text: /*
   * 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. 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.
   *
   *	@(#)nfs_vfsops.c	8.12 (Berkeley) 5/20/95
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD: src/sys/nfsclient/nfs_vfsops.c,v 1.145 2003/11/22 02:21:49 alfred Exp $");
  
  #include "opt_bootp.h"
  #include "opt_nfsroot.h"
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/kernel.h>
  #include <sys/limits.h>
  #include <sys/lock.h>
  #include <sys/malloc.h>
  #include <sys/mbuf.h>
  #include <sys/module.h>
  #include <sys/mount.h>
  #include <sys/proc.h>
  #include <sys/socket.h>
  #include <sys/socketvar.h>
  #include <sys/sockio.h>
  #include <sys/sysctl.h>
  #include <sys/vnode.h>
  
  #include <vm/vm.h>
  #include <vm/vm_extern.h>
  #include <vm/uma.h>
  
  #include <net/if.h>
  #include <net/route.h>
  #include <netinet/in.h>
  
  #include <rpc/rpcclnt.h>
  
  #include <nfs/rpcv2.h>
  #include <nfs/nfsproto.h>
  #include <nfsclient/nfs.h>
  #include <nfsclient/nfsnode.h>
  #include <nfsclient/nfsmount.h>
  #include <nfs/xdr_subs.h>
  #include <nfsclient/nfsm_subs.h>
  #include <nfsclient/nfsdiskless.h>
  
  MALLOC_DEFINE(M_NFSREQ, "NFS req", "NFS request header");
  MALLOC_DEFINE(M_NFSBIGFH, "NFSV3 bigfh", "NFS version 3 file handle");
  MALLOC_DEFINE(M_NFSDIROFF, "NFSV3 diroff", "NFS directory offset data");
  MALLOC_DEFINE(M_NFSHASH, "NFS hash", "NFS hash tables");
  
  uma_zone_t nfsmount_zone;
  
  struct nfsstats	nfsstats;
  SYSCTL_NODE(_vfs, OID_AUTO, nfs, CTLFLAG_RW, 0, "NFS filesystem");
  SYSCTL_STRUCT(_vfs_nfs, NFS_NFSSTATS, nfsstats, CTLFLAG_RD,
  	&nfsstats, nfsstats, "S,nfsstats");
  static int nfs_ip_paranoia = 1;
  SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_ip_paranoia, CTLFLAG_RW,
      &nfs_ip_paranoia, 0, "");
  #ifdef NFS_DEBUG
  int nfs_debug;
  SYSCTL_INT(_vfs_nfs, OID_AUTO, debug, CTLFLAG_RW, &nfs_debug, 0, "");
  #endif
  
  static int	nfs_iosize(struct nfsmount *nmp);
  static void	nfs_decode_args(struct nfsmount *nmp, struct nfs_args *argp);
  static int	mountnfs(struct nfs_args *, struct mount *,
  		    struct sockaddr *, char *, char *, struct vnode **,
  		    struct ucred *cred);
  static vfs_mount_t nfs_mount;
  static vfs_unmount_t nfs_unmount;
  static vfs_root_t nfs_root;
  static vfs_statfs_t nfs_statfs;
  static vfs_sync_t nfs_sync;
  
  /*
   * nfs vfs operations.
   */
  static struct vfsops nfs_vfsops = {
  	.vfs_init =		nfs_init,
  	.vfs_mount =		nfs_mount,
  	.vfs_root =		nfs_root,
  	.vfs_statfs =		nfs_statfs,
  	.vfs_sync =		nfs_sync,
  	.vfs_uninit =		nfs_uninit,
  	.vfs_unmount =		nfs_unmount,
  };
  VFS_SET(nfs_vfsops, nfs, VFCF_NETWORK);
  
  /* So that loader and kldload(2) can find us, wherever we are.. */
  MODULE_VERSION(nfs, 1);
  
  static struct nfs_rpcops nfs_rpcops = {
  	nfs_readrpc,
  	nfs_writerpc,
  	nfs_writebp,
  	nfs_readlinkrpc,
  	nfs_invaldir,
  	nfs_commit,
  };
  
