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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 | /* | |
d164b209 | 22 | * Copyright 2009 Sun Microsystems, Inc. All rights reserved. |
34dc7c2f BB |
23 | * Use is subject to license terms. |
24 | */ | |
25 | ||
34dc7c2f BB |
26 | #include <sys/zfs_context.h> |
27 | #include <sys/spa.h> | |
28 | #include <sys/vdev_impl.h> | |
29 | #include <sys/zio.h> | |
30 | #include <sys/fs/zfs.h> | |
31 | ||
32 | /* | |
33 | * Virtual device vector for mirroring. | |
34 | */ | |
35 | ||
36 | typedef struct mirror_child { | |
37 | vdev_t *mc_vd; | |
38 | uint64_t mc_offset; | |
39 | int mc_error; | |
b128c09f BB |
40 | uint8_t mc_tried; |
41 | uint8_t mc_skipped; | |
42 | uint8_t mc_speculative; | |
34dc7c2f BB |
43 | } mirror_child_t; |
44 | ||
45 | typedef struct mirror_map { | |
46 | int mm_children; | |
47 | int mm_replacing; | |
48 | int mm_preferred; | |
49 | int mm_root; | |
50 | mirror_child_t mm_child[1]; | |
51 | } mirror_map_t; | |
52 | ||
53 | int vdev_mirror_shift = 21; | |
54 | ||
b128c09f BB |
55 | static void |
56 | vdev_mirror_map_free(zio_t *zio) | |
57 | { | |
58 | mirror_map_t *mm = zio->io_vsd; | |
59 | ||
60 | kmem_free(mm, offsetof(mirror_map_t, mm_child[mm->mm_children])); | |
61 | } | |
62 | ||
34dc7c2f BB |
63 | static mirror_map_t * |
64 | vdev_mirror_map_alloc(zio_t *zio) | |
65 | { | |
66 | mirror_map_t *mm = NULL; | |
67 | mirror_child_t *mc; | |
68 | vdev_t *vd = zio->io_vd; | |
69 | int c, d; | |
70 | ||
71 | if (vd == NULL) { | |
72 | dva_t *dva = zio->io_bp->blk_dva; | |
73 | spa_t *spa = zio->io_spa; | |
74 | ||
75 | c = BP_GET_NDVAS(zio->io_bp); | |
76 | ||
77 | mm = kmem_zalloc(offsetof(mirror_map_t, mm_child[c]), KM_SLEEP); | |
78 | mm->mm_children = c; | |
79 | mm->mm_replacing = B_FALSE; | |
80 | mm->mm_preferred = spa_get_random(c); | |
81 | mm->mm_root = B_TRUE; | |
82 | ||
83 | /* | |
84 | * Check the other, lower-index DVAs to see if they're on | |
85 | * the same vdev as the child we picked. If they are, use | |
86 | * them since they are likely to have been allocated from | |
87 | * the primary metaslab in use at the time, and hence are | |
88 | * more likely to have locality with single-copy data. | |
89 | */ | |
90 | for (c = mm->mm_preferred, d = c - 1; d >= 0; d--) { | |
91 | if (DVA_GET_VDEV(&dva[d]) == DVA_GET_VDEV(&dva[c])) | |
92 | mm->mm_preferred = d; | |
93 | } | |
94 | ||
95 | for (c = 0; c < mm->mm_children; c++) { | |
96 | mc = &mm->mm_child[c]; | |
97 | ||
98 | mc->mc_vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[c])); | |
99 | mc->mc_offset = DVA_GET_OFFSET(&dva[c]); | |
100 | } | |
101 | } else { | |
102 | c = vd->vdev_children; | |
103 | ||
104 | mm = kmem_zalloc(offsetof(mirror_map_t, mm_child[c]), KM_SLEEP); | |
105 | mm->mm_children = c; | |
106 | mm->mm_replacing = (vd->vdev_ops == &vdev_replacing_ops || | |
107 | vd->vdev_ops == &vdev_spare_ops); | |
108 | mm->mm_preferred = mm->mm_replacing ? 0 : | |
109 | (zio->io_offset >> vdev_mirror_shift) % c; | |
110 | mm->mm_root = B_FALSE; | |
111 | ||
