xref: /titanic_41/usr/src/uts/common/fs/zfs/sys/zio.h (revision f07d77e6bf1d0fb81fc7a9dd7d2cd03c8be17506)
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/zio_priority.h>
34 #include <sys/zfs_context.h>
35 #include <sys/spa.h>
36 #include <sys/txg.h>
37 #include <sys/avl.h>
38 #include <sys/fs/zfs.h>
39 #include <sys/zio_impl.h>
40 
41 #ifdef	__cplusplus
42 extern "C" {
43 #endif
44 
45 /*
46  * Embedded checksum
47  */
48 #define	ZEC_MAGIC	0x210da7ab10c7a11ULL
49 
50 typedef struct zio_eck {
51 	uint64_t	zec_magic;	/* for validation, endianness	*/
52 	zio_cksum_t	zec_cksum;	/* 256-bit checksum		*/
53 } zio_eck_t;
54 
55 /*
56  * Gang block headers are self-checksumming and contain an array
57  * of block pointers.
58  */
59 #define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
60 #define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
61 	sizeof (zio_eck_t)) / sizeof (blkptr_t))
62 #define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
63 	sizeof (zio_eck_t) - \
64 	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
65 	sizeof (uint64_t))
66 
67 typedef struct zio_gbh {
68 	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
69 	uint64_t		zg_filler[SPA_GBH_FILLER];
70 	zio_eck_t		zg_tail;
71 } zio_gbh_phys_t;
72 
73 enum zio_checksum {
74 	ZIO_CHECKSUM_INHERIT = 0,
75 	ZIO_CHECKSUM_ON,
76 	ZIO_CHECKSUM_OFF,
77 	ZIO_CHECKSUM_LABEL,
78 	ZIO_CHECKSUM_GANG_HEADER,
79 	ZIO_CHECKSUM_ZILOG,
80 	ZIO_CHECKSUM_FLETCHER_2,
81 	ZIO_CHECKSUM_FLETCHER_4,
82 	ZIO_CHECKSUM_SHA256,
83 	ZIO_CHECKSUM_ZILOG2,
84 	ZIO_CHECKSUM_NOPARITY,
85 	ZIO_CHECKSUM_FUNCTIONS
86 };
87 
88 /*
89  * The number of "legacy" compression functions which can be set on individual
90  * objects.
91  */
92 #define	ZIO_CHECKSUM_LEGACY_FUNCTIONS ZIO_CHECKSUM_ZILOG2
93 
94 #define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_4
95 #define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
96 
97 #define	ZIO_CHECKSUM_MASK	0xffULL
98 #define	ZIO_CHECKSUM_VERIFY	(1 << 8)
99 
100 #define	ZIO_DEDUPCHECKSUM	ZIO_CHECKSUM_SHA256
101 #define	ZIO_DEDUPDITTO_MIN	100
102 
103 enum zio_compress {
104 	ZIO_COMPRESS_INHERIT = 0,
105 	ZIO_COMPRESS_ON,
106 	ZIO_COMPRESS_OFF,
107 	ZIO_COMPRESS_LZJB,
108 	ZIO_COMPRESS_EMPTY,
109 	ZIO_COMPRESS_GZIP_1,
110 	ZIO_COMPRESS_GZIP_2,
111 	ZIO_COMPRESS_GZIP_3,
112 	ZIO_COMPRESS_GZIP_4,
113 	ZIO_COMPRESS_GZIP_5,
114 	ZIO_COMPRESS_GZIP_6,
115 	ZIO_COMPRESS_GZIP_7,
116 	ZIO_COMPRESS_GZIP_8,
117 	ZIO_COMPRESS_GZIP_9,
118 	ZIO_COMPRESS_ZLE,
119 	ZIO_COMPRESS_LZ4,
120 	ZIO_COMPRESS_FUNCTIONS
121 };
122 
123 /*
124  * The number of "legacy" compression functions which can be set on individual
125  * objects.
