svcrdma: Move write_info for Reply chunks into struct svc_rdma_send_ctxt

Since the RPC transaction's svc_rdma_send_ctxt will stay around for
the duration of the RDMA Write operation, the write_info structure
for the Reply chunk can reside in the request's svc_rdma_send_ctxt
instead of being allocated separately.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Copy construction of svc_rqst::rq_arg to rdma_read_complete()

Once a set of RDMA Reads are complete, the Read completion handler
will poke the transport to trigger a second call to
svc_rdma_recvfrom(). recvfrom() will then merge the RDMA Read
payloads with the previously received RPC header to form a completed
RPC Call message.

The new code is copied from the svc_rdma_process_read_list() path.
A subsequent patch will make use of this code and remove the code
that this was copied from (svc_rdma_rw.c).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Update some svcrdma DMA-related tracepoints

A send/recv_ctxt already records transport-related information
in the cq.id, thus there is no need to record the IP addresses of
the transport endpoints.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: DMA error tracepoints should report completion IDs

Update the DMA error flow tracepoints to report the completion ID of
the failing context. This ties the wait/failure to a particular
operation or request, which is more useful than knowing only the
failing transport.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: SQ error tracepoints should report completion IDs

Update the Send Queue's error flow tracepoints to report the
completion ID of the waiting or failing context. This ties the
wait/failure to a particular operation or request, which is a little
more useful than knowing only the transport that is about to close.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

rpcrdma: Introduce a simple cid tracepoint class

De-duplicate some code, making it easier to add new tracepoints that
report only a completion ID.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Fix tracepoint printk format

Other tracepoints use "cq.id=" rather than "cq_id=". Let's make it
more reliable to grep for the CQ restracker ID.

Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: trace cc_release calls

This event brackets the svcrdma_post_* trace points. If this trace
event is enabled but does not appear as expected, that indicates a
chunk_ctxt leak.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

trace: Relocate event helper files

Steven Rostedt says:
> The include/trace/events/ directory should only hold files that
> are to create events, not headers that hold helper functions.
>
> Can you please move them out of include/trace/events/ as that
> directory is "special" in the creation of events.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Tracepoints should display tk_pid and cl_clid as a fixed-size field

For certain special cases, RPC-related tracepoints record a -1 as
the task ID or the client ID. It's ugly for a trace event to display
4 billion in these cases.

To help keep SUNRPC tracepoints consistent, create a macro that
defines the print format specifiers for tk_pid and cl_clid. At some
point in the future we might try tk_pid with a wider range of values
than 0..64K so this makes it easier to make that change.

RPC tracepoints now look like this:

<...>-1276 [009] 149.720358: rpc_clnt_new: client=00000005 peer=[192.168.2.55]:20049 program=nfs server=klimt.ib

<...>-1342 [004] 149.921234: rpc_xdr_recvfrom: task:0000001a@00000005 head=[0xff1242d9ab6dc01c,144] page=0 tail=[(nil),0] len=144
<...>-1342 [004] 149.921235: xprt_release_cong: task:0000001a@00000005 snd_task:ffffffff cong=256 cwnd=16384
<...>-1342 [004] 149.921235: xprt_put_cong: task:0000001a@00000005 snd_task:ffffffff cong=0 cwnd=16384

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

xprtrdma: Provide a buffer to pad Write chunks of unaligned length

This is a buffer to be left persistently registered while a
connection is up. Connection tear-down will automatically DMA-unmap,
invalidate, and dereg the MR. A persistently registered buffer is
lower in cost to provide, and it can never be coalesced into the
RDMA segment that carries the data payload.

An RPC that provisions a Write chunk with a non-aligned length now
uses this MR rather than the tail buffer of the RPC's rq_rcv_buf.

Reviewed-By: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

svcrdma: Split svcrmda_wc_{read,write} tracepoints

There are currently three separate purposes being served by single
tracepoints. Split them up, as was done with wc_send.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

svcrdma: Split the svcrdma_wc_send() tracepoint

There are currently three separate purposes being served by a single
tracepoint here. They need to be split up.

svcrdma_wc_send:
- status is always zero, so there's no value in recording it.
- vendor_err is meaningless unless status is not zero, so
there's no value in recording it.
- This tracepoint is needed only when developing modifications,
so it should be left disabled most of the time.

svcrdma_wc_send_flush:
- As above, needed only rarely, and not an error.

svcrdma_wc_send_err:
- This tracepoint can be left persistently enabled because
completion errors are run-time problems (except for FLUSHED_ERR).
- Tracepoint name now ends in _err to reflect its purpose.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

svcrdma: Split the svcrdma_wc_receive() tracepoint

There are currently three separate purposes being served by a single
tracepoint here. They need to be split up.

svcrdma_wc_recv:
- status is always zero, so there's no value in recording it.
- vendor_err is meaningless unless status is not zero, so
there's no value in recording it.
- This tracepoint is needed only when developing modifications,
so it should be left disabled most of the time.

svcrdma_wc_recv_flush:
- As above, needed only rarely, and not an error.

svcrdma_wc_recv_err:
- received is always zero, so there's no value in recording it.
- This tracepoint can be left enabled because completion
errors are run-time problems (except for FLUSHED_ERR).
- Tracepoint name now ends in _err to reflect its purpose.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

xprtrdma: Add an xprtrdma_post_send_err tracepoint

Unlike xprtrdma_post_send(), this one can be left enabled all the
time, and should almost never fire. But we do want to know about
immediate errors when they happen.

