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 /*
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2012, 2020 by Delphix. All rights reserved.
25 * Copyright (c) 2017, Intel Corporation.
26 * Copyright 2020 Joyent, Inc.
27 */
28
29 /*
30 * Virtual Device Labels
31 * ---------------------
32 *
33 * The vdev label serves several distinct purposes:
34 *
35 * 1. Uniquely identify this device as part of a ZFS pool and confirm its
36 * identity within the pool.
37 *
38 * 2. Verify that all the devices given in a configuration are present
39 * within the pool.
40 *
41 * 3. Determine the uberblock for the pool.
42 *
43 * 4. In case of an import operation, determine the configuration of the
44 * toplevel vdev of which it is a part.
45 *
46 * 5. If an import operation cannot find all the devices in the pool,
47 * provide enough information to the administrator to determine which
48 * devices are missing.
49 *
50 * It is important to note that while the kernel is responsible for writing the
51 * label, it only consumes the information in the first three cases. The
52 * latter information is only consumed in userland when determining the
53 * configuration to import a pool.
54 *
55 *
56 * Label Organization
57 * ------------------
58 *
59 * Before describing the contents of the label, it's important to understand how
60 * the labels are written and updated with respect to the uberblock.
61 *
62 * When the pool configuration is altered, either because it was newly created
63 * or a device was added, we want to update all the labels such that we can deal
64 * with fatal failure at any point. To this end, each disk has two labels which
65 * are updated before and after the uberblock is synced. Assuming we have
66 * labels and an uberblock with the following transaction groups:
67 *
68 * L1 UB L2
69 * +------+ +------+ +------+
70 * | | | | | |
71 * | t10 | | t10 | | t10 |
72 * | | | | | |
73 * +------+ +------+ +------+
74 *
75 * In this stable state, the labels and the uberblock were all updated within
76 * the same transaction group (10). Each label is mirrored and checksummed, so
77 * that we can detect when we fail partway through writing the label.
78 *
79 * In order to identify which labels are valid, the labels are written in the
80 * following manner:
81 *
82 * 1. For each vdev, update 'L1' to the new label
83 * 2. Update the uberblock
84 * 3. For each vdev, update 'L2' to the new label
85 *
86 * Given arbitrary failure, we can determine the correct label to use based on
87 * the transaction group. If we fail after updating L1 but before updating the
88 * UB, we will notice that L1's transaction group is greater than the uberblock,
89 * so L2 must be valid. If we fail after writing the uberblock but before
90 * writing L2, we will notice that L2's transaction group is less than L1, and
91 * therefore L1 is valid.
92 *
93 * Another added complexity is that not every label is updated when the config
94 * is synced. If we add a single device, we do not want to have to re-write
95 * every label for every device in the pool. This means that both L1 and L2 may
96 * be older than the pool uberblock, because the necessary information is stored
97 * on another vdev.
98 *
99 *
100 * On-disk Format
101 * --------------
102 *
103 * The vdev label consists of two distinct parts, and is wrapped within the
104 * vdev_label_t structure. The label includes 8k of padding to permit legacy
105 * VTOC disk labels, but is otherwise ignored.
106 *
107 * The first half of the label is a packed nvlist which contains pool wide
108 * properties, per-vdev properties, and configuration information. It is
109 * described in more detail below.
110 *
111 * The latter half of the label consists of a redundant array of uberblocks.
112 * These uberblocks are updated whenever a transaction group is committed,
113 * or when the configuration is updated. When a pool is loaded, we scan each
114 * vdev for the 'best' uberblock.
115 *
116 *
117 * Configuration Information
118 * -------------------------
119 *
120 * The nvlist describing the pool and vdev contains the following elements:
121 *
122 * version ZFS on-disk version
123 * name Pool name
124 * state Pool state
125 * txg Transaction group in which this label was written
126 * pool_guid Unique identifier for this pool
127 * vdev_tree An nvlist describing vdev tree.
128 * features_for_read
129 * An nvlist of the features necessary for reading the MOS.
130 *
131 * Each leaf device label also contains the following:
132 *
133 * top_guid Unique ID for top-level vdev in which this is contained
134 * guid Unique ID for the leaf vdev
135 *
136 * The 'vs' configuration follows the format described in 'spa_config.c'.
137 */
138
139 #include <sys/zfs_context.h>
140 #include <sys/spa.h>
141 #include <sys/spa_impl.h>
142 #include <sys/dmu.h>
143 #include <sys/zap.h>
144 #include <sys/vdev.h>
145 #include <sys/vdev_impl.h>
146 #include <sys/uberblock_impl.h>
147 #include <sys/metaslab.h>
148 #include <sys/metaslab_impl.h>
149 #include <sys/zio.h>
150 #include <sys/dsl_scan.h>
151 #include <sys/abd.h>
152 #include <sys/fs/zfs.h>
153 #include <sys/byteorder.h>
154 #include <sys/zfs_bootenv.h>
155
156 /*
157 * Basic routines to read and write from a vdev label.
158 * Used throughout the rest of this file.
159 */
160 uint64_t
vdev_label_offset(uint64_t psize,int l,uint64_t offset)161 vdev_label_offset(uint64_t psize, int l, uint64_t offset)
162 {
163 ASSERT(offset < sizeof (vdev_label_t));
164 ASSERT(P2PHASE_TYPED(psize, sizeof (vdev_label_t), uint64_t) == 0);
165
166 return (offset + l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ?
167 0 : psize - VDEV_LABELS * sizeof (vdev_label_t)));
168 }
169
170 /*
171 * Returns back the vdev label associated with the passed in offset.
172 */
173 int
vdev_label_number(uint64_t psize,uint64_t offset)174 vdev_label_number(uint64_t psize, uint64_t offset)
175 {
176 int l;
177
178 if (offset >= psize - VDEV_LABEL_END_SIZE) {
179 offset -= psize - VDEV_LABEL_END_SIZE;
180 offset += (VDEV_LABELS / 2) * sizeof (vdev_label_t);
181 }
182 l = offset / sizeof (vdev_label_t);
183 return (l < VDEV_LABELS ? l : -1);
184 }
185
186 static void
vdev_label_read(zio_t * zio,vdev_t * vd,int l,abd_t * buf,uint64_t offset,uint64_t size,zio_done_func_t * done,void * private,int flags)187 vdev_label_read(zio_t *zio, vdev_t *vd, int l, abd_t *buf, uint64_t offset,
188 uint64_t size, zio_done_func_t *done, void *private, int flags)
189 {
190 ASSERT(
191 spa_config_held(zio->io_spa, SCL_STATE, RW_READER) == SCL_STATE ||
192 spa_config_held(zio->io_spa, SCL_STATE, RW_WRITER) == SCL_STATE);
193 ASSERT(flags & ZIO_FLAG_CONFIG_WRITER);
194
195 zio_nowait(zio_read_phys(zio, vd,
196 vdev_label_offset(vd->vdev_psize, l, offset),
197 size, buf, ZIO_CHECKSUM_LABEL, done, private,
198 ZIO_PRIORITY_SYNC_READ, flags, B_TRUE));
199 }
200
201 void
vdev_label_write(zio_t * zio,vdev_t * vd,int l,abd_t * buf,uint64_t offset,uint64_t size,zio_done_func_t * done,void * private,int flags)202 vdev_label_write(zio_t *zio, vdev_t *vd, int l, abd_t *buf, uint64_t offset,
203 uint64_t size, zio_done_func_t *done, void *private, int flags)
204 {
205 ASSERT(
206 spa_config_held(zio->io_spa, SCL_STATE, RW_READER) == SCL_STATE ||
207 spa_config_held(zio->io_spa, SCL_STATE, RW_WRITER) == SCL_STATE);
208 ASSERT(flags & ZIO_FLAG_CONFIG_WRITER);
209
210 zio_nowait(zio_write_phys(zio, vd,
211 vdev_label_offset(vd->vdev_psize, l, offset),
212 size, buf, ZIO_CHECKSUM_LABEL, done, private,
213 ZIO_PRIORITY_SYNC_WRITE, flags, B_TRUE));
214 }
215
216 /*
217 * Generate the nvlist representing this vdev's stats
218 */
219 void
vdev_config_generate_stats(vdev_t * vd,nvlist_t * nv)220 vdev_config_generate_stats(vdev_t *vd, nvlist_t *nv)
221 {
222 nvlist_t *nvx;
223 vdev_stat_t *vs;
224 vdev_stat_ex_t *vsx;
225
226 vs = kmem_alloc(sizeof (*vs), KM_SLEEP);
227 vsx = kmem_alloc(sizeof (*vsx), KM_SLEEP);
228
229 vdev_get_stats_ex(vd, vs, vsx);
230 fnvlist_add_uint64_array(nv, ZPOOL_CONFIG_VDEV_STATS,
231 (uint64_t *)vs, sizeof (*vs) / sizeof (uint64_t));
232
233 /*
234 * Add extended stats into a special extended stats nvlist. This keeps
235 * all the extended stats nicely grouped together. The extended stats
236 * nvlist is then added to the main nvlist.
