path: root/sys/nfs/nfs_vfsops.c

/*	$OpenBSD: nfs_vfsops.c,v 1.126 2021/01/02 02:41:42 cheloha Exp $	*/
/*	$NetBSD: nfs_vfsops.c,v 1.46.4.1 1996/05/25 22:40:35 fvdl Exp $	*/

/*
 * Copyright (c) 1989, 1993, 1995
 *	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_vfsops.c	8.12 (Berkeley) 5/20/95
 */

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/signal.h>
#include <sys/proc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/swap.h>
#include <sys/buf.h>
#include <sys/mbuf.h>
#include <sys/dirent.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/queue.h>

#include <netinet/in.h>

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

extern struct nfsstats nfsstats;
extern int nfs_ticks;
extern u_int32_t nfs_procids[NFS_NPROCS];

int	nfs_sysctl(int *, u_int, void *, size_t *, void *, size_t,
	    struct proc *);
int	nfs_checkexp(struct mount *, struct mbuf *, int *, struct ucred **);
struct	mount *nfs_mount_diskless(struct nfs_dlmount *, char *, int,
	    struct vnode **, struct proc *p);
int	mountnfs(struct nfs_args *, struct mount *, struct mbuf *,
	    const char *, char *, struct vnode **, struct proc *p);
int	nfs_quotactl(struct mount *, int, uid_t, caddr_t, struct proc *);
int	nfs_root(struct mount *, struct vnode **);
int	nfs_start(struct mount *, int, struct proc *);
int	nfs_statfs(struct mount *, struct statfs *, struct proc *);
int	nfs_sync(struct mount *, int, int, struct ucred *, struct proc *);
int	nfs_unmount(struct mount *, int, struct proc *);
void	nfs_reaper(void *);
int	nfs_vget(struct mount *, ino_t, struct vnode **);
int	nfs_vptofh(struct vnode *, struct fid *);
int	nfs_mountroot(void);
void	nfs_decode_args(struct nfsmount *, struct nfs_args *,
	    struct nfs_args *);
int	nfs_fhtovp(struct mount *, struct fid *, struct vnode **);

/*
 * nfs vfs operations.
 */
const struct vfsops nfs_vfsops = {
	.vfs_mount	= nfs_mount,
	.vfs_start	= nfs_start,
	.vfs_unmount	= nfs_unmount,
	.vfs_root	= nfs_root,
	.vfs_quotactl	= nfs_quotactl,
	.vfs_statfs	= nfs_statfs,
	.vfs_sync	= nfs_sync,
	.vfs_vget	= nfs_vget,
	.vfs_fhtovp	= nfs_fhtovp,
	.vfs_vptofh	= nfs_vptofh,
	.vfs_init	= nfs_vfs_init,
	.vfs_sysctl	= nfs_sysctl,
	.vfs_checkexp	= nfs_checkexp,
};

/*
 * nfs statfs call
 */
int
nfs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p)
{
	struct vnode *vp;
	struct nfs_statfs *sfp = NULL;
	struct nfsm_info	info;
	u_int32_t *tl;
	int32_t t1;
	caddr_t cp2;
	struct nfsmount *nmp = VFSTONFS(mp);
	int error = 0, retattr;
	struct ucred *cred;
	u_quad_t tquad;

	info.nmi_v3 = (nmp->nm_flag & NFSMNT_NFSV3);

	error = nfs_root(mp, &vp);
	if (error)
		return (error);
	cred = crget();
	cred->cr_ngroups = 0;
	if (info.nmi_v3 && (nmp->nm_flag & NFSMNT_GOTFSINFO) == 0)
		(void)nfs_fsinfo(nmp, vp, cred, p);
	nfsstats.rpccnt[NFSPROC_FSSTAT]++;
	info.nmi_mb = info.nmi_mreq = nfsm_reqhead(NFSX_FH(info.nmi_v3));
	nfsm_fhtom(&info, vp, info.nmi_v3);

	info.nmi_procp = p;
	info.nmi_cred = cred;
	error = nfs_request(vp, NFSPROC_FSSTAT, &info);
	if (info.nmi_v3)
		nfsm_postop_attr(vp, retattr);
	if (error) {
		m_freem(info.nmi_mrep);
		goto nfsmout;
	}

