xref: /freebsd/sys/geom/geom_slice.c (revision a64729f5077d77e13b9497cb33ecb3c82e606ee8)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2002 Poul-Henning Kamp
5  * Copyright (c) 2002 Networks Associates Technology, Inc.
6  * All rights reserved.
7  *
8  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
9  * and NAI Labs, the Security Research Division of Network Associates, Inc.
10  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
11  * DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The names of the authors may not be used to endorse or promote
22  *    products derived from this software without specific prior written
23  *    permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/bio.h>
43 #include <sys/proc.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/errno.h>
47 #include <sys/sbuf.h>
48 #include <geom/geom.h>
49 #include <geom/geom_slice.h>
50 #include <machine/stdarg.h>
51 
52 static g_access_t g_slice_access;
53 static g_start_t g_slice_start;
54 
55 static struct g_slicer *
56 g_slice_alloc(unsigned nslice, unsigned scsize)
57 {
58 	struct g_slicer *gsp;
59 
60 	gsp = g_malloc(sizeof *gsp, M_WAITOK | M_ZERO);
61 	if (scsize > 0)
62 		gsp->softc = g_malloc(scsize, M_WAITOK | M_ZERO);
63 	else
64 		gsp->softc = NULL;
65 	gsp->slices = g_malloc(nslice * sizeof(struct g_slice),
66 	    M_WAITOK | M_ZERO);
67 	gsp->nslice = nslice;
68 	return (gsp);
69 }
70 
71 static void
72 g_slice_free(struct g_geom *gp)
73 {
74 	struct g_slicer *gsp;
75 
76 	gsp = gp->softc;
77 	gp->softc = NULL;
78 
79 	/*
80 	 * We can get multiple spoiled events before wither-washer
81 	 * detaches our consumer, so this can get called multiple
82 	 * times.
83 	 */
84 	if (gsp == NULL)
85 		return;
86 	g_free(gsp->slices);
87 	g_free(gsp->hotspot);
88 	g_free(gsp->softc);
89 	g_free(gsp);
90 }
91 
92 static int
93 g_slice_access(struct g_provider *pp, int dr, int dw, int de)
94 {
95 	int error;
96 	u_int u;
97 	struct g_geom *gp;
98 	struct g_consumer *cp;
99 	struct g_provider *pp2;
100 	struct g_slicer *gsp;
101 	struct g_slice *gsl, *gsl2;
102 
103 	gp = pp->geom;
104 	cp = LIST_FIRST(&gp->consumer);
105 	KASSERT (cp != NULL, ("g_slice_access but no consumer"));
106 	gsp = gp->softc;
107 	if (dr > 0 || dw > 0 || de > 0) {
108 		gsl = &gsp->slices[pp->index];
109 		for (u = 0; u < gsp->nslice; u++) {
110 			gsl2 = &gsp->slices[u];
111 			if (gsl2->length == 0)
112 				continue;
113 			if (u == pp->index)
114 				continue;
115 			if (gsl->offset + gsl->length <= gsl2->offset)
116 				continue;
117 			if (gsl2->offset + gsl2->length <= gsl->offset)
118 				continue;
119 			/* overlap */
120 			pp2 = gsl2->provider;
121 			if ((pp->acw + dw) > 0 && pp2->ace > 0)
122 				return (EPERM);
123 			if ((pp->ace + de) > 0 && pp2->acw > 0)
124 				return (EPERM);
125 		}
126 	}
127 	/* On first open, grab an extra "exclusive" bit */
128 	if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
129 		de++;
130 	/* ... and let go of it on last close */
131 	if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1)
132 		de--;
133 	error = g_access(cp, dr, dw, de);
134 
135 	/*
136 	 * Free the softc if all providers have been closed and this geom
137 	 * is being removed.
138 	 */
139 	if (error == 0 && (gp->flags & G_GEOM_WITHER) != 0 &&
140 	    (cp->acr + cp->acw + cp->ace) == 0)
141 		g_slice_free(gp);
142 
143 	return (error);
144 }
145 
146 /*
147  * XXX: It should be possible to specify here if we should finish all of the
148  * XXX: bio, or only the non-hot bits.  This would get messy if there were
149  * XXX: two hot spots in the same bio, so for now we simply finish off the
150  * XXX: entire bio.  Modifying hot data on the way to disk is frowned on
151  * XXX: so making that considerably harder is not a bad idea anyway.
