NetBSD/sys/nfs/nfs_node.c

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1993-03-21 12:45:37 +03:00
/*
* Copyright (c) 1989 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* from: @(#)nfs_node.c 7.34 (Berkeley) 5/15/91
* $Id: nfs_node.c,v 1.3 1993/07/28 02:22:25 cgd Exp $
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*/
#include "param.h"
#include "systm.h"
#include "proc.h"
#include "mount.h"
#include "namei.h"
#include "vnode.h"
#include "kernel.h"
#include "malloc.h"
#include "nfsv2.h"
#include "nfs.h"
#include "nfsnode.h"
#include "nfsmount.h"
/* The request list head */
extern struct nfsreq nfsreqh;
#define NFSNOHSZ 512
#if ((NFSNOHSZ&(NFSNOHSZ-1)) == 0)
#define NFSNOHASH(fhsum) ((fhsum)&(NFSNOHSZ-1))
#else
#define NFSNOHASH(fhsum) (((unsigned)(fhsum))%NFSNOHSZ)
#endif
union nhead {
union nhead *nh_head[2];
struct nfsnode *nh_chain[2];
} nhead[NFSNOHSZ];
#define TRUE 1
#define FALSE 0
/*
* Initialize hash links for nfsnodes
* and build nfsnode free list.
*/
nfs_nhinit()
{
register int i;
register union nhead *nh = nhead;
#ifndef lint
if (VN_MAXPRIVATE < sizeof(struct nfsnode))
panic("nfs_nhinit: too small");
#endif /* not lint */
for (i = NFSNOHSZ; --i >= 0; nh++) {
nh->nh_head[0] = nh;
nh->nh_head[1] = nh;
}
}
/*
* Compute an entry in the NFS hash table structure
*/
union nhead *
nfs_hash(fhp)
register nfsv2fh_t *fhp;
{
register u_char *fhpp;
register u_long fhsum;
int i;
fhpp = &fhp->fh_bytes[0];
fhsum = 0;
for (i = 0; i < NFSX_FH; i++)
fhsum += *fhpp++;
return (&nhead[NFSNOHASH(fhsum)]);
}
/*
* 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.
*/
nfs_nget(mntp, fhp, npp)
struct mount *mntp;
register nfsv2fh_t *fhp;
struct nfsnode **npp;
{
register struct nfsnode *np;
register struct vnode *vp;
extern struct vnodeops nfsv2_vnodeops;
struct vnode *nvp;
union nhead *nh;
int error;
nh = nfs_hash(fhp);
loop:
for (np = nh->nh_chain[0]; np != (struct nfsnode *)nh; np = np->n_forw) {
if (mntp != NFSTOV(np)->v_mount ||
bcmp((caddr_t)fhp, (caddr_t)&np->n_fh, NFSX_FH))
continue;
if ((np->n_flag & NLOCKED) != 0) {
np->n_flag |= NWANT;
(void) tsleep((caddr_t)np, PINOD, "nfsnode", 0);
goto loop;
}
vp = NFSTOV(np);
if (vget(vp))
goto loop;
*npp = np;
return(0);
}
if (error = getnewvnode(VT_NFS, mntp, &nfsv2_vnodeops, &nvp)) {
*npp = 0;
return (error);
}
vp = nvp;
np = VTONFS(vp);
np->n_vnode = vp;
/*
* Insert the nfsnode in the hash queue for its new file handle
*/
np->n_flag = 0;
insque(np, nh);
nfs_lock(vp);
bcopy((caddr_t)fhp, (caddr_t)&np->n_fh, NFSX_FH);
np->n_attrstamp = 0;
np->n_direofoffset = 0;
np->n_sillyrename = (struct sillyrename *)0;
np->n_size = 0;
np->n_mtime = 0;
np->n_lockf = 0;
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*npp = np;
return (0);
}
nfs_inactive(vp, p)
struct vnode *vp;
struct proc *p;
{
register struct nfsnode *np;
