subr_disk.c revision 76322 
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 76322 2001-05-06 20:00:03Z 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		return;
90	}
91}
92
93static void
94inherit_raw(dev_t pdev, dev_t dev)
95{
96	dev->si_disk = pdev->si_disk;
97	dev->si_drv1 = pdev->si_drv1;
98	dev->si_drv2 = pdev->si_drv2;
99	dev->si_iosize_max = pdev->si_iosize_max;
100	dev->si_bsize_phys = pdev->si_bsize_phys;
101	dev->si_bsize_best = pdev->si_bsize_best;
102}
103
104dev_t
105disk_create(int unit, struct disk *dp, int flags, struct cdevsw *cdevsw, struct cdevsw *proto)
106{
107	static int once;
108	dev_t dev;
109
110	bzero(dp, sizeof(*dp));
111
112	dev = makedev(cdevsw->d_maj, 0);
113	if (!devsw(dev)) {
114		*proto = *cdevsw;
115		proto->d_open = diskopen;
116		proto->d_close = diskclose;
117		proto->d_ioctl = diskioctl;
118		proto->d_strategy = diskstrategy;
119		proto->d_psize = diskpsize;
120		cdevsw_add(proto);
121	}
122
123	if (bootverbose)
124		printf("Creating DISK %s%d\n", cdevsw->d_name, unit);
125	dev = make_dev(proto, dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
126	    UID_ROOT, GID_OPERATOR, 0640, "%s%d", cdevsw->d_name, unit);
127
128	dev->si_disk = dp;
129	dp->d_dev = dev;
130	dp->d_dsflags = flags;
131	dp->d_devsw = cdevsw;
132	LIST_INSERT_HEAD(&disklist, dp, d_list);
133	if (!once) {
134		EVENTHANDLER_REGISTER(dev_clone, disk_clone, 0, 1000);
135		once++;
136	}
137	return (dev);
138}
139
140int
141disk_dumpcheck(dev_t dev, u_int *count, u_int *blkno, u_int *secsize)
142{
143	struct disk *dp;
144	struct disklabel *dl;
145	u_int boff;
146
147	dp = dev->si_disk;
148	if (!dp)
149		return (ENXIO);
150	if (!dp->d_slice)
151		return (ENXIO);
152	dl = dsgetlabel(dev, dp->d_slice);
153	if (!dl)
154		return (ENXIO);
155	*count = (u_long)Maxmem * PAGE_SIZE / dl->d_secsize;
156	if (dumplo < 0 ||
157	    (dumplo + *count > dl->d_partitions[dkpart(dev)].p_size))
158		return (EINVAL);
159	boff = dl->d_partitions[dkpart(dev)].p_offset +
160	    dp->d_slice->dss_slices[dkslice(dev)].ds_offset;
161	*blkno = boff + dumplo;
162	*secsize = dl->d_secsize;
163	return (0);
164
165}
166
167void
168disk_invalidate (struct disk *disk)
169{
170	if (disk->d_slice)
171		dsgone(&disk->d_slice);
172}
173
174void
175disk_destroy(dev_t dev)
176{
177	LIST_REMOVE(dev->si_disk, d_list);
178	bzero(dev->si_disk, sizeof(*dev->si_disk));
179    	dev->si_disk = NULL;
180	destroy_dev(dev);
181	return;
182}
183
184struct disk *
185disk_enumerate(struct disk *disk)
186{
187	if (!disk)
188		return (LIST_FIRST(&disklist));
189	else
190		return (LIST_NEXT(disk, d_list));
191}
192
193static int
194sysctl_disks(SYSCTL_HANDLER_ARGS)
195{
196	struct disk *disk;
197	int error, first;
198
199	disk = NULL;
200	first = 1;
201
202	while ((disk = disk_enumerate(disk))) {
203		if (!first) {
204			error = SYSCTL_OUT(req, " ", 1);
205			if (error)
206				return error;
207		} else {
208			first = 0;
209		}
210		error = SYSCTL_OUT(req, disk->d_dev->si_name, strlen(disk->d_dev->si_name));
211		if (error)
212			return error;
213	}
214	error = SYSCTL_OUT(req, "", 1);
215	return error;
216}
217
218SYSCTL_PROC(_kern, OID_AUTO, disks, CTLTYPE_STRING | CTLFLAG_RD, 0, NULL,
219    sysctl_disks, "A", "names of available disks");
220
221/*
222 * The cdevsw functions
223 */
224
225static int
226diskopen(dev_t dev, int oflags, int devtype, struct proc *p)
