]>
Commit | Line | Data |
---|---|---|
34dc7c2f BB |
1 | /* |
2 | * CDDL HEADER START | |
3 | * | |
4 | * The contents of this file are subject to the terms of the | |
5 | * Common Development and Distribution License (the "License"). | |
6 | * You may not use this file except in compliance with the License. | |
7 | * | |
8 | * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE | |
9 | * or http://www.opensolaris.org/os/licensing. | |
10 | * See the License for the specific language governing permissions | |
11 | * and limitations under the License. | |
12 | * | |
13 | * When distributing Covered Code, include this CDDL HEADER in each | |
14 | * file and include the License file at usr/src/OPENSOLARIS.LICENSE. | |
15 | * If applicable, add the following below this CDDL HEADER, with the | |
16 | * fields enclosed by brackets "[]" replaced with your own identifying | |
17 | * information: Portions Copyright [yyyy] [name of copyright owner] | |
18 | * | |
19 | * CDDL HEADER END | |
20 | */ | |
21 | /* | |
22 | * Copyright 2007 Sun Microsystems, Inc. All rights reserved. | |
23 | * Use is subject to license terms. | |
24 | */ | |
25 | ||
26 | #pragma ident "@(#)vdev_label.c 1.18 07/12/12 SMI" | |
27 | ||
28 | /* | |
29 | * Virtual Device Labels | |
30 | * --------------------- | |
31 | * | |
32 | * The vdev label serves several distinct purposes: | |
33 | * | |
34 | * 1. Uniquely identify this device as part of a ZFS pool and confirm its | |
35 | * identity within the pool. | |
36 | * | |
37 | * 2. Verify that all the devices given in a configuration are present | |
38 | * within the pool. | |
39 | * | |
40 | * 3. Determine the uberblock for the pool. | |
41 | * | |
42 | * 4. In case of an import operation, determine the configuration of the | |
43 | * toplevel vdev of which it is a part. | |
44 | * | |
45 | * 5. If an import operation cannot find all the devices in the pool, | |
46 | * provide enough information to the administrator to determine which | |
47 | * devices are missing. | |
48 | * | |
49 | * It is important to note that while the kernel is responsible for writing the | |
50 | * label, it only consumes the information in the first three cases. The | |
51 | * latter information is only consumed in userland when determining the | |
52 | * configuration to import a pool. | |
53 | * | |
54 | * | |
55 | * Label Organization | |
56 | * ------------------ | |
57 | * | |
58 | * Before describing the contents of the label, it's important to understand how | |
59 | * the labels are written and updated with respect to the uberblock. | |
60 | * | |
61 | * When the pool configuration is altered, either because it was newly created | |
62 | * or a device was added, we want to update all the labels such that we can deal | |
63 | * with fatal failure at any point. To this end, each disk has two labels which | |
64 | * are updated before and after the uberblock is synced. Assuming we have | |
65 | * labels and an uberblock with the following transaction groups: | |
66 | * | |
67 | * L1 UB L2 | |
68 | * +------+ +------+ +------+ | |
69 | * | | | | | | | |
70 | * | t10 | | t10 | | t10 | | |
71 | * | | | | | | | |
72 | * +------+ +------+ +------+ | |
73 | * | |
74 | * In this stable state, the labels and the uberblock were all updated within | |
75 | * the same transaction group (10). Each label is mirrored and checksummed, so | |
76 | * that we can detect when we fail partway through writing the label. | |
77 | * | |
78 | * In order to identify which labels are valid, the labels are written in the | |
79 | * following manner: | |
80 | * | |
81 | * 1. For each vdev, update 'L1' to the new label | |
82 | * 2. Update the uberblock | |
83 | * 3. For each vdev, update 'L2' to the new label | |
84 | * | |
85 | * Given arbitrary failure, we can determine the correct label to use based on | |
86 | * the transaction group. If we fail after updating L1 but before updating the | |
87 | * UB, we will notice that L1's transaction group is greater than the uberblock, | |
88 | * so L2 must be valid. If we fail after writing the uberblock but before | |
89 | * writing L2, we will notice that L2's transaction group is less than L1, and | |
90 | * therefore L1 is valid. | |
91 | * | |
92 | * Another added complexity is that not every label is updated when the config | |
93 | * is synced. If we add a single device, we do not want to have to re-write | |
94 | * every label for every device in the pool. This means that both L1 and L2 may | |
95 | * be older than the pool uberblock, because the necessary information is stored | |
96 | * on another vdev. | |
97 | * | |
98 | * | |
99 | * On-disk Format | |
100 | * -------------- | |
101 | * | |
102 | * The vdev label consists of two distinct parts, and is wrapped within the | |
103 | * vdev_label_t structure. The label includes 8k of padding to permit legacy | |
104 | * VTOC disk labels, but is otherwise ignored. | |
