aboutsummaryrefslogtreecommitdiffstats
path: root/cmd/zed/agents/zfs_mod.c
blob: 8d0a3b4200860162663953da9959d93b732bacb9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012 by Delphix. All rights reserved.
 * Copyright 2014 Nexenta Systems, Inc. All rights reserved.
 * Copyright (c) 2016, 2017, Intel Corporation.
 * Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
 */

/*
 * ZFS syseventd module.
 *
 * file origin: openzfs/usr/src/cmd/syseventd/modules/zfs_mod/zfs_mod.c
 *
 * The purpose of this module is to identify when devices are added to the
 * system, and appropriately online or replace the affected vdevs.
 *
 * When a device is added to the system:
 *
 * 	1. Search for any vdevs whose devid matches that of the newly added
 *	   device.
 *
 * 	2. If no vdevs are found, then search for any vdevs whose udev path
 *	   matches that of the new device.
 *
 *	3. If no vdevs match by either method, then ignore the event.
 *
 * 	4. Attempt to online the device with a flag to indicate that it should
 *	   be unspared when resilvering completes.  If this succeeds, then the
 *	   same device was inserted and we should continue normally.
 *
 *	5. If the pool does not have the 'autoreplace' property set, attempt to
 *	   online the device again without the unspare flag, which will
 *	   generate a FMA fault.
 *
 *	6. If the pool has the 'autoreplace' property set, and the matching vdev
 *	   is a whole disk, then label the new disk and attempt a 'zpool
 *	   replace'.
 *
 * The module responds to EC_DEV_ADD events.  The special ESC_ZFS_VDEV_CHECK
 * event indicates that a device failed to open during pool load, but the
 * autoreplace property was set.  In this case, we deferred the associated
 * FMA fault until our module had a chance to process the autoreplace logic.
 * If the device could not be replaced, then the second online attempt will
 * trigger the FMA fault that we skipped earlier.
 *
 * ZFS on Linux porting notes:
 *	Linux udev provides a disk insert for both the disk and the partition
 *
 */

#include <ctype.h>
#include <fcntl.h>
#include <libnvpair.h>
#include <libzfs.h>
#include <libzutil.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <sys/list.h>
#include <sys/sunddi.h>
#include <sys/sysevent/eventdefs.h>
#include <sys/sysevent/dev.h>
#include <thread_pool.h>
#include <pthread.h>
#include <unistd.h>
#include <errno.h>
#include "zfs_agents.h"
#include "../zed_log.h"

#define	DEV_BYID_PATH	"/dev/disk/by-id/"
#define	DEV_BYPATH_PATH	"/dev/disk/by-path/"
#define	DEV_BYVDEV_PATH	"/dev/disk/by-vdev/"

typedef void (*zfs_process_func_t)(zpool_handle_t *, nvlist_t *, boolean_t);

libzfs_handle_t *g_zfshdl;
list_t g_pool_list;	/* list of unavailable pools at initialization */
list_t g_device_list;	/* list of disks with asynchronous label request */
tpool_t *g_tpool;
boolean_t g_enumeration_done;
pthread_t g_zfs_tid;	/* zfs_enum_pools() thread */

typedef struct unavailpool {
	zpool_handle_t	*uap_zhp;
	list_node_t	uap_node;
} unavailpool_t;

typedef struct pendingdev {
	char		pd_physpath[128];
	list_node_t	pd_node;
} pendingdev_t;

static int
zfs_toplevel_state(zpool_handle_t *zhp)
{
	nvlist_t *nvroot;
	vdev_stat_t *vs;
	unsigned int c;

	verify(nvlist_lookup_nvlist(zpool_get_config(zhp, NULL),
	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
	verify(nvlist_lookup_uint64_array(nvroot, ZPOOL_CONFIG_VDEV_STATS,
	    (uint64_t **)&vs, &c) == 0);
	return (vs->vs_state);
}

static int
zfs_unavail_pool(zpool_handle_t *zhp, void *data)
{
	zed_log_msg(LOG_INFO, "zfs_unavail_pool: examining '%s' (state %d)",
	    zpool_get_name(zhp), (int)zfs_toplevel_state(zhp));

	if (zfs_toplevel_state(zhp) < VDEV_STATE_DEGRADED) {
		unavailpool_t *uap;
		uap = malloc(sizeof (unavailpool_t));
		uap->uap_zhp = zhp;
		list_insert_tail((list_t *)data, uap);
	} else {
		zpool_close(zhp);
	}
	return (0);
}

