xref: /freebsd/sys/geom/geom_slice.c (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
1 /*-
2  * Copyright (c) 2002 Poul-Henning Kamp
3  * Copyright (c) 2002 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9  * DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The names of the authors may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $FreeBSD$
36  */
37 
38 
39 #include <sys/param.h>
40 #include <sys/stdint.h>
41 #ifndef _KERNEL
42 #include <stdio.h>
43 #include <unistd.h>
44 #include <stdlib.h>
45 #include <signal.h>
46 #include <string.h>
47 #include <err.h>
48 #else
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
52 #include <sys/bio.h>
53 #include <sys/sysctl.h>
54 #include <sys/proc.h>
55 #include <sys/kthread.h>
56 #include <sys/lock.h>
57 #include <sys/mutex.h>
58 #endif
59 #include <sys/errno.h>
60 #include <sys/sbuf.h>
61 #include <geom/geom.h>
62 #include <geom/geom_slice.h>
63 #include <machine/stdarg.h>
64 
65 static g_orphan_t g_slice_orphan;
66 static g_access_t g_slice_access;
67 static g_start_t g_slice_start;
68 
69 static struct g_slicer *
70 g_slice_init(unsigned nslice, unsigned scsize)
71 {
72 	struct g_slicer *gsp;
73 
74 	gsp = g_malloc(sizeof *gsp, M_WAITOK | M_ZERO);
75 	gsp->softc = g_malloc(scsize, M_WAITOK | M_ZERO);
76 	gsp->slices = g_malloc(nslice * sizeof(struct g_slice),
77 	    M_WAITOK | M_ZERO);
78 	gsp->nslice = nslice;
79 	return (gsp);
80 }
81 
82 static int
83 g_slice_access(struct g_provider *pp, int dr, int dw, int de)
84 {
85 	int error, i;
86 	struct g_geom *gp;
87 	struct g_consumer *cp;
88 	struct g_provider *pp2;
89 	struct g_slicer *gsp;
90 	struct g_slice *gsl, *gsl2;
91 
92 	gp = pp->geom;
93 	cp = LIST_FIRST(&gp->consumer);
94 	KASSERT (cp != NULL, ("g_slice_access but no consumer"));
95 	gsp = gp->softc;
96 	gsl = &gsp->slices[pp->index];
97 	for (i = 0; i < gsp->nslice; i++) {
98 		gsl2 = &gsp->slices[i];
99 		if (gsl2->length == 0)
100 			continue;
101 		if (i == pp->index)
102 			continue;
103 		if (gsl->offset + gsl->length <= gsl2->offset)
104 			continue;
105 		if (gsl2->offset + gsl2->length <= gsl->offset)
106 			continue;
107 		/* overlap */
108 		pp2 = gsl2->provider;
109 		if ((pp->acw + dw) > 0 && pp2->ace > 0)
110 			return (EPERM);
111 		if ((pp->ace + de) > 0 && pp2->acw > 0)
112 			return (EPERM);
113 	}
114 	/* On first open, grab an extra "exclusive" bit */
115 	if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
116 		de++;
117 	/* ... and let go of it on last close */
118 	if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1)
119 		de--;
120 	error = g_access_rel(cp, dr, dw, de);
121 	return (error);
122 }
123 
124 static void
125 g_slice_start(struct bio *bp)
126 {
127 	struct bio *bp2;
128 	struct g_provider *pp;
129 	struct g_geom *gp;
130 	struct g_consumer *cp;
131 	struct g_slicer *gsp;
132 	struct g_slice *gsl;
133 	int index;
134 	off_t t;
135 
136 	pp = bp->bio_to;
137 	gp = pp->geom;
138 	gsp = gp->softc;
139 	cp = LIST_FIRST(&gp->consumer);
140 	index = pp->index;
141 	gsl = &gsp->slices[index];
142 	switch(bp->bio_cmd) {
143 	case BIO_READ:
144 	case BIO_WRITE:
145 	case BIO_DELETE:
146 		if (bp->bio_offset > gsl->length) {
147 			g_io_deliver(bp, EINVAL); /* XXX: EWHAT ? */
148 			return;
149 		}
150 		bp2 = g_clone_bio(bp);
151 		if (bp2 == NULL) {
152 			g_io_deliver(bp, ENOMEM);
153 			return;
154 		}
155 		if (bp2->bio_offset + bp2->bio_length > gsl->length)
156 			bp2->bio_length = gsl->length - bp2->bio_offset;
157 		bp2->bio_done = g_std_done;
158 		bp2->bio_offset += gsl->offset;
159 		g_io_request(bp2, cp);
160 		return;
161 	case BIO_GETATTR:
162 	case BIO_SETATTR:
163 		/* Give the real method a chance to override */
