xref: /freebsd/sys/geom/label/g_label.c (revision ebccf1e3a6b11b97cbf5f813dd76636e892a9035)
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("$FreeBSD$");
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 
44 SYSCTL_DECL(_kern_geom);
45 SYSCTL_NODE(_kern_geom, OID_AUTO, label, CTLFLAG_RW, 0, "GEOM_LABEL stuff");
46 u_int g_label_debug = 0;
47 TUNABLE_INT("kern.geom.label.debug", &g_label_debug);
48 SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RW, &g_label_debug, 0,
49     "Debug level");
50 
51 static int g_label_destroy_geom(struct gctl_req *req, struct g_class *mp,
52     struct g_geom *gp);
53 static int g_label_destroy(struct g_geom *gp, boolean_t force);
54 static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
55     int flags __unused);
56 static void g_label_config(struct gctl_req *req, struct g_class *mp,
57     const char *verb);
58 
59 struct 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 which implements looking for volume labels.
71  * 2. Add an 'extern const struct g_label_desc g_label_<your file system>;'.
72  * 3. Add an element to the table below '&g_label_<your_file_system>,'.
73  */
74 const struct g_label_desc *g_labels[] = {
75 	&g_label_ufs,
76 	&g_label_iso9660,
77 	&g_label_msdosfs,
78 	NULL
79 };
80 
81 
82 static int
83 g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
84     struct g_geom *gp __unused)
85 {
86 
87 	/*
88 	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
89 	 * XXX: broken, so we deny unloading when we have geoms.
90 	 */
91 	return (EOPNOTSUPP);
92 }
93 
94 static void
95 g_label_orphan(struct g_consumer *cp __unused)
96 {
97 
98 	KASSERT(1 == 0, ("%s called?", __func__));
99 }
100 
101 static void
102 g_label_start(struct bio *bp __unused)
103 {
104 
105 	KASSERT(1 == 0, ("%s called?", __func__));
106 }
107 
108 static int
109 g_label_access(struct g_provider *pp __unused, int dr __unused, int dw __unused,
110     int de __unused)
111 {
112 
113 	KASSERT(1 == 0, ("%s called", __func__));
114 	return (EOPNOTSUPP);
115 }
116 
117 static struct g_geom *
118 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
119     const char *label, const char *dir, off_t mediasize)
120 {
121 	struct g_geom *gp;
122 	struct g_provider *pp2;
123 	struct g_consumer *cp;
124 	char name[64];
125 
126 	g_topology_assert();
127 
128 	gp = NULL;
129 	cp = NULL;
130 	snprintf(name, sizeof(name), "%s/%s", dir, label);
131 	LIST_FOREACH(gp, &mp->geom, geom) {
132 		pp2 = LIST_FIRST(&gp->provider);
133 		if (pp2 == NULL)
134 			continue;
135 		if (strcmp(pp2->name, name) == 0) {
136 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
137 			    label, name, pp->name);
138 			if (req != NULL) {
139 				gctl_error(req, "Provider %s already exists.",
140 				    name);
141 			}
142 			return (NULL);
143 		}
144 	}
145 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
146 	if (gp == NULL) {
147 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
148 		if (req != NULL)
149 			gctl_error(req, "Cannot create slice %s.", label);
150 		return (NULL);
151 	}
152 	g_access(cp, -1, 0, 0);
153 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
154 	    pp->sectorsize, name);
155 	G_LABEL_DEBUG(0, "Label for provider %s is %s.", pp->name, name);
156 	return (gp);
157 }
158 
159 static int
160 g_label_destroy(struct g_geom *gp, boolean_t force)
161 {
162 	struct g_provider *pp;
163 
164 	g_topology_assert();
165 	pp = LIST_FIRST(&gp->provider);
166 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
167 		if (force) {
168 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
169 			    "can't be definitely removed.", pp->name);
170 		} else {
171 			G_LABEL_DEBUG(1,
172 			    "Provider %s is still open (r%dw%de%d).", pp->name,
173 			    pp->acr, pp->acw, pp->ace);
174 			return (EBUSY);
175 		}
176 	} else {
177 		G_LABEL_DEBUG(0, "Label %s removed.",
178 		    LIST_FIRST(&gp->provider)->name);
179 	}
180 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
181 	return (0);
182 }
183 
184 static int
185 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
186 {
187 	struct g_provider *pp;
188 	u_char *buf;
189 	int error;
190 
191 	g_topology_assert();
192 
193 	pp = cp->provider;
194 	g_topology_unlock();
195 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
196 	    &error);
197 	g_topology_lock();
198 	if (buf == NULL)
199 		return (error);
200 	/* Decode metadata. */
201 	label_metadata_decode(buf, md);
202 	g_free(buf);
203 
204 	return (0);
205 }
206 
207 static struct g_geom *
208 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
209 {
210 	struct g_label_metadata md;
211 	struct g_consumer *cp;
212 	struct g_geom *gp;
213 	int i;
214 
215 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
216 	g_topology_assert();
217 
218 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
219 
220 	if (strcmp(pp->geom->class->name, mp->name) == 0)
221 		return (NULL);
222 
223 	gp = g_new_geomf(mp, "label:taste");
224 	gp->start = g_label_start;
225 	gp->access = g_label_access;
226 	gp->orphan = g_label_orphan;
227 	cp = g_new_consumer(gp);
228 	g_attach(cp, pp);
229 	if (g_access(cp, 1, 0, 0) != 0)
230 		goto end;
231 	do {
232 		if (g_label_read_metadata(cp, &md) != 0)
233 			break;
234 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
235 			break;
236 		if (md.md_version > G_LABEL_VERSION) {
237 			printf("geom_label.ko module is too old to handle %s.\n",
238 			    pp->name);
239 			break;
240 		}
241 
242 		/*
243 		 * Backward compatibility:
244 		 */
245 		/*
246 		 * There was no md_provsize field in earlier versions of
247 		 * metadata.
