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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
25 * Copyright 2013 Joyent, Inc.  All rights reserved.
26 */
27
28#include <sys/zfs_context.h>
29#include <sys/spa_impl.h>
30#include <sys/refcount.h>
31#include <sys/vdev_disk.h>
32#include <sys/vdev_impl.h>
33#include <sys/fs/zfs.h>
34#include <sys/zio.h>
35#include <sys/sunldi.h>
36#include <sys/efi_partition.h>
37#include <sys/fm/fs/zfs.h>
38
39/*
40 * Virtual device vector for disks.
41 */
42
43extern ldi_ident_t zfs_li;
44
45typedef struct vdev_disk_buf {
46	buf_t	vdb_buf;
47	zio_t	*vdb_io;
48} vdev_disk_buf_t;
49
50static void
51vdev_disk_hold(vdev_t *vd)
52{
53	ddi_devid_t devid;
54	char *minor;
55
56	ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
57
58	/*
59	 * We must have a pathname, and it must be absolute.
60	 */
61	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/')
62		return;
63
64	/*
65	 * Only prefetch path and devid info if the device has
66	 * never been opened.
67	 */
68	if (vd->vdev_tsd != NULL)
69		return;
70
71	if (vd->vdev_wholedisk == -1ULL) {
72		size_t len = strlen(vd->vdev_path) + 3;
73		char *buf = kmem_alloc(len, KM_SLEEP);
74
75		(void) snprintf(buf, len, "%ss0", vd->vdev_path);
76
77		(void) ldi_vp_from_name(buf, &vd->vdev_name_vp);
78		kmem_free(buf, len);
79	}
80
81	if (vd->vdev_name_vp == NULL)
82		(void) ldi_vp_from_name(vd->vdev_path, &vd->vdev_name_vp);
83
84	if (vd->vdev_devid != NULL &&
85	    ddi_devid_str_decode(vd->vdev_devid, &devid, &minor) == 0) {
86		(void) ldi_vp_from_devid(devid, minor, &vd->vdev_devid_vp);
87		ddi_devid_str_free(minor);
88		ddi_devid_free(devid);
89	}
90}
91
92static void
93vdev_disk_rele(vdev_t *vd)
94{
95	ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
96
97	if (vd->vdev_name_vp) {
98		VN_RELE_ASYNC(vd->vdev_name_vp,
99		    dsl_pool_vnrele_taskq(vd->vdev_spa->spa_dsl_pool));
100		vd->vdev_name_vp = NULL;
101	}
102	if (vd->vdev_devid_vp) {
103		VN_RELE_ASYNC(vd->vdev_devid_vp,
104		    dsl_pool_vnrele_taskq(vd->vdev_spa->spa_dsl_pool));
105		vd->vdev_devid_vp = NULL;
106	}
107}
108
109static uint64_t
110vdev_disk_get_space(vdev_t *vd, uint64_t capacity, uint_t blksz)
111{
112	ASSERT(vd->vdev_wholedisk);
113
114	vdev_disk_t *dvd = vd->vdev_tsd;
115	dk_efi_t dk_ioc;
116	efi_gpt_t *efi;
117	uint64_t avail_space = 0;
118	int efisize = EFI_LABEL_SIZE * 2;
119
120	dk_ioc.dki_data = kmem_alloc(efisize, KM_SLEEP);
121	dk_ioc.dki_lba = 1;
122	dk_ioc.dki_length = efisize;
123	dk_ioc.dki_data_64 = (uint64_t)(uintptr_t)dk_ioc.dki_data;
124	efi = dk_ioc.dki_data;
125
126	if (ldi_ioctl(dvd->vd_lh, DKIOCGETEFI, (intptr_t)&dk_ioc,
127	    FKIOCTL, kcred, NULL) == 0) {
128		uint64_t efi_altern_lba = LE_64(efi->efi_gpt_AlternateLBA);
129
130		zfs_dbgmsg("vdev %s, capacity %llu, altern lba %llu",
131		    vd->vdev_path, capacity, efi_altern_lba);
132		if (capacity > efi_altern_lba)
133			avail_space = (capacity - efi_altern_lba) * blksz;
134	}
135	kmem_free(dk_ioc.dki_data, efisize);
136	return (avail_space);
137}
138
139/*
140 * We want to be loud in DEBUG kernels when DKIOCGMEDIAINFOEXT fails, or when
141 * even a fallback to DKIOCGMEDIAINFO fails.
