[apple/xnu.git] / bsd / vfs / vfs_vnops.c

/*
 * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * 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 <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/ubc.h>
#include <sys/conf.h>
#include <sys/disk.h>

#include <vm/vm_kern.h>

#include <miscfs/specfs/specdev.h>

static int vn_closefile __P((struct file *fp, struct proc *p));
static int vn_ioctl __P((struct file *fp, u_long com, caddr_t data,
		struct proc *p));
static int vn_read __P((struct file *fp, struct uio *uio,
		struct ucred *cred, int flags, struct proc *p));
static int vn_write __P((struct file *fp, struct uio *uio,
		struct ucred *cred, int flags, struct proc *p));
static int vn_select __P(( struct file *fp, int which, void * wql,
		struct proc *p));

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.
 */
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 vat;
	struct vattr *vap = &vat;
	int error;
	int didhold = 0;

	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;
		bwillwrite();
		if (error = namei(ndp))
			return (error);
		if (ndp->ni_vp == NULL) {
			VATTR_NULL(vap);
			vap->va_type = VREG;
			vap->va_mode = cmode;
			if (fmode & O_EXCL)
				vap->va_vaflags |= VA_EXCLUSIVE;
			VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE);
			if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
			    &ndp->ni_cnd, vap))
				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))
			return (error);
		vp = ndp->ni_vp;
	}
	if (vp->v_type == VSOCK) {
		error = EOPNOTSUPP;
		goto bad;
	}

#if DIAGNOSTIC
	if (UBCINFOMISSING(vp))
		panic("vn_open: ubc_info_init");
#endif /* DIAGNOSTIC */

	if (UBCINFOEXISTS(vp) && ((didhold = ubc_hold(vp)) == 0)) {
		error = ENOENT;
		goto bad;
	}

	if ((fmode & O_CREAT) == 0) {
		if (fmode & FREAD && fmode & (FWRITE | O_TRUNC)) {
			int err = 0;
			if (vp->v_type == VDIR)
				err = EISDIR;
			else
				err = vn_writechk(vp);
			if (err && !(error = VOP_ACCESS(vp, VREAD, cred, p)))
				error = err;
			if (error || (error = VOP_ACCESS(vp, VREAD|VWRITE,
							 cred, p)))
				goto bad;
		} else if (fmode & FREAD) {
			if ((error = VOP_ACCESS(vp, VREAD, cred, p)))
				goto bad;
		} else 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) {
		VOP_UNLOCK(vp, 0, p);				/* XXX */
		VOP_LEASE(vp, p, cred, LEASE_WRITE);
		(void)vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);	/* XXX */
		VATTR_NULL(vap);
		vap->va_size = 0;
		if (error = VOP_SETATTR(vp, vap, cred, p))
			goto bad;
	}

	if (error = VOP_OPEN(vp, fmode, cred, p)) {
		goto bad;
	}

	if (fmode & FWRITE)
		if (++vp->v_writecount <= 0)
			panic("vn_open: v_writecount");
	return (0);
bad:
	VOP_UNLOCK(vp, 0, p);
	if (didhold)
		ubc_rele(vp);
	vrele(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 0
	/* XXXXX Not sure we need this */
	if (vp->v_flag & VTEXT)
		return (ETXTBSY);
#endif /* 0 */
	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);
	ubc_rele(vp);
	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;
	int *aresid;
	struct proc *p;
{
	struct uio auio;
	struct iovec aiov;
	int error=0;

	 /* FIXME XXX */
	if ((ioflg & IO_NODELOCKED) == 0)
		(void)vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
	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, p);
	return (error);
}

/*
 * File table vnode read routine.
 */
static int
vn_read(fp, uio, cred, flags, p)
	struct file *fp;
	struct uio *uio;
	struct ucred *cred;
	int flags;
	struct proc *p;
{
	struct vnode *vp;
	int error, ioflag;
	off_t count;

	if (p != uio->uio_procp)
		panic("vn_read: uio_procp does not match p");

	vp = (struct vnode *)fp->f_data;
	ioflag = 0;
	if (fp->f_flag & FNONBLOCK)
		ioflag |= IO_NDELAY;
	VOP_LEASE(vp, p, cred, LEASE_READ);
	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
	if (error)
		return (error);
	if ((flags & FOF_OFFSET) == 0)
		uio->uio_offset = fp->f_offset;
	count = uio->uio_resid;

	if(UBCINFOEXISTS(vp)) {
		memory_object_t	pager;
		struct iovec    *iov;
		off_t		file_off;
		kern_return_t	kr = KERN_SUCCESS;
		kern_return_t	ret = KERN_SUCCESS;
		int		count;

