xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/zio.h (revision 5d7b4d438c4a51eccc95e77a83a437b4d48380eb)
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) 2013 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 /* N.B. when altering this value, also change BOOTFS_COMPRESS_VALID below */
129 #define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
130 #define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
131 
132 #define	BOOTFS_COMPRESS_VALID(compress)			\
133 	((compress) == ZIO_COMPRESS_LZJB ||		\
134 	(compress) == ZIO_COMPRESS_LZ4 ||		\
135 	((compress) == ZIO_COMPRESS_ON &&		\
136 	ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) ||	\
137 	(compress) == ZIO_COMPRESS_OFF)
138 
139 #define	ZIO_FAILURE_MODE_WAIT		0
140 #define	ZIO_FAILURE_MODE_CONTINUE	1
141 #define	ZIO_FAILURE_MODE_PANIC		2
142 
143 typedef enum zio_priority {
144 	ZIO_PRIORITY_SYNC_READ,
145 	ZIO_PRIORITY_SYNC_WRITE,	/* ZIL */
146 	ZIO_PRIORITY_ASYNC_READ,	/* prefetch */
147 	ZIO_PRIORITY_ASYNC_WRITE,	/* spa_sync() */
148 	ZIO_PRIORITY_SCRUB,		/* asynchronous scrub/resilver reads */
149 	ZIO_PRIORITY_NUM_QUEUEABLE,
150 
151 	ZIO_PRIORITY_NOW		/* non-queued i/os (e.g. free) */
152 } zio_priority_t;
153 
154 #define	ZIO_PIPELINE_CONTINUE		0x100
155 #define	ZIO_PIPELINE_STOP		0x101
156 
157 enum zio_flag {
158 	/*
159 	 * Flags inherited by gang, ddt, and vdev children,
160 	 * and that must be equal for two zios to aggregate
161 	 */
162 	ZIO_FLAG_DONT_AGGREGATE	= 1 << 0,
163 	ZIO_FLAG_IO_REPAIR	= 1 << 1,
164 	ZIO_FLAG_SELF_HEAL	= 1 << 2,
165 	ZIO_FLAG_RESILVER	= 1 << 3,
166 	ZIO_FLAG_SCRUB		= 1 << 4,
167 	ZIO_FLAG_SCAN_THREAD	= 1 << 5,
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 << 6,	/* must be first for INHERIT */
175 	ZIO_FLAG_SPECULATIVE	= 1 << 7,
176 	ZIO_FLAG_CONFIG_WRITER	= 1 << 8,
177 	ZIO_FLAG_DONT_RETRY	= 1 << 9,
178 	ZIO_FLAG_DONT_CACHE	= 1 << 10,
179 	ZIO_FLAG_NODATA		= 1 << 11,
180 	ZIO_FLAG_INDUCE_DAMAGE	= 1 << 12,
181 
182 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
183 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
184 
185 	/*
186 	 * Flags inherited by vdev children.
187 	 */
188 	ZIO_FLAG_IO_RETRY	= 1 << 13,	/* must be first for INHERIT */
189 	ZIO_FLAG_PROBE		= 1 << 14,
190 	ZIO_FLAG_TRYHARD	= 1 << 15,
191 	ZIO_FLAG_OPTIONAL	= 1 << 16,
192 
193 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
194 
195 	/*
196 	 * Flags not inherited by any children.
197 	 */
198 	ZIO_FLAG_DONT_QUEUE	= 1 << 17,	/* must be first for INHERIT */
199 	ZIO_FLAG_DONT_PROPAGATE	= 1 << 18,
200 	ZIO_FLAG_IO_BYPASS	= 1 << 19,
201 	ZIO_FLAG_IO_REWRITE	= 1 << 20,
202 	ZIO_FLAG_RAW		= 1 << 21,
203 	ZIO_FLAG_GANG_CHILD	= 1 << 22,
204 	ZIO_FLAG_DDT_CHILD	= 1 << 23,
205 	ZIO_FLAG_GODFATHER	= 1 << 24,
206 	ZIO_FLAG_NOPWRITE	= 1 << 25,
207 	ZIO_FLAG_REEXECUTED	= 1 << 26,
208 	ZIO_FLAG_DELEGATED	= 1 << 27,
209 };
210 
211 #define	ZIO_FLAG_MUSTSUCCEED		0
212 
213 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
214 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
215 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
216 
217 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
218 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
219 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
220 
221 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
222 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
223 	ZIO_FLAG_CANFAIL)
224 
225 enum zio_child {
226 	ZIO_CHILD_VDEV = 0,
227 	ZIO_CHILD_GANG,
228 	ZIO_CHILD_DDT,
229 	ZIO_CHILD_LOGICAL,
230 	ZIO_CHILD_TYPES
231 };
232 
233 enum zio_wait_type {
234 	ZIO_WAIT_READY = 0,
235 	ZIO_WAIT_DONE,
236 	ZIO_WAIT_TYPES
237 };
238 
239 /*
240  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
241  * graveyard) to indicate checksum errors and fragmentation.