	nfsm_dissect(sfp, struct nfs_statfs *, NFSX_STATFS(info.nmi_v3));
	sbp->f_iosize = min(nmp->nm_rsize, nmp->nm_wsize);
	if (info.nmi_v3) {
		sbp->f_bsize = NFS_FABLKSIZE;
		tquad = fxdr_hyper(&sfp->sf_tbytes);
		sbp->f_blocks = tquad / (u_quad_t)NFS_FABLKSIZE;
		tquad = fxdr_hyper(&sfp->sf_fbytes);
		sbp->f_bfree = tquad / (u_quad_t)NFS_FABLKSIZE;
		tquad = fxdr_hyper(&sfp->sf_abytes);
		sbp->f_bavail = (quad_t)tquad / (quad_t)NFS_FABLKSIZE;

		tquad = fxdr_hyper(&sfp->sf_tfiles);
		sbp->f_files = tquad;
		tquad = fxdr_hyper(&sfp->sf_ffiles);
		sbp->f_ffree = tquad;
		sbp->f_favail = tquad;
	} else {
		sbp->f_bsize = fxdr_unsigned(int32_t, sfp->sf_bsize);
		sbp->f_blocks = fxdr_unsigned(int32_t, sfp->sf_blocks);
		sbp->f_bfree = fxdr_unsigned(int32_t, sfp->sf_bfree);
		sbp->f_bavail = fxdr_unsigned(int32_t, sfp->sf_bavail);
		sbp->f_files = 0;
		sbp->f_ffree = 0;
		sbp->f_favail = 0;
	}
	copy_statfs_info(sbp, mp);
	m_freem(info.nmi_mrep);
nfsmout: 
	vput(vp);
	crfree(cred);
	return (error);
}

/*
 * nfs version 3 fsinfo rpc call
 */
int
nfs_fsinfo(struct nfsmount *nmp, struct vnode *vp, struct ucred *cred,
    struct proc *p)
{
	struct nfsv3_fsinfo *fsp;
	struct nfsm_info	info;
	int32_t t1;
	u_int32_t *tl, pref, max;
	caddr_t cp2;
	int error = 0, retattr;

	nfsstats.rpccnt[NFSPROC_FSINFO]++;
	info.nmi_mb = info.nmi_mreq = nfsm_reqhead(NFSX_FH(1));
	nfsm_fhtom(&info, vp, 1);

	info.nmi_procp = p;
	info.nmi_cred = cred;
	error = nfs_request(vp, NFSPROC_FSINFO, &info);

	nfsm_postop_attr(vp, retattr);
	if (error) {
		m_freem(info.nmi_mrep);
		goto nfsmout;
	}

	nfsm_dissect(fsp, struct nfsv3_fsinfo *, NFSX_V3FSINFO);
	pref = fxdr_unsigned(u_int32_t, fsp->fs_wtpref);
	if (pref < nmp->nm_wsize)
		nmp->nm_wsize = (pref + NFS_FABLKSIZE - 1) &
			~(NFS_FABLKSIZE - 1);
	max = fxdr_unsigned(u_int32_t, fsp->fs_wtmax);
	if (max < nmp->nm_wsize) {
		nmp->nm_wsize = max & ~(NFS_FABLKSIZE - 1);
		if (nmp->nm_wsize == 0)
			nmp->nm_wsize = max;
	}
	pref = fxdr_unsigned(u_int32_t, fsp->fs_rtpref);
	if (pref < nmp->nm_rsize)
		nmp->nm_rsize = (pref + NFS_FABLKSIZE - 1) &
			~(NFS_FABLKSIZE - 1);
	max = fxdr_unsigned(u_int32_t, fsp->fs_rtmax);
	if (max < nmp->nm_rsize) {
		nmp->nm_rsize = max & ~(NFS_FABLKSIZE - 1);
		if (nmp->nm_rsize == 0)
			nmp->nm_rsize = max;
	}
	pref = fxdr_unsigned(u_int32_t, fsp->fs_dtpref);
	if (pref < nmp->nm_readdirsize)
		nmp->nm_readdirsize = (pref + NFS_DIRBLKSIZ - 1) &
			~(NFS_DIRBLKSIZ - 1);
	if (max < nmp->nm_readdirsize) {
		nmp->nm_readdirsize = max & ~(NFS_DIRBLKSIZ - 1);
		if (nmp->nm_readdirsize == 0)
			nmp->nm_readdirsize = max;
	}
	nmp->nm_flag |= NFSMNT_GOTFSINFO;