Note that there is already a similar post_linv_err tracepoint.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add xprtrdma_post_recvs_err() tracepoint

In the vast majority of cases, rc=0. Don't record that in the
post_recvs tracepoint. Instead, add a separate tracepoint that can
be left enabled all the time to capture the very rare immediate
errors returned by ib_post_recv().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Move fr_mr field to struct rpcrdma_mr

Clean up: The last remaining field in struct rpcrdma_frwr has been
removed, so the struct can be eliminated.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

xprtrdma: Remove the RPC/RDMA QP event handler

Clean up: The handler only recorded a trace event. If indeed no
action is needed by the RPC/RDMA consumer, then the event can be
ignored.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

xprtrdma: Don't display r_xprt memory addresses in tracepoints

The remote peer's IP address is sufficient, and does not expose
details of the kernel's memory layout.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

xprtrdma: Add an rpcrdma_mr_completion_class

I found it confusing that the MR_EVENT class displays the mr.id but
the associated COMPLETION_EVENT class displays a cid (that happens
to contain the mr.id!). To make it a little easier on humans who
have to read and interpret these events, create an MR_COMPLETION
class that displays the mr.id in the same way as the MR_EVENT class.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

xprtrdma: Add tracepoints showing FastReg WRs and remote invalidation

The Send signaling logic is a little subtle, so add some
observability around it. For every xprtrdma_mr_fastreg event, there
should be an xprtrdma_mr_localinv or xprtrdma_mr_reminv event.

When these tracepoints are enabled, we can see exactly when an MR is
DMA-mapped, registered, invalidated (either locally or remotely) and
then DMA-unmapped.

kworker/u25:2-190 [000] 787.979512: xprtrdma_mr_map: task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)
kworker/u25:2-190 [000] 787.979515: xprtrdma_chunk_read: task:351@5 pos=148 5608@0x8679e0c8f6f56000:0x00000503 (last)
kworker/u25:2-190 [000] 787.979519: xprtrdma_marshal: task:351@5 xid=0x8679e0c8: hdr=52 xdr=148/5608/0 read list/inline
kworker/u25:2-190 [000] 787.979525: xprtrdma_mr_fastreg: task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)
kworker/u25:2-190 [000] 787.979526: xprtrdma_post_send: task:351@5 cq.id=0 cid=73 (2 SGEs)

...

kworker/5:1H-219 [005] 787.980567: xprtrdma_wc_receive: cq.id=1 cid=161 status=SUCCESS (0/0x0) received=164
kworker/5:1H-219 [005] 787.980571: xprtrdma_post_recvs: peer=[192.168.100.55]:20049 r_xprt=0xffff8884974d4000: 0 new recvs, 70 active (rc 0)
kworker/5:1H-219 [005] 787.980573: xprtrdma_reply: task:351@5 xid=0x8679e0c8 credits=64
kworker/5:1H-219 [005] 787.980576: xprtrdma_mr_reminv: task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)
kworker/5:1H-219 [005] 787.980577: xprtrdma_mr_unmap: mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)

Note that I've moved the xprtrdma_post_send tracepoint so that event
always appears after the xprtrdma_mr_fastreg tracepoint. Otherwise
the event log looks counterintuitive (FastReg is always supposed to
happen before Send).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

xprtrdma: Do not recycle MR after FastReg/LocalInv flushes

Better not to touch MRs involved in a flush or post error until the
Send and Receive Queues are drained and the transport is fully
quiescent. Simply don't insert such MRs back onto the free list.
They remain on mr_all and will be released when the connection is
torn down.

I had thought that recycling would prevent hardware resources from
being tied up for a long time. However, since v5.7, a transport
disconnect destroys the QP and other hardware-owned resources. The
MRs get cleaned up nicely at that point.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

rpcrdma: Capture bytes received in Receive completion tracepoints

Make it easier to spot messages of an unusual size.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

svcrdma: Clean up chunk tracepoints

We already have trace_svcrdma_decode_rseg(), which records each
ingress Read segment. Instead of reporting those again when they
are about to be posted as RDMA Reads, let's fire one tracepoint
before posting each type of chunk.

So we'll get:

nfsd-1998 [002] 321.666615: svcrdma_decode_rseg: cq.id=4 cid=42 segno=0 position=0 192@0x013ca9ebfae14000:0xb0010b05
nfsd-1998 [002] 321.666615: svcrdma_decode_rseg: cq.id=4 cid=42 segno=1 position=0 7688@0x013ca9ebf914e000:0xb0010a05
nfsd-1998 [002] 321.666615: svcrdma_decode_rseg: cq.id=4 cid=42 segno=2 position=0 28@0x013ca9ebfae15000:0xb0010905
nfsd-1998 [002] 321.666622: svcrdma_decode_rqst: cq.id=4 cid=42 xid=0x013ca9eb vers=1 credits=128 proc=RDMA_NOMSG hdrlen=100

nfsd-1998 [002] 321.666642: svcrdma_post_read_chunk: cq.id=3 cid=112 sqecount=3

kworker/2:1H-221 [002] 321.673949: svcrdma_wc_read: cq.id=3 cid=112 status=SUCCESS (0/0x0)

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Support multiple Write chunks in svc_rdma_map_reply_msg()

Refactor: svc_rdma_map_reply_msg() is restructured to DMA map only
the parts of rq_res that do not contain a result payload.

