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freebsd/sys/nfsserver/nfs_srvcache.c
John Baldwin 6cba7f3609 - Add a new function nfsrv_destroycache() to tear down the server request 
cache when unloading the nfsserver module.  This fixes a memory leak and
  a stale pointer.
- Use callout_drain() rather than callout_stop() when unloading the
  nfsserver module.

MFC after:	3 days
2006-08-01 16:27:14 +00:00

386 lines
10 KiB
C
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/*-
* 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.
* 4. 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* 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/param.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/socket.h>
#include <sys/socketvar.h> /* for sodupsockaddr */
#include <sys/eventhandler.h>
#include <netinet/in.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfsserver/nfs.h>
#include <nfsserver/nfsrvcache.h>
static long numnfsrvcache;
static long desirednfsrvcache;
#define NFSRCHASH(xid) \
(&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash])
static LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl;
static TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead;
static u_long nfsrvhash;
static eventhandler_tag nfsrv_nmbclusters_tag;
#define TRUE 1
#define FALSE 0
#define NETFAMILY(rp) \
(((rp)->rc_flag & RC_NAM) ? (rp)->rc_nam->sa_family : AF_INET)
/*
* Static array that defines which nfs rpc's are nonidempotent
*/
static const int nonidempotent[NFS_NPROCS] = {
FALSE,
FALSE,
TRUE,
FALSE,
FALSE,
FALSE,
FALSE,
TRUE,
TRUE,
TRUE,
TRUE,
TRUE,
TRUE,
TRUE,
TRUE,
TRUE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
};
/* True iff the rpc reply is an nfs status ONLY! */
static const int nfsv2_repstat[NFS_NPROCS] = {
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
FALSE,
TRUE,
TRUE,
TRUE,
TRUE,
FALSE,
TRUE,
FALSE,
FALSE,
};
/*
* Size the NFS server's duplicate request cache at 1/2 the nmbclsters, floating
* within a (64, 2048) range. This is to prevent all mbuf clusters being tied up
* in the NFS dupreq cache for small values of nmbclusters.
*/
static void
nfsrvcache_size_change(void *tag)
{
desirednfsrvcache = nmbclusters /2;
if (desirednfsrvcache > NFSRVCACHE_MAX_SIZE)
desirednfsrvcache = NFSRVCACHE_MAX_SIZE;
if (desirednfsrvcache < NFSRVCACHE_MIN_SIZE)
desirednfsrvcache = NFSRVCACHE_MIN_SIZE;
}
/*
* Initialize the server request cache list
*/
void
nfsrv_initcache(void)
{
nfsrvcache_size_change(NULL);
nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, &nfsrvhash);
TAILQ_INIT(&nfsrvlruhead);
nfsrv_nmbclusters_tag = EVENTHANDLER_REGISTER(nmbclusters_change,
nfsrvcache_size_change, NULL, EVENTHANDLER_PRI_FIRST);
}
/*
* Teardown the server request cache list
*/
void
nfsrv_destroycache(void)
{
KASSERT(TAILQ_EMPTY(&nfsrvlruhead), ("%s: pending requests", __func__));
EVENTHANDLER_DEREGISTER(nmbclusters_change, nfsrv_nmbclusters_tag);
hashdestroy(nfsrvhashtbl, M_NFSD, nfsrvhash);
}
/*
* 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 mbuf **repp)
{
struct nfsrvcache *rp;
struct mbuf *mb;
struct sockaddr_in *saddr;
caddr_t bpos;
int ret;
NFSD_LOCK_ASSERT();
/*
* Don't cache recent requests for reliable transport protocols.
* (Maybe we should for the case of a reconnect, but..)
