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.
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.
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]
23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2013 by Delphix. All rights reserved.
28 * Virtual Device Labels
29 * ---------------------
31 * The vdev label serves several distinct purposes:
33 * 1. Uniquely identify this device as part of a ZFS pool and confirm its
34 * identity within the pool.
36 * 2. Verify that all the devices given in a configuration are present
39 * 3. Determine the uberblock for the pool.
41 * 4. In case of an import operation, determine the configuration of the
42 * toplevel vdev of which it is a part.
44 * 5. If an import operation cannot find all the devices in the pool,
45 * provide enough information to the administrator to determine which
46 * devices are missing.
48 * It is important to note that while the kernel is responsible for writing the
49 * label, it only consumes the information in the first three cases. The
50 * latter information is only consumed in userland when determining the
51 * configuration to import a pool.
57 * Before describing the contents of the label, it's important to understand how
58 * the labels are written and updated with respect to the uberblock.
60 * When the pool configuration is altered, either because it was newly created
61 * or a device was added, we want to update all the labels such that we can deal
62 * with fatal failure at any point. To this end, each disk has two labels which
63 * are updated before and after the uberblock is synced. Assuming we have
64 * labels and an uberblock with the following transaction groups:
67 * +------+ +------+ +------+
69 * | t10 | | t10 | | t10 |
71 * +------+ +------+ +------+
73 * In this stable state, the labels and the uberblock were all updated within
74 * the same transaction group (10). Each label is mirrored and checksummed, so
75 * that we can detect when we fail partway through writing the label.
77 * In order to identify which labels are valid, the labels are written in the
80 * 1. For each vdev, update 'L1' to the new label
81 * 2. Update the uberblock
82 * 3. For each vdev, update 'L2' to the new label
84 * Given arbitrary failure, we can determine the correct label to use based on
85 * the transaction group. If we fail after updating L1 but before updating the
86 * UB, we will notice that L1's transaction group is greater than the uberblock,
87 * so L2 must be valid. If we fail after writing the uberblock but before
88 * writing L2, we will notice that L2's transaction group is less than L1, and
89 * therefore L1 is valid.
91 * Another added complexity is that not every label is updated when the config
92 * is synced. If we add a single device, we do not want to have to re-write
93 * every label for every device in the pool. This means that both L1 and L2 may
94 * be older than the pool uberblock, because the necessary information is stored
101 * The vdev label consists of two distinct parts, and is wrapped within the
102 * vdev_label_t structure. The label includes 8k of padding to permit legacy
103 * VTOC disk labels, but is otherwise ignored.
105 * The first half of the label is a packed nvlist which contains pool wide
106 * properties, per-vdev properties, and configuration information. It is
107 * described in more detail below.
109 * The latter half of the label consists of a redundant array of uberblocks.
110 * These uberblocks are updated whenever a transaction group is committed,
111 * or when the configuration is updated. When a pool is loaded, we scan each
112 * vdev for the 'best' uberblock.
115 * Configuration Information
116 * -------------------------
118 * The nvlist describing the pool and vdev contains the following elements:
120 * version ZFS on-disk version
123 * txg Transaction group in which this label was written
124 * pool_guid Unique identifier for this pool
125 * vdev_tree An nvlist describing vdev tree.
127 * An nvlist of the features necessary for reading the MOS.
129 * Each leaf device label also contains the following:
131 * top_guid Unique ID for top-level vdev in which this is contained
132 * guid Unique ID for the leaf vdev
134 * The 'vs' configuration follows the format described in 'spa_config.c'.
137 #include <sys/zfs_context.h>
139 #include <sys/spa_impl.h>
142 #include <sys/vdev.h>
143 #include <sys/vdev_impl.h>
144 #include <sys/uberblock_impl.h>
145 #include <sys/metaslab.h>
147 #include <sys/dsl_scan.h>
149 #include <sys/fs/zfs.h>
152 * Basic routines to read and write from a vdev label.
153 * Used throughout the rest of this file.
156 vdev_label_offset(uint64_t psize
, int l
, uint64_t offset
)
158 ASSERT(offset
< sizeof (vdev_label_t
));
159 ASSERT(P2PHASE_TYPED(psize
, sizeof (vdev_label_t
), uint64_t) == 0);
161 return (offset
+ l
* sizeof (vdev_label_t
) + (l
< VDEV_LABELS
/ 2 ?
162 0 : psize
- VDEV_LABELS
* sizeof (vdev_label_t
)));
166 * Returns back the vdev label associated with the passed in offset.
169 vdev_label_number(uint64_t psize
, uint64_t offset
)
173 if (offset
>= psize
- VDEV_LABEL_END_SIZE
) {
174 offset
-= psize
- VDEV_LABEL_END_SIZE
;
175 offset
+= (VDEV_LABELS
/ 2) * sizeof (vdev_label_t
);
177 l
= offset
/ sizeof (vdev_label_t
);
178 return (l
< VDEV_LABELS
? l
: -1);
182 vdev_label_read(zio_t
*zio
, vdev_t
*vd
, int l
, abd_t
*buf
, uint64_t offset
,
183 uint64_t size
, zio_done_func_t
*done
, void *private, int flags
)
185 ASSERT(spa_config_held(zio
->io_spa
, SCL_STATE_ALL
, RW_WRITER
) ==
187 ASSERT(flags
& ZIO_FLAG_CONFIG_WRITER
);
189 zio_nowait(zio_read_phys(zio
, vd
,
190 vdev_label_offset(vd
->vdev_psize
, l
, offset
),
191 size
, buf
, ZIO_CHECKSUM_LABEL
, done
, private,
192 ZIO_PRIORITY_SYNC_READ
, flags
, B_TRUE
));
196 vdev_label_write(zio_t
*zio
, vdev_t
*vd
, int l
, abd_t
*buf
, uint64_t offset
,
197 uint64_t size
, zio_done_func_t
*done
, void *private, int flags
)
199 ASSERT(spa_config_held(zio
->io_spa
, SCL_ALL
, RW_WRITER
) == SCL_ALL
||
200 (spa_config_held(zio
->io_spa
, SCL_CONFIG
| SCL_STATE
, RW_READER
) ==
201 (SCL_CONFIG
| SCL_STATE
) &&
202 dsl_pool_sync_context(spa_get_dsl(zio
->io_spa
))));
203 ASSERT(flags
& ZIO_FLAG_CONFIG_WRITER
);
205 zio_nowait(zio_write_phys(zio
, vd
,
206 vdev_label_offset(vd
->vdev_psize
, l
, offset
),
207 size
, buf
, ZIO_CHECKSUM_LABEL
, done
, private,
208 ZIO_PRIORITY_SYNC_WRITE
, flags
, B_TRUE
));
212 * Generate the nvlist representing this vdev's stats
215 vdev_config_generate_stats(vdev_t
*vd
, nvlist_t
*nv
)
221 vs
= kmem_alloc(sizeof (*vs
), KM_SLEEP
);
222 vsx
= kmem_alloc(sizeof (*vsx
), KM_SLEEP
);
224 vdev_get_stats_ex(vd
, vs
, vsx
);
225 fnvlist_add_uint64_array(nv
, ZPOOL_CONFIG_VDEV_STATS
,
226 (uint64_t *)vs
, sizeof (*vs
) / sizeof (uint64_t));
228 kmem_free(vs
, sizeof (*vs
));
231 * Add extended stats into a special extended stats nvlist. This keeps
232 * all the extended stats nicely grouped together. The extended stats
233 * nvlist is then added to the main nvlist.
