FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_dev.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("$FreeBSD$");
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/malloc.h>
42 #include <sys/kernel.h>
43 #include <sys/conf.h>
44 #include <sys/bio.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/proc.h>
48 #include <sys/errno.h>
49 #include <sys/time.h>
50 #include <sys/disk.h>
51 #include <sys/fcntl.h>
52 #include <sys/limits.h>
53 #include <geom/geom.h>
54 #include <geom/geom_int.h>
55
56 static d_open_t g_dev_open;
57 static d_close_t g_dev_close;
58 static d_strategy_t g_dev_strategy;
59 static d_ioctl_t g_dev_ioctl;
60
61 static struct cdevsw g_dev_cdevsw = {
62 .d_version = D_VERSION,
63 .d_open = g_dev_open,
64 .d_close = g_dev_close,
65 .d_read = physread,
66 .d_write = physwrite,
67 .d_ioctl = g_dev_ioctl,
68 .d_strategy = g_dev_strategy,
69 .d_name = "g_dev",
70 .d_flags = D_DISK | D_TRACKCLOSE,
71 };
72
73 static g_taste_t g_dev_taste;
74 static g_orphan_t g_dev_orphan;
75 static g_init_t g_dev_init;
76
77 static struct g_class g_dev_class = {
78 .name = "DEV",
79 .version = G_VERSION,
80 .taste = g_dev_taste,
81 .orphan = g_dev_orphan,
82 .init = g_dev_init,
83 };
84
85 static struct unrhdr *unithdr; /* Locked by topology */
86
87 static void
88 g_dev_init(struct g_class *mp)
89 {
90
91 unithdr = new_unrhdr(0, minor2unit(MAXMINOR), NULL);
92 }
93
94 void
95 g_dev_print(void)
96 {
97 struct g_geom *gp;
98 char const *p = "";
99
100 LIST_FOREACH(gp, &g_dev_class.geom, geom) {
101 printf("%s%s", p, gp->name);
102 p = " ";
103 }
104 printf("\n");
105 }
106
107 struct g_provider *
108 g_dev_getprovider(struct cdev *dev)
109 {
110 struct g_consumer *cp;
111
112 g_topology_assert();
113 if (dev == NULL)
114 return (NULL);
115 if (dev->si_devsw != &g_dev_cdevsw)
116 return (NULL);
117 cp = dev->si_drv2;
118 return (cp->provider);
119 }
120
121
122 static struct g_geom *
123 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
124 {
125 struct g_geom *gp;
126 struct g_consumer *cp;
127 int error;
128 struct cdev *dev;
129 u_int unit;
130
131 g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
132 g_topology_assert();
133 LIST_FOREACH(cp, &pp->consumers, consumers)
134 if (cp->geom->class == mp)
135 return (NULL);
136 gp = g_new_geomf(mp, pp->name);
137 cp = g_new_consumer(gp);
138 error = g_attach(cp, pp);
139 KASSERT(error == 0,
140 ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
141 unit = alloc_unr(unithdr);
142 dev = make_dev(&g_dev_cdevsw, unit2minor(unit),
143 UID_ROOT, GID_OPERATOR, 0640, gp->name);
144 if (pp->flags & G_PF_CANDELETE)
145 dev->si_flags |= SI_CANDELETE;
146 dev->si_iosize_max = MAXPHYS;
147 gp->softc = dev;
148 dev->si_drv1 = gp;
149 dev->si_drv2 = cp;
150 return (gp);
151 }
152
153 static int
154 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
155 {
156 struct g_geom *gp;
157 struct g_consumer *cp;
158 int error, r, w, e;
159
160 gp = dev->si_drv1;
161 cp = dev->si_drv2;
162 if (gp == NULL || cp == NULL || gp->softc != dev)
163 return(ENXIO); /* g_dev_taste() not done yet */
164
165 g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
166 gp->name, flags, fmt, td);
167
168 r = flags & FREAD ? 1 : 0;
169 w = flags & FWRITE ? 1 : 0;
170 #ifdef notyet
171 e = flags & O_EXCL ? 1 : 0;
172 #else
173 e = 0;
174 #endif
175 if (w) {
176 /*
177 * When running in very secure mode, do not allow
178 * opens for writing of any disks.
