xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/zio.h (revision 80901aea8e78a2c20751f61f01bebd1d5b5c2ba5)
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 	ZIO_FLAG_NOPWRITE	= 1 << 25,
192 	ZIO_FLAG_REEXECUTED	= 1 << 26,
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 	boolean_t		zp_dedup;
291 	boolean_t		zp_dedup_verify;
292 	boolean_t		zp_nopwrite;
293 } zio_prop_t;
294 
295 typedef struct zio_cksum_report zio_cksum_report_t;
296 
297 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
298     const void *good_data);
299 typedef void zio_cksum_free_f(void *cbdata, size_t size);
300 
301 struct zio_bad_cksum;				/* defined in zio_checksum.h */
302 struct dnode_phys;
303 
304 struct zio_cksum_report {
305 	struct zio_cksum_report *zcr_next;
306 	nvlist_t		*zcr_ereport;
307 	nvlist_t		*zcr_detector;
308 	void			*zcr_cbdata;
309 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
310 	uint64_t		zcr_align;
311 	uint64_t		zcr_length;
312 	zio_cksum_finish_f	*zcr_finish;
313 	zio_cksum_free_f	*zcr_free;
314 
315 	/* internal use only */
316 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
317 };
318 
319 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
320     void *arg);
321 
322 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
323 
324 typedef struct zio_vsd_ops {
325 	zio_done_func_t		*vsd_free;
326 	zio_vsd_cksum_report_f	*vsd_cksum_report;
327 } zio_vsd_ops_t;
328 
329 typedef struct zio_gang_node {
330 	zio_gbh_phys_t		*gn_gbh;
331 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
332 } zio_gang_node_t;
333 
334 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
335     zio_gang_node_t *gn, void *data);
336 
337 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
338 
339 typedef struct zio_transform {
340 	void			*zt_orig_data;
341 	uint64_t		zt_orig_size;
342 	uint64_t		zt_bufsize;
343 	zio_transform_func_t	*zt_transform;
344 	struct zio_transform	*zt_next;
345 } zio_transform_t;
346 
347 typedef int zio_pipe_stage_t(zio_t *zio);
348 
349 /*
350  * The io_reexecute flags are distinct from io_flags because the child must
351  * be able to propagate them to the parent.  The normal io_flags are local
352  * to the zio, not protected by any lock, and not modifiable by children;
353  * the reexecute flags are protected by io_lock, modifiable by children,
354  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
355  */
356 #define	ZIO_REEXECUTE_NOW	0x01
357 #define	ZIO_REEXECUTE_SUSPEND	0x02
358 
359 typedef struct zio_link {
360 	zio_t		*zl_parent;
361 	zio_t		*zl_child;
362 	list_node_t	zl_parent_node;
363 	list_node_t	zl_child_node;
364 } zio_link_t;
365 
366 struct zio {
367 	/* Core information about this I/O */
368 	zbookmark_t	io_bookmark;
369 	zio_prop_t	io_prop;
370 	zio_type_t	io_type;
371 	enum zio_child	io_child_type;
372 	int		io_cmd;
373 	uint8_t		io_priority;
374 	uint8_t		io_reexecute;
375 	uint8_t		io_state[ZIO_WAIT_TYPES];
376 	uint64_t	io_txg;
377 	spa_t		*io_spa;
378 	blkptr_t	*io_bp;
379 	blkptr_t	*io_bp_override;
380 	blkptr_t	io_bp_copy;
381 	list_t		io_parent_list;
382 	list_t		io_child_list;
383 	zio_link_t	*io_walk_link;
384 	zio_t		*io_logical;
385 	zio_transform_t *io_transform_stack;
386 
387 	/* Callback info */
388 	zio_done_func_t	*io_ready;
389 	zio_done_func_t	*io_done;
390 	void		*io_private;
391 	int64_t		io_prev_space_delta;	/* DMU private */
392 	blkptr_t	io_bp_orig;
393 
394 	/* Data represented by this I/O */
395 	void		*io_data;
396 	void		*io_orig_data;
397 	uint64_t	io_size;
398 	uint64_t	io_orig_size;
399 
400 	/* Stuff for the vdev stack */
401 	vdev_t		*io_vd;
402 	void		*io_vsd;
403 	const zio_vsd_ops_t *io_vsd_ops;
404 
405 	uint64_t	io_offset;
406 	uint64_t	io_deadline;
407 	uint64_t	io_timestamp;
408 	avl_node_t	io_offset_node;
409 	avl_node_t	io_deadline_node;
410 	avl_tree_t	*io_vdev_tree;
411 
412 	/* Internal pipeline state */
413 	enum zio_flag	io_flags;
414 	enum zio_stage	io_stage;
415 	enum zio_stage	io_pipeline;
416 	enum zio_flag	io_orig_flags;
417 	enum zio_stage	io_orig_stage;
418 	enum zio_stage	io_orig_pipeline;
419 	int		io_error;
420 	int		io_child_error[ZIO_CHILD_TYPES];
421 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
422 	uint64_t	io_child_count;
423 	uint64_t	io_parent_count;
424 	uint64_t	*io_stall;
425 	zio_t		*io_gang_leader;
426 	zio_gang_node_t	*io_gang_tree;
427 	void		*io_executor;
428 	void		*io_waiter;
429 	kmutex_t	io_lock;
430 	kcondvar_t	io_cv;
431 
432 	/* FMA state */
433 	zio_cksum_report_t *io_cksum_report;
434 	uint64_t	io_ena;
435 
436 	/* Taskq dispatching state */
437 	taskq_ent_t	io_tqent;
438 };
439 
440 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
441     zio_done_func_t *done, void *private, enum zio_flag flags);
442 
443 extern zio_t *zio_root(spa_t *spa,
444     zio_done_func_t *done, void *private, enum zio_flag flags);
445 
446 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
447     uint64_t size, zio_done_func_t *done, void *private,
448     int priority, enum zio_flag flags, const zbookmark_t *zb);
449 
450 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
451     void *data, uint64_t size, const zio_prop_t *zp,
