xref: /freebsd/sys/geom/label/g_label.c (revision aa64588d28258aef88cc33b8043112e8856948d0)
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 <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 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  */
78 const struct g_label_desc *g_labels[] = {
79 	&g_label_ufs_id,
80 	&g_label_ufs_volume,
81 	&g_label_iso9660,
82 	&g_label_msdosfs,
83 	&g_label_ext2fs,
84 	&g_label_reiserfs,
85 	&g_label_ntfs,
86 	&g_label_gpt,
87 	&g_label_gpt_uuid,
88 	NULL
89 };
90 
91 
92 static int
93 g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
94     struct g_geom *gp __unused)
95 {
96 
97 	/*
98 	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
99 	 * XXX: broken, so we deny unloading when we have geoms.
100 	 */
101 	return (EOPNOTSUPP);
102 }
103 
104 static void
105 g_label_orphan(struct g_consumer *cp)
106 {
107 
108 	G_LABEL_DEBUG(1, "Label %s removed.",
109 	    LIST_FIRST(&cp->geom->provider)->name);
110 	g_slice_orphan(cp);
111 }
112 
113 static void
114 g_label_spoiled(struct g_consumer *cp)
115 {
116 
117 	G_LABEL_DEBUG(1, "Label %s removed.",
118 	    LIST_FIRST(&cp->geom->provider)->name);
119 	g_slice_spoiled(cp);
120 }
121 
122 static int
123 g_label_is_name_ok(const char *label)
124 {
125 	const char *s;
126 
127 	/* Check is the label starts from ../ */
128 	if (strncmp(label, "../", 3) == 0)
129 		return (0);
130 	/* Check is the label contains /../ */
131 	if (strstr(label, "/../") != NULL)
132 		return (0);
133 	/* Check is the label ends at ../ */
134 	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
135 		return (0);
136 	return (1);
137 }
138 
139 static struct g_geom *
140 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
141     const char *label, const char *dir, off_t mediasize)
142 {
143 	struct g_geom *gp;
144 	struct g_provider *pp2;
145 	struct g_consumer *cp;
146 	char name[64];
147 
148 	g_topology_assert();
149 
150 	if (!g_label_is_name_ok(label)) {
151 		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
152 		    pp->name);
153 		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
154 		return (NULL);
155 	}
156 	gp = NULL;
157 	cp = NULL;
158 	snprintf(name, sizeof(name), "%s/%s", dir, label);
159 	LIST_FOREACH(gp, &mp->geom, geom) {
160 		pp2 = LIST_FIRST(&gp->provider);
161 		if (pp2 == NULL)
162 			continue;
163 		if (strcmp(pp2->name, name) == 0) {
164 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
165 			    label, name, pp->name);
166 			if (req != NULL) {
167 				gctl_error(req, "Provider %s already exists.",
168 				    name);
169 			}
170 			return (NULL);
171 		}
172 	}
173 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
174 	if (gp == NULL) {
175 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
176 		if (req != NULL)
177 			gctl_error(req, "Cannot create slice %s.", label);
178 		return (NULL);
179 	}
180 	gp->orphan = g_label_orphan;
181 	gp->spoiled = g_label_spoiled;
182 	g_access(cp, -1, 0, 0);
183 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
184 	    pp->sectorsize, name);
185 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
186 	return (gp);
187 }
188 
189 static int
190 g_label_destroy(struct g_geom *gp, boolean_t force)
191 {
192 	struct g_provider *pp;
193 
194 	g_topology_assert();
195 	pp = LIST_FIRST(&gp->provider);
196 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
197 		if (force) {
198 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
199 			    "can't be definitely removed.", pp->name);
200 		} else {
201 			G_LABEL_DEBUG(1,
202 			    "Provider %s is still open (r%dw%de%d).", pp->name,
203 			    pp->acr, pp->acw, pp->ace);
204 			return (EBUSY);
