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