xref: /titanic_51/usr/src/uts/common/fs/zfs/sys/zio.h (revision 13faa91230bde46da937bf33010b9accc5bdeb59)
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_RETRY |		\
157 	ZIO_FLAG_IO_REPAIR |		\
158 	ZIO_FLAG_SPECULATIVE |		\
159 	ZIO_FLAG_RESILVER |		\
160 	ZIO_FLAG_SCRUB |		\
161 	ZIO_FLAG_SCRUB_THREAD |		\
162 	ZIO_FLAG_USER | 		\
163 	ZIO_FLAG_METADATA)
164 
165 #define	ZIO_FLAG_VDEV_INHERIT		\
166 	(ZIO_FLAG_GANG_INHERIT |	\
167 	ZIO_FLAG_DONT_CACHE |		\
168 	ZIO_FLAG_PHYSICAL)
169 
170 /*
171  * We'll take the unused errno 'EBADE' (from the Convergent graveyard)
172  * to indicate checksum errors.
173  */
174 #define	ECKSUM	EBADE
175 
176 typedef struct zio zio_t;
177 typedef void zio_done_func_t(zio_t *zio);
178 
179 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
180 extern char *zio_type_name[ZIO_TYPES];
181 
182 /*
183  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
184  * identifies any block in the pool.  By convention, the meta-objset (MOS)
185  * is objset 0, the meta-dnode is object 0, the root block (osphys_t) is
186  * level -1 of the meta-dnode, and intent log blocks (which are chained
187  * off the root block) have blkid == sequence number.  In summary:
188  *
189  *	mos is objset 0
190  *	meta-dnode is object 0
191  *	root block is <objset, 0, -1, 0>
192  *	intent log is <objset, 0, -1, ZIL sequence number>
193  *
194  * Note: this structure is called a bookmark because its first purpose was
195  * to remember where to resume a pool-wide traverse.  The absolute ordering
196  * for block visitation during traversal is defined in compare_bookmark().
197  *
198  * Note: this structure is passed between userland and the kernel.
199  * Therefore it must not change size or alignment between 32/64 bit
200  * compilation options.
201  */
202 typedef struct zbookmark {
203 	uint64_t	zb_objset;
204 	uint64_t	zb_object;
205 	int64_t		zb_level;
206 	uint64_t	zb_blkid;
207 } zbookmark_t;
208 
209 struct zio {
210 	/* Core information about this I/O */
211 	zio_t		*io_parent;
212 	zio_t		*io_root;
213 	spa_t		*io_spa;
214 	zbookmark_t	io_bookmark;
215 	enum zio_checksum io_checksum;
216 	enum zio_compress io_compress;
217 	int		io_ndvas;
218 	uint64_t	io_txg;
219 	blkptr_t	*io_bp;
220 	blkptr_t	io_bp_copy;
221 	zio_t		*io_child;
222 	zio_t		*io_sibling_prev;
223 	zio_t		*io_sibling_next;
224 	zio_transform_t *io_transform_stack;
225 	zio_t		*io_logical;
226 	list_node_t	zio_link_node;
227 
228 	/* Callback info */
229 	zio_done_func_t	*io_ready;
230 	zio_done_func_t	*io_done;
231 	void		*io_private;
232 	blkptr_t	io_bp_orig;
233 
234 	/* Data represented by this I/O */
235 	void		*io_data;
236 	uint64_t	io_size;
237 
238 	/* Stuff for the vdev stack */
239 	vdev_t		*io_vd;
240 	void		*io_vsd;
241 	uint64_t	io_offset;
242 	uint64_t	io_deadline;
243 	uint64_t	io_timestamp;
244 	avl_node_t	io_offset_node;
245 	avl_node_t	io_deadline_node;
246 	avl_tree_t	*io_vdev_tree;
247 	zio_t		*io_delegate_list;
248 	zio_t		*io_delegate_next;
249 
250 	/* Internal pipeline state */
251 	int		io_flags;
252 	int		io_orig_flags;
253 	enum zio_type	io_type;
254 	enum zio_stage	io_stage;
255 	enum zio_stage	io_orig_stage;
256 	uint8_t		io_stalled;
257 	uint8_t		io_priority;
258 	struct dk_callback io_dk_callback;
259 	int		io_cmd;
260 	int		io_retries;
261 	int		io_error;
262 	uint32_t	io_numerrors;
263 	uint32_t	io_pipeline;
264 	uint32_t	io_orig_pipeline;
265 	uint32_t	io_async_stages;
266 	uint64_t	io_children_notready;
267 	uint64_t	io_children_notdone;
268 	void		*io_waiter;
269 	kmutex_t	io_lock;
270 	kcondvar_t	io_cv;
271 
272 	/* FMA state */
273 	uint64_t	io_ena;
274 };
275 
276 extern zio_t *zio_null(zio_t *pio, spa_t *spa,
277     zio_done_func_t *done, void *private, int flags);
278 
279 extern zio_t *zio_root(spa_t *spa,
280     zio_done_func_t *done, void *private, int flags);
