vfs_syscalls.c

早期freebsd实现

struct chown_args {
	char	*path;
	int	uid;
	int	gid;
};
/* ARGSUSED */
chown(p, uap, retval)
	struct proc *p;
	register struct chown_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct vattr vattr;
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE);
	VOP_LOCK(vp);
	if (vp->v_mount->mnt_flag & MNT_RDONLY)
		error = EROFS;
	else {
		VATTR_NULL(&vattr);
		vattr.va_uid = uap->uid;
		vattr.va_gid = uap->gid;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	vput(vp);
	return (error);
}

/*
 * Set ownership given a file descriptor.
 */
struct fchown_args {
	int	fd;
	int	uid;
	int	gid;
};
/* ARGSUSED */
fchown(p, uap, retval)
	struct proc *p;
	register struct fchown_args *uap;
	int *retval;
{
	struct vattr vattr;
	struct vnode *vp;
	struct file *fp;
	int error;

	if (error = getvnode(p->p_fd, uap->fd, &fp))
		return (error);
	vp = (struct vnode *)fp->f_data;
	LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE);
	VOP_LOCK(vp);
	if (vp->v_mount->mnt_flag & MNT_RDONLY)
		error = EROFS;
	else {
		VATTR_NULL(&vattr);
		vattr.va_uid = uap->uid;
		vattr.va_gid = uap->gid;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	VOP_UNLOCK(vp);
	return (error);
}

/*
 * Set the access and modification times of a file.
 */
struct utimes_args {
	char	*path;
	struct	timeval *tptr;
};
/* ARGSUSED */
utimes(p, uap, retval)
	struct proc *p;
	register struct utimes_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct timeval tv[2];
	struct vattr vattr;
	int error;
	struct nameidata nd;

	VATTR_NULL(&vattr);
	if (uap->tptr == NULL) {
		microtime(&tv[0]);
		tv[1] = tv[0];
		vattr.va_vaflags |= VA_UTIMES_NULL;
	} else if (error = copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof (tv)))
  		return (error);
	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE);
	VOP_LOCK(vp);
	if (vp->v_mount->mnt_flag & MNT_RDONLY)
		error = EROFS;
	else {
		vattr.va_atime.ts_sec = tv[0].tv_sec;
		vattr.va_atime.ts_nsec = tv[0].tv_usec * 1000;
		vattr.va_mtime.ts_sec = tv[1].tv_sec;
		vattr.va_mtime.ts_nsec = tv[1].tv_usec * 1000;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	vput(vp);
	return (error);
}

/*
 * Truncate a file given its path name.
 */
struct truncate_args {
	char	*path;
	int	pad;
	off_t	length;
};
/* ARGSUSED */
truncate(p, uap, retval)
	struct proc *p;
	register struct truncate_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct vattr vattr;
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE);
	VOP_LOCK(vp);
	if (vp->v_type == VDIR)
		error = EISDIR;
	else if ((error = vn_writechk(vp)) == 0 &&
	    (error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p)) == 0) {
		VATTR_NULL(&vattr);
		vattr.va_size = uap->length;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	vput(vp);
	return (error);
}

/*
 * Truncate a file given a file descriptor.
 */
struct ftruncate_args {
	int	fd;
	int	pad;
	off_t	length;
};
/* ARGSUSED */
ftruncate(p, uap, retval)
	struct proc *p;
	register struct ftruncate_args *uap;
	int *retval;
{
	struct vattr vattr;
	struct vnode *vp;
	struct file *fp;
	int error;

	if (error = getvnode(p->p_fd, uap->fd, &fp))
		return (error);
	if ((fp->f_flag & FWRITE) == 0)
		return (EINVAL);
	vp = (struct vnode *)fp->f_data;
	LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE);
	VOP_LOCK(vp);
	if (vp->v_type == VDIR)
		error = EISDIR;
	else if ((error = vn_writechk(vp)) == 0) {
		VATTR_NULL(&vattr);
		vattr.va_size = uap->length;
		error = VOP_SETATTR(vp, &vattr, fp->f_cred, p);
	}
	VOP_UNLOCK(vp);
	return (error);
}