235 nvx
= fnvlist_alloc();
237 /* ZIOs in flight to disk */
238 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_SYNC_R_ACTIVE_QUEUE
,
239 vsx
->vsx_active_queue
[ZIO_PRIORITY_SYNC_READ
]);
241 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_SYNC_W_ACTIVE_QUEUE
,
242 vsx
->vsx_active_queue
[ZIO_PRIORITY_SYNC_WRITE
]);
244 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_R_ACTIVE_QUEUE
,
245 vsx
->vsx_active_queue
[ZIO_PRIORITY_ASYNC_READ
]);
247 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_W_ACTIVE_QUEUE
,
248 vsx
->vsx_active_queue
[ZIO_PRIORITY_ASYNC_WRITE
]);
250 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_SCRUB_ACTIVE_QUEUE
,
251 vsx
->vsx_active_queue
[ZIO_PRIORITY_SCRUB
]);
254 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_SYNC_R_PEND_QUEUE
,
255 vsx
->vsx_pend_queue
[ZIO_PRIORITY_SYNC_READ
]);
257 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_SYNC_W_PEND_QUEUE
,
258 vsx
->vsx_pend_queue
[ZIO_PRIORITY_SYNC_WRITE
]);
260 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_R_PEND_QUEUE
,
261 vsx
->vsx_pend_queue
[ZIO_PRIORITY_ASYNC_READ
]);
263 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_W_PEND_QUEUE
,
264 vsx
->vsx_pend_queue
[ZIO_PRIORITY_ASYNC_WRITE
]);
266 fnvlist_add_uint64(nvx
, ZPOOL_CONFIG_VDEV_SCRUB_PEND_QUEUE
,
267 vsx
->vsx_pend_queue
[ZIO_PRIORITY_SCRUB
]);
270 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_TOT_R_LAT_HISTO
,
271 vsx
->vsx_total_histo
[ZIO_TYPE_READ
],
272 ARRAY_SIZE(vsx
->vsx_total_histo
[ZIO_TYPE_READ
]));
274 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_TOT_W_LAT_HISTO
,
275 vsx
->vsx_total_histo
[ZIO_TYPE_WRITE
],
276 ARRAY_SIZE(vsx
->vsx_total_histo
[ZIO_TYPE_WRITE
]));
278 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_DISK_R_LAT_HISTO
,
279 vsx
->vsx_disk_histo
[ZIO_TYPE_READ
],
280 ARRAY_SIZE(vsx
->vsx_disk_histo
[ZIO_TYPE_READ
]));
282 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_DISK_W_LAT_HISTO
,
283 vsx
->vsx_disk_histo
[ZIO_TYPE_WRITE
],
284 ARRAY_SIZE(vsx
->vsx_disk_histo
[ZIO_TYPE_WRITE
]));
286 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_SYNC_R_LAT_HISTO
,
287 vsx
->vsx_queue_histo
[ZIO_PRIORITY_SYNC_READ
],
288 ARRAY_SIZE(vsx
->vsx_queue_histo
[ZIO_PRIORITY_SYNC_READ
]));
290 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_SYNC_W_LAT_HISTO
,
291 vsx
->vsx_queue_histo
[ZIO_PRIORITY_SYNC_WRITE
],
292 ARRAY_SIZE(vsx
->vsx_queue_histo
[ZIO_PRIORITY_SYNC_WRITE
]));
294 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_R_LAT_HISTO
,
295 vsx
->vsx_queue_histo
[ZIO_PRIORITY_ASYNC_READ
],
296 ARRAY_SIZE(vsx
->vsx_queue_histo
[ZIO_PRIORITY_ASYNC_READ
]));
298 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_W_LAT_HISTO
,
299 vsx
->vsx_queue_histo
[ZIO_PRIORITY_ASYNC_WRITE
],
300 ARRAY_SIZE(vsx
->vsx_queue_histo
[ZIO_PRIORITY_ASYNC_WRITE
]));
302 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_SCRUB_LAT_HISTO
,
303 vsx
->vsx_queue_histo
[ZIO_PRIORITY_SCRUB
],
304 ARRAY_SIZE(vsx
->vsx_queue_histo
[ZIO_PRIORITY_SCRUB
]));
307 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_SYNC_IND_R_HISTO
,
308 vsx
->vsx_ind_histo
[ZIO_PRIORITY_SYNC_READ
],
309 ARRAY_SIZE(vsx
->vsx_ind_histo
[ZIO_PRIORITY_SYNC_READ
]));
311 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_SYNC_IND_W_HISTO
,
312 vsx
->vsx_ind_histo
[ZIO_PRIORITY_SYNC_WRITE
],
313 ARRAY_SIZE(vsx
->vsx_ind_histo
[ZIO_PRIORITY_SYNC_WRITE
]));
315 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_IND_R_HISTO
,
316 vsx
->vsx_ind_histo
[ZIO_PRIORITY_ASYNC_READ
],
317 ARRAY_SIZE(vsx
->vsx_ind_histo
[ZIO_PRIORITY_ASYNC_READ
]));
319 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_IND_W_HISTO
,
320 vsx
->vsx_ind_histo
[ZIO_PRIORITY_ASYNC_WRITE
],
321 ARRAY_SIZE(vsx
->vsx_ind_histo
[ZIO_PRIORITY_ASYNC_WRITE
]));
323 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_IND_SCRUB_HISTO
,
324 vsx
->vsx_ind_histo
[ZIO_PRIORITY_SCRUB
],
325 ARRAY_SIZE(vsx
->vsx_ind_histo
[ZIO_PRIORITY_SCRUB
]));
327 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_SYNC_AGG_R_HISTO
,
328 vsx
->vsx_agg_histo
[ZIO_PRIORITY_SYNC_READ
],
329 ARRAY_SIZE(vsx
->vsx_agg_histo
[ZIO_PRIORITY_SYNC_READ
]));
331 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_SYNC_AGG_W_HISTO
,
332 vsx
->vsx_agg_histo
[ZIO_PRIORITY_SYNC_WRITE
],
333 ARRAY_SIZE(vsx
->vsx_agg_histo
[ZIO_PRIORITY_SYNC_WRITE
]));
335 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_AGG_R_HISTO
,
336 vsx
->vsx_agg_histo
[ZIO_PRIORITY_ASYNC_READ
],
337 ARRAY_SIZE(vsx
->vsx_agg_histo
[ZIO_PRIORITY_ASYNC_READ
]));
339 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_ASYNC_AGG_W_HISTO
,
340 vsx
->vsx_agg_histo
[ZIO_PRIORITY_ASYNC_WRITE
],
341 ARRAY_SIZE(vsx
->vsx_agg_histo
[ZIO_PRIORITY_ASYNC_WRITE
]));
343 fnvlist_add_uint64_array(nvx
, ZPOOL_CONFIG_VDEV_AGG_SCRUB_HISTO
,
344 vsx
->vsx_agg_histo
[ZIO_PRIORITY_SCRUB
],
345 ARRAY_SIZE(vsx
->vsx_agg_histo
[ZIO_PRIORITY_SCRUB
]));
347 /* Add extended stats nvlist to main nvlist */
348 fnvlist_add_nvlist(nv
, ZPOOL_CONFIG_VDEV_STATS_EX
, nvx
);
351 kmem_free(vsx
, sizeof (*vsx
));
355 * Generate the nvlist representing this vdev's config.