112 | for (c = 0; c < mm->mm_children; c++) { | |
113 | mc = &mm->mm_child[c]; | |
114 | mc->mc_vd = vd->vdev_child[c]; | |
115 | mc->mc_offset = zio->io_offset; | |
116 | } | |
117 | } | |
118 | ||
119 | zio->io_vsd = mm; | |
b128c09f | 120 | zio->io_vsd_free = vdev_mirror_map_free; |
34dc7c2f BB |
121 | return (mm); |
122 | } | |
123 | ||
34dc7c2f BB |
124 | static int |
125 | vdev_mirror_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift) | |
126 | { | |
127 | vdev_t *cvd; | |
128 | uint64_t c; | |
129 | int numerrors = 0; | |
130 | int ret, lasterror = 0; | |
131 | ||
132 | if (vd->vdev_children == 0) { | |
133 | vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; | |
134 | return (EINVAL); | |
135 | } | |
136 | ||
137 | for (c = 0; c < vd->vdev_children; c++) { | |
138 | cvd = vd->vdev_child[c]; | |
139 | ||
140 | if ((ret = vdev_open(cvd)) != 0) { | |
141 | lasterror = ret; | |
142 | numerrors++; | |
143 | continue; | |
144 | } | |
145 | ||
146 | *asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1; | |
147 | *ashift = MAX(*ashift, cvd->vdev_ashift); | |
148 | } | |
149 | ||
150 | if (numerrors == vd->vdev_children) { | |
151 | vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; | |
152 | return (lasterror); | |
153 | } | |
154 | ||
155 | return (0); | |
156 | } | |
157 | ||
158 | static void | |
159 | vdev_mirror_close(vdev_t *vd) | |
160 | { | |
161 | uint64_t c; | |
162 | ||
163 | for (c = 0; c < vd->vdev_children; c++) | |
164 | vdev_close(vd->vdev_child[c]); | |
165 | } | |
166 | ||
167 | static void | |
168 | vdev_mirror_child_done(zio_t *zio) | |
169 | { | |
170 | mirror_child_t *mc = zio->io_private; | |
171 | ||
172 | mc->mc_error = zio->io_error; | |
173 | mc->mc_tried = 1; | |
174 | mc->mc_skipped = 0; | |
175 | } | |
176 | ||
177 | static void | |
178 | vdev_mirror_scrub_done(zio_t *zio) | |
179 | { | |
180 | mirror_child_t *mc = zio->io_private; | |
181 | ||
182 | if (zio->io_error == 0) { | |
d164b209 BB |
183 | zio_t *pio; |
184 | ||
185 | mutex_enter(&zio->io_lock); | |
186 | while ((pio = zio_walk_parents(zio)) != NULL) { | |
187 | mutex_enter(&pio->io_lock); | |
188 | ASSERT3U(zio->io_size, >=, pio->io_size); | |
189 | bcopy(zio->io_data, pio->io_data, pio->io_size); | |
190 | mutex_exit(&pio->io_lock); | |
191 | } | |
192 | mutex_exit(&zio->io_lock); | |
34dc7c2f BB |
193 | } |
194 | ||
195 | zio_buf_free(zio->io_data, zio->io_size); | |
196 | ||
197 | mc->mc_error = zio->io_error; | |
198 | mc->mc_tried = 1; | |
199 | mc->mc_skipped = 0; | |
200 | } | |
201 | ||
34dc7c2f BB |
202 | /* |
203 | * Try to find a child whose DTL doesn't contain the block we want to read. | |
204 | * If we can't, try the read on any vdev we haven't already tried. | |
205 | */ | |
206 | static int | |
207 | vdev_mirror_child_select(zio_t *zio) | |
208 | { | |
209 | mirror_map_t *mm = zio->io_vsd; | |
210 | mirror_child_t *mc; | |
211 | uint64_t txg = zio->io_txg; | |
212 | int i, c; | |
213 | ||
214 | ASSERT(zio->io_bp == NULL || zio->io_bp->blk_birth == txg); | |
215 | ||
216 | /* | |
217 | * Try to find a child whose DTL doesn't contain the block to read. | |
