xref: /titanic_50/usr/src/uts/common/fs/zfs/sys/zio.h (revision 7014882c6a3672fd0e5d60200af8643ae53c5928)
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  */
25 /*
26  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
27  * Copyright (c) 2012 by Delphix. 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_FUNCTIONS
84 };
85 
86 #define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_4
87 #define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
88 
89 #define	ZIO_CHECKSUM_MASK	0xffULL
90 #define	ZIO_CHECKSUM_VERIFY	(1 << 8)
91 
92 #define	ZIO_DEDUPCHECKSUM	ZIO_CHECKSUM_SHA256
93 #define	ZIO_DEDUPDITTO_MIN	100
94 
95 enum zio_compress {
96 	ZIO_COMPRESS_INHERIT = 0,
97 	ZIO_COMPRESS_ON,
98 	ZIO_COMPRESS_OFF,
99 	ZIO_COMPRESS_LZJB,
100 	ZIO_COMPRESS_EMPTY,
101 	ZIO_COMPRESS_GZIP_1,
102 	ZIO_COMPRESS_GZIP_2,
103 	ZIO_COMPRESS_GZIP_3,
104 	ZIO_COMPRESS_GZIP_4,
105 	ZIO_COMPRESS_GZIP_5,
106 	ZIO_COMPRESS_GZIP_6,
107 	ZIO_COMPRESS_GZIP_7,
108 	ZIO_COMPRESS_GZIP_8,
109 	ZIO_COMPRESS_GZIP_9,
110 	ZIO_COMPRESS_ZLE,
111 	ZIO_COMPRESS_FUNCTIONS
112 };
113 
114 #define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
115 #define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
116 
117 #define	BOOTFS_COMPRESS_VALID(compress)			\
118 	((compress) == ZIO_COMPRESS_LZJB ||		\
119 	((compress) == ZIO_COMPRESS_ON &&		\
120 	ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) ||	\
121 	(compress) == ZIO_COMPRESS_OFF)
122 
123 #define	ZIO_FAILURE_MODE_WAIT		0
124 #define	ZIO_FAILURE_MODE_CONTINUE	1
125 #define	ZIO_FAILURE_MODE_PANIC		2
126 
127 #define	ZIO_PRIORITY_NOW		(zio_priority_table[0])
128 #define	ZIO_PRIORITY_SYNC_READ		(zio_priority_table[1])
129 #define	ZIO_PRIORITY_SYNC_WRITE		(zio_priority_table[2])
130 #define	ZIO_PRIORITY_LOG_WRITE		(zio_priority_table[3])
131 #define	ZIO_PRIORITY_CACHE_FILL		(zio_priority_table[4])
132 #define	ZIO_PRIORITY_AGG		(zio_priority_table[5])
133 #define	ZIO_PRIORITY_FREE		(zio_priority_table[6])
134 #define	ZIO_PRIORITY_ASYNC_WRITE	(zio_priority_table[7])
135 #define	ZIO_PRIORITY_ASYNC_READ		(zio_priority_table[8])
136 #define	ZIO_PRIORITY_RESILVER		(zio_priority_table[9])
137 #define	ZIO_PRIORITY_SCRUB		(zio_priority_table[10])
138 #define	ZIO_PRIORITY_DDT_PREFETCH	(zio_priority_table[11])
139 #define	ZIO_PRIORITY_TABLE_SIZE		12
140 
141 #define	ZIO_PIPELINE_CONTINUE		0x100
142 #define	ZIO_PIPELINE_STOP		0x101
143 
144 enum zio_flag {
145 	/*
146 	 * Flags inherited by gang, ddt, and vdev children,
147 	 * and that must be equal for two zios to aggregate
148 	 */
149 	ZIO_FLAG_DONT_AGGREGATE	= 1 << 0,
150 	ZIO_FLAG_IO_REPAIR	= 1 << 1,
151 	ZIO_FLAG_SELF_HEAL	= 1 << 2,
152 	ZIO_FLAG_RESILVER	= 1 << 3,
153 	ZIO_FLAG_SCRUB		= 1 << 4,
154 	ZIO_FLAG_SCAN_THREAD	= 1 << 5,
155 
156 #define	ZIO_FLAG_AGG_INHERIT	(ZIO_FLAG_CANFAIL - 1)
157 
158 	/*
159 	 * Flags inherited by ddt, gang, and vdev children.