		pager = (memory_object_t)ubc_getpager(vp);
		file_off = uio->uio_offset;
		iov = uio->uio_iov;
		count = uio->uio_iovcnt;
		while(count) {
			kr = vm_conflict_check(current_map(), 
				(vm_offset_t)iov->iov_base, iov->iov_len, 
				pager, file_off);
			if(kr == KERN_ALREADY_WAITING) {
				if((count != uio->uio_iovcnt) &&
				   (ret != KERN_ALREADY_WAITING)) {
					error = EINVAL;
					goto done;
				}
				ret = KERN_ALREADY_WAITING;
			} else if (kr != KERN_SUCCESS) {
				error = EINVAL;
				goto done;
			}
			if(kr != ret) {
				error = EINVAL;
				goto done;
			}
			file_off += iov->iov_len;
			iov++;
			count--;
		}
		if(ret == KERN_ALREADY_WAITING) {
			uio->uio_resid = 0;
			if ((flags & FOF_OFFSET) == 0)
				fp->f_offset += 
					count - uio->uio_resid;
			error = 0;
			goto done;
		}
	}
	error = VOP_READ(vp, uio, ioflag, cred);
	if ((flags & FOF_OFFSET) == 0)
		fp->f_offset += count - uio->uio_resid;
done:
	VOP_UNLOCK(vp, 0, p);
	return (error);
}


/*
 * File table vnode write routine.
 */
static int
vn_write(fp, uio, cred, flags, p)
	struct file *fp;
	struct uio *uio;
	struct ucred *cred;
	int flags;
	struct proc *p;
{
	struct vnode *vp;
	int error, ioflag;
	off_t count;

	if (p != uio->uio_procp)
		panic("vn_write: uio_procp does not match p");

	vp = (struct vnode *)fp->f_data;
	ioflag = IO_UNIT;
	if (vp->v_type == VREG)
		bwillwrite();
	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 & O_FSYNC) ||
		(vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
		ioflag |= IO_SYNC;
	VOP_LEASE(vp, p, cred, LEASE_WRITE);
	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
	if (error)
		return (error);
	if ((flags & FOF_OFFSET) == 0) {
		uio->uio_offset = fp->f_offset;
		count = uio->uio_resid;
	}

	if(UBCINFOEXISTS(vp)) {
		memory_object_t		pager;
		struct iovec		*iov;
		off_t			file_off;
		kern_return_t		kr = KERN_SUCCESS;
		kern_return_t		ret = KERN_SUCCESS;
		int			count;

		pager = (memory_object_t)ubc_getpager(vp);
		file_off = uio->uio_offset;
		iov = uio->uio_iov;
		count = uio->uio_iovcnt;
		while(count) {
			kr = vm_conflict_check(current_map(), 
				(vm_offset_t)iov->iov_base, 
				iov->iov_len, pager, file_off);
			if(kr == KERN_ALREADY_WAITING) {
				if((count != uio->uio_iovcnt) &&
				   (ret != KERN_ALREADY_WAITING)) {
					error = EINVAL;
					goto done;
				}
				ret = KERN_ALREADY_WAITING;
			} else if (kr != KERN_SUCCESS) {
				error = EINVAL;
				goto done;
			}
			if(kr != ret) {
				error = EINVAL;
				goto done;
			}
			file_off += iov->iov_len;
			iov++;
			count--;
		}
		if(ret == KERN_ALREADY_WAITING) {
			uio->uio_resid = 0;
			if ((flags & FOF_OFFSET) == 0)
				fp->f_offset += 
					count - uio->uio_resid;
			error = 0;
			goto done;
		}
	}
	error = VOP_WRITE(vp, uio, ioflag, cred);

	if ((flags & FOF_OFFSET) == 0) {
		if (ioflag & IO_APPEND)
			fp->f_offset = uio->uio_offset;
		else
			fp->f_offset += count - uio->uio_resid;
	}

