Commit graph

123 commits

Author SHA1 Message Date
Dai Ngo
691d0b7820 SUNRPC: remove the maximum number of retries in call_bind_status
Currently call_bind_status places a hard limit of 3 to the number of
retries on EACCES error. This limit was done to prevent NLM unlock
requests from being hang forever when the server keeps returning garbage.
However this change causes problem for cases when NLM service takes
longer than 9 seconds to register with the port mapper after a restart.

This patch removes this hard coded limit and let the RPC handles
the retry based on the standard hard/soft task semantics.

Fixes: 0b760113a3 ("NLM: Don't hang forever on NLM unlock requests")
Reported-by: Helen Chao <helen.chao@oracle.com>
Tested-by: Helen Chao <helen.chao@oracle.com>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-04-19 17:06:02 -04:00
Linus Torvalds
66b8345585 NFS Client Updates for Linux 6.1
- New Features:
   - Add NFSv4.2 xattr tracepoints
   - Replace xprtiod WQ in rpcrdma
   - Flexfiles cancels I/O on layout recall or revoke
 
 - Bugfixes and Cleanups:
   - Directly use ida_alloc() / ida_free()
   - Don't open-code max_t()
   - Prefer using strscpy over strlcpy
   - Remove unused forward declarations
   - Always return layout states on flexfiles layout return
   - Have LISTXATTR treat NFS4ERR_NOXATTR as an empty reply instead of error
   - Allow more xprtrdma memory allocations to fail without triggering a reclaim
   - Various other xprtrdma clean ups
   - Fix rpc_killall_tasks() races
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Merge tag 'nfs-for-6.1-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "New Features:
   - Add NFSv4.2 xattr tracepoints
   - Replace xprtiod WQ in rpcrdma
   - Flexfiles cancels I/O on layout recall or revoke

  Bugfixes and Cleanups:
   - Directly use ida_alloc() / ida_free()
   - Don't open-code max_t()
   - Prefer using strscpy over strlcpy
   - Remove unused forward declarations
   - Always return layout states on flexfiles layout return
   - Have LISTXATTR treat NFS4ERR_NOXATTR as an empty reply instead of
     error
   - Allow more xprtrdma memory allocations to fail without triggering a
     reclaim
   - Various other xprtrdma clean ups
   - Fix rpc_killall_tasks() races"

* tag 'nfs-for-6.1-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (27 commits)
  NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked
  SUNRPC: Add API to force the client to disconnect
  SUNRPC: Add a helper to allow pNFS drivers to selectively cancel RPC calls
  SUNRPC: Fix races with rpc_killall_tasks()
  xprtrdma: Fix uninitialized variable
  xprtrdma: Prevent memory allocations from driving a reclaim
  xprtrdma: Memory allocation should be allowed to fail during connect
  xprtrdma: MR-related memory allocation should be allowed to fail
  xprtrdma: Clean up synopsis of rpcrdma_regbuf_alloc()
  xprtrdma: Clean up synopsis of rpcrdma_req_create()
  svcrdma: Clean up RPCRDMA_DEF_GFP
  SUNRPC: Replace the use of the xprtiod WQ in rpcrdma
  NFSv4.2: Add a tracepoint for listxattr
  NFSv4.2: Add tracepoints for getxattr, setxattr, and removexattr
  NFSv4.2: Move TRACE_DEFINE_ENUM(NFS4_CONTENT_*) under CONFIG_NFS_V4_2
  NFSv4.2: Add special handling for LISTXATTR receiving NFS4ERR_NOXATTR
  nfs: remove nfs_wait_atomic_killable() and nfs_write_prepare() declaration
  NFSv4: remove nfs4_renewd_prepare_shutdown() declaration
  fs/nfs/pnfs_nfs.c: fix spelling typo and syntax error in comment
  NFSv4/pNFS: Always return layout stats on layout return for flexfiles
  ...
2022-10-13 09:58:42 -07:00
Trond Myklebust
f8423909ec SUNRPC: Add a helper to allow pNFS drivers to selectively cancel RPC calls
Add the helper rpc_cancel_tasks(), which uses a caller-defined selection
function to define a set of in-flight RPC calls to cancel. This is
mainly intended for pNFS drivers which are subject to a layout recall,
and which may therefore want to cancel all pending I/O using that layout
in order to redrive it after the layout recall has been satisfied.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2022-10-06 09:52:09 -04:00
Trond Myklebust
39494194f9 SUNRPC: Fix races with rpc_killall_tasks()
Ensure that we immediately call rpc_exit_task() after waking up, and
that the tk_rpc_status cannot get clobbered by some other function.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2022-10-06 09:52:09 -04:00
Peter Zijlstra
f5d39b0208 freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

