NetBSD/sys/nfs/nfs_srvcache.c

398 lines
10 KiB
C

/* $NetBSD: nfs_srvcache.c,v 1.36 2007/02/05 11:55:45 yamt Exp $ */
/*
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nfs_srvcache.c,v 1.36 2007/02/05 11:55:45 yamt Exp $");
#include "opt_iso.h"
#include <sys/param.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/pool.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <netinet/in.h>
#ifdef ISO
#include <netiso/iso.h>
#endif
#include <nfs/nfsm_subs.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsrvcache.h>
#include <nfs/nfs_var.h>
extern struct nfsstats nfsstats;
extern const int nfsv2_procid[NFS_NPROCS];
long numnfsrvcache, desirednfsrvcache = NFSRVCACHESIZ;
struct pool nfs_reqcache_pool;
#define NFSRCHASH(xid) \
(&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash])
LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl;
TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead;
struct simplelock nfsrv_reqcache_lock = SIMPLELOCK_INITIALIZER;
u_long nfsrvhash;
#if defined(MBUFTRACE)
static struct mowner nfsd_cache_mowner = MOWNER_INIT("nfsd", "cache");
#endif /* defined(MBUFTRACE) */
#define NETFAMILY(rp) \
(((rp)->rc_flag & RC_INETADDR) ? AF_INET : AF_ISO)
static struct nfsrvcache *nfsrv_lookupcache(struct nfsrv_descript *nd);
static void nfsrv_unlockcache(struct nfsrvcache *rp);
/*
* Static array that defines which nfs rpc's are nonidempotent
*/
const int nonidempotent[NFS_NPROCS] = {
FALSE, /* NULL */
FALSE, /* GETATTR */
TRUE, /* SETATTR */
FALSE, /* LOOKUP */
FALSE, /* ACCESS */
FALSE, /* READLINK */
FALSE, /* READ */
TRUE, /* WRITE */
TRUE, /* CREATE */
TRUE, /* MKDIR */
TRUE, /* SYMLINK */
TRUE, /* MKNOD */
TRUE, /* REMOVE */
TRUE, /* RMDIR */
TRUE, /* RENAME */
TRUE, /* LINK */
FALSE, /* READDIR */
FALSE, /* READDIRPLUS */
FALSE, /* FSSTAT */
FALSE, /* FSINFO */
FALSE, /* PATHCONF */
FALSE, /* COMMIT */
FALSE, /* NOOP */
};
/* True iff the rpc reply is an nfs status ONLY! */
static const int nfsv2_repstat[NFS_NPROCS] = {
FALSE, /* NULL */
FALSE, /* GETATTR */
FALSE, /* SETATTR */
FALSE, /* NOOP */
FALSE, /* LOOKUP */
FALSE, /* READLINK */
FALSE, /* READ */
FALSE, /* Obsolete WRITECACHE */
FALSE, /* WRITE */
FALSE, /* CREATE */
TRUE, /* REMOVE */
TRUE, /* RENAME */
TRUE, /* LINK */
TRUE, /* SYMLINK */
FALSE, /* MKDIR */
TRUE, /* RMDIR */
FALSE, /* READDIR */
FALSE, /* STATFS */
};
static void
cleanentry(struct nfsrvcache *rp)
{
if ((rp->rc_flag & RC_REPMBUF) != 0) {
m_freem(rp->rc_reply);
}
if ((rp->rc_flag & RC_NAM) != 0) {
m_free(rp->rc_nam);
}
rp->rc_flag &= ~(RC_REPSTATUS|RC_REPMBUF);
}
/*
* Initialize the server request cache list
*/
void
nfsrv_initcache()
{
nfsrvhashtbl = hashinit(desirednfsrvcache, HASH_LIST, M_NFSD,
M_WAITOK, &nfsrvhash);
TAILQ_INIT(&nfsrvlruhead);
pool_init(&nfs_reqcache_pool, sizeof(struct nfsrvcache), 0, 0, 0,
"nfsreqcachepl", &pool_allocator_nointr);
MOWNER_ATTACH(&nfsd_cache_mowner);
}
/*
* Lookup a cache and lock it
*/
static struct nfsrvcache *
nfsrv_lookupcache(nd)
struct nfsrv_descript *nd;
{
struct nfsrvcache *rp;
LOCK_ASSERT(simple_lock_held(&nfsrv_reqcache_lock));
loop:
LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
if (nd->nd_retxid == rp->rc_xid &&
nd->nd_procnum == rp->rc_proc &&
netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
if ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
(void) ltsleep(rp, PZERO - 1, "nfsrc", 0,
