g_label.c revision 148979 
1/*-
2 * Copyright (c) 2004-2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/geom/label/g_label.c 148979 2005-08-12 00:34:45Z pjd $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/module.h>
34#include <sys/lock.h>
35#include <sys/mutex.h>
36#include <sys/bio.h>
37#include <sys/sysctl.h>
38#include <sys/malloc.h>
39#include <geom/geom.h>
40#include <geom/geom_slice.h>
41#include <geom/label/g_label.h>
42
43
44SYSCTL_DECL(_kern_geom);
45SYSCTL_NODE(_kern_geom, OID_AUTO, label, CTLFLAG_RW, 0, "GEOM_LABEL stuff");
46u_int g_label_debug = 0;
47TUNABLE_INT("kern.geom.label.debug", &g_label_debug);
48SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RW, &g_label_debug, 0,
49    "Debug level");
50
51static int g_label_destroy_geom(struct gctl_req *req, struct g_class *mp,
52    struct g_geom *gp);
53static int g_label_destroy(struct g_geom *gp, boolean_t force);
54static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
55    int flags __unused);
56static void g_label_config(struct gctl_req *req, struct g_class *mp,
57    const char *verb);
58
59struct g_class g_label_class = {
60	.name = G_LABEL_CLASS_NAME,
61	.version = G_VERSION,
62	.ctlreq = g_label_config,
63	.taste = g_label_taste,
64	.destroy_geom = g_label_destroy_geom
65};
66
67/*
68 * To add a new file system where you want to look for volume labels,
69 * you have to:
70 * 1. Add a file g_label_<file system>.c which implements labels recognition.
71 * 2. Add an 'extern const struct g_label_desc g_label_<file system>;' into
72 *    g_label.h file.
73 * 3. Add an element to the table below '&g_label_<file system>,'.
74 * 4. Add your file to sys/conf/files.
75 * 5. Add your file to sys/modules/geom/geom_label/Makefile.
76 * 6. Add your file system to manual page sbin/geom/class/label/glabel.8.
77 */
78const struct g_label_desc *g_labels[] = {
79	&g_label_ufs,
80	&g_label_iso9660,
81	&g_label_msdosfs,
82	&g_label_ext2fs,
83	&g_label_reiserfs,
84	NULL
85};
86
87
88static int
89g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
90    struct g_geom *gp __unused)
91{
92
93	/*
94	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
95	 * XXX: broken, so we deny unloading when we have geoms.
96	 */
97	return (EOPNOTSUPP);
98}
99
100static void
101g_label_orphan(struct g_consumer *cp __unused)
102{
103
104	KASSERT(1 == 0, ("%s called?", __func__));
105}
106
107static void
108g_label_start(struct bio *bp __unused)
109{
110
111	KASSERT(1 == 0, ("%s called?", __func__));
112}
113
114static int
115g_label_access(struct g_provider *pp __unused, int dr __unused, int dw __unused,
116    int de __unused)
117{
118
119	KASSERT(1 == 0, ("%s called", __func__));
120	return (EOPNOTSUPP);
121}
122
123static struct g_geom *
124g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
125    const char *label, const char *dir, off_t mediasize)
126{
127	struct g_geom *gp;
128	struct g_provider *pp2;
129	struct g_consumer *cp;
130	char name[64];
131
132	g_topology_assert();
133
134	gp = NULL;
135	cp = NULL;
136	snprintf(name, sizeof(name), "%s/%s", dir, label);
137	LIST_FOREACH(gp, &mp->geom, geom) {
138		pp2 = LIST_FIRST(&gp->provider);
139		if (pp2 == NULL)
140			continue;
141		if (strcmp(pp2->name, name) == 0) {
142			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
143			    label, name, pp->name);
144			if (req != NULL) {
145				gctl_error(req, "Provider %s already exists.",
146				    name);
147			}
148			return (NULL);
149		}
150	}
151	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
152	if (gp == NULL) {
153		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
154		if (req != NULL)
155			gctl_error(req, "Cannot create slice %s.", label);
156		return (NULL);
157	}
158	g_access(cp, -1, 0, 0);
