linux-stable/fs/nfsd/cache.h
J. Bruce Fields 1091006c5e nfsd: turn on reply cache for NFSv4
It's sort of ridiculous that we've never had a working reply cache for
NFSv4.

On the other hand, we may still not: our current reply cache is likely
not very good, especially in the TCP case (which is the only case that
matters for v4).  What we really need here is some serious testing.

Anyway, here's a start.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-07-18 09:39:01 -04:00

83 lines
1.6 KiB
C

/*
* 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.
*/
struct svc_cacherep {
struct hlist_node c_hash;
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_in c_addr;
__be32 c_xid;
u32 c_prot;
u32 c_proc;
u32 c_vers;
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,
RC_INTR
};
/*
* 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)
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 *);
#ifdef CONFIG_NFSD_V4
void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp);
#else /* CONFIG_NFSD_V4 */
static inline void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp)
{
}
#endif /* CONFIG_NFSD_V4 */
#endif /* NFSCACHE_H */