237 */
238 nvx = fnvlist_alloc();
239
240 /* ZIOs in flight to disk */
241 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_R_ACTIVE_QUEUE,
242 vsx->vsx_active_queue[ZIO_PRIORITY_SYNC_READ]);
243
244 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_W_ACTIVE_QUEUE,
245 vsx->vsx_active_queue[ZIO_PRIORITY_SYNC_WRITE]);
246
247 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_R_ACTIVE_QUEUE,
248 vsx->vsx_active_queue[ZIO_PRIORITY_ASYNC_READ]);
249
250 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_W_ACTIVE_QUEUE,
251 vsx->vsx_active_queue[ZIO_PRIORITY_ASYNC_WRITE]);
252
253 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SCRUB_ACTIVE_QUEUE,
254 vsx->vsx_active_queue[ZIO_PRIORITY_SCRUB]);
255
256 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_TRIM_ACTIVE_QUEUE,
257 vsx->vsx_active_queue[ZIO_PRIORITY_TRIM]);
258
259 /* ZIOs pending */
260 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_R_PEND_QUEUE,
261 vsx->vsx_pend_queue[ZIO_PRIORITY_SYNC_READ]);
262
263 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_W_PEND_QUEUE,
264 vsx->vsx_pend_queue[ZIO_PRIORITY_SYNC_WRITE]);
265
266 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_R_PEND_QUEUE,
267 vsx->vsx_pend_queue[ZIO_PRIORITY_ASYNC_READ]);
268
269 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_W_PEND_QUEUE,
270 vsx->vsx_pend_queue[ZIO_PRIORITY_ASYNC_WRITE]);
271
272 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SCRUB_PEND_QUEUE,
273 vsx->vsx_pend_queue[ZIO_PRIORITY_SCRUB]);
274
275 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_TRIM_PEND_QUEUE,
276 vsx->vsx_pend_queue[ZIO_PRIORITY_TRIM]);
277
278 /* Histograms */
279 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_TOT_R_LAT_HISTO,
280 vsx->vsx_total_histo[ZIO_TYPE_READ],
281 ARRAY_SIZE(vsx->vsx_total_histo[ZIO_TYPE_READ]));
282
283 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_TOT_W_LAT_HISTO,
284 vsx->vsx_total_histo[ZIO_TYPE_WRITE],
285 ARRAY_SIZE(vsx->vsx_total_histo[ZIO_TYPE_WRITE]));
286
287 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_DISK_R_LAT_HISTO,
288 vsx->vsx_disk_histo[ZIO_TYPE_READ],
289 ARRAY_SIZE(vsx->vsx_disk_histo[ZIO_TYPE_READ]));
290
291 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_DISK_W_LAT_HISTO,
292 vsx->vsx_disk_histo[ZIO_TYPE_WRITE],
293 ARRAY_SIZE(vsx->vsx_disk_histo[ZIO_TYPE_WRITE]));
294
295 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_R_LAT_HISTO,
296 vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_READ],
297 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_READ]));
298
299 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_W_LAT_HISTO,
300 vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_WRITE],
301 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_WRITE]));
302
303 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_R_LAT_HISTO,
304 vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_READ],
305 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_READ]));
306
307 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_W_LAT_HISTO,
308 vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_WRITE],
309 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_WRITE]));
310
311 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SCRUB_LAT_HISTO,
312 vsx->vsx_queue_histo[ZIO_PRIORITY_SCRUB],
313 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_SCRUB]));
314
315 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_TRIM_LAT_HISTO,
316 vsx->vsx_queue_histo[ZIO_PRIORITY_TRIM],
317 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_TRIM]));
318
319 /* Request sizes */
320 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_IND_R_HISTO,
321 vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_READ],
322 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_READ]));
323
324 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_IND_W_HISTO,
325 vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_WRITE],
326 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_WRITE]));
327
328 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_IND_R_HISTO,
329 vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_READ],
330 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_READ]));
331
332 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_IND_W_HISTO,
333 vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_WRITE],
334 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_WRITE]));
335
336 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_IND_SCRUB_HISTO,
337 vsx->vsx_ind_histo[ZIO_PRIORITY_SCRUB],
338 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_SCRUB]));
339
340 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_IND_TRIM_HISTO,
341 vsx->vsx_ind_histo[ZIO_PRIORITY_TRIM],
342 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_TRIM]));
343
344 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_AGG_R_HISTO,
345 vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_READ],
346 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_READ]));
347
348 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_AGG_W_HISTO,
349 vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_WRITE],
350 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_WRITE]));
351
352 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_AGG_R_HISTO,
353 vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_READ],
354 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_READ]));
355
356 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_AGG_W_HISTO,
357 vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_WRITE],
358 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_WRITE]));
359
360 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_AGG_SCRUB_HISTO,
361 vsx->vsx_agg_histo[ZIO_PRIORITY_SCRUB],
362 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_SCRUB]));
363
364 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_AGG_TRIM_HISTO,
365 vsx->vsx_agg_histo[ZIO_PRIORITY_TRIM],
366 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_TRIM]));
367
368 /* IO delays */
369 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SLOW_IOS, vs->vs_slow_ios);
370
371 /* Add extended stats nvlist to main nvlist */
372 fnvlist_add_nvlist(nv, ZPOOL_CONFIG_VDEV_STATS_EX, nvx);
373
374 nvlist_free(nvx);
375 kmem_free(vs, sizeof (*vs));
376 kmem_free(vsx, sizeof (*vsx));
377 }
378
379 static void
root_vdev_actions_getprogress(vdev_t * vd,nvlist_t * nvl)380 root_vdev_actions_getprogress(vdev_t *vd, nvlist_t *nvl)
381 {
382 spa_t *spa = vd->vdev_spa;
383
384 if (vd != spa->spa_root_vdev)
385 return;
386
387 /* provide either current or previous scan information */
388 pool_scan_stat_t ps;
389 if (spa_scan_get_stats(spa, &ps) == 0) {
390 fnvlist_add_uint64_array(nvl,
391 ZPOOL_CONFIG_SCAN_STATS, (uint64_t *)&ps,
392 sizeof (pool_scan_stat_t) / sizeof (uint64_t));
393 }
394
395 pool_removal_stat_t prs;
396 if (spa_removal_get_stats(spa, &prs) == 0) {
397 fnvlist_add_uint64_array(nvl,
398 ZPOOL_CONFIG_REMOVAL_STATS, (uint64_t *)&prs,
399 sizeof (prs) / sizeof (uint64_t));
400 }
401
402 pool_checkpoint_stat_t pcs;
403 if (spa_checkpoint_get_stats(spa, &pcs) == 0) {
404 fnvlist_add_uint64_array(nvl,
405 ZPOOL_CONFIG_CHECKPOINT_STATS, (uint64_t *)&pcs,
406 sizeof (pcs) / sizeof (uint64_t));
407 }
408 }
409
410 /*
411 * Generate the nvlist representing this vdev's config.
412 */
413 nvlist_t *
vdev_config_generate(spa_t * spa,vdev_t * vd,boolean_t getstats,vdev_config_flag_t flags)414 vdev_config_generate(spa_t *spa, vdev_t *vd, boolean_t getstats,
415 vdev_config_flag_t flags)
416 {
417 nvlist_t *nv = NULL;
418 vdev_indirect_config_t *vic = &vd->vdev_indirect_config;
419
420 nv = fnvlist_alloc();
421
422 fnvlist_add_string(nv, ZPOOL_CONFIG_TYPE, vd->vdev_ops->vdev_op_type);
423 if (!(flags & (VDEV_CONFIG_SPARE | VDEV_CONFIG_L2CACHE)))
424 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ID, vd->vdev_id);
425 fnvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, vd->vdev_guid);
426
427 if (vd->vdev_path != NULL)
428 fnvlist_add_string(nv, ZPOOL_CONFIG_PATH, vd->vdev_path);
429
430 if (vd->vdev_devid != NULL)
431 fnvlist_add_string(nv, ZPOOL_CONFIG_DEVID, vd->vdev_devid);
432
433 if (vd->vdev_physpath != NULL)
434 fnvlist_add_string(nv, ZPOOL_CONFIG_PHYS_PATH,
435 vd->vdev_physpath);
436
437 if (vd->vdev_fru != NULL)
438 fnvlist_add_string(nv, ZPOOL_CONFIG_FRU, vd->vdev_fru);
439
440 if (vd->vdev_nparity != 0) {
441 ASSERT(strcmp(vd->vdev_ops->vdev_op_type,
442 VDEV_TYPE_RAIDZ) == 0);
443
444 /*
445 * Make sure someone hasn't managed to sneak a fancy new vdev
446 * into a crufty old storage pool.
447 */
448 ASSERT(vd->vdev_nparity == 1 ||
449 (vd->vdev_nparity <= 2 &&
450 spa_version(spa) >= SPA_VERSION_RAIDZ2) ||
451 (vd->vdev_nparity <= 3 &&
452 spa_version(spa) >= SPA_VERSION_RAIDZ3));
453
454 /*
455 * Note that we'll add the nparity tag even on storage pools
456 * that only support a single parity device -- older software
457 * will just ignore it.
