xref: /titanic_52/usr/src/uts/common/fs/zfs/sys/zio.h (revision 283b84606b6fc326692c03273de1774e8c122f9a)
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 by Delphix. All rights reserved.
26  */
27 
28 #ifndef _ZIO_H
29 #define	_ZIO_H
30 
31 #include <sys/zfs_context.h>
32 #include <sys/spa.h>
33 #include <sys/txg.h>
34 #include <sys/avl.h>
35 #include <sys/fs/zfs.h>
36 #include <sys/zio_impl.h>
37 
38 #ifdef	__cplusplus
39 extern "C" {
40 #endif
41 
42 /*
43  * Embedded checksum
44  */
45 #define	ZEC_MAGIC	0x210da7ab10c7a11ULL
46 
47 typedef struct zio_eck {
48 	uint64_t	zec_magic;	/* for validation, endianness	*/
49 	zio_cksum_t	zec_cksum;	/* 256-bit checksum		*/
50 } zio_eck_t;
51 
52 /*
53  * Gang block headers are self-checksumming and contain an array
54  * of block pointers.
55  */
56 #define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
57 #define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
58 	sizeof (zio_eck_t)) / sizeof (blkptr_t))
59 #define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
60 	sizeof (zio_eck_t) - \
61 	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
62 	sizeof (uint64_t))
63 
64 typedef struct zio_gbh {
65 	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
66 	uint64_t		zg_filler[SPA_GBH_FILLER];
67 	zio_eck_t		zg_tail;
68 } zio_gbh_phys_t;
69 
70 enum zio_checksum {
71 	ZIO_CHECKSUM_INHERIT = 0,
72 	ZIO_CHECKSUM_ON,
73 	ZIO_CHECKSUM_OFF,
74 	ZIO_CHECKSUM_LABEL,
75 	ZIO_CHECKSUM_GANG_HEADER,
76 	ZIO_CHECKSUM_ZILOG,
77 	ZIO_CHECKSUM_FLETCHER_2,
78 	ZIO_CHECKSUM_FLETCHER_4,
79 	ZIO_CHECKSUM_SHA256,
80 	ZIO_CHECKSUM_ZILOG2,
81 	ZIO_CHECKSUM_FUNCTIONS
82 };
83 
84 #define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_4
85 #define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
86 
87 #define	ZIO_CHECKSUM_MASK	0xffULL
88 #define	ZIO_CHECKSUM_VERIFY	(1 << 8)
89 
90 #define	ZIO_DEDUPCHECKSUM	ZIO_CHECKSUM_SHA256
91 #define	ZIO_DEDUPDITTO_MIN	100
92 
93 enum zio_compress {
94 	ZIO_COMPRESS_INHERIT = 0,
95 	ZIO_COMPRESS_ON,
96 	ZIO_COMPRESS_OFF,
97 	ZIO_COMPRESS_LZJB,
98 	ZIO_COMPRESS_EMPTY,
99 	ZIO_COMPRESS_GZIP_1,
100 	ZIO_COMPRESS_GZIP_2,
101 	ZIO_COMPRESS_GZIP_3,
102 	ZIO_COMPRESS_GZIP_4,
103 	ZIO_COMPRESS_GZIP_5,
104 	ZIO_COMPRESS_GZIP_6,
105 	ZIO_COMPRESS_GZIP_7,
106 	ZIO_COMPRESS_GZIP_8,
107 	ZIO_COMPRESS_GZIP_9,
108 	ZIO_COMPRESS_ZLE,
109 	ZIO_COMPRESS_FUNCTIONS
110 };
111 
112 #define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
113 #define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
114 
115 #define	BOOTFS_COMPRESS_VALID(compress)			\
116 	((compress) == ZIO_COMPRESS_LZJB ||		\
117 	((compress) == ZIO_COMPRESS_ON &&		\
118 	ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) ||	\
119 	(compress) == ZIO_COMPRESS_OFF)
120 
121 #define	ZIO_FAILURE_MODE_WAIT		0
122 #define	ZIO_FAILURE_MODE_CONTINUE	1
123 #define	ZIO_FAILURE_MODE_PANIC		2
124 
125 #define	ZIO_PRIORITY_NOW		(zio_priority_table[0])
126 #define	ZIO_PRIORITY_SYNC_READ		(zio_priority_table[1])
127 #define	ZIO_PRIORITY_SYNC_WRITE		(zio_priority_table[2])
128 #define	ZIO_PRIORITY_LOG_WRITE		(zio_priority_table[3])
