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 https://opensource.org/licenses/CDDL-1.0.
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, 2020 by Delphix. All rights reserved.
26  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
27  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
28  * Copyright 2016 Toomas Soome <[email protected]>
29  * Copyright (c) 2019, Allan Jude
30  * Copyright (c) 2019, Klara Inc.
31  * Copyright (c) 2019-2020, Michael Niewöhner
32  */
33 
34 #ifndef _ZIO_H
35 #define	_ZIO_H
36 
37 #include <sys/zio_priority.h>
38 #include <sys/zfs_context.h>
39 #include <sys/spa.h>
40 #include <sys/txg.h>
41 #include <sys/avl.h>
42 #include <sys/fs/zfs.h>
43 #include <sys/zio_impl.h>
44 
45 #ifdef	__cplusplus
46 extern "C" {
47 #endif
48 
49 /*
50  * Embedded checksum
51  */
52 #define	ZEC_MAGIC	0x210da7ab10c7a11ULL
53 
54 typedef struct zio_eck {
55 	uint64_t	zec_magic;	/* for validation, endianness	*/
56 	zio_cksum_t	zec_cksum;	/* 256-bit checksum		*/
57 } zio_eck_t;
58 
59 /*
60  * Gang block headers are self-checksumming and contain an array
61  * of block pointers.
62  */
63 #define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
64 #define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
65 	sizeof (zio_eck_t)) / sizeof (blkptr_t))
66 #define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
67 	sizeof (zio_eck_t) - \
68 	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
69 	sizeof (uint64_t))
70 
71 typedef struct zio_gbh {
72 	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
73 	uint64_t		zg_filler[SPA_GBH_FILLER];
74 	zio_eck_t		zg_tail;
75 } zio_gbh_phys_t;
76 
77 enum zio_checksum {
78 	ZIO_CHECKSUM_INHERIT = 0,
79 	ZIO_CHECKSUM_ON,
80 	ZIO_CHECKSUM_OFF,
81 	ZIO_CHECKSUM_LABEL,
82 	ZIO_CHECKSUM_GANG_HEADER,
83 	ZIO_CHECKSUM_ZILOG,
84 	ZIO_CHECKSUM_FLETCHER_2,
85 	ZIO_CHECKSUM_FLETCHER_4,
86 	ZIO_CHECKSUM_SHA256,
87 	ZIO_CHECKSUM_ZILOG2,
88 	ZIO_CHECKSUM_NOPARITY,
89 	ZIO_CHECKSUM_SHA512,
90 	ZIO_CHECKSUM_SKEIN,
91 	ZIO_CHECKSUM_EDONR,
92 	ZIO_CHECKSUM_BLAKE3,
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	(1U << 8)
107 
108 #define	ZIO_DEDUPCHECKSUM	ZIO_CHECKSUM_SHA256
109 
110 /* macros defining encryption lengths */
111 #define	ZIO_OBJSET_MAC_LEN		32
112 #define	ZIO_DATA_IV_LEN			12
113 #define	ZIO_DATA_SALT_LEN		8
114 #define	ZIO_DATA_MAC_LEN		16
115 
116 /*
117  * The number of "legacy" compression functions which can be set on individual
118  * objects.
119  */
120 #define	ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4
121 
122 /*
123  * The meaning of "compress = on" selected by the compression features enabled
124  * on a given pool.