126  */
127 #define	ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4
128 
129 /*
130  * The meaning of "compress = on" selected by the compression features enabled
131  * on a given pool.
132  */
133 #define	ZIO_COMPRESS_LEGACY_ON_VALUE	ZIO_COMPRESS_LZJB
134 #define	ZIO_COMPRESS_LZ4_ON_VALUE	ZIO_COMPRESS_LZ4
135 
136 #define	ZIO_COMPRESS_DEFAULT		ZIO_COMPRESS_OFF
137 
138 #define	BOOTFS_COMPRESS_VALID(compress)			\
139 	((compress) == ZIO_COMPRESS_LZJB ||		\
140 	(compress) == ZIO_COMPRESS_LZ4 ||		\
141 	(compress) == ZIO_COMPRESS_ON ||		\
142 	(compress) == ZIO_COMPRESS_OFF)
143 
144 #define	ZIO_FAILURE_MODE_WAIT		0
145 #define	ZIO_FAILURE_MODE_CONTINUE	1
146 #define	ZIO_FAILURE_MODE_PANIC		2
147 
148 enum zio_flag {
149 	/*
150 	 * Flags inherited by gang, ddt, and vdev children,
151 	 * and that must be equal for two zios to aggregate
152 	 */
153 	ZIO_FLAG_DONT_AGGREGATE	= 1 << 0,
154 	ZIO_FLAG_IO_REPAIR	= 1 << 1,
155 	ZIO_FLAG_SELF_HEAL	= 1 << 2,
156 	ZIO_FLAG_RESILVER	= 1 << 3,
157 	ZIO_FLAG_SCRUB		= 1 << 4,
158 	ZIO_FLAG_SCAN_THREAD	= 1 << 5,
159 	ZIO_FLAG_PHYSICAL	= 1 << 6,
160 
161 #define	ZIO_FLAG_AGG_INHERIT	(ZIO_FLAG_CANFAIL - 1)
162 
163 	/*
164 	 * Flags inherited by ddt, gang, and vdev children.
165 	 */
166 	ZIO_FLAG_CANFAIL	= 1 << 7,	/* must be first for INHERIT */
167 	ZIO_FLAG_SPECULATIVE	= 1 << 8,
168 	ZIO_FLAG_CONFIG_WRITER	= 1 << 9,
169 	ZIO_FLAG_DONT_RETRY	= 1 << 10,
170 	ZIO_FLAG_DONT_CACHE	= 1 << 11,
171 	ZIO_FLAG_NODATA		= 1 << 12,
172 	ZIO_FLAG_INDUCE_DAMAGE	= 1 << 13,
173 
174 #define	ZIO_FLAG_DDT_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
175 #define	ZIO_FLAG_GANG_INHERIT	(ZIO_FLAG_IO_RETRY - 1)
176 
177 	/*
178 	 * Flags inherited by vdev children.
179 	 */
180 	ZIO_FLAG_IO_RETRY	= 1 << 14,	/* must be first for INHERIT */
181 	ZIO_FLAG_PROBE		= 1 << 15,
182 	ZIO_FLAG_TRYHARD	= 1 << 16,
183 	ZIO_FLAG_OPTIONAL	= 1 << 17,
184 
185 #define	ZIO_FLAG_VDEV_INHERIT	(ZIO_FLAG_DONT_QUEUE - 1)
186 
187 	/*
188 	 * Flags not inherited by any children.
