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kernel/include/linux/sunrpc/sched.h
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

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/include/linux/sunrpc/sched.h
*
* Scheduling primitives for kernel Sun RPC.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _LINUX_SUNRPC_SCHED_H_
#define _LINUX_SUNRPC_SCHED_H_
#include <linux/timer.h>
#include <linux/ktime.h>
#include <linux/sunrpc/types.h>
#include <linux/spinlock.h>
#include <linux/wait_bit.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/xdr.h>
/*
* This is the actual RPC procedure call info.
*/
struct rpc_procinfo;
struct rpc_message {
const struct rpc_procinfo *rpc_proc; /* Procedure information */
void * rpc_argp; /* Arguments */
void * rpc_resp; /* Result */
const struct cred * rpc_cred; /* Credentials */
};
struct rpc_call_ops;
struct rpc_wait_queue;
struct rpc_wait {
struct list_head list; /* wait queue links */
struct list_head links; /* Links to related tasks */
struct list_head timer_list; /* Timer list */
};
/*
* This is the RPC task struct
*/
struct rpc_task {
atomic_t tk_count; /* Reference count */
int tk_status; /* result of last operation */
struct list_head tk_task; /* global list of tasks */
/*
* callback to be executed after waking up
* action next procedure for async tasks
*/
void (*tk_callback)(struct rpc_task *);
void (*tk_action)(struct rpc_task *);
unsigned long tk_timeout; /* timeout for rpc_sleep() */
unsigned long tk_runstate; /* Task run status */
struct rpc_wait_queue *tk_waitqueue; /* RPC wait queue we're on */
union {
struct work_struct tk_work; /* Async task work queue */
struct rpc_wait tk_wait; /* RPC wait */
} u;
int tk_rpc_status; /* Result of last RPC operation */
/*
* RPC call state
*/
struct rpc_message tk_msg; /* RPC call info */
void * tk_calldata; /* Caller private data */
const struct rpc_call_ops *tk_ops; /* Caller callbacks */
struct rpc_clnt * tk_client; /* RPC client */
struct rpc_xprt * tk_xprt; /* Transport */
struct rpc_cred * tk_op_cred; /* cred being operated on */
struct rpc_rqst * tk_rqstp; /* RPC request */
struct workqueue_struct *tk_workqueue; /* Normally rpciod, but could
* be any workqueue
*/
ktime_t tk_start; /* RPC task init timestamp */
pid_t tk_owner; /* Process id for batching tasks */
unsigned short tk_flags; /* misc flags */
unsigned short tk_timeouts; /* maj timeouts */
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
unsigned short tk_pid; /* debugging aid */
#endif
unsigned char tk_priority : 2,/* Task priority */
tk_garb_retry : 2,
tk_cred_retry : 2,
tk_rebind_retry : 2;
};
typedef void (*rpc_action)(struct rpc_task *);
struct rpc_call_ops {
void (*rpc_call_prepare)(struct rpc_task *, void *);
void (*rpc_call_done)(struct rpc_task *, void *);
void (*rpc_count_stats)(struct rpc_task *, void *);
void (*rpc_release)(void *);
};
struct rpc_task_setup {
struct rpc_task *task;
struct rpc_clnt *rpc_client;
struct rpc_xprt *rpc_xprt;
struct rpc_cred *rpc_op_cred; /* credential being operated on */
const struct rpc_message *rpc_message;
const struct rpc_call_ops *callback_ops;
void *callback_data;
struct workqueue_struct *workqueue;
unsigned short flags;
signed char priority;
};
/*
* RPC task flags
*/
#define RPC_TASK_ASYNC 0x0001 /* is an async task */
#define RPC_TASK_SWAPPER 0x0002 /* is swapping in/out */
#define RPC_TASK_MOVEABLE 0x0004 /* nfs4.1+ rpc tasks */
#define RPC_TASK_NULLCREDS 0x0010 /* Use AUTH_NULL credential */
#define RPC_CALL_MAJORSEEN 0x0020 /* major timeout seen */
#define RPC_TASK_ROOTCREDS 0x0040 /* force root creds */
#define RPC_TASK_DYNAMIC 0x0080 /* task was kmalloc'ed */
#define RPC_TASK_NO_ROUND_ROBIN 0x0100 /* send requests on "main" xprt */
#define RPC_TASK_SOFT 0x0200 /* Use soft timeouts */
#define RPC_TASK_SOFTCONN 0x0400 /* Fail if can't connect */
#define RPC_TASK_SENT 0x0800 /* message was sent */
#define RPC_TASK_TIMEOUT 0x1000 /* fail with ETIMEDOUT on timeout */
#define RPC_TASK_NOCONNECT 0x2000 /* return ENOTCONN if not connected */
#define RPC_TASK_NO_RETRANS_TIMEOUT 0x4000 /* wait forever for a reply */
#define RPC_TASK_CRED_NOREF 0x8000 /* No refcount on the credential */
#define RPC_IS_ASYNC(t) ((t)->tk_flags & RPC_TASK_ASYNC)
#define RPC_IS_SWAPPER(t) ((t)->tk_flags & RPC_TASK_SWAPPER)
#define RPC_IS_SOFT(t) ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
#define RPC_IS_SOFTCONN(t) ((t)->tk_flags & RPC_TASK_SOFTCONN)
#define RPC_WAS_SENT(t) ((t)->tk_flags & RPC_TASK_SENT)
#define RPC_IS_MOVEABLE(t) ((t)->tk_flags & RPC_TASK_MOVEABLE)
#define RPC_TASK_RUNNING 0
#define RPC_TASK_QUEUED 1
#define RPC_TASK_ACTIVE 2
#define RPC_TASK_NEED_XMIT 3
#define RPC_TASK_NEED_RECV 4
#define RPC_TASK_MSG_PIN_WAIT 5
#define RPC_TASK_SIGNALLED 6
#define rpc_test_and_set_running(t) \
test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_clear_running(t) clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define RPC_IS_QUEUED(t) test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
#define rpc_set_queued(t) set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
#define rpc_clear_queued(t) clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
#define RPC_IS_ACTIVATED(t) test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
#define RPC_SIGNALLED(t) test_bit(RPC_TASK_SIGNALLED, &(t)->tk_runstate)
/*
* Task priorities.