160 	 */
161 	ZIO_FLAG_CANFAIL	= 1 << 6,	/* must be first for INHERIT */
162 	ZIO_FLAG_SPECULATIVE	= 1 << 7,
163 	ZIO_FLAG_CONFIG_WRITER	= 1 << 8,
164 	ZIO_FLAG_DONT_RETRY	= 1 << 9,
165 	ZIO_FLAG_DONT_CACHE	= 1 << 10,
166 	ZIO_FLAG_NODATA		= 1 << 11,
167 	ZIO_FLAG_INDUCE_DAMAGE	= 1 << 12,
168 
169 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
170 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
171 
172 	/*
173 	 * Flags inherited by vdev children.
174 	 */
175 	ZIO_FLAG_IO_RETRY	= 1 << 13,	/* must be first for INHERIT */
176 	ZIO_FLAG_PROBE		= 1 << 14,
177 	ZIO_FLAG_TRYHARD	= 1 << 15,
178 	ZIO_FLAG_OPTIONAL	= 1 << 16,
179 
180 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
181 
182 	/*
183 	 * Flags not inherited by any children.
184 	 */
185 	ZIO_FLAG_DONT_QUEUE	= 1 << 17,	/* must be first for INHERIT */
186 	ZIO_FLAG_DONT_PROPAGATE	= 1 << 18,
187 	ZIO_FLAG_IO_BYPASS	= 1 << 19,
188 	ZIO_FLAG_IO_REWRITE	= 1 << 20,
189 	ZIO_FLAG_RAW		= 1 << 21,
190 	ZIO_FLAG_GANG_CHILD	= 1 << 22,
191 	ZIO_FLAG_DDT_CHILD	= 1 << 23,
192 	ZIO_FLAG_GODFATHER	= 1 << 24
193 };
194 
195 #define	ZIO_FLAG_MUSTSUCCEED		0
196 
197 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
198 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
199 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
200 
201 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
202 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
203 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
204 
205 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
206 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
207 	ZIO_FLAG_CANFAIL)
208 
209 enum zio_child {
210 	ZIO_CHILD_VDEV = 0,
211 	ZIO_CHILD_GANG,
212 	ZIO_CHILD_DDT,
213 	ZIO_CHILD_LOGICAL,
214 	ZIO_CHILD_TYPES
215 };
216 
217 enum zio_wait_type {
218 	ZIO_WAIT_READY = 0,
219 	ZIO_WAIT_DONE,
220 	ZIO_WAIT_TYPES
221 };
222 
223 /*
224  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
225  * graveyard) to indicate checksum errors and fragmentation.
226  */
227 #define	ECKSUM	EBADE
228 #define	EFRAGS	EBADR
229 
230 typedef void zio_done_func_t(zio_t *zio);
231 
232 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
233 extern char *zio_type_name[ZIO_TYPES];
234 
235 /*
236  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
237  * identifies any block in the pool.  By convention, the meta-objset (MOS)
238  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
239  * except root blocks and ZIL blocks, which are defined as follows:
240  *
241  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
242  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
243  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
244  *
245  * Note: this structure is called a bookmark because its original purpose
246  * was to remember where to resume a pool-wide traverse.
247  *
248  * Note: this structure is passed between userland and the kernel.
249  * Therefore it must not change size or alignment between 32/64 bit
250  * compilation options.
251  */
252 typedef struct zbookmark {
253 	uint64_t	zb_objset;
254 	uint64_t	zb_object;
255 	int64_t		zb_level;
256 	uint64_t	zb_blkid;
257 } zbookmark_t;
258 
259 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
260 {                                                       \
261 	(zb)->zb_objset = objset;                       \
262 	(zb)->zb_object = object;                       \
263 	(zb)->zb_level = level;                         \
264 	(zb)->zb_blkid = blkid;                         \
265 }
266 
267 #define	ZB_DESTROYED_OBJSET	(-1ULL)
268 
269 #define	ZB_ROOT_OBJECT		(0ULL)
270 #define	ZB_ROOT_LEVEL		(-1LL)
271 #define	ZB_ROOT_BLKID		(0ULL)
272 
273 #define	ZB_ZIL_OBJECT		(0ULL)
274 #define	ZB_ZIL_LEVEL		(-2LL)
275 
276 #define	ZB_IS_ZERO(zb)						\
277 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
278 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
279 #define	ZB_IS_ROOT(zb)				\
280 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
281 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
282 	(zb)->zb_blkid == ZB_ROOT_BLKID)
283 
284 typedef struct zio_prop {
285 	enum zio_checksum	zp_checksum;
286 	enum zio_compress	zp_compress;
287 	dmu_object_type_t	zp_type;
288 	uint8_t			zp_level;
289 	uint8_t			zp_copies;
290 	uint8_t			zp_dedup;
291 	uint8_t			zp_dedup_verify;
292 } zio_prop_t;
293 
294 typedef struct zio_cksum_report zio_cksum_report_t;
295 