179 */
180 error = securelevel_ge(td->td_ucred, 2);
181 if (error)
182 return (error);
183 }
184 g_topology_lock();
185 if (dev->si_devsw == NULL)
186 error = ENXIO; /* We were orphaned */
187 else
188 error = g_access(cp, r, w, e);
189 g_topology_unlock();
190 return(error);
191 }
192
193 static int
194 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
195 {
196 struct g_geom *gp;
197 struct g_consumer *cp;
198 int error, r, w, e, i;
199
200 gp = dev->si_drv1;
201 cp = dev->si_drv2;
202 if (gp == NULL || cp == NULL)
203 return(ENXIO);
204 g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
205 gp->name, flags, fmt, td);
206 r = flags & FREAD ? -1 : 0;
207 w = flags & FWRITE ? -1 : 0;
208 #ifdef notyet
209 e = flags & O_EXCL ? -1 : 0;
210 #else
211 e = 0;
212 #endif
213 g_topology_lock();
214 if (dev->si_devsw == NULL)
215 error = ENXIO; /* We were orphaned */
216 else
217 error = g_access(cp, r, w, e);
218 for (i = 0; i < 10 * hz;) {
219 if (cp->acr != 0 || cp->acw != 0)
220 break;
221 if (cp->nstart == cp->nend)
222 break;
223 pause("gdevwclose", hz / 10);
224 i += hz / 10;
225 }
226 if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
227 printf("WARNING: Final close of geom_dev(%s) %s %s\n",
228 gp->name,
229 "still has outstanding I/O after 10 seconds.",
230 "Completing close anyway, panic may happen later.");
231 }
232 g_topology_unlock();
233 return (error);
234 }
235
236 /*
237 * XXX: Until we have unmessed the ioctl situation, there is a race against
238 * XXX: a concurrent orphanization. We cannot close it by holding topology
239 * XXX: since that would prevent us from doing our job, and stalling events
240 * XXX: will break (actually: stall) the BSD disklabel hacks.
241 */
242 static int
243 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
244 {
245 struct g_geom *gp;
246 struct g_consumer *cp;
247 struct g_kerneldump kd;
248 off_t offset, length;
249 int i, error;
250 u_int u;
251
252 gp = dev->si_drv1;
253 cp = dev->si_drv2;
254
255 error = 0;
256 KASSERT(cp->acr || cp->acw,
257 ("Consumer with zero access count in g_dev_ioctl"));
258
259 i = IOCPARM_LEN(cmd);
260 switch (cmd) {
261 case DIOCGSECTORSIZE:
262 *(u_int *)data = cp->provider->sectorsize;
263 if (*(u_int *)data == 0)
264 error = ENOENT;
265 break;
266 case DIOCGMEDIASIZE:
267 *(off_t *)data = cp->provider->mediasize;
268 if (*(off_t *)data == 0)
269 error = ENOENT;
270 break;
271 case DIOCGFWSECTORS:
272 error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
273 if (error == 0 && *(u_int *)data == 0)
274 error = ENOENT;
275 break;
276 case DIOCGFWHEADS:
277 error = g_io_getattr("GEOM::fwheads", cp, &i, data);
278 if (error == 0 && *(u_int *)data == 0)
279 error = ENOENT;
280 break;
281 case DIOCGFRONTSTUFF:
282 error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
283 break;
284 case DIOCSKERNELDUMP:
285 u = *((u_int *)data);
286 if (!u) {
287 set_dumper(NULL);
288 error = 0;
289 break;
290 }
291 kd.offset = 0;
292 kd.length = OFF_MAX;
293 i = sizeof kd;
294 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
295 if (!error)
296 dev->si_flags |= SI_DUMPDEV;
297 break;
298 case DIOCGFLUSH:
299 error = g_io_flush(cp);
300 break;
301 case DIOCGDELETE:
302 offset = ((off_t *)data)[0];
303 length = ((off_t *)data)[1];
304 if ((offset % cp->provider->sectorsize) != 0 ||
305 (length % cp->provider->sectorsize) != 0 ||
306 length <= 0 || length > MAXPHYS) {
307 printf("%s: offset=%jd length=%jd\n", __func__, offset,
308 length);
309 error = EINVAL;
310 break;
311 }
312 error = g_delete_data(cp, offset, length);