105 | * | |
106 | * The first half of the label is a packed nvlist which contains pool wide | |
107 | * properties, per-vdev properties, and configuration information. It is | |
108 | * described in more detail below. | |
109 | * | |
110 | * The latter half of the label consists of a redundant array of uberblocks. | |
111 | * These uberblocks are updated whenever a transaction group is committed, | |
112 | * or when the configuration is updated. When a pool is loaded, we scan each | |
113 | * vdev for the 'best' uberblock. | |
114 | * | |
115 | * | |
116 | * Configuration Information | |
117 | * ------------------------- | |
118 | * | |
119 | * The nvlist describing the pool and vdev contains the following elements: | |
120 | * | |
121 | * version ZFS on-disk version | |
122 | * name Pool name | |
123 | * state Pool state | |
124 | * txg Transaction group in which this label was written | |
125 | * pool_guid Unique identifier for this pool | |
126 | * vdev_tree An nvlist describing vdev tree. | |
127 | * | |
128 | * Each leaf device label also contains the following: | |
129 | * | |
130 | * top_guid Unique ID for top-level vdev in which this is contained | |
131 | * guid Unique ID for the leaf vdev | |
132 | * | |
133 | * The 'vs' configuration follows the format described in 'spa_config.c'. | |
134 | */ | |
135 | ||
136 | #include <sys/zfs_context.h> | |
137 | #include <sys/spa.h> | |
138 | #include <sys/spa_impl.h> | |
139 | #include <sys/dmu.h> | |
140 | #include <sys/zap.h> | |
141 | #include <sys/vdev.h> | |
142 | #include <sys/vdev_impl.h> | |
143 | #include <sys/uberblock_impl.h> | |
144 | #include <sys/metaslab.h> | |
145 | #include <sys/zio.h> | |
146 | #include <sys/fs/zfs.h> | |
147 | ||
148 | /* | |
149 | * Basic routines to read and write from a vdev label. | |
150 | * Used throughout the rest of this file. | |
151 | */ | |
152 | uint64_t | |
153 | vdev_label_offset(uint64_t psize, int l, uint64_t offset) | |
154 | { | |
155 | ASSERT(offset < sizeof (vdev_label_t)); | |
156 | ASSERT(P2PHASE_TYPED(psize, sizeof (vdev_label_t), uint64_t) == 0); | |
157 | ||
158 | return (offset + l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? | |
159 | 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); | |
160 | } | |
161 | ||
162 | static void | |
163 | vdev_label_read(zio_t *zio, vdev_t *vd, int l, void *buf, uint64_t offset, | |
164 | uint64_t size, zio_done_func_t *done, void *private) | |
165 | { | |
166 | ASSERT(vd->vdev_children == 0); | |
167 | ||
168 | zio_nowait(zio_read_phys(zio, vd, | |
169 | vdev_label_offset(vd->vdev_psize, l, offset), | |
170 | size, buf, ZIO_CHECKSUM_LABEL, done, private, | |
171 | ZIO_PRIORITY_SYNC_READ, | |
172 | ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, | |
173 | B_TRUE)); | |
174 | } | |
175 | ||
176 | static void | |
177 | vdev_label_write(zio_t *zio, vdev_t *vd, int l, void *buf, uint64_t offset, | |
178 | uint64_t size, zio_done_func_t *done, void *private, int flags) | |
179 | { | |
180 | ASSERT(vd->vdev_children == 0); | |
181 | ||
182 | zio_nowait(zio_write_phys(zio, vd, | |
183 | vdev_label_offset(vd->vdev_psize, l, offset), | |
184 | size, buf, ZIO_CHECKSUM_LABEL, done, private, | |
185 | ZIO_PRIORITY_SYNC_WRITE, flags, B_TRUE)); | |
186 | } | |
187 | ||
188 | /* | |
189 | * Generate the nvlist representing this vdev's config. | |
190 | */ | |
191 | nvlist_t * | |
192 | vdev_config_generate(spa_t *spa, vdev_t *vd, boolean_t getstats, | |
193 | boolean_t isspare, boolean_t isl2cache) | |
194 | { | |
195 | nvlist_t *nv = NULL; | |
196 | ||
197 | VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); | |
198 | ||
199 | VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_TYPE, | |
200 | vd->vdev_ops->vdev_op_type) == 0); | |
201 | if (!isspare && !isl2cache) | |
202 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ID, vd->vdev_id) | |
203 | == 0); | |
204 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, vd->vdev_guid) == 0); | |
205 | ||
206 | if (vd->vdev_path != NULL) | |
207 | VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_PATH, | |
208 | vd->vdev_path) == 0); | |
209 | ||
210 | if (vd->vdev_devid != NULL) | |
211 | VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_DEVID, | |
212 | vd->vdev_devid) == 0); | |
213 | ||
214 | if (vd->vdev_physpath != NULL) | |
215 | VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_PHYS_PATH, | |
216 | vd->vdev_physpath) == 0); | |
217 | ||
218 | if (vd->vdev_nparity != 0) { | |
219 | ASSERT(strcmp(vd->vdev_ops->vdev_op_type, | |
220 | VDEV_TYPE_RAIDZ) == 0); | |
221 | ||
222 | /* | |
223 | * Make sure someone hasn't managed to sneak a fancy new vdev | |
224 | * into a crufty old storage pool. | |
225 | */ | |
226 | ASSERT(vd->vdev_nparity == 1 || | |
227 | (vd->vdev_nparity == 2 && | |
228 | spa_version(spa) >= SPA_VERSION_RAID6)); | |
229 | ||
230 | /* | |
