xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/zio.h (revision 738f37bc3dcd61e8a893af0f2d466d76690b70ec)
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 /* 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 enum zio_flag {
155 	/*
156 	 * Flags inherited by gang, ddt, and vdev children,
157 	 * and that must be equal for two zios to aggregate
158 	 */
159 	ZIO_FLAG_DONT_AGGREGATE	= 1 << 0,
160 	ZIO_FLAG_IO_REPAIR	= 1 << 1,
161 	ZIO_FLAG_SELF_HEAL	= 1 << 2,
162 	ZIO_FLAG_RESILVER	= 1 << 3,
163 	ZIO_FLAG_SCRUB		= 1 << 4,
164 	ZIO_FLAG_SCAN_THREAD	= 1 << 5,
165 	ZIO_FLAG_PHYSICAL	= 1 << 6,
166 
167 #define	ZIO_FLAG_AGG_INHERIT	(ZIO_FLAG_CANFAIL - 1)
168 
169 	/*
170 	 * Flags inherited by ddt, gang, and vdev children.
171 	 */
172 	ZIO_FLAG_CANFAIL	= 1 << 7,	/* must be first for INHERIT */
173 	ZIO_FLAG_SPECULATIVE	= 1 << 8,
174 	ZIO_FLAG_CONFIG_WRITER	= 1 << 9,
175 	ZIO_FLAG_DONT_RETRY	= 1 << 10,
176 	ZIO_FLAG_DONT_CACHE	= 1 << 11,
177 	ZIO_FLAG_NODATA		= 1 << 12,
178 	ZIO_FLAG_INDUCE_DAMAGE	= 1 << 13,
179 
180 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
181 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
182 
183 	/*
184 	 * Flags inherited by vdev children.
185 	 */
186 	ZIO_FLAG_IO_RETRY	= 1 << 14,	/* must be first for INHERIT */
187 	ZIO_FLAG_PROBE		= 1 << 15,
188 	ZIO_FLAG_TRYHARD	= 1 << 16,
189 	ZIO_FLAG_OPTIONAL	= 1 << 17,
190 
191 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
192 
193 	/*
194 	 * Flags not inherited by any children.
195 	 */
196 	ZIO_FLAG_DONT_QUEUE	= 1 << 18,	/* must be first for INHERIT */
197 	ZIO_FLAG_DONT_PROPAGATE	= 1 << 19,
198 	ZIO_FLAG_IO_BYPASS	= 1 << 20,
199 	ZIO_FLAG_IO_REWRITE	= 1 << 21,
200 	ZIO_FLAG_RAW		= 1 << 22,
201 	ZIO_FLAG_GANG_CHILD	= 1 << 23,
202 	ZIO_FLAG_DDT_CHILD	= 1 << 24,
203 	ZIO_FLAG_GODFATHER	= 1 << 25,
204 	ZIO_FLAG_NOPWRITE	= 1 << 26,
205 	ZIO_FLAG_REEXECUTED	= 1 << 27,
206 	ZIO_FLAG_DELEGATED	= 1 << 28,
207 };
208 
209 #define	ZIO_FLAG_MUSTSUCCEED		0
210 
211 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
212 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
213 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
214 
215 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
216 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
217 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
218 
219 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
220 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
221 	ZIO_FLAG_CANFAIL)
222 
223 enum zio_child {
224 	ZIO_CHILD_VDEV = 0,
225 	ZIO_CHILD_GANG,
226 	ZIO_CHILD_DDT,
227 	ZIO_CHILD_LOGICAL,
228 	ZIO_CHILD_TYPES
229 };
230 
231 enum zio_wait_type {
232 	ZIO_WAIT_READY = 0,
233 	ZIO_WAIT_DONE,
234 	ZIO_WAIT_TYPES
235 };
236 
237 /*
238  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
239  * graveyard) to indicate checksum errors and fragmentation.
