Commit Graph

323 Commits

Author SHA1 Message Date
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 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 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
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
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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
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
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
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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.
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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
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
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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 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 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 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 914fcad987 xprtrdma: Fix max_send_wr computation
For FRWR, the computation of max_send_wr is split between
frwr_op_open and rpcrdma_ep_create, which makes it difficult to tell
that the max_send_wr result is currently incorrect if frwr_op_open
has to reduce the credit limit to accommodate a small max_qp_wr.
This is a problem now that extra WRs are needed for backchannel
operations and a drain CQE.

So, refactor the computation so that it is all done in ->ro_open,
and fix the FRWR version of this computation so that it
accommodates HCAs with small max_qp_wr correctly.

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 107c4beb9b xprtrdma: Create transport's CM ID in the correct network namespace
Set up RPC/RDMA transport in mount.nfs's network namespace. This
passes the correct namespace information to the RDMA core, similar
to how RPC sockets are created (see xs_create_sock).

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 52d28fe4f6 xprtrdma: Try to fail quickly if proto=rdma
rdma_resolve_addr(3) says:

> This call is used to map a given destination IP address to a
> usable RDMA address. The IP to RDMA address mapping is done
> using the local routing tables, or via ARP.

If this can't be done, there's no local device that can be used
to establish an RDMA-capable network path to the remote. In this
case, the RDMA CM very quickly posts an RDMA_CM_EVENT_ADDR_ERROR
upcall.

Currently rpcrdma_conn_upcall() converts RDMA_CM_EVENT_ADDR_ERROR
to EHOSTUNREACH. mount.nfs seems to want to retry EHOSTUNREACH
forever, thinking that this is a temporary situation. This makes
mount.nfs appear to hang if I try to mount with proto=rdma through,
say, a conventional Ethernet device.

If the admin has specified proto=rdma along with a server IP address
that requires a network path that does not support RDMA, instead
let's fail with a permanent error. -EPROTONOSUPPORT is returned when
NFSv4 or one of its minor versions is not supported.

-EPROTO is not (currently) retried by mount.nfs.

There are potentially other similar cases where -EPROTO is an
appropriate return code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Olga Kornievskaia <kolga@netapp.com>
Tested-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-07 09:20:03 -04:00
Chuck Lever a2268cfbf5 xprtrdma: Add proper SPDX tags for NetApp-contributed source
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 054f155721 xprtrdma: Fix list corruption / DMAR errors during MR recovery
The ro_release_mr methods check whether mr->mr_list is empty.
Therefore, be sure to always use list_del_init when removing an MR
linked into a list using that field. Otherwise, when recovering from
transport failures or device removal, list corruption can result, or
MRs can get mapped or unmapped an odd number of times, resulting in
IOMMU-related failures.

In general this fix is appropriate back to v4.8. However, code
changes since then make it impossible to apply this patch directly
to stable kernels. The fix would have to be applied by hand or
reworked for kernels earlier than v4.16.

Backport guidance -- there are several cases:
- When creating an MR, initialize mr_list so that using list_empty
  on an as-yet-unused MR is safe.
- When an MR is being handled by the remote invalidation path,
  ensure that mr_list is reinitialized when it is removed from
  rl_registered.
- When an MR is being handled by rpcrdma_destroy_mrs, it is removed
  from mr_all, but it may still be on an rl_registered list. In
  that case, the MR needs to be removed from that list before being
  released.
- Other cases are covered by using list_del_init in rpcrdma_mr_pop.

Fixes: 9d6b040978 ('xprtrdma: Place registered MWs on a ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-01 13:29:43 -04:00
Chuck Lever 2552428863 xprtrdma: Fix corner cases when handling device removal
Michal Kalderon has found some corner cases around device unload
with active NFS mounts that I didn't have the imagination to test
when xprtrdma device removal was added last year.

- The ULP device removal handler is responsible for deallocating
  the PD. That wasn't clear to me initially, and my own testing
  suggested it was not necessary, but that is incorrect.

- The transport destruction path can no longer assume that there
  is a valid ID.

- When destroying a transport, ensure that ib_free_cq() is not
  invoked on a CQ that was already released.

Reported-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Fixes: bebd031866 ("xprtrdma: Support unplugging an HCA from ...")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:07:10 -04:00
Chuck Lever 2dd4a012d9 xprtrdma: Move creation of rl_rdmabuf to rpcrdma_create_req
Refactor: Both rpcrdma_create_req call sites have to allocate the
buffer where the transport header is built, so just move that
allocation into rpcrdma_create_req.

This buffer is a fixed size. There's no needed information available
in call_allocate that is not also available when the transport is
created.

The original purpose for allocating these buffers on demand was to
reduce the possibility that an allocation failure during transport
creation will hork the mount operation during low memory scenarios.
Some relief for this rare possibility is coming up in the next few
patches.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Chuck Lever f287762308 xprtrdma: Chain Send to FastReg WRs
With FRWR, the client transport can perform memory registration and
post a Send with just a single ib_post_send.

This reduces contention between the send_request path and the Send
Completion handlers, and reduces the overhead of registering a chunk
that has multiple segments.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Chuck Lever ae741a8551 xprtrdma: Reduce number of MRs created by rpcrdma_mrs_create
Create fewer MRs on average. Many workloads don't need as many as
32 MRs, and the transport can now quickly restock the MR free list.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Chuck Lever 9e679d5e76 xprtrdma: ->send_request returns -EAGAIN when there are no free MRs
Currently, when the MR free list 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 MRs have been
created. Creating more MRs typically takes less than a millisecond,
and this 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 MR exhaustion is desirable.

