Home | History | Annotate | Line # | Download | only in common
vfs_syscalls_43.c revision 1.13
      1  1.13  augustss /*	$NetBSD: vfs_syscalls_43.c,v 1.13 2000/03/30 11:27:15 augustss 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   1.9   thorpej 
     43   1.9   thorpej #include "fs_union.h"
     44   1.1  christos 
     45   1.1  christos #include <sys/param.h>
     46   1.1  christos #include <sys/systm.h>
     47   1.1  christos #include <sys/filedesc.h>
     48   1.1  christos #include <sys/kernel.h>
     49   1.1  christos #include <sys/proc.h>
     50   1.1  christos #include <sys/file.h>
     51   1.1  christos #include <sys/vnode.h>
     52   1.1  christos #include <sys/namei.h>
     53   1.1  christos #include <sys/dirent.h>
     54   1.1  christos #include <sys/socket.h>
     55   1.1  christos #include <sys/socketvar.h>
     56   1.1  christos #include <sys/stat.h>
     57   1.1  christos #include <sys/ioctl.h>
     58   1.1  christos #include <sys/fcntl.h>
     59   1.1  christos #include <sys/malloc.h>
     60   1.1  christos #include <sys/syslog.h>
     61   1.1  christos #include <sys/unistd.h>
     62   1.1  christos #include <sys/resourcevar.h>
     63   1.1  christos 
     64   1.1  christos #include <sys/mount.h>
     65   1.1  christos #include <sys/syscallargs.h>
     66   1.1  christos 
     67   1.8  christos static void cvtstat __P((struct stat *, struct stat43 *));
     68   1.4  christos 
     69   1.1  christos /*
     70   1.1  christos  * Convert from an old to a new stat structure.
     71   1.1  christos  */
     72   1.4  christos static void
     73   1.1  christos cvtstat(st, ost)
     74   1.1  christos 	struct stat *st;
     75   1.8  christos 	struct stat43 *ost;
     76   1.1  christos {
     77   1.1  christos 
     78   1.1  christos 	ost->st_dev = st->st_dev;
     79   1.1  christos 	ost->st_ino = st->st_ino;
     80  1.11  wrstuden 	ost->st_mode = st->st_mode & 0xffff;
     81   1.1  christos 	ost->st_nlink = st->st_nlink;
     82   1.1  christos 	ost->st_uid = st->st_uid;
     83   1.1  christos 	ost->st_gid = st->st_gid;
     84   1.1  christos 	ost->st_rdev = st->st_rdev;
     85   1.1  christos 	if (st->st_size < (quad_t)1 << 32)
     86   1.1  christos 		ost->st_size = st->st_size;
     87   1.1  christos 	else
     88   1.1  christos 		ost->st_size = -2;
     89   1.1  christos 	ost->st_atime = st->st_atime;
     90   1.1  christos 	ost->st_mtime = st->st_mtime;
     91   1.1  christos 	ost->st_ctime = st->st_ctime;
     92   1.1  christos 	ost->st_blksize = st->st_blksize;
     93   1.1  christos 	ost->st_blocks = st->st_blocks;
     94   1.1  christos 	ost->st_flags = st->st_flags;
     95   1.1  christos 	ost->st_gen = st->st_gen;
     96   1.1  christos }
     97   1.1  christos 
     98   1.1  christos /*
     99   1.1  christos  * Get file status; this version follows links.
    100   1.1  christos  */
    101   1.1  christos /* ARGSUSED */
    102   1.1  christos int
    103   1.3   mycroft compat_43_sys_stat(p, v, retval)
    104   1.1  christos 	struct proc *p;
    105   1.2   thorpej 	void *v;
    106   1.2   thorpej 	register_t *retval;
    107   1.2   thorpej {
    108  1.13  augustss 	struct compat_43_sys_stat_args /* {
    109   1.1  christos 		syscallarg(char *) path;
    110   1.8  christos 		syscallarg(struct stat43 *) ub;
    111   1.2   thorpej 	} */ *uap = v;
    112   1.1  christos 	struct stat sb;
    113   1.8  christos 	struct stat43 osb;
    114   1.1  christos 	int error;
    115   1.1  christos 	struct nameidata nd;
    116   1.1  christos 
    117   1.1  christos 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
    118   1.1  christos 	    SCARG(uap, path), p);
    119   1.4  christos 	if ((error = namei(&nd)) != 0)
    120   1.1  christos 		return (error);
    121   1.1  christos 	error = vn_stat(nd.ni_vp, &sb, p);
    122   1.1  christos 	vput(nd.ni_vp);
    123   1.1  christos 	if (error)
    124   1.1  christos 		return (error);
    125   1.1  christos 	cvtstat(&sb, &osb);
    126   1.1  christos 	error = copyout((caddr_t)&osb, (caddr_t)SCARG(uap, ub), sizeof (osb));
    127   1.1  christos 	return (error);
    128   1.1  christos }
    129   1.1  christos 
    130   1.1  christos /*
    131   1.1  christos  * Get file status; this version does not follow links.
