linux/fs/nfsd/cache.h
J. Bruce Fields 3ba75830ce nfsd4: drc containerization
The nfsd duplicate reply cache should not be shared between network
namespaces.

The most straightforward way to fix this is just to move every global in
the code to per-net-namespace memory, so that's what we do.

Still todo: sort out which members of nfsd_stats should be global and
which per-net-namespace.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-07-03 17:52:08 -04:00

88 lines
1.9 KiB
C

/* 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>
#include "netns.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 {
/* Keep often-read xid, csum in the same cache line: */
__be32 k_xid;
__wsum k_csum;
u32 k_proc;
u32 k_prot;
u32 k_vers;
unsigned int k_len;
struct sockaddr_in6 k_addr;
} c_key;
struct rb_node c_node;
struct list_head c_lru;
unsigned char c_state, /* unused, inprog, done */
c_type, /* status, buffer */
c_secure : 1; /* req came from port < 1024 */
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,
};
/* 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(struct nfsd_net *);
void nfsd_reply_cache_shutdown(struct nfsd_net *);
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 */