xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/zio.h (revision 747cfc73193da6c99aeb06f23e70552319393cc4)
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 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef _ZIO_H
28 #define	_ZIO_H
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <sys/zfs_context.h>
33 #include <sys/spa.h>
34 #include <sys/txg.h>
35 #include <sys/avl.h>
36 #include <sys/dkio.h>
37 #include <sys/fs/zfs.h>
38 #include <sys/zio_impl.h>
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 #define	ZBT_MAGIC	0x210da7ab10c7a11ULL	/* zio data bloc tail */
45 
46 typedef struct zio_block_tail {
47 	uint64_t	zbt_magic;	/* for validation, endianness	*/
48 	zio_cksum_t	zbt_cksum;	/* 256-bit checksum		*/
49 } zio_block_tail_t;
50 
51 /*
52  * Gang block headers are self-checksumming and contain an array
53  * of block pointers.
54  */
55 #define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
56 #define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
57 	sizeof (zio_block_tail_t)) / sizeof (blkptr_t))
58 #define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
59 	sizeof (zio_block_tail_t) - \
60 	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
61 	sizeof (uint64_t))
62 
63 #define	ZIO_GET_IOSIZE(zio)	\
64 	(BP_IS_GANG((zio)->io_bp) ? \
65 	SPA_GANGBLOCKSIZE : BP_GET_PSIZE((zio)->io_bp))
66 
67 typedef struct zio_gbh {
68 	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
69 	uint64_t		zg_filler[SPA_GBH_FILLER];
70 	zio_block_tail_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_FUNCTIONS
84 };
85 
86 #define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_2
87 #define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
88 
89 enum zio_compress {
90 	ZIO_COMPRESS_INHERIT = 0,
91 	ZIO_COMPRESS_ON,
92 	ZIO_COMPRESS_OFF,
93 	ZIO_COMPRESS_LZJB,
94 	ZIO_COMPRESS_EMPTY,
95 	ZIO_COMPRESS_GZIP_1,
96 	ZIO_COMPRESS_GZIP_2,
97 	ZIO_COMPRESS_GZIP_3,
98 	ZIO_COMPRESS_GZIP_4,
99 	ZIO_COMPRESS_GZIP_5,
100 	ZIO_COMPRESS_GZIP_6,
101 	ZIO_COMPRESS_GZIP_7,
102 	ZIO_COMPRESS_GZIP_8,
103 	ZIO_COMPRESS_GZIP_9,
104 	ZIO_COMPRESS_FUNCTIONS
105 };
106 
107 #define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
108 #define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
109 
110 #define	ZIO_FAILURE_MODE_WAIT		0
111 #define	ZIO_FAILURE_MODE_CONTINUE	1
112 #define	ZIO_FAILURE_MODE_PANIC		2
113 
114 #define	ZIO_PRIORITY_NOW		(zio_priority_table[0])
115 #define	ZIO_PRIORITY_SYNC_READ		(zio_priority_table[1])
116 #define	ZIO_PRIORITY_SYNC_WRITE		(zio_priority_table[2])
117 #define	ZIO_PRIORITY_ASYNC_READ		(zio_priority_table[3])
118 #define	ZIO_PRIORITY_ASYNC_WRITE	(zio_priority_table[4])
119 #define	ZIO_PRIORITY_FREE		(zio_priority_table[5])
120 #define	ZIO_PRIORITY_CACHE_FILL		(zio_priority_table[6])
121 #define	ZIO_PRIORITY_LOG_WRITE		(zio_priority_table[7])
122 #define	ZIO_PRIORITY_RESILVER		(zio_priority_table[8])
123 #define	ZIO_PRIORITY_SCRUB		(zio_priority_table[9])
124 #define	ZIO_PRIORITY_TABLE_SIZE		10
125 
126 #define	ZIO_FLAG_MUSTSUCCEED		0x00000
127 #define	ZIO_FLAG_CANFAIL		0x00001
128 #define	ZIO_FLAG_FAILFAST		0x00002
129 #define	ZIO_FLAG_CONFIG_HELD		0x00004
130 #define	ZIO_FLAG_CONFIG_GRABBED		0x00008
131 
132 #define	ZIO_FLAG_DONT_CACHE		0x00010
133 #define	ZIO_FLAG_DONT_QUEUE		0x00020
134 #define	ZIO_FLAG_DONT_PROPAGATE		0x00040
135 #define	ZIO_FLAG_DONT_RETRY		0x00080
136 
137 #define	ZIO_FLAG_PHYSICAL		0x00100
138 #define	ZIO_FLAG_IO_BYPASS		0x00200
139 #define	ZIO_FLAG_IO_REPAIR		0x00400
140 #define	ZIO_FLAG_SPECULATIVE		0x00800
141 
142 #define	ZIO_FLAG_RESILVER		0x01000
143 #define	ZIO_FLAG_SCRUB			0x02000
144 #define	ZIO_FLAG_SCRUB_THREAD		0x04000
145 #define	ZIO_FLAG_SUBBLOCK		0x08000
146 
147 #define	ZIO_FLAG_NOBOOKMARK		0x10000
148 #define	ZIO_FLAG_USER			0x20000
149 #define	ZIO_FLAG_METADATA		0x40000