*/
if (!nd->nd_nam2)
return (RC_DOIT);
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)) {
NFS_DPF(RC, ("H%03x", rp->rc_xid & 0xfff));
if ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
(void) msleep(rp, &nfsd_mtx, PZERO-1,
"nfsrc", 0);
goto loop;
}
rp->rc_flag |= RC_LOCKED;
/* If not at end of LRU chain, move it there */
if (TAILQ_NEXT(rp, rc_lru)) {
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
}
if (rp->rc_state == RC_UNUSED)
panic("nfsrv cache");
if (rp->rc_state == RC_INPROG) {
nfsrvstats.srvcache_inproghits++;
ret = RC_DROPIT;
} else if (rp->rc_flag & RC_REPSTATUS) {
nfsrvstats.srvcache_nonidemdonehits++;
*repp = nfs_rephead(0, nd, rp->rc_status,
&mb, &bpos);
ret = RC_REPLY;
} else if (rp->rc_flag & RC_REPMBUF) {
nfsrvstats.srvcache_nonidemdonehits++;
NFSD_UNLOCK();
*repp = m_copym(rp->rc_reply, 0, M_COPYALL,
M_TRYWAIT);
NFSD_LOCK();
ret = RC_REPLY;
} else {
nfsrvstats.srvcache_idemdonehits++;
rp->rc_state = RC_INPROG;
ret = RC_DOIT;
}
rp->rc_flag &= ~RC_LOCKED;
if (rp->rc_flag & RC_WANTED) {
rp->rc_flag &= ~RC_WANTED;
wakeup(rp);
}
return (ret);
}
}
nfsrvstats.srvcache_misses++;
NFS_DPF(RC, ("M%03x", nd->nd_retxid & 0xfff));
if (numnfsrvcache < desirednfsrvcache) {
NFSD_UNLOCK();
rp = (struct nfsrvcache *)malloc((u_long)sizeof *rp,
M_NFSD, M_WAITOK | M_ZERO);
NFSD_LOCK();
numnfsrvcache++;
rp->rc_flag = RC_LOCKED;
} else {
rp = TAILQ_FIRST(&nfsrvlruhead);
while ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
(void) msleep(rp, &nfsd_mtx, PZERO-1, "nfsrc", 0);
rp = TAILQ_FIRST(&nfsrvlruhead);
}
rp->rc_flag |= RC_LOCKED;
LIST_REMOVE(rp, rc_hash);
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
if (rp->rc_flag & RC_REPMBUF)
m_freem(rp->rc_reply);
if (rp->rc_flag & RC_NAM)
FREE(rp->rc_nam, M_SONAME);
rp->rc_flag &= (RC_LOCKED | RC_WANTED);
}
TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
rp->rc_state = RC_INPROG;
rp->rc_xid = nd->nd_retxid;
saddr = (struct sockaddr_in *)nd->nd_nam;
switch (saddr->sin_family) {
case AF_INET:
rp->rc_flag |= RC_INETADDR;
rp->rc_inetaddr = saddr->sin_addr.s_addr;
break;
/* case AF_INET6: */
/* case AF_ISO: */
default:
/*
* XXXRW: Seems like we should only set RC_NAM if we
* actually manage to set rc_nam to something non-NULL.
*/
rp->rc_flag |= RC_NAM;
rp->rc_nam = sodupsockaddr(nd->nd_nam, M_NOWAIT);
break;
};
rp->rc_proc = nd->nd_procnum;
LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
rp->rc_flag &= ~RC_LOCKED;
if (rp->rc_flag & RC_WANTED) {
rp->rc_flag &= ~RC_WANTED;
wakeup(rp);
}
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;
NFSD_LOCK_ASSERT();
if (!nd->nd_nam2)
return;
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)) {
NFS_DPF(RC, ("U%03x", rp->rc_xid & 0xfff));
if ((rp->rc_flag & RC_LOCKED) != 0) {
rp->rc_flag |= RC_WANTED;
(void) msleep(rp, &nfsd_mtx, PZERO-1,
"nfsrc", 0);
goto loop;
}
rp->rc_flag |= RC_LOCKED;
if (rp->rc_state == RC_DONE) {
/*
* This can occur if the cache is too small.
* Retransmits of the same request aren't
* dropped so we may see the operation
* complete more then once.
*/
if (rp->rc_flag & RC_REPMBUF) {
m_freem(rp->rc_reply);
rp->rc_flag &= ~RC_REPMBUF;
}
}
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[
nfsrvv2_procid[nd->nd_procnum]]) {
rp->rc_status = nd->nd_repstat;
rp->rc_flag |= RC_REPSTATUS;
} else {
NFSD_UNLOCK();
rp->rc_reply = m_copym(repmbuf,
0, M_COPYALL, M_TRYWAIT);
NFSD_LOCK();
rp->rc_flag |= RC_REPMBUF;
}
}
rp->rc_flag &= ~RC_LOCKED;
if (rp->rc_flag & RC_WANTED) {
rp->rc_flag &= ~RC_WANTED;
wakeup(rp);
}
return;
}
}
NFS_DPF(RC, ("L%03x", nd->nd_retxid & 0xfff));
}
/*
* Clean out the cache. Called when the last nfsd terminates.
*/
void
nfsrv_cleancache(void)
{
struct nfsrvcache *rp, *nextrp;
NFSD_LOCK_ASSERT();
TAILQ_FOREACH_SAFE(rp, &nfsrvlruhead, rc_lru, nextrp) {
LIST_REMOVE(rp, rc_hash);
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
if (rp->rc_flag & RC_REPMBUF)
m_freem(rp->rc_reply);
if (rp->rc_flag & RC_NAM)
free(rp->rc_nam, M_SONAME);
free(rp, M_NFSD);
}
numnfsrvcache = 0;
}
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