142 */
143#ifdef DEBUG
144#define	VDEV_DEBUG(...)	cmn_err(CE_NOTE, __VA_ARGS__)
145#else
146#define	VDEV_DEBUG(...)	/* Nothing... */
147#endif
148
149static int
150vdev_disk_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
151    uint64_t *ashift)
152{
153	spa_t *spa = vd->vdev_spa;
154	vdev_disk_t *dvd;
155	union {
156		struct dk_minfo_ext ude;
157		struct dk_minfo ud;
158	} dks;
159	struct dk_minfo_ext *dkmext = &dks.ude;
160	struct dk_minfo *dkm = &dks.ud;
161	int error;
162	dev_t dev;
163	int otyp;
164	boolean_t validate_devid = B_FALSE;
165	ddi_devid_t devid;
166	uint64_t capacity = 0, blksz = 0, pbsize;
167
168	/*
169	 * We must have a pathname, and it must be absolute.
170	 */
171	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
172		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
173		return (SET_ERROR(EINVAL));
174	}
175
176	/*
177	 * Reopen the device if it's not currently open. Otherwise,
178	 * just update the physical size of the device.
179	 */
180	if (vd->vdev_tsd != NULL) {
181		ASSERT(vd->vdev_reopening);
182		dvd = vd->vdev_tsd;
183		goto skip_open;
184	}
185
186	dvd = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);
187
188	/*
189	 * When opening a disk device, we want to preserve the user's original
190	 * intent.  We always want to open the device by the path the user gave
191	 * us, even if it is one of multiple paths to the save device.  But we
192	 * also want to be able to survive disks being removed/recabled.
193	 * Therefore the sequence of opening devices is:
194	 *
195	 * 1. Try opening the device by path.  For legacy pools without the
196	 *    'whole_disk' property, attempt to fix the path by appending 's0'.
197	 *
198	 * 2. If the devid of the device matches the stored value, return
199	 *    success.
200	 *
201	 * 3. Otherwise, the device may have moved.  Try opening the device
202	 *    by the devid instead.
203	 */
204	if (vd->vdev_devid != NULL) {
205		if (ddi_devid_str_decode(vd->vdev_devid, &dvd->vd_devid,
206		    &dvd->vd_minor) != 0) {
207			vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
208			return (SET_ERROR(EINVAL));
209		}
210	}
211
212	error = EINVAL;		/* presume failure */
213
214	if (vd->vdev_path != NULL) {
215
216		if (vd->vdev_wholedisk == -1ULL) {
217			size_t len = strlen(vd->vdev_path) + 3;
218			char *buf = kmem_alloc(len, KM_SLEEP);
219			ldi_handle_t lh;
220
221			(void) snprintf(buf, len, "%ss0", vd->vdev_path);
222
223			if (ldi_open_by_name(buf, spa_mode(spa), kcred,
224			    &lh, zfs_li) == 0) {
225				spa_strfree(vd->vdev_path);
226				vd->vdev_path = buf;
227				vd->vdev_wholedisk = 1ULL;
228				(void) ldi_close(lh, spa_mode(spa), kcred);
229			} else {
230				kmem_free(buf, len);
231			}
232		}
233
234		error = ldi_open_by_name(vd->vdev_path, spa_mode(spa), kcred,
235		    &dvd->vd_lh, zfs_li);
236
237		/*
238		 * Compare the devid to the stored value.
239		 */
240		if (error == 0 && vd->vdev_devid != NULL &&
241		    ldi_get_devid(dvd->vd_lh, &devid) == 0) {
242			if (ddi_devid_compare(devid, dvd->vd_devid) != 0) {
243				error = SET_ERROR(EINVAL);
244				(void) ldi_close(dvd->vd_lh, spa_mode(spa),
245				    kcred);
246				dvd->vd_lh = NULL;
247			}
248			ddi_devid_free(devid);
249		}
250
251		/*
252		 * If we succeeded in opening the device, but 'vdev_wholedisk'
253		 * is not yet set, then this must be a slice.
254		 */
255		if (error == 0 && vd->vdev_wholedisk == -1ULL)
256			vd->vdev_wholedisk = 0;
257	}
258
259	/*
260	 * If we were unable to open by path, or the devid check fails, open by
261	 * devid instead.
