FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_slice.c
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/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/bio.h>
46 #include <sys/sysctl.h>
47 #include <sys/proc.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <sys/errno.h>
51 #include <sys/sbuf.h>
52 #include <geom/geom.h>
53 #include <geom/geom_slice.h>
54 #include <machine/stdarg.h>
55
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_geom *gp)
77 {
78 struct g_slicer *gsp;
79
80 gsp = gp->softc;
81 gp->softc = NULL;
82
83 /*
84 * We can get multiple spoiled events before wither-washer
85 * detaches our consumer, so this can get called multiple
86 * times.
87 */
88 if (gsp == NULL)
89 return;
90 g_free(gsp->slices);
91 g_free(gsp->hotspot);
92 g_free(gsp->softc);
93 g_free(gsp);
94 }
95
96 static int
97 g_slice_access(struct g_provider *pp, int dr, int dw, int de)
98 {
99 int error;
100 u_int u;
101 struct g_geom *gp;
102 struct g_consumer *cp;
103 struct g_provider *pp2;
104 struct g_slicer *gsp;
105 struct g_slice *gsl, *gsl2;
106
107 gp = pp->geom;
108 cp = LIST_FIRST(&gp->consumer);
109 KASSERT (cp != NULL, ("g_slice_access but no consumer"));
110 gsp = gp->softc;
111 if (dr > 0 || dw > 0 || de > 0) {
112 gsl = &gsp->slices[pp->index];
113 for (u = 0; u < gsp->nslice; u++) {
114 gsl2 = &gsp->slices[u];
115 if (gsl2->length == 0)
116 continue;
117 if (u == pp->index)
118 continue;
119 if (gsl->offset + gsl->length <= gsl2->offset)
120 continue;
121 if (gsl2->offset + gsl2->length <= gsl->offset)
122 continue;
123 /* overlap */
124 pp2 = gsl2->provider;
125 if ((pp->acw + dw) > 0 && pp2->ace > 0)
126 return (EPERM);
127 if ((pp->ace + de) > 0 && pp2->acw > 0)
128 return (EPERM);
129 }
130 }
131 /* On first open, grab an extra "exclusive" bit */
132 if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0)
133 de++;
134 /* ... and let go of it on last close */
135 if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1)
136 de--;
137 error = g_access(cp, dr, dw, de);
138
139 /*
140 * Free the softc if all providers have been closed and this geom
141 * is being removed.
142 */
143 if (error == 0 && (gp->flags & G_GEOM_WITHER) != 0 &&
144 (cp->acr + cp->acw + cp->ace) == 0)
145 g_slice_free(gp);
146
147 return (error);
148 }
149
150 /*
151 * XXX: It should be possible to specify here if we should finish all of the
152 * XXX: bio, or only the non-hot bits. This would get messy if there were
153 * XXX: two hot spots in the same bio, so for now we simply finish off the
154 * XXX: entire bio. Modifying hot data on the way to disk is frowned on
155 * XXX: so making that considerably harder is not a bad idea anyway.
156 */
157 void
158 g_slice_finish_hot(struct bio *bp)
159 {
160 struct bio *bp2;
161 struct g_geom *gp;
162 struct g_consumer *cp;
163 struct g_slicer *gsp;
164 struct g_slice *gsl;
165 int idx;
166
167 KASSERT(bp->bio_to != NULL,
168 ("NULL bio_to in g_slice_finish_hot(%p)", bp));
169 KASSERT(bp->bio_from != NULL,
170 ("NULL bio_from in g_slice_finish_hot(%p)", bp));
171 gp = bp->bio_to->geom;
172 gsp = gp->softc;
173 cp = LIST_FIRST(&gp->consumer);
174 KASSERT(cp != NULL, ("NULL consumer in g_slice_finish_hot(%p)", bp));
175 idx = bp->bio_to->index;
176 gsl = &gsp->slices[idx];
177
178 bp2 = g_clone_bio(bp);
179 if (bp2 == NULL) {
180 g_io_deliver(bp, ENOMEM);
181 return;
182 }
183 if (bp2->bio_offset + bp2->bio_length > gsl->length)
184 bp2->bio_length = gsl->length - bp2->bio_offset;
185 bp2->bio_done = g_std_done;
186 bp2->bio_offset += gsl->offset;
187 g_io_request(bp2, cp);
188 return;
189 }
190
191 static void
192 g_slice_done(struct bio *bp)
193 {
194
195 KASSERT(bp->bio_cmd == BIO_GETATTR &&
196 strcmp(bp->bio_attribute, "GEOM::ident") == 0,
197 ("bio_cmd=0x%x bio_attribute=%s", bp->bio_cmd, bp->bio_attribute));
198
199 if (bp->bio_error == 0 && bp->bio_data[0] != '\0') {
200 char idx[8];
201
202 /* Add index to the ident received. */
203 snprintf(idx, sizeof(idx), "s%d",
204 bp->bio_parent->bio_to->index);
