Home | History | Annotate | Line # | Download | only in common
vfs_syscalls_43.c revision 1.1
      1  1.1  christos /*	$NetBSD: vfs_syscalls_43.c,v 1.1 1995/06/24 20:16:25 christos Exp $	*/
      2  1.1  christos 
      3  1.1  christos /*
      4  1.1  christos  * Copyright (c) 1989, 1993
      5  1.1  christos  *	The Regents of the University of California.  All rights reserved.
      6  1.1  christos  * (c) UNIX System Laboratories, Inc.
      7  1.1  christos  * All or some portions of this file are derived from material licensed
      8  1.1  christos  * to the University of California by American Telephone and Telegraph
      9  1.1  christos  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     10  1.1  christos  * the permission of UNIX System Laboratories, Inc.
     11  1.1  christos  *
     12  1.1  christos  * Redistribution and use in source and binary forms, with or without
     13  1.1  christos  * modification, are permitted provided that the following conditions
     14  1.1  christos  * are met:
     15  1.1  christos  * 1. Redistributions of source code must retain the above copyright
     16  1.1  christos  *    notice, this list of conditions and the following disclaimer.
     17  1.1  christos  * 2. Redistributions in binary form must reproduce the above copyright
     18  1.1  christos  *    notice, this list of conditions and the following disclaimer in the
     19  1.1  christos  *    documentation and/or other materials provided with the distribution.
     20  1.1  christos  * 3. All advertising materials mentioning features or use of this software
     21  1.1  christos  *    must display the following acknowledgement:
     22  1.1  christos  *	This product includes software developed by the University of
     23  1.1  christos  *	California, Berkeley and its contributors.
     24  1.1  christos  * 4. Neither the name of the University nor the names of its contributors
     25  1.1  christos  *    may be used to endorse or promote products derived from this software
     26  1.1  christos  *    without specific prior written permission.
     27  1.1  christos  *
     28  1.1  christos  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  1.1  christos  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  1.1  christos  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  1.1  christos  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  1.1  christos  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  1.1  christos  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  1.1  christos  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  1.1  christos  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  1.1  christos  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  1.1  christos  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  1.1  christos  * SUCH DAMAGE.
     39  1.1  christos  *
     40  1.1  christos  *	@(#)vfs_syscalls.c	8.28 (Berkeley) 12/10/94
     41  1.1  christos  */
     42  1.1  christos 
     43  1.1  christos #include <sys/param.h>
     44  1.1  christos #include <sys/systm.h>
     45  1.1  christos #include <sys/filedesc.h>
     46  1.1  christos #include <sys/kernel.h>
     47  1.1  christos #include <sys/proc.h>
     48  1.1  christos #include <sys/file.h>
     49  1.1  christos #include <sys/vnode.h>
     50  1.1  christos #include <sys/namei.h>
     51  1.1  christos #include <sys/dirent.h>
     52  1.1  christos #include <sys/socket.h>
     53  1.1  christos #include <sys/socketvar.h>
     54  1.1  christos #include <sys/stat.h>
     55  1.1  christos #include <sys/ioctl.h>
     56  1.1  christos #include <sys/fcntl.h>
     57  1.1  christos #include <sys/malloc.h>
     58  1.1  christos #include <sys/syslog.h>
     59  1.1  christos #include <sys/unistd.h>
     60  1.1  christos #include <sys/resourcevar.h>
     61  1.1  christos 
     62  1.1  christos #include <sys/mount.h>
     63  1.1  christos #include <sys/syscallargs.h>
     64  1.1  christos 
     65  1.1  christos 
     66  1.1  christos /*
     67  1.1  christos  * Convert from an old to a new stat structure.
