xref: /titanic_52/usr/src/uts/common/fs/zfs/sys/zio.h (revision 0a44ef6d9afbfe052a7e975f55ea0d2954b62a82)
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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef _ZIO_H
27 #define	_ZIO_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/zfs_context.h>
32 #include <sys/spa.h>
33 #include <sys/txg.h>
34 #include <sys/avl.h>
35 #include <sys/dkio.h>
36 #include <sys/fs/zfs.h>
37 #include <sys/zio_impl.h>
38 
39 #ifdef	__cplusplus
40 extern "C" {
41 #endif
42 
43 #define	ZBT_MAGIC	0x210da7ab10c7a11ULL	/* zio data bloc tail */
44 
45 typedef struct zio_block_tail {
46 	uint64_t	zbt_magic;	/* for validation, endianness	*/
47 	zio_cksum_t	zbt_cksum;	/* 256-bit checksum		*/
48 } zio_block_tail_t;
49 
50 /*
51  * Gang block headers are self-checksumming and contain an array
52  * of block pointers.
53  */
54 #define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
55 #define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
56 	sizeof (zio_block_tail_t)) / sizeof (blkptr_t))
57 #define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
58 	sizeof (zio_block_tail_t) - \
59 	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
60 	sizeof (uint64_t))
61 
62 #define	ZIO_GET_IOSIZE(zio)	\
63 	(BP_IS_GANG((zio)->io_bp) ? \
64 	SPA_GANGBLOCKSIZE : BP_GET_PSIZE((zio)->io_bp))
65 
66 typedef struct zio_gbh {
67 	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
68 	uint64_t		zg_filler[SPA_GBH_FILLER];
69 	zio_block_tail_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_FUNCTIONS
83 };
84 
85 #define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_2
86 #define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
87 
88 enum zio_compress {
89 	ZIO_COMPRESS_INHERIT = 0,
90 	ZIO_COMPRESS_ON,
91 	ZIO_COMPRESS_OFF,
92 	ZIO_COMPRESS_LZJB,
93 	ZIO_COMPRESS_EMPTY,
94 	ZIO_COMPRESS_FUNCTIONS
95 };
96 
97 #define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
98 #define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
99 
100 #define	ZIO_PRIORITY_NOW		(zio_priority_table[0])
101 #define	ZIO_PRIORITY_SYNC_READ		(zio_priority_table[1])
102 #define	ZIO_PRIORITY_SYNC_WRITE		(zio_priority_table[2])
103 #define	ZIO_PRIORITY_ASYNC_READ		(zio_priority_table[3])
104 #define	ZIO_PRIORITY_ASYNC_WRITE	(zio_priority_table[4])
105 #define	ZIO_PRIORITY_FREE		(zio_priority_table[5])
106 #define	ZIO_PRIORITY_CACHE_FILL		(zio_priority_table[6])
107 #define	ZIO_PRIORITY_LOG_WRITE		(zio_priority_table[7])
108 #define	ZIO_PRIORITY_RESILVER		(zio_priority_table[8])
109 #define	ZIO_PRIORITY_SCRUB		(zio_priority_table[9])
110 #define	ZIO_PRIORITY_TABLE_SIZE		10
111 
112 #define	ZIO_FLAG_MUSTSUCCEED		0x00000
113 #define	ZIO_FLAG_CANFAIL		0x00001
114 #define	ZIO_FLAG_FAILFAST		0x00002
115 #define	ZIO_FLAG_CONFIG_HELD		0x00004
116 
117 #define	ZIO_FLAG_DONT_CACHE		0x00010
118 #define	ZIO_FLAG_DONT_QUEUE		0x00020
119 #define	ZIO_FLAG_DONT_PROPAGATE		0x00040
120 #define	ZIO_FLAG_DONT_RETRY		0x00080
121 
122 #define	ZIO_FLAG_PHYSICAL		0x00100
123 #define	ZIO_FLAG_IO_BYPASS		0x00200
124 #define	ZIO_FLAG_IO_REPAIR		0x00400
125 #define	ZIO_FLAG_SPECULATIVE		0x00800
126 
127 #define	ZIO_FLAG_RESILVER		0x01000
128 #define	ZIO_FLAG_SCRUB			0x02000
129 #define	ZIO_FLAG_SCRUB_THREAD		0x04000
130 #define	ZIO_FLAG_SUBBLOCK		0x08000
131 
132 #define	ZIO_FLAG_NOBOOKMARK		0x10000
133 #define	ZIO_FLAG_USER			0x20000
134 
135 #define	ZIO_FLAG_GANG_INHERIT		\
136 	(ZIO_FLAG_CANFAIL |		\
137 	ZIO_FLAG_FAILFAST |		\
138 	ZIO_FLAG_CONFIG_HELD |		\
