Commit Graph

288 Commits

Author SHA1 Message Date
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
7de62bc09f SUNRPC dont update timeout value on connection reset
Current behaviour: every time a v3 operation is re-sent to the server
we update (double) the timeout. There is no distinction between whether
or not the previous timer had expired before the re-sent happened.

Here's the scenario:
1. Client sends a v3 operation
2. Server RST-s the connection (prior to the timeout) (eg., connection
is immediately reset)
3. Client re-sends a v3 operation but the timeout is now 120sec.

As a result, an application sees 2mins pause before a retry in case
server again does not reply.

Instead, this patch proposes to keep track off when the minor timeout
should happen and if it didn't, then don't update the new timeout.
Value is updated based on the previous value to make timeouts
predictable.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-08-04 23:17:11 -04:00
911813d7a1 SUNRPC: Trace transport lifetime events
Refactor: Hoist create/destroy/disconnect tracepoints out of
xprtrdma and into the generic RPC client. Some benefits include:

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

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

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-06-11 13:33:48 -04:00
c509f15a58 SUNRPC: Split the xdr_buf event class
To help tie the recorded xdr_buf to a particular RPC transaction,
the client side version of this class should display task ID
information and the server side one should show the request's XID.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-06-11 13:33:48 -04:00
b20dfc3fcd svcrdma: Create a generic tracing class for displaying xdr_buf layout
This class can be used to create trace points in either the RPC
client or RPC server paths. It simply displays the length of each
part of an xdr_buf, which is useful to determine that the transport
and XDR codecs are operating correctly.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-03-16 12:04:32 -04:00
4e121fcae8 Merge tag 'nfs-rdma-for-5.5-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
NFSoRDMA Client Updates for Linux 5.5

New Features:
- New tracepoints for congestion control and Local Invalidate WRs

Bugfixes and Cleanups:
- Eliminate log noise in call_reserveresult
- Fix unstable connections after a reconnect
- Clean up some code duplication
- Close race between waking a sender and posting a receive
- Fix MR list corruption, and clean up MR usage
- Remove unused rpcrdma_sendctx fields
- Try to avoid DMA mapping pages if it is too costly
- Wake pending tasks if connection fails
- Replace some dprintk()s with tracepoints
2019-11-18 10:55:55 +01:00
669996add4 SUNRPC: Destroy the back channel when we destroy the host transport
When we're destroying the host transport mechanism, we should ensure
that we do not leak memory by failing to release any back channel
slots that might still exist.

Reported-by: Neil Brown <neilb@suse.de>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-30 12:04:35 -04:00
bf7ca707ae SUNRPC: Add trace points to observe transport congestion control
To help debug problems with RPC/RDMA credit management, replace
dprintk() call sites in the transport send lock paths with trace
events.

Similar trace points are defined for the non-congestion paths.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24 10:30:39 -04:00
972a2bf7df Merge tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - Dequeue the request from the receive queue while we're re-encoding
     # v4.20+
   - Fix buffer handling of GSS MIC without slack # 5.1

  Features:
   - Increase xprtrdma maximum transport header and slot table sizes
   - Add support for nfs4_call_sync() calls using a custom
     rpc_task_struct
   - Optimize the default readahead size
   - Enable pNFS filelayout LAYOUTGET on OPEN

  Other bugfixes and cleanups:
   - Fix possible null-pointer dereferences and memory leaks
   - Various NFS over RDMA cleanups
   - Various NFS over RDMA comment updates
   - Don't receive TCP data into a reset request buffer
   - Don't try to parse incomplete RPC messages
   - Fix congestion window race with disconnect
   - Clean up pNFS return-on-close error handling
   - Fixes for NFS4ERR_OLD_STATEID handling"

* tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (53 commits)
  pNFS/filelayout: enable LAYOUTGET on OPEN
  NFS: Optimise the default readahead size
  NFSv4: Handle NFS4ERR_OLD_STATEID in LOCKU
  NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE
  NFSv4: Fix OPEN_DOWNGRADE error handling
  pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid
  NFSv4: Add a helper to increment stateid seqids
  NFSv4: Handle RPC level errors in LAYOUTRETURN
  NFSv4: Handle NFS4ERR_DELAY correctly in return-on-close
  NFSv4: Clean up pNFS return-on-close error handling
  pNFS: Ensure we do clear the return-on-close layout stateid on fatal errors
  NFS: remove unused check for negative dentry
  NFSv3: use nfs_add_or_obtain() to create and reference inodes
  NFS: Refactor nfs_instantiate() for dentry referencing callers
  SUNRPC: Fix congestion window race with disconnect
  SUNRPC: Don't try to parse incomplete RPC messages
  SUNRPC: Rename xdr_buf_read_netobj to xdr_buf_read_mic
  SUNRPC: Fix buffer handling of GSS MIC without slack
  SUNRPC: RPC level errors should always set task->tk_rpc_status
  SUNRPC: Don't receive TCP data into a request buffer that has been reset
  ...
2019-09-26 12:20:14 -07:00
8593e01078 SUNRPC: Fix congestion window race with disconnect
If the congestion window closes just as the transport disconnects,
a reconnect is never driven because:

1. The XPRT_CONG_WAIT flag prevents tasks from taking the write lock
2. There's no wake-up of the first task on the xprt->sending queue

To address this, clear the congestion wait flag as part of
completing a disconnect.

Fixes: 75891f502f ("SUNRPC: Support for congestion control ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-09-20 15:15:24 -04:00
cc204d0126 SUNRPC: Dequeue the request from the receive queue while we're re-encoding
Ensure that we dequeue the request from the transport receive queue
while we're re-encoding to prevent issues like use-after-free when
we release the bvec.

Fixes: 7536908982 ("SUNRPC: Ensure the bvecs are reset when we re-encode...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-09-17 15:14:11 -04:00
d5711920ec Revert "NFSv4/flexfiles: Abort I/O early if the layout segment was invalidated"
This reverts commit a79f194aa4.
The mechanism for aborting I/O is racy, since we are not guaranteed that
the request is asleep while we're changing both task->tk_status and
task->tk_action.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v5.1
2019-08-26 15:31:29 -04:00
7536908982 SUNRPC: Ensure the bvecs are reset when we re-encode the RPC request
The bvec tracks the list of pages, so if the number of pages changes
due to a re-encode, we need to reset the bvec as well.

Fixes: 277e4ab7d5 ("SUNRPC: Simplify TCP receive code by switching...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20+
2019-07-18 14:43:52 -04:00
347543e640 Merge tag 'nfs-rdma-for-5.3-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
NFSoRDMA client updates for 5.3

New features:
- Add a way to place MRs back on the free list
- Reduce context switching
- Add new trace events

Bugfixes and cleanups:
- Fix a BUG when tracing is enabled with NFSv4.1
- Fix a use-after-free in rpcrdma_post_recvs
- Replace use of xdr_stream_pos in rpcrdma_marshal_req
- Fix occasional transport deadlock
- Fix show_nfs_errors macros, other tracing improvements
- Remove RPCRDMA_REQ_F_PENDING and fr_state
- Various simplifications and refactors
2019-07-12 12:11:01 -04:00
675dd90ad0 xprtrdma: Modernize ops->connect
Adapt and apply changes that were made to the TCP socket connect
code. See the following commits for details on the purpose of
these changes:

Commit 7196dbb02e ("SUNRPC: Allow changing of the TCP timeout parameters on the fly")
Commit 3851f1cdb2 ("SUNRPC: Limit the reconnect backoff timer to the max RPC message timeout")
Commit 02910177ae ("SUNRPC: Fix reconnection timeouts")

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

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-07-09 10:30:25 -04:00
80d3c45fd7 SUNRPC: Fix possible autodisconnect during connect due to old last_used
Ensure last_used is updated before calling mod_timer inside
xprt_schedule_autodisconnect.  This avoids a possible xprt_autoclose
firing immediately after a successful connect when xprt_unlock_connect
calls xprt_schedule_autodisconnect with an old value of last_used.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-06 14:54:53 -04:00
41adafa02e Merge branch 'bh-remove' 2019-07-06 14:54:51 -04:00
9dfe52a95a SUNRPC: Move call to rpc_count_iostats before rpc_call_done
For diagnostic purposes, it would be useful to have an rpc_iostats
metric of RPCs completing with tk_status < 0.  Unfortunately,
tk_status is reset inside the rpc_call_done functions for each
operation, and the call to tally the per-op metrics comes after
rpc_call_done.  Refactor the call to rpc_count_iostat earlier in
rpc_exit_task so we can count these RPCs completing in error.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-06 14:54:51 -04:00
b5e924191f SUNRPC: Remove the bh-safe lock requirement on xprt->transport_lock
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-06 14:54:48 -04:00
502980e84e Revert "SUNRPC: Declare RPC timers as TIMER_DEFERRABLE"
Jon Hunter reports:
  "I have been noticing intermittent failures with a system suspend test on
   some of our machines that have a NFS mounted root file-system. Bisecting
   this issue points to your commit 431235818b ("SUNRPC: Declare RPC
   timers as TIMER_DEFERRABLE") and reverting this on top of v5.2-rc3 does
   appear to resolve the problem.

