/*-
 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/unistd.h>
#include <sys/fcntl.h>
#include <sys/kernio.h>

struct vnode *
kio_open(const char *file, int flags, int cmode)
{
	struct thread *td = curthread;
	struct nameidata nd;
	int error;

	if (td->td_proc->p_fd->fd_rdir == NULL)
		td->td_proc->p_fd->fd_rdir = rootvnode;
	if (td->td_proc->p_fd->fd_cdir == NULL)
		td->td_proc->p_fd->fd_cdir = rootvnode;

	flags = FFLAGS(flags);
	NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, file, td);
	error = vn_open_cred(&nd, &flags, cmode, td->td_ucred, -1);
	NDFREE(&nd, NDF_ONLY_PNBUF);
	if (error != 0)
		return (NULL);
	/* We just unlock so we hold a reference. */
	VOP_UNLOCK(nd.ni_vp, 0, td);
	return (nd.ni_vp);
}

void
kio_close(struct vnode *vp)
{
	struct thread *td = curthread;

	vn_close(vp, FWRITE, td->td_ucred, td);
}

int
kio_write(struct vnode *vp, void *buf, size_t size)
{
	struct thread *td = curthread;
	struct mount *mp;
	struct uio auio;
	struct iovec aiov;

	bzero(&aiov, sizeof(aiov));
	bzero(&auio, sizeof(auio));

	aiov.iov_base = buf;
	aiov.iov_len = size;

	auio.uio_iov = &aiov;
	auio.uio_offset = 0;
	auio.uio_segflg = UIO_SYSSPACE;
	auio.uio_rw = UIO_WRITE;
	auio.uio_iovcnt = 1;
	auio.uio_resid = size;
	auio.uio_td = td;

	/*
	 * Do all of the junk required to write now.
	 */
	vn_start_write(vp, &mp, V_WAIT);
	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
	VOP_LEASE(vp, td, td->td_ucred, LEASE_WRITE);
	VOP_WRITE(vp, &auio, IO_UNIT | IO_SYNC, td->td_ucred);
	VOP_UNLOCK(vp, 0, td);
	vn_finished_write(mp);
	return (0);
}