d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Update vfs_cache.c to use the <sys/queue.h> macros. This makes it easier

Browse Source 
to read, but doesn't change the speed.

Reviewed by:	phk
Obtained from:	via NetBSD
This commit is contained in:
Poul-Henning Kamp 1995-03-06 06:45:52 +00:00
parent 7cd21d1909
commit 30f467d84a
2 changed files with 69 additions and 118 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

177
sys/kern/vfs_cache.c
View File

@ -30,8 +30,8 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE. * SUCH DAMAGE.
* *
* @(#)vfs_cache.c 8.1 (Berkeley) 6/10/93 * @(#)vfs_cache.c 8.3 (Berkeley) 8/22/94
* $Id: vfs_cache.c,v 1.3 1994/08/02 07:43:15 davidg Exp $ * $Id$
*/ */
#include <sys/param.h> #include <sys/param.h>
@ -64,10 +64,10 @@
/* /*
* Structures associated with name cacheing. * Structures associated with name cacheing.
*/ */
struct namecache **nchashtbl; LIST_HEAD(nchashhead, namecache) *nchashtbl; /* Hash Table */
u_long nchash; /* size of hash table - 1 */ u_long nchash; /* size of hash table - 1 */
long numcache; /* number of cache entries allocated */ long numcache; /* number of cache entries allocated */
struct namecache *nchhead, **nchtail; /* LRU chain pointers */ TAILQ_HEAD(, namecache) nclruhead; /* LRU chain */
struct nchstats nchstats; /* cache effectiveness statistics */ struct nchstats nchstats; /* cache effectiveness statistics */
int doingcache = 1; /* 1 => enable the cache */ int doingcache = 1; /* 1 => enable the cache */
@ -92,28 +92,46 @@ cache_lookup(dvp, vpp, cnp)
struct vnode **vpp; struct vnode **vpp;
struct componentname *cnp; struct componentname *cnp;
{ {
register struct namecache *ncp, *ncq, **ncpp; register struct namecache *ncp,*nnp;
register struct nchashhead *ncpp;
if (!doingcache) if (!doingcache) {
cnp->cn_flags &= ~MAKEENTRY;
return (0); return (0);
}
if (cnp->cn_namelen > NCHNAMLEN) { if (cnp->cn_namelen > NCHNAMLEN) {
nchstats.ncs_long++; nchstats.ncs_long++;
cnp->cn_flags &= ~MAKEENTRY; cnp->cn_flags &= ~MAKEENTRY;
return (0); return (0);
} }
ncpp = &nchashtbl[cnp->cn_hash & nchash]; ncpp = &nchashtbl[cnp->cn_hash & nchash];
for (ncp = *ncpp; ncp; ncp = ncp->nc_forw) { for (ncp = ncpp->lh_first; ncp != 0; ncp = nnp) {
if (ncp->nc_dvp == dvp && if (ncp->nc_dvp == dvp &&
ncp->nc_dvpid == dvp->v_id && ncp->nc_dvpid == dvp->v_id &&
ncp->nc_nlen == cnp->cn_namelen && ncp->nc_nlen == cnp->cn_namelen &&
!bcmp(ncp->nc_name, cnp->cn_nameptr, (u_int)ncp->nc_nlen)) !bcmp(ncp->nc_name, cnp->cn_nameptr, (u_int)ncp->nc_nlen))
break; break;
nnp = ncp->nc_hash.le_next;
#ifdef not_yet_phk
/*
* if not already last and one of the vp's are invalid,
* move to head of LRU
*/
if ((ncp->nc_lru.tqe_next != 0) &&
( (ncp->nc_dvpid != ncp->nc_dvp->v_id) ||
(ncp->nc_vp && (ncp->nc_vpid != ncp->nc_vp->v_id)))) {
LIST_REMOVE(ncp, nc_hash);
ncp->nc_hash.le_prev = 0;
TAILQ_REMOVE(&nclruhead, ncp, nc_lru);
TAILQ_INSERT_HEAD(&nclruhead, ncp, nc_lru);
} }
if (ncp == NULL) { #endif /* not_yet_phk */
}
if (ncp == 0) {
nchstats.ncs_miss++; nchstats.ncs_miss++;
return (0); return (0);
} }
if (!(cnp->cn_flags & MAKEENTRY)) { if ((cnp->cn_flags & MAKEENTRY) == 0) {
nchstats.ncs_badhits++; nchstats.ncs_badhits++;
} else if (ncp->nc_vp == NULL) { } else if (ncp->nc_vp == NULL) {
if (cnp->cn_nameiop != CREATE) { if (cnp->cn_nameiop != CREATE) {
@ -122,15 +140,9 @@ cache_lookup(dvp, vpp, cnp)
* Move this slot to end of LRU chain, * Move this slot to end of LRU chain,
* if not already there. * if not already there.
