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 * Portions Copyright (c) 2012 Martin Matuska <mm@FreeBSD.org>
26 */
27
28#include <sys/zfs_context.h>
29#include <sys/param.h>
30#include <sys/kernel.h>
31#include <sys/bio.h>
32#include <sys/disk.h>
33#include <sys/spa.h>
34#include <sys/spa_impl.h>
35#include <sys/vdev_impl.h>
36#include <sys/fs/zfs.h>
37#include <sys/zio.h>
38#include <geom/geom.h>
39#include <geom/geom_int.h>
40
41/*
42 * Virtual device vector for GEOM.
43 */
44
45static g_attrchanged_t vdev_geom_attrchanged;
46struct g_class zfs_vdev_class = {
47	.name = "ZFS::VDEV",
48	.version = G_VERSION,
49	.attrchanged = vdev_geom_attrchanged,
50};
51
52DECLARE_GEOM_CLASS(zfs_vdev_class, zfs_vdev);
53
54SYSCTL_DECL(_vfs_zfs_vdev);
55/* Don't send BIO_FLUSH. */
56static int vdev_geom_bio_flush_disable;
57SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, bio_flush_disable, CTLFLAG_RWTUN,
58    &vdev_geom_bio_flush_disable, 0, "Disable BIO_FLUSH");
59/* Don't send BIO_DELETE. */
60static int vdev_geom_bio_delete_disable;
61SYSCTL_INT(_vfs_zfs_vdev, OID_AUTO, bio_delete_disable, CTLFLAG_RWTUN,
62    &vdev_geom_bio_delete_disable, 0, "Disable BIO_DELETE");
63
64/* Declare local functions */
65static void vdev_geom_detach(struct g_consumer *cp, boolean_t open_for_read);
66
67/*
68 * Thread local storage used to indicate when a thread is probing geoms
69 * for their guids.  If NULL, this thread is not tasting geoms.  If non NULL,
70 * it is looking for a replacement for the vdev_t* that is its value.
71 */
72uint_t zfs_geom_probe_vdev_key;
73
74static void
75vdev_geom_set_rotation_rate(vdev_t *vd, struct g_consumer *cp)
76{
77	int error;
78	uint16_t rate;
79
80	error = g_getattr("GEOM::rotation_rate", cp, &rate);
81	if (error == 0)
82		vd->vdev_rotation_rate = rate;
83	else
84		vd->vdev_rotation_rate = VDEV_RATE_UNKNOWN;
85}
86
87static void
88vdev_geom_set_physpath(struct g_consumer *cp, boolean_t do_null_update)
89{
90	boolean_t needs_update = B_FALSE;
91	vdev_t *vd;
92	char *physpath;
93	int error, physpath_len;
94
95	if (g_access(cp, 1, 0, 0) != 0)
96		return;
97
98	vd = cp->private;
99	physpath_len = MAXPATHLEN;
100	physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
101	error = g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
102	g_access(cp, -1, 0, 0);
103	if (error == 0) {
104		char *old_physpath;
105
106		/* g_topology lock ensures that vdev has not been closed */
107		g_topology_assert();
108		old_physpath = vd->vdev_physpath;
109		vd->vdev_physpath = spa_strdup(physpath);
110
111		if (old_physpath != NULL) {
112			needs_update = (strcmp(old_physpath,
113						vd->vdev_physpath) != 0);
114			spa_strfree(old_physpath);
115		} else
116			needs_update = do_null_update;
117	}
118	g_free(physpath);
119
120	/*
121	 * If the physical path changed, update the config.
122	 * Only request an update for previously unset physpaths if
123	 * requested by the caller.
124	 */
125	if (needs_update)
126		spa_async_request(vd->vdev_spa, SPA_ASYNC_CONFIG_UPDATE);
127
128}
129
130static void
131vdev_geom_attrchanged(struct g_consumer *cp, const char *attr)
132{
133	vdev_t *vd;
134	char *old_physpath;
135	int error;
136
137	vd = cp->private;
138	if (vd == NULL)
139		return;
140
141	if (strcmp(attr, "GEOM::rotation_rate") == 0) {
142		vdev_geom_set_rotation_rate(vd, cp);
143		return;
144	}
145
146	if (strcmp(attr, "GEOM::physpath") == 0) {
147		vdev_geom_set_physpath(cp, /*do_null_update*/B_TRUE);
148		return;
149	}
150}
151
152static void
153vdev_geom_orphan(struct g_consumer *cp)
154{
155	vdev_t *vd;
156
157	g_topology_assert();
158
159	vd = cp->private;
160	if (vd == NULL) {
161		/* Vdev close in progress.  Ignore the event. */
162		return;
163	}
164
165	/*
166	 * Orphan callbacks occur from the GEOM event thread.