218 | * If a child is known to be completely inaccessible (indicated by | |
219 | * vdev_readable() returning B_FALSE), don't even try. | |
220 | */ | |
221 | for (i = 0, c = mm->mm_preferred; i < mm->mm_children; i++, c++) { | |
222 | if (c >= mm->mm_children) | |
223 | c = 0; | |
224 | mc = &mm->mm_child[c]; | |
225 | if (mc->mc_tried || mc->mc_skipped) | |
226 | continue; | |
b128c09f | 227 | if (!vdev_readable(mc->mc_vd)) { |
34dc7c2f BB |
228 | mc->mc_error = ENXIO; |
229 | mc->mc_tried = 1; /* don't even try */ | |
230 | mc->mc_skipped = 1; | |
231 | continue; | |
232 | } | |
fb5f0bc8 | 233 | if (!vdev_dtl_contains(mc->mc_vd, DTL_MISSING, txg, 1)) |
34dc7c2f BB |
234 | return (c); |
235 | mc->mc_error = ESTALE; | |
236 | mc->mc_skipped = 1; | |
b128c09f | 237 | mc->mc_speculative = 1; |
34dc7c2f BB |
238 | } |
239 | ||
240 | /* | |
241 | * Every device is either missing or has this txg in its DTL. | |
242 | * Look for any child we haven't already tried before giving up. | |
243 | */ | |
244 | for (c = 0; c < mm->mm_children; c++) | |
245 | if (!mm->mm_child[c].mc_tried) | |
246 | return (c); | |
247 | ||
248 | /* | |
249 | * Every child failed. There's no place left to look. | |
250 | */ | |
251 | return (-1); | |
252 | } | |
253 | ||
254 | static int | |
255 | vdev_mirror_io_start(zio_t *zio) | |
256 | { | |
257 | mirror_map_t *mm; | |
258 | mirror_child_t *mc; | |
259 | int c, children; | |
260 | ||
261 | mm = vdev_mirror_map_alloc(zio); | |
262 | ||
263 | if (zio->io_type == ZIO_TYPE_READ) { | |
264 | if ((zio->io_flags & ZIO_FLAG_SCRUB) && !mm->mm_replacing) { | |
265 | /* | |
266 | * For scrubbing reads we need to allocate a read | |
267 | * buffer for each child and issue reads to all | |
268 | * children. If any child succeeds, it will copy its | |
269 | * data into zio->io_data in vdev_mirror_scrub_done. | |
270 | */ | |
271 | for (c = 0; c < mm->mm_children; c++) { | |
272 | mc = &mm->mm_child[c]; | |
273 | zio_nowait(zio_vdev_child_io(zio, zio->io_bp, | |
274 | mc->mc_vd, mc->mc_offset, | |
275 | zio_buf_alloc(zio->io_size), zio->io_size, | |
b128c09f | 276 | zio->io_type, zio->io_priority, 0, |
34dc7c2f BB |
277 | vdev_mirror_scrub_done, mc)); |
278 | } | |
b128c09f | 279 | return (ZIO_PIPELINE_CONTINUE); |
34dc7c2f BB |
280 | } |
281 | /* | |
282 | * For normal reads just pick one child. | |
283 | */ | |
284 | c = vdev_mirror_child_select(zio); | |
285 | children = (c >= 0); | |
286 | } else { | |
287 | ASSERT(zio->io_type == ZIO_TYPE_WRITE); | |
288 | ||
289 | /* | |
fb5f0bc8 | 290 | * Writes go to all children. |
34dc7c2f | 291 | */ |
fb5f0bc8 BB |
292 | c = 0; |
293 | children = mm->mm_children; | |
34dc7c2f BB |
294 | } |
295 | ||
296 | while (children--) { | |
297 | mc = &mm->mm_child[c]; | |
298 | zio_nowait(zio_vdev_child_io(zio, zio->io_bp, | |
b128c09f BB |
299 | mc->mc_vd, mc->mc_offset, zio->io_data, zio->io_size, |
300 | zio->io_type, zio->io_priority, 0, | |
301 | vdev_mirror_child_done, mc)); | |
34dc7c2f BB |
302 | c++; |
303 | } | |
304 | ||
b128c09f | 305 | return (ZIO_PIPELINE_CONTINUE); |