205 if (strlcat(bp->bio_data, idx, bp->bio_length) >=
206 bp->bio_length) {
207 bp->bio_error = EFAULT;
208 }
209 }
210 g_std_done(bp);
211 }
212
213 static void
214 g_slice_start(struct bio *bp)
215 {
216 struct bio *bp2;
217 struct g_provider *pp;
218 struct g_geom *gp;
219 struct g_consumer *cp;
220 struct g_slicer *gsp;
221 struct g_slice *gsl;
222 struct g_slice_hot *ghp;
223 int idx, error;
224 u_int m_index;
225 off_t t;
226
227 pp = bp->bio_to;
228 gp = pp->geom;
229 gsp = gp->softc;
230 cp = LIST_FIRST(&gp->consumer);
231 idx = pp->index;
232 gsl = &gsp->slices[idx];
233 switch(bp->bio_cmd) {
234 case BIO_READ:
235 case BIO_WRITE:
236 case BIO_DELETE:
237 if (bp->bio_offset > gsl->length) {
238 g_io_deliver(bp, EINVAL); /* XXX: EWHAT ? */
239 return;
240 }
241 /*
242 * Check if we collide with any hot spaces, and call the
243 * method once if so.
244 */
245 t = bp->bio_offset + gsl->offset;
246 for (m_index = 0; m_index < gsp->nhotspot; m_index++) {
247 ghp = &gsp->hotspot[m_index];
248 if (t >= ghp->offset + ghp->length)
249 continue;
250 if (t + bp->bio_length <= ghp->offset)
251 continue;
252 switch(bp->bio_cmd) {
253 case BIO_READ: idx = ghp->ract; break;
254 case BIO_WRITE: idx = ghp->wact; break;
255 case BIO_DELETE: idx = ghp->dact; break;
256 }
257 switch(idx) {
258 case G_SLICE_HOT_ALLOW:
259 /* Fall out and continue normal processing */
260 continue;
261 case G_SLICE_HOT_DENY:
262 g_io_deliver(bp, EROFS);
263 return;
264 case G_SLICE_HOT_START:
265 error = gsp->start(bp);
266 if (error && error != EJUSTRETURN)
267 g_io_deliver(bp, error);
268 return;
269 case G_SLICE_HOT_CALL:
270 error = g_post_event(gsp->hot, bp, M_NOWAIT,
271 gp, NULL);
272 if (error)
273 g_io_deliver(bp, error);
274 return;
275 }
276 break;
277 }
278 bp2 = g_clone_bio(bp);
279 if (bp2 == NULL) {
280 g_io_deliver(bp, ENOMEM);
281 return;
282 }
283 if (bp2->bio_offset + bp2->bio_length > gsl->length)
284 bp2->bio_length = gsl->length - bp2->bio_offset;
285 bp2->bio_done = g_std_done;
286 bp2->bio_offset += gsl->offset;
287 g_io_request(bp2, cp);
288 return;
289 case BIO_GETATTR:
290 /* Give the real method a chance to override */
291 if (gsp->start != NULL && gsp->start(bp))
292 return;
293 if (!strcmp("GEOM::ident", bp->bio_attribute)) {
294 bp2 = g_clone_bio(bp);
295 if (bp2 == NULL) {
296 g_io_deliver(bp, ENOMEM);
297 return;
298 }
299 bp2->bio_done = g_slice_done;
300 g_io_request(bp2, cp);
301 return;
302 }
303 if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) {
304 struct g_kerneldump *gkd;
305
306 gkd = (struct g_kerneldump *)bp->bio_data;
307 gkd->offset += gsp->slices[idx].offset;
308 if (gkd->length > gsp->slices[idx].length)
309 gkd->length = gsp->slices[idx].length;
310 /* now, pass it on downwards... */
311 }
312 /* FALLTHROUGH */
313 case BIO_SPEEDUP:
314 case BIO_FLUSH:
315 bp2 = g_clone_bio(bp);
316 if (bp2 == NULL) {
317 g_io_deliver(bp, ENOMEM);
318 return;
319 }
320 bp2->bio_done = g_std_done;
321 g_io_request(bp2, cp);
322 break;
323 default:
324 g_io_deliver(bp, EOPNOTSUPP);
325 return;
326 }
327 }
328
329 void
330 g_slice_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
331 {
332 struct g_slicer *gsp;
333
334 gsp = gp->softc;
335 if (indent == NULL) {
336 sbuf_printf(sb, " i %u", pp->index);
337 sbuf_printf(sb, " o %ju",
338 (uintmax_t)gsp->slices[pp->index].offset);
339 return;
340 }
341 if (pp != NULL) {
342 sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
343 sbuf_printf(sb, "%s<length>%ju</length>\n",
344 indent, (uintmax_t)gsp->slices[pp->index].length);
345 sbuf_printf(sb, "%s<seclength>%ju</seclength>\n", indent,
346 (uintmax_t)gsp->slices[pp->index].length / 512);
347 sbuf_printf(sb, "%s<offset>%ju</offset>\n", indent,
348 (uintmax_t)gsp->slices[pp->index].offset);
349 sbuf_printf(sb, "%s<secoffset>%ju</secoffset>\n", indent,
350 (uintmax_t)gsp->slices[pp->index].offset / 512);
351 }
352 }
353
354 int
355 g_slice_config(struct g_geom *gp, u_int idx, int how, off_t offset, off_t length, u_int sectorsize, const char *fmt, ...)
