/*
* Copyright 2000, International Business Machines Corporation and others.
* All Rights Reserved.
- *
+ *
* This software has been released under the terms of the IBM Public
* License. For details, see the LICENSE file in the top-level source
* directory or online at http://www.openafs.org/dl/license10.html
*/
+/*-
+ * OSI Directory Name Lookup Cache
+ *
+ * Keep a local cache of lookup results to avoid needing to examine the disk
+ * cache, for frequently accessed names.
+ */
+
#include <afsconfig.h>
#include "afs/param.h"
* cache larger names, perhaps by using a better,longer key (SHA) and discarding
* the actual name itself.
* precompute a key and stuff for \sys, and combine the HandleAtName function with
- * this, since we're looking at the name anyway.
+ * this, since we're looking at the name anyway.
*/
struct afs_lock afs_xdnlc;
dnlcstats_t dnlcstats;
-#define NCSIZE 300
+#define NCSIZE 4096
#define NHSIZE 256 /* must be power of 2. == NHASHENT in dir package */
struct nc *ncfreelist = NULL;
static struct nc nameCache[NCSIZE];
#define dnlcHash(ts, hval) for (hval=0; *ts; ts++) { hval *= 173; hval += *ts; }
-#if defined(AFS_FBSD80_ENV) && !defined(UKERNEL)
-#define ma_critical_enter critical_enter
-#define ma_critical_exit critical_exit
-#else
-#define ma_critical_enter() {}
-#define ma_critical_exit() {}
-#endif
-
static struct nc *
GetMeAnEntry(void)
{
break;
}
+ if (nameptr >= NHSIZE)
+ nameptr = 0;
+
TRACE(ScavengeEntryT, nameptr);
tnc = nameHash[nameptr];
if (!tnc) /* May want to consider changing this to return 0 */
osi_dnlc_lookup(struct vcache *adp, char *aname, int locktype)
{
struct vcache *tvc;
- int LRUme;
unsigned int key, skey;
char *ts = aname;
- struct nc *tnc, *tnc1 = 0;
+ struct nc *tnc;
int safety;
#ifdef AFS_DARWIN80_ENV
vnode_t tvp;
#endif
- ma_critical_enter();
-
- if (!afs_usednlc) {
- ma_critical_exit();
+ if (!afs_usednlc)
return 0;
- }
dnlcHash(ts, key); /* leaves ts pointing at the NULL */
- if (ts - aname >= AFSNCNAMESIZE) {
- ma_critical_exit();
+ if (ts - aname >= AFSNCNAMESIZE)
return 0;
- }
skey = key & (NHSIZE - 1);
TRACE(osi_dnlc_lookupT, skey);
if ( /* (tnc->key == key) && */ (tnc->dirp == adp)
&& (!strcmp((char *)tnc->name, aname))) {
tvc = tnc->vp;
- tnc1 = tnc;
break;
} else if (tnc->next == nameHash[skey]) { /* end of list */
break;
ReleaseReadLock(&afs_xdnlc);
ReleaseReadLock(&afs_xvcache);
osi_dnlc_purge();
- ma_critical_exit();
return (0);
}
}
- LRUme = 0; /* (tnc != nameHash[skey]); */
ReleaseReadLock(&afs_xdnlc);
if (!tvc) {
#ifdef AFS_DARWIN80_ENV
||(tvc->f.states & CDeadVnode)
#endif
- )
+ )
{
ReleaseReadLock(&afs_xvcache);
dnlcstats.misses++;
osi_dnlc_remove(adp, aname, tvc);
- ma_critical_exit();
return 0;
}
-#ifdef AFS_OSF_ENV
- VN_HOLD((vnode_t *) tvc);
-#else
-#ifdef AFS_DARWIN80_ENV
+#if defined(AFS_DARWIN80_ENV)
tvp = AFSTOV(tvc);
if (vnode_get(tvp)) {
ReleaseReadLock(&afs_xvcache);
dnlcstats.misses++;
osi_dnlc_remove(adp, aname, tvc);
- ma_critical_exit();
return 0;
}
if (vnode_ref(tvp)) {
AFS_GLOCK();
dnlcstats.misses++;
osi_dnlc_remove(adp, aname, tvc);
- ma_critical_exit();
return 0;
}
#else
-#ifdef AFS_FBSD50_ENV
- /* can't sleep in a critical section */
- ma_critical_exit();
- osi_vnhold(tvc, 0);
- ma_critical_enter();
-#else
osi_vnhold(tvc, 0);
-#endif /* AFS_FBSD80_ENV */
-#endif
#endif
ReleaseReadLock(&afs_xvcache);
-#ifdef notdef
- /*
- * XX If LRUme ever is non-zero change the if statement around because
- * aix's cc with optimizer on won't necessarily check things in order XX
- */
- if (LRUme && (0 == NBObtainWriteLock(&afs_xdnlc))) {
- /* don't block to do this */
- /* tnc might have been moved during race condition, */
- /* but it's always in a legit hash chain when a lock is granted,
- * or else it's on the freelist so prev == NULL,
- * so at worst this is redundant */
- /* Now that we've got it held, and a lock on the dnlc, we
- * should check to be sure that there was no race, and
- * bail out if there was. */
- if (tnc->prev) {
- /* special case for only two elements on list - relative ordering
- * doesn't change */
- if (tnc->prev != tnc->next) {
- /* remove from old location */
- tnc->prev->next = tnc->next;
- tnc->next->prev = tnc->prev;
- /* insert into new location */
- tnc->next = nameHash[skey];
- tnc->prev = tnc->next->prev;
- tnc->next->prev = tnc;
- tnc->prev->next = tnc;
- }
- nameHash[skey] = tnc;
- }
- ReleaseWriteLock(&afs_xdnlc);
- }
-#endif
}
- ma_critical_exit();
return tvc;
}
return 0;
}
-/*!
+/*!
* Remove anything pertaining to this directory. I can invalidate
* things without the lock, since I am just looking through the array,
* but to move things off the lists or into the freelist, I need the
- * write lock
+ * write lock
*
* \param adp vcache entry for the directory to be purged.
* \return 0
return 0;
}
-/*!
- * Remove anything pertaining to this file
+/*!
+ * Remove anything pertaining to this file
*
* \param File vcache entry.
* \return 0
writelocked = (0 == NBObtainWriteLock(&afs_xdnlc, 3));
for (i = 0; i < NCSIZE; i++) {
- if ((nameCache[i].vp == avc)) {
+ if (nameCache[i].vp == avc) {
nameCache[i].dirp = nameCache[i].vp = NULL;
/* can't simply break; because of hard links -- might be two */
/* different entries with same vnode */
git://git.openafs.org / openafs.git / blobdiff