xref: /freebsd/sys/geom/geom_slice.c (revision 6fd05b64b5b65dd4ba9b86482a0634a5f0b96c29)
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 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/bio.h>
44 #include <sys/sysctl.h>
45 #include <sys/proc.h>
46 #include <sys/kthread.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/errno.h>
50 #include <sys/sbuf.h>
51 #include <geom/geom.h>
52 #include <geom/geom_slice.h>
53 #include <machine/stdarg.h>
54 
55 static g_orphan_t g_slice_orphan;
56 static g_access_t g_slice_access;
57 static g_start_t g_slice_start;
58 
59 static struct g_slicer *
60 g_slice_alloc(unsigned nslice, unsigned scsize)
61 {
62 	struct g_slicer *gsp;
63 
64 	gsp = g_malloc(sizeof *gsp, M_WAITOK | M_ZERO);
65 	if (scsize > 0)
66 		gsp->softc = g_malloc(scsize, M_WAITOK | M_ZERO);
67 	else
68 		gsp->softc = NULL;
69 	gsp->slices = g_malloc(nslice * sizeof(struct g_slice),
70 	    M_WAITOK | M_ZERO);
71 	gsp->nslice = nslice;
72 	return (gsp);
73 }
74 
75 static void
76 g_slice_free(struct g_slicer *gsp)
77 {
78 
79 	g_free(gsp->slices);
80 	if (gsp->hotspot != NULL)
81 		g_free(gsp->hotspot);
82 	if (gsp->softc != NULL)
83 		g_free(gsp->softc);
84 	g_free(gsp);
85 }
86 
87 static int
88 g_slice_access(struct g_provider *pp, int dr, int dw, int de)
89 {
90 	int error;
91 	u_int u;
92 	struct g_geom *gp;
93 	struct g_consumer *cp;
94 	struct g_provider *pp2;
95 	struct g_slicer *gsp;
96 	struct g_slice *gsl, *gsl2;
97 
98 	gp = pp->geom;
99 	cp = LIST_FIRST(&gp->consumer);
100 	KASSERT (cp != NULL, ("g_slice_access but no consumer"));
101 	gsp = gp->softc;
102 	if (dr > 0 || dw > 0 || de > 0) {
103 		gsl = &gsp->slices[pp->index];
104 		for (u = 0; u < gsp->nslice; u++) {
105 			gsl2 = &gsp->slices[u];
106 			if (gsl2->length == 0)
107 				continue;
108 			if (u == pp->index)
109 				continue;
110 			if (gsl->offset + gsl->length <= gsl2->offset)
111 				continue;
112 			if (gsl2->offset + gsl2->length <= gsl->offset)
113 				continue;
114 			/* overlap */
115 			pp2 = gsl2->provider;
116 			if ((pp->acw + dw) > 0 && pp2->ace > 0)
117 				return (EPERM);
118 			if ((pp->ace + de) > 0 && pp2->acw > 0)
119 				return (EPERM);
120 		}
121 	}
122 	/* On first open, grab an extra "exclusive" bit */
123 	if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
124 		de++;
125 	/* ... and let go of it on last close */
126 	if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1)
127 		de--;
128 	error = g_access(cp, dr, dw, de);
129 	return (error);
130 }
131 
132 /*
133  * XXX: It should be possible to specify here if we should finish all of the
134  * XXX: bio, or only the non-hot bits.  This would get messy if there were
135  * XXX: two hot spots in the same bio, so for now we simply finish off the
136  * XXX: entire bio.  Modifying hot data on the way to disk is frowned on
137  * XXX: so making that considerably harder is not a bad idea anyway.
