xprt.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/include/linux/sunrpc/xprt.h
*
* Declarations for the RPC transport interface.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _LINUX_SUNRPC_XPRT_H
#define _LINUX_SUNRPC_XPRT_H
#include <linux/uio.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/ktime.h>
#include <linux/kref.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/msg_prot.h>
#define RPC_MIN_SLOT_TABLE (2U)
#define RPC_DEF_SLOT_TABLE (16U)
#define RPC_MAX_SLOT_TABLE_LIMIT (65536U)
#define RPC_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE_LIMIT
#define RPC_CWNDSHIFT (8U)
#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
#define RPC_INITCWND RPC_CWNDSCALE
#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
/*
* This describes a timeout strategy
*/
struct rpc_timeout {
unsigned long to_initval, /* initial timeout */
to_maxval, /* max timeout */
to_increment; /* if !exponential */
unsigned int to_retries; /* max # of retries */
unsigned char to_exponential;
};
enum rpc_display_format_t {
RPC_DISPLAY_ADDR = 0,
RPC_DISPLAY_PORT,
RPC_DISPLAY_PROTO,
RPC_DISPLAY_HEX_ADDR,
RPC_DISPLAY_HEX_PORT,
RPC_DISPLAY_NETID,
RPC_DISPLAY_MAX,
};
struct rpc_task;
struct rpc_xprt;
struct xprt_class;
struct seq_file;
struct svc_serv;
struct net;
/*
* This describes a complete RPC request
*/
struct rpc_rqst {
/*
* This is the user-visible part
*/
struct rpc_xprt * rq_xprt; /* RPC client */
struct xdr_buf rq_snd_buf; /* send buffer */
struct xdr_buf rq_rcv_buf; /* recv buffer */
/*
* This is the private part
*/
struct rpc_task * rq_task; /* RPC task data */
struct rpc_cred * rq_cred; /* Bound cred */
__be32 rq_xid; /* request XID */
int rq_cong; /* has incremented xprt->cong */
u32 rq_seqno; /* gss seq no. used on req. */
int rq_enc_pages_num;
struct page **rq_enc_pages; /* scratch pages for use by
gss privacy code */
void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
union {
struct list_head rq_list; /* Slot allocation list */
struct rb_node rq_recv; /* Receive queue */
};
struct list_head rq_xmit; /* Send queue */
struct list_head rq_xmit2; /* Send queue */
void *rq_buffer; /* Call XDR encode buffer */
size_t rq_callsize;
void *rq_rbuffer; /* Reply XDR decode buffer */
size_t rq_rcvsize;
size_t rq_xmit_bytes_sent; /* total bytes sent */
size_t rq_reply_bytes_recvd; /* total reply bytes */
/* received */
struct xdr_buf rq_private_buf; /* The receive buffer
* used in the softirq.
*/
unsigned long rq_majortimeo; /* major timeout alarm */
unsigned long rq_minortimeo; /* minor timeout alarm */
unsigned long rq_timeout; /* Current timeout value */
ktime_t rq_rtt; /* round-trip time */
unsigned int rq_retries; /* # of retries */
unsigned int rq_connect_cookie;
/* A cookie used to track the
state of the transport
connection */
atomic_t rq_pin;
/*
* Partial send handling
*/
u32 rq_bytes_sent; /* Bytes we have sent */
ktime_t rq_xtime; /* transmit time stamp */
int rq_ntrans;
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
struct list_head rq_bc_list; /* Callback service list */
unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
#endif /* CONFIG_SUNRPC_BACKCHANEL */
};
#define rq_svec rq_snd_buf.head
#define rq_slen rq_snd_buf.len
struct rpc_xprt_ops {
void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
void (*free_slot)(struct rpc_xprt *xprt,
struct rpc_rqst *req);
void (*rpcbind)(struct rpc_task *task);
void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
int (*get_srcaddr)(struct rpc_xprt *xprt, char *buf,
size_t buflen);
unsigned short (*get_srcport)(struct rpc_xprt *xprt);
int (*buf_alloc)(struct rpc_task *task);
void (*buf_free)(struct rpc_task *task);
int (*prepare_request)(struct rpc_rqst *req,
struct xdr_buf *buf);
int (*send_request)(struct rpc_rqst *req);
void (*wait_for_reply_request)(struct rpc_task *task);
void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
void (*release_request)(struct rpc_task *task);
void (*close)(struct rpc_xprt *xprt);
void (*destroy)(struct rpc_xprt *xprt);
void (*set_connect_timeout)(struct rpc_xprt *xprt,
unsigned long connect_timeout,
unsigned long reconnect_timeout);
void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
int (*enable_swap)(struct rpc_xprt *xprt);
void (*disable_swap)(struct rpc_xprt *xprt);
void (*inject_disconnect)(struct rpc_xprt *xprt);
int (*bc_setup)(struct rpc_xprt *xprt,
unsigned int min_reqs);
size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
unsigned int (*bc_num_slots)(struct rpc_xprt *xprt);
void (*bc_free_rqst)(struct rpc_rqst *rqst);
void (*bc_destroy)(struct rpc_xprt *xprt,
unsigned int max_reqs);
};
/*
* RPC transport identifiers
*
* To preserve compatibility with the historical use of raw IP protocol
* id's for transport selection, UDP and TCP identifiers are specified
* with the previous values. No such restriction exists for new transports,
* except that they may not collide with these values (17 and 6,
* respectively).
