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3748 zfs headers should be C++ compatible
Submitted by: Justin Gibbs <justing@spectralogic.com>
Submitted by: Will Andrews <willa@spectralogic.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
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--- old/usr/src/uts/common/fs/zfs/zio.c
+++ new/usr/src/uts/common/fs/zfs/zio.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /*
22 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
25 25 */
26 26
27 27 #include <sys/zfs_context.h>
28 28 #include <sys/fm/fs/zfs.h>
29 29 #include <sys/spa.h>
30 30 #include <sys/txg.h>
31 31 #include <sys/spa_impl.h>
32 32 #include <sys/vdev_impl.h>
33 33 #include <sys/zio_impl.h>
34 34 #include <sys/zio_compress.h>
35 35 #include <sys/zio_checksum.h>
36 36 #include <sys/dmu_objset.h>
37 37 #include <sys/arc.h>
38 38 #include <sys/ddt.h>
39 39
40 40 /*
41 41 * ==========================================================================
42 42 * I/O priority table
43 43 * ==========================================================================
44 44 */
45 45 uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE] = {
46 46 0, /* ZIO_PRIORITY_NOW */
47 47 0, /* ZIO_PRIORITY_SYNC_READ */
48 48 0, /* ZIO_PRIORITY_SYNC_WRITE */
49 49 0, /* ZIO_PRIORITY_LOG_WRITE */
50 50 1, /* ZIO_PRIORITY_CACHE_FILL */
51 51 1, /* ZIO_PRIORITY_AGG */
52 52 4, /* ZIO_PRIORITY_FREE */
53 53 4, /* ZIO_PRIORITY_ASYNC_WRITE */
54 54 6, /* ZIO_PRIORITY_ASYNC_READ */
55 55 10, /* ZIO_PRIORITY_RESILVER */
56 56 20, /* ZIO_PRIORITY_SCRUB */
57 57 2, /* ZIO_PRIORITY_DDT_PREFETCH */
58 58 };
59 59
60 60 /*
61 61 * ==========================================================================
62 62 * I/O type descriptions
63 63 * ==========================================================================
64 64 */
65 65 char *zio_type_name[ZIO_TYPES] = {
66 66 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim",
67 67 "zio_ioctl"
68 68 };
69 69
70 70 /*
71 71 * ==========================================================================
72 72 * I/O kmem caches
73 73 * ==========================================================================
74 74 */
75 75 kmem_cache_t *zio_cache;
76 76 kmem_cache_t *zio_link_cache;
77 77 kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
78 78 kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
79 79
80 80 #ifdef _KERNEL
81 81 extern vmem_t *zio_alloc_arena;
82 82 #endif
83 83 extern int zfs_mg_alloc_failures;
84 84
85 85 /*
86 86 * The following actions directly effect the spa's sync-to-convergence logic.
87 87 * The values below define the sync pass when we start performing the action.
88 88 * Care should be taken when changing these values as they directly impact
89 89 * spa_sync() performance. Tuning these values may introduce subtle performance
90 90 * pathologies and should only be done in the context of performance analysis.
91 91 * These tunables will eventually be removed and replaced with #defines once
92 92 * enough analysis has been done to determine optimal values.
93 93 *
94 94 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that
95 95 * regular blocks are not deferred.
96 96 */
97 97 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */
98 98 int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */
99 99 int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */
100 100
101 101 /*
102 102 * An allocating zio is one that either currently has the DVA allocate
103 103 * stage set or will have it later in its lifetime.
104 104 */
105 105 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE)
106 106
107 107 boolean_t zio_requeue_io_start_cut_in_line = B_TRUE;
108 108
109 109 #ifdef ZFS_DEBUG
110 110 int zio_buf_debug_limit = 16384;
111 111 #else
112 112 int zio_buf_debug_limit = 0;
113 113 #endif
114 114
115 115 void
116 116 zio_init(void)
117 117 {
118 118 size_t c;
119 119 vmem_t *data_alloc_arena = NULL;
120 120
121 121 #ifdef _KERNEL
122 122 data_alloc_arena = zio_alloc_arena;
123 123 #endif
124 124 zio_cache = kmem_cache_create("zio_cache",
125 125 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
126 126 zio_link_cache = kmem_cache_create("zio_link_cache",
127 127 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
128 128
129 129 /*
130 130 * For small buffers, we want a cache for each multiple of
131 131 * SPA_MINBLOCKSIZE. For medium-size buffers, we want a cache
132 132 * for each quarter-power of 2. For large buffers, we want
133 133 * a cache for each multiple of PAGESIZE.
134 134 */
135 135 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
136 136 size_t size = (c + 1) << SPA_MINBLOCKSHIFT;
137 137 size_t p2 = size;
138 138 size_t align = 0;
139 139 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0;
140 140
141 141 while (p2 & (p2 - 1))
142 142 p2 &= p2 - 1;
143 143
144 144 #ifndef _KERNEL
145 145 /*
146 146 * If we are using watchpoints, put each buffer on its own page,
147 147 * to eliminate the performance overhead of trapping to the
148 148 * kernel when modifying a non-watched buffer that shares the
149 149 * page with a watched buffer.
150 150 */
151 151 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE))
152 152 continue;
153 153 #endif
154 154 if (size <= 4 * SPA_MINBLOCKSIZE) {
155 155 align = SPA_MINBLOCKSIZE;
156 156 } else if (IS_P2ALIGNED(size, PAGESIZE)) {
157 157 align = PAGESIZE;
158 158 } else if (IS_P2ALIGNED(size, p2 >> 2)) {
159 159 align = p2 >> 2;
160 160 }
161 161
162 162 if (align != 0) {
163 163 char name[36];
164 164 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size);
165 165 zio_buf_cache[c] = kmem_cache_create(name, size,
166 166 align, NULL, NULL, NULL, NULL, NULL, cflags);
167 167
168 168 /*
169 169 * Since zio_data bufs do not appear in crash dumps, we
170 170 * pass KMC_NOTOUCH so that no allocator metadata is
171 171 * stored with the buffers.
172 172 */
173 173 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size);
174 174 zio_data_buf_cache[c] = kmem_cache_create(name, size,
175 175 align, NULL, NULL, NULL, NULL, data_alloc_arena,
176 176 cflags | KMC_NOTOUCH);
177 177 }
178 178 }
179 179
180 180 while (--c != 0) {
181 181 ASSERT(zio_buf_cache[c] != NULL);
182 182 if (zio_buf_cache[c - 1] == NULL)
183 183 zio_buf_cache[c - 1] = zio_buf_cache[c];
184 184
185 185 ASSERT(zio_data_buf_cache[c] != NULL);
186 186 if (zio_data_buf_cache[c - 1] == NULL)
187 187 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c];
188 188 }
189 189
190 190 /*
191 191 * The zio write taskqs have 1 thread per cpu, allow 1/2 of the taskqs
192 192 * to fail 3 times per txg or 8 failures, whichever is greater.
193 193 */
194 194 zfs_mg_alloc_failures = MAX((3 * max_ncpus / 2), 8);
195 195
196 196 zio_inject_init();
197 197 }
198 198
199 199 void
200 200 zio_fini(void)
201 201 {
202 202 size_t c;
203 203 kmem_cache_t *last_cache = NULL;
204 204 kmem_cache_t *last_data_cache = NULL;
205 205
206 206 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
207 207 if (zio_buf_cache[c] != last_cache) {
208 208 last_cache = zio_buf_cache[c];
209 209 kmem_cache_destroy(zio_buf_cache[c]);
210 210 }
211 211 zio_buf_cache[c] = NULL;
212 212
213 213 if (zio_data_buf_cache[c] != last_data_cache) {
214 214 last_data_cache = zio_data_buf_cache[c];
215 215 kmem_cache_destroy(zio_data_buf_cache[c]);
216 216 }
217 217 zio_data_buf_cache[c] = NULL;
218 218 }
219 219
220 220 kmem_cache_destroy(zio_link_cache);
221 221 kmem_cache_destroy(zio_cache);
222 222
223 223 zio_inject_fini();
224 224 }
225 225
226 226 /*
227 227 * ==========================================================================
228 228 * Allocate and free I/O buffers
229 229 * ==========================================================================
230 230 */
231 231
232 232 /*
233 233 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a
234 234 * crashdump if the kernel panics, so use it judiciously. Obviously, it's
235 235 * useful to inspect ZFS metadata, but if possible, we should avoid keeping
236 236 * excess / transient data in-core during a crashdump.
237 237 */
238 238 void *
239 239 zio_buf_alloc(size_t size)
240 240 {
241 241 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
242 242
243 243 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
244 244
245 245 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE));
246 246 }
247 247
248 248 /*
249 249 * Use zio_data_buf_alloc to allocate data. The data will not appear in a
250 250 * crashdump if the kernel panics. This exists so that we will limit the amount
251 251 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount
252 252 * of kernel heap dumped to disk when the kernel panics)
253 253 */
254 254 void *
255 255 zio_data_buf_alloc(size_t size)
256 256 {
257 257 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
258 258
259 259 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
260 260
261 261 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE));
262 262 }
263 263
264 264 void
265 265 zio_buf_free(void *buf, size_t size)
266 266 {
267 267 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
268 268
269 269 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
270 270
271 271 kmem_cache_free(zio_buf_cache[c], buf);
272 272 }
273 273
274 274 void
275 275 zio_data_buf_free(void *buf, size_t size)
276 276 {
277 277 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
278 278
279 279 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
280 280
281 281 kmem_cache_free(zio_data_buf_cache[c], buf);
282 282 }
283 283
284 284 /*
285 285 * ==========================================================================
286 286 * Push and pop I/O transform buffers
287 287 * ==========================================================================
288 288 */
289 289 static void
290 290 zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize,
291 291 zio_transform_func_t *transform)
292 292 {
293 293 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP);
294 294
295 295 zt->zt_orig_data = zio->io_data;
296 296 zt->zt_orig_size = zio->io_size;
297 297 zt->zt_bufsize = bufsize;
298 298 zt->zt_transform = transform;
299 299
300 300 zt->zt_next = zio->io_transform_stack;
301 301 zio->io_transform_stack = zt;
302 302
303 303 zio->io_data = data;
304 304 zio->io_size = size;
305 305 }
306 306
307 307 static void
308 308 zio_pop_transforms(zio_t *zio)
309 309 {
310 310 zio_transform_t *zt;
311 311
312 312 while ((zt = zio->io_transform_stack) != NULL) {
313 313 if (zt->zt_transform != NULL)
314 314 zt->zt_transform(zio,
315 315 zt->zt_orig_data, zt->zt_orig_size);
316 316
317 317 if (zt->zt_bufsize != 0)
318 318 zio_buf_free(zio->io_data, zt->zt_bufsize);
319 319
320 320 zio->io_data = zt->zt_orig_data;
321 321 zio->io_size = zt->zt_orig_size;
322 322 zio->io_transform_stack = zt->zt_next;
323 323
324 324 kmem_free(zt, sizeof (zio_transform_t));
325 325 }
326 326 }
327 327
328 328 /*
329 329 * ==========================================================================
330 330 * I/O transform callbacks for subblocks and decompression
331 331 * ==========================================================================
332 332 */
333 333 static void
334 334 zio_subblock(zio_t *zio, void *data, uint64_t size)
335 335 {
336 336 ASSERT(zio->io_size > size);
337 337
338 338 if (zio->io_type == ZIO_TYPE_READ)
339 339 bcopy(zio->io_data, data, size);
340 340 }
341 341
342 342 static void
343 343 zio_decompress(zio_t *zio, void *data, uint64_t size)
344 344 {
345 345 if (zio->io_error == 0 &&
346 346 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp),
347 347 zio->io_data, data, zio->io_size, size) != 0)
348 348 zio->io_error = SET_ERROR(EIO);
349 349 }
350 350
351 351 /*
352 352 * ==========================================================================
353 353 * I/O parent/child relationships and pipeline interlocks
354 354 * ==========================================================================
355 355 */
356 356 /*
357 357 * NOTE - Callers to zio_walk_parents() and zio_walk_children must
358 358 * continue calling these functions until they return NULL.
359 359 * Otherwise, the next caller will pick up the list walk in
360 360 * some indeterminate state. (Otherwise every caller would
361 361 * have to pass in a cookie to keep the state represented by
362 362 * io_walk_link, which gets annoying.)
363 363 */
364 364 zio_t *
365 365 zio_walk_parents(zio_t *cio)
366 366 {
367 367 zio_link_t *zl = cio->io_walk_link;
368 368 list_t *pl = &cio->io_parent_list;
369 369
370 370 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl);
371 371 cio->io_walk_link = zl;
372 372
373 373 if (zl == NULL)
374 374 return (NULL);
375 375
376 376 ASSERT(zl->zl_child == cio);
377 377 return (zl->zl_parent);
378 378 }
379 379
380 380 zio_t *
381 381 zio_walk_children(zio_t *pio)
382 382 {
383 383 zio_link_t *zl = pio->io_walk_link;
384 384 list_t *cl = &pio->io_child_list;
385 385
386 386 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl);
387 387 pio->io_walk_link = zl;
388 388
389 389 if (zl == NULL)
390 390 return (NULL);
391 391
392 392 ASSERT(zl->zl_parent == pio);
393 393 return (zl->zl_child);
394 394 }
395 395
396 396 zio_t *
397 397 zio_unique_parent(zio_t *cio)
398 398 {
399 399 zio_t *pio = zio_walk_parents(cio);
400 400
401 401 VERIFY(zio_walk_parents(cio) == NULL);
402 402 return (pio);
403 403 }
404 404
405 405 void
406 406 zio_add_child(zio_t *pio, zio_t *cio)
407 407 {
408 408 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP);
409 409
410 410 /*
411 411 * Logical I/Os can have logical, gang, or vdev children.
412 412 * Gang I/Os can have gang or vdev children.
413 413 * Vdev I/Os can only have vdev children.
414 414 * The following ASSERT captures all of these constraints.