205 		}
206 	} else if (pp != NULL)
207 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
208 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
209 	return (0);
210 }
211 
212 static int
213 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
214 {
215 	struct g_provider *pp;
216 	u_char *buf;
217 	int error;
218 
219 	g_topology_assert();
220 
221 	pp = cp->provider;
222 	g_topology_unlock();
223 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
224 	    &error);
225 	g_topology_lock();
226 	if (buf == NULL)
227 		return (error);
228 	/* Decode metadata. */
229 	label_metadata_decode(buf, md);
230 	g_free(buf);
231 
232 	return (0);
233 }
234 
235 static void
236 g_label_orphan_taste(struct g_consumer *cp __unused)
237 {
238 
239 	KASSERT(1 == 0, ("%s called?", __func__));
240 }
241 
242 static void
243 g_label_start_taste(struct bio *bp __unused)
244 {
245 
246 	KASSERT(1 == 0, ("%s called?", __func__));
247 }
248 
249 static int
250 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
251     int dw __unused, int de __unused)
252 {
253 
254 	KASSERT(1 == 0, ("%s called", __func__));
255 	return (EOPNOTSUPP);
256 }
257 
258 static struct g_geom *
259 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
260 {
261 	struct g_label_metadata md;
262 	struct g_consumer *cp;
263 	struct g_geom *gp;
264 	int i;
265 
266 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
267 	g_topology_assert();
268 
269 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
270 
271 	/* Skip providers that are already open for writing. */
272 	if (pp->acw > 0)
273 		return (NULL);
274 
275 	if (strcmp(pp->geom->class->name, mp->name) == 0)
276 		return (NULL);
277 
278 	gp = g_new_geomf(mp, "label:taste");
279 	gp->start = g_label_start_taste;
280 	gp->access = g_label_access_taste;
281 	gp->orphan = g_label_orphan_taste;
282 	cp = g_new_consumer(gp);
283 	g_attach(cp, pp);
284 	if (g_access(cp, 1, 0, 0) != 0)
285 		goto end;
286 	do {
287 		if (g_label_read_metadata(cp, &md) != 0)
288 			break;
289 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
290 			break;
291 		if (md.md_version > G_LABEL_VERSION) {
292 			printf("geom_label.ko module is too old to handle %s.\n",
293 			    pp->name);
294 			break;
295 		}
296 
297 		/*
298 		 * Backward compatibility:
299 		 */
300 		/*
301 		 * There was no md_provsize field in earlier versions of
302 		 * metadata.
303 		 */
304 		if (md.md_version < 2)
305 			md.md_provsize = pp->mediasize;
306 
307 		if (md.md_provsize != pp->mediasize)
308 			break;
309 
310 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
311 		    pp->mediasize - pp->sectorsize);
312 	} while (0);
313 	for (i = 0; g_labels[i] != NULL; i++) {
314 		char label[64];
315 
316 		if (g_labels[i]->ld_enabled == 0)
317 			continue;
318 		g_topology_unlock();
319 		g_labels[i]->ld_taste(cp, label, sizeof(label));
320 		g_topology_lock();
321 		if (label[0] == '\0')
322 			continue;
323 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
324 		    pp->mediasize);
325 	}
326 	g_access(cp, -1, 0, 0);
327 end:
328 	g_detach(cp);
329 	g_destroy_consumer(cp);
330 	g_destroy_geom(gp);
331 	return (NULL);
332 }
333 
334 static void
335 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
336 {
337 	struct g_provider *pp;
338 	const char *name;
339 	int *nargs;
340 
341 	g_topology_assert();
342 
343 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
344 	if (nargs == NULL) {
345 		gctl_error(req, "No '%s' argument", "nargs");
346 		return;
347 	}
348 	if (*nargs != 2) {
349 		gctl_error(req, "Invalid number of argument.");
350 		return;
351 	}
352 	/*
353 	 * arg1 is the name of provider.