358 vdev_config_generate(spa_t
*spa
, vdev_t
*vd
, boolean_t getstats
,
359 vdev_config_flag_t flags
)
362 nv
= fnvlist_alloc();
364 fnvlist_add_string(nv
, ZPOOL_CONFIG_TYPE
, vd
->vdev_ops
->vdev_op_type
);
365 if (!(flags
& (VDEV_CONFIG_SPARE
| VDEV_CONFIG_L2CACHE
)))
366 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_ID
, vd
->vdev_id
);
367 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_GUID
, vd
->vdev_guid
);
369 if (vd
->vdev_path
!= NULL
)
370 fnvlist_add_string(nv
, ZPOOL_CONFIG_PATH
, vd
->vdev_path
);
372 if (vd
->vdev_devid
!= NULL
)
373 fnvlist_add_string(nv
, ZPOOL_CONFIG_DEVID
, vd
->vdev_devid
);
375 if (vd
->vdev_physpath
!= NULL
)
376 fnvlist_add_string(nv
, ZPOOL_CONFIG_PHYS_PATH
,
379 if (vd
->vdev_enc_sysfs_path
!= NULL
)
380 fnvlist_add_string(nv
, ZPOOL_CONFIG_VDEV_ENC_SYSFS_PATH
,
381 vd
->vdev_enc_sysfs_path
);
383 if (vd
->vdev_fru
!= NULL
)
384 fnvlist_add_string(nv
, ZPOOL_CONFIG_FRU
, vd
->vdev_fru
);
386 if (vd
->vdev_nparity
!= 0) {
387 ASSERT(strcmp(vd
->vdev_ops
->vdev_op_type
,
388 VDEV_TYPE_RAIDZ
) == 0);
391 * Make sure someone hasn't managed to sneak a fancy new vdev
392 * into a crufty old storage pool.
394 ASSERT(vd
->vdev_nparity
== 1 ||
395 (vd
->vdev_nparity
<= 2 &&
396 spa_version(spa
) >= SPA_VERSION_RAIDZ2
) ||
397 (vd
->vdev_nparity
<= 3 &&
398 spa_version(spa
) >= SPA_VERSION_RAIDZ3
));
401 * Note that we'll add the nparity tag even on storage pools
402 * that only support a single parity device -- older software
403 * will just ignore it.
405 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_NPARITY
, vd
->vdev_nparity
);
408 if (vd
->vdev_wholedisk
!= -1ULL)
409 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_WHOLE_DISK
,
412 if (vd
->vdev_not_present
)
413 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_NOT_PRESENT
, 1);
415 if (vd
->vdev_isspare
)
416 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_IS_SPARE
, 1);
418 if (!(flags
& (VDEV_CONFIG_SPARE
| VDEV_CONFIG_L2CACHE
)) &&
419 vd
== vd
->vdev_top
) {
420 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_METASLAB_ARRAY
,
422 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_METASLAB_SHIFT
,
424 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_ASHIFT
, vd
->vdev_ashift
);
425 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_ASIZE
,
427 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_IS_LOG
, vd
->vdev_islog
);
428 if (vd
->vdev_removing
)
429 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_REMOVING
,
433 if (vd
->vdev_dtl_sm
!= NULL
) {
434 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_DTL
,
435 space_map_object(vd
->vdev_dtl_sm
));
439 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_CREATE_TXG
, vd
->vdev_crtxg
);
441 if (flags
& VDEV_CONFIG_MOS
) {
442 if (vd
->vdev_leaf_zap
!= 0) {
443 ASSERT(vd
->vdev_ops
->vdev_op_leaf
);
444 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_VDEV_LEAF_ZAP
,
448 if (vd
->vdev_top_zap
!= 0) {
449 ASSERT(vd
== vd
->vdev_top
);
450 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_VDEV_TOP_ZAP
,
458 vdev_config_generate_stats(vd
, nv
);
460 /* provide either current or previous scan information */
461 if (spa_scan_get_stats(spa
, &ps
) == 0) {
462 fnvlist_add_uint64_array(nv
,
463 ZPOOL_CONFIG_SCAN_STATS
, (uint64_t *)&ps
,
464 sizeof (pool_scan_stat_t
) / sizeof (uint64_t));
468 if (!vd
->vdev_ops
->vdev_op_leaf
) {
472 ASSERT(!vd
->vdev_ishole
);
474 child
= kmem_alloc(vd
->vdev_children
* sizeof (nvlist_t
*),
477 for (c
= 0, idx
= 0; c
< vd
->vdev_children
; c
++) {
478 vdev_t
*cvd
= vd
->vdev_child
[c
];
481 * If we're generating an nvlist of removing
482 * vdevs then skip over any device which is
485 if ((flags
& VDEV_CONFIG_REMOVING
) &&
489 child
[idx
++] = vdev_config_generate(spa
, cvd
,
494 fnvlist_add_nvlist_array(nv
, ZPOOL_CONFIG_CHILDREN
,
498 for (c
= 0; c
< idx
; c
++)
499 nvlist_free(child
[c
]);
501 kmem_free(child
, vd
->vdev_children
* sizeof (nvlist_t
*));
504 const char *aux
= NULL
;
506 if (vd
->vdev_offline
&& !vd
->vdev_tmpoffline
)
507 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_OFFLINE
, B_TRUE
);
508 if (vd
->vdev_resilver_txg
!= 0)
509 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_RESILVER_TXG
,
510 vd
->vdev_resilver_txg
);
511 if (vd
->vdev_faulted
)
512 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_FAULTED
