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 1.8 2008/03/20 02:14:56 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/cothread.h>
51 #include <machine/md_var.h>
59 struct bio_queue_head bio_queue;
63 TAILQ_HEAD(, bio) cotd_queue;
64 TAILQ_HEAD(, bio) cotd_done;
72 static void vkd_io_thread(cothread_t cotd);
73 static void vkd_io_intr(cothread_t cotd);
74 static void vkd_doio(struct vkd_softc *sc, struct bio *bio);
76 static d_strategy_t vkdstrategy;
77 static d_open_t vkdopen;
79 static struct dev_ops vkd_ops = {
80 { "vkd", CDEV_MAJOR, D_DISK },
85 .d_strategy = vkdstrategy,
89 vkdinit(void *dummy __unused)
91 struct vkdisk_info *dsk;
96 for (i = 0; i < DiskNum; i++) {
97 /* check that the 'bus device' has been initialized */
99 if (dsk == NULL || dsk->type != VKD_DISK)
101 if (dsk->fd < 0 || fstat(dsk->fd, &st) < 0)
104 /* and create a new device */
105 sc = kmalloc(sizeof(*sc), M_DEVBUF, M_WAITOK | M_ZERO);
106 sc->unit = dsk->unit;
108 bioq_init(&sc->bio_queue);
109 devstat_add_entry(&sc->stats, "vkd", sc->unit, DEV_BSIZE,
110 DEVSTAT_NO_ORDERED_TAGS,
111 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
112 DEVSTAT_PRIORITY_DISK);
113 sc->dev = disk_create(sc->unit, &sc->disk, &vkd_ops);
114 sc->dev->si_drv1 = sc;
115 sc->dev->si_iosize_max = 256 * 1024;
117 TAILQ_INIT(&sc->cotd_queue);
118 TAILQ_INIT(&sc->cotd_done);
119 sc->cotd = cothread_create(vkd_io_thread, vkd_io_intr, sc,
124 SYSINIT(vkdisk, SI_SUB_DRIVERS, SI_ORDER_FIRST, vkdinit, NULL);
127 vkdopen(struct dev_open_args *ap)
129 struct vkd_softc *sc;
130 struct disk_info info;
134 dev = ap->a_head.a_dev;
136 if (fstat(sc->fd, &st) < 0 || st.st_size == 0)
139 bzero(&info, sizeof(info));
140 info.d_media_blksize = DEV_BSIZE;
141 info.d_media_blocks = st.st_size / info.d_media_blksize;
144 info.d_ncylinders = 1;
145 info.d_secpertrack = info.d_media_blocks;
146 info.d_secpercyl = info.d_secpertrack * info.d_nheads;
148 disk_setdiskinfo(&sc->disk, &info);
153 vkdstrategy(struct dev_strategy_args *ap)
155 struct bio *bio = ap->a_bio;
156 struct vkd_softc *sc;
159 dev = ap->a_head.a_dev;
162 devstat_start_transaction(&sc->stats);
163 cothread_lock(sc->cotd);
164 TAILQ_INSERT_TAIL(&sc->cotd_queue, bio, bio_act);
165 cothread_signal(sc->cotd);
166 cothread_unlock(sc->cotd);
173 vkd_io_intr(cothread_t cotd)
175 struct vkd_softc *sc;
181 while (!TAILQ_EMPTY(&sc->cotd_done)) {
182 bio = TAILQ_FIRST(&sc->cotd_done);
183 TAILQ_REMOVE(&sc->cotd_done, bio, bio_act);
184 devstat_end_transaction_buf(&sc->stats, bio->bio_buf);
187 cothread_unlock(sc->cotd);
191 * WARNING! This runs as a cothread and has no access to mycpu nor can it
192 * make vkernel-specific calls other then cothread_*() calls.
196 vkd_io_thread(cothread_t cotd)
199 struct vkd_softc *sc = cotd->arg;
204 cothread_wait(cotd); /* interlocks cothread lock */
206 while ((bio = TAILQ_FIRST(&sc->cotd_queue)) != NULL) {
207 TAILQ_REMOVE(&sc->cotd_queue, bio, bio_act);
208 cothread_unlock(cotd);
211 TAILQ_INSERT_TAIL(&sc->cotd_done, bio, bio_act);
221 cothread_unlock(cotd);
226 vkd_doio(struct vkd_softc *sc, struct bio *bio)
228 struct buf *bp = bio->bio_buf;
233 n = pread(sc->fd, bp->b_data, bp->b_bcount, bio->bio_offset);
236 /* XXX HANDLE SHORT WRITE XXX */
237 n = pwrite(sc->fd, bp->b_data, bp->b_bcount, bio->bio_offset);
240 if (fsync(sc->fd) < 0)
246 panic("vkd: bad b_cmd %d", bp->b_cmd);
247 break; /* not reached */
249 if (n != bp->b_bcount) {
251 bp->b_flags |= B_ERROR;
253 bp->b_resid = bp->b_bcount - n;