initial commit
[freebsd-arm:freebsd-arm.git] / cddl / contrib / opensolaris / uts / common / fs / zfs / vdev_geom.c
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
23  * All rights reserved.
24  */
25
26 #include <sys/zfs_context.h>
27 #include <sys/param.h>
28 #include <sys/kernel.h>
29 #include <sys/bio.h>
30 #include <sys/disk.h>
31 #include <sys/spa.h>
32 #include <sys/vdev_impl.h>
33 #include <sys/fs/zfs.h>
34 #include <sys/zio.h>
35 #include <geom/geom.h>
36 #include <geom/geom_int.h>
37
38 /*
39  * Virtual device vector for GEOM.
40  */
41
42 struct g_class zfs_vdev_class = {
43         .name = "ZFS::VDEV",
44         .version = G_VERSION,
45 };
46
47 DECLARE_GEOM_CLASS(zfs_vdev_class, zfs_vdev);
48
49 typedef struct vdev_geom_ctx {
50         struct g_consumer *gc_consumer;
51         int gc_state;
52         struct bio_queue_head gc_queue;
53         struct mtx gc_queue_mtx;
54 } vdev_geom_ctx_t;
55
56 static void
57 vdev_geom_release(vdev_t *vd)
58 {
59         vdev_geom_ctx_t *ctx;
60
61         ctx = vd->vdev_tsd;
62         vd->vdev_tsd = NULL;
63
64         mtx_lock(&ctx->gc_queue_mtx);
65         ctx->gc_state = 1;
66         wakeup_one(&ctx->gc_queue);
67         while (ctx->gc_state != 2)
68                 msleep(&ctx->gc_state, &ctx->gc_queue_mtx, 0, "vgeom:w", 0);
69         mtx_unlock(&ctx->gc_queue_mtx);
70         mtx_destroy(&ctx->gc_queue_mtx);
71         kmem_free(ctx, sizeof(*ctx));
72 }
73
74 static void
75 vdev_geom_orphan(struct g_consumer *cp)
76 {
77         struct g_geom *gp;
78         vdev_t *vd;
79         int error;
80
81         g_topology_assert();
82
83         vd = cp->private;
84         gp = cp->geom;
85         error = cp->provider->error;
86
87         ZFS_LOG(1, "Closing access to %s.", cp->provider->name);
88         if (cp->acr + cp->acw + cp->ace > 0)
89                 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
90         ZFS_LOG(1, "Destroyed consumer to %s.", cp->provider->name);
91         g_detach(cp);
92         g_destroy_consumer(cp);
93         /* Destroy geom if there are no consumers left. */
94         if (LIST_EMPTY(&gp->consumer)) {
95                 ZFS_LOG(1, "Destroyed geom %s.", gp->name);
96                 g_wither_geom(gp, error);
97         }
98         vdev_geom_release(vd);
99
100         vd->vdev_remove_wanted = B_TRUE;
101         spa_async_request(vd->vdev_spa, SPA_ASYNC_REMOVE);
102 }
103
104 static struct g_consumer *
105 vdev_geom_attach(struct g_provider *pp, int write)
106 {
107         struct g_geom *gp;
108         struct g_consumer *cp;
109
110         g_topology_assert();
111
112         ZFS_LOG(1, "Attaching to %s.", pp->name);
113         /* Do we have geom already? No? Create one. */
114         LIST_FOREACH(gp, &zfs_vdev_class.geom, geom) {
115                 if (gp->flags & G_GEOM_WITHER)
116                         continue;
117                 if (strcmp(gp->name, "zfs::vdev") != 0)
118                         continue;
119                 break;
120         }
121         if (gp == NULL) {
122                 gp = g_new_geomf(&zfs_vdev_class, "zfs::vdev");
123                 gp->orphan = vdev_geom_orphan;
124                 cp = g_new_consumer(gp);
125                 if (g_attach(cp, pp) != 0) {
126                         g_wither_geom(gp, ENXIO);
127                         return (NULL);
128                 }
129                 if (g_access(cp, 1, write, 1) != 0) {
130                         g_wither_geom(gp, ENXIO);
131                         return (NULL);
132                 }
133                 ZFS_LOG(1, "Created geom and consumer for %s.", pp->name);
134         } else {
135                 /* Check if we are already connected to this provider. */