	freezer_do_not_count();
	schedule();
	freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

	TASK_FREEZABLE	-> TASK_FROZEN
	__TASK_STOPPED	-> TASK_FROZEN
	__TASK_TRACED	-> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
2022-09-07 21:53:50 +02:00
Trond Myklebust
ba8ec7a607 SUNRPC: Shrink size of struct rpc_task
Move the field 'tk_rpc_status' so that we eliminate a 4 byte hole in the
structure.
For x86_64, this shrinks the size of the struct by 8 bytes.

'pahole' output before the change:
        /* size: 232, cachelines: 4, members: 27 */
        /* sum members: 222, holes: 1, sum holes: 4 */
        /* sum bitfield members: 8 bits (1 bytes) */
        /* padding: 5 */
        /* last cacheline: 40 bytes */

'pahole' output after the change:
        /* size: 224, cachelines: 4, members: 27 */
        /* padding: 1 */
        /* last cacheline: 32 bytes */

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-07-23 14:47:28 -04:00
Trond Myklebust
33e5c765bc NFS: Fix memory allocation in rpc_malloc()
When in a low memory situation, we do want rpciod to kick off direct
reclaim in the case where that helps, however we don't want it looping
forever in mempool_alloc().
So first try allocating from the slab using GFP_KERNEL | __GFP_NORETRY,
and then fall back to a GFP_NOWAIT allocation from the mempool.

Ditto for rpc_alloc_task()

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-22 15:52:55 -04:00
NeilBrown
89c2be8a95 NFS: discard NFS_RPC_SWAPFLAGS and RPC_TASK_ROOTCREDS
NFS_RPC_SWAPFLAGS is only used for READ requests.
It sets RPC_TASK_SWAPPER which gives some memory-allocation priority to
requests.  This is not needed for swap READ - though it is for writes
where it is set via a different mechanism.

RPC_TASK_ROOTCREDS causes the 'machine' credential to be used.
This is not needed as the root credential is saved when the swap file is
opened, and this is used for all IO.

So NFS_RPC_SWAPFLAGS isn't needed, and as it is the only user of
RPC_TASK_ROOTCREDS, that isn't needed either.

Remove both.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-13 12:59:35 -04:00
Trond Myklebust
b9f8713f42 SUNRPC: Remove unnecessary memory barriers
The only check for RPC_TASK_RUNNING is the one in rpc_make_runnable(),
which happens under the same spin lock held when we call
rpc_clear_running().

Ditto, the last check for RPC_TASK_QUEUED in rpc_execute() is performed
under the same lock as the one held when we call rpc_clear_queued().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-10-03 20:49:05 -04:00
Olga Kornievskaia
85e39feead NFSv4.1 identify and mark RPC tasks that can move between transports
In preparation for when we can re-try a task on a different transport,
identify and mark such RPC tasks as moveable. Only 4.1+ operarations can
be re-tried on a different transport.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-07-08 14:03:24 -04:00
Trond Myklebust
7eac52648a SUNRPC: Add a flag to avoid reference counts on credentials
Add a flag to signal to the RPC layer that the credential is already
pinned for the duration of the RPC call.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:28 -04:00
Linus Torvalds
972a2bf7df NFS Client Updates for Linux 5.3
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
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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
Trond Myklebust
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
Chuck Lever
691b45ddbd SUNRPC: Remove rpc_wake_up_queued_task_on_wq()
Clean up: commit c544577dad ("SUNRPC: Clean up transport write
space handling") appears to have removed the last caller of
rpc_wake_up_queued_task_on_wq().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20 10:02:22 -04:00
Trond Myklebust
c98ebe2937 Merge branch 'multipath_tcp' 2019-07-06 14:54:52 -04:00
NeilBrown
5a0c257f8e NFS: send state management on a single connection.
With NFSv4.1, different network connections need to be explicitly
bound to a session.  During session startup, this is not possible
so only a single connection must be used for session startup.