34dc7c2f BB |
306 | } |
307 | ||
308 | static int | |
b128c09f BB |
309 | vdev_mirror_worst_error(mirror_map_t *mm) |
310 | { | |
311 | int error[2] = { 0, 0 }; | |
312 | ||
313 | for (int c = 0; c < mm->mm_children; c++) { | |
314 | mirror_child_t *mc = &mm->mm_child[c]; | |
315 | int s = mc->mc_speculative; | |
316 | error[s] = zio_worst_error(error[s], mc->mc_error); | |
317 | } | |
318 | ||
319 | return (error[0] ? error[0] : error[1]); | |
320 | } | |
321 | ||
322 | static void | |
34dc7c2f BB |
323 | vdev_mirror_io_done(zio_t *zio) |
324 | { | |
325 | mirror_map_t *mm = zio->io_vsd; | |
326 | mirror_child_t *mc; | |
327 | int c; | |
328 | int good_copies = 0; | |
329 | int unexpected_errors = 0; | |
330 | ||
34dc7c2f BB |
331 | for (c = 0; c < mm->mm_children; c++) { |
332 | mc = &mm->mm_child[c]; | |
333 | ||
34dc7c2f | 334 | if (mc->mc_error) { |
34dc7c2f BB |
335 | if (!mc->mc_skipped) |
336 | unexpected_errors++; | |
b128c09f BB |
337 | } else if (mc->mc_tried) { |
338 | good_copies++; | |
34dc7c2f BB |
339 | } |
340 | } | |
341 | ||
342 | if (zio->io_type == ZIO_TYPE_WRITE) { | |
343 | /* | |
344 | * XXX -- for now, treat partial writes as success. | |
b128c09f BB |
345 | * |
346 | * Now that we support write reallocation, it would be better | |
347 | * to treat partial failure as real failure unless there are | |
348 | * no non-degraded top-level vdevs left, and not update DTLs | |
349 | * if we intend to reallocate. | |
34dc7c2f BB |
350 | */ |
351 | /* XXPOLICY */ | |
b128c09f BB |
352 | if (good_copies != mm->mm_children) { |
353 | /* | |
354 | * Always require at least one good copy. | |
355 | * | |
356 | * For ditto blocks (io_vd == NULL), require | |
357 | * all copies to be good. | |
358 | * | |
359 | * XXX -- for replacing vdevs, there's no great answer. | |
360 | * If the old device is really dead, we may not even | |
361 | * be able to access it -- so we only want to | |
362 | * require good writes to the new device. But if | |
363 | * the new device turns out to be flaky, we want | |
364 | * to be able to detach it -- which requires all | |
365 | * writes to the old device to have succeeded. | |
366 | */ | |
367 | if (good_copies == 0 || zio->io_vd == NULL) | |
368 | zio->io_error = vdev_mirror_worst_error(mm); | |
369 | } | |
370 | return; | |
34dc7c2f BB |
371 | } |
372 | ||
373 | ASSERT(zio->io_type == ZIO_TYPE_READ); | |
374 | ||
375 | /* | |
376 | * If we don't have a good copy yet, keep trying other children. | |
377 | */ | |
378 | /* XXPOLICY */ | |
379 | if (good_copies == 0 && (c = vdev_mirror_child_select(zio)) != -1) { | |
380 | ASSERT(c >= 0 && c < mm->mm_children); | |
381 | mc = &mm->mm_child[c]; | |
34dc7c2f BB |
382 | zio_vdev_io_redone(zio); |
383 | zio_nowait(zio_vdev_child_io(zio, zio->io_bp, | |
384 | mc->mc_vd, mc->mc_offset, zio->io_data, zio->io_size, | |
b128c09f | 385 | ZIO_TYPE_READ, zio->io_priority, 0, |
34dc7c2f | 386 | vdev_mirror_child_done, mc)); |
b128c09f | 387 | return; |
34dc7c2f BB |
388 | } |
389 | ||
390 | /* XXPOLICY */ | |
b128c09f BB |
391 | if (good_copies == 0) { |