231 | * Note that we'll add the nparity tag even on storage pools | |
232 | * that only support a single parity device -- older software | |
233 | * will just ignore it. | |
234 | */ | |
235 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, | |
236 | vd->vdev_nparity) == 0); | |
237 | } | |
238 | ||
239 | if (vd->vdev_wholedisk != -1ULL) | |
240 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK, | |
241 | vd->vdev_wholedisk) == 0); | |
242 | ||
243 | if (vd->vdev_not_present) | |
244 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT, 1) == 0); | |
245 | ||
246 | if (vd->vdev_isspare) | |
247 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1) == 0); | |
248 | ||
249 | if (!isspare && !isl2cache && vd == vd->vdev_top) { | |
250 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY, | |
251 | vd->vdev_ms_array) == 0); | |
252 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_SHIFT, | |
253 | vd->vdev_ms_shift) == 0); | |
254 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ASHIFT, | |
255 | vd->vdev_ashift) == 0); | |
256 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ASIZE, | |
257 | vd->vdev_asize) == 0); | |
258 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_IS_LOG, | |
259 | vd->vdev_islog) == 0); | |
260 | } | |
261 | ||
262 | if (vd->vdev_dtl.smo_object != 0) | |
263 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_DTL, | |
264 | vd->vdev_dtl.smo_object) == 0); | |
265 | ||
266 | if (getstats) { | |
267 | vdev_stat_t vs; | |
268 | vdev_get_stats(vd, &vs); | |
269 | VERIFY(nvlist_add_uint64_array(nv, ZPOOL_CONFIG_STATS, | |
270 | (uint64_t *)&vs, sizeof (vs) / sizeof (uint64_t)) == 0); | |
271 | } | |
272 | ||
273 | if (!vd->vdev_ops->vdev_op_leaf) { | |
274 | nvlist_t **child; | |
275 | int c; | |
276 | ||
277 | child = kmem_alloc(vd->vdev_children * sizeof (nvlist_t *), | |
278 | KM_SLEEP); | |
279 | ||
280 | for (c = 0; c < vd->vdev_children; c++) | |
281 | child[c] = vdev_config_generate(spa, vd->vdev_child[c], | |
282 | getstats, isspare, isl2cache); | |
283 | ||
284 | VERIFY(nvlist_add_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, | |
285 | child, vd->vdev_children) == 0); | |
286 | ||
287 | for (c = 0; c < vd->vdev_children; c++) | |
288 | nvlist_free(child[c]); | |
289 | ||
290 | kmem_free(child, vd->vdev_children * sizeof (nvlist_t *)); | |
291 | ||
292 | } else { | |
293 | if (vd->vdev_offline && !vd->vdev_tmpoffline) | |
294 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_OFFLINE, | |
295 | B_TRUE) == 0); | |
296 | if (vd->vdev_faulted) | |
297 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_FAULTED, | |
298 | B_TRUE) == 0); | |
299 | if (vd->vdev_degraded) | |
300 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_DEGRADED, | |
301 | B_TRUE) == 0); | |
302 | if (vd->vdev_removed) | |
303 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_REMOVED, | |
304 | B_TRUE) == 0); | |
305 | if (vd->vdev_unspare) | |
306 | VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_UNSPARE, | |
307 | B_TRUE) == 0); | |
308 | } | |
309 | ||
310 | return (nv); | |
311 | } | |
312 | ||
313 | nvlist_t * | |
314 | vdev_label_read_config(vdev_t *vd) | |
315 | { | |
316 | spa_t *spa = vd->vdev_spa; | |
317 | nvlist_t *config = NULL; | |
318 | vdev_phys_t *vp; | |
319 | zio_t *zio; | |
320 | int l; | |
321 | ||
322 | ASSERT(spa_config_held(spa, RW_READER) || | |
323 | spa_config_held(spa, RW_WRITER)); | |
324 | ||
325 | if (!vdev_readable(vd)) | |
326 | return (NULL); | |
327 | ||
328 | vp = zio_buf_alloc(sizeof (vdev_phys_t)); | |
329 | ||
330 | for (l = 0; l < VDEV_LABELS; l++) { | |
331 | ||
332 | zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL | | |
333 | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CONFIG_HELD); | |
334 | ||
335 | vdev_label_read(zio, vd, l, vp, | |
336 | offsetof(vdev_label_t, vl_vdev_phys), | |
337 | sizeof (vdev_phys_t), NULL, NULL); | |
338 | ||
339 | if (zio_wait(zio) == 0 && | |
340 | nvlist_unpack(vp->vp_nvlist, sizeof (vp->vp_nvlist), | |
341 | &config, 0) == 0) | |
342 | break; | |
343 | ||
344 | if (config != NULL) { | |
345 | nvlist_free(config); | |
346 | config = NULL; | |
347 | } | |
348 | } | |
349 | ||
350 | zio_buf_free(vp, sizeof (vdev_phys_t)); | |
351 | ||
352 | return (config); | |
353 | } | |
354 | ||
355 | /* | |
356 | * Determine if a device is in use. The 'spare_guid' parameter will be filled | |
357 | * in with the device guid if this spare is active elsewhere on the system. | |
358 | */ | |
359 | static boolean_t | |
360 | vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason, | |
361 | uint64_t *spare_guid, uint64_t *l2cache_guid) | |
362 | { | |
363 | spa_t *spa = vd->vdev_spa; | |
364 | uint64_t state, pool_guid, device_guid, txg, spare_pool; | |
365 | uint64_t vdtxg = 0; | |
366 | nvlist_t *label; | |
367 | ||
368 | if (spare_guid) | |
369 | *spare_guid = 0ULL; | |
370 | if (l2cache_guid) | |
