/* $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; } }