	m_freem(info.nmi_mrep);
nfsmout: 
	return (error);
}

struct nfs_diskless nfs_diskless;

/*
 * Mount a remote root fs via. NFS.  It goes like this:
 * - Call nfs_boot_init() to fill in the nfs_diskless struct
 *   (using RARP, bootparam RPC, mountd RPC)
 * - hand craft the swap nfs vnode hanging off a fake mount point
 *	if swdevt[0].sw_dev == NODEV
 * - build the rootfs mount point and call mountnfs() to do the rest.
 */
int
nfs_mountroot(void)
{
	struct vattr attr;
	struct mount *mp;
	struct vnode *vp;
	struct proc *procp;
	long n;
	int error;

	procp = curproc; /* XXX */

	/*
	 * Call nfs_boot_init() to fill in the nfs_diskless struct.
	 * Side effect:	 Finds and configures a network interface.
	 */
	nfs_boot_init(&nfs_diskless, procp);

	/*
	 * Create the root mount point.
	 */
	if (nfs_boot_getfh(&nfs_diskless.nd_boot, "root", &nfs_diskless.nd_root, -1))
		panic("nfs_mountroot: root");
	mp = nfs_mount_diskless(&nfs_diskless.nd_root, "/", 0, &vp, procp);
	printf("root on %s\n", nfs_diskless.nd_root.ndm_host);

	/*
	 * Link it into the mount list.
	 */
	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
	rootvp = vp;
	vfs_unbusy(mp);

	/* Get root attributes (for the time). */
	error = VOP_GETATTR(rootvp, &attr, procp->p_ucred, procp);
	if (error) panic("nfs_mountroot: getattr for root");
	n = attr.va_atime.tv_sec;
#ifdef	DEBUG
	printf("root time: 0x%lx\n", n);
#endif
	inittodr(n);

#ifdef notyet
	/* Set up swap credentials. */
	proc0.p_ucred->cr_uid = ntohl(nfs_diskless.swap_ucred.cr_uid);
	proc0.p_ucred->cr_gid = ntohl(nfs_diskless.swap_ucred.cr_gid);
	if ((proc0.p_ucred->cr_ngroups = ntohs(nfs_diskless.swap_ucred.cr_ngroups)) >
		NGROUPS_MAX)
		proc0.p_ucred->cr_ngroups = NGROUPS_MAX;
	for (i = 0; i < proc0.p_ucred->cr_ngroups; i++)
	    proc0.p_ucred->cr_groups[i] = ntohl(nfs_diskless.swap_ucred.cr_groups[i]);
#endif

	/*
	 * "Mount" the swap device.
	 *
	 * On a "dataless" configuration (swap on disk) we will have:
	 *	(swdevt[0].sw_dev != NODEV) identifying the swap device.
	 */
	if (swdevt[0].sw_dev != NODEV) {
		if (bdevvp(swapdev, &swapdev_vp))
			panic("nfs_mountroot: can't setup swap vp");
		printf("swap on device 0x%x\n", swdevt[0].sw_dev);
		return (0);
	}

	/*
	 * If swapping to an nfs node:	(swdevt[0].sw_dev == NODEV)
	 * Create a fake mount point just for the swap vnode so that the
	 * swap file can be on a different server from the rootfs.
	 *
	 * Wait 5 retries, finally no swap is cool. -mickey
	 */
	error = nfs_boot_getfh(&nfs_diskless.nd_boot, "swap", &nfs_diskless.nd_swap, 5);
	if (!error) {
		mp = nfs_mount_diskless(&nfs_diskless.nd_swap, "/swap", 0, &vp,
		    procp);
		vfs_unbusy(mp);