150 #define	ZIO_FLAG_WRITE_RETRY		0x80000
151 
152 #define	ZIO_FLAG_GANG_INHERIT		\
153 	(ZIO_FLAG_CANFAIL |		\
154 	ZIO_FLAG_FAILFAST |		\
155 	ZIO_FLAG_CONFIG_HELD |		\
156 	ZIO_FLAG_DONT_CACHE |		\
157 	ZIO_FLAG_DONT_RETRY |		\
158 	ZIO_FLAG_IO_REPAIR |		\
159 	ZIO_FLAG_SPECULATIVE |		\
160 	ZIO_FLAG_RESILVER |		\
161 	ZIO_FLAG_SCRUB |		\
162 	ZIO_FLAG_SCRUB_THREAD |		\
163 	ZIO_FLAG_USER | 		\
164 	ZIO_FLAG_METADATA)
165 
166 #define	ZIO_FLAG_VDEV_INHERIT		\
167 	(ZIO_FLAG_GANG_INHERIT |	\
168 	ZIO_FLAG_PHYSICAL)
169 
170 #define	ZIO_PIPELINE_CONTINUE		0x100
171 #define	ZIO_PIPELINE_STOP		0x101
172 
173 /*
174  * We'll take the unused errno 'EBADE' (from the Convergent graveyard)
175  * to indicate checksum errors.
176  */
177 #define	ECKSUM	EBADE
178 
179 typedef struct zio zio_t;
180 typedef void zio_done_func_t(zio_t *zio);
181 
182 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
183 extern char *zio_type_name[ZIO_TYPES];
184 
185 /*
186  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
187  * identifies any block in the pool.  By convention, the meta-objset (MOS)
188  * is objset 0, the meta-dnode is object 0, the root block (osphys_t) is
189  * level -1 of the meta-dnode, and intent log blocks (which are chained
190  * off the root block) have blkid == sequence number.  In summary:
191  *
192  *	mos is objset 0
193  *	meta-dnode is object 0
194  *	root block is <objset, 0, -1, 0>
195  *	intent log is <objset, 0, -1, ZIL sequence number>
196  *
197  * Note: this structure is called a bookmark because its first purpose was
198  * to remember where to resume a pool-wide traverse.  The absolute ordering
199  * for block visitation during traversal is defined in compare_bookmark().
200  *
201  * Note: this structure is passed between userland and the kernel.
202  * Therefore it must not change size or alignment between 32/64 bit
203  * compilation options.
204  */
205 typedef struct zbookmark {
206 	uint64_t	zb_objset;
207 	uint64_t	zb_object;
208 	int64_t		zb_level;
209 	uint64_t	zb_blkid;
210 } zbookmark_t;
211 
212 struct zio {
213 	/* Core information about this I/O */
214 	zio_t		*io_parent;
215 	zio_t		*io_root;
216 	spa_t		*io_spa;
217 	zbookmark_t	io_bookmark;
218 	enum zio_checksum io_checksum;
219 	enum zio_compress io_compress;
220 	int		io_ndvas;
221 	uint64_t	io_txg;
222 	blkptr_t	*io_bp;
223 	blkptr_t	io_bp_copy;
224 	zio_t		*io_child;
225 	zio_t		*io_sibling_prev;
226 	zio_t		*io_sibling_next;
227 	zio_transform_t *io_transform_stack;
228 	zio_t		*io_logical;
229 	list_node_t	zio_link_node;
230 
231 	/* Callback info */
232 	zio_done_func_t	*io_ready;
233 	zio_done_func_t	*io_done;
234 	void		*io_private;
235 	blkptr_t	io_bp_orig;
236 
237 	/* Data represented by this I/O */
238 	void		*io_data;
239 	uint64_t	io_size;
240 
241 	/* Stuff for the vdev stack */
242 	vdev_t		*io_vd;
243 	void		*io_vsd;
244 	uint64_t	io_offset;
245 	uint64_t	io_deadline;
246 	uint64_t	io_timestamp;
247 	avl_node_t	io_offset_node;
248 	avl_node_t	io_deadline_node;
249 	avl_tree_t	*io_vdev_tree;
250 	zio_t		*io_delegate_list;
251 	zio_t		*io_delegate_next;
252 
253 	/* Internal pipeline state */
254 	int		io_flags;
255 	int		io_orig_flags;
256 	enum zio_type	io_type;
257 	enum zio_stage	io_stage;
258 	enum zio_stage	io_orig_stage;
259 	uint8_t		io_stalled;
260 	uint8_t		io_priority;
261 	struct dk_callback io_dk_callback;
262 	int		io_cmd;
263 	int		io_retries;
264 	int		io_error;
265 	uint32_t	io_numerrors;
266 	uint32_t	io_pipeline;
267 	uint32_t	io_orig_pipeline;
268 	uint64_t	io_children_notready;
269 	uint64_t	io_children_notdone;
270 	void		*io_waiter;
271 	kmutex_t	io_lock;
272 	kcondvar_t	io_cv;
273 
274 	/* FMA state */
275 	uint64_t	io_ena;
276 };
277 
278 extern zio_t *zio_null(zio_t *pio, spa_t *spa,
279     zio_done_func_t *done, void *private, int flags);
