1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
26  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
27  * Copyright 2016 Toomas Soome <tsoome@me.com>
28  */
29 
30 #ifndef _ZIO_H
31 #define	_ZIO_H
32 
33 #include <sys/zio_priority.h>
34 #include <sys/zfs_context.h>
35 #include <sys/spa.h>
36 #include <sys/txg.h>
37 #include <sys/avl.h>
38 #include <sys/kstat.h>
39 #include <sys/fs/zfs.h>
40 #include <sys/zio_impl.h>
41 
42 #ifdef	__cplusplus
43 extern "C" {
44 #endif
45 
46 /*
47  * Embedded checksum
48  */
49 #define	ZEC_MAGIC	0x210da7ab10c7a11ULL
50 
51 typedef struct zio_eck {
52 	uint64_t	zec_magic;	/* for validation, endianness	*/
53 	zio_cksum_t	zec_cksum;	/* 256-bit checksum		*/
54 } zio_eck_t;
55 
56 /*
57  * Gang block headers are self-checksumming and contain an array
58  * of block pointers.
59  */
60 #define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
61 #define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
62 	sizeof (zio_eck_t)) / sizeof (blkptr_t))
63 #define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
64 	sizeof (zio_eck_t) - \
65 	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
66 	sizeof (uint64_t))
67 
68 typedef struct zio_gbh {
69 	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
70 	uint64_t		zg_filler[SPA_GBH_FILLER];
71 	zio_eck_t		zg_tail;
72 } zio_gbh_phys_t;
73 
74 enum zio_checksum {
75 	ZIO_CHECKSUM_INHERIT = 0,
76 	ZIO_CHECKSUM_ON,
77 	ZIO_CHECKSUM_OFF,
78 	ZIO_CHECKSUM_LABEL,
79 	ZIO_CHECKSUM_GANG_HEADER,
80 	ZIO_CHECKSUM_ZILOG,
81 	ZIO_CHECKSUM_FLETCHER_2,
82 	ZIO_CHECKSUM_FLETCHER_4,
83 	ZIO_CHECKSUM_SHA256,
84 	ZIO_CHECKSUM_ZILOG2,
85 	ZIO_CHECKSUM_NOPARITY,
86 #ifndef __NetBSD__
87 	ZIO_CHECKSUM_SHA512,
88 	ZIO_CHECKSUM_SKEIN,
89 #endif
90 #ifdef illumos
91 	ZIO_CHECKSUM_EDONR,
92 #endif
93 	ZIO_CHECKSUM_FUNCTIONS
94 };
95 
96 /*
97  * The number of "legacy" compression functions which can be set on individual
98  * objects.
99  */
100 #define	ZIO_CHECKSUM_LEGACY_FUNCTIONS ZIO_CHECKSUM_ZILOG2
101 
102 #define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_4
103 #define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
104 
105 #define	ZIO_CHECKSUM_MASK	0xffULL
106 #define	ZIO_CHECKSUM_VERIFY	(1 << 8)
107 
108 #define	ZIO_DEDUPCHECKSUM	ZIO_CHECKSUM_SHA256
109 #define	ZIO_DEDUPDITTO_MIN	100
110 
111 enum zio_compress {
112 	ZIO_COMPRESS_INHERIT = 0,
113 	ZIO_COMPRESS_ON,
114 	ZIO_COMPRESS_OFF,
115 	ZIO_COMPRESS_LZJB,
116 	ZIO_COMPRESS_EMPTY,
117 	ZIO_COMPRESS_GZIP_1,
118 	ZIO_COMPRESS_GZIP_2,
119 	ZIO_COMPRESS_GZIP_3,
120 	ZIO_COMPRESS_GZIP_4,
121 	ZIO_COMPRESS_GZIP_5,
122 	ZIO_COMPRESS_GZIP_6,
123 	ZIO_COMPRESS_GZIP_7,
124 	ZIO_COMPRESS_GZIP_8,
125 	ZIO_COMPRESS_GZIP_9,
126 	ZIO_COMPRESS_ZLE,
127 	ZIO_COMPRESS_LZ4,
128 	ZIO_COMPRESS_FUNCTIONS
129 };
130 
131 /*
132  * The number of "legacy" compression functions which can be set on individual
133  * objects.
