SUNRPC: Make freeing of struct xprt rcu-safe
[linux-2.6-block.git] / include / linux / sunrpc / xprt.h
CommitLineData
1da177e4 1/*
55aa4f58 2 * linux/include/linux/sunrpc/xprt.h
1da177e4
LT
3 *
4 * Declarations for the RPC transport interface.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 */
8
9#ifndef _LINUX_SUNRPC_XPRT_H
10#define _LINUX_SUNRPC_XPRT_H
11
12#include <linux/uio.h>
13#include <linux/socket.h>
14#include <linux/in.h>
ff839970 15#include <linux/ktime.h>
30c5116b 16#include <linux/kref.h>
1da177e4
LT
17#include <linux/sunrpc/sched.h>
18#include <linux/sunrpc/xdr.h>
7adae489 19#include <linux/sunrpc/msg_prot.h>
1da177e4 20
96802a09
FM
21#ifdef __KERNEL__
22
1da177e4
LT
23#define RPC_MIN_SLOT_TABLE (2U)
24#define RPC_DEF_SLOT_TABLE (16U)
d9ba131d 25#define RPC_MAX_SLOT_TABLE_LIMIT (65536U)
88338124 26#define RPC_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE_LIMIT
1da177e4 27
4f4cf5ad
CL
28#define RPC_CWNDSHIFT (8U)
29#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
30#define RPC_INITCWND RPC_CWNDSCALE
31#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
32#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
33
1da177e4
LT
34/*
35 * This describes a timeout strategy
36 */
37struct rpc_timeout {
38 unsigned long to_initval, /* initial timeout */
39 to_maxval, /* max timeout */
40 to_increment; /* if !exponential */
41 unsigned int to_retries; /* max # of retries */
42 unsigned char to_exponential;
43};
44
edb267a6
CL
45enum rpc_display_format_t {
46 RPC_DISPLAY_ADDR = 0,
47 RPC_DISPLAY_PORT,
48 RPC_DISPLAY_PROTO,
fbfe3cc6
CL
49 RPC_DISPLAY_HEX_ADDR,
50 RPC_DISPLAY_HEX_PORT,
4417c8c4 51 RPC_DISPLAY_NETID,
edb267a6
CL
52 RPC_DISPLAY_MAX,
53};
54
529b33c6
CL
55struct rpc_task;
56struct rpc_xprt;
e99170ff 57struct seq_file;
76566773
CL
58struct svc_serv;
59struct net;
529b33c6 60
1da177e4
LT
61/*
62 * This describes a complete RPC request
63 */
64struct rpc_rqst {
65 /*
66 * This is the user-visible part
67 */
68 struct rpc_xprt * rq_xprt; /* RPC client */
69 struct xdr_buf rq_snd_buf; /* send buffer */
70 struct xdr_buf rq_rcv_buf; /* recv buffer */
71
72 /*
73 * This is the private part
74 */
75 struct rpc_task * rq_task; /* RPC task data */
a17c2153 76 struct rpc_cred * rq_cred; /* Bound cred */
d8ed029d 77 __be32 rq_xid; /* request XID */
1da177e4 78 int rq_cong; /* has incremented xprt->cong */
1da177e4 79 u32 rq_seqno; /* gss seq no. used on req. */
ead5e1c2
BF
80 int rq_enc_pages_num;
81 struct page **rq_enc_pages; /* scratch pages for use by
82 gss privacy code */
83 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
1da177e4
LT
84 struct list_head rq_list;
85
02107148 86 __u32 * rq_buffer; /* XDR encode buffer */
c977a2ef 87 size_t rq_callsize,
2bea90d4 88 rq_rcvsize;
d60dbb20
TM
89 size_t rq_xmit_bytes_sent; /* total bytes sent */
90 size_t rq_reply_bytes_recvd; /* total reply bytes */
91 /* received */
02107148 92
1da177e4
LT
93 struct xdr_buf rq_private_buf; /* The receive buffer
94 * used in the softirq.