415 415 */
416 416 ASSERT(cio->io_child_type <= pio->io_child_type);
417 417
418 418 zl->zl_parent = pio;
419 419 zl->zl_child = cio;
420 420
421 421 mutex_enter(&cio->io_lock);
422 422 mutex_enter(&pio->io_lock);
423 423
424 424 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0);
425 425
426 426 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
427 427 pio->io_children[cio->io_child_type][w] += !cio->io_state[w];
428 428
429 429 list_insert_head(&pio->io_child_list, zl);
430 430 list_insert_head(&cio->io_parent_list, zl);
431 431
432 432 pio->io_child_count++;
433 433 cio->io_parent_count++;
434 434
435 435 mutex_exit(&pio->io_lock);
436 436 mutex_exit(&cio->io_lock);
437 437 }
438 438
439 439 static void
440 440 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl)
441 441 {
442 442 ASSERT(zl->zl_parent == pio);
443 443 ASSERT(zl->zl_child == cio);
444 444
445 445 mutex_enter(&cio->io_lock);
446 446 mutex_enter(&pio->io_lock);
447 447
448 448 list_remove(&pio->io_child_list, zl);
449 449 list_remove(&cio->io_parent_list, zl);
450 450
451 451 pio->io_child_count--;
452 452 cio->io_parent_count--;
453 453
454 454 mutex_exit(&pio->io_lock);
455 455 mutex_exit(&cio->io_lock);
456 456
457 457 kmem_cache_free(zio_link_cache, zl);
458 458 }
459 459
460 460 static boolean_t
461 461 zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait)
462 462 {
463 463 uint64_t *countp = &zio->io_children[child][wait];
464 464 boolean_t waiting = B_FALSE;
465 465
466 466 mutex_enter(&zio->io_lock);
467 467 ASSERT(zio->io_stall == NULL);
468 468 if (*countp != 0) {
469 469 zio->io_stage >>= 1;
470 470 zio->io_stall = countp;
471 471 waiting = B_TRUE;
472 472 }
473 473 mutex_exit(&zio->io_lock);
474 474
475 475 return (waiting);
476 476 }
477 477
478 478 static void
479 479 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait)
480 480 {
481 481 uint64_t *countp = &pio->io_children[zio->io_child_type][wait];
482 482 int *errorp = &pio->io_child_error[zio->io_child_type];
483 483
484 484 mutex_enter(&pio->io_lock);
485 485 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
486 486 *errorp = zio_worst_error(*errorp, zio->io_error);
487 487 pio->io_reexecute |= zio->io_reexecute;
488 488 ASSERT3U(*countp, >, 0);
489 489 if (--*countp == 0 && pio->io_stall == countp) {
490 490 pio->io_stall = NULL;
491 491 mutex_exit(&pio->io_lock);
492 492 zio_execute(pio);
493 493 } else {
494 494 mutex_exit(&pio->io_lock);
495 495 }
496 496 }
497 497
498 498 static void
499 499 zio_inherit_child_errors(zio_t *zio, enum zio_child c)
500 500 {
501 501 if (zio->io_child_error[c] != 0 && zio->io_error == 0)
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502 502 zio->io_error = zio->io_child_error[c];
503 503 }
504 504
505 505 /*
506 506 * ==========================================================================
507 507 * Create the various types of I/O (read, write, free, etc)
508 508 * ==========================================================================
509 509 */
510 510 static zio_t *
511 511 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
512 - void *data, uint64_t size, zio_done_func_t *done, void *private,
512 + void *data, uint64_t size, zio_done_func_t *done, void *io_private,
513 513 zio_type_t type, int priority, enum zio_flag flags,
514 514 vdev_t *vd, uint64_t offset, const zbookmark_t *zb,
515 515 enum zio_stage stage, enum zio_stage pipeline)
516 516 {
517 517 zio_t *zio;
518 518
519 519 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
520 520 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0);
521 521 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
522 522
523 523 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER));
524 524 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER));
525 525 ASSERT(vd || stage == ZIO_STAGE_OPEN);
526 526
527 527 zio = kmem_cache_alloc(zio_cache, KM_SLEEP);
528 528 bzero(zio, sizeof (zio_t));
529 529
530 530 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL);
531 531 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL);
532 532
533 533 list_create(&zio->io_parent_list, sizeof (zio_link_t),
534 534 offsetof(zio_link_t, zl_parent_node));
535 535 list_create(&zio->io_child_list, sizeof (zio_link_t),
536 536 offsetof(zio_link_t, zl_child_node));
537 537
538 538 if (vd != NULL)
539 539 zio->io_child_type = ZIO_CHILD_VDEV;
540 540 else if (flags & ZIO_FLAG_GANG_CHILD)
541 541 zio->io_child_type = ZIO_CHILD_GANG;
542 542 else if (flags & ZIO_FLAG_DDT_CHILD)
543 543 zio->io_child_type = ZIO_CHILD_DDT;
544 544 else
545 545 zio->io_child_type = ZIO_CHILD_LOGICAL;
546 546
547 547 if (bp != NULL) {
548 548 zio->io_bp = (blkptr_t *)bp;
549 549 zio->io_bp_copy = *bp;
550 550 zio->io_bp_orig = *bp;
551 551 if (type != ZIO_TYPE_WRITE ||
552 552 zio->io_child_type == ZIO_CHILD_DDT)
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553 553 zio->io_bp = &zio->io_bp_copy; /* so caller can free */
554 554 if (zio->io_child_type == ZIO_CHILD_LOGICAL)
555 555 zio->io_logical = zio;
556 556 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp))
557 557 pipeline |= ZIO_GANG_STAGES;
558 558 }
559 559
560 560 zio->io_spa = spa;
561 561 zio->io_txg = txg;
562 562 zio->io_done = done;
563 - zio->io_private = private;
563 + zio->io_private = io_private;
564 564 zio->io_type = type;
565 565 zio->io_priority = priority;
566 566 zio->io_vd = vd;
567 567 zio->io_offset = offset;
568 568 zio->io_orig_data = zio->io_data = data;
569 569 zio->io_orig_size = zio->io_size = size;
570 570 zio->io_orig_flags = zio->io_flags = flags;
571 571 zio->io_orig_stage = zio->io_stage = stage;
572 572 zio->io_orig_pipeline = zio->io_pipeline = pipeline;
573 573
574 574 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY);
575 575 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE);
576 576
577 577 if (zb != NULL)
578 578 zio->io_bookmark = *zb;
579 579
580 580 if (pio != NULL) {
581 581 if (zio->io_logical == NULL)
582 582 zio->io_logical = pio->io_logical;
583 583 if (zio->io_child_type == ZIO_CHILD_GANG)
584 584 zio->io_gang_leader = pio->io_gang_leader;
585 585 zio_add_child(pio, zio);
586 586 }
587 587
588 588 return (zio);
589 589 }
590 590
591 591 static void
592 592 zio_destroy(zio_t *zio)
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593 593 {
594 594 list_destroy(&zio->io_parent_list);
595 595 list_destroy(&zio->io_child_list);
596 596 mutex_destroy(&zio->io_lock);
597 597 cv_destroy(&zio->io_cv);
598 598 kmem_cache_free(zio_cache, zio);
599 599 }
600 600
601 601 zio_t *
602 602 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done,
603 - void *private, enum zio_flag flags)
603 + void *io_private, enum zio_flag flags)
604 604 {
605 605 zio_t *zio;
606 606
607 - zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private,
607 + zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, io_private,
608 608 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
609 609 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE);
610 610
611 611 return (zio);
612 612 }
613 613
614 614 zio_t *
615 -zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags)
615 +zio_root(spa_t *spa, zio_done_func_t *done, void *io_private,
616 + enum zio_flag flags)
616 617 {
617 - return (zio_null(NULL, spa, NULL, done, private, flags));
618 + return (zio_null(NULL, spa, NULL, done, io_private, flags));
618 619 }
619 620
620 621 zio_t *
621 622 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
622 - void *data, uint64_t size, zio_done_func_t *done, void *private,
623 + void *data, uint64_t size, zio_done_func_t *done, void *io_private,
623 624 int priority, enum zio_flag flags, const zbookmark_t *zb)
624 625 {
625 626 zio_t *zio;
626 627
627 628 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
628 - data, size, done, private,
629 + data, size, done, io_private,
629 630 ZIO_TYPE_READ, priority, flags, NULL, 0, zb,
630 631 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
631 632 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE);
632 633
633 634 return (zio);
634 635 }
635 636
636 637 zio_t *
637 638 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
638 639 void *data, uint64_t size, const zio_prop_t *zp,
639 - zio_done_func_t *ready, zio_done_func_t *done, void *private,
640 + zio_done_func_t *ready, zio_done_func_t *done, void *io_private,
640 641 int priority, enum zio_flag flags, const zbookmark_t *zb)
641 642 {
642 643 zio_t *zio;
643 644
644 645 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF &&
645 646 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS &&
646 647 zp->zp_compress >= ZIO_COMPRESS_OFF &&
647 648 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS &&
648 649 DMU_OT_IS_VALID(zp->zp_type) &&
649 650 zp->zp_level < 32 &&
650 651 zp->zp_copies > 0 &&
651 652 zp->zp_copies <= spa_max_replication(spa));
652 653
653 - zio = zio_create(pio, spa, txg, bp, data, size, done, private,
654 + zio = zio_create(pio, spa, txg, bp, data, size, done, io_private,
654 655 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
655 656 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
656 657 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE);
657 658
658 659 zio->io_ready = ready;
659 660 zio->io_prop = *zp;
660 661
661 662 return (zio);
662 663 }
663 664
664 665 zio_t *
665 666 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data,
666 - uint64_t size, zio_done_func_t *done, void *private, int priority,
667 + uint64_t size, zio_done_func_t *done, void *io_private, int priority,
667 668 enum zio_flag flags, zbookmark_t *zb)
668 669 {
669 670 zio_t *zio;
670 671
671 - zio = zio_create(pio, spa, txg, bp, data, size, done, private,
672 + zio = zio_create(pio, spa, txg, bp, data, size, done, io_private,
672 673 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
673 674 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE);
674 675
675 676 return (zio);
676 677 }
677 678
678 679 void
679 680 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite)
680 681 {
681 682 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
682 683 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
683 684 ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
684 685 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa));
685 686
686 687 /*
687 688 * We must reset the io_prop to match the values that existed
688 689 * when the bp was first written by dmu_sync() keeping in mind
689 690 * that nopwrite and dedup are mutually exclusive.
690 691 */
691 692 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup;
692 693 zio->io_prop.zp_nopwrite = nopwrite;
693 694 zio->io_prop.zp_copies = copies;
694 695 zio->io_bp_override = bp;
695 696 }
696 697
697 698 void
698 699 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp)
699 700 {
700 701 metaslab_check_free(spa, bp);
701 702 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
702 703 }
703 704
704 705 zio_t *
705 706 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
706 707 enum zio_flag flags)
707 708 {
708 709 zio_t *zio;
709 710
710 711 dprintf_bp(bp, "freeing in txg %llu, pass %u",
711 712 (longlong_t)txg, spa->spa_sync_pass);
712 713
713 714 ASSERT(!BP_IS_HOLE(bp));
714 715 ASSERT(spa_syncing_txg(spa) == txg);
715 716 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free);
716 717
717 718 metaslab_check_free(spa, bp);
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718 719
719 720 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
720 721 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, flags,
721 722 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE);
722 723
723 724 return (zio);
724 725 }
725 726
726 727 zio_t *
727 728 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
728 - zio_done_func_t *done, void *private, enum zio_flag flags)
729 + zio_done_func_t *done, void *io_private, enum zio_flag flags)
729 730 {
730 731 zio_t *zio;
731 732
732 733 /*
733 734 * A claim is an allocation of a specific block. Claims are needed
734 735 * to support immediate writes in the intent log. The issue is that
735 736 * immediate writes contain committed data, but in a txg that was
736 737 * *not* committed. Upon opening the pool after an unclean shutdown,
737 738 * the intent log claims all blocks that contain immediate write data
738 739 * so that the SPA knows they're in use.
739 740 *
740 741 * All claims *must* be resolved in the first txg -- before the SPA
741 742 * starts allocating blocks -- so that nothing is allocated twice.
742 743 * If txg == 0 we just verify that the block is claimable.
743 744 */
744 745 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa));
745 746 ASSERT(txg == spa_first_txg(spa) || txg == 0);
746 747 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */
747 748
748 749 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
749 - done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags,
750 + done, io_private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags,
750 751 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE);
751 752
752 753 return (zio);
753 754 }
754 755
755 756 zio_t *
756 757 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
757 - zio_done_func_t *done, void *private, int priority, enum zio_flag flags)
758 + zio_done_func_t *done, void *io_private, int priority, enum zio_flag flags)
758 759 {
759 760 zio_t *zio;
760 761 int c;
761 762
762 763 if (vd->vdev_children == 0) {
763 - zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private,
764 + zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, io_private,
764 765 ZIO_TYPE_IOCTL, priority, flags, vd, 0, NULL,
765 766 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
766 767
767 768 zio->io_cmd = cmd;
768 769 } else {
769 770 zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
770 771
771 772 for (c = 0; c < vd->vdev_children; c++)
772 773 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
773 - done, private, priority, flags));
774 + done, io_private, priority, flags));
774 775 }
775 776
776 777 return (zio);
777 778 }
778 779
779 780 zio_t *
780 781 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
781 - void *data, int checksum, zio_done_func_t *done, void *private,
782 + void *data, int checksum, zio_done_func_t *done, void *io_private,
782 783 int priority, enum zio_flag flags, boolean_t labels)
783 784 {
784 785 zio_t *zio;
785 786
786 787 ASSERT(vd->vdev_children == 0);
787 788 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
788 789 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
789 790 ASSERT3U(offset + size, <=, vd->vdev_psize);
790 791
791 - zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private,
792 - ZIO_TYPE_READ, priority, flags, vd, offset, NULL,
792 + zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done,
793 + io_private, ZIO_TYPE_READ, priority, flags, vd, offset, NULL,
793 794 ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE);
794 795
795 796 zio->io_prop.zp_checksum = checksum;
796 797
797 798 return (zio);
798 799 }
799 800
800 801 zio_t *
801 802 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
802 - void *data, int checksum, zio_done_func_t *done, void *private,
803 + void *data, int checksum, zio_done_func_t *done, void *io_private,
803 804 int priority, enum zio_flag flags, boolean_t labels)
804 805 {
805 806 zio_t *zio;
806 807
807 808 ASSERT(vd->vdev_children == 0);
808 809 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
809 810 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
810 811 ASSERT3U(offset + size, <=, vd->vdev_psize);
811 812
812 - zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private,
813 - ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL,
813 + zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done,
814 + io_private, ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL,
814 815 ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE);
815 816
816 817 zio->io_prop.zp_checksum = checksum;
817 818
818 819 if (zio_checksum_table[checksum].ci_eck) {
819 820 /*
820 821 * zec checksums are necessarily destructive -- they modify
821 822 * the end of the write buffer to hold the verifier/checksum.
822 823 * Therefore, we must make a local copy in case the data is
823 824 * being written to multiple places in parallel.
824 825 */
825 826 void *wbuf = zio_buf_alloc(size);
826 827 bcopy(data, wbuf, size);
827 828 zio_push_transform(zio, wbuf, size, size, NULL);
828 829 }
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829 830
830 831 return (zio);
831 832 }
832 833
833 834 /*
834 835 * Create a child I/O to do some work for us.
835 836 */
836 837 zio_t *
837 838 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset,
838 839 void *data, uint64_t size, int type, int priority, enum zio_flag flags,
839 - zio_done_func_t *done, void *private)
840 + zio_done_func_t *done, void *io_private)
840 841 {
841 842 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE;
842 843 zio_t *zio;
843 844
844 845 ASSERT(vd->vdev_parent ==
845 846 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev));
846 847
847 848 if (type == ZIO_TYPE_READ && bp != NULL) {
848 849 /*
849 850 * If we have the bp, then the child should perform the
850 851 * checksum and the parent need not. This pushes error
851 852 * detection as close to the leaves as possible and
852 853 * eliminates redundant checksums in the interior nodes.
853 854 */
854 855 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY;
855 856 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
856 857 }
857 858
858 859 if (vd->vdev_children == 0)
859 860 offset += VDEV_LABEL_START_SIZE;
860 861
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861 862 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE;
862 863
863 864 /*
864 865 * If we've decided to do a repair, the write is not speculative --
865 866 * even if the original read was.