register struct sillyrename *sp;
struct nfsnode *dnp;
extern int prtactive;
np = VTONFS(vp);
if (prtactive && vp->v_usecount != 0)
vprint("nfs_inactive: pushing active", vp);
nfs_lock(vp);
sp = np->n_sillyrename;
np->n_sillyrename = (struct sillyrename *)0;
if (sp) {
/*
* Remove the silly file that was rename'd earlier
*/
if (!nfs_nget(vp->v_mount, &sp->s_fh, &dnp)) {
sp->s_dvp = NFSTOV(dnp);
nfs_removeit(sp, p);
nfs_nput(sp->s_dvp);
}
crfree(sp->s_cred);
vrele(sp->s_dvp);
free((caddr_t)sp, M_NFSREQ);
}
nfs_unlock(vp);
np->n_flag &= NMODIFIED;
#ifdef notdef
/*
* Scan the request list for any requests left hanging about
*/
s = splnet();
rep = nfsreqh.r_next;
while (rep && rep != &nfsreqh) {
if (rep->r_vp == vp) {
rep->r_prev->r_next = rep2 = rep->r_next;
rep->r_next->r_prev = rep->r_prev;
m_freem(rep->r_mreq);
if (rep->r_mrep != NULL)
m_freem(rep->r_mrep);
free((caddr_t)rep, M_NFSREQ);
rep = rep2;
} else
rep = rep->r_next;
}
splx(s);
#endif
return (0);
}
/*
* Reclaim an nfsnode so that it can be used for other purposes.
*/
nfs_reclaim(vp)
register struct vnode *vp;
{
register struct nfsnode *np = VTONFS(vp);
extern int prtactive;
if (prtactive && vp->v_usecount != 0)
vprint("nfs_reclaim: pushing active", vp);
/*
* Remove the nfsnode from its hash chain.
*/
remque(np);
np->n_forw = np;
np->n_back = np;
cache_purge(vp);
np->n_flag = 0;
np->n_direofoffset = 0;
return (0);
}
/*
* In theory, NFS does not need locking, but we make provision
* for doing it just in case it is needed.
*/
int donfslocking = 0;
/*
* Lock an nfsnode
*/
nfs_lock(vp)
struct vnode *vp;
{
register struct nfsnode *np = VTONFS(vp);
if (!donfslocking)
return;
while (np->n_flag & NLOCKED) {
np->n_flag |= NWANT;
if (np->n_lockholder == curproc->p_pid)
panic("locking against myself");
np->n_lockwaiter = curproc->p_pid;
(void) tsleep((caddr_t)np, PINOD, "nfslock", 0);
}
np->n_lockwaiter = 0;
np->n_lockholder = curproc->p_pid;
np->n_flag |= NLOCKED;
}
/*
* Unlock an nfsnode
*/
nfs_unlock(vp)
struct vnode *vp;
{
register struct nfsnode *np = VTONFS(vp);
np->n_lockholder = 0;
np->n_flag &= ~NLOCKED;
if (np->n_flag & NWANT) {
np->n_flag &= ~NWANT;
wakeup((caddr_t)np);
}
}
/*
* Check for a locked nfsnode
*/
nfs_islocked(vp)
struct vnode *vp;
{
if (VTONFS(vp)->n_flag & NLOCKED)
return (1);
return (0);
}
/*
* Unlock and vrele()
* since I can't decide if dirs. should be locked, I will check for
* the lock and be flexible
*/
nfs_nput(vp)
struct vnode *vp;
{
register struct nfsnode *np = VTONFS(vp);
if (np->n_flag & NLOCKED)
nfs_unlock(vp);
vrele(vp);
}
/*
* Nfs abort op, called after namei() when a CREATE/DELETE isn't actually
* done. Currently nothing to do.
*/
/* ARGSUSED */
nfs_abortop(ndp)
struct nameidata *ndp;
{
if ((ndp->ni_nameiop & (HASBUF | SAVESTART)) == HASBUF)
FREE(ndp->ni_pnbuf, M_NAMEI);
return (0);
}