xref: /freebsd/sys/geom/label/g_label.c (revision 74bf4e164ba5851606a27d4feff27717452583e5)
1 /*-
2  * Copyright (c) 2004 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 SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RW, &g_label_debug, 0,
48     "Debug level");
49 
50 static int g_label_destroy(struct g_geom *gp, boolean_t force);
51 static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
52     int flags __unused);
53 static void g_label_config(struct gctl_req *req, struct g_class *mp,
54     const char *verb);
55 
56 struct g_class g_label_class = {
57 	.name = G_LABEL_CLASS_NAME,
58 	.version = G_VERSION,
59 	.ctlreq = g_label_config,
60 	.taste = g_label_taste
61 };
62 
63 /*
64  * To add a new file system where you want to look for volume labels,
65  * you have to:
66  * 1. Add a file which implements looking for volume labels.
67  * 2. Add an 'extern const struct g_label_desc g_label_<your file system>;'.
68  * 3. Add an element to the table below '&g_label_<your_file_system>,'.
69  */
70 const struct g_label_desc *g_labels[] = {
71 	&g_label_ufs,
72 	&g_label_iso9660,
73 	&g_label_msdosfs,
74 	NULL
75 };
76 
77 
78 static void
79 g_label_orphan(struct g_consumer *cp __unused)
80 {
81 
82 	KASSERT(1 == 0, ("%s called?", __func__));
83 }
84 
85 static void
86 g_label_start(struct bio *bp __unused)
87 {
88 
89 	KASSERT(1 == 0, ("%s called?", __func__));
90 }
91 
92 static int
93 g_label_access(struct g_provider *pp __unused, int dr __unused, int dw __unused,
94     int de __unused)
95 {
96 
97 	KASSERT(1 == 0, ("%s called", __func__));
98 	return (EOPNOTSUPP);
99 }
100 
101 static struct g_geom *
102 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
103     const char *label, const char *dir, off_t mediasize)
104 {
105 	struct g_geom *gp;
106 	struct g_provider *pp2;
107 	struct g_consumer *cp;
108 	char name[64];
109 
110 	g_topology_assert();
111 
112 	gp = NULL;
113 	cp = NULL;
114 	snprintf(name, sizeof(name), "%s/%s", dir, label);
115 	LIST_FOREACH(gp, &mp->geom, geom) {
116 		pp2 = LIST_FIRST(&gp->provider);
117 		if (pp2 == NULL)
118 			continue;
119 		if (strcmp(pp2->name, name) == 0) {
120 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
121 			    label, name, pp->name);
122 			if (req != NULL) {
123 				gctl_error(req, "Provider %s already exists.",
124 				    name);
125 			}
126 			return (NULL);
127 		}
128 	}
129 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
130 	if (gp == NULL) {
131 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
132 		if (req != NULL)
133 			gctl_error(req, "Cannot create slice %s.", label);
134 		return (NULL);
135 	}
136 	g_access(cp, -1, 0, 0);
137 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
138 	    pp->sectorsize, name);
139 	G_LABEL_DEBUG(0, "Label for provider %s is %s.", pp->name, name);
140 	return (gp);
141 }
142 
143 static int
144 g_label_destroy(struct g_geom *gp, boolean_t force)
145 {
146 	struct g_provider *pp;
147 
148 	g_topology_assert();
149 	pp = LIST_FIRST(&gp->provider);
150 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
151 		if (force) {
152 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
153 			    "can't be definitely removed.", pp->name);
154 		} else {
155 			G_LABEL_DEBUG(1,
156 			    "Provider %s is still open (r%dw%de%d).", pp->name,
157 			    pp->acr, pp->acw, pp->ace);
158 			return (EBUSY);
159 		}
160 	} else {
161 		G_LABEL_DEBUG(0, "Label %s removed.",
162 		    LIST_FIRST(&gp->provider)->name);
163 	}
164 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
165 	return (0);
166 }
167 
168 static int
169 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
170 {
171 	struct g_provider *pp;
172 	u_char *buf;
173 	int error;
174 
175 	g_topology_assert();
176 
177 	pp = cp->provider;
178 	g_topology_unlock();
179 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
180 	    &error);
181 	g_topology_lock();
182 	if (buf == NULL)
183 		return (error);
184 	/* Decode metadata. */
185 	label_metadata_decode(buf, md);
186 	g_free(buf);
187 
188 	return (0);
189 }
190 
191 static struct g_geom *
192 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
193 {
194 	struct g_label_metadata md;
195 	struct g_consumer *cp;
196 	struct g_geom *gp;
197 	int i;
198 
199 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
200 	g_topology_assert();
201 
202 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
203 
204 	/* Skip providers with 0 sectorsize. */
205 	if (pp->sectorsize == 0)
206 		return (NULL);
207 	if (strcmp(pp->geom->class->name, mp->name) == 0)
208 		return (NULL);
209 
210 	gp = g_new_geomf(mp, "label:taste");
211 	gp->start = g_label_start;
212 	gp->access = g_label_access;
213 	gp->orphan = g_label_orphan;
214 	cp = g_new_consumer(gp);
215 	g_attach(cp, pp);
216 	if (g_access(cp, 1, 0, 0) != 0)
217 		goto end;
218 	do {
219 		if (g_label_read_metadata(cp, &md) != 0)
220 			break;
221 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
222 			break;
223 		if (md.md_version > G_LABEL_VERSION) {
224 			printf("geom_label.ko module is too old to handle %s.\n",
225 			    pp->name);
226 			break;
227 		}
228 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
229 		    pp->mediasize - pp->sectorsize);
230 	} while (0);
231 	for (i = 0; g_labels[i] != NULL; i++) {
232 		char label[64];
233 
234 		g_topology_unlock();
235 		g_labels[i]->ld_taste(cp, label, sizeof(label));
236 		g_topology_lock();
237 		if (label[0] == '\0')
238 			continue;
239 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
240 		    pp->mediasize);
241 	}
242 	g_access(cp, -1, 0, 0);
243 end:
244 	g_detach(cp);
245 	g_destroy_consumer(cp);
246 	g_destroy_geom(gp);
247 	return (NULL);
248 }
249 
250 static void
251 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
252 {
253 	struct g_provider *pp;
254 	const char *name;
255 	int *nargs;
256 
257 	g_topology_assert();
258 
259 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
260 	if (nargs == NULL) {
261 		gctl_error(req, "No '%s' argument", "nargs");
262 		return;
263 	}
264 	if (*nargs != 2) {
265 		gctl_error(req, "Invalid number of argument.");
266 		return;
267 	}
268 	/*
269 	 * arg1 is the name of provider.