This change has been tested to confirm that it does not cause a
regression in the no Write chunk and single Write chunk cases.
Multiple Write chunks have not been tested.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Support multiple write chunks when pulling up

When counting the number of SGEs needed to construct a Send request,
do not count result payloads. And, when copying the Reply message
into the pull-up buffer, result payloads are not to be copied to the
Send buffer.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Use parsed chunk lists to encode Reply transport headers

Refactor: Instead of re-parsing the ingress RPC Call transport
header when constructing the egress RPC Reply transport header, use
the new parsed Write list and Reply chunk, which are version-
agnostic and already XDR decoded.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Add a "parsed chunk list" data structure

This simple data structure binds the location of each data payload
inside of an RPC message to the chunk that will be used to push it
to or pull it from the client.

There are several benefits to this small additional overhead:

* It enables support for more than one chunk in incoming Read and
Write lists.

* It translates the version-specific on-the-wire format into a
generic in-memory structure, enabling support for multiple
versions of the RPC/RDMA transport protocol.

* It enables the server to re-organize a chunk list if it needs to
adjust where Read chunk data lands in server memory without
altering the contents of the XDR-encoded Receive buffer.

Construction of these lists is done while sanity checking each
incoming RPC/RDMA header. Subsequent patches will make use of the
generated data structures.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

xprtrdma: Trace unmap_sync calls

->buf_free is called nearly once per RPC. Only rarely does
xprt_rdma_free() have to do anything, thus tracing every one of
these calls seems unnecessary. Instead, just throw a trace event
when that one occasional RPC still has MRs that need to be
released.

xprt_rdma_free() is further micro-optimized to reduce the amount of
work done in the common case.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Display the task ID when reporting MR events

Tie each MR event to the requesting rpc_task to make it easier to
follow MR ownership and control flow.

MR unmapping and recycling can happen in the background, after an
MR's mr_req field is stale, so set up a separate tracepoint class
for those events.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Clean up trace_xprtrdma_nomrs()

- Rename it following the "_err" suffix convention
- Replace display of kernel memory addresses
- Tie MR exhaustion to a peer IP address, similar to the createmrs
tracepoint

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Clean up xprtrdma callback tracepoints

- Replace displayed kernel memory addresses
- Tie the XID and event with the peer's IP address

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Clean up tracepoints in the reply path

Replace unnecessary display of kernel memory addresses.

Also, there are no longer any trace_xprtrdma_defer_cmp() call sites.
And remove the trace_xprtrdma_leaked_rep() tracepoint because there
doesn't seem to be an overwhelming need to have a tracepoint for
catching a software bug that has long since been fixed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Clean up reply parsing error tracepoints

- Rename the tracepoints with the "_err" suffix to indicate these
are rare error events
- Replace display of kernel memory addresses
- Tie the XID and error to a connection IP address instead

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Clean up trace_xprtrdma_post_linv

- Replace the display of kernel memory addresses
- Add "_err" to the end of its name to indicate that it's a
tracepoint that fires only when there's an error

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Introduce FRWR completion IDs

Set up a completion ID in each rpcrdma_frwr. The ID is used to match
an incoming completion to a transport (CQ) and other MR-related
activity.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Introduce Send completion IDs

Set up a completion ID in each rpcrdma_req. The ID is used to match
an incoming Send completion to a transport and to a previous
ib_post_send().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Introduce Receive completion IDs

Set up a completion ID in each rpcrdma_rep. The ID is used to match
an incoming Receive completion to a transport and to a previous
ib_post_recv().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Replace dprintk call sites in ERR_CHUNK path

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Hoist trace_xprtrdma_op_setport into generic code

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Remove debugging instrumentation from xprt_release

These instruments don't appear to add any substantial value.

We already have this at the termination of each RPC:

iozone-2617 [002] 975.713126: rpc_stats_latency: task:418@5 xid=0x260eab5d nfsv3 LOOKUP backlog=15 rtt=32 execute=58
iozone-2617 [002] 975.713127: xprt_release_cong: task:418@5 snd_task:4294967295 cong=256 cwnd=16384
iozone-2617 [002] 975.713127: xprt_put_cong: task:418@5 snd_task:4294967295 cong=0 cwnd=16384

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Hoist trace_xprtrdma_op_allocate into generic code

Introduce a tracepoint in call_allocate that reports the exact
sizes in the RPC buffer allocation request and the status of the
result. This helps catch problems with XDR buffer provisioning,
and replaces transport-specific debugging instrumentation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

RDMA/core: Move the rdma_show_ib_cm_event() macro

Refactor: Make it globally available in the utilities header.

