nfs_vfsops.c

早期freebsd实现

/*
 * 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. 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	8.3 (Berkeley) 1/4/94
 */

#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/kernel.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/systm.h>

#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>

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

/*
 * nfs vfs operations.
 */
struct vfsops nfs_vfsops = {
	nfs_mount,
	nfs_start,
	nfs_unmount,
	nfs_root,
	nfs_quotactl,
	nfs_statfs,
	nfs_sync,
	nfs_vget,
	nfs_fhtovp,
	nfs_vptofh,
	nfs_init,
};

/*
 * 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 };

extern u_long nfs_procids[NFS_NPROCS];
extern u_long nfs_prog, nfs_vers;
void nfs_disconnect __P((struct nfsmount *));
void nfsargs_ntoh __P((struct nfs_args *));
static struct mount *nfs_mountdiskless __P((char *, char *, int,
    struct sockaddr_in *, struct nfs_args *, register struct vnode **));

#define TRUE	1
#define	FALSE	0

/*
 * nfs statfs call
 */
int
nfs_statfs(mp, sbp, p)
	struct mount *mp;
	register struct statfs *sbp;
	struct proc *p;
{
	register struct vnode *vp;
	register struct nfsv2_statfs *sfp;
	register caddr_t cp;
	register long t1;
	caddr_t bpos, dpos, cp2;
	int error = 0, isnq;
	struct mbuf *mreq, *mrep, *md, *mb, *mb2;
	struct nfsmount *nmp;
	struct ucred *cred;
	struct nfsnode *np;

	nmp = VFSTONFS(mp);
	isnq = (nmp->nm_flag & NFSMNT_NQNFS);
	if (error = nfs_nget(mp, &nmp->nm_fh, &np))
		return (error);
	vp = NFSTOV(np);
	nfsstats.rpccnt[NFSPROC_STATFS]++;
	cred = crget();
	cred->cr_ngroups = 1;
	nfsm_reqhead(vp, NFSPROC_STATFS, NFSX_FH);
	nfsm_fhtom(vp);
	nfsm_request(vp, NFSPROC_STATFS, p, cred);
	nfsm_dissect(sfp, struct nfsv2_statfs *, NFSX_STATFS(isnq));
	sbp->f_type = MOUNT_NFS;
	sbp->f_flags = nmp->nm_flag;
	sbp->f_iosize = NFS_MAXDGRAMDATA;
	sbp->f_bsize = fxdr_unsigned(long, sfp->sf_bsize);
	sbp->f_blocks = fxdr_unsigned(long, sfp->sf_blocks);
	sbp->f_bfree = fxdr_unsigned(long, sfp->sf_bfree);
	sbp->f_bavail = fxdr_unsigned(long, sfp->sf_bavail);
	if (isnq) {
		sbp->f_files = fxdr_unsigned(long, sfp->sf_files);
		sbp->f_ffree = fxdr_unsigned(long, sfp->sf_ffree);
	} else {
		sbp->f_files = 0;
		sbp->f_ffree = 0;
	}
	if (sbp != &mp->mnt_stat) {
		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
	}
	nfsm_reqdone;
	vrele(vp);
	crfree(cred);
	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.
 * - 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()
{
	register struct mount *mp;
	register struct nfs_diskless *nd = &nfs_diskless;
	struct socket *so;
	struct vnode *vp;
	struct proc *p = curproc;		/* XXX */
	int error, i;

	/*
	 * XXX time must be non-zero when we init the interface or else
	 * the arp code will wedge...
	 */
	if (time.tv_sec == 0)
		time.tv_sec = 1;

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

	/*
	 * Do enough of ifconfig(8) so that the critical net interface can
	 * talk to the server.
	 */
	if (error = socreate(nd->myif.ifra_addr.sa_family, &so, SOCK_DGRAM, 0))
		panic("nfs_mountroot: socreate: %d", error);
	if (error = ifioctl(so, SIOCAIFADDR, (caddr_t)&nd->myif, p))
		panic("nfs_mountroot: SIOCAIFADDR: %d", error);
	soclose(so);

	/*
	 * If the gateway field is filled in, set it as the default route.
	 */
	if (nd->mygateway.sin_len != 0) {
		struct sockaddr_in mask, sin;

		bzero((caddr_t)&mask, sizeof(mask));
		sin = mask;
		sin.sin_family = AF_INET;
		sin.sin_len = sizeof(sin);
		if (error = rtrequest(RTM_ADD, (struct sockaddr *)&sin,
		    (struct sockaddr *)&nd->mygateway,
		    (struct sockaddr *)&mask,
		    RTF_UP | RTF_GATEWAY, (struct rtentry **)0))
			panic("nfs_mountroot: RTM_ADD: %d", error);
	}

