xref: /titanic_51/usr/src/uts/common/fs/zfs/sys/zio.h (revision 733ed7372ce52463509c62783a184105d3f1a618)
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_FUNCTIONS
94 };
95 
96 #define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
97 #define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
98 
99 #define	ZIO_PRIORITY_NOW		(zio_priority_table[0])
100 #define	ZIO_PRIORITY_SYNC_READ		(zio_priority_table[1])
101 #define	ZIO_PRIORITY_SYNC_WRITE		(zio_priority_table[2])
102 #define	ZIO_PRIORITY_ASYNC_READ		(zio_priority_table[3])
103 #define	ZIO_PRIORITY_ASYNC_WRITE	(zio_priority_table[4])
104 #define	ZIO_PRIORITY_FREE		(zio_priority_table[5])
105 #define	ZIO_PRIORITY_CACHE_FILL		(zio_priority_table[6])
106 #define	ZIO_PRIORITY_LOG_WRITE		(zio_priority_table[7])
107 #define	ZIO_PRIORITY_RESILVER		(zio_priority_table[8])
108 #define	ZIO_PRIORITY_SCRUB		(zio_priority_table[9])
109 #define	ZIO_PRIORITY_TABLE_SIZE		10
110 
111 #define	ZIO_FLAG_MUSTSUCCEED		0x00000
112 #define	ZIO_FLAG_CANFAIL		0x00001
113 #define	ZIO_FLAG_FAILFAST		0x00002
114 #define	ZIO_FLAG_CONFIG_HELD		0x00004
115 
116 #define	ZIO_FLAG_DONT_CACHE		0x00010
117 #define	ZIO_FLAG_DONT_QUEUE		0x00020
118 #define	ZIO_FLAG_DONT_PROPAGATE		0x00040
119 #define	ZIO_FLAG_DONT_RETRY		0x00080
120 
121 #define	ZIO_FLAG_PHYSICAL		0x00100
122 #define	ZIO_FLAG_IO_BYPASS		0x00200
123 #define	ZIO_FLAG_IO_REPAIR		0x00400
124 #define	ZIO_FLAG_SPECULATIVE		0x00800
125 
126 #define	ZIO_FLAG_RESILVER		0x01000
127 #define	ZIO_FLAG_SCRUB			0x02000
128 #define	ZIO_FLAG_SUBBLOCK		0x04000
129 
130 #define	ZIO_FLAG_NOBOOKMARK		0x10000
131 
132 #define	ZIO_FLAG_GANG_INHERIT		\
133 	(ZIO_FLAG_CANFAIL |		\
134 	ZIO_FLAG_FAILFAST |		\
135 	ZIO_FLAG_CONFIG_HELD |		\
136 	ZIO_FLAG_DONT_RETRY |		\
137 	ZIO_FLAG_IO_REPAIR |		\
138 	ZIO_FLAG_SPECULATIVE |		\
139 	ZIO_FLAG_RESILVER |		\
140 	ZIO_FLAG_SCRUB)
141 
142 #define	ZIO_FLAG_VDEV_INHERIT		\
143 	(ZIO_FLAG_GANG_INHERIT |	\
144 	ZIO_FLAG_DONT_CACHE |		\
145 	ZIO_FLAG_PHYSICAL)
146 
147 /*
148  * We'll take the unused errno 'EBADE' (from the Convergent graveyard)
149  * to indicate checksum errors.
150  */
151 #define	ECKSUM	EBADE
152 
153 typedef struct zio zio_t;
154 typedef void zio_done_func_t(zio_t *zio);
155 
156 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
157 extern char *zio_type_name[ZIO_TYPES];
158 
159 /*
160  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
161  * identifies any block in the pool.  By convention, the meta-objset (MOS)
162  * is objset 0, the meta-dnode is object 0, the root block (osphys_t) is
163  * level -1 of the meta-dnode, and intent log blocks (which are chained
164  * off the root block) have blkid == sequence number.  In summary:
165  *
166  *	mos is objset 0
167  *	meta-dnode is object 0
168  *	root block is <objset, 0, -1, 0>
169  *	intent log is <objset, 0, -1, ZIL sequence number>
170  *
171  * Note: this structure is called a bookmark because its first purpose was
172  * to remember where to resume a pool-wide traverse.  The absolute ordering
173  * for block visitation during traversal is defined in compare_bookmark().
174  *
175  * Note: this structure is passed between userland and the kernel.
176  * Therefore it must not change size or alignment between 32/64 bit
177  * compilation options.