392 | zio->io_error = vdev_mirror_worst_error(mm); | |
34dc7c2f | 393 | ASSERT(zio->io_error != 0); |
b128c09f | 394 | } |
34dc7c2f | 395 | |
fb5f0bc8 | 396 | if (good_copies && spa_writeable(zio->io_spa) && |
34dc7c2f BB |
397 | (unexpected_errors || |
398 | (zio->io_flags & ZIO_FLAG_RESILVER) || | |
399 | ((zio->io_flags & ZIO_FLAG_SCRUB) && mm->mm_replacing))) { | |
34dc7c2f BB |
400 | /* |
401 | * Use the good data we have in hand to repair damaged children. | |
34dc7c2f | 402 | */ |
34dc7c2f BB |
403 | for (c = 0; c < mm->mm_children; c++) { |
404 | /* | |
405 | * Don't rewrite known good children. | |
406 | * Not only is it unnecessary, it could | |
407 | * actually be harmful: if the system lost | |
408 | * power while rewriting the only good copy, | |
409 | * there would be no good copies left! | |
410 | */ | |
411 | mc = &mm->mm_child[c]; | |
412 | ||
413 | if (mc->mc_error == 0) { | |
414 | if (mc->mc_tried) | |
415 | continue; | |
416 | if (!(zio->io_flags & ZIO_FLAG_SCRUB) && | |
fb5f0bc8 | 417 | !vdev_dtl_contains(mc->mc_vd, DTL_PARTIAL, |
34dc7c2f BB |
418 | zio->io_txg, 1)) |
419 | continue; | |
420 | mc->mc_error = ESTALE; | |
421 | } | |
422 | ||
b128c09f BB |
423 | zio_nowait(zio_vdev_child_io(zio, zio->io_bp, |
424 | mc->mc_vd, mc->mc_offset, | |
425 | zio->io_data, zio->io_size, | |
34dc7c2f | 426 | ZIO_TYPE_WRITE, zio->io_priority, |
fb5f0bc8 BB |
427 | ZIO_FLAG_IO_REPAIR | (unexpected_errors ? |
428 | ZIO_FLAG_SELF_HEAL : 0), NULL, NULL)); | |
34dc7c2f | 429 | } |
34dc7c2f | 430 | } |
34dc7c2f BB |
431 | } |
432 | ||
433 | static void | |
434 | vdev_mirror_state_change(vdev_t *vd, int faulted, int degraded) | |
435 | { | |
436 | if (faulted == vd->vdev_children) | |
437 | vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, | |
438 | VDEV_AUX_NO_REPLICAS); | |
439 | else if (degraded + faulted != 0) | |
440 | vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); | |
441 | else | |
442 | vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); | |
443 | } | |
444 | ||
445 | vdev_ops_t vdev_mirror_ops = { | |
446 | vdev_mirror_open, | |
447 | vdev_mirror_close, | |
34dc7c2f BB |
448 | vdev_default_asize, |
449 | vdev_mirror_io_start, | |
450 | vdev_mirror_io_done, | |
451 | vdev_mirror_state_change, | |
452 | VDEV_TYPE_MIRROR, /* name of this vdev type */ | |
453 | B_FALSE /* not a leaf vdev */ | |
454 | }; | |
455 | ||
456 | vdev_ops_t vdev_replacing_ops = { | |
457 | vdev_mirror_open, | |
458 | vdev_mirror_close, | |
34dc7c2f BB |
459 | vdev_default_asize, |
460 | vdev_mirror_io_start, | |
461 | vdev_mirror_io_done, | |
462 | vdev_mirror_state_change, | |
463 | VDEV_TYPE_REPLACING, /* name of this vdev type */ | |
464 | B_FALSE /* not a leaf vdev */ | |
465 | }; | |
466 | ||
467 | vdev_ops_t vdev_spare_ops = { | |
468 | vdev_mirror_open, | |
469 | vdev_mirror_close, | |
34dc7c2f BB |
470 | vdev_default_asize, |
471 | vdev_mirror_io_start, | |
472 | vdev_mirror_io_done, | |
473 | vdev_mirror_state_change, | |
474 | VDEV_TYPE_SPARE, /* name of this vdev type */ | |
475 | B_FALSE /* not a leaf vdev */ | |
476 | }; |