866 867 */
867 868 if (flags & ZIO_FLAG_IO_REPAIR)
868 869 flags &= ~ZIO_FLAG_SPECULATIVE;
869 870
870 871 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size,
871 - done, private, type, priority, flags, vd, offset, &pio->io_bookmark,
872 - ZIO_STAGE_VDEV_IO_START >> 1, pipeline);
872 + done, io_private, type, priority, flags, vd, offset,
873 + &pio->io_bookmark, ZIO_STAGE_VDEV_IO_START >> 1, pipeline);
873 874
874 875 return (zio);
875 876 }
876 877
877 878 zio_t *
878 879 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size,
879 880 int type, int priority, enum zio_flag flags,
880 - zio_done_func_t *done, void *private)
881 + zio_done_func_t *done, void *io_private)
881 882 {
882 883 zio_t *zio;
883 884
884 885 ASSERT(vd->vdev_ops->vdev_op_leaf);
885 886
886 887 zio = zio_create(NULL, vd->vdev_spa, 0, NULL,
887 - data, size, done, private, type, priority,
888 + data, size, done, io_private, type, priority,
888 889 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY,
889 890 vd, offset, NULL,
890 891 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE);
891 892
892 893 return (zio);
893 894 }
894 895
895 896 void
896 897 zio_flush(zio_t *zio, vdev_t *vd)
897 898 {
898 899 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
899 900 NULL, NULL, ZIO_PRIORITY_NOW,
900 901 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
901 902 }
902 903
903 904 void
904 905 zio_shrink(zio_t *zio, uint64_t size)
905 906 {
906 907 ASSERT(zio->io_executor == NULL);
907 908 ASSERT(zio->io_orig_size == zio->io_size);
908 909 ASSERT(size <= zio->io_size);
909 910
910 911 /*
911 912 * We don't shrink for raidz because of problems with the
912 913 * reconstruction when reading back less than the block size.
913 914 * Note, BP_IS_RAIDZ() assumes no compression.
914 915 */
915 916 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
916 917 if (!BP_IS_RAIDZ(zio->io_bp))
917 918 zio->io_orig_size = zio->io_size = size;
918 919 }
919 920
920 921 /*
921 922 * ==========================================================================
922 923 * Prepare to read and write logical blocks
923 924 * ==========================================================================
924 925 */
925 926
926 927 static int
927 928 zio_read_bp_init(zio_t *zio)
928 929 {
929 930 blkptr_t *bp = zio->io_bp;
930 931
931 932 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF &&
932 933 zio->io_child_type == ZIO_CHILD_LOGICAL &&
933 934 !(zio->io_flags & ZIO_FLAG_RAW)) {
934 935 uint64_t psize = BP_GET_PSIZE(bp);
935 936 void *cbuf = zio_buf_alloc(psize);
936 937
937 938 zio_push_transform(zio, cbuf, psize, psize, zio_decompress);
938 939 }
939 940
940 941 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0)
941 942 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
942 943
943 944 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP)
944 945 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
945 946
946 947 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL)
947 948 zio->io_pipeline = ZIO_DDT_READ_PIPELINE;
948 949
949 950 return (ZIO_PIPELINE_CONTINUE);
950 951 }
951 952
952 953 static int
953 954 zio_write_bp_init(zio_t *zio)
954 955 {
955 956 spa_t *spa = zio->io_spa;
956 957 zio_prop_t *zp = &zio->io_prop;
957 958 enum zio_compress compress = zp->zp_compress;
958 959 blkptr_t *bp = zio->io_bp;
959 960 uint64_t lsize = zio->io_size;
960 961 uint64_t psize = lsize;
961 962 int pass = 1;
962 963
963 964 /*
964 965 * If our children haven't all reached the ready stage,
965 966 * wait for them and then repeat this pipeline stage.
966 967 */
967 968 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) ||
968 969 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY))
969 970 return (ZIO_PIPELINE_STOP);
970 971
971 972 if (!IO_IS_ALLOCATING(zio))
972 973 return (ZIO_PIPELINE_CONTINUE);
973 974
974 975 ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
975 976
976 977 if (zio->io_bp_override) {
977 978 ASSERT(bp->blk_birth != zio->io_txg);
978 979 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0);
979 980
980 981 *bp = *zio->io_bp_override;
981 982 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
982 983
983 984 /*
984 985 * If we've been overridden and nopwrite is set then
985 986 * set the flag accordingly to indicate that a nopwrite
986 987 * has already occurred.
987 988 */
988 989 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) {
989 990 ASSERT(!zp->zp_dedup);
990 991 zio->io_flags |= ZIO_FLAG_NOPWRITE;
991 992 return (ZIO_PIPELINE_CONTINUE);
992 993 }
993 994
994 995 ASSERT(!zp->zp_nopwrite);
995 996
996 997 if (BP_IS_HOLE(bp) || !zp->zp_dedup)
997 998 return (ZIO_PIPELINE_CONTINUE);
998 999
999 1000 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup ||
1000 1001 zp->zp_dedup_verify);
1001 1002
1002 1003 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) {
1003 1004 BP_SET_DEDUP(bp, 1);
1004 1005 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
1005 1006 return (ZIO_PIPELINE_CONTINUE);
1006 1007 }
1007 1008 zio->io_bp_override = NULL;
1008 1009 BP_ZERO(bp);
1009 1010 }
1010 1011
1011 1012 if (bp->blk_birth == zio->io_txg) {
1012 1013 /*
1013 1014 * We're rewriting an existing block, which means we're
1014 1015 * working on behalf of spa_sync(). For spa_sync() to
1015 1016 * converge, it must eventually be the case that we don't
1016 1017 * have to allocate new blocks. But compression changes
1017 1018 * the blocksize, which forces a reallocate, and makes
1018 1019 * convergence take longer. Therefore, after the first
1019 1020 * few passes, stop compressing to ensure convergence.
1020 1021 */
1021 1022 pass = spa_sync_pass(spa);
1022 1023
1023 1024 ASSERT(zio->io_txg == spa_syncing_txg(spa));
1024 1025 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1025 1026 ASSERT(!BP_GET_DEDUP(bp));
1026 1027
1027 1028 if (pass >= zfs_sync_pass_dont_compress)
1028 1029 compress = ZIO_COMPRESS_OFF;
1029 1030
1030 1031 /* Make sure someone doesn't change their mind on overwrites */
1031 1032 ASSERT(MIN(zp->zp_copies + BP_IS_GANG(bp),
1032 1033 spa_max_replication(spa)) == BP_GET_NDVAS(bp));
1033 1034 }
1034 1035
1035 1036 if (compress != ZIO_COMPRESS_OFF) {
1036 1037 void *cbuf = zio_buf_alloc(lsize);
1037 1038 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize);
1038 1039 if (psize == 0 || psize == lsize) {
1039 1040 compress = ZIO_COMPRESS_OFF;
1040 1041 zio_buf_free(cbuf, lsize);
1041 1042 } else {
1042 1043 ASSERT(psize < lsize);
1043 1044 zio_push_transform(zio, cbuf, psize, lsize, NULL);
1044 1045 }
1045 1046 }
1046 1047
1047 1048 /*
1048 1049 * The final pass of spa_sync() must be all rewrites, but the first
1049 1050 * few passes offer a trade-off: allocating blocks defers convergence,
1050 1051 * but newly allocated blocks are sequential, so they can be written
1051 1052 * to disk faster. Therefore, we allow the first few passes of
1052 1053 * spa_sync() to allocate new blocks, but force rewrites after that.
1053 1054 * There should only be a handful of blocks after pass 1 in any case.
1054 1055 */
1055 1056 if (bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == psize &&
1056 1057 pass >= zfs_sync_pass_rewrite) {
1057 1058 ASSERT(psize != 0);
1058 1059 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES;
1059 1060 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages;
1060 1061 zio->io_flags |= ZIO_FLAG_IO_REWRITE;
1061 1062 } else {
1062 1063 BP_ZERO(bp);
1063 1064 zio->io_pipeline = ZIO_WRITE_PIPELINE;
1064 1065 }
1065 1066
1066 1067 if (psize == 0) {
1067 1068 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1068 1069 } else {
1069 1070 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER);
1070 1071 BP_SET_LSIZE(bp, lsize);
1071 1072 BP_SET_PSIZE(bp, psize);
1072 1073 BP_SET_COMPRESS(bp, compress);
1073 1074 BP_SET_CHECKSUM(bp, zp->zp_checksum);
1074 1075 BP_SET_TYPE(bp, zp->zp_type);
1075 1076 BP_SET_LEVEL(bp, zp->zp_level);
1076 1077 BP_SET_DEDUP(bp, zp->zp_dedup);
1077 1078 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
1078 1079 if (zp->zp_dedup) {
1079 1080 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1080 1081 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1081 1082 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE;
1082 1083 }
1083 1084 if (zp->zp_nopwrite) {
1084 1085 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1085 1086 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1086 1087 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE;
1087 1088 }
1088 1089 }
1089 1090
1090 1091 return (ZIO_PIPELINE_CONTINUE);
1091 1092 }
1092 1093
1093 1094 static int
1094 1095 zio_free_bp_init(zio_t *zio)
1095 1096 {
1096 1097 blkptr_t *bp = zio->io_bp;
1097 1098
1098 1099 if (zio->io_child_type == ZIO_CHILD_LOGICAL) {
1099 1100 if (BP_GET_DEDUP(bp))
1100 1101 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE;
1101 1102 }
1102 1103
1103 1104 return (ZIO_PIPELINE_CONTINUE);
1104 1105 }
1105 1106
1106 1107 /*
1107 1108 * ==========================================================================
1108 1109 * Execute the I/O pipeline
1109 1110 * ==========================================================================
1110 1111 */
1111 1112
1112 1113 static void
1113 1114 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline)
1114 1115 {
1115 1116 spa_t *spa = zio->io_spa;
1116 1117 zio_type_t t = zio->io_type;
1117 1118 int flags = (cutinline ? TQ_FRONT : 0);
1118 1119
1119 1120 /*
1120 1121 * If we're a config writer or a probe, the normal issue and
1121 1122 * interrupt threads may all be blocked waiting for the config lock.
1122 1123 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
1123 1124 */
1124 1125 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE))
1125 1126 t = ZIO_TYPE_NULL;
1126 1127
1127 1128 /*
1128 1129 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
1129 1130 */
1130 1131 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux)
1131 1132 t = ZIO_TYPE_NULL;
1132 1133
1133 1134 /*
1134 1135 * If this is a high priority I/O, then use the high priority taskq if
1135 1136 * available.
1136 1137 */
1137 1138 if (zio->io_priority == ZIO_PRIORITY_NOW &&
1138 1139 spa->spa_zio_taskq[t][q + 1].stqs_count != 0)
1139 1140 q++;
1140 1141
1141 1142 ASSERT3U(q, <, ZIO_TASKQ_TYPES);
1142 1143
1143 1144 /*
1144 1145 * NB: We are assuming that the zio can only be dispatched
1145 1146 * to a single taskq at a time. It would be a grievous error
1146 1147 * to dispatch the zio to another taskq at the same time.
1147 1148 */
1148 1149 ASSERT(zio->io_tqent.tqent_next == NULL);
1149 1150 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio,
1150 1151 flags, &zio->io_tqent);
1151 1152 }
1152 1153
1153 1154 static boolean_t
1154 1155 zio_taskq_member(zio_t *zio, zio_taskq_type_t q)
1155 1156 {
1156 1157 kthread_t *executor = zio->io_executor;
1157 1158 spa_t *spa = zio->io_spa;
1158 1159
1159 1160 for (zio_type_t t = 0; t < ZIO_TYPES; t++) {
1160 1161 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1161 1162 uint_t i;
1162 1163 for (i = 0; i < tqs->stqs_count; i++) {
1163 1164 if (taskq_member(tqs->stqs_taskq[i], executor))
1164 1165 return (B_TRUE);
1165 1166 }
1166 1167 }
1167 1168
1168 1169 return (B_FALSE);
1169 1170 }
1170 1171
1171 1172 static int
1172 1173 zio_issue_async(zio_t *zio)
1173 1174 {
1174 1175 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
1175 1176
1176 1177 return (ZIO_PIPELINE_STOP);
1177 1178 }
1178 1179
1179 1180 void
1180 1181 zio_interrupt(zio_t *zio)
1181 1182 {
1182 1183 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE);
1183 1184 }
1184 1185
1185 1186 /*
1186 1187 * Execute the I/O pipeline until one of the following occurs:
1187 1188 * (1) the I/O completes; (2) the pipeline stalls waiting for
1188 1189 * dependent child I/Os; (3) the I/O issues, so we're waiting
1189 1190 * for an I/O completion interrupt; (4) the I/O is delegated by
1190 1191 * vdev-level caching or aggregation; (5) the I/O is deferred
1191 1192 * due to vdev-level queueing; (6) the I/O is handed off to
1192 1193 * another thread. In all cases, the pipeline stops whenever
1193 1194 * there's no CPU work; it never burns a thread in cv_wait().
1194 1195 *
1195 1196 * There's no locking on io_stage because there's no legitimate way
1196 1197 * for multiple threads to be attempting to process the same I/O.
1197 1198 */
1198 1199 static zio_pipe_stage_t *zio_pipeline[];
1199 1200
1200 1201 void
1201 1202 zio_execute(zio_t *zio)
1202 1203 {
1203 1204 zio->io_executor = curthread;
1204 1205
1205 1206 while (zio->io_stage < ZIO_STAGE_DONE) {
1206 1207 enum zio_stage pipeline = zio->io_pipeline;
1207 1208 enum zio_stage stage = zio->io_stage;
1208 1209 int rv;
1209 1210
1210 1211 ASSERT(!MUTEX_HELD(&zio->io_lock));
1211 1212 ASSERT(ISP2(stage));
1212 1213 ASSERT(zio->io_stall == NULL);
1213 1214
1214 1215 do {
1215 1216 stage <<= 1;
1216 1217 } while ((stage & pipeline) == 0);
1217 1218
1218 1219 ASSERT(stage <= ZIO_STAGE_DONE);
1219 1220
1220 1221 /*
1221 1222 * If we are in interrupt context and this pipeline stage
1222 1223 * will grab a config lock that is held across I/O,
1223 1224 * or may wait for an I/O that needs an interrupt thread
1224 1225 * to complete, issue async to avoid deadlock.
1225 1226 *
1226 1227 * For VDEV_IO_START, we cut in line so that the io will
1227 1228 * be sent to disk promptly.