125  */
126 #define	ZIO_COMPRESS_LEGACY_ON_VALUE	ZIO_COMPRESS_LZJB
127 #define	ZIO_COMPRESS_LZ4_ON_VALUE	ZIO_COMPRESS_LZ4
128 
129 #define	ZIO_COMPRESS_DEFAULT		ZIO_COMPRESS_ON
130 
131 #define	BOOTFS_COMPRESS_VALID(compress)			\
132 	((compress) == ZIO_COMPRESS_LZJB ||		\
133 	(compress) == ZIO_COMPRESS_LZ4 ||		\
134 	(compress) == ZIO_COMPRESS_GZIP_1 ||		\
135 	(compress) == ZIO_COMPRESS_GZIP_2 ||		\
136 	(compress) == ZIO_COMPRESS_GZIP_3 ||		\
137 	(compress) == ZIO_COMPRESS_GZIP_4 ||		\
138 	(compress) == ZIO_COMPRESS_GZIP_5 ||		\
139 	(compress) == ZIO_COMPRESS_GZIP_6 ||		\
140 	(compress) == ZIO_COMPRESS_GZIP_7 ||		\
141 	(compress) == ZIO_COMPRESS_GZIP_8 ||		\
142 	(compress) == ZIO_COMPRESS_GZIP_9 ||		\
143 	(compress) == ZIO_COMPRESS_ZLE ||		\
144 	(compress) == ZIO_COMPRESS_ZSTD ||		\
145 	(compress) == ZIO_COMPRESS_ON ||		\
146 	(compress) == ZIO_COMPRESS_OFF)
147 
148 
149 #define	ZIO_COMPRESS_ALGO(x)	(x & SPA_COMPRESSMASK)
150 #define	ZIO_COMPRESS_LEVEL(x)	((x & ~SPA_COMPRESSMASK) >> SPA_COMPRESSBITS)
151 #define	ZIO_COMPRESS_RAW(type, level)	(type | ((level) << SPA_COMPRESSBITS))
152 
153 #define	ZIO_COMPLEVEL_ZSTD(level)	\
154 	ZIO_COMPRESS_RAW(ZIO_COMPRESS_ZSTD, level)
155 
156 #define	ZIO_FAILURE_MODE_WAIT		0
157 #define	ZIO_FAILURE_MODE_CONTINUE	1
158 #define	ZIO_FAILURE_MODE_PANIC		2
159 
160 typedef enum zio_suspend_reason {
161 	ZIO_SUSPEND_NONE = 0,
162 	ZIO_SUSPEND_IOERR,
163 	ZIO_SUSPEND_MMP,
164 } zio_suspend_reason_t;
165 
166 /*
167  * This was originally an enum type. However, those are 32-bit and there is no
168  * way to make a 64-bit enum type. Since we ran out of bits for flags, we were
169  * forced to upgrade it to a uint64_t.
170  */
171 typedef uint64_t zio_flag_t;
172 	/*
173 	 * Flags inherited by gang, ddt, and vdev children,
174 	 * and that must be equal for two zios to aggregate
175 	 */
176 #define	ZIO_FLAG_DONT_AGGREGATE	(1ULL << 0)
177 #define	ZIO_FLAG_IO_REPAIR	(1ULL << 1)
178 #define	ZIO_FLAG_SELF_HEAL	(1ULL << 2)
179 #define	ZIO_FLAG_RESILVER	(1ULL << 3)
180 #define	ZIO_FLAG_SCRUB		(1ULL << 4)
181 #define	ZIO_FLAG_SCAN_THREAD	(1ULL << 5)
182 #define	ZIO_FLAG_PHYSICAL	(1ULL << 6)
183 
184 #define	ZIO_FLAG_AGG_INHERIT	(ZIO_FLAG_CANFAIL - 1)
185 
186 	/*
187 	 * Flags inherited by ddt, gang, and vdev children.
188 	 */
189 #define	ZIO_FLAG_CANFAIL	(1ULL << 7)	/* must be first for INHERIT */
190 #define	ZIO_FLAG_SPECULATIVE	(1ULL << 8)
191 #define	ZIO_FLAG_CONFIG_WRITER	(1ULL << 9)
192 #define	ZIO_FLAG_DONT_RETRY	(1ULL << 10)
193 #define	ZIO_FLAG_NODATA		(1ULL << 12)
194 #define	ZIO_FLAG_INDUCE_DAMAGE	(1ULL << 13)
195 #define	ZIO_FLAG_IO_ALLOCATING	(1ULL << 14)
196 
197 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
198 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
199 
200 	/*
201 	 * Flags inherited by vdev children.
202 	 */
203 #define	ZIO_FLAG_IO_RETRY	(1ULL << 15)	/* must be first for INHERIT */
204 #define	ZIO_FLAG_PROBE		(1ULL << 16)
205 #define	ZIO_FLAG_TRYHARD	(1ULL << 17)
206 #define	ZIO_FLAG_OPTIONAL	(1ULL << 18)
207 
208 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
209 
210 	/*
211 	 * Flags not inherited by any children.