262	 */
263	if (error != 0 && vd->vdev_devid != NULL) {
264		error = ldi_open_by_devid(dvd->vd_devid, dvd->vd_minor,
265		    spa_mode(spa), kcred, &dvd->vd_lh, zfs_li);
266	}
267
268	/*
269	 * If all else fails, then try opening by physical path (if available)
270	 * or the logical path (if we failed due to the devid check).  While not
271	 * as reliable as the devid, this will give us something, and the higher
272	 * level vdev validation will prevent us from opening the wrong device.
273	 */
274	if (error) {
275		if (vd->vdev_devid != NULL)
276			validate_devid = B_TRUE;
277
278		if (vd->vdev_physpath != NULL &&
279		    (dev = ddi_pathname_to_dev_t(vd->vdev_physpath)) != NODEV)
280			error = ldi_open_by_dev(&dev, OTYP_BLK, spa_mode(spa),
281			    kcred, &dvd->vd_lh, zfs_li);
282
283		/*
284		 * Note that we don't support the legacy auto-wholedisk support
285		 * as above.  This hasn't been used in a very long time and we
286		 * don't need to propagate its oddities to this edge condition.
287		 */
288		if (error && vd->vdev_path != NULL)
289			error = ldi_open_by_name(vd->vdev_path, spa_mode(spa),
290			    kcred, &dvd->vd_lh, zfs_li);
291	}
292
293	if (error) {
294		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
295		return (error);
296	}
297
298	/*
299	 * Now that the device has been successfully opened, update the devid
300	 * if necessary.
301	 */
302	if (validate_devid && spa_writeable(spa) &&
303	    ldi_get_devid(dvd->vd_lh, &devid) == 0) {
304		if (ddi_devid_compare(devid, dvd->vd_devid) != 0) {
305			char *vd_devid;
306
307			vd_devid = ddi_devid_str_encode(devid, dvd->vd_minor);
308			zfs_dbgmsg("vdev %s: update devid from %s, "
309			    "to %s", vd->vdev_path, vd->vdev_devid, vd_devid);
310			spa_strfree(vd->vdev_devid);
311			vd->vdev_devid = spa_strdup(vd_devid);
312			ddi_devid_str_free(vd_devid);
313		}
314		ddi_devid_free(devid);
315	}
316
317	/*
318	 * Once a device is opened, verify that the physical device path (if
319	 * available) is up to date.
320	 */
321	if (ldi_get_dev(dvd->vd_lh, &dev) == 0 &&
322	    ldi_get_otyp(dvd->vd_lh, &otyp) == 0) {
323		char *physpath, *minorname;
324
325		physpath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
326		minorname = NULL;
327		if (ddi_dev_pathname(dev, otyp, physpath) == 0 &&
328		    ldi_get_minor_name(dvd->vd_lh, &minorname) == 0 &&
329		    (vd->vdev_physpath == NULL ||
330		    strcmp(vd->vdev_physpath, physpath) != 0)) {
331			if (vd->vdev_physpath)
332				spa_strfree(vd->vdev_physpath);
333			(void) strlcat(physpath, ":", MAXPATHLEN);
334			(void) strlcat(physpath, minorname, MAXPATHLEN);
335			vd->vdev_physpath = spa_strdup(physpath);
336		}
337		if (minorname)
338			kmem_free(minorname, strlen(minorname) + 1);
339		kmem_free(physpath, MAXPATHLEN);
340	}
341
342skip_open:
343	/*
344	 * Determine the actual size of the device.
345	 */
346	if (ldi_get_size(dvd->vd_lh, psize) != 0) {
347		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
348		return (SET_ERROR(EINVAL));
349	}
350
351	*max_psize = *psize;
352
353	/*
354	 * Determine the device's minimum transfer size.
355	 * If the ioctl isn't supported, assume DEV_BSIZE.