    132   1.1  christos  */
    133   1.1  christos /* ARGSUSED */
    134   1.1  christos int
    135   1.3   mycroft compat_43_sys_lstat(p, v, retval)
    136   1.1  christos 	struct proc *p;
    137   1.2   thorpej 	void *v;
    138   1.2   thorpej 	register_t *retval;
    139   1.2   thorpej {
    140  1.13  augustss 	struct compat_43_sys_lstat_args /* {
    141   1.1  christos 		syscallarg(char *) path;
    142  1.10      fvdl 		syscallarg(struct ostat *) ub;
    143   1.2   thorpej 	} */ *uap = v;
    144  1.10      fvdl 	struct vnode *vp, *dvp;
    145  1.10      fvdl 	struct stat sb, sb1;
    146   1.8  christos 	struct stat43 osb;
    147   1.1  christos 	int error;
    148   1.1  christos 	struct nameidata nd;
    149   1.1  christos 
    150  1.10      fvdl 	NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | LOCKPARENT, UIO_USERSPACE,
    151   1.1  christos 	    SCARG(uap, path), p);
    152  1.10      fvdl 	if ((error = namei(&nd)))
    153   1.5  christos 		return (error);
    154  1.10      fvdl 	/*
    155  1.10      fvdl 	 * For symbolic links, always return the attributes of its
    156  1.10      fvdl 	 * containing directory, except for mode, size, and links.
    157  1.10      fvdl 	 */
    158  1.10      fvdl 	vp = nd.ni_vp;
    159  1.10      fvdl 	dvp = nd.ni_dvp;
    160  1.10      fvdl 	if (vp->v_type != VLNK) {
    161  1.10      fvdl 		if (dvp == vp)
    162  1.10      fvdl 			vrele(dvp);
    163  1.10      fvdl 		else
    164  1.10      fvdl 			vput(dvp);
    165  1.10      fvdl 		error = vn_stat(vp, &sb, p);
    166  1.10      fvdl 		vput(vp);
    167  1.10      fvdl 		if (error)
    168  1.10      fvdl 			return (error);
    169  1.10      fvdl 	} else {
    170  1.10      fvdl 		error = vn_stat(dvp, &sb, p);
    171  1.10      fvdl 		vput(dvp);
    172  1.10      fvdl 		if (error) {
    173  1.10      fvdl 			vput(vp);
    174  1.10      fvdl 			return (error);
    175  1.10      fvdl 		}
    176  1.10      fvdl 		error = vn_stat(vp, &sb1, p);
    177  1.10      fvdl 		vput(vp);
    178  1.10      fvdl 		if (error)
    179  1.10      fvdl 			return (error);
    180  1.10      fvdl 		sb.st_mode &= ~S_IFDIR;
    181  1.10      fvdl 		sb.st_mode |= S_IFLNK;
    182  1.10      fvdl 		sb.st_nlink = sb1.st_nlink;
    183  1.10      fvdl 		sb.st_size = sb1.st_size;
    184  1.10      fvdl 		sb.st_blocks = sb1.st_blocks;
    185  1.10      fvdl 	}
    186   1.1  christos 	cvtstat(&sb, &osb);
    187  1.10      fvdl 	error = copyout((caddr_t)&osb, (caddr_t)SCARG(uap, ub), sizeof (osb));
    188   1.1  christos 	return (error);
    189   1.1  christos }
    190   1.1  christos 
    191   1.1  christos /*
    192   1.1  christos  * Return status information about a file descriptor.
