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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/ctype.h>
45 #include <sys/bio.h>
46 #include <sys/bus.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/proc.h>
50 #include <sys/errno.h>
51 #include <sys/time.h>
52 #include <sys/disk.h>
53 #include <sys/fcntl.h>
54 #include <sys/limits.h>
55 #include <sys/sysctl.h>
56 #include <geom/geom.h>
57 #include <geom/geom_int.h>
58 #include <machine/stdarg.h>
59
60 struct g_dev_softc {
61         struct mtx       sc_mtx;
62         struct cdev     *sc_dev;
63         struct cdev     *sc_alias;
64         int              sc_open;
65         int              sc_active;
66 };
67
68 static d_open_t         g_dev_open;
69 static d_close_t        g_dev_close;
70 static d_strategy_t     g_dev_strategy;
71 static d_ioctl_t        g_dev_ioctl;
72
73 static struct cdevsw g_dev_cdevsw = {
74         .d_version =    D_VERSION,
75         .d_open =       g_dev_open,
76         .d_close =      g_dev_close,
77         .d_read =       physread,
78         .d_write =      physwrite,
79         .d_ioctl =      g_dev_ioctl,
80         .d_strategy =   g_dev_strategy,
81         .d_name =       "g_dev",
82         .d_flags =      D_DISK | D_TRACKCLOSE,
83 };
84
85 static g_taste_t g_dev_taste;
86 static g_orphan_t g_dev_orphan;
87 static g_attrchanged_t g_dev_attrchanged;
88
89 static struct g_class g_dev_class       = {
90         .name = "DEV",
91         .version = G_VERSION,
92         .taste = g_dev_taste,
93         .orphan = g_dev_orphan,
94         .attrchanged = g_dev_attrchanged
95 };
96
97 /*
98  * We target 262144 (8 x 32768) sectors by default as this significantly
99  * increases the throughput on commonly used SSD's with a marginal
100  * increase in non-interruptible request latency.
101  */
102 static uint64_t g_dev_del_max_sectors = 262144;
103 SYSCTL_DECL(_kern_geom);
104 SYSCTL_NODE(_kern_geom, OID_AUTO, dev, CTLFLAG_RW, 0, "GEOM_DEV stuff");
105 SYSCTL_QUAD(_kern_geom_dev, OID_AUTO, delete_max_sectors, CTLFLAG_RW,
106     &g_dev_del_max_sectors, 0, "Maximum number of sectors in a single "
107     "delete request sent to the provider. Larger requests are chunked "
108     "so they can be interrupted. (0 = disable chunking)");
109
110 static void
111 g_dev_destroy(void *arg, int flags __unused)
112 {
113         struct g_consumer *cp;
114         struct g_geom *gp;
115         struct g_dev_softc *sc;
116
117         g_topology_assert();
118         cp = arg;
119         gp = cp->geom;
120         sc = cp->private;
121         g_trace(G_T_TOPOLOGY, "g_dev_destroy(%p(%s))", cp, gp->name);
122         if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
123                 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
124         g_detach(cp);
125         g_destroy_consumer(cp);
126         g_destroy_geom(gp);
127         mtx_destroy(&sc->sc_mtx);
128         g_free(sc);
129 }
130
131 void
132 g_dev_print(void)
133 {
134         struct g_geom *gp;
135         char const *p = "";
136
137         LIST_FOREACH(gp, &g_dev_class.geom, geom) {
138                 printf("%s%s", p, gp->name);
139                 p = " ";
140         }
141         printf("\n");
142 }
143
144 static void
145 g_dev_attrchanged(struct g_consumer *cp, const char *attr)
146 {
147         struct g_dev_softc *sc;
148         struct cdev *dev;
149         char buf[SPECNAMELEN + 6];
150
151         sc = cp->private;
152         if (strcmp(attr, "GEOM::media") == 0) {
153                 dev = sc->sc_dev;
154                 snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
155                 devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf, M_WAITOK);
156                 dev = sc->sc_alias;
157                 if (dev != NULL) {
158                         snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
159                         devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf,
160                             M_WAITOK);
161                 }
162                 return;
163         }
164
165         if (strcmp(attr, "GEOM::physpath") != 0)
166                 return;
167
168         if (g_access(cp, 1, 0, 0) == 0) {
169                 char *physpath;
170                 int error, physpath_len;
171
172                 physpath_len = MAXPATHLEN;
173                 physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
174                 error =
175                     g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
176                 g_access(cp, -1, 0, 0);
177                 if (error == 0 && strlen(physpath) != 0) {
178                         struct cdev *old_alias_dev;
179                         struct cdev **alias_devp;
180
181                         dev = sc->sc_dev;
182                         old_alias_dev = sc->sc_alias;
183                         alias_devp = (struct cdev **)&sc->sc_alias;
184                         make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
185                             dev, old_alias_dev, physpath);
186                 } else if (sc->sc_alias) {
187                         destroy_dev((struct cdev *)sc->sc_alias);
188                         sc->sc_alias = NULL;
189                 }
190                 g_free(physpath);
191         }
192 }
193
194 struct g_provider *
195 g_dev_getprovider(struct cdev *dev)
196 {
197         struct g_consumer *cp;
198
199         g_topology_assert();
200         if (dev == NULL)
