C++ (Cpp) osi_vnhold Examples

Example #1

File: afs_osidnlc.c Project: jisqyv/openafs

struct vcache *
osi_dnlc_lookup(struct vcache *adp, char *aname, int locktype)
{
    struct vcache *tvc;
    unsigned int key, skey;
    char *ts = aname;
    struct nc *tnc;
    int safety;
#ifdef AFS_DARWIN80_ENV
    vnode_t tvp;
#endif

    if (!afs_usednlc)
      return 0;

    dnlcHash(ts, key);		/* leaves ts pointing at the NULL */
    if (ts - aname >= AFSNCNAMESIZE)
      return 0;
    skey = key & (NHSIZE - 1);

    TRACE(osi_dnlc_lookupT, skey);
    dnlcstats.lookups++;

    ObtainReadLock(&afs_xvcache);
    ObtainReadLock(&afs_xdnlc);

    for (tvc = NULL, tnc = nameHash[skey], safety = 0; tnc;
	 tnc = tnc->next, safety++) {
	if ( /* (tnc->key == key)  && */ (tnc->dirp == adp)
	    && (!strcmp((char *)tnc->name, aname))) {
	    tvc = tnc->vp;
	    break;
	} else if (tnc->next == nameHash[skey]) {	/* end of list */
	    break;
	} else if (safety > NCSIZE) {
	    afs_warn("DNLC cycle");
	    dnlcstats.cycles++;
	    ReleaseReadLock(&afs_xdnlc);
	    ReleaseReadLock(&afs_xvcache);
	    osi_dnlc_purge();
	    return (0);
	}
    }

    ReleaseReadLock(&afs_xdnlc);

    if (!tvc) {
	ReleaseReadLock(&afs_xvcache);
	dnlcstats.misses++;
    } else {
	if ((tvc->f.states & CVInit)
#ifdef  AFS_DARWIN80_ENV
	    ||(tvc->f.states & CDeadVnode)
#endif
	    )
	{
	    ReleaseReadLock(&afs_xvcache);
	    dnlcstats.misses++;
	    osi_dnlc_remove(adp, aname, tvc);
	    return 0;
	}
#if defined(AFS_DARWIN80_ENV)
	tvp = AFSTOV(tvc);
	if (vnode_get(tvp)) {
	    ReleaseReadLock(&afs_xvcache);
	    dnlcstats.misses++;
	    osi_dnlc_remove(adp, aname, tvc);
	    return 0;
	}
	if (vnode_ref(tvp)) {
	    ReleaseReadLock(&afs_xvcache);
	    AFS_GUNLOCK();
	    vnode_put(tvp);
	    AFS_GLOCK();
	    dnlcstats.misses++;
	    osi_dnlc_remove(adp, aname, tvc);
	    return 0;
	}
#else
	osi_vnhold(tvc, 0);
#endif
	ReleaseReadLock(&afs_xvcache);

    }

    return tvc;
}

Example #2

File: afs_osidnlc.c Project: mattjsm/openafs-netbsd5

struct vcache *
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;
    int safety;
#ifdef AFS_DARWIN80_ENV
    vnode_t tvp;
#endif

    ma_critical_enter();

    if (!afs_usednlc) {
      ma_critical_exit();
      return 0;
    }

    dnlcHash(ts, key);		/* leaves ts pointing at the NULL */
    if (ts - aname >= AFSNCNAMESIZE) {
      ma_critical_exit();
      return 0;
    }
    skey = key & (NHSIZE - 1);

    TRACE(osi_dnlc_lookupT, skey);
    dnlcstats.lookups++;

    ObtainReadLock(&afs_xvcache);
    ObtainReadLock(&afs_xdnlc);

    for (tvc = NULL, tnc = nameHash[skey], safety = 0; tnc;
	 tnc = tnc->next, safety++) {
	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;
	} else if (safety > NCSIZE) {
	    afs_warn("DNLC cycle");
	    dnlcstats.cycles++;
	    ReleaseReadLock(&afs_xdnlc);
	    ReleaseReadLock(&afs_xvcache);
	    osi_dnlc_purge();
	    ma_critical_exit();
	    return (0);
	}
    }

    LRUme = 0;			/* (tnc != nameHash[skey]); */
    ReleaseReadLock(&afs_xdnlc);

    if (!tvc) {
	ReleaseReadLock(&afs_xvcache);
	dnlcstats.misses++;
    } else {
	if ((tvc->f.states & CVInit)
#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;
	}
#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)) {
	    ReleaseReadLock(&afs_xvcache);
	    AFS_GUNLOCK();
	    vnode_put(tvp);
	    AFS_GLOCK();
	    dnlcstats.misses++;
	    osi_dnlc_remove(adp, aname, tvc);
	    ma_critical_exit();
	    return 0;
	}
#elif defined(AFS_FBSD_ENV)
	/* can't sleep in a critical section */
	ma_critical_exit();
	osi_vnhold(tvc, 0);
	ma_critical_enter();
#else
	osi_vnhold(tvc, 0);
#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;
}