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736c6625de
Use an rbtree to ensure the lookup/insert of an entry in a DRC bucket is O(log(N)). Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
87 lines
1.8 KiB
C
87 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Request reply cache. This was heavily inspired by the
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* implementation in 4.3BSD/4.4BSD.
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*
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* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
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*/
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#ifndef NFSCACHE_H
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#define NFSCACHE_H
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#include <linux/sunrpc/svc.h>
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/*
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* Representation of a reply cache entry.
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*
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* Note that we use a sockaddr_in6 to hold the address instead of the more
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* typical sockaddr_storage. This is for space reasons, since sockaddr_storage
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* is much larger than a sockaddr_in6.
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*/
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struct svc_cacherep {
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struct {
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/* Keep often-read xid, csum in the same cache line: */
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__be32 k_xid;
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__wsum k_csum;
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u32 k_proc;
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u32 k_prot;
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u32 k_vers;
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unsigned int k_len;
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struct sockaddr_in6 k_addr;
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} c_key;
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struct rb_node c_node;
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struct list_head c_lru;
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unsigned char c_state, /* unused, inprog, done */
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c_type, /* status, buffer */
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c_secure : 1; /* req came from port < 1024 */
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unsigned long c_timestamp;
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union {
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struct kvec u_vec;
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__be32 u_status;
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} c_u;
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};
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#define c_replvec c_u.u_vec
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#define c_replstat c_u.u_status
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/* cache entry states */
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enum {
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RC_UNUSED,
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RC_INPROG,
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RC_DONE
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};
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/* return values */
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enum {
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RC_DROPIT,
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RC_REPLY,
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RC_DOIT
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};
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/*
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* Cache types.
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* We may want to add more types one day, e.g. for diropres and
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* attrstat replies. Using cache entries with fixed length instead
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* of buffer pointers may be more efficient.
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*/
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enum {
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RC_NOCACHE,
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RC_REPLSTAT,
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RC_REPLBUFF,
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};
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/* Cache entries expire after this time period */
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#define RC_EXPIRE (120 * HZ)
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/* Checksum this amount of the request */
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#define RC_CSUMLEN (256U)
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int nfsd_reply_cache_init(void);
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void nfsd_reply_cache_shutdown(void);
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int nfsd_cache_lookup(struct svc_rqst *);
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void nfsd_cache_update(struct svc_rqst *, int, __be32 *);
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int nfsd_reply_cache_stats_open(struct inode *, struct file *);
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#endif /* NFSCACHE_H */
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