129 #define	ZIO_PRIORITY_CACHE_FILL		(zio_priority_table[4])
130 #define	ZIO_PRIORITY_AGG		(zio_priority_table[5])
131 #define	ZIO_PRIORITY_FREE		(zio_priority_table[6])
132 #define	ZIO_PRIORITY_ASYNC_WRITE	(zio_priority_table[7])
133 #define	ZIO_PRIORITY_ASYNC_READ		(zio_priority_table[8])
134 #define	ZIO_PRIORITY_RESILVER		(zio_priority_table[9])
135 #define	ZIO_PRIORITY_SCRUB		(zio_priority_table[10])
136 #define	ZIO_PRIORITY_DDT_PREFETCH	(zio_priority_table[11])
137 #define	ZIO_PRIORITY_TABLE_SIZE		12
138 
139 #define	ZIO_PIPELINE_CONTINUE		0x100
140 #define	ZIO_PIPELINE_STOP		0x101
141 
142 enum zio_flag {
143 	/*
144 	 * Flags inherited by gang, ddt, and vdev children,
145 	 * and that must be equal for two zios to aggregate
146 	 */
147 	ZIO_FLAG_DONT_AGGREGATE	= 1 << 0,
148 	ZIO_FLAG_IO_REPAIR	= 1 << 1,
149 	ZIO_FLAG_SELF_HEAL	= 1 << 2,
150 	ZIO_FLAG_RESILVER	= 1 << 3,
151 	ZIO_FLAG_SCRUB		= 1 << 4,
152 	ZIO_FLAG_SCAN_THREAD	= 1 << 5,
153 
154 #define	ZIO_FLAG_AGG_INHERIT	(ZIO_FLAG_CANFAIL - 1)
155 
156 	/*
157 	 * Flags inherited by ddt, gang, and vdev children.
158 	 */
159 	ZIO_FLAG_CANFAIL	= 1 << 6,	/* must be first for INHERIT */
160 	ZIO_FLAG_SPECULATIVE	= 1 << 7,
161 	ZIO_FLAG_CONFIG_WRITER	= 1 << 8,
162 	ZIO_FLAG_DONT_RETRY	= 1 << 9,
163 	ZIO_FLAG_DONT_CACHE	= 1 << 10,
164 	ZIO_FLAG_NODATA		= 1 << 11,
165 	ZIO_FLAG_INDUCE_DAMAGE	= 1 << 12,
166 
167 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
168 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
169 
170 	/*
171 	 * Flags inherited by vdev children.
172 	 */
173 	ZIO_FLAG_IO_RETRY	= 1 << 13,	/* must be first for INHERIT */
174 	ZIO_FLAG_PROBE		= 1 << 14,
175 	ZIO_FLAG_TRYHARD	= 1 << 15,
176 	ZIO_FLAG_OPTIONAL	= 1 << 16,
177 
178 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
179 
180 	/*
181 	 * Flags not inherited by any children.
182 	 */
183 	ZIO_FLAG_DONT_QUEUE	= 1 << 17,	/* must be first for INHERIT */
184 	ZIO_FLAG_DONT_PROPAGATE	= 1 << 18,
185 	ZIO_FLAG_IO_BYPASS	= 1 << 19,
186 	ZIO_FLAG_IO_REWRITE	= 1 << 20,
187 	ZIO_FLAG_RAW		= 1 << 21,
188 	ZIO_FLAG_GANG_CHILD	= 1 << 22,
189 	ZIO_FLAG_DDT_CHILD	= 1 << 23,
190 	ZIO_FLAG_GODFATHER	= 1 << 24
191 };
192 
193 #define	ZIO_FLAG_MUSTSUCCEED		0
194 
195 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
196 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
197 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
198 
199 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
200 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
201 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
202 
203 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
204 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
205 	ZIO_FLAG_CANFAIL)
206 
207 enum zio_child {
208 	ZIO_CHILD_VDEV = 0,
209 	ZIO_CHILD_GANG,
210 	ZIO_CHILD_DDT,
211 	ZIO_CHILD_LOGICAL,
212 	ZIO_CHILD_TYPES
213 };
214 
215 enum zio_wait_type {
216 	ZIO_WAIT_READY = 0,
217 	ZIO_WAIT_DONE,
218 	ZIO_WAIT_TYPES
219 };
220 
221 /*
222  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
223  * graveyard) to indicate checksum errors and fragmentation.