212 	 */
213 #define	ZIO_FLAG_DONT_QUEUE	(1ULL << 19)	/* must be first for INHERIT */
214 #define	ZIO_FLAG_DONT_PROPAGATE	(1ULL << 20)
215 #define	ZIO_FLAG_IO_BYPASS	(1ULL << 21)
216 #define	ZIO_FLAG_IO_REWRITE	(1ULL << 22)
217 #define	ZIO_FLAG_RAW_COMPRESS	(1ULL << 23)
218 #define	ZIO_FLAG_RAW_ENCRYPT	(1ULL << 24)
219 #define	ZIO_FLAG_GANG_CHILD	(1ULL << 25)
220 #define	ZIO_FLAG_DDT_CHILD	(1ULL << 26)
221 #define	ZIO_FLAG_GODFATHER	(1ULL << 27)
222 #define	ZIO_FLAG_NOPWRITE	(1ULL << 28)
223 #define	ZIO_FLAG_REEXECUTED	(1ULL << 29)
224 #define	ZIO_FLAG_DELEGATED	(1ULL << 30)
225 
226 #define	ZIO_FLAG_MUSTSUCCEED		0
227 #define	ZIO_FLAG_RAW	(ZIO_FLAG_RAW_COMPRESS | ZIO_FLAG_RAW_ENCRYPT)
228 
229 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
230 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
231 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
232 
233 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
234 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
235 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
236 
237 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
238 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
239 	ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_CANFAIL)
240 
241 #define	ZIO_CHILD_BIT(x)		(1U << (x))
242 #define	ZIO_CHILD_BIT_IS_SET(val, x)	((val) & (1U << (x)))
243 
244 enum zio_child {
245 	ZIO_CHILD_VDEV = 0,
246 	ZIO_CHILD_GANG,
247 	ZIO_CHILD_DDT,
248 	ZIO_CHILD_LOGICAL,
249 	ZIO_CHILD_TYPES
250 };
251 
252 #define	ZIO_CHILD_VDEV_BIT		ZIO_CHILD_BIT(ZIO_CHILD_VDEV)
253 #define	ZIO_CHILD_GANG_BIT		ZIO_CHILD_BIT(ZIO_CHILD_GANG)
254 #define	ZIO_CHILD_DDT_BIT		ZIO_CHILD_BIT(ZIO_CHILD_DDT)
255 #define	ZIO_CHILD_LOGICAL_BIT		ZIO_CHILD_BIT(ZIO_CHILD_LOGICAL)
256 #define	ZIO_CHILD_ALL_BITS					\
257 	(ZIO_CHILD_VDEV_BIT | ZIO_CHILD_GANG_BIT |		\
258 	ZIO_CHILD_DDT_BIT | ZIO_CHILD_LOGICAL_BIT)
259 
260 enum zio_wait_type {
261 	ZIO_WAIT_READY = 0,
262 	ZIO_WAIT_DONE,
263 	ZIO_WAIT_TYPES
264 };
265 
266 typedef void zio_done_func_t(zio_t *zio);
267 
268 extern int zio_exclude_metadata;
269 extern int zio_dva_throttle_enabled;
270 extern const char *const zio_type_name[ZIO_TYPES];
271 
272 /*
273  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
274  * identifies any block in the pool.  By convention, the meta-objset (MOS)
275  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
276  * except root blocks and ZIL blocks, which are defined as follows:
277  *
278  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
279  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
280  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
281  * dnode visit bookmarks are <objset, object id of dnode, -3, 0>.
282  *
283  * Note: this structure is called a bookmark because its original purpose
284  * was to remember where to resume a pool-wide traverse.
285  *
286  * Note: this structure is passed between userland and the kernel, and is
287  * stored on disk (by virtue of being incorporated into other on-disk
288  * structures, e.g. dsl_scan_phys_t).
289  *
290  * If the head_errlog feature is enabled a different on-disk format for error
291  * logs is used. This introduces the use of an error bookmark, a four-tuple
292  * <object, level, blkid, birth> that uniquely identifies any error block
293  * in the pool. The birth transaction group is used to track whether the block
294  * has been overwritten by newer data or added to a snapshot since its marking
295  * as an error.