So add a task flag to disable the default round-robin choice of
connections (when nconnect > 1) and force the use of a single
connection.
Then use that flag on all requests for session management - for
consistence, include NFSv4.0 management (SETCLIENTID) and session
destruction

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-06 14:54:50 -04:00
Trond Myklebust
7e0a0e38fc SUNRPC: Replace the queue timer with a delayed work function
The queue timer function, which walks the RPC queue in order to locate
candidates for waking up is one of the current constraints against
removing the bh-safe queue spin locks. Replace it with a delayed
work queue, so that we can do the actual rpc task wake ups from an
ordinary process context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-06 14:54:48 -04:00
Trond Myklebust
5ad64b36dd SUNRPC: Add tracking of RPC level errors
Add variables to track RPC level errors so that we can distinguish
between issue that arose in the RPC transport layer as opposed to
those arising from the reply message.

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
Trond Myklebust
24a9d9a21e SUNRPC: Simplify queue timeouts using timer_reduce()
Simplify the setting of queue timeouts by using the timer_reduce()
function.

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
Trond Myklebust
5efd1876e6 SUNRPC: Fix up tracking of timeouts
Add a helper to ensure that debugfs and friends print out the
correct current task timeout value.

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
Trond Myklebust
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
Trond Myklebust
8357a9b60f SUNRPC: Remove unused argument 'action' from rpc_sleep_on_priority()
None of the callers set the 'action' argument, so let's just remove it.

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
Trond Myklebust
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
Trond Myklebust
af6b61d7ef Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping"
This reverts commit 009a82f643.

The ability to optimise here relies on compiler being able to optimise
away tail calls to avoid stack overflows. Unfortunately, we are seeing
reports of problems, so let's just revert.

Reported-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-04-11 15:41:14 -04:00
Trond Myklebust
009a82f643 SUNRPC: Micro-optimise when the task is known not to be sleeping
In cases where we know the task is not sleeping, try to optimise
away the indirect call to task->tk_action() by replacing it with
a direct call.
Only change tail calls, to allow gcc to perform tail call
elimination.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-03-10 14:08:19 -04:00
Trond Myklebust
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
NeilBrown
a52458b48a NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.
SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19 13:52:46 -05:00
NeilBrown
1de7eea929 SUNRPC: add side channel to use non-generic cred for rpc call.
The credential passed in rpc_message.rpc_cred is always a
generic credential except in one instance.
When gss_destroying_context() calls rpc_call_null(), it passes
a specific credential that it needs to destroy.
In this case the RPC acts *on* the credential rather than
being authorized by it.

This special case deserves explicit support and providing that will
mean that rpc_message.rpc_cred is *always* generic, allowing
some optimizations.

So add "tk_op_cred" to rpc_task and "rpc_op_cred" to the setup data.
Use this to pass the cred down from rpc_call_null(), and have
rpcauth_bindcred() notice it and bind it in place.

Credit to kernel test robot <fengguang.wu@intel.com> for finding
a bug in earlier version of this patch.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19 13:52:45 -05:00
NeilBrown
a68a72e135 SUNRPC: introduce RPC_TASK_NULLCREDS to request auth_none
In almost all cases the credential stored in rpc_message.rpc_cred
is a "generic" credential.  One of the two expections is when an
AUTH_NULL credential is used such as for RPC ping requests.