/*
 * Two stage replace on Linux
 * since we get disk notifications
 * we can wait for partitioned disk slice to show up!
 *
 * First stage tags the disk, initiates async partitioning, and returns
 * Second stage finds the tag and proceeds to ZFS labeling/replace
 *
 * disk-add --> label-disk + tag-disk --> partition-add --> zpool_vdev_attach
 *
 * 1. physical match with no fs, no partition
 *	tag it top, partition disk
 *
 * 2. physical match again, see partition and tag
 *
 */

/*
 * The device associated with the given vdev (either by devid or physical path)
 * has been added to the system.  If 'isdisk' is set, then we only attempt a
 * replacement if it's a whole disk.  This also implies that we should label the
 * disk first.
 *
 * First, we attempt to online the device (making sure to undo any spare
 * operation when finished).  If this succeeds, then we're done.  If it fails,
 * and the new state is VDEV_CANT_OPEN, it indicates that the device was opened,
 * but that the label was not what we expected.  If the 'autoreplace' property
 * is enabled, then we relabel the disk (if specified), and attempt a 'zpool
 * replace'.  If the online is successful, but the new state is something else
 * (REMOVED or FAULTED), it indicates that we're out of sync or in some sort of
 * race, and we should avoid attempting to relabel the disk.
 *
 * Also can arrive here from a ESC_ZFS_VDEV_CHECK event
 */
static void
zfs_process_add(zpool_handle_t *zhp, nvlist_t *vdev, boolean_t labeled)
{
	char *path;
	vdev_state_t newstate;
	nvlist_t *nvroot, *newvd;
	pendingdev_t *device;
	uint64_t wholedisk = 0ULL;
	uint64_t offline = 0ULL;
	uint64_t guid = 0ULL;
	char *physpath = NULL, *new_devid = NULL, *enc_sysfs_path = NULL;
	char rawpath[PATH_MAX], fullpath[PATH_MAX];
	char devpath[PATH_MAX];
	int ret;
	boolean_t is_dm = B_FALSE;
	boolean_t is_sd = B_FALSE;
	uint_t c;
	vdev_stat_t *vs;

	if (nvlist_lookup_string(vdev, ZPOOL_CONFIG_PATH, &path) != 0)
		return;

	/* Skip healthy disks */
	verify(nvlist_lookup_uint64_array(vdev, ZPOOL_CONFIG_VDEV_STATS,
	    (uint64_t **)&vs, &c) == 0);
	if (vs->vs_state == VDEV_STATE_HEALTHY) {
		zed_log_msg(LOG_INFO, "%s: %s is already healthy, skip it.",
		    __func__, path);
		return;
	}

	(void) nvlist_lookup_string(vdev, ZPOOL_CONFIG_PHYS_PATH, &physpath);
	(void) nvlist_lookup_string(vdev, ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH,
	    &enc_sysfs_path);
	(void) nvlist_lookup_uint64(vdev, ZPOOL_CONFIG_WHOLE_DISK, &wholedisk);
	(void) nvlist_lookup_uint64(vdev, ZPOOL_CONFIG_OFFLINE, &offline);
	(void) nvlist_lookup_uint64(vdev, ZPOOL_CONFIG_GUID, &guid);

	if (offline)
		return;  /* don't intervene if it was taken offline */

	is_dm = zfs_dev_is_dm(path);
	zed_log_msg(LOG_INFO, "zfs_process_add: pool '%s' vdev '%s', phys '%s'"
	    " wholedisk %d, %s dm (guid %llu)", zpool_get_name(zhp), path,
	    physpath ? physpath : "NULL", wholedisk, is_dm ? "is" : "not",
	    (long long unsigned int)guid);

	/*
	 * The VDEV guid is preferred for identification (gets passed in path)
	 */
	if (guid != 0) {
		(void) snprintf(fullpath, sizeof (fullpath), "%llu",
		    (long long unsigned int)guid);
	} else {
		/*
		 * otherwise use path sans partition suffix for whole disks
		 */
		(void) strlcpy(fullpath, path, sizeof (fullpath));
		if (wholedisk) {
			char *spath = zfs_strip_partition(fullpath);
			if (!spath) {
				zed_log_msg(LOG_INFO, "%s: Can't alloc",
				    __func__);
				return;
			}