280 
281 extern zio_t *zio_root(spa_t *spa,
282     zio_done_func_t *done, void *private, int flags);
283 
284 extern zio_t *zio_read(zio_t *pio, spa_t *spa, blkptr_t *bp, void *data,
285     uint64_t size, zio_done_func_t *done, void *private,
286     int priority, int flags, zbookmark_t *zb);
287 
288 extern zio_t *zio_write(zio_t *pio, spa_t *spa, int checksum, int compress,
289     int ncopies, uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
290     zio_done_func_t *ready, zio_done_func_t *done, void *private, int priority,
291     int flags, zbookmark_t *zb);
292 
293 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, int checksum,
294     uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
295     zio_done_func_t *done, void *private, int priority, int flags,
296     zbookmark_t *zb);
297 
298 extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
299     zio_done_func_t *done, void *private);
300 
301 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
302     zio_done_func_t *done, void *private);
303 
304 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
305     zio_done_func_t *done, void *private, int priority, int flags);
306 
307 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
308     uint64_t size, void *data, int checksum,
309     zio_done_func_t *done, void *private, int priority, int flags,
310     boolean_t labels);
311 
312 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
313     uint64_t size, void *data, int checksum,
314     zio_done_func_t *done, void *private, int priority, int flags,
315     boolean_t labels);
316 
317 extern int zio_alloc_blk(spa_t *spa, uint64_t size, blkptr_t *new_bp,
318     blkptr_t *old_bp, uint64_t txg);
319 extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);
320 extern void zio_flush_vdev(spa_t *spa, uint64_t vdev, zio_t **zio);
321 
322 extern int zio_wait(zio_t *zio);
323 extern void zio_nowait(zio_t *zio);
324 extern void zio_execute(zio_t *zio);
325 extern void zio_interrupt(zio_t *zio);
326 
327 extern int zio_wait_for_children_ready(zio_t *zio);
328 extern int zio_wait_for_children_done(zio_t *zio);
329 
330 extern void *zio_buf_alloc(size_t size);
331 extern void zio_buf_free(void *buf, size_t size);
332 extern void *zio_data_buf_alloc(size_t size);
333 extern void zio_data_buf_free(void *buf, size_t size);
334 
335 extern void zio_resubmit_stage_async(void *);
336 
337 /*
338  * Delegate I/O to a child vdev.
339  */
340 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
341     uint64_t offset, void *data, uint64_t size, int type, int priority,
342     int flags, zio_done_func_t *done, void *private);
343 
344 extern void zio_vdev_io_bypass(zio_t *zio);
345 extern void zio_vdev_io_reissue(zio_t *zio);
346 extern void zio_vdev_io_redone(zio_t *zio);
347 
348 extern void zio_checksum_verified(zio_t *zio);
349 extern void zio_set_gang_verifier(zio_t *zio, zio_cksum_t *zcp);
350 
351 extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
352 extern uint8_t zio_compress_select(uint8_t child, uint8_t parent);
353 
354 extern boolean_t zio_should_retry(zio_t *zio);
355 extern int zio_vdev_resume_io(spa_t *);
356 
357 /*
358  * Initial setup and teardown.
359  */
360 extern void zio_init(void);
361 extern void zio_fini(void);
362 
363 /*
364  * Fault injection
365  */
366 struct zinject_record;
367 extern uint32_t zio_injection_enabled;
368 extern int zio_inject_fault(char *name, int flags, int *id,
369     struct zinject_record *record);
370 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
371     struct zinject_record *record);
372 extern int zio_clear_fault(int id);
373 extern int zio_handle_fault_injection(zio_t *zio, int error);
374 extern int zio_handle_device_injection(vdev_t *vd, int error);
375 
376 #ifdef	__cplusplus
377 }
378 #endif
379 
380 #endif	/* _ZIO_H */
381