139 	ZIO_FLAG_DONT_RETRY |		\
140 	ZIO_FLAG_IO_REPAIR |		\
141 	ZIO_FLAG_SPECULATIVE |		\
142 	ZIO_FLAG_RESILVER |		\
143 	ZIO_FLAG_SCRUB |		\
144 	ZIO_FLAG_SCRUB_THREAD)
145 
146 #define	ZIO_FLAG_VDEV_INHERIT		\
147 	(ZIO_FLAG_GANG_INHERIT |	\
148 	ZIO_FLAG_DONT_CACHE |		\
149 	ZIO_FLAG_PHYSICAL)
150 
151 /*
152  * We'll take the unused errno 'EBADE' (from the Convergent graveyard)
153  * to indicate checksum errors.
154  */
155 #define	ECKSUM	EBADE
156 
157 typedef struct zio zio_t;
158 typedef void zio_done_func_t(zio_t *zio);
159 
160 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
161 extern char *zio_type_name[ZIO_TYPES];
162 
163 /*
164  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
165  * identifies any block in the pool.  By convention, the meta-objset (MOS)
166  * is objset 0, the meta-dnode is object 0, the root block (osphys_t) is
167  * level -1 of the meta-dnode, and intent log blocks (which are chained
168  * off the root block) have blkid == sequence number.  In summary:
169  *
170  *	mos is objset 0
171  *	meta-dnode is object 0
172  *	root block is <objset, 0, -1, 0>
173  *	intent log is <objset, 0, -1, ZIL sequence number>
174  *
175  * Note: this structure is called a bookmark because its first purpose was
176  * to remember where to resume a pool-wide traverse.  The absolute ordering
177  * for block visitation during traversal is defined in compare_bookmark().
178  *
179  * Note: this structure is passed between userland and the kernel.
180  * Therefore it must not change size or alignment between 32/64 bit
181  * compilation options.
182  */
183 typedef struct zbookmark {
184 	uint64_t	zb_objset;
185 	uint64_t	zb_object;
186 	int64_t		zb_level;
187 	uint64_t	zb_blkid;
188 } zbookmark_t;
189 
190 struct zio {
191 	/* Core information about this I/O */
192 	zio_t		*io_parent;
193 	zio_t		*io_root;
194 	spa_t		*io_spa;
195 	zbookmark_t	io_bookmark;
196 	enum zio_checksum io_checksum;
197 	enum zio_compress io_compress;
198 	int		io_ndvas;
199 	uint64_t	io_txg;
200 	blkptr_t	*io_bp;
201 	blkptr_t	io_bp_copy;
202 	zio_t		*io_child;
203 	zio_t		*io_sibling_prev;
204 	zio_t		*io_sibling_next;
205 	zio_transform_t *io_transform_stack;
206 	zio_t		*io_logical;
207 
208 	/* Callback info */
209 	zio_done_func_t	*io_done;
210 	void		*io_private;
211 	blkptr_t	io_bp_orig;
212 
213 	/* Data represented by this I/O */
214 	void		*io_data;
215 	uint64_t	io_size;
216 
217 	/* Stuff for the vdev stack */
218 	vdev_t		*io_vd;
219 	void		*io_vsd;
220 	uint64_t	io_offset;
221 	uint64_t	io_deadline;
222 	uint64_t	io_timestamp;
223 	avl_node_t	io_offset_node;
224 	avl_node_t	io_deadline_node;
225 	avl_tree_t	*io_vdev_tree;
226 	zio_t		*io_delegate_list;
227 	zio_t		*io_delegate_next;
228 
229 	/* Internal pipeline state */
230 	int		io_flags;
231 	enum zio_type	io_type;
232 	enum zio_stage	io_stage;
233 	uint8_t		io_stalled;
234 	uint8_t		io_priority;
235 	struct dk_callback io_dk_callback;
236 	int		io_cmd;
237 	int		io_retries;
238 	int		io_error;
239 	uint32_t	io_numerrors;
240 	uint32_t	io_pipeline;
241 	uint32_t	io_async_stages;
242 	uint64_t	io_children_notready;
243 	uint64_t	io_children_notdone;
244 	void		*io_waiter;
245 	kmutex_t	io_lock;
246 	kcondvar_t	io_cv;
247 
248 	/* FMA state */
249 	uint64_t	io_ena;
250 };
251 
252 extern zio_t *zio_null(zio_t *pio, spa_t *spa,
253     zio_done_func_t *done, void *private, int flags);
254 
255 extern zio_t *zio_root(spa_t *spa,
256     zio_done_func_t *done, void *private, int flags);
257 