167	 * Concurrent with this call, new I/O requests may be
168	 * working their way through GEOM about to find out
169	 * (only once executed by the g_down thread) that we've
170	 * been orphaned from our disk provider.  These I/Os
171	 * must be retired before we can detach our consumer.
172	 * This is most easily achieved by acquiring the
173	 * SPA ZIO configuration lock as a writer, but doing
174	 * so with the GEOM topology lock held would cause
175	 * a lock order reversal.  Instead, rely on the SPA's
176	 * async removal support to invoke a close on this
177	 * vdev once it is safe to do so.
178	 */
179	vd->vdev_remove_wanted = B_TRUE;
180	spa_async_request(vd->vdev_spa, SPA_ASYNC_REMOVE);
181}
182
183static struct g_consumer *
184vdev_geom_attach(struct g_provider *pp, vdev_t *vd)
185{
186	struct g_geom *gp;
187	struct g_consumer *cp;
188	int error;
189
190	g_topology_assert();
191
192	ZFS_LOG(1, "Attaching to %s.", pp->name);
193
194	if (pp->sectorsize > VDEV_PAD_SIZE || !ISP2(pp->sectorsize)) {
195		ZFS_LOG(1, "Failing attach of %s. Incompatible sectorsize %d\n",
196		    pp->name, pp->sectorsize);
197		return (NULL);
198	} else if (pp->mediasize < SPA_MINDEVSIZE) {
199		ZFS_LOG(1, "Failing attach of %s. Incompatible mediasize %ju\n",
200		    pp->name, pp->mediasize);
201		return (NULL);
202	}
203
204	/* Do we have geom already? No? Create one. */
205	LIST_FOREACH(gp, &zfs_vdev_class.geom, geom) {
206		if (gp->flags & G_GEOM_WITHER)
207			continue;
208		if (strcmp(gp->name, "zfs::vdev") != 0)
209			continue;
210		break;
211	}
212	if (gp == NULL) {
213		gp = g_new_geomf(&zfs_vdev_class, "zfs::vdev");
214		gp->orphan = vdev_geom_orphan;
215		gp->attrchanged = vdev_geom_attrchanged;
216		cp = g_new_consumer(gp);
217		error = g_attach(cp, pp);
218		if (error != 0) {
219			ZFS_LOG(1, "%s(%d): g_attach failed: %d\n", __func__,
220			    __LINE__, error);
221			vdev_geom_detach(cp, B_FALSE);
222			return (NULL);
223		}
224		error = g_access(cp, 1, 0, 1);
225		if (error != 0) {
226			ZFS_LOG(1, "%s(%d): g_access failed: %d", __func__,
227			       __LINE__, error);
228			vdev_geom_detach(cp, B_FALSE);
229			return (NULL);
230		}
231		ZFS_LOG(1, "Created geom and consumer for %s.", pp->name);
232	} else {
233		/* Check if we are already connected to this provider. */
234		LIST_FOREACH(cp, &gp->consumer, consumer) {
235			if (cp->provider == pp) {
236				ZFS_LOG(1, "Found consumer for %s.", pp->name);
237				break;
238			}
239		}
240		if (cp == NULL) {
241			cp = g_new_consumer(gp);
242			error = g_attach(cp, pp);
243			if (error != 0) {
244				ZFS_LOG(1, "%s(%d): g_attach failed: %d\n",
245				    __func__, __LINE__, error);
246				vdev_geom_detach(cp, B_FALSE);
247				return (NULL);
248			}
249			error = g_access(cp, 1, 0, 1);
250			if (error != 0) {
251				ZFS_LOG(1, "%s(%d): g_access failed: %d\n",
252				    __func__, __LINE__, error);
253				vdev_geom_detach(cp, B_FALSE);
254				return (NULL);
255			}
256			ZFS_LOG(1, "Created consumer for %s.", pp->name);
257		} else {
258			error = g_access(cp, 1, 0, 1);
259			if (error != 0) {
260				ZFS_LOG(1, "%s(%d): g_access failed: %d\n",
261				    __func__, __LINE__, error);
262				return (NULL);
263			}
264			ZFS_LOG(1, "Used existing consumer for %s.", pp->name);
265		}
266	}
267
268	/*
269	 * BUG: cp may already belong to a vdev.  This could happen if:
270	 * 1) That vdev is a shared spare, or
271	 * 2) We are trying to reopen a missing vdev and we are scanning by
272	 *    guid.  In that case, we'll ultimately fail to open this consumer,
273	 *    but not until after setting the private field.
