Commit Graph

896 Commits

Author SHA1 Message Date
Chuck Lever
9bef848f44 xprtrdma: Remove unused fields from rpcrdma_ia
Clean up. The last use of these fields was in commit 173b8f49b3
("xprtrdma: Demote "connect" log messages") .

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever
ddbb347f0c xprtrdma: Cull dprintk() call sites
Clean up: Remove dprintk() call sites that report rare or impossible
errors. Leave a few that display high-value low noise status
information.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever
92f4433e56 xprtrdma: Simplify locking that protects the rl_allreqs list
Clean up: There's little chance of contention between the use of
rb_lock and rb_reqslock, so merge the two. This avoids having to
take both in some (possibly future) cases.

Transport tear-down is already serialized, thus there is no need for
locking at all when destroying rpcrdma_reqs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever
236b0943d1 xprtrdma: Expose transport header errors
For better observability of parsing errors, return the error code
generated in the decoders to the upper layer consumer.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever
889ee07f7e xprtrdma: Remove request_module from backchannel
Since commit ffe1f0df58 ("rpcrdma: Merge svcrdma and xprtrdma
modules into one"), the forward and backchannel components are part
of the same kernel module. A separate request_module() call in the
backchannel code is no longer necessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever
15303d9ecd xprtrdma: Recognize XDRBUF_SPARSE_PAGES
Commit 431f6eb357 ("SUNRPC: Add a label for RPC calls that require
allocation on receive") didn't update similar logic in rpc_rdma.c.
I don't think this is a bug, per-se; the commit just adds more
careful checking for broken upper layer behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever
0a93fbcb16 xprtrdma: Plant XID in on-the-wire RDMA offset (FRWR)
Place the associated RPC transaction's XID in the upper 32 bits of
each RDMA segment's rdma_offset field. There are two reasons to do
this:

- The R_key only has 8 bits that are different from registration to
  registration. The XID adds more uniqueness to each RDMA segment to
  reduce the likelihood of a software bug on the server reading from
  or writing into memory it's not supposed to.

- On-the-wire RDMA Read and Write requests do not otherwise carry
  any identifier that matches them up to an RPC. The XID in the
  upper 32 bits will act as an eye-catcher in network captures.

Suggested-by: Tom Talpey <ttalpey@microsoft.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever
5f62412be3 xprtrdma: Remove rpcrdma_memreg_ops
Clean up: Now that there is only FRWR, there is no need for a memory
registration switch. The indirect calls to the memreg operations can
be replaced with faster direct calls.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever
ba69cd122e xprtrdma: Remove support for FMR memory registration
FMR is not supported on most recent RDMA devices. It is also less
secure than FRWR because an FMR memory registration can expose
adjacent bytes to remote reading or writing. As discussed during the
RDMA BoF at LPC 2018, it is time to remove support for FMR in the
NFS/RDMA client stack.

Note that NFS/RDMA server-side uses either local memory registration
or FRWR. FMR is not used.

There are a few Infiniband/RoCE devices in the kernel tree that do
not appear to support MEM_MGT_EXTENSIONS (FRWR), and therefore will
not support client-side NFS/RDMA after this patch. These are:

 - mthca
 - qib
 - hns (RoCE)

Users of these devices can use NFS/TCP on IPoIB instead.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever
a78868497c xprtrdma: Reduce max_frwr_depth
Some devices advertise a large max_fast_reg_page_list_len
capability, but perform optimally when MRs are significantly smaller
than that depth -- probably when the MR itself is no larger than a
page.

By default, the RDMA R/W core API uses max_sge_rd as the maximum
page depth for MRs. For some devices, the value of max_sge_rd is
1, which is also not optimal. Thus, when max_sge_rd is larger than
1, use that value. Otherwise use the value of the
max_fast_reg_page_list_len attribute.

I've tested this with CX-3 Pro, FastLinq, and CX-5 devices. It
reproducibly improves the throughput of large I/Os by several
percent.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever
6946f82380 xprtrdma: Fix ri_max_segs and the result of ro_maxpages
With certain combinations of krb5i/p, MR size, and r/wsize, I/O can
fail with EMSGSIZE. This is because the calculated value of
ri_max_segs (the max number of MRs per RPC) exceeded
RPCRDMA_MAX_HDR_SEGS, which caused Read or Write list encoding to
walk off the end of the transport header.

Once that was addressed, the ro_maxpages result has to be corrected
to account for the number of MRs needed for Reply chunks, which is
2 MRs smaller than a normal Read or Write chunk.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever
0c0829bcf5 xprtrdma: Don't wake pending tasks until disconnect is done
Transport disconnect processing does a "wake pending tasks" at
various points.

Suppose an RPC Reply is being processed. The RPC task that Reply
goes with is waiting on the pending queue. If a disconnect wake-up
happens before reply processing is done, that reply, even if it is
good, is thrown away, and the RPC has to be sent again.

This window apparently does not exist for socket transports because
there is a lock held while a reply is being received which prevents
the wake-up call until after reply processing is done.

To resolve this, all RPC replies being processed on an RPC-over-RDMA
transport have to complete before pending tasks are awoken due to a
transport disconnect.

Callers that already hold the transport write lock may invoke
->ops->close directly. Others use a generic helper that schedules
a close when the write lock can be taken safely.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever
3d433ad812 xprtrdma: No qp_event disconnect
After thinking about this more, and auditing other kernel ULP imple-
mentations, I believe that a DISCONNECT cm_event will occur after a
fatal QP event. If that's the case, there's no need for an explicit
disconnect in the QP event handler.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever
6d2d0ee27c xprtrdma: Replace rpcrdma_receive_wq with a per-xprt workqueue
To address a connection-close ordering problem, we need the ability
to drain the RPC completions running on rpcrdma_receive_wq for just
one transport. Give each transport its own RPC completion workqueue,
and drain that workqueue when disconnecting the transport.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever
6ceea36890 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>
2019-01-02 12:05:16 -05:00
Chuck Lever
b674c4b4a1 xprtrdma: Ensure MRs are DMA-unmapped when posting LOCAL_INV fails
The recovery case in frwr_op_unmap_sync needs to DMA unmap each MR.
frwr_release_mr does not DMA-unmap, but the recycle worker does.

Fixes: 61da886bf7 ("xprtrdma: Explicitly resetting MRs is ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever
e2f34e2671 xprtrdma: Yet another double DMA-unmap
While chasing yet another set of DMAR fault reports, I noticed that
the frwr recycler conflates whether or not an MR has been DMA
unmapped with frwr->fr_state. Actually the two have only an indirect
relationship. It's in fact impossible to guess reliably whether the
MR has been DMA unmapped based on its fr_state field, especially as
the surrounding code and its assumptions have changed over time.

A better approach is to track the DMA mapping status explicitly so
that the recycler is less brittle to unexpected situations, and
attempts to DMA-unmap a second time are prevented.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org # v4.20
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Vasily Averin
64e20ba204 sunrpc: remove unused xpo_prep_reply_hdr callback
xpo_prep_reply_hdr are not used now.

It was defined for tcp transport only, however it cannot be
called indirectly, so let's move it to its caller and
remove unused callback.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-27 21:01:41 -05:00
Vasily Averin
7ef88ff85f sunrpc: remove svc_rdma_bc_class
Remove svc_xprt_class svc_rdma_bc_class and related functions.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-27 21:01:41 -05:00
Vasily Averin
4aa5cffefa sunrpc: remove unused bc_up operation from rpc_xprt_ops
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-27 21:01:41 -05:00
Vasily Averin
a289ce5311 sunrpc: replace svc_serv->sv_bc_xprt by boolean flag
svc_serv-> sv_bc_xprt is netns-unsafe and cannot be used as pointer.
To prevent its misuse in future it is replaced by new boolean flag.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-27 21:01:41 -05:00
Kamal Heib
3023a1e936 RDMA: Start use ib_device_ops
Make all the required change to start use the ib_device_ops structure.

Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-12-12 07:40:16 -07:00
Chuck Lever
97bce63408 svcrdma: Optimize the logic that selects the R_key to invalidate
o Select the R_key to invalidate while the CPU cache still contains
  the received RPC Call transport header, rather than waiting until
  we're about to send the RPC Reply.

o Choose Send With Invalidate if there is exactly one distinct R_key
  in the received transport header. If there's more than one, the
  client will have to perform local invalidation after it has
  already waited for remote invalidation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-11-28 18:36:03 -05:00
Linus Torvalds
310c7585e8 Olga added support for the NFSv4.2 asynchronous copy protocol. We
already supported COPY, by copying a limited amount of data and then
 returning a short result, letting the client resend.  The asynchronous
 protocol should offer better performance at the expense of some
 complexity.
 