296 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
297     const void *good_data);
298 typedef void zio_cksum_free_f(void *cbdata, size_t size);
299 
300 struct zio_bad_cksum;				/* defined in zio_checksum.h */
301 struct dnode_phys;
302 
303 struct zio_cksum_report {
304 	struct zio_cksum_report *zcr_next;
305 	nvlist_t		*zcr_ereport;
306 	nvlist_t		*zcr_detector;
307 	void			*zcr_cbdata;
308 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
309 	uint64_t		zcr_align;
310 	uint64_t		zcr_length;
311 	zio_cksum_finish_f	*zcr_finish;
312 	zio_cksum_free_f	*zcr_free;
313 
314 	/* internal use only */
315 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
316 };
317 
318 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
319     void *arg);
320 
321 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
322 
323 typedef struct zio_vsd_ops {
324 	zio_done_func_t		*vsd_free;
325 	zio_vsd_cksum_report_f	*vsd_cksum_report;
326 } zio_vsd_ops_t;
327 
328 typedef struct zio_gang_node {
329 	zio_gbh_phys_t		*gn_gbh;
330 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
331 } zio_gang_node_t;
332 
333 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
334     zio_gang_node_t *gn, void *data);
335 
336 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
337 
338 typedef struct zio_transform {
339 	void			*zt_orig_data;
340 	uint64_t		zt_orig_size;
341 	uint64_t		zt_bufsize;
342 	zio_transform_func_t	*zt_transform;
343 	struct zio_transform	*zt_next;
344 } zio_transform_t;
345 
346 typedef int zio_pipe_stage_t(zio_t *zio);
347 
348 /*
349  * The io_reexecute flags are distinct from io_flags because the child must
350  * be able to propagate them to the parent.  The normal io_flags are local
351  * to the zio, not protected by any lock, and not modifiable by children;
352  * the reexecute flags are protected by io_lock, modifiable by children,
353  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
354  */
355 #define	ZIO_REEXECUTE_NOW	0x01
356 #define	ZIO_REEXECUTE_SUSPEND	0x02
357 
358 typedef struct zio_link {
359 	zio_t		*zl_parent;
360 	zio_t		*zl_child;
361 	list_node_t	zl_parent_node;
362 	list_node_t	zl_child_node;
363 } zio_link_t;
364 
365 struct zio {
366 	/* Core information about this I/O */
367 	zbookmark_t	io_bookmark;
368 	zio_prop_t	io_prop;
369 	zio_type_t	io_type;
370 	enum zio_child	io_child_type;
371 	int		io_cmd;
372 	uint8_t		io_priority;
373 	uint8_t		io_reexecute;
374 	uint8_t		io_state[ZIO_WAIT_TYPES];
375 	uint64_t	io_txg;
376 	spa_t		*io_spa;
377 	blkptr_t	*io_bp;
378 	blkptr_t	*io_bp_override;
379 	blkptr_t	io_bp_copy;
380 	list_t		io_parent_list;
381 	list_t		io_child_list;
382 	zio_link_t	*io_walk_link;
383 	zio_t		*io_logical;
384 	zio_transform_t *io_transform_stack;
385 
386 	/* Callback info */
387 	zio_done_func_t	*io_ready;
388 	zio_done_func_t	*io_done;
389 	void		*io_private;
390 	int64_t		io_prev_space_delta;	/* DMU private */
391 	blkptr_t	io_bp_orig;
392 
393 	/* Data represented by this I/O */
394 	void		*io_data;
395 	void		*io_orig_data;
396 	uint64_t	io_size;
397 	uint64_t	io_orig_size;
398 
399 	/* Stuff for the vdev stack */
400 	vdev_t		*io_vd;
401 	void		*io_vsd;
402 	const zio_vsd_ops_t *io_vsd_ops;
403 
404 	uint64_t	io_offset;
405 	uint64_t	io_deadline;
406 	avl_node_t	io_offset_node;
407 	avl_node_t	io_deadline_node;
408 	avl_tree_t	*io_vdev_tree;
409 
410 	/* Internal pipeline state */
411 	enum zio_flag	io_flags;
412 	enum zio_stage	io_stage;
413 	enum zio_stage	io_pipeline;
414 	enum zio_flag	io_orig_flags;
415 	enum zio_stage	io_orig_stage;
416 	enum zio_stage	io_orig_pipeline;
417 	int		io_error;
418 	int		io_child_error[ZIO_CHILD_TYPES];
419 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
420 	uint64_t	io_child_count;
421 	uint64_t	io_parent_count;
422 	uint64_t	*io_stall;
423 	zio_t		*io_gang_leader;
424 	zio_gang_node_t	*io_gang_tree;
425 	void		*io_executor;
426 	void		*io_waiter;
427 	kmutex_t	io_lock;
428 	kcondvar_t	io_cv;
429 
430 	/* FMA state */
431 	zio_cksum_report_t *io_cksum_report;
432 	uint64_t	io_ena;
433 
434 	/* Taskq dispatching state */
435 	taskq_ent_t	io_tqent;
436 };
437 
438 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
439     zio_done_func_t *done, void *private, enum zio_flag flags);
440 
441 extern zio_t *zio_root(spa_t *spa,
442     zio_done_func_t *done, void *private, enum zio_flag flags);
443 
444 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