  /*
   * This structure must be filled in by a primary bootstrap or bootstrap
   * server for a diskless/dataless machine. It is initialized below just
   * to ensure that it is allocated to initialized data (.data not .bss).
   */
  struct nfs_diskless nfs_diskless = { { { 0 } } };
  struct nfsv3_diskless nfsv3_diskless = { { { 0 } } };
  int nfs_diskless_valid = 0;
  
  SYSCTL_INT(_vfs_nfs, OID_AUTO, diskless_valid, CTLFLAG_RD,
  	&nfs_diskless_valid, 0, "");
  
  SYSCTL_STRING(_vfs_nfs, OID_AUTO, diskless_rootpath, CTLFLAG_RD,
  	nfsv3_diskless.root_hostnam, 0, "");
  
  SYSCTL_OPAQUE(_vfs_nfs, OID_AUTO, diskless_rootaddr, CTLFLAG_RD,
  	&nfsv3_diskless.root_saddr, sizeof nfsv3_diskless.root_saddr,
  	"%Ssockaddr_in", "");
  
  
  void		nfsargs_ntoh(struct nfs_args *);
  static int	nfs_mountdiskless(char *, char *, int,
  		    struct sockaddr_in *, struct nfs_args *,
  		    struct thread *, struct vnode **, struct mount *);
  static void	nfs_convert_diskless(void);
  static void	nfs_convert_oargs(struct nfs_args *args,
  		    struct onfs_args *oargs);
  
  static int
  nfs_iosize(struct nfsmount *nmp)
  {
  	int iosize;
  
  	/*
  	 * Calculate the size used for io buffers.  Use the larger
  	 * of the two sizes to minimise nfs requests but make sure
  	 * that it is at least one VM page to avoid wasting buffer
  	 * space.
  	 */
  	iosize = max(nmp->nm_rsize, nmp->nm_wsize);
  	if (iosize < PAGE_SIZE) iosize = PAGE_SIZE;
  	return iosize;
  }
  
  static void
  nfs_convert_oargs(struct nfs_args *args, struct onfs_args *oargs)
  {
  
  	args->version = NFS_ARGSVERSION;
  	args->addr = oargs->addr;
  	args->addrlen = oargs->addrlen;
  	args->sotype = oargs->sotype;
  	args->proto = oargs->proto;
  	args->fh = oargs->fh;
  	args->fhsize = oargs->fhsize;
  	args->flags = oargs->flags;
  	args->wsize = oargs->wsize;
  	args->rsize = oargs->rsize;
  	args->readdirsize = oargs->readdirsize;
  	args->timeo = oargs->timeo;
  	args->retrans = oargs->retrans;
  	args->maxgrouplist = oargs->maxgrouplist;
  	args->readahead = oargs->readahead;
  	args->deadthresh = oargs->deadthresh;
  	args->hostname = oargs->hostname;
  }
  
  static void
  nfs_convert_diskless(void)
  {
  
  	bcopy(&nfs_diskless.myif, &nfsv3_diskless.myif,
  		sizeof(struct ifaliasreq));
  	bcopy(&nfs_diskless.mygateway, &nfsv3_diskless.mygateway,
  		sizeof(struct sockaddr_in));
  	nfs_convert_oargs(&nfsv3_diskless.root_args,&nfs_diskless.root_args);
  	nfsv3_diskless.root_fhsize = NFSX_V2FH;
  	bcopy(nfs_diskless.root_fh, nfsv3_diskless.root_fh, NFSX_V2FH);
  	bcopy(&nfs_diskless.root_saddr,&nfsv3_diskless.root_saddr,
  		sizeof(struct sockaddr_in));
  	bcopy(nfs_diskless.root_hostnam, nfsv3_diskless.root_hostnam, MNAMELEN);
  	nfsv3_diskless.root_time = nfs_diskless.root_time;
  	bcopy(nfs_diskless.my_hostnam, nfsv3_diskless.my_hostnam,
  		MAXHOSTNAMELEN);
  	nfs_diskless_valid = 3;
  }
  
  /*
   * nfs statfs call
   */
  static int
  nfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
  {
  	struct vnode *vp;
  	struct nfs_statfs *sfp;
  	caddr_t bpos, dpos;
  	struct nfsmount *nmp = VFSTONFS(mp);
  	int error = 0, v3 = (nmp->nm_flag & NFSMNT_NFSV3), retattr;
  	struct mbuf *mreq, *mrep, *md, *mb;
  	struct nfsnode *np;
  	u_quad_t tquad;
  	int bsize;
  