*/ */
if (ncp->nc_nxt) { if (ncp->nc_lru.tqe_next != 0) {
/* remove from LRU chain */ TAILQ_REMOVE(&nclruhead, ncp, nc_lru);
*ncp->nc_prev = ncp->nc_nxt; TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru);
ncp->nc_nxt->nc_prev = ncp->nc_prev;
/* and replace at end of it */
ncp->nc_nxt = NULL;
ncp->nc_prev = nchtail;
*nchtail = ncp;
nchtail = &ncp->nc_nxt;
} }
return (ENOENT); return (ENOENT);
} }
@ -141,16 +153,14 @@ cache_lookup(dvp, vpp, cnp)
/* /*
* move this slot to end of LRU chain, if not already there * move this slot to end of LRU chain, if not already there
*/ */
if (ncp->nc_nxt) { if (ncp->nc_lru.tqe_next != 0) {
/* remove from LRU chain */ TAILQ_REMOVE(&nclruhead, ncp, nc_lru);
*ncp->nc_prev = ncp->nc_nxt; TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru);
ncp->nc_nxt->nc_prev = ncp->nc_prev;
/* and replace at end of it */
ncp->nc_nxt = NULL;
ncp->nc_prev = nchtail;
*nchtail = ncp;
nchtail = &ncp->nc_nxt;
} }
#ifdef not_yet_phk
/* Touch the parent vnode */
vtouch(ncp->nc_dvp);
#endif /* not_yet_phk */
*vpp = ncp->nc_vp; *vpp = ncp->nc_vp;
return (-1); return (-1);
} }
@ -160,30 +170,10 @@ cache_lookup(dvp, vpp, cnp)
* the cache entry is invalid, or otherwise don't * the cache entry is invalid, or otherwise don't
* want cache entry to exist. * want cache entry to exist.
*/ */
/* remove from LRU chain */ TAILQ_REMOVE(&nclruhead, ncp, nc_lru);
ncq = ncp->nc_nxt; LIST_REMOVE(ncp, nc_hash);
if (ncq) ncp->nc_hash.le_prev = 0;
ncq->nc_prev = ncp->nc_prev; TAILQ_INSERT_HEAD(&nclruhead, ncp, nc_lru);
else
nchtail = ncp->nc_prev;
*ncp->nc_prev = ncq;
/* remove from hash chain */
ncq = ncp->nc_forw;
if (ncq)
ncq->nc_back = ncp->nc_back;
*ncp->nc_back = ncq;
/* and make a dummy hash chain */
ncp->nc_forw = NULL;
ncp->nc_back = NULL;
/* insert at head of LRU list (first to grab) */
ncq = nchhead;
if (ncq)
ncq->nc_prev = &ncp->nc_nxt;
else
nchtail = &ncp->nc_nxt;
nchhead = ncp;
ncp->nc_nxt = ncq;
ncp->nc_prev = &nchhead;
return (0); return (0);
} }
@ -196,7 +186,8 @@ cache_enter(dvp, vp, cnp)
struct vnode *vp; struct vnode *vp;
struct componentname *cnp; struct componentname *cnp;
{ {
register struct namecache *ncp, *ncq, **ncpp; register struct namecache *ncp;
register struct nchashhead *ncpp;
#ifdef DIAGNOSTIC #ifdef DIAGNOSTIC
if (cnp->cn_namelen > NCHNAMLEN) if (cnp->cn_namelen > NCHNAMLEN)
@ -212,27 +203,14 @@ cache_enter(dvp, vp, cnp)
malloc((u_long)sizeof *ncp, M_CACHE, M_WAITOK); malloc((u_long)sizeof *ncp, M_CACHE, M_WAITOK);