     68  1.1  christos  */
     69  1.1  christos static int
     70  1.1  christos cvtstat(st, ost)
     71  1.1  christos 	struct stat *st;
     72  1.1  christos 	struct ostat *ost;
     73  1.1  christos {
     74  1.1  christos 
     75  1.1  christos 	ost->st_dev = st->st_dev;
     76  1.1  christos 	ost->st_ino = st->st_ino;
     77  1.1  christos 	ost->st_mode = st->st_mode;
     78  1.1  christos 	ost->st_nlink = st->st_nlink;
     79  1.1  christos 	ost->st_uid = st->st_uid;
     80  1.1  christos 	ost->st_gid = st->st_gid;
     81  1.1  christos 	ost->st_rdev = st->st_rdev;
     82  1.1  christos 	if (st->st_size < (quad_t)1 << 32)
     83  1.1  christos 		ost->st_size = st->st_size;
     84  1.1  christos 	else
     85  1.1  christos 		ost->st_size = -2;
     86  1.1  christos 	ost->st_atime = st->st_atime;
     87  1.1  christos 	ost->st_mtime = st->st_mtime;
     88  1.1  christos 	ost->st_ctime = st->st_ctime;
     89  1.1  christos 	ost->st_blksize = st->st_blksize;
     90  1.1  christos 	ost->st_blocks = st->st_blocks;
     91  1.1  christos 	ost->st_flags = st->st_flags;
     92  1.1  christos 	ost->st_gen = st->st_gen;
     93  1.1  christos }
     94  1.1  christos 
     95  1.1  christos /*
     96  1.1  christos  * Get file status; this version follows links.
     97  1.1  christos  */
     98  1.1  christos /* ARGSUSED */
     99  1.1  christos int
    100  1.1  christos compat_43_stat(p, uap, retval)
    101  1.1  christos 	struct proc *p;
    102  1.1  christos 	register struct compat_43_stat_args /* {
    103  1.1  christos 		syscallarg(char *) path;
    104  1.1  christos 		syscallarg(struct ostat *) ub;
    105  1.1  christos 	} */ *uap;
    106  1.1  christos 	register_t *retval;
    107  1.1  christos {
    108  1.1  christos 	struct stat sb;
    109  1.1  christos 	struct ostat osb;
    110  1.1  christos 	int error;
    111  1.1  christos 	struct nameidata nd;
    112  1.1  christos 
    113  1.1  christos 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
    114  1.1  christos 	    SCARG(uap, path), p);
    115  1.1  christos 	if (error = namei(&nd))
    116  1.1  christos 		return (error);
    117  1.1  christos 	error = vn_stat(nd.ni_vp, &sb, p);
    118  1.1  christos 	vput(nd.ni_vp);
    119  1.1  christos 	if (error)
    120  1.1  christos 		return (error);
    121  1.1  christos 	cvtstat(&sb, &osb);
    122  1.1  christos 	error = copyout((caddr_t)&osb, (caddr_t)SCARG(uap, ub), sizeof (osb));
    123  1.1  christos 	return (error);
    124  1.1  christos }
    125  1.1  christos 
    126  1.1  christos 
    127  1.1  christos /*
    128  1.1  christos  * Get file status; this version does not follow links.
    129  1.1  christos  */
    130  1.1  christos /* ARGSUSED */
    131  1.1  christos int
    132  1.1  christos compat_43_lstat(p, uap, retval)
    133  1.1  christos 	struct proc *p;
    134  1.1  christos 	register struct compat_43_lstat_args /* {
    135  1.1  christos 		syscallarg(char *) path;
    136  1.1  christos 		syscallarg(struct ostat *) ub;
    137  1.1  christos 	} */ *uap;
    138  1.1  christos 	register_t *retval;
    139  1.1  christos {
    140  1.1  christos 	struct vnode *vp, *dvp;
    141  1.1  christos 	struct stat sb, sb1;
    142  1.1  christos 	struct ostat osb;
    143  1.1  christos 	int error;
    144  1.1  christos 	struct nameidata nd;
    145  1.1  christos 
    146  1.1  christos 	NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | LOCKPARENT, UIO_USERSPACE,
    147  1.1  christos 	    SCARG(uap, path), p);
    148  1.1  christos 	if (error = namei(&nd))
    149  1.1  christos 		return (error);
    150  1.1  christos 	/*
    151  1.1  christos 	 * For symbolic links, always return the attributes of its
    152  1.1  christos 	 * containing directory, except for mode, size, and links.