296  */
297 struct zbookmark_phys {
298 	uint64_t	zb_objset;
299 	uint64_t	zb_object;
300 	int64_t		zb_level;
301 	uint64_t	zb_blkid;
302 };
303 
304 struct zbookmark_err_phys {
305 	uint64_t	zb_object;
306 	int64_t		zb_level;
307 	uint64_t	zb_blkid;
308 	uint64_t	zb_birth;
309 };
310 
311 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
312 {                                                       \
313 	(zb)->zb_objset = objset;                       \
314 	(zb)->zb_object = object;                       \
315 	(zb)->zb_level = level;                         \
316 	(zb)->zb_blkid = blkid;                         \
317 }
318 
319 #define	ZB_DESTROYED_OBJSET	(-1ULL)
320 
321 #define	ZB_ROOT_OBJECT		(0ULL)
322 #define	ZB_ROOT_LEVEL		(-1LL)
323 #define	ZB_ROOT_BLKID		(0ULL)
324 
325 #define	ZB_ZIL_OBJECT		(0ULL)
326 #define	ZB_ZIL_LEVEL		(-2LL)
327 
328 #define	ZB_DNODE_LEVEL		(-3LL)
329 #define	ZB_DNODE_BLKID		(0ULL)
330 
331 #define	ZB_IS_ZERO(zb)						\
332 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
333 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
334 #define	ZB_IS_ROOT(zb)				\
335 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
336 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
337 	(zb)->zb_blkid == ZB_ROOT_BLKID)
338 
339 typedef struct zio_prop {
340 	enum zio_checksum	zp_checksum;
341 	enum zio_compress	zp_compress;
342 	uint8_t			zp_complevel;
343 	uint8_t			zp_level;
344 	uint8_t			zp_copies;
345 	dmu_object_type_t	zp_type;
346 	boolean_t		zp_dedup;
347 	boolean_t		zp_dedup_verify;
348 	boolean_t		zp_nopwrite;
349 	boolean_t		zp_brtwrite;
350 	boolean_t		zp_encrypt;
351 	boolean_t		zp_byteorder;
352 	uint8_t			zp_salt[ZIO_DATA_SALT_LEN];
353 	uint8_t			zp_iv[ZIO_DATA_IV_LEN];
354 	uint8_t			zp_mac[ZIO_DATA_MAC_LEN];
355 	uint32_t		zp_zpl_smallblk;
356 } zio_prop_t;
357 
358 typedef struct zio_cksum_report zio_cksum_report_t;
359 
360 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
361     const abd_t *good_data);
362 typedef void zio_cksum_free_f(void *cbdata, size_t size);
363 
364 struct zio_bad_cksum;				/* defined in zio_checksum.h */
365 struct dnode_phys;
366 struct abd;
367 
368 struct zio_cksum_report {
369 	struct zio_cksum_report *zcr_next;
370 	nvlist_t		*zcr_ereport;
371 	nvlist_t		*zcr_detector;
372 	void			*zcr_cbdata;
373 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
374 	uint64_t		zcr_sector;
375 	uint64_t		zcr_align;
376 	uint64_t		zcr_length;
377 	zio_cksum_finish_f	*zcr_finish;
378 	zio_cksum_free_f	*zcr_free;
379 
380 	/* internal use only */
381 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
382 };
383 
384 typedef struct zio_vsd_ops {
385 	zio_done_func_t		*vsd_free;
386 } zio_vsd_ops_t;
387 
388 typedef struct zio_gang_node {
389 	zio_gbh_phys_t		*gn_gbh;
390 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
391 } zio_gang_node_t;
392 
393 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
394     zio_gang_node_t *gn, struct abd *data, uint64_t offset);
395 
396 typedef void zio_transform_func_t(zio_t *zio, struct abd *data, uint64_t size);
397 
398 typedef struct zio_transform {
399 	struct abd		*zt_orig_abd;
400 	uint64_t		zt_orig_size;
401 	uint64_t		zt_bufsize;
402 	zio_transform_func_t	*zt_transform;
403 	struct zio_transform	*zt_next;
404 } zio_transform_t;
405 
406 typedef zio_t *zio_pipe_stage_t(zio_t *zio);
407 
408 /*
409  * The io_reexecute flags are distinct from io_flags because the child must
410  * be able to propagate them to the parent.  The normal io_flags are local
411  * to the zio, not protected by any lock, and not modifiable by children;
412  * the reexecute flags are protected by io_lock, modifiable by children,
413  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
414  */
415 #define	ZIO_REEXECUTE_NOW	0x01
416 #define	ZIO_REEXECUTE_SUSPEND	0x02
417 
418 /*
419  * The io_trim flags are used to specify the type of TRIM to perform.  They
420  * only apply to ZIO_TYPE_TRIM zios are distinct from io_flags.
