NetBSD/sys/kern/vfs_vnops.c

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/* $NetBSD: vfs_vnops.c,v 1.19 1995/05/23 06:11:29 mycroft Exp $ */
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/*
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* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.
*
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* @(#)vfs_vnops.c 8.5 (Berkeley) 12/8/94
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*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
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#include <vm/vm.h>
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struct fileops vnops =
{ vn_read, vn_write, vn_ioctl, vn_select, vn_closefile };
/*
* Common code for vnode open operations.
* Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
*/
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vn_open(ndp, fmode, cmode)
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register struct nameidata *ndp;
int fmode, cmode;
{
register struct vnode *vp;
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register struct proc *p = ndp->ni_cnd.cn_proc;
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register struct ucred *cred = p->p_ucred;
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struct vattr va;
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int error;
if (fmode & O_CREAT) {
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ndp->ni_cnd.cn_nameiop = CREATE;
ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
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if ((fmode & O_EXCL) == 0)
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ndp->ni_cnd.cn_flags |= FOLLOW;
if (error = namei(ndp))
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return (error);
if (ndp->ni_vp == NULL) {
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VATTR_NULL(&va);
va.va_type = VREG;
va.va_mode = cmode;
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VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE);
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if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
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&ndp->ni_cnd, &va))
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return (error);
fmode &= ~O_TRUNC;
vp = ndp->ni_vp;
} else {
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VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
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if (ndp->ni_dvp == ndp->ni_vp)
vrele(ndp->ni_dvp);
else
vput(ndp->ni_dvp);
ndp->ni_dvp = NULL;
vp = ndp->ni_vp;
if (fmode & O_EXCL) {
error = EEXIST;
goto bad;
}
fmode &= ~O_CREAT;
}
} else {
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ndp->ni_cnd.cn_nameiop = LOOKUP;
ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF;
if (error = namei(ndp))
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return (error);
vp = ndp->ni_vp;
}
if (vp->v_type == VSOCK) {
error = EOPNOTSUPP;
goto bad;
}
if ((fmode & O_CREAT) == 0) {
if (fmode & FREAD) {
if (error = VOP_ACCESS(vp, VREAD, cred, p))
goto bad;
}
if (fmode & (FWRITE | O_TRUNC)) {
if (vp->v_type == VDIR) {
error = EISDIR;
goto bad;
}
if ((error = vn_writechk(vp)) ||
(error = VOP_ACCESS(vp, VWRITE, cred, p)))
goto bad;
}
}
if (fmode & O_TRUNC) {
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VOP_UNLOCK(vp); /* XXX */
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VOP_LEASE(vp, p, cred, LEASE_WRITE);
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VOP_LOCK(vp); /* XXX */
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VATTR_NULL(&va);
va.va_size = 0;
if (error = VOP_SETATTR(vp, &va, cred, p))
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goto bad;
}
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if (error = VOP_OPEN(vp, fmode, cred, p))
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goto bad;
if (fmode & FWRITE)
vp->v_writecount++;
return (0);
bad:
vput(vp);
return (error);
}
/*
* Check for write permissions on the specified vnode.
* The read-only status of the file system is checked.
* Also, prototype text segments cannot be written.
*/
vn_writechk(vp)
register struct vnode *vp;
{
/*
* Disallow write attempts on read-only file systems;
* unless the file is a socket or a block or character
* device resident on the file system.
*/
if (vp->v_mount->mnt_flag & MNT_RDONLY) {
switch (vp->v_type) {
case VREG: case VDIR: case VLNK:
return (EROFS);
}
}
/*
* If there's shared text associated with
* the vnode, try to free it up once. If
* we fail, we can't allow writing.
*/
if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp))
return (ETXTBSY);
return (0);
}
/*
* Vnode close call
*/
vn_close(vp, flags, cred, p)
register struct vnode *vp;
int flags;
struct ucred *cred;
struct proc *p;
{
int error;
if (flags & FWRITE)
vp->v_writecount--;
error = VOP_CLOSE(vp, flags, cred, p);
vrele(vp);
return (error);
}
/*
* Package up an I/O request on a vnode into a uio and do it.