189 	 */
190 	ZIO_FLAG_DONT_QUEUE	= 1 << 18,	/* must be first for INHERIT */
191 	ZIO_FLAG_DONT_PROPAGATE	= 1 << 19,
192 	ZIO_FLAG_IO_BYPASS	= 1 << 20,
193 	ZIO_FLAG_IO_REWRITE	= 1 << 21,
194 	ZIO_FLAG_RAW		= 1 << 22,
195 	ZIO_FLAG_GANG_CHILD	= 1 << 23,
196 	ZIO_FLAG_DDT_CHILD	= 1 << 24,
197 	ZIO_FLAG_GODFATHER	= 1 << 25,
198 	ZIO_FLAG_NOPWRITE	= 1 << 26,
199 	ZIO_FLAG_REEXECUTED	= 1 << 27,
200 	ZIO_FLAG_DELEGATED	= 1 << 28,
201 };
202 
203 #define	ZIO_FLAG_MUSTSUCCEED		0
204 
205 #define	ZIO_DDT_CHILD_FLAGS(zio)				\
206 	(((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |		\
207 	ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
208 
209 #define	ZIO_GANG_CHILD_FLAGS(zio)				\
210 	(((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |		\
211 	ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
212 
213 #define	ZIO_VDEV_CHILD_FLAGS(zio)				\
214 	(((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |		\
215 	ZIO_FLAG_CANFAIL)
216 
217 #define	ZIO_CHILD_BIT(x)		(1 << (x))
218 #define	ZIO_CHILD_BIT_IS_SET(val, x)	((val) & (1 << (x)))
219 
220 enum zio_child {
221 	ZIO_CHILD_VDEV = 0,
222 	ZIO_CHILD_GANG,
223 	ZIO_CHILD_DDT,
224 	ZIO_CHILD_LOGICAL,
225 	ZIO_CHILD_TYPES
226 };
227 
228 #define	ZIO_CHILD_VDEV_BIT		ZIO_CHILD_BIT(ZIO_CHILD_VDEV)
229 #define	ZIO_CHILD_GANG_BIT		ZIO_CHILD_BIT(ZIO_CHILD_GANG)
230 #define	ZIO_CHILD_DDT_BIT		ZIO_CHILD_BIT(ZIO_CHILD_DDT)
231 #define	ZIO_CHILD_LOGICAL_BIT		ZIO_CHILD_BIT(ZIO_CHILD_LOGICAL)
232 #define	ZIO_CHILD_ALL_BITS					\
233 	(ZIO_CHILD_VDEV_BIT | ZIO_CHILD_GANG_BIT | 		\
234 	ZIO_CHILD_DDT_BIT | ZIO_CHILD_LOGICAL_BIT)
235 
236 enum zio_wait_type {
237 	ZIO_WAIT_READY = 0,
238 	ZIO_WAIT_DONE,
239 	ZIO_WAIT_TYPES
240 };
241 
242 /*
243  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
244  * graveyard) to indicate checksum errors and fragmentation.
245  */
246 #define	ECKSUM	EBADE
247 #define	EFRAGS	EBADR
248 
249 typedef void zio_done_func_t(zio_t *zio);
250 
251 extern const char *zio_type_name[ZIO_TYPES];
252 
253 /*
254  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
255  * identifies any block in the pool.  By convention, the meta-objset (MOS)
256  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
257  * except root blocks and ZIL blocks, which are defined as follows:
258  *
259  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
260  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
261  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
262  * dnode visit bookmarks are <objset, object id of dnode, -3, 0>.
263  *
264  * Note: this structure is called a bookmark because its original purpose
265  * was to remember where to resume a pool-wide traverse.
266  *
267  * Note: this structure is passed between userland and the kernel, and is
268  * stored on disk (by virtue of being incorporated into other on-disk
269  * structures, e.g. dsl_scan_phys_t).