    193   1.1  christos  */
    194   1.1  christos /* ARGSUSED */
    195   1.4  christos int
    196   1.3   mycroft compat_43_sys_fstat(p, v, retval)
    197   1.1  christos 	struct proc *p;
    198   1.2   thorpej 	void *v;
    199   1.2   thorpej 	register_t *retval;
    200   1.2   thorpej {
    201  1.13  augustss 	struct compat_43_sys_fstat_args /* {
    202   1.1  christos 		syscallarg(int) fd;
    203   1.8  christos 		syscallarg(struct stat43 *) sb;
    204   1.2   thorpej 	} */ *uap = v;
    205   1.1  christos 	int fd = SCARG(uap, fd);
    206  1.13  augustss 	struct filedesc *fdp = p->p_fd;
    207  1.13  augustss 	struct file *fp;
    208   1.1  christos 	struct stat ub;
    209   1.8  christos 	struct stat43 oub;
    210   1.1  christos 	int error;
    211   1.1  christos 
    212   1.1  christos 	if ((u_int)fd >= fdp->fd_nfiles ||
    213   1.1  christos 	    (fp = fdp->fd_ofiles[fd]) == NULL)
    214   1.1  christos 		return (EBADF);
    215   1.1  christos 	switch (fp->f_type) {
    216   1.1  christos 
    217   1.1  christos 	case DTYPE_VNODE:
    218   1.1  christos 		error = vn_stat((struct vnode *)fp->f_data, &ub, p);
    219   1.1  christos 		break;
    220   1.1  christos 
    221   1.1  christos 	case DTYPE_SOCKET:
    222   1.1  christos 		error = soo_stat((struct socket *)fp->f_data, &ub);
    223   1.1  christos 		break;
    224   1.1  christos 
    225   1.1  christos 	default:
    226   1.1  christos 		panic("ofstat");
    227   1.1  christos 		/*NOTREACHED*/
    228   1.1  christos 	}
    229   1.1  christos 	cvtstat(&ub, &oub);
    230   1.1  christos 	if (error == 0)
    231   1.1  christos 		error = copyout((caddr_t)&oub, (caddr_t)SCARG(uap, sb),
    232   1.1  christos 		    sizeof (oub));
    233   1.1  christos 	return (error);
    234   1.1  christos }
    235   1.1  christos 
    236   1.1  christos 
    237   1.1  christos /*
    238   1.1  christos  * Truncate a file given a file descriptor.
    239   1.1  christos  */
    240   1.1  christos /* ARGSUSED */
    241   1.1  christos int
    242   1.3   mycroft compat_43_sys_ftruncate(p, v, retval)
    243   1.1  christos 	struct proc *p;
    244   1.2   thorpej 	void *v;
    245   1.2   thorpej 	register_t *retval;
    246   1.2   thorpej {
    247  1.13  augustss 	struct compat_43_sys_ftruncate_args /* {
    248   1.1  christos 		syscallarg(int) fd;
    249   1.1  christos 		syscallarg(long) length;
    250   1.2   thorpej 	} */ *uap = v;
    251   1.3   mycroft 	struct sys_ftruncate_args /* {
    252   1.1  christos 		syscallarg(int) fd;
    253   1.1  christos 		syscallarg(int) pad;
    254   1.1  christos 		syscallarg(off_t) length;
    255   1.1  christos 	} */ nuap;
    256   1.1  christos 
    257   1.1  christos 	SCARG(&nuap, fd) = SCARG(uap, fd);
    258   1.1  christos 	SCARG(&nuap, length) = SCARG(uap, length);
    259   1.3   mycroft 	return (sys_ftruncate(p, &nuap, retval));
    260   1.1  christos }
    261   1.1  christos 
    262   1.1  christos /*
    263   1.1  christos  * Truncate a file given its path name.
    264   1.1  christos  */
    265   1.1  christos /* ARGSUSED */
    266   1.1  christos int
    267   1.3   mycroft compat_43_sys_truncate(p, v, retval)
    268   1.1  christos 	struct proc *p;
    269   1.2   thorpej 	void *v;
    270   1.2   thorpej 	register_t *retval;
    271   1.2   thorpej {
    272  1.13  augustss 	struct compat_43_sys_truncate_args /* {
    273   1.1  christos 		syscallarg(char *) path;
    274   1.1  christos 		syscallarg(long) length;
    275   1.2   thorpej 	} */ *uap = v;
    276   1.3   mycroft 	struct sys_truncate_args /* {
    277   1.1  christos 		syscallarg(char *) path;
    278   1.1  christos 		syscallarg(int) pad;
    279   1.1  christos 		syscallarg(off_t) length;
    280   1.1  christos 	} */ nuap;
    281   1.1  christos 
    282   1.1  christos 	SCARG(&nuap, path) = SCARG(uap, path);
    283   1.1  christos 	SCARG(&nuap, length) = SCARG(uap, length);
    284   1.3   mycroft 	return (sys_truncate(p, &nuap, retval));
    285   1.1  christos }
    286   1.1  christos 
    287   1.1  christos 
    288   1.1  christos /*
    289   1.1  christos  * Reposition read/write file offset.