This is the same mechanism that the TCP transport utilizes when
handling write buffer space exhaustion.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Chuck Lever 8a14793e7a xprtrdma: Remove xprt-specific connect cookie
Clean up: The generic rq_connect_cookie is sufficient to detect RPC
Call retransmission.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Chuck Lever b7e85fff52 xprtrdma: Remove arbitrary limit on initiator depth
Clean up: We need to check only that the value does not exceed the
range of the u8 field it's going into.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Chuck Lever e89e8d8fcd xprtrdma: Fix BUG after a device removal
Michal Kalderon reports a BUG that occurs just after device removal:

[  169.112490] rpcrdma: removing device qedr0 for 192.168.110.146:20049
[  169.143909] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[  169.181837] IP: rpcrdma_dma_unmap_regbuf+0xa/0x60 [rpcrdma]

The RPC/RDMA client transport attempts to allocate some resources
on demand. Registered buffers are one such resource. These are
allocated (or re-allocated) by xprt_rdma_allocate to hold RPC Call
and Reply messages. A hardware resource is associated with each of
these buffers, as they can be used for a Send or Receive Work
Request.

If a device is removed from under an NFS/RDMA mount, the transport
layer is responsible for releasing all hardware resources before
the device can be finally unplugged. A BUG results when the NFS
mount hasn't yet seen much activity: the transport tries to release
resources that haven't yet been allocated.

rpcrdma_free_regbuf() already checks for this case, so just move
that check to cover the DEVICE_REMOVAL case as well.

Reported-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Fixes: bebd031866 ("xprtrdma: Support unplugging an HCA ...")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-02-02 13:31:04 -05:00
Chuck Lever 1179e2c27e xprtrdma: Fix calculation of ri_max_send_sges
Commit 16f906d66c ("xprtrdma: Reduce required number of send
SGEs") introduced the rpcrdma_ia::ri_max_send_sges field. This fixes
a problem where xprtrdma would not work if the device's max_sge
capability was small (low single digits).

At least RPCRDMA_MIN_SEND_SGES are needed for the inline parts of
each RPC. ri_max_send_sges is set to this value:

  ia->ri_max_send_sges = max_sge - RPCRDMA_MIN_SEND_SGES;

Then when marshaling each RPC, rpcrdma_args_inline uses that value
to determine whether the device has enough Send SGEs to convey an
NFS WRITE payload inline, or whether instead a Read chunk is
required.

More recently, commit ae72950abf ("xprtrdma: Add data structure to
manage RDMA Send arguments") used the ri_max_send_sges value to
calculate the size of an array, but that commit erroneously assumed
ri_max_send_sges contains a value similar to the device's max_sge,
and not one that was reduced by the minimum SGE count.

This assumption results in the calculated size of the sendctx's
Send SGE array to be too small. When the array is used to marshal
an RPC, the code can write Send SGEs into the following sendctx
element in that array, corrupting it. When the device's max_sge is
large, this issue is entirely harmless; but it results in an oops
in the provider's post_send method, if dev.attrs.max_sge is small.

So let's straighten this out: ri_max_send_sges will now contain a
value with the same meaning as dev.attrs.max_sge, which makes
the code easier to understand, and enables rpcrdma_sendctx_create
to calculate the size of the SGE array correctly.

Reported-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Fixes: 16f906d66c ("xprtrdma: Reduce required number of send SGEs")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-02-02 13:29:57 -05:00
Chuck Lever 9ab6d89e74 xprtrdma: Correct some documenting comments
Fix kernel-doc warnings in net/sunrpc/xprtrdma/ .

net/sunrpc/xprtrdma/verbs.c:1575: warning: No description found for parameter 'count'
net/sunrpc/xprtrdma/verbs.c:1575: warning: Excess function parameter 'min_reqs' description in 'rpcrdma_ep_post_extra_recv'

net/sunrpc/xprtrdma/backchannel.c:288: warning: No description found for parameter 'r_xprt'
net/sunrpc/xprtrdma/backchannel.c:288: warning: Excess function parameter 'xprt' description in 'rpcrdma_bc_receive_call'

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23 09:44:39 -05:00
Chuck Lever ae72467625 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>
2018-01-23 09:44:38 -05:00
Chuck Lever 643cf3237d 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>
2018-01-23 09:44:38 -05:00
Chuck Lever b4744e00a3 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>
2018-01-23 09:44:37 -05:00
Chuck Lever 1c443effa3 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>
2018-01-23 09:44:36 -05:00
Chuck Lever 2937fede11 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>
2018-01-23 09:44:36 -05:00
Chuck Lever b4a7f91c1d 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>
2018-01-23 09:44:35 -05:00
Chuck Lever 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>
2018-01-23 09:44:35 -05:00
Chuck Lever ec12e479e3 xprtrdma: Introduce rpcrdma_mw_unmap_and_put
Clean up: Code review suggested that a common bit of code can be
placed into a helper function, and this gives us fewer places to
stick an "I DMA unmapped something" trace point.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:52 -05:00
Chuck Lever 96ceddea37 xprtrdma: Remove usage of "mw"
Clean up: struct rpcrdma_mw was named after Memory Windows, but
xprtrdma no longer supports a Memory Window registration mode.
Rename rpcrdma_mw and its fields to reduce confusion and make
the code more sensible to read.

Renaming "mw" was suggested by Tom Talpey, the author of the
original xprtrdma implementation. It's a good idea, but I haven't
done this until now because it's a huge diffstat for no benefit
other than code readability.

However, I'm about to introduce static trace points that expose
a few of xprtrdma's internal data structures. They should make sense
in the trace report, and it's reasonable to treat trace points as a
kernel API contract which might be difficult to change later.

While I'm churning things up, two additional changes:
- rename variables unhelpfully called "r" to "mr", to improve code
  clarity, and
- rename the MR-related helper functions using the form
  "rpcrdma_mr_<verb>", to be consistent with other areas of the
  code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:51 -05:00
Chuck Lever ce5b371782 xprtrdma: Replace all usage of "frmr" with "frwr"
Clean up: Over time, the industry has adopted the term "frwr"
instead of "frmr". The term "frwr" is now more widely recognized.

For the past couple of years I've attempted to add new code using
"frwr" , but there still remains plenty of older code that still
uses "frmr". Replace all usage of "frmr" to avoid confusion.

While we're churning code, rename variables unhelpfully called "f"
to "frwr", to improve code clarity.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:50 -05:00
Chuck Lever dd229cee4e xprtrdma: Remove another sockaddr_storage field (cdata::addr)
Save more space in struct rpcrdma_xprt by removing the redundant
"addr" field from struct rpcrdma_create_data_internal. Wherever
we have rpcrdma_xprt, we also have the rpc_xprt, which has a
sockaddr_storage field with the same content.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:45 -05:00
Chuck Lever d461f1f2fb xprtrdma: Initialize the xprt address string array earlier
This makes the address strings available for debugging messages in
earlier stages of transport set up.

