bufcache.h revision 1.2
1 /* $NetBSD: bufcache.h,v 1.2 2003/08/07 10:04:22 agc 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 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1989, 1993 42 * The Regents of the University of California. All rights reserved. 43 * (c) UNIX System Laboratories, Inc. 44 * All or some portions of this file are derived from material licensed 45 * to the University of California by American Telephone and Telegraph 46 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 47 * the permission of UNIX System Laboratories, Inc. 48 * 49 * Redistribution and use in source and binary forms, with or without 50 * modification, are permitted provided that the following conditions 51 * are met: 52 * 1. Redistributions of source code must retain the above copyright 53 * notice, this list of conditions and the following disclaimer. 54 * 2. Redistributions in binary form must reproduce the above copyright 55 * notice, this list of conditions and the following disclaimer in the 56 * documentation and/or other materials provided with the distribution. 57 * 3. Neither the name of the University nor the names of its contributors 58 * may be used to endorse or promote products derived from this software 59 * without specific prior written permission. 60 * 61 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 62 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 63 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 64 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 65 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 66 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 67 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 68 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 69 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 70 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 71 * SUCH DAMAGE. 72 * 73 * @(#)buf.h 8.9 (Berkeley) 3/30/95 74 */ 75 76 #define BUF_CACHE_SIZE 1000 77 78 /* 79 * The buffer header describes an I/O operation. 80 */ 81 struct ubuf { 82 LIST_ENTRY(ubuf) b_hash; /* Hash chain. */ 83 LIST_ENTRY(ubuf) b_vnbufs; /* Buffer's associated vnode. */ 84 TAILQ_ENTRY(ubuf) b_freelist; /* Free list position if not active. */ 85 volatile long b_flags; /* B_* flags. */ 86 long b_bcount; /* Valid bytes in buffer. */ 87 #undef b_data 88 char *b_data; /* Data in buffer */ 89 daddr_t b_lblkno; /* Logical block number. */ 90 daddr_t b_blkno; /* Underlying physical block number */ 91 struct uvnode *b_vp; /* File vnode. */ 92 }; 93 94 #define b_bufsize b_bcount 95 96 /* 97 * These flags are kept in b_flags. 98 */ 99 #define B_AGE 0x00000001 /* Move to age queue when I/O done. */ 100 #define B_NEEDCOMMIT 0x00000002 /* Needs committing to stable storage */ 101 #define B_BUSY 0x00000010 /* I/O in progress. */ 102 #define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */ 103 #define B_DONE 0x00000200 /* I/O completed. */ 104 #define B_ERROR 0x00000800 /* I/O error occurred. */ 105 #define B_GATHERED 0x00001000 /* LFS: already in a segment. */ 106 #define B_INVAL 0x00002000 /* Does not contain valid info. */ 107 #define B_LOCKED 0x00004000 /* Locked in core (not reusable). */ 108 #define B_READ 0x00100000 /* Read buffer. */ 109 110 LIST_HEAD(bufhash_struct, ubuf); 111 112 void bufinit(void); 113 void bufstats(void); 114 void buf_destroy(struct ubuf *); 115 void bremfree(struct ubuf *); 116 struct ubuf *incore(struct uvnode *, int); 117 struct ubuf *getblk(struct uvnode *, daddr_t, int); 118 void bwrite(struct ubuf *); 119 void brelse(struct ubuf *); 120 int bread(struct uvnode *, daddr_t, int, struct ucred *, struct ubuf **); 121 void reassignbuf(struct ubuf *, struct uvnode *); 122
Indexes created Fri Sep 26 08:10:20 GMT 2025