452     zio_done_func_t *ready, zio_done_func_t *done, void *private,
453     int priority, enum zio_flag flags, const zbookmark_t *zb);
454 
455 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
456     void *data, uint64_t size, zio_done_func_t *done, void *private,
457     int priority, enum zio_flag flags, zbookmark_t *zb);
458 
459 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
460     boolean_t nopwrite);
461 
462 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
463 
464 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
465     const blkptr_t *bp,
466     zio_done_func_t *done, void *private, enum zio_flag flags);
467 
468 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
469     zio_done_func_t *done, void *private, int priority, enum zio_flag flags);
470 
471 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
472     uint64_t size, void *data, int checksum,
473     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
474     boolean_t labels);
475 
476 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
477     uint64_t size, void *data, int checksum,
478     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
479     boolean_t labels);
480 
481 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
482     const blkptr_t *bp, enum zio_flag flags);
483 
484 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
485     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
486 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
487 extern void zio_flush(zio_t *zio, vdev_t *vd);
488 extern void zio_shrink(zio_t *zio, uint64_t size);
489 
490 extern int zio_wait(zio_t *zio);
491 extern void zio_nowait(zio_t *zio);
492 extern void zio_execute(zio_t *zio);
493 extern void zio_interrupt(zio_t *zio);
494 
495 extern zio_t *zio_walk_parents(zio_t *cio);
496 extern zio_t *zio_walk_children(zio_t *pio);
497 extern zio_t *zio_unique_parent(zio_t *cio);
498 extern void zio_add_child(zio_t *pio, zio_t *cio);
499 
500 extern void *zio_buf_alloc(size_t size);
501 extern void zio_buf_free(void *buf, size_t size);
502 extern void *zio_data_buf_alloc(size_t size);
503 extern void zio_data_buf_free(void *buf, size_t size);
504 
505 extern void zio_resubmit_stage_async(void *);
506 
507 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
508     uint64_t offset, void *data, uint64_t size, int type, int priority,
509     enum zio_flag flags, zio_done_func_t *done, void *private);
510 
511 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
512     void *data, uint64_t size, int type, int priority,
513     enum zio_flag flags, zio_done_func_t *done, void *private);
514 
515 extern void zio_vdev_io_bypass(zio_t *zio);
516 extern void zio_vdev_io_reissue(zio_t *zio);
517 extern void zio_vdev_io_redone(zio_t *zio);
518 
519 extern void zio_checksum_verified(zio_t *zio);
520 extern int zio_worst_error(int e1, int e2);
521 
522 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
523     enum zio_checksum parent);
524 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
525     enum zio_checksum child, enum zio_checksum parent);
526 extern enum zio_compress zio_compress_select(enum zio_compress child,
527     enum zio_compress parent);
528 
529 extern void zio_suspend(spa_t *spa, zio_t *zio);
530 extern int zio_resume(spa_t *spa);
531 extern void zio_resume_wait(spa_t *spa);
532 
533 /*
534  * Initial setup and teardown.
535  */
536 extern void zio_init(void);
537 extern void zio_fini(void);
538 
539 /*
540  * Fault injection
541  */
542 struct zinject_record;
543 extern uint32_t zio_injection_enabled;
544 extern int zio_inject_fault(char *name, int flags, int *id,
545     struct zinject_record *record);
546 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
547     struct zinject_record *record);
548 extern int zio_clear_fault(int id);
549 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
550 extern int zio_handle_fault_injection(zio_t *zio, int error);
551 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
552 extern int zio_handle_label_injection(zio_t *zio, int error);
553 extern void zio_handle_ignored_writes(zio_t *zio);
554 extern uint64_t zio_handle_io_delay(zio_t *zio);
555 
556 /*
557  * Checksum ereport functions
558  */
559 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
560     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
561 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
562     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
563 
564 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
565 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
566 
567 /* If we have the good data in hand, this function can be used */
568 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
569     struct zio *zio, uint64_t offset, uint64_t length,
570     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
571 
572 /* Called from spa_sync(), but primarily an injection handler */
573 extern void spa_handle_ignored_writes(spa_t *spa);
574 
575 /* zbookmark functions */
576 boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
577     const zbookmark_t *zb1, const zbookmark_t *zb2);
578 
579 #ifdef	__cplusplus
580 }
581 #endif
582 
583 #endif	/* _ZIO_H */
584