    153  1.1  christos 	 */
    154  1.1  christos 	vp = nd.ni_vp;
    155  1.1  christos 	dvp = nd.ni_dvp;
    156  1.1  christos 	if (vp->v_type != VLNK) {
    157  1.1  christos 		if (dvp == vp)
    158  1.1  christos 			vrele(dvp);
    159  1.1  christos 		else
    160  1.1  christos 			vput(dvp);
    161  1.1  christos 		error = vn_stat(vp, &sb, p);
    162  1.1  christos 		vput(vp);
    163  1.1  christos 		if (error)
    164  1.1  christos 			return (error);
    165  1.1  christos 	} else {
    166  1.1  christos 		error = vn_stat(dvp, &sb, p);
    167  1.1  christos 		vput(dvp);
    168  1.1  christos 		if (error) {
    169  1.1  christos 			vput(vp);
    170  1.1  christos 			return (error);
    171  1.1  christos 		}
    172  1.1  christos 		error = vn_stat(vp, &sb1, p);
    173  1.1  christos 		vput(vp);
    174  1.1  christos 		if (error)
    175  1.1  christos 			return (error);
    176  1.1  christos 		sb.st_mode &= ~S_IFDIR;
    177  1.1  christos 		sb.st_mode |= S_IFLNK;
    178  1.1  christos 		sb.st_nlink = sb1.st_nlink;
    179  1.1  christos 		sb.st_size = sb1.st_size;
    180  1.1  christos 		sb.st_blocks = sb1.st_blocks;
    181  1.1  christos 	}
    182  1.1  christos 	cvtstat(&sb, &osb);
    183  1.1  christos 	error = copyout((caddr_t)&osb, (caddr_t)SCARG(uap, ub), sizeof (osb));
    184  1.1  christos 	return (error);
    185  1.1  christos }
    186  1.1  christos 
    187  1.1  christos 
    188  1.1  christos /*
    189  1.1  christos  * Return status information about a file descriptor.
    190  1.1  christos  */
    191  1.1  christos /* ARGSUSED */
    192  1.1  christos compat_43_fstat(p, uap, retval)
    193  1.1  christos 	struct proc *p;
    194  1.1  christos 	register struct compat_43_fstat_args /* {
    195  1.1  christos 		syscallarg(int) fd;
    196  1.1  christos 		syscallarg(struct ostat *) sb;
    197  1.1  christos 	} */ *uap;
    198  1.1  christos 	register_t *retval;
    199  1.1  christos {
    200  1.1  christos 	int fd = SCARG(uap, fd);
    201  1.1  christos 	register struct filedesc *fdp = p->p_fd;
    202  1.1  christos 	register struct file *fp;
    203  1.1  christos 	struct stat ub;
    204  1.1  christos 	struct ostat oub;
    205  1.1  christos 	int error;
    206  1.1  christos 
    207  1.1  christos 	if ((u_int)fd >= fdp->fd_nfiles ||
    208  1.1  christos 	    (fp = fdp->fd_ofiles[fd]) == NULL)
    209  1.1  christos 		return (EBADF);
    210  1.1  christos 	switch (fp->f_type) {
    211  1.1  christos 
    212  1.1  christos 	case DTYPE_VNODE:
    213  1.1  christos 		error = vn_stat((struct vnode *)fp->f_data, &ub, p);
    214  1.1  christos 		break;
    215  1.1  christos 
    216  1.1  christos 	case DTYPE_SOCKET:
    217  1.1  christos 		error = soo_stat((struct socket *)fp->f_data, &ub);
    218  1.1  christos 		break;
    219  1.1  christos 
    220  1.1  christos 	default:
    221  1.1  christos 		panic("ofstat");
    222  1.1  christos 		/*NOTREACHED*/
    223  1.1  christos 	}
    224  1.1  christos 	cvtstat(&ub, &oub);
    225  1.1  christos 	if (error == 0)
    226  1.1  christos 		error = copyout((caddr_t)&oub, (caddr_t)SCARG(uap, sb),
    227  1.1  christos 		    sizeof (oub));
    228  1.1  christos 	return (error);
    229  1.1  christos }
    230  1.1  christos 
    231  1.1  christos 
    232  1.1  christos /*
    233  1.1  christos  * Truncate a file given a file descriptor.