274	 * The solution is to:
275	 * 1) Don't set the private field until after the open succeeds, and
276	 * 2) Set it to a linked list of vdevs, not just a single vdev
277	 */
278	cp->private = vd;
279	if (vd != NULL) {
280		vd->vdev_tsd = cp;
281		vdev_geom_set_physpath(cp, /*do_null_update*/B_FALSE);
282	}
283
284	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
285	return (cp);
286}
287
288static void
289vdev_geom_detach(struct g_consumer *cp, boolean_t open_for_read)
290{
291	struct g_geom *gp;
292	vdev_t *vd;
293
294	g_topology_assert();
295
296	ZFS_LOG(1, "Detaching from %s.",
297	    cp->provider && cp->provider->name ? cp->provider->name : "NULL");
298
299	vd = cp->private;
300	cp->private = NULL;
301
302	gp = cp->geom;
303	if (open_for_read)
304		g_access(cp, -1, 0, -1);
305	/* Destroy consumer on last close. */
306	if (cp->acr == 0 && cp->ace == 0) {
307		if (cp->acw > 0)
308			g_access(cp, 0, -cp->acw, 0);
309		if (cp->provider != NULL) {
310			ZFS_LOG(1, "Destroying consumer for %s.",
311			    cp->provider->name ? cp->provider->name : "NULL");
312			g_detach(cp);
313		}
314		g_destroy_consumer(cp);
315	}
316	/* Destroy geom if there are no consumers left. */
317	if (LIST_EMPTY(&gp->consumer)) {
318		ZFS_LOG(1, "Destroyed geom %s.", gp->name);
319		g_wither_geom(gp, ENXIO);
320	}
321}
322
323static void
324vdev_geom_close_locked(vdev_t *vd)
325{
326	struct g_consumer *cp;
327
328	g_topology_assert();
329
330	cp = vd->vdev_tsd;
331	vd->vdev_tsd = NULL;
332	vd->vdev_delayed_close = B_FALSE;
333	if (cp == NULL)
334		return;
335
336	ZFS_LOG(1, "Closing access to %s.", cp->provider->name);
337
338	vdev_geom_detach(cp, B_TRUE);
339}
340
341/*
342 * Issue one or more bios to the vdev in parallel
343 * cmds, datas, offsets, errors, and sizes are arrays of length ncmds.  Each IO
344 * operation is described by parallel entries from each array.  There may be
345 * more bios actually issued than entries in the array
346 */
347static void
348vdev_geom_io(struct g_consumer *cp, int *cmds, void **datas, off_t *offsets,
349    off_t *sizes, int *errors, int ncmds)
350{
351	struct bio **bios;
352	u_char *p;
353	off_t off, maxio, s, end;
354	int i, n_bios, j;
355	size_t bios_size;
356
357	maxio = MAXPHYS - (MAXPHYS % cp->provider->sectorsize);
358	n_bios = 0;
359
360	/* How many bios are required for all commands ? */
361	for (i = 0; i < ncmds; i++)
362		n_bios += (sizes[i] + maxio - 1) / maxio;
363
364	/* Allocate memory for the bios */
365	bios_size = n_bios * sizeof(struct bio*);
366	bios = kmem_zalloc(bios_size, KM_SLEEP);
367
368	/* Prepare and issue all of the bios */
369	for (i = j = 0; i < ncmds; i++) {
370		off = offsets[i];
371		p = datas[i];
372		s = sizes[i];
373		end = off + s;
374		ASSERT((off % cp->provider->sectorsize) == 0);
375		ASSERT((s % cp->provider->sectorsize) == 0);
376
377		for (; off < end; off += maxio, p += maxio, s -= maxio, j++) {
378			bios[j] = g_alloc_bio();
379			bios[j]->bio_cmd = cmds[i];
380			bios[j]->bio_done = NULL;
381			bios[j]->bio_offset = off;
382			bios[j]->bio_length = MIN(s, maxio);
383			bios[j]->bio_data = p;
384			g_io_request(bios[j], cp);
385		}
386	}
387	ASSERT(j == n_bios);
388
389	/* Wait for all of the bios to complete, and clean them up */
390	for (i = j = 0; i < ncmds; i++) {
391		off = offsets[i];
392		s = sizes[i];
393		end = off + s;
394
395		for (; off < end; off += maxio, s -= maxio, j++) {