, B_TRUE
);
513 if (vd
->vdev_degraded
)
514 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_DEGRADED
, B_TRUE
);
515 if (vd
->vdev_removed
)
516 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_REMOVED
, B_TRUE
);
517 if (vd
->vdev_unspare
)
518 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_UNSPARE
, B_TRUE
);
520 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_IS_HOLE
, B_TRUE
);
522 switch (vd
->vdev_stat
.vs_aux
) {
523 case VDEV_AUX_ERR_EXCEEDED
:
524 aux
= "err_exceeded";
527 case VDEV_AUX_EXTERNAL
:
533 fnvlist_add_string(nv
, ZPOOL_CONFIG_AUX_STATE
, aux
);
535 if (vd
->vdev_splitting
&& vd
->vdev_orig_guid
!= 0LL) {
536 fnvlist_add_uint64(nv
, ZPOOL_CONFIG_ORIG_GUID
,
545 * Generate a view of the top-level vdevs. If we currently have holes
546 * in the namespace, then generate an array which contains a list of holey
547 * vdevs. Additionally, add the number of top-level children that currently
551 vdev_top_config_generate(spa_t
*spa
, nvlist_t
*config
)
553 vdev_t
*rvd
= spa
->spa_root_vdev
;
557 array
= kmem_alloc(rvd
->vdev_children
* sizeof (uint64_t), KM_SLEEP
);
559 for (c
= 0, idx
= 0; c
< rvd
->vdev_children
; c
++) {
560 vdev_t
*tvd
= rvd
->vdev_child
[c
];
562 if (tvd
->vdev_ishole
)
567 VERIFY(nvlist_add_uint64_array(config
, ZPOOL_CONFIG_HOLE_ARRAY
,
571 VERIFY(nvlist_add_uint64(config
, ZPOOL_CONFIG_VDEV_CHILDREN
,
572 rvd
->vdev_children
) == 0);
574 kmem_free(array
, rvd
->vdev_children
* sizeof (uint64_t));
578 * Returns the configuration from the label of the given vdev. For vdevs
579 * which don't have a txg value stored on their label (i.e. spares/cache)
580 * or have not been completely initialized (txg = 0) just return
581 * the configuration from the first valid label we find. Otherwise,
582 * find the most up-to-date label that does not exceed the specified
586 vdev_label_read_config(vdev_t
*vd
, uint64_t txg
)
588 spa_t
*spa
= vd
->vdev_spa
;
589 nvlist_t
*config
= NULL
;
593 uint64_t best_txg
= 0;
595 int flags
= ZIO_FLAG_CONFIG_WRITER
| ZIO_FLAG_CANFAIL
|
596 ZIO_FLAG_SPECULATIVE
;
599 ASSERT(spa_config_held(spa
, SCL_STATE_ALL
, RW_WRITER
) == SCL_STATE_ALL
);
601 if (!vdev_readable(vd
))
604 vp_abd
= abd_alloc_linear(sizeof (vdev_phys_t
), B_TRUE
);
605 vp
= abd_to_buf(vp_abd
);
608 for (l
= 0; l
< VDEV_LABELS
; l
++) {
609 nvlist_t
*label
= NULL
;
611 zio
= zio_root(spa
, NULL
, NULL
, flags
);
613 vdev_label_read(zio
, vd
, l
, vp_abd
,
614 offsetof(vdev_label_t
, vl_vdev_phys
),
615 sizeof (vdev_phys_t
), NULL
, NULL
, flags
);
617 if (zio_wait(zio
) == 0 &&
618 nvlist_unpack(vp
->vp_nvlist
, sizeof (vp
->vp_nvlist
),
620 uint64_t label_txg
= 0;
623 * Auxiliary vdevs won't have txg values in their
624 * labels and newly added vdevs may not have been
625 * completely initialized so just return the
626 * configuration from the first valid label we
629 error
= nvlist_lookup_uint64(label
,
630 ZPOOL_CONFIG_POOL_TXG
, &label_txg
);
631 if ((error
|| label_txg
== 0) && !config
) {
634 } else if (label_txg
<= txg
&& label_txg
> best_txg
) {
635 best_txg
= label_txg
;
637 config
= fnvlist_dup(label
);
647 if (config
== NULL
&& !(flags
& ZIO_FLAG_TRYHARD
)) {
648 flags
|= ZIO_FLAG_TRYHARD
;
658 * Determine if a device is in use. The 'spare_guid' parameter will be filled
659 * in with the device guid if this spare is active elsewhere on the system.
662 vdev_inuse(vdev_t
*vd
, uint64_t crtxg
, vdev_labeltype_t reason
,
663 uint64_t *spare_guid
, uint64_t *l2cache_guid
)
665 spa_t
*spa
= vd
->vdev_spa
;
666 uint64_t state
, pool_guid
, device_guid
, txg
, spare_pool
;
673 *l2cache_guid
= 0ULL;
676 * Read the label, if any, and perform some basic sanity checks.
678 if ((label
= vdev_label_read_config(vd
, -1ULL)) == NULL
)
681 (void) nvlist_lookup_uint64(label
, ZPOOL_CONFIG_CREATE_TXG
,
684 if (nvlist_lookup_uint64(label
, ZPOOL_CONFIG_POOL_STATE
,
686 nvlist_lookup_uint64(label
, ZPOOL_CONFIG_GUID
,
687 &device_guid
) != 0) {
692 if (state
!= POOL_STATE_SPARE
&& state
!= POOL_STATE_L2CACHE
&&
693 (nvlist_lookup_uint64(label
, ZPOOL_CONFIG_POOL_GUID
,
695 nvlist_lookup_uint64(label
, ZPOOL_CONFIG_POOL_TXG
,
704 * Check to see if this device indeed belongs to the pool it claims to
705 * be a part of. The only way this is allowed is if the device is a hot
706 * spare (which we check for later on).
