336 lines
12 KiB
C
336 lines
12 KiB
C
/* $NetBSD: buf.h,v 1.75 2004/09/18 16:40:11 yamt 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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#ifndef _SYS_BUF_H_
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#define _SYS_BUF_H_
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#include <sys/pool.h>
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#include <sys/queue.h>
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#include <sys/lock.h>
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struct buf;
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struct mount;
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struct vnode;
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#define NOLIST ((struct buf *)0x87654321)
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/*
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* To avoid including <ufs/ffs/softdep.h>
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*/
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LIST_HEAD(workhead, worklist);
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/*
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* Device driver buffer queue.
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*/
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struct bufq_state {
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void (*bq_put)(struct bufq_state *, struct buf *);
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struct buf *(*bq_get)(struct bufq_state *, int);
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void *bq_private;
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int bq_flags; /* Flags from bufq_alloc() */
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};
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/*
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* Flags for bufq_alloc.
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*/
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#define BUFQ_SORT_RAWBLOCK 0x0001 /* Sort by b_rawblkno */
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#define BUFQ_SORT_CYLINDER 0x0002 /* Sort by b_cylinder, b_rawblkno */
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#define BUFQ_FCFS 0x0010 /* First-come first-serve */
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#define BUFQ_DISKSORT 0x0020 /* Min seek sort */
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#define BUFQ_READ_PRIO 0x0030 /* Min seek and read priority */
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#define BUFQ_PRIOCSCAN 0x0040 /* Per-priority CSCAN */
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#define BUFQ_SORT_MASK 0x000f
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#define BUFQ_METHOD_MASK 0x00f0
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#ifdef _KERNEL
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extern int bufq_disk_default_strat;
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#define BUFQ_DISK_DEFAULT_STRAT() bufq_disk_default_strat
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void bufq_alloc(struct bufq_state *, int);
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void bufq_free(struct bufq_state *);
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#define BUFQ_PUT(bufq, bp) \
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(*(bufq)->bq_put)((bufq), (bp)) /* Put buffer in queue */
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#define BUFQ_GET(bufq) \
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(*(bufq)->bq_get)((bufq), 1) /* Get and remove buffer from queue */
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#define BUFQ_PEEK(bufq) \
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(*(bufq)->bq_get)((bufq), 0) /* Get buffer from queue */
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#endif /* _KERNEL */
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/*
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* These are currently used only by the soft dependency code, hence
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* are stored once in a global variable. If other subsystems wanted
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* to use these hooks, a pointer to a set of bio_ops could be added
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* to each buffer.
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*/
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struct bio_ops {
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void (*io_start)(struct buf *);
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void (*io_complete)(struct buf *);
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void (*io_deallocate)(struct buf *);
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int (*io_fsync)(struct vnode *);
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int (*io_sync)(struct mount *);
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void (*io_movedeps)(struct buf *, struct buf *);
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int (*io_countdeps)(struct buf *, int);
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void (*io_pageiodone)(struct buf *);
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};
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/*
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* The buffer header describes an I/O operation in the kernel.
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*/
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struct buf {
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TAILQ_ENTRY(buf) b_actq; /* Device driver queue when active. */
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struct simplelock b_interlock; /* Lock for b_flags changes */
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volatile int b_flags; /* B_* flags. */
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int b_error; /* Errno value. */
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int b_prio; /* Hint for buffer queue discipline. */
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int b_bufsize; /* Allocated buffer size. */
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int b_bcount; /* Valid bytes in buffer. */
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int b_resid; /* Remaining I/O. */
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dev_t b_dev; /* Device associated with buffer. */
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struct {
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caddr_t b_addr; /* Memory, superblocks, indirect etc. */
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} b_un;
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daddr_t b_blkno; /* Underlying physical block number
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(partition relative) */
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daddr_t b_rawblkno; /* Raw underlying physical block
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number (not partition relative) */
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/* Function to call upon completion. */
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void (*b_iodone)(struct buf *);
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struct proc *b_proc; /* Associated proc if B_PHYS set. */
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struct vnode *b_vp; /* File vnode. */
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struct workhead b_dep; /* List of filesystem dependencies. */
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void *b_saveaddr; /* Original b_addr for physio. */
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/*
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* private data for owner.
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* - buffer cache buffers are owned by corresponding filesystem.
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* - non-buffer cache buffers are owned by subsystem which
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* allocated them. (filesystem, disk driver, etc)
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*/
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union {
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void *bf_private;
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off_t bf_dcookie; /* NFS: Offset cookie if dir block */
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} b_fspriv;
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#define b_private b_fspriv.bf_private
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#define b_dcookie b_fspriv.bf_dcookie
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/*
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* buffer cache specific data
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*/
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LIST_ENTRY(buf) b_hash; /* Hash chain. */
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LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */
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TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */
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daddr_t b_lblkno; /* Logical block number. */
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int b_freelistindex; /* Free list index. (BQ_) */
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};
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#define BUF_INIT(bp) \
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do { \
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LIST_INIT(&(bp)->b_dep); \
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simple_lock_init(&(bp)->b_interlock); \
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(bp)->b_dev = NODEV; \
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BIO_SETPRIO((bp), BPRIO_DEFAULT); \
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} while (/*CONSTCOND*/0)
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/*
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* For portability with historic industry practice, the cylinder number has
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* to be maintained in the `b_resid' field.
