android_kernel_xiaomi_sm8350/include/linux/sunrpc/sched.h
Ricardo Labiaga 55ae1aabfb nfs41: Add backchannel processing support to RPC state machine
Adds rpc_run_bc_task() which is called by the NFS callback service to
process backchannel requests.  It performs similar work to rpc_run_task()
though "schedules" the backchannel task to be executed starting at the
call_trasmit state in the RPC state machine.

It also introduces some miscellaneous updates to the argument validation,
call_transmit, and transport cleanup functions to take into account
that there are now forechannel and backchannel tasks.

Backchannel requests do not carry an RPC message structure, since the
payload has already been XDR encoded using the existing NFSv4 callback
mechanism.

Introduce a new transmit state for the client to reply on to backchannel
requests.  This new state simply reserves the transport and issues the
reply.  In case of a connection related error, disconnects the transport and
drops the reply.  It requires the forechannel to re-establish the connection
and the server to retransmit the request, as stated in NFSv4.1 section
2.9.2 "Client and Server Transport Behavior".

Note: There is no need to loop attempting to reserve the transport.  If EAGAIN
is returned by xprt_prepare_transmit(), return with tk_status == 0,
setting tk_action to call_bc_transmit.  rpc_execute() will invoke it again
after the task is taken off the sleep queue.

[nfs41: rpc_run_bc_task() need not be exported outside RPC module]
[nfs41: New call_bc_transmit RPC state]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: Backchannel: No need to loop in call_bc_transmit()]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[rpc_count_iostats incorrectly exits early]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[Convert rpc_reply_expected() to inline function]
[Remove unnecessary BUG_ON()]
[Rename variable]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-06-17 14:11:24 -07:00