240  */
241 #define	ECKSUM	EBADE
242 #define	EFRAGS	EBADR
243 
244 typedef void zio_done_func_t(zio_t *zio);
245 
246 extern const char *zio_type_name[ZIO_TYPES];
247 
248 /*
249  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
250  * identifies any block in the pool.  By convention, the meta-objset (MOS)
251  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
252  * except root blocks and ZIL blocks, which are defined as follows:
253  *
254  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
255  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
256  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
257  *
258  * Note: this structure is called a bookmark because its original purpose
259  * was to remember where to resume a pool-wide traverse.
260  *
261  * Note: this structure is passed between userland and the kernel, and is
262  * stored on disk (by virtue of being incorporated into other on-disk
263  * structures, e.g. dsl_scan_phys_t).
264  */
265 typedef struct zbookmark_phys {
266 	uint64_t	zb_objset;
267 	uint64_t	zb_object;
268 	int64_t		zb_level;
269 	uint64_t	zb_blkid;
270 } zbookmark_phys_t;
271 
272 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
273 {                                                       \
274 	(zb)->zb_objset = objset;                       \
275 	(zb)->zb_object = object;                       \
276 	(zb)->zb_level = level;                         \
277 	(zb)->zb_blkid = blkid;                         \
278 }
279 
280 #define	ZB_DESTROYED_OBJSET	(-1ULL)
281 
282 #define	ZB_ROOT_OBJECT		(0ULL)
283 #define	ZB_ROOT_LEVEL		(-1LL)
284 #define	ZB_ROOT_BLKID		(0ULL)
285 
286 #define	ZB_ZIL_OBJECT		(0ULL)
287 #define	ZB_ZIL_LEVEL		(-2LL)
288 
289 #define	ZB_IS_ZERO(zb)						\
290 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
291 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
292 #define	ZB_IS_ROOT(zb)				\
293 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
294 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
295 	(zb)->zb_blkid == ZB_ROOT_BLKID)
296 
297 typedef struct zio_prop {
298 	enum zio_checksum	zp_checksum;
299 	enum zio_compress	zp_compress;
300 	dmu_object_type_t	zp_type;
301 	uint8_t			zp_level;
302 	uint8_t			zp_copies;
303 	boolean_t		zp_dedup;
304 	boolean_t		zp_dedup_verify;
305 	boolean_t		zp_nopwrite;
306 } zio_prop_t;
307 
308 typedef struct zio_cksum_report zio_cksum_report_t;
309 
310 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
311     const void *good_data);
312 typedef void zio_cksum_free_f(void *cbdata, size_t size);
313 
314 struct zio_bad_cksum;				/* defined in zio_checksum.h */
315 struct dnode_phys;
316 
317 struct zio_cksum_report {
318 	struct zio_cksum_report *zcr_next;
319 	nvlist_t		*zcr_ereport;
320 	nvlist_t		*zcr_detector;
321 	void			*zcr_cbdata;
322 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
323 	uint64_t		zcr_align;
324 	uint64_t		zcr_length;
325 	zio_cksum_finish_f	*zcr_finish;
326 	zio_cksum_free_f	*zcr_free;
327 
328 	/* internal use only */
329 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
330 };
331 
332 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
333     void *arg);
334 
335 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
336 
337 typedef struct zio_vsd_ops {
338 	zio_done_func_t		*vsd_free;
339 	zio_vsd_cksum_report_f	*vsd_cksum_report;
340 } zio_vsd_ops_t;
341 
342 typedef struct zio_gang_node {
343 	zio_gbh_phys_t		*gn_gbh;
344 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
345 } zio_gang_node_t;
346 
347 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
348     zio_gang_node_t *gn, void *data);
349 
350 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
351 
352 typedef struct zio_transform {
353 	void			*zt_orig_data;
354 	uint64_t		zt_orig_size;
355 	uint64_t		zt_bufsize;
356 	zio_transform_func_t	*zt_transform;
357 	struct zio_transform	*zt_next;
358 } zio_transform_t;
359 
360 typedef int zio_pipe_stage_t(zio_t *zio);
361 
362 /*
363  * The io_reexecute flags are distinct from io_flags because the child must
