NetBSD/sys/kern/vfs_vnops.c

571 lines
13 KiB
C

/* $NetBSD: vfs_vnops.c,v 1.30 1998/07/28 18:37:48 thorpej Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (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.
*
* @(#)vfs_vnops.c 8.14 (Berkeley) 6/15/95
*/
#include "fs_union.h"
#include "opt_uvm.h"
#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>
#include <sys/poll.h>
#include <vm/vm.h>
#if defined(UVM)
#include <uvm/uvm_extern.h>
#endif
#ifdef UNION
#include <miscfs/union/union.h>
#endif
struct fileops vnops =
{ vn_read, vn_write, vn_ioctl, vn_poll, vn_closefile };
/*
* Common code for vnode open operations.
* Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
*/
int
vn_open(ndp, fmode, cmode)
register struct nameidata *ndp;
int fmode, cmode;
{
register struct vnode *vp;
register struct proc *p = ndp->ni_cnd.cn_proc;
register struct ucred *cred = p->p_ucred;
struct vattr va;
int error;
if (fmode & O_CREAT) {
ndp->ni_cnd.cn_nameiop = CREATE;
ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
if ((fmode & O_EXCL) == 0)
ndp->ni_cnd.cn_flags |= FOLLOW;
if ((error = namei(ndp)) != 0)
return (error);
if (ndp->ni_vp == NULL) {
VATTR_NULL(&va);
va.va_type = VREG;
va.va_mode = cmode;
if (fmode & O_EXCL)
va.va_vaflags |= VA_EXCLUSIVE;
VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE);
error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
&ndp->ni_cnd, &va);
if (error)
return (error);
fmode &= ~O_TRUNC;
vp = ndp->ni_vp;
} else {
VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
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 {
ndp->ni_cnd.cn_nameiop = LOOKUP;
ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF;
if ((error = namei(ndp)) != 0)
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)) != 0)
goto bad;
}
if (fmode & (FWRITE | O_TRUNC)) {
if (vp->v_type == VDIR) {
error = EISDIR;
goto bad;
}
if ((error = vn_writechk(vp)) != 0 ||
(error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0)
goto bad;
}
}
if (fmode & O_TRUNC) {
VOP_UNLOCK(vp, 0); /* XXX */
VOP_LEASE(vp, p, cred, LEASE_WRITE);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */
VATTR_NULL(&va);
va.va_size = 0;
if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0)
goto bad;
}
if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0)
goto bad;
if (fmode & FWRITE)
vp->v_writecount++;
return (0);
bad:
vput(vp);
return (error);
}
/*
* Check for write permissions on the specified vnode.
* Prototype text segments cannot be written.
*/
int
vn_writechk(vp)
register struct vnode *vp;
{
/*
* If there's shared text associated with
* the vnode, try to free it up once. If
* we fail, we can't allow writing.
*/
#if defined(UVM)
if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp))
return (ETXTBSY);
#else
if ((vp->v_flag & VTEXT) && !vnode_pager_uncache(vp))
return (ETXTBSY);
#endif
return (0);
}
/*
* Vnode close call
*/
int
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.
*/
int
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;
size_t *aresid;
struct proc *p;
{
struct uio auio;
struct iovec aiov;
int error;
if ((ioflg & IO_NODELOCKED) == 0)
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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;
if (rw == UIO_READ) {
error = VOP_READ(vp, &auio, ioflg, cred);
} else {
error = VOP_WRITE(vp, &auio, ioflg, cred);
}
if (aresid)
*aresid = auio.uio_resid;
else
if (auio.uio_resid && error == 0)
error = EIO;
if ((ioflg & IO_NODELOCKED) == 0)
VOP_UNLOCK(vp, 0);
return (error);
}
int
vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies)
struct file *fp;
char *buf;
int segflg, *done, *ncookies;
u_int count;
struct proc *p;
off_t **cookies;
{
struct vnode *vp = (struct vnode *)fp->f_data;
struct iovec aiov;
struct uio auio;
int error, eofflag;
unionread:
if (vp->v_type != VDIR)
return (EINVAL);
aiov.iov_base = buf;
aiov.iov_len = count;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_READ;
auio.uio_segflg = segflg;
auio.uio_procp = p;
auio.uio_resid = count;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
auio.uio_offset = fp->f_offset;
error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies,
ncookies);
fp->f_offset = auio.uio_offset;
VOP_UNLOCK(vp, 0);
if (error)
return (error);
#ifdef UNION
{
extern int (**union_vnodeop_p) __P((void *));
extern struct vnode *union_dircache __P((struct vnode *));
if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) {
struct vnode *lvp;
lvp = union_dircache(vp);
if (lvp != NULLVP) {
struct vattr va;
/*
* If the directory is opaque,
* then don't show lower entries
*/
error = VOP_GETATTR(vp, &va, fp->f_cred, p);
if (va.va_flags & OPAQUE) {
vput(lvp);
lvp = NULL;
}
}
if (lvp != NULLVP) {
error = VOP_OPEN(lvp, FREAD, fp->f_cred, p);
if (error) {
vput(lvp);
return (error);
}
VOP_UNLOCK(lvp, 0);
fp->f_data = (caddr_t) lvp;
fp->f_offset = 0;
error = vn_close(vp, FREAD, fp->f_cred, p);
if (error)
return (error);
vp = lvp;
goto unionread;
}
}
}
#endif /* UNION */
if (count == auio.uio_resid && (vp->v_flag & VROOT) &&
(vp->v_mount->mnt_flag & MNT_UNION)) {
struct vnode *tvp = vp;
vp = vp->v_mount->mnt_vnodecovered;
VREF(vp);
fp->f_data = (caddr_t) vp;
fp->f_offset = 0;
vrele(tvp);
goto unionread;
}
*done = count - auio.uio_resid;
return error;
}
/*
* File table vnode read routine.