708 if (state
!= POOL_STATE_SPARE
&& state
!= POOL_STATE_L2CACHE
&&
709 !spa_guid_exists(pool_guid
, device_guid
) &&
710 !spa_spare_exists(device_guid
, NULL
, NULL
) &&
711 !spa_l2cache_exists(device_guid
, NULL
))
715 * If the transaction group is zero, then this an initialized (but
716 * unused) label. This is only an error if the create transaction
717 * on-disk is the same as the one we're using now, in which case the
718 * user has attempted to add the same vdev multiple times in the same
721 if (state
!= POOL_STATE_SPARE
&& state
!= POOL_STATE_L2CACHE
&&
722 txg
== 0 && vdtxg
== crtxg
)
726 * Check to see if this is a spare device. We do an explicit check for
727 * spa_has_spare() here because it may be on our pending list of spares
728 * to add. We also check if it is an l2cache device.
730 if (spa_spare_exists(device_guid
, &spare_pool
, NULL
) ||
731 spa_has_spare(spa
, device_guid
)) {
733 *spare_guid
= device_guid
;
736 case VDEV_LABEL_CREATE
:
737 case VDEV_LABEL_L2CACHE
:
740 case VDEV_LABEL_REPLACE
:
741 return (!spa_has_spare(spa
, device_guid
) ||
744 case VDEV_LABEL_SPARE
:
745 return (spa_has_spare(spa
, device_guid
));
752 * Check to see if this is an l2cache device.
754 if (spa_l2cache_exists(device_guid
, NULL
))
758 * We can't rely on a pool's state if it's been imported
759 * read-only. Instead we look to see if the pools is marked
760 * read-only in the namespace and set the state to active.
762 if (state
!= POOL_STATE_SPARE
&& state
!= POOL_STATE_L2CACHE
&&
763 (spa
= spa_by_guid(pool_guid
, device_guid
)) != NULL
&&
764 spa_mode(spa
) == FREAD
)
765 state
= POOL_STATE_ACTIVE
;
768 * If the device is marked ACTIVE, then this device is in use by another
769 * pool on the system.
771 return (state
== POOL_STATE_ACTIVE
);
775 * Initialize a vdev label. We check to make sure each leaf device is not in
776 * use, and writable. We put down an initial label which we will later
777 * overwrite with a complete label. Note that it's important to do this
778 * sequentially, not in parallel, so that we catch cases of multiple use of the
779 * same leaf vdev in the vdev we're creating -- e.g. mirroring a disk with
783 vdev_label_init(vdev_t
*vd
, uint64_t crtxg
, vdev_labeltype_t reason
)
785 spa_t
*spa
= vd
->vdev_spa
;
796 uint64_t spare_guid
= 0, l2cache_guid
= 0;
797 int flags
= ZIO_FLAG_CONFIG_WRITER
| ZIO_FLAG_CANFAIL
;
801 ASSERT(spa_config_held(spa
, SCL_ALL
, RW_WRITER
) == SCL_ALL
);
803 for (c
= 0; c
< vd
->vdev_children
; c
++)
804 if ((error
= vdev_label_init(vd
->vdev_child
[c
],
805 crtxg
, reason
)) != 0)
808 /* Track the creation time for this vdev */
809 vd
->vdev_crtxg
= crtxg
;
811 if (!vd
->vdev_ops
->vdev_op_leaf
|| !spa_writeable(spa
))
815 * Dead vdevs cannot be initialized.
817 if (vdev_is_dead(vd
))
818 return (SET_ERROR(EIO
));
821 * Determine if the vdev is in use.
823 if (reason
!= VDEV_LABEL_REMOVE
&& reason
!= VDEV_LABEL_SPLIT
&&
824 vdev_inuse(vd
, crtxg
, reason
, &spare_guid
, &l2cache_guid
))
825 return (SET_ERROR(EBUSY
));
828 * If this is a request to add or replace a spare or l2cache device
829 * that is in use elsewhere on the system, then we must update the
830 * guid (which was initialized to a random value) to reflect the
831 * actual GUID (which is shared between multiple pools).
833 if (reason
!= VDEV_LABEL_REMOVE
&& reason
!= VDEV_LABEL_L2CACHE
&&
834 spare_guid
!= 0ULL) {
835 uint64_t guid_delta
= spare_guid
- vd
->vdev_guid
;
837 vd
->vdev_guid
+= guid_delta
;
839 for (pvd
= vd
; pvd
!= NULL
; pvd
= pvd
->vdev_parent
)
840 pvd
->vdev_guid_sum
+= guid_delta
;
843 * If this is a replacement, then we want to fallthrough to the
844 * rest of the code. If we're adding a spare, then it's already
845 * labeled appropriately and we can just return.
847 if (reason
== VDEV_LABEL_SPARE
)
849 ASSERT(reason
== VDEV_LABEL_REPLACE
||
850 reason
== VDEV_LABEL_SPLIT
);
853 if (reason
!= VDEV_LABEL_REMOVE
&& reason
!= VDEV_LABEL_SPARE
&&
854 l2cache_guid
!= 0ULL) {
855 uint64_t guid_delta
= l2cache_guid
- vd
->vdev_guid
;
857 vd
->vdev_guid
+= guid_delta
;
859 for (pvd
= vd
; pvd
!= NULL
; pvd
= pvd
->vdev_parent
)
860 pvd
->vdev_guid_sum
+= guid_delta
;
863 * If this is a replacement, then we want to fallthrough to the
864 * rest of the code. If we're adding an l2cache, then it's
865 * already labeled appropriately and we can just return.
867 if (reason
== VDEV_LABEL_L2CACHE
)
869 ASSERT(reason
== VDEV_LABEL_REPLACE
);
873 * Initialize its label.
875 vp_abd
= abd_alloc_linear(sizeof (vdev_phys_t
), B_TRUE
);
876 abd_zero(vp_abd
, sizeof (vdev_phys_t
));
877 vp
= abd_to_buf(vp_abd
);
880 * Generate a label describing the pool and our top-level vdev.
881 * We mark it as being from txg 0 to indicate that it's not
882 * really part of an active pool just yet. The labels will
883 * be written again with a meaningful txg by spa_sync().
885 if (reason
== VDEV_LABEL_SPARE
||
886 (reason
== VDEV_LABEL_REMOVE
&& vd
->vdev_isspare
)) {
888 * For inactive hot spares, we generate a special label that
889 * identifies as a mutually shared hot spare. We write the
890 * label if we are adding a hot spare, or if we are removing an
891 * active hot spare (in which case we want to revert the
894 VERIFY(nvlist_alloc(&label
, NV_UNIQUE_NAME
, KM_SLEEP
) == 0);
896 VERIFY(nvlist_add_uint64(label
, ZPOOL_CONFIG_VERSION
,
897 spa_version(spa
)) == 0);
898 VERIFY(nvlist_add_uint64(label
, ZPOOL_CONFIG_POOL_STATE
,
899 POOL_STATE_SPARE
) == 0);
900 VERIFY(nvlist_add_uint64(label
, ZPOOL_CONFIG_GUID
,
901 vd
->vdev_guid
) == 0);
902 } else if (reason
== VDEV_LABEL_L2CACHE
||
903 (reason
== VDEV_LABEL_REMOVE
&& vd
->vdev_isl2cache
)) {
905 * For level 2 ARC devices, add a special label.
