FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_slice.c
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: releng/8.1/sys/geom/geom_slice.c 202427 2010-01-15 23:56:19Z mav $");
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_done(struct bio *bp)
176 {
177
178 KASSERT(bp->bio_cmd == BIO_GETATTR &&
179 strcmp(bp->bio_attribute, "GEOM::ident") == 0,
180 ("bio_cmd=0x%x bio_attribute=%s", bp->bio_cmd, bp->bio_attribute));
181
182 if (bp->bio_error == 0 && bp->bio_data[0] != '\0') {
183 char idx[8];
184
185 /* Add index to the ident received. */
186 snprintf(idx, sizeof(idx), "s%d",
187 bp->bio_parent->bio_to->index);
188 if (strlcat(bp->bio_data, idx, bp->bio_length) >=
189 bp->bio_length) {
190 bp->bio_error = EFAULT;
191 }
192 }
193 g_std_done(bp);
194 }
195
196 static void
197 g_slice_start(struct bio *bp)
198 {
199 struct bio *bp2;
200 struct g_provider *pp;
201 struct g_geom *gp;
202 struct g_consumer *cp;
203 struct g_slicer *gsp;
204 struct g_slice *gsl;
205 struct g_slice_hot *ghp;
206 int idx, error;
207 u_int m_index;
208 off_t t;
209
210 pp = bp->bio_to;
211 gp = pp->geom;
212 gsp = gp->softc;
213 cp = LIST_FIRST(&gp->consumer);
214 idx = pp->index;
215 gsl = &gsp->slices[idx];
216 switch(bp->bio_cmd) {
217 case BIO_READ:
218 case BIO_WRITE:
219 case BIO_DELETE:
220 if (bp->bio_offset > gsl->length) {
221 g_io_deliver(bp, EINVAL); /* XXX: EWHAT ? */
222 return;
223 }
224 /*
225 * Check if we collide with any hot spaces, and call the
226 * method once if so.
227 */
228 t = bp->bio_offset + gsl->offset;
229 for (m_index = 0; m_index < gsp->nhotspot; m_index++) {
230 ghp = &gsp->hotspot[m_index];
231 if (t >= ghp->offset + ghp->length)
232 continue;
233 if (t + bp->bio_length <= ghp->offset)
234 continue;
235 switch(bp->bio_cmd) {
236 case BIO_READ: idx = ghp->ract; break;
237 case BIO_WRITE: idx = ghp->wact; break;
238 case BIO_DELETE: idx = ghp->dact; break;
239 }
240 switch(idx) {
241 case G_SLICE_HOT_ALLOW:
242 /* Fall out and continue normal processing */
243 continue;
244 case G_SLICE_HOT_DENY:
245 g_io_deliver(bp, EROFS);
246 return;
247 case G_SLICE_HOT_START:
248 error = gsp->start(bp);
249 if (error && error != EJUSTRETURN)
250 g_io_deliver(bp, error);
251 return;
252 case G_SLICE_HOT_CALL:
253 error = g_post_event(gsp->hot, bp, M_NOWAIT,
254 gp, NULL);
255 if (error)
256 g_io_deliver(bp, error);
257 return;
258 }
259 break;
260 }
261 bp2 = g_clone_bio(bp);
262 if (bp2 == NULL) {
263 g_io_deliver(bp, ENOMEM);
264 return;
265 }
266 if (bp2->bio_offset + bp2->bio_length > gsl->length)
267 bp2->bio_length = gsl->length - bp2->bio_offset;
268 bp2->bio_done = g_std_done;
269 bp2->bio_offset += gsl->offset;
270 g_io_request(bp2, cp);
271 return;
272 case BIO_GETATTR:
273 /* Give the real method a chance to override */
274 if (gsp->start != NULL && gsp->start(bp))
275 return;
276 if (!strcmp("GEOM::ident", bp->bio_attribute)) {
277 bp2 = g_clone_bio(bp);
278 if (bp2 == NULL) {
279 g_io_deliver(bp, ENOMEM);
280 return;
281 }
282 bp2->bio_done = g_slice_done;
283 g_io_request(bp2, cp);
284 return;
285 }
286 if (!strcmp("GEOM::kerneldump", bp->bio_attribute)) {
287 struct g_kerneldump *gkd;
288
289 gkd = (struct g_kerneldump *)bp->bio_data;
290 gkd->offset += gsp->slices[idx].offset;
291 if (gkd->length > gsp->slices[idx].length)
292 gkd->length = gsp->slices[idx].length;
293 /* now, pass it on downwards... */
294 }
295 /* FALLTHROUGH */
296 case BIO_FLUSH:
297 bp2 = g_clone_bio(bp);
