xref: /titanic_44/usr/src/uts/common/fs/zfs/sys/spa.h (revision 940c61f284366ef6845abe1c4002504280d7f0f2)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright 2013 Saso Kiselkov. All rights reserved.
24  * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
25  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
26  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
27  */
28 
29 #ifndef _SYS_SPA_H
30 #define	_SYS_SPA_H
31 
32 #include <sys/avl.h>
33 #include <sys/zfs_context.h>
34 #include <sys/nvpair.h>
35 #include <sys/sysmacros.h>
36 #include <sys/types.h>
37 #include <sys/fs/zfs.h>
38 
39 #ifdef	__cplusplus
40 extern "C" {
41 #endif
42 
43 /*
44  * Forward references that lots of things need.
45  */
46 typedef struct spa spa_t;
47 typedef struct vdev vdev_t;
48 typedef struct metaslab metaslab_t;
49 typedef struct metaslab_group metaslab_group_t;
50 typedef struct metaslab_class metaslab_class_t;
51 typedef struct zio zio_t;
52 typedef struct zilog zilog_t;
53 typedef struct spa_aux_vdev spa_aux_vdev_t;
54 typedef struct ddt ddt_t;
55 typedef struct ddt_entry ddt_entry_t;
56 struct dsl_pool;
57 struct dsl_dataset;
58 
59 /*
60  * General-purpose 32-bit and 64-bit bitfield encodings.
61  */
62 #define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))
63 #define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))
64 #define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))
65 #define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))
66 
67 #define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)
68 #define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)
69 
70 #define	BF32_SET(x, low, len, val) do { \
71 	ASSERT3U(val, <, 1U << (len)); \
72 	ASSERT3U(low + len, <=, 32); \
73 	(x) ^= BF32_ENCODE((x >> low) ^ (val), low, len); \
74 _NOTE(CONSTCOND) } while (0)
75 
76 #define	BF64_SET(x, low, len, val) do { \
77 	ASSERT3U(val, <, 1ULL << (len)); \
78 	ASSERT3U(low + len, <=, 64); \
79 	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len)); \
80 _NOTE(CONSTCOND) } while (0)
81 
82 #define	BF32_GET_SB(x, low, len, shift, bias)	\
83 	((BF32_GET(x, low, len) + (bias)) << (shift))
84 #define	BF64_GET_SB(x, low, len, shift, bias)	\
85 	((BF64_GET(x, low, len) + (bias)) << (shift))
86 
87 #define	BF32_SET_SB(x, low, len, shift, bias, val) do { \
88 	ASSERT(IS_P2ALIGNED(val, 1U << shift)); \
89 	ASSERT3S((val) >> (shift), >=, bias); \
90 	BF32_SET(x, low, len, ((val) >> (shift)) - (bias)); \
91 _NOTE(CONSTCOND) } while (0)
92 #define	BF64_SET_SB(x, low, len, shift, bias, val) do { \
93 	ASSERT(IS_P2ALIGNED(val, 1ULL << shift)); \
94 	ASSERT3S((val) >> (shift), >=, bias); \
95 	BF64_SET(x, low, len, ((val) >> (shift)) - (bias)); \
96 _NOTE(CONSTCOND) } while (0)
97 
98 /*
99  * We currently support block sizes from 512 bytes to 16MB.
100  * The benefits of larger blocks, and thus larger IO, need to be weighed
101  * against the cost of COWing a giant block to modify one byte, and the
102  * large latency of reading or writing a large block.
103  *
104  * Note that although blocks up to 16MB are supported, the recordsize
105  * property can not be set larger than zfs_max_recordsize (default 1MB).
106  * See the comment near zfs_max_recordsize in dsl_dataset.c for details.
107  *
108  * Note that although the LSIZE field of the blkptr_t can store sizes up
109  * to 32MB, the dnode's dn_datablkszsec can only store sizes up to
110  * 32MB - 512 bytes.  Therefore, we limit SPA_MAXBLOCKSIZE to 16MB.
