vfs_syscalls.c

早期freebsd实现

			break;
		default:
			error = EINVAL;
			break;
		}
	}
	if (!error) {
		LEASE_CHECK(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
		error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
	} else {
		VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
		if (nd.ni_dvp == vp)
			vrele(nd.ni_dvp);
		else
			vput(nd.ni_dvp);
		if (vp)
			vrele(vp);
	}
	return (error);
}

/*
 * Create named pipe.
 */
struct mkfifo_args {
	char	*path;
	int	mode;
};
/* ARGSUSED */
mkfifo(p, uap, retval)
	struct proc *p;
	register struct mkfifo_args *uap;
	int *retval;
{
	struct vattr vattr;
	int error;
	struct nameidata nd;

#ifndef FIFO
	return (EOPNOTSUPP);
#else
	NDINIT(&nd, CREATE, LOCKPARENT, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	if (nd.ni_vp != NULL) {
		VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
		if (nd.ni_dvp == nd.ni_vp)
			vrele(nd.ni_dvp);
		else
			vput(nd.ni_dvp);
		vrele(nd.ni_vp);
		return (EEXIST);
	}
	VATTR_NULL(&vattr);
	vattr.va_type = VFIFO;
	vattr.va_mode = (uap->mode & ALLPERMS) &~ p->p_fd->fd_cmask;
	LEASE_CHECK(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
	return (VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr));
#endif /* FIFO */
}

/*
 * Make a hard file link.
 */
struct link_args {
	char	*path;
	char	*link;
};
/* ARGSUSED */
link(p, uap, retval)
	struct proc *p;
	register struct link_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct nameidata nd;
	int error;

	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	if (vp->v_type != VDIR ||
	    (error = suser(p->p_ucred, &p->p_acflag)) == 0) {
		nd.ni_cnd.cn_nameiop = CREATE;
		nd.ni_cnd.cn_flags = LOCKPARENT;
		nd.ni_dirp = uap->link;
		if ((error = namei(&nd)) == 0) {
			if (nd.ni_vp != NULL)
				error = EEXIST;
			if (!error) {
				LEASE_CHECK(nd.ni_dvp,
				    p, p->p_ucred, LEASE_WRITE);
				LEASE_CHECK(vp,
				    p, p->p_ucred, LEASE_WRITE);
				error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
			} else {
				VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
				if (nd.ni_dvp == nd.ni_vp)
					vrele(nd.ni_dvp);
				else
					vput(nd.ni_dvp);
				if (nd.ni_vp)
					vrele(nd.ni_vp);
			}
		}
	}
	vrele(vp);
	return (error);
}

/*
 * Make a symbolic link.
 */
struct symlink_args {
	char	*path;
	char	*link;
};
/* ARGSUSED */
symlink(p, uap, retval)
	struct proc *p;
	register struct symlink_args *uap;
	int *retval;
{
	struct vattr vattr;
	char *path;
	int error;
	struct nameidata nd;

	MALLOC(path, char *, MAXPATHLEN, M_NAMEI, M_WAITOK);
	if (error = copyinstr(uap->path, path, MAXPATHLEN, NULL))
		goto out;
	NDINIT(&nd, CREATE, LOCKPARENT, UIO_USERSPACE, uap->link, p);
	if (error = namei(&nd))
		goto out;
	if (nd.ni_vp) {
		VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
		if (nd.ni_dvp == nd.ni_vp)
			vrele(nd.ni_dvp);
		else
			vput(nd.ni_dvp);
		vrele(nd.ni_vp);
		error = EEXIST;
		goto out;
	}
	VATTR_NULL(&vattr);
	vattr.va_mode = ACCESSPERMS &~ p->p_fd->fd_cmask;
	LEASE_CHECK(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
	error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr, path);
out:
	FREE(path, M_NAMEI);
	return (error);
}

/*
 * Delete a name from the filesystem.
 */
struct unlink_args {
	char	*path;
};
/* ARGSUSED */
unlink(p, uap, retval)
	struct proc *p;
	struct unlink_args *uap;
	int *retval;
{
	register struct vnode *vp;
	int error;
	struct nameidata nd;

	NDINIT(&nd, DELETE, LOCKPARENT, 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 = suser(p->p_ucred, &p->p_acflag)) == 0) {
		/*
		 * The root of a mounted filesystem cannot be deleted.
		 */
		if (vp->v_flag & VROOT)
			error = EBUSY;
		else
			(void)vnode_pager_uncache(vp);
	}

	if (!error) {
		LEASE_CHECK(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
		error = VOP_REMOVE(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);
}