270  */
271 typedef struct zbookmark_phys {
272 	uint64_t	zb_objset;
273 	uint64_t	zb_object;
274 	int64_t		zb_level;
275 	uint64_t	zb_blkid;
276 } zbookmark_phys_t;
277 
278 #define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
279 {                                                       \
280 	(zb)->zb_objset = objset;                       \
281 	(zb)->zb_object = object;                       \
282 	(zb)->zb_level = level;                         \
283 	(zb)->zb_blkid = blkid;                         \
284 }
285 
286 #define	ZB_DESTROYED_OBJSET	(-1ULL)
287 
288 #define	ZB_ROOT_OBJECT		(0ULL)
289 #define	ZB_ROOT_LEVEL		(-1LL)
290 #define	ZB_ROOT_BLKID		(0ULL)
291 
292 #define	ZB_ZIL_OBJECT		(0ULL)
293 #define	ZB_ZIL_LEVEL		(-2LL)
294 
295 #define	ZB_DNODE_LEVEL		(-3LL)
296 #define	ZB_DNODE_BLKID		(0ULL)
297 
298 #define	ZB_IS_ZERO(zb)						\
299 	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
300 	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
301 #define	ZB_IS_ROOT(zb)				\
302 	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
303 	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
304 	(zb)->zb_blkid == ZB_ROOT_BLKID)
305 
306 typedef struct zio_prop {
307 	enum zio_checksum	zp_checksum;
308 	enum zio_compress	zp_compress;
309 	dmu_object_type_t	zp_type;
310 	uint8_t			zp_level;
311 	uint8_t			zp_copies;
312 	boolean_t		zp_dedup;
313 	boolean_t		zp_dedup_verify;
314 	boolean_t		zp_nopwrite;
315 } zio_prop_t;
316 
317 typedef struct zio_cksum_report zio_cksum_report_t;
318 
319 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
320     const void *good_data);
321 typedef void zio_cksum_free_f(void *cbdata, size_t size);
322 
323 struct zio_bad_cksum;				/* defined in zio_checksum.h */
324 struct dnode_phys;
325 
326 struct zio_cksum_report {
327 	struct zio_cksum_report *zcr_next;
328 	nvlist_t		*zcr_ereport;
329 	nvlist_t		*zcr_detector;
330 	void			*zcr_cbdata;
331 	size_t			zcr_cbinfo;	/* passed to zcr_free() */
332 	uint64_t		zcr_align;
333 	uint64_t		zcr_length;
334 	zio_cksum_finish_f	*zcr_finish;
335 	zio_cksum_free_f	*zcr_free;
336 
337 	/* internal use only */
338 	struct zio_bad_cksum	*zcr_ckinfo;	/* information from failure */
339 };
340 
341 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
342     void *arg);
343 
344 zio_vsd_cksum_report_f	zio_vsd_default_cksum_report;
345 
346 typedef struct zio_vsd_ops {
347 	zio_done_func_t		*vsd_free;
348 	zio_vsd_cksum_report_f	*vsd_cksum_report;
349 } zio_vsd_ops_t;
350 
351 typedef struct zio_gang_node {
352 	zio_gbh_phys_t		*gn_gbh;
353 	struct zio_gang_node	*gn_child[SPA_GBH_NBLKPTRS];
354 } zio_gang_node_t;
355 
356 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
357     zio_gang_node_t *gn, void *data);
358 
359 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
360 
361 typedef struct zio_transform {
362 	void			*zt_orig_data;
363 	uint64_t		zt_orig_size;
364 	uint64_t		zt_bufsize;
365 	zio_transform_func_t	*zt_transform;
366 	struct zio_transform	*zt_next;
367 } zio_transform_t;
368 
369 typedef int zio_pipe_stage_t(zio_t *zio);
370 
371 /*
372  * The io_reexecute flags are distinct from io_flags because the child must
373  * be able to propagate them to the parent.  The normal io_flags are local
374  * to the zio, not protected by any lock, and not modifiable by children;
375  * the reexecute flags are protected by io_lock, modifiable by children,
376  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
377  */
378 #define	ZIO_REEXECUTE_NOW	0x01
379 #define	ZIO_REEXECUTE_SUSPEND	0x02
380 
381 typedef struct zio_link {
382 	zio_t		*zl_parent;
383 	zio_t		*zl_child;
384 	list_node_t	zl_parent_node;
385 	list_node_t	zl_child_node;
386 } zio_link_t;
387 
388 struct zio {
389 	/* Core information about this I/O */
390 	zbookmark_phys_t	io_bookmark;
391 	zio_prop_t	io_prop;
392 	zio_type_t	io_type;
393 	enum zio_child	io_child_type;
394 	int		io_cmd;