111  */
112 #define	SPA_MINBLOCKSHIFT	9
113 #define	SPA_OLD_MAXBLOCKSHIFT	17
114 #define	SPA_MAXBLOCKSHIFT	24
115 #define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)
116 #define	SPA_OLD_MAXBLOCKSIZE	(1ULL << SPA_OLD_MAXBLOCKSHIFT)
117 #define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)
118 
119 /*
120  * Size of block to hold the configuration data (a packed nvlist)
121  */
122 #define	SPA_CONFIG_BLOCKSIZE	(1ULL << 14)
123 
124 /*
125  * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
126  * The ASIZE encoding should be at least 64 times larger (6 more bits)
127  * to support up to 4-way RAID-Z mirror mode with worst-case gang block
128  * overhead, three DVAs per bp, plus one more bit in case we do anything
129  * else that expands the ASIZE.
130  */
131 #define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/
132 #define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/
133 #define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/
134 
135 /*
136  * All SPA data is represented by 128-bit data virtual addresses (DVAs).
137  * The members of the dva_t should be considered opaque outside the SPA.
138  */
139 typedef struct dva {
140 	uint64_t	dva_word[2];
141 } dva_t;
142 
143 /*
144  * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
145  */
146 typedef struct zio_cksum {
147 	uint64_t	zc_word[4];
148 } zio_cksum_t;
149 
150 /*
151  * Each block is described by its DVAs, time of birth, checksum, etc.
152  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
153  *
154  *	64	56	48	40	32	24	16	8	0
155  *	+-------+-------+-------+-------+-------+-------+-------+-------+
156  * 0	|		vdev1		| GRID  |	  ASIZE		|
157  *	+-------+-------+-------+-------+-------+-------+-------+-------+
158  * 1	|G|			 offset1				|
159  *	+-------+-------+-------+-------+-------+-------+-------+-------+
160  * 2	|		vdev2		| GRID  |	  ASIZE		|
161  *	+-------+-------+-------+-------+-------+-------+-------+-------+
162  * 3	|G|			 offset2				|
163  *	+-------+-------+-------+-------+-------+-------+-------+-------+
164  * 4	|		vdev3		| GRID  |	  ASIZE		|
165  *	+-------+-------+-------+-------+-------+-------+-------+-------+
166  * 5	|G|			 offset3				|
167  *	+-------+-------+-------+-------+-------+-------+-------+-------+
168  * 6	|BDX|lvl| type	| cksum |E| comp|    PSIZE	|     LSIZE	|
169  *	+-------+-------+-------+-------+-------+-------+-------+-------+
170  * 7	|			padding					|
171  *	+-------+-------+-------+-------+-------+-------+-------+-------+
172  * 8	|			padding					|
173  *	+-------+-------+-------+-------+-------+-------+-------+-------+
174  * 9	|			physical birth txg			|
175  *	+-------+-------+-------+-------+-------+-------+-------+-------+
176  * a	|			logical birth txg			|
177  *	+-------+-------+-------+-------+-------+-------+-------+-------+
178  * b	|			fill count				|
179  *	+-------+-------+-------+-------+-------+-------+-------+-------+
180  * c	|			checksum[0]				|
181  *	+-------+-------+-------+-------+-------+-------+-------+-------+
182  * d	|			checksum[1]				|
183  *	+-------+-------+-------+-------+-------+-------+-------+-------+
184  * e	|			checksum[2]				|
185  *	+-------+-------+-------+-------+-------+-------+-------+-------+
186  * f	|			checksum[3]				|
187  *	+-------+-------+-------+-------+-------+-------+-------+-------+
188  *
189  * Legend:
190  *
191  * vdev		virtual device ID
192  * offset	offset into virtual device
193  * LSIZE	logical size
194  * PSIZE	physical size (after compression)
195  * ASIZE	allocated size (including RAID-Z parity and gang block headers)
196  * GRID		RAID-Z layout information (reserved for future use)
197  * cksum	checksum function
198  * comp		compression function
199  * G		gang block indicator
200  * B		byteorder (endianness)
201  * D		dedup
202  * X		encryption (on version 30, which is not supported)
203  * E		blkptr_t contains embedded data (see below)
204  * lvl		level of indirection
205  * type		DMU object type
206  * phys birth	txg of block allocation; zero if same as logical birth txg
207  * log. birth	transaction group in which the block was logically born
208  * fill count	number of non-zero blocks under this bp
209  * checksum[4]	256-bit checksum of the data this bp describes
210  */
211 
212 /*
213  * "Embedded" blkptr_t's don't actually point to a block, instead they
214  * have a data payload embedded in the blkptr_t itself.  See the comment
215  * in blkptr.c for more details.