134  */
135 #define	ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4
136 
137 /*
138  * The meaning of "compress = on" selected by the compression features enabled
139  * on a given pool.
140  */
141 #define	ZIO_COMPRESS_LEGACY_ON_VALUE	ZIO_COMPRESS_LZJB
142 #define	ZIO_COMPRESS_LZ4_ON_VALUE	ZIO_COMPRESS_LZ4
143 
144 #define	ZIO_COMPRESS_DEFAULT		ZIO_COMPRESS_OFF
145 
146 #define	BOOTFS_COMPRESS_VALID(compress)			\
147 	((compress) == ZIO_COMPRESS_LZJB ||		\
148 	(compress) == ZIO_COMPRESS_LZ4 ||		\
149 	(compress) == ZIO_COMPRESS_ON ||		\
150 	(compress) == ZIO_COMPRESS_OFF)
151 
152 #define	ZIO_FAILURE_MODE_WAIT		0
153 #define	ZIO_FAILURE_MODE_CONTINUE	1
154 #define	ZIO_FAILURE_MODE_PANIC		2
155 
156 enum zio_flag {
157 	/*
158 	 * Flags inherited by gang, ddt, and vdev children,
159 	 * and that must be equal for two zios to aggregate
160 	 */
161 	ZIO_FLAG_DONT_AGGREGATE	= 1 << 0,
162 	ZIO_FLAG_IO_REPAIR	= 1 << 1,
163 	ZIO_FLAG_SELF_HEAL	= 1 << 2,
164 	ZIO_FLAG_RESILVER	= 1 << 3,
165 	ZIO_FLAG_SCRUB		= 1 << 4,
166 	ZIO_FLAG_SCAN_THREAD	= 1 << 5,
167 	ZIO_FLAG_PHYSICAL	= 1 << 6,
168 
169 #define	ZIO_FLAG_AGG_INHERIT	(ZIO_FLAG_CANFAIL - 1)
170 
171 	/*
172 	 * Flags inherited by ddt, gang, and vdev children.
173 	 */
174 	ZIO_FLAG_CANFAIL	= 1 << 7,	/* must be first for INHERIT */
175 	ZIO_FLAG_SPECULATIVE	= 1 << 8,
176 	ZIO_FLAG_CONFIG_WRITER	= 1 << 9,
177 	ZIO_FLAG_DONT_RETRY	= 1 << 10,
178 	ZIO_FLAG_DONT_CACHE	= 1 << 11,
179 	ZIO_FLAG_NODATA		= 1 << 12,
180 	ZIO_FLAG_INDUCE_DAMAGE	= 1 << 13,
181 	ZIO_FLAG_IO_ALLOCATING	= 1 << 14,
182 
183 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
184 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
185 
186 	/*
187 	 * Flags inherited by vdev children.
188 	 */
189 	ZIO_FLAG_IO_RETRY	= 1 << 15,	/* must be first for INHERIT */
190 	ZIO_FLAG_PROBE		= 1 << 16,
191 	ZIO_FLAG_TRYHARD	= 1 << 17,
192 	ZIO_FLAG_OPTIONAL	= 1 << 18,
193 
194 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
195 
196 	/*
197 	 * Flags not inherited by any children.
