xref: /titanic_50/usr/src/uts/common/fs/zfs/sys/zio.h (revision bbe876c07ed632b8f85e195d41e7948382064a95)
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, 2014 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  */
29 
30 #ifndef _ZIO_H
31 #define	_ZIO_H
32 
33 #include <sys/zfs_context.h>
34 #include <sys/spa.h>
35 #include <sys/txg.h>
36 #include <sys/avl.h>
37 #include <sys/fs/zfs.h>
38 #include <sys/zio_impl.h>
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 /*
45  * Embedded checksum
46  */
47 #define	ZEC_MAGIC	0x210da7ab10c7a11ULL
48 
49 typedef struct zio_eck {
50 	uint64_t	zec_magic;	/* for validation, endianness	*/
51 	zio_cksum_t	zec_cksum;	/* 256-bit checksum		*/
52 } zio_eck_t;
53 
54 /*
55  * Gang block headers are self-checksumming and contain an array
56  * of block pointers.
57  */
58 #define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
59 #define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
60 	sizeof (zio_eck_t)) / sizeof (blkptr_t))
61 #define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
62 	sizeof (zio_eck_t) - \
63 	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
64 	sizeof (uint64_t))
65 
66 typedef struct zio_gbh {
67 	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
68 	uint64_t		zg_filler[SPA_GBH_FILLER];
69 	zio_eck_t		zg_tail;
70 } zio_gbh_phys_t;
71 
72 enum zio_checksum {
73 	ZIO_CHECKSUM_INHERIT = 0,
74 	ZIO_CHECKSUM_ON,
75 	ZIO_CHECKSUM_OFF,
76 	ZIO_CHECKSUM_LABEL,
77 	ZIO_CHECKSUM_GANG_HEADER,
78 	ZIO_CHECKSUM_ZILOG,
79 	ZIO_CHECKSUM_FLETCHER_2,
80 	ZIO_CHECKSUM_FLETCHER_4,
81 	ZIO_CHECKSUM_SHA256,
82 	ZIO_CHECKSUM_ZILOG2,
83 	ZIO_CHECKSUM_NOPARITY,
84 	ZIO_CHECKSUM_FUNCTIONS
85 };
86 
87 /*
88  * The number of "legacy" compression functions which can be set on individual
89  * objects.
90  */
91 #define	ZIO_CHECKSUM_LEGACY_FUNCTIONS ZIO_CHECKSUM_ZILOG2
92 
93 #define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_4
94 #define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
95 
96 #define	ZIO_CHECKSUM_MASK	0xffULL
97 #define	ZIO_CHECKSUM_VERIFY	(1 << 8)
98 
99 #define	ZIO_DEDUPCHECKSUM	ZIO_CHECKSUM_SHA256
100 #define	ZIO_DEDUPDITTO_MIN	100
101 
102 enum zio_compress {
103 	ZIO_COMPRESS_INHERIT = 0,
104 	ZIO_COMPRESS_ON,
105 	ZIO_COMPRESS_OFF,
106 	ZIO_COMPRESS_LZJB,
107 	ZIO_COMPRESS_EMPTY,
108 	ZIO_COMPRESS_GZIP_1,
109 	ZIO_COMPRESS_GZIP_2,
110 	ZIO_COMPRESS_GZIP_3,
111 	ZIO_COMPRESS_GZIP_4,
112 	ZIO_COMPRESS_GZIP_5,
113 	ZIO_COMPRESS_GZIP_6,
114 	ZIO_COMPRESS_GZIP_7,
115 	ZIO_COMPRESS_GZIP_8,
116 	ZIO_COMPRESS_GZIP_9,
117 	ZIO_COMPRESS_ZLE,
118 	ZIO_COMPRESS_LZ4,
119 	ZIO_COMPRESS_FUNCTIONS
120 };
121 
122 /*
123  * The number of "legacy" compression functions which can be set on individual
124  * objects.
125  */
126 #define	ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4
127 
128 /*
129  * The meaning of "compress = on" selected by the compression features enabled
130  * on a given pool.