/*
 * Reposition read/write file offset.
 */
struct lseek_args {
	int	fd;
	int	pad;
	off_t	offset;
	int	whence;
};
lseek(p, uap, retval)
	struct proc *p;
	register struct lseek_args *uap;
	int *retval;
{
	struct ucred *cred = p->p_ucred;
	register struct filedesc *fdp = p->p_fd;
	register struct file *fp;
	struct vattr vattr;
	int error;

	if ((u_int)uap->fd >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[uap->fd]) == NULL)
		return (EBADF);
	if (fp->f_type != DTYPE_VNODE)
		return (ESPIPE);
	switch (uap->whence) {
	case L_INCR:
		fp->f_offset += uap->offset;
		break;
	case L_XTND:
		if (error =
		    VOP_GETATTR((struct vnode *)fp->f_data, &vattr, cred, p))
			return (error);
		fp->f_offset = uap->offset + vattr.va_size;
		break;
	case L_SET:
		fp->f_offset = uap->offset;
		break;
	default:
		return (EINVAL);
	}
	*(off_t *)retval = fp->f_offset;
	return (0);
}

#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
/*
 * Reposition read/write file offset.
 */
struct olseek_args {
	int	fd;
	long	offset;
	int	whence;
};
olseek(p, uap, retval)
	struct proc *p;
	register struct olseek_args *uap;
	int *retval;
{
	struct lseek_args nuap;
	off_t qret;
	int error;

	nuap.fd = uap->fd;
	nuap.offset = uap->offset;
	nuap.whence = uap->whence;
	error = lseek(p, &nuap, &qret);
	*(long *)retval = qret;
	return (error);
}
#endif /* COMPAT_43 */

/*
 * Check access permissions.
 */
struct access_args {
	char	*path;
	int	flags;
};
access(p, uap, retval)
	struct proc *p;
	register struct access_args *uap;
	int *retval;
{
	register struct ucred *cred = p->p_ucred;
	register struct vnode *vp;
	int error, flags, t_gid, t_uid;
	struct nameidata nd;

	t_uid = cred->cr_uid;
	t_gid = cred->cr_groups[0];
	cred->cr_uid = p->p_cred->p_ruid;
	cred->cr_groups[0] = p->p_cred->p_rgid;
	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		goto out1;
	vp = nd.ni_vp;

	/* Flags == 0 means only check for existence. */
	if (uap->flags) {
		flags = 0;
		if (uap->flags & R_OK)
			flags |= VREAD;
		if (uap->flags & W_OK)
			flags |= VWRITE;
		if (uap->flags & X_OK)
			flags |= VEXEC;
		if ((flags & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
			error = VOP_ACCESS(vp, flags, cred, p);
	}
	vput(vp);
out1:
	cred->cr_uid = t_uid;
	cred->cr_groups[0] = t_gid;
	return (error);
}

#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
/*
 * Get file status; this version follows links.
 */
struct ostat_args {
	char	*path;
	struct ostat *ub;
};
/* ARGSUSED */
ostat(p, uap, retval)
	struct proc *p;
	register struct ostat_args *uap;
	int *retval;
{
	struct stat sb;
	struct ostat osb;
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	error = vn_stat(nd.ni_vp, &sb, p);
	vput(nd.ni_vp);
	if (error)
		return (error);
	cvtstat(&sb, &osb);
	error = copyout((caddr_t)&osb, (caddr_t)uap->ub, sizeof (osb));
	return (error);
}

/*
 * Get file status; this version does not follow links.
 */
struct olstat_args {
	char	*path;
	struct ostat *ub;
};
/* ARGSUSED */
olstat(p, uap, retval)
	struct proc *p;
	register struct olstat_args *uap;
	int *retval;
{
	struct stat sb;
	struct ostat osb;
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	error = vn_stat(nd.ni_vp, &sb, p);
	vput(nd.ni_vp);
	if (error)
		return (error);
	cvtstat(&sb, &osb);
	error = copyout((caddr_t)&osb, (caddr_t)uap->ub, sizeof (osb));
	return (error);
}

/*
 * Convert from an old to a new stat structure.
 */
cvtstat(st, ost)
	struct stat *st;
	struct ostat *ost;
{

	ost->st_dev = st->st_dev;
	ost->st_ino = st->st_ino;
	ost->st_mode = st->st_mode;
	ost->st_nlink = st->st_nlink;
	ost->st_uid = st->st_uid;
	ost->st_gid = st->st_gid;
	ost->st_rdev = st->st_rdev;
	if (st->st_size < (quad_t)1 << 32)
		ost->st_size = st->st_size;
	else
		ost->st_size = -2;
	ost->st_atime = st->st_atime;
	ost->st_mtime = st->st_mtime;
	ost->st_ctime = st->st_ctime;
	ost->st_blksize = st->st_blksize;
	ost->st_blocks = st->st_blocks;
	ost->st_flags = st->st_flags;
	ost->st_gen = st->st_gen;
}
#endif /* COMPAT_43 || COMPAT_SUNOS */