138  */
139 void
140 g_slice_finish_hot(struct bio *bp)
141 {
142 	struct bio *bp2;
143 	struct g_geom *gp;
144 	struct g_consumer *cp;
145 	struct g_slicer *gsp;
146 	struct g_slice *gsl;
147 	int idx;
148 
149 	KASSERT(bp->bio_to != NULL,
150 	    ("NULL bio_to in g_slice_finish_hot(%p)", bp));
151 	KASSERT(bp->bio_from != NULL,
152 	    ("NULL bio_from in g_slice_finish_hot(%p)", bp));
153 	gp = bp->bio_to->geom;
154 	gsp = gp->softc;
155 	cp = LIST_FIRST(&gp->consumer);
156 	KASSERT(cp != NULL, ("NULL consumer in g_slice_finish_hot(%p)", bp));
157 	idx = bp->bio_to->index;
158 	gsl = &gsp->slices[idx];
159 
160 	bp2 = g_clone_bio(bp);
161 	if (bp2 == NULL) {
162 		g_io_deliver(bp, ENOMEM);
163 		return;
164 	}
165 	if (bp2->bio_offset + bp2->bio_length > gsl->length)
166 		bp2->bio_length = gsl->length - bp2->bio_offset;
167 	bp2->bio_done = g_std_done;
168 	bp2->bio_offset += gsl->offset;
169 	g_io_request(bp2, cp);
170 	return;
171 }
172 
173 static void
174 g_slice_start(struct bio *bp)
175 {
176 	struct bio *bp2;
177 	struct g_provider *pp;
178 	struct g_geom *gp;
179 	struct g_consumer *cp;
180 	struct g_slicer *gsp;
181 	struct g_slice *gsl;
182 	struct g_slice_hot *ghp;
183 	int idx, error;
184 	u_int m_index;
185 	off_t t;
186 
187 	pp = bp->bio_to;
188 	gp = pp->geom;
189 	gsp = gp->softc;
190 	cp = LIST_FIRST(&gp->consumer);
191 	idx = pp->index;
192 	gsl = &gsp->slices[idx];
193 	switch(bp->bio_cmd) {
194 	case BIO_READ:
195 	case BIO_WRITE:
196 	case BIO_DELETE:
197 		if (bp->bio_offset > gsl->length) {
198 			g_io_deliver(bp, EINVAL); /* XXX: EWHAT ? */
199 			return;
200 		}
201 		/*
202 		 * Check if we collide with any hot spaces, and call the
203 		 * method once if so.
204 		 */
205 		t = bp->bio_offset + gsl->offset;
206 		for (m_index = 0; m_index < gsp->nhotspot; m_index++) {
207 			ghp = &gsp->hotspot[m_index];
208 			if (t >= ghp->offset + ghp->length)
209 				continue;
210 			if (t + bp->bio_length <= ghp->offset)
211 				continue;
212 			switch(bp->bio_cmd) {
213 			case BIO_READ:		idx = ghp->ract; break;
214 			case BIO_WRITE:		idx = ghp->wact; break;
215 			case BIO_DELETE:	idx = ghp->dact; break;
216 			}
217 			switch(idx) {
218 			case G_SLICE_HOT_ALLOW:
219 				/* Fall out and continue normal processing */
220 				continue;
221 			case G_SLICE_HOT_DENY:
222 				g_io_deliver(bp, EROFS);
223 				return;
224 			case G_SLICE_HOT_START:
225 				error = gsp->start(bp);
226 				if (error && error != EJUSTRETURN)
227 					g_io_deliver(bp, error);
228 				return;
229 			case G_SLICE_HOT_CALL:
230 				error = g_post_event(gsp->hot, bp, M_NOWAIT,
231 				    gp, NULL);
232 				if (error)
233 					g_io_deliver(bp, error);
234 				return;
235 			}
236 			break;
237 		}
238 		bp2 = g_clone_bio(bp);
239 		if (bp2 == NULL) {
240 			g_io_deliver(bp, ENOMEM);
241 			return;
242 		}
243 		if (bp2->bio_offset + bp2->bio_length > gsl->length)
244 			bp2->bio_length = gsl->length - bp2->bio_offset;
245 		bp2->bio_done = g_std_done;
246 		bp2->bio_offset += gsl->offset;
247 		g_io_request(bp2, cp);
248 		return;
249 	case BIO_GETATTR:
250 		/* Give the real method a chance to override */
251 		if (gsp->start != NULL && gsp->start(bp))
252 			return;
253 		if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) {
254 			struct g_kerneldump *gkd;
255 
256 			gkd = (struct g_kerneldump *)bp->bio_data;
257 			gkd->offset += gsp->slices[idx].offset;
258 			if (gkd->length > gsp->slices[idx].length)
259 				gkd->length = gsp->slices[idx].length;
260 			/* now, pass it on downwards... */
261 		}
262 		bp2 = g_clone_bio(bp);
263 		if (bp2 == NULL) {
264 			g_io_deliver(bp, ENOMEM);
265 			return;
266 		}
267 		bp2->bio_done = g_std_done;
268 		g_io_request(bp2, cp);
269 		break;
270 	default:
271 		g_io_deliver(bp, EOPNOTSUPP);
272 		return;
273 	}
274 }
275 
276 void
277 g_slice_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
278 {
279 	struct g_slicer *gsp;
280 
281 	gsp = gp->softc;
282 	if (indent == NULL) {
283 		sbuf_printf(sb, " i %u", pp->index);
284 		sbuf_printf(sb, " o %ju",
285 		    (uintmax_t)gsp->slices[pp->index].offset);
286 		return;
287 	}
288 	if (pp != NULL) {
289 		sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
290 		sbuf_printf(sb, "%s<length>%ju</length>\n",
291 		    indent, (uintmax_t)gsp->slices[pp->index].length);
292 		sbuf_printf(sb, "%s<seclength>%ju</seclength>\n", indent,
293 		    (uintmax_t)gsp->slices[pp->index].length / 512);
294 		sbuf_printf(sb, "%s<offset>%ju</offset>\n", indent,
295 		    (uintmax_t)gsp->slices[pp->index].offset);
296 		sbuf_printf(sb, "%s<secoffset>%ju</secoffset>\n", indent,
297 		    (uintmax_t)gsp->slices[pp->index].offset / 512);
298 	}
299 }
300 
301 int
302 g_slice_config(struct g_geom *gp, u_int idx, int how, off_t offset, off_t length, u_int sectorsize, const char *fmt, ...)
