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: releng/6.0/sys/geom/geom_dev.c 143790 2005-03-18 06:57:58Z phk $");
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 /*
142 * XXX: I'm not 100% sure we can call make_dev(9) without Giant
143 * yet. Once we can, we don't need to drop topology here either.
144 */
145 unit = alloc_unr(unithdr);
146 g_topology_unlock();
147 mtx_lock(&Giant);
148 dev = make_dev(&g_dev_cdevsw, unit2minor(unit),
149 UID_ROOT, GID_OPERATOR, 0640, gp->name);
150 if (pp->flags & G_PF_CANDELETE)
151 dev->si_flags |= SI_CANDELETE;
152 mtx_unlock(&Giant);
153 g_topology_lock();
154 dev->si_iosize_max = MAXPHYS;
155 gp->softc = dev;
156 dev->si_drv1 = gp;
157 dev->si_drv2 = cp;
158 return (gp);
159 }
160
161 static int
162 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
163 {
164 struct g_geom *gp;
165 struct g_consumer *cp;
166 int error, r, w, e;
167
168 gp = dev->si_drv1;
169 cp = dev->si_drv2;
170 if (gp == NULL || cp == NULL || gp->softc != dev)
171 return(ENXIO); /* g_dev_taste() not done yet */
172
173 g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
174 gp->name, flags, fmt, td);
175
176 r = flags & FREAD ? 1 : 0;
177 w = flags & FWRITE ? 1 : 0;
178 #ifdef notyet
179 e = flags & O_EXCL ? 1 : 0;
180 #else
181 e = 0;
182 #endif
183 if (w) {
184 /*
185 * When running in very secure mode, do not allow
186 * opens for writing of any disks.
187 */
188 error = securelevel_ge(td->td_ucred, 2);
189 if (error)
190 return (error);
191 }
192 g_topology_lock();
193 if (dev->si_devsw == NULL)
194 error = ENXIO; /* We were orphaned */
195 else
196 error = g_access(cp, r, w, e);
197 g_topology_unlock();
198 return(error);
199 }
200
201 static int
202 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
203 {
204 struct g_geom *gp;
205 struct g_consumer *cp;
206 int error, r, w, e, i;
207
208 gp = dev->si_drv1;
209 cp = dev->si_drv2;
210 if (gp == NULL || cp == NULL)
211 return(ENXIO);
212 g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
213 gp->name, flags, fmt, td);
214 r = flags & FREAD ? -1 : 0;
215 w = flags & FWRITE ? -1 : 0;
216 #ifdef notyet
217 e = flags & O_EXCL ? -1 : 0;
218 #else
219 e = 0;
220 #endif
221 g_topology_lock();
222 if (dev->si_devsw == NULL)
223 error = ENXIO; /* We were orphaned */
224 else
225 error = g_access(cp, r, w, e);
226 for (i = 0; i < 10 * hz;) {
227 if (cp->acr != 0 || cp->acw != 0)
228 break;
229 if (cp->nstart == cp->nend)
230 break;
231 tsleep(&i, PRIBIO, "gdevwclose", hz / 10);
232 i += hz / 10;
233 }
234 if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
235 printf("WARNING: Final close of geom_dev(%s) %s %s\n",
236 gp->name,
237 "still has outstanding I/O after 10 seconds.",
238 "Completing close anyway, panic may happen later.");
239 }
240 g_topology_unlock();
241 return (error);
242 }
243
244 /*
245 * XXX: Until we have unmessed the ioctl situation, there is a race against
246 * XXX: a concurrent orphanization. We cannot close it by holding topology
247 * XXX: since that would prevent us from doing our job, and stalling events
248 * XXX: will break (actually: stall) the BSD disklabel hacks.