396			errors[i] = biowait(bios[j], "vdev_geom_io") || errors[i];
397			g_destroy_bio(bios[j]);
398		}
399	}
400	kmem_free(bios, bios_size);
401}
402
403static int
404vdev_geom_read_config(struct g_consumer *cp, nvlist_t **config)
405{
406	struct g_provider *pp;
407	vdev_phys_t *vdev_lists[VDEV_LABELS];
408	char *p, *buf;
409	size_t buflen;
410	uint64_t psize, state, txg;
411	off_t offsets[VDEV_LABELS];
412	off_t size;
413	off_t sizes[VDEV_LABELS];
414	int cmds[VDEV_LABELS];
415	int errors[VDEV_LABELS];
416	int l, len;
417
418	g_topology_assert_not();
419
420	pp = cp->provider;
421	ZFS_LOG(1, "Reading config from %s...", pp->name);
422
423	psize = pp->mediasize;
424	psize = P2ALIGN(psize, (uint64_t)sizeof(vdev_label_t));
425
426	size = sizeof(*vdev_lists[0]) + pp->sectorsize -
427	    ((sizeof(*vdev_lists[0]) - 1) % pp->sectorsize) - 1;
428
429	buflen = sizeof(vdev_lists[0]->vp_nvlist);
430
431	*config = NULL;
432	/* Create all of the IO requests */
433	for (l = 0; l < VDEV_LABELS; l++) {
434		cmds[l] = BIO_READ;
435		vdev_lists[l] = kmem_alloc(size, KM_SLEEP);
436		offsets[l] = vdev_label_offset(psize, l, 0) + VDEV_SKIP_SIZE;
437		sizes[l] = size;
438		errors[l] = 0;
439		ASSERT(offsets[l] % pp->sectorsize == 0);
440	}
441
442	/* Issue the IO requests */
443	vdev_geom_io(cp, cmds, (void**)vdev_lists, offsets, sizes, errors,
444	    VDEV_LABELS);
445
446	/* Parse the labels */
447	for (l = 0; l < VDEV_LABELS; l++) {
448		if (errors[l] != 0)
449			continue;
450
451		buf = vdev_lists[l]->vp_nvlist;
452
453		if (nvlist_unpack(buf, buflen, config, 0) != 0)
454			continue;
455
456		if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
457		    &state) != 0 || state > POOL_STATE_L2CACHE) {
458			nvlist_free(*config);
459			*config = NULL;
460			continue;
461		}
462
463		if (state != POOL_STATE_SPARE &&
464		    state != POOL_STATE_L2CACHE &&
465		    (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
466		    &txg) != 0 || txg == 0)) {
467			nvlist_free(*config);
468			*config = NULL;
469			continue;
470		}
471
472		break;
473	}
474
475	/* Free the label storage */
476	for (l = 0; l < VDEV_LABELS; l++)
477		kmem_free(vdev_lists[l], size);
478
479	return (*config == NULL ? ENOENT : 0);
480}
481
482static void
483resize_configs(nvlist_t ***configs, uint64_t *count, uint64_t id)
484{
485	nvlist_t **new_configs;
486	uint64_t i;
487
488	if (id < *count)
489		return;
490	new_configs = kmem_zalloc((id + 1) * sizeof(nvlist_t *),
491	    KM_SLEEP);
492	for (i = 0; i < *count; i++)
493		new_configs[i] = (*configs)[i];
494	if (*configs != NULL)
495		kmem_free(*configs, *count * sizeof(void *));
496	*configs = new_configs;
497	*count = id + 1;
498}
499
500static void
501process_vdev_config(nvlist_t ***configs, uint64_t *count, nvlist_t *cfg,
502    const char *name, uint64_t* known_pool_guid)
503{
504	nvlist_t *vdev_tree;
505	uint64_t pool_guid;
506	uint64_t vdev_guid, known_guid;
507	uint64_t id, txg, known_txg;
508	char *pname;
509	int i;
510
511	if (nvlist_lookup_string(cfg, ZPOOL_CONFIG_POOL_NAME, &pname) != 0 ||
512	    strcmp(pname, name) != 0)
513		goto ignore;
514
515	if (nvlist_lookup_uint64(cfg, ZPOOL_CONFIG_POOL_GUID, &pool_guid) != 0)
516		goto ignore;
517
518	if (nvlist_lookup_uint64(cfg, ZPOOL_CONFIG_TOP_GUID, &vdev_guid) != 0)
519		goto ignore;
520
521	if (nvlist_lookup_nvlist(cfg, ZPOOL_CONFIG_VDEV_TREE, &vdev_tree) != 0)
522		goto ignore;
523
524	if (nvlist_lookup_uint64(vdev_tree, ZPOOL_CONFIG_ID, &id) != 0)