356 {
357 struct g_provider *pp, *pp2;
358 struct g_slicer *gsp;
359 struct g_slice *gsl;
360 va_list ap;
361 struct sbuf *sb;
362 int acc;
363
364 g_trace(G_T_TOPOLOGY, "g_slice_config(%s, %d, %d)",
365 gp->name, idx, how);
366 g_topology_assert();
367 gsp = gp->softc;
368 if (idx >= gsp->nslice)
369 return(EINVAL);
370 gsl = &gsp->slices[idx];
371 pp = gsl->provider;
372 if (pp != NULL)
373 acc = pp->acr + pp->acw + pp->ace;
374 else
375 acc = 0;
376 if (acc != 0 && how != G_SLICE_CONFIG_FORCE) {
377 if (length < gsl->length)
378 return(EBUSY);
379 if (offset != gsl->offset)
380 return(EBUSY);
381 }
382 /* XXX: check offset + length <= MEDIASIZE */
383 if (how == G_SLICE_CONFIG_CHECK)
384 return (0);
385 gsl->length = length;
386 gsl->offset = offset;
387 gsl->sectorsize = sectorsize;
388 if (length == 0) {
389 if (pp == NULL)
390 return (0);
391 if (bootverbose)
392 printf("GEOM: Deconfigure %s\n", pp->name);
393 g_wither_provider(pp, ENXIO);
394 gsl->provider = NULL;
395 gsp->nprovider--;
396 return (0);
397 }
398 if (pp != NULL) {
399 if (bootverbose)
400 printf("GEOM: Reconfigure %s, start %jd length %jd end %jd\n",
401 pp->name, (intmax_t)offset, (intmax_t)length,
402 (intmax_t)(offset + length - 1));
403 g_resize_provider(pp, gsl->length);
404 return (0);
405 }
406 sb = sbuf_new_auto();
407 va_start(ap, fmt);
408 sbuf_vprintf(sb, fmt, ap);
409 va_end(ap);
410 sbuf_finish(sb);
411 pp = g_new_providerf(gp, "%s", sbuf_data(sb));
412 pp2 = LIST_FIRST(&gp->consumer)->provider;
413 pp->stripesize = pp2->stripesize;
414 pp->stripeoffset = pp2->stripeoffset + offset;
415 if (pp->stripesize > 0)
416 pp->stripeoffset %= pp->stripesize;
417 if (gsp->nhotspot == 0) {
418 pp->flags |= pp2->flags & G_PF_ACCEPT_UNMAPPED;
419 pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
420 }
421 if (0 && bootverbose)
422 printf("GEOM: Configure %s, start %jd length %jd end %jd\n",
423 pp->name, (intmax_t)offset, (intmax_t)length,
424 (intmax_t)(offset + length - 1));
425 pp->index = idx;
426 pp->mediasize = gsl->length;
427 pp->sectorsize = gsl->sectorsize;
428 gsl->provider = pp;
429 gsp->nprovider++;
430 g_error_provider(pp, 0);
431 sbuf_delete(sb);
432 return(0);
433 }
434
435 /*
436 * Configure "hotspots". A hotspot is a piece of the parent device which
437 * this particular slicer cares about for some reason. Typically because
438 * it contains meta-data used to configure the slicer.
439 * A hotspot is identified by its index number. The offset and length are
440 * relative to the parent device, and the three "?act" fields specify
441 * what action to take on BIO_READ, BIO_DELETE and BIO_WRITE.