136                 LIST_FOREACH(cp, &gp->consumer, consumer) {
137                         if (cp->provider == pp) {
138                                 ZFS_LOG(1, "Found consumer for %s.", pp->name);
139                                 break;
140                         }
141                 }
142                 if (cp == NULL) {
143                         cp = g_new_consumer(gp);
144                         if (g_attach(cp, pp) != 0) {
145                                 g_destroy_consumer(cp);
146                                 return (NULL);
147                         }
148                         if (g_access(cp, 1, write, 1) != 0) {
149                                 g_detach(cp);
150                                 g_destroy_consumer(cp);
151                                 return (NULL);
152                         }
153                         ZFS_LOG(1, "Created consumer for %s.", pp->name);
154                 } else {
155                         if (g_access(cp, 1, cp->acw > 0 ? 0 : write, 1) != 0)
156                                 return (NULL);
157                         ZFS_LOG(1, "Used existing consumer for %s.", pp->name);
158                 }
159         }
160         return (cp);
161 }
162
163 static void
164 vdev_geom_detach(void *arg, int flag __unused)
165 {
166         struct g_geom *gp;
167         struct g_consumer *cp;
168
169         g_topology_assert();
170         cp = arg;
171         gp = cp->geom;
172
173         ZFS_LOG(1, "Closing access to %s.", cp->provider->name);
174         g_access(cp, -1, 0, -1);
175         /* Destroy consumer on last close. */
176         if (cp->acr == 0 && cp->ace == 0) {
177                 ZFS_LOG(1, "Destroyed consumer to %s.", cp->provider->name);
178                 if (cp->acw > 0)
179                         g_access(cp, 0, -cp->acw, 0);
180                 g_detach(cp);
181                 g_destroy_consumer(cp);
182         }
183         /* Destroy geom if there are no consumers left. */
184         if (LIST_EMPTY(&gp->consumer)) {
185                 ZFS_LOG(1, "Destroyed geom %s.", gp->name);
186                 g_wither_geom(gp, ENXIO);
187         }
188 }
189
190 static void
191 vdev_geom_worker(void *arg)
192 {
193         vdev_geom_ctx_t *ctx;
194         zio_t *zio;
195         struct bio *bp;
196
197         thread_lock(curthread);
198         sched_prio(curthread, PRIBIO);
199         thread_unlock(curthread);
200
201         ctx = arg;
202         for (;;) {
203                 mtx_lock(&ctx->gc_queue_mtx);
204                 bp = bioq_takefirst(&ctx->gc_queue);
205                 if (bp == NULL) {
206                         if (ctx->gc_state == 1) {
207                                 ctx->gc_state = 2;
208                                 wakeup_one(&ctx->gc_state);
209                                 mtx_unlock(&ctx->gc_queue_mtx);
210                                 kthread_exit();
211                         }
212                         msleep(&ctx->gc_queue, &ctx->gc_queue_mtx,
213                             PRIBIO | PDROP, "vgeom:io", 0);
214                         continue;
215                 }
216                 mtx_unlock(&ctx->gc_queue_mtx);
217                 zio = bp->bio_caller1;
218                 zio->io_error = bp->bio_error;
219                 if (bp->bio_cmd == BIO_FLUSH && bp->bio_error == ENOTSUP) {
220                         vdev_t *vd;
221
222                         /*
223                          * If we get ENOTSUP, we know that no future
224                          * attempts will ever succeed.  In this case we
225                          * set a persistent bit so that we don't bother
226                          * with the ioctl in the future.