    290   1.1  christos  */
    291   1.1  christos int
    292   1.3   mycroft compat_43_sys_lseek(p, v, retval)
    293   1.1  christos 	struct proc *p;
    294   1.2   thorpej 	void *v;
    295   1.2   thorpej 	register_t *retval;
    296   1.2   thorpej {
    297  1.13  augustss 	struct compat_43_sys_lseek_args /* {
    298   1.1  christos 		syscallarg(int) fd;
    299   1.1  christos 		syscallarg(long) offset;
    300   1.1  christos 		syscallarg(int) whence;
    301   1.2   thorpej 	} */ *uap = v;
    302   1.3   mycroft 	struct sys_lseek_args /* {
    303   1.1  christos 		syscallarg(int) fd;
    304   1.1  christos 		syscallarg(int) pad;
    305   1.1  christos 		syscallarg(off_t) offset;
    306   1.1  christos 		syscallarg(int) whence;
    307   1.1  christos 	} */ nuap;
    308   1.1  christos 	off_t qret;
    309   1.1  christos 	int error;
    310   1.1  christos 
    311   1.1  christos 	SCARG(&nuap, fd) = SCARG(uap, fd);
    312   1.1  christos 	SCARG(&nuap, offset) = SCARG(uap, offset);
    313   1.1  christos 	SCARG(&nuap, whence) = SCARG(uap, whence);
    314   1.3   mycroft 	error = sys_lseek(p, &nuap, (register_t *)&qret);
    315   1.1  christos 	*(long *)retval = qret;
    316   1.1  christos 	return (error);
    317   1.1  christos }
    318   1.1  christos 
    319   1.1  christos 
    320   1.1  christos /*
    321   1.1  christos  * Create a file.
    322   1.1  christos  */
    323   1.1  christos int
    324   1.3   mycroft compat_43_sys_creat(p, v, retval)
    325   1.1  christos 	struct proc *p;
    326   1.2   thorpej 	void *v;
    327   1.2   thorpej 	register_t *retval;
    328   1.2   thorpej {
    329  1.13  augustss 	struct compat_43_sys_creat_args /* {
    330   1.1  christos 		syscallarg(char *) path;
    331   1.1  christos 		syscallarg(int) mode;
    332   1.2   thorpej 	} */ *uap = v;
    333   1.3   mycroft 	struct sys_open_args /* {
    334   1.1  christos 		syscallarg(char *) path;
    335   1.1  christos 		syscallarg(int) flags;
    336   1.1  christos 		syscallarg(int) mode;
    337   1.1  christos 	} */ nuap;
    338   1.1  christos 
    339   1.1  christos 	SCARG(&nuap, path) = SCARG(uap, path);
    340   1.1  christos 	SCARG(&nuap, mode) = SCARG(uap, mode);
    341   1.1  christos 	SCARG(&nuap, flags) = O_WRONLY | O_CREAT | O_TRUNC;
    342   1.3   mycroft 	return (sys_open(p, &nuap, retval));
    343   1.1  christos }
    344   1.1  christos 
    345   1.1  christos /*ARGSUSED*/
    346   1.1  christos int
    347   1.3   mycroft compat_43_sys_quota(p, v, retval)
    348   1.1  christos 	struct proc *p;
    349   1.3   mycroft 	void *v;
    350   1.1  christos 	register_t *retval;
    351   1.1  christos {
    352   1.1  christos 
    353   1.1  christos 	return (ENOSYS);
    354   1.1  christos }
    355   1.1  christos 
    356   1.1  christos 
    357   1.1  christos /*
    358   1.1  christos  * Read a block of directory entries in a file system independent format.
