replies are not involved in any way with rr_base.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The rl_base field is currently the buffer where each RPC/RDMA call
header is built.

The inline threshold is an agreed-on size limit to for RDMA SEND
operations that pass between client and server. The sum of the
RPC/RDMA header size and the RPC header size must be less than or
equal to this threshold.

Increasing the r/wsize maximum will require MAX_SEGS to grow
significantly, but the inline threshold size won't change (both
sides agree on it). The server's inline threshold doesn't change.

Since an RPC/RDMA header can never be larger than the inline
threshold, make all RPC/RDMA header buffers the size of the
inline threshold.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Because internal memory registration is an expensive and synchronous
operation, xprtrdma pre-registers send and receive buffers at mount
time, and then re-uses them for each RPC.

A "hardway" allocation is a memory allocation and registration that
replaces a send buffer during the processing of an RPC. Hardway must
be done if the RPC send buffer is too small to accommodate an RPC's
call and reply headers.

For xprtrdma, each RPC send buffer is currently part of struct
rpcrdma_req so that xprt_rdma_free(), which is passed nothing but
the address of an RPC send buffer, can find its matching struct
rpcrdma_req and rpcrdma_rep quickly via container_of / offsetof.

That means that hardway currently has to replace a whole rpcrmda_req
when it replaces an RPC send buffer. This is often a fairly hefty
chunk of contiguous memory due to the size of the rl_segments array
and the fact that both the send and receive buffers are part of
struct rpcrdma_req.

Some obscure re-use of fields in rpcrdma_req is done so that
xprt_rdma_free() can detect replaced rpcrdma_req structs, and
restore the original.

This commit breaks apart the RPC send buffer and struct rpcrdma_req
so that increasing the size of the rl_segments array does not change
the alignment of each RPC send buffer. (Increasing rl_segments is
needed to bump up the maximum r/wsize for NFS/RDMA).

This change opens up some interesting possibilities for improving
the design of xprt_rdma_allocate().

xprt_rdma_allocate() is now the one place where RPC send buffers
are allocated or re-allocated, and they are now always left in place
by xprt_rdma_free().

A large re-allocation that includes both the rl_segments array and
the RPC send buffer is no longer needed. Send buffer re-allocation
becomes quite rare. Good send buffer alignment is guaranteed no
matter what the size of the rl_segments array is.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

There are several spots that allocate a buffer via kmalloc (usually
contiguously with another data structure) and then register that
buffer internally. I'd like to split the buffers out of these data
structures to allow the data structures to scale.

Start by adding functions that can kmalloc and register a buffer,
and can manage/preserve the buffer's associated ib_sge and ib_mr
fields.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Move the details of how to create and destroy rpcrdma_req and
rpcrdma_rep structures into helper functions.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: There is one call site for rpcrdma_buffer_create(). All of
the arguments there are fields of an rpcrdma_xprt.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Reduce stack footprint of the connection upcall handler function.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Device attributes are large, and are used in more than one place.
Stash a copy in dynamically allocated memory.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If ib_query_qp() fails or the memory registration mode isn't
supported, don't leak the PD. An orphaned IB/core resource will
cause IB module removal to hang.

Fixes: bd7ed1d1 ("RPC/RDMA: check selected memory registration ...")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: The rep_func field always refers to rpcrdma_conn_func().
rep_func should have been removed by commit b45ccfd2 ("xprtrdma:
Remove MEMWINDOWS registration modes").
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Reduce work in the receive CQ handler, which can be run at hardware
interrupt level, by moving the RPC/RDMA credit update logic to the
RPC reply handler.

This has some additional benefits: More header sanity checking is
done before trusting the incoming credit value, and the receive CQ
handler no longer touches the RPC/RDMA header (the CPU stalls while
waiting for the header contents to be brought into the cache).

This further extends work begun by commit e7ce710a ("xprtrdma:
Avoid deadlock when credit window is reset").
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: Since commit 0ac531c1 ("xprtrdma: Remove REGISTER
memory registration mode"), the rl_mr pointer is no longer used
anywhere.

After removal, there's only a single member of the mr_chunk union,
so mr_chunk can be removed as well, in favor of a single pointer
field.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: This field is not used.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Make it easier to grep the system log for specific error conditions.

The wc.opcode field is not included because opcode numbers are
sparse, and because wc.opcode is not necessarily valid when
completion reports an error.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

An async error upcall is a hard error, and should be reported in
the system log.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Currently rpcrdma_flush_cqs() attempts to avoid code duplication,
and simply invokes rpcrdma_recvcq_upcall and rpcrdma_sendcq_upcall.

1. rpcrdma_flush_cqs() can run concurrently with provider upcalls.
   Both flush_cqs() and the upcalls were invoking ib_poll_cq() in
   different threads using the same wc buffers (ep->rep_recv_wcs
   and ep->rep_send_wcs), added by commit 1c00dd07 ("xprtrmda:
   Reduce calls to ib_poll_cq() in completion handlers").

   During transport disconnect processing, this sometimes resulted
   in the same reply getting added to the rpcrdma_tasklets_g list
   more than once, which corrupted the list.

2. The upcall functions drain only a limited number of CQEs,
   thanks to the poll budget added by commit 8301a2c0
   ("xprtrdma: Limit work done by completion handler").

Fixes: a7bc211a ("xprtrdma: On disconnect, don't ignore ... ")
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=276Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Restore the separate function that schedules the reply handling
tasklet. I need to call it from two different paths.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

When using RPCRDMA_MTHCAFMR memory registration, after a few
transport disconnect / reconnect cycles, ib_map_phys_fmr() starts to
return EINVAL because the provider has exhausted its map pool.