227                          */
228                         vd = zio->io_vd;
229                         vd->vdev_nowritecache = B_TRUE;
230                 }
231                 g_destroy_bio(bp);
232                 zio_interrupt(zio);
233         }
234 }
235
236 static uint64_t
237 nvlist_get_guid(nvlist_t *list)
238 {
239         nvpair_t *elem = NULL;
240         uint64_t value;
241
242         while ((elem = nvlist_next_nvpair(list, elem)) != NULL) {
243                 if (nvpair_type(elem) == DATA_TYPE_UINT64 &&
244                     strcmp(nvpair_name(elem), "guid") == 0) {
245                         VERIFY(nvpair_value_uint64(elem, &value) == 0);
246                         return (value);
247                 }
248         }
249         return (0);
250 }
251
252 static int
253 vdev_geom_io(struct g_consumer *cp, int cmd, void *data, off_t offset, off_t size)
254 {
255         struct bio *bp;
256         u_char *p;
257         off_t off;
258         int error;
259
260         ASSERT((offset % cp->provider->sectorsize) == 0);
261         ASSERT((size % cp->provider->sectorsize) == 0);
262
263         bp = g_alloc_bio();
264         off = offset;
265         offset += size;
266         p = data;
267         error = 0;
268
269         for (; off < offset; off += MAXPHYS, p += MAXPHYS, size -= MAXPHYS) {
270                 bzero(bp, sizeof(*bp));
271                 bp->bio_cmd = cmd;
272                 bp->bio_done = NULL;
273                 bp->bio_offset = off;
274                 bp->bio_length = MIN(size, MAXPHYS);
275                 bp->bio_data = p;
276                 g_io_request(bp, cp);
277                 error = biowait(bp, "vdev_geom_io");
278                 if (error != 0)
279                         break;
280         }
281
282         g_destroy_bio(bp);
283         return (error);
284 }
285
286 static uint64_t
287 vdev_geom_read_guid(struct g_consumer *cp)
288 {
289         struct g_provider *pp;
290         vdev_label_t *label;
291         char *p, *buf;
292         size_t buflen;
293         uint64_t psize;
294         off_t offset, size;
295         uint64_t guid;
296         int error, l, len, iszvol;
297
298         g_topology_assert_not();
299
300         pp = cp->provider;
301         ZFS_LOG(1, "Reading guid from %s...", pp->name);
302         if (g_getattr("ZFS::iszvol", cp, &iszvol) == 0 && iszvol) {
303                 ZFS_LOG(1, "Skipping ZVOL-based provider %s.", pp->name);
304                 return (0);
305         }
306
307         psize = pp->mediasize;
308         psize = P2ALIGN(psize, (uint64_t)sizeof(vdev_label_t));
309
310         size = sizeof(*label) + pp->sectorsize -
311             ((sizeof(*label) - 1) % pp->sectorsize) - 1;
312
313         guid = 0;
314         label = kmem_alloc(size, KM_SLEEP);
315         buflen = sizeof(label->vl_vdev_phys.vp_nvlist);
316
317         for (l = 0; l < VDEV_LABELS; l++) {
318                 nvlist_t *config = NULL;
319
320                 offset = vdev_label_offset(psize, l, 0);
321                 if ((offset % pp->sectorsize) != 0)
322                         continue;
323
324                 if (vdev_geom_io(cp, BIO_READ, label, offset, size) != 0)
325                         continue;
326                 buf = label->vl_vdev_phys.vp_nvlist;
327
328                 if (nvlist_unpack(buf, buflen, &config, 0) != 0)
329                         continue;
330
331                 guid = nvlist_get_guid(config);
332                 nvlist_free(config);
333                 if (guid != 0)
334                         break;
335         }
336
337         kmem_free(label, size);
338         if (guid != 0)
339                 ZFS_LOG(1, "guid for %s is %ju", pp->name, (uintmax_t)guid);
340         return (guid);
341 }
342
343 struct vdev_geom_find {
344         uint64_t guid;
345         int write;
346         struct g_consumer *cp;
347 };
348
349 static void
