xref: /OK3568_Linux_fs/kernel/fs/nfsd/cache.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Request reply cache. This was heavily inspired by the
4*4882a593Smuzhiyun  * implementation in 4.3BSD/4.4BSD.
5*4882a593Smuzhiyun  *
6*4882a593Smuzhiyun  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun #ifndef NFSCACHE_H
10*4882a593Smuzhiyun #define NFSCACHE_H
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include <linux/sunrpc/svc.h>
13*4882a593Smuzhiyun #include "netns.h"
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun /*
16*4882a593Smuzhiyun  * Representation of a reply cache entry.
17*4882a593Smuzhiyun  *
18*4882a593Smuzhiyun  * Note that we use a sockaddr_in6 to hold the address instead of the more
19*4882a593Smuzhiyun  * typical sockaddr_storage. This is for space reasons, since sockaddr_storage
20*4882a593Smuzhiyun  * is much larger than a sockaddr_in6.
21*4882a593Smuzhiyun  */
22*4882a593Smuzhiyun struct svc_cacherep {
23*4882a593Smuzhiyun 	struct {
24*4882a593Smuzhiyun 		/* Keep often-read xid, csum in the same cache line: */
25*4882a593Smuzhiyun 		__be32			k_xid;
26*4882a593Smuzhiyun 		__wsum			k_csum;
27*4882a593Smuzhiyun 		u32			k_proc;
28*4882a593Smuzhiyun 		u32			k_prot;
29*4882a593Smuzhiyun 		u32			k_vers;
30*4882a593Smuzhiyun 		unsigned int		k_len;
31*4882a593Smuzhiyun 		struct sockaddr_in6	k_addr;
32*4882a593Smuzhiyun 	} c_key;
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun 	struct rb_node		c_node;
35*4882a593Smuzhiyun 	struct list_head	c_lru;
36*4882a593Smuzhiyun 	unsigned char		c_state,	/* unused, inprog, done */
37*4882a593Smuzhiyun 				c_type,		/* status, buffer */
38*4882a593Smuzhiyun 				c_secure : 1;	/* req came from port < 1024 */
39*4882a593Smuzhiyun 	unsigned long		c_timestamp;
40*4882a593Smuzhiyun 	union {
41*4882a593Smuzhiyun 		struct kvec	u_vec;
42*4882a593Smuzhiyun 		__be32		u_status;
43*4882a593Smuzhiyun 	}			c_u;
44*4882a593Smuzhiyun };
45*4882a593Smuzhiyun 
46*4882a593Smuzhiyun #define c_replvec		c_u.u_vec
47*4882a593Smuzhiyun #define c_replstat		c_u.u_status
48*4882a593Smuzhiyun 
49*4882a593Smuzhiyun /* cache entry states */
50*4882a593Smuzhiyun enum {
51*4882a593Smuzhiyun 	RC_UNUSED,
52*4882a593Smuzhiyun 	RC_INPROG,
53*4882a593Smuzhiyun 	RC_DONE
54*4882a593Smuzhiyun };
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun /* return values */
57*4882a593Smuzhiyun enum {
58*4882a593Smuzhiyun 	RC_DROPIT,
59*4882a593Smuzhiyun 	RC_REPLY,
60*4882a593Smuzhiyun 	RC_DOIT
61*4882a593Smuzhiyun };
62*4882a593Smuzhiyun 
63*4882a593Smuzhiyun /*
64*4882a593Smuzhiyun  * Cache types.
65*4882a593Smuzhiyun  * We may want to add more types one day, e.g. for diropres and
66*4882a593Smuzhiyun  * attrstat replies. Using cache entries with fixed length instead
67*4882a593Smuzhiyun  * of buffer pointers may be more efficient.
68*4882a593Smuzhiyun  */
69*4882a593Smuzhiyun enum {
70*4882a593Smuzhiyun 	RC_NOCACHE,
71*4882a593Smuzhiyun 	RC_REPLSTAT,
72*4882a593Smuzhiyun 	RC_REPLBUFF,
73*4882a593Smuzhiyun };
74*4882a593Smuzhiyun 
75*4882a593Smuzhiyun /* Cache entries expire after this time period */
76*4882a593Smuzhiyun #define RC_EXPIRE		(120 * HZ)
77*4882a593Smuzhiyun 
78*4882a593Smuzhiyun /* Checksum this amount of the request */
79*4882a593Smuzhiyun #define RC_CSUMLEN		(256U)
80*4882a593Smuzhiyun 
81*4882a593Smuzhiyun int	nfsd_drc_slab_create(void);
82*4882a593Smuzhiyun void	nfsd_drc_slab_free(void);
83*4882a593Smuzhiyun int	nfsd_reply_cache_init(struct nfsd_net *);
84*4882a593Smuzhiyun void	nfsd_reply_cache_shutdown(struct nfsd_net *);
85*4882a593Smuzhiyun int	nfsd_cache_lookup(struct svc_rqst *);
86*4882a593Smuzhiyun void	nfsd_cache_update(struct svc_rqst *, int, __be32 *);
87*4882a593Smuzhiyun int	nfsd_reply_cache_stats_open(struct inode *, struct file *);
88*4882a593Smuzhiyun 
89*4882a593Smuzhiyun #endif /* NFSCACHE_H */
90