 The other highlight is Trond's work to convert the duplicate reply cache
 to a red-black tree, and to move it and some other server caches to RCU.
 (Previously these have meant taking global spinlocks on every RPC.)
 
 Otherwise, some RDMA work and miscellaneous bugfixes.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJb2KWzAAoJECebzXlCjuG+gcQP/3DldB86CFxgSFx0t+h+s+TV
 CdYJDPyLyRkEMiD+4dCPPuhueve+j5BPHVsDbn98FTWrEn131NMIs6uhU/VGTtAU
 6a8f/ExtZ5U7s39MJCzlk2ozVElBc3QPp7p3p9NKn0Wi0PXbVgjuIqR5o2vwa8Si
 KOVdLm6ylfav/HTH8DO6zFPJRsTgTwcJOivXXshjpglMKAcw8AuqSsGgBrDeGpgU
 u91Vi0EM1vt96+CA6a01mTgC/sFX7EqGvxUUHOrKWf5cIjnpT3FDvouYPxi+GH8Z
 SIDlaMQyXF5m4m6MhELNTP4v97XAHyPJtvLkEe5lggTyABPiA2heo9e8onysWkzV
 1v8OZHCVFa1UL34mDlnFxbFCYVr7FFKMGjTBR/ntinobPfAbWRCO1Hdd+bBGPDD4
 byf7ctDVp7KQ2bSatIdlYavikuGDHWFDZHzPHlqkD3gpIZSNvhe26sV3NZqIFlXO
 cMUega2Y5mXmULauHhxAcNGtDK7dF5hHoMWKJy0DNxiyDiDLylwDOIfwt1De3Q7V
 ycd/wUytUS2LkAhyS2mvoDK6eXTBAeQwzmXAqveh6rewwO83HC/t9mtKBBDomvKG
 xRpRPmmbj9ijbwkilEBmijjR47wrihmEVIFahznEerZ+//QOfVVOB0MNtzIyU9/k
 CnP1ZNvOs3LR1pxxwFa8
 =TTo0
 -----END PGP SIGNATURE-----

Merge tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Olga added support for the NFSv4.2 asynchronous copy protocol. We
  already supported COPY, by copying a limited amount of data and then
  returning a short result, letting the client resend. The asynchronous
  protocol should offer better performance at the expense of some
  complexity.

  The other highlight is Trond's work to convert the duplicate reply
  cache to a red-black tree, and to move it and some other server caches
  to RCU. (Previously these have meant taking global spinlocks on every
  RPC)

  Otherwise, some RDMA work and miscellaneous bugfixes"

* tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux: (30 commits)
  lockd: fix access beyond unterminated strings in prints
  nfsd: Fix an Oops in free_session()
  nfsd: correctly decrement odstate refcount in error path
  svcrdma: Increase the default connection credit limit
  svcrdma: Remove try_module_get from backchannel
  svcrdma: Remove ->release_rqst call in bc reply handler
  svcrdma: Reduce max_send_sges
  nfsd: fix fall-through annotations
  knfsd: Improve lookup performance in the duplicate reply cache using an rbtree
  knfsd: Further simplify the cache lookup
  knfsd: Simplify NFS duplicate replay cache
  knfsd: Remove dead code from nfsd_cache_lookup
  SUNRPC: Simplify TCP receive code
  SUNRPC: Replace the cache_detail->hash_lock with a regular spinlock
  SUNRPC: Remove non-RCU protected lookup
  NFS: Fix up a typo in nfs_dns_ent_put
  NFS: Lockless DNS lookups
  knfsd: Lockless lookup of NFSv4 identities.
  SUNRPC: Lockless server RPCSEC_GSS context lookup
  knfsd: Allow lockless lookups of the exports
  ...
2018-10-30 13:03:29 -07:00
Chuck Lever
07880fa496 svcrdma: Remove try_module_get from backchannel
Since commit ffe1f0df58 ("rpcrdma: Merge svcrdma and xprtrdma
modules into one"), the forward and backchannel components are part
of the same kernel module. A separate try_module_get() call in the
backchannel code is no longer necessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29 16:58:04 -04:00
Chuck Lever
596f2a1950 svcrdma: Remove ->release_rqst call in bc reply handler
Similar to a change made in the client's forward channel reply
handler: The xprt_release_rqst_cong() call is not necessary.

Also, release xprt->recv_lock when taking xprt->transport_lock
to avoid disabling and enabling BH's while holding another
spin lock.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29 16:58:04 -04:00
Chuck Lever
f3c1fd0ee2 svcrdma: Reduce max_send_sges
There's no need to request a large number of send SGEs because the
inline threshold already constrains the number of SGEs per Send.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-10-29 16:58:04 -04:00
Trond Myklebust
93bdcf9fdb NFS RDMA client updates for Linux 4.20
Stable bugfixes:
 - Reset credit grant properly after a disconnect
 
 Other bugfixes and cleanups:
 - xprt_release_rqst_cong is called outside of transport_lock
 - Create more MRs at a time and toss out old ones during recovery
 - Various improvements to the RDMA connection and disconnection code:
   - Improve naming of trace events, functions, and variables
   - Add documenting comments
   - Fix metrics and stats reporting
 - Fix a tracepoint sparse warning
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEnZ5MQTpR7cLU7KEp18tUv7ClQOsFAlvHmcUACgkQ18tUv7Cl
 QOv5Mg//ZIL92L6WqW2C+Tddr4UcPg1YphBEwGo3+TrswSRg3ncDiTQ8ycOOrmoy
 7m5Oe5I1uEM0Ejqu0lh0uoxJlxRtMF0pwpnTA2Mx6bb4GLSTXjJQomKBhZ3v6owo
 RQaQZTnAT+T5w1jZMuImdZ+c1zNNiFonSdPO7Er5jbdczvY6N7bg84goLoXLZkjk
 cuYFbBl3DAyoUJ1usgiuCZLbMcEe0isJEtFU45dLkxxFkvNk+gO8UtA48qe0rFNg
 8LQMHqhXDhHbdqLFpIRdvaanRpi8VjhCukE+Af9z/y0XNPYItWKTm0clkZ1bu/D4
 /Q6gUnCU8KeSzlPqrT7nATO6L5sHlqlE9vSbJpWguvgBg9JbMDZquh0gejVqGr4t
 1YbJyNh/anl5Xm56CIADEbQK3QocyDRwk9tQhlOUEwBu7rgQrU7NO+1CHgXRD94c
 iNI892W9FZZQxKOkWnb3DtgpnmuQ4k9tLND/SSnqOllADpztDag+czOxtOHOxlK0
 sVh4U82JtYtP9ubhKzFvTDlFv3rcjE86Nn55mAgCFk/XBDLF3kMjjZcS527YLkWY
 OqDVeKin7nKv1ZfeV9msWbaKp4w2sNhgtROGQr4g1/FktRXS6b8XsTxn7anyVYzM
 l8SJx66q8XFaWcp0Kwp55oOyhh16dhhel34lWi+wAlF79ypMGlE=
 =SxSD
 -----END PGP SIGNATURE-----

Merge tag 'nfs-rdma-for-4.20-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

NFS RDMA client updates for Linux 4.20

Stable bugfixes:
- Reset credit grant properly after a disconnect

Other bugfixes and cleanups:
- xprt_release_rqst_cong is called outside of transport_lock
- Create more MRs at a time and toss out old ones during recovery
- Various improvements to the RDMA connection and disconnection code:
  - Improve naming of trace events, functions, and variables
  - Add documenting comments
  - Fix metrics and stats reporting
- Fix a tracepoint sparse warning

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-10-18 17:29:00 -04:00
Chuck Lever
ad0911802c xprtrdma: Clean up xprt_rdma_disconnect_inject
Clean up: Use the appropriate C macro instead of open-coding
container_of() .

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 14:19:31 -04:00
Chuck Lever
f26c32fa5c xprtrdma: Add documenting comments
Clean up: fill in or update documenting comments for transport
switch entry points.

For xprt_rdma_allocate:

The first paragraph is no longer true since commit 5a6d1db455
("SUNRPC: Add a transport-specific private field in rpc_rqst").