			(void) strlcpy(fullpath, spath, sizeof (fullpath));
			free(spath);
		}
	}

	/*
	 * Attempt to online the device.
	 */
	if (zpool_vdev_online(zhp, fullpath,
	    ZFS_ONLINE_CHECKREMOVE | ZFS_ONLINE_UNSPARE, &newstate) == 0 &&
	    (newstate == VDEV_STATE_HEALTHY ||
	    newstate == VDEV_STATE_DEGRADED)) {
		zed_log_msg(LOG_INFO, "  zpool_vdev_online: vdev %s is %s",
		    fullpath, (newstate == VDEV_STATE_HEALTHY) ?
		    "HEALTHY" : "DEGRADED");
		return;
	}

	/*
	 * vdev_id alias rule for using scsi_debug devices (FMA automated
	 * testing)
	 */
	if (physpath != NULL && strcmp("scsidebug", physpath) == 0)
		is_sd = B_TRUE;

	/*
	 * If the pool doesn't have the autoreplace property set, then use
	 * vdev online to trigger a FMA fault by posting an ereport.
	 */
	if (!zpool_get_prop_int(zhp, ZPOOL_PROP_AUTOREPLACE, NULL) ||
	    !(wholedisk || is_dm) || (physpath == NULL)) {
		(void) zpool_vdev_online(zhp, fullpath, ZFS_ONLINE_FORCEFAULT,
		    &newstate);
		zed_log_msg(LOG_INFO, "Pool's autoreplace is not enabled or "
		    "not a whole disk for '%s'", fullpath);
		return;
	}

	/*
	 * Convert physical path into its current device node.  Rawpath
	 * needs to be /dev/disk/by-vdev for a scsi_debug device since
	 * /dev/disk/by-path will not be present.
	 */
	(void) snprintf(rawpath, sizeof (rawpath), "%s%s",
	    is_sd ? DEV_BYVDEV_PATH : DEV_BYPATH_PATH, physpath);

	if (realpath(rawpath, devpath) == NULL && !is_dm) {
		zed_log_msg(LOG_INFO, "  realpath: %s failed (%s)",
		    rawpath, strerror(errno));

		(void) zpool_vdev_online(zhp, fullpath, ZFS_ONLINE_FORCEFAULT,
		    &newstate);

		zed_log_msg(LOG_INFO, "  zpool_vdev_online: %s FORCEFAULT (%s)",
		    fullpath, libzfs_error_description(g_zfshdl));
		return;
	}

	/* Only autoreplace bad disks */
	if ((vs->vs_state != VDEV_STATE_DEGRADED) &&
	    (vs->vs_state != VDEV_STATE_FAULTED) &&
	    (vs->vs_state != VDEV_STATE_CANT_OPEN)) {
		return;
	}

	nvlist_lookup_string(vdev, "new_devid", &new_devid);

	if (is_dm) {
		/* Don't label device mapper or multipath disks. */
	} else if (!labeled) {
		/*
		 * we're auto-replacing a raw disk, so label it first
		 */
		char *leafname;

		/*
		 * If this is a request to label a whole disk, then attempt to
		 * write out the label.  Before we can label the disk, we need
		 * to map the physical string that was matched on to the under
		 * lying device node.
		 *
		 * If any part of this process fails, then do a force online
		 * to trigger a ZFS fault for the device (and any hot spare
		 * replacement).
		 */
		leafname = strrchr(devpath, '/') + 1;

		/*
		 * If this is a request to label a whole disk, then attempt to
		 * write out the label.
		 */
		if (zpool_label_disk(g_zfshdl, zhp, leafname) != 0) {
			zed_log_msg(LOG_INFO, "  zpool_label_disk: could not "
			    "label '%s' (%s)", leafname,
			    libzfs_error_description(g_zfshdl));

			(void) zpool_vdev_online(zhp, fullpath,
			    ZFS_ONLINE_FORCEFAULT, &newstate);
			return;
		}

