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[src/trunk]: src/sys/nfs simplelock for nfsd request cache.
details: https://anonhg.NetBSD.org/src/rev/09c2ae82f7fa
branches: trunk
changeset: 547509:09c2ae82f7fa
user: yamt <yamt%NetBSD.org@localhost>
date: Wed May 21 14:13:34 2003 +0000
description:
simplelock for nfsd request cache.
diffstat:
sys/nfs/nfs_srvcache.c | 215 +++++++++++++++++++++++++++++-------------------
1 files changed, 130 insertions(+), 85 deletions(-)
diffs (truncated from 312 to 300 lines):
diff -r 10ae338a0331 -r 09c2ae82f7fa sys/nfs/nfs_srvcache.c
--- a/sys/nfs/nfs_srvcache.c Wed May 21 13:56:21 2003 +0000
+++ b/sys/nfs/nfs_srvcache.c Wed May 21 14:13:34 2003 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: nfs_srvcache.c,v 1.26 2003/05/21 13:56:21 yamt Exp $ */
+/* $NetBSD: nfs_srvcache.c,v 1.27 2003/05/21 14:13:34 yamt Exp $ */
/*
* Copyright (c) 1989, 1993
@@ -45,7 +45,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_srvcache.c,v 1.26 2003/05/21 13:56:21 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_srvcache.c,v 1.27 2003/05/21 14:13:34 yamt Exp $");
#include "opt_iso.h"
@@ -54,6 +54,7 @@
#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>
@@ -82,11 +83,15 @@
(&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;
#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
*/
@@ -156,6 +161,53 @@
}
/*
+ * 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
@@ -187,73 +239,68 @@
*/
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)) {
- if ((rp->rc_flag & RC_LOCKED) != 0) {
- rp->rc_flag |= RC_WANTED;
- (void) tsleep(rp, 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) {
- 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;
- }
- rp->rc_flag &= ~RC_LOCKED;
- if (rp->rc_flag & RC_WANTED) {
- rp->rc_flag &= ~RC_WANTED;
- wakeup(rp);
- }
- return 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((char *)rp, 0, sizeof *rp);
- numnfsrvcache++;
+ 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) tsleep(rp, PZERO-1, "nfsrc", 0);
+ (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);
if (rp->rc_flag & RC_REPMBUF)
m_freem(rp->rc_reply);
if (rp->rc_flag & RC_NAM)
(void) m_free(rp->rc_nam);
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 = mtod(nd->nd_nam, struct sockaddr_in *);
@@ -269,12 +316,19 @@
break;
};
rp->rc_proc = nd->nd_procnum;
+ simple_lock(&nfsrv_reqcache_lock);
+ if (nfsrv_lookupcache(nd)) {
+ /*
+ * other thread made duplicate cache entry.
+ */
+ simple_unlock(&nfsrv_reqcache_lock);
+ pool_put(&nfs_reqcache_pool, rp);
+ goto found;
+ }
+ TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
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);
- }
+ nfsrv_unlockcache(rp);
+ simple_unlock(&nfsrv_reqcache_lock);
return RC_DOIT;
}
@@ -291,40 +345,29 @@
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)) {
- if ((rp->rc_flag & RC_LOCKED) != 0) {
- rp->rc_flag |= RC_WANTED;
- (void) tsleep(rp, PZERO-1, "nfsrc", 0);
- goto loop;
+ simple_lock(&nfsrv_reqcache_lock);
+ rp = nfsrv_lookupcache(nd);
+ simple_unlock(&nfsrv_reqcache_lock);
+ if (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);
+ rp->rc_flag |= RC_REPMBUF;
}
- rp->rc_flag |= RC_LOCKED;
- 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);
- rp->rc_flag |= RC_REPMBUF;
- }
- }
- rp->rc_flag &= ~RC_LOCKED;
- if (rp->rc_flag & RC_WANTED) {
- rp->rc_flag &= ~RC_WANTED;
- wakeup(rp);
- }
- return;
}
+ simple_lock(&nfsrv_reqcache_lock);
+ nfsrv_unlockcache(rp);
+ simple_unlock(&nfsrv_reqcache_lock);
}
}
@@ -336,6 +379,7 @@
{
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