Link: https://lore.kernel.org/r/159767239131.2968.9520990257041764685.stgit@klimt.1015granger.net
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

svcrdma: Display chunk completion ID when posting a rw_ctxt

Re-use the post_rw tracepoint (safely) to trace cc_info lifetime
events, including completion IDs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Record send_ctxt completion ID in trace_svcrdma_post_send()

First, refactor: Dereference the svc_rdma_send_ctxt inside
svc_rdma_send() instead of at every call site.

Then, it can be passed into trace_svcrdma_post_send() to get the
proper completion ID.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Introduce Send completion IDs

Set up a completion ID in each svc_rdma_send_ctxt. The ID is used
to match an incoming Send completion to a transport and to a
previous ib_post_send().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Record Receive completion ID in svc_rdma_decode_rqst

When recording a trace event in the Receive path, tie decoding
results and errors to an incoming Receive completion.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Introduce Receive completion IDs

Set up a completion ID in each svc_rdma_recv_ctxt. The ID is used
to match an incoming Receive completion to a transport and to a
previous ib_post_recv().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Introduce infrastructure to support completion IDs

The goal is to replace CQE kernel memory addresses in completion-
related tracepoints.

Each completion ID matches an incoming Send or Receive completion
to a Completion Queue and to a previous ib_post_*(). The ID can
then be displayed in an error message or recorded in a trace
record.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Clean up trace_svcrdma_send_failed() tracepoint

- Use the _err naming convention instead
- Remove display of kernel memory address of the controlling xprt

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

SUNRPC: Trace transport lifetime events

Refactor: Hoist create/destroy/disconnect tracepoints out of
xprtrdma and into the generic RPC client. Some benefits include:

- Enable tracing of xprt lifetime events for the socket transport
types

- Expose the different types of disconnect to help run down
issues with lingering connections

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Trace a few more generic svc_xprt events

In lieu of dprintks or tracepoints in each individual transport
implementation, introduce tracepoints in the generic part of the RPC
layer. These typically fire for connection lifetime events, so
shouldn't contribute a lot of noise.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Add tracepoints to report ->xpo_accept failures

Failure to accept a connection is typically due to a problem
specific to a transport type. Also, ->xpo_accept returns NULL
on error rather than reporting a specific problem.

So, add failure-specific tracepoints in svc_rdma_accept().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Rename tracepoints that record header decoding errors

Clean up: Use a consistent naming convention so that these trace
points can be enabled quickly via a glob.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: trace undersized Write chunks

Clean up: Replace a dprintk call site.

This is the last remaining dprintk call site in svc_rdma_rw.c, so
remove dprintk infrastructure as well.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Trace page overruns when constructing RDMA Reads

Clean up: Replace a dprintk call site with a tracepoint.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Clean up handling of get_rw_ctx errors

Clean up: Replace two dprintk call sites with a tracepoint.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Clean up the tracing for rw_ctx_init errors

- De-duplicate code
- Rename the tracepoint with "_err" to allow enabling via glob
- Report the sg_cnt for the failing rw_ctx
- Fix a dumb signage issue

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

xprtrdma: Fix trace point use-after-free race

It's not safe to use resources pointed to by the @send_wr of
ib_post_send() _after_ that function returns. Those resources are
typically freed by the Send completion handler, which can run before
ib_post_send() returns.

Thus the trace points currently around ib_post_send() in the
client's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.

Fixes: ab03eff58eb5 ("xprtrdma: Add trace points in RPC Call transmit paths")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

svcrdma: Fix trace point use-after-free race

I hit this while testing nfsd-5.7 with kernel memory debugging
enabled on my server:

Mar 30 13:21:45 klimt kernel: BUG: unable to handle page fault for address: ffff8887e6c279a8
Mar 30 13:21:45 klimt kernel: #PF: supervisor read access in kernel mode
Mar 30 13:21:45 klimt kernel: #PF: error_code(0x0000) - not-present page
Mar 30 13:21:45 klimt kernel: PGD 3601067 P4D 3601067 PUD 87c519067 PMD 87c3e2067 PTE 800ffff8193d8060
Mar 30 13:21:45 klimt kernel: Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
Mar 30 13:21:45 klimt kernel: CPU: 2 PID: 1933 Comm: nfsd Not tainted 5.6.0-rc6-00040-g881e87a3c6f9 #1591
Mar 30 13:21:45 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Mar 30 13:21:45 klimt kernel: RIP: 0010:svc_rdma_post_chunk_ctxt+0xab/0x284 [rpcrdma]
Mar 30 13:21:45 klimt kernel: Code: c1 83 34 02 00 00 29 d0 85 c0 7e 72 48 8b bb a0 02 00 00 48 8d 54 24 08 4c 89 e6 48 8b 07 48 8b 40 20 e8 5a 5c 2b e1 41 89 c6 <8b> 45 20 89 44 24 04 8b 05 02 e9 01 00 85 c0 7e 33 e9 5e 01 00 00
Mar 30 13:21:45 klimt kernel: RSP: 0018:ffffc90000dfbdd8 EFLAGS: 00010286
Mar 30 13:21:45 klimt kernel: RAX: 0000000000000000 RBX: ffff8887db8db400 RCX: 0000000000000030
Mar 30 13:21:45 klimt kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000246
Mar 30 13:21:45 klimt kernel: RBP: ffff8887e6c27988 R08: 0000000000000000 R09: 0000000000000004
Mar 30 13:21:45 klimt kernel: R10: ffffc90000dfbdd8 R11: 00c068ef00000000 R12: ffff8887eb4e4a80
Mar 30 13:21:45 klimt kernel: R13: ffff8887db8db634 R14: 0000000000000000 R15: ffff8887fc931000
Mar 30 13:21:45 klimt kernel: FS: 0000000000000000(0000) GS:ffff88885bd00000(0000) knlGS:0000000000000000
Mar 30 13:21:45 klimt kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8 CR3: 000000081b72e002 CR4: 00000000001606e0
Mar 30 13:21:45 klimt kernel: Call Trace:
Mar 30 13:21:45 klimt kernel: ? svc_rdma_vec_to_sg+0x7f/0x7f [rpcrdma]
Mar 30 13:21:45 klimt kernel: svc_rdma_send_write_chunk+0x59/0xce [rpcrdma]
Mar 30 13:21:45 klimt kernel: svc_rdma_sendto+0xf9/0x3ae [rpcrdma]
Mar 30 13:21:45 klimt kernel: ? nfsd_destroy+0x51/0x51 [nfsd]
Mar 30 13:21:45 klimt kernel: svc_send+0x105/0x1e3 [sunrpc]
Mar 30 13:21:45 klimt kernel: nfsd+0xf2/0x149 [nfsd]
Mar 30 13:21:45 klimt kernel: kthread+0xf6/0xfb
Mar 30 13:21:45 klimt kernel: ? kthread_queue_delayed_work+0x74/0x74
Mar 30 13:21:45 klimt kernel: ret_from_fork+0x3a/0x50
Mar 30 13:21:45 klimt kernel: Modules linked in: ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue ib_umad ib_ipoib mlx4_ib sb_edac x86_pkg_temp_thermal iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper crypto_simd cryptd pcspkr rpcrdma i2c_i801 rdma_ucm lpc_ich mfd_core ib_iser rdma_cm iw_cm ib_cm mei_me raid0 libiscsi mei sg scsi_transport_iscsi ioatdma wmi ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter nfsd nfs_acl lockd auth_rpcgss grace sunrpc ip_tables xfs libcrc32c mlx4_en sd_mod sr_mod cdrom mlx4_core crc32c_intel igb nvme i2c_algo_bit ahci i2c_core libahci nvme_core dca libata t10_pi qedr dm_mirror dm_region_hash dm_log dm_mod dax qede qed crc8 ib_uverbs ib_core
Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8
Mar 30 13:21:45 klimt kernel: ---[ end trace 87971d2ad3429424 ]---

It's absolutely not safe to use resources pointed to by the @send_wr
argument of ib_post_send() _after_ that function returns. Those
resources are typically freed by the Send completion handler, which
can run before ib_post_send() returns.

Thus the trace points currently around ib_post_send() in the
server's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.

Fixes: bd2abef33394 ("svcrdma: Trace key RDMA API events")
Fixes: 4201c7464753 ("svcrdma: Introduce svc_rdma_send_ctxt")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprt

Change the rpcrdma_xprt_disconnect() function so that it no longer
waits for the DISCONNECTED event. This prevents blocking if the
remote is unresponsive.

In rpcrdma_xprt_disconnect(), the transport's rpcrdma_ep is
detached. Upon return from rpcrdma_xprt_disconnect(), the transport
(r_xprt) is ready immediately for a new connection.

The RDMA_CM_DEVICE_REMOVAL and RDMA_CM_DISCONNECTED events are now
handled almost identically.

However, because the lifetimes of rpcrdma_xprt structures and
rpcrdma_ep structures are now independent, creating an rpcrdma_ep
needs to take a module ref count. The ep now owns most of the
hardware resources for a transport.

Also, a kref is needed to ensure that rpcrdma_ep sticks around
long enough for the cm_event_handler to finish.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Extract sockaddr from struct rdma_cm_id

rpcrdma_cm_event_handler() is always passed an @id pointer that is
valid. However, in a subsequent patch, we won't be able to extract
an r_xprt in every case. So instead of using the r_xprt's
presentation address strings, extract them from struct rdma_cm_id.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Merge struct rpcrdma_ia into struct rpcrdma_ep

I eventually want to allocate rpcrdma_ep separately from struct
rpcrdma_xprt so that on occasion there can be more than one ep per
xprt.

The new struct rpcrdma_ep will contain all the fields currently in
rpcrdma_ia and in rpcrdma_ep. This is all the device and CM settings
for the connection, in addition to per-connection settings
negotiated with the remote.

Take this opportunity to rename the existing ep fields from rep_* to
re_* to disambiguate these from struct rpcrdma_rep.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Disconnect on flushed completion

Completion errors after a disconnect often occur much sooner than a
CM_DISCONNECT event. Use this to try to detect connection loss more
quickly.