    234  1.1  christos  */
    235  1.1  christos /* ARGSUSED */
    236  1.1  christos int
    237  1.1  christos compat_43_ftruncate(p, uap, retval)
    238  1.1  christos 	struct proc *p;
    239  1.1  christos 	register struct compat_43_ftruncate_args /* {
    240  1.1  christos 		syscallarg(int) fd;
    241  1.1  christos 		syscallarg(long) length;
    242  1.1  christos 	} */ *uap;
    243  1.1  christos 	register_t *retval;
    244  1.1  christos {
    245  1.1  christos 	struct ftruncate_args /* {
    246  1.1  christos 		syscallarg(int) fd;
    247  1.1  christos 		syscallarg(int) pad;
    248  1.1  christos 		syscallarg(off_t) length;
    249  1.1  christos 	} */ nuap;
    250  1.1  christos 
    251  1.1  christos 	SCARG(&nuap, fd) = SCARG(uap, fd);
    252  1.1  christos 	SCARG(&nuap, length) = SCARG(uap, length);
    253  1.1  christos 	return (ftruncate(p, &nuap, retval));
    254  1.1  christos }
    255  1.1  christos 
    256  1.1  christos /*
    257  1.1  christos  * Truncate a file given its path name.
    258  1.1  christos  */
    259  1.1  christos /* ARGSUSED */
    260  1.1  christos int
    261  1.1  christos compat_43_truncate(p, uap, retval)
    262  1.1  christos 	struct proc *p;
    263  1.1  christos 	register struct compat_43_truncate_args /* {
    264  1.1  christos 		syscallarg(char *) path;
    265  1.1  christos 		syscallarg(long) length;
    266  1.1  christos 	} */ *uap;
    267  1.1  christos 	register_t *retval;
    268  1.1  christos {
    269  1.1  christos 	struct truncate_args /* {
    270  1.1  christos 		syscallarg(char *) path;
    271  1.1  christos 		syscallarg(int) pad;
    272  1.1  christos 		syscallarg(off_t) length;
    273  1.1  christos 	} */ nuap;
    274  1.1  christos 
    275  1.1  christos 	SCARG(&nuap, path) = SCARG(uap, path);
    276  1.1  christos 	SCARG(&nuap, length) = SCARG(uap, length);
    277  1.1  christos 	return (truncate(p, &nuap, retval));
    278  1.1  christos }
    279  1.1  christos 
    280  1.1  christos 
    281  1.1  christos /*
    282  1.1  christos  * Reposition read/write file offset.