152  */
153 void
154 g_slice_finish_hot(struct bio *bp)
155 {
156 	struct bio *bp2;
157 	struct g_geom *gp;
158 	struct g_consumer *cp;
159 	struct g_slicer *gsp;
160 	struct g_slice *gsl;
161 	int idx;
162 
163 	KASSERT(bp->bio_to != NULL,
164 	    ("NULL bio_to in g_slice_finish_hot(%p)", bp));
165 	KASSERT(bp->bio_from != NULL,
166 	    ("NULL bio_from in g_slice_finish_hot(%p)", bp));
167 	gp = bp->bio_to->geom;
168 	gsp = gp->softc;
169 	cp = LIST_FIRST(&gp->consumer);
170 	KASSERT(cp != NULL, ("NULL consumer in g_slice_finish_hot(%p)", bp));
171 	idx = bp->bio_to->index;
172 	gsl = &gsp->slices[idx];
173 
174 	bp2 = g_clone_bio(bp);
175 	if (bp2 == NULL) {
176 		g_io_deliver(bp, ENOMEM);
177 		return;
178 	}
179 	if (bp2->bio_offset + bp2->bio_length > gsl->length)
180 		bp2->bio_length = gsl->length - bp2->bio_offset;
181 	bp2->bio_done = g_std_done;
182 	bp2->bio_offset += gsl->offset;
183 	g_io_request(bp2, cp);
184 	return;
185 }
186 
187 static void
188 g_slice_done(struct bio *bp)
189 {
190 
191 	KASSERT(bp->bio_cmd == BIO_GETATTR &&
192 	    strcmp(bp->bio_attribute, "GEOM::ident") == 0,
193 	    ("bio_cmd=0x%x bio_attribute=%s", bp->bio_cmd, bp->bio_attribute));
194 
195 	if (bp->bio_error == 0 && bp->bio_data[0] != '\0') {
196 		char idx[8];
197 
198 		/* Add index to the ident received. */
199 		snprintf(idx, sizeof(idx), "s%d",
200 		    bp->bio_parent->bio_to->index);
201 		if (strlcat(bp->bio_data, idx, bp->bio_length) >=
202 		    bp->bio_length) {
203 			bp->bio_error = EFAULT;
204 		}
205 	}
206 	g_std_done(bp);
207 }
208 
209 static void
210 g_slice_start(struct bio *bp)
211 {
212 	struct bio *bp2;
213 	struct g_provider *pp;
214 	struct g_geom *gp;
215 	struct g_consumer *cp;
216 	struct g_slicer *gsp;
217 	struct g_slice *gsl;
218 	struct g_slice_hot *ghp;
219 	int idx, error;
220 	u_int m_index;
221 	off_t t;
222 
223 	pp = bp->bio_to;
224 	gp = pp->geom;
225 	gsp = gp->softc;
226 	cp = LIST_FIRST(&gp->consumer);
227 	idx = pp->index;
228 	gsl = &gsp->slices[idx];
229 	switch(bp->bio_cmd) {
230 	case BIO_READ:
231 	case BIO_WRITE:
232 	case BIO_DELETE:
233 		if (bp->bio_offset > gsl->length) {
234 			g_io_deliver(bp, EINVAL); /* XXX: EWHAT ? */
235 			return;
236 		}
237 		/*
238 		 * Check if we collide with any hot spaces, and call the
239 		 * method once if so.