		/*
		 * The disk labeling is asynchronous on Linux. Just record
		 * this label request and return as there will be another
		 * disk add event for the partition after the labeling is
		 * completed.
		 */
		device = malloc(sizeof (pendingdev_t));
		(void) strlcpy(device->pd_physpath, physpath,
		    sizeof (device->pd_physpath));
		list_insert_tail(&g_device_list, device);

		zed_log_msg(LOG_INFO, "  zpool_label_disk: async '%s' (%llu)",
		    leafname, (u_longlong_t)guid);

		return;	/* resumes at EC_DEV_ADD.ESC_DISK for partition */

	} else /* labeled */ {
		boolean_t found = B_FALSE;
		/*
		 * match up with request above to label the disk
		 */
		for (device = list_head(&g_device_list); device != NULL;
		    device = list_next(&g_device_list, device)) {
			if (strcmp(physpath, device->pd_physpath) == 0) {
				list_remove(&g_device_list, device);
				free(device);
				found = B_TRUE;
				break;
			}
			zed_log_msg(LOG_INFO, "zpool_label_disk: %s != %s",
			    physpath, device->pd_physpath);
		}
		if (!found) {
			/* unexpected partition slice encountered */
			zed_log_msg(LOG_INFO, "labeled disk %s unexpected here",
			    fullpath);
			(void) zpool_vdev_online(zhp, fullpath,
			    ZFS_ONLINE_FORCEFAULT, &newstate);
			return;
		}

		zed_log_msg(LOG_INFO, "  zpool_label_disk: resume '%s' (%llu)",
		    physpath, (u_longlong_t)guid);

		(void) snprintf(devpath, sizeof (devpath), "%s%s",
		    DEV_BYID_PATH, new_devid);
	}

	/*
	 * Construct the root vdev to pass to zpool_vdev_attach().  While adding
	 * the entire vdev structure is harmless, we construct a reduced set of
	 * path/physpath/wholedisk to keep it simple.
	 */
	if (nvlist_alloc(&nvroot, NV_UNIQUE_NAME, 0) != 0) {
		zed_log_msg(LOG_WARNING, "zfs_mod: nvlist_alloc out of memory");
		return;
	}
	if (nvlist_alloc(&newvd, NV_UNIQUE_NAME, 0) != 0) {
		zed_log_msg(LOG_WARNING, "zfs_mod: nvlist_alloc out of memory");
		nvlist_free(nvroot);
		return;
	}

	if (nvlist_add_string(newvd, ZPOOL_CONFIG_TYPE, VDEV_TYPE_DISK) != 0 ||
	    nvlist_add_string(newvd, ZPOOL_CONFIG_PATH, path) != 0 ||
	    nvlist_add_string(newvd, ZPOOL_CONFIG_DEVID, new_devid) != 0 ||
	    (physpath != NULL && nvlist_add_string(newvd,
	    ZPOOL_CONFIG_PHYS_PATH, physpath) != 0) ||
	    (enc_sysfs_path != NULL && nvlist_add_string(newvd,
	    ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH, enc_sysfs_path) != 0) ||
	    nvlist_add_uint64(newvd, ZPOOL_CONFIG_WHOLE_DISK, wholedisk) != 0 ||
	    nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE, VDEV_TYPE_ROOT) != 0 ||
	    nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN, &newvd,
	    1) != 0) {
		zed_log_msg(LOG_WARNING, "zfs_mod: unable to add nvlist pairs");
		nvlist_free(newvd);
		nvlist_free(nvroot);
		return;
	}

	nvlist_free(newvd);

	/*
	 * Wait for udev to verify the links exist, then auto-replace
	 * the leaf disk at same physical location.
	 */
	if (zpool_label_disk_wait(path, 3000) != 0) {
		zed_log_msg(LOG_WARNING, "zfs_mod: expected replacement "
		    "disk %s is missing", path);
		nvlist_free(nvroot);
		return;
	}

	ret = zpool_vdev_attach(zhp, fullpath, path, nvroot, B_TRUE, B_FALSE);

	zed_log_msg(LOG_INFO, "  zpool_vdev_replace: %s with %s (%s)",
	    fullpath, path, (ret == 0) ? "no errors" :
	    libzfs_error_description(g_zfshdl));

	nvlist_free(nvroot);
}

/*
 * Utility functions to find a vdev matching given criteria.
 */
typedef struct dev_data {
	const char		*dd_compare;
	const char		*dd_prop;
	zfs_process_func_t	dd_func;
	boolean_t		dd_found;
	boolean_t		dd_islabeled;
	uint64_t		dd_pool_guid;
	uint64_t		dd_vdev_guid;
	const char		*dd_new_devid;
} dev_data_t;

static void
zfs_iter_vdev(zpool_handle_t *zhp, nvlist_t *nvl, void *data)
{
	dev_data_t *dp = data;
	char *path = NULL;
	uint_t c, children;
	nvlist_t **child;

