ufs_mount.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)ufs_mount.c	4.4	(ULTRIX)	2/28/91";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986, 87, 89 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/


/***********************************************************************
 *		Modification History
 *
 * 27 Feb 91 -- chet
 *	Fix filesystem timestamping.
 *
 * 21 Jan 91 -- dws
 *	Added initialization of partition ID in ufs_mount().
 *
 * 17 Nov 89 -- prs
 *	Fixed the error message in ufs_mount() when the default
 *	clean byte timeout factor does not exist.
 *
 * 14 Jun 89 -- condylis
 *      Added code to insure we are placing a unique dev
 *      number in the mount table entry.
 *
 * 14 Jun 89 -- prs
 *	Added clean byte timeout logic.
 *
 * 13-Jun-89 -- Fred Canter
 *	Fix improper use of DEVIOCGET category_stat.
 *
 * 03-May-89 -- Tim Burke
 *      Allow for the unit number of root disks to be 3 digits; ie ra100a.
 *
 * 06 Apr 89 -- prs
 *	Added SMP quota locks.
 *
 * 28 Jul 88 -- prs
 *	SMP - System call turn on.
 *
 * 19 May 88 -- prs
 *	SMP - Added locks around calls to driver routines.
 *
 * 06 Apr 88 -- prs
 *      Changed handling of the clean byte in the super block
 *      from the fs_fmod field to fs_clean.
 *
 * 12-11-87	Robin L. and Larry C.
 *	Added new kmalloc memory allocation to system.
 *
 * 27 Oct 87 -- rsp
 *	Added bzero just before DEVIOCGET request.
 *
 * 12 May 87 -- prs
 *	Added call to check_mountp to verify local mount point
 *	exists.
 *
 * 02 Mar 87 -- logcher
 *	Merged in diskless changes, added changes for new ops
 *
 * 15 Jan 87 -- prs
 *	Added or'ing in the M_QUOTA bit to the mount structures flags
 *	field.
 *
 * 04 Dec 86 -- prs
 *	Made changes to not set FS_CLEAN byte if a file system
 *	was mounted with -o force in ufs_sbupdat.
 *
 * 11 Sep 86 -- koehler
 *	made changes for synchronous fs and user level mounts
 *
 ***********************************************************************/


#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/gnode_common.h"
#include "../ufs/ufs_inode.h"
#include "../h/gnode.h"
#include "../h/proc.h"
#include "../ufs/fs.h"
#include "../h/fs_types.h"
#include "../h/buf.h"
#include "../h/mount.h"
#include "../h/file.h"
#include "../h/kernel.h"
#include "../h/conf.h"
#include "../h/ioctl.h"
#include "../h/devio.h"
#include "../ufs/ufs_mount.h"
#include "../h/kmalloc.h"
#include "../h/cpudata.h"

int		ufs_umount(),	ufs_sbupdat(),	ufs_ginit(),	ufs_inactive();
struct gnode	*ufs_namei();
int		ufs_link(),	ufs_unlink(),	ufs_rmdir();
struct gnode	*ufs_mkdir();
struct gnode	*ufs_maknode();
int		ufs_rename(),	ufs_getdirent();
struct gnode	*ufs_galloc();
int		ufs_syncgp(),	ufs_gfree(),	ufs_gtrunc();
int		ufs_rwgp();
int		ufs_rlock();
int		ufs_seek(),	ufs_stat(),	ufs_glock();
int		ufs_gunlock(),	ufs_gupdat(),	ufs_open();
int		ufs_close(),	ufs_select(),	ufs_readlink();
int		ufs_symlink();
struct fs_data	*ufs_getfsdata();
int		ufs_fcntl(),	ufs_bmap();


struct	mount_ops Ufs_mount_ops = {
/* begin mount ops */
	ufs_umount,
	ufs_sbupdat,
	ufs_ginit,
	0,		/* match */
	0,		/* reclaim */
	ufs_inactive,
	ufs_getfsdata,
};
struct	gnode_ops Ufs_gnode_ops = {
/* begin gnode ops */
	ufs_namei,
	ufs_link,
	ufs_unlink,
	ufs_mkdir,
	ufs_rmdir,
	ufs_maknode,
	ufs_rename,
	ufs_getdirent,
	0,
	ufs_syncgp,
	ufs_gtrunc,
	0, 		/*getval*/
	ufs_rwgp,
	ufs_rlock,
	ufs_seek,
	ufs_stat,
	ufs_glock,
	ufs_gunlock,
	ufs_gupdat,
	ufs_open,
	ufs_close,
	ufs_select,
	ufs_readlink,
	ufs_symlink,
	ufs_fcntl,
	0,		/* gfreegn */
	ufs_bmap
};

struct  mount_ops  *ufs_mount_ops = &Ufs_mount_ops;
struct  gnode_ops  *ufs_gnode_ops = &Ufs_gnode_ops;

gno_t rootino = (gno_t) ROOTINO;