To improve consistency, don't pass an explicit credential in
these cases, but instead pass NULL and set a task flag,
similar to RPC_TASK_ROOTCREDS, which requests that NULL credentials
be used by default.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19 13:52:45 -05:00
NeilBrown
ecd5f97e1c SUNRPC: discard RPC_DO_ROOTOVERRIDE()
it is never used.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19 13:52:45 -05:00
Trond Myklebust
f42f7c2830 SUNRPC: Fix priority queue fairness
Fix up the priority queue to not batch by owner, but by queue, so that
we allow '1 << priority' elements to be dequeued before switching to
the next priority queue.
The owner field is still used to wake up requests in round robin order
by owner to avoid single processes hogging the RPC layer by loading the
queues.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:16 -04:00
Trond Myklebust
359c48c04a SUNRPC: Add a helper to wake up a sleeping rpc_task and set its status
Add a helper that will wake up a task that is sleeping on a specific
queue, and will set the value of task->tk_status. This is mainly
intended for use by the transport layer to notify the task of an
error condition.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:14 -04:00
Trond Myklebust
cf9946cd61 SUNRPC: Refactor the transport request pinning
We are going to need to pin for both send and receive.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:14 -04:00
Trond Myklebust
7ebbbc6e7b SUNRPC: Simplify identification of when the message send/receive is complete
Add states to indicate that the message send and receive are not yet
complete.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30 15:35:14 -04:00
Trond Myklebust
2275cde4cc SUNRPC: Queue latency-sensitive socket tasks to xprtiod
The response to a write_space notification is very latency sensitive,
so we should queue it to the lower latency xprtiod_workqueue. This
is something we already do for the other cases where an rpc task
holds the transport XPRT_LOCKED bitlock.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-02-07 09:25:52 -05:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Trond Myklebust
729749bb8d SUNRPC: Don't hold the transport lock across socket copy operations
Instead add a mechanism to ensure that the request doesn't disappear
from underneath us while copying from the socket. We do this by
preventing xprt_release() from freeing the XDR buffers until the
flag RPC_TASK_MSG_RECV has been cleared from the request.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
2017-08-16 15:10:15 -04:00
Linus Torvalds
6240300597 Chuck's RDMA update overhauls the "call receive" side of the
RPC-over-RDMA transport to use the new rdma_rw API.
 
 Christoph cleaned the way nfs operations are declared, removing a bunch
 of function-pointer casts and declaring the operation vectors as const.
 
 Christoph's changes touch both client and server, and both client and
 server pulls this time around should be based on the same commits from
 Christoph.
 
 (Note: Anna and I initially didn't coordinate this well and we realized
 our pull requests were going to leave you with Christoph's 33 patches
 duplicated between our two trees.  We decided a last-minute rebase was
 the lesser of two evils, so her pull request will show that last-minute
 rebase.  Yell if that was the wrong choice, and we'll know better for
 next time....)
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Merge tag 'nfsd-4.13' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Chuck's RDMA update overhauls the "call receive" side of the
  RPC-over-RDMA transport to use the new rdma_rw API.

  Christoph cleaned the way nfs operations are declared, removing a
  bunch of function-pointer casts and declaring the operation vectors as
  const.

  Christoph's changes touch both client and server, and both client and
  server pulls this time around should be based on the same commits from
  Christoph"

