subr_disk.c revision 77408 
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 77408 2001-05-29 18:19:57Z 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/bio.h>
18#include <sys/conf.h>
19#include <sys/disk.h>
20#include <sys/malloc.h>
21#include <sys/sysctl.h>
22#include <machine/md_var.h>
23#include <sys/ctype.h>
24
25static MALLOC_DEFINE(M_DISK, "disk", "disk data");
26
27static d_strategy_t diskstrategy;
28static d_open_t diskopen;
29static d_close_t diskclose;
30static d_ioctl_t diskioctl;
31static d_psize_t diskpsize;
32
33static LIST_HEAD(, disk) disklist = LIST_HEAD_INITIALIZER(&disklist);
34
35static void
36disk_clone(void *arg, char *name, int namelen, dev_t *dev)
37{
38	struct disk *dp;
39	char const *d;
40	int i, u, s, p;
41	dev_t pdev;
42
43	if (*dev != NODEV)
44		return;
45
46	LIST_FOREACH(dp, &disklist, d_list) {
47		d = dp->d_devsw->d_name;
48		i = strlen(d);
49		if (bcmp(d, name, i) != 0)
50			continue;
51		u = 0;
52		if (!isdigit(name[i]))
53			continue;
54		while (isdigit(name[i])) {
55			u *= 10;
56			u += name[i++] - '0';
57		}
58		if (u > DKMAXUNIT)
59			continue;
60		p = RAW_PART;
61		s = WHOLE_DISK_SLICE;
62		pdev = makedev(dp->d_devsw->d_maj, dkmakeminor(u, s, p));
63		if (pdev->si_disk == NULL)
64			continue;
65		if (name[i] != '\0') {
66			if (name[i] == 's') {
67				s = 0;
68				i++;
69				if (!isdigit(name[i]))
70					continue;
71				while (isdigit(name[i])) {
72					s *= 10;
73					s += name[i++] - '0';
74				}
75				s += BASE_SLICE - 1;
76			} else {
77				s = COMPATIBILITY_SLICE;
78			}
79			if (name[i] == '\0')
80				;
81			else if (name[i] < 'a' || name[i] > 'h')
82				continue;
83			else
84				p = name[i] - 'a';
85		}
86
87		*dev = make_dev(pdev->si_devsw, dkmakeminor(u, s, p),
88		    UID_ROOT, GID_OPERATOR, 0640, name);
89		dev_depends(pdev, *dev);
90		return;
91	}
92}
93
94static void
95inherit_raw(dev_t pdev, dev_t dev)
96{
97	dev->si_disk = pdev->si_disk;
98	dev->si_drv1 = pdev->si_drv1;
99	dev->si_drv2 = pdev->si_drv2;
100	dev->si_iosize_max = pdev->si_iosize_max;
101	dev->si_bsize_phys = pdev->si_bsize_phys;
102	dev->si_bsize_best = pdev->si_bsize_best;
103}
104
105dev_t
106disk_create(int unit, struct disk *dp, int flags, struct cdevsw *cdevsw, struct cdevsw *proto)
107{
108	static int once;
109	dev_t dev;
110
111	if (!once) {
112		EVENTHANDLER_REGISTER(dev_clone, disk_clone, 0, 1000);
113		once++;
114	}
115
116	bzero(dp, sizeof(*dp));
117
118	if (proto->d_open != diskopen) {
119		*proto = *cdevsw;
120		proto->d_open = diskopen;
121		proto->d_close = diskclose;
122		proto->d_ioctl = diskioctl;
123		proto->d_strategy = diskstrategy;
124		proto->d_psize = diskpsize;
125		cdevsw_add(proto);
126	}
127
128	if (bootverbose)
129		printf("Creating DISK %s%d\n", cdevsw->d_name, unit);
130	dev = make_dev(proto, dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
131	    UID_ROOT, GID_OPERATOR, 0640, "%s%d", cdevsw->d_name, unit);
132
133	dev->si_disk = dp;
134	dp->d_dev = dev;
135	dp->d_dsflags = flags;
136	dp->d_devsw = cdevsw;
137	LIST_INSERT_HEAD(&disklist, dp, d_list);
138
139	return (dev);
140}
141
142int
143disk_dumpcheck(dev_t dev, u_int *count, u_int *blkno, u_int *secsize)
144{
145	struct disk *dp;
146	struct disklabel *dl;
147	u_int boff;
148
149	dp = dev->si_disk;
150	if (!dp)
151		return (ENXIO);
152	if (!dp->d_slice)
153		return (ENXIO);
154	dl = dsgetlabel(dev, dp->d_slice);
155	if (!dl)
156		return (ENXIO);
157	*count = (u_long)Maxmem * PAGE_SIZE / dl->d_secsize;
158	if (dumplo < 0 ||
159	    (dumplo + *count > dl->d_partitions[dkpart(dev)].p_size))
160		return (EINVAL);
161	boff = dl->d_partitions[dkpart(dev)].p_offset +
162	    dp->d_slice->dss_slices[dkslice(dev)].ds_offset;
163	*blkno = boff + dumplo;
164	*secsize = dl->d_secsize;
165	return (0);
166
167}
168
169void
170disk_invalidate (struct disk *disk)
171{
172	if (disk->d_slice)
173		dsgone(&disk->d_slice);
174}
175
176void
177disk_destroy(dev_t dev)
178{
179	LIST_REMOVE(dev->si_disk, d_list);
180	bzero(dev->si_disk, sizeof(*dev->si_disk));
181    	dev->si_disk = NULL;
182	destroy_dev(dev);
183	return;
184}
185
186struct disk *
187disk_enumerate(struct disk *disk)
188{
189	if (!disk)
190		return (LIST_FIRST(&disklist));
191	else
192		return (LIST_NEXT(disk, d_list));
