sbin/fsck_lfs/bufcache.h

   1 /*      $NetBSD: bufcache.h,v 1.10 2008/04/28 20:23:08 martin Exp $     */
   2
   3 /*-
   4  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
   9  * NASA Ames Research Center.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30  * POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * Copyright (c) 1982, 1986, 1989, 1993
  35  *      The Regents of the University of California.  All rights reserved.
  36  * (c) UNIX System Laboratories, Inc.
  37  * All or some portions of this file are derived from material licensed
  38  * to the University of California by American Telephone and Telegraph
  39  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  40  * the permission of UNIX System Laboratories, Inc.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)buf.h       8.9 (Berkeley) 3/30/95
  67  */
  68
  69 #define BUF_CACHE_SIZE 1000
  70
  71 /*
  72  * The buffer header describes an I/O operation.
  73  */
  74 struct ubuf {
  75         LIST_ENTRY(ubuf) b_hash;        /* Hash chain. */
  76         LIST_ENTRY(ubuf) b_vnbufs;      /* Buffer's associated vnode. */
  77         TAILQ_ENTRY(ubuf) b_freelist;   /* Free list position if not active. */
  78         volatile long   b_flags;        /* B_* flags. */
  79         long    b_bcount;               /* Valid bytes in buffer. */
  80 #undef b_data
  81         char    *b_data;                /* Data in buffer */
  82         daddr_t b_lblkno;               /* Logical block number. */
  83         daddr_t b_blkno;                /* Underlying physical block number */
  84         struct  uvnode *b_vp;           /* File vnode. */
  85         int     b_hashval;              /* Hash value */
  86         void    (*b_iodone)(void *);    /* unused */
  87 };
  88
  89 #define b_bufsize b_bcount
  90
  91 /*
  92  * These flags are kept in b_flags.
  93  */
  94 #define B_AGE           0x00000001      /* Move to age queue when I/O done. */
  95 #define B_NEEDCOMMIT    0x00000002      /* Needs committing to stable storage */
  96 #define B_BUSY          0x00000010      /* I/O in progress. */
  97 #define B_DELWRI        0x00000080      /* Delay I/O until buffer reused. */
  98 #define B_DONE          0x00000200      /* I/O completed. */
  99 #define B_ERROR         0x00000800      /* I/O error occurred. */
 100 #define B_GATHERED      0x00001000      /* LFS: already in a segment. */
 101 #define B_INVAL         0x00002000      /* Does not contain valid info. */
 102 #define B_LOCKED        0x00004000      /* Locked in core (not reusable). */
 103 #define B_READ          0x00100000      /* Read buffer. */
 104 #define B_DONTFREE      0x00010000      /* b_data not managed by bufcache */
 105
 106 #define b_cflags        b_flags
 107
 108 LIST_HEAD(bufhash_struct, ubuf);
 109
 110 #if !defined(NOCRED)
 111 #define NOCRED  ((void *)-1)    /* dummy; not actually used */
 112 #endif /* !defined(NOCRED) */
 113
 114 void bufinit(int);
 115 void bufrehash(int);
 116 void bufstats(void);
 117 void buf_destroy(struct ubuf *);
 118 void bremfree(struct ubuf *);
 119 struct ubuf *incore(struct uvnode *, int);
 120 struct ubuf *getblk(struct uvnode *, daddr_t, int);
 121 void bwrite(struct ubuf *);
 122 void brelse(struct ubuf *, int);
 123 int bread(struct uvnode *, daddr_t, int, void *, int, struct ubuf **);
 124 void reassignbuf(struct ubuf *, struct uvnode *);
 125 void dump_free_lists(void);