xref: /freebsd/sys/geom/label/g_label.c (revision 50dad48bb740a8e56d185d9e8c165e0758f46e25)
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/malloc.h>
38 #include <sys/libkern.h>
39 #include <sys/sysctl.h>
40 #include <geom/geom.h>
41 #include <geom/geom_slice.h>
42 #include <geom/label/g_label.h>
43 
44 FEATURE(geom_label, "GEOM labeling support");
45 
46 SYSCTL_DECL(_kern_geom);
47 SYSCTL_NODE(_kern_geom, OID_AUTO, label, CTLFLAG_RW, 0, "GEOM_LABEL stuff");
48 u_int g_label_debug = 0;
49 TUNABLE_INT("kern.geom.label.debug", &g_label_debug);
50 SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RW, &g_label_debug, 0,
51     "Debug level");
52 
53 static int g_label_destroy_geom(struct gctl_req *req, struct g_class *mp,
54     struct g_geom *gp);
55 static int g_label_destroy(struct g_geom *gp, boolean_t force);
56 static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
57     int flags __unused);
58 static void g_label_config(struct gctl_req *req, struct g_class *mp,
59     const char *verb);
60 
61 struct g_class g_label_class = {
62 	.name = G_LABEL_CLASS_NAME,
63 	.version = G_VERSION,
64 	.ctlreq = g_label_config,
65 	.taste = g_label_taste,
66 	.destroy_geom = g_label_destroy_geom
67 };
68 
69 /*
70  * To add a new file system where you want to look for volume labels,
71  * you have to:
72  * 1. Add a file g_label_<file system>.c which implements labels recognition.
73  * 2. Add an 'extern const struct g_label_desc g_label_<file system>;' into
74  *    g_label.h file.
75  * 3. Add an element to the table below '&g_label_<file system>,'.
76  * 4. Add your file to sys/conf/files.
77  * 5. Add your file to sys/modules/geom/geom_label/Makefile.
78  * 6. Add your file system to manual page sbin/geom/class/label/glabel.8.
79  */
80 const struct g_label_desc *g_labels[] = {
81 	&g_label_ufs_id,
82 	&g_label_ufs_volume,
83 	&g_label_iso9660,
84 	&g_label_msdosfs,
85 	&g_label_ext2fs,
86 	&g_label_reiserfs,
87 	&g_label_ntfs,
88 	&g_label_gpt,
89 	&g_label_gpt_uuid,
90 	NULL
91 };
92 
93 
94 static int
95 g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
96     struct g_geom *gp __unused)
97 {
98 
99 	/*
100 	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
101 	 * XXX: broken, so we deny unloading when we have geoms.
102 	 */
103 	return (EOPNOTSUPP);
104 }
105 
106 static void
107 g_label_orphan(struct g_consumer *cp)
108 {
109 
110 	G_LABEL_DEBUG(1, "Label %s removed.",
111 	    LIST_FIRST(&cp->geom->provider)->name);
112 	g_slice_orphan(cp);
113 }
114 
115 static void
116 g_label_spoiled(struct g_consumer *cp)
117 {
118 
119 	G_LABEL_DEBUG(1, "Label %s removed.",
120 	    LIST_FIRST(&cp->geom->provider)->name);
121 	g_slice_spoiled(cp);
122 }
123 
124 static int
125 g_label_is_name_ok(const char *label)
126 {
127 	const char *s;
128 
129 	/* Check if the label starts from ../ */
130 	if (strncmp(label, "../", 3) == 0)
131 		return (0);
132 	/* Check if the label contains /../ */
133 	if (strstr(label, "/../") != NULL)
134 		return (0);
135 	/* Check if the label ends at ../ */
136 	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
137 		return (0);
138 	return (1);
139 }
140 
141 static struct g_geom *
142 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
143     const char *label, const char *dir, off_t mediasize)
144 {
145 	struct g_geom *gp;
146 	struct g_provider *pp2;
147 	struct g_consumer *cp;
148 	char name[64];
149 
150 	g_topology_assert();
151 
152 	if (!g_label_is_name_ok(label)) {
153 		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
154 		    pp->name);
155 		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
156 		if (req != NULL)
157 			gctl_error(req, "Label name %s is invalid.", label);
158 		return (NULL);
159 	}
160 	gp = NULL;
161 	cp = NULL;
162 	snprintf(name, sizeof(name), "%s/%s", dir, label);
163 	LIST_FOREACH(gp, &mp->geom, geom) {
164 		pp2 = LIST_FIRST(&gp->provider);
165 		if (pp2 == NULL)
166 			continue;
167 		if (strcmp(pp2->name, name) == 0) {
168 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
169 			    label, name, pp->name);
170 			if (req != NULL) {
171 				gctl_error(req, "Provider %s already exists.",
172 				    name);
173 			}
174 			return (NULL);
175 		}
176 	}
177 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
178 	if (gp == NULL) {
179 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
180 		if (req != NULL)
181 			gctl_error(req, "Cannot create slice %s.", label);
182 		return (NULL);