354 	 */
355 	name = gctl_get_asciiparam(req, "arg1");
356 	if (name == NULL) {
357 		gctl_error(req, "No 'arg%d' argument", 1);
358 		return;
359 	}
360 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
361 		name += strlen("/dev/");
362 	pp = g_provider_by_name(name);
363 	if (pp == NULL) {
364 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
365 		gctl_error(req, "Provider %s is invalid.", name);
366 		return;
367 	}
368 	/*
369 	 * arg0 is the label.
370 	 */
371 	name = gctl_get_asciiparam(req, "arg0");
372 	if (name == NULL) {
373 		gctl_error(req, "No 'arg%d' argument", 0);
374 		return;
375 	}
376 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
377 }
378 
379 static const char *
380 g_label_skip_dir(const char *name)
381 {
382 	char path[64];
383 	u_int i;
384 
385 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
386 		name += strlen("/dev/");
387 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
388 		name += strlen(G_LABEL_DIR "/");
389 	for (i = 0; g_labels[i] != NULL; i++) {
390 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
391 		if (strncmp(name, path, strlen(path)) == 0) {
392 			name += strlen(path);
393 			break;
394 		}
395 	}
396 	return (name);
397 }
398 
399 static struct g_geom *
400 g_label_find_geom(struct g_class *mp, const char *name)
401 {
402 	struct g_geom *gp;
403 	struct g_provider *pp;
404 	const char *pname;
405 
406 	name = g_label_skip_dir(name);
407 	LIST_FOREACH(gp, &mp->geom, geom) {
408 		pp = LIST_FIRST(&gp->provider);
409 		pname = g_label_skip_dir(pp->name);
410 		if (strcmp(pname, name) == 0)
411 			return (gp);
412 	}
413 	return (NULL);
414 }
415 
416 static void
417 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
418 {
419 	int *nargs, *force, error, i;
420 	struct g_geom *gp;
421 	const char *name;
422 	char param[16];
423 
424 	g_topology_assert();
425 
426 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
427 	if (nargs == NULL) {
428 		gctl_error(req, "No '%s' argument", "nargs");
429 		return;
430 	}
431 	if (*nargs <= 0) {
432 		gctl_error(req, "Missing device(s).");
433 		return;
434 	}
435 	force = gctl_get_paraml(req, "force", sizeof(*force));
436 	if (force == NULL) {
437 		gctl_error(req, "No 'force' argument");
438 		return;
439 	}
440 
441 	for (i = 0; i < *nargs; i++) {
442 		snprintf(param, sizeof(param), "arg%d", i);
443 		name = gctl_get_asciiparam(req, param);
444 		if (name == NULL) {
445 			gctl_error(req, "No 'arg%d' argument", i);
446 			return;
447 		}
448 		gp = g_label_find_geom(mp, name);
449 		if (gp == NULL) {
450 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
451 			gctl_error(req, "Label %s is invalid.", name);
452 			return;
453 		}
454 		error = g_label_destroy(gp, *force);
455 		if (error != 0) {
456 			gctl_error(req, "Cannot destroy label %s (error=%d).",
457 			    LIST_FIRST(&gp->provider)->name, error);
458 			return;
459 		}
460 	}
461 }
462 
463 static void
464 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
465 {
466 	uint32_t *version;
467 
468 	g_topology_assert();
469 
470 	version = gctl_get_paraml(req, "version", sizeof(*version));
471 	if (version == NULL) {
472 		gctl_error(req, "No '%s' argument.", "version");
473 		return;
474 	}
475 	if (*version != G_LABEL_VERSION) {
476 		gctl_error(req, "Userland and kernel parts are out of sync.");
477 		return;
478 	}
479 
480 	if (strcmp(verb, "create") == 0) {
481 		g_label_ctl_create(req, mp);
482 		return;
483 	} else if (strcmp(verb, "destroy") == 0 ||
484 	    strcmp(verb, "stop") == 0) {
485 		g_label_ctl_destroy(req, mp);
486 		return;
487 	}
488 
489 	gctl_error(req, "Unknown verb.");
490 }
491 
492 DECLARE_GEOM_CLASS(g_label_class, g_label);
493