242  */
243 #define	ECKSUM	EBADE
244 #define	EFRAGS	EBADR
245 
246 typedef void zio_done_func_t(zio_t *zio);
247 
248 extern const char *zio_type_name[ZIO_TYPES];
249 
250 /*
251  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
252  * identifies any block in the pool.  By convention, the meta-objset (MOS)
253  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
254  * except root blocks and ZIL blocks, which are defined as follows:
255  *
256  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
257  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
258  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
259  *
260  * Note: this structure is called a bookmark because its original purpose
261  * was to remember where to resume a pool-wide traverse.
262  *
263  * Note: this structure is passed between userland and the kernel.
264  * Therefore it must not change size or alignment between 32/64 bit
265  * compilation options.
266  */
267 typedef struct zbookmark {
268 	uint64_t	zb_objset;
269 	uint64_t	zb_object;
270 	int64_t		zb_level;
271 	uint64_t	zb_blkid;
272 } zbookmark_t;
273 
274 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
275 {                                                       \
276 	(zb)->zb_objset = objset;                       \
277 	(zb)->zb_object = object;                       \
278 	(zb)->zb_level = level;                         \
279 	(zb)->zb_blkid = blkid;                         \
280 }
281 
282 #define	ZB_DESTROYED_OBJSET	(-1ULL)
283 
284 #define	ZB_ROOT_OBJECT		(0ULL)
285 #define	ZB_ROOT_LEVEL		(-1LL)
286 #define	ZB_ROOT_BLKID		(0ULL)
287 
288 #define	ZB_ZIL_OBJECT		(0ULL)
289 #define	ZB_ZIL_LEVEL		(-2LL)
290 
291 #define	ZB_IS_ZERO(zb)						\
292 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
293 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
294 #define	ZB_IS_ROOT(zb)				\
295 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
296 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
297 	(zb)->zb_blkid == ZB_ROOT_BLKID)
298 
299 typedef struct zio_prop {
300 	enum zio_checksum	zp_checksum;
301 	enum zio_compress	zp_compress;
302 	dmu_object_type_t	zp_type;
303 	uint8_t			zp_level;
304 	uint8_t			zp_copies;
305 	boolean_t		zp_dedup;
306 	boolean_t		zp_dedup_verify;
307 	boolean_t		zp_nopwrite;
308 } zio_prop_t;
309 
310 typedef struct zio_cksum_report zio_cksum_report_t;
311 
312 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
313     const void *good_data);
314 typedef void zio_cksum_free_f(void *cbdata, size_t size);
315 
316 struct zio_bad_cksum;				/* defined in zio_checksum.h */
317 struct dnode_phys;
318 
319 struct zio_cksum_report {
320 	struct zio_cksum_report *zcr_next;
321 	nvlist_t		*zcr_ereport;
322 	nvlist_t		*zcr_detector;
323 	void			*zcr_cbdata;
324 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
325 	uint64_t		zcr_align;
326 	uint64_t		zcr_length;
327 	zio_cksum_finish_f	*zcr_finish;
328 	zio_cksum_free_f	*zcr_free;
329 
330 	/* internal use only */
331 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
332 };
333 
334 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
335     void *arg);
336 
337 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
338 
339 typedef struct zio_vsd_ops {
340 	zio_done_func_t		*vsd_free;
341 	zio_vsd_cksum_report_f	*vsd_cksum_report;
342 } zio_vsd_ops_t;
343 
344 typedef struct zio_gang_node {
345 	zio_gbh_phys_t		*gn_gbh;
346 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
347 } zio_gang_node_t;
348 
349 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
350     zio_gang_node_t *gn, void *data);
351 
352 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
353 
354 typedef struct zio_transform {
355 	void			*zt_orig_data;
356 	uint64_t		zt_orig_size;
357 	uint64_t		zt_bufsize;
358 	zio_transform_func_t	*zt_transform;
359 	struct zio_transform	*zt_next;
360 } zio_transform_t;
361 
362 typedef int zio_pipe_stage_t(zio_t *zio);
363 
364 /*
365  * The io_reexecute flags are distinct from io_flags because the child must
366  * be able to propagate them to the parent.  The normal io_flags are local
