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/6.2/sys/geom/geom_slice.c 156163 2006-03-01 17:57:11Z pjd $");
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 bp2 = g_clone_bio(bp);
264 if (bp2 == NULL) {
265 g_io_deliver(bp, ENOMEM);
266 return;
267 }
268 bp2->bio_done = g_std_done;
269 g_io_request(bp2, cp);
270 break;
271 default:
272 g_io_deliver(bp, EOPNOTSUPP);
273 return;
274 }
275 }
276
277 void
278 g_slice_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
279 {
280 struct g_slicer *gsp;
281
282 gsp = gp->softc;
283 if (indent == NULL) {
284 sbuf_printf(sb, " i %u", pp->index);
285 sbuf_printf(sb, " o %ju",
286 (uintmax_t)gsp->slices[pp->index].offset);
287 return;
288 }
289 if (pp != NULL) {
290 sbuf_printf(sb, "%s<index>%u</index>\n", indent, pp->index);
291 sbuf_printf(sb, "%s<length>%ju</length>\n",
292 indent, (uintmax_t)gsp->slices[pp->index].length);
293 sbuf_printf(sb, "%s<seclength>%ju</seclength>\n", indent,
294 (uintmax_t)gsp->slices[pp->index].length / 512);
295 sbuf_printf(sb, "%s<offset>%ju</offset>\n", indent,
296 (uintmax_t)gsp->slices[pp->index].offset);
297 sbuf_printf(sb, "%s<secoffset>%ju</secoffset>\n", indent,
298 (uintmax_t)gsp->slices[pp->index].offset / 512);
299 }
300 }
301
302 int
303 g_slice_config(struct g_geom *gp, u_int idx, int how, off_t offset, off_t length, u_int sectorsize, const char *fmt, ...)
304 {
305 struct g_provider *pp, *pp2;
306 struct g_slicer *gsp;
307 struct g_slice *gsl;
308 va_list ap;
309 struct sbuf *sb;
310 int acc;
311
312 g_trace(G_T_TOPOLOGY, "g_slice_config(%s, %d, %d)",
313 gp->name, idx, how);
314 g_topology_assert();
315 gsp = gp->softc;
316 if (idx >= gsp->nslice)
317 return(EINVAL);
318 gsl = &gsp->slices[idx];
319 pp = gsl->provider;
320 if (pp != NULL)
321 acc = pp->acr + pp->acw + pp->ace;
322 else
323 acc = 0;
324 if (acc != 0 && how != G_SLICE_CONFIG_FORCE) {
325 if (length < gsl->length)
326 return(EBUSY);
327 if (offset != gsl->offset)
328 return(EBUSY);
329 }
330 /* XXX: check offset + length <= MEDIASIZE */
331 if (how == G_SLICE_CONFIG_CHECK)
332 return (0);
333 gsl->length = length;
334 gsl->offset = offset;
335 gsl->sectorsize = sectorsize;
336 if (length == 0) {
337 if (pp == NULL)
338 return (0);
339 if (bootverbose)
340 printf("GEOM: Deconfigure %s\n", pp->name);
341 pp->flags |= G_PF_WITHER;
342 g_orphan_provider(pp, ENXIO);
343 gsl->provider = NULL;
344 gsp->nprovider--;
345 return (0);
346 }
347 if (pp != NULL) {
348 if (bootverbose)
349 printf("GEOM: Reconfigure %s, start %jd length %jd end %jd\n",
350 pp->name, (intmax_t)offset, (intmax_t)length,
351 (intmax_t)(offset + length - 1));
352 pp->mediasize = gsl->length;
353 return (0);
354 }
355 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
356 va_start(ap, fmt);
357 sbuf_vprintf(sb, fmt, ap);
358 va_end(ap);
359 sbuf_finish(sb);
360 pp = g_new_providerf(gp, sbuf_data(sb));
361 pp2 = LIST_FIRST(&gp->consumer)->provider;
362 pp->flags = pp2->flags & G_PF_CANDELETE;
363 if (pp2->stripesize > 0) {
364 pp->stripesize = pp2->stripesize;
365 pp->stripeoffset = (pp2->stripeoffset + offset) % pp->stripesize;
366 }
367 if (0 && bootverbose)
368 printf("GEOM: Configure %s, start %jd length %jd end %jd\n",
369 pp->name, (intmax_t)offset, (intmax_t)length,
370 (intmax_t)(offset + length - 1));
371 pp->index = idx;
372 pp->mediasize = gsl->length;
373 pp->sectorsize = gsl->sectorsize;
374 gsl->provider = pp;
375 gsp->nprovider++;
376 g_error_provider(pp, 0);
377 sbuf_delete(sb);
378 return(0);
379 }
380
381 /*
382 * Configure "hotspots". A hotspot is a piece of the parent device which
383 * this particular slicer cares about for some reason. Typically because
384 * it contains meta-data used to configure the slicer.