1228 1229 */
1229 1230 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL &&
1230 1231 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) {
1231 1232 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
1232 1233 zio_requeue_io_start_cut_in_line : B_FALSE;
1233 1234 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
1234 1235 return;
1235 1236 }
1236 1237
1237 1238 zio->io_stage = stage;
1238 1239 rv = zio_pipeline[highbit(stage) - 1](zio);
1239 1240
1240 1241 if (rv == ZIO_PIPELINE_STOP)
1241 1242 return;
1242 1243
1243 1244 ASSERT(rv == ZIO_PIPELINE_CONTINUE);
1244 1245 }
1245 1246 }
1246 1247
1247 1248 /*
1248 1249 * ==========================================================================
1249 1250 * Initiate I/O, either sync or async
1250 1251 * ==========================================================================
1251 1252 */
1252 1253 int
1253 1254 zio_wait(zio_t *zio)
1254 1255 {
1255 1256 int error;
1256 1257
1257 1258 ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
1258 1259 ASSERT(zio->io_executor == NULL);
1259 1260
1260 1261 zio->io_waiter = curthread;
1261 1262
1262 1263 zio_execute(zio);
1263 1264
1264 1265 mutex_enter(&zio->io_lock);
1265 1266 while (zio->io_executor != NULL)
1266 1267 cv_wait(&zio->io_cv, &zio->io_lock);
1267 1268 mutex_exit(&zio->io_lock);
1268 1269
1269 1270 error = zio->io_error;
1270 1271 zio_destroy(zio);
1271 1272
1272 1273 return (error);
1273 1274 }
1274 1275
1275 1276 void
1276 1277 zio_nowait(zio_t *zio)
1277 1278 {
1278 1279 ASSERT(zio->io_executor == NULL);
1279 1280
1280 1281 if (zio->io_child_type == ZIO_CHILD_LOGICAL &&
1281 1282 zio_unique_parent(zio) == NULL) {
1282 1283 /*
1283 1284 * This is a logical async I/O with no parent to wait for it.
1284 1285 * We add it to the spa_async_root_zio "Godfather" I/O which
1285 1286 * will ensure they complete prior to unloading the pool.
1286 1287 */
1287 1288 spa_t *spa = zio->io_spa;
1288 1289
1289 1290 zio_add_child(spa->spa_async_zio_root, zio);
1290 1291 }
1291 1292
1292 1293 zio_execute(zio);
1293 1294 }
1294 1295
1295 1296 /*
1296 1297 * ==========================================================================
1297 1298 * Reexecute or suspend/resume failed I/O
1298 1299 * ==========================================================================
1299 1300 */
1300 1301
1301 1302 static void
1302 1303 zio_reexecute(zio_t *pio)
1303 1304 {
1304 1305 zio_t *cio, *cio_next;
1305 1306
1306 1307 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL);
1307 1308 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN);
1308 1309 ASSERT(pio->io_gang_leader == NULL);
1309 1310 ASSERT(pio->io_gang_tree == NULL);
1310 1311
1311 1312 pio->io_flags = pio->io_orig_flags;
1312 1313 pio->io_stage = pio->io_orig_stage;
1313 1314 pio->io_pipeline = pio->io_orig_pipeline;
1314 1315 pio->io_reexecute = 0;
1315 1316 pio->io_flags |= ZIO_FLAG_REEXECUTED;
1316 1317 pio->io_error = 0;
1317 1318 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
1318 1319 pio->io_state[w] = 0;
1319 1320 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
1320 1321 pio->io_child_error[c] = 0;
1321 1322
1322 1323 if (IO_IS_ALLOCATING(pio))
1323 1324 BP_ZERO(pio->io_bp);
1324 1325
1325 1326 /*
1326 1327 * As we reexecute pio's children, new children could be created.
1327 1328 * New children go to the head of pio's io_child_list, however,
1328 1329 * so we will (correctly) not reexecute them. The key is that
1329 1330 * the remainder of pio's io_child_list, from 'cio_next' onward,
1330 1331 * cannot be affected by any side effects of reexecuting 'cio'.
1331 1332 */
1332 1333 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) {
1333 1334 cio_next = zio_walk_children(pio);
1334 1335 mutex_enter(&pio->io_lock);
1335 1336 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
1336 1337 pio->io_children[cio->io_child_type][w]++;
1337 1338 mutex_exit(&pio->io_lock);
1338 1339 zio_reexecute(cio);
1339 1340 }
1340 1341
1341 1342 /*
1342 1343 * Now that all children have been reexecuted, execute the parent.
1343 1344 * We don't reexecute "The Godfather" I/O here as it's the
1344 1345 * responsibility of the caller to wait on him.
1345 1346 */
1346 1347 if (!(pio->io_flags & ZIO_FLAG_GODFATHER))
1347 1348 zio_execute(pio);
1348 1349 }
1349 1350
1350 1351 void
1351 1352 zio_suspend(spa_t *spa, zio_t *zio)
1352 1353 {
1353 1354 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC)
1354 1355 fm_panic("Pool '%s' has encountered an uncorrectable I/O "
1355 1356 "failure and the failure mode property for this pool "
1356 1357 "is set to panic.", spa_name(spa));
1357 1358
1358 1359 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0);
1359 1360
1360 1361 mutex_enter(&spa->spa_suspend_lock);
1361 1362
1362 1363 if (spa->spa_suspend_zio_root == NULL)
1363 1364 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL,
1364 1365 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
1365 1366 ZIO_FLAG_GODFATHER);
1366 1367
1367 1368 spa->spa_suspended = B_TRUE;
1368 1369
1369 1370 if (zio != NULL) {
1370 1371 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
1371 1372 ASSERT(zio != spa->spa_suspend_zio_root);
1372 1373 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1373 1374 ASSERT(zio_unique_parent(zio) == NULL);
1374 1375 ASSERT(zio->io_stage == ZIO_STAGE_DONE);
1375 1376 zio_add_child(spa->spa_suspend_zio_root, zio);
1376 1377 }
1377 1378
1378 1379 mutex_exit(&spa->spa_suspend_lock);
1379 1380 }
1380 1381
1381 1382 int
1382 1383 zio_resume(spa_t *spa)
1383 1384 {
1384 1385 zio_t *pio;
1385 1386
1386 1387 /*
1387 1388 * Reexecute all previously suspended i/o.
1388 1389 */
1389 1390 mutex_enter(&spa->spa_suspend_lock);
1390 1391 spa->spa_suspended = B_FALSE;
1391 1392 cv_broadcast(&spa->spa_suspend_cv);
1392 1393 pio = spa->spa_suspend_zio_root;
1393 1394 spa->spa_suspend_zio_root = NULL;
1394 1395 mutex_exit(&spa->spa_suspend_lock);
1395 1396
1396 1397 if (pio == NULL)
1397 1398 return (0);
1398 1399
1399 1400 zio_reexecute(pio);
1400 1401 return (zio_wait(pio));
1401 1402 }
1402 1403
1403 1404 void
1404 1405 zio_resume_wait(spa_t *spa)
1405 1406 {
1406 1407 mutex_enter(&spa->spa_suspend_lock);
1407 1408 while (spa_suspended(spa))
1408 1409 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock);
1409 1410 mutex_exit(&spa->spa_suspend_lock);
1410 1411 }
1411 1412
1412 1413 /*
1413 1414 * ==========================================================================
1414 1415 * Gang blocks.
1415 1416 *
1416 1417 * A gang block is a collection of small blocks that looks to the DMU
1417 1418 * like one large block. When zio_dva_allocate() cannot find a block
1418 1419 * of the requested size, due to either severe fragmentation or the pool
1419 1420 * being nearly full, it calls zio_write_gang_block() to construct the
1420 1421 * block from smaller fragments.
1421 1422 *
1422 1423 * A gang block consists of a gang header (zio_gbh_phys_t) and up to
1423 1424 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
1424 1425 * an indirect block: it's an array of block pointers. It consumes
1425 1426 * only one sector and hence is allocatable regardless of fragmentation.
1426 1427 * The gang header's bps point to its gang members, which hold the data.
1427 1428 *
1428 1429 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
1429 1430 * as the verifier to ensure uniqueness of the SHA256 checksum.
1430 1431 * Critically, the gang block bp's blk_cksum is the checksum of the data,
1431 1432 * not the gang header. This ensures that data block signatures (needed for
1432 1433 * deduplication) are independent of how the block is physically stored.
1433 1434 *
1434 1435 * Gang blocks can be nested: a gang member may itself be a gang block.
1435 1436 * Thus every gang block is a tree in which root and all interior nodes are
1436 1437 * gang headers, and the leaves are normal blocks that contain user data.
1437 1438 * The root of the gang tree is called the gang leader.
1438 1439 *
1439 1440 * To perform any operation (read, rewrite, free, claim) on a gang block,
1440 1441 * zio_gang_assemble() first assembles the gang tree (minus data leaves)
1441 1442 * in the io_gang_tree field of the original logical i/o by recursively
1442 1443 * reading the gang leader and all gang headers below it. This yields
1443 1444 * an in-core tree containing the contents of every gang header and the
1444 1445 * bps for every constituent of the gang block.
1445 1446 *
1446 1447 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
1447 1448 * and invokes a callback on each bp. To free a gang block, zio_gang_issue()
1448 1449 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
1449 1450 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
1450 1451 * zio_read_gang() is a wrapper around zio_read() that omits reading gang
1451 1452 * headers, since we already have those in io_gang_tree. zio_rewrite_gang()
1452 1453 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
1453 1454 * of the gang header plus zio_checksum_compute() of the data to update the
1454 1455 * gang header's blk_cksum as described above.
1455 1456 *
1456 1457 * The two-phase assemble/issue model solves the problem of partial failure --
1457 1458 * what if you'd freed part of a gang block but then couldn't read the
1458 1459 * gang header for another part? Assembling the entire gang tree first
1459 1460 * ensures that all the necessary gang header I/O has succeeded before
1460 1461 * starting the actual work of free, claim, or write. Once the gang tree
1461 1462 * is assembled, free and claim are in-memory operations that cannot fail.
1462 1463 *
1463 1464 * In the event that a gang write fails, zio_dva_unallocate() walks the
1464 1465 * gang tree to immediately free (i.e. insert back into the space map)
1465 1466 * everything we've allocated. This ensures that we don't get ENOSPC
1466 1467 * errors during repeated suspend/resume cycles due to a flaky device.
1467 1468 *
1468 1469 * Gang rewrites only happen during sync-to-convergence. If we can't assemble
1469 1470 * the gang tree, we won't modify the block, so we can safely defer the free
1470 1471 * (knowing that the block is still intact). If we *can* assemble the gang
1471 1472 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
1472 1473 * each constituent bp and we can allocate a new block on the next sync pass.
1473 1474 *
1474 1475 * In all cases, the gang tree allows complete recovery from partial failure.
1475 1476 * ==========================================================================
1476 1477 */
1477 1478
1478 1479 static zio_t *
1479 1480 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1480 1481 {
1481 1482 if (gn != NULL)
1482 1483 return (pio);
1483 1484
1484 1485 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp),
1485 1486 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
1486 1487 &pio->io_bookmark));
1487 1488 }
1488 1489
1489 1490 zio_t *
1490 1491 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1491 1492 {
1492 1493 zio_t *zio;
1493 1494
1494 1495 if (gn != NULL) {
1495 1496 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
1496 1497 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority,
1497 1498 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
1498 1499 /*
1499 1500 * As we rewrite each gang header, the pipeline will compute
1500 1501 * a new gang block header checksum for it; but no one will
1501 1502 * compute a new data checksum, so we do that here. The one
1502 1503 * exception is the gang leader: the pipeline already computed
1503 1504 * its data checksum because that stage precedes gang assembly.
1504 1505 * (Presently, nothing actually uses interior data checksums;
1505 1506 * this is just good hygiene.)
1506 1507 */
1507 1508 if (gn != pio->io_gang_leader->io_gang_tree) {
1508 1509 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp),
1509 1510 data, BP_GET_PSIZE(bp));
1510 1511 }
1511 1512 /*
1512 1513 * If we are here to damage data for testing purposes,
1513 1514 * leave the GBH alone so that we can detect the damage.
1514 1515 */
1515 1516 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE)
1516 1517 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
1517 1518 } else {
1518 1519 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
1519 1520 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority,
1520 1521 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
1521 1522 }
1522 1523
1523 1524 return (zio);
1524 1525 }
1525 1526
1526 1527 /* ARGSUSED */
1527 1528 zio_t *
1528 1529 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1529 1530 {
1530 1531 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp,
1531 1532 ZIO_GANG_CHILD_FLAGS(pio)));
1532 1533 }
1533 1534
1534 1535 /* ARGSUSED */
1535 1536 zio_t *
1536 1537 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1537 1538 {
1538 1539 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp,
1539 1540 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)));
1540 1541 }
1541 1542
1542 1543 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = {
1543 1544 NULL,
1544 1545 zio_read_gang,
1545 1546 zio_rewrite_gang,
1546 1547 zio_free_gang,
1547 1548 zio_claim_gang,
1548 1549 NULL
1549 1550 };
1550 1551
1551 1552 static void zio_gang_tree_assemble_done(zio_t *zio);
1552 1553
1553 1554 static zio_gang_node_t *
1554 1555 zio_gang_node_alloc(zio_gang_node_t **gnpp)
1555 1556 {
1556 1557 zio_gang_node_t *gn;
1557 1558
1558 1559 ASSERT(*gnpp == NULL);
1559 1560
1560 1561 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP);
1561 1562 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE);
1562 1563 *gnpp = gn;
1563 1564
1564 1565 return (gn);
1565 1566 }
1566 1567
1567 1568 static void
1568 1569 zio_gang_node_free(zio_gang_node_t **gnpp)
1569 1570 {
1570 1571 zio_gang_node_t *gn = *gnpp;
1571 1572
1572 1573 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
1573 1574 ASSERT(gn->gn_child[g] == NULL);
1574 1575
1575 1576 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE);
1576 1577 kmem_free(gn, sizeof (*gn));
1577 1578 *gnpp = NULL;
1578 1579 }
1579 1580
1580 1581 static void
1581 1582 zio_gang_tree_free(zio_gang_node_t **gnpp)
1582 1583 {
1583 1584 zio_gang_node_t *gn = *gnpp;
1584 1585
1585 1586 if (gn == NULL)
1586 1587 return;
1587 1588
1588 1589 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
1589 1590 zio_gang_tree_free(&gn->gn_child[g]);
1590 1591
1591 1592 zio_gang_node_free(gnpp);
1592 1593 }
1593 1594
1594 1595 static void
1595 1596 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp)
1596 1597 {
1597 1598 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp);
1598 1599
1599 1600 ASSERT(gio->io_gang_leader == gio);
1600 1601 ASSERT(BP_IS_GANG(bp));
1601 1602
1602 1603 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh,
1603 1604 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn,
1604 1605 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark));
1605 1606 }
1606 1607
1607 1608 static void
1608 1609 zio_gang_tree_assemble_done(zio_t *zio)
1609 1610 {
1610 1611 zio_t *gio = zio->io_gang_leader;
1611 1612 zio_gang_node_t *gn = zio->io_private;
1612 1613 blkptr_t *bp = zio->io_bp;
1613 1614
1614 1615 ASSERT(gio == zio_unique_parent(zio));
1615 1616 ASSERT(zio->io_child_count == 0);
1616 1617
1617 1618 if (zio->io_error)
1618 1619 return;
1619 1620
1620 1621 if (BP_SHOULD_BYTESWAP(bp))
1621 1622 byteswap_uint64_array(zio->io_data, zio->io_size);
1622 1623
1623 1624 ASSERT(zio->io_data == gn->gn_gbh);
1624 1625 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE);
1625 1626 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
1626 1627
1627 1628 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
1628 1629 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
1629 1630 if (!BP_IS_GANG(gbp))
1630 1631 continue;
1631 1632 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]);
1632 1633 }
1633 1634 }
1634 1635
1635 1636 static void
1636 1637 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data)
1637 1638 {
1638 1639 zio_t *gio = pio->io_gang_leader;
1639 1640 zio_t *zio;
1640 1641
1641 1642 ASSERT(BP_IS_GANG(bp) == !!gn);
1642 1643 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp));
1643 1644 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree);
1644 1645
1645 1646 /*
1646 1647 * If you're a gang header, your data is in gn->gn_gbh.