258 extern zio_t *zio_read(zio_t *pio, spa_t *spa, blkptr_t *bp, void *data,
259     uint64_t size, zio_done_func_t *done, void *private,
260     int priority, int flags, zbookmark_t *zb);
261 
262 extern zio_t *zio_write(zio_t *pio, spa_t *spa, int checksum, int compress,
263     int ncopies, uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
264     zio_done_func_t *done, void *private, int priority, int flags,
265     zbookmark_t *zb);
266 
267 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, int checksum,
268     uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
269     zio_done_func_t *done, void *private, int priority, int flags,
270     zbookmark_t *zb);
271 
272 extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
273     zio_done_func_t *done, void *private);
274 
275 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
276     zio_done_func_t *done, void *private);
277 
278 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
279     zio_done_func_t *done, void *private, int priority, int flags);
280 
281 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
282     uint64_t size, void *data, int checksum,
283     zio_done_func_t *done, void *private, int priority, int flags);
284 
285 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
286     uint64_t size, void *data, int checksum,
287     zio_done_func_t *done, void *private, int priority, int flags);
288 
289 extern int zio_alloc_blk(spa_t *spa, uint64_t size, blkptr_t *new_bp,
290     blkptr_t *old_bp, uint64_t txg);
291 extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);
292 
293 extern int zio_wait(zio_t *zio);
294 extern void zio_nowait(zio_t *zio);
295 
296 extern void *zio_buf_alloc(size_t size);
297 extern void zio_buf_free(void *buf, size_t size);
298 
299 /*
300  * Move an I/O to the next stage of the pipeline and execute that stage.
301  * There's no locking on io_stage because there's no legitimate way for
302  * multiple threads to be attempting to process the same I/O.
303  */
304 extern void zio_next_stage(zio_t *zio);
305 extern void zio_next_stage_async(zio_t *zio);
306 extern void zio_wait_children_done(zio_t *zio);
307 
308 /*
309  * Delegate I/O to a child vdev.
310  */
311 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
312     uint64_t offset, void *data, uint64_t size, int type, int priority,
313     int flags, zio_done_func_t *done, void *private);
314 
315 extern void zio_vdev_io_bypass(zio_t *zio);
316 extern void zio_vdev_io_reissue(zio_t *zio);
317 extern void zio_vdev_io_redone(zio_t *zio);
318 
319 extern void zio_checksum_verified(zio_t *zio);
320 extern void zio_set_gang_verifier(zio_t *zio, zio_cksum_t *zcp);
321 
322 extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
323 extern uint8_t zio_compress_select(uint8_t child, uint8_t parent);
324 
325 boolean_t zio_should_retry(zio_t *zio);
326 
327 /*
328  * Initial setup and teardown.
329  */
330 extern void zio_init(void);
331 extern void zio_fini(void);
332 
333 /*
334  * Fault injection
335  */
336 struct zinject_record;
337 extern uint32_t zio_injection_enabled;
338 extern int zio_inject_fault(char *name, int flags, int *id,
339     struct zinject_record *record);
340 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
341     struct zinject_record *record);
342 extern int zio_clear_fault(int id);
343 extern int zio_handle_fault_injection(zio_t *zio, int error);
344 extern int zio_handle_device_injection(vdev_t *vd, int error);
345 
346 #ifdef	__cplusplus
347 }
348 #endif
349 
350 #endif	/* _ZIO_H */
351