  #ifndef nolint
  	sfp = NULL;
  #endif
  	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
  	if (error)
  		return (error);
  	vp = NFSTOV(np);
  	if (v3 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
  		(void)nfs_fsinfo(nmp, vp, td->td_ucred, td);
  	nfsstats.rpccnt[NFSPROC_FSSTAT]++;
  	mreq = nfsm_reqhead(vp, NFSPROC_FSSTAT, NFSX_FH(v3));
  	mb = mreq;
  	bpos = mtod(mb, caddr_t);
  	nfsm_fhtom(vp, v3);
  	nfsm_request(vp, NFSPROC_FSSTAT, td, td->td_ucred);
  	if (v3)
  		nfsm_postop_attr(vp, retattr);
  	if (error) {
  		if (mrep != NULL)
  			m_freem(mrep);
  		goto nfsmout;
  	}
  	sfp = nfsm_dissect(struct nfs_statfs *, NFSX_STATFS(v3));
  	sbp->f_flags = nmp->nm_flag;
  	sbp->f_iosize = nfs_iosize(nmp);
  	if (v3) {
  		for (bsize = NFS_FABLKSIZE; ; bsize *= 2) {
  			sbp->f_bsize = bsize;
  			tquad = fxdr_hyper(&sfp->sf_tbytes);
  			if (((long)(tquad / bsize) > LONG_MAX) ||
  			    ((long)(tquad / bsize) < LONG_MIN))
  				continue;
  			sbp->f_blocks = tquad / bsize;
  			tquad = fxdr_hyper(&sfp->sf_fbytes);
  			if (((long)(tquad / bsize) > LONG_MAX) ||
  			    ((long)(tquad / bsize) < LONG_MIN))
  				continue;
  			sbp->f_bfree = tquad / bsize;
  			tquad = fxdr_hyper(&sfp->sf_abytes);
  			if (((long)(tquad / bsize) > LONG_MAX) ||
  			    ((long)(tquad / bsize) < LONG_MIN))
  				continue;
  			sbp->f_bavail = tquad / bsize;
  			sbp->f_files = (fxdr_unsigned(int32_t,
  			    sfp->sf_tfiles.nfsuquad[1]) & 0x7fffffff);
  			sbp->f_ffree = (fxdr_unsigned(int32_t,
  			    sfp->sf_ffiles.nfsuquad[1]) & 0x7fffffff);
  			break;
  		}
  	} 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;
  	}
  	if (sbp != &mp->mnt_stat) {
  		sbp->f_type = mp->mnt_vfc->vfc_typenum;
  		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
  		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
  	}
  	m_freem(mrep);
  nfsmout:
  	vput(vp);
  	return (error);
  }
  
  /*
   * nfs version 3 fsinfo rpc call
   */
  int
  nfs_fsinfo(struct nfsmount *nmp, struct vnode *vp, struct ucred *cred,
      struct thread *td)
  {
  	struct nfsv3_fsinfo *fsp;
  	u_int32_t pref, max;
  	caddr_t bpos, dpos;
  	int error = 0, retattr;
  	struct mbuf *mreq, *mrep, *md, *mb;
  	u_int64_t maxfsize;
  