	/*
	 * First iterate over any children.
	 */
	if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN,
	    &child, &children) == 0) {
		for (c = 0; c < children; c++)
			zfs_iter_vdev(zhp, child[c], data);
	}

	/*
	 * Iterate over any spares and cache devices
	 */
	if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_SPARES,
	    &child, &children) == 0) {
		for (c = 0; c < children; c++)
			zfs_iter_vdev(zhp, child[c], data);
	}
	if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_L2CACHE,
	    &child, &children) == 0) {
		for (c = 0; c < children; c++)
			zfs_iter_vdev(zhp, child[c], data);
	}

	/* once a vdev was matched and processed there is nothing left to do */
	if (dp->dd_found)
		return;

	/*
	 * Match by GUID if available otherwise fallback to devid or physical
	 */
	if (dp->dd_vdev_guid != 0) {
		uint64_t guid;

		if (nvlist_lookup_uint64(nvl, ZPOOL_CONFIG_GUID,
		    &guid) != 0 || guid != dp->dd_vdev_guid) {
			return;
		}
		zed_log_msg(LOG_INFO, "  zfs_iter_vdev: matched on %llu", guid);
		dp->dd_found = B_TRUE;

	} else if (dp->dd_compare != NULL) {
		/*
		 * NOTE: On Linux there is an event for partition, so unlike
		 * illumos, substring matching is not required to accommodate
		 * the partition suffix. An exact match will be present in
		 * the dp->dd_compare value.
		 */
		if (nvlist_lookup_string(nvl, dp->dd_prop, &path) != 0 ||
		    strcmp(dp->dd_compare, path) != 0)
			return;

		zed_log_msg(LOG_INFO, "  zfs_iter_vdev: matched %s on %s",
		    dp->dd_prop, path);
		dp->dd_found = B_TRUE;

		/* pass the new devid for use by replacing code */
		if (dp->dd_new_devid != NULL) {
			(void) nvlist_add_string(nvl, "new_devid",
			    dp->dd_new_devid);
		}
	}

	(dp->dd_func)(zhp, nvl, dp->dd_islabeled);
}

static void
zfs_enable_ds(void *arg)
{
	unavailpool_t *pool = (unavailpool_t *)arg;

	(void) zpool_enable_datasets(pool->uap_zhp, NULL, 0);
	zpool_close(pool->uap_zhp);
	free(pool);
}

static int
zfs_iter_pool(zpool_handle_t *zhp, void *data)
{
	nvlist_t *config, *nvl;
	dev_data_t *dp = data;
	uint64_t pool_guid;
	unavailpool_t *pool;

	zed_log_msg(LOG_INFO, "zfs_iter_pool: evaluating vdevs on %s (by %s)",
	    zpool_get_name(zhp), dp->dd_vdev_guid ? "GUID" : dp->dd_prop);

	/*
	 * For each vdev in this pool, look for a match to apply dd_func
	 */
	if ((config = zpool_get_config(zhp, NULL)) != NULL) {
		if (dp->dd_pool_guid == 0 ||
		    (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
		    &pool_guid) == 0 && pool_guid == dp->dd_pool_guid)) {
			(void) nvlist_lookup_nvlist(config,
			    ZPOOL_CONFIG_VDEV_TREE, &nvl);
			zfs_iter_vdev(zhp, nvl, data);
		}
	}

