2 * Copyright (c) 2006 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * $DragonFly: src/sys/dev/virtual/disk/vdisk.c,v 1.7 2007/07/02 17:15:10 dillon Exp $
40 #include <sys/types.h>
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
48 #include <sys/devicestat.h>
50 #include <machine/md_var.h>
58 struct bio_queue_head bio_queue;
62 thread_t iotd; /* dedicated io thread */
70 static void vkd_io_thread(void *arg);
71 static void vkd_doio(struct vkd_softc *sc, struct bio *bio);
73 static d_strategy_t vkdstrategy;
74 static d_open_t vkdopen;
76 static struct dev_ops vkd_ops = {
77 { "vkd", CDEV_MAJOR, D_DISK },
82 .d_strategy = vkdstrategy,
86 vkdinit(void *dummy __unused)
88 struct vkdisk_info *dsk;
93 for (i = 0; i < DiskNum; i++) {
94 /* check that the 'bus device' has been initialized */
96 if (dsk == NULL || dsk->type != VKD_DISK)
98 if (dsk->fd < 0 || fstat(dsk->fd, &st) < 0)
101 /* and create a new device */
102 sc = kmalloc(sizeof(*sc), M_DEVBUF, M_WAITOK | M_ZERO);
103 sc->unit = dsk->unit;
105 spin_init(&sc->spin);
106 bioq_init(&sc->bio_queue);
107 devstat_add_entry(&sc->stats, "vkd", sc->unit, DEV_BSIZE,
108 DEVSTAT_NO_ORDERED_TAGS,
109 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
110 DEVSTAT_PRIORITY_DISK);
111 sc->dev = disk_create(sc->unit, &sc->disk, &vkd_ops);
112 sc->dev->si_drv1 = sc;
113 sc->dev->si_iosize_max = 256 * 1024;
115 int xcpu = ncpus - 1;
116 lwkt_create(vkd_io_thread, sc, &sc->iotd, NULL,
117 0, xcpu, "vkd%d-io", sc->unit);
118 usched_mastermask &= ~(1 << xcpu);
123 SYSINIT(vkdisk, SI_SUB_DRIVERS, SI_ORDER_FIRST, vkdinit, NULL);
126 vkdopen(struct dev_open_args *ap)
128 struct vkd_softc *sc;
129 struct disk_info info;
133 dev = ap->a_head.a_dev;
135 if (fstat(sc->fd, &st) < 0 || st.st_size == 0)
138 bzero(&info, sizeof(info));
139 info.d_media_blksize = DEV_BSIZE;
140 info.d_media_blocks = st.st_size / info.d_media_blksize;
143 info.d_ncylinders = 1;
144 info.d_secpertrack = info.d_media_blocks;
145 info.d_secpercyl = info.d_secpertrack * info.d_nheads;
147 disk_setdiskinfo(&sc->disk, &info);
152 vkdstrategy(struct dev_strategy_args *ap)
154 struct bio *bio = ap->a_bio;
155 struct vkd_softc *sc;
158 dev = ap->a_head.a_dev;
162 spin_lock_wr(&sc->spin);
163 bioqdisksort(&sc->bio_queue, bio);
164 spin_unlock_wr(&sc->spin);
167 bioqdisksort(&sc->bio_queue, bio);
168 while ((bio = bioq_first(&sc->bio_queue)) != NULL) {
169 bioq_remove(&sc->bio_queue, bio);
179 vkd_io_thread(void *arg)
182 struct vkd_softc *sc;
188 kprintf("vkd%d I/O helper on cpu %d\n", sc->unit, mycpu->gd_cpuid);
190 spin_lock_wr(&sc->spin);
192 while ((bio = bioq_first(&sc->bio_queue)) != NULL) {
193 bioq_remove(&sc->bio_queue, bio);
194 spin_unlock_wr(&sc->spin);
199 if ((++count & 3) == 0)
201 spin_lock_wr(&sc->spin);
203 msleep(sc->iotd, &sc->spin, 0, "bioq", 0);
206 spin_unlock_wr(&sc->spin);
211 vkd_doio(struct vkd_softc *sc, struct bio *bio)
213 struct buf *bp = bio->bio_buf;
216 devstat_start_transaction(&sc->stats);
220 n = pread(sc->fd, bp->b_data, bp->b_bcount, bio->bio_offset);
223 /* XXX HANDLE SHORT WRITE XXX */
224 n = pwrite(sc->fd, bp->b_data, bp->b_bcount, bio->bio_offset);
227 panic("vkd: bad b_cmd %d", bp->b_cmd);
228 break; /* not reached */
230 if (n != bp->b_bcount) {
232 bp->b_flags |= B_ERROR;
235 bp->b_resid = bp->b_bcount - n;
236 devstat_end_transaction_buf(&sc->stats, bp);