		/*
		 * Since the swap file is not the root dir of a file system,
		 * hack it to a regular file.
		 */
		vp->v_type = VREG;
		vp->v_flag = 0;

		/*
		 * Next line is a hack to make swapmount() work on NFS
		 * swap files.
		 */
		swdevt[0].sw_dev = NETDEV;
		/* end hack */
		nfs_diskless.sw_vp = vp;

		/*
		 * Find out how large the swap file is.
		 */
		error = VOP_GETATTR(vp, &attr, procp->p_ucred, procp);
		if (error)
			printf("nfs_mountroot: getattr for swap\n");
		n = (long) (attr.va_size >> DEV_BSHIFT);

		printf("swap on %s\n", nfs_diskless.nd_swap.ndm_host);
#ifdef	DEBUG
		printf("swap size: 0x%lx (blocks)\n", n);
#endif
		return (0);
	}

	printf("WARNING: no swap\n");
	swdevt[0].sw_dev = NODEV;
	return (0);
}

/*
 * Internal version of mount system call for diskless setup.
 */
struct mount *
nfs_mount_diskless(struct nfs_dlmount *ndmntp, char *mntname, int mntflag,
    struct vnode **vpp, struct proc *p)
{
	struct mount *mp;
	struct mbuf *m;
	int error;

	if (vfs_rootmountalloc("nfs", mntname, &mp))
		panic("nfs_mount_diskless: vfs_rootmountalloc failed");
	mp->mnt_flag |= mntflag;

	/* Get mbuf for server sockaddr. */
	m = m_get(M_WAIT, MT_SONAME);
	bcopy(ndmntp->ndm_args.addr, mtod(m, caddr_t),
	    (m->m_len = ndmntp->ndm_args.addr->sa_len));

	error = mountnfs(&ndmntp->ndm_args, mp, m, mntname,
	    ndmntp->ndm_args.hostname, vpp, p);
	if (error)
		panic("nfs_mountroot: mount %s failed: %d", mntname, error);

	return (mp);
}

void
nfs_decode_args(struct nfsmount *nmp, struct nfs_args *argp,
    struct nfs_args *nargp)
{
	int adjsock = 0;
	int maxio;

#if 0
	/* Re-bind if rsrvd port requested and wasn't on one */
	adjsock = !(nmp->nm_flag & NFSMNT_RESVPORT)
		  && (argp->flags & NFSMNT_RESVPORT);
#endif
	/* Also re-bind if we're switching to/from a connected UDP socket */
	adjsock |= ((nmp->nm_flag & NFSMNT_NOCONN) !=
	    (argp->flags & NFSMNT_NOCONN));

	nmp->nm_flag =
	    (argp->flags & ~NFSMNT_INTERNAL) | (nmp->nm_flag & NFSMNT_INTERNAL);

	if ((argp->flags & NFSMNT_TIMEO) && argp->timeo > 0) {
		nmp->nm_timeo = (argp->timeo * NFS_HZ + 5) / 10;
		if (nmp->nm_timeo < NFS_MINTIMEO)
			nmp->nm_timeo = NFS_MINTIMEO;
		else if (nmp->nm_timeo > NFS_MAXTIMEO)
			nmp->nm_timeo = NFS_MAXTIMEO;
	}

	if ((argp->flags & NFSMNT_RETRANS) && argp->retrans > 1)
		nmp->nm_retry = MIN(argp->retrans, NFS_MAXREXMIT);
	if (!(nmp->nm_flag & NFSMNT_SOFT))
		nmp->nm_retry = NFS_MAXREXMIT + 1; /* past clip limit */

	if (argp->flags & NFSMNT_NFSV3) {
		if (argp->sotype == SOCK_DGRAM)
			maxio = NFS_MAXDGRAMDATA;
		else
			maxio = NFS_MAXDATA;
	} else
		maxio = NFS_V2MAXDATA;