* tag 'nfsd-4.13' of git://linux-nfs.org/~bfields/linux: (53 commits)
  svcrdma: fix an incorrect check on -E2BIG and -EINVAL
  nfsd4: factor ctime into change attribute
  svcrdma: Remove svc_rdma_chunk_ctxt::cc_dir field
  svcrdma: use offset_in_page() macro
  svcrdma: Clean up after converting svc_rdma_recvfrom to rdma_rw API
  svcrdma: Clean-up svc_rdma_unmap_dma
  svcrdma: Remove frmr cache
  svcrdma: Remove unused Read completion handlers
  svcrdma: Properly compute .len and .buflen for received RPC Calls
  svcrdma: Use generic RDMA R/W API in RPC Call path
  svcrdma: Add recvfrom helpers to svc_rdma_rw.c
  sunrpc: Allocate up to RPCSVC_MAXPAGES per svc_rqst
  svcrdma: Don't account for Receive queue "starvation"
  svcrdma: Improve Reply chunk sanity checking
  svcrdma: Improve Write chunk sanity checking
  svcrdma: Improve Read chunk sanity checking
  svcrdma: Remove svc_rdma_marshal.c
  svcrdma: Avoid Send Queue overflow
  svcrdma: Squelch disconnection messages
  sunrpc: Disable splice for krb5i
  ...
2017-07-13 13:56:24 -07:00
Ingo Molnar
5dd43ce2f6 sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>
The wait_bit*() types and APIs are mixed into wait.h, but they
are a pretty orthogonal extension of wait-queues.

Furthermore, only about 50 kernel files use these APIs, while
over 1000 use the regular wait-queue functionality.

So clean up the main wait.h by moving the wait-bit functionality
out of it, into a separate .h and .c file:

  include/linux/wait_bit.h  for types and APIs
  kernel/sched/wait_bit.c   for the implementation

Update all header dependencies.

This reduces the size of wait.h rather significantly, by about 30%.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20 12:19:09 +02:00
Christoph Hellwig
499b498810 sunrpc: mark all struct rpc_procinfo instances as const
struct rpc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-15 17:42:20 +02:00
Chuck Lever
3435c74aed SUNRPC: Generalize the RPC buffer release API
xprtrdma needs to allocate the Call and Reply buffers separately.
TBH, the reliance on using a single buffer for the pair of XDR
buffers is transport implementation-specific.

Instead of passing just the rq_buffer into the buf_free method, pass
the task structure and let buf_free take care of freeing both
XDR buffers at once.

There's a micro-optimization here. In the common case, both
xprt_release and the transport's buf_free method were checking if
rq_buffer was NULL. Now the check is done only once per RPC.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19 13:08:37 -04:00
Chuck Lever
5fe6eaa1f9 SUNRPC: Generalize the RPC buffer allocation API
xprtrdma needs to allocate the Call and Reply buffers separately.
TBH, the reliance on using a single buffer for the pair of XDR
buffers is transport implementation-specific.

Transports that want to allocate separate Call and Reply buffers
will ignore the "size" argument anyway.  Don't bother passing it.

The buf_alloc method can't return two pointers. Instead, make the
method's return value an error code, and set the rq_buffer pointer
in the method itself.

This gives call_allocate an opportunity to terminate an RPC instead
of looping forever when a permanent problem occurs. If a request is
just bogus, or the transport is in a state where it can't allocate
resources for any request, there needs to be a way to kill the RPC
right there and not loop.

This immediately fixes a rare problem in the backchannel send path,
which loops if the server happens to send a CB request whose
call+reply size is larger than a page (which it shouldn't do yet).

One more issue: looks like xprt_inject_disconnect was incorrectly
placed in the failure path in call_allocate. It needs to be in the
success path, as it is for other call-sites.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-09-19 13:08:37 -04:00
Trond Myklebust
f1dc237c60 SUNRPC: Reduce latency when send queue is congested
Use the low latency transport workqueue to process the task that is
next in line on the xprt->sending queue.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-06-13 12:35:51 -04:00
Trond Myklebust
40a5f1b19b SUNRPC: RPC transport queue must be low latency
rpciod can easily get congested due to the long list of queued rpc_tasks.
Having the receive queue wait in turn for those tasks to complete can
therefore be a bottleneck.

