/*      $NetBSD: wapbl.h,v 1.21 2018/12/10 21:19:33 jdolecek Exp $      */

/*-
 * Copyright (c) 2003,2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Wasabi Systems, 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.
 *
 * 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.
 */

#ifndef _SYS_WAPBL_H
#define _SYS_WAPBL_H

#include <sys/mutex.h>

#if defined(_KERNEL) || defined(_KMEMUSER)
#include <miscfs/specfs/specdev.h>
#endif

/* This header file describes the api and data structures for
 * write ahead physical block logging (WAPBL) support.
 */

#if defined(_KERNEL_OPT)
#include "opt_wapbl.h"
#endif

#ifdef WAPBL_DEBUG
#ifndef WAPBL_DEBUG_PRINT
#define WAPBL_DEBUG_PRINT (WAPBL_PRINT_REPLAY | WAPBL_PRINT_OPEN)
#endif

#if 0
#define WAPBL_DEBUG_BUFBYTES
#endif

#endif

#ifdef WAPBL_DEBUG_PRINT

enum {
        WAPBL_PRINT_OPEN = 0x1,
        WAPBL_PRINT_FLUSH = 0x2,
        WAPBL_PRINT_TRUNCATE = 0x4,
        WAPBL_PRINT_TRANSACTION = 0x8,
        WAPBL_PRINT_BUFFER = 0x10,
        WAPBL_PRINT_BUFFER2 = 0x20,
        WAPBL_PRINT_ALLOC = 0x40,
        WAPBL_PRINT_INODE = 0x80,
        WAPBL_PRINT_WRITE = 0x100,
        WAPBL_PRINT_IO = 0x200,
        WAPBL_PRINT_REPLAY = 0x400,
        WAPBL_PRINT_ERROR = 0x800,
        WAPBL_PRINT_DISCARD = 0x1000,
        WAPBL_PRINT_BIODONE = 0x2000,
};

#define WAPBL_PRINTF(mask, a) if (wapbl_debug_print & (mask)) printf  a
extern int wapbl_debug_print;
#else
#define WAPBL_PRINTF(mask, a)
#endif

/****************************************************************/

#include <sys/queue.h>
#include <sys/vnode.h>
#include <sys/buf.h>

#ifdef _KERNEL

struct wapbl_entry;
struct wapbl_replay;
struct wapbl;

struct wapbl_dealloc {
        TAILQ_ENTRY(wapbl_dealloc) wd_entries;
        daddr_t wd_blkno;       /* address of block */
        int wd_len;             /* size of block */
};

typedef void (*wapbl_flush_fn_t)(struct mount *, struct wapbl_dealloc *);

/*
 * This structure holds per transaction log information
 */
struct wapbl_entry {
        struct wapbl *we_wapbl;
        SIMPLEQ_ENTRY(wapbl_entry) we_entries;
        size_t we_bufcount;             /* Count of unsynced buffers */
        size_t we_reclaimable_bytes;    /* Number on disk bytes for this
                                           transaction */
        int     we_error;
#ifdef WAPBL_DEBUG_BUFBYTES
        size_t we_unsynced_bufbytes;    /* Byte count of unsynced buffers */
#endif
};

/* Start using a log */
int     wapbl_start(struct wapbl **, struct mount *, struct vnode *, daddr_t,
                    size_t, size_t, struct wapbl_replay *,
                    wapbl_flush_fn_t, wapbl_flush_fn_t);

/* Discard the current transaction, potentially dangerous */
void    wapbl_discard(struct wapbl *);

/* stop using a log */
int     wapbl_stop(struct wapbl *, int);

/*
 * Begin a new transaction or increment transaction recursion
 * level if called while a transaction is already in progress
 * by the current process.
 */
int     wapbl_begin(struct wapbl *, const char *, int);


/* End a transaction or decrement the transaction recursion level */
void    wapbl_end(struct wapbl *);

/*
 * Add a new buffer to the current transaction.  The buffers
 * data will be copied to the current transaction log and the
 * buffer will be marked B_LOCKED so that it will not be
 * flushed to disk by the syncer or reallocated.
 */
void    wapbl_add_buf(struct wapbl *, struct buf *);