356	 */
357	if ((error = ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFOEXT,
358	    (intptr_t)dkmext, FKIOCTL, kcred, NULL)) == 0) {
359		capacity = dkmext->dki_capacity - 1;
360		blksz = dkmext->dki_lbsize;
361		pbsize = dkmext->dki_pbsize;
362	} else if ((error = ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFO,
363	    (intptr_t)dkm, FKIOCTL, kcred, NULL)) == 0) {
364		VDEV_DEBUG(
365		    "vdev_disk_open(\"%s\"): fallback to DKIOCGMEDIAINFO\n",
366		    vd->vdev_path);
367		capacity = dkm->dki_capacity - 1;
368		blksz = dkm->dki_lbsize;
369		pbsize = blksz;
370	} else {
371		VDEV_DEBUG("vdev_disk_open(\"%s\"): "
372		    "both DKIOCGMEDIAINFO{,EXT} calls failed, %d\n",
373		    vd->vdev_path, error);
374		pbsize = DEV_BSIZE;
375	}
376
377	*ashift = highbit(MAX(pbsize, SPA_MINBLOCKSIZE)) - 1;
378
379	if (vd->vdev_wholedisk == 1) {
380		int wce = 1;
381
382		if (error == 0) {
383			/*
384			 * If we have the capability to expand, we'd have
385			 * found out via success from DKIOCGMEDIAINFO{,EXT}.
386			 * Adjust max_psize upward accordingly since we know
387			 * we own the whole disk now.
388			 */
389			*max_psize += vdev_disk_get_space(vd, capacity, blksz);
390			zfs_dbgmsg("capacity change: vdev %s, psize %llu, "
391			    "max_psize %llu", vd->vdev_path, *psize,
392			    *max_psize);
393		}
394
395		/*
396		 * Since we own the whole disk, try to enable disk write
397		 * caching.  We ignore errors because it's OK if we can't do it.
398		 */
399		(void) ldi_ioctl(dvd->vd_lh, DKIOCSETWCE, (intptr_t)&wce,
400		    FKIOCTL, kcred, NULL);
401	}
402
403	/*
404	 * Clear the nowritecache bit, so that on a vdev_reopen() we will
405	 * try again.
406	 */
407	vd->vdev_nowritecache = B_FALSE;
408
409	return (0);
410}
411
412static void
413vdev_disk_close(vdev_t *vd)
414{
415	vdev_disk_t *dvd = vd->vdev_tsd;
416
417	if (vd->vdev_reopening || dvd == NULL)
418		return;
419
420	if (dvd->vd_minor != NULL)
421		ddi_devid_str_free(dvd->vd_minor);
422
423	if (dvd->vd_devid != NULL)
424		ddi_devid_free(dvd->vd_devid);
425
426	if (dvd->vd_lh != NULL)
427		(void) ldi_close(dvd->vd_lh, spa_mode(vd->vdev_spa), kcred);
428
429	vd->vdev_delayed_close = B_FALSE;
430	kmem_free(dvd, sizeof (vdev_disk_t));
431	vd->vdev_tsd = NULL;
432}
433
434int
435vdev_disk_physio(vdev_t *vd, caddr_t data,
436    size_t size, uint64_t offset, int flags, boolean_t isdump)
437{
438	vdev_disk_t *dvd = vd->vdev_tsd;
439
440	ASSERT(vd->vdev_ops == &vdev_disk_ops);
441
442	/*
443	 * If in the context of an active crash dump, use the ldi_dump(9F)
444	 * call instead of ldi_strategy(9F) as usual.
445	 */
446	if (isdump) {
447		ASSERT3P(dvd, !=, NULL);
448		return (ldi_dump(dvd->vd_lh, data, lbtodb(offset),
449		    lbtodb(size)));
450	}
451
452	return (vdev_disk_ldi_physio(dvd->vd_lh, data, size, offset, flags));
453}
454
455int
456vdev_disk_ldi_physio(ldi_handle_t vd_lh, caddr_t data,
457    size_t size, uint64_t offset, int flags)
458{
459	buf_t *bp;
460	int error = 0;
461
462	if (vd_lh == NULL)
463		return (SET_ERROR(EINVAL));
464
465	ASSERT(flags & B_READ || flags & B_WRITE);
466
467	bp = getrbuf(KM_SLEEP);
468	bp->b_flags = flags | B_BUSY | B_NOCACHE | B_FAILFAST;
469	bp->b_bcount = size;
470	bp->b_un.b_addr = (void *)data;
471	bp->b_lblkno = lbtodb(offset);
472	bp->b_bufsize = size;
473
474	error = ldi_strategy(vd_lh, bp);
475	ASSERT(error == 0);
476	if ((error = biowait(bp)) == 0 && bp->b_resid != 0)
477		error = SET_ERROR(EIO);
478	freerbuf(bp);
479
480	return (error);
481}
482
483static void
484vdev_disk_io_intr(buf_t *bp)
485{
486	vdev_disk_buf_t *vdb = (vdev_disk_buf_t *)bp;
487	zio_t *zio = vdb->vdb_io;
488
489	/*
490	 * The rest of the zio stack only deals with EIO, ECKSUM, and ENXIO.