216  *
217  * The blkptr_t is laid out as follows:
218  *
219  *	64	56	48	40	32	24	16	8	0
220  *	+-------+-------+-------+-------+-------+-------+-------+-------+
221  * 0	|      payload                                                  |
222  * 1	|      payload                                                  |
223  * 2	|      payload                                                  |
224  * 3	|      payload                                                  |
225  * 4	|      payload                                                  |
226  * 5	|      payload                                                  |
227  *	+-------+-------+-------+-------+-------+-------+-------+-------+
228  * 6	|BDX|lvl| type	| etype |E| comp| PSIZE|              LSIZE	|
229  *	+-------+-------+-------+-------+-------+-------+-------+-------+
230  * 7	|      payload                                                  |
231  * 8	|      payload                                                  |
232  * 9	|      payload                                                  |
233  *	+-------+-------+-------+-------+-------+-------+-------+-------+
234  * a	|			logical birth txg			|
235  *	+-------+-------+-------+-------+-------+-------+-------+-------+
236  * b	|      payload                                                  |
237  * c	|      payload                                                  |
238  * d	|      payload                                                  |
239  * e	|      payload                                                  |
240  * f	|      payload                                                  |
241  *	+-------+-------+-------+-------+-------+-------+-------+-------+
242  *
243  * Legend:
244  *
245  * payload		contains the embedded data
246  * B (byteorder)	byteorder (endianness)
247  * D (dedup)		padding (set to zero)
248  * X			encryption (set to zero; see above)
249  * E (embedded)		set to one
250  * lvl			indirection level
251  * type			DMU object type
252  * etype		how to interpret embedded data (BP_EMBEDDED_TYPE_*)
253  * comp			compression function of payload
254  * PSIZE		size of payload after compression, in bytes
255  * LSIZE		logical size of payload, in bytes
256  *			note that 25 bits is enough to store the largest
257  *			"normal" BP's LSIZE (2^16 * 2^9) in bytes
258  * log. birth		transaction group in which the block was logically born
259  *
260  * Note that LSIZE and PSIZE are stored in bytes, whereas for non-embedded
261  * bp's they are stored in units of SPA_MINBLOCKSHIFT.
262  * Generally, the generic BP_GET_*() macros can be used on embedded BP's.
263  * The B, D, X, lvl, type, and comp fields are stored the same as with normal
264  * BP's so the BP_SET_* macros can be used with them.  etype, PSIZE, LSIZE must
265  * be set with the BPE_SET_* macros.  BP_SET_EMBEDDED() should be called before
266  * other macros, as they assert that they are only used on BP's of the correct
267  * "embedded-ness".