    283  1.1  christos  */
    284  1.1  christos int
    285  1.1  christos compat_43_lseek(p, uap, retval)
    286  1.1  christos 	struct proc *p;
    287  1.1  christos 	register struct compat_43_lseek_args /* {
    288  1.1  christos 		syscallarg(int) fd;
    289  1.1  christos 		syscallarg(long) offset;
    290  1.1  christos 		syscallarg(int) whence;
    291  1.1  christos 	} */ *uap;
    292  1.1  christos 	register_t *retval;
    293  1.1  christos {
    294  1.1  christos 	struct lseek_args /* {
    295  1.1  christos 		syscallarg(int) fd;
    296  1.1  christos 		syscallarg(int) pad;
    297  1.1  christos 		syscallarg(off_t) offset;
    298  1.1  christos 		syscallarg(int) whence;
    299  1.1  christos 	} */ nuap;
    300  1.1  christos 	off_t qret;
    301  1.1  christos 	int error;
    302  1.1  christos 
    303  1.1  christos 	SCARG(&nuap, fd) = SCARG(uap, fd);
    304  1.1  christos 	SCARG(&nuap, offset) = SCARG(uap, offset);
    305  1.1  christos 	SCARG(&nuap, whence) = SCARG(uap, whence);
    306  1.1  christos 	error = lseek(p, &nuap, &qret);
    307  1.1  christos 	*(long *)retval = qret;
    308  1.1  christos 	return (error);
    309  1.1  christos }
    310  1.1  christos 
    311  1.1  christos 
    312  1.1  christos /*
    313  1.1  christos  * Create a file.
    314  1.1  christos  */
    315  1.1  christos int
    316  1.1  christos compat_43_creat(p, uap, retval)
    317  1.1  christos 	struct proc *p;
    318  1.1  christos 	register struct compat_43_creat_args /* {
    319  1.1  christos 		syscallarg(char *) path;
    320  1.1  christos 		syscallarg(int) mode;
    321  1.1  christos 	} */ *uap;
    322  1.1  christos 	register_t *retval;
    323  1.1  christos {
    324  1.1  christos 	struct open_args /* {
    325  1.1  christos 		syscallarg(char *) path;
    326  1.1  christos 		syscallarg(int) flags;
    327  1.1  christos 		syscallarg(int) mode;
    328  1.1  christos 	} */ nuap;
    329  1.1  christos 
    330  1.1  christos 	SCARG(&nuap, path) = SCARG(uap, path);
    331  1.1  christos 	SCARG(&nuap, mode) = SCARG(uap, mode);
    332  1.1  christos 	SCARG(&nuap, flags) = O_WRONLY | O_CREAT | O_TRUNC;
    333  1.1  christos 	return (open(p, &nuap, retval));
    334  1.1  christos }
    335  1.1  christos 
    336  1.1  christos /*ARGSUSED*/
    337  1.1  christos int
    338  1.1  christos compat_43_quota(p, uap, retval)
    339  1.1  christos 	struct proc *p;
    340  1.1  christos 	void *uap;
    341  1.1  christos 	register_t *retval;
    342  1.1  christos {
    343  1.1  christos 
    344  1.1  christos 	return (ENOSYS);
    345  1.1  christos }
    346  1.1  christos 
    347  1.1  christos 
    348  1.1  christos /*
    349  1.1  christos  * Read a block of directory entries in a file system independent format.
    350  1.1  christos  */
    351  1.1  christos int
    352  1.1  christos compat_43_getdirentries(p, uap, retval)
    353  1.1  christos 	struct proc *p;
    354  1.1  christos 	register struct compat_43_getdirentries_args /* {
    355  1.1  christos 		syscallarg(int) fd;
    356  1.1  christos 		syscallarg(char *) buf;
    357  1.1  christos 		syscallarg(u_int) count;
    358  1.1  christos 		syscallarg(long *) basep;
    359  1.1  christos 	} */ *uap;
