subr_disk.c revision 77215 
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 77215 2001-05-26 08:27:58Z 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, cdev;
110	int i;
111	char buf[20];
112
113	if (!once) {
114		EVENTHANDLER_REGISTER(dev_clone, disk_clone, 0, 1000);
115		once++;
116	}
117
118	bzero(dp, sizeof(*dp));
119
120	if (proto->d_open != diskopen) {
121		*proto = *cdevsw;
122		proto->d_open = diskopen;
123		proto->d_close = diskclose;
124		proto->d_ioctl = diskioctl;
125		proto->d_strategy = diskstrategy;
126		proto->d_psize = diskpsize;
127	}
128
129	if (bootverbose)
130		printf("Creating DISK %s%d\n", cdevsw->d_name, unit);
131	dev = make_dev(proto, dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
132	    UID_ROOT, GID_OPERATOR, 0640, "%s%d", cdevsw->d_name, unit);
133
134	dev->si_disk = dp;
135	dp->d_dev = dev;
136	dp->d_dsflags = flags;
137	dp->d_devsw = cdevsw;
138	LIST_INSERT_HEAD(&disklist, dp, d_list);
139
140	sprintf(buf, "%sc", dev->si_name);
141	cdev = NODEV;
142	disk_clone(NULL, buf, strlen(buf), &cdev);
143	for (i = 1; i < 5; i++) {
144		sprintf(buf, "%ss%d", dev->si_name, i);
145		cdev = NODEV;
146		disk_clone(NULL, buf, strlen(buf), &cdev);
147	}
148	return (dev);
149}
150
151int
152disk_dumpcheck(dev_t dev, u_int *count, u_int *blkno, u_int *secsize)
153{
154	struct disk *dp;
155	struct disklabel *dl;
156	u_int boff;
157
158	dp = dev->si_disk;
159	if (!dp)
160		return (ENXIO);
161	if (!dp->d_slice)
162		return (ENXIO);
163	dl = dsgetlabel(dev, dp->d_slice);
164	if (!dl)
165		return (ENXIO);
166	*count = (u_long)Maxmem * PAGE_SIZE / dl->d_secsize;
167	if (dumplo < 0 ||
168	    (dumplo + *count > dl->d_partitions[dkpart(dev)].p_size))
169		return (EINVAL);
170	boff = dl->d_partitions[dkpart(dev)].p_offset +
171	    dp->d_slice->dss_slices[dkslice(dev)].ds_offset;
172	*blkno = boff + dumplo;
173	*secsize = dl->d_secsize;
174	return (0);
175
176}
177
178void
179disk_invalidate (struct disk *disk)
180{
181	if (disk->d_slice)
182		dsgone(&disk->d_slice);
183}
184
185void
186disk_destroy(dev_t dev)
187{
188	LIST_REMOVE(dev->si_disk, d_list);
189	bzero(dev->si_disk, sizeof(*dev->si_disk));
190    	dev->si_disk = NULL;
191	destroy_dev(dev);
192	return;
193}
194
195struct disk *
196disk_enumerate(struct disk *disk)
197{
198	if (!disk)
199		return (LIST_FIRST(&disklist));
200	else
201		return (LIST_NEXT(disk, d_list));
202}
203
204static int
205sysctl_disks(SYSCTL_HANDLER_ARGS)
206{
207	struct disk *disk;
208	int error, first;
209
210	disk = NULL;
211	first = 1;
212
213	while ((disk = disk_enumerate(disk))) {
214		if (!first) {
215			error = SYSCTL_OUT(req, " ", 1);
216			if (error)
217				return error;
218		} else {
219			first = 0;
220		}
221		error = SYSCTL_OUT(req, disk->d_dev->si_name, strlen(disk->d_dev->si_name));
222		if (error)
223			return error;
224	}
225	error = SYSCTL_OUT(req, "", 1);
226	return error;
227}
228
229SYSCTL_PROC(_kern, OID_AUTO, disks, CTLTYPE_STRING | CTLFLAG_RD, 0, NULL,
230    sysctl_disks, "A", "names of available disks");
231
232/*
233 * The cdevsw functions
234 */
235
236static int
237diskopen(dev_t dev, int oflags, int devtype, struct proc *p)
238{
239	dev_t pdev;
240	struct disk *dp;
241	int error;
242
243	error = 0;
244	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
245