421  */
422 enum trim_flag {
423 	ZIO_TRIM_SECURE		= 1U << 0,
424 };
425 
426 typedef struct zio_alloc_list {
427 	list_t  zal_list;
428 	uint64_t zal_size;
429 } zio_alloc_list_t;
430 
431 typedef struct zio_link {
432 	zio_t		*zl_parent;
433 	zio_t		*zl_child;
434 	list_node_t	zl_parent_node;
435 	list_node_t	zl_child_node;
436 } zio_link_t;
437 
438 enum zio_qstate {
439 	ZIO_QS_NONE = 0,
440 	ZIO_QS_QUEUED,
441 	ZIO_QS_ACTIVE,
442 };
443 
444 struct zio {
445 	/* Core information about this I/O */
446 	zbookmark_phys_t	io_bookmark;
447 	zio_prop_t	io_prop;
448 	zio_type_t	io_type;
449 	enum zio_child	io_child_type;
450 	enum trim_flag	io_trim_flags;
451 	int		io_cmd;
452 	zio_priority_t	io_priority;
453 	uint8_t		io_reexecute;
454 	uint8_t		io_state[ZIO_WAIT_TYPES];
455 	uint64_t	io_txg;
456 	spa_t		*io_spa;
457 	blkptr_t	*io_bp;
458 	blkptr_t	*io_bp_override;
459 	blkptr_t	io_bp_copy;
460 	list_t		io_parent_list;
461 	list_t		io_child_list;
462 	zio_t		*io_logical;
463 	zio_transform_t *io_transform_stack;
464 
465 	/* Callback info */
466 	zio_done_func_t	*io_ready;
467 	zio_done_func_t	*io_children_ready;
468 	zio_done_func_t	*io_done;
469 	void		*io_private;
470 	int64_t		io_prev_space_delta;	/* DMU private */
471 	blkptr_t	io_bp_orig;
472 	/* io_lsize != io_orig_size iff this is a raw write */
473 	uint64_t	io_lsize;
474 
475 	/* Data represented by this I/O */
476 	struct abd	*io_abd;
477 	struct abd	*io_orig_abd;
478 	uint64_t	io_size;
479 	uint64_t	io_orig_size;
480 
481 	/* Stuff for the vdev stack */
482 	vdev_t		*io_vd;
483 	void		*io_vsd;
484 	const zio_vsd_ops_t *io_vsd_ops;
485 	metaslab_class_t *io_metaslab_class;	/* dva throttle class */
486 
487 	enum zio_qstate	io_queue_state;	/* vdev queue state */
488 	union {
489 		list_node_t l;
490 		avl_node_t a;
491 	} io_queue_node ____cacheline_aligned;	/* allocator and vdev queues */
492 	avl_node_t	io_offset_node;	/* vdev offset queues */
493 	uint64_t	io_offset;
494 	hrtime_t	io_timestamp;	/* submitted at */
495 	hrtime_t	io_queued_timestamp;
496 	hrtime_t	io_target_timestamp;
497 	hrtime_t	io_delta;	/* vdev queue service delta */
498 	hrtime_t	io_delay;	/* Device access time (disk or */
499 					/* file). */
500 	zio_alloc_list_t 	io_alloc_list;
501 
502 	/* Internal pipeline state */
503 	zio_flag_t	io_flags;
504 	enum zio_stage	io_stage;
505 	enum zio_stage	io_pipeline;
506 	zio_flag_t	io_orig_flags;
507 	enum zio_stage	io_orig_stage;
508 	enum zio_stage	io_orig_pipeline;
509 	enum zio_stage	io_pipeline_trace;
510 	int		io_error;
511 	int		io_child_error[ZIO_CHILD_TYPES];
512 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
513 	uint64_t	*io_stall;
514 	zio_t		*io_gang_leader;
515 	zio_gang_node_t	*io_gang_tree;
516 	void		*io_executor;
517 	void		*io_waiter;
518 	void		*io_bio;
519 	kmutex_t	io_lock;
520 	kcondvar_t	io_cv;
521 	int		io_allocator;
522 
523 	/* FMA state */
524 	zio_cksum_report_t *io_cksum_report;
525 	uint64_t	io_ena;
526 
527 	/* Taskq dispatching state */
528 	taskq_ent_t	io_tqent;
529 };
530 
531 enum blk_verify_flag {
532 	BLK_VERIFY_ONLY,
533 	BLK_VERIFY_LOG,
534 	BLK_VERIFY_HALT
535 };
536 
537 enum blk_config_flag {
538 	BLK_CONFIG_HELD,   // SCL_VDEV held for writer
539 	BLK_CONFIG_NEEDED, // SCL_VDEV should be obtained for reader
540 	BLK_CONFIG_SKIP,   // skip checks which require SCL_VDEV
541 };
542 
543 extern int zio_bookmark_compare(const void *, const void *);
544 
545 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
546     zio_done_func_t *done, void *priv, zio_flag_t flags);
547 
548 extern zio_t *zio_root(spa_t *spa,
549     zio_done_func_t *done, void *priv, zio_flag_t flags);
550 
551 extern void zio_destroy(zio_t *zio);
552 
553 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