298 if (bp2 == NULL) {
299 g_io_deliver(bp, ENOMEM);
300 return;
301 }
302 bp2->bio_done = g_std_done;
303 g_io_request(bp2, cp);
304 break;
305 default:
306 g_io_deliver(bp, EOPNOTSUPP);
307 return;
308 }
309 }
310
311 void
312 g_slice_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
313 {
314 struct g_slicer *gsp;
315
316 gsp = gp->softc;
317 if (indent == NULL) {
318 sbuf_printf(sb, " i %u", pp->index);
319 sbuf_printf(sb, " o %ju",
320 (uintmax_t)gsp->slices[pp->index].offset);
321 return;
322 }
323 if (pp != NULL) {
324 sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
325 sbuf_printf(sb, "%s<length>%ju</length>\n",
326 indent, (uintmax_t)gsp->slices[pp->index].length);
327 sbuf_printf(sb, "%s<seclength>%ju</seclength>\n", indent,
328 (uintmax_t)gsp->slices[pp->index].length / 512);
329 sbuf_printf(sb, "%s<offset>%ju</offset>\n", indent,
330 (uintmax_t)gsp->slices[pp->index].offset);
331 sbuf_printf(sb, "%s<secoffset>%ju</secoffset>\n", indent,
332 (uintmax_t)gsp->slices[pp->index].offset / 512);
333 }
334 }
335
336 int
337 g_slice_config(struct g_geom *gp, u_int idx, int how, off_t offset, off_t length, u_int sectorsize, const char *fmt, ...)
338 {
339 struct g_provider *pp, *pp2;
340 struct g_slicer *gsp;
341 struct g_slice *gsl;
342 va_list ap;
343 struct sbuf *sb;
344 int acc;
345
346 g_trace(G_T_TOPOLOGY, "g_slice_config(%s, %d, %d)",
347 gp->name, idx, how);
348 g_topology_assert();
349 gsp = gp->softc;
350 if (idx >= gsp->nslice)
351 return(EINVAL);
352 gsl = &gsp->slices[idx];
353 pp = gsl->provider;
354 if (pp != NULL)
355 acc = pp->acr + pp->acw + pp->ace;
356 else
357 acc = 0;
358 if (acc != 0 && how != G_SLICE_CONFIG_FORCE) {
359 if (length < gsl->length)
360 return(EBUSY);
361 if (offset != gsl->offset)
362 return(EBUSY);
363 }
364 /* XXX: check offset + length <= MEDIASIZE */
365 if (how == G_SLICE_CONFIG_CHECK)
366 return (0);
367 gsl->length = length;
368 gsl->offset = offset;
369 gsl->sectorsize = sectorsize;
370 if (length == 0) {
371 if (pp == NULL)
372 return (0);
373 if (bootverbose)
374 printf("GEOM: Deconfigure %s\n", pp->name);
375 g_wither_provider(pp, ENXIO);
376 gsl->provider = NULL;
377 gsp->nprovider--;
378 return (0);
379 }
380 if (pp != NULL) {
381 if (bootverbose)
382 printf("GEOM: Reconfigure %s, start %jd length %jd end %jd\n",
383 pp->name, (intmax_t)offset, (intmax_t)length,
384 (intmax_t)(offset + length - 1));
385 pp->mediasize = gsl->length;
386 return (0);
387 }
388 sb = sbuf_new_auto();
389 va_start(ap, fmt);
390 sbuf_vprintf(sb, fmt, ap);
391 va_end(ap);
392 sbuf_finish(sb);
393 pp = g_new_providerf(gp, sbuf_data(sb));
394 pp2 = LIST_FIRST(&gp->consumer)->provider;
395 pp->flags = pp2->flags & G_PF_CANDELETE;
396 pp->stripesize = pp2->stripesize;
397 pp->stripeoffset = pp2->stripeoffset + offset;
398 if (pp->stripesize > 0)
399 pp->stripeoffset %= pp->stripesize;
400 if (0 && bootverbose)
401 printf("GEOM: Configure %s, start %jd length %jd end %jd\n",
402 pp->name, (intmax_t)offset, (intmax_t)length,
403 (intmax_t)(offset + length - 1));
404 pp->index = idx;
405 pp->mediasize = gsl->length;
406 pp->sectorsize = gsl->sectorsize;
407 gsl->provider = pp;
408 gsp->nprovider++;
409 g_error_provider(pp, 0);
410 sbuf_delete(sb);
411 return(0);
412 }
413
414 /*
415 * Configure "hotspots". A hotspot is a piece of the parent device which
416 * this particular slicer cares about for some reason. Typically because
417 * it contains meta-data used to configure the slicer.