164 		if (gsp->start(bp))
165 			return;
166 		if (!strcmp("GEOM::frontstuff", bp->bio_attribute)) {
167 			t = gsp->cfrontstuff;
168 			if (gsp->frontstuff > t)
169 				t = gsp->frontstuff;
170 			t -= gsl->offset;
171 			if (t < 0)
172 				t = 0;
173 			if (t > gsl->length)
174 				t = gsl->length;
175 			g_handleattr_off_t(bp, "GEOM::frontstuff", t);
176 			return;
177 		}
178 #ifdef _KERNEL
179 		if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) {
180 			struct g_kerneldump *gkd;
181 
182 			gkd = (struct g_kerneldump *)bp->bio_data;
183 			gkd->offset += gsp->slices[index].offset;
184 			if (gkd->length > gsp->slices[index].length)
185 				gkd->length = gsp->slices[index].length;
186 			/* now, pass it on downwards... */
187 		}
188 #endif
189 		bp2 = g_clone_bio(bp);
190 		if (bp2 == NULL) {
191 			g_io_deliver(bp, ENOMEM);
192 			return;
193 		}
194 		bp2->bio_done = g_std_done;
195 		g_io_request(bp2, cp);
196 		break;
197 	default:
198 		g_io_deliver(bp, EOPNOTSUPP);
199 		return;
200 	}
201 }
202 
203 void
204 g_slice_dumpconf(struct sbuf *sb, char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
205 {
206 	struct g_slicer *gsp;
207 
208 	gsp = gp->softc;
209 	if (gp != NULL && (pp == NULL && cp == NULL)) {
210 		sbuf_printf(sb, "%s<frontstuff>%ju</frontstuff>\n",
211 		    indent, (intmax_t)gsp->frontstuff);
212 	}
213 	if (pp != NULL) {
214 		sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
215 		sbuf_printf(sb, "%s<length>%ju</length>\n",
216 		    indent, (uintmax_t)gsp->slices[pp->index].length);
217 		sbuf_printf(sb, "%s<seclength>%ju</seclength>\n", indent,
218 		    (uintmax_t)gsp->slices[pp->index].length / 512);
219 		sbuf_printf(sb, "%s<offset>%ju</offset>\n", indent,
220 		    (uintmax_t)gsp->slices[pp->index].offset);
221 		sbuf_printf(sb, "%s<secoffset>%ju</secoffset>\n", indent,
222 		    (uintmax_t)gsp->slices[pp->index].offset / 512);
223 	}
224 }
225 
226 int
227 g_slice_config(struct g_geom *gp, int index, int how, off_t offset, off_t length, u_int sectorsize, char *fmt, ...)
228 {
229 	struct g_provider *pp;
230 	struct g_slicer *gsp;
231 	struct g_slice *gsl;
232 	va_list ap;
233 	struct sbuf *sb;
234 	int error, acc;
235 
236 	g_trace(G_T_TOPOLOGY, "g_slice_config(%s, %d, %d)",
237 	     gp->name, index, how);
238 	g_topology_assert();
239 	gsp = gp->softc;
240 	error = 0;
241 	if (index >= gsp->nslice)
242 		return(EINVAL);
243 	gsl = &gsp->slices[index];
244 	pp = gsl->provider;
245 	if (pp != NULL)
246 		acc = pp->acr + pp->acw + pp->ace;
247 	else
248 		acc = 0;
249 	if (acc != 0 && how != G_SLICE_CONFIG_FORCE) {
250 		if (length < gsl->length)
251 			return(EBUSY);
252 		if (offset != gsl->offset)
253 			return(EBUSY);
254 	}
255 	/* XXX: check offset + length <= MEDIASIZE */
256 	if (how == G_SLICE_CONFIG_CHECK)
257 		return (0);
258 	gsl->length = length;
259 	gsl->offset = offset;
260 	gsl->sectorsize = sectorsize;
261 	if (length != 0 && pp != NULL)
262 		return (0);
263 	if (length == 0 && pp == NULL)
264 		return (0);
265 	if (length == 0 && pp != NULL) {
266 		g_orphan_provider(pp, ENXIO);
267 		gsl->provider = NULL;
268 		gsp->nprovider--;
269 		return (0);
270 	}
271 	va_start(ap, fmt);
272 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
273 	sbuf_vprintf(sb, fmt, ap);
274 	sbuf_finish(sb);
275 	pp = g_new_providerf(gp, sbuf_data(sb));
276 	pp->index = index;
277 	pp->mediasize = gsl->length;
278 	pp->sectorsize = gsl->sectorsize;
279 	gsl->provider = pp;
280 	gsp->nprovider++;
281 	g_error_provider(pp, 0);
282 	sbuf_delete(sb);
283 	return(0);
284 }
285 
286 struct g_provider *
287 g_slice_addslice(struct g_geom *gp, int index, off_t offset, off_t length, u_int sectorsize, char *fmt, ...)