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*/
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#define b_cylinder b_resid /* Cylinder number for disksort(). */
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/* Device driver compatibility definitions. */
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#define b_data b_un.b_addr /* b_un.b_addr is not changeable. */
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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_ASYNC 0x00000004 /* Start I/O, do not wait. */
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#define B_BAD 0x00000008 /* Bad block revectoring in progress. */
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#define B_BUSY 0x00000010 /* I/O in progress. */
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#define B_SCANNED 0x00000020 /* Block already pushed during sync */
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#define B_CALL 0x00000040 /* Call b_iodone from biodone. */
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#define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */
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#define B_DIRTY 0x00000100 /* Dirty page to be pushed out async. */
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#define B_DONE 0x00000200 /* I/O completed. */
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#define B_EINTR 0x00000400 /* I/O was interrupted */
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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_NOCACHE 0x00008000 /* Do not cache block after use. */
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#define B_CACHE 0x00020000 /* Bread found us in the cache. */
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#define B_PHYS 0x00040000 /* I/O to user memory. */
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#define B_RAW 0x00080000 /* Set by physio for raw transfers. */
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#define B_READ 0x00100000 /* Read buffer. */
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#define B_TAPE 0x00200000 /* Magnetic tape I/O. */
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#define B_WANTED 0x00800000 /* Process wants this buffer. */
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#define B_WRITE 0x00000000 /* Write buffer (pseudo flag). */
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#define B_XXX 0x02000000 /* Debugging flag. */
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#define B_VFLUSH 0x04000000 /* Buffer is being synced. */
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/*
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* This structure describes a clustered I/O. It is stored in the b_saveaddr
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* field of the buffer on which I/O is done. At I/O completion, cluster
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* callback uses the structure to parcel I/O's to individual buffers, and
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* then free's this structure.
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*/
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struct cluster_save {
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long bs_bcount; /* Saved b_bcount. */
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long bs_bufsize; /* Saved b_bufsize. */
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void *bs_saveaddr; /* Saved b_addr. */
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int bs_nchildren; /* Number of associated buffers. */
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struct buf **bs_children; /* List of associated buffers. */
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};
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/*
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* Zero out the buffer's data area.
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*/
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#define clrbuf(bp) \
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do { \
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memset((bp)->b_data, 0, (u_int)(bp)->b_bcount); \
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(bp)->b_resid = 0; \
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} while (/* CONSTCOND */ 0)
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/* Flags to low-level allocation routines. */
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#define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */
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#define B_SYNC 0x02 /* Do all allocations synchronously. */
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#define B_METAONLY 0x04 /* Return indirect block buffer. */
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#ifdef _KERNEL
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#define BIO_GETPRIO(bp) ((bp)->b_prio)
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#define BIO_SETPRIO(bp, prio) (bp)->b_prio = (prio)
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#define BIO_COPYPRIO(bp1, bp2) BIO_SETPRIO(bp1, BIO_GETPRIO(bp2))
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#define BPRIO_NPRIO 3
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#define BPRIO_TIMECRITICAL 2
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#define BPRIO_TIMELIMITED 1
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#define BPRIO_TIMENONCRITICAL 0
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#define BPRIO_DEFAULT BPRIO_TIMELIMITED
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extern struct bio_ops bioops;
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extern u_int nbuf; /* The number of buffer headers */
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extern struct buf *buf; /* The buffer headers. */
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extern char *buffers; /* The buffer contents. */
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extern u_int bufpages; /* Number of memory pages in the buffer pool. */
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/*
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* Pool of I/O buffers. Access to this pool must be protected with
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* splbio().
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*/
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extern struct pool bufpool;
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__BEGIN_DECLS
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void allocbuf(struct buf *, int, int);
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void bawrite(struct buf *);
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void bdirty(struct buf *);
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void bdwrite(struct buf *);
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void biodone(struct buf *);
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int biowait(struct buf *);
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int bread(struct vnode *, daddr_t, int, struct ucred *, struct buf **);
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int breada(struct vnode *, daddr_t, int, daddr_t, int, struct ucred *,
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struct buf **);
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int breadn(struct vnode *, daddr_t, int, daddr_t *, int *, int,
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struct ucred *, struct buf **);
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void brelse(struct buf *);
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void bremfree(struct buf *);
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void bufinit(void);
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int bwrite(struct buf *);
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struct buf *getblk(struct vnode *, daddr_t, int, int, int);
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struct buf *geteblk(int);
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struct buf *getnewbuf(int, int, int);
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struct buf *incore(struct vnode *, daddr_t);
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void minphys(struct buf *);
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int physio(void (*)(struct buf *), struct buf *, dev_t, int,
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void (*)(struct buf *), struct uio *);
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void brelvp(struct buf *);
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void reassignbuf(struct buf *, struct vnode *);
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void bgetvp(struct vnode *, struct buf *);
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int buf_syncwait(void);
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u_long buf_memcalc(void);
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int buf_drain(int);
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int buf_setvalimit(vsize_t);
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#ifdef DDB
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void vfs_buf_print(struct buf *, int, void (*)(const char *, ...));
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#endif
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__END_DECLS
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#endif
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#endif /* !_SYS_BUF_H_ */
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