193}
194
195static int
196sysctl_disks(SYSCTL_HANDLER_ARGS)
197{
198	struct disk *disk;
199	int error, first;
200
201	disk = NULL;
202	first = 1;
203
204	while ((disk = disk_enumerate(disk))) {
205		if (!first) {
206			error = SYSCTL_OUT(req, " ", 1);
207			if (error)
208				return error;
209		} else {
210			first = 0;
211		}
212		error = SYSCTL_OUT(req, disk->d_dev->si_name, strlen(disk->d_dev->si_name));
213		if (error)
214			return error;
215	}
216	error = SYSCTL_OUT(req, "", 1);
217	return error;
218}
219
220SYSCTL_PROC(_kern, OID_AUTO, disks, CTLTYPE_STRING | CTLFLAG_RD, 0, NULL,
221    sysctl_disks, "A", "names of available disks");
222
223/*
224 * The cdevsw functions
225 */
226
227static int
228diskopen(dev_t dev, int oflags, int devtype, struct proc *p)
229{
230	dev_t pdev;
231	struct disk *dp;
232	int error;
233
234	error = 0;
235	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
236
237	dp = pdev->si_disk;
238	if (!dp)
239		return (ENXIO);
240
241	while (dp->d_flags & DISKFLAG_LOCK) {
242		dp->d_flags |= DISKFLAG_WANTED;
243		error = tsleep(dp, PRIBIO | PCATCH, "diskopen", hz);
244		if (error)
245			return (error);
246	}
247	dp->d_flags |= DISKFLAG_LOCK;
248
249	if (!dsisopen(dp->d_slice)) {
250		if (!pdev->si_iosize_max)
251			pdev->si_iosize_max = dev->si_iosize_max;
252		error = dp->d_devsw->d_open(pdev, oflags, devtype, p);
253	}
254
255	/* Inherit properties from the whole/raw dev_t */
256	inherit_raw(pdev, dev);
257
258	if (error)
259		goto out;
260
261	error = dsopen(dev, devtype, dp->d_dsflags, &dp->d_slice, &dp->d_label);
262
263	if (!dsisopen(dp->d_slice))
264		dp->d_devsw->d_close(pdev, oflags, devtype, p);
265out:
266	dp->d_flags &= ~DISKFLAG_LOCK;
267	if (dp->d_flags & DISKFLAG_WANTED) {
268		dp->d_flags &= ~DISKFLAG_WANTED;
269		wakeup(dp);
270	}
271
272	return(error);
273}
274
275static int
276diskclose(dev_t dev, int fflag, int devtype, struct proc *p)
277{
278	struct disk *dp;
279	int error;
280	dev_t pdev;
281
282	error = 0;
283	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
284	dp = pdev->si_disk;
285	if (!dp)
286		return (ENXIO);
287	dsclose(dev, devtype, dp->d_slice);
288	if (!dsisopen(dp->d_slice))
289		error = dp->d_devsw->d_close(dp->d_dev, fflag, devtype, p);
290	return (error);
291}
292
293static void
294diskstrategy(struct bio *bp)
295{
296	dev_t pdev;
297	struct disk *dp;
298
299	pdev = dkmodpart(dkmodslice(bp->bio_dev, WHOLE_DISK_SLICE), RAW_PART);
300	dp = pdev->si_disk;
301	bp->bio_resid = bp->bio_bcount;
302	if (dp != bp->bio_dev->si_disk)
303		inherit_raw(pdev, bp->bio_dev);
304
305	if (!dp) {
306		biofinish(bp, NULL, ENXIO);
307		return;
308	}
309
310	if (dscheck(bp, dp->d_slice) <= 0) {
311		biodone(bp);
312		return;
313	}
314
315	if (bp->bio_bcount == 0) {
316		biodone(bp);
317		return;
318	}
319
320	KASSERT(dp->d_devsw != NULL, ("NULL devsw"));
321	KASSERT(dp->d_devsw->d_strategy != NULL, ("NULL d_strategy"));
322	dp->d_devsw->d_strategy(bp);
323	return;
324
325}
326
327static int
328diskioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct proc *p)
329{
330	struct disk *dp;
331	int error;
332	dev_t pdev;
333
334	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
335	dp = pdev->si_disk;
336	if (!dp)
337		return (ENXIO);
338	error = dsioctl(dev, cmd, data, fflag, &dp->d_slice);
339	if (error == ENOIOCTL)
340		error = dp->d_devsw->d_ioctl(dev, cmd, data, fflag, p);
341	return (error);
342}
343
344static int
345diskpsize(dev_t dev)
346{
347	struct disk *dp;
348	dev_t pdev;
349
350	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
351	dp = pdev->si_disk;
352	if (!dp)
353		return (-1);
354	if (dp != dev->si_disk) {
355		dev->si_drv1 = pdev->si_drv1;
356		dev->si_drv2 = pdev->si_drv2;
357		/* XXX: don't set bp->b_dev->si_disk (?) */
358	}
359	return (dssize(dev, &dp->d_slice));
360}
361
362SYSCTL_DECL(_debug_sizeof);
363
364SYSCTL_INT(_debug_sizeof, OID_AUTO, disklabel, CTLFLAG_RD,
365    0, sizeof(struct disklabel), "sizeof(struct disklabel)");
366
367SYSCTL_INT(_debug_sizeof, OID_AUTO, diskslices, CTLFLAG_RD,
368    0, sizeof(struct diskslices), "sizeof(struct diskslices)");
369
370SYSCTL_INT(_debug_sizeof, OID_AUTO, disk, CTLFLAG_RD,
371    0, sizeof(struct disk), "sizeof(struct disk)");
372