364  * be able to propagate them to the parent.  The normal io_flags are local
365  * to the zio, not protected by any lock, and not modifiable by children;
366  * the reexecute flags are protected by io_lock, modifiable by children,
367  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
368  */
369 #define	ZIO_REEXECUTE_NOW	0x01
370 #define	ZIO_REEXECUTE_SUSPEND	0x02
371 
372 typedef struct zio_link {
373 	zio_t		*zl_parent;
374 	zio_t		*zl_child;
375 	list_node_t	zl_parent_node;
376 	list_node_t	zl_child_node;
377 } zio_link_t;
378 
379 struct zio {
380 	/* Core information about this I/O */
381 	zbookmark_phys_t	io_bookmark;
382 	zio_prop_t	io_prop;
383 	zio_type_t	io_type;
384 	enum zio_child	io_child_type;
385 	int		io_cmd;
386 	zio_priority_t	io_priority;
387 	uint8_t		io_reexecute;
388 	uint8_t		io_state[ZIO_WAIT_TYPES];
389 	uint64_t	io_txg;
390 	spa_t		*io_spa;
391 	blkptr_t	*io_bp;
392 	blkptr_t	*io_bp_override;
393 	blkptr_t	io_bp_copy;
394 	list_t		io_parent_list;
395 	list_t		io_child_list;
396 	zio_link_t	*io_walk_link;
397 	zio_t		*io_logical;
398 	zio_transform_t *io_transform_stack;
399 
400 	/* Callback info */
401 	zio_done_func_t	*io_ready;
402 	zio_done_func_t	*io_physdone;
403 	zio_done_func_t	*io_done;
404 	void		*io_private;
405 	int64_t		io_prev_space_delta;	/* DMU private */
406 	blkptr_t	io_bp_orig;
407 
408 	/* Data represented by this I/O */
409 	void		*io_data;
410 	void		*io_orig_data;
411 	uint64_t	io_size;
412 	uint64_t	io_orig_size;
413 
414 	/* Stuff for the vdev stack */
415 	vdev_t		*io_vd;
416 	void		*io_vsd;
417 	const zio_vsd_ops_t *io_vsd_ops;
418 
419 	uint64_t	io_offset;
420 	hrtime_t	io_timestamp;
421 	avl_node_t	io_queue_node;
422 
423 	/* Internal pipeline state */
424 	enum zio_flag	io_flags;
425 	enum zio_stage	io_stage;
426 	enum zio_stage	io_pipeline;
427 	enum zio_flag	io_orig_flags;
428 	enum zio_stage	io_orig_stage;
429 	enum zio_stage	io_orig_pipeline;
430 	int		io_error;
431 	int		io_child_error[ZIO_CHILD_TYPES];
432 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
433 	uint64_t	io_child_count;
434 	uint64_t	io_phys_children;
435 	uint64_t	io_parent_count;
436 	uint64_t	*io_stall;
437 	zio_t		*io_gang_leader;
438 	zio_gang_node_t	*io_gang_tree;
439 	void		*io_executor;
440 	void		*io_waiter;
441 	kmutex_t	io_lock;
442 	kcondvar_t	io_cv;
443 
444 	/* FMA state */
445 	zio_cksum_report_t *io_cksum_report;
446 	uint64_t	io_ena;
447 
448 	/* Taskq dispatching state */
449 	taskq_ent_t	io_tqent;
450 };
451 
452 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
453     zio_done_func_t *done, void *private, enum zio_flag flags);
454 
455 extern zio_t *zio_root(spa_t *spa,
456     zio_done_func_t *done, void *private, enum zio_flag flags);
457 
458 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
459     uint64_t size, zio_done_func_t *done, void *private,
460     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
461 
462 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
463     void *data, uint64_t size, const zio_prop_t *zp,
464     zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done,
465     void *private,
466     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
467 
468 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
469     void *data, uint64_t size, zio_done_func_t *done, void *private,
470     zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb);
471 
472 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
473     boolean_t nopwrite);
474 
475 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
476 
477 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
478     const blkptr_t *bp,
479     zio_done_func_t *done, void *private, enum zio_flag flags);
480 
481 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
482     zio_done_func_t *done, void *private, enum zio_flag flags);
483 
484 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
485     uint64_t size, void *data, int checksum,
486     zio_done_func_t *done, void *private, zio_priority_t priority,
487     enum zio_flag flags, boolean_t labels);
488 