303 {
304 	struct g_provider *pp, *pp2;
305 	struct g_slicer *gsp;
306 	struct g_slice *gsl;
307 	va_list ap;
308 	struct sbuf *sb;
309 	int acc;
310 
311 	g_trace(G_T_TOPOLOGY, "g_slice_config(%s, %d, %d)",
312 	     gp->name, idx, how);
313 	g_topology_assert();
314 	gsp = gp->softc;
315 	if (idx >= gsp->nslice)
316 		return(EINVAL);
317 	gsl = &gsp->slices[idx];
318 	pp = gsl->provider;
319 	if (pp != NULL)
320 		acc = pp->acr + pp->acw + pp->ace;
321 	else
322 		acc = 0;
323 	if (acc != 0 && how != G_SLICE_CONFIG_FORCE) {
324 		if (length < gsl->length)
325 			return(EBUSY);
326 		if (offset != gsl->offset)
327 			return(EBUSY);
328 	}
329 	/* XXX: check offset + length <= MEDIASIZE */
330 	if (how == G_SLICE_CONFIG_CHECK)
331 		return (0);
332 	gsl->length = length;
333 	gsl->offset = offset;
334 	gsl->sectorsize = sectorsize;
335 	if (length == 0) {
336 		if (pp == NULL)
337 			return (0);
338 		if (bootverbose)
339 			printf("GEOM: Deconfigure %s\n", pp->name);
340 		g_orphan_provider(pp, ENXIO);
341 		gsl->provider = NULL;
342 		gsp->nprovider--;
343 		return (0);
344 	}
345 	if (pp != NULL) {
346 		if (bootverbose)
347 			printf("GEOM: Reconfigure %s, start %jd length %jd end %jd\n",
348 			    pp->name, (intmax_t)offset, (intmax_t)length,
349 			    (intmax_t)(offset + length - 1));
350 		pp->mediasize = gsl->length;
351 		return (0);
352 	}
353 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
354 	va_start(ap, fmt);
355 	sbuf_vprintf(sb, fmt, ap);
356 	va_end(ap);
357 	sbuf_finish(sb);
358 	pp = g_new_providerf(gp, sbuf_data(sb));
359 	pp2 = LIST_FIRST(&gp->consumer)->provider;
360 	pp->flags = pp2->flags & G_PF_CANDELETE;
361 	if (pp2->stripesize > 0) {
362 		pp->stripesize = pp2->stripesize;
363 		pp->stripeoffset = (pp2->stripeoffset + offset) % pp->stripesize;
364 	}
365 	if (bootverbose)
366 		printf("GEOM: Configure %s, start %jd length %jd end %jd\n",
367 		    pp->name, (intmax_t)offset, (intmax_t)length,
368 		    (intmax_t)(offset + length - 1));
369 	pp->index = idx;
370 	pp->mediasize = gsl->length;
371 	pp->sectorsize = gsl->sectorsize;
372 	gsl->provider = pp;
373 	gsp->nprovider++;
374 	g_error_provider(pp, 0);
375 	sbuf_delete(sb);
376 	return(0);
377 }
378 
379 /*
380  * Configure "hotspots".  A hotspot is a piece of the parent device which
381  * this particular slicer cares about for some reason.  Typically because
382  * it contains meta-data used to configure the slicer.
383  * A hotspot is identified by its index number. The offset and length are
384  * relative to the parent device, and the three "?act" fields specify
385  * what action to take on BIO_READ, BIO_DELETE and BIO_WRITE.