95 */
96 unsigned long rq_majortimeo; /* major timeout alarm */
97 unsigned long rq_timeout; /* Current timeout value */
d60dbb20 98 ktime_t rq_rtt; /* round-trip time */
1da177e4 99 unsigned int rq_retries; /* # of retries */
7c1d71cf
TM
100 unsigned int rq_connect_cookie;
101 /* A cookie used to track the
102 state of the transport
103 connection */
1da177e4
LT
104
105 /*
106 * Partial send handling
107 */
1da177e4
LT
108 u32 rq_bytes_sent; /* Bytes we have sent */
109
ff839970 110 ktime_t rq_xtime; /* transmit time stamp */
1da177e4 111 int rq_ntrans;
56632b5b 112
9e00abc3 113#if defined(CONFIG_SUNRPC_BACKCHANNEL)
56632b5b
RL
114 struct list_head rq_bc_list; /* Callback service list */
115 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
116 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
9e00abc3 117#endif /* CONFIG_SUNRPC_BACKCHANEL */
1da177e4
LT
118};
119#define rq_svec rq_snd_buf.head
120#define rq_slen rq_snd_buf.len
121
a246b010 122struct rpc_xprt_ops {
470056c2 123 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
43cedbf0 124 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
49e9a890 125 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
f39c1bfb 126 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
bbf7c1dd 127 void (*rpcbind)(struct rpc_task *task);
92200412 128 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
1b092092 129 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
02107148 130 void * (*buf_alloc)(struct rpc_task *task, size_t size);
c5a4dd8b 131 void (*buf_free)(void *buffer);
a246b010 132 int (*send_request)(struct rpc_task *task);
fe3aca29 133 void (*set_retrans_timeout)(struct rpc_task *task);
6a24dfb6 134 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
a58dd398 135 void (*release_request)(struct rpc_task *task);
a246b010
CL
136 void (*close)(struct rpc_xprt *xprt);
137 void (*destroy)(struct rpc_xprt *xprt);
262ca07d 138 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
d67fa4d8
JL
139 int (*enable_swap)(struct rpc_xprt *xprt);
140 void (*disable_swap)(struct rpc_xprt *xprt);
4a068258 141 void (*inject_disconnect)(struct rpc_xprt *xprt);
42e5c3e2
CL
142 int (*bc_setup)(struct rpc_xprt *xprt,
143 unsigned int min_reqs);
76566773 144 int (*bc_up)(struct svc_serv *serv, struct net *net);
42e5c3e2
CL
145 void (*bc_free_rqst)(struct rpc_rqst *rqst);
146 void (*bc_destroy)(struct rpc_xprt *xprt,
147 unsigned int max_reqs);
a246b010 148};
1da177e4 149
f300baba
AB
150/*
151 * RPC transport identifiers
152 *
153 * To preserve compatibility with the historical use of raw IP protocol
154 * id's for transport selection, UDP and TCP identifiers are specified
155 * with the previous values. No such restriction exists for new transports,
156 * except that they may not collide with these values (17 and 6,
157 * respectively).
158 */
159#define XPRT_TRANSPORT_BC (1 << 31)
160enum xprt_transports {
161 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
162 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
163 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
176e21ee 164 XPRT_TRANSPORT_RDMA = 256,
94684319 165 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
176e21ee 166 XPRT_TRANSPORT_LOCAL = 257,
f300baba
AB
167};
168
1da177e4 169struct rpc_xprt {
30c5116b 170 struct kref kref; /* Reference count */
a246b010 171 struct rpc_xprt_ops * ops; /* transport methods */
1da177e4 172
ba7392bb 173 const struct rpc_timeout *timeout; /* timeout parms */
c4efcb1d
CL
174 struct sockaddr_storage addr; /* server address */
175 size_t addrlen; /* size of server address */
1da177e4
LT
176 int prot; /* IP protocol */
177
178 unsigned long cong; /* current congestion */
179 unsigned long cwnd; /* congestion window */
180
1da177e4
LT
181 size_t max_payload; /* largest RPC payload size,
182 in bytes */
808012fb
CL
183 unsigned int tsh_size; /* size of transport specific
184 header */
1da177e4 185
4a68179d 186 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
1da177e4 187 struct rpc_wait_queue sending; /* requests waiting to send */
1da177e4
LT
188 struct rpc_wait_queue pending; /* requests in flight */
189 struct rpc_wait_queue backlog; /* waiting for slot */
190 struct list_head free; /* free slots */
d9ba131d
TM
191 unsigned int max_reqs; /* max number of slots */
192 unsigned int min_reqs; /* min number of slots */
193 atomic_t num_reqs; /* total slots */
2226feb6 194 unsigned long state; /* transport state */
d19751e7 195 unsigned char resvport : 1; /* use a reserved port */
8e228133 196 atomic_t swapper; /* we're swapping over this
a564b8f0 197 transport */
a509050b 198 unsigned int bind_index; /* bind function index */
1da177e4 199
1da177e4 200 /*
55aa4f58 201 * Connection of transports