525		goto ignore;
526
527	VERIFY(nvlist_lookup_uint64(cfg, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
528
529	if (*known_pool_guid != 0) {
530		if (pool_guid != *known_pool_guid)
531			goto ignore;
532	} else
533		*known_pool_guid = pool_guid;
534
535	resize_configs(configs, count, id);
536
537	if ((*configs)[id] != NULL) {
538		VERIFY(nvlist_lookup_uint64((*configs)[id],
539		    ZPOOL_CONFIG_POOL_TXG, &known_txg) == 0);
540		if (txg <= known_txg)
541			goto ignore;
542		nvlist_free((*configs)[id]);
543	}
544
545	(*configs)[id] = cfg;
546	return;
547
548ignore:
549	nvlist_free(cfg);
550}
551
552int
553vdev_geom_read_pool_label(const char *name,
554    nvlist_t ***configs, uint64_t *count)
555{
556	struct g_class *mp;
557	struct g_geom *gp;
558	struct g_provider *pp;
559	struct g_consumer *zcp;
560	nvlist_t *vdev_cfg;
561	uint64_t pool_guid;
562	int error;
563
564	DROP_GIANT();
565	g_topology_lock();
566
567	*configs = NULL;
568	*count = 0;
569	pool_guid = 0;
570	LIST_FOREACH(mp, &g_classes, class) {
571		if (mp == &zfs_vdev_class)
572			continue;
573		LIST_FOREACH(gp, &mp->geom, geom) {
574			if (gp->flags & G_GEOM_WITHER)
575				continue;
576			LIST_FOREACH(pp, &gp->provider, provider) {
577				if (pp->flags & G_PF_WITHER)
578					continue;
579				zcp = vdev_geom_attach(pp, NULL);
580				if (zcp == NULL)
581					continue;
582				g_topology_unlock();
583				error = vdev_geom_read_config(zcp, &vdev_cfg);
584				g_topology_lock();
585				vdev_geom_detach(zcp, B_TRUE);
586				if (error)
587					continue;
588				ZFS_LOG(1, "successfully read vdev config");
589
590				process_vdev_config(configs, count,
591				    vdev_cfg, name, &pool_guid);
592			}
593		}
594	}
595	g_topology_unlock();
596	PICKUP_GIANT();
597
598	return (*count > 0 ? 0 : ENOENT);
599}
600
601enum match {
602	NO_MATCH,
603	TOP_MATCH,
604	FULL_MATCH
605};
606
607static enum match
608vdev_attach_ok(vdev_t *vd, struct g_provider *pp)
609{
610	nvlist_t *config;
611	uint64_t pool_guid, top_guid, vdev_guid;
612	struct g_consumer *cp;
613
614	cp = vdev_geom_attach(pp, NULL);
615	if (cp == NULL) {
616		ZFS_LOG(1, "Unable to attach tasting instance to %s.",
617		    pp->name);
618		return (NO_MATCH);
619	}
620	g_topology_unlock();
621	if (vdev_geom_read_config(cp, &config) != 0) {
622		g_topology_lock();
623		vdev_geom_detach(cp, B_TRUE);
624		ZFS_LOG(1, "Unable to read config from %s.", pp->name);
625		return (NO_MATCH);
626	}
627	g_topology_lock();
628	vdev_geom_detach(cp, B_TRUE);
629
630	pool_guid = 0;
631	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid);
632	top_guid = 0;
633	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_TOP_GUID, &top_guid);
634	vdev_guid = 0;
635	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, &vdev_guid);
636	nvlist_free(config);
637
638	/*
639	 * Check that the label's pool guid matches the desired guid.
640	 * Inactive spares and L2ARCs do not have any pool guid in the label.
641	 */
642	if (pool_guid != 0 && pool_guid != spa_guid(vd->vdev_spa)) {
643		ZFS_LOG(1, "pool guid mismatch for provider %s: %ju != %ju.",
644		    pp->name,
645		    (uintmax_t)spa_guid(vd->vdev_spa), (uintmax_t)pool_guid);
646		return (NO_MATCH);
647	}
648
649	/*
650	 * Check that the label's vdev guid matches the desired guid.
651	 * The second condition handles possible race on vdev detach, when
652	 * remaining vdev receives GUID of destroyed top level mirror vdev.