Note that other kernel ULPs do take care to disconnect explicitly
when a WR is flushed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Invoke rpcrdma_ia_open in the connect worker

Move rdma_cm_id creation into rpcrdma_ep_create() so that it is now
responsible for allocating all per-connection hardware resources.

With this clean-up, all three arms of the switch statement in
rpcrdma_ep_connect are exactly the same now, thus the switch can be
removed.

Because device removal behaves a little differently than
disconnection, there is a little more work to be done before
rpcrdma_ep_destroy() can release the connection's rdma_cm_id. So
it is not quite symmetrical with rpcrdma_ep_create() yet.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Enhance MR-related trace points

Two changes:
- Show the number of SG entries that were mapped. This helps debug
DMA-related problems.
- Record the MR's resource ID instead of its memory address. This
groups each MR with its associated rdma-tool output, and reduces
needless exposure of memory addresses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

svcrdma: Avoid DMA mapping small RPC Replies

On some platforms, DMA mapping part of a page is more costly than
copying bytes. Indeed, not involving the I/O MMU can help the
RPC/RDMA transport scale better for tiny I/Os across more RDMA
devices. This is because interaction with the I/O MMU is eliminated
for each of these small I/Os. Without the explicit unmapping, the
NIC no longer needs to do a costly internal TLB shoot down for
buffers that are just a handful of bytes.

Since pull-up is now a more a frequent operation, I've introduced a
trace point in the pull-up path. It can be used for debugging or
user-space tools that count pull-up frequency.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Rename svcrdma_encode trace points in send routines

These trace points are misnamed:

trace_svcrdma_encode_wseg
trace_svcrdma_encode_write
trace_svcrdma_encode_reply
trace_svcrdma_encode_rseg
trace_svcrdma_encode_read
trace_svcrdma_encode_pzr

Because they actually trace posting on the Send Queue. Let's rename
them so that I can add trace points in the chunk list encoders that
actually do trace chunk list encoding events.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Use struct xdr_stream to decode ingress transport headers

The logic that checks incoming network headers has to be scrupulous.

De-duplicate: replace open-coded buffer overflow checks with the use
of xdr_stream helpers that are used most everywhere else XDR
decoding is done.

One minor change to the sanity checks: instead of checking the
length of individual segments, cap the length of the whole chunk
to be sure it can fit in the set of pages available in rq_pages.
This should be a better test of whether the server can handle the
chunks in each request.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

svcrdma: Remove svcrdma_cm_event() trace point

Clean up. This trace point is no longer needed because the RDMA/core
CMA code has an equivalent trace point that was added by commit
ed999f820a6c ("RDMA/cma: Add trace points in RDMA Connection
Manager").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

xprtrdma: Make sendctx queue lifetime the same as connection lifetime

The size of the sendctx queue depends on the value stored in
ia->ri_max_send_sges. This value is determined by querying the
underlying device.

Eventually, rpcrdma_ia_open() and rpcrdma_ep_create() will be called
in the connect worker rather than at transport set-up time. The
underlying device will not have been chosen device set-up time.

The sendctx queue will thus have to be created after the underlying
device has been chosen via address and route resolution; in other
words, in the connect worker.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

ftrace: Rework event_create_dir()

Rework event_create_dir() to use an array of static data instead of
function pointers where possible.

The problem is that it would call the function pointer on module load
before parse_args(), possibly even before jump_labels were initialized.
Luckily the generated functions don't use jump_labels but it still seems
fragile. It also gets in the way of changing when we make the module map
executable.

The generated function are basically calling trace_define_field() with a
bunch of static arguments. So instead of a function, capture these
arguments in a static array, avoiding the function call.

Now there are a number of cases where the fields are dynamic (syscall
arguments, kprobes and uprobes), in which case a static array does not
work, for these we preserve the function call. Luckily all these cases
are not related to modules and so we can retain the function call for
them.

Also fix up all broken tracepoint definitions that now generate a
compile error.

Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191111132458.342979914@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

xprtrdma: Replace dprintk in xprt_rdma_set_port

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Replace dprintk() in rpcrdma_update_connect_private()

Clean up: Use a single trace point to record each connection's
negotiated inline thresholds and the computed maximum byte size
of transport headers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Refine trace_xprtrdma_fixup

Slightly reduce overhead and display more useful information.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Report the computed connect delay

For debugging, the op_connect trace point should report the computed
connect delay. We can then ensure that the delay is computed at the
proper times, for example.

As a further clean-up, remove a few low-value "heartbeat" trace
points in the connect path.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Pull up sometimes

On some platforms, DMA mapping part of a page is more costly than
copying bytes. Restore the pull-up code and use that when we
think it's going to be faster. The heuristic for now is to pull-up
when the size of the RPC message body fits in the buffer underlying
the head iovec.