489 extern zio_t *zio_write_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_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
495     const blkptr_t *bp, enum zio_flag flags);
496 
497 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
498     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
499 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
500 extern void zio_flush(zio_t *zio, vdev_t *vd);
501 extern void zio_shrink(zio_t *zio, uint64_t size);
502 
503 extern int zio_wait(zio_t *zio);
504 extern void zio_nowait(zio_t *zio);
505 extern void zio_execute(zio_t *zio);
506 extern void zio_interrupt(zio_t *zio);
507 
508 extern zio_t *zio_walk_parents(zio_t *cio);
509 extern zio_t *zio_walk_children(zio_t *pio);
510 extern zio_t *zio_unique_parent(zio_t *cio);
511 extern void zio_add_child(zio_t *pio, zio_t *cio);
512 
513 extern void *zio_buf_alloc(size_t size);
514 extern void zio_buf_free(void *buf, size_t size);
515 extern void *zio_data_buf_alloc(size_t size);
516 extern void zio_data_buf_free(void *buf, size_t size);
517 
518 extern void zio_resubmit_stage_async(void *);
519 
520 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
521     uint64_t offset, void *data, uint64_t size, int type,
522     zio_priority_t priority, enum zio_flag flags,
523     zio_done_func_t *done, void *private);
524 
525 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
526     void *data, uint64_t size, int type, zio_priority_t priority,
527     enum zio_flag flags, zio_done_func_t *done, void *private);
528 
529 extern void zio_vdev_io_bypass(zio_t *zio);
530 extern void zio_vdev_io_reissue(zio_t *zio);
531 extern void zio_vdev_io_redone(zio_t *zio);
532 
533 extern void zio_checksum_verified(zio_t *zio);
534 extern int zio_worst_error(int e1, int e2);
535 
536 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
537     enum zio_checksum parent);
538 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
539     enum zio_checksum child, enum zio_checksum parent);
540 extern enum zio_compress zio_compress_select(enum zio_compress child,
541     enum zio_compress parent);
542 
543 extern void zio_suspend(spa_t *spa, zio_t *zio);
544 extern int zio_resume(spa_t *spa);
545 extern void zio_resume_wait(spa_t *spa);
546 
547 /*
548  * Initial setup and teardown.
549  */
550 extern void zio_init(void);
551 extern void zio_fini(void);
552 
553 /*
554  * Fault injection
555  */
556 struct zinject_record;
557 extern uint32_t zio_injection_enabled;
558 extern int zio_inject_fault(char *name, int flags, int *id,
559     struct zinject_record *record);
560 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
561     struct zinject_record *record);
562 extern int zio_clear_fault(int id);
563 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
564 extern int zio_handle_fault_injection(zio_t *zio, int error);
565 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
566 extern int zio_handle_label_injection(zio_t *zio, int error);
567 extern void zio_handle_ignored_writes(zio_t *zio);
568 extern uint64_t zio_handle_io_delay(zio_t *zio);
569 
570 /*
571  * Checksum ereport functions
572  */
573 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
574     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
575 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
576     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
577 
578 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
579 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
580 
581 /* If we have the good data in hand, this function can be used */
582 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
583     struct zio *zio, uint64_t offset, uint64_t length,
584     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
585 
586 /* Called from spa_sync(), but primarily an injection handler */
587 extern void spa_handle_ignored_writes(spa_t *spa);
588 
589 /* zbookmark_phys functions */
590 boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
591     const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
592 
593 #ifdef	__cplusplus
594 }
595 #endif
596 
597 #endif	/* _ZIO_H */
598