9bf7a991c5
when there is no memory available to do so. Use the uvnode's strategy routine to retrieve data from the device, rather than always using pread(). Add a buffer header flag that specifies external management of the buffer's data area. All of this in support of a new cleaner, which is not included in this commit.
126 lines
5.7 KiB
C
126 lines
5.7 KiB
C
/* $NetBSD: bufcache.h,v 1.5 2005/05/20 18:59:36 perseant Exp $ */
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/*-
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* Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
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* NASA Ames Research Center.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)buf.h 8.9 (Berkeley) 3/30/95
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*/
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#define BUF_CACHE_SIZE 1000
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/*
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* The buffer header describes an I/O operation.
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*/
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struct ubuf {
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LIST_ENTRY(ubuf) b_hash; /* Hash chain. */
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LIST_ENTRY(ubuf) b_vnbufs; /* Buffer's associated vnode. */
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TAILQ_ENTRY(ubuf) b_freelist; /* Free list position if not active. */
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volatile long b_flags; /* B_* flags. */
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long b_bcount; /* Valid bytes in buffer. */
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#undef b_data
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char *b_data; /* Data in buffer */
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daddr_t b_lblkno; /* Logical block number. */
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daddr_t b_blkno; /* Underlying physical block number */
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struct uvnode *b_vp; /* File vnode. */
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int b_hashval; /* Hash value */
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};
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#define b_bufsize b_bcount
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/*
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* These flags are kept in b_flags.
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*/
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#define B_AGE 0x00000001 /* Move to age queue when I/O done. */
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#define B_NEEDCOMMIT 0x00000002 /* Needs committing to stable storage */
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#define B_BUSY 0x00000010 /* I/O in progress. */
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#define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */
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#define B_DONE 0x00000200 /* I/O completed. */
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#define B_ERROR 0x00000800 /* I/O error occurred. */
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#define B_GATHERED 0x00001000 /* LFS: already in a segment. */
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#define B_INVAL 0x00002000 /* Does not contain valid info. */
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#define B_LOCKED 0x00004000 /* Locked in core (not reusable). */
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#define B_READ 0x00100000 /* Read buffer. */
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#define B_DONTFREE 0x00010000 /* b_data not managed by bufcache */
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LIST_HEAD(bufhash_struct, ubuf);
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void bufinit(int);
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void bufrehash(int);
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void bufstats(void);
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void buf_destroy(struct ubuf *);
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void bremfree(struct ubuf *);
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struct ubuf *incore(struct uvnode *, int);
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struct ubuf *getblk(struct uvnode *, daddr_t, int);
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void bwrite(struct ubuf *);
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void brelse(struct ubuf *);
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int bread(struct uvnode *, daddr_t, int, struct ucred *, struct ubuf **);
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void reassignbuf(struct ubuf *, struct uvnode *);
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void dump_free_lists(void);
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