458 */
459 fnvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, vd->vdev_nparity);
460 }
461
462 if (vd->vdev_wholedisk != -1ULL)
463 fnvlist_add_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK,
464 vd->vdev_wholedisk);
465
466 if (vd->vdev_not_present && !(flags & VDEV_CONFIG_MISSING))
467 fnvlist_add_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT, 1);
468
469 if (vd->vdev_isspare)
470 fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1);
471
472 if (!(flags & (VDEV_CONFIG_SPARE | VDEV_CONFIG_L2CACHE)) &&
473 vd == vd->vdev_top) {
474 fnvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY,
475 vd->vdev_ms_array);
476 fnvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_SHIFT,
477 vd->vdev_ms_shift);
478 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ASHIFT, vd->vdev_ashift);
479 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ASIZE,
480 vd->vdev_asize);
481 fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_LOG, vd->vdev_islog);
482 if (vd->vdev_removing) {
483 fnvlist_add_uint64(nv, ZPOOL_CONFIG_REMOVING,
484 vd->vdev_removing);
485 }
486
487 /* zpool command expects alloc class data */
488 if (getstats && vd->vdev_alloc_bias != VDEV_BIAS_NONE) {
489 const char *bias = NULL;
490
491 switch (vd->vdev_alloc_bias) {
492 case VDEV_BIAS_LOG:
493 bias = VDEV_ALLOC_BIAS_LOG;
494 break;
495 case VDEV_BIAS_SPECIAL:
496 bias = VDEV_ALLOC_BIAS_SPECIAL;
497 break;
498 case VDEV_BIAS_DEDUP:
499 bias = VDEV_ALLOC_BIAS_DEDUP;
500 break;
501 default:
502 ASSERT3U(vd->vdev_alloc_bias, ==,
503 VDEV_BIAS_NONE);
504 }
505 fnvlist_add_string(nv, ZPOOL_CONFIG_ALLOCATION_BIAS,
506 bias);
507 }
508 }
509
510 if (vd->vdev_dtl_sm != NULL) {
511 fnvlist_add_uint64(nv, ZPOOL_CONFIG_DTL,
512 space_map_object(vd->vdev_dtl_sm));
513 }
514
515 if (vic->vic_mapping_object != 0) {
516 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_OBJECT,
517 vic->vic_mapping_object);
518 }
519
520 if (vic->vic_births_object != 0) {
521 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_BIRTHS,
522 vic->vic_births_object);
523 }
524
525 if (vic->vic_prev_indirect_vdev != UINT64_MAX) {
526 fnvlist_add_uint64(nv, ZPOOL_CONFIG_PREV_INDIRECT_VDEV,
527 vic->vic_prev_indirect_vdev);
528 }
529
530 if (vd->vdev_crtxg)
531 fnvlist_add_uint64(nv, ZPOOL_CONFIG_CREATE_TXG, vd->vdev_crtxg);
532
533 if (flags & VDEV_CONFIG_MOS) {
534 if (vd->vdev_leaf_zap != 0) {
535 ASSERT(vd->vdev_ops->vdev_op_leaf);
536 fnvlist_add_uint64(nv, ZPOOL_CONFIG_VDEV_LEAF_ZAP,
537 vd->vdev_leaf_zap);
538 }
539
540 if (vd->vdev_top_zap != 0) {
541 ASSERT(vd == vd->vdev_top);
542 fnvlist_add_uint64(nv, ZPOOL_CONFIG_VDEV_TOP_ZAP,
543 vd->vdev_top_zap);
544 }
545
546 if (vd->vdev_resilver_deferred) {
547 ASSERT(vd->vdev_ops->vdev_op_leaf);
548 ASSERT(spa->spa_resilver_deferred);
549 fnvlist_add_boolean(nv, ZPOOL_CONFIG_RESILVER_DEFER);
550 }
551 }
552
553 if (getstats) {
554 vdev_config_generate_stats(vd, nv);
555
556 root_vdev_actions_getprogress(vd, nv);
557
558 /*
559 * Note: this can be called from open context
560 * (spa_get_stats()), so we need the rwlock to prevent
561 * the mapping from being changed by condensing.
562 */
563 rw_enter(&vd->vdev_indirect_rwlock, RW_READER);
564 if (vd->vdev_indirect_mapping != NULL) {
565 ASSERT(vd->vdev_indirect_births != NULL);
566 vdev_indirect_mapping_t *vim =
567 vd->vdev_indirect_mapping;
568 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_SIZE,
569 vdev_indirect_mapping_size(vim));
570 }
571 rw_exit(&vd->vdev_indirect_rwlock);
572 if (vd->vdev_mg != NULL &&
573 vd->vdev_mg->mg_fragmentation != ZFS_FRAG_INVALID) {
574 /*
575 * Compute approximately how much memory would be used
576 * for the indirect mapping if this device were to
577 * be removed.
578 *
579 * Note: If the frag metric is invalid, then not
580 * enough metaslabs have been converted to have
581 * histograms.
582 */
583 uint64_t seg_count = 0;
584 uint64_t to_alloc = vd->vdev_stat.vs_alloc;
585
586 /*
587 * There are the same number of allocated segments
588 * as free segments, so we will have at least one
589 * entry per free segment. However, small free
590 * segments (smaller than vdev_removal_max_span)
591 * will be combined with adjacent allocated segments
592 * as a single mapping.
593 */
594 for (int i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i++) {
595 if (1ULL << (i + 1) < vdev_removal_max_span) {
596 to_alloc +=
597 vd->vdev_mg->mg_histogram[i] <<
598 i + 1;
599 } else {
600 seg_count +=
601 vd->vdev_mg->mg_histogram[i];
602 }
603 }
604
605 /*
606 * The maximum length of a mapping is
607 * zfs_remove_max_segment, so we need at least one entry
608 * per zfs_remove_max_segment of allocated data.
609 */
610 seg_count += to_alloc / zfs_remove_max_segment;
611
612 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_SIZE,
613 seg_count *
614 sizeof (vdev_indirect_mapping_entry_phys_t));
615 }
616 }
617
618 if (!vd->vdev_ops->vdev_op_leaf) {
619 nvlist_t **child;
620 int c, idx;
621
622 ASSERT(!vd->vdev_ishole);
623
624 child = kmem_alloc(vd->vdev_children * sizeof (nvlist_t *),
625 KM_SLEEP);
626
627 for (c = 0, idx = 0; c < vd->vdev_children; c++) {
628 vdev_t *cvd = vd->vdev_child[c];
629
630 /*
631 * If we're generating an nvlist of removing
632 * vdevs then skip over any device which is
633 * not being removed.
634 */
635 if ((flags & VDEV_CONFIG_REMOVING) &&
636 !cvd->vdev_removing)
637 continue;
638
639 child[idx++] = vdev_config_generate(spa, cvd,
640 getstats, flags);
641 }
642
643 if (idx) {
644 fnvlist_add_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
645 child, idx);
646 }
647
648 for (c = 0; c < idx; c++)
649 nvlist_free(child[c]);
650
651 kmem_free(child, vd->vdev_children * sizeof (nvlist_t *));
652
653 } else {
654 const char *aux = NULL;
655
656 if (vd->vdev_offline && !vd->vdev_tmpoffline)
657 fnvlist_add_uint64(nv, ZPOOL_CONFIG_OFFLINE, B_TRUE);
658 if (vd->vdev_resilver_txg != 0)
659 fnvlist_add_uint64(nv, ZPOOL_CONFIG_RESILVER_TXG,
660 vd->vdev_resilver_txg);
661 if (vd->vdev_faulted)
662 fnvlist_add_uint64(nv, ZPOOL_CONFIG_FAULTED, B_TRUE);
663 if (vd->vdev_degraded)
664 fnvlist_add_uint64(nv, ZPOOL_CONFIG_DEGRADED, B_TRUE);
665 if (vd->vdev_removed)
666 fnvlist_add_uint64(nv, ZPOOL_CONFIG_REMOVED, B_TRUE);
667 if (vd->vdev_unspare)
668 fnvlist_add_uint64(nv, ZPOOL_CONFIG_UNSPARE, B_TRUE);
669 if (vd->vdev_ishole)
670 fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_HOLE, B_TRUE);
671
672 switch (vd->vdev_stat.vs_aux) {
673 case VDEV_AUX_ERR_EXCEEDED:
674 aux = "err_exceeded";
675 break;
676
677 case VDEV_AUX_EXTERNAL:
678 aux = "external";
679 break;
680 }
681
682 if (aux != NULL)
683 fnvlist_add_string(nv, ZPOOL_CONFIG_AUX_STATE, aux);
684
685 if (vd->vdev_splitting && vd->vdev_orig_guid != 0LL) {
686 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ORIG_GUID,
687 vd->vdev_orig_guid);
688 }
689 }
690
691 return (nv);
692 }
693
694 /*
695 * Generate a view of the top-level vdevs. If we currently have holes
696 * in the namespace, then generate an array which contains a list of holey
697 * vdevs. Additionally, add the number of top-level children that currently
698 * exist.