	if ((argp->flags & NFSMNT_WSIZE) && argp->wsize > 0) {
		int osize = nmp->nm_wsize;
		nmp->nm_wsize = argp->wsize;
		/* Round down to multiple of blocksize */
		nmp->nm_wsize &= ~(NFS_FABLKSIZE - 1);
		if (nmp->nm_wsize <= 0)
			nmp->nm_wsize = NFS_FABLKSIZE;
		adjsock |= (nmp->nm_wsize != osize);
	}
	if (nmp->nm_wsize > maxio)
		nmp->nm_wsize = maxio;
	if (nmp->nm_wsize > MAXBSIZE)
		nmp->nm_wsize = MAXBSIZE;

	if ((argp->flags & NFSMNT_RSIZE) && argp->rsize > 0) {
		int osize = nmp->nm_rsize;
		nmp->nm_rsize = argp->rsize;
		/* Round down to multiple of blocksize */
		nmp->nm_rsize &= ~(NFS_FABLKSIZE - 1);
		if (nmp->nm_rsize <= 0)
			nmp->nm_rsize = NFS_FABLKSIZE;
		adjsock |= (nmp->nm_rsize != osize);
	}
	if (nmp->nm_rsize > maxio)
		nmp->nm_rsize = maxio;
	if (nmp->nm_rsize > MAXBSIZE)
		nmp->nm_rsize = MAXBSIZE;

	if ((argp->flags & NFSMNT_READDIRSIZE) && argp->readdirsize > 0) {
		nmp->nm_readdirsize = argp->readdirsize;
		/* Round down to multiple of blocksize */
		nmp->nm_readdirsize &= ~(NFS_DIRBLKSIZ - 1);
		if (nmp->nm_readdirsize < NFS_DIRBLKSIZ)
			nmp->nm_readdirsize = NFS_DIRBLKSIZ;
	} else if (argp->flags & NFSMNT_RSIZE)
		nmp->nm_readdirsize = nmp->nm_rsize;

	if (nmp->nm_readdirsize > maxio)
		nmp->nm_readdirsize = maxio;

	if ((argp->flags & NFSMNT_MAXGRPS) && argp->maxgrouplist >= 0 &&
		argp->maxgrouplist <= NFS_MAXGRPS)
		nmp->nm_numgrps = argp->maxgrouplist;
	if ((argp->flags & NFSMNT_READAHEAD) && argp->readahead >= 0 &&
		argp->readahead <= NFS_MAXRAHEAD)
		nmp->nm_readahead = argp->readahead;
	if (argp->flags & NFSMNT_ACREGMIN && argp->acregmin >= 0) {
		if (argp->acregmin > 0xffff)
			nmp->nm_acregmin = 0xffff;
		else
			nmp->nm_acregmin = argp->acregmin;
	}
	if (argp->flags & NFSMNT_ACREGMAX && argp->acregmax >= 0) {
		if (argp->acregmax > 0xffff)
			nmp->nm_acregmax = 0xffff;
		else
			nmp->nm_acregmax = argp->acregmax;
	}
	if (nmp->nm_acregmin > nmp->nm_acregmax)
	  nmp->nm_acregmin = nmp->nm_acregmax;

	if (argp->flags & NFSMNT_ACDIRMIN && argp->acdirmin >= 0) {
		if (argp->acdirmin > 0xffff)
			nmp->nm_acdirmin = 0xffff;
		else
			nmp->nm_acdirmin = argp->acdirmin;
	}
	if (argp->flags & NFSMNT_ACDIRMAX && argp->acdirmax >= 0) {
		if (argp->acdirmax > 0xffff)
			nmp->nm_acdirmax = 0xffff;
		else
			nmp->nm_acdirmax = argp->acdirmax;
	}
	if (nmp->nm_acdirmin > nmp->nm_acdirmax)
	  nmp->nm_acdirmin = nmp->nm_acdirmax;

	if (nmp->nm_so && adjsock) {
		nfs_disconnect(nmp);
		if (nmp->nm_sotype == SOCK_DGRAM)
			while (nfs_connect(nmp, NULL)) {
				printf("nfs_args: retrying connect\n");
				tsleep_nsec(&nowake, PSOCK, "nfscon",
				    SEC_TO_NSEC(1));
			}
	}