    359   1.1  christos  */
    360   1.1  christos int
    361   1.3   mycroft compat_43_sys_getdirentries(p, v, retval)
    362   1.1  christos 	struct proc *p;
    363   1.2   thorpej 	void *v;
    364   1.2   thorpej 	register_t *retval;
    365   1.2   thorpej {
    366  1.13  augustss 	struct compat_43_sys_getdirentries_args /* {
    367   1.1  christos 		syscallarg(int) fd;
    368   1.1  christos 		syscallarg(char *) buf;
    369   1.1  christos 		syscallarg(u_int) count;
    370   1.1  christos 		syscallarg(long *) basep;
    371   1.2   thorpej 	} */ *uap = v;
    372  1.13  augustss 	struct vnode *vp;
    373   1.1  christos 	struct file *fp;
    374   1.1  christos 	struct uio auio, kuio;
    375   1.1  christos 	struct iovec aiov, kiov;
    376   1.1  christos 	struct dirent *dp, *edp;
    377   1.1  christos 	caddr_t dirbuf;
    378   1.1  christos 	int error, eofflag, readcnt;
    379   1.1  christos 	long loff;
    380   1.1  christos 
    381  1.12   thorpej 	/* getvnode() will use the descriptor for us */
    382   1.4  christos 	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
    383   1.1  christos 		return (error);
    384  1.12   thorpej 	if ((fp->f_flag & FREAD) == 0) {
    385  1.12   thorpej 		error = EBADF;
    386  1.12   thorpej 		goto out;
    387  1.12   thorpej 	}
    388   1.1  christos 	vp = (struct vnode *)fp->f_data;
    389   1.1  christos unionread:
    390  1.12   thorpej 	if (vp->v_type != VDIR) {
    391  1.12   thorpej 		error = EINVAL;
    392  1.12   thorpej 		goto out;
    393  1.12   thorpej 	}
    394   1.1  christos 	aiov.iov_base = SCARG(uap, buf);
    395   1.1  christos 	aiov.iov_len = SCARG(uap, count);
    396   1.1  christos 	auio.uio_iov = &aiov;
    397   1.1  christos 	auio.uio_iovcnt = 1;
    398   1.1  christos 	auio.uio_rw = UIO_READ;
    399   1.1  christos 	auio.uio_segflg = UIO_USERSPACE;
    400   1.1  christos 	auio.uio_procp = p;
    401   1.1  christos 	auio.uio_resid = SCARG(uap, count);
    402  1.10      fvdl 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    403   1.1  christos 	loff = auio.uio_offset = fp->f_offset;
    404   1.1  christos #	if (BYTE_ORDER != LITTLE_ENDIAN)
    405   1.1  christos 		if (vp->v_mount->mnt_maxsymlinklen <= 0) {
    406   1.1  christos 			error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag,
    407  1.10      fvdl 			    (off_t **)0, (int *)0);
    408   1.1  christos 			fp->f_offset = auio.uio_offset;
    409   1.1  christos 		} else
    410   1.1  christos #	endif
    411   1.1  christos 	{
    412   1.1  christos 		kuio = auio;
    413   1.1  christos 		kuio.uio_iov = &kiov;
    414   1.1  christos 		kuio.uio_segflg = UIO_SYSSPACE;
    415   1.1  christos 		kiov.iov_len = SCARG(uap, count);
    416   1.1  christos 		MALLOC(dirbuf, caddr_t, SCARG(uap, count), M_TEMP, M_WAITOK);
    417   1.1  christos 		kiov.iov_base = dirbuf;
    418   1.1  christos 		error = VOP_READDIR(vp, &kuio, fp->f_cred, &eofflag,
    419  1.10      fvdl 			    (off_t **)0, (int *)0);
    420   1.1  christos 		fp->f_offset = kuio.uio_offset;
    421   1.1  christos 		if (error == 0) {
    422   1.1  christos 			readcnt = SCARG(uap, count) - kuio.uio_resid;
    423   1.1  christos 			edp = (struct dirent *)&dirbuf[readcnt];
    424   1.1  christos 			for (dp = (struct dirent *)dirbuf; dp < edp; ) {
    425   1.1  christos #				if (BYTE_ORDER == LITTLE_ENDIAN)
    426   1.1  christos 					/*
    427   1.1  christos 					 * The expected low byte of
    428   1.1  christos 					 * dp->d_namlen is our dp->d_type.
    429   1.1  christos 					 * The high MBZ byte of dp->d_namlen
    430   1.1  christos 					 * is our dp->d_namlen.
    431   1.1  christos 					 */
    432   1.1  christos 					dp->d_type = dp->d_namlen;
    433   1.1  christos 					dp->d_namlen = 0;
    434   1.1  christos #				else
    435   1.1  christos 					/*
    436   1.1  christos 					 * The dp->d_type is the high byte
    437   1.1  christos 					 * of the expected dp->d_namlen,
    438   1.1  christos 					 * so must be zero'ed.