/* Remove a buffer from the current transaction. */
void    wapbl_remove_buf(struct wapbl *, struct buf *);

void    wapbl_resize_buf(struct wapbl *, struct buf *, long, long);

/*
 * This will flush all completed transactions to disk and
 * start asynchronous writes on the associated buffers
 */
int     wapbl_flush(struct wapbl *, int);

/*
 * Inodes that are allocated but have zero link count
 * must be registered with the current transaction
 * so they may be recorded in the log and cleaned up later.
 * registration/unregistration of ino numbers already registered is ok.
 */
void    wapbl_register_inode(struct wapbl *, ino_t, mode_t);
void    wapbl_unregister_inode(struct wapbl *, ino_t, mode_t);

/*
 * Metadata block deallocations must be registered so
 * that revocations records can be written and to prevent
 * the corresponding blocks from being reused as data
 * blocks until the log is on disk.
 */
int     wapbl_register_deallocation(struct wapbl *, daddr_t, int, bool,
                void **);
void    wapbl_unregister_deallocation(struct wapbl *, void *);

void    wapbl_jlock_assert(struct wapbl *wl);
void    wapbl_junlock_assert(struct wapbl *wl);

void    wapbl_print(struct wapbl *wl, int full, void (*pr)(const char *, ...)
    __printflike(1, 2));

#if defined(WAPBL_DEBUG) || defined(DDB)
void    wapbl_dump(struct wapbl *);
#endif

void    wapbl_biodone(struct buf *);

extern const struct wapbl_ops wapbl_ops;

static __inline struct mount *
wapbl_vptomp(struct vnode *vp)
{
        struct mount *mp;

        mp = NULL;
        if (vp != NULL) {
                if (vp->v_type == VBLK)
                        mp = spec_node_getmountedfs(vp);
                else
                        mp = vp->v_mount;
        }

        return mp;
}

static __inline bool
wapbl_vphaswapbl(struct vnode *vp)
{
        struct mount *mp;

        if (vp == NULL)
                return false;

        mp = wapbl_vptomp(vp);
        return mp && mp->mnt_wapbl;
}

#endif /* _KERNEL */

/****************************************************************/
/* Replay support */

#ifdef WAPBL_INTERNAL
LIST_HEAD(wapbl_blk_head, wapbl_blk);
struct wapbl_replay {
        struct vnode *wr_logvp;
        struct vnode *wr_devvp;
        daddr_t wr_logpbn;

        int wr_log_dev_bshift;
        int wr_fs_dev_bshift;
        int64_t wr_circ_off;
        int64_t wr_circ_size;   
        uint32_t wr_generation;

        void *wr_scratch;

        struct wapbl_blk_head *wr_blkhash;
        u_long wr_blkhashmask;
        int wr_blkhashcnt;

        off_t wr_inodeshead;
        off_t wr_inodestail;
        int wr_inodescnt;
        struct {
                uint32_t wr_inumber;
                uint32_t wr_imode;
        } *wr_inodes;
};

#define wapbl_replay_isopen(wr) ((wr)->wr_scratch != 0)

/* Supply this to provide i/o support */
int wapbl_write(void *, size_t, struct vnode *, daddr_t);
int wapbl_read(void *, size_t, struct vnode *, daddr_t);

/****************************************************************/
#else
struct wapbl_replay;
#endif /* WAPBL_INTERNAL */

/****************************************************************/

int     wapbl_replay_start(struct wapbl_replay **, struct vnode *,
        daddr_t, size_t, size_t);
void    wapbl_replay_stop(struct wapbl_replay *);
void    wapbl_replay_free(struct wapbl_replay *);
int     wapbl_replay_write(struct wapbl_replay *, struct vnode *);
int     wapbl_replay_can_read(struct wapbl_replay *, daddr_t, long);
int     wapbl_replay_read(struct wapbl_replay *, void *, daddr_t, long);

/****************************************************************/

#endif /* !_SYS_WAPBL_H */