	/* Update nargp based on nmp */
	nargp->wsize = nmp->nm_wsize;
	nargp->rsize = nmp->nm_rsize;
	nargp->readdirsize = nmp->nm_readdirsize;
	nargp->timeo = nmp->nm_timeo;
	nargp->retrans = nmp->nm_retry;
	nargp->maxgrouplist = nmp->nm_numgrps;
	nargp->readahead = nmp->nm_readahead;
	nargp->acregmin = nmp->nm_acregmin;
	nargp->acregmax = nmp->nm_acregmax;
	nargp->acdirmin = nmp->nm_acdirmin;
	nargp->acdirmax = nmp->nm_acdirmax;
}

/*
 * VFS Operations.
 *
 * mount system call
 * It seems a bit dumb to copyinstr() the host here and then
 * bcopy() it in mountnfs(), but I wanted to detect errors before
 * doing the sockargs() call because sockargs() allocates an mbuf and
 * an error after that means that I have to release the mbuf.
 */
/* ARGSUSED */
int
nfs_mount(struct mount *mp, const char *path, void *data,
    struct nameidata *ndp, struct proc *p)
{
	int error;
	struct nfs_args *args = data;
	struct mbuf *nam;
	struct vnode *vp;
	char hst[MNAMELEN];
	size_t len;
	u_char nfh[NFSX_V3FHMAX];

	if (args &&
	    (args->flags & (NFSMNT_NFSV3|NFSMNT_RDIRPLUS)) == NFSMNT_RDIRPLUS)
		return (EINVAL);

	if (nfs_niothreads < 0) {
		nfs_niothreads = 4;
		nfs_getset_niothreads(1);
	}

	if (mp->mnt_flag & MNT_UPDATE) {
		struct nfsmount *nmp = VFSTONFS(mp);

		if (nmp == NULL)
			return (EIO);
		/*
		 * When doing an update, we can't change from or to
		 * v3.
		 */
		if (args) {
			args->flags = (args->flags & ~(NFSMNT_NFSV3)) |
			    (nmp->nm_flag & (NFSMNT_NFSV3));
			nfs_decode_args(nmp, args, &mp->mnt_stat.mount_info.nfs_args);
		}
		return (0);
	}
	if (args->fhsize < 0 || args->fhsize > NFSX_V3FHMAX)
		return (EINVAL);
	error = copyin(args->fh, nfh, args->fhsize);
	if (error)
		return (error);
	error = copyinstr(args->hostname, hst, MNAMELEN-1, &len);
	if (error)
		return (error);
	memset(&hst[len], 0, MNAMELEN - len);
	/* sockargs() call must be after above copyin() calls */
	error = sockargs(&nam, args->addr, args->addrlen, MT_SONAME);
	if (error)
		return (error);
	args->fh = nfh;
	error = mountnfs(args, mp, nam, path, hst, &vp, p);
	return (error);
}

/*
 * Common code for mount and mountroot
 */
int
mountnfs(struct nfs_args *argp, struct mount *mp, struct mbuf *nam,
    const char *pth, char *hst, struct vnode **vpp, struct proc *p)
{
	struct nfsmount *nmp;
	struct nfsnode *np;
	struct vnode *vp;
	struct vattr attr;
	int error;

	if (mp->mnt_flag & MNT_UPDATE) {
		nmp = VFSTONFS(mp);
		/* update paths, file handles, etc, here	XXX */
		m_freem(nam);
		return (0);
	} else {
		nmp = malloc(sizeof(*nmp), M_NFSMNT,
		    M_WAITOK|M_ZERO);
		mp->mnt_data = nmp;
	}