418 * A hotspot is identified by its index number. The offset and length are
419 * relative to the parent device, and the three "?act" fields specify
420 * what action to take on BIO_READ, BIO_DELETE and BIO_WRITE.
421 *
422 * XXX: There may be a race relative to g_slice_start() here, if an existing
423 * XXX: hotspot is changed wile I/O is happening. Should this become a problem
424 * XXX: we can protect the hotspot stuff with a mutex.
425 */
426
427 int
428 g_slice_conf_hot(struct g_geom *gp, u_int idx, off_t offset, off_t length, int ract, int dact, int wact)
429 {
430 struct g_slicer *gsp;
431 struct g_slice_hot *gsl, *gsl2;
432
433 g_trace(G_T_TOPOLOGY, "g_slice_conf_hot(%s, idx: %d, off: %jd, len: %jd)",
434 gp->name, idx, (intmax_t)offset, (intmax_t)length);
435 g_topology_assert();
436 gsp = gp->softc;
437 gsl = gsp->hotspot;
438 if(idx >= gsp->nhotspot) {
439 gsl2 = g_malloc((idx + 1) * sizeof *gsl2, M_WAITOK | M_ZERO);
440 if (gsp->hotspot != NULL)
441 bcopy(gsp->hotspot, gsl2, gsp->nhotspot * sizeof *gsl2);
442 gsp->hotspot = gsl2;
443 if (gsp->hotspot != NULL)
444 g_free(gsl);
445 gsl = gsl2;
446 gsp->nhotspot = idx + 1;
447 }
448 gsl[idx].offset = offset;
449 gsl[idx].length = length;
450 KASSERT(!((ract | dact | wact) & G_SLICE_HOT_START)
451 || gsp->start != NULL, ("G_SLICE_HOT_START but no slice->start"));
452 /* XXX: check that we _have_ a start function if HOT_START specified */
453 gsl[idx].ract = ract;
454 gsl[idx].dact = dact;
455 gsl[idx].wact = wact;
456 return (0);
457 }
458
459 void
460 g_slice_spoiled(struct g_consumer *cp)
461 {
462 struct g_geom *gp;
463 struct g_slicer *gsp;
464
465 g_topology_assert();
466 gp = cp->geom;
467 g_trace(G_T_TOPOLOGY, "g_slice_spoiled(%p/%s)", cp, gp->name);
468 gsp = gp->softc;
469 gp->softc = NULL;
470 g_slice_free(gsp);
471 g_wither_geom(gp, ENXIO);
472 }
473
474 int
475 g_slice_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
476 {
477
478 g_slice_spoiled(LIST_FIRST(&gp->consumer));
479 return (0);
480 }
481
482 struct g_geom *
483 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)
484 {
485 struct g_geom *gp;
486 struct g_slicer *gsp;
487 struct g_consumer *cp;
488 void **vp;
489 int error;
490
491 g_topology_assert();
492 vp = (void **)extrap;
493 gp = g_new_geomf(mp, "%s", pp->name);
494 gsp = g_slice_alloc(slices, extra);
495 gsp->start = start;
496 gp->access = g_slice_access;
497 gp->orphan = g_slice_orphan;
498 gp->softc = gsp;
499 gp->start = g_slice_start;
500 gp->spoiled = g_slice_spoiled;
501 if (gp->dumpconf == NULL)
502 gp->dumpconf = g_slice_dumpconf;
503 if (gp->class->destroy_geom == NULL)
504 gp->class->destroy_geom = g_slice_destroy_geom;
505 cp = g_new_consumer(gp);
506 error = g_attach(cp, pp);
507 if (error == 0)
508 error = g_access(cp, 1, 0, 0);
509 if (error) {
510 g_wither_geom(gp, ENXIO);
511 return (NULL);
512 }
513 if (extrap != NULL)
514 *vp = gsp->softc;
515 *cpp = cp;
516 return (gp);
517 }
518
519 void
520 g_slice_orphan(struct g_consumer *cp)
521 {
522
523 g_trace(G_T_TOPOLOGY, "g_slice_orphan(%p/%s)", cp, cp->provider->name);
524 g_topology_assert();
525 KASSERT(cp->provider->error != 0,
526 ("g_slice_orphan with error == 0"));
527
528 /* XXX: Not good enough we leak the softc and its suballocations */
529 g_slice_free(cp->geom->softc);
530 g_wither_geom(cp->geom, cp->provider->error);
531 }
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