xref: /titanic_50/usr/src/uts/common/fs/zfs/sys/zio.h (revision 4e5b757fbcf21077677360be274461dcd9064106)
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_PRIORITY_NOW		(zio_priority_table[0])
111 #define	ZIO_PRIORITY_SYNC_READ		(zio_priority_table[1])
112 #define	ZIO_PRIORITY_SYNC_WRITE		(zio_priority_table[2])
113 #define	ZIO_PRIORITY_ASYNC_READ		(zio_priority_table[3])
114 #define	ZIO_PRIORITY_ASYNC_WRITE	(zio_priority_table[4])
115 #define	ZIO_PRIORITY_FREE		(zio_priority_table[5])
116 #define	ZIO_PRIORITY_CACHE_FILL		(zio_priority_table[6])
117 #define	ZIO_PRIORITY_LOG_WRITE		(zio_priority_table[7])
118 #define	ZIO_PRIORITY_RESILVER		(zio_priority_table[8])
119 #define	ZIO_PRIORITY_SCRUB		(zio_priority_table[9])
120 #define	ZIO_PRIORITY_TABLE_SIZE		10
121 
122 #define	ZIO_FLAG_MUSTSUCCEED		0x00000
123 #define	ZIO_FLAG_CANFAIL		0x00001
124 #define	ZIO_FLAG_FAILFAST		0x00002
125 #define	ZIO_FLAG_CONFIG_HELD		0x00004
126 #define	ZIO_FLAG_CONFIG_GRABBED		0x00008
127 
128 #define	ZIO_FLAG_DONT_CACHE		0x00010
129 #define	ZIO_FLAG_DONT_QUEUE		0x00020
130 #define	ZIO_FLAG_DONT_PROPAGATE		0x00040
131 #define	ZIO_FLAG_DONT_RETRY		0x00080
132 
133 #define	ZIO_FLAG_PHYSICAL		0x00100
134 #define	ZIO_FLAG_IO_BYPASS		0x00200
135 #define	ZIO_FLAG_IO_REPAIR		0x00400
136 #define	ZIO_FLAG_SPECULATIVE		0x00800
137 
138 #define	ZIO_FLAG_RESILVER		0x01000
139 #define	ZIO_FLAG_SCRUB			0x02000
140 #define	ZIO_FLAG_SCRUB_THREAD		0x04000
141 #define	ZIO_FLAG_SUBBLOCK		0x08000
142 
143 #define	ZIO_FLAG_NOBOOKMARK		0x10000
144 #define	ZIO_FLAG_USER			0x20000
145 
146 #define	ZIO_FLAG_METADATA		0x40000
147 
148 #define	ZIO_FLAG_GANG_INHERIT		\
149 	(ZIO_FLAG_CANFAIL |		\
150 	ZIO_FLAG_FAILFAST |		\
151 	ZIO_FLAG_CONFIG_HELD |		\
152 	ZIO_FLAG_DONT_RETRY |		\
153 	ZIO_FLAG_IO_REPAIR |		\
154 	ZIO_FLAG_SPECULATIVE |		\
155 	ZIO_FLAG_RESILVER |		\
156 	ZIO_FLAG_SCRUB |		\
157 	ZIO_FLAG_SCRUB_THREAD)
158 
159 #define	ZIO_FLAG_VDEV_INHERIT		\
160 	(ZIO_FLAG_GANG_INHERIT |	\
161 	ZIO_FLAG_DONT_CACHE |		\
162 	ZIO_FLAG_PHYSICAL)
163 
164 /*
165  * We'll take the unused errno 'EBADE' (from the Convergent graveyard)
166  * to indicate checksum errors.
167  */
168 #define	ECKSUM	EBADE
169 
170 typedef struct zio zio_t;
171 typedef void zio_done_func_t(zio_t *zio);
172 
173 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
174 extern char *zio_type_name[ZIO_TYPES];
175 
176 /*
177  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
178  * identifies any block in the pool.  By convention, the meta-objset (MOS)
179  * is objset 0, the meta-dnode is object 0, the root block (osphys_t) is
180  * level -1 of the meta-dnode, and intent log blocks (which are chained
181  * off the root block) have blkid == sequence number.  In summary:
182  *
183  *	mos is objset 0
184  *	meta-dnode is object 0
185  *	root block is <objset, 0, -1, 0>
186  *	intent log is <objset, 0, -1, ZIL sequence number>
187  *
188  * Note: this structure is called a bookmark because its first purpose was
189  * to remember where to resume a pool-wide traverse.  The absolute ordering
190  * for block visitation during traversal is defined in compare_bookmark().
191  *
192  * Note: this structure is passed between userland and the kernel.
193  * Therefore it must not change size or alignment between 32/64 bit
194  * compilation options.