The second paragraph is no longer true since commit 54cbd6b0c6
("xprtrdma: Delay DMA mapping Send and Receive buffers").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 14:10:55 -04:00
Chuck Lever
61c208a5ca xprtrdma: Report when there were zero posted Receives
To show that a caller did attempt to allocate and post more Receive
buffers, the trace point in rpcrdma_post_recvs() should report when
rpcrdma_post_recvs() was invoked but no new Receive buffers were
posted.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 14:02:01 -04:00
Chuck Lever
512ccfb61a xprtrdma: Move rb_flags initialization
Clean up: rb_flags might be used for other things besides
RPCRDMA_BUF_F_EMPTY_SCQ, so initialize it in a generic spot
instead of in a send-completion-queue-related helper.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 13:39:02 -04:00
Chuck Lever
f7d4668155 xprtrdma: Don't disable BH's in backchannel server
Clean up: This code was copied from xprtsock.c and
backchannel_rqst.c. For rpcrdma, the backchannel server runs
exclusively in process context, thus disabling bottom-halves is
unnecessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 10:23:45 -04:00
Chuck Lever
83e301dd13 xprtrdma: Remove memory address of "ep" from an error message
Clean up: Replace the hashed memory address of the target rpcrdma_ep
with the server's IP address and port. The server address is more
useful in an administrative error message.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 10:05:37 -04:00
Chuck Lever
f9521d53e8 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>
2018-10-03 09:14:57 -04:00
Chuck Lever
31e62d25b5 xprtrdma: Simplify RPC wake-ups on connect
Currently, when a connection is established, rpcrdma_conn_upcall
invokes rpcrdma_conn_func and then
wake_up_all(&ep->rep_connect_wait). The former wakes waiting RPCs,
but the connect worker is not done yet, and that leads to races,
double wakes, and difficulty understanding how this logic is
supposed to work.

Instead, collect all the "connection established" logic in the
connect worker (xprt_rdma_connect_worker). A disconnect worker is
retained to handle provider upcalls safely.

Fixes: 254f91e2fa ("xprtrdma: RPC/RDMA must invoke ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 08:58:41 -04:00
Chuck Lever
316a616e78 xprtrdma: Re-organize the switch() in rpcrdma_conn_upcall
Clean up: Eliminate the FALLTHROUGH into the default arm to make the
switch easier to understand.

Also, as long as I'm here, do not display the memory address of the
target rpcrdma_ep. A hashed memory address is of marginal use here.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-03 08:39:39 -04:00
Chuck Lever
aadc5a9448 xprtrdma: Eliminate "connstate" variable from rpcrdma_conn_upcall()
Clean up.

Since commit 173b8f49b3 ("xprtrdma: Demote "connect" log messages")
there has been no need to initialize connstat to zero. In fact, in
this code path there's now no reason not to set rep_connected
directly.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 16:16:54 -04:00
Chuck Lever
ed97f1f79b xprtrdma: Conventional variable names in rpcrdma_conn_upcall
Clean up: The convention throughout other parts of xprtrdma is to
name variables of type struct rpcrdma_xprt "r_xprt", not "xprt".
This convention enables the use of the name "xprt" for a "struct
rpc_xprt" type variable, as in other parts of the RPC client.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 16:15:36 -04:00
Chuck Lever
ae38288eb7 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>
2018-10-02 16:14:05 -04:00
Chuck Lever
8440a88611 sunrpc: Report connect_time in seconds
The way connection-oriented transports report connect_time is wrong:
it's supposed to be in seconds, not in jiffies.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 16:11:00 -04:00
Chuck Lever
3968a8a531 sunrpc: Fix connect metrics
For TCP, the logic in xprt_connect_status is currently never invoked
to record a successful connection. Commit 2a4919919a ("SUNRPC:
Return EAGAIN instead of ENOTCONN when waking up xprt->pending")
changed the way TCP xprt's are awoken after a connect succeeds.

Instead, change connection-oriented transports to bump connect_count
and compute connect_time the moment that XPRT_CONNECTED is set.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 16:08:12 -04:00
Chuck Lever
d379eaa838 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>
2018-10-02 15:55:36 -04:00
Chuck Lever
61da886bf7 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 e2ac236c0b ("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>
2018-10-02 15:48:12 -04:00
Chuck Lever
c421ece68f xprtrdma: Create more MRs at a time
Some devices require more than 3 MRs to build a single 1MB I/O.
Ensure that rpcrdma_mrs_create() will add enough MRs to build that
I/O.

In a subsequent patch I'm changing the MR recovery logic to just
toss out the MRs. In that case it's possible for ->send_request to
loop acquiring some MRs, not getting enough, getting called again,
recycling the previous MRs, then not getting enough, lather rinse
repeat. Thus first we need to ensure enough MRs are created to
prevent that loop.

I'm "reusing" ia->ri_max_segs. All of its accessors seem to want the
maximum number of data segments plus two, so I'm going to bake that
into the initial calculation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 15:46:35 -04:00
Chuck Lever
ef739b2175 xprtrdma: Reset credit grant properly after a disconnect
On a fresh connection, an RPC/RDMA client is supposed to send only
one RPC Call until it gets a credit grant in the first RPC Reply
from the server [RFC 8166, Section 3.3.3].

There is a bug in the Linux client's credit accounting mechanism
introduced by commit e7ce710a88 ("xprtrdma: Avoid deadlock when
credit window is reset"). On connect, it simply dumps all pending
RPC Calls onto the new connection.

Servers have been tolerant of this bad behavior. Currently no server
implementation ever changes its credit grant over reconnects, and
servers always repost enough Receives before connections are fully
established.

To correct this issue, ensure that the client resets both the credit
grant _and_ the congestion window when handling a reconnect.

Fixes: e7ce710a88 ("xprtrdma: Avoid deadlock when credit ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 15:45:09 -04:00
Chuck Lever
91ca18660e xprtrdma: xprt_release_rqst_cong is called outside of transport_lock
Since commit ce7c252a8c ("SUNRPC: Add a separate spinlock to
protect the RPC request receive list") the RPC/RDMA reply handler
has been calling xprt_release_rqst_cong without holding
xprt->transport_lock.

I think the only way this call is ever made is if the credit grant
increases and there are RPCs pending. Current server implementations
do not change their credit grant during operation (except at
connect time).

Commit e7ce710a88 ("xprtrdma: Avoid deadlock when credit window is
reset") added the ->release_rqst call because UDP invokes
xprt_adjust_cwnd(), which calls __xprt_put_cong() after adjusting
xprt->cwnd. Both xprt_release() and ->xprt_release_xprt already wake
another task in this case, so it is safe to remove this call from
the reply handler.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 15:26:30 -04:00
Trond Myklebust
adfa71446d SUNRPC: Cleanup: remove the unused 'task' argument from the request_send()
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:16 -04:00
Trond Myklebust
c544577dad SUNRPC: Clean up transport write space handling
Treat socket write space handling in the same way we now treat transport
congestion: by denying the XPRT_LOCK until the transport signals that it
has free buffer space.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:15 -04:00
Trond Myklebust
75891f502f SUNRPC: Support for congestion control when queuing is enabled
Both RDMA and UDP transports require the request to get a "congestion control"
credit before they can be transmitted. Right now, this is done when
the request locks the socket. We'd like it to happen when a request attempts
to be transmitted for the first time.
In order to support retransmission of requests that already hold such
credits, we also want to ensure that they get queued first, so that we
don't deadlock with requests that have yet to obtain a credit.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:15 -04:00
Trond Myklebust
50f484e298 SUNRPC: Treat the task and request as separate in the xprt_ops->send_request()
When we shift to using the transmit queue, then the task that holds the
write lock will not necessarily be the same as the one being transmitted.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:15 -04:00
Trond Myklebust
edc81dcd5b SUNRPC: Refactor xprt_transmit() to remove the reply queue code
Separate out the action of adding a request to the reply queue so that the
backchannel code can simply skip calling it altogether.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:14 -04:00
Trond Myklebust
75c84151a9 SUNRPC: Rename xprt->recv_lock to xprt->queue_lock
We will use the same lock to protect both the transmit and receive queues.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:14 -04:00
Linus Torvalds
53a01c9a5f NFS client updates for Linux 4.19
Stable bufixes:
 - v3.17+: Fix an off-by-one in bl_map_stripe()
 - v4.9+: NFSv4 client live hangs after live data migration recovery
 - v4.18+: xprtrdma: Fix disconnect regression
 - v4.14+: Fix locking in pnfs_generic_recover_commit_reqs
 - v4.9+: Fix a sleep in atomic context in nfs4_callback_sequence()
 