    439   1.1  christos 					 */
    440   1.1  christos 					dp->d_type = 0;
    441   1.1  christos #				endif
    442   1.1  christos 				if (dp->d_reclen > 0) {
    443   1.1  christos 					dp = (struct dirent *)
    444   1.1  christos 					    ((char *)dp + dp->d_reclen);
    445   1.1  christos 				} else {
    446   1.1  christos 					error = EIO;
    447   1.1  christos 					break;
    448   1.1  christos 				}
    449   1.1  christos 			}
    450   1.1  christos 			if (dp >= edp)
    451   1.1  christos 				error = uiomove(dirbuf, readcnt, &auio);
    452   1.1  christos 		}
    453   1.1  christos 		FREE(dirbuf, M_TEMP);
    454   1.1  christos 	}
    455  1.10      fvdl 	VOP_UNLOCK(vp, 0);
    456   1.1  christos 	if (error)
    457  1.12   thorpej 		goto out;
    458   1.1  christos 
    459   1.1  christos #ifdef UNION
    460   1.1  christos {
    461   1.4  christos 	extern int (**union_vnodeop_p) __P((void *));
    462   1.1  christos 	extern struct vnode *union_dircache __P((struct vnode *));
    463   1.1  christos 
    464   1.1  christos 	if ((SCARG(uap, count) == auio.uio_resid) &&
    465   1.1  christos 	    (vp->v_op == union_vnodeop_p)) {
    466   1.1  christos 		struct vnode *lvp;
    467   1.1  christos 
    468   1.1  christos 		lvp = union_dircache(vp);
    469   1.1  christos 		if (lvp != NULLVP) {
    470   1.1  christos 			struct vattr va;
    471   1.1  christos 
    472   1.1  christos 			/*
    473   1.1  christos 			 * If the directory is opaque,
    474   1.1  christos 			 * then don't show lower entries
    475   1.1  christos 			 */
    476   1.1  christos 			error = VOP_GETATTR(vp, &va, fp->f_cred, p);
    477   1.1  christos 			if (va.va_flags & OPAQUE) {
    478   1.1  christos 				vput(lvp);
    479   1.1  christos 				lvp = NULL;
    480   1.1  christos 			}
    481   1.1  christos 		}
    482   1.1  christos 
    483   1.1  christos 		if (lvp != NULLVP) {
    484   1.1  christos 			error = VOP_OPEN(lvp, FREAD, fp->f_cred, p);
    485  1.10      fvdl 			VOP_UNLOCK(lvp, 0);
    486   1.1  christos 
    487   1.1  christos 			if (error) {
    488   1.1  christos 				vrele(lvp);
    489  1.12   thorpej 				goto out;
    490   1.1  christos 			}
    491   1.1  christos 			fp->f_data = (caddr_t) lvp;
    492   1.1  christos 			fp->f_offset = 0;
    493   1.1  christos 			error = vn_close(vp, FREAD, fp->f_cred, p);
    494   1.1  christos 			if (error)
    495  1.12   thorpej 				goto out;
    496   1.1  christos 			vp = lvp;
    497   1.1  christos 			goto unionread;
    498   1.1  christos 		}
    499   1.1  christos 	}
    500   1.1  christos }
    501   1.1  christos #endif /* UNION */
    502   1.1  christos 
    503   1.1  christos 	if ((SCARG(uap, count) == auio.uio_resid) &&
    504   1.1  christos 	    (vp->v_flag & VROOT) &&
    505   1.1  christos 	    (vp->v_mount->mnt_flag & MNT_UNION)) {
    506   1.1  christos 		struct vnode *tvp = vp;
    507   1.1  christos 		vp = vp->v_mount->mnt_vnodecovered;
    508   1.1  christos 		VREF(vp);
    509   1.1  christos 		fp->f_data = (caddr_t) vp;
    510   1.1  christos 		fp->f_offset = 0;
    511   1.1  christos 		vrele(tvp);
    512   1.1  christos 		goto unionread;
    513   1.1  christos 	}
    514   1.1  christos 	error = copyout((caddr_t)&loff, (caddr_t)SCARG(uap, basep),
    515   1.1  christos 	    sizeof(long));
    516   1.1  christos 	*retval = SCARG(uap, count) - auio.uio_resid;
    517  1.12   thorpej  out:
    518  1.12   thorpej 	FILE_UNUSE(fp, p);
    519   1.1  christos 	return (error);
    520   1.1  christos }
    521