350 vdev_geom_taste_orphan(struct g_consumer *cp)
351 {
352
353         KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
354             cp->provider->name));
355 }
356
357 static void
358 vdev_geom_attach_by_guid_event(void *arg, int flags __unused)
359 {
360         struct vdev_geom_find *ap;
361         struct g_class *mp;
362         struct g_geom *gp, *zgp;
363         struct g_provider *pp;
364         struct g_consumer *zcp;
365         uint64_t guid;
366
367         g_topology_assert();
368
369         ap = arg;
370
371         zgp = g_new_geomf(&zfs_vdev_class, "zfs::vdev::taste");
372         /* This orphan function should be never called. */
373         zgp->orphan = vdev_geom_taste_orphan;
374         zcp = g_new_consumer(zgp);
375
376         LIST_FOREACH(mp, &g_classes, class) {
377                 if (mp == &zfs_vdev_class)
378                         continue;
379                 LIST_FOREACH(gp, &mp->geom, geom) {
380                         if (gp->flags & G_GEOM_WITHER)
381                                 continue;
382                         LIST_FOREACH(pp, &gp->provider, provider) {
383                                 if (pp->flags & G_PF_WITHER)
384                                         continue;
385                                 g_attach(zcp, pp);
386                                 if (g_access(zcp, 1, 0, 0) != 0) {
387                                         g_detach(zcp);
388                                         continue;
389                                 }
390                                 g_topology_unlock();
391                                 guid = vdev_geom_read_guid(zcp);
392                                 g_topology_lock();
393                                 g_access(zcp, -1, 0, 0);
394                                 g_detach(zcp);
395                                 if (guid != ap->guid)
396                                         continue;
397                                 ap->cp = vdev_geom_attach(pp, ap->write);
398                                 if (ap->cp == NULL) {
399                                         printf("ZFS WARNING: Cannot open %s "
400                                             "for writting.\n", pp->name);
401                                         continue;
402                                 }
403                                 goto end;
404                         }
405                 }
406         }
407         ap->cp = NULL;
408 end:
409         g_destroy_consumer(zcp);
410         g_destroy_geom(zgp);
411 }
412
413 static struct g_consumer *
414 vdev_geom_attach_by_guid(uint64_t guid, int write)
415 {
416         struct vdev_geom_find *ap;
417         struct g_consumer *cp;
418
419         ap = kmem_zalloc(sizeof(*ap), KM_SLEEP);
420         ap->guid = guid;
421         ap->write = write;
422         g_waitfor_event(vdev_geom_attach_by_guid_event, ap, M_WAITOK, NULL);
423         cp = ap->cp;
424         kmem_free(ap, sizeof(*ap));
425         return (cp);
426 }
427
428 static struct g_consumer *
429 vdev_geom_open_by_guid(vdev_t *vd)
430 {
431         struct g_consumer *cp;
432         char *buf;
433         size_t len;
434
435         ZFS_LOG(1, "Searching by guid [%ju].", (uintmax_t)vd->vdev_guid);
436         cp = vdev_geom_attach_by_guid(vd->vdev_guid, !!(spa_mode & FWRITE));
437         if (cp != NULL) {
438                 len = strlen(cp->provider->name) + strlen("/dev/") + 1;
439                 buf = kmem_alloc(len, KM_SLEEP);
440
441                 snprintf(buf, len, "/dev/%s", cp->provider->name);
442                 spa_strfree(vd->vdev_path);
443                 vd->vdev_path = buf;
444
445                 ZFS_LOG(1, "Attach by guid [%ju] succeeded, provider %s.",
446                     (uintmax_t)vd->vdev_guid, vd->vdev_path);
447         } else {
448                 ZFS_LOG(1, "Search by guid [%ju] failed.",