653	 */
654	if (vdev_guid == vd->vdev_guid) {
655		ZFS_LOG(1, "guids match for provider %s.", pp->name);
656		return (FULL_MATCH);
657	} else if (top_guid == vd->vdev_guid && vd == vd->vdev_top) {
658		ZFS_LOG(1, "top vdev guid match for provider %s.", pp->name);
659		return (TOP_MATCH);
660	}
661	ZFS_LOG(1, "vdev guid mismatch for provider %s: %ju != %ju.",
662	    pp->name, (uintmax_t)vd->vdev_guid, (uintmax_t)vdev_guid);
663	return (NO_MATCH);
664}
665
666static struct g_consumer *
667vdev_geom_attach_by_guids(vdev_t *vd)
668{
669	struct g_class *mp;
670	struct g_geom *gp;
671	struct g_provider *pp;
672	struct g_consumer *cp;
673	enum match m;
674
675	g_topology_assert();
676
677	cp = NULL;
678	LIST_FOREACH(mp, &g_classes, class) {
679		if (mp == &zfs_vdev_class)
680			continue;
681		LIST_FOREACH(gp, &mp->geom, geom) {
682			if (gp->flags & G_GEOM_WITHER)
683				continue;
684			LIST_FOREACH(pp, &gp->provider, provider) {
685				m = vdev_attach_ok(vd, pp);
686				if (m == NO_MATCH)
687					continue;
688				if (cp != NULL) {
689					if (m == FULL_MATCH)
690						vdev_geom_detach(cp, B_TRUE);
691					else
692						continue;
693				}
694				cp = vdev_geom_attach(pp, vd);
695				if (cp == NULL) {
696					printf("ZFS WARNING: Unable to "
697					    "attach to %s.\n", pp->name);
698					continue;
699				}
700				if (m == FULL_MATCH)
701					return (cp);
702			}
703		}
704	}
705	return (cp);
706}
707
708static struct g_consumer *
709vdev_geom_open_by_guids(vdev_t *vd)
710{
711	struct g_consumer *cp;
712	char *buf;
713	size_t len;
714
715	g_topology_assert();
716
717	ZFS_LOG(1, "Searching by guids [%ju:%ju].",
718		(uintmax_t)spa_guid(vd->vdev_spa), (uintmax_t)vd->vdev_guid);
719	cp = vdev_geom_attach_by_guids(vd);
720	if (cp != NULL) {
721		len = strlen(cp->provider->name) + strlen("/dev/") + 1;
722		buf = kmem_alloc(len, KM_SLEEP);
723
724		snprintf(buf, len, "/dev/%s", cp->provider->name);
725		spa_strfree(vd->vdev_path);
726		vd->vdev_path = buf;
727
728		ZFS_LOG(1, "Attach by guid [%ju:%ju] succeeded, provider %s.",
729		    (uintmax_t)spa_guid(vd->vdev_spa),
730		    (uintmax_t)vd->vdev_guid, vd->vdev_path);
731	} else {
732		ZFS_LOG(1, "Search by guid [%ju:%ju] failed.",
733		    (uintmax_t)spa_guid(vd->vdev_spa),
734		    (uintmax_t)vd->vdev_guid);
735	}
736
737	return (cp);
738}
739
740static struct g_consumer *
741vdev_geom_open_by_path(vdev_t *vd, int check_guid)
742{
743	struct g_provider *pp;
744	struct g_consumer *cp;
745
746	g_topology_assert();
747
748	cp = NULL;
749	pp = g_provider_by_name(vd->vdev_path + sizeof("/dev/") - 1);
750	if (pp != NULL) {
751		ZFS_LOG(1, "Found provider by name %s.", vd->vdev_path);
752		if (!check_guid || vdev_attach_ok(vd, pp) == FULL_MATCH)
753			cp = vdev_geom_attach(pp, vd);
754	}
755
756	return (cp);
757}
758
759static int
760vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
761    uint64_t *logical_ashift, uint64_t *physical_ashift)
762{
763	struct g_provider *pp;
764	struct g_consumer *cp;
765	size_t bufsize;
766	int error;
767
768	/* Set the TLS to indicate downstack that we should not access zvols*/
769	VERIFY(tsd_set(zfs_geom_probe_vdev_key, vd) == 0);
770
771	/*
772	 * We must have a pathname, and it must be absolute.
773	 */
774	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
775		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
776		return (EINVAL);
777	}
778
779	/*
780	 * Reopen the device if it's not currently open. Otherwise,
781	 * just update the physical size of the device.
782	 */
783	if ((cp = vd->vdev_tsd) != NULL) {
784		ASSERT(vd->vdev_reopening);
785		goto skip_open;
786	}
787
788	DROP_GIANT();
789	g_topology_lock();
790	error = 0;
791
792	if (vd->vdev_spa->spa_splitting_newspa ||
793	    (vd->vdev_prevstate == VDEV_STATE_UNKNOWN &&
794	     vd->vdev_spa->spa_load_state == SPA_LOAD_NONE ||
795	     vd->vdev_spa->spa_load_state == SPA_LOAD_CREATE)) {
796		/*
797		 * We are dealing with a vdev that hasn't been previously
798		 * opened (since boot), and we are not loading an
799		 * existing pool configuration.  This looks like a
800		 * vdev add operation to a new or existing pool.
801		 * Assume the user knows what he/she is doing and find
802		 * GEOM provider by its name, ignoring GUID mismatches.
