xref: /freebsd/sys/geom/label/g_label.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
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 ((pp2->flags & G_PF_ORPHAN) != 0)
168 			continue;
169 		if (strcmp(pp2->name, name) == 0) {
170 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
171 			    label, name, pp->name);
172 			if (req != NULL) {
173 				gctl_error(req, "Provider %s already exists.",
174 				    name);
175 			}
176 			return (NULL);
177 		}
178 	}
179 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
180 	if (gp == NULL) {
181 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
182 		if (req != NULL)
183 			gctl_error(req, "Cannot create slice %s.", label);
184 		return (NULL);
185 	}
186 	gp->orphan = g_label_orphan;
187 	gp->spoiled = g_label_spoiled;
188 	g_access(cp, -1, 0, 0);
189 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
190 	    pp->sectorsize, name);
191 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
192 	return (gp);
193 }
194 
195 static int
196 g_label_destroy(struct g_geom *gp, boolean_t force)
197 {
198 	struct g_provider *pp;
199 
200 	g_topology_assert();
201 	pp = LIST_FIRST(&gp->provider);
202 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
203 		if (force) {
204 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
205 			    "can't be definitely removed.", pp->name);
206 		} else {
207 			G_LABEL_DEBUG(1,
208 			    "Provider %s is still open (r%dw%de%d).", pp->name,
209 			    pp->acr, pp->acw, pp->ace);
210 			return (EBUSY);
211 		}
212 	} else if (pp != NULL)
213 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
214 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
215 	return (0);
216 }
217 
218 static int
219 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
220 {
221 	struct g_provider *pp;
222 	u_char *buf;
223 	int error;
224 
225 	g_topology_assert();
226 
227 	pp = cp->provider;
228 	g_topology_unlock();
229 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
230 	    &error);
231 	g_topology_lock();
232 	if (buf == NULL)
233 		return (error);
234 	/* Decode metadata. */
235 	label_metadata_decode(buf, md);
236 	g_free(buf);
237 
238 	return (0);
239 }
240 
241 static void
242 g_label_orphan_taste(struct g_consumer *cp __unused)
243 {
244 
245 	KASSERT(1 == 0, ("%s called?", __func__));
246 }
247 
248 static void
249 g_label_start_taste(struct bio *bp __unused)
250 {
251 
252 	KASSERT(1 == 0, ("%s called?", __func__));
253 }
254 
255 static int
256 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
257     int dw __unused, int de __unused)
258 {
259 
260 	KASSERT(1 == 0, ("%s called", __func__));
261 	return (EOPNOTSUPP);
262 }
263 
264 static struct g_geom *
265 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
266 {
267 	struct g_label_metadata md;
268 	struct g_consumer *cp;
269 	struct g_geom *gp;
270 	int i;
271 
272 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
273 	g_topology_assert();
274 
275 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
276 
277 	/* Skip providers that are already open for writing. */
278 	if (pp->acw > 0)
279 		return (NULL);
280 
281 	if (strcmp(pp->geom->class->name, mp->name) == 0)
282 		return (NULL);
283 
284 	gp = g_new_geomf(mp, "label:taste");
285 	gp->start = g_label_start_taste;
286 	gp->access = g_label_access_taste;
287 	gp->orphan = g_label_orphan_taste;
288 	cp = g_new_consumer(gp);
289 	g_attach(cp, pp);
290 	if (g_access(cp, 1, 0, 0) != 0)
291 		goto end;
292 	do {
293 		if (g_label_read_metadata(cp, &md) != 0)
294 			break;
295 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
296 			break;
297 		if (md.md_version > G_LABEL_VERSION) {
298 			printf("geom_label.ko module is too old to handle %s.\n",
299 			    pp->name);
300 			break;
301 		}
302 
303 		/*
304 		 * Backward compatibility:
305 		 */
306 		/*
307 		 * There was no md_provsize field in earlier versions of
308 		 * metadata.
309 		 */
310 		if (md.md_version < 2)
311 			md.md_provsize = pp->mediasize;
312 
313 		if (md.md_provsize != pp->mediasize)
314 			break;
315 
316 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
317 		    pp->mediasize - pp->sectorsize);
318 	} while (0);
319 	for (i = 0; g_labels[i] != NULL; i++) {
320 		char label[64];
321 
322 		if (g_labels[i]->ld_enabled == 0)
323 			continue;
324 		g_topology_unlock();
325 		g_labels[i]->ld_taste(cp, label, sizeof(label));
326 		g_topology_lock();
327 		if (label[0] == '\0')
328 			continue;
329 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
330 		    pp->mediasize);
331 	}
332 	g_access(cp, -1, 0, 0);
333 end:
334 	g_detach(cp);
335 	g_destroy_consumer(cp);
336 	g_destroy_geom(gp);
337 	return (NULL);
338 }
339 
340 static void
341 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
342 {
343 	struct g_provider *pp;
344 	const char *name;
345 	int *nargs;
346 
347 	g_topology_assert();
348 
349 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
350 	if (nargs == NULL) {
351 		gctl_error(req, "No '%s' argument", "nargs");
352 		return;
353 	}
354 	if (*nargs != 2) {
355 		gctl_error(req, "Invalid number of arguments.");
356 		return;
357 	}
358 	/*
359 	 * arg1 is the name of provider.