	/*
	 * Set the credentials on successful writes
	 */
	if ((error == 0) && (vp->v_tag == VT_NFS) && (UBCINFOEXISTS(vp))) {
		ubc_setcred(vp, p);
	}

done:
	VOP_UNLOCK(vp, 0, p);
	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 vattr;
	register struct vattr *vap;
	int error;
	u_short mode;

	vap = &vattr;
	error = VOP_GETATTR(vp, vap, p->p_ucred, p);
	if (error)
		return (error);
	/*
	 * Copy from vattr table
	 */
	sb->st_dev = vap->va_fsid;
	sb->st_ino = vap->va_fileid;
	mode = vap->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 = vap->va_nlink;
	sb->st_uid = vap->va_uid;
	sb->st_gid = vap->va_gid;
	sb->st_rdev = vap->va_rdev;
	sb->st_size = vap->va_size;
	sb->st_atimespec = vap->va_atime;
	sb->st_mtimespec = vap->va_mtime;
	sb->st_ctimespec = vap->va_ctime;
	sb->st_blksize = vap->va_blocksize;
	sb->st_flags = vap->va_flags;
	/* Do not give the generation number out to unpriviledged users */
	if (suser(p->p_ucred, &p->p_acflag))
		sb->st_gen = 0; 
	else
		sb->st_gen = vap->va_gen;
	sb->st_blocks = vap->va_bytes / S_BLKSIZE;
	return (0);
}

/*
 * File table vnode ioctl routine.
 */
static 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;
	struct vnode *ttyvp;
	
	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:

	  /* Should not be able to set block size from user space */
	  if(com == DKIOCSETBLOCKSIZE)
	    return (EPERM);
	  
	  if (com == FIODTYPE) {
	    if (vp->v_type == VBLK) {
	      if (major(vp->v_rdev) >= nblkdev)
		return (ENXIO);
	      *(int *)data = bdevsw[major(vp->v_rdev)].d_type;
	    } else if (vp->v_type == VCHR) {
	      if (major(vp->v_rdev) >= nchrdev)
		return (ENXIO);
	      *(int *)data = cdevsw[major(vp->v_rdev)].d_type;
	    } else {
	      return (ENOTTY);
	    }
	    return (0);
	  }
	  error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p);
	  if (error == 0 && com == TIOCSCTTY) {
	    VREF(vp);
	    ttyvp = p->p_session->s_ttyvp;
	    p->p_session->s_ttyvp = vp;
	    if (ttyvp)
	      vrele(ttyvp);
	  }
	  return (error);
	}
}

/*
 * File table vnode select routine.
 */
static int
vn_select(fp, which, wql, p)
	struct file *fp;
	int which;
	void * wql;
	struct proc *p;
{

	return(VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag,
		fp->f_cred, wql, p));
}

/*
 * Check that the vnode is still valid, and if so
 * acquire requested lock.
 */
int
vn_lock(vp, flags, p)
	struct vnode *vp;
	int flags;
	struct proc *p;
{
	int error;
	
	do {
		if ((flags & LK_INTERLOCK) == 0)
			simple_lock(&vp->v_interlock);
		if (vp->v_flag & VXLOCK) {
			while (vp->v_flag & VXLOCK) {
				vp->v_flag |= VXWANT;
				simple_unlock(&vp->v_interlock);
				(void)tsleep((caddr_t)vp, PINOD, "vn_lock", 0);
			}
			error = ENOENT;
		} else {
			error = VOP_LOCK(vp, flags | LK_INTERLOCK, p);
			if (error == 0)
				return (error);
		}
		flags &= ~LK_INTERLOCK;
	} while (flags & LK_RETRY);
	return (error);
}