The first benefit is to get rid of the single-use rep_remote_addr
field, saving 128+ bytes in struct rpcrdma_ep.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:45 -05:00
Chuck Lever 3f0e3edd6a xprtrdma: Remove ri_reminv_expected
Clean up.

Commit b5f0afbea4 ("xprtrdma: Per-connection pad optimization")
should have removed this.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:43 -05:00
Chuck Lever c34416182f xprtrdma: Per-mode handling for Remote Invalidation
Refactoring change: Remote Invalidation is particular to the memory
registration mode that is use. Use a callout instead of a generic
function to handle Remote Invalidation.

This gets rid of the 8-byte flags field in struct rpcrdma_mw, of
which only a single bit flag has been allocated.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:43 -05:00
Chuck Lever d698c4a02e xprtrdma: Fix backchannel allocation of extra rpcrdma_reps
The backchannel code uses rpcrdma_recv_buffer_put to add new reps
to the free rep list. This also decrements rb_recv_count, which
spoofs the receive overrun logic in rpcrdma_buffer_get_rep.

Commit 9b06688bc3 ("xprtrdma: Fix additional uses of
spin_lock_irqsave(rb_lock)") replaced the original open-coded
list_add with a call to rpcrdma_recv_buffer_put(), but then a year
later, commit 05c974669e ("xprtrdma: Fix receive buffer
accounting") added rep accounting to rpcrdma_recv_buffer_put.
It was an oversight to let the backchannel continue to use this
function.

The fix this, let's combine the "add to free list" logic with
rpcrdma_create_rep.

Also, do not allocate RPCRDMA_MAX_BC_REQUESTS rpcrdma_reps in
rpcrdma_buffer_create and then allocate additional rpcrdma_reps in
rpcrdma_bc_setup_reps. Allocating the extra reps during backchannel
set-up is sufficient.

Fixes: 05c974669e ("xprtrdma: Fix receive buffer accounting")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16 11:19:41 -05:00
Chuck Lever ccede75985 xprtrdma: Spread reply processing over more CPUs
Commit d8f532d20e ("xprtrdma: Invoke rpcrdma_reply_handler
directly from RECV completion") introduced a performance regression
for NFS I/O small enough to not need memory registration. In multi-
threaded benchmarks that generate primarily small I/O requests,
IOPS throughput is reduced by nearly a third. This patch restores
the previous level of throughput.

Because workqueues are typically BOUND (in particular ib_comp_wq,
nfsiod_workqueue, and rpciod_workqueue), NFS/RDMA workloads tend
to aggregate on the CPU that is handling Receive completions.

The usual approach to addressing this problem is to create a QP
and CQ for each CPU, and then schedule transactions on the QP
for the CPU where you want the transaction to complete. The
transaction then does not require an extra context switch during
completion to end up on the same CPU where the transaction was
started.

This approach doesn't work for the Linux NFS/RDMA client because
currently the Linux NFS client does not support multiple connections
per client-server pair, and the RDMA core API does not make it
straightforward for ULPs to determine which CPU is responsible for
handling Receive completions for a CQ.

So for the moment, record the CPU number in the rpcrdma_req before
the transport sends each RPC Call. Then during Receive completion,
queue the RPC completion on that same CPU.

Additionally, move all RPC completion processing to the deferred
handler so that even RPCs with simple small replies complete on
the CPU that sent the corresponding RPC Call.

Fixes: d8f532d20e ("xprtrdma: Invoke rpcrdma_reply_handler ...")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-12-15 14:31:50 -05:00
Chuck Lever 62b56a6755 xprtrdma: Update copyright notices
Credit work contributed by Oracle engineers since 2014.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 16:43:43 -05:00
Chuck Lever 1b746c1e9c xprtrdma: Remove include for linux/prefetch.h
Clean up. This include should have been removed by
commit 23826c7aea ("xprtrdma: Serialize credit accounting again").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 16:43:42 -05:00
Chuck Lever a4699f5647 xprtrdma: Put Send CQ in IB_POLL_WORKQUEUE mode
Lift the Send and LocalInv completion handlers out of soft IRQ mode
to make room for other work. Also, move the Send CQ to a different
CPU than the CPU where the Receive CQ is running, for improved
scalability.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 16:43:42 -05:00
Chuck Lever 6f0afc2825 xprtrdma: Remove atomic send completion counting
The sendctx circular queue now guarantees that xprtrdma cannot
overflow the Send Queue, so remove the remaining bits of the
original Send WQE counting mechanism.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 13:47:58 -05:00
Chuck Lever 01bb35c89d xprtrdma: RPC completion should wait for Send completion
When an RPC Call includes a file data payload, that payload can come
from pages in the page cache, or a user buffer (for direct I/O).

If the payload can fit inline, xprtrdma includes it in the Send
using a scatter-gather technique. xprtrdma mustn't allow the RPC
consumer to re-use the memory where that payload resides before the
Send completes. Otherwise, the new contents of that memory would be
exposed by an HCA retransmit of the Send operation.

So, block RPC completion on Send completion, but only in the case
where a separate file data payload is part of the Send. This
prevents the reuse of that memory while it is still part of a Send
operation without an undue cost to other cases.

Waiting is avoided in the common case because typically the Send
will have completed long before the RPC Reply arrives.

These days, an RPC timeout will trigger a disconnect, which tears
down the QP. The disconnect flushes all waiting Sends. This bounds
the amount of time the reply handler has to wait for a Send
completion.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 13:47:57 -05:00
Chuck Lever 531cca0c9b xprtrdma: Add a field of bit flags to struct rpcrdma_req
We have one boolean flag in rpcrdma_req today. I'd like to add more
flags, so convert that boolean to a bit flag.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 13:47:57 -05:00
Chuck Lever ae72950abf xprtrdma: Add data structure to manage RDMA Send arguments
Problem statement:

Recently Sagi Grimberg <sagi@grimberg.me> observed that kernel RDMA-
enabled storage initiators don't handle delayed Send completion
correctly. If Send completion is delayed beyond the end of a ULP
transaction, the ULP may release resources that are still being used
by the HCA to complete a long-running Send operation.