*/
int
vn_read(fp, offset, uio, cred, flags)
struct file *fp;
off_t *offset;
struct uio *uio;
struct ucred *cred;
int flags;
{
struct vnode *vp = (struct vnode *)fp->f_data;
int count, error;
VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
uio->uio_offset = *offset;
count = uio->uio_resid;
error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0,
cred);
if (flags & FOF_UPDATE_OFFSET)
*offset += count - uio->uio_resid;
VOP_UNLOCK(vp, 0);
return (error);
}
/*
* File table vnode write routine.
*/
int
vn_write(fp, offset, uio, cred, flags)
struct file *fp;
off_t *offset;
struct uio *uio;
struct ucred *cred;
int flags;
{
struct vnode *vp = (struct vnode *)fp->f_data;
int count, error, ioflag = IO_UNIT;
if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
ioflag |= IO_APPEND;
if (fp->f_flag & FNONBLOCK)
ioflag |= IO_NDELAY;
if (fp->f_flag & FFSYNC ||
(vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
ioflag |= IO_SYNC;
VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
uio->uio_offset = *offset;
count = uio->uio_resid;
error = VOP_WRITE(vp, uio, ioflag, cred);
if (flags & FOF_UPDATE_OFFSET) {
if (ioflag & IO_APPEND)
*offset = uio->uio_offset;
else
*offset += count - uio->uio_resid;
}
VOP_UNLOCK(vp, 0);
return (error);
}
/*
* File table vnode stat routine.
*/
int
vn_stat(vp, sb, p)
struct vnode *vp;
register struct stat *sb;
struct proc *p;
{
struct vattr va;
int error;
u_short mode;
error = VOP_GETATTR(vp, &va, p->p_ucred, p);
if (error)
return (error);
/*
* Copy from vattr table
*/
sb->st_dev = va.va_fsid;
sb->st_ino = va.va_fileid;
mode = va.va_mode;
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;
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 = 0;
sb->st_blocks = va.va_bytes / S_BLKSIZE;
return (0);
}
/*
* File table vnode ioctl routine.
*/
int
vn_ioctl(fp, com, data, p)
struct file *fp;
u_long com;
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) {
error = VOP_GETATTR(vp, &vattr, p->p_ucred, p);
if (error)
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);
p->p_session->s_ttyvp = vp;
VREF(vp);
}
return (error);
}
}
/*
* File table vnode poll routine.
*/
int
vn_poll(fp, events, p)
struct file *fp;
int events;
struct proc *p;
{
return (VOP_POLL(((struct vnode *)fp->f_data), events, p));
}
/*
* Check that the vnode is still valid, and if so
* acquire requested lock.
*/
int
vn_lock(vp, flags)
struct vnode *vp;
int flags;
{
int error;
do {
if ((flags & LK_INTERLOCK) == 0)
simple_lock(&vp->v_interlock);
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vn_lock", 0);
error = ENOENT;
} else {
error = VOP_LOCK(vp, flags | LK_INTERLOCK);
if (error == 0)
return (error);
}
flags &= ~LK_INTERLOCK;
} while (flags & LK_RETRY);
return (error);
}
/*
* File table vnode close routine.
*/
int
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));
}