227{
228	dev_t pdev;
229	struct disk *dp;
230	int error;
231
232	error = 0;
233	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
234
235	dp = pdev->si_disk;
236	if (!dp)
237		return (ENXIO);
238
239	while (dp->d_flags & DISKFLAG_LOCK) {
240		dp->d_flags |= DISKFLAG_WANTED;
241		error = tsleep(dp, PRIBIO | PCATCH, "diskopen", hz);
242		if (error)
243			return (error);
244	}
245	dp->d_flags |= DISKFLAG_LOCK;
246
247	if (!dsisopen(dp->d_slice)) {
248		if (!pdev->si_iosize_max)
249			pdev->si_iosize_max = dev->si_iosize_max;
250		error = dp->d_devsw->d_open(pdev, oflags, devtype, p);
251	}
252
253	/* Inherit properties from the whole/raw dev_t */
254	inherit_raw(pdev, dev);
255
256	if (error)
257		goto out;
258
259	error = dsopen(dev, devtype, dp->d_dsflags, &dp->d_slice, &dp->d_label);
260
261	if (!dsisopen(dp->d_slice))
262		dp->d_devsw->d_close(pdev, oflags, devtype, p);
263out:
264	dp->d_flags &= ~DISKFLAG_LOCK;
265	if (dp->d_flags & DISKFLAG_WANTED) {
266		dp->d_flags &= ~DISKFLAG_WANTED;
267		wakeup(dp);
268	}
269
270	return(error);
271}
272
273static int
274diskclose(dev_t dev, int fflag, int devtype, struct proc *p)
275{
276	struct disk *dp;
277	int error;
278	dev_t pdev;
279
280	error = 0;
281	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
282	dp = pdev->si_disk;
283	if (!dp)
284		return (ENXIO);
285	dsclose(dev, devtype, dp->d_slice);
286	if (!dsisopen(dp->d_slice))
287		error = dp->d_devsw->d_close(dp->d_dev, fflag, devtype, p);
288	return (error);
289}
290
291static void
292diskstrategy(struct bio *bp)
293{
294	dev_t pdev;
295	struct disk *dp;
296
297	pdev = dkmodpart(dkmodslice(bp->bio_dev, WHOLE_DISK_SLICE), RAW_PART);
298	dp = pdev->si_disk;
299	if (dp != bp->bio_dev->si_disk)
300		inherit_raw(pdev, bp->bio_dev);
301
302	if (!dp) {
303		biofinish(bp, NULL, ENXIO);
304		return;
305	}
306
307	if (dscheck(bp, dp->d_slice) <= 0) {
308		biodone(bp);
309		return;
310	}
311
312	KASSERT(dp->d_devsw != NULL, ("NULL devsw"));
313	KASSERT(dp->d_devsw->d_strategy != NULL, ("NULL d_strategy"));
314	dp->d_devsw->d_strategy(bp);
315	return;
316
317}
318
319static int
320diskioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct proc *p)
321{
322	struct disk *dp;
323	int error;
324	dev_t pdev;
325
326	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
327	dp = pdev->si_disk;
328	if (!dp)
329		return (ENXIO);
330	error = dsioctl(dev, cmd, data, fflag, &dp->d_slice);
331	if (error == ENOIOCTL)
332		error = dp->d_devsw->d_ioctl(dev, cmd, data, fflag, p);
333	return (error);
334}
335
336static int
337diskpsize(dev_t dev)
338{
339	struct disk *dp;
340	dev_t pdev;
341
342	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
343	dp = pdev->si_disk;
344	if (!dp)
345		return (-1);
346	if (dp != dev->si_disk) {
347		dev->si_drv1 = pdev->si_drv1;
348		dev->si_drv2 = pdev->si_drv2;
349		/* XXX: don't set bp->b_dev->si_disk (?) */
350	}
351	return (dssize(dev, &dp->d_slice));
352}
353
354SYSCTL_DECL(_debug_sizeof);
355
356SYSCTL_INT(_debug_sizeof, OID_AUTO, disklabel, CTLFLAG_RD,
357    0, sizeof(struct disklabel), "sizeof(struct disklabel)");
358
359SYSCTL_INT(_debug_sizeof, OID_AUTO, diskslices, CTLFLAG_RD,
360    0, sizeof(struct diskslices), "sizeof(struct diskslices)");
361
362SYSCTL_INT(_debug_sizeof, OID_AUTO, disk, CTLFLAG_RD,
363    0, sizeof(struct disk), "sizeof(struct disk)");
364