263 lines
7.9 KiB
C

/*
* 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/sunrpc/types.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/xdr.h>
/*
* This is the actual RPC procedure call info.
*/
struct rpc_procinfo;
struct rpc_message {
struct rpc_procinfo * rpc_proc; /* Procedure information */
void * rpc_argp; /* Arguments */
void * rpc_resp; /* Result */
struct rpc_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 */
unsigned long expires;
};
/*
* This is the RPC task struct
*/
struct rpc_task {
#ifdef RPC_DEBUG
unsigned long tk_magic; /* 0xf00baa */
#endif
atomic_t tk_count; /* Reference count */
struct list_head tk_task; /* global list of tasks */
struct rpc_clnt * tk_client; /* RPC client */
struct rpc_rqst * tk_rqstp; /* RPC request */
int tk_status; /* result of last operation */
/*
* RPC call state
*/
struct rpc_message tk_msg; /* RPC call info */
__u8 tk_garb_retry;
__u8 tk_cred_retry;
/*
* callback to be executed after waking up
* action next procedure for async tasks
* tk_ops caller callbacks
*/
void (*tk_callback)(struct rpc_task *);
void (*tk_action)(struct rpc_task *);
const struct rpc_call_ops *tk_ops;
void * tk_calldata;
unsigned long tk_timeout; /* timeout for rpc_sleep() */
unsigned short tk_flags; /* misc flags */
unsigned long tk_runstate; /* Task run status */
struct workqueue_struct *tk_workqueue; /* Normally rpciod, but could
* be any workqueue
*/
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;
unsigned short tk_timeouts; /* maj timeouts */
size_t tk_bytes_sent; /* total bytes sent */
unsigned long tk_start; /* RPC task init timestamp */
long tk_rtt; /* round-trip time (jiffies) */
pid_t tk_owner; /* Process id for batching tasks */
unsigned char tk_priority : 2;/* Task priority */
#ifdef RPC_DEBUG
unsigned short tk_pid; /* debugging aid */
#endif
};
#define tk_xprt tk_client->cl_xprt
/* support walking a list of tasks on a wait queue */
#define task_for_each(task, pos, head) \
list_for_each(pos, head) \
if ((task=list_entry(pos, struct rpc_task, u.tk_wait.list)),1)
#define task_for_first(task, head) \
if (!list_empty(head) && \
((task=list_entry((head)->next, struct rpc_task, u.tk_wait.list)),1))
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_release)(void *);
};
struct rpc_task_setup {
struct rpc_task *task;
struct rpc_clnt *rpc_client;
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_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_KILLED 0x0100 /* task was killed */
#define RPC_TASK_SOFT 0x0200 /* Use soft timeouts */
#define RPC_IS_ASYNC(t) ((t)->tk_flags & RPC_TASK_ASYNC)
#define RPC_IS_SWAPPER(t) ((t)->tk_flags & RPC_TASK_SWAPPER)
#define RPC_DO_ROOTOVERRIDE(t) ((t)->tk_flags & RPC_TASK_ROOTCREDS)
#define RPC_ASSASSINATED(t) ((t)->tk_flags & RPC_TASK_KILLED)
#define RPC_IS_SOFT(t) ((t)->tk_flags & RPC_TASK_SOFT)
#define RPC_TASK_RUNNING 0
#define RPC_TASK_QUEUED 1
#define RPC_TASK_ACTIVE 2
#define RPC_IS_RUNNING(t) test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_set_running(t) set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_test_and_set_running(t) \
test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
#define rpc_clear_running(t) \
do { \
smp_mb__before_clear_bit(); \
clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate); \
smp_mb__after_clear_bit(); \
} while (0)
#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) \
do { \
smp_mb__before_clear_bit(); \
clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate); \
smp_mb__after_clear_bit(); \
} while (0)
#define RPC_IS_ACTIVATED(t) test_bit(RPC_TASK_ACTIVE, &(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_NR_PRIORITY (1 + RPC_PRIORITY_HIGH - RPC_PRIORITY_LOW)
struct rpc_timer {
struct timer_list timer;
struct list_head list;
unsigned long expires;
};
/*
* RPC synchronization objects
*/
struct rpc_wait_queue {
spinlock_t lock;
struct list_head tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
pid_t owner; /* process id of last task serviced */
unsigned char maxpriority; /* maximum priority (0 if queue is not a priority queue) */
unsigned char priority; /* current priority */
unsigned char count; /* # task groups remaining serviced so far */
unsigned char nr; /* # tasks remaining for cookie */
unsigned short qlen; /* total # tasks waiting in queue */
struct rpc_timer timer_list;
#ifdef RPC_DEBUG
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_BATCH_COUNT 16
#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,
const struct rpc_call_ops *ops);
void rpc_put_task(struct rpc_task *);
void rpc_exit_task(struct rpc_task *);
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 *);
void rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
rpc_action action);
void rpc_wake_up_queued_task(struct rpc_wait_queue *,
struct rpc_task *);
void rpc_wake_up(struct rpc_wait_queue *);
struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
void rpc_wake_up_status(struct rpc_wait_queue *, int);
void rpc_delay(struct rpc_task *, unsigned long);
void * rpc_malloc(struct rpc_task *, size_t);
void rpc_free(void *);
int rpciod_up(void);
void rpciod_down(void);
int __rpc_wait_for_completion_task(struct rpc_task *task, int (*)(void *));
#ifdef RPC_DEBUG
void rpc_show_tasks(void);
#endif
int rpc_init_mempool(void);
void rpc_destroy_mempool(void);
extern struct workqueue_struct *rpciod_workqueue;
void rpc_prepare_task(struct rpc_task *task);
static inline void rpc_exit(struct rpc_task *task, int status)
{
task->tk_status = status;
task->tk_action = rpc_exit_task;
}
static inline int rpc_wait_for_completion_task(struct rpc_task *task)
{
return __rpc_wait_for_completion_task(task, NULL);
}
#ifdef RPC_DEBUG
static inline const char * rpc_qname(struct rpc_wait_queue *q)
{
return ((q && q->name) ? q->name : "unknown");
}
#endif
#endif /* _LINUX_SUNRPC_SCHED_H_ */