  	nfsstats.rpccnt[NFSPROC_FSINFO]++;
  	mreq = nfsm_reqhead(vp, NFSPROC_FSINFO, NFSX_FH(1));
  	mb = mreq;
  	bpos = mtod(mb, caddr_t);
  	nfsm_fhtom(vp, 1);
  	nfsm_request(vp, NFSPROC_FSINFO, td, cred);
  	nfsm_postop_attr(vp, retattr);
  	if (!error) {
  		fsp = nfsm_dissect(struct nfsv3_fsinfo *, NFSX_V3FSINFO);
  		pref = fxdr_unsigned(u_int32_t, fsp->fs_wtpref);
  		if (pref < nmp->nm_wsize && pref >= NFS_FABLKSIZE)
  			nmp->nm_wsize = (pref + NFS_FABLKSIZE - 1) &
  				~(NFS_FABLKSIZE - 1);
  		max = fxdr_unsigned(u_int32_t, fsp->fs_wtmax);
  		if (max < nmp->nm_wsize && max > 0) {
  			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 && pref >= NFS_FABLKSIZE)
  			nmp->nm_rsize = (pref + NFS_FABLKSIZE - 1) &
  				~(NFS_FABLKSIZE - 1);
  		max = fxdr_unsigned(u_int32_t, fsp->fs_rtmax);
  		if (max < nmp->nm_rsize && max > 0) {
  			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 && pref >= NFS_DIRBLKSIZ)
  			nmp->nm_readdirsize = (pref + NFS_DIRBLKSIZ - 1) &
  				~(NFS_DIRBLKSIZ - 1);
  		if (max < nmp->nm_readdirsize && max > 0) {
  			nmp->nm_readdirsize = max & ~(NFS_DIRBLKSIZ - 1);
  			if (nmp->nm_readdirsize == 0)
  				nmp->nm_readdirsize = max;
  		}
  		maxfsize = fxdr_hyper(&fsp->fs_maxfilesize);
  		if (maxfsize > 0 && maxfsize < nmp->nm_maxfilesize)
  			nmp->nm_maxfilesize = maxfsize;
  		nmp->nm_state |= NFSSTA_GOTFSINFO;
  	}
  	m_freem(mrep);
  nfsmout:
  	return (error);
  }
  
  /*
   * Mount a remote root fs via. nfs. This depends on the info in the
   * nfs_diskless structure that has been filled in properly by some primary
   * bootstrap.
   * It goes something like this:
   * - do enough of "ifconfig" by calling ifioctl() so that the system
   *   can talk to the server
   * - If nfs_diskless.mygateway is filled in, use that address as
   *   a default gateway.
   * - build the rootfs mount point and call mountnfs() to do the rest.
   */
  int
  nfs_mountroot(struct mount *mp, struct thread *td)
  {
  	struct nfsv3_diskless *nd = &nfsv3_diskless;
  	struct socket *so;
  	struct vnode *vp;
  	int error, i;
  	u_long l;
  	char buf[128];
  
  	GIANT_REQUIRED;		/* XXX until socket locking done */
  
  #if defined(BOOTP_NFSROOT) && defined(BOOTP)
  	bootpc_init();		/* use bootp to get nfs_diskless filled in */
  #elif defined(NFS_ROOT)
  	nfs_setup_diskless();
  #endif
  
  	if (nfs_diskless_valid == 0)
  		return (-1);
  	if (nfs_diskless_valid == 1)
  		nfs_convert_diskless();
  
  	/*
  	 * XXX splnet, so networks will receive...
  	 */
  	splnet();
  
  	/*
  	 * Do enough of ifconfig(8) so that the critical net interface can
  	 * talk to the server.
  	 */
  	error = socreate(nd->myif.ifra_addr.sa_family, &so, SOCK_DGRAM, 0,
  	    td->td_ucred, td);
  	if (error)
  		panic("nfs_mountroot: socreate(%04x): %d",
  			nd->myif.ifra_addr.sa_family, error);
  
  #if 0 /* XXX Bad idea */
  	/*
  	 * We might not have been told the right interface, so we pass
  	 * over the first ten interfaces of the same kind, until we get
  	 * one of them configured.
  	 */
  
  	for (i = strlen(nd->myif.ifra_name) - 1;
  		nd->myif.ifra_name[i] >= '0' &&
  		nd->myif.ifra_name[i] <= '9';
  		nd->myif.ifra_name[i] ++) {
  		error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, td);
  		if(!error)
  			break;
  	}
  #endif
  	error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, td);
  	if (error)
  		panic("nfs_mountroot: SIOCAIFADDR: %d", error);
  	soclose(so);
  
  	/*
  	 * If the gateway field is filled in, set it as the default route.
  	 * Note that pxeboot will set a default route of 0 if the route
  	 * is not set by the DHCP server.  Check also for a value of 0
  	 * to avoid panicking inappropriately in that situation.
  	 */
  	if (nd->mygateway.sin_len != 0 &&
  	    nd->mygateway.sin_addr.s_addr != 0) {
  		struct sockaddr_in mask, sin;
  
  		bzero((caddr_t)&mask, sizeof(mask));
  		sin = mask;
  		sin.sin_family = AF_INET;
  		sin.sin_len = sizeof(sin);
  		error = rtrequest(RTM_ADD, (struct sockaddr *)&sin,
  		    (struct sockaddr *)&nd->mygateway,
  		    (struct sockaddr *)&mask,
  		    RTF_UP | RTF_GATEWAY, NULL);
  		if (error)
  			panic("nfs_mountroot: RTM_ADD: %d", error);
  	}
  