395 	zio_priority_t	io_priority;
396 	uint8_t		io_reexecute;
397 	uint8_t		io_state[ZIO_WAIT_TYPES];
398 	uint64_t	io_txg;
399 	spa_t		*io_spa;
400 	blkptr_t	*io_bp;
401 	blkptr_t	*io_bp_override;
402 	blkptr_t	io_bp_copy;
403 	list_t		io_parent_list;
404 	list_t		io_child_list;
405 	zio_link_t	*io_walk_link;
406 	zio_t		*io_logical;
407 	zio_transform_t *io_transform_stack;
408 
409 	/* Callback info */
410 	zio_done_func_t	*io_ready;
411 	zio_done_func_t	*io_physdone;
412 	zio_done_func_t	*io_done;
413 	void		*io_private;
414 	int64_t		io_prev_space_delta;	/* DMU private */
415 	blkptr_t	io_bp_orig;
416 
417 	/* Data represented by this I/O */
418 	void		*io_data;
419 	void		*io_orig_data;
420 	uint64_t	io_size;
421 	uint64_t	io_orig_size;
422 
423 	/* Stuff for the vdev stack */
424 	vdev_t		*io_vd;
425 	void		*io_vsd;
426 	const zio_vsd_ops_t *io_vsd_ops;
427 
428 	uint64_t	io_offset;
429 	hrtime_t	io_timestamp;
430 	avl_node_t	io_queue_node;
431 	avl_node_t	io_offset_node;
432 
433 	/* Internal pipeline state */
434 	enum zio_flag	io_flags;
435 	enum zio_stage	io_stage;
436 	enum zio_stage	io_pipeline;
437 	enum zio_flag	io_orig_flags;
438 	enum zio_stage	io_orig_stage;
439 	enum zio_stage	io_orig_pipeline;
440 	int		io_error;
441 	int		io_child_error[ZIO_CHILD_TYPES];
442 	uint64_t	io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
443 	uint64_t	io_child_count;
444 	uint64_t	io_phys_children;
445 	uint64_t	io_parent_count;
446 	uint64_t	*io_stall;
447 	zio_t		*io_gang_leader;
448 	zio_gang_node_t	*io_gang_tree;
449 	void		*io_executor;
450 	void		*io_waiter;
451 	kmutex_t	io_lock;
452 	kcondvar_t	io_cv;
453 
454 	/* FMA state */
455 	zio_cksum_report_t *io_cksum_report;
456 	uint64_t	io_ena;
457 
458 	/* Taskq dispatching state */
459 	taskq_ent_t	io_tqent;
460 };
461 
462 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
463     zio_done_func_t *done, void *private, enum zio_flag flags);
464 
465 extern zio_t *zio_root(spa_t *spa,
466     zio_done_func_t *done, void *private, enum zio_flag flags);
467 
468 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
469     uint64_t size, zio_done_func_t *done, void *private,
470     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
471 
472 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
473     void *data, uint64_t size, const zio_prop_t *zp,
474     zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done,
475     void *private,
476     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
477 
478 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
479     void *data, uint64_t size, zio_done_func_t *done, void *private,
480     zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb);
481 
482 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
483     boolean_t nopwrite);
484 
485 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
486 
487 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
488     const blkptr_t *bp,
489     zio_done_func_t *done, void *private, enum zio_flag flags);
490 
491 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
492     zio_done_func_t *done, void *private, enum zio_flag flags);
493 
494 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
495     uint64_t size, void *data, int checksum,
496     zio_done_func_t *done, void *private, zio_priority_t priority,
497     enum zio_flag flags, boolean_t labels);
498 
499 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
500     uint64_t size, void *data, int checksum,
501     zio_done_func_t *done, void *private, zio_priority_t priority,
502     enum zio_flag flags, boolean_t labels);
503 
504 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
505     const blkptr_t *bp, enum zio_flag flags);
506 
507 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
508     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
509 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