240 		 */
241 		t = bp->bio_offset + gsl->offset;
242 		for (m_index = 0; m_index < gsp->nhotspot; m_index++) {
243 			ghp = &gsp->hotspot[m_index];
244 			if (t >= ghp->offset + ghp->length)
245 				continue;
246 			if (t + bp->bio_length <= ghp->offset)
247 				continue;
248 			switch(bp->bio_cmd) {
249 			case BIO_READ:		idx = ghp->ract; break;
250 			case BIO_WRITE:		idx = ghp->wact; break;
251 			case BIO_DELETE:	idx = ghp->dact; break;
252 			}
253 			switch(idx) {
254 			case G_SLICE_HOT_ALLOW:
255 				/* Fall out and continue normal processing */
256 				continue;
257 			case G_SLICE_HOT_DENY:
258 				g_io_deliver(bp, EROFS);
259 				return;
260 			case G_SLICE_HOT_START:
261 				error = gsp->start(bp);
262 				if (error && error != EJUSTRETURN)
263 					g_io_deliver(bp, error);
264 				return;
265 			case G_SLICE_HOT_CALL:
266 				error = g_post_event(gsp->hot, bp, M_NOWAIT,
267 				    gp, NULL);
268 				if (error)
269 					g_io_deliver(bp, error);
270 				return;
271 			}
272 			break;
273 		}
274 		bp2 = g_clone_bio(bp);
275 		if (bp2 == NULL) {
276 			g_io_deliver(bp, ENOMEM);
277 			return;
278 		}
279 		if (bp2->bio_offset + bp2->bio_length > gsl->length)
280 			bp2->bio_length = gsl->length - bp2->bio_offset;
281 		bp2->bio_done = g_std_done;
282 		bp2->bio_offset += gsl->offset;
283 		g_io_request(bp2, cp);
284 		return;
285 	case BIO_GETATTR:
286 		/* Give the real method a chance to override */
287 		if (gsp->start != NULL && gsp->start(bp))
288 			return;
289 		if (!strcmp("GEOM::ident", bp->bio_attribute)) {
290 			bp2 = g_clone_bio(bp);
291 			if (bp2 == NULL) {
292 				g_io_deliver(bp, ENOMEM);
293 				return;
294 			}
295 			bp2->bio_done = g_slice_done;
296 			g_io_request(bp2, cp);
297 			return;
298 		}
299 		if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) {
300 			struct g_kerneldump *gkd;
301 
302 			gkd = (struct g_kerneldump *)bp->bio_data;
303 			gkd->offset += gsp->slices[idx].offset;
304 			if (gkd->length > gsp->slices[idx].length)
305 				gkd->length = gsp->slices[idx].length;
306 			/* now, pass it on downwards... */
307 		}
308 		/* FALLTHROUGH */
309 	case BIO_SPEEDUP:
310 	case BIO_FLUSH:
311 		bp2 = g_clone_bio(bp);
312 		if (bp2 == NULL) {
313 			g_io_deliver(bp, ENOMEM);
314 			return;
315 		}
316 		bp2->bio_done = g_std_done;
317 		g_io_request(bp2, cp);
318 		break;
319 	default:
320 		g_io_deliver(bp, EOPNOTSUPP);
321 		return;
322 	}
323 }
324 
325 void
326 g_slice_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
327 {
328 	struct g_slicer *gsp;
329 
330 	gsp = gp->softc;
331 	if (indent == NULL) {
332 		sbuf_printf(sb, " i %u", pp->index);
333 		sbuf_printf(sb, " o %ju",
334 		    (uintmax_t)gsp->slices[pp->index].offset);
335 		return;
336 	}
337 	if (pp != NULL) {
338 		sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
339 		sbuf_printf(sb, "%s<length>%ju</length>\n",
340 		    indent, (uintmax_t)gsp->slices[pp->index].length);
341 		sbuf_printf(sb, "%s<seclength>%ju</seclength>\n", indent,
342 		    (uintmax_t)gsp->slices[pp->index].length / 512);
343 		sbuf_printf(sb, "%s<offset>%ju</offset>\n", indent,
344 		    (uintmax_t)gsp->slices[pp->index].offset);
345 		sbuf_printf(sb, "%s<secoffset>%ju</secoffset>\n", indent,
346 		    (uintmax_t)gsp->slices[pp->index].offset / 512);
347 	}
348 }
349 
350 int
351 g_slice_config(struct g_geom *gp, u_int idx, int how, off_t offset, off_t length, u_int sectorsize, const char *fmt, ...)