* Note: if you change these, you must also change
* the task initialization definitions below.
*/
#define RPC_PRIORITY_LOW (-1)
#define RPC_PRIORITY_NORMAL (0)
#define RPC_PRIORITY_HIGH (1)
#define RPC_PRIORITY_PRIVILEGED (2)
#define RPC_NR_PRIORITY (1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
struct rpc_timer {
struct list_head list;
unsigned long expires;
struct delayed_work dwork;
};
/*
* RPC synchronization objects
*/
struct rpc_wait_queue {
spinlock_t lock;
struct list_head tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
unsigned char maxpriority; /* maximum priority (0 if queue is not a priority queue) */
unsigned char priority; /* current priority */
unsigned char nr; /* # tasks remaining for cookie */
unsigned short qlen; /* total # tasks waiting in queue */
struct rpc_timer timer_list;
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
const char * name;
#endif
};
/*
* This is the # requests to send consecutively
* from a single cookie. The aim is to improve
* performance of NFS operations such as read/write.
*/
#define RPC_IS_PRIORITY(q) ((q)->maxpriority > 0)
/*
* Function prototypes
*/
struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
void rpc_put_task(struct rpc_task *);
void rpc_put_task_async(struct rpc_task *);
void rpc_signal_task(struct rpc_task *);
void rpc_exit_task(struct rpc_task *);
void rpc_exit(struct rpc_task *, int);
void rpc_release_calldata(const struct rpc_call_ops *, void *);
void rpc_killall_tasks(struct rpc_clnt *);
void rpc_execute(struct rpc_task *);
void rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
void rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
void rpc_destroy_wait_queue(struct rpc_wait_queue *);
unsigned long rpc_task_timeout(const struct rpc_task *task);
void rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
struct rpc_task *task,
rpc_action action,
unsigned long timeout);
void rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
rpc_action action);
void rpc_sleep_on_priority_timeout(struct rpc_wait_queue *queue,
struct rpc_task *task,
unsigned long timeout,
int priority);
void rpc_sleep_on_priority(struct rpc_wait_queue *,
struct rpc_task *,
int priority);
void rpc_wake_up_queued_task(struct rpc_wait_queue *,
struct rpc_task *);
void rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
struct rpc_task *,
int);
void rpc_wake_up(struct rpc_wait_queue *);
struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
struct rpc_wait_queue *,
bool (*)(struct rpc_task *, void *),
void *);
struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
bool (*)(struct rpc_task *, void *),
void *);
void rpc_wake_up_status(struct rpc_wait_queue *, int);
void rpc_delay(struct rpc_task *, unsigned long);
int rpc_malloc(struct rpc_task *);
void rpc_free(struct rpc_task *);
int rpciod_up(void);
void rpciod_down(void);
int __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *);
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
struct net;
void rpc_show_tasks(struct net *);
#endif
int rpc_init_mempool(void);
void rpc_destroy_mempool(void);
extern struct workqueue_struct *rpciod_workqueue;
extern struct workqueue_struct *xprtiod_workqueue;
void rpc_prepare_task(struct rpc_task *task);
static inline int rpc_wait_for_completion_task(struct rpc_task *task)
{
return __rpc_wait_for_completion_task(task, NULL);
}
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
static inline const char * rpc_qname(const struct rpc_wait_queue *q)
{
return ((q && q->name) ? q->name : "unknown");
}
static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
const char *name)
{
q->name = name;
}
#else
static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
const char *name)
{
}
#endif
#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
#else
static inline int
rpc_clnt_swap_activate(struct rpc_clnt *clnt)
{
return -EINVAL;
}
static inline void
rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
{
}
#endif /* CONFIG_SUNRPC_SWAP */
#endif /* _LINUX_SUNRPC_SCHED_H_ */
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