*/
vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p)
enum uio_rw rw;
struct vnode *vp;
caddr_t base;
int len;
off_t offset;
enum uio_seg segflg;
int ioflg;
struct ucred *cred;
int *aresid;
struct proc *p;
{
struct uio auio;
struct iovec aiov;
int error;
if ((ioflg & IO_NODELOCKED) == 0)
VOP_LOCK(vp);
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
aiov.iov_base = base;
aiov.iov_len = len;
auio.uio_resid = len;
auio.uio_offset = offset;
auio.uio_segflg = segflg;
auio.uio_rw = rw;
auio.uio_procp = p;
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if (rw == UIO_READ) {
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error = VOP_READ(vp, &auio, ioflg, cred);
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} else {
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error = VOP_WRITE(vp, &auio, ioflg, cred);
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}
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if (aresid)
*aresid = auio.uio_resid;
else
if (auio.uio_resid && error == 0)
error = EIO;
if ((ioflg & IO_NODELOCKED) == 0)
VOP_UNLOCK(vp);
return (error);
}
/*
* File table vnode read routine.
*/
vn_read(fp, uio, cred)
struct file *fp;
struct uio *uio;
struct ucred *cred;
{
register struct vnode *vp = (struct vnode *)fp->f_data;
int count, error;
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VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ);
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VOP_LOCK(vp);
uio->uio_offset = fp->f_offset;
count = uio->uio_resid;
error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0,
cred);
fp->f_offset += count - uio->uio_resid;
VOP_UNLOCK(vp);
return (error);
}
/*
* File table vnode write routine.
*/
vn_write(fp, uio, cred)
struct file *fp;
struct uio *uio;
struct ucred *cred;
{
register struct vnode *vp = (struct vnode *)fp->f_data;
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int count, error, ioflag = IO_UNIT;
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if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
ioflag |= IO_APPEND;
if (fp->f_flag & FNONBLOCK)
ioflag |= IO_NDELAY;
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VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE);
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VOP_LOCK(vp);
uio->uio_offset = fp->f_offset;
count = uio->uio_resid;
error = VOP_WRITE(vp, uio, ioflag, cred);
if (ioflag & IO_APPEND)
fp->f_offset = uio->uio_offset;
else
fp->f_offset += count - uio->uio_resid;
VOP_UNLOCK(vp);
return (error);
}
/*
* File table vnode stat routine.
*/
vn_stat(vp, sb, p)
struct vnode *vp;
register struct stat *sb;
struct proc *p;
{
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struct vattr va;
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int error;
u_short mode;
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error = VOP_GETATTR(vp, &va, p->p_ucred, p);
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if (error)
return (error);
/*
* Copy from vattr table
*/
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sb->st_dev = va.va_fsid;
sb->st_ino = va.va_fileid;
mode = va.va_mode;
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switch (vp->v_type) {
case VREG:
mode |= S_IFREG;
break;
case VDIR:
mode |= S_IFDIR;
break;
case VBLK:
mode |= S_IFBLK;
break;
case VCHR:
mode |= S_IFCHR;
break;
case VLNK:
mode |= S_IFLNK;
break;
case VSOCK:
mode |= S_IFSOCK;
break;
case VFIFO:
mode |= S_IFIFO;
break;
default:
return (EBADF);
};
sb->st_mode = mode;
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sb->st_nlink = va.va_nlink;
sb->st_uid = va.va_uid;
sb->st_gid = va.va_gid;
sb->st_rdev = va.va_rdev;
sb->st_size = va.va_size;
sb->st_atimespec = va.va_atime;
sb->st_mtimespec = va.va_mtime;
sb->st_ctimespec = va.va_ctime;
sb->st_blksize = va.va_blocksize;
sb->st_flags = va.va_flags;
sb->st_gen = va.va_gen;
sb->st_blocks = va.va_bytes / S_BLKSIZE;
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return (0);
}
/*
* File table vnode ioctl routine.
*/
vn_ioctl(fp, com, data, p)
struct file *fp;
u_long com;
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caddr_t data;
struct proc *p;
{
register struct vnode *vp = ((struct vnode *)fp->f_data);
struct vattr vattr;
int error;
switch (vp->v_type) {
case VREG:
case VDIR:
if (com == FIONREAD) {
if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p))
return (error);
*(int *)data = vattr.va_size - fp->f_offset;
return (0);
}
if (com == FIONBIO || com == FIOASYNC) /* XXX */
return (0); /* XXX */
/* fall into ... */
default:
return (ENOTTY);
case VFIFO:
case VCHR:
case VBLK:
error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p);
if (error == 0 && com == TIOCSCTTY) {
if (p->p_session->s_ttyvp)
vrele(p->p_session->s_ttyvp);
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p->p_session->s_ttyvp = vp;
VREF(vp);
}
return (error);
}
}
/*
* File table vnode select routine.
*/
vn_select(fp, which, p)
struct file *fp;
int which;
struct proc *p;
{
return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag,
fp->f_cred, p));
}
/*
* File table vnode close routine.
*/
vn_closefile(fp, p)
struct file *fp;
struct proc *p;
{
return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
fp->f_cred, p));
}