449                     (uintmax_t)vd->vdev_guid);
450         }
451
452         return (cp);
453 }
454
455 static struct g_consumer *
456 vdev_geom_open_by_path(vdev_t *vd, int check_guid)
457 {
458         struct g_provider *pp;
459         struct g_consumer *cp;
460         uint64_t guid;
461
462         cp = NULL;
463         g_topology_lock();
464         pp = g_provider_by_name(vd->vdev_path + sizeof("/dev/") - 1);
465         if (pp != NULL) {
466                 ZFS_LOG(1, "Found provider by name %s.", vd->vdev_path);
467                 cp = vdev_geom_attach(pp, !!(spa_mode & FWRITE));
468                 if (cp != NULL && check_guid) {
469                         g_topology_unlock();
470                         guid = vdev_geom_read_guid(cp);
471                         g_topology_lock();
472                         if (guid != vd->vdev_guid) {
473                                 vdev_geom_detach(cp, 0);
474                                 cp = NULL;
475                                 ZFS_LOG(1, "guid mismatch for provider %s: "
476                                     "%ju != %ju.", vd->vdev_path,
477                                     (uintmax_t)vd->vdev_guid, (uintmax_t)guid);
478                         } else {
479                                 ZFS_LOG(1, "guid match for provider %s.",
480                                     vd->vdev_path);
481                         }
482                 }
483         }
484         g_topology_unlock();
485
486         return (cp);
487 }
488
489 static int
490 vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
491 {
492         vdev_geom_ctx_t *ctx;
493         struct g_provider *pp;
494         struct g_consumer *cp;
495         int owned;
496
497         /*
498          * We must have a pathname, and it must be absolute.
499          */
500         if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
501                 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
502                 return (EINVAL);
503         }
504
505         vd->vdev_tsd = NULL;
506
507         if ((owned = mtx_owned(&Giant)))
508                 mtx_unlock(&Giant);
509         cp = vdev_geom_open_by_path(vd, 1);
510         if (cp == NULL) {
511                 /*
512                  * The device at vd->vdev_path doesn't have the expected guid.
513                  * The disks might have merely moved around so try all other
514                  * geom providers to find one with the right guid.
515                  */
516                 cp = vdev_geom_open_by_guid(vd);
517         }
518         if (cp == NULL)
519                 cp = vdev_geom_open_by_path(vd, 0);
520         if (cp == NULL) {
521                 ZFS_LOG(1, "Provider %s not found.", vd->vdev_path);
522                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
523                 if (owned)
524                         mtx_lock(&Giant);
525                 return (EACCES);
526         }
527         if (owned)
528                 mtx_lock(&Giant);
529
530         cp->private = vd;
531
532         ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP);
533         bioq_init(&ctx->gc_queue);
534         mtx_init(&ctx->gc_queue_mtx, "zfs:vdev:geom:queue", NULL, MTX_DEF);
535         ctx->gc_consumer = cp;
536         ctx->gc_state = 0;
537
538         vd->vdev_tsd = ctx;
539         pp = cp->provider;
540
541         kproc_kthread_add(vdev_geom_worker, ctx, &zfsproc, NULL, 0, 0,
542             "zfskern", "vdev %s", pp->name);
543
544         /*
545          * Determine the actual size of the device.
546          */
547         *psize = pp->mediasize;
548
549         /*
550          * Determine the device's minimum transfer size.
551          */
552         *ashift = highbit(MAX(pp->sectorsize, SPA_MINBLOCKSIZE)) - 1;
553
554         /*
555          * Clear the nowritecache bit, so that on a vdev_reopen() we will
556          * try again.