/*
 * File table vnode close routine.
 */
static 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));
}
Commit	Line	Data
1c79356b	1	/*
9bccf70c	2	* Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
1c79356b A	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
d7e50217	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
1c79356b	7	*
d7e50217 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
d7e50217 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
1c79356b A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	26	/*
	27	* Copyright (c) 1982, 1986, 1989, 1993
	28	* The Regents of the University of California. All rights reserved.
	29	* (c) UNIX System Laboratories, Inc.
	30	* All or some portions of this file are derived from material licensed
	31	* to the University of California by American Telephone and Telegraph
	32	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	33	* the permission of UNIX System Laboratories, Inc.
	34	*
	35	* Redistribution and use in source and binary forms, with or without
	36	* modification, are permitted provided that the following conditions
	37	* are met:
	38	* 1. Redistributions of source code must retain the above copyright
	39	* notice, this list of conditions and the following disclaimer.
	40	* 2. Redistributions in binary form must reproduce the above copyright
	41	* notice, this list of conditions and the following disclaimer in the
	42	* documentation and/or other materials provided with the distribution.
	43	* 3. All advertising materials mentioning features or use of this software
	44	* must display the following acknowledgement:
	45	* This product includes software developed by the University of
	46	* California, Berkeley and its contributors.
	47	* 4. Neither the name of the University nor the names of its contributors
	48	* may be used to endorse or promote products derived from this software
	49	* without specific prior written permission.
	50	*
	51	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	52	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	53	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	54	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	55	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	56	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	57	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	58	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	59	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	60	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	61	* SUCH DAMAGE.
	62	*
	63	* @(#)vfs_vnops.c 8.14 (Berkeley) 6/15/95
	64	*
1c79356b A	65	*/
	66
	67	#include <sys/param.h>
	68	#include <sys/systm.h>
	69	#include <sys/kernel.h>
	70	#include <sys/file.h>
	71	#include <sys/stat.h>
	72	#include <sys/buf.h>
	73	#include <sys/proc.h>
	74	#include <sys/mount.h>
	75	#include <sys/namei.h>
	76	#include <sys/vnode.h>
	77	#include <sys/ioctl.h>
	78	#include <sys/tty.h>
	79	#include <sys/ubc.h>
9bccf70c A	80	#include <sys/conf.h>
	81	#include <sys/disk.h>
	82
	83	#include <vm/vm_kern.h>
	84
	85	#include <miscfs/specfs/specdev.h>
	86
	87	static int vn_closefile __P((struct file fp, struct proc p));
	88	static int vn_ioctl __P((struct file *fp, u_long com, caddr_t data,
	89	struct proc *p));
	90	static int vn_read __P((struct file fp, struct uio uio,
	91	struct ucred cred, int flags, struct proc p));
	92	static int vn_write __P((struct file fp, struct uio uio,
	93	struct ucred cred, int flags, struct proc p));
	94	static int vn_select __P(( struct file fp, int which, void wql,
	95	struct proc *p));
1c79356b A	96
	97	struct fileops vnops =
	98	{ vn_read, vn_write, vn_ioctl, vn_select, vn_closefile };
	99
	100	/*
	101	* Common code for vnode open operations.
