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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Request reply cache. This was heavily inspired by the
* implementation in 4.3BSD/4.4BSD.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef NFSCACHE_H
#define NFSCACHE_H
#include <linux/sunrpc/svc.h>
/*
* Representation of a reply cache entry.
*
* Note that we use a sockaddr_in6 to hold the address instead of the more
* typical sockaddr_storage. This is for space reasons, since sockaddr_storage
* is much larger than a sockaddr_in6.
*/
struct svc_cacherep {
struct list_head c_lru;
unsigned char c_state, /* unused, inprog, done */
c_type, /* status, buffer */
c_secure : 1; /* req came from port < 1024 */
struct sockaddr_in6 c_addr;
__be32 c_xid;
u32 c_prot;
u32 c_proc;
u32 c_vers;
unsigned int c_len;
__wsum c_csum;
unsigned long c_timestamp;
union {
struct kvec u_vec;
__be32 u_status;
} c_u;
};
#define c_replvec c_u.u_vec
#define c_replstat c_u.u_status
/* cache entry states */
enum {
RC_UNUSED,
RC_INPROG,
RC_DONE
};
/* return values */
enum {
RC_DROPIT,
RC_REPLY,
RC_DOIT
};
/*
* Cache types.
* We may want to add more types one day, e.g. for diropres and
* attrstat replies. Using cache entries with fixed length instead
* of buffer pointers may be more efficient.
*/
enum {
RC_NOCACHE,
RC_REPLSTAT,
RC_REPLBUFF,
};
/*
* If requests are retransmitted within this interval, they're dropped.
*/
#define RC_DELAY (HZ/5)
/* Cache entries expire after this time period */
#define RC_EXPIRE (120 * HZ)
/* Checksum this amount of the request */
#define RC_CSUMLEN (256U)
int nfsd_reply_cache_init(void);
void nfsd_reply_cache_shutdown(void);
int nfsd_cache_lookup(struct svc_rqst *);
void nfsd_cache_update(struct svc_rqst *, int, __be32 *);
int nfsd_reply_cache_stats_open(struct inode *, struct file *);
#endif /* NFSCACHE_H */
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