198 	 */
199 	ZIO_FLAG_DONT_QUEUE	= 1 << 19,	/* must be first for INHERIT */
200 	ZIO_FLAG_DONT_PROPAGATE	= 1 << 20,
201 	ZIO_FLAG_IO_BYPASS	= 1 << 21,
202 	ZIO_FLAG_IO_REWRITE	= 1 << 22,
203 	ZIO_FLAG_RAW		= 1 << 23,
204 	ZIO_FLAG_GANG_CHILD	= 1 << 24,
205 	ZIO_FLAG_DDT_CHILD	= 1 << 25,
206 	ZIO_FLAG_GODFATHER	= 1 << 26,
207 	ZIO_FLAG_NOPWRITE	= 1 << 27,
208 	ZIO_FLAG_REEXECUTED	= 1 << 28,
209 	ZIO_FLAG_DELEGATED	= 1 << 29,
210 };
211 
212 #define	ZIO_FLAG_MUSTSUCCEED		0
213 
214 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
215 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
216 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
217 
218 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
219 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
220 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
221 
222 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
223 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
224 	ZIO_FLAG_CANFAIL)
225 
226 enum zio_child {
227 	ZIO_CHILD_VDEV = 0,
228 	ZIO_CHILD_GANG,
229 	ZIO_CHILD_DDT,
230 	ZIO_CHILD_LOGICAL,
231 	ZIO_CHILD_TYPES
232 };
233 
234 enum zio_wait_type {
235 	ZIO_WAIT_READY = 0,
236 	ZIO_WAIT_DONE,
237 	ZIO_WAIT_TYPES
238 };
239 
240 /*
241  * We'll take the number 122 and 123 to indicate checksum errors and
242  * fragmentation. Those doesn't collide with any errno values as they
243  * are greater than ELAST.
244  */
245 #define	ECKSUM	122
246 #define	EFRAGS	123
247 
248 typedef void zio_done_func_t(zio_t *zio);
249 
250 extern boolean_t zio_dva_throttle_enabled;
251 extern const char *zio_type_name[ZIO_TYPES];
252 
253 /*
254  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
255  * identifies any block in the pool.  By convention, the meta-objset (MOS)
256  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
257  * except root blocks and ZIL blocks, which are defined as follows:
258  *
259  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
260  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
261  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
262  * dnode visit bookmarks are <objset, object id of dnode, -3, 0>.
263  *
264  * Note: this structure is called a bookmark because its original purpose
265  * was to remember where to resume a pool-wide traverse.
266  *
267  * Note: this structure is passed between userland and the kernel, and is
268  * stored on disk (by virtue of being incorporated into other on-disk
269  * structures, e.g. dsl_scan_phys_t).
270  */
271 typedef struct zbookmark_phys {
272 	uint64_t	zb_objset;
273 	uint64_t	zb_object;
274 	int64_t		zb_level;
275 	uint64_t	zb_blkid;
276 } zbookmark_phys_t;
277 
278 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
279 {                                                       \
280 	(zb)->zb_objset = objset;                       \
281 	(zb)->zb_object = object;                       \
282 	(zb)->zb_level = level;                         \
283 	(zb)->zb_blkid = blkid;                         \
284 }
285 
286 #define	ZB_DESTROYED_OBJSET	(-1ULL)
287 
288 #define	ZB_ROOT_OBJECT		(0ULL)
289 #define	ZB_ROOT_LEVEL		(-1LL)
290 #define	ZB_ROOT_BLKID		(0ULL)
291 
292 #define	ZB_ZIL_OBJECT		(0ULL)
293 #define	ZB_ZIL_LEVEL		(-2LL)
294 
295 #define	ZB_DNODE_LEVEL		(-3LL)
296 #define	ZB_DNODE_BLKID		(0ULL)
297 
298 #define	ZB_IS_ZERO(zb)						\
299 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
300 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
301 #define	ZB_IS_ROOT(zb)				\
302 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
303 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
304 	(zb)->zb_blkid == ZB_ROOT_BLKID)
305 
306 typedef struct zio_prop {
307 	enum zio_checksum	zp_checksum;
308 	enum zio_compress	zp_compress;
309 	dmu_object_type_t	zp_type;
310 	uint8_t			zp_level;
311 	uint8_t			zp_copies;
312 	boolean_t		zp_dedup;
313 	boolean_t		zp_dedup_verify;
314 	boolean_t		zp_nopwrite;
315 } zio_prop_t;
316 
317 typedef struct zio_cksum_report zio_cksum_report_t;