699 */
700 void
vdev_top_config_generate(spa_t * spa,nvlist_t * config)701 vdev_top_config_generate(spa_t *spa, nvlist_t *config)
702 {
703 vdev_t *rvd = spa->spa_root_vdev;
704 uint64_t *array;
705 uint_t c, idx;
706
707 array = kmem_alloc(rvd->vdev_children * sizeof (uint64_t), KM_SLEEP);
708
709 for (c = 0, idx = 0; c < rvd->vdev_children; c++) {
710 vdev_t *tvd = rvd->vdev_child[c];
711
712 if (tvd->vdev_ishole) {
713 array[idx++] = c;
714 }
715 }
716
717 if (idx) {
718 VERIFY(nvlist_add_uint64_array(config, ZPOOL_CONFIG_HOLE_ARRAY,
719 array, idx) == 0);
720 }
721
722 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
723 rvd->vdev_children) == 0);
724
725 kmem_free(array, rvd->vdev_children * sizeof (uint64_t));
726 }
727
728 /*
729 * Returns the configuration from the label of the given vdev. For vdevs
730 * which don't have a txg value stored on their label (i.e. spares/cache)
731 * or have not been completely initialized (txg = 0) just return
732 * the configuration from the first valid label we find. Otherwise,
733 * find the most up-to-date label that does not exceed the specified
734 * 'txg' value.
735 */
736 nvlist_t *
vdev_label_read_config(vdev_t * vd,uint64_t txg)737 vdev_label_read_config(vdev_t *vd, uint64_t txg)
738 {
739 spa_t *spa = vd->vdev_spa;
740 nvlist_t *config = NULL;
741 vdev_phys_t *vp;
742 abd_t *vp_abd;
743 zio_t *zio;
744 uint64_t best_txg = 0;
745 uint64_t label_txg = 0;
746 int error = 0;
747 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL |
748 ZIO_FLAG_SPECULATIVE;
749
750 ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL);
751
752 if (!vdev_readable(vd))
753 return (NULL);
754
755 vp_abd = abd_alloc_linear(sizeof (vdev_phys_t), B_TRUE);
756 vp = abd_to_buf(vp_abd);
757
758 retry:
759 for (int l = 0; l < VDEV_LABELS; l++) {
760 nvlist_t *label = NULL;
761
762 zio = zio_root(spa, NULL, NULL, flags);
763
764 vdev_label_read(zio, vd, l, vp_abd,
765 offsetof(vdev_label_t, vl_vdev_phys),
766 sizeof (vdev_phys_t), NULL, NULL, flags);
767
768 if (zio_wait(zio) == 0 &&
769 nvlist_unpack(vp->vp_nvlist, sizeof (vp->vp_nvlist),
770 &label, 0) == 0) {
771 /*
772 * Auxiliary vdevs won't have txg values in their
773 * labels and newly added vdevs may not have been
774 * completely initialized so just return the
775 * configuration from the first valid label we
776 * encounter.
777 */
778 error = nvlist_lookup_uint64(label,
779 ZPOOL_CONFIG_POOL_TXG, &label_txg);
780 if ((error || label_txg == 0) && !config) {
781 config = label;
782 break;
783 } else if (label_txg <= txg && label_txg > best_txg) {
784 best_txg = label_txg;
785 nvlist_free(config);
786 config = fnvlist_dup(label);
787 }
788 }
789
790 if (label != NULL) {
791 nvlist_free(label);
792 label = NULL;
793 }
794 }
795
796 if (config == NULL && !(flags & ZIO_FLAG_TRYHARD)) {
797 flags |= ZIO_FLAG_TRYHARD;
798 goto retry;
799 }
800
801 /*
802 * We found a valid label but it didn't pass txg restrictions.
803 */
804 if (config == NULL && label_txg != 0) {
805 vdev_dbgmsg(vd, "label discarded as txg is too large "
806 "(%llu > %llu)", (u_longlong_t)label_txg,
807 (u_longlong_t)txg);
808 }
809
810 abd_free(vp_abd);
811
812 return (config);
813 }
814
815 /*
816 * Determine if a device is in use. The 'spare_guid' parameter will be filled
817 * in with the device guid if this spare is active elsewhere on the system.
818 */
819 static boolean_t
vdev_inuse(vdev_t * vd,uint64_t crtxg,vdev_labeltype_t reason,uint64_t * spare_guid,uint64_t * l2cache_guid)820 vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason,
821 uint64_t *spare_guid, uint64_t *l2cache_guid)
822 {
823 spa_t *spa = vd->vdev_spa;
824 uint64_t state, pool_guid, device_guid, txg, spare_pool;
825 uint64_t vdtxg = 0;
826 nvlist_t *label;
827
828 if (spare_guid)
829 *spare_guid = 0ULL;
830 if (l2cache_guid)
831 *l2cache_guid = 0ULL;
832
833 /*
834 * Read the label, if any, and perform some basic sanity checks.
835 */
836 if ((label = vdev_label_read_config(vd, -1ULL)) == NULL)
837 return (B_FALSE);
838
839 (void) nvlist_lookup_uint64(label, ZPOOL_CONFIG_CREATE_TXG,
840 &vdtxg);
841
842 if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE,
843 &state) != 0 ||
844 nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID,
845 &device_guid) != 0) {
846 nvlist_free(label);
847 return (B_FALSE);
848 }
849
850 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
851 (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_GUID,
852 &pool_guid) != 0 ||
853 nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
854 &txg) != 0)) {
855 nvlist_free(label);
856 return (B_FALSE);
857 }
858
859 nvlist_free(label);
860
861 /*
862 * Check to see if this device indeed belongs to the pool it claims to
863 * be a part of. The only way this is allowed is if the device is a hot
864 * spare (which we check for later on).
865 */
866 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
867 !spa_guid_exists(pool_guid, device_guid) &&
868 !spa_spare_exists(device_guid, NULL, NULL) &&
869 !spa_l2cache_exists(device_guid, NULL))
870 return (B_FALSE);
871
872 /*
873 * If the transaction group is zero, then this an initialized (but
874 * unused) label. This is only an error if the create transaction
875 * on-disk is the same as the one we're using now, in which case the
876 * user has attempted to add the same vdev multiple times in the same
877 * transaction.
878 */
879 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
880 txg == 0 && vdtxg == crtxg)
881 return (B_TRUE);
882
883 /*
884 * Check to see if this is a spare device. We do an explicit check for
885 * spa_has_spare() here because it may be on our pending list of spares
886 * to add. We also check if it is an l2cache device.
887 */
888 if (spa_spare_exists(device_guid, &spare_pool, NULL) ||
889 spa_has_spare(spa, device_guid)) {
890 if (spare_guid)
891 *spare_guid = device_guid;
892
893 switch (reason) {
894 case VDEV_LABEL_CREATE:
895 case VDEV_LABEL_L2CACHE:
896 return (B_TRUE);
897
898 case VDEV_LABEL_REPLACE:
899 return (!spa_has_spare(spa, device_guid) ||
900 spare_pool != 0ULL);
901
902 case VDEV_LABEL_SPARE:
903 return (spa_has_spare(spa, device_guid));
904 }
905 }
906
907 /*
908 * Check to see if this is an l2cache device.
909 */
910 if (spa_l2cache_exists(device_guid, NULL))
911 return (B_TRUE);
912
913 /*
914 * We can't rely on a pool's state if it's been imported
915 * read-only. Instead we look to see if the pools is marked
916 * read-only in the namespace and set the state to active.
917 */
918 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
919 (spa = spa_by_guid(pool_guid, device_guid)) != NULL &&
920 spa_mode(spa) == FREAD)
921 state = POOL_STATE_ACTIVE;
922
923 /*
924 * If the device is marked ACTIVE, then this device is in use by another
925 * pool on the system.
926 */
927 return (state == POOL_STATE_ACTIVE);
928 }
929
930 /*
931 * Initialize a vdev label. We check to make sure each leaf device is not in
932 * use, and writable. We put down an initial label which we will later
933 * overwrite with a complete label. Note that it's important to do this
934 * sequentially, not in parallel, so that we catch cases of multiple use of the
935 * same leaf vdev in the vdev we're creating -- e.g. mirroring a disk with
936 * itself.
937 */
938 int
vdev_label_init(vdev_t * vd,uint64_t crtxg,vdev_labeltype_t reason)939 vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason)
940 {
941 spa_t *spa = vd->vdev_spa;
942 nvlist_t *label;
943 vdev_phys_t *vp;
944 abd_t *vp_abd;
945 abd_t *bootenv;
946 uberblock_t *ub;
947 abd_t *ub_abd;
948 zio_t *zio;
949 char *buf;
950 size_t buflen;
951 int error;
952 uint64_t spare_guid = 0, l2cache_guid;
953 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL;
954
955 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
956
957 for (int c = 0; c < vd->vdev_children; c++)
958 if ((error = vdev_label_init(vd->vdev_child[c],
959 crtxg, reason)) != 0)
960 return (error);
961
962 /* Track the creation time for this vdev */
963 vd->vdev_crtxg = crtxg;
964
965 if (!vd->vdev_ops->vdev_op_leaf || !spa_writeable(spa))
966 return (0);
967
968 /*
969 * Dead vdevs cannot be initialized.
970 */
971 if (vdev_is_dead(vd))
972 return (SET_ERROR(EIO));
973
974 /*
975 * Determine if the vdev is in use.