131  */
132 #define	ZIO_COMPRESS_LEGACY_ON_VALUE	ZIO_COMPRESS_LZJB
133 #define	ZIO_COMPRESS_LZ4_ON_VALUE	ZIO_COMPRESS_LZ4
134 
135 #define	ZIO_COMPRESS_DEFAULT		ZIO_COMPRESS_OFF
136 
137 #define	BOOTFS_COMPRESS_VALID(compress)			\
138 	((compress) == ZIO_COMPRESS_LZJB ||		\
139 	(compress) == ZIO_COMPRESS_LZ4 ||		\
140 	(compress) == ZIO_COMPRESS_ON ||		\
141 	(compress) == ZIO_COMPRESS_OFF)
142 
143 #define	ZIO_FAILURE_MODE_WAIT		0
144 #define	ZIO_FAILURE_MODE_CONTINUE	1
145 #define	ZIO_FAILURE_MODE_PANIC		2
146 
147 typedef enum zio_priority {
148 	ZIO_PRIORITY_SYNC_READ,
149 	ZIO_PRIORITY_SYNC_WRITE,	/* ZIL */
150 	ZIO_PRIORITY_ASYNC_READ,	/* prefetch */
151 	ZIO_PRIORITY_ASYNC_WRITE,	/* spa_sync() */
152 	ZIO_PRIORITY_SCRUB,		/* asynchronous scrub/resilver reads */
153 	ZIO_PRIORITY_NUM_QUEUEABLE,
154 
155 	ZIO_PRIORITY_NOW		/* non-queued i/os (e.g. free) */
156 } zio_priority_t;
157 
158 enum zio_flag {
159 	/*
160 	 * Flags inherited by gang, ddt, and vdev children,
161 	 * and that must be equal for two zios to aggregate
162 	 */
163 	ZIO_FLAG_DONT_AGGREGATE	= 1 << 0,
164 	ZIO_FLAG_IO_REPAIR	= 1 << 1,
165 	ZIO_FLAG_SELF_HEAL	= 1 << 2,
166 	ZIO_FLAG_RESILVER	= 1 << 3,
167 	ZIO_FLAG_SCRUB		= 1 << 4,
168 	ZIO_FLAG_SCAN_THREAD	= 1 << 5,
169 	ZIO_FLAG_PHYSICAL	= 1 << 6,
170 
171 #define	ZIO_FLAG_AGG_INHERIT	(ZIO_FLAG_CANFAIL - 1)
172 
173 	/*
174 	 * Flags inherited by ddt, gang, and vdev children.
175 	 */
176 	ZIO_FLAG_CANFAIL	= 1 << 7,	/* must be first for INHERIT */
177 	ZIO_FLAG_SPECULATIVE	= 1 << 8,
178 	ZIO_FLAG_CONFIG_WRITER	= 1 << 9,
179 	ZIO_FLAG_DONT_RETRY	= 1 << 10,
180 	ZIO_FLAG_DONT_CACHE	= 1 << 11,
181 	ZIO_FLAG_NODATA		= 1 << 12,
182 	ZIO_FLAG_INDUCE_DAMAGE	= 1 << 13,
183 
184 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
185 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
186 
187 	/*
188 	 * Flags inherited by vdev children.
189 	 */
190 	ZIO_FLAG_IO_RETRY	= 1 << 14,	/* must be first for INHERIT */
191 	ZIO_FLAG_PROBE		= 1 << 15,
192 	ZIO_FLAG_TRYHARD	= 1 << 16,
193 	ZIO_FLAG_OPTIONAL	= 1 << 17,
194 
195 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
196 
197 	/*
198 	 * Flags not inherited by any children.
199 	 */
200 	ZIO_FLAG_DONT_QUEUE	= 1 << 18,	/* must be first for INHERIT */
201 	ZIO_FLAG_DONT_PROPAGATE	= 1 << 19,
202 	ZIO_FLAG_IO_BYPASS	= 1 << 20,
203 	ZIO_FLAG_IO_REWRITE	= 1 << 21,
204 	ZIO_FLAG_RAW		= 1 << 22,
205 	ZIO_FLAG_GANG_CHILD	= 1 << 23,
206 	ZIO_FLAG_DDT_CHILD	= 1 << 24,
207 	ZIO_FLAG_GODFATHER	= 1 << 25,
208 	ZIO_FLAG_NOPWRITE	= 1 << 26,
209 	ZIO_FLAG_REEXECUTED	= 1 << 27,
210 	ZIO_FLAG_DELEGATED	= 1 << 28,
211 };
212 
213 #define	ZIO_FLAG_MUSTSUCCEED		0
214 
215 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
216 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
217 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
218 
219 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
220 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
221 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
222 
223 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
224 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
225 	ZIO_FLAG_CANFAIL)
226 
227 enum zio_child {
228 	ZIO_CHILD_VDEV = 0,
229 	ZIO_CHILD_GANG,
230 	ZIO_CHILD_DDT,
231 	ZIO_CHILD_LOGICAL,
232 	ZIO_CHILD_TYPES
233 };
234 
235 enum zio_wait_type {
236 	ZIO_WAIT_READY = 0,
237 	ZIO_WAIT_DONE,
238 	ZIO_WAIT_TYPES
239 };
240 
241 /*
242  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
243  * graveyard) to indicate checksum errors and fragmentation.
