NFS: Treat ENETUNREACH errors as fatal in containers

Propagate the NFS_MOUNT_NETUNREACH_FATAL flag to work with the generic
NFS client. If the flag is set, the client will receive ENETDOWN and
ENETU

NFS: Treat ENETUNREACH errors as fatal in containers

Propagate the NFS_MOUNT_NETUNREACH_FATAL flag to work with the generic
NFS client. If the flag is set, the client will receive ENETDOWN and
ENETUNREACH errors from the RPC layer, and is expected to treat them as
being fatal.

Signed-off-by: Trond Myklebust <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Tested-by: Jeff Layton <[email protected]>
Acked-by: Chuck Lever <[email protected]>

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SUNRPC: Prevent looping due to rpc_signal_task() races

If rpc_signal_task() is called while a task is in an rpc_call_done()
callback function, and the latter calls rpc_restart_call(), the task can
e

SUNRPC: Prevent looping due to rpc_signal_task() races

If rpc_signal_task() is called while a task is in an rpc_call_done()
callback function, and the latter calls rpc_restart_call(), the task can
end up looping due to the RPC_TASK_SIGNALLED flag being set without the
tk_rpc_status being set.
Removing the redundant mechanism for signalling the task fixes the
looping behaviour.

Reported-by: Li Lingfeng <[email protected]>
Fixes: 39494194f93b ("SUNRPC: Fix races with rpc_killall_tasks()")
Signed-off-by: Trond Myklebust <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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SUNRPC: convert RPC_TASK_* constants to enum

The RPC_TASK_* constants are defined as macros, which means that most
kernel builds will not contain their definitions in the debuginfo.
However, it's qu

SUNRPC: convert RPC_TASK_* constants to enum

The RPC_TASK_* constants are defined as macros, which means that most
kernel builds will not contain their definitions in the debuginfo.
However, it's quite useful for debuggers to be able to view the task
state constant and interpret it correctly. Conversion to an enum will
ensure the constants are present in debuginfo and can be interpreted by
debuggers without needing to hard-code them and track their changes.

Signed-off-by: Stephen Brennan <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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SUNRPC: increase size of rpc_wait_queue.qlen from unsigned short to unsigned int

When the NFS client is under extreme load the rpc_wait_queue.qlen counter
can be overflowed. Here is an instant of th

SUNRPC: increase size of rpc_wait_queue.qlen from unsigned short to unsigned int

When the NFS client is under extreme load the rpc_wait_queue.qlen counter
can be overflowed. Here is an instant of the backlog queue overflow in a
real world environment shown by drgn helper:

rpc_task_stats(rpc_clnt):
-------------------------
rpc_clnt: 0xffff92b65d2bae00
rpc_xprt: 0xffff9275db64f000
Queue: sending[64887] pending[524] backlog[30441] binding[0]
XMIT task: 0xffff925c6b1d8e98
WRITE: 750654
__dta_call_status_580: 65463
__dta_call_transmit_status_579: 1
call_reserveresult: 685189
nfs_client_init_is_complete: 1
COMMIT: 584
call_reserveresult: 573
__dta_call_status_580: 11
ACCESS: 1
__dta_call_status_580: 1
GETATTR: 10
__dta_call_status_580: 4
call_reserveresult: 6
751249 tasks for server 111.222.333.444
Total tasks: 751249

count_rpc_wait_queues(xprt):
----------------------------
**** rpc_xprt: 0xffff9275db64f000 num_reqs: 65511
wait_queue: xprt_binding[0] cnt: 0
wait_queue: xprt_binding[1] cnt: 0
wait_queue: xprt_binding[2] cnt: 0
wait_queue: xprt_binding[3] cnt: 0
rpc_wait_queue[xprt_binding].qlen: 0 maxpriority: 0
wait_queue: xprt_sending[0] cnt: 0
wait_queue: xprt_sending[1] cnt: 64887
wait_queue: xprt_sending[2] cnt: 0
wait_queue: xprt_sending[3] cnt: 0
rpc_wait_queue[xprt_sending].qlen: 64887 maxpriority: 3
wait_queue: xprt_pending[0] cnt: 524
wait_queue: xprt_pending[1] cnt: 0
wait_queue: xprt_pending[2] cnt: 0
wait_queue: xprt_pending[3] cnt: 0
rpc_wait_queue[xprt_pending].qlen: 524 maxpriority: 0
wait_queue: xprt_backlog[0] cnt: 0
wait_queue: xprt_backlog[1] cnt: 685801
wait_queue: xprt_backlog[2] cnt: 0
wait_queue: xprt_backlog[3] cnt: 0
rpc_wait_queue[xprt_backlog].qlen: 30441 maxpriority: 3 [task cnt mismatch]

There is no effect on operations when this overflow occurs. However
it causes confusion when trying to diagnose the performance problem.

Signed-off-by: Dai Ngo <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>

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NFSv4.1: Use the nfs_client's rpc timeouts for backchannel

For backchannel requests that lookup the appropriate nfs_client, use the
state-management rpc_clnt's rpc_timeout parameters for the backcha

NFSv4.1: Use the nfs_client's rpc timeouts for backchannel

For backchannel requests that lookup the appropriate nfs_client, use the
state-management rpc_clnt's rpc_timeout parameters for the backchannel's
response. When the nfs_client cannot be found, fall back to using the
xprt's default timeout parameters.

Signed-off-by: Benjamin Coddington <[email protected]>
Tested-by: Chuck Lever <[email protected]>
Tested-by: Jeff Layton <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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 unlo

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: 0b760113a3a1 ("NLM: Don't hang forever on NLM unlock requests")
Reported-by: Helen Chao <[email protected]>
Tested-by: Helen Chao <[email protected]>
Signed-off-by: Dai Ngo <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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

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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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: Tr

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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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
ensu

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) <[email protected]>
Reviewed-by: Ingo Molnar <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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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' outpu

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 <[email protected]>

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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 memp

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 <[email protected]>

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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

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 <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>

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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

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 <[email protected]>

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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+ op

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 <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>

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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 Mykleb

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 <[email protected]>

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Revert "NFSv4/flexfiles: Abort I/O early if the layout segment was invalidated"

This reverts commit a79f194aa4879e9baad118c3f8bb2ca24dbef765.
The mechanism for aborting I/O is racy, since we are not

Revert "NFSv4/flexfiles: Abort I/O early if the layout segment was invalidated"

This reverts commit a79f194aa4879e9baad118c3f8bb2ca24dbef765.
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 <[email protected]>
Cc: [email protected] # v5.1

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SUNRPC: Remove rpc_wake_up_queued_task_on_wq()

Clean up: commit c544577daddb ("SUNRPC: Clean up transport write
space handling") appears to have removed the last caller of
rpc_wake_up_queued_task_on

SUNRPC: Remove rpc_wake_up_queued_task_on_wq()

Clean up: commit c544577daddb ("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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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 singl

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 <[email protected]>
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>

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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

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 <[email protected]>

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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 r

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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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SUNRPC: Simplify queue timeouts using timer_reduce()

Simplify the setting of queue timeouts by using the timer_reduce()
function.

Signed-off-by: Trond Myklebust <[email protected]>
Si

SUNRPC: Simplify queue timeouts using timer_reduce()

Simplify the setting of queue timeouts by using the timer_reduce()
function.

Signed-off-by: Trond Myklebust <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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 <[email protected]

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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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 t

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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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@hammersp

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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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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.
Le

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 <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

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