	102	* Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
	103	*/
9bccf70c	104	int
1c79356b A	105	vn_open(ndp, fmode, cmode)
	106	register struct nameidata *ndp;
	107	int fmode, cmode;
	108	{
	109	register struct vnode *vp;
	110	register struct proc *p = ndp->ni_cnd.cn_proc;
	111	register struct ucred *cred = p->p_ucred;
	112	struct vattr vat;
	113	struct vattr *vap = &vat;
	114	int error;
9bccf70c	115	int didhold = 0;
1c79356b A	116
	117	if (fmode & O_CREAT) {
	118	ndp->ni_cnd.cn_nameiop = CREATE;
	119	ndp->ni_cnd.cn_flags = LOCKPARENT \| LOCKLEAF;
	120	if ((fmode & O_EXCL) == 0)
	121	ndp->ni_cnd.cn_flags \|= FOLLOW;
9bccf70c	122	bwillwrite();
1c79356b A	123	if (error = namei(ndp))
	124	return (error);
	125	if (ndp->ni_vp == NULL) {
	126	VATTR_NULL(vap);
	127	vap->va_type = VREG;
	128	vap->va_mode = cmode;
	129	if (fmode & O_EXCL)
	130	vap->va_vaflags \|= VA_EXCLUSIVE;
	131	VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE);
	132	if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
	133	&ndp->ni_cnd, vap))
	134	return (error);
	135	fmode &= ~O_TRUNC;
	136	vp = ndp->ni_vp;
	137	} else {
	138	VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
	139	if (ndp->ni_dvp == ndp->ni_vp)
	140	vrele(ndp->ni_dvp);
	141	else
	142	vput(ndp->ni_dvp);
	143	ndp->ni_dvp = NULL;
	144	vp = ndp->ni_vp;
	145	if (fmode & O_EXCL) {
	146	error = EEXIST;
	147	goto bad;
	148	}
	149	fmode &= ~O_CREAT;
	150	}
	151	} else {
	152	ndp->ni_cnd.cn_nameiop = LOOKUP;
	153	ndp->ni_cnd.cn_flags = FOLLOW \| LOCKLEAF;
	154	if (error = namei(ndp))
	155	return (error);
	156	vp = ndp->ni_vp;
	157	}
	158	if (vp->v_type == VSOCK) {
	159	error = EOPNOTSUPP;
	160	goto bad;
	161	}
9bccf70c A	162
	163	#if DIAGNOSTIC
	164	if (UBCINFOMISSING(vp))
	165	panic("vn_open: ubc_info_init");
	166	#endif /* DIAGNOSTIC */
	167
	168	if (UBCINFOEXISTS(vp) && ((didhold = ubc_hold(vp)) == 0)) {
	169	error = ENOENT;
	170	goto bad;
	171	}
	172
1c79356b A	173	if ((fmode & O_CREAT) == 0) {
	174	if (fmode & FREAD && fmode & (FWRITE \| O_TRUNC)) {
	175	int err = 0;
	176	if (vp->v_type == VDIR)
	177	err = EISDIR;
	178	else
	179	err = vn_writechk(vp);
	180	if (err && !(error = VOP_ACCESS(vp, VREAD, cred, p)))
	181	error = err;
	182	if (error \|\| (error = VOP_ACCESS(vp, VREAD\|VWRITE,
	183	cred, p)))
	184	goto bad;
	185	} else if (fmode & FREAD) {
	186	if ((error = VOP_ACCESS(vp, VREAD, cred, p)))
	187	goto bad;
	188	} else if (fmode & (FWRITE \| O_TRUNC)) {
	189	if (vp->v_type == VDIR) {
	190	error = EISDIR;
	191	goto bad;
	192	}
	193	if ((error = vn_writechk(vp)) \|\|
	194	(error = VOP_ACCESS(vp, VWRITE, cred, p)))
	195	goto bad;
	196	}
	197	}
	198	if (fmode & O_TRUNC) {
	199	VOP_UNLOCK(vp, 0, p); /* XXX */
	200	VOP_LEASE(vp, p, cred, LEASE_WRITE);
0b4e3aa0	201	(void)vn_lock(vp, LK_EXCLUSIVE \| LK_RETRY, p); /* XXX */
1c79356b A	202	VATTR_NULL(vap);
	203	vap->va_size = 0;
	204	if (error = VOP_SETATTR(vp, vap, cred, p))
	205	goto bad;
	206	}
0b4e3aa0	207
0b4e3aa0	208	if (error = VOP_OPEN(vp, fmode, cred, p)) {
0b4e3aa0 A	209	goto bad;
	210	}
	211
1c79356b A	212	if (fmode & FWRITE)
	213	if (++vp->v_writecount <= 0)
	214	panic("vn_open: v_writecount");
	215	return (0);
	216	bad:
9bccf70c A	217	VOP_UNLOCK(vp, 0, p);
	218	if (didhold)
	219	ubc_rele(vp);
	220	vrele(vp);
1c79356b A	221	return (error);
	222	}
	223
	224	/*
	225	* Check for write permissions on the specified vnode.
	226	* Prototype text segments cannot be written.
	227	*/
9bccf70c	228	int
1c79356b A	229	vn_writechk(vp)
	230	register struct vnode *vp;
	231	{
	232
	233	/*
	234	* If there's shared text associated with
	235	* the vnode, try to free it up once. If
	236	* we fail, we can't allow writing.
	237	*/
	238	#if 0
	239	/* XXXXX Not sure we need this */