1da177e4 202 */
a8ce4a8f 203 unsigned long bind_timeout,
03bf4b70 204 reestablish_timeout;
7c1d71cf
TM
205 unsigned int connect_cookie; /* A cookie that gets bumped
206 every time the transport
207 is reconnected */
03bf4b70 208
1da177e4 209 /*
55aa4f58 210 * Disconnection of idle transports
1da177e4
LT
211 */
212 struct work_struct task_cleanup;
213 struct timer_list timer;
03bf4b70
CL
214 unsigned long last_used,
215 idle_timeout;
1da177e4
LT
216
217 /*
218 * Send stuff
219 */
4a0f8c04 220 spinlock_t transport_lock; /* lock transport info */
5dc07727 221 spinlock_t reserve_lock; /* lock slot table */
e744cf2e 222 u32 xid; /* Next XID value to use */
1da177e4 223 struct rpc_task * snd_task; /* Task blocked in send */
4cfc7e60 224 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
9e00abc3 225#if defined(CONFIG_SUNRPC_BACKCHANNEL)
56632b5b
RL
226 struct svc_serv *bc_serv; /* The RPC service which will */
227 /* process the callback */
0d2a970d
TM
228 int bc_alloc_count; /* Total number of preallocs */
229 atomic_t bc_free_slots;
56632b5b
RL
230 spinlock_t bc_pa_lock; /* Protects the preallocated
231 * items */
232 struct list_head bc_pa_list; /* List of preallocated
233 * backchannel rpc_rqst's */
9e00abc3 234#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1da177e4
LT
235 struct list_head recv;
236
262ca07d
CL
237 struct {
238 unsigned long bind_count, /* total number of binds */
239 connect_count, /* total number of connects */
240 connect_start, /* connect start timestamp */
241 connect_time, /* jiffies waiting for connect */
242 sends, /* how many complete requests */
243 recvs, /* how many complete requests */
15a45206
AA
244 bad_xids, /* lookup_rqst didn't find XID */
245 max_slots; /* max rpc_slots used */
262ca07d
CL
246
247 unsigned long long req_u, /* average requests on the wire */
15a45206
AA
248 bklog_u, /* backlog queue utilization */
249 sending_u, /* send q utilization */
250 pending_u; /* pend q utilization */
262ca07d 251 } stat;
1da177e4 252
37aa2133 253 struct net *xprt_net;
4e0038b6 254 const char *servername;
b454ae90 255 const char *address_strings[RPC_DISPLAY_MAX];
388f0c77
JL
256#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
257 struct dentry *debugfs; /* debugfs directory */
4a068258 258 atomic_t inject_disconnect;
388f0c77 259#endif
fda1bfef 260 struct rcu_head rcu;
1da177e4
LT
261};
262
9e00abc3 263#if defined(CONFIG_SUNRPC_BACKCHANNEL)
56632b5b
RL
264/*
265 * Backchannel flags
266 */
267#define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
268 /* buffer in use */
9e00abc3 269#endif /* CONFIG_SUNRPC_BACKCHANNEL */
56632b5b 270
9e00abc3 271#if defined(CONFIG_SUNRPC_BACKCHANNEL)
55ae1aab
RL
272static inline int bc_prealloc(struct rpc_rqst *req)
273{
274 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
275}
276#else
277static inline int bc_prealloc(struct rpc_rqst *req)
278{
279 return 0;
280}
9e00abc3 281#endif /* CONFIG_SUNRPC_BACKCHANNEL */
55ae1aab 282
b7993ceb 283#define XPRT_CREATE_INFINITE_SLOTS (1U)
33d90ac0 284#define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
b7993ceb 285
3c341b0b 286struct xprt_create {
4fa016eb 287 int ident; /* XPRT_TRANSPORT identifier */
9a23e332 288 struct net * net;
d3bc9a1d 289 struct sockaddr * srcaddr; /* optional local address */
96802a09
FM
290 struct sockaddr * dstaddr; /* remote peer address */
291 size_t addrlen;
4e0038b6 292 const char *servername;
f300baba 293 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
b7993ceb 294 unsigned int flags;
96802a09 295};
1da177e4 296
81c098af
TT
297struct xprt_class {
298 struct list_head list;
4fa016eb 299 int ident; /* XPRT_TRANSPORT identifier */
3c341b0b 300 struct rpc_xprt * (*setup)(struct xprt_create *);
81c098af
TT
301 struct module *owner;
302 char name[32];
303};
304
55aa4f58
CL
305/*
306 * Generic internal transport functions
307 */
3c341b0b 308struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
55aa4f58
CL
309void xprt_connect(struct rpc_task *task);
310void xprt_reserve(struct rpc_task *task);
ba60eb25 311void xprt_retry_reserve(struct rpc_task *task);
43cedbf0
TM
312int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
313int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
f39c1bfb
TM
314void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
315void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
90051ea7 316bool xprt_prepare_transmit(struct rpc_task *task);
55aa4f58 317void xprt_transmit(struct rpc_task *task);
e0ab53de 318void xprt_end_transmit(struct rpc_task *task);
1da177e4 319int xprt_adjust_timeout(struct rpc_rqst *req);
49e9a890
CL
320void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
321void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