976 */
977 if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_SPLIT &&
978 vdev_inuse(vd, crtxg, reason, &spare_guid, &l2cache_guid))
979 return (SET_ERROR(EBUSY));
980
981 /*
982 * If this is a request to add or replace a spare or l2cache device
983 * that is in use elsewhere on the system, then we must update the
984 * guid (which was initialized to a random value) to reflect the
985 * actual GUID (which is shared between multiple pools).
986 */
987 if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_L2CACHE &&
988 spare_guid != 0ULL) {
989 uint64_t guid_delta = spare_guid - vd->vdev_guid;
990
991 vd->vdev_guid += guid_delta;
992
993 for (vdev_t *pvd = vd; pvd != NULL; pvd = pvd->vdev_parent)
994 pvd->vdev_guid_sum += guid_delta;
995
996 /*
997 * If this is a replacement, then we want to fallthrough to the
998 * rest of the code. If we're adding a spare, then it's already
999 * labeled appropriately and we can just return.
1000 */
1001 if (reason == VDEV_LABEL_SPARE)
1002 return (0);
1003 ASSERT(reason == VDEV_LABEL_REPLACE ||
1004 reason == VDEV_LABEL_SPLIT);
1005 }
1006
1007 if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_SPARE &&
1008 l2cache_guid != 0ULL) {
1009 uint64_t guid_delta = l2cache_guid - vd->vdev_guid;
1010
1011 vd->vdev_guid += guid_delta;
1012
1013 for (vdev_t *pvd = vd; pvd != NULL; pvd = pvd->vdev_parent)
1014 pvd->vdev_guid_sum += guid_delta;
1015
1016 /*
1017 * If this is a replacement, then we want to fallthrough to the
1018 * rest of the code. If we're adding an l2cache, then it's
1019 * already labeled appropriately and we can just return.
1020 */
1021 if (reason == VDEV_LABEL_L2CACHE)
1022 return (0);
1023 ASSERT(reason == VDEV_LABEL_REPLACE);
1024 }
1025
1026 /*
1027 * Initialize its label.
1028 */
1029 vp_abd = abd_alloc_linear(sizeof (vdev_phys_t), B_TRUE);
1030 abd_zero(vp_abd, sizeof (vdev_phys_t));
1031 vp = abd_to_buf(vp_abd);
1032
1033 /*
1034 * Generate a label describing the pool and our top-level vdev.
1035 * We mark it as being from txg 0 to indicate that it's not
1036 * really part of an active pool just yet. The labels will
1037 * be written again with a meaningful txg by spa_sync().
1038 */
1039 if (reason == VDEV_LABEL_SPARE ||
1040 (reason == VDEV_LABEL_REMOVE && vd->vdev_isspare)) {
1041 /*
1042 * For inactive hot spares, we generate a special label that
1043 * identifies as a mutually shared hot spare. We write the
1044 * label if we are adding a hot spare, or if we are removing an
1045 * active hot spare (in which case we want to revert the
1046 * labels).
1047 */
1048 VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1049
1050 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION,
1051 spa_version(spa)) == 0);
1052 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE,
1053 POOL_STATE_SPARE) == 0);
1054 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID,
1055 vd->vdev_guid) == 0);
1056 } else if (reason == VDEV_LABEL_L2CACHE ||
1057 (reason == VDEV_LABEL_REMOVE && vd->vdev_isl2cache)) {
1058 /*
1059 * For level 2 ARC devices, add a special label.
1060 */
1061 VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1062
1063 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION,
1064 spa_version(spa)) == 0);
1065 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE,
1066 POOL_STATE_L2CACHE) == 0);
1067 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID,
1068 vd->vdev_guid) == 0);
1069 } else {
1070 uint64_t txg = 0ULL;
1071
1072 if (reason == VDEV_LABEL_SPLIT)
1073 txg = spa->spa_uberblock.ub_txg;
1074 label = spa_config_generate(spa, vd, txg, B_FALSE);
1075
1076 /*
1077 * Add our creation time. This allows us to detect multiple
1078 * vdev uses as described above, and automatically expires if we
1079 * fail.
1080 */
1081 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_CREATE_TXG,
1082 crtxg) == 0);
1083 }
1084
1085 buf = vp->vp_nvlist;
1086 buflen = sizeof (vp->vp_nvlist);
1087
1088 error = nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP);
1089 if (error != 0) {
1090 nvlist_free(label);
1091 abd_free(vp_abd);
1092 /* EFAULT means nvlist_pack ran out of room */
1093 return (error == EFAULT ? ENAMETOOLONG : EINVAL);
1094 }
1095
1096 /*
1097 * Initialize uberblock template.
1098 */
1099 ub_abd = abd_alloc_linear(VDEV_UBERBLOCK_RING, B_TRUE);
1100 abd_zero(ub_abd, VDEV_UBERBLOCK_RING);
1101 abd_copy_from_buf(ub_abd, &spa->spa_uberblock, sizeof (uberblock_t));
1102 ub = abd_to_buf(ub_abd);
1103 ub->ub_txg = 0;
1104
1105 /* Initialize the 2nd padding area. */
1106 bootenv = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE);
1107 abd_zero(bootenv, VDEV_PAD_SIZE);
1108
1109 /*
1110 * Write everything in parallel.
1111 */
1112 retry:
1113 zio = zio_root(spa, NULL, NULL, flags);
1114
1115 for (int l = 0; l < VDEV_LABELS; l++) {
1116
1117 vdev_label_write(zio, vd, l, vp_abd,
1118 offsetof(vdev_label_t, vl_vdev_phys),
1119 sizeof (vdev_phys_t), NULL, NULL, flags);
1120
1121 /*
1122 * Skip the 1st padding area.
1123 * Zero out the 2nd padding area where it might have
1124 * left over data from previous filesystem format.
1125 */
1126 vdev_label_write(zio, vd, l, bootenv,
1127 offsetof(vdev_label_t, vl_be),
1128 VDEV_PAD_SIZE, NULL, NULL, flags);
1129
1130 vdev_label_write(zio, vd, l, ub_abd,
1131 offsetof(vdev_label_t, vl_uberblock),
1132 VDEV_UBERBLOCK_RING, NULL, NULL, flags);
1133 }
1134
1135 error = zio_wait(zio);
1136
1137 if (error != 0 && !(flags & ZIO_FLAG_TRYHARD)) {
1138 flags |= ZIO_FLAG_TRYHARD;
1139 goto retry;
1140 }
1141
1142 nvlist_free(label);
1143 abd_free(bootenv);
1144 abd_free(ub_abd);
1145 abd_free(vp_abd);
1146
1147 /*
1148 * If this vdev hasn't been previously identified as a spare, then we
1149 * mark it as such only if a) we are labeling it as a spare, or b) it
1150 * exists as a spare elsewhere in the system. Do the same for
1151 * level 2 ARC devices.
1152 */
1153 if (error == 0 && !vd->vdev_isspare &&
1154 (reason == VDEV_LABEL_SPARE ||
1155 spa_spare_exists(vd->vdev_guid, NULL, NULL)))
1156 spa_spare_add(vd);
1157
1158 if (error == 0 && !vd->vdev_isl2cache &&
1159 (reason == VDEV_LABEL_L2CACHE ||
1160 spa_l2cache_exists(vd->vdev_guid, NULL)))
1161 spa_l2cache_add(vd);
1162
1163 return (error);
1164 }
1165
1166 /*
1167 * Done callback for vdev_label_read_bootenv_impl. If this is the first
1168 * callback to finish, store our abd in the callback pointer. Otherwise, we
1169 * just free our abd and return.
1170 */
1171 static void
vdev_label_read_bootenv_done(zio_t * zio)1172 vdev_label_read_bootenv_done(zio_t *zio)
1173 {
1174 zio_t *rio = zio->io_private;
1175 abd_t **cbp = rio->io_private;
1176
1177 ASSERT3U(zio->io_size, ==, VDEV_PAD_SIZE);
1178
1179 if (zio->io_error == 0) {
1180 mutex_enter(&rio->io_lock);
1181 if (*cbp == NULL) {
1182 /* Will free this buffer in vdev_label_read_bootenv. */
1183 *cbp = zio->io_abd;
1184 } else {
1185 abd_free(zio->io_abd);
1186 }
1187 mutex_exit(&rio->io_lock);
1188 } else {
1189 abd_free(zio->io_abd);
1190 }
1191 }
1192
1193 static void
vdev_label_read_bootenv_impl(zio_t * zio,vdev_t * vd,int flags)1194 vdev_label_read_bootenv_impl(zio_t *zio, vdev_t *vd, int flags)
1195 {
1196 for (int c = 0; c < vd->vdev_children; c++)
1197 vdev_label_read_bootenv_impl(zio, vd->vdev_child[c], flags);
1198
1199 /*
1200 * We just use the first label that has a correct checksum; the
1201 * bootloader should have rewritten them all to be the same on boot,
1202 * and any changes we made since boot have been the same across all
1203 * labels.