445     uint64_t size, zio_done_func_t *done, void *private,
446     int priority, enum zio_flag flags, const zbookmark_t *zb);
447 
448 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
449     void *data, uint64_t size, const zio_prop_t *zp,
450     zio_done_func_t *ready, zio_done_func_t *done, void *private,
451     int priority, enum zio_flag flags, const zbookmark_t *zb);
452 
453 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
454     void *data, uint64_t size, zio_done_func_t *done, void *private,
455     int priority, enum zio_flag flags, zbookmark_t *zb);
456 
457 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies);
458 
459 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
460 
461 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
462     const blkptr_t *bp,
463     zio_done_func_t *done, void *private, enum zio_flag flags);
464 
465 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
466     zio_done_func_t *done, void *private, int priority, enum zio_flag flags);
467 
468 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
469     uint64_t size, void *data, int checksum,
470     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
471     boolean_t labels);
472 
473 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
474     uint64_t size, void *data, int checksum,
475     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
476     boolean_t labels);
477 
478 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
479     const blkptr_t *bp, enum zio_flag flags);
480 
481 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
482     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
483 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
484 extern void zio_flush(zio_t *zio, vdev_t *vd);
485 extern void zio_shrink(zio_t *zio, uint64_t size);
486 
487 extern int zio_wait(zio_t *zio);
488 extern void zio_nowait(zio_t *zio);
489 extern void zio_execute(zio_t *zio);
490 extern void zio_interrupt(zio_t *zio);
491 
492 extern zio_t *zio_walk_parents(zio_t *cio);
493 extern zio_t *zio_walk_children(zio_t *pio);
494 extern zio_t *zio_unique_parent(zio_t *cio);
495 extern void zio_add_child(zio_t *pio, zio_t *cio);
496 
497 extern void *zio_buf_alloc(size_t size);
498 extern void zio_buf_free(void *buf, size_t size);
499 extern void *zio_data_buf_alloc(size_t size);
500 extern void zio_data_buf_free(void *buf, size_t size);
501 
502 extern void zio_resubmit_stage_async(void *);
503 
504 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
505     uint64_t offset, void *data, uint64_t size, int type, int priority,
506     enum zio_flag flags, zio_done_func_t *done, void *private);
507 
508 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
509     void *data, uint64_t size, int type, int priority,
510     enum zio_flag flags, zio_done_func_t *done, void *private);
511 
512 extern void zio_vdev_io_bypass(zio_t *zio);
513 extern void zio_vdev_io_reissue(zio_t *zio);
514 extern void zio_vdev_io_redone(zio_t *zio);
515 
516 extern void zio_checksum_verified(zio_t *zio);
517 extern int zio_worst_error(int e1, int e2);
518 
519 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
520     enum zio_checksum parent);
521 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
522     enum zio_checksum child, enum zio_checksum parent);
523 extern enum zio_compress zio_compress_select(enum zio_compress child,
524     enum zio_compress parent);
525 
526 extern void zio_suspend(spa_t *spa, zio_t *zio);
527 extern int zio_resume(spa_t *spa);
528 extern void zio_resume_wait(spa_t *spa);
529 
530 /*
531  * Initial setup and teardown.
532  */
533 extern void zio_init(void);
534 extern void zio_fini(void);
535 
536 /*
537  * Fault injection
538  */
539 struct zinject_record;
540 extern uint32_t zio_injection_enabled;
541 extern int zio_inject_fault(char *name, int flags, int *id,
542     struct zinject_record *record);
543 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
544     struct zinject_record *record);
545 extern int zio_clear_fault(int id);
546 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
547 extern int zio_handle_fault_injection(zio_t *zio, int error);
548 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
549 extern int zio_handle_label_injection(zio_t *zio, int error);
550 extern void zio_handle_ignored_writes(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