/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95
*/
/*
* Reference: Chet Juszczak, "Improving the Performance and Correctness
* of an NFS Server", in Proc. Winter 1989 USENIX Conference,
* pages 53-63. San Diego, February 1989.
*/
/*
* Look for the request in the cache
* If found then
* return action and optionally reply
* else
* insert it in the cache
*
* The rules are as follows:
* - if in progress, return DROP request
* - if completed within DELAY of the current time, return DROP it
* - if completed a longer time ago return REPLY if the reply was cached or
* return DOIT
* Update/add new request at end of lru list
*/
int
nfsrv_getcache(struct nfsrv_descript *nd, struct nfssvc_sock *slp, struct mbuf **repp)
{
struct nfsrvcache *rp, *rpdup;
struct mbuf *mb;
struct sockaddr_in *saddr;
char *bpos;
int ret;
mutex_enter(&nfsrv_reqcache_lock);
rp = nfsrv_lookupcache(nd);
if (rp) {
mutex_exit(&nfsrv_reqcache_lock);
found:
/* If not at end of LRU chain, move it there */
if (TAILQ_NEXT(rp, rc_lru)) { /* racy but ok */
mutex_enter(&nfsrv_reqcache_lock);
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
mutex_exit(&nfsrv_reqcache_lock);
}
if (rp->rc_state == RC_UNUSED)
panic("nfsrv cache");
if (rp->rc_state == RC_INPROG) {
nfsstats.srvcache_inproghits++;
ret = RC_DROPIT;
} else if (rp->rc_flags & RC_REPSTATUS) {
nfsstats.srvcache_nonidemdonehits++;
nfs_rephead(0, nd, slp, rp->rc_status,
0, (u_quad_t *)0, repp, &mb, &bpos);
ret = RC_REPLY;
} else if (rp->rc_flags & RC_REPMBUF) {
nfsstats.srvcache_nonidemdonehits++;
*repp = m_copym(rp->rc_reply, 0, M_COPYALL,
M_WAIT);
ret = RC_REPLY;
} else {
nfsstats.srvcache_idemdonehits++;
rp->rc_state = RC_INPROG;
ret = RC_DOIT;
}
mutex_enter(&nfsrv_reqcache_lock);
nfsrv_unlockcache(rp);
mutex_exit(&nfsrv_reqcache_lock);
return ret;
}
nfsstats.srvcache_misses++;
if (numnfsrvcache < desirednfsrvcache) {
numnfsrvcache++;
mutex_exit(&nfsrv_reqcache_lock);
rp = pool_get(&nfs_reqcache_pool, PR_WAITOK);
memset(rp, 0, sizeof *rp);
cv_init(&rp->rc_cv, "nfsdrc");
rp->rc_gflags = RC_G_LOCKED;
} else {
rp = TAILQ_FIRST(&nfsrvlruhead);
while ((rp->rc_gflags & RC_G_LOCKED) != 0) {
cv_wait(&rp->rc_cv, &nfsrv_reqcache_lock);
rp = TAILQ_FIRST(&nfsrvlruhead);
}
rp->rc_gflags |= RC_G_LOCKED;
LIST_REMOVE(rp, rc_hash);
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
mutex_exit(&nfsrv_reqcache_lock);
cleanentry(rp);
rp->rc_flags = 0;
}
rp->rc_state = RC_INPROG;
rp->rc_xid = nd->nd_retxid;
saddr = mtod(nd->nd_nam, struct sockaddr_in *);
switch (saddr->sin_family) {
case AF_INET:
rp->rc_flags |= RC_INETADDR;
rp->rc_inetaddr = saddr->sin_addr.s_addr;
break;
default:
rp->rc_flags |= RC_NAM;
rp->rc_nam = m_copym(nd->nd_nam, 0, M_COPYALL, M_WAIT);
m_claimm(rp->rc_nam, &nfsd_cache_mowner);
break;
};
rp->rc_proc = nd->nd_procnum;
mutex_enter(&nfsrv_reqcache_lock);
rpdup = nfsrv_lookupcache(nd);
if (rpdup != NULL) {
/*
* other thread made duplicate cache entry.
*/
KASSERT(numnfsrvcache > 0);
numnfsrvcache--;
mutex_exit(&nfsrv_reqcache_lock);
cleanentry(rp);
cv_destroy(&rp->rc_cv);
pool_put(&nfs_reqcache_pool, rp);
rp = rpdup;
goto found;
}
TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
nfsrv_unlockcache(rp);
mutex_exit(&nfsrv_reqcache_lock);
return RC_DOIT;
}
/*
* Update a request cache entry after the rpc has been done
*/
void
nfsrv_updatecache(struct nfsrv_descript *nd, int repvalid, struct mbuf *repmbuf)
{
struct nfsrvcache *rp;
mutex_enter(&nfsrv_reqcache_lock);
rp = nfsrv_lookupcache(nd);
mutex_exit(&nfsrv_reqcache_lock);
if (rp) {
cleanentry(rp);
rp->rc_state = RC_DONE;
/*
* If we have a valid reply update status and save
* the reply for non-idempotent rpc's.
*/
if (repvalid && nonidempotent[nd->nd_procnum]) {
if ((nd->nd_flag & ND_NFSV3) == 0 &&
nfsv2_repstat[nfsv2_procid[nd->nd_procnum]]) {
rp->rc_status = nd->nd_repstat;
rp->rc_flags |= RC_REPSTATUS;
} else {
rp->rc_reply = m_copym(repmbuf,
0, M_COPYALL, M_WAIT);
m_claimm(rp->rc_reply, &nfsd_cache_mowner);
rp->rc_flags |= RC_REPMBUF;
}
}
mutex_enter(&nfsrv_reqcache_lock);
nfsrv_unlockcache(rp);
mutex_exit(&nfsrv_reqcache_lock);
}
}
/*
* Clean out the cache. Called when the last nfsd terminates.
*/
void
nfsrv_cleancache(void)
{
struct nfsrvcache *rp;