	240	if (vp->v_flag & VTEXT)
	241	return (ETXTBSY);
	242	#endif /* 0 */
	243	return (0);
	244	}
	245
	246	/*
	247	* Vnode close call
	248	*/
9bccf70c	249	int
1c79356b A	250	vn_close(vp, flags, cred, p)
	251	register struct vnode *vp;
	252	int flags;
	253	struct ucred *cred;
	254	struct proc *p;
	255	{
	256	int error;
1c79356b A	257
	258	if (flags & FWRITE)
	259	vp->v_writecount--;
	260	error = VOP_CLOSE(vp, flags, cred, p);
	261	ubc_rele(vp);
	262	vrele(vp);
	263	return (error);
	264	}
	265
	266	/*
	267	* Package up an I/O request on a vnode into a uio and do it.
	268	*/
9bccf70c	269	int
1c79356b A	270	vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p)
	271	enum uio_rw rw;
	272	struct vnode *vp;
	273	caddr_t base;
	274	int len;
	275	off_t offset;
	276	enum uio_seg segflg;
	277	int ioflg;
	278	struct ucred *cred;
	279	int *aresid;
	280	struct proc *p;
	281	{
	282	struct uio auio;
	283	struct iovec aiov;
	284	int error=0;
	285
	286	/* FIXME XXX */
	287	if ((ioflg & IO_NODELOCKED) == 0)
0b4e3aa0	288	(void)vn_lock(vp, LK_EXCLUSIVE \| LK_RETRY, p);
1c79356b A	289	auio.uio_iov = &aiov;
	290	auio.uio_iovcnt = 1;
	291	aiov.iov_base = base;
	292	aiov.iov_len = len;
	293	auio.uio_resid = len;
	294	auio.uio_offset = offset;
	295	auio.uio_segflg = segflg;
	296	auio.uio_rw = rw;
	297	auio.uio_procp = p;
	298
	299	if (rw == UIO_READ)
	300	error = VOP_READ(vp, &auio, ioflg, cred);
	301	else
	302	error = VOP_WRITE(vp, &auio, ioflg, cred);
	303
	304	if (aresid)
	305	*aresid = auio.uio_resid;
	306	else
	307	if (auio.uio_resid && error == 0)
	308	error = EIO;
	309	if ((ioflg & IO_NODELOCKED) == 0)
	310	VOP_UNLOCK(vp, 0, p);
	311	return (error);
	312	}
	313
	314	/*
	315	* File table vnode read routine.
	316	*/
9bccf70c A	317	static int
9bccf70c A	318	vn_read(fp, uio, cred, flags, p)
1c79356b A	319	struct file *fp;
	320	struct uio *uio;
	321	struct ucred *cred;
9bccf70c A	322	int flags;
9bccf70c A	323	struct proc *p;
1c79356b	324	{
9bccf70c A	325	struct vnode *vp;
9bccf70c A	326	int error, ioflag;
1c79356b A	327	off_t count;
1c79356b A	328
9bccf70c A	329	if (p != uio->uio_procp)
	330	panic("vn_read: uio_procp does not match p");
	331
	332	vp = (struct vnode *)fp->f_data;
	333	ioflag = 0;
	334	if (fp->f_flag & FNONBLOCK)
	335	ioflag \|= IO_NDELAY;
1c79356b	336	VOP_LEASE(vp, p, cred, LEASE_READ);
9bccf70c A	337	error = vn_lock(vp, LK_EXCLUSIVE \| LK_RETRY, p);
	338	if (error)
	339	return (error);
	340	if ((flags & FOF_OFFSET) == 0)
	341	uio->uio_offset = fp->f_offset;
1c79356b A	342	count = uio->uio_resid;
1c79356b A	343
9bccf70c A	344	if(UBCINFOEXISTS(vp)) {
	345	memory_object_t pager;
	346	struct iovec *iov;
	347	off_t file_off;
	348	kern_return_t kr = KERN_SUCCESS;
	349	kern_return_t ret = KERN_SUCCESS;
	350	int count;
	351
	352	pager = (memory_object_t)ubc_getpager(vp);
	353	file_off = uio->uio_offset;
	354	iov = uio->uio_iov;
	355	count = uio->uio_iovcnt;
	356	while(count) {
	357	kr = vm_conflict_check(current_map(),
	358	(vm_offset_t)iov->iov_base, iov->iov_len,
	359	pager, file_off);
	360	if(kr == KERN_ALREADY_WAITING) {
	361	if((count != uio->uio_iovcnt) &&
	362	(ret != KERN_ALREADY_WAITING)) {
	363	error = EINVAL;
	364	goto done;
	365	}
	366	ret = KERN_ALREADY_WAITING;
	367	} else if (kr != KERN_SUCCESS) {
	368	error = EINVAL;
	369	goto done;
	370	}
	371	if(kr != ret) {
	372	error = EINVAL;
	373	goto done;
	374	}
	375	file_off += iov->iov_len;
	376	iov++;
	377	count--;
	378	}
	379	if(ret == KERN_ALREADY_WAITING) {
	380	uio->uio_resid = 0;
	381	if ((flags & FOF_OFFSET) == 0)
	382	fp->f_offset +=
	383	count - uio->uio_resid;
	384	error = 0;
	385	goto done;
	386	}
	387	}
	388	error = VOP_READ(vp, uio, ioflag, cred);
	389	if ((flags & FOF_OFFSET) == 0)
	390	fp->f_offset += count - uio->uio_resid;