159	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
160	    pp->sectorsize, name);
161	G_LABEL_DEBUG(0, "Label for provider %s is %s.", pp->name, name);
162	return (gp);
163}
164
165static int
166g_label_destroy(struct g_geom *gp, boolean_t force)
167{
168	struct g_provider *pp;
169
170	g_topology_assert();
171	pp = LIST_FIRST(&gp->provider);
172	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
173		if (force) {
174			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
175			    "can't be definitely removed.", pp->name);
176		} else {
177			G_LABEL_DEBUG(1,
178			    "Provider %s is still open (r%dw%de%d).", pp->name,
179			    pp->acr, pp->acw, pp->ace);
180			return (EBUSY);
181		}
182	} else {
183		G_LABEL_DEBUG(0, "Label %s removed.",
184		    LIST_FIRST(&gp->provider)->name);
185	}
186	g_slice_spoiled(LIST_FIRST(&gp->consumer));
187	return (0);
188}
189
190static int
191g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
192{
193	struct g_provider *pp;
194	u_char *buf;
195	int error;
196
197	g_topology_assert();
198
199	pp = cp->provider;
200	g_topology_unlock();
201	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
202	    &error);
203	g_topology_lock();
204	if (buf == NULL)
205		return (error);
206	/* Decode metadata. */
207	label_metadata_decode(buf, md);
208	g_free(buf);
209
210	return (0);
211}
212
213static struct g_geom *
214g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
215{
216	struct g_label_metadata md;
217	struct g_consumer *cp;
218	struct g_geom *gp;
219	int i;
220
221	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
222	g_topology_assert();
223
224	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
225
226	if (strcmp(pp->geom->class->name, mp->name) == 0)
227		return (NULL);
228
229	gp = g_new_geomf(mp, "label:taste");
230	gp->start = g_label_start;
231	gp->access = g_label_access;
232	gp->orphan = g_label_orphan;
233	cp = g_new_consumer(gp);
234	g_attach(cp, pp);
235	if (g_access(cp, 1, 0, 0) != 0)
236		goto end;
237	do {
238		if (g_label_read_metadata(cp, &md) != 0)
239			break;
240		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
241			break;
242		if (md.md_version > G_LABEL_VERSION) {
243			printf("geom_label.ko module is too old to handle %s.\n",
244			    pp->name);
245			break;
246		}
247
248		/*
249		 * Backward compatibility:
250		 */
251		/*
252		 * There was no md_provsize field in earlier versions of
253		 * metadata.
254		 */
255		if (md.md_version < 2)
256			md.md_provsize = pp->mediasize;
257
258		if (md.md_provsize != pp->mediasize)
259			break;
260
261		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
262		    pp->mediasize - pp->sectorsize);
263	} while (0);
264	for (i = 0; g_labels[i] != NULL; i++) {
265		char label[64];
266		char *p;
267
268		g_topology_unlock();
269		g_labels[i]->ld_taste(cp, label, sizeof(label));
270		g_topology_lock();
271		if (label[0] == '\0')
272			continue;
273		/*
274		 * Don't allow / in labels.
275		 */
276		for (p = label; *p != '\0'; p++) {
277			if (*p == '/')
278				*p = '_';
279		}
280		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
281		    pp->mediasize);
282	}
283	g_access(cp, -1, 0, 0);
284end:
285	g_detach(cp);
286	g_destroy_consumer(cp);
287	g_destroy_geom(gp);
288	return (NULL);
289}
290
291static void
292g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
293{
294	struct g_provider *pp;
295	const char *name;
296	int *nargs;
297
298	g_topology_assert();
299
300	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
301	if (nargs == NULL) {
302		gctl_error(req, "No '%s' argument", "nargs");
303		return;
304	}
305	if (*nargs != 2) {
306		gctl_error(req, "Invalid number of argument.");
307		return;
308	}
309	/*
310	 * arg1 is the name of provider.