1204 */
1205 if (vd->vdev_ops->vdev_op_leaf && vdev_readable(vd)) {
1206 for (int l = 0; l < VDEV_LABELS; l++) {
1207 vdev_label_read(zio, vd, l,
1208 abd_alloc_linear(VDEV_PAD_SIZE, B_FALSE),
1209 offsetof(vdev_label_t, vl_be), VDEV_PAD_SIZE,
1210 vdev_label_read_bootenv_done, zio, flags);
1211 }
1212 }
1213 }
1214
1215 int
vdev_label_read_bootenv(vdev_t * rvd,nvlist_t * bootenv)1216 vdev_label_read_bootenv(vdev_t *rvd, nvlist_t *bootenv)
1217 {
1218 nvlist_t *config;
1219 spa_t *spa = rvd->vdev_spa;
1220 abd_t *abd = NULL;
1221 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL |
1222 ZIO_FLAG_SPECULATIVE | ZIO_FLAG_TRYHARD;
1223
1224 ASSERT(bootenv);
1225 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1226
1227 zio_t *zio = zio_root(spa, NULL, &abd, flags);
1228 vdev_label_read_bootenv_impl(zio, rvd, flags);
1229 int err = zio_wait(zio);
1230
1231 if (abd != NULL) {
1232 char *buf;
1233 vdev_boot_envblock_t *vbe = abd_to_buf(abd);
1234
1235 vbe->vbe_version = ntohll(vbe->vbe_version);
1236 switch (vbe->vbe_version) {
1237 case VB_RAW:
1238 /*
1239 * if we have textual data in vbe_bootenv, create nvlist
1240 * with key "envmap".
1241 */
1242 fnvlist_add_uint64(bootenv, BOOTENV_VERSION, VB_RAW);
1243 vbe->vbe_bootenv[sizeof (vbe->vbe_bootenv) - 1] = '\0';
1244 fnvlist_add_string(bootenv, GRUB_ENVMAP,
1245 vbe->vbe_bootenv);
1246 break;
1247
1248 case VB_NVLIST:
1249 err = nvlist_unpack(vbe->vbe_bootenv,
1250 sizeof (vbe->vbe_bootenv), &config, 0);
1251 if (err == 0) {
1252 fnvlist_merge(bootenv, config);
1253 nvlist_free(config);
1254 break;
1255 }
1256 /* FALLTHROUGH */
1257 default:
1258 /* Check for FreeBSD zfs bootonce command string */
1259 buf = abd_to_buf(abd);
1260 if (*buf == '\0') {
1261 fnvlist_add_uint64(bootenv, BOOTENV_VERSION,
1262 VB_NVLIST);
1263 break;
1264 }
1265 fnvlist_add_string(bootenv, FREEBSD_BOOTONCE, buf);
1266 }
1267
1268 /*
1269 * abd was allocated in vdev_label_read_bootenv_impl()
1270 */
1271 abd_free(abd);
1272 /*
1273 * If we managed to read any successfully,
1274 * return success.
1275 */
1276 return (0);
1277 }
1278 return (err);
1279 }
1280
1281 int
vdev_label_write_bootenv(vdev_t * vd,nvlist_t * env)1282 vdev_label_write_bootenv(vdev_t *vd, nvlist_t *env)
1283 {
1284 zio_t *zio;
1285 spa_t *spa = vd->vdev_spa;
1286 vdev_boot_envblock_t *bootenv;
1287 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL;
1288 int error;
1289 size_t nvsize;
1290 char *nvbuf;
1291
1292 error = nvlist_size(env, &nvsize, NV_ENCODE_XDR);
1293 if (error != 0)
1294 return (SET_ERROR(error));
1295
1296 if (nvsize >= sizeof (bootenv->vbe_bootenv)) {
1297 return (SET_ERROR(E2BIG));
1298 }
1299
1300 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1301
1302 error = ENXIO;
1303 for (int c = 0; c < vd->vdev_children; c++) {
1304 int child_err;
1305
1306 child_err = vdev_label_write_bootenv(vd->vdev_child[c], env);
1307 /*
1308 * As long as any of the disks managed to write all of their
1309 * labels successfully, return success.
1310 */
1311 if (child_err == 0)
1312 error = child_err;
1313 }
1314
1315 if (!vd->vdev_ops->vdev_op_leaf || vdev_is_dead(vd) ||
1316 !vdev_writeable(vd)) {
1317 return (error);
1318 }
1319 ASSERT3U(sizeof (*bootenv), ==, VDEV_PAD_SIZE);
1320 abd_t *abd = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE);
1321 abd_zero(abd, VDEV_PAD_SIZE);
1322
1323 bootenv = abd_borrow_buf_copy(abd, VDEV_PAD_SIZE);
1324 nvbuf = bootenv->vbe_bootenv;
1325 nvsize = sizeof (bootenv->vbe_bootenv);
1326
1327 bootenv->vbe_version = fnvlist_lookup_uint64(env, BOOTENV_VERSION);
1328 switch (bootenv->vbe_version) {
1329 case VB_RAW:
1330 if (nvlist_lookup_string(env, GRUB_ENVMAP, &nvbuf) == 0) {
1331 (void) strlcpy(bootenv->vbe_bootenv, nvbuf, nvsize);
1332 }
1333 error = 0;
1334 break;
1335
1336 case VB_NVLIST:
1337 error = nvlist_pack(env, &nvbuf, &nvsize, NV_ENCODE_XDR,
1338 KM_SLEEP);
1339 break;
1340
1341 default:
1342 error = EINVAL;
1343 break;
1344 }
1345
1346 if (error == 0) {
1347 bootenv->vbe_version = htonll(bootenv->vbe_version);
1348 abd_return_buf_copy(abd, bootenv, VDEV_PAD_SIZE);
1349 } else {
1350 abd_free(abd);
1351 return (SET_ERROR(error));
1352 }
1353
1354 retry:
1355 zio = zio_root(spa, NULL, NULL, flags);
1356 for (int l = 0; l < VDEV_LABELS; l++) {
1357 vdev_label_write(zio, vd, l, abd,
1358 offsetof(vdev_label_t, vl_be),
1359 VDEV_PAD_SIZE, NULL, NULL, flags);
1360 }
1361
1362 error = zio_wait(zio);
1363 if (error != 0 && !(flags & ZIO_FLAG_TRYHARD)) {
1364 flags |= ZIO_FLAG_TRYHARD;
1365 goto retry;
1366 }
1367
1368 abd_free(abd);
1369 return (error);
1370 }
1371
1372 /*
1373 * ==========================================================================
1374 * uberblock load/sync
1375 * ==========================================================================
1376 */
1377
1378 /*
1379 * Consider the following situation: txg is safely synced to disk. We've
1380 * written the first uberblock for txg + 1, and then we lose power. When we
1381 * come back up, we fail to see the uberblock for txg + 1 because, say,
1382 * it was on a mirrored device and the replica to which we wrote txg + 1
1383 * is now offline. If we then make some changes and sync txg + 1, and then
1384 * the missing replica comes back, then for a few seconds we'll have two
1385 * conflicting uberblocks on disk with the same txg. The solution is simple:
1386 * among uberblocks with equal txg, choose the one with the latest timestamp.
1387 */
1388 static int
vdev_uberblock_compare(const uberblock_t * ub1,const uberblock_t * ub2)1389 vdev_uberblock_compare(const uberblock_t *ub1, const uberblock_t *ub2)
1390 {
1391 int cmp = TREE_CMP(ub1->ub_txg, ub2->ub_txg);
1392
1393 if (likely(cmp))
1394 return (cmp);
1395
1396 cmp = TREE_CMP(ub1->ub_timestamp, ub2->ub_timestamp);
1397 if (likely(cmp))
1398 return (cmp);
1399
1400 /*
1401 * If MMP_VALID(ub) && MMP_SEQ_VALID(ub) then the host has an MMP-aware
1402 * ZFS, e.g. zfsonlinux >= 0.7.
1403 *
1404 * If one ub has MMP and the other does not, they were written by
1405 * different hosts, which matters for MMP. So we treat no MMP/no SEQ as
1406 * a 0 value.
1407 *
1408 * Since timestamp and txg are the same if we get this far, either is
1409 * acceptable for importing the pool.
1410 */
1411 unsigned int seq1 = 0;
1412 unsigned int seq2 = 0;
1413
1414 if (MMP_VALID(ub1) && MMP_SEQ_VALID(ub1))
1415 seq1 = MMP_SEQ(ub1);
1416
1417 if (MMP_VALID(ub2) && MMP_SEQ_VALID(ub2))
1418 seq2 = MMP_SEQ(ub2);
1419
1420 return (TREE_CMP(seq1, seq2));
1421 }
1422
1423 struct ubl_cbdata {
1424 uberblock_t *ubl_ubbest; /* Best uberblock */
1425 vdev_t *ubl_vd; /* vdev associated with the above */
1426 };
1427
1428 static void
vdev_uberblock_load_done(zio_t * zio)1429 vdev_uberblock_load_done(zio_t *zio)
1430 {
1431 vdev_t *vd = zio->io_vd;
1432 spa_t *spa = zio->io_spa;
1433 zio_t *rio = zio->io_private;
1434 uberblock_t *ub = abd_to_buf(zio->io_abd);
1435 struct ubl_cbdata *cbp = rio->io_private;
1436
1437 ASSERT3U(zio->io_size, ==, VDEV_UBERBLOCK_SIZE(vd));
1438
1439 if (zio->io_error == 0 && uberblock_verify(ub) == 0) {
1440 mutex_enter(&rio->io_lock);
1441 if (ub->ub_txg <= spa->spa_load_max_txg &&
1442 vdev_uberblock_compare(ub, cbp->ubl_ubbest) > 0) {
1443 /*
1444 * Keep track of the vdev in which this uberblock
1445 * was found. We will use this information later
1446 * to obtain the config nvlist associated with
1447 * this uberblock.