386  *
387  * XXX: There may be a race relative to g_slice_start() here, if an existing
388  * XXX: hotspot is changed wile I/O is happening.  Should this become a problem
389  * XXX: we can protect the hotspot stuff with a mutex.
390  */
391 
392 int
393 g_slice_conf_hot(struct g_geom *gp, u_int idx, off_t offset, off_t length, int ract, int dact, int wact)
394 {
395 	struct g_slicer *gsp;
396 	struct g_slice_hot *gsl, *gsl2;
397 
398 	g_trace(G_T_TOPOLOGY, "g_slice_conf_hot(%s, idx: %d, off: %jd, len: %jd)",
399 	    gp->name, idx, (intmax_t)offset, (intmax_t)length);
400 	g_topology_assert();
401 	gsp = gp->softc;
402 	gsl = gsp->hotspot;
403 	if(idx >= gsp->nhotspot) {
404 		gsl2 = g_malloc((idx + 1) * sizeof *gsl2, M_WAITOK | M_ZERO);
405 		if (gsp->hotspot != NULL)
406 			bcopy(gsp->hotspot, gsl2, gsp->nhotspot * sizeof *gsl2);
407 		gsp->hotspot = gsl2;
408 		if (gsp->hotspot != NULL)
409 			g_free(gsl);
410 		gsl = gsl2;
411 		gsp->nhotspot = idx + 1;
412 	}
413 	gsl[idx].offset = offset;
414 	gsl[idx].length = length;
415 	KASSERT(!((ract | dact | wact) & G_SLICE_HOT_START)
416 	    || gsp->start != NULL, ("G_SLICE_HOT_START but no slice->start"));
417 	/* XXX: check that we _have_ a start function if HOT_START specified */
418 	gsl[idx].ract = ract;
419 	gsl[idx].dact = dact;
420 	gsl[idx].wact = wact;
421 	return (0);
422 }
423 
424 void
425 g_slice_spoiled(struct g_consumer *cp)
426 {
427 	struct g_geom *gp;
428 	struct g_slicer *gsp;
429 
430 	g_topology_assert();
431 	gp = cp->geom;
432 	g_trace(G_T_TOPOLOGY, "g_slice_spoiled(%p/%s)", cp, gp->name);
433 	gsp = gp->softc;
434 	gp->softc = NULL;
435 	g_slice_free(gsp);
436 	g_wither_geom(gp, ENXIO);
437 }
438 
439 int
440 g_slice_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
441 {
442 
443 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
444 	return (0);
445 }
446 
447 struct g_geom *
448 g_slice_new(struct g_class *mp, u_int slices, struct g_provider *pp, struct g_consumer **cpp, void *extrap, int extra, g_slice_start_t *start)
449 {
450 	struct g_geom *gp;
451 	struct g_slicer *gsp;
452 	struct g_consumer *cp;
453 	void **vp;
454 	int error;
455 
456 	g_topology_assert();
457 	vp = (void **)extrap;
458 	gp = g_new_geomf(mp, "%s", pp->name);
459 	gsp = g_slice_alloc(slices, extra);
460 	gsp->start = start;
461 	gp->access = g_slice_access;
462 	gp->orphan = g_slice_orphan;
463 	gp->softc = gsp;
464 	gp->start = g_slice_start;
465 	gp->spoiled = g_slice_spoiled;
466 	gp->dumpconf = g_slice_dumpconf;
467 	if (gp->class->destroy_geom == NULL)
468 		gp->class->destroy_geom = g_slice_destroy_geom;
469 	cp = g_new_consumer(gp);
470 	error = g_attach(cp, pp);
471 	if (error == 0)
472 		error = g_access(cp, 1, 0, 0);
473 	if (error) {
474 		g_wither_geom(gp, ENXIO);
475 		return (NULL);
476 	}
477 	if (extrap != NULL)
478 		*vp = gsp->softc;
479 	*cpp = cp;
480 	return (gp);
481 }
482 
483 static void
484 g_slice_orphan(struct g_consumer *cp)
485 {
486 
487 	g_trace(G_T_TOPOLOGY, "g_slice_orphan(%p/%s)", cp, cp->provider->name);
488 	g_topology_assert();
489 	KASSERT(cp->provider->error != 0,
490 	    ("g_slice_orphan with error == 0"));
491 
492 	/* XXX: Not good enough we leak the softc and its suballocations */
493 	g_slice_free(cp->geom->softc);
494 	g_wither_geom(cp->geom, cp->provider->error);
495 }
496