246	dp = pdev->si_disk;
247	if (!dp)
248		return (ENXIO);
249
250	while (dp->d_flags & DISKFLAG_LOCK) {
251		dp->d_flags |= DISKFLAG_WANTED;
252		error = tsleep(dp, PRIBIO | PCATCH, "diskopen", hz);
253		if (error)
254			return (error);
255	}
256	dp->d_flags |= DISKFLAG_LOCK;
257
258	if (!dsisopen(dp->d_slice)) {
259		if (!pdev->si_iosize_max)
260			pdev->si_iosize_max = dev->si_iosize_max;
261		error = dp->d_devsw->d_open(pdev, oflags, devtype, p);
262	}
263
264	/* Inherit properties from the whole/raw dev_t */
265	inherit_raw(pdev, dev);
266
267	if (error)
268		goto out;
269
270	error = dsopen(dev, devtype, dp->d_dsflags, &dp->d_slice, &dp->d_label);
271
272	if (!dsisopen(dp->d_slice))
273		dp->d_devsw->d_close(pdev, oflags, devtype, p);
274out:
275	dp->d_flags &= ~DISKFLAG_LOCK;
276	if (dp->d_flags & DISKFLAG_WANTED) {
277		dp->d_flags &= ~DISKFLAG_WANTED;
278		wakeup(dp);
279	}
280
281	return(error);
282}
283
284static int
285diskclose(dev_t dev, int fflag, int devtype, struct proc *p)
286{
287	struct disk *dp;
288	int error;
289	dev_t pdev;
290
291	error = 0;
292	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
293	dp = pdev->si_disk;
294	if (!dp)
295		return (ENXIO);
296	dsclose(dev, devtype, dp->d_slice);
297	if (!dsisopen(dp->d_slice))
298		error = dp->d_devsw->d_close(dp->d_dev, fflag, devtype, p);
299	return (error);
300}
301
302static void
303diskstrategy(struct bio *bp)
304{
305	dev_t pdev;
306	struct disk *dp;
307
308	pdev = dkmodpart(dkmodslice(bp->bio_dev, WHOLE_DISK_SLICE), RAW_PART);
309	dp = pdev->si_disk;
310	bp->bio_resid = bp->bio_bcount;
311	if (dp != bp->bio_dev->si_disk)
312		inherit_raw(pdev, bp->bio_dev);
313
314	if (!dp) {
315		biofinish(bp, NULL, ENXIO);
316		return;
317	}
318
319	if (dscheck(bp, dp->d_slice) <= 0) {
320		biodone(bp);
321		return;
322	}
323
324	if (bp->bio_bcount == 0) {
325		biodone(bp);
326		return;
327	}
328
329	KASSERT(dp->d_devsw != NULL, ("NULL devsw"));
330	KASSERT(dp->d_devsw->d_strategy != NULL, ("NULL d_strategy"));
331	dp->d_devsw->d_strategy(bp);
332	return;
333
334}
335
336static int
337diskioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct proc *p)
338{
339	struct disk *dp;
340	int error;
341	dev_t pdev;
342
343	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
344	dp = pdev->si_disk;
345	if (!dp)
346		return (ENXIO);
347	error = dsioctl(dev, cmd, data, fflag, &dp->d_slice);
348	if (error == ENOIOCTL)
349		error = dp->d_devsw->d_ioctl(dev, cmd, data, fflag, p);
350	return (error);
351}
352
353static int
354diskpsize(dev_t dev)
355{
356	struct disk *dp;
357	dev_t pdev;
358
359	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
360	dp = pdev->si_disk;
361	if (!dp)
362		return (-1);
363	if (dp != dev->si_disk) {
364		dev->si_drv1 = pdev->si_drv1;
365		dev->si_drv2 = pdev->si_drv2;
366		/* XXX: don't set bp->b_dev->si_disk (?) */
367	}
368	return (dssize(dev, &dp->d_slice));
369}
370
371SYSCTL_DECL(_debug_sizeof);
372
373SYSCTL_INT(_debug_sizeof, OID_AUTO, disklabel, CTLFLAG_RD,
374    0, sizeof(struct disklabel), "sizeof(struct disklabel)");
375
376SYSCTL_INT(_debug_sizeof, OID_AUTO, diskslices, CTLFLAG_RD,
377    0, sizeof(struct diskslices), "sizeof(struct diskslices)");
378
379SYSCTL_INT(_debug_sizeof, OID_AUTO, disk, CTLFLAG_RD,
380    0, sizeof(struct disk), "sizeof(struct disk)");
381