  	/*
  	 * Create the rootfs mount point.
  	 */
  	nd->root_args.fh = nd->root_fh;
  	nd->root_args.fhsize = nd->root_fhsize;
  	l = ntohl(nd->root_saddr.sin_addr.s_addr);
  	snprintf(buf, sizeof(buf), "%ld.%ld.%ld.%ld:%s",
  		(l >> 24) & 0xff, (l >> 16) & 0xff,
  		(l >>  8) & 0xff, (l >>  0) & 0xff, nd->root_hostnam);
  	printf("NFS ROOT: %s\n", buf);
  	if ((error = nfs_mountdiskless(buf, "/", MNT_RDONLY,
  	    &nd->root_saddr, &nd->root_args, td, &vp, mp)) != 0) {
  		return (error);
  	}
  
  	rootvp = vp;
  
  	/*
  	 * This is not really an nfs issue, but it is much easier to
  	 * set hostname here and then let the "/etc/rc.xxx" files
  	 * mount the right /var based upon its preset value.
  	 */
  	bcopy(nd->my_hostnam, hostname, MAXHOSTNAMELEN);
  	hostname[MAXHOSTNAMELEN - 1] = '\0';
  	for (i = 0; i < MAXHOSTNAMELEN; i++)
  		if (hostname[i] == '\0')
  			break;
  	inittodr(ntohl(nd->root_time));
  	return (0);
  }
  
  /*
   * Internal version of mount system call for diskless setup.
   */
  static int
  nfs_mountdiskless(char *path, char *which, int mountflag,
      struct sockaddr_in *sin, struct nfs_args *args, struct thread *td,
      struct vnode **vpp, struct mount *mp)
  {
  	struct sockaddr *nam;
  	int error;
  
  	mp->mnt_kern_flag = 0;
  	mp->mnt_flag = mountflag;
  	nam = dup_sockaddr((struct sockaddr *)sin, 1);
  	if ((error = mountnfs(args, mp, nam, which, path, vpp,
  	    td->td_ucred)) != 0) {
  		printf("nfs_mountroot: mount %s on %s: %d", path, which, error);
  		FREE(nam, M_SONAME);
  		return (error);
  	}
  	(void) copystr(which, mp->mnt_stat.f_mntonname, MNAMELEN - 1, 0);
  	return (0);
  }
  
  static void
  nfs_decode_args(struct nfsmount *nmp, struct nfs_args *argp)
  {
  	int s;
  	int adjsock;
  	int maxio;
  
  	s = splnet();
  	/*
  	 * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
  	 * no sense in that context.
  	 */
  	if (argp->sotype == SOCK_STREAM)
  		nmp->nm_flag &= ~NFSMNT_NOCONN;
  
  	/* Also clear RDIRPLUS if not NFSv3, it crashes some servers */
  	if ((argp->flags & NFSMNT_NFSV3) == 0)
  		nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
  
  	/* Re-bind if rsrvd port requested and wasn't on one */
  	adjsock = !(nmp->nm_flag & NFSMNT_RESVPORT)
  		  && (argp->flags & NFSMNT_RESVPORT);
  	/* Also re-bind if we're switching to/from a connected UDP socket */
  	adjsock |= ((nmp->nm_flag & NFSMNT_NOCONN) !=
  		    (argp->flags & NFSMNT_NOCONN));
  
  	/* Update flags atomically.  Don't change the lock bits. */
  	nmp->nm_flag = argp->flags | nmp->nm_flag;
  	splx(s);
  
  	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 = argp->retrans;
  		if (nmp->nm_retry > NFS_MAXREXMIT)
  			nmp->nm_retry = NFS_MAXREXMIT;
  	}
  