	391	done:
1c79356b A	392	VOP_UNLOCK(vp, 0, p);
	393	return (error);
	394	}
	395
	396
	397	/*
	398	* File table vnode write routine.
	399	*/
9bccf70c A	400	static int
9bccf70c A	401	vn_write(fp, uio, cred, flags, p)
1c79356b A	402	struct file *fp;
	403	struct uio *uio;
	404	struct ucred *cred;
9bccf70c A	405	int flags;
9bccf70c A	406	struct proc *p;
1c79356b	407	{
9bccf70c A	408	struct vnode *vp;
9bccf70c A	409	int error, ioflag;
1c79356b A	410	off_t count;
1c79356b A	411
9bccf70c A	412	if (p != uio->uio_procp)
	413	panic("vn_write: uio_procp does not match p");
	414
	415	vp = (struct vnode *)fp->f_data;
	416	ioflag = IO_UNIT;
	417	if (vp->v_type == VREG)
	418	bwillwrite();
1c79356b A	419	if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
	420	ioflag \|= IO_APPEND;
	421	if (fp->f_flag & FNONBLOCK)
	422	ioflag \|= IO_NDELAY;
	423	if ((fp->f_flag & O_FSYNC) \|\|
	424	(vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
	425	ioflag \|= IO_SYNC;
	426	VOP_LEASE(vp, p, cred, LEASE_WRITE);
9bccf70c A	427	error = vn_lock(vp, LK_EXCLUSIVE \| LK_RETRY, p);
	428	if (error)
	429	return (error);
	430	if ((flags & FOF_OFFSET) == 0) {
	431	uio->uio_offset = fp->f_offset;
	432	count = uio->uio_resid;
	433	}
1c79356b	434
9bccf70c A	435	if(UBCINFOEXISTS(vp)) {
	436	memory_object_t pager;
	437	struct iovec *iov;
	438	off_t file_off;
	439	kern_return_t kr = KERN_SUCCESS;
	440	kern_return_t ret = KERN_SUCCESS;
	441	int count;
	442
	443	pager = (memory_object_t)ubc_getpager(vp);
	444	file_off = uio->uio_offset;
	445	iov = uio->uio_iov;
	446	count = uio->uio_iovcnt;
	447	while(count) {
	448	kr = vm_conflict_check(current_map(),
	449	(vm_offset_t)iov->iov_base,
	450	iov->iov_len, pager, file_off);
	451	if(kr == KERN_ALREADY_WAITING) {
	452	if((count != uio->uio_iovcnt) &&
	453	(ret != KERN_ALREADY_WAITING)) {
	454	error = EINVAL;
	455	goto done;
	456	}
	457	ret = KERN_ALREADY_WAITING;
	458	} else if (kr != KERN_SUCCESS) {
	459	error = EINVAL;
	460	goto done;
	461	}
	462	if(kr != ret) {
	463	error = EINVAL;
	464	goto done;
	465	}
	466	file_off += iov->iov_len;
	467	iov++;
	468	count--;
	469	}
	470	if(ret == KERN_ALREADY_WAITING) {
	471	uio->uio_resid = 0;
	472	if ((flags & FOF_OFFSET) == 0)
	473	fp->f_offset +=
	474	count - uio->uio_resid;
	475	error = 0;
	476	goto done;
	477	}
	478	}
1c79356b A	479	error = VOP_WRITE(vp, uio, ioflag, cred);
1c79356b A	480
9bccf70c A	481	if ((flags & FOF_OFFSET) == 0) {
	482	if (ioflag & IO_APPEND)
	483	fp->f_offset = uio->uio_offset;
	484	else
	485	fp->f_offset += count - uio->uio_resid;
	486	}
	487
1c79356b A	488	/*
	489	* Set the credentials on successful writes
	490	*/
	491	if ((error == 0) && (vp->v_tag == VT_NFS) && (UBCINFOEXISTS(vp))) {
	492	ubc_setcred(vp, p);
	493	}
	494
9bccf70c	495	done:
1c79356b A	496	VOP_UNLOCK(vp, 0, p);
	497	return (error);
	498	}
	499
	500	/*
	501	* File table vnode stat routine.
	502	*/
9bccf70c	503	int
1c79356b A	504	vn_stat(vp, sb, p)
	505	struct vnode *vp;
	506	register struct stat *sb;
	507	struct proc *p;
	508	{
	509	struct vattr vattr;
	510	register struct vattr *vap;
	511	int error;
	512	u_short mode;
	513
	514	vap = &vattr;
	515	error = VOP_GETATTR(vp, vap, p->p_ucred, p);
	516	if (error)
	517	return (error);
	518	/*
	519	* Copy from vattr table
	520	*/
	521	sb->st_dev = vap->va_fsid;
	522	sb->st_ino = vap->va_fileid;
	523	mode = vap->va_mode;
	524	switch (vp->v_type) {
	525	case VREG:
	526	mode \|= S_IFREG;
	527	break;
	528	case VDIR:
	529	mode \|= S_IFDIR;
	530	break;
	531	case VBLK:
	532	mode \|= S_IFBLK;
	533	break;
	534	case VCHR:
	535	mode \|= S_IFCHR;
	536	break;
	537	case VLNK:
	538	mode \|= S_IFLNK;
	539	break;
	540	case VSOCK:
	541	mode \|= S_IFSOCK;
	542	break;
	543	case VFIFO:
	544	mode \|= S_IFIFO;
	545	break;
	546	default:
	547	return (EBADF);
	548	};
	549	sb->st_mode = mode;
	550	sb->st_nlink = vap->va_nlink;
	551	sb->st_uid = vap->va_uid;
	552	sb->st_gid = vap->va_gid;
	553	sb->st_rdev = vap->va_rdev;
	554	sb->st_size = vap->va_size;
	555	sb->st_atimespec = vap->va_atime;
	556	sb->st_mtimespec = vap->va_mtime;
	557	sb->st_ctimespec = vap->va_ctime;
	558	sb->st_blksize = vap->va_blocksize;
	559	sb->st_flags = vap->va_flags;
	560	/* Do not give the generation number out to unpriviledged users */
	561	if (suser(p->p_ucred, &p->p_acflag))
	562	sb->st_gen = 0;
	563	else
	564	sb->st_gen = vap->va_gen;
	565	sb->st_blocks = vap->va_bytes / S_BLKSIZE;
	566	return (0);
	567	}
568
569	/*
570	* File table vnode ioctl routine.
571	*/
9bccf70c	572	static int
1c79356b A	573	vn_ioctl(fp, com, data, p)
	574	struct file *fp;
	575	u_long com;
	576	caddr_t data;
	577	struct proc *p;
	578	{
	579	register struct vnode vp = ((struct vnode )fp->f_data);
	580	struct vattr vattr;
	581	int error;
fa4905b1	582	struct vnode *ttyvp;
9bccf70c	583
1c79356b A	584	switch (vp->v_type) {
	585
	586	case VREG:
	587	case VDIR:
	588	if (com == FIONREAD) {
	589	if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p))
	590	return (error);
	591	(int )data = vattr.va_size - fp->f_offset;
	592	return (0);
	593	}
	594	if (com == FIONBIO \|\| com == FIOASYNC) /* XXX */
	595	return (0); /* XXX */
	596	/* fall into ... */
	597
	598	default:
	599	return (ENOTTY);
	600
	601	case VFIFO:
	602	case VCHR:
	603	case VBLK:
9bccf70c A	604
	605	/* Should not be able to set block size from user space */
	606	if(com == DKIOCSETBLOCKSIZE)
	607	return (EPERM);
	608
	609	if (com == FIODTYPE) {
	610	if (vp->v_type == VBLK) {
	611	if (major(vp->v_rdev) >= nblkdev)
	612	return (ENXIO);
	613	(int )data = bdevsw[major(vp->v_rdev)].d_type;
	614	} else if (vp->v_type == VCHR) {
	615	if (major(vp->v_rdev) >= nchrdev)
	616	return (ENXIO);
	617	(int )data = cdevsw[major(vp->v_rdev)].d_type;
	618	} else {
	619	return (ENOTTY);
	620	}
	621	return (0);
	622	}
	623	error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p);
	624	if (error == 0 && com == TIOCSCTTY) {
	625	VREF(vp);
	626	ttyvp = p->p_session->s_ttyvp;
	627	p->p_session->s_ttyvp = vp;
	628	if (ttyvp)
	629	vrele(ttyvp);
	630	}
	631	return (error);
1c79356b A	632	}
	633	}
	634
	635	/*
	636	* File table vnode select routine.
	637	*/
9bccf70c	638	static int
0b4e3aa0	639	vn_select(fp, which, wql, p)
1c79356b A	640	struct file *fp;
1c79356b A	641	int which;
0b4e3aa0	642	void * wql;
1c79356b A	643	struct proc *p;
	644	{
	645
0b4e3aa0 A	646	return(VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag,
0b4e3aa0 A	647	fp->f_cred, wql, p));
1c79356b A	648	}
	649
	650	/*
	651	* Check that the vnode is still valid, and if so
	652	* acquire requested lock.
	653	*/
	654	int
	655	vn_lock(vp, flags, p)
	656	struct vnode *vp;
	657	int flags;
	658	struct proc *p;
	659	{
	660	int error;
	661
	662	do {
	663	if ((flags & LK_INTERLOCK) == 0)
	664	simple_lock(&vp->v_interlock);
	665	if (vp->v_flag & VXLOCK) {
	666	while (vp->v_flag & VXLOCK) {
	667	vp->v_flag \|= VXWANT;
	668	simple_unlock(&vp->v_interlock);
0b4e3aa0	669	(void)tsleep((caddr_t)vp, PINOD, "vn_lock", 0);
1c79356b A	670	}
	671	error = ENOENT;
	672	} else {
	673	error = VOP_LOCK(vp, flags \| LK_INTERLOCK, p);
	674	if (error == 0)
	675	return (error);
	676	}
	677	flags &= ~LK_INTERLOCK;
	678	} while (flags & LK_RETRY);
	679	return (error);
	680	}
	681
	682	/*
	683	* File table vnode close routine.
	684	*/
9bccf70c	685	static int
1c79356b A	686	vn_closefile(fp, p)
	687	struct file *fp;
	688	struct proc *p;
	689	{
	690
	691	return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
	692	fp->f_cred, p));
	693	}