491	 * Rather than teach the rest of the stack about other error
492	 * possibilities (EFAULT, etc), we normalize the error value here.
493	 */
494	zio->io_error = (geterror(bp) != 0 ? EIO : 0);
495
496	if (zio->io_error == 0 && bp->b_resid != 0)
497		zio->io_error = SET_ERROR(EIO);
498
499	kmem_free(vdb, sizeof (vdev_disk_buf_t));
500
501	zio_interrupt(zio);
502}
503
504static void
505vdev_disk_ioctl_free(zio_t *zio)
506{
507	kmem_free(zio->io_vsd, sizeof (struct dk_callback));
508}
509
510static const zio_vsd_ops_t vdev_disk_vsd_ops = {
511	vdev_disk_ioctl_free,
512	zio_vsd_default_cksum_report
513};
514
515static void
516vdev_disk_ioctl_done(void *zio_arg, int error)
517{
518	zio_t *zio = zio_arg;
519
520	zio->io_error = error;
521
522	zio_interrupt(zio);
523}
524
525static int
526vdev_disk_io_start(zio_t *zio)
527{
528	vdev_t *vd = zio->io_vd;
529	vdev_disk_t *dvd = vd->vdev_tsd;
530	vdev_disk_buf_t *vdb;
531	struct dk_callback *dkc;
532	buf_t *bp;
533	int error;
534
535	if (zio->io_type == ZIO_TYPE_IOCTL) {
536		/* XXPOLICY */
537		if (!vdev_readable(vd)) {
538			zio->io_error = SET_ERROR(ENXIO);
539			return (ZIO_PIPELINE_CONTINUE);
540		}
541
542		switch (zio->io_cmd) {
543
544		case DKIOCFLUSHWRITECACHE:
545
546			if (zfs_nocacheflush)
547				break;
548
549			if (vd->vdev_nowritecache) {
550				zio->io_error = SET_ERROR(ENOTSUP);
551				break;
552			}
553
554			zio->io_vsd = dkc = kmem_alloc(sizeof (*dkc), KM_SLEEP);
555			zio->io_vsd_ops = &vdev_disk_vsd_ops;
556
557			dkc->dkc_callback = vdev_disk_ioctl_done;
558			dkc->dkc_flag = FLUSH_VOLATILE;
559			dkc->dkc_cookie = zio;
560
561			error = ldi_ioctl(dvd->vd_lh, zio->io_cmd,
562			    (uintptr_t)dkc, FKIOCTL, kcred, NULL);
563
564			if (error == 0) {
565				/*
566				 * The ioctl will be done asychronously,
567				 * and will call vdev_disk_ioctl_done()
568				 * upon completion.
569				 */
570				return (ZIO_PIPELINE_STOP);
571			}
572
573			if (error == ENOTSUP || error == ENOTTY) {
574				/*
575				 * If we get ENOTSUP or ENOTTY, we know that
576				 * no future attempts will ever succeed.
577				 * In this case we set a persistent bit so
578				 * that we don't bother with the ioctl in the
579				 * future.
580				 */
581				vd->vdev_nowritecache = B_TRUE;
582			}
583			zio->io_error = error;
584
585			break;
586
587		default:
588			zio->io_error = SET_ERROR(ENOTSUP);
589		}
590
591		return (ZIO_PIPELINE_CONTINUE);
592	}
593
594	vdb = kmem_alloc(sizeof (vdev_disk_buf_t), KM_SLEEP);
595
596	vdb->vdb_io = zio;
597	bp = &vdb->vdb_buf;
598
599	bioinit(bp);
600	bp->b_flags = B_BUSY | B_NOCACHE |
601	    (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
602	if (!(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)))
603		bp->b_flags |= B_FAILFAST;
604	bp->b_bcount = zio->io_size;
605	bp->b_un.b_addr = zio->io_data;
606	bp->b_lblkno = lbtodb(zio->io_offset);
607	bp->b_bufsize = zio->io_size;
608	bp->b_iodone = (int (*)())vdev_disk_io_intr;
609
610	/* ldi_strategy() will return non-zero only on programming errors */
611	VERIFY(ldi_strategy(dvd->vd_lh, bp) == 0);
612
613	return (ZIO_PIPELINE_STOP);
614}
615
616static void
617vdev_disk_io_done(zio_t *zio)
618{
619	vdev_t *vd = zio->io_vd;
620
621	/*
622	 * If the device returned EIO, then attempt a DKIOCSTATE ioctl to see if
623	 * the device has been removed.  If this is the case, then we trigger an
624	 * asynchronous removal of the device. Otherwise, probe the device and
625	 * make sure it's still accessible.
