/*	$OpenBSD: nfs_node.c,v 1.42 2008/08/09 10:14:02 thib Exp $	*/
/*	$NetBSD: nfs_node.c,v 1.16 1996/02/18 11:53:42 fvdl Exp $	*/

/*
 * 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.
 * 3. 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_node.c	8.6 (Berkeley) 5/22/95
 */


#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/hash.h>
#include <sys/rwlock.h>
#include <sys/queue.h>

#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsnode.h>
#include <nfs/nfsmount.h>
#include <nfs/nfs_var.h>

LIST_HEAD(nfsnodehashhead, nfsnode) *nfsnodehashtbl;
u_long nfsnodehash;
struct rwlock nfs_hashlock = RWLOCK_INITIALIZER("nfshshlk");

struct pool nfs_node_pool;

extern int prtactive;

#define TRUE	1
#define	FALSE	0

#define	nfs_hash(x,y)	hash32_buf((x), (y), HASHINIT)

/*
 * Initialize hash links for nfsnodes
 * and build nfsnode free list.
 */
void
nfs_nhinit()
{
	nfsnodehashtbl = hashinit(desiredvnodes, M_NFSNODE, M_WAITOK, &nfsnodehash);
	pool_init(&nfs_node_pool, sizeof(struct nfsnode), 0, 0, 0, "nfsnodepl",
	    &pool_allocator_nointr);
}

/*
 * Look up a vnode/nfsnode by file handle.
 * Callers must check for mount points!!
 * In all cases, a pointer to a
 * nfsnode structure is returned.
 */
int
nfs_nget(mntp, fhp, fhsize, npp)
	struct mount *mntp;
	nfsfh_t *fhp;
	int fhsize;
	struct nfsnode **npp;
{
	struct proc *p = curproc;	/* XXX */
	struct nfsnode *np;
	struct nfsnodehashhead *nhpp;
	struct vnode *vp;
	extern int (**nfsv2_vnodeop_p)(void *);
	struct vnode *nvp;
	int error;

	nhpp = NFSNOHASH(nfs_hash(fhp, fhsize));
loop:
	LIST_FOREACH(np, nhpp, n_hash) {
		if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize ||
		    bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize))
			continue;
		vp = NFSTOV(np);
		if (vget(vp, LK_EXCLUSIVE, p))
			goto loop;
		*npp = np;
		return(0);
	}
	if (rw_enter(&nfs_hashlock, RW_WRITE|RW_SLEEPFAIL))
		goto loop;
	error = getnewvnode(VT_NFS, mntp, nfsv2_vnodeop_p, &nvp);
	if (error) {
		*npp = 0;
		rw_exit(&nfs_hashlock);
		return (error);
	}
	vp = nvp;
	np = pool_get(&nfs_node_pool, PR_WAITOK | PR_ZERO);
	vp->v_data = np;
	np->n_vnode = vp;

	rw_init(&np->n_commitlock, "nfs_commitlk");

	/* 
	 * Are we getting the root? If so, make sure the vnode flags
	 * are correct 
	 */
	{
		struct nfsmount *nmp = VFSTONFS(mntp);
		if ((fhsize == nmp->nm_fhsize) &&
		    !bcmp(fhp, nmp->nm_fh, fhsize)) {
			if (vp->v_type == VNON)
				vp->v_type = VDIR;
			vp->v_flag |= VROOT;
		}
	}
	
	LIST_INSERT_HEAD(nhpp, np, n_hash);
	np->n_fhp = &np->n_fh;
	bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize);
	np->n_fhsize = fhsize;
	np->n_accstamp = -1;
	rw_exit(&nfs_hashlock);
	*npp = np;
	return (0);
}

int
nfs_inactive(v)
	void *v;
{
	struct vop_inactive_args *ap = v;
	struct nfsnode *np;
	struct sillyrename *sp;
	struct proc *p = curproc;	/* XXX */

	np = VTONFS(ap->a_vp);

#ifdef DIAGNOSTIC
	if (prtactive && ap->a_vp->v_usecount != 0)
		vprint("nfs_inactive: pushing active", ap->a_vp);
#endif

	if (ap->a_vp->v_type != VDIR) {
		sp = np->n_sillyrename;
		np->n_sillyrename = (struct sillyrename *)0;
	} else
		sp = (struct sillyrename *)0;
	if (sp) {
		/*
		 * Remove the silly file that was rename'd earlier
		 */
		nfs_vinvalbuf(ap->a_vp, 0, sp->s_cred, p);
		nfs_removeit(sp);
		crfree(sp->s_cred);
		vrele(sp->s_dvp);
		free(sp, M_NFSREQ);
	}
	np->n_flag &= (NMODIFIED | NFLUSHINPROG | NFLUSHWANT);

	VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
	return (0);
}

/*
 * Reclaim an nfsnode so that it can be used for other purposes.
 */
int
nfs_reclaim(v)
	void *v;
{
	struct vop_reclaim_args *ap = v;
	struct vnode *vp = ap->a_vp;
	struct nfsnode *np = VTONFS(vp);

#ifdef DIAGNOSTIC
	if (prtactive && vp->v_usecount != 0)
		vprint("nfs_reclaim: pushing active", vp);
#endif

	if (np->n_hash.le_prev != NULL)
		LIST_REMOVE(np, n_hash);

	if (np->n_rcred)
		crfree(np->n_rcred);
	if (np->n_wcred)
		crfree(np->n_wcred);
	cache_purge(vp);
	pool_put(&nfs_node_pool, vp->v_data);
	vp->v_data = NULL;
	return (0);
}