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      1 /*	$NetBSD: bufq.h,v 1.11 2016/11/16 00:46:46 pgoyette Exp $	*/
      2 /*	NetBSD: buf.h,v 1.75 2004/09/18 16:40:11 yamt Exp 	*/
      3 
      4 /*-
      5  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
      6  * All rights reserved.
      7  *
      8  * This code is derived from software contributed to The NetBSD Foundation
      9  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
     10  * NASA Ames Research Center.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 /*
     35  * Copyright (c) 1982, 1986, 1989, 1993
     36  *	The Regents of the University of California.  All rights reserved.
     37  * (c) UNIX System Laboratories, Inc.
     38  * All or some portions of this file are derived from material licensed
     39  * to the University of California by American Telephone and Telegraph
     40  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     41  * the permission of UNIX System Laboratories, Inc.
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. Neither the name of the University nor the names of its contributors
     52  *    may be used to endorse or promote products derived from this software
     53  *    without specific prior written permission.
     54  *
     55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     65  * SUCH DAMAGE.
     66  *
     67  *	@(#)buf.h	8.9 (Berkeley) 3/30/95
     68  */
     69 
     70 #if !defined(_KERNEL)
     71 #error not supposed to be exposed to userland.
     72 #endif
     73 
     74 struct buf;
     75 struct bufq_state;
     76 
     77 /*
     78  * Special strategies for bufq_alloc.
     79  */
     80 #define	BUFQ_STRAT_ANY		NULL 	/* let bufq_alloc select one. */
     81 #define	BUFQ_DISK_DEFAULT_STRAT	BUFQ_STRAT_ANY	/* default for disks. */
     82 
     83 /*
     84  * Flags for bufq_alloc.
     85  */
     86 #define BUFQ_SORT_RAWBLOCK	0x0001	/* Sort by b_rawblkno */
     87 #define BUFQ_SORT_CYLINDER	0x0002	/* Sort by b_cylinder, b_rawblkno */
     88 
     89 #define BUFQ_SORT_MASK		0x000f
     90 
     91 #define	BUFQ_EXACT		0x0010	/* Don't fall back to other strategy */
     92 
     93 void	bufq_init(void);
     94 int	bufq_alloc(struct bufq_state **, const char *, int);
     95 void	bufq_drain(struct bufq_state *);
     96 void	bufq_free(struct bufq_state *);
     97 /* Put buffer in queue */
     98 void	bufq_put(struct bufq_state *, struct buf *);
     99 /* Get and remove buffer from queue */
    100 struct buf *bufq_get(struct bufq_state *);
    101 /* Get buffer from queue */
    102 struct buf *bufq_peek(struct bufq_state *);
    103 /* Remove specified buffer from queue */
    104 struct buf *bufq_cancel(struct bufq_state *, struct buf *);
    105 const char *bufq_getstrategyname(struct bufq_state *);
    106 void	bufq_move(struct bufq_state *, struct bufq_state *);
    107