554     struct abd *data, uint64_t lsize, zio_done_func_t *done, void *priv,
555     zio_priority_t priority, zio_flag_t flags, const zbookmark_phys_t *zb);
556 
557 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
558     struct abd *data, uint64_t size, uint64_t psize, const zio_prop_t *zp,
559     zio_done_func_t *ready, zio_done_func_t *children_ready,
560     zio_done_func_t *done, void *priv, zio_priority_t priority,
561     zio_flag_t flags, const zbookmark_phys_t *zb);
562 
563 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
564     struct abd *data, uint64_t size, zio_done_func_t *done, void *priv,
565     zio_priority_t priority, zio_flag_t flags, zbookmark_phys_t *zb);
566 
567 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
568     boolean_t nopwrite, boolean_t brtwrite);
569 
570 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
571 
572 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
573     const blkptr_t *bp,
574     zio_done_func_t *done, void *priv, zio_flag_t flags);
575 
576 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
577     zio_done_func_t *done, void *priv, zio_flag_t flags);
578 
579 extern zio_t *zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
580     zio_done_func_t *done, void *priv, zio_priority_t priority,
581     zio_flag_t flags, enum trim_flag trim_flags);
582 
583 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
584     uint64_t size, struct abd *data, int checksum,
585     zio_done_func_t *done, void *priv, zio_priority_t priority,
586     zio_flag_t flags, boolean_t labels);
587 
588 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
589     uint64_t size, struct abd *data, int checksum,
590     zio_done_func_t *done, void *priv, zio_priority_t priority,
591     zio_flag_t flags, boolean_t labels);
592 
593 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
594     const blkptr_t *bp, zio_flag_t flags);
595 
596 extern int zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg,
597     blkptr_t *new_bp, uint64_t size, boolean_t *slog);
598 extern void zio_flush(zio_t *zio, vdev_t *vd);
599 extern void zio_shrink(zio_t *zio, uint64_t size);
600 
601 extern int zio_wait(zio_t *zio);
602 extern void zio_nowait(zio_t *zio);
603 extern void zio_execute(void *zio);
604 extern void zio_interrupt(void *zio);
605 extern void zio_delay_init(zio_t *zio);
606 extern void zio_delay_interrupt(zio_t *zio);
607 extern void zio_deadman(zio_t *zio, const char *tag);
608 
609 extern zio_t *zio_walk_parents(zio_t *cio, zio_link_t **);
610 extern zio_t *zio_walk_children(zio_t *pio, zio_link_t **);
611 extern zio_t *zio_unique_parent(zio_t *cio);
612 extern void zio_add_child(zio_t *pio, zio_t *cio);
613 extern void zio_add_child_first(zio_t *pio, zio_t *cio);
614 
615 extern void *zio_buf_alloc(size_t size);
616 extern void zio_buf_free(void *buf, size_t size);
617 extern void *zio_data_buf_alloc(size_t size);
618 extern void zio_data_buf_free(void *buf, size_t size);
619 
620 extern void zio_push_transform(zio_t *zio, struct abd *abd, uint64_t size,
621     uint64_t bufsize, zio_transform_func_t *transform);
622 extern void zio_pop_transforms(zio_t *zio);
623 
624 extern void zio_resubmit_stage_async(void *);
625 
626 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
627     uint64_t offset, struct abd *data, uint64_t size, int type,
628     zio_priority_t priority, zio_flag_t flags,
629     zio_done_func_t *done, void *priv);
630 
631 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
632     struct abd *data, uint64_t size, zio_type_t type, zio_priority_t priority,
633     zio_flag_t flags, zio_done_func_t *done, void *priv);
634 
635 extern void zio_vdev_io_bypass(zio_t *zio);