510 extern void zio_flush(zio_t *zio, vdev_t *vd);
511 extern void zio_shrink(zio_t *zio, uint64_t size);
512 
513 extern int zio_wait(zio_t *zio);
514 extern void zio_nowait(zio_t *zio);
515 extern void zio_execute(zio_t *zio);
516 extern void zio_interrupt(zio_t *zio);
517 
518 extern zio_t *zio_walk_parents(zio_t *cio);
519 extern zio_t *zio_walk_children(zio_t *pio);
520 extern zio_t *zio_unique_parent(zio_t *cio);
521 extern void zio_add_child(zio_t *pio, zio_t *cio);
522 
523 extern void *zio_buf_alloc(size_t size);
524 extern void zio_buf_free(void *buf, size_t size);
525 extern void *zio_data_buf_alloc(size_t size);
526 extern void zio_data_buf_free(void *buf, size_t size);
527 
528 extern void zio_resubmit_stage_async(void *);
529 
530 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
531     uint64_t offset, void *data, uint64_t size, int type,
532     zio_priority_t priority, enum zio_flag flags,
533     zio_done_func_t *done, void *private);
534 
535 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
536     void *data, uint64_t size, int type, zio_priority_t priority,
537     enum zio_flag flags, zio_done_func_t *done, void *private);
538 
539 extern void zio_vdev_io_bypass(zio_t *zio);
540 extern void zio_vdev_io_reissue(zio_t *zio);
541 extern void zio_vdev_io_redone(zio_t *zio);
542 
543 extern void zio_checksum_verified(zio_t *zio);
544 extern int zio_worst_error(int e1, int e2);
545 
546 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
547     enum zio_checksum parent);
548 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
549     enum zio_checksum child, enum zio_checksum parent);
550 extern enum zio_compress zio_compress_select(spa_t *spa,
551     enum zio_compress child, enum zio_compress parent);
552 
553 extern void zio_suspend(spa_t *spa, zio_t *zio);
554 extern int zio_resume(spa_t *spa);
555 extern void zio_resume_wait(spa_t *spa);
556 
557 /*
558  * Initial setup and teardown.
559  */
560 extern void zio_init(void);
561 extern void zio_fini(void);
562 
563 /*
564  * Fault injection
565  */
566 struct zinject_record;
567 extern uint32_t zio_injection_enabled;
568 extern int zio_inject_fault(char *name, int flags, int *id,
569     struct zinject_record *record);
570 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
571     struct zinject_record *record);
572 extern int zio_clear_fault(int id);
573 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
574 extern int zio_handle_fault_injection(zio_t *zio, int error);
575 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
576 extern int zio_handle_label_injection(zio_t *zio, int error);
577 extern void zio_handle_ignored_writes(zio_t *zio);
578 extern uint64_t zio_handle_io_delay(zio_t *zio);
579 
580 /*
581  * Checksum ereport functions
582  */
583 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
584     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
585 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
586     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
587 
588 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
589 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
590 
591 /* If we have the good data in hand, this function can be used */
592 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
593     struct zio *zio, uint64_t offset, uint64_t length,
594     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
595 
596 /* Called from spa_sync(), but primarily an injection handler */
597 extern void spa_handle_ignored_writes(spa_t *spa);
598 
599 /* zbookmark_phys functions */
600 boolean_t zbookmark_subtree_completed(const struct dnode_phys *dnp,
601     const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block);
602 int zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2,
603     uint8_t ibs2, const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
604 
605 #ifdef	__cplusplus
606 }
607 #endif
608 
609 #endif	/* _ZIO_H */
610