371 | *l2cache_guid = 0ULL; | |
372 | ||
373 | /* | |
374 | * Read the label, if any, and perform some basic sanity checks. | |
375 | */ | |
376 | if ((label = vdev_label_read_config(vd)) == NULL) | |
377 | return (B_FALSE); | |
378 | ||
379 | (void) nvlist_lookup_uint64(label, ZPOOL_CONFIG_CREATE_TXG, | |
380 | &vdtxg); | |
381 | ||
382 | if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE, | |
383 | &state) != 0 || | |
384 | nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID, | |
385 | &device_guid) != 0) { | |
386 | nvlist_free(label); | |
387 | return (B_FALSE); | |
388 | } | |
389 | ||
390 | if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE && | |
391 | (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_GUID, | |
392 | &pool_guid) != 0 || | |
393 | nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG, | |
394 | &txg) != 0)) { | |
395 | nvlist_free(label); | |
396 | return (B_FALSE); | |
397 | } | |
398 | ||
399 | nvlist_free(label); | |
400 | ||
401 | /* | |
402 | * Check to see if this device indeed belongs to the pool it claims to | |
403 | * be a part of. The only way this is allowed is if the device is a hot | |
404 | * spare (which we check for later on). | |
405 | */ | |
406 | if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE && | |
407 | !spa_guid_exists(pool_guid, device_guid) && | |
408 | !spa_spare_exists(device_guid, NULL) && | |
409 | !spa_l2cache_exists(device_guid, NULL)) | |
410 | return (B_FALSE); | |
411 | ||
412 | /* | |
413 | * If the transaction group is zero, then this an initialized (but | |
414 | * unused) label. This is only an error if the create transaction | |
415 | * on-disk is the same as the one we're using now, in which case the | |
416 | * user has attempted to add the same vdev multiple times in the same | |
417 | * transaction. | |
418 | */ | |
419 | if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE && | |
420 | txg == 0 && vdtxg == crtxg) | |
421 | return (B_TRUE); | |
422 | ||
423 | /* | |
424 | * Check to see if this is a spare device. We do an explicit check for | |
425 | * spa_has_spare() here because it may be on our pending list of spares | |
426 | * to add. We also check if it is an l2cache device. | |
427 | */ | |
428 | if (spa_spare_exists(device_guid, &spare_pool) || | |
429 | spa_has_spare(spa, device_guid)) { | |
430 | if (spare_guid) | |
431 | *spare_guid = device_guid; | |
432 | ||
433 | switch (reason) { | |
434 | case VDEV_LABEL_CREATE: | |
435 | case VDEV_LABEL_L2CACHE: | |
436 | return (B_TRUE); | |
437 | ||
438 | case VDEV_LABEL_REPLACE: | |
439 | return (!spa_has_spare(spa, device_guid) || | |
440 | spare_pool != 0ULL); | |
441 | ||
442 | case VDEV_LABEL_SPARE: | |
443 | return (spa_has_spare(spa, device_guid)); | |
444 | } | |
445 | } | |
446 | ||
447 | /* | |
448 | * Check to see if this is an l2cache device. | |
449 | */ | |
450 | if (spa_l2cache_exists(device_guid, NULL)) | |
451 | return (B_TRUE); | |
452 | ||
453 | /* | |
454 | * If the device is marked ACTIVE, then this device is in use by another | |
455 | * pool on the system. | |
456 | */ | |
457 | return (state == POOL_STATE_ACTIVE); | |
458 | } | |
459 | ||
460 | /* | |
461 | * Initialize a vdev label. We check to make sure each leaf device is not in | |
462 | * use, and writable. We put down an initial label which we will later | |
463 | * overwrite with a complete label. Note that it's important to do this | |
464 | * sequentially, not in parallel, so that we catch cases of multiple use of the | |
465 | * same leaf vdev in the vdev we're creating -- e.g. mirroring a disk with | |
466 | * itself. | |
467 | */ | |
468 | int | |
469 | vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason) | |
470 | { | |
471 | spa_t *spa = vd->vdev_spa; | |
472 | nvlist_t *label; | |
473 | vdev_phys_t *vp; | |
474 | vdev_boot_header_t *vb; | |
475 | uberblock_t *ub; | |
476 | zio_t *zio; | |
477 | int l, c, n; | |
478 | char *buf; | |
479 | size_t buflen; | |
480 | int error; | |
481 | uint64_t spare_guid, l2cache_guid; | |
482 | int flags = ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL; | |
483 | ||
484 | ASSERT(spa_config_held(spa, RW_WRITER)); | |
485 | ||
486 | for (c = 0; c < vd->vdev_children; c++) | |
487 | if ((error = vdev_label_init(vd->vdev_child[c], | |
488 | crtxg, reason)) != 0) | |
489 | return (error); | |
490 | ||
491 | if (!vd->vdev_ops->vdev_op_leaf) | |
492 | return (0); | |
493 | ||
494 | /* | |
495 | * Dead vdevs cannot be initialized. | |
496 | */ | |
497 | if (vdev_is_dead(vd)) | |
498 | return (EIO); | |
499 | ||
500 | /* | |
501 | * Determine if the vdev is in use. | |
502 | */ | |
503 | if (reason != VDEV_LABEL_REMOVE && | |
504 | vdev_inuse(vd, crtxg, reason, &spare_guid, &l2cache_guid)) | |
505 | return (EBUSY); | |
506 | ||
507 | ASSERT(reason != VDEV_LABEL_REMOVE || | |
508 | vdev_inuse(vd, crtxg, reason, NULL, NULL)); | |
509 | ||
510 | /* | |