  	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) {
  		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;
  	}
  	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) {
  		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;
  	}
  	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;
  	}
  	if (nmp->nm_readdirsize > maxio)
  		nmp->nm_readdirsize = maxio;
  	if (nmp->nm_readdirsize > nmp->nm_rsize)
  		nmp->nm_readdirsize = nmp->nm_rsize;
  
  	if ((argp->flags & NFSMNT_ACREGMIN) && argp->acregmin >= 0)
  		nmp->nm_acregmin = argp->acregmin;
  	else
  		nmp->nm_acregmin = NFS_MINATTRTIMO;
  	if ((argp->flags & NFSMNT_ACREGMAX) && argp->acregmax >= 0)
  		nmp->nm_acregmax = argp->acregmax;
  	else
  		nmp->nm_acregmax = NFS_MAXATTRTIMO;
  	if ((argp->flags & NFSMNT_ACDIRMIN) && argp->acdirmin >= 0)
  		nmp->nm_acdirmin = argp->acdirmin;
  	else
  		nmp->nm_acdirmin = NFS_MINDIRATTRTIMO;
  	if ((argp->flags & NFSMNT_ACDIRMAX) && argp->acdirmax >= 0)
  		nmp->nm_acdirmax = argp->acdirmax;
  	else
  		nmp->nm_acdirmax = NFS_MAXDIRATTRTIMO;
  	if (nmp->nm_acdirmin > nmp->nm_acdirmax)
  		nmp->nm_acdirmin = nmp->nm_acdirmax;
  	if (nmp->nm_acregmin > nmp->nm_acregmax)
  		nmp->nm_acregmin = nmp->nm_acregmax;
  
  	if ((argp->flags & NFSMNT_MAXGRPS) && argp->maxgrouplist >= 0) {
  		if (argp->maxgrouplist <= NFS_MAXGRPS)
  			nmp->nm_numgrps = argp->maxgrouplist;
  		else
  			nmp->nm_numgrps = NFS_MAXGRPS;
  	}
  	if ((argp->flags & NFSMNT_READAHEAD) && argp->readahead >= 0) {
  		if (argp->readahead <= NFS_MAXRAHEAD)
  			nmp->nm_readahead = argp->readahead;
  		else
  			nmp->nm_readahead = NFS_MAXRAHEAD;
  	}
  	if ((argp->flags & NFSMNT_DEADTHRESH) && argp->deadthresh >= 0) {
  		if (argp->deadthresh <= NFS_MAXDEADTHRESH)
  			nmp->nm_deadthresh = argp->deadthresh;
  		else
  			nmp->nm_deadthresh = NFS_MAXDEADTHRESH;
  	}
  
  	adjsock |= ((nmp->nm_sotype != argp->sotype) ||
  		    (nmp->nm_soproto != argp->proto));
  	nmp->nm_sotype = argp->sotype;
  	nmp->nm_soproto = argp->proto;
  
  	if (nmp->nm_so && adjsock) {
  		nfs_safedisconnect(nmp);
  		if (nmp->nm_sotype == SOCK_DGRAM)
  			while (nfs_connect(nmp, NULL)) {
  				printf("nfs_args: retrying connect\n");
  				(void) tsleep((caddr_t)&lbolt,
  					      PSOCK, "nfscon", 0);
  			}
  	}
  }
  
  /*
   * VFS Operations.
   *
   * mount system call
   * It seems a bit dumb to copyinstr() the host and path here and then
   * bcopy() them 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 */
  static int
  nfs_mount(struct mount *mp, char *path, caddr_t data, struct nameidata *ndp,
      struct thread *td)
  {
  	int error;
  	struct nfs_args args;
  	struct sockaddr *nam;
  	struct vnode *vp;
  	char hst[MNAMELEN];
  	size_t len;
  	u_char nfh[NFSX_V3FHMAX];
  