201                 return (NULL);
202         if (dev->si_devsw != &g_dev_cdevsw)
203                 return (NULL);
204         cp = dev->si_drv2;
205         return (cp->provider);
206 }
207
208 static struct g_geom *
209 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
210 {
211         struct g_geom *gp;
212         struct g_consumer *cp;
213         struct g_dev_softc *sc;
214         int error, len;
215         struct cdev *dev, *adev;
216         char buf[64], *val;
217
218         g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
219         g_topology_assert();
220         gp = g_new_geomf(mp, "%s", pp->name);
221         sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
222         mtx_init(&sc->sc_mtx, "g_dev", NULL, MTX_DEF);
223         cp = g_new_consumer(gp);
224         cp->private = sc;
225         cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
226         error = g_attach(cp, pp);
227         KASSERT(error == 0,
228             ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
229         error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
230             &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
231         if (error != 0) {
232                 printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
233                     __func__, gp->name, error);
234                 g_detach(cp);
235                 g_destroy_consumer(cp);
236                 g_destroy_geom(gp);
237                 mtx_destroy(&sc->sc_mtx);
238                 g_free(sc);
239                 return (NULL);
240         }
241         dev->si_flags |= SI_UNMAPPED;
242         sc->sc_dev = dev;
243
244         /* Search for device alias name and create it if found. */
245         adev = NULL;
246         for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
247                 snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
248                 buf[14 + len] = 0;
249                 val = getenv(buf);
250                 if (val != NULL) {
251                         snprintf(buf, sizeof(buf), "%s%s",
252                             val, gp->name + len);
253                         freeenv(val);
254                         make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
255                             &adev, dev, "%s", buf);
256                         adev->si_flags |= SI_UNMAPPED;
257                         break;
258                 }
259         }
260
261         dev->si_iosize_max = MAXPHYS;
262         dev->si_drv2 = cp;
263         if (adev != NULL) {
264                 adev->si_iosize_max = MAXPHYS;
265                 adev->si_drv2 = cp;
266         }
267
268         g_dev_attrchanged(cp, "GEOM::physpath");
269
270         return (gp);
271 }
272
273 static int
274 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
275 {
276         struct g_consumer *cp;
277         struct g_dev_softc *sc;
278         int error, r, w, e;
279
280         cp = dev->si_drv2;
281         if (cp == NULL)
282                 return(ENXIO);          /* g_dev_taste() not done yet */
283         g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
284             cp->geom->name, flags, fmt, td);
285
286         r = flags & FREAD ? 1 : 0;
287         w = flags & FWRITE ? 1 : 0;
288 #ifdef notyet
289         e = flags & O_EXCL ? 1 : 0;
290 #else
291         e = 0;
292 #endif
293         if (w) {
294                 /*
295                  * When running in very secure mode, do not allow
296                  * opens for writing of any disks.
297                  */
298                 error = securelevel_ge(td->td_ucred, 2);
299                 if (error)
300                         return (error);
301         }
302         g_topology_lock();
303         error = g_access(cp, r, w, e);
304         g_topology_unlock();
305         if (error == 0) {
306                 sc = cp->private;
307                 mtx_lock(&sc->sc_mtx);
308                 if (sc->sc_open == 0 && sc->sc_active != 0)
309                         wakeup(&sc->sc_active);
310                 sc->sc_open += r + w + e;
311                 mtx_unlock(&sc->sc_mtx);
312         }
313         return(error);
314 }
315
316 static int
317 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
318 {
319         struct g_consumer *cp;
320         struct g_dev_softc *sc;
321         int error, r, w, e;
322
323         cp = dev->si_drv2;
324         if (cp == NULL)
325                 return(ENXIO);
326         g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
327             cp->geom->name, flags, fmt, td);
328         
329         r = flags & FREAD ? -1 : 0;
330         w = flags & FWRITE ? -1 : 0;
331 #ifdef notyet
332         e = flags & O_EXCL ? -1 : 0;
333 #else
334         e = 0;
335 #endif
336         sc = cp->private;
337         mtx_lock(&sc->sc_mtx);
338         sc->sc_open += r + w + e;
339         while (sc->sc_open == 0 && sc->sc_active != 0)
340                 msleep(&sc->sc_active, &sc->sc_mtx, 0, "PRIBIO", 0);
341         mtx_unlock(&sc->sc_mtx);
342         g_topology_lock();
343         error = g_access(cp, r, w, e);
344         g_topology_unlock();
345         return (error);
346 }
347
348 /*
349  * XXX: Until we have unmessed the ioctl situation, there is a race against
350  * XXX: a concurrent orphanization.  We cannot close it by holding topology
351  * XXX: since that would prevent us from doing our job, and stalling events
352  * XXX: will break (actually: stall) the BSD disklabel hacks.