	/*
	 * if this pool was originally unavailable,
	 * then enable its datasets asynchronously
	 */
	if (g_enumeration_done)  {
		for (pool = list_head(&g_pool_list); pool != NULL;
		    pool = list_next(&g_pool_list, pool)) {

			if (strcmp(zpool_get_name(zhp),
			    zpool_get_name(pool->uap_zhp)))
				continue;
			if (zfs_toplevel_state(zhp) >= VDEV_STATE_DEGRADED) {
				list_remove(&g_pool_list, pool);
				(void) tpool_dispatch(g_tpool, zfs_enable_ds,
				    pool);
				break;
			}
		}
	}

	zpool_close(zhp);
	return (dp->dd_found);	/* cease iteration after a match */
}

/*
 * Given a physical device location, iterate over all
 * (pool, vdev) pairs which correspond to that location.
 */
static boolean_t
devphys_iter(const char *physical, const char *devid, zfs_process_func_t func,
    boolean_t is_slice)
{
	dev_data_t data = { 0 };

	data.dd_compare = physical;
	data.dd_func = func;
	data.dd_prop = ZPOOL_CONFIG_PHYS_PATH;
	data.dd_found = B_FALSE;
	data.dd_islabeled = is_slice;
	data.dd_new_devid = devid;	/* used by auto replace code */

	(void) zpool_iter(g_zfshdl, zfs_iter_pool, &data);

	return (data.dd_found);
}

/*
 * Given a device identifier, find any vdevs with a matching devid.
 * On Linux we can match devid directly which is always a whole disk.
 */
static boolean_t
devid_iter(const char *devid, zfs_process_func_t func, boolean_t is_slice)
{
	dev_data_t data = { 0 };

	data.dd_compare = devid;
	data.dd_func = func;
	data.dd_prop = ZPOOL_CONFIG_DEVID;
	data.dd_found = B_FALSE;
	data.dd_islabeled = is_slice;
	data.dd_new_devid = devid;

	(void) zpool_iter(g_zfshdl, zfs_iter_pool, &data);

	return (data.dd_found);
}

/*
 * Handle a EC_DEV_ADD.ESC_DISK event.
 *
 * illumos
 *	Expects: DEV_PHYS_PATH string in schema
 *	Matches: vdev's ZPOOL_CONFIG_PHYS_PATH or ZPOOL_CONFIG_DEVID
 *
 *      path: '/dev/dsk/c0t1d0s0' (persistent)
 *     devid: 'id1,sd@SATA_____Hitachi_HDS72101______JP2940HZ3H74MC/a'
 * phys_path: '/pci@0,0/pci103c,1609@11/disk@1,0:a'
 *
 * linux
 *	provides: DEV_PHYS_PATH and DEV_IDENTIFIER strings in schema
 *	Matches: vdev's ZPOOL_CONFIG_PHYS_PATH or ZPOOL_CONFIG_DEVID
 *
 *      path: '/dev/sdc1' (not persistent)
 *     devid: 'ata-SAMSUNG_HD204UI_S2HGJD2Z805891-part1'
 * phys_path: 'pci-0000:04:00.0-sas-0x4433221106000000-lun-0'
 */
static int
zfs_deliver_add(nvlist_t *nvl, boolean_t is_lofi)
{
	char *devpath = NULL, *devid;
	boolean_t is_slice;

	/*
	 * Expecting a devid string and an optional physical location
	 */
	if (nvlist_lookup_string(nvl, DEV_IDENTIFIER, &devid) != 0)
		return (-1);

	(void) nvlist_lookup_string(nvl, DEV_PHYS_PATH, &devpath);

	is_slice = (nvlist_lookup_boolean(nvl, DEV_IS_PART) == 0);

	zed_log_msg(LOG_INFO, "zfs_deliver_add: adding %s (%s) (is_slice %d)",
	    devid, devpath ? devpath : "NULL", is_slice);

	/*
	 * Iterate over all vdevs looking for a match in the following order:
	 * 1. ZPOOL_CONFIG_DEVID (identifies the unique disk)
	 * 2. ZPOOL_CONFIG_PHYS_PATH (identifies disk physical location).
	 *
	 * For disks, we only want to pay attention to vdevs marked as whole
	 * disks or are a multipath device.
	 */
	if (!devid_iter(devid, zfs_process_add, is_slice) && devpath != NULL)
		(void) devphys_iter(devpath, devid, zfs_process_add, is_slice);

	return (0);
}

/*
 * Called when we receive a VDEV_CHECK event, which indicates a device could not
 * be opened during initial pool open, but the autoreplace property was set on
 * the pool.  In this case, we treat it as if it were an add event.
 */
static int
zfs_deliver_check(nvlist_t *nvl)
{
	dev_data_t data = { 0 };

	if (nvlist_lookup_uint64(nvl, ZFS_EV_POOL_GUID,
	    &data.dd_pool_guid) != 0 ||
	    nvlist_lookup_uint64(nvl, ZFS_EV_VDEV_GUID,
	    &data.dd_vdev_guid) != 0 ||
	    data.dd_vdev_guid == 0)
		return (0);

	zed_log_msg(LOG_INFO, "zfs_deliver_check: pool '%llu', vdev %llu",
	    data.dd_pool_guid, data.dd_vdev_guid);

	data.dd_func = zfs_process_add;