This is a common design trait amongst our initiators. Most Send
operations are faster than the ULP transaction they are part of.
Waiting for a completion for these is typically unnecessary.

Infrequently, a network partition or some other problem crops up
where an ordering problem can occur. In NFS parlance, the RPC Reply
arrives and completes the RPC, but the HCA is still retrying the
Send WR that conveyed the RPC Call. In this case, the HCA can try
to use memory that has been invalidated or DMA unmapped, and the
connection is lost. If that memory has been re-used for something
else (possibly not related to NFS), and the Send retransmission
exposes that data on the wire.

Thus we cannot assume that it is safe to release Send-related
resources just because a ULP reply has arrived.

After some analysis, we have determined that the completion
housekeeping will not be difficult for xprtrdma:

 - Inline Send buffers are registered via the local DMA key, and
   are already left DMA mapped for the lifetime of a transport
   connection, thus no additional handling is necessary for those
 - Gathered Sends involving page cache pages _will_ need to
   DMA unmap those pages after the Send completes. But like
   inline send buffers, they are registered via the local DMA key,
   and thus will not need to be invalidated

In addition, RPC completion will need to wait for Send completion
in the latter case. However, nearly always, the Send that conveys
the RPC Call will have completed long before the RPC Reply
arrives, and thus no additional latency will be accrued.

Design notes:

In this patch, the rpcrdma_sendctx object is introduced, and a
lock-free circular queue is added to manage a set of them per
transport.

The RPC client's send path already prevents sending more than one
RPC Call at the same time. This allows us to treat the consumer
side of the queue (rpcrdma_sendctx_get_locked) as if there is a
single consumer thread.

The producer side of the queue (rpcrdma_sendctx_put_locked) is
invoked only from the Send completion handler, which is a single
thread of execution (soft IRQ).

The only care that needs to be taken is with the tail index, which
is shared between the producer and consumer. Only the producer
updates the tail index. The consumer compares the head with the
tail to ensure that the a sendctx that is in use is never handed
out again (or, expressed more conventionally, the queue is empty).

When the sendctx queue empties completely, there are enough Sends
outstanding that posting more Send operations can result in a Send
Queue overflow. In this case, the ULP is told to wait and try again.
This introduces strong Send Queue accounting to xprtrdma.

As a final touch, Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
suggested a mechanism that does not require signaling every Send.
We signal once every N Sends, and perform SGE unmapping of N Send
operations during that one completion.

Reported-by: Sagi Grimberg <sagi@grimberg.me>
Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 13:47:56 -05:00
Chuck Lever be798f9082 xprtrdma: Decode credits field in rpcrdma_reply_handler
We need to decode and save the incoming rdma_credits field _after_
we know that the direction of the message is "forward direction
Reply". Otherwise, the credits value in reverse direction Calls is
also used to update the forward direction credits.

It is safe to decode the rdma_credits field in rpcrdma_reply_handler
now that rpcrdma_reply_handler is single-threaded. Receives complete
in the same order as they were sent on the NFS server.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 13:47:55 -05:00
Chuck Lever d8f532d20e xprtrdma: Invoke rpcrdma_reply_handler directly from RECV completion
I noticed that the soft IRQ thread looked pretty busy under heavy
I/O workloads. perf suggested one area that was expensive was the
queue_work() call in rpcrdma_wc_receive. That gave me some ideas.

Instead of scheduling a separate worker to process RPC Replies,
promote the Receive completion handler to IB_POLL_WORKQUEUE, and
invoke rpcrdma_reply_handler directly.

Note that the poll workqueue is single-threaded. In order to keep
memory invalidation from serializing all RPC Replies, handle any
necessary invalidation tasks in a separate multi-threaded workqueue.

This provides a two-tier scheme, similar to OS I/O interrupt
handlers: A fast interrupt handler that schedules the slow handler
and re-enables the interrupt, and a slower handler that is invoked
for any needed heavy lifting.

Benefits include:
- One less context switch for RPCs that don't register memory
- Receive completion handling is moved out of soft IRQ context to
  make room for other users of soft IRQ
- The same CPU core now DMA syncs and XDR decodes the Receive buffer

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 13:47:54 -05:00
Chuck Lever 9590d083c1 xprtrdma: Use xprt_pin_rqst in rpcrdma_reply_handler
Adopt the use of xprt_pin_rqst to eliminate contention between
Call-side users of rb_lock and the use of rb_lock in
rpcrdma_reply_handler.

This replaces the mechanism introduced in 431af645cf ("xprtrdma:
Fix client lock-up after application signal fires").

Use recv_lock to quickly find the completing rqst, pin it, then
drop the lock. At that point invalidation and pull-up of the Reply
XDR can be done. Both are often expensive operations.

Finally, take recv_lock again to signal completion to the RPC
layer. It also protects adjustment of "cwnd".

This greatly reduces the amount of time a lock is held by the
reply handler. Comparing lock_stat results shows a marked decrease
in contention on rb_lock and recv_lock.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[trond.myklebust@primarydata.com: Remove call to rpcrdma_buffer_put() from
   the "out_norqst:" path in rpcrdma_reply_handler.]
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-05 18:27:07 -04:00
Chuck Lever c1bcb68e39 xprtrdma: Clean up XDR decoding in rpcrdma_update_granted_credits()
Clean up: Replace C-structure based XDR decoding for consistency
with other areas.

struct rpcrdma_rep is rearranged slightly so that the relevant fields
are in cache when the Receive completion handler is invoked.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-08 10:52:01 -04:00
Chuck Lever e2a6719041 xprtrdma: Remove rpcrdma_rep::rr_len
This field is no longer used outside the Receive completion handler.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-08 10:52:01 -04:00
Chuck Lever fdf503e302 xprtrdma: Remove opcode check in Receive completion handler
Clean up: The opcode check is no longer necessary, because since
commit 2fa8f88d88 ("xprtrdma: Use new CQ API for RPC-over-RDMA
client send CQs"), this completion handler is invoked only for
RECV work requests.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-08 10:52:00 -04:00
Chuck Lever 96f8778f70 xprtrdma: Add xdr_init_decode to rpcrdma_reply_handler()
Transport header decoding deals with untrusted input data, therefore
decoding this header needs to be hardened.