  	if (path == NULL)
  		return (nfs_mountroot(mp, td));
  	error = copyin(data, (caddr_t)&args, sizeof (struct nfs_args));
  	if (error)
  		return (error);
  	if (args.version != NFS_ARGSVERSION) {
  #ifdef COMPAT_PRELITE2
  		/*
  		 * If the argument version is unknown, then assume the
  		 * caller is a pre-lite2 4.4BSD client and convert its
  		 * arguments.
  		 */
  		struct onfs_args oargs;
  		error = copyin(data, (caddr_t)&oargs, sizeof (struct onfs_args));
  		if (error)
  			return (error);
  		nfs_convert_oargs(&args,&oargs);
  #else /* !COMPAT_PRELITE2 */
  		return (EPROGMISMATCH);
  #endif /* COMPAT_PRELITE2 */
  	}
  	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, switch lockd strategies or change cookie translation
  		 */
  		args.flags = (args.flags &
  		    ~(NFSMNT_NFSV3 | NFSMNT_NOLOCKD /*|NFSMNT_XLATECOOKIE*/)) |
  		    (nmp->nm_flag &
  			(NFSMNT_NFSV3 | NFSMNT_NOLOCKD /*|NFSMNT_XLATECOOKIE*/));
  		nfs_decode_args(nmp, &args);
  		return (0);
  	}
  
  	/*
  	 * Make the nfs_ip_paranoia sysctl serve as the default connection
  	 * or no-connection mode for those protocols that support 
  	 * no-connection mode (the flag will be cleared later for protocols
  	 * that do not support no-connection mode).  This will allow a client
  	 * to receive replies from a different IP then the request was
  	 * sent to.  Note: default value for nfs_ip_paranoia is 1 (paranoid),
  	 * not 0.
  	 */
  	if (nfs_ip_paranoia == 0)
  		args.flags |= NFSMNT_NOCONN;
  	if (args.fhsize < 0 || args.fhsize > NFSX_V3FHMAX)
  		return (EINVAL);
  	error = copyin((caddr_t)args.fh, (caddr_t)nfh, args.fhsize);
  	if (error)
  		return (error);
  	error = copyinstr(args.hostname, hst, MNAMELEN-1, &len);
  	if (error)
  		return (error);
  	bzero(&hst[len], MNAMELEN - len);
  	/* sockargs() call must be after above copyin() calls */
  	error = getsockaddr(&nam, (caddr_t)args.addr, args.addrlen);
  	if (error)
  		return (error);
  	args.fh = nfh;
  	error = mountnfs(&args, mp, nam, path, hst, &vp, td->td_ucred);
  	return (error);
  }
  
  /*
   * Common code for mount and mountroot
   */
  static int
  mountnfs(struct nfs_args *argp, struct mount *mp, struct sockaddr *nam,
      char *pth, char *hst, struct vnode **vpp, struct ucred *cred)
  {
  	struct nfsmount *nmp;
  	struct nfsnode *np;
  	int error;
  	struct vattr attrs;
  
  	if (mp->mnt_flag & MNT_UPDATE) {
  		nmp = VFSTONFS(mp);
  		/* update paths, file handles, etc, here	XXX */
  		FREE(nam, M_SONAME);
  		return (0);
  	} else {
  		nmp = uma_zalloc(nfsmount_zone, M_WAITOK);
  		bzero((caddr_t)nmp, sizeof (struct nfsmount));
  		TAILQ_INIT(&nmp->nm_bufq);
  		mp->mnt_data = (qaddr_t)nmp;
  	}
  	vfs_getnewfsid(mp);
  	nmp->nm_mountp = mp;
  
  	/*
  	 * V2 can only handle 32 bit filesizes.  A 4GB-1 limit may be too
  	 * high, depending on whether we end up with negative offsets in
  	 * the client or server somewhere.  2GB-1 may be safer.
  	 *
  	 * For V3, nfs_fsinfo will adjust this as necessary.  Assume maximum
  	 * that we can handle until we find out otherwise.
  	 * XXX Our "safe" limit on the client is what we can store in our
  	 * buffer cache using signed(!) block numbers.
  	 */
  	if ((argp->flags & NFSMNT_NFSV3) == 0)
  		nmp->nm_maxfilesize = 0xffffffffLL;
  	else
  		nmp->nm_maxfilesize = (u_int64_t)0x80000000 * DEV_BSIZE - 1;
  
  	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_deadthresh = NFS_MAXDEADTHRESH;
  	nmp->nm_fhsize = argp->fhsize;
  	bcopy((caddr_t)argp->fh, (caddr_t)nmp->nm_fh, argp->fhsize);
  	bcopy(hst, mp->mnt_stat.f_mntfromname, MNAMELEN);
  	bcopy(pth, mp->mnt_stat.f_mntonname, MNAMELEN);
  	nmp->nm_nam = nam;
  	/* Set up the sockets and per-host congestion */
  	nmp->nm_sotype = argp->sotype;
  	nmp->nm_soproto = argp->proto;
  	nmp->nm_rpcops = &nfs_rpcops;
  
  	nfs_decode_args(nmp, argp);
  