268  */
269 
270 #define	BPE_GET_ETYPE(bp)	\
271 	(ASSERT(BP_IS_EMBEDDED(bp)), \
272 	BF64_GET((bp)->blk_prop, 40, 8))
273 #define	BPE_SET_ETYPE(bp, t)	do { \
274 	ASSERT(BP_IS_EMBEDDED(bp)); \
275 	BF64_SET((bp)->blk_prop, 40, 8, t); \
276 _NOTE(CONSTCOND) } while (0)
277 
278 #define	BPE_GET_LSIZE(bp)	\
279 	(ASSERT(BP_IS_EMBEDDED(bp)), \
280 	BF64_GET_SB((bp)->blk_prop, 0, 25, 0, 1))
281 #define	BPE_SET_LSIZE(bp, x)	do { \
282 	ASSERT(BP_IS_EMBEDDED(bp)); \
283 	BF64_SET_SB((bp)->blk_prop, 0, 25, 0, 1, x); \
284 _NOTE(CONSTCOND) } while (0)
285 
286 #define	BPE_GET_PSIZE(bp)	\
287 	(ASSERT(BP_IS_EMBEDDED(bp)), \
288 	BF64_GET_SB((bp)->blk_prop, 25, 7, 0, 1))
289 #define	BPE_SET_PSIZE(bp, x)	do { \
290 	ASSERT(BP_IS_EMBEDDED(bp)); \
291 	BF64_SET_SB((bp)->blk_prop, 25, 7, 0, 1, x); \
292 _NOTE(CONSTCOND) } while (0)
293 
294 typedef enum bp_embedded_type {
295 	BP_EMBEDDED_TYPE_DATA,
296 	BP_EMBEDDED_TYPE_RESERVED, /* Reserved for an unintegrated feature. */
297 	NUM_BP_EMBEDDED_TYPES = BP_EMBEDDED_TYPE_RESERVED
298 } bp_embedded_type_t;
299 
300 #define	BPE_NUM_WORDS 14
301 #define	BPE_PAYLOAD_SIZE (BPE_NUM_WORDS * sizeof (uint64_t))
302 #define	BPE_IS_PAYLOADWORD(bp, wp) \
303 	((wp) != &(bp)->blk_prop && (wp) != &(bp)->blk_birth)
304 
305 #define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
306 #define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
307 
308 /*
309  * A block is a hole when it has either 1) never been written to, or
310  * 2) is zero-filled. In both cases, ZFS can return all zeroes for all reads
311  * without physically allocating disk space. Holes are represented in the
312  * blkptr_t structure by zeroed blk_dva. Correct checking for holes is
313  * done through the BP_IS_HOLE macro. For holes, the logical size, level,
314  * DMU object type, and birth times are all also stored for holes that
315  * were written to at some point (i.e. were punched after having been filled).
316  */
317 typedef struct blkptr {
318 	dva_t		blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
319 	uint64_t	blk_prop;	/* size, compression, type, etc	    */
320 	uint64_t	blk_pad[2];	/* Extra space for the future	    */
321 	uint64_t	blk_phys_birth;	/* txg when block was allocated	    */
322 	uint64_t	blk_birth;	/* transaction group at birth	    */
323 	uint64_t	blk_fill;	/* fill count			    */
324 	zio_cksum_t	blk_cksum;	/* 256-bit checksum		    */
325 } blkptr_t;
326 
327 /*
328  * Macros to get and set fields in a bp or DVA.
329  */
330 #define	DVA_GET_ASIZE(dva)	\
331 	BF64_GET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, SPA_MINBLOCKSHIFT, 0)
332 #define	DVA_SET_ASIZE(dva, x)	\
333 	BF64_SET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, \
334 	SPA_MINBLOCKSHIFT, 0, x)
335 
336 #define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
337 #define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
338 
339 #define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
340 #define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
341 
342 #define	DVA_GET_OFFSET(dva)	\
343 	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
344 #define	DVA_SET_OFFSET(dva, x)	\
345 	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
346 
347 #define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
348 #define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