 Features:
 - Add support for asynchronous server-side COPY operations
 
 Other bugfixes and cleanups:
 - Optitmizations and fixes involving NFS v4.1 / pNFS layout handling
 - Optimize lseek(fd, SEEK_CUR, 0) on directories to avoid locking
 - Immediately reschedule writeback when the server replies with an error
 - Fix excessive attribute revalidation in nfs_execute_ok()
 - Add error checking to nfs_idmap_prepare_message()
 - Use new vm_fault_t return type
 - Return a delegation when reclaiming one that the server has recalled
 - Referrals should inherit proto setting from parents
 - Make rpc_auth_create_args a const
 - Improvements to rpc_iostats tracking
 - Fix a potential reference leak when there is an error processing a callback
 - Fix rmdir / mkdir / rename nlink accounting
 - Fix updating inode change attribute
 - Fix error handling in nfsn4_sp4_select_mode()
 - Use an appropriate work queue for direct-write completion
 - Don't busy wait if NFSv4 session draining is interrupted
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEnZ5MQTpR7cLU7KEp18tUv7ClQOsFAlt/CYIACgkQ18tUv7Cl
 QOu8gBAA0xQWmgRoG6oIdYUxvgYqhuJmMqC4SU1E6mCJ93xEuUSvEFw51X+84KCt
 r6UPkp/bKiVe3EIinKTplIzuxgggXNG0EQmO46FYNTl7nqpN85ffLsQoWsiD23fp
 j8afqKPFR2zfhHXLKQC7k1oiOpwGqJ+EJWgIW4llE80pSNaErEoEaDqSPds5thMN
 dHEjjLr8ef6cbBux6sSPjwWGNbE82uoSu3MDuV2+e62hpGkgvuEYo1vyE6ujeZW5
 MUsmw+AHZkwro0msTtNBOHcPZAS0q/2UMPzl1tsDeCWNl2mugqZ6szQLSS2AThKq
 Zr6iK9Q5dWjJfrQHcjRMnYJB+SCX1SfPA7ASuU34opwcWPjecbS9Q92BNTByQYwN
 o9ngs2K0mZfqpYESMAmf7Il134cCBrtEp3skGko2KopJcYcE5YUFhdKihi1yQQjU
 UbOOubMpQk8vY9DpDCAwGbICKwUZwGvq27uuUWL20kFVDb1+jvfHwcV4KjRAJo/E
 J9aFtU+qOh4rMPMnYlEVZcAZBGfenlv/DmBl1upRpjzBkteUpUJsAbCmGyAk4616
 3RECasehgsjNCQpFIhv3FpUkWzP5jt0T3gRr1NeY6WKJZwYnHEJr9PtapS+EIsCT
 tB5DvvaJqFtuHFOxzn+KlGaxdSodHF7klOq7NM3AC0cX8AkWqaU=
 =8+9t
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.19-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "These patches include adding async support for the v4.2 COPY
  operation. I think Bruce is planning to send the server patches for
  the next release, but I figured we could get the client side out of
  the way now since it's been in my tree for a while. This shouldn't
  cause any problems, since the server will still respond with
  synchronous copies even if the client requests async.

  Features:
   - Add support for asynchronous server-side COPY operations

  Stable bufixes:
   - Fix an off-by-one in bl_map_stripe() (v3.17+)
   - NFSv4 client live hangs after live data migration recovery (v4.9+)
   - xprtrdma: Fix disconnect regression (v4.18+)
   - Fix locking in pnfs_generic_recover_commit_reqs (v4.14+)
   - Fix a sleep in atomic context in nfs4_callback_sequence() (v4.9+)

  Other bugfixes and cleanups:
   - Optimizations and fixes involving NFS v4.1 / pNFS layout handling
   - Optimize lseek(fd, SEEK_CUR, 0) on directories to avoid locking
   - Immediately reschedule writeback when the server replies with an
     error
   - Fix excessive attribute revalidation in nfs_execute_ok()
   - Add error checking to nfs_idmap_prepare_message()
   - Use new vm_fault_t return type
   - Return a delegation when reclaiming one that the server has
     recalled
   - Referrals should inherit proto setting from parents
   - Make rpc_auth_create_args a const
   - Improvements to rpc_iostats tracking
   - Fix a potential reference leak when there is an error processing a
     callback
   - Fix rmdir / mkdir / rename nlink accounting
   - Fix updating inode change attribute
   - Fix error handling in nfsn4_sp4_select_mode()
   - Use an appropriate work queue for direct-write completion
   - Don't busy wait if NFSv4 session draining is interrupted"

* tag 'nfs-for-4.19-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (54 commits)
  pNFS: Remove unwanted optimisation of layoutget
  pNFS/flexfiles: ff_layout_pg_init_read should exit on error
  pNFS: Treat RECALLCONFLICT like DELAY...
  pNFS: When updating the stateid in layoutreturn, also update the recall range
  NFSv4: Fix a sleep in atomic context in nfs4_callback_sequence()
  NFSv4: Fix locking in pnfs_generic_recover_commit_reqs
  NFSv4: Fix a typo in nfs4_init_channel_attrs()
  NFSv4: Don't busy wait if NFSv4 session draining is interrupted
  NFS recover from destination server reboot for copies
  NFS add a simple sync nfs4_proc_commit after async COPY
  NFS handle COPY ERR_OFFLOAD_NO_REQS
  NFS send OFFLOAD_CANCEL when COPY killed
  NFS export nfs4_async_handle_error
  NFS handle COPY reply CB_OFFLOAD call race
  NFS add support for asynchronous COPY
  NFS COPY xdr handle async reply
  NFS OFFLOAD_CANCEL xdr
  NFS CB_OFFLOAD xdr
  NFS: Use an appropriate work queue for direct-write completion
  NFSv4: Fix error handling in nfs4_sp4_select_mode()
  ...
2018-08-23 16:03:58 -07:00
Linus Torvalds
9157141c95 A mistake on my part caused me to tag my branch 6 commits too early,
missing Chuck's fixes for the problem with callbacks over GSS from
 multi-homed servers, and a smaller fix from Laura Abbott.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJbftA8AAoJECebzXlCjuG+QPMQALieEKkX0YoqRhPz5G+RrWFy
 KgOBFAoiRcjFQD6wMt9FzD6qYEZqSJ+I2b+K5N3BkdyDDQu845iD0wK0zBGhMgLm
 7ith85nphIMbe18+5jPorqAsI9RlfBQjiSGw1MEx5dicLQQzTObHL5q+l5jcWna4
 jWS3yUKv1URpOsR1hIryw74ktSnhuH8n//zmntw8aWrCkq3hnXOZK/agtYxZ7Viv
 V3kiQsiNpL2FPRcHN7ejhLUTnRkkuD2iYKrzP/SpTT/JfdNEUXlMhKkAySogNpus
 nvR9X7hwta8Lgrt7PSB9ibFTXtCupmuICg5mbDWy6nXea2NvpB01QhnTzrlX17Eh
 Yfk/18z95b6Qs1v4m3SI8ESmyc6l5dMZozLudtHzifyCqooWZriEhCR1PlQfQ/FJ
 4cYQ8U/qiMiZIJXL7N2wpSoSaWR5bqU1rXen29Np1WEDkiv4Nf5u2fsCXzv0ZH2C
 ReWpNkbnNxsNiKpp4geBZtlcSEU1pk+1PqE0MagTdBV3iptiUHRSP4jR7qLnc0zT
 J1lCvU7Fodnt9vNSxMpt2Jd6XxQ6xtx7n6aMQAiYFnXDs+hP2hPnJVCScnYW3L6R
 2r1sHRKKeoOzCJ2thw+zu4lOwMm7WPkJPWAYfv90reWkiKoy2vG0S9P7wsNGoJuW
 fuEjB2b9pow1Ffynat6q
 =JnLK
 -----END PGP SIGNATURE-----

Merge tag 'nfsd-4.19-1' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Chuck Lever fixed a problem with NFSv4.0 callbacks over GSS from
  multi-homed servers.

  The only new feature is a minor bit of protocol (change_attr_type)
  which the client doesn't even use yet.

  Other than that, various bugfixes and cleanup"

* tag 'nfsd-4.19-1' of git://linux-nfs.org/~bfields/linux: (27 commits)
  sunrpc: Add comment defining gssd upcall API keywords
  nfsd: Remove callback_cred
  nfsd: Use correct credential for NFSv4.0 callback with GSS
  sunrpc: Extract target name into svc_cred
  sunrpc: Enable the kernel to specify the hostname part of service principals
  sunrpc: Don't use stack buffer with scatterlist
  rpc: remove unneeded variable 'ret' in rdma_listen_handler
  nfsd: use true and false for boolean values
  nfsd: constify write_op[]
  fs/nfsd: Delete invalid assignment statements in nfsd4_decode_exchange_id
  NFSD: Handle full-length symlinks
  NFSD: Refactor the generic write vector fill helper
  svcrdma: Clean up Read chunk path
  svcrdma: Avoid releasing a page in svc_xprt_release()
  nfsd: Mark expected switch fall-through
  sunrpc: remove redundant variables 'checksumlen','blocksize' and 'data'
  nfsd: fix leaked file lock with nfs exported overlayfs
  nfsd: don't advertise a SCSI layout for an unsupported request_queue
  nfsd: fix corrupted reply to badly ordered compound
  nfsd: clarify check_op_ordering
  ...
2018-08-23 16:00:10 -07:00
zhong jiang
ac5bb5b3b0 rpc: remove unneeded variable 'ret' in rdma_listen_handler
The ret is not modified after initalization, So just remove the variable
and return 0.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09 16:11:21 -04:00
Chuck Lever
07d0ff3b0c svcrdma: Clean up Read chunk path
Simplify the error handling at the tail of recv_read_chunk() by
re-arranging rq_pages[] housekeeping and documenting it properly.