195  */
196 typedef struct zbookmark {
197 	uint64_t	zb_objset;
198 	uint64_t	zb_object;
199 	int64_t		zb_level;
200 	uint64_t	zb_blkid;
201 } zbookmark_t;
202 
203 struct zio {
204 	/* Core information about this I/O */
205 	zio_t		*io_parent;
206 	zio_t		*io_root;
207 	spa_t		*io_spa;
208 	zbookmark_t	io_bookmark;
209 	enum zio_checksum io_checksum;
210 	enum zio_compress io_compress;
211 	int		io_ndvas;
212 	uint64_t	io_txg;
213 	blkptr_t	*io_bp;
214 	blkptr_t	io_bp_copy;
215 	zio_t		*io_child;
216 	zio_t		*io_sibling_prev;
217 	zio_t		*io_sibling_next;
218 	zio_transform_t *io_transform_stack;
219 	zio_t		*io_logical;
220 
221 	/* Callback info */
222 	zio_done_func_t	*io_ready;
223 	zio_done_func_t	*io_done;
224 	void		*io_private;
225 	blkptr_t	io_bp_orig;
226 
227 	/* Data represented by this I/O */
228 	void		*io_data;
229 	uint64_t	io_size;
230 
231 	/* Stuff for the vdev stack */
232 	vdev_t		*io_vd;
233 	void		*io_vsd;
234 	uint64_t	io_offset;
235 	uint64_t	io_deadline;
236 	uint64_t	io_timestamp;
237 	avl_node_t	io_offset_node;
238 	avl_node_t	io_deadline_node;
239 	avl_tree_t	*io_vdev_tree;
240 	zio_t		*io_delegate_list;
241 	zio_t		*io_delegate_next;
242 
243 	/* Internal pipeline state */
244 	int		io_flags;
245 	enum zio_type	io_type;
246 	enum zio_stage	io_stage;
247 	uint8_t		io_stalled;
248 	uint8_t		io_priority;
249 	struct dk_callback io_dk_callback;
250 	int		io_cmd;
251 	int		io_retries;
252 	int		io_error;
253 	uint32_t	io_numerrors;
254 	uint32_t	io_pipeline;
255 	uint32_t	io_async_stages;
256 	uint64_t	io_children_notready;
257 	uint64_t	io_children_notdone;
258 	void		*io_waiter;
259 	kmutex_t	io_lock;
260 	kcondvar_t	io_cv;
261 
262 	/* FMA state */
263 	uint64_t	io_ena;
264 };
265 
266 extern zio_t *zio_null(zio_t *pio, spa_t *spa,
267     zio_done_func_t *done, void *private, int flags);
268 
269 extern zio_t *zio_root(spa_t *spa,
270     zio_done_func_t *done, void *private, int flags);
271 
272 extern zio_t *zio_read(zio_t *pio, spa_t *spa, blkptr_t *bp, void *data,
273     uint64_t size, zio_done_func_t *done, void *private,
274     int priority, int flags, zbookmark_t *zb);
275 
276 extern zio_t *zio_write(zio_t *pio, spa_t *spa, int checksum, int compress,
277     int ncopies, uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
278     zio_done_func_t *ready, zio_done_func_t *done, void *private, int priority,
279     int flags, zbookmark_t *zb);
280 
281 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, int checksum,
282     uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
283     zio_done_func_t *done, void *private, int priority, int flags,
284     zbookmark_t *zb);
285 
286 extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
287     zio_done_func_t *done, void *private);
288 
289 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
290     zio_done_func_t *done, void *private);
291 
292 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
293     zio_done_func_t *done, void *private, int priority, int flags);
294 
295 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
296     uint64_t size, void *data, int checksum,
297     zio_done_func_t *done, void *private, int priority, int flags);
298 
299 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
300     uint64_t size, void *data, int checksum,
301     zio_done_func_t *done, void *private, int priority, int flags);
302 
303 extern int zio_alloc_blk(spa_t *spa, uint64_t size, blkptr_t *new_bp,
304     blkptr_t *old_bp, uint64_t txg);
305 extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);
306 
307 extern int zio_wait(zio_t *zio);
308 extern void zio_nowait(zio_t *zio);
309 
310 extern void *zio_buf_alloc(size_t size);
311 extern void zio_buf_free(void *buf, size_t size);
312 extern void *zio_data_buf_alloc(size_t size);
313 extern void zio_data_buf_free(void *buf, size_t size);
314 
315 /*
316  * Move an I/O to the next stage of the pipeline and execute that stage.
317  * There's no locking on io_stage because there's no legitimate way for
318  * multiple threads to be attempting to process the same I/O.
319  */
320 extern void zio_next_stage(zio_t *zio);
321 extern void zio_next_stage_async(zio_t *zio);
322 extern void zio_wait_children_done(zio_t *zio);
323 
324 /*
325  * Delegate I/O to a child vdev.
326  */
327 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
328     uint64_t offset, void *data, uint64_t size, int type, int priority,
329     int flags, zio_done_func_t *done, void *private);
330 
331 extern void zio_vdev_io_bypass(zio_t *zio);
332 extern void zio_vdev_io_reissue(zio_t *zio);
333 extern void zio_vdev_io_redone(zio_t *zio);
334 
335 extern void zio_checksum_verified(zio_t *zio);
336 extern void zio_set_gang_verifier(zio_t *zio, zio_cksum_t *zcp);
337 
338 extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
339 extern uint8_t zio_compress_select(uint8_t child, uint8_t parent);
340 
341 boolean_t zio_should_retry(zio_t *zio);
342 
343 /*
344  * Initial setup and teardown.
345  */
346 extern void zio_init(void);
347 extern void zio_fini(void);
348 
349 /*
350  * Fault injection
351  */
352 struct zinject_record;
353 extern uint32_t zio_injection_enabled;
354 extern int zio_inject_fault(char *name, int flags, int *id,
355     struct zinject_record *record);
356 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
357     struct zinject_record *record);
358 extern int zio_clear_fault(int id);
359 extern int zio_handle_fault_injection(zio_t *zio, int error);
360 extern int zio_handle_device_injection(vdev_t *vd, int error);
361 
362 #ifdef	__cplusplus
363 }
364 #endif
365 
366 #endif	/* _ZIO_H */
367