	vfs_getnewfsid(mp);
	nmp->nm_mountp = mp;
	nmp->nm_timeo = NFS_TIMEO;
	nmp->nm_retry = NFS_RETRANS;
	nmp->nm_wsize = NFS_WSIZE;
	nmp->nm_rsize = NFS_RSIZE;
	nmp->nm_readdirsize = NFS_READDIRSIZE;
	nmp->nm_numgrps = NFS_MAXGRPS;
	nmp->nm_readahead = NFS_DEFRAHEAD;
	nmp->nm_acregmin = NFS_MINATTRTIMO;
	nmp->nm_acregmax = NFS_MAXATTRTIMO;
	nmp->nm_acdirmin = NFS_MINATTRTIMO;
	nmp->nm_acdirmax = NFS_MAXATTRTIMO;
	mp->mnt_stat.f_namemax = MAXNAMLEN;
	memset(mp->mnt_stat.f_mntonname, 0, MNAMELEN);
	strlcpy(mp->mnt_stat.f_mntonname, pth, MNAMELEN);
	memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
	strlcpy(mp->mnt_stat.f_mntfromname, hst, MNAMELEN);
	memset(mp->mnt_stat.f_mntfromspec, 0, MNAMELEN);
	strlcpy(mp->mnt_stat.f_mntfromspec, hst, MNAMELEN);
	bcopy(argp, &mp->mnt_stat.mount_info.nfs_args, sizeof(*argp));
	nmp->nm_nam = nam;
	nfs_decode_args(nmp, argp, &mp->mnt_stat.mount_info.nfs_args);

	nfs_ninit(nmp);
	TAILQ_INIT(&nmp->nm_reqsq);
	timeout_set_proc(&nmp->nm_rtimeout, nfs_timer, nmp);

	/* Set up the sockets and per-host congestion */
	nmp->nm_sotype = argp->sotype;
	nmp->nm_soproto = argp->proto;

	/*
	 * For Connection based sockets (TCP,...) defer the connect until
	 * the first request, in case the server is not responding.
	 */
	if (nmp->nm_sotype == SOCK_DGRAM &&
	    (error = nfs_connect(nmp, NULL)))
		goto bad;

	/*
	 * This is silly, but it has to be set so that vinifod() works.
	 * We do not want to do an nfs_statfs() here since we can get
	 * stuck on a dead server and we are holding a lock on the mount
	 * point.
	 */
	mp->mnt_stat.f_iosize = NFS_MAXDGRAMDATA;
	error = nfs_nget(mp, (nfsfh_t *)argp->fh, argp->fhsize, &np);
	if (error)
		goto bad;
	vp = NFSTOV(np);
	error = VOP_GETATTR(vp, &attr, p->p_ucred, p);
	if (error) {
		vput(vp);
		goto bad;
	}

	/*
	 * A reference count is needed on the nfsnode representing the
	 * remote root.  If this object is not persistent, then backward
	 * traversals of the mount point (i.e. "..") will not work if
	 * the nfsnode gets flushed out of the cache. Ufs does not have
	 * this problem, because one can identify root inodes by their
	 * number == ROOTINO (2).  So, just unlock, but no rele.
	 */
	nmp->nm_vnode = vp;
	if (vp->v_type == VNON)
		vp->v_type = VDIR;
	vp->v_flag = VROOT;
	VOP_UNLOCK(vp);
	*vpp = vp;

	return (0);
bad:
	nfs_disconnect(nmp);
	free(nmp, M_NFSMNT, sizeof(*nmp));
	m_freem(nam);
	return (error);
}

/* unmount system call */
int
nfs_unmount(struct mount *mp, int mntflags, struct proc *p)
{
	struct nfsmount *nmp;
	struct vnode *vp;
	int error, flags = 0;

	nmp = VFSTONFS(mp);
	error = nfs_root(mp, &vp);
	if (error)
		return (error);

	if ((mntflags & MNT_FORCE) == 0 && vp->v_usecount > 2) {
		vput(vp);
		return (EBUSY);
	}

	if (mntflags & MNT_FORCE)
		flags |= FORCECLOSE;

	error = vflush(mp, vp, flags);
	if (error) {
		vput(vp);
		return (error);
	}

	/*
	 * There are two references count to get rid of here: one
	 * from mountnfs() and one from nfs_root() above.
	 */
	vrele(vp);
	vput(vp);
	vgone(vp);
	nfs_disconnect(nmp);
	m_freem(nmp->nm_nam);
	timeout_del(&nmp->nm_rtimeout);
	timeout_set_proc(&nmp->nm_rtimeout, nfs_reaper, nmp);
	timeout_add(&nmp->nm_rtimeout, 0);
	mp->mnt_data = NULL;
	return (0);
}