    360  1.1  christos 	register_t *retval;
    361  1.1  christos {
    362  1.1  christos 	register struct vnode *vp;
    363  1.1  christos 	struct file *fp;
    364  1.1  christos 	struct uio auio, kuio;
    365  1.1  christos 	struct iovec aiov, kiov;
    366  1.1  christos 	struct dirent *dp, *edp;
    367  1.1  christos 	caddr_t dirbuf;
    368  1.1  christos 	int error, eofflag, readcnt;
    369  1.1  christos 	long loff;
    370  1.1  christos 
    371  1.1  christos 	if (error = getvnode(p->p_fd, SCARG(uap, fd), &fp))
    372  1.1  christos 		return (error);
    373  1.1  christos 	if ((fp->f_flag & FREAD) == 0)
    374  1.1  christos 		return (EBADF);
    375  1.1  christos 	vp = (struct vnode *)fp->f_data;
    376  1.1  christos unionread:
    377  1.1  christos 	if (vp->v_type != VDIR)
    378  1.1  christos 		return (EINVAL);
    379  1.1  christos 	aiov.iov_base = SCARG(uap, buf);
    380  1.1  christos 	aiov.iov_len = SCARG(uap, count);
    381  1.1  christos 	auio.uio_iov = &aiov;
    382  1.1  christos 	auio.uio_iovcnt = 1;
    383  1.1  christos 	auio.uio_rw = UIO_READ;
    384  1.1  christos 	auio.uio_segflg = UIO_USERSPACE;
    385  1.1  christos 	auio.uio_procp = p;
    386  1.1  christos 	auio.uio_resid = SCARG(uap, count);
    387  1.1  christos 	VOP_LOCK(vp);
    388  1.1  christos 	loff = auio.uio_offset = fp->f_offset;
    389  1.1  christos #	if (BYTE_ORDER != LITTLE_ENDIAN)
    390  1.1  christos 		if (vp->v_mount->mnt_maxsymlinklen <= 0) {
    391  1.1  christos 			error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag,
    392  1.1  christos 			    (u_long *)0, 0);
    393  1.1  christos 			fp->f_offset = auio.uio_offset;
    394  1.1  christos 		} else
    395  1.1  christos #	endif
    396  1.1  christos 	{
    397  1.1  christos 		kuio = auio;
    398  1.1  christos 		kuio.uio_iov = &kiov;
    399  1.1  christos 		kuio.uio_segflg = UIO_SYSSPACE;
    400  1.1  christos 		kiov.iov_len = SCARG(uap, count);
    401  1.1  christos 		MALLOC(dirbuf, caddr_t, SCARG(uap, count), M_TEMP, M_WAITOK);
    402  1.1  christos 		kiov.iov_base = dirbuf;
    403  1.1  christos 		error = VOP_READDIR(vp, &kuio, fp->f_cred, &eofflag,
    404  1.1  christos 			    (u_long *)0, 0);
    405  1.1  christos 		fp->f_offset = kuio.uio_offset;
    406  1.1  christos 		if (error == 0) {
    407  1.1  christos 			readcnt = SCARG(uap, count) - kuio.uio_resid;
    408  1.1  christos 			edp = (struct dirent *)&dirbuf[readcnt];
    409  1.1  christos 			for (dp = (struct dirent *)dirbuf; dp < edp; ) {
    410  1.1  christos #				if (BYTE_ORDER == LITTLE_ENDIAN)
    411  1.1  christos 					/*
    412  1.1  christos 					 * The expected low byte of
    413  1.1  christos 					 * dp->d_namlen is our dp->d_type.
    414  1.1  christos 					 * The high MBZ byte of dp->d_namlen
    415  1.1  christos 					 * is our dp->d_namlen.
    416  1.1  christos 					 */
    417  1.1  christos 					dp->d_type = dp->d_namlen;
    418  1.1  christos 					dp->d_namlen = 0;
    419  1.1  christos #				else
    420  1.1  christos 					/*
    421  1.1  christos 					 * The dp->d_type is the high byte
    422  1.1  christos 					 * of the expected dp->d_namlen,
    423  1.1  christos 					 * so must be zero'ed.