318 
319 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
320     const void *good_data);
321 typedef void zio_cksum_free_f(void *cbdata, size_t size);
322 
323 struct zio_bad_cksum;				/* defined in zio_checksum.h */
324 struct dnode_phys;
325 
326 struct zio_cksum_report {
327 	struct zio_cksum_report *zcr_next;
328 	nvlist_t		*zcr_ereport;
329 	nvlist_t		*zcr_detector;
330 	void			*zcr_cbdata;
331 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
332 	uint64_t		zcr_align;
333 	uint64_t		zcr_length;
334 	zio_cksum_finish_f	*zcr_finish;
335 	zio_cksum_free_f	*zcr_free;
336 
337 	/* internal use only */
338 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
339 };
340 
341 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
342     void *arg);
343 
344 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
345 
346 typedef struct zio_vsd_ops {
347 	zio_done_func_t		*vsd_free;
348 	zio_vsd_cksum_report_f	*vsd_cksum_report;
349 } zio_vsd_ops_t;
350 
351 typedef struct zio_gang_node {
352 	zio_gbh_phys_t		*gn_gbh;
353 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
354 } zio_gang_node_t;
355 
356 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
357     zio_gang_node_t *gn, void *data);
358 
359 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
360 
361 typedef struct zio_transform {
362 	void			*zt_orig_data;
363 	uint64_t		zt_orig_size;
364 	uint64_t		zt_bufsize;
365 	zio_transform_func_t	*zt_transform;
366 	struct zio_transform	*zt_next;
367 } zio_transform_t;
368 
369 typedef int zio_pipe_stage_t(zio_t *zio);
370 
371 /*
372  * The io_reexecute flags are distinct from io_flags because the child must
373  * be able to propagate them to the parent.  The normal io_flags are local
374  * to the zio, not protected by any lock, and not modifiable by children;
375  * the reexecute flags are protected by io_lock, modifiable by children,
376  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
377  */
378 #define	ZIO_REEXECUTE_NOW	0x01
379 #define	ZIO_REEXECUTE_SUSPEND	0x02
380 
381 typedef struct zio_alloc_list {
382 	list_t  zal_list;
383 	uint64_t zal_size;
384 } zio_alloc_list_t;
385 
386 typedef struct zio_link {
387 	zio_t		*zl_parent;
388 	zio_t		*zl_child;
389 	list_node_t	zl_parent_node;
390 	list_node_t	zl_child_node;
391 } zio_link_t;
392 
393 /*
394  * Used for TRIM kstat.
395  */
396 typedef struct zio_trim_stats {
397 	/*
398 	 * Number of bytes successfully TRIMmed.
399 	 */
400 	kstat_named_t bytes;
401 
402 	/*
403 	 * Number of successful TRIM requests.
404 	 */
405 	kstat_named_t success;
406 
407 	/*
408 	 * Number of TRIM requests that failed because TRIM is not
409 	 * supported.
410 	 */
411 	kstat_named_t unsupported;
412 
413 	/*
414 	 * Number of TRIM requests that failed for other reasons.
415 	 */
416 	kstat_named_t failed;
417 } zio_trim_stats_t;
418 
419 extern zio_trim_stats_t zio_trim_stats;
420 
421 #define ZIO_TRIM_STAT_INCR(stat, val) \
422 	atomic_add_64(&zio_trim_stats.stat.value.ui64, (val));
423 #define ZIO_TRIM_STAT_BUMP(stat) \
424 	ZIO_TRIM_STAT_INCR(stat, 1);
425 
426 struct zio {
427 	/* Core information about this I/O */
428 	zbookmark_phys_t	io_bookmark;
429 	zio_prop_t	io_prop;
430 	zio_type_t	io_type;
431 	enum zio_child	io_child_type;
432 	int		io_cmd;
433 	zio_priority_t	io_priority;
434 	uint8_t		io_reexecute;
435 	uint8_t		io_state[ZIO_WAIT_TYPES];
436 	uint64_t	io_txg;
437 	spa_t		*io_spa;
438 	blkptr_t	*io_bp;
439 	blkptr_t	*io_bp_override;
440 	blkptr_t	io_bp_copy;
441 	list_t		io_parent_list;
442 	list_t		io_child_list;
443 	zio_t		*io_logical;
444 	zio_transform_t *io_transform_stack;
445 
446 	/* Callback info */
447 	zio_done_func_t	*io_ready;
448 	zio_done_func_t	*io_children_ready;
449 	zio_done_func_t	*io_physdone;
450 	zio_done_func_t	*io_done;
451 	void		*io_private;
452 	int64_t		io_prev_space_delta;	/* DMU private */
453 	blkptr_t	io_bp_orig;
454 
455 	/* Data represented by this I/O */
456 	void		*io_data;
457 	void		*io_orig_data;
458 	uint64_t	io_size;