557          */
558         vd->vdev_nowritecache = B_FALSE;
559
560         return (0);
561 }
562
563 static void
564 vdev_geom_close(vdev_t *vd)
565 {
566         vdev_geom_ctx_t *ctx;
567         struct g_consumer *cp;
568
569         if ((ctx = vd->vdev_tsd) == NULL)
570                 return;
571         if ((cp = ctx->gc_consumer) == NULL)
572                 return;
573         vdev_geom_release(vd);
574         g_post_event(vdev_geom_detach, cp, M_WAITOK, NULL);
575 }
576
577 static void
578 vdev_geom_io_intr(struct bio *bp)
579 {
580         vdev_geom_ctx_t *ctx;
581         zio_t *zio;
582
583         zio = bp->bio_caller1;
584         ctx = zio->io_vd->vdev_tsd;
585
586         if ((zio->io_error = bp->bio_error) == 0 && bp->bio_resid != 0)
587                 zio->io_error = EIO;
588
589         mtx_lock(&ctx->gc_queue_mtx);
590         bioq_insert_tail(&ctx->gc_queue, bp);
591         wakeup_one(&ctx->gc_queue);
592         mtx_unlock(&ctx->gc_queue_mtx);
593 }
594
595 static int
596 vdev_geom_io_start(zio_t *zio)
597 {
598         vdev_t *vd;
599         vdev_geom_ctx_t *ctx;
600         struct g_consumer *cp;
601         struct bio *bp;
602         int error;
603
604         cp = NULL;
605
606         vd = zio->io_vd;
607         ctx = vd->vdev_tsd;
608         if (ctx != NULL)
609                 cp = ctx->gc_consumer;
610
611         if (zio->io_type == ZIO_TYPE_IOCTL) {
612                 /* XXPOLICY */
613                 if (!vdev_readable(vd)) {
614                         zio->io_error = ENXIO;
615                         return (ZIO_PIPELINE_CONTINUE);
616                 }
617
618                 switch (zio->io_cmd) {
619
620                 case DKIOCFLUSHWRITECACHE:
621
622                         if (zfs_nocacheflush)
623                                 break;
624
625                         if (vd->vdev_nowritecache) {
626                                 zio->io_error = ENOTSUP;
627                                 break;
628                         }
629
630                         goto sendreq;
631                 default:
632                         zio->io_error = ENOTSUP;
633                 }
634
635                 return (ZIO_PIPELINE_CONTINUE);
636         }
637 sendreq:
638         if (cp == NULL) {
639                 zio->io_error = ENXIO;
640                 return (ZIO_PIPELINE_CONTINUE);
641         }
642         bp = g_alloc_bio();
643         bp->bio_caller1 = zio;
644         switch (zio->io_type) {
645         case ZIO_TYPE_READ:
646         case ZIO_TYPE_WRITE:
647                 bp->bio_cmd = zio->io_type == ZIO_TYPE_READ ? BIO_READ : BIO_WRITE;
648                 bp->bio_data = zio->io_data;
649                 bp->bio_offset = zio->io_offset;
650                 bp->bio_length = zio->io_size;
651                 break;
652         case ZIO_TYPE_IOCTL:
653                 bp->bio_cmd = BIO_FLUSH;
654                 bp->bio_data = NULL;
655                 bp->bio_offset = cp->provider->mediasize;
656                 bp->bio_length = 0;
657                 break;
658         }
659         bp->bio_done = vdev_geom_io_intr;
660
661         g_io_request(bp, cp);
662
663         return (ZIO_PIPELINE_STOP);
664 }
665
666 static void
667 vdev_geom_io_done(zio_t *zio)
668 {
669 }
670
671 vdev_ops_t vdev_geom_ops = {
672         vdev_geom_open,
673         vdev_geom_close,
674         vdev_default_asize,
675         vdev_geom_io_start,
676         vdev_geom_io_done,
677         NULL,
678         VDEV_TYPE_DISK,         /* name of this vdev type */
679         B_TRUE                  /* leaf vdev */
680 };