Indeed, not involving the I/O MMU can help the RPC/RDMA transport
scale better for tiny I/Os across more RDMA devices. This is because
interaction with the I/O MMU is eliminated, as is handling a Send
completion, for each of these small I/Os. Without the explicit
unmapping, the NIC no longer needs to do a costly internal TLB shoot
down for buffers that are just a handful of bytes.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Move the rpcrdma_sendctx::sc_wr field

Clean up: This field is not needed in the Send completion handler,
so it can be moved to struct rpcrdma_req to reduce the size of
struct rpcrdma_sendctx, and to reduce the amount of memory that
is sloshed between the sending process and the Send completion
process.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add unique trace points for posting Local Invalidate WRs

When adding frwr_unmap_async way back when, I re-used the existing
trace_xprtrdma_post_send() trace point to record the return code
of ib_post_send.

Unfortunately there are some cases where re-using that trace point
causes a crash. Instead, construct a trace point specific to posting
Local Invalidate WRs that will always be safe to use in that context,
and will act as a trace log eye-catcher for Local Invalidation.

Fixes: 847568942f93 ("xprtrdma: Remove fr_state")
Fixes: d8099feda483 ("xprtrdma: Reduce context switching due ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Bill Baker <bill.baker@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

svcrdma: Improve DMA mapping trace points

Capture the total size of Sends, the size of DMA map and the
matching DMA unmap to ensure operation is correct.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

xprtrdma: Cache free MRs in each rpcrdma_req

Instead of a globally-contended MR free list, cache MRs in each
rpcrdma_req as they are released. This means acquiring and releasing
an MR will be lock-free in the common case, even outside the
transport send lock.

The original idea of per-rpcrdma_req MR free lists was suggested by
Shirley Ma <shirley.ma@oracle.com> several years ago. I just now
figured out how to make that idea work with on-demand MR allocation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Move rpcrdma_mr_get out of frwr_map

Refactor: Retrieve an MR and handle error recovery entirely in
rpc_rdma.c, as this is not a device-specific function.

Note that since commit 89f90fe1ad8b ("SUNRPC: Allow calls to
xprt_transmit() to drain the entire transmit queue"), the
xprt_transmit function handles the cond_resched. The transport no
longer has to do this itself.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Rename CQE field in Receive trace points

Make the field name the same for all trace points that handle
pointers to struct rpcrdma_rep. That makes it easy to grep for
matching rep points in trace output.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Modernize ops->connect

Adapt and apply changes that were made to the TCP socket connect
code. See the following commits for details on the purpose of
these changes:

Commit 7196dbb02ea0 ("SUNRPC: Allow changing of the TCP timeout parameters on the fly")
Commit 3851f1cdb2b8 ("SUNRPC: Limit the reconnect backoff timer to the max RPC message timeout")
Commit 02910177aede ("SUNRPC: Fix reconnection timeouts")

Some common transport code is moved to xprt.c to satisfy the code
duplication police.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Reduce context switching due to Local Invalidation

Since commit ba69cd122ece ("xprtrdma: Remove support for FMR memory
registration"), FRWR is the only supported memory registration mode.

We can take advantage of the asynchronous nature of FRWR's LOCAL_INV
Work Requests to get rid of the completion wait by having the
LOCAL_INV completion handler take care of DMA unmapping MRs and
waking the upper layer RPC waiter.

This eliminates two context switches when local invalidation is
necessary. As a side benefit, we will no longer need the per-xprt
deferred completion work queue.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Remove fr_state

Now that both the Send and Receive completions are handled in
process context, it is safe to DMA unmap and return MRs to the
free or recycle lists directly in the completion handlers.

Doing this means rpcrdma_frwr no longer needs to track the state of
each MR, meaning that a VALID or FLUSHED MR can no longer appear on
an xprt's MR free list. Thus there is no longer a need to track the
MR's registration state in rpcrdma_frwr.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Fix occasional transport deadlock

Under high I/O workloads, I've noticed that an RPC/RDMA transport
occasionally deadlocks (IOPS goes to zero, and doesn't recover).
Diagnosis shows that the sendctx queue is empty, but when sendctxs
are returned to the queue, the xprt_write_space wake-up never
occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.

I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented
via an atomic bit. Just one of those is sufficient. Removing
EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock
un-reproducible.

Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and
is therefore removed.

Unfortunately this patch does not apply cleanly to stable. If
needed, someone will have to port it and test it.

Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Replace use of xdr_stream_pos in rpcrdma_marshal_req

This is a latent bug. xdr_stream_pos works by subtracting
xdr_stream::nwords from xdr_buf::len. But xdr_stream::nwords is not
initialized by xdr_init_encode().

It works today only because all fields in rpcrdma_req::rl_stream
are initialized to zero by rpcrdma_req_create, making the
subtraction in xdr_stream_pos always a no-op.

I found this issue via code inspection. It was introduced by commit
39f4cd9e9982 ("xprtrdma: Harden chunk list encoding against send
buffer overflow"), but the code has changed enough since then that
this fix can't be automatically applied to stable.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Fix a BUG when tracing is enabled with NFSv4.1 on RDMA

A backchannel reply does not set task->tk_client.