353  */
354 static int
355 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
356 {
357         struct g_consumer *cp;
358         struct g_provider *pp;
359         struct g_kerneldump kd;
360         off_t offset, length, chunk;
361         int i, error;
362         u_int u;
363
364         cp = dev->si_drv2;
365         pp = cp->provider;
366
367         error = 0;
368         KASSERT(cp->acr || cp->acw,
369             ("Consumer with zero access count in g_dev_ioctl"));
370
371         i = IOCPARM_LEN(cmd);
372         switch (cmd) {
373         case DIOCGSECTORSIZE:
374                 *(u_int *)data = cp->provider->sectorsize;
375                 if (*(u_int *)data == 0)
376                         error = ENOENT;
377                 break;
378         case DIOCGMEDIASIZE:
379                 *(off_t *)data = cp->provider->mediasize;
380                 if (*(off_t *)data == 0)
381                         error = ENOENT;
382                 break;
383         case DIOCGFWSECTORS:
384                 error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
385                 if (error == 0 && *(u_int *)data == 0)
386                         error = ENOENT;
387                 break;
388         case DIOCGFWHEADS:
389                 error = g_io_getattr("GEOM::fwheads", cp, &i, data);
390                 if (error == 0 && *(u_int *)data == 0)
391                         error = ENOENT;
392                 break;
393         case DIOCGFRONTSTUFF:
394                 error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
395                 break;
396         case DIOCSKERNELDUMP:
397                 u = *((u_int *)data);
398                 if (!u) {
399                         set_dumper(NULL, NULL);
400                         error = 0;
401                         break;
402                 }
403                 kd.offset = 0;
404                 kd.length = OFF_MAX;
405                 i = sizeof kd;
406                 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
407                 if (!error) {
408                         error = set_dumper(&kd.di, devtoname(dev));
409                         if (!error)
410                                 dev->si_flags |= SI_DUMPDEV;
411                 }
412                 break;
413         case DIOCGFLUSH:
414                 error = g_io_flush(cp);
415                 break;
416         case DIOCGDELETE:
417                 offset = ((off_t *)data)[0];
418                 length = ((off_t *)data)[1];
419                 if ((offset % cp->provider->sectorsize) != 0 ||
420                     (length % cp->provider->sectorsize) != 0 || length <= 0) {
421                         printf("%s: offset=%jd length=%jd\n", __func__, offset,
422                             length);
423                         error = EINVAL;
424                         break;
425                 }
426                 while (length > 0) { 
427                         chunk = length;
428                         if (g_dev_del_max_sectors != 0 && chunk >
429                             g_dev_del_max_sectors * cp->provider->sectorsize) {
430                                 chunk = g_dev_del_max_sectors *
431                                     cp->provider->sectorsize;
432                         }
433                         error = g_delete_data(cp, offset, chunk);
434                         length -= chunk;
435                         offset += chunk;
436                         if (error)
437                                 break;
438                         /*
439                          * Since the request size can be large, the service
440                          * time can be is likewise.  We make this ioctl
441                          * interruptible by checking for signals for each bio.
