171 lines
5.7 KiB
C
171 lines
5.7 KiB
C
/* $NetBSD: bufq_fcfs.c,v 1.13 2017/05/04 11:03:27 kamil Exp $ */
|
|
/* NetBSD: subr_disk.c,v 1.61 2004/09/25 03:30:44 thorpej Exp */
|
|
|
|
/*-
|
|
* Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
|
|
* NASA Ames Research Center.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
/*
|
|
* Copyright (c) 1982, 1986, 1988, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
* (c) UNIX System Laboratories, Inc.
|
|
* All or some portions of this file are derived from material licensed
|
|
* to the University of California by American Telephone and Telegraph
|
|
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
|
|
* the permission of UNIX System Laboratories, Inc.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__KERNEL_RCSID(0, "$NetBSD: bufq_fcfs.c,v 1.13 2017/05/04 11:03:27 kamil Exp $");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/buf.h>
|
|
#include <sys/bufq.h>
|
|
#include <sys/bufq_impl.h>
|
|
#include <sys/kmem.h>
|
|
#include <sys/module.h>
|
|
|
|
/*
|
|
* First-come first-served sort for disks.
|
|
*
|
|
* Requests are appended to the queue without any reordering.
|
|
*/
|
|
|
|
struct bufq_fcfs {
|
|
TAILQ_HEAD(, buf) bq_head; /* actual list of buffers */
|
|
};
|
|
|
|
static void bufq_fcfs_init(struct bufq_state *);
|
|
static void bufq_fcfs_put(struct bufq_state *, struct buf *);
|
|
static struct buf *bufq_fcfs_get(struct bufq_state *, int);
|
|
|
|
BUFQ_DEFINE(fcfs, 10, bufq_fcfs_init);
|
|
|
|
static void
|
|
bufq_fcfs_put(struct bufq_state *bufq, struct buf *bp)
|
|
{
|
|
struct bufq_fcfs *fcfs = bufq_private(bufq);
|
|
|
|
TAILQ_INSERT_TAIL(&fcfs->bq_head, bp, b_actq);
|
|
}
|
|
|
|
static struct buf *
|
|
bufq_fcfs_get(struct bufq_state *bufq, int remove)
|
|
{
|
|
struct bufq_fcfs *fcfs = bufq_private(bufq);
|
|
struct buf *bp;
|
|
|
|
bp = TAILQ_FIRST(&fcfs->bq_head);
|
|
|
|
if (bp != NULL && remove)
|
|
TAILQ_REMOVE(&fcfs->bq_head, bp, b_actq);
|
|
|
|
return (bp);
|
|
}
|
|
|
|
static struct buf *
|
|
bufq_fcfs_cancel(struct bufq_state *bufq, struct buf *buf)
|
|
{
|
|
struct bufq_fcfs *fcfs = bufq_private(bufq);
|
|
struct buf *bp;
|
|
|
|
TAILQ_FOREACH(bp, &fcfs->bq_head, b_actq) {
|
|
if (bp == buf) {
|
|
TAILQ_REMOVE(&fcfs->bq_head, bp, b_actq);
|
|
return buf;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
bufq_fcfs_fini(struct bufq_state *bufq)
|
|
{
|
|
|
|
KASSERT(bufq->bq_private != NULL);
|
|
kmem_free(bufq->bq_private, sizeof(struct bufq_fcfs));
|
|
}
|
|
|
|
static void
|
|
bufq_fcfs_init(struct bufq_state *bufq)
|
|
{
|
|
struct bufq_fcfs *fcfs;
|
|
|
|
bufq->bq_get = bufq_fcfs_get;
|
|
bufq->bq_put = bufq_fcfs_put;
|
|
bufq->bq_cancel = bufq_fcfs_cancel;
|
|
bufq->bq_fini = bufq_fcfs_fini;
|
|
bufq->bq_private = kmem_zalloc(sizeof(struct bufq_fcfs), KM_SLEEP);
|
|
fcfs = (struct bufq_fcfs *)bufq->bq_private;
|
|
TAILQ_INIT(&fcfs->bq_head);
|
|
}
|
|
|
|
MODULE(MODULE_CLASS_BUFQ, bufq_fcfs, NULL);
|
|
|
|
static int
|
|
bufq_fcfs_modcmd(modcmd_t cmd, void *opaque)
|
|
{
|
|
|
|
switch (cmd) {
|
|
case MODULE_CMD_INIT:
|
|
return bufq_register(&bufq_strat_fcfs);
|
|
case MODULE_CMD_FINI:
|
|
return bufq_unregister(&bufq_strat_fcfs);
|
|
default:
|
|
return ENOTTY;
|
|
}
|
|
}
|