NB: In this path, svc_rdma_recvfrom returns zero. Therefore no
subsequent reply processing is done on the svc_rqstp, and thus the
rq_respages field does not need to be updated.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09 16:11:21 -04:00
Chuck Lever
a53d5cb064 svcrdma: Avoid releasing a page in svc_xprt_release()
svc_xprt_release() invokes svc_free_res_pages(), which releases
pages between rq_respages and rq_next_page.

Historically, the RPC/RDMA transport has set these two pointers to
be different by one, which means:

- one page gets released when svc_recv returns 0. This normally
happens whenever one or more RDMA Reads need to be dispatched to
complete construction of an RPC Call.

- one page gets released after every call to svc_send.

In both cases, this released page is immediately refilled by
svc_alloc_arg. There does not seem to be a reason for releasing this
page.

To avoid this unnecessary memory allocator traffic, set rq_next_page
more carefully.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09 16:11:21 -04:00
YueHaibing
9cc3b98d1f sunrpc: remove redundant variables 'checksumlen','blocksize' and 'data'
Variables 'checksumlen','blocksize' and 'data' are being assigned,
but are never used, hence they are redundant and can be removed.

Fix the following warning:

  net/sunrpc/auth_gss/gss_krb5_wrap.c:443:7: warning: variable ‘blocksize’ set but not used [-Wunused-but-set-variable]
  net/sunrpc/auth_gss/gss_krb5_crypto.c:376:15: warning: variable ‘checksumlen’ set but not used [-Wunused-but-set-variable]
  net/sunrpc/xprtrdma/svc_rdma.c:97:9: warning: variable ‘data’ set but not used [-Wunused-but-set-variable]

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09 16:11:21 -04:00
Chuck Lever
8d4fb8ff42 xprtrdma: Fix disconnect regression
I found that injecting disconnects with v4.18-rc resulted in
random failures of the multi-threaded git regression test.

The root cause appears to be that, after a reconnect, the
RPC/RDMA transport is waking pending RPCs before the transport has
posted enough Receive buffers to receive the Replies. If a Reply
arrives before enough Receive buffers are posted, the connection
is dropped. A few connection drops happen in quick succession as
the client and server struggle to regain credit synchronization.

This regression was introduced with commit 7c8d9e7c88 ("xprtrdma:
Move Receive posting to Receive handler"). The client is supposed to
post a single Receive when a connection is established because
it's not supposed to send more than one RPC Call before it gets
a fresh credit grant in the first RPC Reply [RFC 8166, Section
3.3.3].

Unfortunately there appears to be a longstanding bug in the Linux
client's credit accounting mechanism. On connect, it simply dumps
all pending RPC Calls onto the new connection. It's possible it has
done this ever since the RPC/RDMA transport was added to the kernel
ten years ago.

Servers have so far been tolerant of this bad behavior. Currently no
server implementation ever changes its credit grant over reconnects,
and servers always repost enough Receives before connections are
fully established.

The Linux client implementation used to post a Receive before each
of these Calls. This has covered up the flooding send behavior.

I could try to correct this old bug so that the client sends exactly
one RPC Call and waits for a Reply. Since we are so close to the
next merge window, I'm going to instead provide a simple patch to
post enough Receives before a reconnect completes (based on the
number of credits granted to the previous connection).

The spurious disconnects will be gone, but the client will still
send multiple RPC Calls immediately after a reconnect.

Addressing the latter problem will wait for a merge window because
a) I expect it to be a large change requiring lots of testing, and
b) obviously the Linux client has interoperated successfully since
day zero while still being broken.

Fixes: 7c8d9e7c88 ("xprtrdma: Move Receive posting to ... ")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-08-08 16:49:47 -04:00
Bart Van Assche
d34ac5cd3a RDMA, core and ULPs: Declare ib_post_send() and ib_post_recv() arguments const
Since neither ib_post_send() nor ib_post_recv() modify the data structure
their second argument points at, declare that argument const. This change
makes it necessary to declare the 'bad_wr' argument const too and also to
modify all ULPs that call ib_post_send(), ib_post_recv() or
ib_post_srq_recv(). This patch does not change any functionality but makes
it possible for the compiler to verify whether the
ib_post_(send|recv|srq_recv) really do not modify the posted work request.

To make this possible, only one cast had to be introduce that casts away
constness, namely in rpcrdma_post_recvs(). The only way I can think of to
avoid that cast is to introduce an additional loop in that function or to
change the data type of bad_wr from struct ib_recv_wr ** into int
(an index that refers to an element in the work request list). However,
both approaches would require even more extensive changes than this
patch.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-30 20:09:34 -06:00
Jason Gunthorpe
5d85a822fa net/xprtrdma: Restore needed argument to ib_post_send
The call in svc_rdma_post_chunk_ctxt() does actually use bad_wr.

Fixes: ed288d74a9 ("net/xprtrdma: Simplify ib_post_(send|recv|srq_recv)() calls")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-26 11:36:50 -06:00
Bart Van Assche
ed288d74a9 net/xprtrdma: Simplify ib_post_(send|recv|srq_recv)() calls
Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL
as third argument to ib_post_(send|recv|srq_recv)().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-24 16:06:37 -06:00
Steve Wise
33023fb85a IB/core: add max_send_sge and max_recv_sge attributes
This patch replaces the ib_device_attr.max_sge with max_send_sge and
max_recv_sge. It allows ulps to take advantage of devices that have very
different send and recv sge depths.  For example cxgb4 has a max_recv_sge
of 4, yet a max_send_sge of 16.  Splitting out these attributes allows
much more efficient use of the SQ for cxgb4 with ulps that use the RDMA_RW
API. Consider a large RDMA WRITE that has 16 scattergather entries.
With max_sge of 4, the ulp would send 4 WRITE WRs, but with max_sge of
16, it can be done with 1 WRITE WR.

Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-06-18 13:17:28 -06:00
Linus Torvalds
0725d4e1b8 NFS client updates for Linux 4.18
Highlights include:
 
 Stable fixes:
 - Fix a 1-byte stack overflow in nfs_idmap_read_and_verify_message
 - Fix a hang due to incorrect error returns in rpcrdma_convert_iovs()
 - Revert an incorrect change to the NFSv4.1 callback channel
 - Fix a bug in the NFSv4.1 sequence error handling
 
 Features and optimisations:
 - Support for piggybacking a LAYOUTGET operation to the OPEN compound
 - RDMA performance enhancements to deal with transport congestion
 - Add proper SPDX tags for NetApp-contributed RDMA source
 - Do not request delegated file attributes (size+change) from the server
 - Optimise away a GETATTR in the lookup revalidate code when doing NFSv4 OPEN
 - Optimise away unnecessary lookups for rename targets
 - Misc performance improvements when freeing NFSv4 delegations
 