626	 */
627	if (zio->io_error == EIO && !vd->vdev_remove_wanted) {
628		vdev_disk_t *dvd = vd->vdev_tsd;
629		int state = DKIO_NONE;
630
631		if (ldi_ioctl(dvd->vd_lh, DKIOCSTATE, (intptr_t)&state,
632		    FKIOCTL, kcred, NULL) == 0 && state != DKIO_INSERTED) {
633			/*
634			 * We post the resource as soon as possible, instead of
635			 * when the async removal actually happens, because the
636			 * DE is using this information to discard previous I/O
637			 * errors.
638			 */
639			zfs_post_remove(zio->io_spa, vd);
640			vd->vdev_remove_wanted = B_TRUE;
641			spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
642		} else if (!vd->vdev_delayed_close) {
643			vd->vdev_delayed_close = B_TRUE;
644		}
645	}
646}
647
648vdev_ops_t vdev_disk_ops = {
649	vdev_disk_open,
650	vdev_disk_close,
651	vdev_default_asize,
652	vdev_disk_io_start,
653	vdev_disk_io_done,
654	NULL,
655	vdev_disk_hold,
656	vdev_disk_rele,
657	VDEV_TYPE_DISK,		/* name of this vdev type */
658	B_TRUE			/* leaf vdev */
659};
660
661/*
662 * Given the root disk device devid or pathname, read the label from
663 * the device, and construct a configuration nvlist.
664 */
665int
666vdev_disk_read_rootlabel(char *devpath, char *devid, nvlist_t **config)
667{
668	ldi_handle_t vd_lh;
669	vdev_label_t *label;
670	uint64_t s, size;
671	int l;
672	ddi_devid_t tmpdevid;
673	int error = -1;
674	char *minor_name;
675
676	/*
677	 * Read the device label and build the nvlist.
678	 */
679	if (devid != NULL && ddi_devid_str_decode(devid, &tmpdevid,
680	    &minor_name) == 0) {
681		error = ldi_open_by_devid(tmpdevid, minor_name,
682		    FREAD, kcred, &vd_lh, zfs_li);
683		ddi_devid_free(tmpdevid);
684		ddi_devid_str_free(minor_name);
685	}
686
687	if (error && (error = ldi_open_by_name(devpath, FREAD, kcred, &vd_lh,
688	    zfs_li)))
689		return (error);
690
691	if (ldi_get_size(vd_lh, &s)) {
692		(void) ldi_close(vd_lh, FREAD, kcred);
693		return (SET_ERROR(EIO));
694	}
695
696	size = P2ALIGN_TYPED(s, sizeof (vdev_label_t), uint64_t);
697	label = kmem_alloc(sizeof (vdev_label_t), KM_SLEEP);
698
699	*config = NULL;
700	for (l = 0; l < VDEV_LABELS; l++) {
701		uint64_t offset, state, txg = 0;
702
703		/* read vdev label */
704		offset = vdev_label_offset(size, l, 0);
705		if (vdev_disk_ldi_physio(vd_lh, (caddr_t)label,
706		    VDEV_SKIP_SIZE + VDEV_PHYS_SIZE, offset, B_READ) != 0)
707			continue;
708
709		if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
710		    sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0) {
711			*config = NULL;
712			continue;
713		}
714
715		if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
716		    &state) != 0 || state >= POOL_STATE_DESTROYED) {
717			nvlist_free(*config);
718			*config = NULL;
719			continue;
720		}
721
722		if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
723		    &txg) != 0 || txg == 0) {
724			nvlist_free(*config);
725			*config = NULL;
726			continue;
727		}
728
729		break;
730	}
731
732	kmem_free(label, sizeof (vdev_label_t));
733	(void) ldi_close(vd_lh, FREAD, kcred);
734	if (*config == NULL)
735		error = SET_ERROR(EIDRM);
736
737	return (error);
738}
739