385 * A hotspot is identified by its index number. The offset and length are
386 * relative to the parent device, and the three "?act" fields specify
387 * what action to take on BIO_READ, BIO_DELETE and BIO_WRITE.
388 *
389 * XXX: There may be a race relative to g_slice_start() here, if an existing
390 * XXX: hotspot is changed wile I/O is happening. Should this become a problem
391 * XXX: we can protect the hotspot stuff with a mutex.
392 */
393
394 int
395 g_slice_conf_hot(struct g_geom *gp, u_int idx, off_t offset, off_t length, int ract, int dact, int wact)
396 {
397 struct g_slicer *gsp;
398 struct g_slice_hot *gsl, *gsl2;
399
400 g_trace(G_T_TOPOLOGY, "g_slice_conf_hot(%s, idx: %d, off: %jd, len: %jd)",
401 gp->name, idx, (intmax_t)offset, (intmax_t)length);
402 g_topology_assert();
403 gsp = gp->softc;
404 gsl = gsp->hotspot;
405 if(idx >= gsp->nhotspot) {
406 gsl2 = g_malloc((idx + 1) * sizeof *gsl2, M_WAITOK | M_ZERO);
407 if (gsp->hotspot != NULL)
408 bcopy(gsp->hotspot, gsl2, gsp->nhotspot * sizeof *gsl2);
409 gsp->hotspot = gsl2;
410 if (gsp->hotspot != NULL)
411 g_free(gsl);
412 gsl = gsl2;
413 gsp->nhotspot = idx + 1;
414 }
415 gsl[idx].offset = offset;
416 gsl[idx].length = length;
417 KASSERT(!((ract | dact | wact) & G_SLICE_HOT_START)
418 || gsp->start != NULL, ("G_SLICE_HOT_START but no slice->start"));
419 /* XXX: check that we _have_ a start function if HOT_START specified */
420 gsl[idx].ract = ract;
421 gsl[idx].dact = dact;
422 gsl[idx].wact = wact;
423 return (0);
424 }
425
426 void
427 g_slice_spoiled(struct g_consumer *cp)
428 {
429 struct g_geom *gp;
430 struct g_slicer *gsp;
431
432 g_topology_assert();
433 gp = cp->geom;
434 g_trace(G_T_TOPOLOGY, "g_slice_spoiled(%p/%s)", cp, gp->name);
435 gsp = gp->softc;
436 gp->softc = NULL;
437 g_slice_free(gsp);
438 g_wither_geom(gp, ENXIO);
439 }
440
441 int
442 g_slice_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
443 {
444
445 g_slice_spoiled(LIST_FIRST(&gp->consumer));
446 return (0);
447 }
448
449 struct g_geom *
450 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)
451 {
452 struct g_geom *gp;
453 struct g_slicer *gsp;
454 struct g_consumer *cp;
455 void **vp;
456 int error;
457
458 g_topology_assert();
459 vp = (void **)extrap;
460 gp = g_new_geomf(mp, "%s", pp->name);
461 gsp = g_slice_alloc(slices, extra);
462 gsp->start = start;
463 gp->access = g_slice_access;
464 gp->orphan = g_slice_orphan;
465 gp->softc = gsp;
466 gp->start = g_slice_start;
467 gp->spoiled = g_slice_spoiled;
468 if (gp->dumpconf == NULL)
469 gp->dumpconf = g_slice_dumpconf;
470 if (gp->class->destroy_geom == NULL)
471 gp->class->destroy_geom = g_slice_destroy_geom;
472 cp = g_new_consumer(gp);
473 error = g_attach(cp, pp);
474 if (error == 0)
475 error = g_access(cp, 1, 0, 0);
476 if (error) {
477 g_wither_geom(gp, ENXIO);
478 return (NULL);
479 }
480 if (extrap != NULL)
481 *vp = gsp->softc;
482 *cpp = cp;
483 return (gp);
484 }
485
486 void
487 g_slice_orphan(struct g_consumer *cp)
488 {
489
490 g_trace(G_T_TOPOLOGY, "g_slice_orphan(%p/%s)", cp, cp->provider->name);
491 g_topology_assert();
492 KASSERT(cp->provider->error != 0,
493 ("g_slice_orphan with error == 0"));
494
495 /* XXX: Not good enough we leak the softc and its suballocations */
496 g_slice_free(cp->geom->softc);
497 g_wither_geom(cp->geom, cp->provider->error);
498 }
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