244  */
245 #define	ECKSUM	EBADE
246 #define	EFRAGS	EBADR
247 
248 typedef void zio_done_func_t(zio_t *zio);
249 
250 extern const char *zio_type_name[ZIO_TYPES];
251 
252 /*
253  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
254  * identifies any block in the pool.  By convention, the meta-objset (MOS)
255  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
256  * except root blocks and ZIL blocks, which are defined as follows:
257  *
258  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
259  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
260  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
261  *
262  * Note: this structure is called a bookmark because its original purpose
263  * was to remember where to resume a pool-wide traverse.
264  *
265  * Note: this structure is passed between userland and the kernel, and is
266  * stored on disk (by virtue of being incorporated into other on-disk
267  * structures, e.g. dsl_scan_phys_t).
268  */
269 typedef struct zbookmark_phys {
270 	uint64_t	zb_objset;
271 	uint64_t	zb_object;
272 	int64_t		zb_level;
273 	uint64_t	zb_blkid;
274 } zbookmark_phys_t;
275 
276 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
277 {                                                       \
278 	(zb)->zb_objset = objset;                       \
279 	(zb)->zb_object = object;                       \
280 	(zb)->zb_level = level;                         \
281 	(zb)->zb_blkid = blkid;                         \
282 }
283 
284 #define	ZB_DESTROYED_OBJSET	(-1ULL)
285 
286 #define	ZB_ROOT_OBJECT		(0ULL)
287 #define	ZB_ROOT_LEVEL		(-1LL)
288 #define	ZB_ROOT_BLKID		(0ULL)
289 
290 #define	ZB_ZIL_OBJECT		(0ULL)
291 #define	ZB_ZIL_LEVEL		(-2LL)
292 
293 #define	ZB_IS_ZERO(zb)						\
294 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
295 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
296 #define	ZB_IS_ROOT(zb)				\
297 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
298 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
299 	(zb)->zb_blkid == ZB_ROOT_BLKID)
300 
301 typedef struct zio_prop {
302 	enum zio_checksum	zp_checksum;
303 	enum zio_compress	zp_compress;
304 	dmu_object_type_t	zp_type;
305 	uint8_t			zp_level;
306 	uint8_t			zp_copies;
307 	boolean_t		zp_dedup;
308 	boolean_t		zp_dedup_verify;
309 	boolean_t		zp_nopwrite;
310 } zio_prop_t;
311 
312 typedef struct zio_cksum_report zio_cksum_report_t;
313 
314 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
315     const void *good_data);
316 typedef void zio_cksum_free_f(void *cbdata, size_t size);
317 
318 struct zio_bad_cksum;				/* defined in zio_checksum.h */
319 struct dnode_phys;
320 
321 struct zio_cksum_report {
322 	struct zio_cksum_report *zcr_next;
323 	nvlist_t		*zcr_ereport;
324 	nvlist_t		*zcr_detector;
325 	void			*zcr_cbdata;
326 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
327 	uint64_t		zcr_align;
328 	uint64_t		zcr_length;
329 	zio_cksum_finish_f	*zcr_finish;
330 	zio_cksum_free_f	*zcr_free;
331 
332 	/* internal use only */
333 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
334 };
335 
336 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
337     void *arg);
338 
339 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
340 
341 typedef struct zio_vsd_ops {
342 	zio_done_func_t		*vsd_free;
343 	zio_vsd_cksum_report_f	*vsd_cksum_report;
344 } zio_vsd_ops_t;
345 
346 typedef struct zio_gang_node {
347 	zio_gbh_phys_t		*gn_gbh;
348 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
349 } zio_gang_node_t;
350 
351 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
352     zio_gang_node_t *gn, void *data);
353 
354 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
355 
356 typedef struct zio_transform {
357 	void			*zt_orig_data;
358 	uint64_t		zt_orig_size;
359 	uint64_t		zt_bufsize;
360 	zio_transform_func_t	*zt_transform;
361 	struct zio_transform	*zt_next;
362 } zio_transform_t;
363 
364 typedef int zio_pipe_stage_t(zio_t *zio);
365 
366 /*
367  * The io_reexecute flags are distinct from io_flags because the child must
368  * be able to propagate them to the parent.  The normal io_flags are local