Adopt the same infrastructure that is used when XDR decoding NFS
replies. This is slightly more CPU-intensive than the replaced code,
but we're not adding new atomics, locking, or context switches. The
cost is manageable.

Start by initializing an xdr_stream in rpcrdma_reply_handler().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-08 10:52:00 -04:00
Chuck Lever 173b8f49b3 xprtrdma: Demote "connect" log messages
Some have complained about the log messages generated when xprtrdma
opens or closes a connection to a server. When an NFS mount is
mostly idle these can appear every few minutes as the client idles
out the connection and reconnects.

Connection and disconnection is a normal part of operation, and not
exceptional, so change these to dprintk's for now. At some point
all of these will be converted to tracepoints, but that's for
another day.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13 16:00:12 -04:00
Chuck Lever 431af645cf xprtrdma: Fix client lock-up after application signal fires
After a signal, the RPC client aborts synchronous RPCs running on
behalf of the signaled application.

The server is still executing those RPCs, and will write the results
back into the client's memory when it's done. By the time the server
writes the results, that memory is likely being used for other
purposes. Therefore xprtrdma has to immediately invalidate all
memory regions used by those aborted RPCs to prevent the server's
writes from clobbering that re-used memory.

With FMR memory registration, invalidation takes a relatively long
time. In fact, the invalidation is often still running when the
server tries to write the results into the memory regions that are
being invalidated.

This sets up a race between two processes:

1.  After the signal, xprt_rdma_free calls ro_unmap_safe.
2.  While ro_unmap_safe is still running, the server replies and
    rpcrdma_reply_handler runs, calling ro_unmap_sync.

Both processes invoke ib_unmap_fmr on the same FMR.

The mlx4 driver allows two ib_unmap_fmr calls on the same FMR at
the same time, but HCAs generally don't tolerate this. Sometimes
this can result in a system crash.

If the HCA happens to survive, rpcrdma_reply_handler continues. It
removes the rpc_rqst from rq_list and releases the transport_lock.
This enables xprt_rdma_free to run in another process, and the
rpc_rqst is released while rpcrdma_reply_handler is still waiting
for the ib_unmap_fmr call to finish.

But further down in rpcrdma_reply_handler, the transport_lock is
taken again, and "rqst" is dereferenced. If "rqst" has already been
released, this triggers a general protection fault. Since bottom-
halves are disabled, the system locks up.

Address both issues by reversing the order of the xprt_lookup_rqst
call and the ro_unmap_sync call. Introduce a separate lookup
mechanism for rpcrdma_req's to enable calling ro_unmap_sync before
xprt_lookup_rqst. Now the handler takes the transport_lock once
and holds it for the XID lookup and RPC completion.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a7 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13 16:00:11 -04:00
Chuck Lever a80d66c9e0 xprtrdma: Rename rpcrdma_req::rl_free
Clean up: I'm about to use the rl_free field for purposes other than
a free list. So use a more generic name.

This is a refactoring change only.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a7 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13 16:00:10 -04:00
Chuck Lever 4b196dc6fe xprtrdma: Pre-mark remotely invalidated MRs
There are rare cases where an rpcrdma_req and its matched
rpcrdma_rep can be re-used, via rpcrdma_buffer_put, while the RPC
reply handler is still using that req. This is typically due to a
signal firing at just the wrong instant.

As part of closing this race window, avoid using the wrong
rpcrdma_rep to detect remotely invalidated MRs. Mark MRs as
invalidated while we are sure the rep is still OK to use.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a7 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13 16:00:10 -04:00
Chuck Lever 7d7fa9b550 xprtrdma: Annotate receive workqueue
Micro-optimize the receive workqueue by marking it's anchor "read-
mostly."

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:31 -04:00
Chuck Lever 56a6bd154d xprtrdma: Revert commit d0f36c46de
Device removal is now adequately supported. Pinning the underlying
device driver to prevent removal while an NFS mount is active is no
longer necessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:30 -04:00
Chuck Lever a9b0e381ca xprtrdma: Restore transport after device removal
After a device removal, enable the transport connect worker to
restore normal operation if there is another device with
connectivity to the server.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:28 -04:00
Chuck Lever 1890896b4e xprtrdma: Refactor rpcrdma_ep_connect
I'm about to add another arm to

    if (ep->rep_connected != 0)

It will be cleaner to use a switch statement here. We'll be looking
for a couple of specific errnos, or "anything else," basically to
sort out the difference between a normal reconnect and recovery from
device removal.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:27 -04:00
Chuck Lever bebd031866 xprtrdma: Support unplugging an HCA from under an NFS mount
The device driver for the underlying physical device associated
with an RPC-over-RDMA transport can be removed while RPC-over-RDMA
transports are still in use (ie, while NFS filesystems are still
mounted and active). The IB core performs a connection event upcall
to request that consumers free all RDMA resources associated with
a transport.

There may be pending RPCs when this occurs. Care must be taken to
release associated resources without leaving references that can
trigger a subsequent crash if a signal or soft timeout occurs. We
rely on the caller of the transport's ->close method to ensure that
the previous RPC task has invoked xprt_release but the transport
remains write-locked.

A DEVICE_REMOVE upcall forces a disconnect then sleeps. When ->close
is invoked, it destroys the transport's H/W resources, then wakes
the upcall, which completes and allows the core driver unload to
continue.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=266
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:24 -04:00
Chuck Lever 91a10c5297 xprtrdma: Use same device when mapping or syncing DMA buffers
When the underlying device driver is reloaded, ia->ri_device will be
replaced. All cached copies of that device pointer have to be
updated as well.

Commit 54cbd6b0c6 ("xprtrdma: Delay DMA mapping Send and Receive
buffers") added the rg_device field to each regbuf. As part of
handling a device removal, rpcrdma_dma_unmap_regbuf is invoked on
all regbufs for a transport.