#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
/*
 * Truncate a file given its path name.
 */
struct otruncate_args {
	char	*path;
	long	length;
};
/* ARGSUSED */
otruncate(p, uap, retval)
	struct proc *p;
	register struct otruncate_args *uap;
	int *retval;
{
	struct truncate_args nuap;

	nuap.path = uap->path;
	nuap.length = uap->length;
	return (truncate(p, &nuap, retval));
}

/*
 * Truncate a file given a file descriptor.
 */
struct oftruncate_args {
	int	fd;
	long	length;
};
/* ARGSUSED */
oftruncate(p, uap, retval)
	struct proc *p;
	register struct oftruncate_args *uap;
	int *retval;
{
	struct ftruncate_args nuap;

	nuap.fd = uap->fd;
	nuap.length = uap->length;
	return (ftruncate(p, &nuap, retval));
}
#endif /* COMPAT_43 || COMPAT_SUNOS */

/*
 * Sync an open file.
 */
struct fsync_args {
	int	fd;
};
/* ARGSUSED */
fsync(p, uap, retval)
	struct proc *p;
	struct fsync_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct file *fp;
	int error;

	if (error = getvnode(p->p_fd, uap->fd, &fp))
		return (error);
	vp = (struct vnode *)fp->f_data;
	VOP_LOCK(vp);
	error = VOP_FSYNC(vp, fp->f_cred, MNT_WAIT, p);
	VOP_UNLOCK(vp);
	return (error);
}

/*
 * Rename files.  Source and destination must either both be directories,
 * or both not be directories.  If target is a directory, it must be empty.
 */
struct rename_args {
	char	*from;
	char	*to;
};
/* ARGSUSED */
rename(p, uap, retval)
	struct proc *p;
	register struct rename_args *uap;
	int *retval;
{
	register struct vnode *tvp, *fvp, *tdvp;
	struct nameidata fromnd, tond;
	int error;

	NDINIT(&fromnd, DELETE, WANTPARENT | SAVESTART, UIO_USERSPACE,
		uap->from, p);
	if (error = namei(&fromnd))
		return (error);
	fvp = fromnd.ni_vp;
	NDINIT(&tond, RENAME, LOCKPARENT | LOCKLEAF | NOCACHE | SAVESTART,
		UIO_USERSPACE, uap->to, p);
	if (error = namei(&tond)) {
		VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
		vrele(fromnd.ni_dvp);
		vrele(fvp);
		goto out1;
	}
	tdvp = tond.ni_dvp;
	tvp = tond.ni_vp;
	if (tvp != NULL) {
		if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
			error = ENOTDIR;
			goto out;
		} else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
			error = EISDIR;
			goto out;
		}
	}
	if (fvp == tdvp)
		error = EINVAL;
	/*
	 * If source is the same as the destination (that is the
	 * same inode number with the same name in the same directory),
	 * then there is nothing to do.
	 */
	if (fvp == tvp && fromnd.ni_dvp == tdvp &&
	    fromnd.ni_cnd.cn_namelen == tond.ni_cnd.cn_namelen &&
	    !bcmp(fromnd.ni_cnd.cn_nameptr, tond.ni_cnd.cn_nameptr,
	      fromnd.ni_cnd.cn_namelen))
		error = -1;
out:
	if (!error) {
		LEASE_CHECK(tdvp, p, p->p_ucred, LEASE_WRITE);
		if (fromnd.ni_dvp != tdvp)
			LEASE_CHECK(fromnd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
		if (tvp)
			LEASE_CHECK(tvp, p, p->p_ucred, LEASE_WRITE);
		error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
				   tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
	} else {
		VOP_ABORTOP(tond.ni_dvp, &tond.ni_cnd);
		if (tdvp == tvp)
			vrele(tdvp);
		else
			vput(tdvp);
		if (tvp)
			vput(tvp);
		VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
		vrele(fromnd.ni_dvp);
		vrele(fvp);
	}
	vrele(tond.ni_startdir);
	FREE(tond.ni_cnd.cn_pnbuf, M_NAMEI);
out1:
	if (fromnd.ni_startdir)
		vrele(fromnd.ni_startdir);
	FREE(fromnd.ni_cnd.cn_pnbuf, M_NAMEI);
	if (error == -1)
		return (0);
	return (error);
}

/*
 * Make a directory file.
 */
struct mkdir_args {
	char	*path;
	int	mode;
};
/* ARGSUSED */
mkdir(p, uap, retval)
	struct proc *p;
	register struct mkdir_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct vattr vattr;
	int error;
	struct nameidata nd;