224  */
225 #define	ECKSUM	EBADE
226 #define	EFRAGS	EBADR
227 
228 typedef void zio_done_func_t(zio_t *zio);
229 
230 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
231 extern char *zio_type_name[ZIO_TYPES];
232 
233 /*
234  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
235  * identifies any block in the pool.  By convention, the meta-objset (MOS)
236  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
237  * except root blocks and ZIL blocks, which are defined as follows:
238  *
239  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
240  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
241  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
242  *
243  * Note: this structure is called a bookmark because its original purpose
244  * was to remember where to resume a pool-wide traverse.
245  *
246  * Note: this structure is passed between userland and the kernel.
247  * Therefore it must not change size or alignment between 32/64 bit
248  * compilation options.
249  */
250 typedef struct zbookmark {
251 	uint64_t	zb_objset;
252 	uint64_t	zb_object;
253 	int64_t		zb_level;
254 	uint64_t	zb_blkid;
255 } zbookmark_t;
256 
257 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
258 {                                                       \
259 	(zb)->zb_objset = objset;                       \
260 	(zb)->zb_object = object;                       \
261 	(zb)->zb_level = level;                         \
262 	(zb)->zb_blkid = blkid;                         \
263 }
264 
265 #define	ZB_DESTROYED_OBJSET	(-1ULL)
266 
267 #define	ZB_ROOT_OBJECT		(0ULL)
268 #define	ZB_ROOT_LEVEL		(-1LL)
269 #define	ZB_ROOT_BLKID		(0ULL)
270 
271 #define	ZB_ZIL_OBJECT		(0ULL)
272 #define	ZB_ZIL_LEVEL		(-2LL)
273 
274 #define	ZB_IS_ZERO(zb)						\
275 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
276 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
277 #define	ZB_IS_ROOT(zb)				\
278 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
279 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
280 	(zb)->zb_blkid == ZB_ROOT_BLKID)
281 
282 typedef struct zio_prop {
283 	enum zio_checksum	zp_checksum;
284 	enum zio_compress	zp_compress;
285 	dmu_object_type_t	zp_type;
286 	uint8_t			zp_level;
287 	uint8_t			zp_copies;
288 	uint8_t			zp_dedup;
289 	uint8_t			zp_dedup_verify;
290 } zio_prop_t;
291 
292 typedef struct zio_cksum_report zio_cksum_report_t;
293 
294 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
295     const void *good_data);
296 typedef void zio_cksum_free_f(void *cbdata, size_t size);
297 
298 struct zio_bad_cksum;				/* defined in zio_checksum.h */
299 struct dnode_phys;
300 
301 struct zio_cksum_report {
302 	struct zio_cksum_report *zcr_next;
303 	nvlist_t		*zcr_ereport;
304 	nvlist_t		*zcr_detector;
305 	void			*zcr_cbdata;
306 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
307 	uint64_t		zcr_align;
308 	uint64_t		zcr_length;
309 	zio_cksum_finish_f	*zcr_finish;
310 	zio_cksum_free_f	*zcr_free;
311 
312 	/* internal use only */
313 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
314 };
315 
316 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
317     void *arg);
318 
319 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
320 
321 typedef struct zio_vsd_ops {
322 	zio_done_func_t		*vsd_free;
323 	zio_vsd_cksum_report_f	*vsd_cksum_report;
324 } zio_vsd_ops_t;
325 
326 typedef struct zio_gang_node {
327 	zio_gbh_phys_t		*gn_gbh;
328 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
329 } zio_gang_node_t;
330 
331 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
332     zio_gang_node_t *gn, void *data);
333 
334 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
335 
336 typedef struct zio_transform {
337 	void			*zt_orig_data;
338 	uint64_t		zt_orig_size;
339 	uint64_t		zt_bufsize;
340 	zio_transform_func_t	*zt_transform;
341 	struct zio_transform	*zt_next;
342 } zio_transform_t;
343 
344 typedef int zio_pipe_stage_t(zio_t *zio);
345 
346 /*
347  * The io_reexecute flags are distinct from io_flags because the child must
348  * be able to propagate them to the parent.  The normal io_flags are local