Simply calling rpcrdma_dma_map_regbuf for each Receive buffer after
the driver has been reloaded should reinitialize rg_device correctly
for every case except rpcrdma_wc_receive, which still uses
rpcrdma_rep::rr_device.

Ensure the same device that was used to map a Receive buffer is also
used to sync it in rpcrdma_wc_receive by using rg_device there
instead of rr_device.

This is the only use of rr_device, so it can be removed.

The use of regbufs in the send path is also updated, for
completeness.

Fixes: 54cbd6b0c6 ("xprtrdma: Delay DMA mapping Send and ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:22 -04:00
Chuck Lever fff09594ed xprtrdma: Refactor rpcrdma_ia_open()
In order to unload a device driver and reload it, xprtrdma will need
to close a transport's interface adapter, and then call
rpcrdma_ia_open again, possibly finding a different interface
adapter.

Make rpcrdma_ia_open safe to call on the same transport multiple
times.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:20 -04:00
Chuck Lever 9378b274e1 xprtrdma: Cancel refresh worker during buffer shutdown
Trying to create MRs while the transport is being torn down can
cause a crash.

Fixes: e2ac236c0b ("xprtrdma: Allocate MRs on demand")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:14 -04:00
Chuck Lever eed50879d6 xprtrdma: Squelch kbuild sparse complaint
New complaint from kbuild for 4.9.y:

net/sunrpc/xprtrdma/verbs.c:489:19: sparse: incompatible types in
    comparison expression (different type sizes)

verbs.c:
489	max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES);

I can't reproduce this running sparse here. Likewise, "make W=1
net/sunrpc/xprtrdma/verbs.o" never indicated any issue.

A little poking suggests that because the range of its values is
small, gcc can make the actual width of RPCRDMA_MAX_SEND_SGES
smaller than the width of an unsigned integer.

Fixes: 16f906d66c ("xprtrdma: Reduce required number of send SGEs")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-03-17 16:05:21 -04:00
Chuck Lever 9a5c63e9c4 xprtrdma: Refactor management of mw_list field
Clean up some duplicate code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10 14:02:37 -05:00
Chuck Lever 0a90487bf7 xprtrdma: Handle stale connection rejection
A server rejects a connection attempt with STALE_CONNECTION when a
client attempts to connect to a working remote service, but uses a
QPN and GUID that corresponds to an old connection that was
abandoned. This might occur after a client crashes and restarts.

Fix rpcrdma_conn_upcall() to distinguish between a normal rejection
and rejection of stale connection parameters.

As an additional clean-up, remove the code that retries the
connection attempt with different ORD/IRD values. Code audit of
other ULP initiators shows no similar special case handling of
initiator_depth or responder_resources.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10 14:02:36 -05:00
Chuck Lever 16f906d66c xprtrdma: Reduce required number of send SGEs
The MAX_SEND_SGES check introduced in commit 655fec6987
("xprtrdma: Use gathered Send for large inline messages") fails
for devices that have a small max_sge.

Instead of checking for a large fixed maximum number of SGEs,
check for a minimum small number. RPC-over-RDMA will switch to
using a Read chunk if an xdr_buf has more pages than can fit in
the device's max_sge limit. This is considerably better than
failing all together to mount the server.

This fix supports devices that have as few as three send SGEs
available.

Reported-by: Selvin Xavier <selvin.xavier@broadcom.com>
Reported-by: Devesh Sharma <devesh.sharma@broadcom.com>
Reported-by: Honggang Li <honli@redhat.com>
Reported-by: Ram Amrani <Ram.Amrani@cavium.com>
Fixes: 655fec6987 ("xprtrdma: Use gathered Send for large ...")
Cc: stable@vger.kernel.org # v4.9+
Tested-by: Honggang Li <honli@redhat.com>
Tested-by: Ram Amrani <Ram.Amrani@cavium.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10 14:02:36 -05:00
Chuck Lever c95a3c6b88 xprtrdma: Disable pad optimization by default
Commit d5440e27d3 ("xprtrdma: Enable pad optimization") made the
Linux client omit XDR round-up padding in normal Read and Write
chunks so that the client doesn't have to register and invalidate
3-byte memory regions that contain no real data.

Unfortunately, my cheery 2014 assessment that this optimization "is
supported now by both Linux and Solaris servers" was premature.
We've found bugs in Solaris in this area since commit d5440e27d3
("xprtrdma: Enable pad optimization") was merged (SYMLINK is the
main offender).

So for maximum interoperability, I'm disabling this optimization
again. If a CM private message is exchanged when connecting, the
client recognizes that the server is Linux, and enables the
optimization for that connection.

Until now the Solaris server bugs did not impact common operations,
and were thus largely benign. Soon, less capable devices on Linux
NFS/RDMA clients will make use of Read chunks more often, and these
Solaris bugs will prevent interoperation in more cases.

Fixes: 677eb17e94 ("xprtrdma: Fix XDR tail buffer marshalling")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10 14:02:36 -05:00
Chuck Lever b5f0afbea4 xprtrdma: Per-connection pad optimization
Pad optimization is changed by echoing into
/proc/sys/sunrpc/rdma_pad_optimize. This is a global setting,
affecting all RPC-over-RDMA connections to all servers.

The marshaling code picks up that value and uses it for decisions
about how to construct each RPC-over-RDMA frame. Having it change
suddenly in mid-operation can result in unexpected failures. And
some servers a client mounts might need chunk round-up, while
others don't.

So instead, copy the pad_optimize setting into each connection's
rpcrdma_ia when the transport is created, and use the copy, which
can't change during the life of the connection, instead.

This also removes a hack: rpcrdma_convert_iovs was using
the remote-invalidation-expected flag to predict when it could leave
out Write chunk padding. This is because the Linux server handles
implicit XDR padding on Write chunks correctly, and only Linux
servers can set the connection's remote-invalidation-expected flag.

It's more sensible to use the pad optimization setting instead.