907 VERIFY(nvlist_alloc(&label
, NV_UNIQUE_NAME
, KM_SLEEP
) == 0);
909 VERIFY(nvlist_add_uint64(label
, ZPOOL_CONFIG_VERSION
,
910 spa_version(spa
)) == 0);
911 VERIFY(nvlist_add_uint64(label
, ZPOOL_CONFIG_POOL_STATE
,
912 POOL_STATE_L2CACHE
) == 0);
913 VERIFY(nvlist_add_uint64(label
, ZPOOL_CONFIG_GUID
,
914 vd
->vdev_guid
) == 0);
918 if (reason
== VDEV_LABEL_SPLIT
)
919 txg
= spa
->spa_uberblock
.ub_txg
;
920 label
= spa_config_generate(spa
, vd
, txg
, B_FALSE
);
923 * Add our creation time. This allows us to detect multiple
924 * vdev uses as described above, and automatically expires if we
927 VERIFY(nvlist_add_uint64(label
, ZPOOL_CONFIG_CREATE_TXG
,
932 buflen
= sizeof (vp
->vp_nvlist
);
934 error
= nvlist_pack(label
, &buf
, &buflen
, NV_ENCODE_XDR
, KM_SLEEP
);
938 /* EFAULT means nvlist_pack ran out of room */
939 return (error
== EFAULT
? ENAMETOOLONG
: EINVAL
);
943 * Initialize uberblock template.
945 ub_abd
= abd_alloc_linear(VDEV_UBERBLOCK_RING
, B_TRUE
);
946 abd_zero(ub_abd
, VDEV_UBERBLOCK_RING
);
947 abd_copy_from_buf(ub_abd
, &spa
->spa_uberblock
, sizeof (uberblock_t
));
948 ub
= abd_to_buf(ub_abd
);
951 /* Initialize the 2nd padding area. */
952 pad2
= abd_alloc_for_io(VDEV_PAD_SIZE
, B_TRUE
);
953 abd_zero(pad2
, VDEV_PAD_SIZE
);
956 * Write everything in parallel.
959 zio
= zio_root(spa
, NULL
, NULL
, flags
);
961 for (l
= 0; l
< VDEV_LABELS
; l
++) {
963 vdev_label_write(zio
, vd
, l
, vp_abd
,
964 offsetof(vdev_label_t
, vl_vdev_phys
),
965 sizeof (vdev_phys_t
), NULL
, NULL
, flags
);
968 * Skip the 1st padding area.
969 * Zero out the 2nd padding area where it might have
970 * left over data from previous filesystem format.
972 vdev_label_write(zio
, vd
, l
, pad2
,
973 offsetof(vdev_label_t
, vl_pad2
),
974 VDEV_PAD_SIZE
, NULL
, NULL
, flags
);
976 vdev_label_write(zio
, vd
, l
, ub_abd
,
977 offsetof(vdev_label_t
, vl_uberblock
),
978 VDEV_UBERBLOCK_RING
, NULL
, NULL
, flags
);
981 error
= zio_wait(zio
);
983 if (error
!= 0 && !(flags
& ZIO_FLAG_TRYHARD
)) {
984 flags
|= ZIO_FLAG_TRYHARD
;
994 * If this vdev hasn't been previously identified as a spare, then we
995 * mark it as such only if a) we are labeling it as a spare, or b) it
996 * exists as a spare elsewhere in the system. Do the same for
997 * level 2 ARC devices.
999 if (error
== 0 && !vd
->vdev_isspare
&&
1000 (reason
== VDEV_LABEL_SPARE
||
1001 spa_spare_exists(vd
->vdev_guid
, NULL
, NULL
)))
1004 if (error
== 0 && !vd
->vdev_isl2cache
&&
1005 (reason
== VDEV_LABEL_L2CACHE
||
1006 spa_l2cache_exists(vd
->vdev_guid
, NULL
)))
1007 spa_l2cache_add(vd
);
1013 * ==========================================================================
1014 * uberblock load/sync
1015 * ==========================================================================
1019 * Consider the following situation: txg is safely synced to disk. We've
1020 * written the first uberblock for txg + 1, and then we lose power. When we
1021 * come back up, we fail to see the uberblock for txg + 1 because, say,
1022 * it was on a mirrored device and the replica to which we wrote txg + 1
1023 * is now offline. If we then make some changes and sync txg + 1, and then
1024 * the missing replica comes back, then for a few seconds we'll have two
1025 * conflicting uberblocks on disk with the same txg. The solution is simple:
1026 * among uberblocks with equal txg, choose the one with the latest timestamp.
1029 vdev_uberblock_compare(const uberblock_t
*ub1
, const uberblock_t
*ub2
)
1031 int cmp
= AVL_CMP(ub1
->ub_txg
, ub2
->ub_txg
);
1035 return (AVL_CMP(ub1
->ub_timestamp
, ub2
->ub_timestamp
));
1039 uberblock_t
*ubl_ubbest
; /* Best uberblock */
1040 vdev_t
*ubl_vd
; /* vdev associated with the above */
1044 vdev_uberblock_load_done(zio_t
*zio
)
1046 vdev_t
*vd
= zio
->io_vd
;
1047 spa_t
*spa
= zio
->io_spa
;
1048 zio_t
*rio
= zio
->io_private
;
1049 uberblock_t
*ub
= abd_to_buf(zio
->io_abd
);
1050 struct ubl_cbdata
*cbp
= rio
->io_private
;
1052 ASSERT3U(zio
->io_size
, ==, VDEV_UBERBLOCK_SIZE(vd
));
1054 if (zio
->io_error
== 0 && uberblock_verify(ub
) == 0) {
1055 mutex_enter(&rio
->io_lock
);
1056 if (ub
->ub_txg
<= spa
->spa_load_max_txg
&&
1057 vdev_uberblock_compare(ub
, cbp
->ubl_ubbest
) > 0) {
1059 * Keep track of the vdev in which this uberblock
1060 * was found. We will use this information later
1061 * to obtain the config nvlist associated with
1064 *cbp
->ubl_ubbest
= *ub
;
1067 mutex_exit(&rio
->io_lock
);
1070 abd_free(zio
->io_abd
);
1074 vdev_uberblock_load_impl(zio_t
*zio
, vdev_t
*vd
, int flags
,
1075 struct ubl_cbdata
*cbp
)
1079 for (c
= 0; c
< vd
->vdev_children
; c
++)
1080 vdev_uberblock_load_impl(zio
, vd
->vdev_child
[c
], flags
, cbp
);
1082 if (vd
->vdev_ops
->vdev_op_leaf
&& vdev_readable(vd
)) {
1083 for (l
= 0; l
< VDEV_LABELS
; l
++) {
1084 for (n
= 0; n
< VDEV_UBERBLOCK_COUNT(vd
); n
++) {
1085 vdev_label_read(zio
, vd
, l
,
1086 abd_alloc_linear(VDEV_UBERBLOCK_SIZE(vd
),
1087 B_TRUE
), VDEV_UBERBLOCK_OFFSET(vd
, n
),
1088 VDEV_UBERBLOCK_SIZE(vd
),
1089 vdev_uberblock_load_done
, zio
, flags
);
1096 * Reads the 'best' uberblock from disk along with its associated
1097 * configuration. First, we read the uberblock array of each label of each
1098 * vdev, keeping track of the uberblock with the highest txg in each array.