*/
#define XPRT_TRANSPORT_BC (1 << 31)
enum xprt_transports {
XPRT_TRANSPORT_UDP = IPPROTO_UDP,
XPRT_TRANSPORT_TCP = IPPROTO_TCP,
XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
XPRT_TRANSPORT_RDMA = 256,
XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
XPRT_TRANSPORT_LOCAL = 257,
};
struct rpc_sysfs_xprt;
struct rpc_xprt {
struct kref kref; /* Reference count */
const struct rpc_xprt_ops *ops; /* transport methods */
unsigned int id; /* transport id */
const struct rpc_timeout *timeout; /* timeout parms */
struct sockaddr_storage addr; /* server address */
size_t addrlen; /* size of server address */
int prot; /* IP protocol */
unsigned long cong; /* current congestion */
unsigned long cwnd; /* congestion window */
size_t max_payload; /* largest RPC payload size,
in bytes */
struct rpc_wait_queue binding; /* requests waiting on rpcbind */
struct rpc_wait_queue sending; /* requests waiting to send */
struct rpc_wait_queue pending; /* requests in flight */
struct rpc_wait_queue backlog; /* waiting for slot */
struct list_head free; /* free slots */
unsigned int max_reqs; /* max number of slots */
unsigned int min_reqs; /* min number of slots */
unsigned int num_reqs; /* total slots */
unsigned long state; /* transport state */
unsigned char resvport : 1, /* use a reserved port */
reuseport : 1; /* reuse port on reconnect */
atomic_t swapper; /* we're swapping over this
transport */
unsigned int bind_index; /* bind function index */
/*
* Multipath
*/
struct list_head xprt_switch;
/*
* Connection of transports
*/
unsigned long bind_timeout,
reestablish_timeout;
unsigned int connect_cookie; /* A cookie that gets bumped
every time the transport
is reconnected */
/*
* Disconnection of idle transports
*/
struct work_struct task_cleanup;
struct timer_list timer;
unsigned long last_used,
idle_timeout,
connect_timeout,
max_reconnect_timeout;
/*
* Send stuff
*/
atomic_long_t queuelen;
spinlock_t transport_lock; /* lock transport info */
spinlock_t reserve_lock; /* lock slot table */
spinlock_t queue_lock; /* send/receive queue lock */
u32 xid; /* Next XID value to use */
struct rpc_task * snd_task; /* Task blocked in send */
struct list_head xmit_queue; /* Send queue */
atomic_long_t xmit_queuelen;
struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
struct svc_serv *bc_serv; /* The RPC service which will */
/* process the callback */
unsigned int bc_alloc_max;
unsigned int bc_alloc_count; /* Total number of preallocs */
atomic_t bc_slot_count; /* Number of allocated slots */
spinlock_t bc_pa_lock; /* Protects the preallocated
* items */
struct list_head bc_pa_list; /* List of preallocated
* backchannel rpc_rqst's */
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
struct rb_root recv_queue; /* Receive queue */
struct {
unsigned long bind_count, /* total number of binds */
connect_count, /* total number of connects */
connect_start, /* connect start timestamp */
connect_time, /* jiffies waiting for connect */
sends, /* how many complete requests */
recvs, /* how many complete requests */
bad_xids, /* lookup_rqst didn't find XID */
max_slots; /* max rpc_slots used */
unsigned long long req_u, /* average requests on the wire */
bklog_u, /* backlog queue utilization */
sending_u, /* send q utilization */
pending_u; /* pend q utilization */
} stat;
struct net *xprt_net;
netns_tracker ns_tracker;
const char *servername;
const char *address_strings[RPC_DISPLAY_MAX];
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
struct dentry *debugfs; /* debugfs directory */
#endif
struct rcu_head rcu;
const struct xprt_class *xprt_class;
struct rpc_sysfs_xprt *xprt_sysfs;
bool main; /*mark if this is the 1st transport */
};
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
/*
* Backchannel flags
*/
#define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
/* buffer in use */
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
static inline int bc_prealloc(struct rpc_rqst *req)
{
return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
}
#else
static inline int bc_prealloc(struct rpc_rqst *req)
{
return 0;
}
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
#define XPRT_CREATE_INFINITE_SLOTS (1U)
#define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
struct xprt_create {
int ident; /* XPRT_TRANSPORT identifier */
struct net * net;
struct sockaddr * srcaddr; /* optional local address */
struct sockaddr * dstaddr; /* remote peer address */
size_t addrlen;
const char *servername;
struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
struct rpc_xprt_switch *bc_xps;
unsigned int flags;
};
struct xprt_class {
struct list_head list;
int ident; /* XPRT_TRANSPORT identifier */
struct rpc_xprt * (*setup)(struct xprt_create *);
struct module *owner;
char name[32];
const char * netid[];
};