/*
 * Delay nfs mount point free until pending or sleeping timeouts have finished.
 */
void
nfs_reaper(void *arg)
{
	struct nfsmount *nmp = arg;

	free(nmp, M_NFSMNT, sizeof(*nmp));
}

/*
 * Return root of a filesystem
 */
int
nfs_root(struct mount *mp, struct vnode **vpp)
{
	struct vnode *vp;
	struct nfsmount *nmp;
	int error;

	nmp = VFSTONFS(mp);
	vp = nmp->nm_vnode;
	vref(vp);
	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
	if (error) {
		vrele(vp);
		return (error);
	}
	*vpp = vp;
	return (0);
}

/*
 * Flush out the buffer cache
 */
int
nfs_sync(struct mount *mp, int waitfor, int stall, struct ucred *cred, struct proc *p)
{
	struct vnode *vp;
	int error, allerror = 0;

	/*
	 * Don't traverse the vnode list if we want to skip all of them.
	 */
	if (waitfor == MNT_LAZY)
		return (allerror);

	/*
	 * Force stale buffer cache information to be flushed.
	 */
loop:
	TAILQ_FOREACH(vp, &mp->mnt_vnodelist, v_mntvnodes) {
		/*
		 * If the vnode that we are about to sync is no longer
		 * associated with this mount point, start over.
		 */
		if (vp->v_mount != mp)
			goto loop;
		if (VOP_ISLOCKED(vp) || LIST_EMPTY(&vp->v_dirtyblkhd))
			continue;
		if (vget(vp, LK_EXCLUSIVE))
			goto loop;
		error = VOP_FSYNC(vp, cred, waitfor, p);
		if (error)
			allerror = error;
		vput(vp);
	}

	return (allerror);
}

/*
 * NFS flat namespace lookup.
 * Currently unsupported.
 */
/* ARGSUSED */
int
nfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
{

	return (EOPNOTSUPP);
}

/*
 * Do that sysctl thang...
 */
int
nfs_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
    size_t newlen, struct proc *p)
{
	int rv;

	/*
	 * All names at this level are terminal.
	 */
	if(namelen > 1)
		return ENOTDIR;	/* overloaded */

	switch(name[0]) {
	case NFS_NFSSTATS:
		if(!oldp) {
			*oldlenp = sizeof nfsstats;
			return 0;
		}

		if(*oldlenp < sizeof nfsstats) {
			*oldlenp = sizeof nfsstats;
			return ENOMEM;
		}

		rv = copyout(&nfsstats, oldp, sizeof nfsstats);
		if(rv) return rv;

		if(newp && newlen != sizeof nfsstats)
			return EINVAL;

		if(newp) {
			return copyin(newp, &nfsstats, sizeof nfsstats);
		}
		return 0;

	case NFS_NIOTHREADS:
		nfs_getset_niothreads(0);

		rv = sysctl_int(oldp, oldlenp, newp, newlen, &nfs_niothreads);
		if (newp)
			nfs_getset_niothreads(1);

		return rv;

	default:
		return EOPNOTSUPP;
	}
}


/*
 * At this point, this should never happen
 */
/* ARGSUSED */
int
nfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
{
	return (EINVAL);
}

/*
 * Vnode pointer to File handle, should never happen either
 */
/* ARGSUSED */
int
nfs_vptofh(struct vnode *vp, struct fid *fhp)
{
	return (EINVAL);
}

/*
 * Vfs start routine, a no-op.
 */
/* ARGSUSED */
int
nfs_start(struct mount *mp, int flags, struct proc *p)
{
	return (0);
}

/*
 * Do operations associated with quotas, not supported
 */
/* ARGSUSED */
int
nfs_quotactl(struct mount *mp, int cmd, uid_t uid, caddr_t arg, struct proc *p)
{
	return (EOPNOTSUPP);
}

/*
 * check export permission, not supported
 */
/* ARGUSED */
int
nfs_checkexp(struct mount *mp, struct mbuf *nam, int *exflagsp,
    struct ucred **credanonp)
{
	return (EOPNOTSUPP);
}