Fixes: 677eb17e94 ("xprtrdma: Fix XDR tail buffer marshalling")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10 14:02:36 -05:00
Chuck Lever 2f6922ca33 xprtrdma: Shorten QP access error message
Clean up: The convention for this type of warning message is not to
show the function name or "RPC:       ".

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-11-29 16:45:44 -05:00
Chuck Lever 6d6bf72de9 xprtrdma: Squelch "max send, max recv" messages at connect time
Clean up: This message was intended to be a dprintk, as it is on the
server-side.

Fixes: 87cfb9a0c8 ('xprtrdma: Client-side support for ...')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-11-29 16:45:44 -05:00
Chuck Lever 109b88ab9d xprtrdma: Address coverity complaint about wait_for_completion()
> ** CID 114101:  Error handling issues  (CHECKED_RETURN)
> /net/sunrpc/xprtrdma/verbs.c: 355 in rpcrdma_create_id()

Commit 5675add36e ("RPC/RDMA: harden connection logic against
missing/late rdma_cm upcalls.") replaced wait_for_completion() calls
with these two call sites.

The original wait_for_completion() calls were added in the initial
commit of verbs.c, which was commit c56c65fb67 ("RPCRDMA: rpc rdma
verbs interface implementation"), but these returned void.

rpcrdma_create_id() is called by the RDMA connect worker, which
probably won't ever be interrupted. It is also called by
rpcrdma_ia_open which is in the synchronous mount path, and ^C is
possible there.

Add a bit of logic at those two call sites to return if the waits
return ERESTARTSYS.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-11-29 16:45:44 -05:00
Chuck Lever 8d38de6564 xprtrdma: Make FRWR send queue entry accounting more accurate
Verbs providers may perform house-keeping on the Send Queue during
each signaled send completion. It is necessary therefore for a verbs
consumer (like xprtrdma) to occasionally force a signaled send
completion if it runs unsignaled most of the time.

xprtrdma does not require signaled completions for Send or FastReg
Work Requests, but does signal some LocalInv Work Requests. To
ensure that Send Queue house-keeping can run before the Send Queue
is more than half-consumed, xprtrdma forces a signaled completion
on occasion by counting the number of Send Queue Entries it
consumes. It currently does this by counting each ib_post_send as
one Entry.

Commit c9918ff56d ("xprtrdma: Add ro_unmap_sync method for FRWR")
introduced the ability for frwr_op_unmap_sync to post more than one
Work Request with a single post_send. Thus the underlying assumption
of one Send Queue Entry per ib_post_send is no longer true.

Also, FastReg Work Requests are currently never signaled. They
should be signaled once in a while, just as Send is, to keep the
accounting of consumed SQEs accurate.

While we're here, convert the CQCOUNT macros to the currently
preferred kernel coding style, which is inline functions.

Fixes: c9918ff56d ("xprtrdma: Add ro_unmap_sync method for FRWR")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-11-29 16:45:44 -05:00
Linus Torvalds c4a86165d1 NFS client updates for Linux 4.9
Highlights include:
 
 Stable bugfixes:
 - sunrpc: fix writ espace race causing stalls
 - NFS: Fix inode corruption in nfs_prime_dcache()
 - NFSv4: Don't report revoked delegations as valid in
   nfs_have_delegation()
 - NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is
   invalid
 - NFSv4: Open state recovery must account for file permission changes
 - NFSv4.2: Fix a reference leak in nfs42_proc_layoutstats_generic
 
 Features:
 - Add support for tracking multiple layout types with an ordered list
 - Add support for using multiple backchannel threads on the client
 - Add support for pNFS file layout session trunking
 - Delay xprtrdma use of DMA API (for device driver removal)
 - Add support for xprtrdma remote invalidation
 - Add support for larger xprtrdma inline thresholds
 - Use a scatter/gather list for sending xprtrdma RPC calls
 - Add support for the CB_NOTIFY_LOCK callback
 - Improve hashing sunrpc auth_creds by using both uid and gid
 
 Bugfixes:
 - Fix xprtrdma use of DMA API
 - Validate filenames before adding to the dcache
 - Fix corruption of xdr->nwords in xdr_copy_to_scratch
 - Fix setting buffer length in xdr_set_next_buffer()
 - Don't deadlock the state manager on the SEQUENCE status flags
 - Various delegation and stateid related fixes
 - Retry operations if an interrupted slot receives EREMOTEIO
 - Make nfs boot time y2038 safe
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Merge tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "Highlights include:

  Stable bugfixes:
   - sunrpc: fix writ espace race causing stalls
   - NFS: Fix inode corruption in nfs_prime_dcache()
   - NFSv4: Don't report revoked delegations as valid in nfs_have_delegation()
   - NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid
   - NFSv4: Open state recovery must account for file permission changes
   - NFSv4.2: Fix a reference leak in nfs42_proc_layoutstats_generic

  Features:
   - Add support for tracking multiple layout types with an ordered list
   - Add support for using multiple backchannel threads on the client
   - Add support for pNFS file layout session trunking
   - Delay xprtrdma use of DMA API (for device driver removal)
   - Add support for xprtrdma remote invalidation
   - Add support for larger xprtrdma inline thresholds
   - Use a scatter/gather list for sending xprtrdma RPC calls
   - Add support for the CB_NOTIFY_LOCK callback
   - Improve hashing sunrpc auth_creds by using both uid and gid

  Bugfixes:
   - Fix xprtrdma use of DMA API
   - Validate filenames before adding to the dcache
   - Fix corruption of xdr->nwords in xdr_copy_to_scratch
   - Fix setting buffer length in xdr_set_next_buffer()
   - Don't deadlock the state manager on the SEQUENCE status flags
   - Various delegation and stateid related fixes
   - Retry operations if an interrupted slot receives EREMOTEIO
   - Make nfs boot time y2038 safe"

* tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (100 commits)
  NFSv4.2: Fix a reference leak in nfs42_proc_layoutstats_generic
  fs: nfs: Make nfs boot time y2038 safe
  sunrpc: replace generic auth_cred hash with auth-specific function
  sunrpc: add RPCSEC_GSS hash_cred() function
  sunrpc: add auth_unix hash_cred() function
  sunrpc: add generic_auth hash_cred() function
  sunrpc: add hash_cred() function to rpc_authops struct
  Retry operation on EREMOTEIO on an interrupted slot
  pNFS: Fix atime updates on pNFS clients
  sunrpc: queue work on system_power_efficient_wq
  NFSv4.1: Even if the stateid is OK, we may need to recover the open modes
  NFSv4: If recovery failed for a specific open stateid, then don't retry
  NFSv4: Fix retry issues with nfs41_test/free_stateid
  NFSv4: Open state recovery must account for file permission changes
  NFSv4: Mark the lock and open stateids as invalid after freeing them
  NFSv4: Don't test open_stateid unless it is set
  NFSv4: nfs4_do_handle_exception() handle revoke/expiry of a single stateid
  NFS: Always call nfs_inode_find_state_and_recover() when revoking a delegation
  NFSv4: Fix a race when updating an open_stateid
  NFSv4: Fix a race in nfs_inode_reclaim_delegation()
  ...
2016-10-13 21:28:20 -07:00
Linus Torvalds b9044ac829 Merge of primary rdma-core code for 4.9
- Updates to mlx5
 - Updates to mlx4 (two conflicts, both minor and easily resolved)
 - Updates to iw_cxgb4 (one conflict, not so obvious to resolve, proper
   resolution is to keep the code in cxgb4_main.c as it is in Linus'
   tree as attach_uld was refactored and moved into cxgb4_uld.c)
 - Improvements to uAPI (moved vendor specific API elements to uAPI area)
 - Add hns-roce driver and hns and hns-roce ACPI reset support
 - Conversion of all rdma code away from deprecated
   create_singlethread_workqueue
 - Security improvement: remove unsafe ib_get_dma_mr (breaks lustre in
   staging)
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull main rdma updates from Doug Ledford:
 "This is the main pull request for the rdma stack this release.  The
  code has been through 0day and I had it tagged for linux-next testing
  for a couple days.

  Summary:

   - updates to mlx5

   - updates to mlx4 (two conflicts, both minor and easily resolved)

   - updates to iw_cxgb4 (one conflict, not so obvious to resolve,
     proper resolution is to keep the code in cxgb4_main.c as it is in
     Linus' tree as attach_uld was refactored and moved into
     cxgb4_uld.c)

   - improvements to uAPI (moved vendor specific API elements to uAPI
     area)

   - add hns-roce driver and hns and hns-roce ACPI reset support

   - conversion of all rdma code away from deprecated
     create_singlethread_workqueue

   - security improvement: remove unsafe ib_get_dma_mr (breaks lustre in
     staging)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (75 commits)
  staging/lustre: Disable InfiniBand support
  iw_cxgb4: add fast-path for small REG_MR operations
  cxgb4: advertise support for FR_NSMR_TPTE_WR
  IB/core: correctly handle rdma_rw_init_mrs() failure
  IB/srp: Fix infinite loop when FMR sg[0].offset != 0
  IB/srp: Remove an unused argument
  IB/core: Improve ib_map_mr_sg() documentation
  IB/mlx4: Fix possible vl/sl field mismatch in LRH header in QP1 packets
  IB/mthca: Move user vendor structures
  IB/nes: Move user vendor structures
  IB/ocrdma: Move user vendor structures
  IB/mlx4: Move user vendor structures
  IB/cxgb4: Move user vendor structures
  IB/cxgb3: Move user vendor structures
  IB/mlx5: Move and decouple user vendor structures
  IB/{core,hw}: Add constant for node_desc
  ipoib: Make ipoib_warn ratelimited
  IB/mlx4/alias_GUID: Remove deprecated create_singlethread_workqueue
  IB/ipoib_verbs: Remove deprecated create_singlethread_workqueue
  IB/ipoib: Remove deprecated create_singlethread_workqueue
  ...
2016-10-09 17:04:33 -07:00
Christoph Hellwig ed082d36a7 IB/core: add support to create a unsafe global rkey to ib_create_pd
Instead of exposing ib_get_dma_mr to ULPs and letting them use it more or
less unchecked, this moves the capability of creating a global rkey into
the RDMA core, where it can be easily audited.  It also prints a warning
everytime this feature is used as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-09-23 13:47:44 -04:00
Chuck Lever 496b77a5c5 xprtrdma: Eliminate rpcrdma_receive_worker()
Clean up: the extra layer of indirection doesn't add value.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19 13:08:38 -04:00
Chuck Lever 1519e9697d xprtrdma: Rename rpcrdma_receive_wc()
Clean up: When converting xprtrdma to use the new CQ API, I missed a
spot. The naming convention elsewhere is:

  {svc_rdma,rpcrdma}_wc_{operation}

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19 13:08:38 -04:00
Chuck Lever 655fec6987 xprtrdma: Use gathered Send for large inline messages
An RPC Call message that is sent inline but that has a data payload
(ie, one or more items in rq_snd_buf's page list) must be "pulled
up:"

- call_allocate has to reserve enough RPC Call buffer space to
accommodate the data payload

- call_transmit has to memcopy the rq_snd_buf's page list and tail
into its head iovec before it is sent

As the inline threshold is increased beyond its current 1KB default,
however, this means data payloads of more than a few KB are copied
by the host CPU. For example, if the inline threshold is increased
just to 4KB, then NFS WRITE requests up to 4KB would involve a
memcpy of the NFS WRITE's payload data into the RPC Call buffer.
This is an undesirable amount of participation by the host CPU.

The inline threshold may be much larger than 4KB in the future,
after negotiation with a peer server.

Instead of copying the components of rq_snd_buf into its head iovec,
construct a gather list of these components, and send them all in
place. The same approach is already used in the Linux server's
RPC-over-RDMA reply path.

This mechanism also eliminates the need for rpcrdma_tail_pullup,
which is used to manage the XDR pad and trailing inline content when
a Read list is present.

This requires that the pages in rq_snd_buf's page list be DMA-mapped
during marshaling, and unmapped when a data-bearing RPC is
completed. This is slightly less efficient for very small I/O
payloads, but significantly more efficient as data payload size and
inline threshold increase past a kilobyte.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19 13:08:38 -04:00