369  * to the zio, not protected by any lock, and not modifiable by children;
370  * the reexecute flags are protected by io_lock, modifiable by children,
371  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
372  */
373 #define	ZIO_REEXECUTE_NOW	0x01
374 #define	ZIO_REEXECUTE_SUSPEND	0x02
375 
376 typedef struct zio_link {
377 	zio_t		*zl_parent;
378 	zio_t		*zl_child;
379 	list_node_t	zl_parent_node;
380 	list_node_t	zl_child_node;
381 } zio_link_t;
382 
383 struct zio {
384 	/* Core information about this I/O */
385 	zbookmark_phys_t	io_bookmark;
386 	zio_prop_t	io_prop;
387 	zio_type_t	io_type;
388 	enum zio_child	io_child_type;
389 	int		io_cmd;
390 	zio_priority_t	io_priority;
391 	uint8_t		io_reexecute;
392 	uint8_t		io_state[ZIO_WAIT_TYPES];
393 	uint64_t	io_txg;
394 	spa_t		*io_spa;
395 	blkptr_t	*io_bp;
396 	blkptr_t	*io_bp_override;
397 	blkptr_t	io_bp_copy;
398 	list_t		io_parent_list;
399 	list_t		io_child_list;
400 	zio_link_t	*io_walk_link;
401 	zio_t		*io_logical;
402 	zio_transform_t *io_transform_stack;
403 
404 	/* Callback info */
405 	zio_done_func_t	*io_ready;
406 	zio_done_func_t	*io_physdone;
407 	zio_done_func_t	*io_done;
408 	void		*io_private;
409 	int64_t		io_prev_space_delta;	/* DMU private */
410 	blkptr_t	io_bp_orig;
411 
412 	/* Data represented by this I/O */
413 	void		*io_data;
414 	void		*io_orig_data;
415 	uint64_t	io_size;
416 	uint64_t	io_orig_size;
417 
418 	/* Stuff for the vdev stack */
419 	vdev_t		*io_vd;
420 	void		*io_vsd;
421 	const zio_vsd_ops_t *io_vsd_ops;
422 
423 	uint64_t	io_offset;
424 	hrtime_t	io_timestamp;
425 	avl_node_t	io_queue_node;
426 	avl_node_t	io_offset_node;
427 
428 	/* Internal pipeline state */
429 	enum zio_flag	io_flags;
430 	enum zio_stage	io_stage;
431 	enum zio_stage	io_pipeline;
432 	enum zio_flag	io_orig_flags;
433 	enum zio_stage	io_orig_stage;
434 	enum zio_stage	io_orig_pipeline;
435 	int		io_error;
436 	int		io_child_error[ZIO_CHILD_TYPES];
437 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
438 	uint64_t	io_child_count;
439 	uint64_t	io_phys_children;
440 	uint64_t	io_parent_count;
441 	uint64_t	*io_stall;
442 	zio_t		*io_gang_leader;
443 	zio_gang_node_t	*io_gang_tree;
444 	void		*io_executor;
445 	void		*io_waiter;
446 	kmutex_t	io_lock;
447 	kcondvar_t	io_cv;
448 
449 	/* FMA state */
450 	zio_cksum_report_t *io_cksum_report;
451 	uint64_t	io_ena;
452 
453 	/* Taskq dispatching state */
454 	taskq_ent_t	io_tqent;
455 };
456 
457 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
458     zio_done_func_t *done, void *private, enum zio_flag flags);
459 
460 extern zio_t *zio_root(spa_t *spa,
461     zio_done_func_t *done, void *private, enum zio_flag flags);
462 
463 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
464     uint64_t size, zio_done_func_t *done, void *private,
465     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
466 
467 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
468     void *data, uint64_t size, const zio_prop_t *zp,
469     zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done,
470     void *private,
471     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
472 
473 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
474     void *data, uint64_t size, zio_done_func_t *done, void *private,
475     zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb);
476 
477 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
478     boolean_t nopwrite);
479 
480 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
481 
482 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
483     const blkptr_t *bp,
484     zio_done_func_t *done, void *private, enum zio_flag flags);
485 
486 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
487     zio_done_func_t *done, void *private, enum zio_flag flags);
488 
489 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
490     uint64_t size, void *data, int checksum,
491     zio_done_func_t *done, void *private, zio_priority_t priority,
492     enum zio_flag flags, boolean_t labels);
493 
494 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
495     uint64_t size, void *data, int checksum,