 Bugfixes and cleanups:
 - Try to fail quickly if proto=rdma
 - Clean up RDMA receive trace points
 - Fix sillyrename to return the delegation when appropriate
 - Misc attribute revalidation fixes
 - Immediately clear the pNFS layout on a file when the server returns ESTALE
 - Return NFS4ERR_DELAY when delegation/layout recalls fail due to igrab()
 - Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJbH8gIAAoJEA4mA3inWBJcpzYQAJYY3ykt9oLQgm/2b/D/weDe
 6890M9W5nIeuZq5soWSpYsZTxqIFbGV4laG/eCTW1gUN1TitSZsoOp7kqhRHXOjq
 Rv3ZvjlZsP2qv2SnzsEmhJsynfyB46d19smSTJhgQ8dnXhaZv04Wsd4krLHx0z6p
 uUUis5Q1m+vL7HsFPp3iUareO/DFKeSkw2cQ2V5ksTIEiAzX7GC+Ex/KKWf82nrJ
 hm7+Nq7rLf1QHJkQvsc3fYCMR4gIzEwUu6F8RyxCoAVgD6O90Hx6NbxnINaHDD4N
 U0nRP5LwCyN9hbPWvwcH7Sn4ePDTos2yj2tFO5NP9btTLDVLFSGYZ2a74d9PRdAf
 9jn6f6juSDwI7T6NXvkHzzkJG6Or9ABAUZo+yX5JoD6lmgOcPUJpLRy6fu7UxAuN
 a5OZ7d9edYpOi0Kys8sDSIlLlxZtFkvybOMVuI3dSHsI+c0g39w8oarpqT2wXWMs
 /ZtFz0FCreHhKkNtz7Z49z1UQHDv/XYM0WkcO+eaeK58RLIEE0pZHoMvPKP63lkI
 nbbgHvBRAu38Jtvvu65Hpb/VpBcqNGM5hjN1cfW/BOqAPKW23s4vWVj+/1silfW/
 uw0MkNrDC9endoALp/YMCcMwPvEw9Awt9y4KjMgfVgSnKwXd0HaSZ2zE6aJU3Wry
 Fy2Tv0e0OH3z9Bi/LNuJ
 =YWSl
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:

   - Fix a 1-byte stack overflow in nfs_idmap_read_and_verify_message

   - Fix a hang due to incorrect error returns in rpcrdma_convert_iovs()

   - Revert an incorrect change to the NFSv4.1 callback channel

   - Fix a bug in the NFSv4.1 sequence error handling

  Features and optimisations:

   - Support for piggybacking a LAYOUTGET operation to the OPEN compound

   - RDMA performance enhancements to deal with transport congestion

   - Add proper SPDX tags for NetApp-contributed RDMA source

   - Do not request delegated file attributes (size+change) from the
     server

   - Optimise away a GETATTR in the lookup revalidate code when doing
     NFSv4 OPEN

   - Optimise away unnecessary lookups for rename targets

   - Misc performance improvements when freeing NFSv4 delegations

  Bugfixes and cleanups:

   - Try to fail quickly if proto=rdma

   - Clean up RDMA receive trace points

   - Fix sillyrename to return the delegation when appropriate

   - Misc attribute revalidation fixes

   - Immediately clear the pNFS layout on a file when the server returns
     ESTALE

   - Return NFS4ERR_DELAY when delegation/layout recalls fail due to
     igrab()

   - Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY"

* tag 'nfs-for-4.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (80 commits)
  skip LAYOUTRETURN if layout is invalid
  NFSv4.1: Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY
  NFSv4: Fix a typo in nfs41_sequence_process
  NFSv4: Revert commit 5f83d86cf5 ("NFSv4.x: Fix wraparound issues..")
  NFSv4: Return NFS4ERR_DELAY when a layout recall fails due to igrab()
  NFSv4: Return NFS4ERR_DELAY when a delegation recall fails due to igrab()
  NFSv4.0: Remove transport protocol name from non-UCS client ID
  NFSv4.0: Remove cl_ipaddr from non-UCS client ID
  NFSv4: Fix a compiler warning when CONFIG_NFS_V4_1 is undefined
  NFS: Filter cache invalidation when holding a delegation
  NFS: Ignore NFS_INO_REVAL_FORCED in nfs_check_inode_attributes()
  NFS: Improve caching while holding a delegation
  NFS: Fix attribute revalidation
  NFS: fix up nfs_setattr_update_inode
  NFSv4: Ensure the inode is clean when we set a delegation
  NFSv4: Ignore NFS_INO_REVAL_FORCED in nfs4_proc_access
  NFSv4: Don't ask for delegated attributes when adding a hard link
  NFSv4: Don't ask for delegated attributes when revalidating the inode
  NFS: Pass the inode down to the getattr() callback
  NFSv4: Don't request size+change attribute if they are delegated to us
  ...
2018-06-12 10:09:03 -07:00
Linus Torvalds
89e255678f A relatively quiet cycle for nfsd. The largest piece is an RDMA update
from Chuck Lever with new trace points, miscellaneous cleanups, and
 streamlining of the send and receive paths.  Other than that, some
 miscellaneous bugfixes.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJbHtKUAAoJECebzXlCjuG+dfgP/2Z9PiJXlxKC2iISgkfMGmBd
 MmWZYekYMtCe5raoiI720W5cGL7uBLoKnc+r57+n7bEGxV9OFwtspmKGn17P/zrY
 YcBIdN7gjpqn8wrflLR4D09bGpnmaZG26jIt/v0TS+N1aFKO3gNXb0ZVSjUadlI0
 UsKRbYxr8qucIENVtXhfA0eRivddadsKopAEwflUrxf+8oEaYszPFUfNXcGDpdHK
 +6D2lFjr/Fn+z97Rbz/G3fMfldpYhUOpH28DOiCuKEpgamK3dYjx1WoGUANxcj3o
 RsbHGZnMR6842Nj5aHus0k6Ao9bgqt6lx+jKlkvWYK+G2EfMfV9Z1gAipPY+IMbd
 Zk5A4pnFpI1UG3sUlcnpaxAM/pHBs7heYGqj0hyocG8rB4V7SDZxp21Lv1fjTH/A
 XHAkdiT4iSgI11J8YbmDBR1S7bAnfNm7GT24DsAkZLzh2f5Miq5m/ZMxDxQLAFCJ
 3YKo2aNVjKvA/aOKDe5RMLZUhnmuhb8aMIDuQY2Ir1EK4S+7EYOiYAvqlbJrM3Ro
 aLmb9BUzRRWmRydMKOeGkWiMj49lHRW6oJxvb33PDZEEqW/AlvmYEyMGfjhXzPDE
 OZkvbdYrni4n5YboplxNnJyL0NJ6l5YAikV94SBWBknrnNv1psSZbDKoIgp2ghhQ
 rdP842qSmDiZiXVlTr3e
 =PuEk
 -----END PGP SIGNATURE-----

Merge tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "A relatively quiet cycle for nfsd.

  The largest piece is an RDMA update from Chuck Lever with new trace
  points, miscellaneous cleanups, and streamlining of the send and
  receive paths.

  Other than that, some miscellaneous bugfixes"

* tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linux: (26 commits)
  nfsd: fix error handling in nfs4_set_delegation()
  nfsd: fix potential use-after-free in nfsd4_decode_getdeviceinfo
  Fix 16-byte memory leak in gssp_accept_sec_context_upcall
  svcrdma: Fix incorrect return value/type in svc_rdma_post_recvs
  svcrdma: Remove unused svc_rdma_op_ctxt
  svcrdma: Persistently allocate and DMA-map Send buffers
  svcrdma: Simplify svc_rdma_send()
  svcrdma: Remove post_send_wr
  svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxt
  svcrdma: Introduce svc_rdma_send_ctxt
  svcrdma: Clean up Send SGE accounting
  svcrdma: Refactor svc_rdma_dma_map_buf
  svcrdma: Allocate recv_ctxt's on CPU handling Receives
  svcrdma: Persistently allocate and DMA-map Receive buffers
  svcrdma: Preserve Receive buffer until svc_rdma_sendto
  svcrdma: Simplify svc_rdma_recv_ctxt_put
  svcrdma: Remove sc_rq_depth
  svcrdma: Introduce svc_rdma_recv_ctxt
  svcrdma: Trace key RDMA API events
  svcrdma: Trace key RPC/RDMA protocol events
  ...
2018-06-12 09:49:33 -07:00
Chuck Lever
af7fd74ec2 svcrdma: Fix incorrect return value/type in svc_rdma_post_recvs
This crept in during the development process and wasn't caught
before I posted the "final" version.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 0b2613c5883f ('svcrdma: Allocate recv_ctxt's on CPU ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-06-08 16:28:55 -04:00
Trond Myklebust
fcda3d5d22 NFS-over-RDMA client updates for Linux 4.18
Stable patches:
 - xprtrdma: Return -ENOBUFS when no pages are available
 