511 | * If this is a request to add or replace a spare or l2cache device | |
512 | * that is in use elsewhere on the system, then we must update the | |
513 | * guid (which was initialized to a random value) to reflect the | |
514 | * actual GUID (which is shared between multiple pools). | |
515 | */ | |
516 | if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_L2CACHE && | |
517 | spare_guid != 0ULL) { | |
518 | vdev_t *pvd = vd->vdev_parent; | |
519 | ||
520 | for (; pvd != NULL; pvd = pvd->vdev_parent) { | |
521 | pvd->vdev_guid_sum -= vd->vdev_guid; | |
522 | pvd->vdev_guid_sum += spare_guid; | |
523 | } | |
524 | ||
525 | vd->vdev_guid = vd->vdev_guid_sum = spare_guid; | |
526 | ||
527 | /* | |
528 | * If this is a replacement, then we want to fallthrough to the | |
529 | * rest of the code. If we're adding a spare, then it's already | |
530 | * labeled appropriately and we can just return. | |
531 | */ | |
532 | if (reason == VDEV_LABEL_SPARE) | |
533 | return (0); | |
534 | ASSERT(reason == VDEV_LABEL_REPLACE); | |
535 | } | |
536 | ||
537 | if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_SPARE && | |
538 | l2cache_guid != 0ULL) { | |
539 | vdev_t *pvd = vd->vdev_parent; | |
540 | ||
541 | for (; pvd != NULL; pvd = pvd->vdev_parent) { | |
542 | pvd->vdev_guid_sum -= vd->vdev_guid; | |
543 | pvd->vdev_guid_sum += l2cache_guid; | |
544 | } | |
545 | ||
546 | vd->vdev_guid = vd->vdev_guid_sum = l2cache_guid; | |
547 | ||
548 | /* | |
549 | * If this is a replacement, then we want to fallthrough to the | |
550 | * rest of the code. If we're adding an l2cache, then it's | |
551 | * already labeled appropriately and we can just return. | |
552 | */ | |
553 | if (reason == VDEV_LABEL_L2CACHE) | |
554 | return (0); | |
555 | ASSERT(reason == VDEV_LABEL_REPLACE); | |
556 | } | |
557 | ||
558 | /* | |
559 | * Initialize its label. | |
560 | */ | |
561 | vp = zio_buf_alloc(sizeof (vdev_phys_t)); | |
562 | bzero(vp, sizeof (vdev_phys_t)); | |
563 | ||
564 | /* | |
565 | * Generate a label describing the pool and our top-level vdev. | |
566 | * We mark it as being from txg 0 to indicate that it's not | |
567 | * really part of an active pool just yet. The labels will | |
568 | * be written again with a meaningful txg by spa_sync(). | |
569 | */ | |
570 | if (reason == VDEV_LABEL_SPARE || | |
571 | (reason == VDEV_LABEL_REMOVE && vd->vdev_isspare)) { | |
572 | /* | |
573 | * For inactive hot spares, we generate a special label that | |
574 | * identifies as a mutually shared hot spare. We write the | |
575 | * label if we are adding a hot spare, or if we are removing an | |
576 | * active hot spare (in which case we want to revert the | |
577 | * labels). | |
578 | */ | |
579 | VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0); | |
580 | ||
581 | VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION, | |
582 | spa_version(spa)) == 0); | |
583 | VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE, | |
584 | POOL_STATE_SPARE) == 0); | |
585 | VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID, | |
586 | vd->vdev_guid) == 0); | |
587 | } else if (reason == VDEV_LABEL_L2CACHE || | |
588 | (reason == VDEV_LABEL_REMOVE && vd->vdev_isl2cache)) { | |
589 | /* | |
590 | * For level 2 ARC devices, add a special label. | |
591 | */ | |
592 | VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0); | |
593 | ||
594 | VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION, | |
595 | spa_version(spa)) == 0); | |
596 | VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE, | |
597 | POOL_STATE_L2CACHE) == 0); | |
598 | VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID, | |
599 | vd->vdev_guid) == 0); | |
600 | } else { | |
601 | label = spa_config_generate(spa, vd, 0ULL, B_FALSE); | |
602 | ||
603 | /* | |
604 | * Add our creation time. This allows us to detect multiple | |
605 | * vdev uses as described above, and automatically expires if we | |
606 | * fail. | |
607 | */ | |
608 | VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_CREATE_TXG, | |
609 | crtxg) == 0); | |
610 | } | |
611 | ||
612 | buf = vp->vp_nvlist; | |
613 | buflen = sizeof (vp->vp_nvlist); | |
614 | ||
615 | error = nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP); | |
616 | if (error != 0) { | |
617 | nvlist_free(label); | |
618 | zio_buf_free(vp, sizeof (vdev_phys_t)); | |
619 | /* EFAULT means nvlist_pack ran out of room */ | |
620 | return (error == EFAULT ? ENAMETOOLONG : EINVAL); | |
621 | } | |
622 | ||
623 | /* | |
624 | * Initialize boot block header. | |
625 | */ | |
626 | vb = zio_buf_alloc(sizeof (vdev_boot_header_t)); | |
627 | bzero(vb, sizeof (vdev_boot_header_t)); | |
628 | vb->vb_magic = VDEV_BOOT_MAGIC; | |
629 | vb->vb_version = VDEV_BOOT_VERSION; | |
630 | vb->vb_offset = VDEV_BOOT_OFFSET; | |
631 | vb->vb_size = VDEV_BOOT_SIZE; | |
632 | ||
633 | /* | |
634 | * Initialize uberblock template. | |