496     zio_done_func_t *done, void *private, zio_priority_t priority,
497     enum zio_flag flags, boolean_t labels);
498 
499 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
500     const blkptr_t *bp, enum zio_flag flags);
501 
502 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
503     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
504 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
505 extern void zio_flush(zio_t *zio, vdev_t *vd);
506 extern void zio_shrink(zio_t *zio, uint64_t size);
507 
508 extern int zio_wait(zio_t *zio);
509 extern void zio_nowait(zio_t *zio);
510 extern void zio_execute(zio_t *zio);
511 extern void zio_interrupt(zio_t *zio);
512 
513 extern zio_t *zio_walk_parents(zio_t *cio);
514 extern zio_t *zio_walk_children(zio_t *pio);
515 extern zio_t *zio_unique_parent(zio_t *cio);
516 extern void zio_add_child(zio_t *pio, zio_t *cio);
517 
518 extern void *zio_buf_alloc(size_t size);
519 extern void zio_buf_free(void *buf, size_t size);
520 extern void *zio_data_buf_alloc(size_t size);
521 extern void zio_data_buf_free(void *buf, size_t size);
522 
523 extern void zio_resubmit_stage_async(void *);
524 
525 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
526     uint64_t offset, void *data, uint64_t size, int type,
527     zio_priority_t priority, enum zio_flag flags,
528     zio_done_func_t *done, void *private);
529 
530 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
531     void *data, uint64_t size, int type, zio_priority_t priority,
532     enum zio_flag flags, zio_done_func_t *done, void *private);
533 
534 extern void zio_vdev_io_bypass(zio_t *zio);
535 extern void zio_vdev_io_reissue(zio_t *zio);
536 extern void zio_vdev_io_redone(zio_t *zio);
537 
538 extern void zio_checksum_verified(zio_t *zio);
539 extern int zio_worst_error(int e1, int e2);
540 
541 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
542     enum zio_checksum parent);
543 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
544     enum zio_checksum child, enum zio_checksum parent);
545 extern enum zio_compress zio_compress_select(spa_t *spa,
546     enum zio_compress child, enum zio_compress parent);
547 
548 extern void zio_suspend(spa_t *spa, zio_t *zio);
549 extern int zio_resume(spa_t *spa);
550 extern void zio_resume_wait(spa_t *spa);
551 
552 /*
553  * Initial setup and teardown.
554  */
555 extern void zio_init(void);
556 extern void zio_fini(void);
557 
558 /*
559  * Fault injection
560  */
561 struct zinject_record;
562 extern uint32_t zio_injection_enabled;
563 extern int zio_inject_fault(char *name, int flags, int *id,
564     struct zinject_record *record);
565 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
566     struct zinject_record *record);
567 extern int zio_clear_fault(int id);
568 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
569 extern int zio_handle_fault_injection(zio_t *zio, int error);
570 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
571 extern int zio_handle_label_injection(zio_t *zio, int error);
572 extern void zio_handle_ignored_writes(zio_t *zio);
573 extern uint64_t zio_handle_io_delay(zio_t *zio);
574 
575 /*
576  * Checksum ereport functions
577  */
578 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
579     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
580 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
581     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
582 
583 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
584 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
585 
586 /* If we have the good data in hand, this function can be used */
587 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
588     struct zio *zio, uint64_t offset, uint64_t length,
589     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
590 
591 /* Called from spa_sync(), but primarily an injection handler */
592 extern void spa_handle_ignored_writes(spa_t *spa);
593 
594 /* zbookmark_phys functions */
595 boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
596     const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
597 
598 #ifdef	__cplusplus
599 }
600 #endif
601 
602 #endif	/* _ZIO_H */
603