/*      $NetBSD: bufcache.h,v 1.14 2018/03/30 12:56:46 christos Exp $   */

/*-
 * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * 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.
 */

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *      @(#)buf.h       8.9 (Berkeley) 3/30/95
 */

#define BUF_CACHE_SIZE 1000

/*
 * The buffer header describes an I/O operation.
 */
struct ubuf {
        LIST_ENTRY(ubuf) b_hash;        /* Hash chain. */
        LIST_ENTRY(ubuf) b_vnbufs;      /* Buffer's associated vnode. */
        TAILQ_ENTRY(ubuf) b_freelist;   /* Free list position if not active. */
        volatile long   b_flags;        /* B_* flags. */
        long    b_bcount;               /* Valid bytes in buffer. */
#undef b_data
        char    *b_data;                /* Data in buffer */
        daddr_t b_lblkno;               /* Logical block number. */
        daddr_t b_blkno;                /* Underlying physical block number */
        struct  uvnode *b_vp;           /* File vnode. */
        int     b_hashval;              /* Hash value */
        void    (*b_iodone)(void *);    /* unused */
};

#define b_bufsize b_bcount

/*
 * These flags are kept in b_flags.
 */
#define B_AGE           0x00000001      /* Move to age queue when I/O done. */
#define B_BUSY          0x00000010      /* I/O in progress. */
#define B_DELWRI        0x00000080      /* Delay I/O until buffer reused. */
#define B_DONE          0x00000200      /* I/O completed. */
#define B_ERROR         0x00000800      /* I/O error occurred. */
#define B_GATHERED      0x00001000      /* LFS: already in a segment. */
#define B_INVAL         0x00002000      /* Does not contain valid info. */
#define B_LOCKED        0x00004000      /* Locked in core (not reusable). */
#define B_READ          0x00100000      /* Read buffer. */
#define B_DONTFREE      0x00010000      /* b_data not managed by bufcache */

#define b_cflags        b_flags

LIST_HEAD(bufhash_struct, ubuf);

#if !defined(NOCRED)
#define NOCRED  ((void *)-1)    /* dummy; not actually used */
#endif /* !defined(NOCRED) */

void bufinit(int);
void bufrehash(int);
void bufstats(void);
void buf_destroy(struct ubuf *);
void bremfree(struct ubuf *);
struct ubuf *incore(struct uvnode *, daddr_t);
struct ubuf *getblk(struct uvnode *, daddr_t, int);
void bwrite(struct ubuf *);
void brelse(struct ubuf *, int);
int bread(struct uvnode *, daddr_t, int, int, struct ubuf **);
void reassignbuf(struct ubuf *, struct uvnode *);
void dump_free_lists(void);