288 {
289 	struct g_provider *pp;
290 	struct g_slicer *gsp;
291 	va_list ap;
292 	struct sbuf *sb;
293 
294 	g_trace(G_T_TOPOLOGY, "g_slice_addslice()");
295 	g_topology_assert();
296 	gsp = gp->softc;
297 	va_start(ap, fmt);
298 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
299 	sbuf_vprintf(sb, fmt, ap);
300 	sbuf_finish(sb);
301 	pp = g_new_providerf(gp, sbuf_data(sb));
302 
303 	pp->index = index;
304 	gsp->slices[index].length = length;
305 	gsp->slices[index].offset = offset;
306 	gsp->slices[index].provider = pp;
307 	gsp->slices[index].sectorsize = sectorsize;
308 	pp->mediasize = gsp->slices[index].length;
309 	pp->sectorsize = gsp->slices[index].sectorsize;
310 	sbuf_delete(sb);
311 	return(pp);
312 }
313 
314 struct g_geom *
315 g_slice_new(struct g_class *mp, int slices, struct g_provider *pp, struct g_consumer **cpp, void *extrap, int extra, g_slice_start_t *start)
316 {
317 	struct g_geom *gp;
318 	struct g_slicer *gsp;
319 	struct g_consumer *cp;
320 	void **vp;
321 	int error, i;
322 
323 	g_topology_assert();
324 	vp = (void **)extrap;
325 	gp = g_new_geomf(mp, "%s", pp->name);
326 	gsp = g_slice_init(slices, extra);
327 	gsp->start = start;
328 	gp->access = g_slice_access;
329 	gp->orphan = g_slice_orphan;
330 	gp->softc = gsp;
331 	gp->start = g_slice_start;
332 	gp->spoiled = g_std_spoiled;
333 	gp->dumpconf = g_slice_dumpconf;
334 	cp = g_new_consumer(gp);
335 	error = g_attach(cp, pp);
336 	if (error == 0)
337 		error = g_access_rel(cp, 1, 0, 0);
338 	if (error) {
339 		if (cp->provider != NULL)
340 			g_detach(cp);
341 		g_destroy_consumer(cp);
342 		g_free(gsp->slices);
343 		g_free(gp->softc);
344 		g_destroy_geom(gp);
345 		return (NULL);
346 	}
347 	/* Find out if there are any magic bytes on the consumer */
348 	i = sizeof gsp->cfrontstuff;
349 	error = g_io_getattr("GEOM::frontstuff", cp, &i, &gsp->cfrontstuff);
350 	if (error)
351 		gsp->cfrontstuff = 0;
352 	*vp = gsp->softc;
353 	*cpp = cp;
354 	return (gp);
355 }
356 
357 static void
358 g_slice_orphan(struct g_consumer *cp)
359 {
360 	struct g_geom *gp;
361 	struct g_provider *pp;
362 	int error;
363 
364 	g_trace(G_T_TOPOLOGY, "g_slice_orphan(%p/%s)", cp, cp->provider->name);
365 	g_topology_assert();
366 	KASSERT(cp->provider->error != 0,
367 	    ("g_slice_orphan with error == 0"));
368 
369 	gp = cp->geom;
370 	gp->flags |= G_GEOM_WITHER;
371 	error = cp->provider->error;
372 	LIST_FOREACH(pp, &gp->provider, provider)
373 		g_orphan_provider(pp, error);
374 	return;
375 }
376