subr_bufq.c revision 1.1
1 /* $NetBSD: subr_bufq.c,v 1.1 2005/10/15 17:29:26 yamt Exp $ */ 2 /* $NetBSD: subr_bufq.c,v 1.1 2005/10/15 17:29:26 yamt Exp $ */ 3 4 /*- 5 * Copyright (c) 1996, 1997, 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 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the NetBSD 23 * Foundation, Inc. and its contributors. 24 * 4. Neither the name of The NetBSD Foundation nor the names of its 25 * contributors may be used to endorse or promote products derived 26 * from this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 38 * POSSIBILITY OF SUCH DAMAGE. 39 */ 40 41 /* 42 * Copyright (c) 1982, 1986, 1988, 1993 43 * The Regents of the University of California. All rights reserved. 44 * (c) UNIX System Laboratories, Inc. 45 * All or some portions of this file are derived from material licensed 46 * to the University of California by American Telephone and Telegraph 47 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 48 * the permission of UNIX System Laboratories, Inc. 49 * 50 * Redistribution and use in source and binary forms, with or without 51 * modification, are permitted provided that the following conditions 52 * are met: 53 * 1. Redistributions of source code must retain the above copyright 54 * notice, this list of conditions and the following disclaimer. 55 * 2. Redistributions in binary form must reproduce the above copyright 56 * notice, this list of conditions and the following disclaimer in the 57 * documentation and/or other materials provided with the distribution. 58 * 3. Neither the name of the University nor the names of its contributors 59 * may be used to endorse or promote products derived from this software 60 * without specific prior written permission. 61 * 62 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 63 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 64 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 65 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 66 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 67 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 68 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 69 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 70 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 71 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 72 * SUCH DAMAGE. 73 * 74 * @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94 75 */ 76 77 #include <sys/cdefs.h> 78 __KERNEL_RCSID(0, "$NetBSD: subr_bufq.c,v 1.1 2005/10/15 17:29:26 yamt Exp $"); 79 80 #include <sys/param.h> 81 #include <sys/systm.h> 82 #include <sys/buf.h> 83 #include <sys/bufq.h> 84 #include <sys/bufq_impl.h> 85 #include <sys/malloc.h> 86 87 BUFQ_DEFINE(dummy, 0, NULL); /* so that bufq_strats won't be empty */ 88 89 #define STRAT_MATCH(id, bs) \ 90 ((id) == BUFQ_STRAT_ANY || strcmp((id), (bs)->bs_name) == 0) 91 92 /* 93 * Create a device buffer queue. 94 */ 95 int 96 bufq_alloc(struct bufq_state **bufqp, const char *strategy, int flags) 97 { 98 __link_set_decl(bufq_strats, const struct bufq_strat); 99 const struct bufq_strat *bsp; 100 const struct bufq_strat * const *it; 101 struct bufq_state *bufq; 102 int error = 0; 103 104 KASSERT((flags & BUFQ_EXACT) == 0 || strategy != BUFQ_STRAT_ANY); 105 106 switch (flags & BUFQ_SORT_MASK) { 107 case BUFQ_SORT_RAWBLOCK: 108 case BUFQ_SORT_CYLINDER: 109 break; 110 case 0: 111 /* 112 * for strategies which don't care about block numbers. 113 * eg. fcfs 114 */ 115 flags |= BUFQ_SORT_RAWBLOCK; 116 break; 117 default: 118 panic("bufq_alloc: sort out of range"); 119 } 120 121 /* 122 * select strategy. 123 * if a strategy specified by flags is found, use it. 124 * otherwise, select one with the largest bs_prio. 125 */ 126 bsp = NULL; 127 __link_set_foreach(it, bufq_strats) { 128 if ((*it) == &bufq_strat_dummy) 129 continue; 130 if (STRAT_MATCH(strategy, (*it))) { 131 bsp = *it; 132 break; 133 } 134 if (bsp == NULL || (*it)->bs_prio > bsp->bs_prio) 135 bsp = *it; 136 } 137 138 if (bsp == NULL) { 139 panic("bufq_alloc: no strategy"); 140 } 141 if (!STRAT_MATCH(strategy, bsp)) { 142 if ((flags & BUFQ_EXACT)) { 143 error = ENOENT; 144 goto out; 145 } 146 #if defined(DEBUG) 147 printf("bufq_alloc: '%s' is not available. using '%s'.\n", 148 strategy, bsp->bs_name); 149 #endif 150 } 151 #if defined(BUFQ_DEBUG) 152 /* XXX aprint? */ 153 printf("bufq_alloc: using '%s'\n", bsp->bs_name); 154 #endif 155 156 *bufqp = bufq = malloc(sizeof(*bufq), M_DEVBUF, M_WAITOK | M_ZERO); 157 bufq->bq_flags = flags; 158 (*bsp->bs_initfn)(bufq); 159 160 out: 161 return 0; 162 } 163 164 void 165 bufq_put(struct bufq_state *bufq, struct buf *bp) 166 { 167 168 (*bufq->bq_put)(bufq, bp); 169 } 170 171 struct buf * 172 bufq_get(struct bufq_state *bufq) 173 { 174 175 return (*bufq->bq_get)(bufq, 1); 176 } 177 178 struct buf * 179 bufq_peek(struct bufq_state *bufq) 180 { 181 182 return (*bufq->bq_get)(bufq, 0); 183 } 184 185 /* 186 * Drain a device buffer queue. 187 */ 188 void 189 bufq_drain(struct bufq_state *bufq) 190 { 191 struct buf *bp; 192 193 while ((bp = BUFQ_GET(bufq)) != NULL) { 194 bp->b_error = EIO; 195 bp->b_flags |= B_ERROR; 196 bp->b_resid = bp->b_bcount; 197 biodone(bp); 198 } 199 } 200 201 /* 202 * Destroy a device buffer queue. 203 */ 204 void 205 bufq_free(struct bufq_state *bufq) 206 { 207 208 KASSERT(bufq->bq_private != NULL); 209 KASSERT(BUFQ_PEEK(bufq) == NULL); 210 211 free(bufq->bq_private, M_DEVBUF); 212 free(bufq, M_DEVBUF); 213 } 214
Indexes created Tue Sep 23 02:09:52 GMT 2025