/*      $NetBSD: v7fs_io_kern.c,v 1.5 2017/08/27 06:18:16 skrll Exp $   */

/*-
 * Copyright (c) 2004, 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__KERNEL_RCSID(0, "$NetBSD: v7fs_io_kern.c,v 1.5 2017/08/27 06:18:16 skrll Exp $");

#if defined _KERNEL_OPT
#include "opt_v7fs.h"
#endif

#include <sys/param.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/kmem.h>
#include <sys/kauth.h>
#include <sys/mutex.h>

#include <fs/v7fs/v7fs.h>
#include "v7fs_endian.h"
#include "v7fs_impl.h"

#ifdef V7FS_IO_DEBUG
#define DPRINTF(fmt, args...)   printf("%s: " fmt, __func__, ##args)
#else
#define DPRINTF(fmt, args...)   ((void)0)
#endif

struct local_io {
        struct vnode *vp;
        kauth_cred_t cred;
};

static bool v7fs_os_read_n(void *, uint8_t *, daddr_t, int);
static bool v7fs_os_read(void *, uint8_t *, daddr_t);
static bool v7fs_os_write_n(void *, uint8_t *, daddr_t, int);
static bool v7fs_os_write(void *, uint8_t *, daddr_t);
static void v7fs_os_lock(void *);
static void v7fs_os_unlock(void *);
static bool lock_init(struct lock_ops *);

int
v7fs_io_init(struct v7fs_self **fs,
    const struct v7fs_mount_device *mount_device, size_t block_size)
{
        struct vnode *vp = mount_device->device.vnode;
        struct v7fs_self *p;
        struct local_io *local;
        int error = 0;

        p = kmem_zalloc(sizeof(*p), KM_SLEEP);
        p->scratch_free = -1;
        p->scratch_remain = V7FS_SELF_NSCRATCH;

        /* Endian */
        p->endian = mount_device->endian;
#ifdef V7FS_EI
        v7fs_endian_init(p);
#endif
        /* IO */
        local = kmem_zalloc(sizeof(*local), KM_SLEEP);
        p->io.read = v7fs_os_read;
        p->io.read_n = v7fs_os_read_n;
        p->io.write = v7fs_os_write;
        p->io.write_n = v7fs_os_write_n;
        p->scratch_free = -1; /* free all scratch buffer */

        p->io.cookie = local;
        local->vp = vp;
        local->cred = NOCRED;   /* upper layer check cred. */

        /*LOCK */
        error = ENOMEM;
        if (!lock_init(&p->sb_lock))
                goto errexit;
        if (!lock_init(&p->ilist_lock))
                goto errexit;
        if (!lock_init(&p->mem_lock))
                goto errexit;
        error = 0;

        *fs = p;
        return 0;

errexit:
        v7fs_io_fini(p);
        return error;
}

static bool
lock_init(struct lock_ops *ops)
{
        ops->cookie = kmem_zalloc(sizeof(kmutex_t), KM_SLEEP);
        mutex_init(ops->cookie, MUTEX_DEFAULT, IPL_NONE);
        ops->lock = v7fs_os_lock;
        ops->unlock = v7fs_os_unlock;
        return true;
}

void
v7fs_io_fini(struct v7fs_self *fs)
{
        if (fs->io.cookie) {
                kmem_free(fs->io.cookie, sizeof(struct local_io));
        }
        if (fs->sb_lock.cookie) {
                mutex_destroy(fs->sb_lock.cookie);
                kmem_free(fs->sb_lock.cookie, sizeof(kmutex_t));
        }
        if (fs->ilist_lock.cookie) {
                mutex_destroy(fs->ilist_lock.cookie);
                kmem_free(fs->ilist_lock.cookie, sizeof(kmutex_t));
        }
        if (fs->mem_lock.cookie) {
                mutex_destroy(fs->mem_lock.cookie);
                kmem_free(fs->mem_lock.cookie, sizeof(kmutex_t));
        }
        kmem_free(fs, sizeof(*fs));
}

static bool
v7fs_os_read_n(void *self, uint8_t *buf, daddr_t block, int count)
{
        int i;

        for (i = 0; i < count; i++) {
                if (!v7fs_os_read(self, buf, block))
                        return false;
                buf += DEV_BSIZE;
                block++;
        }

        return true;
}

static bool
v7fs_os_read(void *self, uint8_t *buf, daddr_t block)
{
        struct local_io *bio = (struct local_io *)self;
        struct buf *bp = NULL;

        if (bread(bio->vp, block, DEV_BSIZE, 0, &bp) != 0)
                goto error_exit;
        memcpy(buf, bp->b_data, DEV_BSIZE);
        brelse(bp, 0);

        return true;
error_exit:
        DPRINTF("block %ld read failed.\n", (long)block);

        if (bp != NULL)
                brelse(bp, 0);
        return false;
}

static bool
v7fs_os_write_n(void *self, uint8_t *buf, daddr_t block, int count)
{
        int i;

        for (i = 0; i < count; i++) {
                if (!v7fs_os_write(self, buf, block))
                        return false;
                buf += DEV_BSIZE;
                block++;
        }

        return true;
}

static bool
v7fs_os_write(void *self, uint8_t *buf, daddr_t block)
{
        struct local_io *bio = (struct local_io *)self;
        struct buf *bp;

        if ((bp = getblk(bio->vp, block, DEV_BSIZE, 0, 0)) == 0) {
                DPRINTF("getblk failed. block=%ld\n", (long)block);
                return false;
        }

        memcpy(bp->b_data, buf, DEV_BSIZE);

        if (bwrite(bp) != 0) {
                DPRINTF("bwrite failed. block=%ld\n", (long)block);
                return false;
        }

        return true;
}

static void
v7fs_os_lock(void *self)
{

        mutex_enter((kmutex_t *)self);
}

static void
v7fs_os_unlock(void *self)
{

        mutex_exit((kmutex_t *)self);
}