Address the problem by separating the workqueues into:
- rpciod: manages rpc_tasks
- xprtiod: manages transport related work.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-06-13 12:35:51 -04:00
Trond Myklebust
9d61498d5f SUNRPC: Allow caller to specify the transport to use
This is needed in order to allow the NFSv4.1 backchannel and
BIND_CONN_TO_SESSION function to work.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-02-05 18:48:55 -05:00
Trond Myklebust
fb43d17210 SUNRPC: Use the multipath iterator to assign a transport to each task
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-02-05 18:48:55 -05:00
Trond Myklebust
5edd1051f4 SUNRPC: Reorder rpc_task to put waitqueue related info in same cachelines
Try to group all the data required by the waitqueues, their timers and timer
callbacks into the same cachelines for performance. With this reordering,
"pahole" reports the following structure on x86_64:

struct rpc_task {
        atomic_t                   tk_count;             /*     0     4 */
        int                        tk_status;            /*     4     4 */
        struct list_head           tk_task;              /*     8    16 */
        void                       (*tk_callback)(struct rpc_task *); /*    24
        void                       (*tk_action)(struct rpc_task *); /*    32
        long unsigned int          tk_timeout;           /*    40     8 */
        long unsigned int          tk_runstate;          /*    48     8 */
        struct rpc_wait_queue *    tk_waitqueue;         /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        union {
                struct work_struct tk_work;              /*          64 */
                struct rpc_wait    tk_wait;              /*          56 */
        } u;                                             /*    64    64 */
        /* --- cacheline 2 boundary (128 bytes) --- */
        struct rpc_message         tk_msg;               /*   128    32 */
        void *                     tk_calldata;          /*   160     8 */
        const struct rpc_call_ops  * tk_ops;             /*   168     8 */
        struct rpc_clnt *          tk_client;            /*   176     8 */
        struct rpc_rqst *          tk_rqstp;             /*   184     8 */
        /* --- cacheline 3 boundary (192 bytes) --- */
        struct workqueue_struct *  tk_workqueue;         /*   192     8 */
        ktime_t                    tk_start;             /*   200     8 */
        pid_t                      tk_owner;             /*   208     4 */
        short unsigned int         tk_flags;             /*   212     2 */
        short unsigned int         tk_timeouts;          /*   214     2 */
        short unsigned int         tk_pid;               /*   216     2 */
        unsigned char              tk_priority:2;        /*   218: 6  1 */
        unsigned char              tk_garb_retry:2;      /*   218: 4  1 */
        unsigned char              tk_cred_retry:2;      /*   218: 2  1 */
        unsigned char              tk_rebind_retry:2;    /*   218: 0  1 */

        /* size: 224, cachelines: 4, members: 24 */
        /* padding: 5 */
        /* last cacheline: 32 bytes */
};

whereas on i386, it reports everything fitting into the 1st cacheline.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-01-31 21:37:22 -05:00
Jeff Layton
3c87ef6efb sunrpc: keep a count of swapfiles associated with the rpc_clnt
Jerome reported seeing a warning pop when working with a swapfile on
NFS. The nfs_swap_activate can end up calling sk_set_memalloc while
holding the rcu_read_lock and that function can sleep.

To fix that, we need to take a reference to the xprt while holding the
rcu_read_lock, set the socket up for swapping and then drop that
reference. But, xprt_put is not exported and having NFS deal with the
underlying xprt is a bit of layering violation anyway.

Fix this by adding a set of activate/deactivate functions that take a
rpc_clnt pointer instead of an rpc_xprt, and have nfs_swap_activate and
nfs_swap_deactivate call those.

Also, add a per-rpc_clnt atomic counter to keep track of the number of
active swapfiles associated with it. When the counter does a 0->1
transition, we enable swapping on the xprt, when we do a 1->0 transition
we disable swapping on it.

This also allows us to be a bit more selective with the RPC_TASK_SWAPPER
flag. If non-swapper and swapper clnts are sharing a xprt, then we only
need to flag the tasks from the swapper clnt with that flag.

Acked-by: Mel Gorman <mgorman@suse.de>
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-10 18:26:14 -04:00
Trond Myklebust
0f41979164 SUNRPC: Remove unused argument 'tk_ops' in rpc_run_bc_task
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-05 11:15:42 -04:00
Jeff Layton
1306729b0d sunrpc: eliminate RPC_TRACEPOINTS
It's always set to the same value as CONFIG_TRACEPOINTS, so we can just
use that instead.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-11-24 17:33:12 -05:00