usr/src/sys/nfs/nfs_node.c

/*
 * 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.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)nfs_node.c  7.47 (Berkeley) %G%
 */

#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 <nfs/rpcv2.h>
#include <nfs/nfsv2.h>
#include <nfs/nfs.h>
#include <nfs/nfsnode.h>
#include <nfs/nfsmount.h>
#include <nfs/nqnfs.h>

struct nfsnode **nheadhashtbl;
u_long nheadhash;
#define NFSNOHASH(fhsum)        ((fhsum)&nheadhash)

#define TRUE    1
#define FALSE   0

/*
 * Initialize hash links for nfsnodes
 * and build nfsnode free list.
 */
nfs_nhinit()
{

#ifndef lint
        if ((sizeof(struct nfsnode) - 1) & sizeof(struct nfsnode))
                printf("nfs_nhinit: bad size %d\n", sizeof(struct nfsnode));
#endif /* not lint */
        nheadhashtbl = hashinit(desiredvnodes, M_NFSNODE, &nheadhash);
}

/*
 * Compute an entry in the NFS hash table structure
 */
struct nfsnode **
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 (&nheadhashtbl[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, *nq, **nhpp;
        register struct vnode *vp;
        extern int (**nfsv2_vnodeop_p)();
        struct vnode *nvp;
        int error;

        nhpp = nfs_hash(fhp);
loop:
        for (np = *nhpp; np; np = np->n_forw) {
                if (mntp != NFSTOV(np)->v_mount ||
                    bcmp((caddr_t)fhp, (caddr_t)&np->n_fh, NFSX_FH))
                        continue;
                vp = NFSTOV(np);
                if (vget(vp))
                        goto loop;
                *npp = np;
                return(0);
        }
        if (error = getnewvnode(VT_NFS, mntp, nfsv2_vnodeop_p, &nvp)) {
                *npp = 0;
                return (error);
        }
        vp = nvp;
        MALLOC(np, struct nfsnode *, sizeof *np, M_NFSNODE, M_WAITOK);
        vp->v_data = np;
        np->n_vnode = vp;
        /*
         * Insert the nfsnode in the hash queue for its new file handle
         */
        np->n_flag = 0;
        if (nq = *nhpp)
                nq->n_back = &np->n_forw;
        np->n_forw = nq;
        np->n_back = nhpp;
        *nhpp = np;
        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;
        if (VFSTONFS(mntp)->nm_flag & NFSMNT_NQNFS) {
                np->n_brev = 0;
                np->n_lrev = 0;
                np->n_expiry = (time_t)0;
                np->n_tnext = (struct nfsnode *)0;
        }
        *npp = np;
        return (0);
}

nfs_inactive(ap)
        struct vop_inactive_args /* {
                struct vnode *a_vp;
        } */ *ap;
{
        register struct nfsnode *np;
        register struct sillyrename *sp;
        struct proc *p = curproc;       /* XXX */
        extern int prtactive;

        np = VTONFS(ap->a_vp);
        if (prtactive && ap->a_vp->v_usecount != 0)
                vprint("nfs_inactive: pushing active", ap->a_vp);
        sp = np->n_sillyrename;
        np->n_sillyrename = (struct sillyrename *)0;
        if (sp) {
                /*
                 * Remove the silly file that was rename'd earlier
                 */
                (void) nfs_vinvalbuf(ap->a_vp, 0, sp->s_cred, p, 1);
                nfs_removeit(sp);
                crfree(sp->s_cred);
                vrele(sp->s_dvp);
#ifdef SILLYSEPARATE
                free((caddr_t)sp, M_NFSREQ);
#endif
        }
        np->n_flag &= (NMODIFIED | NFLUSHINPROG | NFLUSHWANT | NQNFSEVICTED);
        return (0);
}

/*
 * Reclaim an nfsnode so that it can be used for other purposes.
 */
nfs_reclaim(ap)
        struct vop_reclaim_args /* {
                struct vnode *a_vp;
        } */ *ap;
{
        register struct vnode *vp = ap->a_vp;
        register struct nfsnode *np = VTONFS(vp);
        register struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        register struct nfsnode *nq;
        extern int prtactive;

        if (prtactive && vp->v_usecount != 0)
                vprint("nfs_reclaim: pushing active", vp);
        /*
         * Remove the nfsnode from its hash chain.
         */
        if (nq = np->n_forw)
                nq->n_back = np->n_back;
        *np->n_back = nq;

        /*
         * For nqnfs, take it off the timer queue as required.
         */
        if ((nmp->nm_flag & NFSMNT_NQNFS) && np->n_tnext) {
                if (np->n_tnext == (struct nfsnode *)nmp)
                        nmp->nm_tprev = np->n_tprev;
                else
                        np->n_tnext->n_tprev = np->n_tprev;
                if (np->n_tprev == (struct nfsnode *)nmp)
                        nmp->nm_tnext = np->n_tnext;
                else
                        np->n_tprev->n_tnext = np->n_tnext;
        }
        cache_purge(vp);
        FREE(vp->v_data, M_NFSNODE);
        vp->v_data = (void *)0;
        return (0);
}

/*
 * Lock an nfsnode
 */
nfs_lock(ap)
        struct vop_lock_args /* {
                struct vnode *a_vp;
        } */ *ap;
{
        register struct vnode *vp = ap->a_vp;

        /*
         * Ugh, another place where interruptible mounts will get hung.
         * If you make this sleep interruptible, then you have to fix all
         * the VOP_LOCK() calls to expect interruptibility.
         */
        while (vp->v_flag & VXLOCK) {
                vp->v_flag |= VXWANT;
                sleep((caddr_t)vp, PINOD);
        }
        if (vp->v_tag == VT_NON)
                return (ENOENT);
        return (0);
}

/*
 * Unlock an nfsnode
 */
nfs_unlock(ap)
        struct vop_unlock_args /* {
                struct vnode *a_vp;
        } */ *ap;
{

        return (0);
}

/*
 * Check for a locked nfsnode
 */
nfs_islocked(ap)
        struct vop_islocked_args /* {
                struct vnode *a_vp;
        } */ *ap;
{

        return (0);
}

/*
 * Nfs abort op, called after namei() when a CREATE/DELETE isn't actually
 * done. Currently nothing to do.
 */
/* ARGSUSED */
int
nfs_abortop(ap)
        struct vop_abortop_args /* {
                struct vnode *a_dvp;
                struct componentname *a_cnp;
        } */ *ap;
{

        if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
                FREE(ap->a_cnp->cn_pnbuf, M_NAMEI);
        return (0);
}