subr_disk.c revision 55763 
1/*
2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
8 *
9 * $FreeBSD: head/sys/kern/subr_disk.c 55763 2000-01-10 12:21:39Z phk $
10 *
11 */
12
13#include <sys/param.h>
14#include <sys/systm.h>
15#include <sys/kernel.h>
16#include <sys/sysctl.h>
17#include <sys/buf.h>
18#include <sys/conf.h>
19#include <sys/disk.h>
20#include <sys/malloc.h>
21#include <machine/md_var.h>
22
23MALLOC_DEFINE(M_DISK, "disk", "disk data");
24
25static d_strategy_t diskstrategy;
26static d_open_t diskopen;
27static d_close_t diskclose;
28static d_ioctl_t diskioctl;
29static d_psize_t diskpsize;
30
31dev_t
32disk_create(int unit, struct disk *dp, int flags, struct cdevsw *cdevsw, struct cdevsw *proto)
33{
34	dev_t dev;
35
36	bzero(dp, sizeof(*dp));
37
38	dev = makedev(cdevsw->d_maj, 0);
39	if (!devsw(dev)) {
40		*proto = *cdevsw;
41		proto->d_open = diskopen;
42		proto->d_close = diskclose;
43		proto->d_ioctl = diskioctl;
44		proto->d_strategy = diskstrategy;
45		proto->d_psize = diskpsize;
46		cdevsw_add(proto);
47	}
48
49	if (bootverbose)
50		printf("Creating DISK %s%d\n", cdevsw->d_name, unit);
51	dev = make_dev(proto, dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
52	    0, 0, 0, "r%s%d", cdevsw->d_name, unit);
53
54	dev->si_disk = dp;
55	dp->d_dev = dev;
56	dp->d_dsflags = flags;
57	dp->d_devsw = cdevsw;
58	return (dev);
59}
60
61int
62disk_dumpcheck(dev_t dev, u_int *count, u_int *blkno, u_int *secsize)
63{
64	struct disk *dp;
65	struct disklabel *dl;
66	u_int boff;
67
68	dp = dev->si_disk;
69	if (!dp)
70		return (ENXIO);
71	if (!dp->d_slice)
72		return (ENXIO);
73	dl = dsgetlabel(dev, dp->d_slice);
74	if (!dl)
75		return (ENXIO);
76	*count = (u_long)Maxmem * PAGE_SIZE / dl->d_secsize;
77	if (dumplo < 0 ||
78	    (dumplo + *count > dl->d_partitions[dkpart(dev)].p_size))
79		return (EINVAL);
80	boff = dl->d_partitions[dkpart(dev)].p_offset +
81	    dp->d_slice->dss_slices[dkslice(dev)].ds_offset;
82	*blkno = boff + dumplo;
83	*secsize = dl->d_secsize;
84	return (0);
85
86}
87
88void
89disk_invalidate (struct disk *disk)
90{
91	dsgone(&disk->d_slice);
92}
93
94void
95disk_delete(dev_t dev)
96{
97	return;
98}
99
100/*
101 * The cdevsw functions
102 */
103
104static int
105diskopen(dev_t dev, int oflags, int devtype, struct proc *p)
106{
107	dev_t pdev;
108	struct disk *dp;
109	int error;
110
111	error = 0;
112	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
113
114	dp = pdev->si_disk;
115	if (!dp)
116		return (ENXIO);
117
118	while (dp->d_flags & DISKFLAG_LOCK) {
119		dp->d_flags |= DISKFLAG_WANTED;
120		error = tsleep(dp, PRIBIO | PCATCH, "diskopen", hz);
121		if (error)
122			return (error);
123	}
124	dp->d_flags |= DISKFLAG_LOCK;
125
126	if (!dsisopen(dp->d_slice)) {
127		if (!pdev->si_iosize_max)
128			pdev->si_iosize_max = dev->si_iosize_max;
129		error = dp->d_devsw->d_open(pdev, oflags, devtype, p);
130	}
131