    424  1.1  christos 					 */
    425  1.1  christos 					dp->d_type = 0;
    426  1.1  christos #				endif
    427  1.1  christos 				if (dp->d_reclen > 0) {
    428  1.1  christos 					dp = (struct dirent *)
    429  1.1  christos 					    ((char *)dp + dp->d_reclen);
    430  1.1  christos 				} else {
    431  1.1  christos 					error = EIO;
    432  1.1  christos 					break;
    433  1.1  christos 				}
    434  1.1  christos 			}
    435  1.1  christos 			if (dp >= edp)
    436  1.1  christos 				error = uiomove(dirbuf, readcnt, &auio);
    437  1.1  christos 		}
    438  1.1  christos 		FREE(dirbuf, M_TEMP);
    439  1.1  christos 	}
    440  1.1  christos 	VOP_UNLOCK(vp);
    441  1.1  christos 	if (error)
    442  1.1  christos 		return (error);
    443  1.1  christos 
    444  1.1  christos #ifdef UNION
    445  1.1  christos {
    446  1.1  christos 	extern int (**union_vnodeop_p)();
    447  1.1  christos 	extern struct vnode *union_dircache __P((struct vnode *));
    448  1.1  christos 
    449  1.1  christos 	if ((SCARG(uap, count) == auio.uio_resid) &&
    450  1.1  christos 	    (vp->v_op == union_vnodeop_p)) {
    451  1.1  christos 		struct vnode *lvp;
    452  1.1  christos 
    453  1.1  christos 		lvp = union_dircache(vp);
    454  1.1  christos 		if (lvp != NULLVP) {
    455  1.1  christos 			struct vattr va;
    456  1.1  christos 
    457  1.1  christos 			/*
    458  1.1  christos 			 * If the directory is opaque,
    459  1.1  christos 			 * then don't show lower entries
    460  1.1  christos 			 */
    461  1.1  christos 			error = VOP_GETATTR(vp, &va, fp->f_cred, p);
    462  1.1  christos 			if (va.va_flags & OPAQUE) {
    463  1.1  christos 				vput(lvp);
    464  1.1  christos 				lvp = NULL;
    465  1.1  christos 			}
    466  1.1  christos 		}
    467  1.1  christos 
    468  1.1  christos 		if (lvp != NULLVP) {
    469  1.1  christos 			error = VOP_OPEN(lvp, FREAD, fp->f_cred, p);
    470  1.1  christos 			VOP_UNLOCK(lvp);
    471  1.1  christos 
    472  1.1  christos 			if (error) {
    473  1.1  christos 				vrele(lvp);
    474  1.1  christos 				return (error);
    475  1.1  christos 			}
    476  1.1  christos 			fp->f_data = (caddr_t) lvp;
    477  1.1  christos 			fp->f_offset = 0;
    478  1.1  christos 			error = vn_close(vp, FREAD, fp->f_cred, p);
    479  1.1  christos 			if (error)
    480  1.1  christos 				return (error);
    481  1.1  christos 			vp = lvp;
    482  1.1  christos 			goto unionread;
    483  1.1  christos 		}
    484  1.1  christos 	}
    485  1.1  christos }
    486  1.1  christos #endif /* UNION */
    487  1.1  christos 
    488  1.1  christos 	if ((SCARG(uap, count) == auio.uio_resid) &&
    489  1.1  christos 	    (vp->v_flag & VROOT) &&
    490  1.1  christos 	    (vp->v_mount->mnt_flag & MNT_UNION)) {
    491  1.1  christos 		struct vnode *tvp = vp;
    492  1.1  christos 		vp = vp->v_mount->mnt_vnodecovered;
    493  1.1  christos 		VREF(vp);
    494  1.1  christos 		fp->f_data = (caddr_t) vp;
    495  1.1  christos 		fp->f_offset = 0;
    496  1.1  christos 		vrele(tvp);
    497  1.1  christos 		goto unionread;
    498  1.1  christos 	}
    499  1.1  christos 	error = copyout((caddr_t)&loff, (caddr_t)SCARG(uap, basep),
    500  1.1  christos 	    sizeof(long));
    501  1.1  christos 	*retval = SCARG(uap, count) - auio.uio_resid;
    502  1.1  christos 	return (error);
    503  1.1  christos }
    504