1647 1648 * If you're a gang member, your data is in 'data' and gn == NULL.
1648 1649 */
1649 1650 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data);
1650 1651
1651 1652 if (gn != NULL) {
1652 1653 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
1653 1654
1654 1655 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
1655 1656 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
1656 1657 if (BP_IS_HOLE(gbp))
1657 1658 continue;
1658 1659 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data);
1659 1660 data = (char *)data + BP_GET_PSIZE(gbp);
1660 1661 }
1661 1662 }
1662 1663
1663 1664 if (gn == gio->io_gang_tree)
1664 1665 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data);
1665 1666
1666 1667 if (zio != pio)
1667 1668 zio_nowait(zio);
1668 1669 }
1669 1670
1670 1671 static int
1671 1672 zio_gang_assemble(zio_t *zio)
1672 1673 {
1673 1674 blkptr_t *bp = zio->io_bp;
1674 1675
1675 1676 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL);
1676 1677 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
1677 1678
1678 1679 zio->io_gang_leader = zio;
1679 1680
1680 1681 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree);
1681 1682
1682 1683 return (ZIO_PIPELINE_CONTINUE);
1683 1684 }
1684 1685
1685 1686 static int
1686 1687 zio_gang_issue(zio_t *zio)
1687 1688 {
1688 1689 blkptr_t *bp = zio->io_bp;
1689 1690
1690 1691 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE))
1691 1692 return (ZIO_PIPELINE_STOP);
1692 1693
1693 1694 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio);
1694 1695 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
1695 1696
1696 1697 if (zio->io_child_error[ZIO_CHILD_GANG] == 0)
1697 1698 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data);
1698 1699 else
1699 1700 zio_gang_tree_free(&zio->io_gang_tree);
1700 1701
1701 1702 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1702 1703
1703 1704 return (ZIO_PIPELINE_CONTINUE);
1704 1705 }
1705 1706
1706 1707 static void
1707 1708 zio_write_gang_member_ready(zio_t *zio)
1708 1709 {
1709 1710 zio_t *pio = zio_unique_parent(zio);
1710 1711 zio_t *gio = zio->io_gang_leader;
1711 1712 dva_t *cdva = zio->io_bp->blk_dva;
1712 1713 dva_t *pdva = pio->io_bp->blk_dva;
1713 1714 uint64_t asize;
1714 1715
1715 1716 if (BP_IS_HOLE(zio->io_bp))
1716 1717 return;
1717 1718
1718 1719 ASSERT(BP_IS_HOLE(&zio->io_bp_orig));
1719 1720
1720 1721 ASSERT(zio->io_child_type == ZIO_CHILD_GANG);
1721 1722 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies);
1722 1723 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp));
1723 1724 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp));
1724 1725 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp));
1725 1726
1726 1727 mutex_enter(&pio->io_lock);
1727 1728 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) {
1728 1729 ASSERT(DVA_GET_GANG(&pdva[d]));
1729 1730 asize = DVA_GET_ASIZE(&pdva[d]);
1730 1731 asize += DVA_GET_ASIZE(&cdva[d]);
1731 1732 DVA_SET_ASIZE(&pdva[d], asize);
1732 1733 }
1733 1734 mutex_exit(&pio->io_lock);
1734 1735 }
1735 1736
1736 1737 static int
1737 1738 zio_write_gang_block(zio_t *pio)
1738 1739 {
1739 1740 spa_t *spa = pio->io_spa;
1740 1741 blkptr_t *bp = pio->io_bp;
1741 1742 zio_t *gio = pio->io_gang_leader;
1742 1743 zio_t *zio;
1743 1744 zio_gang_node_t *gn, **gnpp;
1744 1745 zio_gbh_phys_t *gbh;
1745 1746 uint64_t txg = pio->io_txg;
1746 1747 uint64_t resid = pio->io_size;
1747 1748 uint64_t lsize;
1748 1749 int copies = gio->io_prop.zp_copies;
1749 1750 int gbh_copies = MIN(copies + 1, spa_max_replication(spa));
1750 1751 zio_prop_t zp;
1751 1752 int error;
1752 1753
1753 1754 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE,
1754 1755 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp,
1755 1756 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER);
1756 1757 if (error) {
1757 1758 pio->io_error = error;
1758 1759 return (ZIO_PIPELINE_CONTINUE);
1759 1760 }
1760 1761
1761 1762 if (pio == gio) {
1762 1763 gnpp = &gio->io_gang_tree;
1763 1764 } else {
1764 1765 gnpp = pio->io_private;
1765 1766 ASSERT(pio->io_ready == zio_write_gang_member_ready);
1766 1767 }
1767 1768
1768 1769 gn = zio_gang_node_alloc(gnpp);
1769 1770 gbh = gn->gn_gbh;
1770 1771 bzero(gbh, SPA_GANGBLOCKSIZE);
1771 1772
1772 1773 /*
1773 1774 * Create the gang header.
1774 1775 */
1775 1776 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL,
1776 1777 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
1777 1778
1778 1779 /*
1779 1780 * Create and nowait the gang children.
1780 1781 */
1781 1782 for (int g = 0; resid != 0; resid -= lsize, g++) {
1782 1783 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g),
1783 1784 SPA_MINBLOCKSIZE);
1784 1785 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid);
1785 1786
1786 1787 zp.zp_checksum = gio->io_prop.zp_checksum;
1787 1788 zp.zp_compress = ZIO_COMPRESS_OFF;
1788 1789 zp.zp_type = DMU_OT_NONE;
1789 1790 zp.zp_level = 0;
1790 1791 zp.zp_copies = gio->io_prop.zp_copies;
1791 1792 zp.zp_dedup = B_FALSE;
1792 1793 zp.zp_dedup_verify = B_FALSE;
1793 1794 zp.zp_nopwrite = B_FALSE;
1794 1795
1795 1796 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g],
1796 1797 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp,
1797 1798 zio_write_gang_member_ready, NULL, &gn->gn_child[g],
1798 1799 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
1799 1800 &pio->io_bookmark));
1800 1801 }
1801 1802
1802 1803 /*
1803 1804 * Set pio's pipeline to just wait for zio to finish.
1804 1805 */
1805 1806 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1806 1807
1807 1808 zio_nowait(zio);
1808 1809
1809 1810 return (ZIO_PIPELINE_CONTINUE);
1810 1811 }
1811 1812
1812 1813 /*
1813 1814 * The zio_nop_write stage in the pipeline determines if allocating
1814 1815 * a new bp is necessary. By leveraging a cryptographically secure checksum,
1815 1816 * such as SHA256, we can compare the checksums of the new data and the old
1816 1817 * to determine if allocating a new block is required. The nopwrite
1817 1818 * feature can handle writes in either syncing or open context (i.e. zil
1818 1819 * writes) and as a result is mutually exclusive with dedup.
1819 1820 */
1820 1821 static int
1821 1822 zio_nop_write(zio_t *zio)
1822 1823 {
1823 1824 blkptr_t *bp = zio->io_bp;
1824 1825 blkptr_t *bp_orig = &zio->io_bp_orig;
1825 1826 zio_prop_t *zp = &zio->io_prop;
1826 1827
1827 1828 ASSERT(BP_GET_LEVEL(bp) == 0);
1828 1829 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1829 1830 ASSERT(zp->zp_nopwrite);
1830 1831 ASSERT(!zp->zp_dedup);
1831 1832 ASSERT(zio->io_bp_override == NULL);
1832 1833 ASSERT(IO_IS_ALLOCATING(zio));
1833 1834
1834 1835 /*
1835 1836 * Check to see if the original bp and the new bp have matching
1836 1837 * characteristics (i.e. same checksum, compression algorithms, etc).
1837 1838 * If they don't then just continue with the pipeline which will
1838 1839 * allocate a new bp.
1839 1840 */
1840 1841 if (BP_IS_HOLE(bp_orig) ||
1841 1842 !zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_dedup ||
1842 1843 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) ||
1843 1844 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) ||
1844 1845 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) ||
1845 1846 zp->zp_copies != BP_GET_NDVAS(bp_orig))
1846 1847 return (ZIO_PIPELINE_CONTINUE);
1847 1848
1848 1849 /*
1849 1850 * If the checksums match then reset the pipeline so that we
1850 1851 * avoid allocating a new bp and issuing any I/O.
1851 1852 */
1852 1853 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) {
1853 1854 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup);
1854 1855 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig));
1855 1856 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig));
1856 1857 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF);
1857 1858 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop,
1858 1859 sizeof (uint64_t)) == 0);
1859 1860
1860 1861 *bp = *bp_orig;
1861 1862 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1862 1863 zio->io_flags |= ZIO_FLAG_NOPWRITE;
1863 1864 }
1864 1865
1865 1866 return (ZIO_PIPELINE_CONTINUE);
1866 1867 }
1867 1868
1868 1869 /*
1869 1870 * ==========================================================================
1870 1871 * Dedup
1871 1872 * ==========================================================================
1872 1873 */
1873 1874 static void
1874 1875 zio_ddt_child_read_done(zio_t *zio)
1875 1876 {
1876 1877 blkptr_t *bp = zio->io_bp;
1877 1878 ddt_entry_t *dde = zio->io_private;
1878 1879 ddt_phys_t *ddp;
1879 1880 zio_t *pio = zio_unique_parent(zio);
1880 1881
1881 1882 mutex_enter(&pio->io_lock);
1882 1883 ddp = ddt_phys_select(dde, bp);
1883 1884 if (zio->io_error == 0)
1884 1885 ddt_phys_clear(ddp); /* this ddp doesn't need repair */
1885 1886 if (zio->io_error == 0 && dde->dde_repair_data == NULL)
1886 1887 dde->dde_repair_data = zio->io_data;
1887 1888 else
1888 1889 zio_buf_free(zio->io_data, zio->io_size);
1889 1890 mutex_exit(&pio->io_lock);
1890 1891 }
1891 1892
1892 1893 static int
1893 1894 zio_ddt_read_start(zio_t *zio)
1894 1895 {
1895 1896 blkptr_t *bp = zio->io_bp;
1896 1897
1897 1898 ASSERT(BP_GET_DEDUP(bp));
1898 1899 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
1899 1900 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1900 1901
1901 1902 if (zio->io_child_error[ZIO_CHILD_DDT]) {
1902 1903 ddt_t *ddt = ddt_select(zio->io_spa, bp);
1903 1904 ddt_entry_t *dde = ddt_repair_start(ddt, bp);
1904 1905 ddt_phys_t *ddp = dde->dde_phys;
1905 1906 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp);
1906 1907 blkptr_t blk;
1907 1908
1908 1909 ASSERT(zio->io_vsd == NULL);
1909 1910 zio->io_vsd = dde;
1910 1911
1911 1912 if (ddp_self == NULL)
1912 1913 return (ZIO_PIPELINE_CONTINUE);
1913 1914
1914 1915 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
1915 1916 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self)
1916 1917 continue;
1917 1918 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp,
1918 1919 &blk);
1919 1920 zio_nowait(zio_read(zio, zio->io_spa, &blk,
1920 1921 zio_buf_alloc(zio->io_size), zio->io_size,
1921 1922 zio_ddt_child_read_done, dde, zio->io_priority,
1922 1923 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE,
1923 1924 &zio->io_bookmark));
1924 1925 }
1925 1926 return (ZIO_PIPELINE_CONTINUE);
1926 1927 }
1927 1928
1928 1929 zio_nowait(zio_read(zio, zio->io_spa, bp,
1929 1930 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority,
1930 1931 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark));
1931 1932
1932 1933 return (ZIO_PIPELINE_CONTINUE);
1933 1934 }
1934 1935
1935 1936 static int
1936 1937 zio_ddt_read_done(zio_t *zio)
1937 1938 {
1938 1939 blkptr_t *bp = zio->io_bp;
1939 1940
1940 1941 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE))
1941 1942 return (ZIO_PIPELINE_STOP);
1942 1943
1943 1944 ASSERT(BP_GET_DEDUP(bp));
1944 1945 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
1945 1946 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1946 1947
1947 1948 if (zio->io_child_error[ZIO_CHILD_DDT]) {
1948 1949 ddt_t *ddt = ddt_select(zio->io_spa, bp);
1949 1950 ddt_entry_t *dde = zio->io_vsd;
1950 1951 if (ddt == NULL) {
1951 1952 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE);
1952 1953 return (ZIO_PIPELINE_CONTINUE);
1953 1954 }
1954 1955 if (dde == NULL) {
1955 1956 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1;
1956 1957 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
1957 1958 return (ZIO_PIPELINE_STOP);
1958 1959 }
1959 1960 if (dde->dde_repair_data != NULL) {
1960 1961 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size);
1961 1962 zio->io_child_error[ZIO_CHILD_DDT] = 0;
1962 1963 }
1963 1964 ddt_repair_done(ddt, dde);
1964 1965 zio->io_vsd = NULL;
1965 1966 }
1966 1967
1967 1968 ASSERT(zio->io_vsd == NULL);
1968 1969
1969 1970 return (ZIO_PIPELINE_CONTINUE);
1970 1971 }
1971 1972
1972 1973 static boolean_t
1973 1974 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde)
1974 1975 {
1975 1976 spa_t *spa = zio->io_spa;
1976 1977
1977 1978 /*
1978 1979 * Note: we compare the original data, not the transformed data,
1979 1980 * because when zio->io_bp is an override bp, we will not have
1980 1981 * pushed the I/O transforms. That's an important optimization
1981 1982 * because otherwise we'd compress/encrypt all dmu_sync() data twice.