/*
 * Get file status; this version follows links.
 */
struct stat_args {
	char	*path;
	struct stat *ub;
};
/* ARGSUSED */
stat(p, uap, retval)
	struct proc *p;
	register struct stat_args *uap;
	int *retval;
{
	struct stat sb;
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	error = vn_stat(nd.ni_vp, &sb, p);
	vput(nd.ni_vp);
	if (error)
		return (error);
	error = copyout((caddr_t)&sb, (caddr_t)uap->ub, sizeof (sb));
	return (error);
}

/*
 * Get file status; this version does not follow links.
 */
struct lstat_args {
	char	*path;
	struct stat *ub;
};
/* ARGSUSED */
lstat(p, uap, retval)
	struct proc *p;
	register struct lstat_args *uap;
	int *retval;
{
	int error;
	struct vnode *vp, *dvp;
	struct stat sb, sb1;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | LOCKPARENT, UIO_USERSPACE,
	    uap->path, p);
	if (error = namei(&nd))
		return (error);
	/*
	 * For symbolic links, always return the attributes of its
	 * containing directory, except for mode, size, and links.
	 */
	vp = nd.ni_vp;
	dvp = nd.ni_dvp;
	if (vp->v_type != VLNK) {
		if (dvp == vp)
			vrele(dvp);
		else
			vput(dvp);
		error = vn_stat(vp, &sb, p);
		vput(vp);
		if (error)
			return (error);
	} else {
		error = vn_stat(dvp, &sb, p);
		vput(dvp);
		if (error) {
			vput(vp);
			return (error);
		}
		error = vn_stat(vp, &sb1, p);
		vput(vp);
		if (error)
			return (error);
		sb.st_mode &= ~S_IFDIR;
		sb.st_mode |= S_IFLNK;
		sb.st_nlink = sb1.st_nlink;
		sb.st_size = sb1.st_size;
		sb.st_blocks = sb1.st_blocks;
	}
	error = copyout((caddr_t)&sb, (caddr_t)uap->ub, sizeof (sb));
	return (error);
}

/*
 * Get configurable pathname variables.
 */
struct pathconf_args {
	char	*path;
	int	name;
};
/* ARGSUSED */
pathconf(p, uap, retval)
	struct proc *p;
	register struct pathconf_args *uap;
	int *retval;
{
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	error = VOP_PATHCONF(nd.ni_vp, uap->name, retval);
	vput(nd.ni_vp);
	return (error);
}

/*
 * Return target name of a symbolic link.
 */
struct readlink_args {
	char	*path;
	char	*buf;
	int	count;
};
/* ARGSUSED */
readlink(p, uap, retval)
	struct proc *p;
	register struct readlink_args *uap;
	int *retval;
{
	register struct vnode *vp;
	struct iovec aiov;
	struct uio auio;
	int error;
	struct nameidata nd;

	NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, p);
	if (error = namei(&nd))
		return (error);
	vp = nd.ni_vp;
	if (vp->v_type != VLNK)
		error = EINVAL;
	else {
		aiov.iov_base = uap->buf;
		aiov.iov_len = uap->count;
		auio.uio_iov = &aiov;
		auio.uio_iovcnt = 1;
		auio.uio_offset = 0;
		auio.uio_rw = UIO_READ;
		auio.uio_segflg = UIO_USERSPACE;
		auio.uio_procp = p;
		auio.uio_resid = uap->count;
		error = VOP_READLINK(vp, &auio, p->p_ucred);
	}
	vput(vp);
	*retval = uap->count - auio.uio_resid;
	return (error);
}

/*
 * Change flags of a file given a path name.
 */
struct chflags_args {
	char	*path;
	int	flags;
};
/* ARGSUSED */
chflags(p, uap, retval)
	struct proc *p;
	register struct chflags_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_flags = uap->flags;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	vput(vp);
	return (error);
}

/*
 * Change flags of a file given a file descriptor.
 */
struct fchflags_args {
	int	fd;
	int	flags;
};
/* ARGSUSED */
fchflags(p, uap, retval)
	struct proc *p;
	register struct fchflags_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_flags = uap->flags;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	VOP_UNLOCK(vp);
	return (error);
}

/*
 * Change mode of a file given path name.
 */
struct chmod_args {
	char	*path;
	int	mode;
};
/* ARGSUSED */
chmod(p, uap, retval)
	struct proc *p;
	register struct chmod_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_mode = uap->mode & ALLPERMS;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	vput(vp);
	return (error);
}

/*
 * Change mode of a file given a file descriptor.
 */
struct fchmod_args {
	int	fd;
	int	mode;
};
/* ARGSUSED */
fchmod(p, uap, retval)
	struct proc *p;
	register struct fchmod_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_mode = uap->mode & ALLPERMS;
		error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
	}
	VOP_UNLOCK(vp);
	return (error);
}

/*
 * Set ownership given a path name.
 */