313 break;
314 case DIOCGIDENT:
315 error = g_io_getattr("GEOM::ident", cp, &i, data);
316 break;
317
318 default:
319 if (cp->provider->geom->ioctl != NULL) {
320 error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
321 } else {
322 error = ENOIOCTL;
323 }
324 }
325
326 return (error);
327 }
328
329 static void
330 g_dev_done(struct bio *bp2)
331 {
332 struct bio *bp;
333
334 bp = bp2->bio_parent;
335 bp->bio_error = bp2->bio_error;
336 if (bp->bio_error != 0) {
337 g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
338 bp2, bp->bio_error);
339 bp->bio_flags |= BIO_ERROR;
340 } else {
341 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
342 bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
343 }
344 bp->bio_resid = bp->bio_length - bp2->bio_completed;
345 bp->bio_completed = bp2->bio_completed;
346 g_destroy_bio(bp2);
347 biodone(bp);
348 }
349
350 static void
351 g_dev_strategy(struct bio *bp)
352 {
353 struct g_consumer *cp;
354 struct bio *bp2;
355 struct cdev *dev;
356
357 KASSERT(bp->bio_cmd == BIO_READ ||
358 bp->bio_cmd == BIO_WRITE ||
359 bp->bio_cmd == BIO_DELETE,
360 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
361 dev = bp->bio_dev;
362 cp = dev->si_drv2;
363 KASSERT(cp->acr || cp->acw,
364 ("Consumer with zero access count in g_dev_strategy"));
365
366 if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
367 (bp->bio_bcount % cp->provider->sectorsize) != 0) {
368 bp->bio_resid = bp->bio_bcount;
369 biofinish(bp, NULL, EINVAL);
370 return;
371 }
372
373 for (;;) {
374 /*
375 * XXX: This is not an ideal solution, but I belive it to
376 * XXX: deadlock safe, all things considered.
377 */
378 bp2 = g_clone_bio(bp);
379 if (bp2 != NULL)
380 break;
381 pause("gdstrat", hz / 10);
382 }
383 KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
384 bp2->bio_done = g_dev_done;
385 g_trace(G_T_BIO,
386 "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
387 bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
388 bp2->bio_data, bp2->bio_cmd);
389 g_io_request(bp2, cp);
390 KASSERT(cp->acr || cp->acw,
391 ("g_dev_strategy raced with g_dev_close and lost"));
392
393 }
394
395 /*
396 * g_dev_orphan()
397 *
398 * Called from below when the provider orphaned us.
399 * - Clear any dump settings.
400 * - Destroy the struct cdev *to prevent any more request from coming in. The
401 * provider is already marked with an error, so anything which comes in
402 * in the interrim will be returned immediately.
403 * - Wait for any outstanding I/O to finish.
404 * - Set our access counts to zero, whatever they were.
405 * - Detach and self-destruct.
406 */
407
408 static void
409 g_dev_orphan(struct g_consumer *cp)
410 {
411 struct g_geom *gp;
412 struct cdev *dev;
413 u_int unit;
414
415 g_topology_assert();
416 gp = cp->geom;
417 dev = gp->softc;
418 g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
419
420 /* Reset any dump-area set on this device */
421 if (dev->si_flags & SI_DUMPDEV)
422 set_dumper(NULL);
423
424 /* Destroy the struct cdev *so we get no more requests */
425 unit = dev2unit(dev);
426 destroy_dev(dev);
427 free_unr(unithdr, unit);
428
429 /* Wait for the cows to come home */
430 while (cp->nstart != cp->nend)
431 pause("gdevorphan", hz / 10);
432
433 if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
434 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
435
436 g_detach(cp);
437 g_destroy_consumer(cp);
438 g_destroy_geom(gp);
439 }
440
441 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
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