352 {
353 	struct g_provider *pp, *pp2;
354 	struct g_slicer *gsp;
355 	struct g_slice *gsl;
356 	va_list ap;
357 	struct sbuf *sb;
358 	int acc;
359 
360 	g_trace(G_T_TOPOLOGY, "g_slice_config(%s, %d, %d)",
361 	     gp->name, idx, how);
362 	g_topology_assert();
363 	gsp = gp->softc;
364 	if (idx >= gsp->nslice)
365 		return(EINVAL);
366 	gsl = &gsp->slices[idx];
367 	pp = gsl->provider;
368 	if (pp != NULL)
369 		acc = pp->acr + pp->acw + pp->ace;
370 	else
371 		acc = 0;
372 	if (acc != 0 && how != G_SLICE_CONFIG_FORCE) {
373 		if (length < gsl->length)
374 			return(EBUSY);
375 		if (offset != gsl->offset)
376 			return(EBUSY);
377 	}
378 	/* XXX: check offset + length <= MEDIASIZE */
379 	if (how == G_SLICE_CONFIG_CHECK)
380 		return (0);
381 	gsl->length = length;
382 	gsl->offset = offset;
383 	gsl->sectorsize = sectorsize;
384 	if (length == 0) {
385 		if (pp == NULL)
386 			return (0);
387 		if (bootverbose)
388 			printf("GEOM: Deconfigure %s\n", pp->name);
389 		g_wither_provider(pp, ENXIO);
390 		gsl->provider = NULL;
391 		gsp->nprovider--;
392 		return (0);
393 	}
394 	if (pp != NULL) {
395 		if (bootverbose)
396 			printf("GEOM: Reconfigure %s, start %jd length %jd end %jd\n",
397 			    pp->name, (intmax_t)offset, (intmax_t)length,
398 			    (intmax_t)(offset + length - 1));
399 		g_resize_provider(pp, gsl->length);
400 		return (0);
401 	}
402 	sb = sbuf_new_auto();
403 	va_start(ap, fmt);
404 	sbuf_vprintf(sb, fmt, ap);
405 	va_end(ap);
406 	sbuf_finish(sb);
407 	pp = g_new_providerf(gp, "%s", sbuf_data(sb));
408 	pp2 = LIST_FIRST(&gp->consumer)->provider;
409 	pp->stripesize = pp2->stripesize;
410 	pp->stripeoffset = pp2->stripeoffset + offset;
411 	if (pp->stripesize > 0)
412 		pp->stripeoffset %= pp->stripesize;
413 	if (gsp->nhotspot == 0) {
414 		pp->flags |= pp2->flags & G_PF_ACCEPT_UNMAPPED;
415 		pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
416 	}
417 	if (0 && bootverbose)
418 		printf("GEOM: Configure %s, start %jd length %jd end %jd\n",
419 		    pp->name, (intmax_t)offset, (intmax_t)length,
420 		    (intmax_t)(offset + length - 1));
421 	pp->index = idx;
422 	pp->mediasize = gsl->length;
423 	pp->sectorsize = gsl->sectorsize;
424 	gsl->provider = pp;
425 	gsp->nprovider++;
426 	g_error_provider(pp, 0);
427 	sbuf_delete(sb);
428 	return(0);
429 }
430 
431 /*
432  * Configure "hotspots".  A hotspot is a piece of the parent device which
433  * this particular slicer cares about for some reason.  Typically because
434  * it contains meta-data used to configure the slicer.
435  * A hotspot is identified by its index number. The offset and length are
436  * relative to the parent device, and the three "?act" fields specify
437  * what action to take on BIO_READ, BIO_DELETE and BIO_WRITE.
438  *
439  * XXX: There may be a race relative to g_slice_start() here, if an existing
440  * XXX: hotspot is changed wile I/O is happening.  Should this become a problem
441  * XXX: we can protect the hotspot stuff with a mutex.