459 	uint64_t	io_orig_size;
460 
461 	/* Stuff for the vdev stack */
462 	vdev_t		*io_vd;
463 	void		*io_vsd;
464 	const zio_vsd_ops_t *io_vsd_ops;
465 
466 	uint64_t	io_offset;
467 	hrtime_t	io_timestamp;
468 	hrtime_t	io_queued_timestamp;
469 	hrtime_t	io_target_timestamp;
470 	avl_node_t	io_queue_node;
471 	avl_node_t	io_offset_node;
472 	avl_node_t	io_alloc_node;
473 	zio_alloc_list_t 	io_alloc_list;
474 
475 	/* Internal pipeline state */
476 	enum zio_flag	io_flags;
477 	enum zio_stage	io_stage;
478 	enum zio_stage	io_pipeline;
479 	enum zio_flag	io_orig_flags;
480 	enum zio_stage	io_orig_stage;
481 	enum zio_stage	io_orig_pipeline;
482 	enum zio_stage	io_pipeline_trace;
483 	int		io_error;
484 	int		io_child_error[ZIO_CHILD_TYPES];
485 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
486 	uint64_t	io_child_count;
487 	uint64_t	io_phys_children;
488 	uint64_t	io_parent_count;
489 	uint64_t	*io_stall;
490 	zio_t		*io_gang_leader;
491 	zio_gang_node_t	*io_gang_tree;
492 	void		*io_executor;
493 	void		*io_waiter;
494 	kmutex_t	io_lock;
495 	kcondvar_t	io_cv;
496 
497 	/* FMA state */
498 	zio_cksum_report_t *io_cksum_report;
499 	uint64_t	io_ena;
500 
501 	/* Taskq dispatching state */
502 	taskq_ent_t	io_tqent;
503 
504 	avl_node_t	io_trim_node;
505 	list_node_t	io_trim_link;
506 };
507 
508 extern int zio_timestamp_compare(const void *, const void *);
509 
510 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
511     zio_done_func_t *done, void *priv, enum zio_flag flags);
512 
513 extern zio_t *zio_root(spa_t *spa,
514     zio_done_func_t *done, void *priv, enum zio_flag flags);
515 
516 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
517     uint64_t size, zio_done_func_t *done, void *priv,
518     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
519 
520 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
521     void *data, uint64_t size, const zio_prop_t *zp,
522     zio_done_func_t *ready, zio_done_func_t *children_ready,
523     zio_done_func_t *physdone, zio_done_func_t *done,
524     void *priv, zio_priority_t priority, enum zio_flag flags,
525     const zbookmark_phys_t *zb);
526 
527 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
528     void *data, uint64_t size, zio_done_func_t *done, void *priv,
529     zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb);
530 
531 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
532     boolean_t nopwrite);
533 
534 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
535 
536 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
537     const blkptr_t *bp,
538     zio_done_func_t *done, void *priv, enum zio_flag flags);
539 
540 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
541     uint64_t offset, uint64_t size, zio_done_func_t *done, void *priv,
542     zio_priority_t priority, enum zio_flag flags);
543 
544 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
545     uint64_t size, void *data, int checksum,
546     zio_done_func_t *done, void *priv, zio_priority_t priority,
547     enum zio_flag flags, boolean_t labels);
548 
549 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
550     uint64_t size, void *data, int checksum,
551     zio_done_func_t *done, void *priv, zio_priority_t priority,
552     enum zio_flag flags, boolean_t labels);
553 
554 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
555     const blkptr_t *bp, uint64_t size, enum zio_flag flags);
556 
557 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
558     blkptr_t *old_bp, uint64_t size, boolean_t *slog);
559 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
560 extern void zio_flush(zio_t *zio, vdev_t *vd);
561 extern zio_t *zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset,
562     uint64_t size);
563 extern void zio_shrink(zio_t *zio, uint64_t size);
564 
565 extern int zio_wait(zio_t *zio);
566 extern void zio_nowait(zio_t *zio);
567 extern void zio_execute(zio_t *zio);
568 extern void zio_interrupt(zio_t *zio);
