xref: /freebsd/sys/geom/geom_slice.c (revision 7bd6fde3951af84ef3b68e4d1eadc1840c2fc1b3)
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_access_t g_slice_access;
56 static g_start_t g_slice_start;
57 
58 static struct g_slicer *
59 g_slice_alloc(unsigned nslice, unsigned scsize)
60 {
61 	struct g_slicer *gsp;
62 
63 	gsp = g_malloc(sizeof *gsp, M_WAITOK | M_ZERO);
64 	if (scsize > 0)
65 		gsp->softc = g_malloc(scsize, M_WAITOK | M_ZERO);
66 	else
67 		gsp->softc = NULL;
68 	gsp->slices = g_malloc(nslice * sizeof(struct g_slice),
69 	    M_WAITOK | M_ZERO);
70 	gsp->nslice = nslice;
71 	return (gsp);
72 }
73 
74 static void
75 g_slice_free(struct g_slicer *gsp)
76 {
77 
78 	if (gsp == NULL)	/* XXX: phk thinks about this */
79 		return;
80 	g_free(gsp->slices);
81 	if (gsp->hotspot != NULL)
82 		g_free(gsp->hotspot);
83 	if (gsp->softc != NULL)
84 		g_free(gsp->softc);
85 	g_free(gsp);
86 }
87 
88 static int
89 g_slice_access(struct g_provider *pp, int dr, int dw, int de)
90 {
91 	int error;
92 	u_int u;
93 	struct g_geom *gp;
94 	struct g_consumer *cp;
95 	struct g_provider *pp2;
96 	struct g_slicer *gsp;
97 	struct g_slice *gsl, *gsl2;
98 
99 	gp = pp->geom;
100 	cp = LIST_FIRST(&gp->consumer);
101 	KASSERT (cp != NULL, ("g_slice_access but no consumer"));
102 	gsp = gp->softc;
103 	if (dr > 0 || dw > 0 || de > 0) {
104 		gsl = &gsp->slices[pp->index];
105 		for (u = 0; u < gsp->nslice; u++) {
106 			gsl2 = &gsp->slices[u];
107 			if (gsl2->length == 0)
108 				continue;
109 			if (u == pp->index)
110 				continue;
111 			if (gsl->offset + gsl->length <= gsl2->offset)
112 				continue;
113 			if (gsl2->offset + gsl2->length <= gsl->offset)
114 				continue;
115 			/* overlap */
116 			pp2 = gsl2->provider;
117 			if ((pp->acw + dw) > 0 && pp2->ace > 0)
118 				return (EPERM);
119 			if ((pp->ace + de) > 0 && pp2->acw > 0)
120 				return (EPERM);
121 		}
122 	}
123 	/* On first open, grab an extra "exclusive" bit */
124 	if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
125 		de++;
126 	/* ... and let go of it on last close */
127 	if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1)
128 		de--;
129 	error = g_access(cp, dr, dw, de);
130 	return (error);
131 }
132 
133 /*
134  * XXX: It should be possible to specify here if we should finish all of the
135  * XXX: bio, or only the non-hot bits.  This would get messy if there were
136  * XXX: two hot spots in the same bio, so for now we simply finish off the
137  * XXX: entire bio.  Modifying hot data on the way to disk is frowned on
138  * XXX: so making that considerably harder is not a bad idea anyway.