1982 1983 */
1983 1984 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
1984 1985 zio_t *lio = dde->dde_lead_zio[p];
1985 1986
1986 1987 if (lio != NULL) {
1987 1988 return (lio->io_orig_size != zio->io_orig_size ||
1988 1989 bcmp(zio->io_orig_data, lio->io_orig_data,
1989 1990 zio->io_orig_size) != 0);
1990 1991 }
1991 1992 }
1992 1993
1993 1994 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
1994 1995 ddt_phys_t *ddp = &dde->dde_phys[p];
1995 1996
1996 1997 if (ddp->ddp_phys_birth != 0) {
1997 1998 arc_buf_t *abuf = NULL;
1998 1999 uint32_t aflags = ARC_WAIT;
1999 2000 blkptr_t blk = *zio->io_bp;
2000 2001 int error;
2001 2002
2002 2003 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
2003 2004
2004 2005 ddt_exit(ddt);
2005 2006
2006 2007 error = arc_read(NULL, spa, &blk,
2007 2008 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ,
2008 2009 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
2009 2010 &aflags, &zio->io_bookmark);
2010 2011
2011 2012 if (error == 0) {
2012 2013 if (arc_buf_size(abuf) != zio->io_orig_size ||
2013 2014 bcmp(abuf->b_data, zio->io_orig_data,
2014 2015 zio->io_orig_size) != 0)
2015 2016 error = SET_ERROR(EEXIST);
2016 2017 VERIFY(arc_buf_remove_ref(abuf, &abuf));
2017 2018 }
2018 2019
2019 2020 ddt_enter(ddt);
2020 2021 return (error != 0);
2021 2022 }
2022 2023 }
2023 2024
2024 2025 return (B_FALSE);
2025 2026 }
2026 2027
2027 2028 static void
2028 2029 zio_ddt_child_write_ready(zio_t *zio)
2029 2030 {
2030 2031 int p = zio->io_prop.zp_copies;
2031 2032 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
2032 2033 ddt_entry_t *dde = zio->io_private;
2033 2034 ddt_phys_t *ddp = &dde->dde_phys[p];
2034 2035 zio_t *pio;
2035 2036
2036 2037 if (zio->io_error)
2037 2038 return;
2038 2039
2039 2040 ddt_enter(ddt);
2040 2041
2041 2042 ASSERT(dde->dde_lead_zio[p] == zio);
2042 2043
2043 2044 ddt_phys_fill(ddp, zio->io_bp);
2044 2045
2045 2046 while ((pio = zio_walk_parents(zio)) != NULL)
2046 2047 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg);
2047 2048
2048 2049 ddt_exit(ddt);
2049 2050 }
2050 2051
2051 2052 static void
2052 2053 zio_ddt_child_write_done(zio_t *zio)
2053 2054 {
2054 2055 int p = zio->io_prop.zp_copies;
2055 2056 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
2056 2057 ddt_entry_t *dde = zio->io_private;
2057 2058 ddt_phys_t *ddp = &dde->dde_phys[p];
2058 2059
2059 2060 ddt_enter(ddt);
2060 2061
2061 2062 ASSERT(ddp->ddp_refcnt == 0);
2062 2063 ASSERT(dde->dde_lead_zio[p] == zio);
2063 2064 dde->dde_lead_zio[p] = NULL;
2064 2065
2065 2066 if (zio->io_error == 0) {
2066 2067 while (zio_walk_parents(zio) != NULL)
2067 2068 ddt_phys_addref(ddp);
2068 2069 } else {
2069 2070 ddt_phys_clear(ddp);
2070 2071 }
2071 2072
2072 2073 ddt_exit(ddt);
2073 2074 }
2074 2075
2075 2076 static void
2076 2077 zio_ddt_ditto_write_done(zio_t *zio)
2077 2078 {
2078 2079 int p = DDT_PHYS_DITTO;
2079 2080 zio_prop_t *zp = &zio->io_prop;
2080 2081 blkptr_t *bp = zio->io_bp;
2081 2082 ddt_t *ddt = ddt_select(zio->io_spa, bp);
2082 2083 ddt_entry_t *dde = zio->io_private;
2083 2084 ddt_phys_t *ddp = &dde->dde_phys[p];
2084 2085 ddt_key_t *ddk = &dde->dde_key;
2085 2086
2086 2087 ddt_enter(ddt);
2087 2088
2088 2089 ASSERT(ddp->ddp_refcnt == 0);
2089 2090 ASSERT(dde->dde_lead_zio[p] == zio);
2090 2091 dde->dde_lead_zio[p] = NULL;
2091 2092
2092 2093 if (zio->io_error == 0) {
2093 2094 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum));
2094 2095 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP);
2095 2096 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp));
2096 2097 if (ddp->ddp_phys_birth != 0)
2097 2098 ddt_phys_free(ddt, ddk, ddp, zio->io_txg);
2098 2099 ddt_phys_fill(ddp, bp);
2099 2100 }
2100 2101
2101 2102 ddt_exit(ddt);
2102 2103 }
2103 2104
2104 2105 static int
2105 2106 zio_ddt_write(zio_t *zio)
2106 2107 {
2107 2108 spa_t *spa = zio->io_spa;
2108 2109 blkptr_t *bp = zio->io_bp;
2109 2110 uint64_t txg = zio->io_txg;
2110 2111 zio_prop_t *zp = &zio->io_prop;
2111 2112 int p = zp->zp_copies;
2112 2113 int ditto_copies;
2113 2114 zio_t *cio = NULL;
2114 2115 zio_t *dio = NULL;
2115 2116 ddt_t *ddt = ddt_select(spa, bp);
2116 2117 ddt_entry_t *dde;
2117 2118 ddt_phys_t *ddp;
2118 2119
2119 2120 ASSERT(BP_GET_DEDUP(bp));
2120 2121 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum);
2121 2122 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override);
2122 2123
2123 2124 ddt_enter(ddt);
2124 2125 dde = ddt_lookup(ddt, bp, B_TRUE);
2125 2126 ddp = &dde->dde_phys[p];
2126 2127
2127 2128 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) {
2128 2129 /*
2129 2130 * If we're using a weak checksum, upgrade to a strong checksum
2130 2131 * and try again. If we're already using a strong checksum,
2131 2132 * we can't resolve it, so just convert to an ordinary write.
2132 2133 * (And automatically e-mail a paper to Nature?)
2133 2134 */
2134 2135 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) {
2135 2136 zp->zp_checksum = spa_dedup_checksum(spa);
2136 2137 zio_pop_transforms(zio);
2137 2138 zio->io_stage = ZIO_STAGE_OPEN;
2138 2139 BP_ZERO(bp);
2139 2140 } else {
2140 2141 zp->zp_dedup = B_FALSE;
2141 2142 }
2142 2143 zio->io_pipeline = ZIO_WRITE_PIPELINE;
2143 2144 ddt_exit(ddt);
2144 2145 return (ZIO_PIPELINE_CONTINUE);
2145 2146 }
2146 2147
2147 2148 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp);
2148 2149 ASSERT(ditto_copies < SPA_DVAS_PER_BP);
2149 2150
2150 2151 if (ditto_copies > ddt_ditto_copies_present(dde) &&
2151 2152 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) {
2152 2153 zio_prop_t czp = *zp;
2153 2154
2154 2155 czp.zp_copies = ditto_copies;
2155 2156
2156 2157 /*
2157 2158 * If we arrived here with an override bp, we won't have run
2158 2159 * the transform stack, so we won't have the data we need to
2159 2160 * generate a child i/o. So, toss the override bp and restart.
2160 2161 * This is safe, because using the override bp is just an
2161 2162 * optimization; and it's rare, so the cost doesn't matter.
2162 2163 */
2163 2164 if (zio->io_bp_override) {
2164 2165 zio_pop_transforms(zio);
2165 2166 zio->io_stage = ZIO_STAGE_OPEN;
2166 2167 zio->io_pipeline = ZIO_WRITE_PIPELINE;
2167 2168 zio->io_bp_override = NULL;
2168 2169 BP_ZERO(bp);
2169 2170 ddt_exit(ddt);
2170 2171 return (ZIO_PIPELINE_CONTINUE);
2171 2172 }
2172 2173
2173 2174 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data,
2174 2175 zio->io_orig_size, &czp, NULL,
2175 2176 zio_ddt_ditto_write_done, dde, zio->io_priority,
2176 2177 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
2177 2178
2178 2179 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL);
2179 2180 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio;
2180 2181 }
2181 2182
2182 2183 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) {
2183 2184 if (ddp->ddp_phys_birth != 0)
2184 2185 ddt_bp_fill(ddp, bp, txg);
2185 2186 if (dde->dde_lead_zio[p] != NULL)
2186 2187 zio_add_child(zio, dde->dde_lead_zio[p]);
2187 2188 else
2188 2189 ddt_phys_addref(ddp);
2189 2190 } else if (zio->io_bp_override) {
2190 2191 ASSERT(bp->blk_birth == txg);
2191 2192 ASSERT(BP_EQUAL(bp, zio->io_bp_override));
2192 2193 ddt_phys_fill(ddp, bp);
2193 2194 ddt_phys_addref(ddp);
2194 2195 } else {
2195 2196 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data,
2196 2197 zio->io_orig_size, zp, zio_ddt_child_write_ready,
2197 2198 zio_ddt_child_write_done, dde, zio->io_priority,
2198 2199 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
2199 2200
2200 2201 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL);
2201 2202 dde->dde_lead_zio[p] = cio;
2202 2203 }
2203 2204
2204 2205 ddt_exit(ddt);
2205 2206
2206 2207 if (cio)
2207 2208 zio_nowait(cio);
2208 2209 if (dio)
2209 2210 zio_nowait(dio);
2210 2211
2211 2212 return (ZIO_PIPELINE_CONTINUE);
2212 2213 }
2213 2214
2214 2215 ddt_entry_t *freedde; /* for debugging */
2215 2216
2216 2217 static int
2217 2218 zio_ddt_free(zio_t *zio)
2218 2219 {
2219 2220 spa_t *spa = zio->io_spa;
2220 2221 blkptr_t *bp = zio->io_bp;
2221 2222 ddt_t *ddt = ddt_select(spa, bp);
2222 2223 ddt_entry_t *dde;
2223 2224 ddt_phys_t *ddp;
2224 2225
2225 2226 ASSERT(BP_GET_DEDUP(bp));
2226 2227 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2227 2228
2228 2229 ddt_enter(ddt);
2229 2230 freedde = dde = ddt_lookup(ddt, bp, B_TRUE);
2230 2231 ddp = ddt_phys_select(dde, bp);
2231 2232 ddt_phys_decref(ddp);
2232 2233 ddt_exit(ddt);
2233 2234
2234 2235 return (ZIO_PIPELINE_CONTINUE);
2235 2236 }
2236 2237
2237 2238 /*
2238 2239 * ==========================================================================
2239 2240 * Allocate and free blocks
2240 2241 * ==========================================================================
2241 2242 */
2242 2243 static int
2243 2244 zio_dva_allocate(zio_t *zio)
2244 2245 {
2245 2246 spa_t *spa = zio->io_spa;
2246 2247 metaslab_class_t *mc = spa_normal_class(spa);
2247 2248 blkptr_t *bp = zio->io_bp;
2248 2249 int error;
2249 2250 int flags = 0;
2250 2251
2251 2252 if (zio->io_gang_leader == NULL) {
2252 2253 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2253 2254 zio->io_gang_leader = zio;
2254 2255 }
2255 2256
2256 2257 ASSERT(BP_IS_HOLE(bp));
2257 2258 ASSERT0(BP_GET_NDVAS(bp));
2258 2259 ASSERT3U(zio->io_prop.zp_copies, >, 0);
2259 2260 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa));
2260 2261 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
2261 2262
2262 2263 /*
2263 2264 * The dump device does not support gang blocks so allocation on
2264 2265 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid
2265 2266 * the "fast" gang feature.
2266 2267 */
2267 2268 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0;
2268 2269 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ?
2269 2270 METASLAB_GANG_CHILD : 0;
2270 2271 error = metaslab_alloc(spa, mc, zio->io_size, bp,
2271 2272 zio->io_prop.zp_copies, zio->io_txg, NULL, flags);
2272 2273
2273 2274 if (error) {
2274 2275 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, "
2275 2276 "size %llu, error %d", spa_name(spa), zio, zio->io_size,
2276 2277 error);
2277 2278 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE)
2278 2279 return (zio_write_gang_block(zio));
2279 2280 zio->io_error = error;
2280 2281 }
2281 2282
2282 2283 return (ZIO_PIPELINE_CONTINUE);
2283 2284 }
2284 2285
2285 2286 static int
2286 2287 zio_dva_free(zio_t *zio)
2287 2288 {
2288 2289 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE);
2289 2290
2290 2291 return (ZIO_PIPELINE_CONTINUE);
2291 2292 }
2292 2293
2293 2294 static int
2294 2295 zio_dva_claim(zio_t *zio)
2295 2296 {
2296 2297 int error;
2297 2298
2298 2299 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg);
2299 2300 if (error)
2300 2301 zio->io_error = error;
2301 2302
2302 2303 return (ZIO_PIPELINE_CONTINUE);
2303 2304 }
2304 2305
2305 2306 /*
2306 2307 * Undo an allocation. This is used by zio_done() when an I/O fails
2307 2308 * and we want to give back the block we just allocated.
2308 2309 * This handles both normal blocks and gang blocks.
2309 2310 */
2310 2311 static void
2311 2312 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp)
2312 2313 {
2313 2314 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
2314 2315 ASSERT(zio->io_bp_override == NULL);
2315 2316
2316 2317 if (!BP_IS_HOLE(bp))
2317 2318 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE);
2318 2319
2319 2320 if (gn != NULL) {
2320 2321 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2321 2322 zio_dva_unallocate(zio, gn->gn_child[g],
2322 2323 &gn->gn_gbh->zg_blkptr[g]);
2323 2324 }
2324 2325 }
2325 2326 }
2326 2327
2327 2328 /*
2328 2329 * Try to allocate an intent log block. Return 0 on success, errno on failure.
2329 2330 */
2330 2331 int
2331 2332 zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp,
2332 2333 uint64_t size, boolean_t use_slog)
2333 2334 {
2334 2335 int error = 1;
2335 2336
2336 2337 ASSERT(txg > spa_syncing_txg(spa));
2337 2338
2338 2339 /*
2339 2340 * ZIL blocks are always contiguous (i.e. not gang blocks) so we
2340 2341 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang"
2341 2342 * when allocating them.
2342 2343 */
2343 2344 if (use_slog) {
2344 2345 error = metaslab_alloc(spa, spa_log_class(spa), size,
2345 2346 new_bp, 1, txg, old_bp,
2346 2347 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID);
2347 2348 }
2348 2349
2349 2350 if (error) {
2350 2351 error = metaslab_alloc(spa, spa_normal_class(spa), size,
2351 2352 new_bp, 1, txg, old_bp,
2352 2353 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID);
2353 2354 }
2354 2355
2355 2356 if (error == 0) {
2356 2357 BP_SET_LSIZE(new_bp, size);
2357 2358 BP_SET_PSIZE(new_bp, size);
2358 2359 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF);
2359 2360 BP_SET_CHECKSUM(new_bp,
2360 2361 spa_version(spa) >= SPA_VERSION_SLIM_ZIL
2361 2362 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG);
2362 2363 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
2363 2364 BP_SET_LEVEL(new_bp, 0);
2364 2365 BP_SET_DEDUP(new_bp, 0);
2365 2366 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER);
2366 2367 }
2367 2368
2368 2369 return (error);
2369 2370 }
2370 2371
2371 2372 /*
2372 2373 * Free an intent log block.
2373 2374 */
2374 2375 void
2375 2376 zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp)
2376 2377 {
2377 2378 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG);
2378 2379 ASSERT(!BP_IS_GANG(bp));
2379 2380
2380 2381 zio_free(spa, txg, bp);
2381 2382 }
2382 2383
2383 2384 /*
2384 2385 * ==========================================================================
2385 2386 * Read and write to physical devices
2386 2387 * ==========================================================================
2387 2388 */
2388 2389 static int
2389 2390 zio_vdev_io_start(zio_t *zio)
2390 2391 {
2391 2392 vdev_t *vd = zio->io_vd;
2392 2393 uint64_t align;
2393 2394 spa_t *spa = zio->io_spa;
2394 2395
2395 2396 ASSERT(zio->io_error == 0);
2396 2397 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0);
2397 2398
2398 2399 if (vd == NULL) {
2399 2400 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
2400 2401 spa_config_enter(spa, SCL_ZIO, zio, RW_READER);
2401 2402
2402 2403 /*
2403 2404 * The mirror_ops handle multiple DVAs in a single BP.