1448 */
1449 *cbp->ubl_ubbest = *ub;
1450 cbp->ubl_vd = vd;
1451 }
1452 mutex_exit(&rio->io_lock);
1453 }
1454
1455 abd_free(zio->io_abd);
1456 }
1457
1458 static void
vdev_uberblock_load_impl(zio_t * zio,vdev_t * vd,int flags,struct ubl_cbdata * cbp)1459 vdev_uberblock_load_impl(zio_t *zio, vdev_t *vd, int flags,
1460 struct ubl_cbdata *cbp)
1461 {
1462 for (int c = 0; c < vd->vdev_children; c++)
1463 vdev_uberblock_load_impl(zio, vd->vdev_child[c], flags, cbp);
1464
1465 if (vd->vdev_ops->vdev_op_leaf && vdev_readable(vd)) {
1466 for (int l = 0; l < VDEV_LABELS; l++) {
1467 for (int n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) {
1468 vdev_label_read(zio, vd, l,
1469 abd_alloc_linear(VDEV_UBERBLOCK_SIZE(vd),
1470 B_TRUE), VDEV_UBERBLOCK_OFFSET(vd, n),
1471 VDEV_UBERBLOCK_SIZE(vd),
1472 vdev_uberblock_load_done, zio, flags);
1473 }
1474 }
1475 }
1476 }
1477
1478 /*
1479 * Reads the 'best' uberblock from disk along with its associated
1480 * configuration. First, we read the uberblock array of each label of each
1481 * vdev, keeping track of the uberblock with the highest txg in each array.
1482 * Then, we read the configuration from the same vdev as the best uberblock.
1483 */
1484 void
vdev_uberblock_load(vdev_t * rvd,uberblock_t * ub,nvlist_t ** config)1485 vdev_uberblock_load(vdev_t *rvd, uberblock_t *ub, nvlist_t **config)
1486 {
1487 zio_t *zio;
1488 spa_t *spa = rvd->vdev_spa;
1489 struct ubl_cbdata cb;
1490 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL |
1491 ZIO_FLAG_SPECULATIVE | ZIO_FLAG_TRYHARD;
1492
1493 ASSERT(ub);
1494 ASSERT(config);
1495
1496 bzero(ub, sizeof (uberblock_t));
1497 *config = NULL;
1498
1499 cb.ubl_ubbest = ub;
1500 cb.ubl_vd = NULL;
1501
1502 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1503 zio = zio_root(spa, NULL, &cb, flags);
1504 vdev_uberblock_load_impl(zio, rvd, flags, &cb);
1505 (void) zio_wait(zio);
1506
1507 /*
1508 * It's possible that the best uberblock was discovered on a label
1509 * that has a configuration which was written in a future txg.
1510 * Search all labels on this vdev to find the configuration that
1511 * matches the txg for our uberblock.
1512 */
1513 if (cb.ubl_vd != NULL) {
1514 vdev_dbgmsg(cb.ubl_vd, "best uberblock found for spa %s. "
1515 "txg %llu", spa->spa_name, (u_longlong_t)ub->ub_txg);
1516
1517 *config = vdev_label_read_config(cb.ubl_vd, ub->ub_txg);
1518 if (*config == NULL && spa->spa_extreme_rewind) {
1519 vdev_dbgmsg(cb.ubl_vd, "failed to read label config. "
1520 "Trying again without txg restrictions.");
1521 *config = vdev_label_read_config(cb.ubl_vd, UINT64_MAX);
1522 }
1523 if (*config == NULL) {
1524 vdev_dbgmsg(cb.ubl_vd, "failed to read label config");
1525 }
1526 }
1527 spa_config_exit(spa, SCL_ALL, FTAG);
1528 }
1529
1530 /*
1531 * On success, increment root zio's count of good writes.
1532 * We only get credit for writes to known-visible vdevs; see spa_vdev_add().
1533 */
1534 static void
vdev_uberblock_sync_done(zio_t * zio)1535 vdev_uberblock_sync_done(zio_t *zio)
1536 {
1537 uint64_t *good_writes = zio->io_private;
1538
1539 if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0)
1540 atomic_inc_64(good_writes);
1541 }
1542
1543 /*
1544 * Write the uberblock to all labels of all leaves of the specified vdev.
1545 */
1546 static void
vdev_uberblock_sync(zio_t * zio,uint64_t * good_writes,uberblock_t * ub,vdev_t * vd,int flags)1547 vdev_uberblock_sync(zio_t *zio, uint64_t *good_writes,
1548 uberblock_t *ub, vdev_t *vd, int flags)
1549 {
1550 for (uint64_t c = 0; c < vd->vdev_children; c++) {
1551 vdev_uberblock_sync(zio, good_writes,
1552 ub, vd->vdev_child[c], flags);
1553 }
1554
1555 if (!vd->vdev_ops->vdev_op_leaf)
1556 return;
1557
1558 if (!vdev_writeable(vd))
1559 return;
1560
1561 int m = spa_multihost(vd->vdev_spa) ? MMP_BLOCKS_PER_LABEL : 0;
1562 int n = ub->ub_txg % (VDEV_UBERBLOCK_COUNT(vd) - m);
1563
1564 /* Copy the uberblock_t into the ABD */
1565 abd_t *ub_abd = abd_alloc_for_io(VDEV_UBERBLOCK_SIZE(vd), B_TRUE);
1566 abd_zero(ub_abd, VDEV_UBERBLOCK_SIZE(vd));
1567 abd_copy_from_buf(ub_abd, ub, sizeof (uberblock_t));
1568
1569 for (int l = 0; l < VDEV_LABELS; l++)
1570 vdev_label_write(zio, vd, l, ub_abd,
1571 VDEV_UBERBLOCK_OFFSET(vd, n), VDEV_UBERBLOCK_SIZE(vd),
1572 vdev_uberblock_sync_done, good_writes,
1573 flags | ZIO_FLAG_DONT_PROPAGATE);
1574
1575 abd_free(ub_abd);
1576 }
1577
1578 /* Sync the uberblocks to all vdevs in svd[] */
1579 int
vdev_uberblock_sync_list(vdev_t ** svd,int svdcount,uberblock_t * ub,int flags)1580 vdev_uberblock_sync_list(vdev_t **svd, int svdcount, uberblock_t *ub, int flags)
1581 {
1582 spa_t *spa = svd[0]->vdev_spa;
1583 zio_t *zio;
1584 uint64_t good_writes = 0;
1585
1586 zio = zio_root(spa, NULL, NULL, flags);
1587
1588 for (int v = 0; v < svdcount; v++)
1589 vdev_uberblock_sync(zio, &good_writes, ub, svd[v], flags);
1590
1591 (void) zio_wait(zio);
1592
1593 /*
1594 * Flush the uberblocks to disk. This ensures that the odd labels
1595 * are no longer needed (because the new uberblocks and the even
1596 * labels are safely on disk), so it is safe to overwrite them.
1597 */
1598 zio = zio_root(spa, NULL, NULL, flags);
1599
1600 for (int v = 0; v < svdcount; v++) {
1601 if (vdev_writeable(svd[v])) {
1602 zio_flush(zio, svd[v]);
1603 }
1604 }
1605
1606 (void) zio_wait(zio);
1607
1608 return (good_writes >= 1 ? 0 : EIO);
1609 }
1610
1611 /*
1612 * On success, increment the count of good writes for our top-level vdev.
1613 */
1614 static void
vdev_label_sync_done(zio_t * zio)1615 vdev_label_sync_done(zio_t *zio)
1616 {
1617 uint64_t *good_writes = zio->io_private;
1618
1619 if (zio->io_error == 0)
1620 atomic_inc_64(good_writes);
1621 }
1622
1623 /*
1624 * If there weren't enough good writes, indicate failure to the parent.
1625 */
1626 static void
vdev_label_sync_top_done(zio_t * zio)1627 vdev_label_sync_top_done(zio_t *zio)
1628 {
1629 uint64_t *good_writes = zio->io_private;
1630
1631 if (*good_writes == 0)
1632 zio->io_error = SET_ERROR(EIO);
1633
1634 kmem_free(good_writes, sizeof (uint64_t));
1635 }
1636
1637 /*
1638 * We ignore errors for log and cache devices, simply free the private data.
1639 */
1640 static void
vdev_label_sync_ignore_done(zio_t * zio)1641 vdev_label_sync_ignore_done(zio_t *zio)
1642 {
1643 kmem_free(zio->io_private, sizeof (uint64_t));
1644 }
1645
1646 /*
1647 * Write all even or odd labels to all leaves of the specified vdev.