	(void) zpool_iter(g_zfshdl, zfs_iter_pool, &data);

	return (0);
}

static int
zfsdle_vdev_online(zpool_handle_t *zhp, void *data)
{
	char *devname = data;
	boolean_t avail_spare, l2cache;
	nvlist_t *tgt;
	int error;

	zed_log_msg(LOG_INFO, "zfsdle_vdev_online: searching for '%s' in '%s'",
	    devname, zpool_get_name(zhp));

	if ((tgt = zpool_find_vdev_by_physpath(zhp, devname,
	    &avail_spare, &l2cache, NULL)) != NULL) {
		char *path, fullpath[MAXPATHLEN];
		uint64_t wholedisk;

		error = nvlist_lookup_string(tgt, ZPOOL_CONFIG_PATH, &path);
		if (error) {
			zpool_close(zhp);
			return (0);
		}

		error = nvlist_lookup_uint64(tgt, ZPOOL_CONFIG_WHOLE_DISK,
		    &wholedisk);
		if (error)
			wholedisk = 0;

		if (wholedisk) {
			path = strrchr(path, '/');
			if (path != NULL) {
				path = zfs_strip_partition(path + 1);
				if (path == NULL) {
					zpool_close(zhp);
					return (0);
				}
			} else {
				zpool_close(zhp);
				return (0);
			}

			(void) strlcpy(fullpath, path, sizeof (fullpath));
			free(path);

			/*
			 * We need to reopen the pool associated with this
			 * device so that the kernel can update the size of
			 * the expanded device.  When expanding there is no
			 * need to restart the scrub from the beginning.
			 */
			boolean_t scrub_restart = B_FALSE;
			(void) zpool_reopen_one(zhp, &scrub_restart);
		} else {
			(void) strlcpy(fullpath, path, sizeof (fullpath));
		}

		if (zpool_get_prop_int(zhp, ZPOOL_PROP_AUTOEXPAND, NULL)) {
			vdev_state_t newstate;

			if (zpool_get_state(zhp) != POOL_STATE_UNAVAIL) {
				error = zpool_vdev_online(zhp, fullpath, 0,
				    &newstate);
				zed_log_msg(LOG_INFO, "zfsdle_vdev_online: "
				    "setting device '%s' to ONLINE state "
				    "in pool '%s': %d", fullpath,
				    zpool_get_name(zhp), error);
			}
		}
		zpool_close(zhp);
		return (1);
	}
	zpool_close(zhp);
	return (0);
}

/*
 * This function handles the ESC_DEV_DLE device change event.  Use the
 * provided vdev guid when looking up a disk or partition, when the guid
 * is not present assume the entire disk is owned by ZFS and append the
 * expected -part1 partition information then lookup by physical path.
 */
static int
zfs_deliver_dle(nvlist_t *nvl)
{
	char *devname, name[MAXPATHLEN];
	uint64_t guid;

	if (nvlist_lookup_uint64(nvl, ZFS_EV_VDEV_GUID, &guid) == 0) {
		sprintf(name, "%llu", (u_longlong_t)guid);
	} else if (nvlist_lookup_string(nvl, DEV_PHYS_PATH, &devname) == 0) {
		strlcpy(name, devname, MAXPATHLEN);
		zfs_append_partition(name, MAXPATHLEN);
	} else {
		zed_log_msg(LOG_INFO, "zfs_deliver_dle: no guid or physpath");
	}

	if (zpool_iter(g_zfshdl, zfsdle_vdev_online, name) != 1) {
		zed_log_msg(LOG_INFO, "zfs_deliver_dle: device '%s' not "
		    "found", name);
		return (1);
	}