132	/* Inherit properties from the whole/raw dev_t */
133	dev->si_disk = pdev->si_disk;
134	dev->si_drv1 = pdev->si_drv1;
135	dev->si_drv2 = pdev->si_drv2;
136	dev->si_iosize_max = pdev->si_iosize_max;
137	dev->si_bsize_phys = pdev->si_bsize_phys;
138	dev->si_bsize_best = pdev->si_bsize_best;
139
140	if (error)
141		goto out;
142
143	error = dsopen(dev, devtype, dp->d_dsflags, &dp->d_slice, &dp->d_label);
144
145	if (!dsisopen(dp->d_slice))
146		dp->d_devsw->d_close(pdev, oflags, devtype, p);
147out:
148	dp->d_flags &= ~DISKFLAG_LOCK;
149	if (dp->d_flags & DISKFLAG_WANTED) {
150		dp->d_flags &= ~DISKFLAG_WANTED;
151		wakeup(dp);
152	}
153
154	return(error);
155}
156
157static int
158diskclose(dev_t dev, int fflag, int devtype, struct proc *p)
159{
160	struct disk *dp;
161	int error;
162
163	error = 0;
164	dp = dev->si_disk;
165	dsclose(dev, devtype, dp->d_slice);
166	if (!dsisopen(dp->d_slice)) {
167		error = dp->d_devsw->d_close(dp->d_dev, fflag, devtype, p);
168	}
169	return (error);
170}
171
172static void
173diskstrategy(struct buf *bp)
174{
175	dev_t pdev;
176	struct disk *dp;
177
178	dp = bp->b_dev->si_disk;
179	if (!dp) {
180		pdev = dkmodpart(dkmodslice(bp->b_dev, WHOLE_DISK_SLICE), RAW_PART);
181		dp = bp->b_dev->si_disk = pdev->si_disk;
182		bp->b_dev->si_drv1 = pdev->si_drv1;
183		bp->b_dev->si_drv2 = pdev->si_drv2;
184		bp->b_dev->si_iosize_max = pdev->si_iosize_max;
185		bp->b_dev->si_bsize_phys = pdev->si_bsize_phys;
186		bp->b_dev->si_bsize_best = pdev->si_bsize_best;
187	}
188
189	if (!dp) {
190		bp->b_error = ENXIO;
191		bp->b_flags |= B_ERROR;
192		biodone(bp);
193		return;
194	}
195
196	if (dscheck(bp, dp->d_slice) <= 0) {
197		biodone(bp);
198		return;
199	}
200
201	dp->d_devsw->d_strategy(bp);
202	return;
203
204}
205
206static int
207diskioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct proc *p)
208{
209	struct disk *dp;
210	int error;
211
212	dp = dev->si_disk;
213	error = dsioctl(dev, cmd, data, fflag, &dp->d_slice);
214	if (error == ENOIOCTL)
215		error = dp->d_devsw->d_ioctl(dev, cmd, data, fflag, p);
216	return (error);
217}
218
219static int
220diskpsize(dev_t dev)
221{
222	struct disk *dp;
223	dev_t pdev;
224
225	dp = dev->si_disk;
226	if (!dp) {
227		pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
228		dp = pdev->si_disk;
229		dev->si_drv1 = pdev->si_drv1;
230		dev->si_drv2 = pdev->si_drv2;
231		/* XXX: don't set bp->b_dev->si_disk (?) */
232	}
233	return (dssize(dev, &dp->d_slice));
234}
235
236SYSCTL_DECL(_debug_sizeof);
237
238SYSCTL_INT(_debug_sizeof, OID_AUTO, disklabel, CTLFLAG_RD,
239    0, sizeof(struct disklabel), "sizeof(struct disklabel)");
240
241SYSCTL_INT(_debug_sizeof, OID_AUTO, diskslices, CTLFLAG_RD,
242    0, sizeof(struct diskslices), "sizeof(struct diskslices)");
243
244SYSCTL_INT(_debug_sizeof, OID_AUTO, disk, CTLFLAG_RD,
245    0, sizeof(struct disk), "sizeof(struct disk)");
246