367  * to the zio, not protected by any lock, and not modifiable by children;
368  * the reexecute flags are protected by io_lock, modifiable by children,
369  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
370  */
371 #define	ZIO_REEXECUTE_NOW	0x01
372 #define	ZIO_REEXECUTE_SUSPEND	0x02
373 
374 typedef struct zio_link {
375 	zio_t		*zl_parent;
376 	zio_t		*zl_child;
377 	list_node_t	zl_parent_node;
378 	list_node_t	zl_child_node;
379 } zio_link_t;
380 
381 struct zio {
382 	/* Core information about this I/O */
383 	zbookmark_t	io_bookmark;
384 	zio_prop_t	io_prop;
385 	zio_type_t	io_type;
386 	enum zio_child	io_child_type;
387 	int		io_cmd;
388 	zio_priority_t	io_priority;
389 	uint8_t		io_reexecute;
390 	uint8_t		io_state[ZIO_WAIT_TYPES];
391 	uint64_t	io_txg;
392 	spa_t		*io_spa;
393 	blkptr_t	*io_bp;
394 	blkptr_t	*io_bp_override;
395 	blkptr_t	io_bp_copy;
396 	list_t		io_parent_list;
397 	list_t		io_child_list;
398 	zio_link_t	*io_walk_link;
399 	zio_t		*io_logical;
400 	zio_transform_t *io_transform_stack;
401 
402 	/* Callback info */
403 	zio_done_func_t	*io_ready;
404 	zio_done_func_t	*io_physdone;
405 	zio_done_func_t	*io_done;
406 	void		*io_private;
407 	int64_t		io_prev_space_delta;	/* DMU private */
408 	blkptr_t	io_bp_orig;
409 
410 	/* Data represented by this I/O */
411 	void		*io_data;
412 	void		*io_orig_data;
413 	uint64_t	io_size;
414 	uint64_t	io_orig_size;
415 
416 	/* Stuff for the vdev stack */
417 	vdev_t		*io_vd;
418 	void		*io_vsd;
419 	const zio_vsd_ops_t *io_vsd_ops;
420 
421 	uint64_t	io_offset;
422 	hrtime_t	io_timestamp;
423 	avl_node_t	io_queue_node;
424 
425 	/* Internal pipeline state */
426 	enum zio_flag	io_flags;
427 	enum zio_stage	io_stage;
428 	enum zio_stage	io_pipeline;
429 	enum zio_flag	io_orig_flags;
430 	enum zio_stage	io_orig_stage;
431 	enum zio_stage	io_orig_pipeline;
432 	int		io_error;
433 	int		io_child_error[ZIO_CHILD_TYPES];
434 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
435 	uint64_t	io_child_count;
436 	uint64_t	io_phys_children;
437 	uint64_t	io_parent_count;
438 	uint64_t	*io_stall;
439 	zio_t		*io_gang_leader;
440 	zio_gang_node_t	*io_gang_tree;
441 	void		*io_executor;
442 	void		*io_waiter;
443 	kmutex_t	io_lock;
444 	kcondvar_t	io_cv;
445 
446 	/* FMA state */
447 	zio_cksum_report_t *io_cksum_report;
448 	uint64_t	io_ena;
449 
450 	/* Taskq dispatching state */
451 	taskq_ent_t	io_tqent;
452 };
453 
454 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
455     zio_done_func_t *done, void *private, enum zio_flag flags);
456 
457 extern zio_t *zio_root(spa_t *spa,
458     zio_done_func_t *done, void *private, enum zio_flag flags);
459 
460 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
461     uint64_t size, zio_done_func_t *done, void *private,
462     zio_priority_t priority, enum zio_flag flags, const zbookmark_t *zb);
463 
464 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
465     void *data, uint64_t size, const zio_prop_t *zp,
466     zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done,
467     void *private,
468     zio_priority_t priority, enum zio_flag flags, const zbookmark_t *zb);
469 
470 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
471     void *data, uint64_t size, zio_done_func_t *done, void *private,
472     zio_priority_t priority, enum zio_flag flags, zbookmark_t *zb);
473 
474 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
475     boolean_t nopwrite);
476 
477 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
478 
479 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
480     const blkptr_t *bp,
481     zio_done_func_t *done, void *private, enum zio_flag flags);
482 
483 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
484     zio_done_func_t *done, void *private, enum zio_flag flags);
485 
486 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
487     uint64_t size, void *data, int checksum,
488     zio_done_func_t *done, void *private, zio_priority_t priority,
489     enum zio_flag flags, boolean_t labels);
490 
491 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
492     uint64_t size, void *data, int checksum,