	NDINIT(&nd, CREATE, LOCKPARENT, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	if (vp != NULL) {
		VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
		if (nd.ni_dvp == vp)
			vrele(nd.ni_dvp);
		else
			vput(nd.ni_dvp);
		vrele(vp);
		return (EEXIST);
	}
	VATTR_NULL(&vattr);
	vattr.va_type = VDIR;
	vattr.va_mode = (uap->mode & ACCESSPERMS) &~ p->p_fd->fd_cmask;
	LEASE_CHECK(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
	error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
	if (!error)
		vput(nd.ni_vp);
	return (error);
}

/*
 * Remove a directory file.
 */
struct rmdir_args {
	char	*path;
};
/* ARGSUSED */
rmdir(p, uap, retval)
	struct proc *p;
	struct rmdir_args *uap;
	int *retval;
{
	register struct vnode *vp;
	int error;
	struct nameidata nd;

	NDINIT(&nd, DELETE, LOCKPARENT | LOCKLEAF, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	if (vp->v_type != VDIR) {
		error = ENOTDIR;
		goto out;
	}
	/*
	 * No rmdir "." please.
	 */
	if (nd.ni_dvp == vp) {
		error = EINVAL;
		goto out;
	}
	/*
	 * The root of a mounted filesystem cannot be deleted.
	 */
	if (vp->v_flag & VROOT)
		error = EBUSY;
out:
	if (!error) {
		LEASE_CHECK(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
		LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE);
		error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
	} else {
		VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
		if (nd.ni_dvp == vp)
			vrele(nd.ni_dvp);
		else
			vput(nd.ni_dvp);
		vput(vp);
	}
	return (error);
}

#ifdef COMPAT_43
/*
 * Read a block of directory entries in a file system independent format.
 */
struct ogetdirentries_args {
	int	fd;
	char	*buf;
	u_int	count;
	long	*basep;
};
ogetdirentries(p, uap, retval)
	struct proc *p;
	register struct ogetdirentries_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct file *fp;
	struct uio auio, kuio;
	struct iovec aiov, kiov;
	struct dirent *dp, *edp;
	caddr_t dirbuf;
	int error, readcnt;
	long loff;

	if (error = getvnode(p->p_fd, uap->fd, &fp))
		return (error);
	if ((fp->f_flag & FREAD) == 0)
		return (EBADF);
	vp = (struct vnode *)fp->f_data;
	if (vp->v_type != VDIR)
		return (EINVAL);
	aiov.iov_base = uap->buf;
	aiov.iov_len = uap->count;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_rw = UIO_READ;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_procp = p;
	auio.uio_resid = uap->count;
	VOP_LOCK(vp);
	loff = auio.uio_offset = fp->f_offset;
#	if (BYTE_ORDER != LITTLE_ENDIAN)
		if (vp->v_mount->mnt_maxsymlinklen <= 0) {
			error = VOP_READDIR(vp, &auio, fp->f_cred);
			fp->f_offset = auio.uio_offset;
		} else
#	endif
	{
		kuio = auio;
		kuio.uio_iov = &kiov;
		kuio.uio_segflg = UIO_SYSSPACE;
		kiov.iov_len = uap->count;
		MALLOC(dirbuf, caddr_t, uap->count, M_TEMP, M_WAITOK);
		kiov.iov_base = dirbuf;
		error = VOP_READDIR(vp, &kuio, fp->f_cred);
		fp->f_offset = kuio.uio_offset;
		if (error == 0) {
			readcnt = uap->count - kuio.uio_resid;
			edp = (struct dirent *)&dirbuf[readcnt];
			for (dp = (struct dirent *)dirbuf; dp < edp; ) {
#				if (BYTE_ORDER == LITTLE_ENDIAN)
					/*
					 * The expected low byte of
					 * dp->d_namlen is our dp->d_type.
					 * The high MBZ byte of dp->d_namlen
					 * is our dp->d_namlen.
					 */
					dp->d_type = dp->d_namlen;
					dp->d_namlen = 0;
#				else
					/*
					 * The dp->d_type is the high byte
					 * of the expected dp->d_namlen,
					 * so must be zero'ed.
					 */
					dp->d_type = 0;
#				endif
				if (dp->d_reclen > 0) {
					dp = (struct dirent *)
					    ((char *)dp + dp->d_reclen);
				} else {
					error = EIO;
					break;
				}
			}
			if (dp >= edp)
				error = uiomove(dirbuf, readcnt, &auio);
		}
		FREE(dirbuf, M_TEMP);
	}
	VOP_UNLOCK(vp);
	if (error)
		return (error);
	error = copyout((caddr_t)&loff, (caddr_t)uap->basep, sizeof(long));
	*retval = uap->count - auio.uio_resid;
	return (error);
}
#endif