   The cause of the suspend failure appears to be a long delay observed
   sometimes when resuming from suspend, and this is causing our test to
   timeout."

This reverts commit 431235818b.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-06-21 14:43:42 -04:00
457c899653 treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:45 +02:00
1f7d1c73c5 SUNRPC: Update comments based on recent changes
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 15:38:02 -04:00
da953063bd SUNRPC: Start the first major timeout calculation at task creation
When calculating the major timeout for a new task, when we know that the
connection has been broken, use the task->tk_start to ensure that we also
take into account the time spent waiting for a slot or session slot. This
ensures that we fail over soft requests relatively quickly once the
connection has actually been broken, and the first requests have
started to fail.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
9e910bff74 SUNRPC: Ensure that the transport layer respect major timeouts
Ensure that when in the transport layer, we don't sleep past
a major timeout.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
431235818b SUNRPC: Declare RPC timers as TIMER_DEFERRABLE
Don't wake idle CPUs only for the purpose of servicing an RPC
queue timeout.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
6b2e685627 SUNRPC: Add function rpc_sleep_on_timeout()
Clean up the RPC task sleep interfaces by replacing the task->tk_timeout
'hidden parameter' to rpc_sleep_on() with a new function that takes an
absolute timeout.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
8ba6a92d01 SUNRPC: Refactor xprt_request_wait_receive()
Convert the transport callback to actually put the request to sleep
instead of just setting a timeout. This is in preparation for
rpc_sleep_on_timeout().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:12 -04:00
ae67bd3821 SUNRPC: Fix up task signalling
The RPC_TASK_KILLED flag should really not be set from another context
because it can clobber data in the struct task when task->tk_flags is
changed non-atomically.
Let's therefore swap out RPC_TASK_KILLED with an atomic flag, and add
a function to set that flag and safely wake up the task.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:12 -04:00
27adc78592 SUNRPC: Use the ENOTCONN error on socket disconnect
When the socket is closed, we currently send an EAGAIN error to all
pending requests in order to ask them to retransmit. Use ENOTCONN
instead, to ensure that they try to reconnect before attempting to
transmit.
This also helps SOFTCONN tasks to behave correctly in this
situation.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-03-15 13:08:20 -04:00
a79f194aa4 NFSv4/flexfiles: Abort I/O early if the layout segment was invalidated
If a layout segment gets invalidated while a pNFS I/O operation
is queued for transmission, then we ideally want to abort
immediately. This is particularly the case when there is a large
number of I/O related RPCs queued in the RPC layer, and the layout
segment gets invalidated due to an ENOSPC error, or an EACCES (because
the client was fenced). We may end up forced to spam the MDS with a
lot of otherwise unnecessary LAYOUTERRORs after that I/O fails.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-03-01 16:20:16 -05:00
06b5fc3ad9 Merge tag 'nfs-rdma-for-5.1-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
NFSoRDMA client updates for 5.1

New features:
- Convert rpc auth layer to use xdr_streams
- Config option to disable insecure enctypes
- Reduce size of RPC receive buffers

Bugfixes and cleanups:
- Fix sparse warnings
- Check inline size before providing a write chunk
- Reduce the receive doorbell rate
- Various tracepoint improvements

[Trond: Fix up merge conflicts]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-25 09:35:49 -05:00
0472e47660 SUNRPC: Convert socket page send code to use iov_iter()
Simplify the page send code using iov_iter and bvecs.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-20 17:35:58 -05:00
b9779a54bb SUNRPC: Ensure rq_bytes_sent is reset before request transmission
When we resend a request, ensure that the 'rq_bytes_sent' is reset
to zero.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-20 17:33:55 -05:00
a1231fda7e SUNRPC: Set memalloc_nofs_save() on all rpciod/xprtiod jobs
Set memalloc_nofs_save() on all the rpciod/xprtiod jobs so that we
ensure memory allocations for asynchronous rpc calls don't ever end
up recursing back to the NFS layer for memory reclaim.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-20 15:14:21 -05:00
0c77668ddb SUNRPC: Introduce trace points in rpc_auth_gss.ko
Add infrastructure for trace points in the RPC_AUTH_GSS kernel
module, and add a few sample trace points. These report exceptional
or unexpected events, and observe the assignment of GSS sequence
numbers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-02-14 09:20:40 -05:00
deaa5c96c2 SUNRPC: Address Kerberos performance/behavior regression
When using Kerberos with v4.20, I've observed frequent connection
loss on heavy workloads. I traced it down to the client underrunning
the GSS sequence number window -- NFS servers are required to drop
the RPC with the low sequence number, and also drop the connection
to signal that an RPC was dropped.