2404 2405 */
2405 2406 return (vdev_mirror_ops.vdev_op_io_start(zio));
2406 2407 }
2407 2408
2408 2409 /*
2409 2410 * We keep track of time-sensitive I/Os so that the scan thread
2410 2411 * can quickly react to certain workloads. In particular, we care
2411 2412 * about non-scrubbing, top-level reads and writes with the following
2412 2413 * characteristics:
2413 2414 * - synchronous writes of user data to non-slog devices
2414 2415 * - any reads of user data
2415 2416 * When these conditions are met, adjust the timestamp of spa_last_io
2416 2417 * which allows the scan thread to adjust its workload accordingly.
2417 2418 */
2418 2419 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL &&
2419 2420 vd == vd->vdev_top && !vd->vdev_islog &&
2420 2421 zio->io_bookmark.zb_objset != DMU_META_OBJSET &&
2421 2422 zio->io_txg != spa_syncing_txg(spa)) {
2422 2423 uint64_t old = spa->spa_last_io;
2423 2424 uint64_t new = ddi_get_lbolt64();
2424 2425 if (old != new)
2425 2426 (void) atomic_cas_64(&spa->spa_last_io, old, new);
2426 2427 }
2427 2428
2428 2429 align = 1ULL << vd->vdev_top->vdev_ashift;
2429 2430
2430 2431 if (P2PHASE(zio->io_size, align) != 0) {
2431 2432 uint64_t asize = P2ROUNDUP(zio->io_size, align);
2432 2433 char *abuf = zio_buf_alloc(asize);
2433 2434 ASSERT(vd == vd->vdev_top);
2434 2435 if (zio->io_type == ZIO_TYPE_WRITE) {
2435 2436 bcopy(zio->io_data, abuf, zio->io_size);
2436 2437 bzero(abuf + zio->io_size, asize - zio->io_size);
2437 2438 }
2438 2439 zio_push_transform(zio, abuf, asize, asize, zio_subblock);
2439 2440 }
2440 2441
2441 2442 ASSERT(P2PHASE(zio->io_offset, align) == 0);
2442 2443 ASSERT(P2PHASE(zio->io_size, align) == 0);
2443 2444 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa));
2444 2445
2445 2446 /*
2446 2447 * If this is a repair I/O, and there's no self-healing involved --
2447 2448 * that is, we're just resilvering what we expect to resilver --
2448 2449 * then don't do the I/O unless zio's txg is actually in vd's DTL.
2449 2450 * This prevents spurious resilvering with nested replication.
2450 2451 * For example, given a mirror of mirrors, (A+B)+(C+D), if only
2451 2452 * A is out of date, we'll read from C+D, then use the data to
2452 2453 * resilver A+B -- but we don't actually want to resilver B, just A.
2453 2454 * The top-level mirror has no way to know this, so instead we just
2454 2455 * discard unnecessary repairs as we work our way down the vdev tree.
2455 2456 * The same logic applies to any form of nested replication:
2456 2457 * ditto + mirror, RAID-Z + replacing, etc. This covers them all.
2457 2458 */
2458 2459 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) &&
2459 2460 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) &&
2460 2461 zio->io_txg != 0 && /* not a delegated i/o */
2461 2462 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) {
2462 2463 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
2463 2464 zio_vdev_io_bypass(zio);
2464 2465 return (ZIO_PIPELINE_CONTINUE);
2465 2466 }
2466 2467
2467 2468 if (vd->vdev_ops->vdev_op_leaf &&
2468 2469 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) {
2469 2470
2470 2471 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0)
2471 2472 return (ZIO_PIPELINE_CONTINUE);
2472 2473
2473 2474 if ((zio = vdev_queue_io(zio)) == NULL)
2474 2475 return (ZIO_PIPELINE_STOP);
2475 2476
2476 2477 if (!vdev_accessible(vd, zio)) {
2477 2478 zio->io_error = SET_ERROR(ENXIO);
2478 2479 zio_interrupt(zio);
2479 2480 return (ZIO_PIPELINE_STOP);
2480 2481 }
2481 2482 }
2482 2483
2483 2484 return (vd->vdev_ops->vdev_op_io_start(zio));
2484 2485 }
2485 2486
2486 2487 static int
2487 2488 zio_vdev_io_done(zio_t *zio)
2488 2489 {
2489 2490 vdev_t *vd = zio->io_vd;
2490 2491 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops;
2491 2492 boolean_t unexpected_error = B_FALSE;
2492 2493
2493 2494 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE))
2494 2495 return (ZIO_PIPELINE_STOP);
2495 2496
2496 2497 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
2497 2498
2498 2499 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) {
2499 2500
2500 2501 vdev_queue_io_done(zio);
2501 2502
2502 2503 if (zio->io_type == ZIO_TYPE_WRITE)
2503 2504 vdev_cache_write(zio);
2504 2505
2505 2506 if (zio_injection_enabled && zio->io_error == 0)
2506 2507 zio->io_error = zio_handle_device_injection(vd,
2507 2508 zio, EIO);
2508 2509
2509 2510 if (zio_injection_enabled && zio->io_error == 0)
2510 2511 zio->io_error = zio_handle_label_injection(zio, EIO);
2511 2512
2512 2513 if (zio->io_error) {
2513 2514 if (!vdev_accessible(vd, zio)) {
2514 2515 zio->io_error = SET_ERROR(ENXIO);
2515 2516 } else {
2516 2517 unexpected_error = B_TRUE;
2517 2518 }
2518 2519 }
2519 2520 }
2520 2521
2521 2522 ops->vdev_op_io_done(zio);
2522 2523
2523 2524 if (unexpected_error)
2524 2525 VERIFY(vdev_probe(vd, zio) == NULL);
2525 2526
2526 2527 return (ZIO_PIPELINE_CONTINUE);
2527 2528 }
2528 2529
2529 2530 /*
2530 2531 * For non-raidz ZIOs, we can just copy aside the bad data read from the
2531 2532 * disk, and use that to finish the checksum ereport later.
2532 2533 */
2533 2534 static void
2534 2535 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr,
2535 2536 const void *good_buf)
2536 2537 {
2537 2538 /* no processing needed */
2538 2539 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE);
2539 2540 }
2540 2541
2541 2542 /*ARGSUSED*/
2542 2543 void
2543 2544 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored)
2544 2545 {
2545 2546 void *buf = zio_buf_alloc(zio->io_size);
2546 2547
2547 2548 bcopy(zio->io_data, buf, zio->io_size);
2548 2549
2549 2550 zcr->zcr_cbinfo = zio->io_size;
2550 2551 zcr->zcr_cbdata = buf;
2551 2552 zcr->zcr_finish = zio_vsd_default_cksum_finish;
2552 2553 zcr->zcr_free = zio_buf_free;
2553 2554 }
2554 2555
2555 2556 static int
2556 2557 zio_vdev_io_assess(zio_t *zio)
2557 2558 {
2558 2559 vdev_t *vd = zio->io_vd;
2559 2560
2560 2561 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE))
2561 2562 return (ZIO_PIPELINE_STOP);
2562 2563
2563 2564 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
2564 2565 spa_config_exit(zio->io_spa, SCL_ZIO, zio);
2565 2566
2566 2567 if (zio->io_vsd != NULL) {
2567 2568 zio->io_vsd_ops->vsd_free(zio);
2568 2569 zio->io_vsd = NULL;
2569 2570 }
2570 2571
2571 2572 if (zio_injection_enabled && zio->io_error == 0)
2572 2573 zio->io_error = zio_handle_fault_injection(zio, EIO);
2573 2574
2574 2575 /*
2575 2576 * If the I/O failed, determine whether we should attempt to retry it.
2576 2577 *
2577 2578 * On retry, we cut in line in the issue queue, since we don't want
2578 2579 * compression/checksumming/etc. work to prevent our (cheap) IO reissue.
2579 2580 */
2580 2581 if (zio->io_error && vd == NULL &&
2581 2582 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) {
2582 2583 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */
2583 2584 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */
2584 2585 zio->io_error = 0;
2585 2586 zio->io_flags |= ZIO_FLAG_IO_RETRY |
2586 2587 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE;
2587 2588 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1;
2588 2589 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE,
2589 2590 zio_requeue_io_start_cut_in_line);
2590 2591 return (ZIO_PIPELINE_STOP);
2591 2592 }
2592 2593
2593 2594 /*
2594 2595 * If we got an error on a leaf device, convert it to ENXIO
2595 2596 * if the device is not accessible at all.
2596 2597 */
2597 2598 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf &&
2598 2599 !vdev_accessible(vd, zio))
2599 2600 zio->io_error = SET_ERROR(ENXIO);
2600 2601
2601 2602 /*
2602 2603 * If we can't write to an interior vdev (mirror or RAID-Z),
2603 2604 * set vdev_cant_write so that we stop trying to allocate from it.
2604 2605 */
2605 2606 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE &&
2606 2607 vd != NULL && !vd->vdev_ops->vdev_op_leaf) {
2607 2608 vd->vdev_cant_write = B_TRUE;
2608 2609 }
2609 2610
2610 2611 if (zio->io_error)
2611 2612 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2612 2613
2613 2614 return (ZIO_PIPELINE_CONTINUE);
2614 2615 }
2615 2616
2616 2617 void
2617 2618 zio_vdev_io_reissue(zio_t *zio)
2618 2619 {
2619 2620 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
2620 2621 ASSERT(zio->io_error == 0);
2621 2622
2622 2623 zio->io_stage >>= 1;
2623 2624 }
2624 2625
2625 2626 void
2626 2627 zio_vdev_io_redone(zio_t *zio)
2627 2628 {
2628 2629 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE);
2629 2630
2630 2631 zio->io_stage >>= 1;
2631 2632 }
2632 2633
2633 2634 void
2634 2635 zio_vdev_io_bypass(zio_t *zio)
2635 2636 {
2636 2637 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
2637 2638 ASSERT(zio->io_error == 0);
2638 2639
2639 2640 zio->io_flags |= ZIO_FLAG_IO_BYPASS;
2640 2641 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1;
2641 2642 }
2642 2643
2643 2644 /*
2644 2645 * ==========================================================================
2645 2646 * Generate and verify checksums
2646 2647 * ==========================================================================
2647 2648 */
2648 2649 static int
2649 2650 zio_checksum_generate(zio_t *zio)
2650 2651 {
2651 2652 blkptr_t *bp = zio->io_bp;
2652 2653 enum zio_checksum checksum;
2653 2654
2654 2655 if (bp == NULL) {
2655 2656 /*
2656 2657 * This is zio_write_phys().
2657 2658 * We're either generating a label checksum, or none at all.
2658 2659 */
2659 2660 checksum = zio->io_prop.zp_checksum;
2660 2661
2661 2662 if (checksum == ZIO_CHECKSUM_OFF)
2662 2663 return (ZIO_PIPELINE_CONTINUE);
2663 2664
2664 2665 ASSERT(checksum == ZIO_CHECKSUM_LABEL);
2665 2666 } else {
2666 2667 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) {
2667 2668 ASSERT(!IO_IS_ALLOCATING(zio));
2668 2669 checksum = ZIO_CHECKSUM_GANG_HEADER;
2669 2670 } else {
2670 2671 checksum = BP_GET_CHECKSUM(bp);
2671 2672 }
2672 2673 }
2673 2674
2674 2675 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size);
2675 2676
2676 2677 return (ZIO_PIPELINE_CONTINUE);
2677 2678 }
2678 2679
2679 2680 static int
2680 2681 zio_checksum_verify(zio_t *zio)
2681 2682 {
2682 2683 zio_bad_cksum_t info;
2683 2684 blkptr_t *bp = zio->io_bp;
2684 2685 int error;
2685 2686
2686 2687 ASSERT(zio->io_vd != NULL);
2687 2688
2688 2689 if (bp == NULL) {
2689 2690 /*
2690 2691 * This is zio_read_phys().
2691 2692 * We're either verifying a label checksum, or nothing at all.
2692 2693 */
2693 2694 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF)
2694 2695 return (ZIO_PIPELINE_CONTINUE);
2695 2696
2696 2697 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL);
2697 2698 }
2698 2699
2699 2700 if ((error = zio_checksum_error(zio, &info)) != 0) {
2700 2701 zio->io_error = error;
2701 2702 if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
2702 2703 zfs_ereport_start_checksum(zio->io_spa,
2703 2704 zio->io_vd, zio, zio->io_offset,
2704 2705 zio->io_size, NULL, &info);
2705 2706 }
2706 2707 }
2707 2708
2708 2709 return (ZIO_PIPELINE_CONTINUE);
2709 2710 }
2710 2711
2711 2712 /*
2712 2713 * Called by RAID-Z to ensure we don't compute the checksum twice.
2713 2714 */
2714 2715 void
2715 2716 zio_checksum_verified(zio_t *zio)
2716 2717 {
2717 2718 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
2718 2719 }
2719 2720
2720 2721 /*
2721 2722 * ==========================================================================
2722 2723 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
2723 2724 * An error of 0 indictes success. ENXIO indicates whole-device failure,
2724 2725 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO
2725 2726 * indicate errors that are specific to one I/O, and most likely permanent.
2726 2727 * Any other error is presumed to be worse because we weren't expecting it.
2727 2728 * ==========================================================================
2728 2729 */
2729 2730 int
2730 2731 zio_worst_error(int e1, int e2)
2731 2732 {
2732 2733 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO };
2733 2734 int r1, r2;
2734 2735
2735 2736 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++)
2736 2737 if (e1 == zio_error_rank[r1])
2737 2738 break;
2738 2739
2739 2740 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++)
2740 2741 if (e2 == zio_error_rank[r2])
2741 2742 break;
2742 2743
2743 2744 return (r1 > r2 ? e1 : e2);
2744 2745 }
2745 2746
2746 2747 /*
2747 2748 * ==========================================================================
2748 2749 * I/O completion
2749 2750 * ==========================================================================
2750 2751 */
2751 2752 static int
2752 2753 zio_ready(zio_t *zio)
2753 2754 {
2754 2755 blkptr_t *bp = zio->io_bp;
2755 2756 zio_t *pio, *pio_next;
2756 2757
2757 2758 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) ||
2758 2759 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY))
2759 2760 return (ZIO_PIPELINE_STOP);
2760 2761
2761 2762 if (zio->io_ready) {
2762 2763 ASSERT(IO_IS_ALLOCATING(zio));
2763 2764 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) ||
2764 2765 (zio->io_flags & ZIO_FLAG_NOPWRITE));
2765 2766 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0);
2766 2767
2767 2768 zio->io_ready(zio);
2768 2769 }
2769 2770
2770 2771 if (bp != NULL && bp != &zio->io_bp_copy)
2771 2772 zio->io_bp_copy = *bp;
2772 2773
2773 2774 if (zio->io_error)
2774 2775 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2775 2776
2776 2777 mutex_enter(&zio->io_lock);
2777 2778 zio->io_state[ZIO_WAIT_READY] = 1;
2778 2779 pio = zio_walk_parents(zio);
2779 2780 mutex_exit(&zio->io_lock);
2780 2781
2781 2782 /*
2782 2783 * As we notify zio's parents, new parents could be added.
2783 2784 * New parents go to the head of zio's io_parent_list, however,
2784 2785 * so we will (correctly) not notify them. The remainder of zio's
2785 2786 * io_parent_list, from 'pio_next' onward, cannot change because
2786 2787 * all parents must wait for us to be done before they can be done.