442 *
443 * XXX: There may be a race relative to g_slice_start() here, if an existing
444 * XXX: hotspot is changed wile I/O is happening. Should this become a problem
445 * XXX: we can protect the hotspot stuff with a mutex.
446 */
447
448 int
449 g_slice_conf_hot(struct g_geom *gp, u_int idx, off_t offset, off_t length, int ract, int dact, int wact)
450 {
451 struct g_slicer *gsp;
452 struct g_slice_hot *gsl, *gsl2;
453 struct g_consumer *cp;
454 struct g_provider *pp;
455
456 g_trace(G_T_TOPOLOGY, "g_slice_conf_hot(%s, idx: %d, off: %jd, len: %jd)",
457 gp->name, idx, (intmax_t)offset, (intmax_t)length);
458 g_topology_assert();
459 gsp = gp->softc;
460 /* Deny unmapped I/O and direct dispatch if hotspots are used. */
461 if (gsp->nhotspot == 0) {
462 LIST_FOREACH(pp, &gp->provider, provider)
463 pp->flags &= ~(G_PF_ACCEPT_UNMAPPED |
464 G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE);
465 LIST_FOREACH(cp, &gp->consumer, consumer)
466 cp->flags &= ~(G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE);
467 }
468 gsl = gsp->hotspot;
469 if(idx >= gsp->nhotspot) {
470 gsl2 = g_malloc((idx + 1) * sizeof *gsl2, M_WAITOK | M_ZERO);
471 if (gsp->hotspot != NULL)
472 bcopy(gsp->hotspot, gsl2, gsp->nhotspot * sizeof *gsl2);
473 gsp->hotspot = gsl2;
474 if (gsp->hotspot != NULL)
475 g_free(gsl);
476 gsl = gsl2;
477 gsp->nhotspot = idx + 1;
478 }
479 gsl[idx].offset = offset;
480 gsl[idx].length = length;
481 KASSERT(!((ract | dact | wact) & G_SLICE_HOT_START)
482 || gsp->start != NULL, ("G_SLICE_HOT_START but no slice->start"));
483 /* XXX: check that we _have_ a start function if HOT_START specified */
484 gsl[idx].ract = ract;
485 gsl[idx].dact = dact;
486 gsl[idx].wact = wact;
487 return (0);
488 }
489
490 void
491 g_slice_orphan(struct g_consumer *cp)
492 {
493 struct g_geom *gp;
494
495 g_topology_assert();
496 gp = cp->geom;
497 g_trace(G_T_TOPOLOGY, "%s(%p/%s)", __func__, cp, gp->name);
498 g_wither_geom(gp, ENXIO);
499
500 /*
501 * We can safely free the softc now if there are no accesses,
502 * otherwise g_slice_access() will do that after the last close.
503 */
504 if ((cp->acr + cp->acw + cp->ace) == 0)
505 g_slice_free(gp);
506 }
507
508 void
509 g_slice_spoiled(struct g_consumer *cp)
510 {
511
512 g_trace(G_T_TOPOLOGY, "%s(%p/%s)", __func__, cp, cp->geom->name);
513 cp->flags |= G_CF_ORPHAN;
514 g_slice_orphan(cp);
515 }
516
517 int
518 g_slice_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
519 {
520
521 g_slice_spoiled(LIST_FIRST(&gp->consumer));
522 return (0);
523 }
524
525 struct g_geom *
526 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)
527 {
528 struct g_geom *gp;
529 struct g_slicer *gsp;
530 struct g_consumer *cp;
531 void **vp;
532 int error;
533
534 g_topology_assert();
535 vp = (void **)extrap;
536 gp = g_new_geomf(mp, "%s", pp->name);
537 gsp = g_slice_alloc(slices, extra);
538 gsp->start = start;
539 gp->softc = gsp;
540 gp->start = g_slice_start;
541 gp->access = g_slice_access;
542 gp->orphan = g_slice_orphan;
543 gp->spoiled = g_slice_spoiled;
544 if (gp->dumpconf == NULL)
545 gp->dumpconf = g_slice_dumpconf;
546 if (gp->class->destroy_geom == NULL)
547 gp->class->destroy_geom = g_slice_destroy_geom;
548 cp = g_new_consumer(gp);
549 cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
550 error = g_attach(cp, pp);
551 if (error == 0)
552 error = g_access(cp, 1, 0, 0);
553 if (error) {
554 g_wither_geom(gp, ENXIO);
555 return (NULL);
556 }
557 if (extrap != NULL)
558 *vp = gsp->softc;
559 *cpp = cp;
560 return (gp);
561 }
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