1099 * Then, we read the configuration from the same vdev as the best uberblock.
1102 vdev_uberblock_load(vdev_t
*rvd
, uberblock_t
*ub
, nvlist_t
**config
)
1105 spa_t
*spa
= rvd
->vdev_spa
;
1106 struct ubl_cbdata cb
;
1107 int flags
= ZIO_FLAG_CONFIG_WRITER
| ZIO_FLAG_CANFAIL
|
1108 ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_TRYHARD
;
1113 bzero(ub
, sizeof (uberblock_t
));
1119 spa_config_enter(spa
, SCL_ALL
, FTAG
, RW_WRITER
);
1120 zio
= zio_root(spa
, NULL
, &cb
, flags
);
1121 vdev_uberblock_load_impl(zio
, rvd
, flags
, &cb
);
1122 (void) zio_wait(zio
);
1125 * It's possible that the best uberblock was discovered on a label
1126 * that has a configuration which was written in a future txg.
1127 * Search all labels on this vdev to find the configuration that
1128 * matches the txg for our uberblock.
1130 if (cb
.ubl_vd
!= NULL
)
1131 *config
= vdev_label_read_config(cb
.ubl_vd
, ub
->ub_txg
);
1132 spa_config_exit(spa
, SCL_ALL
, FTAG
);
1136 * On success, increment root zio's count of good writes.
1137 * We only get credit for writes to known-visible vdevs; see spa_vdev_add().
1140 vdev_uberblock_sync_done(zio_t
*zio
)
1142 uint64_t *good_writes
= zio
->io_private
;
1144 if (zio
->io_error
== 0 && zio
->io_vd
->vdev_top
->vdev_ms_array
!= 0)
1145 atomic_inc_64(good_writes
);
1149 * Write the uberblock to all labels of all leaves of the specified vdev.
1152 vdev_uberblock_sync(zio_t
*zio
, uberblock_t
*ub
, vdev_t
*vd
, int flags
)
1157 for (c
= 0; c
< vd
->vdev_children
; c
++)
1158 vdev_uberblock_sync(zio
, ub
, vd
->vdev_child
[c
], flags
);
1160 if (!vd
->vdev_ops
->vdev_op_leaf
)
1163 if (!vdev_writeable(vd
))
1166 n
= ub
->ub_txg
& (VDEV_UBERBLOCK_COUNT(vd
) - 1);
1168 /* Copy the uberblock_t into the ABD */
1169 ub_abd
= abd_alloc_for_io(VDEV_UBERBLOCK_SIZE(vd
), B_TRUE
);
1170 abd_zero(ub_abd
, VDEV_UBERBLOCK_SIZE(vd
));
1171 abd_copy_from_buf(ub_abd
, ub
, sizeof (uberblock_t
));
1173 for (l
= 0; l
< VDEV_LABELS
; l
++)
1174 vdev_label_write(zio
, vd
, l
, ub_abd
,
1175 VDEV_UBERBLOCK_OFFSET(vd
, n
), VDEV_UBERBLOCK_SIZE(vd
),
1176 vdev_uberblock_sync_done
, zio
->io_private
,
1177 flags
| ZIO_FLAG_DONT_PROPAGATE
);
1182 /* Sync the uberblocks to all vdevs in svd[] */
1184 vdev_uberblock_sync_list(vdev_t
**svd
, int svdcount
, uberblock_t
*ub
, int flags
)
1186 spa_t
*spa
= svd
[0]->vdev_spa
;
1188 uint64_t good_writes
= 0;
1191 zio
= zio_root(spa
, NULL
, &good_writes
, flags
);
1193 for (v
= 0; v
< svdcount
; v
++)
1194 vdev_uberblock_sync(zio
, ub
, svd
[v
], flags
);
1196 (void) zio_wait(zio
);
1199 * Flush the uberblocks to disk. This ensures that the odd labels
1200 * are no longer needed (because the new uberblocks and the even
1201 * labels are safely on disk), so it is safe to overwrite them.
1203 zio
= zio_root(spa
, NULL
, NULL
, flags
);
1205 for (v
= 0; v
< svdcount
; v
++)
1206 zio_flush(zio
, svd
[v
]);
1208 (void) zio_wait(zio
);
1210 return (good_writes
>= 1 ? 0 : EIO
);
1214 * On success, increment the count of good writes for our top-level vdev.
1217 vdev_label_sync_done(zio_t
*zio
)
1219 uint64_t *good_writes
= zio
->io_private
;
1221 if (zio
->io_error
== 0)
1222 atomic_inc_64(good_writes
);
1226 * If there weren't enough good writes, indicate failure to the parent.
1229 vdev_label_sync_top_done(zio_t
*zio
)
1231 uint64_t *good_writes
= zio
->io_private
;
1233 if (*good_writes
== 0)
1234 zio
->io_error
= SET_ERROR(EIO
);
1236 kmem_free(good_writes
, sizeof (uint64_t));
1240 * We ignore errors for log and cache devices, simply free the private data.
1243 vdev_label_sync_ignore_done(zio_t
*zio
)
1245 kmem_free(zio
->io_private
, sizeof (uint64_t));
1249 * Write all even or odd labels to all leaves of the specified vdev.
1252 vdev_label_sync(zio_t
*zio
, vdev_t
*vd
, int l
, uint64_t txg
, int flags
)
1261 for (c
= 0; c
< vd
->vdev_children
; c
++)
1262 vdev_label_sync(zio
, vd
->vdev_child
[c
], l
, txg
, flags
);
1264 if (!vd
->vdev_ops
->vdev_op_leaf
)
1267 if (!vdev_writeable(vd
))
1271 * Generate a label describing the top-level config to which we belong.
