linux-stable.git/include/linux/sunrpc/sched.h, branch v5.1.4

Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping"

2019-04-11T19:41:14+00:00

This reverts commit 009a82f6437490c262584d65a14094a818bcb747.

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 
Signed-off-by: Trond Myklebust

SUNRPC: Micro-optimise when the task is known not to be sleeping

2019-03-10T18:08:19+00:00

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

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

2019-03-01T21:20:16+00:00

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

NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

2018-12-19T18:52:46+00:00

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 
Acked-by: J. Bruce Fields 
Signed-off-by: Anna Schumaker

SUNRPC: add side channel to use non-generic cred for rpc call.

2018-12-19T18:52:45+00:00

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  for finding
a bug in earlier version of this patch.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

SUNRPC: introduce RPC_TASK_NULLCREDS to request auth_none

2018-12-19T18:52:45+00:00

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 
Signed-off-by: Anna Schumaker

SUNRPC: discard RPC_DO_ROOTOVERRIDE()

2018-12-19T18:52:45+00:00

it is never used.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker

SUNRPC: Fix priority queue fairness

2018-09-30T19:35:16+00:00

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

SUNRPC: Add a helper to wake up a sleeping rpc_task and set its status

2018-09-30T19:35:14+00:00

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

SUNRPC: Refactor the transport request pinning

2018-09-30T19:35:14+00:00

We are going to need to pin for both send and receive.

Signed-off-by: Trond Myklebust