139  */
140 void
141 g_slice_finish_hot(struct bio *bp)
142 {
143 	struct bio *bp2;
144 	struct g_geom *gp;
145 	struct g_consumer *cp;
146 	struct g_slicer *gsp;
147 	struct g_slice *gsl;
148 	int idx;
149 
150 	KASSERT(bp->bio_to != NULL,
151 	    ("NULL bio_to in g_slice_finish_hot(%p)", bp));
152 	KASSERT(bp->bio_from != NULL,
153 	    ("NULL bio_from in g_slice_finish_hot(%p)", bp));
154 	gp = bp->bio_to->geom;
155 	gsp = gp->softc;
156 	cp = LIST_FIRST(&gp->consumer);
157 	KASSERT(cp != NULL, ("NULL consumer in g_slice_finish_hot(%p)", bp));
158 	idx = bp->bio_to->index;
159 	gsl = &gsp->slices[idx];
160 
161 	bp2 = g_clone_bio(bp);
162 	if (bp2 == NULL) {
163 		g_io_deliver(bp, ENOMEM);
164 		return;
165 	}
166 	if (bp2->bio_offset + bp2->bio_length > gsl->length)
167 		bp2->bio_length = gsl->length - bp2->bio_offset;
168 	bp2->bio_done = g_std_done;
169 	bp2->bio_offset += gsl->offset;
170 	g_io_request(bp2, cp);
171 	return;
172 }
173 
174 static void
175 g_slice_start(struct bio *bp)
176 {
177 	struct bio *bp2;
178 	struct g_provider *pp;
179 	struct g_geom *gp;
180 	struct g_consumer *cp;
181 	struct g_slicer *gsp;
182 	struct g_slice *gsl;
183 	struct g_slice_hot *ghp;
184 	int idx, error;
185 	u_int m_index;
186 	off_t t;
187 
188 	pp = bp->bio_to;
189 	gp = pp->geom;
190 	gsp = gp->softc;
191 	cp = LIST_FIRST(&gp->consumer);
192 	idx = pp->index;
193 	gsl = &gsp->slices[idx];
194 	switch(bp->bio_cmd) {
195 	case BIO_READ:
196 	case BIO_WRITE:
197 	case BIO_DELETE:
198 		if (bp->bio_offset > gsl->length) {
199 			g_io_deliver(bp, EINVAL); /* XXX: EWHAT ? */
200 			return;
201 		}
202 		/*
203 		 * Check if we collide with any hot spaces, and call the
204 		 * method once if so.
205 		 */
206 		t = bp->bio_offset + gsl->offset;
207 		for (m_index = 0; m_index < gsp->nhotspot; m_index++) {
208 			ghp = &gsp->hotspot[m_index];
209 			if (t >= ghp->offset + ghp->length)
210 				continue;
211 			if (t + bp->bio_length <= ghp->offset)
212 				continue;
213 			switch(bp->bio_cmd) {
214 			case BIO_READ:		idx = ghp->ract; break;
215 			case BIO_WRITE:		idx = ghp->wact; break;
216 			case BIO_DELETE:	idx = ghp->dact; break;
217 			}
218 			switch(idx) {
219 			case G_SLICE_HOT_ALLOW:
220 				/* Fall out and continue normal processing */
221 				continue;
222 			case G_SLICE_HOT_DENY:
223 				g_io_deliver(bp, EROFS);
224 				return;
225 			case G_SLICE_HOT_START:
226 				error = gsp->start(bp);
227 				if (error && error != EJUSTRETURN)
228 					g_io_deliver(bp, error);
229 				return;
230 			case G_SLICE_HOT_CALL:
231 				error = g_post_event(gsp->hot, bp, M_NOWAIT,
232 				    gp, NULL);
233 				if (error)
234 					g_io_deliver(bp, error);
235 				return;
236 			}
237 			break;
238 		}
239 		bp2 = g_clone_bio(bp);
240 		if (bp2 == NULL) {
241 			g_io_deliver(bp, ENOMEM);
242 			return;
243 		}
244 		if (bp2->bio_offset + bp2->bio_length > gsl->length)
245 			bp2->bio_length = gsl->length - bp2->bio_offset;
246 		bp2->bio_done = g_std_done;
247 		bp2->bio_offset += gsl->offset;
248 		g_io_request(bp2, cp);
249 		return;
250 	case BIO_GETATTR:
251 		/* Give the real method a chance to override */
252 		if (gsp->start != NULL && gsp->start(bp))
253 			return;
254 		if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) {
255 			struct g_kerneldump *gkd;
256 
257 			gkd = (struct g_kerneldump *)bp->bio_data;
258 			gkd->offset += gsp->slices[idx].offset;
259 			if (gkd->length > gsp->slices[idx].length)
260 				gkd->length = gsp->slices[idx].length;
261 			/* now, pass it on downwards... */
262 		}
263 		/* FALLTHROUGH */
264 	case BIO_FLUSH:
265 		bp2 = g_clone_bio(bp);
266 		if (bp2 == NULL) {
267 			g_io_deliver(bp, ENOMEM);
268 			return;
269 		}
270 		bp2->bio_done = g_std_done;
271 		g_io_request(bp2, cp);
272 		break;
273 	default:
274 		g_io_deliver(bp, EOPNOTSUPP);
275 		return;
276 	}
277 }
278 
279 void
280 g_slice_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
281 {
282 	struct g_slicer *gsp;
283 
284 	gsp = gp->softc;
285 	if (indent == NULL) {
286 		sbuf_printf(sb, " i %u", pp->index);
287 		sbuf_printf(sb, " o %ju",
288 		    (uintmax_t)gsp->slices[pp->index].offset);
289 		return;
290 	}
291 	if (pp != NULL) {
292 		sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
293 		sbuf_printf(sb, "%s<length>%ju</length>\n",
294 		    indent, (uintmax_t)gsp->slices[pp->index].length);
295 		sbuf_printf(sb, "%s<seclength>%ju</seclength>\n", indent,
296 		    (uintmax_t)gsp->slices[pp->index].length / 512);
297 		sbuf_printf(sb, "%s<offset>%ju</offset>\n", indent,
298 		    (uintmax_t)gsp->slices[pp->index].offset);
299 		sbuf_printf(sb, "%s<secoffset>%ju</secoffset>\n", indent,
300 		    (uintmax_t)gsp->slices[pp->index].offset / 512);
301 	}
302 }
303 
304 int
305 g_slice_config(struct g_geom *gp, u_int idx, int how, off_t offset, off_t length, u_int sectorsize, const char *fmt, ...)