1273 label
= spa_config_generate(vd
->vdev_spa
, vd
, txg
, B_FALSE
);
1275 vp_abd
= abd_alloc_linear(sizeof (vdev_phys_t
), B_TRUE
);
1276 abd_zero(vp_abd
, sizeof (vdev_phys_t
));
1277 vp
= abd_to_buf(vp_abd
);
1279 buf
= vp
->vp_nvlist
;
1280 buflen
= sizeof (vp
->vp_nvlist
);
1282 if (!nvlist_pack(label
, &buf
, &buflen
, NV_ENCODE_XDR
, KM_SLEEP
)) {
1283 for (; l
< VDEV_LABELS
; l
+= 2) {
1284 vdev_label_write(zio
, vd
, l
, vp_abd
,
1285 offsetof(vdev_label_t
, vl_vdev_phys
),
1286 sizeof (vdev_phys_t
),
1287 vdev_label_sync_done
, zio
->io_private
,
1288 flags
| ZIO_FLAG_DONT_PROPAGATE
);
1297 vdev_label_sync_list(spa_t
*spa
, int l
, uint64_t txg
, int flags
)
1299 list_t
*dl
= &spa
->spa_config_dirty_list
;
1305 * Write the new labels to disk.
1307 zio
= zio_root(spa
, NULL
, NULL
, flags
);
1309 for (vd
= list_head(dl
); vd
!= NULL
; vd
= list_next(dl
, vd
)) {
1310 uint64_t *good_writes
;
1313 ASSERT(!vd
->vdev_ishole
);
1315 good_writes
= kmem_zalloc(sizeof (uint64_t), KM_SLEEP
);
1316 vio
= zio_null(zio
, spa
, NULL
,
1317 (vd
->vdev_islog
|| vd
->vdev_aux
!= NULL
) ?
1318 vdev_label_sync_ignore_done
: vdev_label_sync_top_done
,
1319 good_writes
, flags
);
1320 vdev_label_sync(vio
, vd
, l
, txg
, flags
);
1324 error
= zio_wait(zio
);
1327 * Flush the new labels to disk.
1329 zio
= zio_root(spa
, NULL
, NULL
, flags
);
1331 for (vd
= list_head(dl
); vd
!= NULL
; vd
= list_next(dl
, vd
))
1334 (void) zio_wait(zio
);
1340 * Sync the uberblock and any changes to the vdev configuration.
1342 * The order of operations is carefully crafted to ensure that
1343 * if the system panics or loses power at any time, the state on disk
1344 * is still transactionally consistent. The in-line comments below
1345 * describe the failure semantics at each stage.
1347 * Moreover, vdev_config_sync() is designed to be idempotent: if it fails
1348 * at any time, you can just call it again, and it will resume its work.
1351 vdev_config_sync(vdev_t
**svd
, int svdcount
, uint64_t txg
)
1353 spa_t
*spa
= svd
[0]->vdev_spa
;
1354 uberblock_t
*ub
= &spa
->spa_uberblock
;
1358 int flags
= ZIO_FLAG_CONFIG_WRITER
| ZIO_FLAG_CANFAIL
;
1362 * Normally, we don't want to try too hard to write every label and
1363 * uberblock. If there is a flaky disk, we don't want the rest of the
1364 * sync process to block while we retry. But if we can't write a
1365 * single label out, we should retry with ZIO_FLAG_TRYHARD before
1366 * bailing out and declaring the pool faulted.
1369 if ((flags
& ZIO_FLAG_TRYHARD
) != 0)
1371 flags
|= ZIO_FLAG_TRYHARD
;
1374 ASSERT(ub
->ub_txg
<= txg
);
1377 * If this isn't a resync due to I/O errors,
1378 * and nothing changed in this transaction group,
1379 * and the vdev configuration hasn't changed,
1380 * then there's nothing to do.
1382 if (ub
->ub_txg
< txg
&&
1383 uberblock_update(ub
, spa
->spa_root_vdev
, txg
) == B_FALSE
&&
1384 list_is_empty(&spa
->spa_config_dirty_list
))
1387 if (txg
> spa_freeze_txg(spa
))
1390 ASSERT(txg
<= spa
->spa_final_txg
);
1393 * Flush the write cache of every disk that's been written to
1394 * in this transaction group. This ensures that all blocks
1395 * written in this txg will be committed to stable storage
1396 * before any uberblock that references them.
1398 zio
= zio_root(spa
, NULL
, NULL
, flags
);
1400 for (vd
= txg_list_head(&spa
->spa_vdev_txg_list
, TXG_CLEAN(txg
)); vd
;
1401 vd
= txg_list_next(&spa
->spa_vdev_txg_list
, vd
, TXG_CLEAN(txg
)))
1404 (void) zio_wait(zio
);
1407 * Sync out the even labels (L0, L2) for every dirty vdev. If the
1408 * system dies in the middle of this process, that's OK: all of the
1409 * even labels that made it to disk will be newer than any uberblock,
1410 * and will therefore be considered invalid. The odd labels (L1, L3),
1411 * which have not yet been touched, will still be valid. We flush
1412 * the new labels to disk to ensure that all even-label updates
1413 * are committed to stable storage before the uberblock update.
1415 if ((error
= vdev_label_sync_list(spa
, 0, txg
, flags
)) != 0)
1419 * Sync the uberblocks to all vdevs in svd[].
1420 * If the system dies in the middle of this step, there are two cases
1421 * to consider, and the on-disk state is consistent either way:
1423 * (1) If none of the new uberblocks made it to disk, then the
1424 * previous uberblock will be the newest, and the odd labels
1425 * (which had not yet been touched) will be valid with respect
1426 * to that uberblock.
1428 * (2) If one or more new uberblocks made it to disk, then they
1429 * will be the newest, and the even labels (which had all
1430 * been successfully committed) will be valid with respect
1431 * to the new uberblocks.
1433 if ((error
= vdev_uberblock_sync_list(svd
, svdcount
, ub
, flags
)) != 0)
1437 * Sync out odd labels for every dirty vdev. If the system dies
1438 * in the middle of this process, the even labels and the new
1439 * uberblocks will suffice to open the pool. The next time
1440 * the pool is opened, the first thing we'll do -- before any
1441 * user data is modified -- is mark every vdev dirty so that
1442 * all labels will be brought up to date. We flush the new labels
1443 * to disk to ensure that all odd-label updates are committed to
1444 * stable storage before the next transaction group begins.
1446 if ((error
= vdev_label_sync_list(spa
, 1, txg
, flags
)) != 0)