635 | */ | |
636 | ub = zio_buf_alloc(VDEV_UBERBLOCK_SIZE(vd)); | |
637 | bzero(ub, VDEV_UBERBLOCK_SIZE(vd)); | |
638 | *ub = spa->spa_uberblock; | |
639 | ub->ub_txg = 0; | |
640 | ||
641 | /* | |
642 | * Write everything in parallel. | |
643 | */ | |
644 | zio = zio_root(spa, NULL, NULL, flags); | |
645 | ||
646 | for (l = 0; l < VDEV_LABELS; l++) { | |
647 | ||
648 | vdev_label_write(zio, vd, l, vp, | |
649 | offsetof(vdev_label_t, vl_vdev_phys), | |
650 | sizeof (vdev_phys_t), NULL, NULL, flags); | |
651 | ||
652 | vdev_label_write(zio, vd, l, vb, | |
653 | offsetof(vdev_label_t, vl_boot_header), | |
654 | sizeof (vdev_boot_header_t), NULL, NULL, flags); | |
655 | ||
656 | for (n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) { | |
657 | vdev_label_write(zio, vd, l, ub, | |
658 | VDEV_UBERBLOCK_OFFSET(vd, n), | |
659 | VDEV_UBERBLOCK_SIZE(vd), NULL, NULL, flags); | |
660 | } | |
661 | } | |
662 | ||
663 | error = zio_wait(zio); | |
664 | ||
665 | nvlist_free(label); | |
666 | zio_buf_free(ub, VDEV_UBERBLOCK_SIZE(vd)); | |
667 | zio_buf_free(vb, sizeof (vdev_boot_header_t)); | |
668 | zio_buf_free(vp, sizeof (vdev_phys_t)); | |
669 | ||
670 | /* | |
671 | * If this vdev hasn't been previously identified as a spare, then we | |
672 | * mark it as such only if a) we are labeling it as a spare, or b) it | |
673 | * exists as a spare elsewhere in the system. Do the same for | |
674 | * level 2 ARC devices. | |
675 | */ | |
676 | if (error == 0 && !vd->vdev_isspare && | |
677 | (reason == VDEV_LABEL_SPARE || | |
678 | spa_spare_exists(vd->vdev_guid, NULL))) | |
679 | spa_spare_add(vd); | |
680 | ||
681 | if (error == 0 && !vd->vdev_isl2cache && | |
682 | (reason == VDEV_LABEL_L2CACHE || | |
683 | spa_l2cache_exists(vd->vdev_guid, NULL))) | |
684 | spa_l2cache_add(vd); | |
685 | ||
686 | return (error); | |
687 | } | |
688 | ||
689 | /* | |
690 | * ========================================================================== | |
691 | * uberblock load/sync | |
692 | * ========================================================================== | |
693 | */ | |
694 | ||
695 | /* | |
696 | * Consider the following situation: txg is safely synced to disk. We've | |
697 | * written the first uberblock for txg + 1, and then we lose power. When we | |
698 | * come back up, we fail to see the uberblock for txg + 1 because, say, | |
699 | * it was on a mirrored device and the replica to which we wrote txg + 1 | |
700 | * is now offline. If we then make some changes and sync txg + 1, and then | |
701 | * the missing replica comes back, then for a new seconds we'll have two | |
702 | * conflicting uberblocks on disk with the same txg. The solution is simple: | |
703 | * among uberblocks with equal txg, choose the one with the latest timestamp. | |
704 | */ | |
705 | static int | |
706 | vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2) | |
707 | { | |
708 | if (ub1->ub_txg < ub2->ub_txg) | |
709 | return (-1); | |
710 | if (ub1->ub_txg > ub2->ub_txg) | |
711 | return (1); | |
712 | ||
713 | if (ub1->ub_timestamp < ub2->ub_timestamp) | |
714 | return (-1); | |
715 | if (ub1->ub_timestamp > ub2->ub_timestamp) | |
716 | return (1); | |
717 | ||
718 | return (0); | |
719 | } | |
720 | ||
721 | static void | |
722 | vdev_uberblock_load_done(zio_t *zio) | |
723 | { | |
724 | uberblock_t *ub = zio->io_data; | |
725 | uberblock_t *ubbest = zio->io_private; | |
726 | spa_t *spa = zio->io_spa; | |
727 | ||
728 | ASSERT3U(zio->io_size, ==, VDEV_UBERBLOCK_SIZE(zio->io_vd)); | |
729 | ||
730 | if (zio->io_error == 0 && uberblock_verify(ub) == 0) { | |
731 | mutex_enter(&spa->spa_uberblock_lock); | |
732 | if (vdev_uberblock_compare(ub, ubbest) > 0) | |
733 | *ubbest = *ub; | |
734 | mutex_exit(&spa->spa_uberblock_lock); | |
735 | } | |
736 | ||
737 | zio_buf_free(zio->io_data, zio->io_size); | |
738 | } | |
739 | ||
740 | void | |
741 | vdev_uberblock_load(zio_t *zio, vdev_t *vd, uberblock_t *ubbest) | |
742 | { | |
743 | int l, c, n; | |
744 | ||
745 | for (c = 0; c < vd->vdev_children; c++) | |
746 | vdev_uberblock_load(zio, vd->vdev_child[c], ubbest); | |
747 | ||
748 | if (!vd->vdev_ops->vdev_op_leaf) | |
749 | return; | |
750 | ||
751 | if (vdev_is_dead(vd)) | |
752 | return; | |
753 | ||
754 | for (l = 0; l < VDEV_LABELS; l++) { | |
755 | for (n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) { | |
756 | vdev_label_read(zio, vd, l, | |
757 | zio_buf_alloc(VDEV_UBERBLOCK_SIZE(vd)), | |
758 | VDEV_UBERBLOCK_OFFSET(vd, n), | |
759 | VDEV_UBERBLOCK_SIZE(vd), | |
760 | vdev_uberblock_load_done, ubbest); | |
761 | } | |
762 | } | |
763 | } | |
764 | ||
765 | /* | |
766 | * On success, increment root zio's count of good writes. | |
767 | * We only get credit for writes to known-visible vdevs; see spa_vdev_add(). | |
768 | */ | |
769 | static void | |
770 | vdev_uberblock_sync_done(zio_t *zio) | |
771 | { | |