/*
* Generic internal transport functions
*/
struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
void xprt_connect(struct rpc_task *task);
unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
void xprt_reconnect_backoff(struct rpc_xprt *xprt,
unsigned long init_to);
void xprt_reserve(struct rpc_task *task);
void xprt_retry_reserve(struct rpc_task *task);
int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_free_slot(struct rpc_xprt *xprt,
struct rpc_rqst *req);
bool xprt_prepare_transmit(struct rpc_task *task);
void xprt_request_enqueue_transmit(struct rpc_task *task);
int xprt_request_enqueue_receive(struct rpc_task *task);
void xprt_request_wait_receive(struct rpc_task *task);
void xprt_request_dequeue_xprt(struct rpc_task *task);
bool xprt_request_need_retransmit(struct rpc_task *task);
void xprt_transmit(struct rpc_task *task);
void xprt_end_transmit(struct rpc_task *task);
int xprt_adjust_timeout(struct rpc_rqst *req);
void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_release(struct rpc_task *task);
struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
void xprt_put(struct rpc_xprt *xprt);
struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
unsigned int num_prealloc,
unsigned int max_req);
void xprt_free(struct rpc_xprt *);
void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task);
bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
void xprt_cleanup_ids(void);
static inline int
xprt_enable_swap(struct rpc_xprt *xprt)
{
return xprt->ops->enable_swap(xprt);
}
static inline void
xprt_disable_swap(struct rpc_xprt *xprt)
{
xprt->ops->disable_swap(xprt);
}
/*
* Transport switch helper functions
*/
int xprt_register_transport(struct xprt_class *type);
int xprt_unregister_transport(struct xprt_class *type);
int xprt_find_transport_ident(const char *);
void xprt_wait_for_reply_request_def(struct rpc_task *task);
void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
bool xprt_write_space(struct rpc_xprt *xprt);
void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
void xprt_update_rtt(struct rpc_task *task);
void xprt_complete_rqst(struct rpc_task *task, int copied);
void xprt_pin_rqst(struct rpc_rqst *req);
void xprt_unpin_rqst(struct rpc_rqst *req);
void xprt_release_rqst_cong(struct rpc_task *task);
bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
void xprt_disconnect_done(struct rpc_xprt *xprt);
void xprt_force_disconnect(struct rpc_xprt *xprt);
void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
void xprt_unlock_connect(struct rpc_xprt *, void *);
void xprt_release_write(struct rpc_xprt *, struct rpc_task *);
/*
* Reserved bit positions in xprt->state
*/
#define XPRT_LOCKED (0)
#define XPRT_CONNECTED (1)
#define XPRT_CONNECTING (2)
#define XPRT_CLOSE_WAIT (3)
#define XPRT_BOUND (4)
#define XPRT_BINDING (5)
#define XPRT_CLOSING (6)
#define XPRT_OFFLINE (7)
#define XPRT_REMOVE (8)
#define XPRT_CONGESTED (9)
#define XPRT_CWND_WAIT (10)
#define XPRT_WRITE_SPACE (11)
#define XPRT_SND_IS_COOKIE (12)
static inline void xprt_set_connected(struct rpc_xprt *xprt)
{
set_bit(XPRT_CONNECTED, &xprt->state);
}
static inline void xprt_clear_connected(struct rpc_xprt *xprt)
{
clear_bit(XPRT_CONNECTED, &xprt->state);
}
static inline int xprt_connected(struct rpc_xprt *xprt)
{
return test_bit(XPRT_CONNECTED, &xprt->state);
}
static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
{
return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
}
static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
{
return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
}
static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
{
smp_mb__before_atomic();
clear_bit(XPRT_CONNECTING, &xprt->state);
smp_mb__after_atomic();
}
static inline int xprt_connecting(struct rpc_xprt *xprt)
{
return test_bit(XPRT_CONNECTING, &xprt->state);
}
static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
{
return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
}
static inline void xprt_set_bound(struct rpc_xprt *xprt)
{
test_and_set_bit(XPRT_BOUND, &xprt->state);
}
static inline int xprt_bound(struct rpc_xprt *xprt)
{
return test_bit(XPRT_BOUND, &xprt->state);
}
static inline void xprt_clear_bound(struct rpc_xprt *xprt)
{
clear_bit(XPRT_BOUND, &xprt->state);
}
static inline void xprt_clear_binding(struct rpc_xprt *xprt)
{
smp_mb__before_atomic();
clear_bit(XPRT_BINDING, &xprt->state);
smp_mb__after_atomic();
}
static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
{
return test_and_set_bit(XPRT_BINDING, &xprt->state);
}
void xprt_set_offline_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
void xprt_set_online_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
void xprt_delete_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
#endif /* _LINUX_SUNRPC_XPRT_H */