311	 */
312	name = gctl_get_asciiparam(req, "arg1");
313	if (name == NULL) {
314		gctl_error(req, "No 'arg%d' argument", 1);
315		return;
316	}
317	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
318		name += strlen("/dev/");
319	pp = g_provider_by_name(name);
320	if (pp == NULL) {
321		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
322		gctl_error(req, "Provider %s is invalid.", name);
323		return;
324	}
325	/*
326	 * arg0 is the label.
327	 */
328	name = gctl_get_asciiparam(req, "arg0");
329	if (name == NULL) {
330		gctl_error(req, "No 'arg%d' argument", 0);
331		return;
332	}
333	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
334}
335
336static const char *
337g_label_skip_dir(const char *name)
338{
339	char path[64];
340	u_int i;
341
342	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
343		name += strlen("/dev/");
344	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
345		name += strlen(G_LABEL_DIR "/");
346	for (i = 0; g_labels[i] != NULL; i++) {
347		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
348		if (strncmp(name, path, strlen(path)) == 0) {
349			name += strlen(path);
350			break;
351		}
352	}
353	return (name);
354}
355
356static struct g_geom *
357g_label_find_geom(struct g_class *mp, const char *name)
358{
359	struct g_geom *gp;
360	struct g_provider *pp;
361	const char *pname;
362
363	name = g_label_skip_dir(name);
364	LIST_FOREACH(gp, &mp->geom, geom) {
365		pp = LIST_FIRST(&gp->provider);
366		pname = g_label_skip_dir(pp->name);
367		if (strcmp(pname, name) == 0)
368			return (gp);
369	}
370	return (NULL);
371}
372
373static void
374g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
375{
376	int *nargs, *force, error, i;
377	struct g_geom *gp;
378	const char *name;
379	char param[16];
380
381	g_topology_assert();
382
383	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
384	if (nargs == NULL) {
385		gctl_error(req, "No '%s' argument", "nargs");
386		return;
387	}
388	if (*nargs <= 0) {
389		gctl_error(req, "Missing device(s).");
390		return;
391	}
392	force = gctl_get_paraml(req, "force", sizeof(*force));
393	if (force == NULL) {
394		gctl_error(req, "No 'force' argument");
395		return;
396	}
397
398	for (i = 0; i < *nargs; i++) {
399		snprintf(param, sizeof(param), "arg%d", i);
400		name = gctl_get_asciiparam(req, param);
401		if (name == NULL) {
402			gctl_error(req, "No 'arg%d' argument", i);
403			return;
404		}
405		gp = g_label_find_geom(mp, name);
406		if (gp == NULL) {
407			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
408			gctl_error(req, "Label %s is invalid.", name);
409			return;
410		}
411		error = g_label_destroy(gp, *force);
412		if (error != 0) {
413			gctl_error(req, "Cannot destroy label %s (error=%d).",
414			    LIST_FIRST(&gp->provider)->name, error);
415			return;
416		}
417	}
418}
419
420static void
421g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
422{
423	uint32_t *version;
424
425	g_topology_assert();
426
427	version = gctl_get_paraml(req, "version", sizeof(*version));
428	if (version == NULL) {
429		gctl_error(req, "No '%s' argument.", "version");
430		return;
431	}
432	if (*version != G_LABEL_VERSION) {
433		gctl_error(req, "Userland and kernel parts are out of sync.");
434		return;
435	}
436
437	if (strcmp(verb, "create") == 0) {
438		g_label_ctl_create(req, mp);
439		return;
440	} else if (strcmp(verb, "destroy") == 0 ||
441	    strcmp(verb, "stop") == 0) {
442		g_label_ctl_destroy(req, mp);
443		return;
444	}
445
446	gctl_error(req, "Unknown verb.");
447}
448
449DECLARE_GEOM_CLASS(g_label_class, g_label);
450