2787 2788 */
2788 2789 for (; pio != NULL; pio = pio_next) {
2789 2790 pio_next = zio_walk_parents(zio);
2790 2791 zio_notify_parent(pio, zio, ZIO_WAIT_READY);
2791 2792 }
2792 2793
2793 2794 if (zio->io_flags & ZIO_FLAG_NODATA) {
2794 2795 if (BP_IS_GANG(bp)) {
2795 2796 zio->io_flags &= ~ZIO_FLAG_NODATA;
2796 2797 } else {
2797 2798 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE);
2798 2799 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
2799 2800 }
2800 2801 }
2801 2802
2802 2803 if (zio_injection_enabled &&
2803 2804 zio->io_spa->spa_syncing_txg == zio->io_txg)
2804 2805 zio_handle_ignored_writes(zio);
2805 2806
2806 2807 return (ZIO_PIPELINE_CONTINUE);
2807 2808 }
2808 2809
2809 2810 static int
2810 2811 zio_done(zio_t *zio)
2811 2812 {
2812 2813 spa_t *spa = zio->io_spa;
2813 2814 zio_t *lio = zio->io_logical;
2814 2815 blkptr_t *bp = zio->io_bp;
2815 2816 vdev_t *vd = zio->io_vd;
2816 2817 uint64_t psize = zio->io_size;
2817 2818 zio_t *pio, *pio_next;
2818 2819
2819 2820 /*
2820 2821 * If our children haven't all completed,
2821 2822 * wait for them and then repeat this pipeline stage.
2822 2823 */
2823 2824 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) ||
2824 2825 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) ||
2825 2826 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) ||
2826 2827 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE))
2827 2828 return (ZIO_PIPELINE_STOP);
2828 2829
2829 2830 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
2830 2831 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
2831 2832 ASSERT(zio->io_children[c][w] == 0);
2832 2833
2833 2834 if (bp != NULL) {
2834 2835 ASSERT(bp->blk_pad[0] == 0);
2835 2836 ASSERT(bp->blk_pad[1] == 0);
2836 2837 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 ||
2837 2838 (bp == zio_unique_parent(zio)->io_bp));
2838 2839 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) &&
2839 2840 zio->io_bp_override == NULL &&
2840 2841 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) {
2841 2842 ASSERT(!BP_SHOULD_BYTESWAP(bp));
2842 2843 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp));
2843 2844 ASSERT(BP_COUNT_GANG(bp) == 0 ||
2844 2845 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp)));
2845 2846 }
2846 2847 if (zio->io_flags & ZIO_FLAG_NOPWRITE)
2847 2848 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig));
2848 2849 }
2849 2850
2850 2851 /*
2851 2852 * If there were child vdev/gang/ddt errors, they apply to us now.
2852 2853 */
2853 2854 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV);
2854 2855 zio_inherit_child_errors(zio, ZIO_CHILD_GANG);
2855 2856 zio_inherit_child_errors(zio, ZIO_CHILD_DDT);
2856 2857
2857 2858 /*
2858 2859 * If the I/O on the transformed data was successful, generate any
2859 2860 * checksum reports now while we still have the transformed data.
2860 2861 */
2861 2862 if (zio->io_error == 0) {
2862 2863 while (zio->io_cksum_report != NULL) {
2863 2864 zio_cksum_report_t *zcr = zio->io_cksum_report;
2864 2865 uint64_t align = zcr->zcr_align;
2865 2866 uint64_t asize = P2ROUNDUP(psize, align);
2866 2867 char *abuf = zio->io_data;
2867 2868
2868 2869 if (asize != psize) {
2869 2870 abuf = zio_buf_alloc(asize);
2870 2871 bcopy(zio->io_data, abuf, psize);
2871 2872 bzero(abuf + psize, asize - psize);
2872 2873 }
2873 2874
2874 2875 zio->io_cksum_report = zcr->zcr_next;
2875 2876 zcr->zcr_next = NULL;
2876 2877 zcr->zcr_finish(zcr, abuf);
2877 2878 zfs_ereport_free_checksum(zcr);
2878 2879
2879 2880 if (asize != psize)
2880 2881 zio_buf_free(abuf, asize);
2881 2882 }
2882 2883 }
2883 2884
2884 2885 zio_pop_transforms(zio); /* note: may set zio->io_error */
2885 2886
2886 2887 vdev_stat_update(zio, psize);
2887 2888
2888 2889 if (zio->io_error) {
2889 2890 /*
2890 2891 * If this I/O is attached to a particular vdev,
2891 2892 * generate an error message describing the I/O failure
2892 2893 * at the block level. We ignore these errors if the
2893 2894 * device is currently unavailable.
2894 2895 */
2895 2896 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd))
2896 2897 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0);
2897 2898
2898 2899 if ((zio->io_error == EIO || !(zio->io_flags &
2899 2900 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) &&
2900 2901 zio == lio) {
2901 2902 /*
2902 2903 * For logical I/O requests, tell the SPA to log the
2903 2904 * error and generate a logical data ereport.
2904 2905 */
2905 2906 spa_log_error(spa, zio);
2906 2907 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio,
2907 2908 0, 0);
2908 2909 }
2909 2910 }
2910 2911
2911 2912 if (zio->io_error && zio == lio) {
2912 2913 /*
2913 2914 * Determine whether zio should be reexecuted. This will
2914 2915 * propagate all the way to the root via zio_notify_parent().
2915 2916 */
2916 2917 ASSERT(vd == NULL && bp != NULL);
2917 2918 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2918 2919
2919 2920 if (IO_IS_ALLOCATING(zio) &&
2920 2921 !(zio->io_flags & ZIO_FLAG_CANFAIL)) {
2921 2922 if (zio->io_error != ENOSPC)
2922 2923 zio->io_reexecute |= ZIO_REEXECUTE_NOW;
2923 2924 else
2924 2925 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
2925 2926 }
2926 2927
2927 2928 if ((zio->io_type == ZIO_TYPE_READ ||
2928 2929 zio->io_type == ZIO_TYPE_FREE) &&
2929 2930 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) &&
2930 2931 zio->io_error == ENXIO &&
2931 2932 spa_load_state(spa) == SPA_LOAD_NONE &&
2932 2933 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE)
2933 2934 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
2934 2935
2935 2936 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute)
2936 2937 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
2937 2938
2938 2939 /*
2939 2940 * Here is a possibly good place to attempt to do
2940 2941 * either combinatorial reconstruction or error correction
2941 2942 * based on checksums. It also might be a good place
2942 2943 * to send out preliminary ereports before we suspend
2943 2944 * processing.
2944 2945 */
2945 2946 }
2946 2947
2947 2948 /*
2948 2949 * If there were logical child errors, they apply to us now.
2949 2950 * We defer this until now to avoid conflating logical child
2950 2951 * errors with errors that happened to the zio itself when
2951 2952 * updating vdev stats and reporting FMA events above.
2952 2953 */
2953 2954 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL);
2954 2955
2955 2956 if ((zio->io_error || zio->io_reexecute) &&
2956 2957 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio &&
2957 2958 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)))
2958 2959 zio_dva_unallocate(zio, zio->io_gang_tree, bp);
2959 2960
2960 2961 zio_gang_tree_free(&zio->io_gang_tree);
2961 2962
2962 2963 /*
2963 2964 * Godfather I/Os should never suspend.
2964 2965 */
2965 2966 if ((zio->io_flags & ZIO_FLAG_GODFATHER) &&
2966 2967 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND))
2967 2968 zio->io_reexecute = 0;
2968 2969
2969 2970 if (zio->io_reexecute) {
2970 2971 /*
2971 2972 * This is a logical I/O that wants to reexecute.
2972 2973 *
2973 2974 * Reexecute is top-down. When an i/o fails, if it's not
2974 2975 * the root, it simply notifies its parent and sticks around.
2975 2976 * The parent, seeing that it still has children in zio_done(),
2976 2977 * does the same. This percolates all the way up to the root.
2977 2978 * The root i/o will reexecute or suspend the entire tree.
2978 2979 *
2979 2980 * This approach ensures that zio_reexecute() honors
2980 2981 * all the original i/o dependency relationships, e.g.
2981 2982 * parents not executing until children are ready.
2982 2983 */
2983 2984 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2984 2985
2985 2986 zio->io_gang_leader = NULL;
2986 2987
2987 2988 mutex_enter(&zio->io_lock);
2988 2989 zio->io_state[ZIO_WAIT_DONE] = 1;
2989 2990 mutex_exit(&zio->io_lock);
2990 2991
2991 2992 /*
2992 2993 * "The Godfather" I/O monitors its children but is
2993 2994 * not a true parent to them. It will track them through
2994 2995 * the pipeline but severs its ties whenever they get into
2995 2996 * trouble (e.g. suspended). This allows "The Godfather"
2996 2997 * I/O to return status without blocking.
2997 2998 */
2998 2999 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) {
2999 3000 zio_link_t *zl = zio->io_walk_link;
3000 3001 pio_next = zio_walk_parents(zio);
3001 3002
3002 3003 if ((pio->io_flags & ZIO_FLAG_GODFATHER) &&
3003 3004 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) {
3004 3005 zio_remove_child(pio, zio, zl);
3005 3006 zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
3006 3007 }
3007 3008 }
3008 3009
3009 3010 if ((pio = zio_unique_parent(zio)) != NULL) {
3010 3011 /*
3011 3012 * We're not a root i/o, so there's nothing to do
3012 3013 * but notify our parent. Don't propagate errors
3013 3014 * upward since we haven't permanently failed yet.
3014 3015 */
3015 3016 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
3016 3017 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE;
3017 3018 zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
3018 3019 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) {
3019 3020 /*
3020 3021 * We'd fail again if we reexecuted now, so suspend
3021 3022 * until conditions improve (e.g. device comes online).
3022 3023 */
3023 3024 zio_suspend(spa, zio);
3024 3025 } else {
3025 3026 /*
3026 3027 * Reexecution is potentially a huge amount of work.
3027 3028 * Hand it off to the otherwise-unused claim taskq.
3028 3029 */
3029 3030 ASSERT(zio->io_tqent.tqent_next == NULL);
3030 3031 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM,
3031 3032 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio,
3032 3033 0, &zio->io_tqent);
3033 3034 }
3034 3035 return (ZIO_PIPELINE_STOP);
3035 3036 }
3036 3037
3037 3038 ASSERT(zio->io_child_count == 0);
3038 3039 ASSERT(zio->io_reexecute == 0);
3039 3040 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL));
3040 3041
3041 3042 /*
3042 3043 * Report any checksum errors, since the I/O is complete.
3043 3044 */
3044 3045 while (zio->io_cksum_report != NULL) {
3045 3046 zio_cksum_report_t *zcr = zio->io_cksum_report;
3046 3047 zio->io_cksum_report = zcr->zcr_next;
3047 3048 zcr->zcr_next = NULL;
3048 3049 zcr->zcr_finish(zcr, NULL);
3049 3050 zfs_ereport_free_checksum(zcr);
3050 3051 }
3051 3052
3052 3053 /*
3053 3054 * It is the responsibility of the done callback to ensure that this
3054 3055 * particular zio is no longer discoverable for adoption, and as
3055 3056 * such, cannot acquire any new parents.
3056 3057 */
3057 3058 if (zio->io_done)
3058 3059 zio->io_done(zio);
3059 3060
3060 3061 mutex_enter(&zio->io_lock);
3061 3062 zio->io_state[ZIO_WAIT_DONE] = 1;
3062 3063 mutex_exit(&zio->io_lock);
3063 3064
3064 3065 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) {
3065 3066 zio_link_t *zl = zio->io_walk_link;
3066 3067 pio_next = zio_walk_parents(zio);
3067 3068 zio_remove_child(pio, zio, zl);
3068 3069 zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
3069 3070 }
3070 3071
3071 3072 if (zio->io_waiter != NULL) {
3072 3073 mutex_enter(&zio->io_lock);
3073 3074 zio->io_executor = NULL;
3074 3075 cv_broadcast(&zio->io_cv);
3075 3076 mutex_exit(&zio->io_lock);
3076 3077 } else {
3077 3078 zio_destroy(zio);
3078 3079 }
3079 3080
3080 3081 return (ZIO_PIPELINE_STOP);
3081 3082 }
3082 3083
3083 3084 /*
3084 3085 * ==========================================================================
3085 3086 * I/O pipeline definition
3086 3087 * ==========================================================================
3087 3088 */
3088 3089 static zio_pipe_stage_t *zio_pipeline[] = {
3089 3090 NULL,
3090 3091 zio_read_bp_init,
3091 3092 zio_free_bp_init,
3092 3093 zio_issue_async,
3093 3094 zio_write_bp_init,
3094 3095 zio_checksum_generate,
3095 3096 zio_nop_write,
3096 3097 zio_ddt_read_start,
3097 3098 zio_ddt_read_done,
3098 3099 zio_ddt_write,
3099 3100 zio_ddt_free,
3100 3101 zio_gang_assemble,
3101 3102 zio_gang_issue,
3102 3103 zio_dva_allocate,
3103 3104 zio_dva_free,
3104 3105 zio_dva_claim,
3105 3106 zio_ready,
3106 3107 zio_vdev_io_start,
3107 3108 zio_vdev_io_done,
3108 3109 zio_vdev_io_assess,
3109 3110 zio_checksum_verify,
3110 3111 zio_done
3111 3112 };
3112 3113
3113 3114 /* dnp is the dnode for zb1->zb_object */
3114 3115 boolean_t
3115 3116 zbookmark_is_before(const dnode_phys_t *dnp, const zbookmark_t *zb1,
3116 3117 const zbookmark_t *zb2)
3117 3118 {
3118 3119 uint64_t zb1nextL0, zb2thisobj;
3119 3120
3120 3121 ASSERT(zb1->zb_objset == zb2->zb_objset);
3121 3122 ASSERT(zb2->zb_level == 0);
3122 3123
3123 3124 /*
3124 3125 * A bookmark in the deadlist is considered to be after
3125 3126 * everything else.
3126 3127 */
3127 3128 if (zb2->zb_object == DMU_DEADLIST_OBJECT)
3128 3129 return (B_TRUE);
3129 3130
3130 3131 /* The objset_phys_t isn't before anything. */
3131 3132 if (dnp == NULL)
3132 3133 return (B_FALSE);
3133 3134
3134 3135 zb1nextL0 = (zb1->zb_blkid + 1) <<
3135 3136 ((zb1->zb_level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT));
3136 3137
3137 3138 zb2thisobj = zb2->zb_object ? zb2->zb_object :
3138 3139 zb2->zb_blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT);
3139 3140
3140 3141 if (zb1->zb_object == DMU_META_DNODE_OBJECT) {
3141 3142 uint64_t nextobj = zb1nextL0 *
3142 3143 (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT) >> DNODE_SHIFT;
3143 3144 return (nextobj <= zb2thisobj);
3144 3145 }
3145 3146
3146 3147 if (zb1->zb_object < zb2thisobj)
3147 3148 return (B_TRUE);
3148 3149 if (zb1->zb_object > zb2thisobj)
3149 3150 return (B_FALSE);
3150 3151 if (zb2->zb_object == DMU_META_DNODE_OBJECT)
3151 3152 return (B_FALSE);
3152 3153 return (zb1nextL0 <= zb2->zb_blkid);
3153 3154 }
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