248 		 */
249 		if (md.md_version < 2)
250 			md.md_provsize = pp->mediasize;
251 
252 		if (md.md_provsize != pp->mediasize)
253 			break;
254 
255 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
256 		    pp->mediasize - pp->sectorsize);
257 	} while (0);
258 	for (i = 0; g_labels[i] != NULL; i++) {
259 		char label[64];
260 
261 		g_topology_unlock();
262 		g_labels[i]->ld_taste(cp, label, sizeof(label));
263 		g_topology_lock();
264 		if (label[0] == '\0')
265 			continue;
266 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
267 		    pp->mediasize);
268 	}
269 	g_access(cp, -1, 0, 0);
270 end:
271 	g_detach(cp);
272 	g_destroy_consumer(cp);
273 	g_destroy_geom(gp);
274 	return (NULL);
275 }
276 
277 static void
278 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
279 {
280 	struct g_provider *pp;
281 	const char *name;
282 	int *nargs;
283 
284 	g_topology_assert();
285 
286 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
287 	if (nargs == NULL) {
288 		gctl_error(req, "No '%s' argument", "nargs");
289 		return;
290 	}
291 	if (*nargs != 2) {
292 		gctl_error(req, "Invalid number of argument.");
293 		return;
294 	}
295 	/*
296 	 * arg1 is the name of provider.
297 	 */
298 	name = gctl_get_asciiparam(req, "arg1");
299 	if (name == NULL) {
300 		gctl_error(req, "No 'arg%d' argument", 1);
301 		return;
302 	}
303 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
304 		name += strlen("/dev/");
305 	pp = g_provider_by_name(name);
306 	if (pp == NULL) {
307 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
308 		gctl_error(req, "Provider %s is invalid.", name);
309 		return;
310 	}
311 	/*
312 	 * arg0 is the label.
313 	 */
314 	name = gctl_get_asciiparam(req, "arg0");
315 	if (name == NULL) {
316 		gctl_error(req, "No 'arg%d' argument", 0);
317 		return;
318 	}
319 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
320 }
321 
322 static const char *
323 g_label_skip_dir(const char *name)
324 {
325 	char path[64];
326 	u_int i;
327 
328 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
329 		name += strlen("/dev/");
330 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
331 		name += strlen(G_LABEL_DIR "/");
332 	for (i = 0; g_labels[i] != NULL; i++) {
333 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
334 		if (strncmp(name, path, strlen(path)) == 0) {
335 			name += strlen(path);
336 			break;
337 		}
338 	}
339 	return (name);
340 }
341 
342 static struct g_geom *
343 g_label_find_geom(struct g_class *mp, const char *name)
344 {
345 	struct g_geom *gp;
346 	struct g_provider *pp;
347 	const char *pname;
348 
349 	name = g_label_skip_dir(name);
350 	LIST_FOREACH(gp, &mp->geom, geom) {
351 		pp = LIST_FIRST(&gp->provider);
352 		pname = g_label_skip_dir(pp->name);
353 		if (strcmp(pname, name) == 0)
354 			return (gp);
355 	}
356 	return (NULL);
357 }
358 
359 static void
360 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
361 {
362 	int *nargs, *force, error, i;
363 	struct g_geom *gp;
364 	const char *name;
365 	char param[16];
366 
367 	g_topology_assert();
368 
369 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
370 	if (nargs == NULL) {
371 		gctl_error(req, "No '%s' argument", "nargs");
372 		return;
373 	}
374 	if (*nargs <= 0) {
375 		gctl_error(req, "Missing device(s).");
376 		return;
377 	}
378 	force = gctl_get_paraml(req, "force", sizeof(*force));
379 	if (force == NULL) {
380 		gctl_error(req, "No 'force' argument");
381 		return;
382 	}
383 
384 	for (i = 0; i < *nargs; i++) {
385 		snprintf(param, sizeof(param), "arg%d", i);
386 		name = gctl_get_asciiparam(req, param);
387 		if (name == NULL) {
388 			gctl_error(req, "No 'arg%d' argument", i);
389 			return;
390 		}
391 		gp = g_label_find_geom(mp, name);
392 		if (gp == NULL) {
393 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
394 			gctl_error(req, "Label %s is invalid.", name);
395 			return;
396 		}
397 		error = g_label_destroy(gp, *force);
398 		if (error != 0) {
399 			gctl_error(req, "Cannot destroy label %s (error=%d).",
400 			    LIST_FIRST(&gp->provider)->name, error);
401 			return;
402 		}
403 	}
404 }
405 
406 static void
407 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
408 {
409 	uint32_t *version;
410 
411 	g_topology_assert();
412 
413 	version = gctl_get_paraml(req, "version", sizeof(*version));
414 	if (version == NULL) {
415 		gctl_error(req, "No '%s' argument.", "version");
416 		return;
417 	}
418 	if (*version != G_LABEL_VERSION) {
419 		gctl_error(req, "Userland and kernel parts are out of sync.");
420 		return;
421 	}
422 
423 	if (strcmp(verb, "create") == 0) {
424 		g_label_ctl_create(req, mp);
425 		return;
426 	} else if (strcmp(verb, "destroy") == 0 ||
427 	    strcmp(verb, "stop") == 0) {
428 		g_label_ctl_destroy(req, mp);
429 		return;
430 	}
431 
432 	gctl_error(req, "Unknown verb.");
433 }
434 
435 DECLARE_GEOM_CLASS(g_label_class, g_label);
436