442                          */
443                         if (SIGPENDING(td))
444                                 break;
445                 }
446                 break;
447         case DIOCGIDENT:
448                 error = g_io_getattr("GEOM::ident", cp, &i, data);
449                 break;
450         case DIOCGPROVIDERNAME:
451                 if (pp == NULL)
452                         return (ENOENT);
453                 strlcpy(data, pp->name, i);
454                 break;
455         case DIOCGSTRIPESIZE:
456                 *(off_t *)data = cp->provider->stripesize;
457                 break;
458         case DIOCGSTRIPEOFFSET:
459                 *(off_t *)data = cp->provider->stripeoffset;
460                 break;
461         case DIOCGPHYSPATH:
462                 error = g_io_getattr("GEOM::physpath", cp, &i, data);
463                 if (error == 0 && *(char *)data == '\0')
464                         error = ENOENT;
465                 break;
466         default:
467                 if (cp->provider->geom->ioctl != NULL) {
468                         error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
469                 } else {
470                         error = ENOIOCTL;
471                 }
472         }
473
474         return (error);
475 }
476
477 static void
478 g_dev_done(struct bio *bp2)
479 {
480         struct g_consumer *cp;
481         struct g_dev_softc *sc;
482         struct bio *bp;
483         int destroy;
484
485         cp = bp2->bio_from;
486         sc = cp->private;
487         bp = bp2->bio_parent;
488         bp->bio_error = bp2->bio_error;
489         bp->bio_completed = bp2->bio_completed;
490         bp->bio_resid = bp->bio_length - bp2->bio_completed;
491         if (bp2->bio_error != 0) {
492                 g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
493                     bp2, bp2->bio_error);
494                 bp->bio_flags |= BIO_ERROR;
495         } else {
496                 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
497                     bp2, bp, bp2->bio_resid, (intmax_t)bp2->bio_completed);
498         }
499         g_destroy_bio(bp2);
500         destroy = 0;
501         mtx_lock(&sc->sc_mtx);
502         if ((--sc->sc_active) == 0) {
503                 if (sc->sc_open == 0)
504                         wakeup(&sc->sc_active);
505                 if (sc->sc_dev == NULL)
506                         destroy = 1;
507         }
508         mtx_unlock(&sc->sc_mtx);
509         if (destroy)
510                 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
511         biodone(bp);
512 }
513
514 static void
515 g_dev_strategy(struct bio *bp)
516 {
517         struct g_consumer *cp;
518         struct bio *bp2;
519         struct cdev *dev;
520         struct g_dev_softc *sc;
521
522         KASSERT(bp->bio_cmd == BIO_READ ||
523                 bp->bio_cmd == BIO_WRITE ||
524                 bp->bio_cmd == BIO_DELETE ||
525                 bp->bio_cmd == BIO_FLUSH,
526                 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
527         dev = bp->bio_dev;
528         cp = dev->si_drv2;
529         sc = cp->private;
530         KASSERT(cp->acr || cp->acw,
531             ("Consumer with zero access count in g_dev_strategy"));
532 #ifdef INVARIANTS
533         if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
534             (bp->bio_bcount % cp->provider->sectorsize) != 0) {
535                 bp->bio_resid = bp->bio_bcount;
536                 biofinish(bp, NULL, EINVAL);
537                 return;
538         }
539 #endif
540         mtx_lock(&sc->sc_mtx);
541         KASSERT(sc->sc_open > 0, ("Closed device in g_dev_strategy"));
542         sc->sc_active++;
543         mtx_unlock(&sc->sc_mtx);
544
545         for (;;) {
546                 /*
547                  * XXX: This is not an ideal solution, but I belive it to
548                  * XXX: deadlock safe, all things considered.
549                  */
550                 bp2 = g_clone_bio(bp);
551                 if (bp2 != NULL)
552                         break;
553                 pause("gdstrat", hz / 10);
554         }
555         KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
556         bp2->bio_done = g_dev_done;
557         g_trace(G_T_BIO,
558             "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
559             bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
560             bp2->bio_data, bp2->bio_cmd);
561         g_io_request(bp2, cp);
562         KASSERT(cp->acr || cp->acw,
563             ("g_dev_strategy raced with g_dev_close and lost"));
564
565 }
566
567 /*
568  * g_dev_callback()
569  *
570  * Called by devfs when asynchronous device destruction is completed.
571  * - Mark that we have no attached device any more.
572  * - If there are no outstanding requests, schedule geom destruction.
573  *   Otherwise destruction will be scheduled later by g_dev_done().
574  */
575
576 static void
577 g_dev_callback(void *arg)
578 {
579         struct g_consumer *cp;
580         struct g_dev_softc *sc;
581         int destroy;
582
583         cp = arg;
584         sc = cp->private;
585         g_trace(G_T_TOPOLOGY, "g_dev_callback(%p(%s))", cp, cp->geom->name);
586
587         mtx_lock(&sc->sc_mtx);
588         sc->sc_dev = NULL;
589         sc->sc_alias = NULL;
590         destroy = (sc->sc_active == 0);
591         mtx_unlock(&sc->sc_mtx);
592         if (destroy)
593                 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
594 }
595
596 /*
597  * g_dev_orphan()
598  *
599  * Called from below when the provider orphaned us.
600  * - Clear any dump settings.
601  * - Request asynchronous device destruction to prevent any more requests
602  *   from coming in.  The provider is already marked with an error, so
603  *   anything which comes in in the interrim will be returned immediately.
604  */
605
606 static void
607 g_dev_orphan(struct g_consumer *cp)
608 {
609         struct cdev *dev;
610         struct g_dev_softc *sc;
611
612         g_topology_assert();
613         sc = cp->private;
614         dev = sc->sc_dev;
615         g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, cp->geom->name);
616
617         /* Reset any dump-area set on this device */
618         if (dev->si_flags & SI_DUMPDEV)
619                 set_dumper(NULL, NULL);
620
621         /* Destroy the struct cdev *so we get no more requests */
622         destroy_dev_sched_cb(dev, g_dev_callback, cp);
623 }
624
625 DECLARE_GEOM_CLASS(g_dev_class, g_dev);