178  */
179 typedef struct zbookmark {
180 	uint64_t	zb_objset;
181 	uint64_t	zb_object;
182 	int64_t		zb_level;
183 	uint64_t	zb_blkid;
184 } zbookmark_t;
185 
186 struct zio {
187 	/* Core information about this I/O */
188 	zio_t		*io_parent;
189 	zio_t		*io_root;
190 	spa_t		*io_spa;
191 	zbookmark_t	io_bookmark;
192 	enum zio_checksum io_checksum;
193 	enum zio_compress io_compress;
194 	int		io_ndvas;
195 	uint64_t	io_txg;
196 	blkptr_t	*io_bp;
197 	blkptr_t	io_bp_copy;
198 	zio_t		*io_child;
199 	zio_t		*io_sibling_prev;
200 	zio_t		*io_sibling_next;
201 	zio_transform_t *io_transform_stack;
202 	zio_t		*io_logical;
203 
204 	/* Callback info */
205 	zio_done_func_t	*io_done;
206 	void		*io_private;
207 	blkptr_t	io_bp_orig;
208 
209 	/* Data represented by this I/O */
210 	void		*io_data;
211 	uint64_t	io_size;
212 
213 	/* Stuff for the vdev stack */
214 	vdev_t		*io_vd;
215 	void		*io_vsd;
216 	uint64_t	io_offset;
217 	uint64_t	io_deadline;
218 	uint64_t	io_timestamp;
219 	avl_node_t	io_offset_node;
220 	avl_node_t	io_deadline_node;
221 	avl_tree_t	*io_vdev_tree;
222 	zio_t		*io_delegate_list;
223 	zio_t		*io_delegate_next;
224 
225 	/* Internal pipeline state */
226 	int		io_flags;
227 	enum zio_type	io_type;
228 	enum zio_stage	io_stage;
229 	uint8_t		io_stalled;
230 	uint8_t		io_priority;
231 	struct dk_callback io_dk_callback;
232 	int		io_cmd;
233 	int		io_retries;
234 	int		io_error;
235 	uint32_t	io_numerrors;
236 	uint32_t	io_pipeline;
237 	uint32_t	io_async_stages;
238 	uint64_t	io_children_notready;
239 	uint64_t	io_children_notdone;
240 	void		*io_waiter;
241 	kmutex_t	io_lock;
242 	kcondvar_t	io_cv;
243 
244 	/* FMA state */
245 	uint64_t	io_ena;
246 };
247 
248 extern zio_t *zio_null(zio_t *pio, spa_t *spa,
249     zio_done_func_t *done, void *private, int flags);
250 
251 extern zio_t *zio_root(spa_t *spa,
252     zio_done_func_t *done, void *private, int flags);
253 
254 extern zio_t *zio_read(zio_t *pio, spa_t *spa, blkptr_t *bp, void *data,
255     uint64_t size, zio_done_func_t *done, void *private,
256     int priority, int flags, zbookmark_t *zb);
257 
258 extern zio_t *zio_write(zio_t *pio, spa_t *spa, int checksum, int compress,
259     int ncopies, uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
260     zio_done_func_t *done, void *private, int priority, int flags,
261     zbookmark_t *zb);
262 
263 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, int checksum,
264     uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
265     zio_done_func_t *done, void *private, int priority, int flags,
266     zbookmark_t *zb);
267 
268 extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
269     zio_done_func_t *done, void *private);
270 
271 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
272     zio_done_func_t *done, void *private);
273 
274 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
275     zio_done_func_t *done, void *private, int priority, int flags);
276 
277 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
278     uint64_t size, void *data, int checksum,
279     zio_done_func_t *done, void *private, int priority, int flags);
280 
281 extern zio_t *zio_write_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 int zio_alloc_blk(spa_t *spa, int checksum, uint64_t size,
286     blkptr_t *bp, uint64_t txg);
287 extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);
288 
289 extern int zio_wait(zio_t *zio);
290 extern void zio_nowait(zio_t *zio);
291 
292 extern void *zio_buf_alloc(size_t size);
293 extern void zio_buf_free(void *buf, size_t size);
294 
295 /*
296  * Move an I/O to the next stage of the pipeline and execute that stage.
297  * There's no locking on io_stage because there's no legitimate way for
298  * multiple threads to be attempting to process the same I/O.
299  */
300 extern void zio_next_stage(zio_t *zio);
301 extern void zio_next_stage_async(zio_t *zio);
302 extern void zio_wait_children_done(zio_t *zio);
303 
304 /*
305  * Delegate I/O to a child vdev.
306  */
307 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
308     uint64_t offset, void *data, uint64_t size, int type, int priority,
309     int flags, zio_done_func_t *done, void *private);
310 
311 extern void zio_vdev_io_bypass(zio_t *zio);
312 extern void zio_vdev_io_reissue(zio_t *zio);
313 extern void zio_vdev_io_redone(zio_t *zio);
314 
315 extern void zio_checksum_verified(zio_t *zio);
316 extern void zio_set_gang_verifier(zio_t *zio, zio_cksum_t *zcp);
317 
318 extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
319 extern uint8_t zio_compress_select(uint8_t child, uint8_t parent);
320 
321 boolean_t zio_should_retry(zio_t *zio);
322 
323 /*
324  * Initial setup and teardown.
325  */
326 extern void zio_init(void);
327 extern void zio_fini(void);
328 
329 /*
330  * Fault injection
331  */
332 struct zinject_record;
333 extern uint32_t zio_injection_enabled;
334 extern int zio_inject_fault(char *name, int flags, int *id,
335     struct zinject_record *record);
336 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
337     struct zinject_record *record);
338 extern int zio_clear_fault(int id);
339 extern int zio_handle_fault_injection(zio_t *zio, int error);
340 extern int zio_handle_device_injection(vdev_t *vd, int error);
341 
342 #ifdef	__cplusplus
343 }
344 #endif
345 
346 #endif	/* _ZIO_H */
347