Make sure that all FMRs are unmapped during transport disconnect,
and that ->send_request remarshals them during an RPC retransmit.
This resets the transport's MRs to ensure that none are leaked
during a disconnect.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Recent work made FRMR registration and invalidation completions
unsignaled. This greatly reduces the adapter interrupt rate.

Every so often, however, a posted send Work Request is allowed to
signal. Otherwise, the provider's Work Queue will wrap and the
workload will hang.

The number of Work Requests that are allowed to remain unsignaled is
determined by the value of req_cqinit. Currently, this is set to the
size of the send Work Queue divided by two, minus 1.

For FRMR, the send Work Queue is the maximum number of concurrent
RPCs (currently 32) times the maximum number of Work Requests an
RPC might use (currently 7, though some adapters may need more).

For mlx4, this is 224 entries. This leaves completion signaling
disabled for 111 send Work Requests.

Some providers hold back dispatching Work Requests until a CQE is
generated.  If completions are disabled, then no CQEs are generated
for quite some time, and that can stall the Work Queue.

I've seen this occur running xfstests generic/113 over NFSv4, where
eventually, posting a FAST_REG_MR Work Request fails with -ENOMEM
because the Work Queue has overflowed. The connection is dropped
and re-established.

Cap the rep_cqinit setting so completions are not left turned off
for too long.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=269Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The RPC/RDMA send_request method and the chunk registration code
expects an errno from the registration function. This allows
the upper layers to distinguish between a recoverable failure
(for example, temporary memory exhaustion) and a hard failure
(for example, a bug in the registration logic).
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

It's always set to whatever CONFIG_SUNRPC_DEBUG is, so just use that.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit 38ca83a5 added RDMA_CM_EVENT_TIMEWAIT_EXIT. But that status
is relevant only for consumers that re-use their QPs on new
connections. xprtrdma creates a fresh QP on reconnection, so that
event should be explicitly ignored.

Squelch the alarming "unexpected CM event" message.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up.

RPCRDMA_PERSISTENT_REGISTRATION was a compile-time switch between
RPCRDMA_REGISTER mode and RPCRDMA_ALLPHYSICAL mode.  Since
RPCRDMA_REGISTER has been removed, there's no need for the extra
conditional compilation.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: The return code is used only for dprintk's that are
already redundant.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Minor optimization: grab rpcrdma_tk_lock_g and disable hard IRQs
just once after clearing the receive completion queue.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Currently rpcrdma_buffer_create() allocates struct rpcrdma_mw's as
a single contiguous area of memory. It amounts to quite a bit of
memory, and there's no requirement for these to be carved from a
single piece of contiguous memory.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: Name frmr_wr after the opcode of the Work Request,
consistent with the send and local invalidation paths.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Instead of relying on a completion to change the state of an FRMR
to FRMR_IS_INVALID, set it in advance. If an error occurs, a completion
will fire anyway and mark the FRMR FRMR_IS_STALE.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Instead of relying on a completion to change the state of an FRMR
to FRMR_IS_VALID, set it in advance. If an error occurs, a completion
will fire anyway and mark the FRMR FRMR_IS_STALE.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Any FRMR arriving in rpcrdma_register_frmr_external() is now
guaranteed to be either invalid, or to be targeted by a queued
LOCAL_INV that will invalidate it before the adapter processes
the FAST_REG_MR being built here.

The problem with current arrangement of chaining a LOCAL_INV to the
FAST_REG_MR is that if the transport is not connected, the LOCAL_INV
is flushed and the FAST_REG_MR is flushed. This leaves the FRMR
valid with the old rkey. But rpcrdma_register_frmr_external() has
already bumped the in-memory rkey.

Next time through rpcrdma_register_frmr_external(), a LOCAL_INV and
FAST_REG_MR is attempted again because the FRMR is still valid. But
the rkey no longer matches the hardware's rkey, and a memory
management operation error occurs.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

When a LOCAL_INV Work Request is flushed, it leaves an FRMR in the
VALID state. This FRMR can be returned by rpcrdma_buffer_get(), and
must be knocked down in rpcrdma_register_frmr_external() before it
can be re-used.

Instead, capture these in rpcrdma_buffer_get(), and reset them.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

FAST_REG_MR Work Requests update a Memory Region's rkey. Rkey's are
used to block unwanted access to the memory controlled by an MR. The
rkey is passed to the receiver (the NFS server, in our case), and is
also used by xprtrdma to invalidate the MR when the RPC is complete.

When a FAST_REG_MR Work Request is flushed after a transport
disconnect, xprtrdma cannot tell whether the WR actually hit the
adapter or not. So it is indeterminant at that point whether the
existing rkey is still valid.

After the transport connection is re-established, the next
FAST_REG_MR or LOCAL_INV Work Request against that MR can sometimes
fail because the rkey value does not match what xprtrdma expects.

The only reliable way to recover in this case is to deregister and
register the MR before it is used again. These operations can be
done only in a process context, so handle it in the transport
connect worker.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the rb_mws list is exhausted, clean up and return NULL so that
call_allocate() will delay and try again.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

During connection loss recovery, need to visit every MW in a
buffer pool. Any MW that is in use by an RPC will not be on the
rb_mws list.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If posting a FAST_REG_MR Work Reqeust fails, revert the rkey update
to avoid subsequent IB_WC_MW_BIND_ERR completions.
Suggested-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean ups:
 - make it obvious that the rl_mw field is a pointer -- allocated
   separately, not as part of struct rpcrdma_mr_seg
 - promote "struct {} frmr;" to a named type
 - promote the state enum to a named type
 - name the MW state field the same way other fields in
   rpcrdma_mw are named
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma is currently throwing away queued completions during
a reconnect. RPC replies posted just before connection loss, or
successful completions that change the state of an FRMR, can be
missed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Tested-by: NDevesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>