bzero((char *)ncp, sizeof *ncp); bzero((char *)ncp, sizeof *ncp);
numcache++; numcache++;
} else if (!nchhead) { } else if (ncp = nclruhead.tqh_first) {
TAILQ_REMOVE(&nclruhead, ncp, nc_lru);
if (ncp->nc_hash.le_prev != 0) {
LIST_REMOVE(ncp, nc_hash);
ncp->nc_hash.le_prev = 0;
}
} else
return; return;
} else {
ncp = nchhead;
/* remove from lru chain */
ncq = ncp->nc_nxt;
if (ncq)
ncq->nc_prev = ncp->nc_prev;
else
nchtail = ncp->nc_prev;
*ncp->nc_prev = ncq;
/* remove from old hash chain, if on one */
if (ncp->nc_back) {
ncq = ncp->nc_forw;
if (ncq)
ncq->nc_back = ncp->nc_back;
*ncp->nc_back = ncq;
ncp->nc_forw = NULL;
ncp->nc_back = NULL;
}
}
/* grab the vnode we just found */ /* grab the vnode we just found */
ncp->nc_vp = vp; ncp->nc_vp = vp;
if (vp) if (vp)
@ -244,19 +222,9 @@ cache_enter(dvp, vp, cnp)
ncp->nc_dvpid = dvp->v_id; ncp->nc_dvpid = dvp->v_id;
ncp->nc_nlen = cnp->cn_namelen; ncp->nc_nlen = cnp->cn_namelen;
bcopy(cnp->cn_nameptr, ncp->nc_name, (unsigned)ncp->nc_nlen); bcopy(cnp->cn_nameptr, ncp->nc_name, (unsigned)ncp->nc_nlen);
/* link at end of lru chain */ TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru);
ncp->nc_nxt = NULL;
ncp->nc_prev = nchtail;
*nchtail = ncp;
nchtail = &ncp->nc_nxt;
/* and insert on hash chain */
ncpp = &nchashtbl[cnp->cn_hash & nchash]; ncpp = &nchashtbl[cnp->cn_hash & nchash];
ncq = *ncpp; LIST_INSERT_HEAD(ncpp, ncp, nc_hash);
if (ncq)
ncq->nc_back = &ncp->nc_forw;
ncp->nc_forw = ncq;
ncp->nc_back = ncpp;
*ncpp = ncp;
} }
/* /*
@ -266,7 +234,7 @@ void
nchinit() nchinit()
{ {
nchtail = &nchhead; TAILQ_INIT(&nclruhead);
nchashtbl = hashinit(desiredvnodes, M_CACHE, &nchash); nchashtbl = hashinit(desiredvnodes, M_CACHE, &nchash);
} }
@ -278,13 +246,14 @@ void
cache_purge(vp) cache_purge(vp)
struct vnode *vp; struct vnode *vp;
{ {
struct namecache *ncp, **ncpp; struct namecache *ncp;
struct nchashhead *ncpp;
vp->v_id = ++nextvnodeid; vp->v_id = ++nextvnodeid;
if (nextvnodeid != 0) if (nextvnodeid != 0)
return; return;
for (ncpp = &nchashtbl[nchash]; ncpp >= nchashtbl; ncpp--) { for (ncpp = &nchashtbl[nchash]; ncpp >= nchashtbl; ncpp--) {
for (ncp = *ncpp; ncp; ncp = ncp->nc_forw) { for (ncp = ncpp->lh_first; ncp != 0; ncp = ncp->nc_hash.le_next) {
ncp->nc_vpid = 0; ncp->nc_vpid = 0;
ncp->nc_dvpid = 0; ncp->nc_dvpid = 0;
} }
@ -306,39 +275,21 @@ cache_purgevfs(mp)
{ {
register struct namecache *ncp, *nxtcp; register struct namecache *ncp, *nxtcp;
for (ncp = nchhead; ncp; ncp = nxtcp) { for (ncp = nclruhead.tqh_first; ncp != 0; ncp = nxtcp) {