349  * to the zio, not protected by any lock, and not modifiable by children;
350  * the reexecute flags are protected by io_lock, modifiable by children,
351  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
352  */
353 #define	ZIO_REEXECUTE_NOW	0x01
354 #define	ZIO_REEXECUTE_SUSPEND	0x02
355 
356 typedef struct zio_link {
357 	zio_t		*zl_parent;
358 	zio_t		*zl_child;
359 	list_node_t	zl_parent_node;
360 	list_node_t	zl_child_node;
361 } zio_link_t;
362 
363 struct zio {
364 	/* Core information about this I/O */
365 	zbookmark_t	io_bookmark;
366 	zio_prop_t	io_prop;
367 	zio_type_t	io_type;
368 	enum zio_child	io_child_type;
369 	int		io_cmd;
370 	uint8_t		io_priority;
371 	uint8_t		io_reexecute;
372 	uint8_t		io_state[ZIO_WAIT_TYPES];
373 	uint64_t	io_txg;
374 	spa_t		*io_spa;
375 	blkptr_t	*io_bp;
376 	blkptr_t	*io_bp_override;
377 	blkptr_t	io_bp_copy;
378 	list_t		io_parent_list;
379 	list_t		io_child_list;
380 	zio_link_t	*io_walk_link;
381 	zio_t		*io_logical;
382 	zio_transform_t *io_transform_stack;
383 
384 	/* Callback info */
385 	zio_done_func_t	*io_ready;
386 	zio_done_func_t	*io_done;
387 	void		*io_private;
388 	int64_t		io_prev_space_delta;	/* DMU private */
389 	blkptr_t	io_bp_orig;
390 
391 	/* Data represented by this I/O */
392 	void		*io_data;
393 	void		*io_orig_data;
394 	uint64_t	io_size;
395 	uint64_t	io_orig_size;
396 
397 	/* Stuff for the vdev stack */
398 	vdev_t		*io_vd;
399 	void		*io_vsd;
400 	const zio_vsd_ops_t *io_vsd_ops;
401 
402 	uint64_t	io_offset;
403 	uint64_t	io_deadline;
404 	uint64_t	io_timestamp;
405 	avl_node_t	io_offset_node;
406 	avl_node_t	io_deadline_node;
407 	avl_tree_t	*io_vdev_tree;
408 
409 	/* Internal pipeline state */
410 	enum zio_flag	io_flags;
411 	enum zio_stage	io_stage;
412 	enum zio_stage	io_pipeline;
413 	enum zio_flag	io_orig_flags;
414 	enum zio_stage	io_orig_stage;
415 	enum zio_stage	io_orig_pipeline;
416 	int		io_error;
417 	int		io_child_error[ZIO_CHILD_TYPES];
418 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
419 	uint64_t	io_child_count;
420 	uint64_t	io_parent_count;
421 	uint64_t	*io_stall;
422 	zio_t		*io_gang_leader;
423 	zio_gang_node_t	*io_gang_tree;
424 	void		*io_executor;
425 	void		*io_waiter;
426 	kmutex_t	io_lock;
427 	kcondvar_t	io_cv;
428 
429 	/* FMA state */
430 	zio_cksum_report_t *io_cksum_report;
431 	uint64_t	io_ena;
432 
433 	/* Taskq dispatching state */
434 	taskq_ent_t	io_tqent;
435 };
436 
437 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
438     zio_done_func_t *done, void *private, enum zio_flag flags);
439 
440 extern zio_t *zio_root(spa_t *spa,
441     zio_done_func_t *done, void *private, enum zio_flag flags);
442 
443 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
444     uint64_t size, zio_done_func_t *done, void *private,
445     int priority, enum zio_flag flags, const zbookmark_t *zb);
446 
447 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
448     void *data, uint64_t size, const zio_prop_t *zp,
449     zio_done_func_t *ready, zio_done_func_t *done, void *private,
450     int priority, enum zio_flag flags, const zbookmark_t *zb);
451 
452 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
453     void *data, uint64_t size, zio_done_func_t *done, void *private,
454     int priority, enum zio_flag flags, zbookmark_t *zb);
455 
456 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies);
457 
458 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
459 
460 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
461     const blkptr_t *bp,
462     zio_done_func_t *done, void *private, enum zio_flag flags);
463 
464 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
465     zio_done_func_t *done, void *private, int priority, enum zio_flag flags);
466 
467 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
468     uint64_t size, void *data, int checksum,
469     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
470     boolean_t labels);
471 
472 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
473     uint64_t size, void *data, int checksum,