183 	}
184 	gp->orphan = g_label_orphan;
185 	gp->spoiled = g_label_spoiled;
186 	g_access(cp, -1, 0, 0);
187 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
188 	    pp->sectorsize, name);
189 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
190 	return (gp);
191 }
192 
193 static int
194 g_label_destroy(struct g_geom *gp, boolean_t force)
195 {
196 	struct g_provider *pp;
197 
198 	g_topology_assert();
199 	pp = LIST_FIRST(&gp->provider);
200 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
201 		if (force) {
202 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
203 			    "can't be definitely removed.", pp->name);
204 		} else {
205 			G_LABEL_DEBUG(1,
206 			    "Provider %s is still open (r%dw%de%d).", pp->name,
207 			    pp->acr, pp->acw, pp->ace);
208 			return (EBUSY);
209 		}
210 	} else if (pp != NULL)
211 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
212 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
213 	return (0);
214 }
215 
216 static int
217 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
218 {
219 	struct g_provider *pp;
220 	u_char *buf;
221 	int error;
222 
223 	g_topology_assert();
224 
225 	pp = cp->provider;
226 	g_topology_unlock();
227 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
228 	    &error);
229 	g_topology_lock();
230 	if (buf == NULL)
231 		return (error);
232 	/* Decode metadata. */
233 	label_metadata_decode(buf, md);
234 	g_free(buf);
235 
236 	return (0);
237 }
238 
239 static void
240 g_label_orphan_taste(struct g_consumer *cp __unused)
241 {
242 
243 	KASSERT(1 == 0, ("%s called?", __func__));
244 }
245 
246 static void
247 g_label_start_taste(struct bio *bp __unused)
248 {
249 
250 	KASSERT(1 == 0, ("%s called?", __func__));
251 }
252 
253 static int
254 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
255     int dw __unused, int de __unused)
256 {
257 
258 	KASSERT(1 == 0, ("%s called", __func__));
259 	return (EOPNOTSUPP);
260 }
261 
262 static struct g_geom *
263 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
264 {
265 	struct g_label_metadata md;
266 	struct g_consumer *cp;
267 	struct g_geom *gp;
268 	int i;
269 
270 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
271 	g_topology_assert();
272 
273 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
274 
275 	/* Skip providers that are already open for writing. */
276 	if (pp->acw > 0)
277 		return (NULL);
278 
279 	if (strcmp(pp->geom->class->name, mp->name) == 0)
280 		return (NULL);
281 
282 	gp = g_new_geomf(mp, "label:taste");
283 	gp->start = g_label_start_taste;
284 	gp->access = g_label_access_taste;
285 	gp->orphan = g_label_orphan_taste;
286 	cp = g_new_consumer(gp);
287 	g_attach(cp, pp);
288 	if (g_access(cp, 1, 0, 0) != 0)
289 		goto end;
290 	do {
291 		if (g_label_read_metadata(cp, &md) != 0)
292 			break;
293 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
294 			break;
295 		if (md.md_version > G_LABEL_VERSION) {
296 			printf("geom_label.ko module is too old to handle %s.\n",
297 			    pp->name);
298 			break;
299 		}
300 
301 		/*
302 		 * Backward compatibility:
303 		 */
304 		/*
305 		 * There was no md_provsize field in earlier versions of
306 		 * metadata.
307 		 */
308 		if (md.md_version < 2)
309 			md.md_provsize = pp->mediasize;
310 
311 		if (md.md_provsize != pp->mediasize)
312 			break;
313 
314 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
315 		    pp->mediasize - pp->sectorsize);
316 	} while (0);
317 	for (i = 0; g_labels[i] != NULL; i++) {
318 		char label[64];
319 
320 		if (g_labels[i]->ld_enabled == 0)
321 			continue;
322 		g_topology_unlock();
323 		g_labels[i]->ld_taste(cp, label, sizeof(label));
324 		g_topology_lock();
325 		if (label[0] == '\0')
326 			continue;
327 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
328 		    pp->mediasize);
329 	}
330 	g_access(cp, -1, 0, 0);
331 end:
332 	g_detach(cp);
333 	g_destroy_consumer(cp);
334 	g_destroy_geom(gp);
335 	return (NULL);
336 }
337 
338 static void
339 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
340 {
341 	struct g_provider *pp;
342 	const char *name;
343 	int *nargs;
344 
345 	g_topology_assert();
346 
347 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
348 	if (nargs == NULL) {
349 		gctl_error(req, "No '%s' argument", "nargs");
350 		return;
351 	}
352 	if (*nargs != 2) {
353 		gctl_error(req, "Invalid number of arguments.");
354 		return;
355 	}
356 	/*
357 	 * arg1 is the name of provider.