772 | uint64_t *good_writes = zio->io_private; | |
773 | ||
774 | if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0) | |
775 | atomic_add_64(good_writes, 1); | |
776 | } | |
777 | ||
778 | /* | |
779 | * Write the uberblock to all labels of all leaves of the specified vdev. | |
780 | */ | |
781 | static void | |
782 | vdev_uberblock_sync(zio_t *zio, uberblock_t *ub, vdev_t *vd) | |
783 | { | |
784 | int l, c, n; | |
785 | uberblock_t *ubbuf; | |
786 | ||
787 | for (c = 0; c < vd->vdev_children; c++) | |
788 | vdev_uberblock_sync(zio, ub, vd->vdev_child[c]); | |
789 | ||
790 | if (!vd->vdev_ops->vdev_op_leaf) | |
791 | return; | |
792 | ||
793 | if (vdev_is_dead(vd)) | |
794 | return; | |
795 | ||
796 | n = ub->ub_txg & (VDEV_UBERBLOCK_COUNT(vd) - 1); | |
797 | ||
798 | ubbuf = zio_buf_alloc(VDEV_UBERBLOCK_SIZE(vd)); | |
799 | bzero(ubbuf, VDEV_UBERBLOCK_SIZE(vd)); | |
800 | *ubbuf = *ub; | |
801 | ||
802 | for (l = 0; l < VDEV_LABELS; l++) | |
803 | vdev_label_write(zio, vd, l, ubbuf, | |
804 | VDEV_UBERBLOCK_OFFSET(vd, n), | |
805 | VDEV_UBERBLOCK_SIZE(vd), | |
806 | vdev_uberblock_sync_done, zio->io_private, | |
807 | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE); | |
808 | ||
809 | zio_buf_free(ubbuf, VDEV_UBERBLOCK_SIZE(vd)); | |
810 | } | |
811 | ||
812 | int | |
813 | vdev_uberblock_sync_list(vdev_t **svd, int svdcount, uberblock_t *ub, int flags) | |
814 | { | |
815 | spa_t *spa = svd[0]->vdev_spa; | |
816 | int v; | |
817 | zio_t *zio; | |
818 | uint64_t good_writes = 0; | |
819 | ||
820 | zio = zio_root(spa, NULL, &good_writes, flags); | |
821 | ||
822 | for (v = 0; v < svdcount; v++) | |
823 | vdev_uberblock_sync(zio, ub, svd[v]); | |
824 | ||
825 | (void) zio_wait(zio); | |
826 | ||
827 | /* | |
828 | * Flush the uberblocks to disk. This ensures that the odd labels | |
829 | * are no longer needed (because the new uberblocks and the even | |
830 | * labels are safely on disk), so it is safe to overwrite them. | |
831 | */ | |
832 | zio = zio_root(spa, NULL, NULL, flags); | |
833 | ||
834 | for (v = 0; v < svdcount; v++) | |
835 | zio_flush(zio, svd[v]); | |
836 | ||
837 | (void) zio_wait(zio); | |
838 | ||
839 | return (good_writes >= 1 ? 0 : EIO); | |
840 | } | |
841 | ||
842 | /* | |
843 | * On success, increment the count of good writes for our top-level vdev. | |
844 | */ | |
845 | static void | |
846 | vdev_label_sync_done(zio_t *zio) | |
847 | { | |
848 | uint64_t *good_writes = zio->io_private; | |
849 | ||
850 | if (zio->io_error == 0) | |
851 | atomic_add_64(good_writes, 1); | |
852 | } | |
853 | ||
854 | /* | |
855 | * If there weren't enough good writes, indicate failure to the parent. | |
856 | */ | |
857 | static void | |
858 | vdev_label_sync_top_done(zio_t *zio) | |
859 | { | |
860 | uint64_t *good_writes = zio->io_private; | |
861 | ||
862 | if (*good_writes == 0) | |
863 | zio->io_error = EIO; | |
864 | ||
865 | kmem_free(good_writes, sizeof (uint64_t)); | |
866 | } | |
867 | ||
868 | /* | |
869 | * Write all even or odd labels to all leaves of the specified vdev. | |
870 | */ | |
871 | static void | |
872 | vdev_label_sync(zio_t *zio, vdev_t *vd, int l, uint64_t txg) | |
873 | { | |
874 | nvlist_t *label; | |
875 | vdev_phys_t *vp; | |
876 | char *buf; | |
877 | size_t buflen; | |
878 | int c; | |
879 | ||
880 | for (c = 0; c < vd->vdev_children; c++) | |
881 | vdev_label_sync(zio, vd->vdev_child[c], l, txg); | |
882 | ||
883 | if (!vd->vdev_ops->vdev_op_leaf) | |
884 | return; | |
885 | ||
886 | if (vdev_is_dead(vd)) | |
887 | return; | |
888 | ||
889 | /* | |
890 | * Generate a label describing the top-level config to which we belong. | |
891 | */ | |
892 | label = spa_config_generate(vd->vdev_spa, vd, txg, B_FALSE); | |
893 | ||
894 | vp = zio_buf_alloc(sizeof (vdev_phys_t)); | |
895 | bzero(vp, sizeof (vdev_phys_t)); | |
896 | ||
897 | buf = vp->vp_nvlist; | |
898 | buflen = sizeof (vp->vp_nvlist); | |
899 | ||
900 | if (nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP) == 0) { | |
901 | for (; l < VDEV_LABELS; l += 2) { | |
902 | vdev_label_write(zio, vd, l, vp, | |
903 | offsetof(vdev_label_t, vl_vdev_phys), | |
904 | sizeof (vdev_phys_t), | |
905 | vdev_label_sync_done, zio->io_private, | |
906 | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE); | |
907 | } | |
908 | } | |
909 | ||
910 | zio_buf_free(vp, sizeof (vdev_phys_t)); | |
911 | nvlist_free(label); | |
912 | } | |
913 | ||
914 | int | |
915 | vdev_label_sync_list(spa_t *spa, int l, int flags, uint64_t txg) | |
916 | { | |
917 | list_t *dl = &spa->spa_dirty_list; | |
918 | vdev_t *vd; | |
919 | zio_t *zio; | |
920 | int error; | |
921 | ||
922 | /* | |
923 | * Write the new labels to disk. | |
924 | */ | |
925 | zio = zio_root(spa, NULL, NULL, flags); | |
926 | ||
927 | for (vd = list_head(dl); vd != NULL; vd = list_next(dl, vd)) { | |
928 | uint64_t *good_writes = kmem_zalloc(sizeof (uint64_t), | |
929 | KM_SLEEP); | |