55aa4f58 322void xprt_release(struct rpc_task *task);
30c5116b 323struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
6b6ca86b 324void xprt_put(struct rpc_xprt *xprt);
d9ba131d
TM
325struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
326 unsigned int num_prealloc,
327 unsigned int max_req);
e204e621 328void xprt_free(struct rpc_xprt *);
55aa4f58 329
d8ed029d 330static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
808012fb
CL
331{
332 return p + xprt->tsh_size;
333}
334
d67fa4d8
JL
335static inline int
336xprt_enable_swap(struct rpc_xprt *xprt)
337{
338 return xprt->ops->enable_swap(xprt);
339}
340
341static inline void
342xprt_disable_swap(struct rpc_xprt *xprt)
343{
344 xprt->ops->disable_swap(xprt);
345}
346
55aa4f58
CL
347/*
348 * Transport switch helper functions
349 */
81c098af
TT
350int xprt_register_transport(struct xprt_class *type);
351int xprt_unregister_transport(struct xprt_class *type);
441e3e24 352int xprt_load_transport(const char *);
fe3aca29
CL
353void xprt_set_retrans_timeout_def(struct rpc_task *task);
354void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
55aa4f58 355void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
b6ddf64f 356void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
c7b2cae8 357void xprt_write_space(struct rpc_xprt *xprt);
6a24dfb6 358void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
d8ed029d 359struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
1570c1e4 360void xprt_complete_rqst(struct rpc_task *task, int copied);
a58dd398 361void xprt_release_rqst_cong(struct rpc_task *task);
62da3b24 362void xprt_disconnect_done(struct rpc_xprt *xprt);
66af1e55 363void xprt_force_disconnect(struct rpc_xprt *xprt);
7c1d71cf 364void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
55aa4f58 365
718ba5b8
TM
366bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
367void xprt_unlock_connect(struct rpc_xprt *, void *);
368
2226feb6
CL
369/*
370 * Reserved bit positions in xprt->state
371 */
372#define XPRT_LOCKED (0)
373#define XPRT_CONNECTED (1)
374#define XPRT_CONNECTING (2)
632e3bdc 375#define XPRT_CLOSE_WAIT (3)
ec739ef0 376#define XPRT_BOUND (4)
4a68179d 377#define XPRT_BINDING (5)
3b948ae5 378#define XPRT_CLOSING (6)
ba60eb25 379#define XPRT_CONGESTED (9)
2226feb6
CL
380
381static inline void xprt_set_connected(struct rpc_xprt *xprt)
382{
383 set_bit(XPRT_CONNECTED, &xprt->state);
384}
385
386static inline void xprt_clear_connected(struct rpc_xprt *xprt)
387{
388 clear_bit(XPRT_CONNECTED, &xprt->state);
389}
390
391static inline int xprt_connected(struct rpc_xprt *xprt)
392{
393 return test_bit(XPRT_CONNECTED, &xprt->state);
394}
395
396static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
397{
398 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
399}
400
401static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
402{
403 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
404}
405
406static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
407{
4e857c58 408 smp_mb__before_atomic();
2226feb6 409 clear_bit(XPRT_CONNECTING, &xprt->state);
4e857c58 410 smp_mb__after_atomic();
2226feb6
CL
411}
412
413static inline int xprt_connecting(struct rpc_xprt *xprt)
414{
415 return test_bit(XPRT_CONNECTING, &xprt->state);
416}
417
418static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
419{
420 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
421}
1da177e4 422
ec739ef0
CL
423static inline void xprt_set_bound(struct rpc_xprt *xprt)
424{
425 test_and_set_bit(XPRT_BOUND, &xprt->state);
426}
427
428static inline int xprt_bound(struct rpc_xprt *xprt)
429{
430 return test_bit(XPRT_BOUND, &xprt->state);
431}
432
433static inline void xprt_clear_bound(struct rpc_xprt *xprt)
434{
435 clear_bit(XPRT_BOUND, &xprt->state);
436}
437
4a68179d
CL
438static inline void xprt_clear_binding(struct rpc_xprt *xprt)
439{
4e857c58 440 smp_mb__before_atomic();
4a68179d 441 clear_bit(XPRT_BINDING, &xprt->state);
4e857c58 442 smp_mb__after_atomic();
4a68179d
CL
443}
444
445static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
446{
447 return test_and_set_bit(XPRT_BINDING, &xprt->state);
448}
449
4a068258
CL
450#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
451extern unsigned int rpc_inject_disconnect;
452static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
453{
454 if (!rpc_inject_disconnect)
455 return;
456 if (atomic_dec_return(&xprt->inject_disconnect))
457 return;
458 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
459 xprt->ops->inject_disconnect(xprt);
460}
461#else
462static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
463{
464}
465#endif
466
1da177e4
LT
467#endif /* __KERNEL__*/
468
469#endif /* _LINUX_SUNRPC_XPRT_H */