636 extern void zio_vdev_io_reissue(zio_t *zio);
637 extern void zio_vdev_io_redone(zio_t *zio);
638 
639 extern void zio_change_priority(zio_t *pio, zio_priority_t priority);
640 
641 extern void zio_checksum_verified(zio_t *zio);
642 extern int zio_worst_error(int e1, int e2);
643 
644 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
645     enum zio_checksum parent);
646 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
647     enum zio_checksum child, enum zio_checksum parent);
648 extern enum zio_compress zio_compress_select(spa_t *spa,
649     enum zio_compress child, enum zio_compress parent);
650 extern uint8_t zio_complevel_select(spa_t *spa, enum zio_compress compress,
651     uint8_t child, uint8_t parent);
652 
653 extern void zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t);
654 extern int zio_resume(spa_t *spa);
655 extern void zio_resume_wait(spa_t *spa);
656 
657 extern boolean_t zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp,
658     enum blk_config_flag blk_config, enum blk_verify_flag blk_verify);
659 
660 /*
661  * Initial setup and teardown.
662  */
663 extern void zio_init(void);
664 extern void zio_fini(void);
665 
666 /*
667  * Fault injection
668  */
669 struct zinject_record;
670 extern uint32_t zio_injection_enabled;
671 extern int zio_inject_fault(char *name, int flags, int *id,
672     struct zinject_record *record);
673 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
674     struct zinject_record *record);
675 extern int zio_clear_fault(int id);
676 extern void zio_handle_panic_injection(spa_t *spa, const char *tag,
677     uint64_t type);
678 extern int zio_handle_decrypt_injection(spa_t *spa, const zbookmark_phys_t *zb,
679     uint64_t type, int error);
680 extern int zio_handle_fault_injection(zio_t *zio, int error);
681 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
682 extern int zio_handle_device_injections(vdev_t *vd, zio_t *zio, int err1,
683     int err2);
684 extern int zio_handle_label_injection(zio_t *zio, int error);
685 extern void zio_handle_ignored_writes(zio_t *zio);
686 extern hrtime_t zio_handle_io_delay(zio_t *zio);
687 
688 /*
689  * Checksum ereport functions
690  */
691 extern int zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd,
692     const zbookmark_phys_t *zb, struct zio *zio, uint64_t offset,
693     uint64_t length, struct zio_bad_cksum *info);
694 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
695     const abd_t *good_data, const abd_t *bad_data, boolean_t drop_if_identical);
696 
697 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
698 
699 /* If we have the good data in hand, this function can be used */
700 extern int zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
701     const zbookmark_phys_t *zb, struct zio *zio, uint64_t offset,
702     uint64_t length, const abd_t *good_data, const abd_t *bad_data,
703     struct zio_bad_cksum *info);
704 
705 void zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr);
706 extern void zfs_ereport_snapshot_post(const char *subclass, spa_t *spa,
707     const char *name);
708 
709 /* Called from spa_sync(), but primarily an injection handler */
710 extern void spa_handle_ignored_writes(spa_t *spa);
711 
712 /* zbookmark_phys functions */
713 boolean_t zbookmark_subtree_completed(const struct dnode_phys *dnp,
714     const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block);
715 boolean_t zbookmark_subtree_tbd(const struct dnode_phys *dnp,
716     const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block);
717 int zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2,
718     uint8_t ibs2, const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
719 
720 #ifdef	__cplusplus
721 }
722 #endif
723 
724 #endif	/* _ZIO_H */
725