if (ncp->nc_dvp == NULL || ncp->nc_dvp->v_mount != mp) { if (ncp->nc_dvp == NULL || ncp->nc_dvp->v_mount != mp) {
nxtcp = ncp->nc_nxt; nxtcp = ncp->nc_lru.tqe_next;
continue; continue;
} }
/* free the resources we had */ /* free the resources we had */
ncp->nc_vp = NULL; ncp->nc_vp = NULL;
ncp->nc_dvp = NULL; ncp->nc_dvp = NULL;
/* remove from old hash chain, if on one */ TAILQ_REMOVE(&nclruhead, ncp, nc_lru);
if (ncp->nc_back) { if (ncp->nc_hash.le_prev != 0) {
nxtcp = ncp->nc_forw; LIST_REMOVE(ncp, nc_hash);
if (nxtcp) ncp->nc_hash.le_prev = 0;
nxtcp->nc_back = ncp->nc_back;
*ncp->nc_back = nxtcp;
ncp->nc_forw = NULL;
ncp->nc_back = NULL;
} }
/* delete this entry from LRU chain */
nxtcp = ncp->nc_nxt;
if (nxtcp)
nxtcp->nc_prev = ncp->nc_prev;
else
nchtail = ncp->nc_prev;
*ncp->nc_prev = nxtcp;
/* cause rescan of list, it may have altered */ /* cause rescan of list, it may have altered */
/* also put the now-free entry at head of LRU */ nxtcp = nclruhead.tqh_first;
nxtcp = nchhead; TAILQ_INSERT_HEAD(&nclruhead, ncp, nc_lru);
if (nxtcp)
nxtcp->nc_prev = &ncp->nc_nxt;
else
nchtail = &ncp->nc_nxt;
nchhead = ncp;
ncp->nc_nxt = nxtcp;
ncp->nc_prev = &nchhead;
} }
} }

10
sys/sys/namei.h
View File

@ -31,12 +31,14 @@
* SUCH DAMAGE. * SUCH DAMAGE.
* *
* @(#)namei.h 8.2 (Berkeley) 1/4/94 * @(#)namei.h 8.2 (Berkeley) 1/4/94
* $Id: namei.h,v 1.2 1994/08/02 07:53:18 davidg Exp $ * $Id: namei.h,v 1.3 1994/09/27 20:33:41 phk Exp $
*/ */
#ifndef _SYS_NAMEI_H_ #ifndef _SYS_NAMEI_H_
#define _SYS_NAMEI_H_ #define _SYS_NAMEI_H_
#include <sys/queue.h>
/* /*
* Encapsulation of namei parameters. * Encapsulation of namei parameters.
*/ */
@ -155,10 +157,8 @@ struct nameidata {
#define NCHNAMLEN 31 /* maximum name segment length we bother with */ #define NCHNAMLEN 31 /* maximum name segment length we bother with */
struct namecache { struct namecache {
struct namecache *nc_forw; /* hash chain */ LIST_ENTRY(namecache) nc_hash; /* hash chain */
struct namecache **nc_back; /* hash chain */ TAILQ_ENTRY(namecache) nc_lru; /* LRU chain */
struct namecache *nc_nxt; /* LRU chain */
struct namecache **nc_prev; /* LRU chain */
struct vnode *nc_dvp; /* vnode of parent of name */ struct vnode *nc_dvp; /* vnode of parent of name */
u_long nc_dvpid; /* capability number of nc_dvp */ u_long nc_dvpid; /* capability number of nc_dvp */
struct vnode *nc_vp; /* vnode the name refers to */ struct vnode *nc_vp; /* vnode the name refers to */