442  */
443 
444 int
445 g_slice_conf_hot(struct g_geom *gp, u_int idx, off_t offset, off_t length, int ract, int dact, int wact)
446 {
447 	struct g_slicer *gsp;
448 	struct g_slice_hot *gsl, *gsl2;
449 	struct g_consumer *cp;
450 	struct g_provider *pp;
451 
452 	g_trace(G_T_TOPOLOGY, "g_slice_conf_hot(%s, idx: %d, off: %jd, len: %jd)",
453 	    gp->name, idx, (intmax_t)offset, (intmax_t)length);
454 	g_topology_assert();
455 	gsp = gp->softc;
456 	/* Deny unmapped I/O and direct dispatch if hotspots are used. */
457 	if (gsp->nhotspot == 0) {
458 		LIST_FOREACH(pp, &gp->provider, provider)
459 			pp->flags &= ~(G_PF_ACCEPT_UNMAPPED |
460 			    G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE);
461 		LIST_FOREACH(cp, &gp->consumer, consumer)
462 			cp->flags &= ~(G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE);
463 	}
464 	gsl = gsp->hotspot;
465 	if(idx >= gsp->nhotspot) {
466 		gsl2 = g_malloc((idx + 1) * sizeof *gsl2, M_WAITOK | M_ZERO);
467 		if (gsp->hotspot != NULL)
468 			bcopy(gsp->hotspot, gsl2, gsp->nhotspot * sizeof *gsl2);
469 		gsp->hotspot = gsl2;
470 		if (gsp->hotspot != NULL)
471 			g_free(gsl);
472 		gsl = gsl2;
473 		gsp->nhotspot = idx + 1;
474 	}
475 	gsl[idx].offset = offset;
476 	gsl[idx].length = length;
477 	KASSERT(!((ract | dact | wact) & G_SLICE_HOT_START)
478 	    || gsp->start != NULL, ("G_SLICE_HOT_START but no slice->start"));
479 	/* XXX: check that we _have_ a start function if HOT_START specified */
480 	gsl[idx].ract = ract;
481 	gsl[idx].dact = dact;
482 	gsl[idx].wact = wact;
483 	return (0);
484 }
485 
486 void
487 g_slice_orphan(struct g_consumer *cp)
488 {
489 	struct g_geom *gp;
490 
491 	g_topology_assert();
492 	gp = cp->geom;
493 	g_trace(G_T_TOPOLOGY, "%s(%p/%s)", __func__, cp, gp->name);
494 	g_wither_geom(gp, ENXIO);
495 
496 	/*
497 	 * We can safely free the softc now if there are no accesses,
498 	 * otherwise g_slice_access() will do that after the last close.
499 	 */
500 	if ((cp->acr + cp->acw + cp->ace) == 0)
501 		g_slice_free(gp);
502 }
503 
504 void
505 g_slice_spoiled(struct g_consumer *cp)
506 {
507 
508 	g_trace(G_T_TOPOLOGY, "%s(%p/%s)", __func__, cp, cp->geom->name);
509 	cp->flags |= G_CF_ORPHAN;
510 	g_slice_orphan(cp);
511 }
512 
513 int
514 g_slice_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
515 {
516 
517 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
518 	return (0);
519 }
520 
521 struct g_geom *
522 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)
523 {
524 	struct g_geom *gp;
525 	struct g_slicer *gsp;
526 	struct g_consumer *cp;
527 	void **vp;
528 	int error;
529 
530 	g_topology_assert();
531 	vp = (void **)extrap;
532 	gp = g_new_geomf(mp, "%s", pp->name);
533 	gsp = g_slice_alloc(slices, extra);
534 	gsp->start = start;
535 	gp->softc = gsp;
536 	gp->start = g_slice_start;
537 	gp->access = g_slice_access;
538 	gp->orphan = g_slice_orphan;
539 	gp->spoiled = g_slice_spoiled;
540 	if (gp->dumpconf == NULL)
541 		gp->dumpconf = g_slice_dumpconf;
542 	if (gp->class->destroy_geom == NULL)
543 		gp->class->destroy_geom = g_slice_destroy_geom;
544 	cp = g_new_consumer(gp);
545 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
546 	error = g_attach(cp, pp);
547 	if (error == 0)
548 		error = g_access(cp, 1, 0, 0);
549 	if (error) {
550 		g_wither_geom(gp, ENXIO);
551 		return (NULL);
552 	}
553 	if (extrap != NULL)
554 		*vp = gsp->softc;
555 	*cpp = cp;
556 	return (gp);
557 }
558