493     zio_done_func_t *done, void *private, zio_priority_t priority,
494     enum zio_flag flags, boolean_t labels);
495 
496 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
497     const blkptr_t *bp, enum zio_flag flags);
498 
499 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
500     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
501 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
502 extern void zio_flush(zio_t *zio, vdev_t *vd);
503 extern void zio_shrink(zio_t *zio, uint64_t size);
504 
505 extern int zio_wait(zio_t *zio);
506 extern void zio_nowait(zio_t *zio);
507 extern void zio_execute(zio_t *zio);
508 extern void zio_interrupt(zio_t *zio);
509 
510 extern zio_t *zio_walk_parents(zio_t *cio);
511 extern zio_t *zio_walk_children(zio_t *pio);
512 extern zio_t *zio_unique_parent(zio_t *cio);
513 extern void zio_add_child(zio_t *pio, zio_t *cio);
514 
515 extern void *zio_buf_alloc(size_t size);
516 extern void zio_buf_free(void *buf, size_t size);
517 extern void *zio_data_buf_alloc(size_t size);
518 extern void zio_data_buf_free(void *buf, size_t size);
519 
520 extern void zio_resubmit_stage_async(void *);
521 
522 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
523     uint64_t offset, void *data, uint64_t size, int type,
524     zio_priority_t priority, enum zio_flag flags,
525     zio_done_func_t *done, void *private);
526 
527 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
528     void *data, uint64_t size, int type, zio_priority_t priority,
529     enum zio_flag flags, zio_done_func_t *done, void *private);
530 
531 extern void zio_vdev_io_bypass(zio_t *zio);
532 extern void zio_vdev_io_reissue(zio_t *zio);
533 extern void zio_vdev_io_redone(zio_t *zio);
534 
535 extern void zio_checksum_verified(zio_t *zio);
536 extern int zio_worst_error(int e1, int e2);
537 
538 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
539     enum zio_checksum parent);
540 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
541     enum zio_checksum child, enum zio_checksum parent);
542 extern enum zio_compress zio_compress_select(enum zio_compress child,
543     enum zio_compress parent);
544 
545 extern void zio_suspend(spa_t *spa, zio_t *zio);
546 extern int zio_resume(spa_t *spa);
547 extern void zio_resume_wait(spa_t *spa);
548 
549 /*
550  * Initial setup and teardown.
551  */
552 extern void zio_init(void);
553 extern void zio_fini(void);
554 
555 /*
556  * Fault injection
557  */
558 struct zinject_record;
559 extern uint32_t zio_injection_enabled;
560 extern int zio_inject_fault(char *name, int flags, int *id,
561     struct zinject_record *record);
562 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
563     struct zinject_record *record);
564 extern int zio_clear_fault(int id);
565 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
566 extern int zio_handle_fault_injection(zio_t *zio, int error);
567 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
568 extern int zio_handle_label_injection(zio_t *zio, int error);
569 extern void zio_handle_ignored_writes(zio_t *zio);
570 extern uint64_t zio_handle_io_delay(zio_t *zio);
571 
572 /*
573  * Checksum ereport functions
574  */
575 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
576     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
577 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
578     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
579 
580 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
581 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
582 
583 /* If we have the good data in hand, this function can be used */
584 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
585     struct zio *zio, uint64_t offset, uint64_t length,
586     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
587 
588 /* Called from spa_sync(), but primarily an injection handler */
589 extern void spa_handle_ignored_writes(spa_t *spa);
590 
591 /* zbookmark functions */
592 boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
593     const zbookmark_t *zb1, const zbookmark_t *zb2);
594 
595 #ifdef	__cplusplus
596 }
597 #endif
598 
599 #endif	/* _ZIO_H */
600