270 	 */
271 	name = gctl_get_asciiparam(req, "arg1");
272 	if (name == NULL) {
273 		gctl_error(req, "No 'arg%d' argument", 1);
274 		return;
275 	}
276 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
277 		name += strlen("/dev/");
278 	pp = g_provider_by_name(name);
279 	if (pp == NULL) {
280 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
281 		gctl_error(req, "Provider %s is invalid.", name);
282 		return;
283 	}
284 	/*
285 	 * arg0 is the label.
286 	 */
287 	name = gctl_get_asciiparam(req, "arg0");
288 	if (name == NULL) {
289 		gctl_error(req, "No 'arg%d' argument", 0);
290 		return;
291 	}
292 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
293 }
294 
295 static const char *
296 g_label_skip_dir(const char *name)
297 {
298 	char path[64];
299 	u_int i;
300 
301 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
302 		name += strlen("/dev/");
303 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
304 		name += strlen(G_LABEL_DIR "/");
305 	for (i = 0; g_labels[i] != NULL; i++) {
306 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
307 		if (strncmp(name, path, strlen(path)) == 0) {
308 			name += strlen(path);
309 			break;
310 		}
311 	}
312 	return (name);
313 }
314 
315 static struct g_geom *
316 g_label_find_geom(struct g_class *mp, const char *name)
317 {
318 	struct g_geom *gp;
319 	struct g_provider *pp;
320 	const char *pname;
321 
322 	name = g_label_skip_dir(name);
323 	LIST_FOREACH(gp, &mp->geom, geom) {
324 		pp = LIST_FIRST(&gp->provider);
325 		pname = g_label_skip_dir(pp->name);
326 		if (strcmp(pname, name) == 0)
327 			return (gp);
328 	}
329 	return (NULL);
330 }
331 
332 static void
333 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
334 {
335 	int *nargs, *force, error, i;
336 	struct g_geom *gp;
337 	const char *name;
338 	char param[16];
339 
340 	g_topology_assert();
341 
342 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
343 	if (nargs == NULL) {
344 		gctl_error(req, "No '%s' argument", "nargs");
345 		return;
346 	}
347 	if (*nargs <= 0) {
348 		gctl_error(req, "Missing device(s).");
349 		return;
350 	}
351 	force = gctl_get_paraml(req, "force", sizeof(*force));
352 	if (force == NULL) {
353 		gctl_error(req, "No 'force' argument");
354 		return;
355 	}
356 
357 	for (i = 0; i < *nargs; i++) {
358 		snprintf(param, sizeof(param), "arg%d", i);
359 		name = gctl_get_asciiparam(req, param);
360 		if (name == NULL) {
361 			gctl_error(req, "No 'arg%d' argument", i);
362 			return;
363 		}
364 		gp = g_label_find_geom(mp, name);
365 		if (gp == NULL) {
366 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
367 			gctl_error(req, "Label %s is invalid.", name);
368 			return;
369 		}
370 		error = g_label_destroy(gp, *force);
371 		if (error != 0) {
372 			gctl_error(req, "Cannot destroy label %s (error=%d).",
373 			    LIST_FIRST(&gp->provider)->name, error);
374 			return;
375 		}
376 	}
377 }
378 
379 static void
380 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
381 {
382 	uint32_t *version;
383 
384 	g_topology_assert();
385 
386 	version = gctl_get_paraml(req, "version", sizeof(*version));
387 	if (version == NULL) {
388 		gctl_error(req, "No '%s' argument.", "version");
389 		return;
390 	}
391 	if (*version != G_LABEL_VERSION) {
392 		gctl_error(req, "Userland and kernel parts are out of sync.");
393 		return;
394 	}
395 
396 	if (strcmp(verb, "create") == 0) {
397 		g_label_ctl_create(req, mp);
398 		return;
399 	} else if (strcmp(verb, "destroy") == 0 ||
400 	    strcmp(verb, "stop") == 0) {
401 		g_label_ctl_destroy(req, mp);
402 		return;
403 	}
404 
405 	gctl_error(req, "Unknown verb.");
406 }
407 
408 DECLARE_GEOM_CLASS(g_label_class, g_label);
409