  	/*
  	 * 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_iosize(nmp);
  	/*
  	 * 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).
  	 */
  	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
  	if (error)
  		goto bad;
  	*vpp = NFSTOV(np);
  
  	/*
  	 * Get file attributes for the mountpoint.  This has the side
  	 * effect of filling in (*vpp)->v_type with the correct value.
  	 */
  	VOP_GETATTR(*vpp, &attrs, curthread->td_ucred, curthread);
  
  	/*
  	 * Lose the lock but keep the ref.
  	 */
  	VOP_UNLOCK(*vpp, 0, curthread);
  
  	return (0);
  bad:
  	nfs_disconnect(nmp);
  	uma_zfree(nfsmount_zone, nmp);
  	FREE(nam, M_SONAME);
  	return (error);
  }
  
  /*
   * unmount system call
   */
  static int
  nfs_unmount(struct mount *mp, int mntflags, struct thread *td)
  {
  	struct nfsmount *nmp;
  	int error, flags = 0;
  
  	if (mntflags & MNT_FORCE)
  		flags |= FORCECLOSE;
  	nmp = VFSTONFS(mp);
  	/*
  	 * Goes something like this..
  	 * - Call vflush() to clear out vnodes for this filesystem
  	 * - Close the socket
  	 * - Free up the data structures
  	 */
  	/* In the forced case, cancel any outstanding requests. */
  	if (flags & FORCECLOSE) {
  		error = nfs_nmcancelreqs(nmp);
  		if (error)
  			return (error);
  	}
  	/* We hold 1 extra ref on the root vnode; see comment in mountnfs(). */
  	error = vflush(mp, 1, flags);
  	if (error)
  		return (error);
  
  	/*
  	 * We are now committed to the unmount.
  	 */
  	nfs_disconnect(nmp);
  	FREE(nmp->nm_nam, M_SONAME);
  
  	uma_zfree(nfsmount_zone, nmp);
  	return (0);
  }
  
  /*
   * Return root of a filesystem
   */
  static int
  nfs_root(struct mount *mp, struct vnode **vpp)
  {
  	struct vnode *vp;
  	struct nfsmount *nmp;
  	struct nfsnode *np;
  	int error;
  
  	nmp = VFSTONFS(mp);
  	error = nfs_nget(mp, (nfsfh_t *)nmp->nm_fh, nmp->nm_fhsize, &np);
  	if (error)
  		return (error);
  	vp = NFSTOV(np);
  	if (vp->v_type == VNON)
  	    vp->v_type = VDIR;
  	vp->v_vflag |= VV_ROOT;
  	*vpp = vp;
  	return (0);
  }
  
  /*
   * Flush out the buffer cache
   */
  /* ARGSUSED */
  static int
  nfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct thread *td)
  {
  	struct vnode *vp, *vnp;
  	int error, allerror = 0;
  
  	/*
  	 * Force stale buffer cache information to be flushed.
  	 */
  	MNT_ILOCK(mp);
  loop:
  	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
  	     vp != NULL;
  	     vp = vnp) {
  		/*
  		 * 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;
  		vnp = TAILQ_NEXT(vp, v_nmntvnodes);
  		VI_LOCK(vp);
  		MNT_IUNLOCK(mp);
  		if (VOP_ISLOCKED(vp, NULL) || TAILQ_EMPTY(&vp->v_dirtyblkhd) ||
  		    waitfor == MNT_LAZY) {
  			VI_UNLOCK(vp);
  			MNT_ILOCK(mp);
  			continue;
  		}
  		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
  			MNT_ILOCK(mp);
  			goto loop;
  		}
  		error = VOP_FSYNC(vp, cred, waitfor, td);
  		if (error)
  			allerror = error;
  		VOP_UNLOCK(vp, 0, td);
  		vrele(vp);
  
  		MNT_ILOCK(mp);
  	}
  	MNT_IUNLOCK(mp);
  	return (allerror);
  }
  