803		 *
804		 * XXPOLICY: It would be safer to only allow a device
805		 *           that is unlabeled or labeled but missing
806		 *           GUID information to be opened in this fashion,
807		 *           unless we are doing a split, in which case we
808		 *           should allow any guid.
809		 */
810		cp = vdev_geom_open_by_path(vd, 0);
811	} else {
812		/*
813		 * Try using the recorded path for this device, but only
814		 * accept it if its label data contains the expected GUIDs.
815		 */
816		cp = vdev_geom_open_by_path(vd, 1);
817		if (cp == NULL) {
818			/*
819			 * The device at vd->vdev_path doesn't have the
820			 * expected GUIDs. The disks might have merely
821			 * moved around so try all other GEOM providers
822			 * to find one with the right GUIDs.
823			 */
824			cp = vdev_geom_open_by_guids(vd);
825		}
826	}
827
828	/* Clear the TLS now that tasting is done */
829	VERIFY(tsd_set(zfs_geom_probe_vdev_key, NULL) == 0);
830
831	if (cp == NULL) {
832		ZFS_LOG(1, "Provider %s not found.", vd->vdev_path);
833		error = ENOENT;
834	} else if (cp->provider->sectorsize > VDEV_PAD_SIZE ||
835	    !ISP2(cp->provider->sectorsize)) {
836		ZFS_LOG(1, "Provider %s has unsupported sectorsize.",
837		    vd->vdev_path);
838
839		vdev_geom_close_locked(vd);
840		error = EINVAL;
841		cp = NULL;
842	} else if (cp->acw == 0 && (spa_mode(vd->vdev_spa) & FWRITE) != 0) {
843		int i;
844
845		for (i = 0; i < 5; i++) {
846			error = g_access(cp, 0, 1, 0);
847			if (error == 0)
848				break;
849			g_topology_unlock();
850			tsleep(vd, 0, "vdev", hz / 2);
851			g_topology_lock();
852		}
853		if (error != 0) {
854			printf("ZFS WARNING: Unable to open %s for writing (error=%d).\n",
855			    vd->vdev_path, error);
856			vdev_geom_close_locked(vd);
857			cp = NULL;
858		}
859	}
860
861	/* Fetch initial physical path information for this device. */
862	if (cp != NULL)
863		vdev_geom_attrchanged(cp, "GEOM::physpath");
864
865	g_topology_unlock();
866	PICKUP_GIANT();
867	if (cp == NULL) {
868		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
869		return (error);
870	}
871skip_open:
872	pp = cp->provider;
873
874	/*
875	 * Determine the actual size of the device.
876	 */
877	*max_psize = *psize = pp->mediasize;
878
879	/*
880	 * Determine the device's minimum transfer size and preferred
881	 * transfer size.
882	 */
883	*logical_ashift = highbit(MAX(pp->sectorsize, SPA_MINBLOCKSIZE)) - 1;
884	*physical_ashift = 0;
885	if (pp->stripesize > (1 << *logical_ashift) && ISP2(pp->stripesize) &&
886	    pp->stripesize <= (1 << SPA_MAXASHIFT) && pp->stripeoffset == 0)
887		*physical_ashift = highbit(pp->stripesize) - 1;
888
889	/*
890	 * Clear the nowritecache settings, so that on a vdev_reopen()
891	 * we will try again.
892	 */
893	vd->vdev_nowritecache = B_FALSE;
894
895	/*
896	 * Determine the device's rotation rate.
897	 */
898	vdev_geom_set_rotation_rate(vd, cp);
899
900	return (0);
901}
902
903static void
904vdev_geom_close(vdev_t *vd)
905{
906
907	if (vd->vdev_reopening)
908		return;
909
910	DROP_GIANT();
911	g_topology_lock();
912	vdev_geom_close_locked(vd);
913	g_topology_unlock();
914	PICKUP_GIANT();
915}
916
917static void
918vdev_geom_io_intr(struct bio *bp)
919{
920	vdev_t *vd;
921	zio_t *zio;
922
923	zio = bp->bio_caller1;
924	vd = zio->io_vd;
925	zio->io_error = bp->bio_error;
926	if (zio->io_error == 0 && bp->bio_resid != 0)
927		zio->io_error = SET_ERROR(EIO);
928
929	switch(zio->io_error) {
930	case ENOTSUP:
931		/*
932		 * If we get ENOTSUP for BIO_FLUSH or BIO_DELETE we know
933		 * that future attempts will never succeed. In this case
934		 * we set a persistent flag so that we don't bother with
935		 * requests in the future.