/* this routine has lousy error codes */
/* this routine has races if running twice */
struct mount *
ufs_mount(devname, name, ronly, mp, fs_specific)
	char *devname;
	char *name;
	int ronly;
	register struct mount *mp;
	struct ufs_specific *fs_specific;
{
	dev_t	dev;
	register struct buf *tp = NULL;
	register struct buf *bp = NULL;
	register struct fs *fs;
	register struct mount *nmp;
	register struct gnode *gp;
	int blks;
	caddr_t space;
	int i, size;
	int root;
	struct gnode gnode;
	struct devget devget;
	struct ufs_specific ufs_sp;
	int force = 0;
	int saveaffinity;
	extern struct lock_t lk_mount_table;

	/* special case this when we are mounting the root fs */
	
	root = devname == NULL;
	
	if (!root) { /* we are not mounting / */
		if (u.u_error = getmdev(&dev, devname, u.u_uid)) {
			goto done;
		}
		GETMP(nmp, dev);
		if (nmp != NULL) {
			u.u_error = EBUSY; /* someone has us mounted */
		        goto done;
		}
		if (fs_specific != NULL) {
			u.u_error = copyin((caddr_t) fs_specific, (caddr_t)
			&ufs_sp, sizeof(ufs_sp));
			if (u.u_error)
				goto done;
			fs_specific = &ufs_sp;
		}
		/*
		 * check_mountp will verify local mount point exists and is
		 * ok to mount on.
		 */
		if (!(check_mountp(mp, name)))
			goto done;
	} else {
		force = 1;
		dev = rootdev;		/* map the root device from config */
	}

	/* 
	 * this is a hack but I can't see a way around it
	 * we need a gnode before we have the system mounted so we push 
	 * one on the stack and hand craft it. The gget at the end replaces
	 * this fake gnode with the real one.
	 */
		
	gnode.g_mode = GFBLK;
	gnode.g_dev = gnode.g_rdev = dev;
	gnode.g_ops = ufs_gnode_ops;	/* set pointer to file ops */
	gnode.g_mp = mp;
	mp->m_rootgp = &gnode;
	
	/* set up some stuff that smount cannot accomplish */
	
	/* Search mount table for entry using tdev */
	smp_lock(&lk_mount_table, LK_RETRY);
	for (nmp = mount; nmp < &mount[nmount]; nmp++) {
		if (nmp->m_dev == dev) {
			smp_unlock(&lk_mount_table);
			u.u_error = EBUSY;
			goto done;
		}
	}
		
	mp->m_dev = dev;
	smp_unlock(&lk_mount_table);
	mp->iostrat = bdevsw[major(dev)].d_strategy;	/* set this now! */
	mp->m_ops = ufs_mount_ops;

	mp->m_flags = ((ronly) ? M_RONLY : 0) | M_LOCAL;
	if (fs_specific != NULL) {
		int pg_thresh = fs_specific->ufs_pgthresh * 1024;
		mp->m_flags |= (fs_specific->ufs_flags & (M_RONLY | M_NOEXEC |
			M_QUOTA | M_NOSUID | M_NODEV | M_FORCE | M_SYNC));

		mp->m_fs_data->fd_pgthresh = 
			clrnd(btoc((pg_thresh > MINPGTHRESH) ?
				pg_thresh : MINPGTHRESH));
		
		/* only the superuser can mount forceably */

		force = (fs_specific->ufs_flags & M_FORCE) && (u.u_uid == 0);
	} else {
		/*
		 * if we don't specify the threshhold, use 64kB
		 */
		mp->m_fs_data->fd_pgthresh = clrnd(btoc(MINPGTHRESH * 8));
	}

	CALL_TO_NONSMP_DRIVER(bdevsw[major(dev)], saveaffinity);
	u.u_error = (*bdevsw[major(dev)].d_open)(dev, ronly ? FREAD : FREAD|FWRITE);
	RETURN_FROM_NONSMP_DRIVER(bdevsw[major(dev)], saveaffinity);
	if (u.u_error)
		goto done;

	bzero(&devget,sizeof(struct devget));
	CALL_TO_NONSMP_DRIVER(bdevsw[major(dev)], saveaffinity);
	u.u_error = (*bdevsw[major(dev)].d_ioctl)(dev, DEVIOCGET, &devget, 0);
	RETURN_FROM_NONSMP_DRIVER(bdevsw[major(dev)], saveaffinity);

	if (u.u_error) {
		if (!root) {
			printf("file system device ioctl failure");
		} else {
			printf("root file system device ioctl failure");
		}
	}

	if (devget.stat & DEV_OFFLINE) {
		u.u_error = ENODEV;
		goto ERROR;
	}
	if ((devget.stat & DEV_WRTLCK) && !ronly) {
		if (!root) {
			u.u_error = EROFS;
			goto ERROR;