/*
 * Read a block of directory entries in a file system independent format.
 */
struct getdirentries_args {
	int	fd;
	char	*buf;
	u_int	count;
	long	*basep;
};
getdirentries(p, uap, retval)
	struct proc *p;
	register struct getdirentries_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct file *fp;
	struct uio auio;
	struct iovec aiov;
	long loff;
	int error;

	if (error = getvnode(p->p_fd, uap->fd, &fp))
		return (error);
	if ((fp->f_flag & FREAD) == 0)
		return (EBADF);
	vp = (struct vnode *)fp->f_data;
unionread:
	if (vp->v_type != VDIR)
		return (EINVAL);
	aiov.iov_base = uap->buf;
	aiov.iov_len = uap->count;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_rw = UIO_READ;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_procp = p;
	auio.uio_resid = uap->count;
	VOP_LOCK(vp);
	loff = auio.uio_offset = fp->f_offset;
	error = VOP_READDIR(vp, &auio, fp->f_cred);
	fp->f_offset = auio.uio_offset;
	VOP_UNLOCK(vp);
	if (error)
		return (error);

#ifdef UNION
{
	extern int (**union_vnodeop_p)();
	extern struct vnode *union_lowervp __P((struct vnode *));

	if ((uap->count == auio.uio_resid) &&
	    (vp->v_op == union_vnodeop_p)) {
		struct vnode *tvp = vp;

		vp = union_lowervp(vp);
		if (vp != NULLVP) {
			VOP_LOCK(vp);
			error = VOP_OPEN(vp, FREAD);
			VOP_UNLOCK(vp);

			if (error) {
				vrele(vp);
				return (error);
			}
			fp->f_data = (caddr_t) vp;
			fp->f_offset = 0;
			error = vn_close(tvp, FREAD, fp->f_cred, p);
			if (error)
				return (error);
			goto unionread;
		}
	}
}
#endif

	if ((uap->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;
	}
	error = copyout((caddr_t)&loff, (caddr_t)uap->basep, sizeof(long));
	*retval = uap->count - auio.uio_resid;
	return (error);
}

/*
 * Set the mode mask for creation of filesystem nodes.
 */
struct umask_args {
	int	newmask;
};
mode_t				/* XXX */
umask(p, uap, retval)
	struct proc *p;
	struct umask_args *uap;
	int *retval;
{
	register struct filedesc *fdp;

	fdp = p->p_fd;
	*retval = fdp->fd_cmask;
	fdp->fd_cmask = uap->newmask & ALLPERMS;
	return (0);
}

/*
 * Void all references to file by ripping underlying filesystem
 * away from vnode.
 */
struct revoke_args {
	char	*path;
};
/* ARGSUSED */
revoke(p, uap, retval)
	struct proc *p;
	register struct revoke_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct vattr vattr;
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	if (vp->v_type != VCHR && vp->v_type != VBLK) {
		error = EINVAL;
		goto out;
	}
	if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p))
		goto out;
	if (p->p_ucred->cr_uid != vattr.va_uid &&
	    (error = suser(p->p_ucred, &p->p_acflag)))
		goto out;
	if (vp->v_usecount > 1 || (vp->v_flag & VALIASED))
		vgoneall(vp);
out:
	vrele(vp);
	return (error);
}

/*
 * Convert a user file descriptor to a kernel file entry.
 */
getvnode(fdp, fd, fpp)
	struct filedesc *fdp;
	struct file **fpp;
	int fd;
{
	struct file *fp;

	if ((u_int)fd >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[fd]) == NULL)
		return (EBADF);
	if (fp->f_type != DTYPE_VNODE)
		return (EINVAL);
	*fpp = fp;
	return (0);
}