&nfsrv_reqcache_lock);
goto loop;
}
rp->rc_flag |= RC_LOCKED;
break;
}
}
return rp;
}
/*
* Unlock a cache
*/
static void
nfsrv_unlockcache(rp)
struct nfsrvcache *rp;
{
LOCK_ASSERT(simple_lock_held(&nfsrv_reqcache_lock));
rp->rc_flag &= ~RC_LOCKED;
if (rp->rc_flag & RC_WANTED) {
rp->rc_flag &= ~RC_WANTED;
wakeup(rp);
}
}
/*
* 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(nd, slp, repp)
struct nfsrv_descript *nd;
struct nfssvc_sock *slp;
struct mbuf **repp;
{
struct nfsrvcache *rp, *rpdup;
struct mbuf *mb;
struct sockaddr_in *saddr;
caddr_t bpos;
int ret;
simple_lock(&nfsrv_reqcache_lock);
rp = nfsrv_lookupcache(nd);
if (rp) {
simple_unlock(&nfsrv_reqcache_lock);
found:
/* If not at end of LRU chain, move it there */
if (TAILQ_NEXT(rp, rc_lru)) { /* racy but ok */
simple_lock(&nfsrv_reqcache_lock);
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
simple_unlock(&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_flag & 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_flag & 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;
}
simple_lock(&nfsrv_reqcache_lock);
nfsrv_unlockcache(rp);
simple_unlock(&nfsrv_reqcache_lock);
return ret;
}
nfsstats.srvcache_misses++;
if (numnfsrvcache < desirednfsrvcache) {
numnfsrvcache++;
simple_unlock(&nfsrv_reqcache_lock);
rp = pool_get(&nfs_reqcache_pool, PR_WAITOK);
memset(rp, 0, sizeof *rp);
rp->rc_flag = RC_LOCKED;
} else {
rp = TAILQ_FIRST(&nfsrvlruhead);
while ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
(void) ltsleep(rp, PZERO-1, "nfsrc", 0,
&nfsrv_reqcache_lock);
rp = TAILQ_FIRST(&nfsrvlruhead);
}
rp->rc_flag |= RC_LOCKED;
LIST_REMOVE(rp, rc_hash);
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
simple_unlock(&nfsrv_reqcache_lock);
cleanentry(rp);
rp->rc_flag &= (RC_LOCKED | RC_WANTED);
}
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_flag |= RC_INETADDR;
rp->rc_inetaddr = saddr->sin_addr.s_addr;
break;
case AF_ISO:
default:
rp->rc_flag |= 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;
simple_lock(&nfsrv_reqcache_lock);
rpdup = nfsrv_lookupcache(nd);
if (rpdup != NULL) {
/*
* other thread made duplicate cache entry.
*/
simple_unlock(&nfsrv_reqcache_lock);
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);
simple_unlock(&nfsrv_reqcache_lock);
return RC_DOIT;
}
/*
* Update a request cache entry after the rpc has been done
*/
void
nfsrv_updatecache(nd, repvalid, repmbuf)
struct nfsrv_descript *nd;
int repvalid;
struct mbuf *repmbuf;
{
struct nfsrvcache *rp;
simple_lock(&nfsrv_reqcache_lock);
rp = nfsrv_lookupcache(nd);
simple_unlock(&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_flag |= RC_REPSTATUS;
} else {
rp->rc_reply = m_copym(repmbuf,
0, M_COPYALL, M_WAIT);
m_claimm(rp->rc_reply, &nfsd_cache_mowner);
rp->rc_flag |= RC_REPMBUF;
}
}
simple_lock(&nfsrv_reqcache_lock);
nfsrv_unlockcache(rp);
simple_unlock(&nfsrv_reqcache_lock);
}
}
/*
* Clean out the cache. Called when the last nfsd terminates.
*/
void
nfsrv_cleancache()
{
struct nfsrvcache *rp, *nextrp;
simple_lock(&nfsrv_reqcache_lock);
for (rp = TAILQ_FIRST(&nfsrvlruhead); rp != 0; rp = nextrp) {
nextrp = TAILQ_NEXT(rp, rc_lru);
LIST_REMOVE(rp, rc_hash);
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
KASSERT((rp->rc_flag & (RC_LOCKED|RC_WANTED)) == 0);
cleanentry(rp);
pool_put(&nfs_reqcache_pool, rp);
}
numnfsrvcache = 0;
simple_unlock(&nfsrv_reqcache_lock);
}