	/*
	 * If swapping to an nfs node (indicated by 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.
	 */
	if (swdevt[0].sw_dev == NODEV) {
		nd->swap_args.fh = (nfsv2fh_t *)nd->swap_fh;
		(void) nfs_mountdiskless(nd->swap_hostnam, "/swap", 0,
		    &nd->swap_saddr, &nd->swap_args, &vp);
	
		/*
		 * 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;
		swapdev_vp = vp;
		VREF(vp);
		swdevt[0].sw_vp = vp;
		swdevt[0].sw_nblks = ntohl(nd->swap_nblks);
	} else if (bdevvp(swapdev, &swapdev_vp))
		panic("nfs_mountroot: can't setup swapdev_vp");

	/*
	 * Create the rootfs mount point.
	 */
	nd->root_args.fh = (nfsv2fh_t *)nd->root_fh;
	mp = nfs_mountdiskless(nd->root_hostnam, "/", MNT_RDONLY,
	    &nd->root_saddr, &nd->root_args, &vp);

	if (vfs_lock(mp))
		panic("nfs_mountroot: vfs_lock");
	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
	mp->mnt_flag |= MNT_ROOTFS;
	mp->mnt_vnodecovered = NULLVP;
	vfs_unlock(mp);
	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;
	hostnamelen = i;
	inittodr(ntohl(nd->root_time));
	return (0);
}

/*
 * Internal version of mount system call for diskless setup.
 */
static struct mount *
nfs_mountdiskless(path, which, mountflag, sin, args, vpp)
	char *path;
	char *which;
	int mountflag;
	struct sockaddr_in *sin;
	struct nfs_args *args;
	register struct vnode **vpp;
{
	register struct mount *mp;
	register struct mbuf *m;
	register int error;

	mp = (struct mount *)malloc((u_long)sizeof(struct mount),
	    M_MOUNT, M_NOWAIT);
	if (mp == NULL)
		panic("nfs_mountroot: %s mount malloc", which);
	bzero((char *)mp, (u_long)sizeof(struct mount));
	mp->mnt_op = &nfs_vfsops;
	mp->mnt_flag = mountflag;

	MGET(m, MT_SONAME, M_DONTWAIT);
	if (m == NULL)
		panic("nfs_mountroot: %s mount mbuf", which);
	bcopy((caddr_t)sin, mtod(m, caddr_t), sin->sin_len);
	m->m_len = sin->sin_len;
	nfsargs_ntoh(args);
	if (error = mountnfs(args, mp, m, which, path, vpp))
		panic("nfs_mountroot: mount %s on %s: %d", path, which, error);

	return (mp);
}

/*
 * Convert the integer fields of the nfs_args structure from net byte order
 * to host byte order. Called by nfs_mountroot() above.
 */
void
nfsargs_ntoh(nfsp)
	register struct nfs_args *nfsp;
{

	NTOHL(nfsp->sotype);
	NTOHL(nfsp->proto);
	NTOHL(nfsp->flags);
	NTOHL(nfsp->wsize);
	NTOHL(nfsp->rsize);
	NTOHL(nfsp->timeo);
	NTOHL(nfsp->retrans);
	NTOHL(nfsp->maxgrouplist);
	NTOHL(nfsp->readahead);
	NTOHL(nfsp->leaseterm);
	NTOHL(nfsp->deadthresh);
}

/*
 * 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 */
int
nfs_mount(mp, path, data, ndp, p)
	struct mount *mp;
	char *path;
	caddr_t data;
	struct nameidata *ndp;
	struct proc *p;
{
	int error;
	struct nfs_args args;
	struct mbuf *nam;
	struct vnode *vp;
	char pth[MNAMELEN], hst[MNAMELEN];
	u_int len;
	nfsv2fh_t nfh;

	if (error = copyin(data, (caddr_t)&args, sizeof (struct nfs_args)))
		return (error);
	if (error = copyin((caddr_t)args.fh, (caddr_t)&nfh, sizeof (nfsv2fh_t)))
		return (error);
	if (error = copyinstr(path, pth, MNAMELEN-1, &len))
		return (error);
	bzero(&pth[len], MNAMELEN - len);
	if (error = copyinstr(args.hostname, hst, MNAMELEN-1, &len))
		return (error);
	bzero(&hst[len], MNAMELEN - len);