1648 */
1649 static void
vdev_label_sync(zio_t * zio,uint64_t * good_writes,vdev_t * vd,int l,uint64_t txg,int flags)1650 vdev_label_sync(zio_t *zio, uint64_t *good_writes,
1651 vdev_t *vd, int l, uint64_t txg, int flags)
1652 {
1653 nvlist_t *label;
1654 vdev_phys_t *vp;
1655 abd_t *vp_abd;
1656 char *buf;
1657 size_t buflen;
1658
1659 for (int c = 0; c < vd->vdev_children; c++) {
1660 vdev_label_sync(zio, good_writes,
1661 vd->vdev_child[c], l, txg, flags);
1662 }
1663
1664 if (!vd->vdev_ops->vdev_op_leaf)
1665 return;
1666
1667 if (!vdev_writeable(vd))
1668 return;
1669
1670 /*
1671 * Generate a label describing the top-level config to which we belong.
1672 */
1673 label = spa_config_generate(vd->vdev_spa, vd, txg, B_FALSE);
1674
1675 vp_abd = abd_alloc_linear(sizeof (vdev_phys_t), B_TRUE);
1676 abd_zero(vp_abd, sizeof (vdev_phys_t));
1677 vp = abd_to_buf(vp_abd);
1678
1679 buf = vp->vp_nvlist;
1680 buflen = sizeof (vp->vp_nvlist);
1681
1682 if (nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP) == 0) {
1683 for (; l < VDEV_LABELS; l += 2) {
1684 vdev_label_write(zio, vd, l, vp_abd,
1685 offsetof(vdev_label_t, vl_vdev_phys),
1686 sizeof (vdev_phys_t),
1687 vdev_label_sync_done, good_writes,
1688 flags | ZIO_FLAG_DONT_PROPAGATE);
1689 }
1690 }
1691
1692 abd_free(vp_abd);
1693 nvlist_free(label);
1694 }
1695
1696 int
vdev_label_sync_list(spa_t * spa,int l,uint64_t txg,int flags)1697 vdev_label_sync_list(spa_t *spa, int l, uint64_t txg, int flags)
1698 {
1699 list_t *dl = &spa->spa_config_dirty_list;
1700 vdev_t *vd;
1701 zio_t *zio;
1702 int error;
1703
1704 /*
1705 * Write the new labels to disk.
1706 */
1707 zio = zio_root(spa, NULL, NULL, flags);
1708
1709 for (vd = list_head(dl); vd != NULL; vd = list_next(dl, vd)) {
1710 uint64_t *good_writes = kmem_zalloc(sizeof (uint64_t),
1711 KM_SLEEP);
1712
1713 ASSERT(!vd->vdev_ishole);
1714
1715 zio_t *vio = zio_null(zio, spa, NULL,
1716 (vd->vdev_islog || vd->vdev_aux != NULL) ?
1717 vdev_label_sync_ignore_done : vdev_label_sync_top_done,
1718 good_writes, flags);
1719 vdev_label_sync(vio, good_writes, vd, l, txg, flags);
1720 zio_nowait(vio);
1721 }
1722
1723 error = zio_wait(zio);
1724
1725 /*
1726 * Flush the new labels to disk.
1727 */
1728 zio = zio_root(spa, NULL, NULL, flags);
1729
1730 for (vd = list_head(dl); vd != NULL; vd = list_next(dl, vd))
1731 zio_flush(zio, vd);
1732
1733 (void) zio_wait(zio);
1734
1735 return (error);
1736 }
1737
1738 /*
1739 * Sync the uberblock and any changes to the vdev configuration.
1740 *
1741 * The order of operations is carefully crafted to ensure that
1742 * if the system panics or loses power at any time, the state on disk
1743 * is still transactionally consistent. The in-line comments below
1744 * describe the failure semantics at each stage.
1745 *
1746 * Moreover, vdev_config_sync() is designed to be idempotent: if it fails
1747 * at any time, you can just call it again, and it will resume its work.
1748 */
1749 int
vdev_config_sync(vdev_t ** svd,int svdcount,uint64_t txg)1750 vdev_config_sync(vdev_t **svd, int svdcount, uint64_t txg)
1751 {
1752 spa_t *spa = svd[0]->vdev_spa;
1753 uberblock_t *ub = &spa->spa_uberblock;
1754 int error = 0;
1755 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL;
1756
1757 ASSERT(svdcount != 0);
1758 retry:
1759 /*
1760 * Normally, we don't want to try too hard to write every label and
1761 * uberblock. If there is a flaky disk, we don't want the rest of the
1762 * sync process to block while we retry. But if we can't write a
1763 * single label out, we should retry with ZIO_FLAG_TRYHARD before
1764 * bailing out and declaring the pool faulted.
1765 */
1766 if (error != 0) {
1767 if ((flags & ZIO_FLAG_TRYHARD) != 0)
1768 return (error);
1769 flags |= ZIO_FLAG_TRYHARD;
1770 }
1771
1772 ASSERT(ub->ub_txg <= txg);
1773
1774 /*
1775 * If this isn't a resync due to I/O errors,
1776 * and nothing changed in this transaction group,
1777 * and the vdev configuration hasn't changed,
1778 * then there's nothing to do.
1779 */
1780 if (ub->ub_txg < txg) {
1781 boolean_t changed = uberblock_update(ub, spa->spa_root_vdev,
1782 txg, spa->spa_mmp.mmp_delay);
1783
1784 if (!changed && list_is_empty(&spa->spa_config_dirty_list))
1785 return (0);
1786 }
1787
1788 if (txg > spa_freeze_txg(spa))
1789 return (0);
1790
1791 ASSERT(txg <= spa->spa_final_txg);
1792
1793 /*
1794 * Flush the write cache of every disk that's been written to
1795 * in this transaction group. This ensures that all blocks
1796 * written in this txg will be committed to stable storage
1797 * before any uberblock that references them.
1798 */
1799 zio_t *zio = zio_root(spa, NULL, NULL, flags);
1800
1801 for (vdev_t *vd =
1802 txg_list_head(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)); vd != NULL;
1803 vd = txg_list_next(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg)))
1804 zio_flush(zio, vd);
1805
1806 (void) zio_wait(zio);
1807
1808 /*
1809 * Sync out the even labels (L0, L2) for every dirty vdev. If the
1810 * system dies in the middle of this process, that's OK: all of the
1811 * even labels that made it to disk will be newer than any uberblock,
1812 * and will therefore be considered invalid. The odd labels (L1, L3),
1813 * which have not yet been touched, will still be valid. We flush
1814 * the new labels to disk to ensure that all even-label updates
1815 * are committed to stable storage before the uberblock update.
1816 */
1817 if ((error = vdev_label_sync_list(spa, 0, txg, flags)) != 0) {
1818 if ((flags & ZIO_FLAG_TRYHARD) != 0) {
1819 zfs_dbgmsg("vdev_label_sync_list() returned error %d "
1820 "for pool '%s' when syncing out the even labels "
1821 "of dirty vdevs", error, spa_name(spa));
1822 }
1823 goto retry;
1824 }
1825
1826 /*
1827 * Sync the uberblocks to all vdevs in svd[].
1828 * If the system dies in the middle of this step, there are two cases
1829 * to consider, and the on-disk state is consistent either way:
1830 *
1831 * (1) If none of the new uberblocks made it to disk, then the
1832 * previous uberblock will be the newest, and the odd labels
1833 * (which had not yet been touched) will be valid with respect
1834 * to that uberblock.
1835 *
1836 * (2) If one or more new uberblocks made it to disk, then they
1837 * will be the newest, and the even labels (which had all
1838 * been successfully committed) will be valid with respect
1839 * to the new uberblocks.
1840 */
1841 if ((error = vdev_uberblock_sync_list(svd, svdcount, ub, flags)) != 0) {
1842 if ((flags & ZIO_FLAG_TRYHARD) != 0) {
1843 zfs_dbgmsg("vdev_uberblock_sync_list() returned error "
1844 "%d for pool '%s'", error, spa_name(spa));
1845 }
1846 goto retry;
1847 }
1848
1849 if (spa_multihost(spa))
1850 mmp_update_uberblock(spa, ub);
1851
1852 /*
1853 * Sync out odd labels for every dirty vdev. If the system dies
1854 * in the middle of this process, the even labels and the new
1855 * uberblocks will suffice to open the pool. The next time
1856 * the pool is opened, the first thing we'll do -- before any
1857 * user data is modified -- is mark every vdev dirty so that
1858 * all labels will be brought up to date. We flush the new labels
1859 * to disk to ensure that all odd-label updates are committed to
1860 * stable storage before the next transaction group begins.
1861 */
1862 if ((error = vdev_label_sync_list(spa, 1, txg, flags)) != 0) {
1863 if ((flags & ZIO_FLAG_TRYHARD) != 0) {
1864 zfs_dbgmsg("vdev_label_sync_list() returned error %d "
1865 "for pool '%s' when syncing out the odd labels of "
1866 "dirty vdevs", error, spa_name(spa));
1867 }
1868 goto retry;
1869 }
1870
1871 return (0);
1872 }
1873