360 	 */
361 	name = gctl_get_asciiparam(req, "arg1");
362 	if (name == NULL) {
363 		gctl_error(req, "No 'arg%d' argument", 1);
364 		return;
365 	}
366 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
367 		name += strlen("/dev/");
368 	pp = g_provider_by_name(name);
369 	if (pp == NULL) {
370 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
371 		gctl_error(req, "Provider %s is invalid.", name);
372 		return;
373 	}
374 	/*
375 	 * arg0 is the label.
376 	 */
377 	name = gctl_get_asciiparam(req, "arg0");
378 	if (name == NULL) {
379 		gctl_error(req, "No 'arg%d' argument", 0);
380 		return;
381 	}
382 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
383 }
384 
385 static const char *
386 g_label_skip_dir(const char *name)
387 {
388 	char path[64];
389 	u_int i;
390 
391 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
392 		name += strlen("/dev/");
393 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
394 		name += strlen(G_LABEL_DIR "/");
395 	for (i = 0; g_labels[i] != NULL; i++) {
396 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
397 		if (strncmp(name, path, strlen(path)) == 0) {
398 			name += strlen(path);
399 			break;
400 		}
401 	}
402 	return (name);
403 }
404 
405 static struct g_geom *
406 g_label_find_geom(struct g_class *mp, const char *name)
407 {
408 	struct g_geom *gp;
409 	struct g_provider *pp;
410 	const char *pname;
411 
412 	name = g_label_skip_dir(name);
413 	LIST_FOREACH(gp, &mp->geom, geom) {
414 		pp = LIST_FIRST(&gp->provider);
415 		pname = g_label_skip_dir(pp->name);
416 		if (strcmp(pname, name) == 0)
417 			return (gp);
418 	}
419 	return (NULL);
420 }
421 
422 static void
423 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
424 {
425 	int *nargs, *force, error, i;
426 	struct g_geom *gp;
427 	const char *name;
428 	char param[16];
429 
430 	g_topology_assert();
431 
432 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
433 	if (nargs == NULL) {
434 		gctl_error(req, "No '%s' argument", "nargs");
435 		return;
436 	}
437 	if (*nargs <= 0) {
438 		gctl_error(req, "Missing device(s).");
439 		return;
440 	}
441 	force = gctl_get_paraml(req, "force", sizeof(*force));
442 	if (force == NULL) {
443 		gctl_error(req, "No 'force' argument");
444 		return;
445 	}
446 
447 	for (i = 0; i < *nargs; i++) {
448 		snprintf(param, sizeof(param), "arg%d", i);
449 		name = gctl_get_asciiparam(req, param);
450 		if (name == NULL) {
451 			gctl_error(req, "No 'arg%d' argument", i);
452 			return;
453 		}
454 		gp = g_label_find_geom(mp, name);
455 		if (gp == NULL) {
456 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
457 			gctl_error(req, "Label %s is invalid.", name);
458 			return;
459 		}
460 		error = g_label_destroy(gp, *force);
461 		if (error != 0) {
462 			gctl_error(req, "Cannot destroy label %s (error=%d).",
463 			    LIST_FIRST(&gp->provider)->name, error);
464 			return;
465 		}
466 	}
467 }
468 
469 static void
470 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
471 {
472 	uint32_t *version;
473 
474 	g_topology_assert();
475 
476 	version = gctl_get_paraml(req, "version", sizeof(*version));
477 	if (version == NULL) {
478 		gctl_error(req, "No '%s' argument.", "version");
479 		return;
480 	}
481 	if (*version != G_LABEL_VERSION) {
482 		gctl_error(req, "Userland and kernel parts are out of sync.");
483 		return;
484 	}
485 
486 	if (strcmp(verb, "create") == 0) {
487 		g_label_ctl_create(req, mp);
488 		return;
489 	} else if (strcmp(verb, "destroy") == 0 ||
490 	    strcmp(verb, "stop") == 0) {
491 		g_label_ctl_destroy(req, mp);
492 		return;
493 	}
494 
495 	gctl_error(req, "Unknown verb.");
496 }
497 
498 DECLARE_GEOM_CLASS(g_label_class, g_label);
499