 New features:
 - Add ->alloc_slot() and ->free_slot() functions
 
 Bugfixes and cleanups:
 - Add missing SPDX tags to some files
 - Try to fail mount quickly if client has no RDMA devices
 - Create transport IDs in the correct network namespace
 - Fix max_send_wr computation
 - Clean up receive tracepoints
 - Refactor receive handling
 - Remove unused functions
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEnZ5MQTpR7cLU7KEp18tUv7ClQOsFAlsRiOMACgkQ18tUv7Cl
 QOuIdQ//QdZmGkZ/5chQat5F4EBSY9vFc5pIz3XCIGZ5dtxABPSsxrn0kWj0UWN/
 MBIYla6tLJ7j2bZ+6U/1YuF6QehpGXZYsWxtp9JLE/bXiaGt404QFrUN1dr23gyP
 +k2pT6V0h7vSDoQROQT496Lh6w8xCd7RZVE3u34k0sj2+iohqybiuE+5oSDcjfQ3
 ArEi80Er5gGhnLTSwkx/6eOL0T2LVGRKNXUItYksQamRqQBq4N6jWlbAxZTtr4mq
 CwEi/Mv/SLBkgaN5kjQRFkU/MRNwAhYOQB59Al2Na20xkvEL91mDsh1s10ViqiVQ
 d7aux1Pcft/EQdDOZA2gq4qtlt1jPl/8rVLSj2FyvkwAAHW+ltmLSfv2jgWw/+v/
 pKDkPIVCxCTwK8qEOnZizh1irfX8Eih6Pu6MoOleUqaNu14yvOZDANy7bREFA4Uj
 OckhiAcisahlHCzpvunPg1auQ6Ee1KSYoIZR3ARYcKcPs0L2ik/HiKDoMrYqDCtW
 9NGCfDtuZ7xEwpbN+5a5QMcIyU2BRrt4/i5sPVpN0smLuG9Scm3M0PqjHlXex7jo
 d27Yfk07Na9oQ8wqGAv6NkIk89RuyHSgIh5T5zf9R/71osEE+2lBiZWZaNbbRFqd
 u+RaA/sX5rzL0Hi5Nz2yhTNN5PPeP4FIipk60XG0WucXfdMFAls=
 =I9YU
 -----END PGP SIGNATURE-----

Merge tag 'nfs-rdma-for-4.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

NFS-over-RDMA client updates for Linux 4.18

Stable patches:
- xprtrdma: Return -ENOBUFS when no pages are available

New features:
- Add ->alloc_slot() and ->free_slot() functions

Bugfixes and cleanups:
- Add missing SPDX tags to some files
- Try to fail mount quickly if client has no RDMA devices
- Create transport IDs in the correct network namespace
- Fix max_send_wr computation
- Clean up receive tracepoints
- Refactor receive handling
- Remove unused functions
2018-06-04 18:57:13 -04:00
Chuck Lever
11d0ac16b0 xprtrdma: Remove transfertypes array
Clean up: This array was used in a dprintk that was replaced by a
trace point in commit ab03eff58e ("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>
2018-06-01 13:56:30 -04:00
Chuck Lever
8335640cf8 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>
2018-06-01 13:56:30 -04:00
Chuck Lever
2fad659209 xprtrdma: Wait on empty sendctx queue
Currently, when the sendctx queue is exhausted during marshaling, the
RPC/RDMA transport places the RPC task on the delayq, which forces a
wait for HZ >> 2 before the marshal and send is retried.

With this change, the transport now places such an RPC task on the
pending queue, and wakes it just as soon as more sendctxs become
available. This typically takes less than a millisecond, and the
write_space waking mechanism is less deadlock-prone.

Moreover, the waiting RPC task is holding the transport's write
lock, which blocks the transport from sending RPCs. Therefore faster
recovery from sendctx queue exhaustion is desirable.

Cf. commit 5804891455d5 ("xprtrdma: ->send_request returns -EAGAIN
when there are no free MRs").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-06-01 13:56:30 -04:00
Chuck Lever
ed3aa74245 xprtrdma: Move common wait_for_buffer_space call to parent function
Clean up: The logic to wait for write space is common to a bunch of
the encoding helper functions. Lift it out and put it in the tail
of rpcrdma_marshal_req().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-06-01 13:56:30 -04:00
Chuck Lever
a8f688ec43 xprtrdma: Return -ENOBUFS when no pages are available
The use of -EAGAIN in rpcrdma_convert_iovs() is a latent bug: the
transport never calls xprt_write_space() when more pages become
available. -ENOBUFS will trigger the correct "delay briefly and call
again" logic.

Fixes: 7a89f9c626 ("xprtrdma: Honor ->send_request API contract")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-06-01 13:56:30 -04:00
Linus Torvalds
a1f45efbb9 NFS client fixes for Linux 4.17-rc4
Bugfixes:
 - Fix a possible NFSoRDMA list corruption during recovery
 - Fix sunrpc tracepoint crashes
 
 Other change:
 - Update Trond's email in the MAINTAINERS file
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEnZ5MQTpR7cLU7KEp18tUv7ClQOsFAlr2ABEACgkQ18tUv7Cl
 QOvLew//WipZ1of+dZpiGa95pqVKBrIxq5R1y8LACmEKaiyfHOOoFcaopI7YDU1r
 OkBRZkldMLKOSGZsQ9xEjh3OOPgW60oInFZ2sD2qjnph23x09IcDbiCp8iJ0PTFI
 iD9ioUKc3h7FSl0pJQSjIo9+9fFsTZzIioxP7tDZt2Kog5OMIZeWAqRIj1xmgu5i
 TX793gTFJ+SfMSkvWZM5oOHVEmW/oXAgWsgaVXEqkdjK2JI6KYKqAgMj0CLvvNIo
 S2eeJjbyd9Hl59lDo50NzrZEQESlPYod6ZDfEOmF50mxC3MCLlmtAgwXKknVaY1N
 1L4tFuBoXBLV0jctBztuqMIDKXncoNlsCvr38WqkBaFxikKpK8dFqeByh+wCTdtz
 pwMPHFDQmQB1mIwqzQa+O6MAZ5n3a/cgyWQtoymlq5ddQU3roB2euWXRmaoXPudY
 SnmEVYxq839Ukw16qNa1HkKkroy8Zzqr5+sS30w/l916U9/S3ZolXF+XU5ux+6hQ
 Mlu9aW5SCP4S5QresaAcjPcBdLvbjN8/h/I8bdCmPRCGVKSkcxSz2MZYUli8UxAq
 tht4tQtuCY1XInQPnuf20egnJnrhpgQjb8Xx5BvTtcEkFvz9F36lzK4ot0lqQzTo
 tGDDW8gpeskt0Z1PC4eD1gq/E+FSywP7gg/g32AMdk2GpCewBog=
 =xfe9
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.17-2' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client fixes from Anna Schumaker:
 "These patches fix both a possible corruption during NFSoRDMA MR
  recovery, and a sunrpc tracepoint crash.

  Additionally, Trond has a new email address to put in the MAINTAINERS
  file"

* tag 'nfs-for-4.17-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  Change Trond's email address in MAINTAINERS
  sunrpc: Fix latency trace point crashes
  xprtrdma: Fix list corruption / DMAR errors during MR recovery
2018-05-11 13:56:43 -07:00
Chuck Lever
99722fe4d5 svcrdma: Persistently allocate and DMA-map Send buffers
While sending each RPC Reply, svc_rdma_sendto allocates and DMA-
maps a separate buffer where the RPC/RDMA transport header is
constructed. The buffer is unmapped and released in the Send
completion handler. This is significant per-RPC overhead,
especially for small RPCs.

Instead, allocate and DMA-map a buffer, and cache it in each
svc_rdma_send_ctxt. This buffer and its mapping can be re-used
for each RPC, saving the cost of memory allocation and DMA
mapping.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
3abb03face svcrdma: Simplify svc_rdma_send()
Clean up: No current caller of svc_rdma_send's passes in a chained
WR. The logic that counts the chain length can be replaced with a
constant (1).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
986b78894b svcrdma: Remove post_send_wr
Clean up: Now that the send_wr is part of the svc_rdma_send_ctxt,
svc_rdma_post_send_wr is nearly empty.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
25fd86eca1 svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxt
Receive buffers are always the same size, but each Send WR has a
variable number of SGEs, based on the contents of the xdr_buf being
sent.

While assembling a Send WR, keep track of the number of SGEs so that
we don't exceed the device's maximum, or walk off the end of the
Send SGE array.

For now the Send path just fails if it exceeds the maximum.

The current logic in svc_rdma_accept bases the maximum number of
Send SGEs on the largest NFS request that can be sent or received.
In the transport layer, the limit is actually based on the
capabilities of the underlying device, not on properties of the
Upper Layer Protocol.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
4201c74647 svcrdma: Introduce svc_rdma_send_ctxt
svc_rdma_op_ctxt's are pre-allocated and maintained on a per-xprt
free list. This eliminates the overhead of calling kmalloc / kfree,
both of which grab a globally shared lock that disables interrupts.
Introduce a replacement to svc_rdma_op_ctxt's that is built
especially for the svcrdma Send path.

Subsequent patches will take advantage of this new structure by
allocating real resources which are then cached in these objects.
The allocations are freed when the transport is torn down.