306 {
307 	struct g_provider *pp, *pp2;
308 	struct g_slicer *gsp;
309 	struct g_slice *gsl;
310 	va_list ap;
311 	struct sbuf *sb;
312 	int acc;
313 
314 	g_trace(G_T_TOPOLOGY, "g_slice_config(%s, %d, %d)",
315 	     gp->name, idx, how);
316 	g_topology_assert();
317 	gsp = gp->softc;
318 	if (idx >= gsp->nslice)
319 		return(EINVAL);
320 	gsl = &gsp->slices[idx];
321 	pp = gsl->provider;
322 	if (pp != NULL)
323 		acc = pp->acr + pp->acw + pp->ace;
324 	else
325 		acc = 0;
326 	if (acc != 0 && how != G_SLICE_CONFIG_FORCE) {
327 		if (length < gsl->length)
328 			return(EBUSY);
329 		if (offset != gsl->offset)
330 			return(EBUSY);
331 	}
332 	/* XXX: check offset + length <= MEDIASIZE */
333 	if (how == G_SLICE_CONFIG_CHECK)
334 		return (0);
335 	gsl->length = length;
336 	gsl->offset = offset;
337 	gsl->sectorsize = sectorsize;
338 	if (length == 0) {
339 		if (pp == NULL)
340 			return (0);
341 		if (bootverbose)
342 			printf("GEOM: Deconfigure %s\n", pp->name);
343 		g_wither_provider(pp, ENXIO);
344 		gsl->provider = NULL;
345 		gsp->nprovider--;
346 		return (0);
347 	}
348 	if (pp != NULL) {
349 		if (bootverbose)
350 			printf("GEOM: Reconfigure %s, start %jd length %jd end %jd\n",
351 			    pp->name, (intmax_t)offset, (intmax_t)length,
352 			    (intmax_t)(offset + length - 1));
353 		pp->mediasize = gsl->length;
354 		return (0);
355 	}
356 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
357 	va_start(ap, fmt);
358 	sbuf_vprintf(sb, fmt, ap);
359 	va_end(ap);
360 	sbuf_finish(sb);
361 	pp = g_new_providerf(gp, sbuf_data(sb));
362 	pp2 = LIST_FIRST(&gp->consumer)->provider;
363 	pp->flags = pp2->flags & G_PF_CANDELETE;
364 	if (pp2->stripesize > 0) {
365 		pp->stripesize = pp2->stripesize;
366 		pp->stripeoffset = (pp2->stripeoffset + offset) % pp->stripesize;
367 	}
368 	if (0 && bootverbose)
369 		printf("GEOM: Configure %s, start %jd length %jd end %jd\n",
370 		    pp->name, (intmax_t)offset, (intmax_t)length,
371 		    (intmax_t)(offset + length - 1));
372 	pp->index = idx;
373 	pp->mediasize = gsl->length;
374 	pp->sectorsize = gsl->sectorsize;
375 	gsl->provider = pp;
376 	gsp->nprovider++;
377 	g_error_provider(pp, 0);
378 	sbuf_delete(sb);
379 	return(0);
380 }
381 
382 /*
383  * Configure "hotspots".  A hotspot is a piece of the parent device which
384  * this particular slicer cares about for some reason.  Typically because
385  * it contains meta-data used to configure the slicer.
386  * A hotspot is identified by its index number. The offset and length are
387  * relative to the parent device, and the three "?act" fields specify
388  * what action to take on BIO_READ, BIO_DELETE and BIO_WRITE.