930 | zio_t *vio = zio_null(zio, spa, vdev_label_sync_top_done, | |
931 | good_writes, flags); | |
932 | vdev_label_sync(vio, vd, l, txg); | |
933 | zio_nowait(vio); | |
934 | } | |
935 | ||
936 | error = zio_wait(zio); | |
937 | ||
938 | /* | |
939 | * Flush the new labels to disk. | |
940 | */ | |
941 | zio = zio_root(spa, NULL, NULL, flags); | |
942 | ||
943 | for (vd = list_head(dl); vd != NULL; vd = list_next(dl, vd)) | |
944 | zio_flush(zio, vd); | |
945 | ||
946 | (void) zio_wait(zio); | |
947 | ||
948 | return (error); | |
949 | } | |
950 | ||
951 | /* | |
952 | * Sync the uberblock and any changes to the vdev configuration. | |
953 | * | |
954 | * The order of operations is carefully crafted to ensure that | |
955 | * if the system panics or loses power at any time, the state on disk | |
956 | * is still transactionally consistent. The in-line comments below | |
957 | * describe the failure semantics at each stage. | |
958 | * | |
959 | * Moreover, vdev_config_sync() is designed to be idempotent: if it fails | |
960 | * at any time, you can just call it again, and it will resume its work. | |
961 | */ | |
962 | int | |
963 | vdev_config_sync(vdev_t **svd, int svdcount, uint64_t txg) | |
964 | { | |
965 | spa_t *spa = svd[0]->vdev_spa; | |
966 | uberblock_t *ub = &spa->spa_uberblock; | |
967 | vdev_t *vd; | |
968 | zio_t *zio; | |
969 | int error; | |
970 | int flags = ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL; | |
971 | ||
972 | ASSERT(ub->ub_txg <= txg); | |
973 | ||
974 | /* | |
975 | * If this isn't a resync due to I/O errors, | |
976 | * and nothing changed in this transaction group, | |
977 | * and the vdev configuration hasn't changed, | |
978 | * then there's nothing to do. | |
979 | */ | |
980 | if (ub->ub_txg < txg && | |
981 | uberblock_update(ub, spa->spa_root_vdev, txg) == B_FALSE && | |
982 | list_is_empty(&spa->spa_dirty_list)) | |
983 | return (0); | |
984 | ||
985 | if (txg > spa_freeze_txg(spa)) | |
986 | return (0); | |
987 | ||
988 | ASSERT(txg <= spa->spa_final_txg); | |
989 | ||
990 | /* | |
991 | * Flush the write cache of every disk that's been written to | |
992 | * in this transaction group. This ensures that all blocks | |
993 | * written in this txg will be committed to stable storage | |
994 | * before any uberblock that references them. | |
995 | */ | |
996 | zio = zio_root(spa, NULL, NULL, flags); | |
997 | ||
998 | for (vd = txg_list_head(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)); vd; | |
999 | vd = txg_list_next(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg))) | |
1000 | zio_flush(zio, vd); | |
1001 | ||
1002 | (void) zio_wait(zio); | |
1003 | ||
1004 | /* | |
1005 | * Sync out the even labels (L0, L2) for every dirty vdev. If the | |
1006 | * system dies in the middle of this process, that's OK: all of the | |
1007 | * even labels that made it to disk will be newer than any uberblock, | |
1008 | * and will therefore be considered invalid. The odd labels (L1, L3), | |
1009 | * which have not yet been touched, will still be valid. We flush | |
1010 | * the new labels to disk to ensure that all even-label updates | |
1011 | * are committed to stable storage before the uberblock update. | |
1012 | */ | |
1013 | if ((error = vdev_label_sync_list(spa, 0, flags, txg)) != 0) | |
1014 | return (error); | |
1015 | ||
1016 | /* | |
1017 | * Sync the uberblocks to all vdevs in svd[]. | |
1018 | * If the system dies in the middle of this step, there are two cases | |
1019 | * to consider, and the on-disk state is consistent either way: | |
1020 | * | |
1021 | * (1) If none of the new uberblocks made it to disk, then the | |
1022 | * previous uberblock will be the newest, and the odd labels | |
1023 | * (which had not yet been touched) will be valid with respect | |
1024 | * to that uberblock. | |
1025 | * | |
1026 | * (2) If one or more new uberblocks made it to disk, then they | |
1027 | * will be the newest, and the even labels (which had all | |
1028 | * been successfully committed) will be valid with respect | |
1029 | * to the new uberblocks. | |
1030 | */ | |
1031 | if ((error = vdev_uberblock_sync_list(svd, svdcount, ub, flags)) != 0) | |
1032 | return (error); | |
1033 | ||
1034 | /* | |
1035 | * Sync out odd labels for every dirty vdev. If the system dies | |
1036 | * in the middle of this process, the even labels and the new | |
1037 | * uberblocks will suffice to open the pool. The next time | |
1038 | * the pool is opened, the first thing we'll do -- before any | |
1039 | * user data is modified -- is mark every vdev dirty so that | |
1040 | * all labels will be brought up to date. We flush the new labels | |
1041 | * to disk to ensure that all odd-label updates are committed to | |
1042 | * stable storage before the next transaction group begins. | |
1043 | */ | |
1044 | return (vdev_label_sync_list(spa, 1, flags, txg)); | |
1045 | } |