474     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
475     boolean_t labels);
476 
477 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
478     const blkptr_t *bp, enum zio_flag flags);
479 
480 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
481     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
482 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
483 extern void zio_flush(zio_t *zio, vdev_t *vd);
484 extern void zio_shrink(zio_t *zio, uint64_t size);
485 
486 extern int zio_wait(zio_t *zio);
487 extern void zio_nowait(zio_t *zio);
488 extern void zio_execute(zio_t *zio);
489 extern void zio_interrupt(zio_t *zio);
490 
491 extern zio_t *zio_walk_parents(zio_t *cio);
492 extern zio_t *zio_walk_children(zio_t *pio);
493 extern zio_t *zio_unique_parent(zio_t *cio);
494 extern void zio_add_child(zio_t *pio, zio_t *cio);
495 
496 extern void *zio_buf_alloc(size_t size);
497 extern void zio_buf_free(void *buf, size_t size);
498 extern void *zio_data_buf_alloc(size_t size);
499 extern void zio_data_buf_free(void *buf, size_t size);
500 
501 extern void zio_resubmit_stage_async(void *);
502 
503 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
504     uint64_t offset, void *data, uint64_t size, int type, int priority,
505     enum zio_flag flags, zio_done_func_t *done, void *private);
506 
507 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
508     void *data, uint64_t size, int type, int priority,
509     enum zio_flag flags, zio_done_func_t *done, void *private);
510 
511 extern void zio_vdev_io_bypass(zio_t *zio);
512 extern void zio_vdev_io_reissue(zio_t *zio);
513 extern void zio_vdev_io_redone(zio_t *zio);
514 
515 extern void zio_checksum_verified(zio_t *zio);
516 extern int zio_worst_error(int e1, int e2);
517 
518 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
519     enum zio_checksum parent);
520 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
521     enum zio_checksum child, enum zio_checksum parent);
522 extern enum zio_compress zio_compress_select(enum zio_compress child,
523     enum zio_compress parent);
524 
525 extern void zio_suspend(spa_t *spa, zio_t *zio);
526 extern int zio_resume(spa_t *spa);
527 extern void zio_resume_wait(spa_t *spa);
528 
529 /*
530  * Initial setup and teardown.
531  */
532 extern void zio_init(void);
533 extern void zio_fini(void);
534 
535 /*
536  * Fault injection
537  */
538 struct zinject_record;
539 extern uint32_t zio_injection_enabled;
540 extern int zio_inject_fault(char *name, int flags, int *id,
541     struct zinject_record *record);
542 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
543     struct zinject_record *record);
544 extern int zio_clear_fault(int id);
545 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
546 extern int zio_handle_fault_injection(zio_t *zio, int error);
547 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
548 extern int zio_handle_label_injection(zio_t *zio, int error);
549 extern void zio_handle_ignored_writes(zio_t *zio);
550 extern uint64_t zio_handle_io_delay(zio_t *zio);
551 
552 /*
553  * Checksum ereport functions
554  */
555 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
556     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
557 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
558     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
559 
560 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
561 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
562 
563 /* If we have the good data in hand, this function can be used */
564 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
565     struct zio *zio, uint64_t offset, uint64_t length,
566     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
567 
568 /* Called from spa_sync(), but primarily an injection handler */
569 extern void spa_handle_ignored_writes(spa_t *spa);
570 
571 /* zbookmark functions */
572 boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
573     const zbookmark_t *zb1, const zbookmark_t *zb2);
574 
575 #ifdef	__cplusplus
576 }
577 #endif
578 
579 #endif	/* _ZIO_H */
580