Bisected to commit 918f3c1fe8 ("SUNRPC: Improve latency for
interactive tasks").

I've got a one-line workaround for this issue, which is easy to
backport to v4.20 while a more permanent solution is being derived.
Essentially, tk_owner-based sorting is disabled for RPCs that carry
a GSS sequence number.

Fixes: 918f3c1fe8 ("SUNRPC: Improve latency for interactive ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-15 15:36:41 -05:00
e66721f043 SUNRPC: Ensure rq_bytes_sent is reset before request transmission
When we resend a request, ensure that the 'rq_bytes_sent' is reset
to zero.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-15 15:28:18 -05:00
abc1327577 SUNRPC: Remove xprt_connect_status()
Over the years, xprt_connect_status() has been superseded by
call_connect_status(), which now handles all the errors that
xprt_connect_status() does and more. Since the latter converts
all errors that it doesn't recognise to EIO, then it is time
for it to be retired.

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
2018-12-18 11:04:10 -05:00
0445f92c5d SUNRPC: Fix disconnection races
When the socket is closed, we need to call xprt_disconnect_done() in order
to clean up the XPRT_WRITE_SPACE flag, and wake up the sleeping tasks.

However, we also want to ensure that we don't wake them up before the socket
is closed, since that would cause thundering herd issues with everyone
piling up to retransmit before the TCP shutdown dance has completed.
Only the task that holds XPRT_LOCKED needs to wake up early in order to
allow the close to complete.

Reported-by: Dave Wysochanski <dwysocha@redhat.com>
Reported-by: Scott Mayhew <smayhew@redhat.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
2018-12-18 11:03:57 -05:00
0a9a4304f3 SUNRPC: Fix a potential race in xprt_connect()
If an asynchronous connection attempt completes while another task is
in xprt_connect(), then the call to rpc_sleep_on() could end up
racing with the call to xprt_wake_pending_tasks().
So add a second test of the connection state after we've put the
task to sleep and set the XPRT_CONNECTING flag, when we know that there
can be no asynchronous connection attempts still in progress.

Fixes: 0b9e794313 ("SUNRPC: Move the test for XPRT_CONNECTING into...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-12-02 09:43:57 -05:00
71700bb960 SUNRPC: Fix a memory leak in call_encode()
If we retransmit an RPC request, we currently end up clobbering the
value of req->rq_rcv_buf.bvec that was allocated by the initial call to
xprt_request_prepare(req).

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-12-02 09:43:57 -05:00
93bdcf9fdb 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
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
9d96acbc7f SUNRPC: Add a bvec array to struct xdr_buf for use with iovec_iter()
Add a bvec array to struct xdr_buf, and have the client allocate it
when we need to receive data into pages.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:16 -04:00
79c99152a3 SUNRPC: Convert the xprt->sending queue back to an ordinary wait queue
We no longer need priority semantics on the xprt->sending queue, because
the order in which tasks are sent is now dictated by their position in
the send queue.
Note that the backlog queue remains a priority queue, meaning that
slot resources are still managed in order of task priority.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:16 -04:00
95f7691daa SUNRPC: Convert xprt receive queue to use an rbtree
If the server is slow, we can find ourselves with quite a lot of entries
on the receive queue. Converting the search from an O(n) to O(log(n))
can make a significant difference, particularly since we have to hold
a number of locks while searching.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:16 -04:00
bd79bc579c SUNRPC: Don't take transport->lock unnecessarily when taking XPRT_LOCK
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:16 -04:00
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
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
36bd7de949 SUNRPC: Turn off throttling of RPC slots for TCP sockets
The theory was that we would need to grab the socket lock anyway, so we
might as well use it to gate the allocation of RPC slots for a TCP
socket.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:15 -04:00