358 	 */
359 	name = gctl_get_asciiparam(req, "arg1");
360 	if (name == NULL) {
361 		gctl_error(req, "No 'arg%d' argument", 1);
362 		return;
363 	}
364 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
365 		name += strlen("/dev/");
366 	pp = g_provider_by_name(name);
367 	if (pp == NULL) {
368 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
369 		gctl_error(req, "Provider %s is invalid.", name);
370 		return;
371 	}
372 	/*
373 	 * arg0 is the label.
374 	 */
375 	name = gctl_get_asciiparam(req, "arg0");
376 	if (name == NULL) {
377 		gctl_error(req, "No 'arg%d' argument", 0);
378 		return;
379 	}
380 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
381 }
382 
383 static const char *
384 g_label_skip_dir(const char *name)
385 {
386 	char path[64];
387 	u_int i;
388 
389 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
390 		name += strlen("/dev/");
391 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
392 		name += strlen(G_LABEL_DIR "/");
393 	for (i = 0; g_labels[i] != NULL; i++) {
394 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
395 		if (strncmp(name, path, strlen(path)) == 0) {
396 			name += strlen(path);
397 			break;
398 		}
399 	}
400 	return (name);
401 }
402 
403 static struct g_geom *
404 g_label_find_geom(struct g_class *mp, const char *name)
405 {
406 	struct g_geom *gp;
407 	struct g_provider *pp;
408 	const char *pname;
409 
410 	name = g_label_skip_dir(name);
411 	LIST_FOREACH(gp, &mp->geom, geom) {
412 		pp = LIST_FIRST(&gp->provider);
413 		pname = g_label_skip_dir(pp->name);
414 		if (strcmp(pname, name) == 0)
415 			return (gp);
416 	}
417 	return (NULL);
418 }
419 
420 static void
421 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
422 {
423 	int *nargs, *force, error, i;
424 	struct g_geom *gp;
425 	const char *name;
426 	char param[16];
427 
428 	g_topology_assert();
429 
430 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
431 	if (nargs == NULL) {
432 		gctl_error(req, "No '%s' argument", "nargs");
433 		return;
434 	}
435 	if (*nargs <= 0) {
436 		gctl_error(req, "Missing device(s).");
437 		return;
438 	}
439 	force = gctl_get_paraml(req, "force", sizeof(*force));
440 	if (force == NULL) {
441 		gctl_error(req, "No 'force' argument");
442 		return;
443 	}
444 
445 	for (i = 0; i < *nargs; i++) {
446 		snprintf(param, sizeof(param), "arg%d", i);
447 		name = gctl_get_asciiparam(req, param);
448 		if (name == NULL) {
449 			gctl_error(req, "No 'arg%d' argument", i);
450 			return;
451 		}
452 		gp = g_label_find_geom(mp, name);
453 		if (gp == NULL) {
454 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
455 			gctl_error(req, "Label %s is invalid.", name);
456 			return;
457 		}
458 		error = g_label_destroy(gp, *force);
459 		if (error != 0) {
460 			gctl_error(req, "Cannot destroy label %s (error=%d).",
461 			    LIST_FIRST(&gp->provider)->name, error);
462 			return;
463 		}
464 	}
465 }
466 
467 static void
468 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
469 {
470 	uint32_t *version;
471 
472 	g_topology_assert();
473 
474 	version = gctl_get_paraml(req, "version", sizeof(*version));
475 	if (version == NULL) {
476 		gctl_error(req, "No '%s' argument.", "version");
477 		return;
478 	}
479 	if (*version != G_LABEL_VERSION) {
480 		gctl_error(req, "Userland and kernel parts are out of sync.");
481 		return;
482 	}
483 
484 	if (strcmp(verb, "create") == 0) {
485 		g_label_ctl_create(req, mp);
486 		return;
487 	} else if (strcmp(verb, "destroy") == 0 ||
488 	    strcmp(verb, "stop") == 0) {
489 		g_label_ctl_destroy(req, mp);
490 		return;
491 	}
492 
493 	gctl_error(req, "Unknown verb.");
494 }
495 
496 DECLARE_GEOM_CLASS(g_label_class, g_label);
497