Fixes: 0c77668ddb4e ("SUNRPC: Introduce trace points in ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Trace marshaling failures

Record an event when rpcrdma_marshal_req returns a non-zero return
value to help track down why an xprt close might have occurred.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

SUNRPC: Introduce trace points in rpc_auth_gss.ko

Add infrastructure for trace points in the RPC_AUTH_GSS kernel
module, and add a few sample trace points. These report exceptional
or unexpected events, and observe the assignment of GSS sequence
numbers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Prevent leak of rpcrdma_rep objects

If a reply has been processed but the RPC is later retransmitted
anyway, the req->rl_reply field still contains the only pointer to
the old rpcrdma rep. When the next reply comes in, the reply handler
will stomp on the rl_reply field, leaking the old rep.

A trace event is added to capture such leaks.

This problem seems to be worsened by the restructuring of the RPC
Call path in v4.20. Fully addressing this issue will require at
least a re-architecture of the disconnect logic, which is not
appropriate during -rc.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Trace mapping, alloc, and dereg failures

These are rare, but can be helpful at tracking down DMAR and other
problems.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points for calls to transport switch methods

Name them "trace_xprtrdma_op_*" so they can be easily enabled as a
group. No trace point is added where the generic layer already has
observability.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Clean up of xprtrdma chunk trace points

The chunk-related trace points capture nearly the same information
as the MR-related trace points.

Also, rename them so globbing can be used to enable or disable
these trace points more easily.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Refactor Receive accounting

Clean up: Divide the work cleanly:

- rpcrdma_wc_receive is responsible only for RDMA Receives
- rpcrdma_reply_handler is responsible only for RPC Replies
- the posted send and receive counts both belong in rpcrdma_ep

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Squelch a sparse warning

linux/include/trace/events/rpcrdma.h:501:1: warning: expression using sizeof bool
linux/include/trace/events/rpcrdma.h:501:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1)

Fixes: ab03eff58eb5 ("xprtrdma: Add trace points in RPC Call ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Rename rpcrdma_qp_async_error_upcall

Clean up: Use a function name that is consistent with the RDMA core
API and with other consumers. Because this is a function that is
invoked from outside the rpcrdma.ko module, add an appropriate
documenting comment.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Rename rpcrdma_conn_upcall

Clean up: Use a function name that is consistent with the RDMA core
API and with other consumers. Because this is a function that is
invoked from outside the rpcrdma.ko module, add an appropriate
documenting comment.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Name MR trace events consistently

Clean up the names of trace events related to MRs so that it's
easy to enable these with a glob.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Explicitly resetting MRs is no longer necessary

When a memory operation fails, the MR's driver state might not match
its hardware state. The only reliable recourse is to dereg the MR.
This is done in ->ro_recover_mr, which then attempts to allocate a
fresh MR to replace the released MR.

Since commit e2ac236c0b651 ("xprtrdma: Allocate MRs on demand"),
xprtrdma dynamically allocates MRs. It can add more MRs whenever
they are needed.

That makes it possible to simply release an MR when a memory
operation fails, instead of "recovering" it. It will automatically
be replaced by the on-demand MR allocator.

This commit is a little larger than I wanted, but it replaces
->ro_recover_mr, rb_recovery_lock, rb_recovery_worker, and the
rb_stale_mrs list with a generic work queue.

Since MRs are no longer orphaned, the mrs_orphaned metric is no
longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace_xprtrdma_dma_map(mr)

Matches trace_xprtrdma_dma_unmap(mr).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

svcrdma: Trace key RDMA API events

This includes:
* Posting on the Send and Receive queues
* Send, Receive, Read, and Write completion
* Connect upcalls
* QP errors

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

svcrdma: Trace key RPC/RDMA protocol events

This includes:
* Transport accept and tear-down
* Decisions about using Write and Reply chunks
* Each RDMA segment that is handled
* Whenever an RDMA_ERR is sent

As a clean-up, I've standardized the order of the includes, and
removed some now redundant dprintk call sites.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

xprtrdma: Remove rpcrdma_ep_{post_recv, post_extra_recv}

Clean up: These functions are no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Move Receive posting to Receive handler

Receive completion and Reply handling are done by a BOUND
workqueue, meaning they run on only one CPU.

Posting receives is currently done in the send_request path, which
on large systems is typically done on a different CPU than the one
handling Receive completions. This results in movement of
Receive-related cachelines between the sending and receiving CPUs.

More importantly, it means that currently Receives are posted while
the transport's write lock is held, which is unnecessary and costly.

Finally, allocation of Receive buffers is performed on-demand in
the Receive completion handler. This helps guarantee that they are
allocated on the same NUMA node as the CPU that handles Receive
completions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Clean up Receive trace points

For clarity, report the posting and completion of Receive CQEs.

Also, the wc->byte_len field contains garbage if wc->status is
non-zero, and the vendor error field contains garbage if wc->status
is zero. For readability, don't save those fields in those cases.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Instrument allocation/release of rpcrdma_req/rep objects

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points to instrument QP and CQ access upcalls

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points in the client-side backchannel code paths

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points for connect events

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points to instrument MR allocation and recovery

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points to instrument memory invalidation

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points in reply decoder path

This includes decoding Write and Reply chunks, and fixing up inline
payloads.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points to instrument memory registration

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points in the RPC Reply handler paths

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma: Add trace points in RPC Call transmit paths

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

rpcrdma: infrastructure for static trace points in rpcrdma.ko

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>