309 lines
11 KiB
C
309 lines
11 KiB
C
/* $OpenBSD: buf.h,v 1.114 2024/02/03 18:51:58 beck Exp $ */
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/* $NetBSD: buf.h,v 1.25 1997/04/09 21:12:17 mycroft Exp $ */
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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 8.7 (Berkeley) 1/21/94
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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/queue.h>
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#include <sys/tree.h>
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#include <sys/mutex.h>
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#include <uvm/uvm_extern.h>
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#define NOLIST ((struct buf *)0x87654321)
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struct buf;
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struct vnode;
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LIST_HEAD(bufhead, buf);
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/*
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* Buffer queues
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*/
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#define BUFQ_NSCAN_N 128
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#define BUFQ_FIFO 0
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#define BUFQ_NSCAN 1
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#define BUFQ_DEFAULT BUFQ_NSCAN
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#define BUFQ_HOWMANY 2
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/*
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* Write limits for bufq - defines high and low water marks for how
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* many kva slots are allowed to be consumed to parallelize writes from
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* the buffer cache from any individual bufq.
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*/
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#define BUFQ_HI 128
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#define BUFQ_LOW 64
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struct bufq_impl;
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struct bufq {
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SLIST_ENTRY(bufq) bufq_entries;
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struct mutex bufq_mtx;
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void *bufq_data;
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u_int bufq_outstanding;
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u_int bufq_hi;
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u_int bufq_low;
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int bufq_waiting;
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int bufq_stop;
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int bufq_type;
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const struct bufq_impl *bufq_impl;
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};
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int bufq_init(struct bufq *, int);
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int bufq_switch(struct bufq *, int);
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void bufq_destroy(struct bufq *);
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void bufq_queue(struct bufq *, struct buf *);
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struct buf *bufq_dequeue(struct bufq *);
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void bufq_requeue(struct bufq *, struct buf *);
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int bufq_peek(struct bufq *);
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void bufq_drain(struct bufq *);
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void bufq_wait(struct bufq *);
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void bufq_done(struct bufq *, struct buf *);
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void bufq_quiesce(void);
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void bufq_restart(void);
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/* fifo */
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SIMPLEQ_HEAD(bufq_fifo_head, buf);
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struct bufq_fifo {
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SIMPLEQ_ENTRY(buf) bqf_entries;
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};
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/* nscan */
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SIMPLEQ_HEAD(bufq_nscan_head, buf);
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struct bufq_nscan {
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SIMPLEQ_ENTRY(buf) bqf_entries;
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};
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/* bufq link in struct buf */
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union bufq_data {
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struct bufq_fifo bufq_data_fifo;
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struct bufq_nscan bufq_data_nscan;
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};
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/* The buffer header describes an I/O operation in the kernel. */
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struct buf {
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RBT_ENTRY(buf) b_rbbufs; /* vnode "hash" tree */
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LIST_ENTRY(buf) b_list; /* All allocated buffers. */
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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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int cache; /* which cache are we in */
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struct proc *b_proc; /* Associated proc; NULL if kernel. */
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volatile long b_flags; /* B_* flags. */
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long b_bufsize; /* Allocated buffer size. */
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long b_bcount; /* Valid bytes in buffer. */
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size_t b_resid; /* Remaining I/O. */
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int b_error; /* Errno value. */
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dev_t b_dev; /* Device associated with buffer. */
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caddr_t b_data; /* associated data */
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void *b_saveaddr; /* Original b_data for physio. */
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TAILQ_ENTRY(buf) b_valist; /* LRU of va to reuse. */
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union bufq_data b_bufq;
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struct bufq *b_bq; /* What bufq this buf is on */
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struct uvm_object *b_pobj;
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struct uvm_object b_uobj; /* Object containing the pages */
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off_t b_poffs; /* Offset within object */
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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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/* Function to call upon completion.