	return (0);
}

/*
 * syseventd daemon module event handler
 *
 * Handles syseventd daemon zfs device related events:
 *
 *	EC_DEV_ADD.ESC_DISK
 *	EC_DEV_STATUS.ESC_DEV_DLE
 *	EC_ZFS.ESC_ZFS_VDEV_CHECK
 *
 * Note: assumes only one thread active at a time (not thread safe)
 */
static int
zfs_slm_deliver_event(const char *class, const char *subclass, nvlist_t *nvl)
{
	int ret;
	boolean_t is_lofi = B_FALSE, is_check = B_FALSE, is_dle = B_FALSE;

	if (strcmp(class, EC_DEV_ADD) == 0) {
		/*
		 * We're mainly interested in disk additions, but we also listen
		 * for new loop devices, to allow for simplified testing.
		 */
		if (strcmp(subclass, ESC_DISK) == 0)
			is_lofi = B_FALSE;
		else if (strcmp(subclass, ESC_LOFI) == 0)
			is_lofi = B_TRUE;
		else
			return (0);

		is_check = B_FALSE;
	} else if (strcmp(class, EC_ZFS) == 0 &&
	    strcmp(subclass, ESC_ZFS_VDEV_CHECK) == 0) {
		/*
		 * This event signifies that a device failed to open
		 * during pool load, but the 'autoreplace' property was
		 * set, so we should pretend it's just been added.
		 */
		is_check = B_TRUE;
	} else if (strcmp(class, EC_DEV_STATUS) == 0 &&
	    strcmp(subclass, ESC_DEV_DLE) == 0) {
		is_dle = B_TRUE;
	} else {
		return (0);
	}

	if (is_dle)
		ret = zfs_deliver_dle(nvl);
	else if (is_check)
		ret = zfs_deliver_check(nvl);
	else
		ret = zfs_deliver_add(nvl, is_lofi);

	return (ret);
}

/*ARGSUSED*/
static void *
zfs_enum_pools(void *arg)
{
	(void) zpool_iter(g_zfshdl, zfs_unavail_pool, (void *)&g_pool_list);
	/*
	 * Linux - instead of using a thread pool, each list entry
	 * will spawn a thread when an unavailable pool transitions
	 * to available. zfs_slm_fini will wait for these threads.
	 */
	g_enumeration_done = B_TRUE;
	return (NULL);
}

/*
 * called from zed daemon at startup
 *
 * sent messages from zevents or udev monitor
 *
 * For now, each agent has its own libzfs instance
 */
int
zfs_slm_init()
{
	if ((g_zfshdl = libzfs_init()) == NULL)
		return (-1);

	/*
	 * collect a list of unavailable pools (asynchronously,
	 * since this can take a while)
	 */
	list_create(&g_pool_list, sizeof (struct unavailpool),
	    offsetof(struct unavailpool, uap_node));

	if (pthread_create(&g_zfs_tid, NULL, zfs_enum_pools, NULL) != 0) {
		list_destroy(&g_pool_list);
		libzfs_fini(g_zfshdl);
		return (-1);
	}

	list_create(&g_device_list, sizeof (struct pendingdev),
	    offsetof(struct pendingdev, pd_node));

	return (0);
}

void
zfs_slm_fini()
{
	unavailpool_t *pool;
	pendingdev_t *device;

	/* wait for zfs_enum_pools thread to complete */
	(void) pthread_join(g_zfs_tid, NULL);
	/* destroy the thread pool */
	if (g_tpool != NULL) {
		tpool_wait(g_tpool);
		tpool_destroy(g_tpool);
	}

	while ((pool = (list_head(&g_pool_list))) != NULL) {
		list_remove(&g_pool_list, pool);
		zpool_close(pool->uap_zhp);
		free(pool);
	}
	list_destroy(&g_pool_list);

	while ((device = (list_head(&g_device_list))) != NULL) {
		list_remove(&g_device_list, device);
		free(device);
	}
	list_destroy(&g_device_list);

	libzfs_fini(g_zfshdl);
}

void
zfs_slm_event(const char *class, const char *subclass, nvlist_t *nvl)
{
	zed_log_msg(LOG_INFO, "zfs_slm_event: %s.%s", class, subclass);
	(void) zfs_slm_deliver_event(class, subclass, nvl);
}