936		 */
937		switch(bp->bio_cmd) {
938		case BIO_FLUSH:
939			vd->vdev_nowritecache = B_TRUE;
940			break;
941		case BIO_DELETE:
942			vd->vdev_notrim = B_TRUE;
943			break;
944		}
945		break;
946	case ENXIO:
947		if (!vd->vdev_remove_wanted) {
948			/*
949			 * If provider's error is set we assume it is being
950			 * removed.
951			 */
952			if (bp->bio_to->error != 0) {
953				vd->vdev_remove_wanted = B_TRUE;
954				spa_async_request(zio->io_spa,
955				    SPA_ASYNC_REMOVE);
956			} else if (!vd->vdev_delayed_close) {
957				vd->vdev_delayed_close = B_TRUE;
958			}
959		}
960		break;
961	}
962	g_destroy_bio(bp);
963	zio_delay_interrupt(zio);
964}
965
966static void
967vdev_geom_io_start(zio_t *zio)
968{
969	vdev_t *vd;
970	struct g_consumer *cp;
971	struct bio *bp;
972	int error;
973
974	vd = zio->io_vd;
975
976	switch (zio->io_type) {
977	case ZIO_TYPE_IOCTL:
978		/* XXPOLICY */
979		if (!vdev_readable(vd)) {
980			zio->io_error = SET_ERROR(ENXIO);
981			zio_interrupt(zio);
982			return;
983		} else {
984			switch (zio->io_cmd) {
985			case DKIOCFLUSHWRITECACHE:
986				if (zfs_nocacheflush || vdev_geom_bio_flush_disable)
987					break;
988				if (vd->vdev_nowritecache) {
989					zio->io_error = SET_ERROR(ENOTSUP);
990					break;
991				}
992				goto sendreq;
993			default:
994				zio->io_error = SET_ERROR(ENOTSUP);
995			}
996		}
997
998		zio_execute(zio);
999		return;
1000	case ZIO_TYPE_FREE:
1001		if (vd->vdev_notrim) {
1002			zio->io_error = SET_ERROR(ENOTSUP);
1003		} else if (!vdev_geom_bio_delete_disable) {
1004			goto sendreq;
1005		}
1006		zio_execute(zio);
1007		return;
1008	}
1009sendreq:
1010	ASSERT(zio->io_type == ZIO_TYPE_READ ||
1011	    zio->io_type == ZIO_TYPE_WRITE ||
1012	    zio->io_type == ZIO_TYPE_FREE ||
1013	    zio->io_type == ZIO_TYPE_IOCTL);
1014
1015	cp = vd->vdev_tsd;
1016	if (cp == NULL) {
1017		zio->io_error = SET_ERROR(ENXIO);
1018		zio_interrupt(zio);
1019		return;
1020	}
1021	bp = g_alloc_bio();
1022	bp->bio_caller1 = zio;
1023	switch (zio->io_type) {
1024	case ZIO_TYPE_READ:
1025	case ZIO_TYPE_WRITE:
1026		zio->io_target_timestamp = zio_handle_io_delay(zio);
1027		bp->bio_cmd = zio->io_type == ZIO_TYPE_READ ? BIO_READ : BIO_WRITE;
1028		bp->bio_data = zio->io_data;
1029		bp->bio_offset = zio->io_offset;
1030		bp->bio_length = zio->io_size;
1031		break;
1032	case ZIO_TYPE_FREE:
1033		bp->bio_cmd = BIO_DELETE;
1034		bp->bio_data = NULL;
1035		bp->bio_offset = zio->io_offset;
1036		bp->bio_length = zio->io_size;
1037		break;
1038	case ZIO_TYPE_IOCTL:
1039		bp->bio_cmd = BIO_FLUSH;
1040		bp->bio_flags |= BIO_ORDERED;
1041		bp->bio_data = NULL;
1042		bp->bio_offset = cp->provider->mediasize;
1043		bp->bio_length = 0;
1044		break;
1045	}
1046	bp->bio_done = vdev_geom_io_intr;
1047
1048	g_io_request(bp, cp);
1049}
1050
1051static void
1052vdev_geom_io_done(zio_t *zio)
1053{
1054}
1055
1056static void
1057vdev_geom_hold(vdev_t *vd)
1058{
1059}
1060
1061static void
1062vdev_geom_rele(vdev_t *vd)
1063{
1064}
1065
1066vdev_ops_t vdev_geom_ops = {
1067	vdev_geom_open,
1068	vdev_geom_close,
1069	vdev_default_asize,
1070	vdev_geom_io_start,
1071	vdev_geom_io_done,
1072	NULL,
1073	vdev_geom_hold,
1074	vdev_geom_rele,
1075	VDEV_TYPE_DISK,		/* name of this vdev type */
1076	B_TRUE			/* leaf vdev */
1077};
1078