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* Will be called at splbio(). */
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void (*b_iodone)(struct buf *);
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struct vnode *b_vp; /* Device vnode. */
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int b_dirtyoff; /* Offset in buffer of dirty region. */
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int b_dirtyend; /* Offset of end of dirty region. */
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int b_validoff; /* Offset in buffer of valid region. */
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int b_validend; /* Offset of end of valid region. */
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};
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TAILQ_HEAD(bufqueue, buf);
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struct bufcache {
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int64_t hotbufpages;
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int64_t warmbufpages;
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int64_t cachepages;
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struct bufqueue hotqueue;
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struct bufqueue coldqueue;
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struct bufqueue warmqueue;
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};
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/* Device driver compatibility definitions. */
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#define b_active b_bcount /* Driver queue head: drive active. */
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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_WRITE 0x00000000 /* Write buffer (pseudo flag). */
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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_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_CACHE 0x00000020 /* Bread found us in the cache. */
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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_DONE 0x00000100 /* I/O completed. */
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#define B_EINTR 0x00000200 /* I/O was interrupted */
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#define B_ERROR 0x00000400 /* I/O error occurred. */
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#define B_INVAL 0x00000800 /* Does not contain valid info. */
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#define B_NOCACHE 0x00001000 /* Do not cache block after use. */
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#define B_PHYS 0x00002000 /* I/O to user memory. */
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#define B_RAW 0x00004000 /* Set by physio for raw transfers. */
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#define B_READ 0x00008000 /* Read buffer. */
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#define B_WANTED 0x00010000 /* Process wants this buffer. */
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#define B_WRITEINPROG 0x00020000 /* Write in progress. */
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#define B_XXX 0x00040000 /* Debugging flag. */
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#define B_DEFERRED 0x00080000 /* Skipped over for cleaning */
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#define B_SCANNED 0x00100000 /* Block already pushed during sync */
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#define B_PDAEMON 0x00200000 /* I/O started by pagedaemon */
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#define B_RELEASED 0x00400000 /* free this buffer after its kvm */
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#define B_WARM 0x00800000 /* buffer is or has been on the warm queue */
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#define B_COLD 0x01000000 /* buffer is on the cold queue */
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#define B_BC 0x02000000 /* buffer is managed by the cache */
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#define B_DMA 0x04000000 /* buffer is DMA reachable */
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#define B_BITS "\20\001AGE\002NEEDCOMMIT\003ASYNC\004BAD\005BUSY" \
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"\006CACHE\007CALL\010DELWRI\011DONE\012EINTR\013ERROR" \
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"\014INVAL\015NOCACHE\016PHYS\017RAW\020READ" \
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"\021WANTED\022WRITEINPROG\023XXX(FORMAT)\024DEFERRED" \
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"\025SCANNED\026DAEMON\027RELEASED\030WARM\031COLD\032BC\033DMA"
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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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bzero((bp)->b_data, (bp)->b_bcount); \
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(bp)->b_resid = 0; \
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}
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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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struct cluster_info {
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daddr_t ci_lastr; /* last read (read-ahead) */
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daddr_t ci_lastw; /* last write (write cluster) */
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daddr_t ci_cstart; /* start block of cluster */
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daddr_t ci_lasta; /* last allocation */
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int ci_clen; /* length of current cluster */
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int ci_ralen; /* Read-ahead length */
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daddr_t ci_maxra; /* last readahead block */
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};
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#ifdef _KERNEL
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__BEGIN_DECLS
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/* Kva slots (of size MAXPHYS) reserved for syncer and cleaner. */
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#define RESERVE_SLOTS 4
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/* Buffer cache pages reserved for syncer and cleaner. */
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#define RESERVE_PAGES (RESERVE_SLOTS * MAXPHYS / PAGE_SIZE)
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/* Minimum size of the buffer cache, in pages. */
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#define BCACHE_MIN (RESERVE_PAGES * 2)
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#define UNCLEAN_PAGES (bcstats.numbufpages - bcstats.numcleanpages)
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extern struct proc *cleanerproc;
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extern long bufpages; /* Max number of pages for buffers' data */
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extern struct pool bufpool;
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extern struct bufhead bufhead;
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void bawrite(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 buf **);
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int breadn(struct vnode *, daddr_t, int, daddr_t *, int *, int,
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struct buf **);
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void brelse(struct buf *);
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#define bremfree bufcache_take
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void bufinit(void);
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void buf_dirty(struct buf *);
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void buf_undirty(struct buf *);
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void buf_adjcnt(struct buf *, long);
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int bwrite(struct buf *);
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struct buf *getblk(struct vnode *, daddr_t, int, int, uint64_t);
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struct buf *geteblk(size_t);
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struct buf *incore(struct vnode *, daddr_t);
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/*
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* bufcache functions
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*/
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void bufcache_take(struct buf *);
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void bufcache_release(struct buf *);
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int buf_flip_high(struct buf *);
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void buf_flip_dma(struct buf *);
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struct buf *bufcache_getcleanbuf(int, int);
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struct buf *bufcache_getdirtybuf(void);
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/*
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* buf_kvm_init initializes the kvm handling for buffers.
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* buf_acquire sets the B_BUSY flag and ensures that the buffer is
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* mapped in the kvm.
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* buf_release clears the B_BUSY flag and allows the buffer to become
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* unmapped.
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* buf_unmap is for internal use only. Unmaps the buffer from kvm.
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*/
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void buf_mem_init(vsize_t);
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void buf_acquire(struct buf *);
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void buf_acquire_nomap(struct buf *);
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void buf_map(struct buf *);
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void buf_release(struct buf *);
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int buf_dealloc_mem(struct buf *);
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void buf_fix_mapping(struct buf *, vsize_t);
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void buf_alloc_pages(struct buf *, vsize_t);
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void buf_free_pages(struct buf *);
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void minphys(struct buf *bp);
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int physio(void (*strategy)(struct buf *), dev_t dev, int flags,
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void (*minphys)(struct buf *), struct uio *uio);
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void brelvp(struct buf *);
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void reassignbuf(struct buf *);
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void bgetvp(struct vnode *, struct buf *);
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void buf_replacevnode(struct buf *, struct vnode *);
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void buf_daemon(void *);
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void buf_replacevnode(struct buf *, struct vnode *);
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int bread_cluster(struct vnode *, daddr_t, int, struct buf **);
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__END_DECLS
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#endif /* _KERNEL */
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#endif /* !_SYS_BUF_H_ */
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