281 
282 extern zio_t *zio_read(zio_t *pio, spa_t *spa, blkptr_t *bp, void *data,
283     uint64_t size, zio_done_func_t *done, void *private,
284     int priority, int flags, zbookmark_t *zb);
285 
286 extern zio_t *zio_write(zio_t *pio, spa_t *spa, int checksum, int compress,
287     int ncopies, uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
288     zio_done_func_t *ready, zio_done_func_t *done, void *private, int priority,
289     int flags, zbookmark_t *zb);
290 
291 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, int checksum,
292     uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
293     zio_done_func_t *done, void *private, int priority, int flags,
294     zbookmark_t *zb);
295 
296 extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
297     zio_done_func_t *done, void *private);
298 
299 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
300     zio_done_func_t *done, void *private);
301 
302 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
303     zio_done_func_t *done, void *private, int priority, int flags);
304 
305 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
306     uint64_t size, void *data, int checksum,
307     zio_done_func_t *done, void *private, int priority, int flags);
308 
309 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
310     uint64_t size, void *data, int checksum,
311     zio_done_func_t *done, void *private, int priority, int flags);
312 
313 extern int zio_alloc_blk(spa_t *spa, uint64_t size, blkptr_t *new_bp,
314     blkptr_t *old_bp, uint64_t txg);
315 extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);
316 extern void zio_flush_vdev(spa_t *spa, uint64_t vdev, zio_t **zio);
317 
318 extern int zio_wait(zio_t *zio);
319 extern void zio_nowait(zio_t *zio);
320 
321 extern void *zio_buf_alloc(size_t size);
322 extern void zio_buf_free(void *buf, size_t size);
323 extern void *zio_data_buf_alloc(size_t size);
324 extern void zio_data_buf_free(void *buf, size_t size);
325 
326 /*
327  * Move an I/O to the next stage of the pipeline and execute that stage.
328  * There's no locking on io_stage because there's no legitimate way for
329  * multiple threads to be attempting to process the same I/O.
330  */
331 extern void zio_next_stage(zio_t *zio);
332 extern void zio_next_stage_async(zio_t *zio);
333 extern void zio_resubmit_stage_async(void *);
334 extern void zio_wait_children_done(zio_t *zio);
335 
336 /*
337  * Delegate I/O to a child vdev.
338  */
339 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
340     uint64_t offset, void *data, uint64_t size, int type, int priority,
341     int flags, zio_done_func_t *done, void *private);
342 
343 extern void zio_vdev_io_bypass(zio_t *zio);
344 extern void zio_vdev_io_reissue(zio_t *zio);
345 extern void zio_vdev_io_redone(zio_t *zio);
346 
347 extern void zio_checksum_verified(zio_t *zio);
348 extern void zio_set_gang_verifier(zio_t *zio, zio_cksum_t *zcp);
349 
350 extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
351 extern uint8_t zio_compress_select(uint8_t child, uint8_t parent);
352 
353 extern boolean_t zio_should_retry(zio_t *zio);
354 extern int zio_vdev_resume_io(spa_t *);
355 
356 /*
357  * Initial setup and teardown.
358  */
359 extern void zio_init(void);
360 extern void zio_fini(void);
361 
362 /*
363  * Fault injection
364  */
365 struct zinject_record;
366 extern uint32_t zio_injection_enabled;
367 extern int zio_inject_fault(char *name, int flags, int *id,
368     struct zinject_record *record);
369 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
370     struct zinject_record *record);
371 extern int zio_clear_fault(int id);
372 extern int zio_handle_fault_injection(zio_t *zio, int error);
373 extern int zio_handle_device_injection(vdev_t *vd, int error);
374 
375 #ifdef	__cplusplus
376 }
377 #endif
378 
379 #endif	/* _ZIO_H */
380