389  *
390  * XXX: There may be a race relative to g_slice_start() here, if an existing
391  * XXX: hotspot is changed wile I/O is happening.  Should this become a problem
392  * XXX: we can protect the hotspot stuff with a mutex.
393  */
394 
395 int
396 g_slice_conf_hot(struct g_geom *gp, u_int idx, off_t offset, off_t length, int ract, int dact, int wact)
397 {
398 	struct g_slicer *gsp;
399 	struct g_slice_hot *gsl, *gsl2;
400 
401 	g_trace(G_T_TOPOLOGY, "g_slice_conf_hot(%s, idx: %d, off: %jd, len: %jd)",
402 	    gp->name, idx, (intmax_t)offset, (intmax_t)length);
403 	g_topology_assert();
404 	gsp = gp->softc;
405 	gsl = gsp->hotspot;
406 	if(idx >= gsp->nhotspot) {
407 		gsl2 = g_malloc((idx + 1) * sizeof *gsl2, M_WAITOK | M_ZERO);
408 		if (gsp->hotspot != NULL)
409 			bcopy(gsp->hotspot, gsl2, gsp->nhotspot * sizeof *gsl2);
410 		gsp->hotspot = gsl2;
411 		if (gsp->hotspot != NULL)
412 			g_free(gsl);
413 		gsl = gsl2;
414 		gsp->nhotspot = idx + 1;
415 	}
416 	gsl[idx].offset = offset;
417 	gsl[idx].length = length;
418 	KASSERT(!((ract | dact | wact) & G_SLICE_HOT_START)
419 	    || gsp->start != NULL, ("G_SLICE_HOT_START but no slice->start"));
420 	/* XXX: check that we _have_ a start function if HOT_START specified */
421 	gsl[idx].ract = ract;
422 	gsl[idx].dact = dact;
423 	gsl[idx].wact = wact;
424 	return (0);
425 }
426 
427 void
428 g_slice_spoiled(struct g_consumer *cp)
429 {
430 	struct g_geom *gp;
431 	struct g_slicer *gsp;
432 
433 	g_topology_assert();
434 	gp = cp->geom;
435 	g_trace(G_T_TOPOLOGY, "g_slice_spoiled(%p/%s)", cp, gp->name);
436 	gsp = gp->softc;
437 	gp->softc = NULL;
438 	g_slice_free(gsp);
439 	g_wither_geom(gp, ENXIO);
440 }
441 
442 int
443 g_slice_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
444 {
445 
446 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
447 	return (0);
448 }
449 
450 struct g_geom *
451 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)
452 {
453 	struct g_geom *gp;
454 	struct g_slicer *gsp;
455 	struct g_consumer *cp;
456 	void **vp;
457 	int error;
458 
459 	g_topology_assert();
460 	vp = (void **)extrap;
461 	gp = g_new_geomf(mp, "%s", pp->name);
462 	gsp = g_slice_alloc(slices, extra);
463 	gsp->start = start;
464 	gp->access = g_slice_access;
465 	gp->orphan = g_slice_orphan;
466 	gp->softc = gsp;
467 	gp->start = g_slice_start;
468 	gp->spoiled = g_slice_spoiled;
469 	if (gp->dumpconf == NULL)
470 		gp->dumpconf = g_slice_dumpconf;
471 	if (gp->class->destroy_geom == NULL)
472 		gp->class->destroy_geom = g_slice_destroy_geom;
473 	cp = g_new_consumer(gp);
474 	error = g_attach(cp, pp);
475 	if (error == 0)
476 		error = g_access(cp, 1, 0, 0);
477 	if (error) {
478 		g_wither_geom(gp, ENXIO);
479 		return (NULL);
480 	}
481 	if (extrap != NULL)
482 		*vp = gsp->softc;
483 	*cpp = cp;
484 	return (gp);
485 }
486 
487 void
488 g_slice_orphan(struct g_consumer *cp)
489 {
490 
491 	g_trace(G_T_TOPOLOGY, "g_slice_orphan(%p/%s)", cp, cp->provider->name);
492 	g_topology_assert();
493 	KASSERT(cp->provider->error != 0,
494 	    ("g_slice_orphan with error == 0"));
495 
496 	/* XXX: Not good enough we leak the softc and its suballocations */
497 	g_slice_free(cp->geom->softc);
498 	g_wither_geom(cp->geom, cp->provider->error);
499 }
500