I've renamed the structure so that static type checking can be used
to ensure that uses of op_ctxt and send_ctxt are not confused. As an
additional clean up, structure fields are renamed to conform with
kernel coding conventions.

Additional clean ups:
- Handle svc_rdma_send_ctxt_get allocation failure at each call
  site, rather than pre-allocating and hoping we guessed correctly
- All send_ctxt_put call-sites request page freeing, so remove
  the @free_pages argument
- All send_ctxt_put call-sites unmap SGEs, so fold that into
  svc_rdma_send_ctxt_put

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
232627905f svcrdma: Clean up Send SGE accounting
Clean up: Since there's already a svc_rdma_op_ctxt being passed
around with the running count of mapped SGEs, drop unneeded
parameters to svc_rdma_post_send_wr().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
f016f305f9 svcrdma: Refactor svc_rdma_dma_map_buf
Clean up: svc_rdma_dma_map_buf does mostly the same thing as
svc_rdma_dma_map_page, so let's fold these together.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
eb5d7a622e svcrdma: Allocate recv_ctxt's on CPU handling Receives
There is a significant latency penalty when processing an ingress
Receive if the Receive buffer resides in memory that is not on the
same NUMA node as the the CPU handling completions for a CQ.

The system administrator and the device driver determine which CPU
handles completions. This CPU does not change during life of the CQ.
Further the Upper Layer does not have any visibility of which CPU it
is.

Allocating Receive buffers in the Receive completion handler
guarantees that Receive buffers are allocated on the preferred NUMA
node for that CQ.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
3316f06311 svcrdma: Persistently allocate and DMA-map Receive buffers
The current Receive path uses an array of pages which are allocated
and DMA mapped when each Receive WR is posted, and then handed off
to the upper layer in rqstp::rq_arg. The page flip releases unused
pages in the rq_pages pagelist. This mechanism introduces a
significant amount of overhead.

So instead, kmalloc the Receive buffer, and leave it DMA-mapped
while the transport remains connected. This confers a number of
benefits:

* Each Receive WR requires only one receive SGE, no matter how large
  the inline threshold is. This helps the server-side NFS/RDMA
  transport operate on less capable RDMA devices.

* The Receive buffer is left allocated and mapped all the time. This
  relieves svc_rdma_post_recv from the overhead of allocating and
  DMA-mapping a fresh buffer.

* svc_rdma_wc_receive no longer has to DMA unmap the Receive buffer.
  It has to DMA sync only the number of bytes that were received.

* svc_rdma_build_arg_xdr no longer has to free a page in rq_pages
  for each page in the Receive buffer, making it a constant-time
  function.

* The Receive buffer is now plugged directly into the rq_arg's
  head[0].iov_vec, and can be larger than a page without spilling
  over into rq_arg's page list. This enables simplification of
  the RDMA Read path in subsequent patches.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
3a88092ee3 svcrdma: Preserve Receive buffer until svc_rdma_sendto
Rather than releasing the incoming svc_rdma_recv_ctxt at the end of
svc_rdma_recvfrom, hold onto it until svc_rdma_sendto.

This permits the contents of the Receive buffer to be preserved
through svc_process and then referenced directly in sendto as it
constructs Write and Reply chunks to return to the client.

The real changes will come in subsequent patches.

Note: I cannot use ->xpo_release_rqst for this purpose because that
is called _before_ ->xpo_sendto. svc_rdma_sendto uses information in
the received Call transport header to construct the Reply transport
header, which is preserved in the RPC's Receive buffer.

The historical comment in svc_send() isn't helpful: it is already
obvious that ->xpo_release_rqst is being called before ->xpo_sendto,
but there is no explanation for this ordering going back to the
beginning of the git era.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
1e5f416074 svcrdma: Simplify svc_rdma_recv_ctxt_put
Currently svc_rdma_recv_ctxt_put's callers have to know whether they
want to free the ctxt's pages or not. This means the human
developers have to know when and why to set that free_pages
argument.

Instead, the ctxt should carry that information with it so that
svc_rdma_recv_ctxt_put does the right thing no matter who is
calling.

We want to keep track of the number of pages in the Receive buffer
separately from the number of pages pulled over by RDMA Read. This
is so that the correct number of pages can be freed properly and
that number is well-documented.

So now, rc_hdr_count is the number of pages consumed by head[0]
(ie., the page index where the Read chunk should start); and
rc_page_count is always the number of pages that need to be released
when the ctxt is put.

The @free_pages argument is no longer needed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
2c577bfea8 svcrdma: Remove sc_rq_depth
Clean up: No need to retain rq_depth in struct svcrdma_xprt, it is
used only in svc_rdma_accept().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
ecf85b2384 svcrdma: Introduce svc_rdma_recv_ctxt
svc_rdma_op_ctxt's are pre-allocated and maintained on a per-xprt
free list. This eliminates the overhead of calling kmalloc / kfree,
both of which grab a globally shared lock that disables interrupts.
To reduce contention further, separate the use of these objects in
the Receive and Send paths in svcrdma.

Subsequent patches will take advantage of this separation by
allocating real resources which are then cached in these objects.
The allocations are freed when the transport is torn down.

I've renamed the structure so that static type checking can be used
to ensure that uses of op_ctxt and recv_ctxt are not confused. As an
additional clean up, structure fields are renamed to conform with
kernel coding conventions.

As a final clean up, helpers related to recv_ctxt are moved closer
to the functions that use them.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
bd2abef333 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>
2018-05-11 15:48:57 -04:00
Chuck Lever
98895edbe3 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>
2018-05-11 15:48:57 -04:00
Chuck Lever
b6e717cbf2 xprtrdma: Prepare RPC/RDMA includes for server-side trace points
Clean up: Move #include <trace/events/rpcrdma.h> into source files,
similar to how it is done with trace/events/sunrpc.h.

Server-side trace points will be part of the rpcrdma subsystem,
just like the client-side trace points.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
8dafcbee41 svcrdma: Use passed-in net namespace when creating RDMA listener
Ensure each RDMA listener and its children transports are created in
the same net namespace as the user that started the NFS service.
This is similar to how listener sockets are created in
svc_create_socket, required for enabling support for containers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
bcf3ffd405 svcrdma: Add proper SPDX tags for NetApp-contributed source
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever
efd81e90d3 xprtrdma: Make rpcrdma_sendctx_put_locked() a static function
Clean up: The only call site is in the same file as the function's
definition.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-07 09:20:04 -04:00
Chuck Lever
9d95cd534c xprtrdma: Remove rpcrdma_buffer_get_rep_locked()
Clean up: There is only one remaining call site for this helper.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-07 09:20:04 -04:00
Chuck Lever
e68699cc1a xprtrdma: Remove rpcrdma_buffer_get_req_locked()
Clean up. There is only one call-site for this helper, and it can be
simplified by using list_first_entry_or_null().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-07 09:20:04 -04:00
Chuck Lever
a7986f0998 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>
2018-05-07 09:20:04 -04:00
Chuck Lever
7c8d9e7c88 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>
2018-05-07 09:20:04 -04:00
Chuck Lever
0e0b854cfb 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>
2018-05-07 09:20:03 -04:00
Chuck Lever
edb41e61a5 xprtrdma: Make rpc_rqst part of rpcrdma_req
This simplifies allocation of the generic RPC slot and xprtrdma
specific per-RPC resources.

It also makes xprtrdma more like the socket-based transports:
->buf_alloc and ->buf_free are now responsible only for send and
receive buffers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-07 09:20:03 -04:00
Chuck Lever
48be539dd4 xprtrdma: Introduce ->alloc_slot call-out for xprtrdma
rpcrdma_buffer_get acquires an rpcrdma_req and rep for each RPC.
Currently this is done in the call_allocate action, and sometimes it
can fail if there are many outstanding RPCs.

When call_allocate fails, the RPC task is put on the delayq. It is
awoken a few milliseconds later, but there's no guarantee it will
get a buffer at that time. The RPC task can be repeatedly put back
to sleep or even starved.

The call_allocate action should rarely fail. The delayq mechanism is
not meant to deal with transport congestion.

In the current sunrpc stack, there is a friendlier way to deal with
this situation. These objects are actually tantamount to an RPC
slot (rpc_rqst) and there is a separate FSM action, distinct from
call_allocate, for allocating slot resources. This is the
call_reserve action.

When allocation fails during this action, the RPC is placed on the
transport's backlog queue. The backlog mechanism provides a stronger
guarantee that when the RPC is awoken, a buffer will be available
for it; and backlogged RPCs are awoken one-at-a-time.

To make slot resource allocation occur in the call_reserve action,
create special ->alloc_slot and ->free_slot call-outs for xprtrdma.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-07 09:20:03 -04:00