249 */
250 static int
251 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
252 {
253 struct g_geom *gp;
254 struct g_consumer *cp;
255 struct g_kerneldump kd;
256 int i, error;
257 u_int u;
258
259 gp = dev->si_drv1;
260 cp = dev->si_drv2;
261
262 error = 0;
263 KASSERT(cp->acr || cp->acw,
264 ("Consumer with zero access count in g_dev_ioctl"));
265
266 i = IOCPARM_LEN(cmd);
267 switch (cmd) {
268 case DIOCGSECTORSIZE:
269 *(u_int *)data = cp->provider->sectorsize;
270 if (*(u_int *)data == 0)
271 error = ENOENT;
272 break;
273 case DIOCGMEDIASIZE:
274 *(off_t *)data = cp->provider->mediasize;
275 if (*(off_t *)data == 0)
276 error = ENOENT;
277 break;
278 case DIOCGFWSECTORS:
279 error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
280 if (error == 0 && *(u_int *)data == 0)
281 error = ENOENT;
282 break;
283 case DIOCGFWHEADS:
284 error = g_io_getattr("GEOM::fwheads", cp, &i, data);
285 if (error == 0 && *(u_int *)data == 0)
286 error = ENOENT;
287 break;
288 case DIOCGFRONTSTUFF:
289 error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
290 break;
291 case DIOCSKERNELDUMP:
292 u = *((u_int *)data);
293 if (!u) {
294 set_dumper(NULL);
295 error = 0;
296 break;
297 }
298 kd.offset = 0;
299 kd.length = OFF_MAX;
300 i = sizeof kd;
301 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
302 if (!error)
303 dev->si_flags |= SI_DUMPDEV;
304 break;
305
306 default:
307 if (cp->provider->geom->ioctl != NULL) {
308 error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
309 } else {
310 error = ENOIOCTL;
311 }
312 }
313
314 return (error);
315 }
316
317 static void
318 g_dev_done(struct bio *bp2)
319 {
320 struct bio *bp;
321
322 bp = bp2->bio_parent;
323 bp->bio_error = bp2->bio_error;
324 if (bp->bio_error != 0) {
325 g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
326 bp2, bp->bio_error);
327 bp->bio_flags |= BIO_ERROR;
328 } else {
329 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
330 bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
331 }
332 bp->bio_resid = bp->bio_length - bp2->bio_completed;
333 bp->bio_completed = bp2->bio_completed;
334 g_destroy_bio(bp2);
335 biodone(bp);
336 }
337
338 static void
339 g_dev_strategy(struct bio *bp)
340 {
341 struct g_consumer *cp;
342 struct bio *bp2;
343 struct cdev *dev;
344
345 KASSERT(bp->bio_cmd == BIO_READ ||
346 bp->bio_cmd == BIO_WRITE ||
347 bp->bio_cmd == BIO_DELETE,
348 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
349 dev = bp->bio_dev;
350 cp = dev->si_drv2;
351 KASSERT(cp->acr || cp->acw,
352 ("Consumer with zero access count in g_dev_strategy"));
353
354 if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
355 (bp->bio_bcount % cp->provider->sectorsize) != 0) {
356 biofinish(bp, NULL, EINVAL);
357 return;
358 }
359
360 for (;;) {
361 /*
362 * XXX: This is not an ideal solution, but I belive it to
363 * XXX: deadlock safe, all things considered.
364 */
365 bp2 = g_clone_bio(bp);
366 if (bp2 != NULL)
367 break;
368 tsleep(&bp, PRIBIO, "gdstrat", hz / 10);
369 }
370 KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
371 bp2->bio_done = g_dev_done;
372 g_trace(G_T_BIO,
373 "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
374 bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
375 bp2->bio_data, bp2->bio_cmd);
376 g_io_request(bp2, cp);
377 KASSERT(cp->acr || cp->acw,
378 ("g_dev_strategy raced with g_dev_close and lost"));
379
380 }
381
382 /*
383 * g_dev_orphan()
384 *
385 * Called from below when the provider orphaned us.
386 * - Clear any dump settings.
387 * - Destroy the struct cdev *to prevent any more request from coming in. The
388 * provider is already marked with an error, so anything which comes in
389 * in the interrim will be returned immediately.
390 * - Wait for any outstanding I/O to finish.
391 * - Set our access counts to zero, whatever they were.
392 * - Detach and self-destruct.
393 */
394
395 static void
396 g_dev_orphan(struct g_consumer *cp)
397 {
398 struct g_geom *gp;
399 struct cdev *dev;
400 u_int unit;
401
402 g_topology_assert();
403 gp = cp->geom;
404 dev = gp->softc;
405 g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
406
407 /* Reset any dump-area set on this device */
408 if (dev->si_flags & SI_DUMPDEV)
409 set_dumper(NULL);
410
411 /* Destroy the struct cdev *so we get no more requests */
412 unit = dev2unit(dev);
413 destroy_dev(dev);
414 free_unr(unithdr, unit);
415
416 /* Wait for the cows to come home */
417 while (cp->nstart != cp->nend)
418 msleep(&dev, NULL, PRIBIO, "gdevorphan", hz / 10);
419
420 if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
421 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
422
423 g_detach(cp);
424 g_destroy_consumer(cp);
425 g_destroy_geom(gp);
426 }
427
428 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
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