569 extern void zio_delay_init(zio_t *zio);
570 extern void zio_delay_interrupt(zio_t *zio);
571 
572 extern zio_t *zio_walk_parents(zio_t *cio, zio_link_t **);
573 extern zio_t *zio_walk_children(zio_t *pio, zio_link_t **);
574 extern zio_t *zio_unique_parent(zio_t *cio);
575 extern void zio_add_child(zio_t *pio, zio_t *cio);
576 
577 extern void *zio_buf_alloc(size_t size);
578 extern void *zio_buf_alloc_nowait(size_t size);
579 extern void zio_buf_free(void *buf, size_t size);
580 extern void *zio_data_buf_alloc(size_t size);
581 extern void zio_data_buf_free(void *buf, size_t size);
582 
583 extern void zio_push_transform(zio_t *zio, void *data, uint64_t size,
584     uint64_t bufsize, zio_transform_func_t *transform);
585 extern void zio_pop_transforms(zio_t *zio);
586 
587 extern void zio_resubmit_stage_async(void *);
588 
589 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
590     uint64_t offset, void *data, uint64_t size, int type,
591     zio_priority_t priority, enum zio_flag flags,
592     zio_done_func_t *done, void *priv);
593 
594 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
595     void *data, uint64_t size, int type, zio_priority_t priority,
596     enum zio_flag flags, zio_done_func_t *done, void *priv);
597 
598 extern void zio_vdev_io_bypass(zio_t *zio);
599 extern void zio_vdev_io_reissue(zio_t *zio);
600 extern void zio_vdev_io_redone(zio_t *zio);
601 
602 extern void zio_checksum_verified(zio_t *zio);
603 extern int zio_worst_error(int e1, int e2);
604 
605 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
606     enum zio_checksum parent);
607 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
608     enum zio_checksum child, enum zio_checksum parent);
609 extern enum zio_compress zio_compress_select(spa_t *spa,
610     enum zio_compress child, enum zio_compress parent);
611 
612 extern void zio_suspend(spa_t *spa, zio_t *zio);
613 extern int zio_resume(spa_t *spa);
614 extern void zio_resume_wait(spa_t *spa);
615 
616 /*
617  * Initial setup and teardown.
618  */
619 extern void zio_init(void);
620 extern void zio_fini(void);
621 
622 /*
623  * Fault injection
624  */
625 struct zinject_record;
626 extern uint32_t zio_injection_enabled;
627 extern int zio_inject_fault(char *name, int flags, int *id,
628     struct zinject_record *record);
629 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
630     struct zinject_record *record);
631 extern int zio_clear_fault(int id);
632 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
633 extern int zio_handle_fault_injection(zio_t *zio, int error);
634 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
635 extern int zio_handle_label_injection(zio_t *zio, int error);
636 extern void zio_handle_ignored_writes(zio_t *zio);
637 extern hrtime_t zio_handle_io_delay(zio_t *zio);
638 
639 /*
640  * Checksum ereport functions
641  */
642 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
643     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
644 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
645     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
646 
647 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
648 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
649 
650 /* If we have the good data in hand, this function can be used */
651 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
652     struct zio *zio, uint64_t offset, uint64_t length,
653     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
654 
655 /* Called from spa_sync(), but primarily an injection handler */
656 extern void spa_handle_ignored_writes(spa_t *spa);
657 
658 /* zbookmark_phys functions */
659 boolean_t zbookmark_subtree_completed(const struct dnode_phys *dnp,
660     const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block);
661 int zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2,
662     uint8_t ibs2, const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
663 
664 #ifdef	__cplusplus
665 }
666 #endif
667 
668 #endif	/* _ZIO_H */
669