349 
350 #define	BP_GET_LSIZE(bp)	\
351 	(BP_IS_EMBEDDED(bp) ?	\
352 	(BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA ? BPE_GET_LSIZE(bp) : 0): \
353 	BF64_GET_SB((bp)->blk_prop, 0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1))
354 #define	BP_SET_LSIZE(bp, x)	do { \
355 	ASSERT(!BP_IS_EMBEDDED(bp)); \
356 	BF64_SET_SB((bp)->blk_prop, \
357 	    0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
358 _NOTE(CONSTCOND) } while (0)
359 
360 #define	BP_GET_PSIZE(bp)	\
361 	(BP_IS_EMBEDDED(bp) ? 0 : \
362 	BF64_GET_SB((bp)->blk_prop, 16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1))
363 #define	BP_SET_PSIZE(bp, x)	do { \
364 	ASSERT(!BP_IS_EMBEDDED(bp)); \
365 	BF64_SET_SB((bp)->blk_prop, \
366 	    16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
367 _NOTE(CONSTCOND) } while (0)
368 
369 #define	BP_GET_COMPRESS(bp)		BF64_GET((bp)->blk_prop, 32, 7)
370 #define	BP_SET_COMPRESS(bp, x)		BF64_SET((bp)->blk_prop, 32, 7, x)
371 
372 #define	BP_IS_EMBEDDED(bp)		BF64_GET((bp)->blk_prop, 39, 1)
373 #define	BP_SET_EMBEDDED(bp, x)		BF64_SET((bp)->blk_prop, 39, 1, x)
374 
375 #define	BP_GET_CHECKSUM(bp)		\
376 	(BP_IS_EMBEDDED(bp) ? ZIO_CHECKSUM_OFF : \
377 	BF64_GET((bp)->blk_prop, 40, 8))
378 #define	BP_SET_CHECKSUM(bp, x)		do { \
379 	ASSERT(!BP_IS_EMBEDDED(bp)); \
380 	BF64_SET((bp)->blk_prop, 40, 8, x); \
381 _NOTE(CONSTCOND) } while (0)
382 
383 #define	BP_GET_TYPE(bp)			BF64_GET((bp)->blk_prop, 48, 8)
384 #define	BP_SET_TYPE(bp, x)		BF64_SET((bp)->blk_prop, 48, 8, x)
385 
386 #define	BP_GET_LEVEL(bp)		BF64_GET((bp)->blk_prop, 56, 5)
387 #define	BP_SET_LEVEL(bp, x)		BF64_SET((bp)->blk_prop, 56, 5, x)
388 
389 #define	BP_GET_DEDUP(bp)		BF64_GET((bp)->blk_prop, 62, 1)
390 #define	BP_SET_DEDUP(bp, x)		BF64_SET((bp)->blk_prop, 62, 1, x)
391 
392 #define	BP_GET_BYTEORDER(bp)		BF64_GET((bp)->blk_prop, 63, 1)
393 #define	BP_SET_BYTEORDER(bp, x)		BF64_SET((bp)->blk_prop, 63, 1, x)
394 
395 #define	BP_PHYSICAL_BIRTH(bp)		\
396 	(BP_IS_EMBEDDED(bp) ? 0 : \
397 	(bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
398 
399 #define	BP_SET_BIRTH(bp, logical, physical)	\
400 {						\
401 	ASSERT(!BP_IS_EMBEDDED(bp));		\
402 	(bp)->blk_birth = (logical);		\
403 	(bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
404 }
405 
406 #define	BP_GET_FILL(bp) (BP_IS_EMBEDDED(bp) ? 1 : (bp)->blk_fill)
407 
408 #define	BP_GET_ASIZE(bp)	\
409 	(BP_IS_EMBEDDED(bp) ? 0 : \
410 	DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
411 	DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
412 	DVA_GET_ASIZE(&(bp)->blk_dva[2]))
413 
414 #define	BP_GET_UCSIZE(bp) \
415 	((BP_GET_LEVEL(bp) > 0 || DMU_OT_IS_METADATA(BP_GET_TYPE(bp))) ? \
416 	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp))
417 
418 #define	BP_GET_NDVAS(bp)	\
419 	(BP_IS_EMBEDDED(bp) ? 0 : \
420 	!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
421 	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
422 	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
423 
424 #define	BP_COUNT_GANG(bp)	\
425 	(BP_IS_EMBEDDED(bp) ? 0 : \
426 	(DVA_GET_GANG(&(bp)->blk_dva[0]) + \
427 	DVA_GET_GANG(&(bp)->blk_dva[1]) + \
428 	DVA_GET_GANG(&(bp)->blk_dva[2])))
429 
430 #define	DVA_EQUAL(dva1, dva2)	\
431 	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
432 	(dva1)->dva_word[0] == (dva2)->dva_word[0])
433 
434 #define	BP_EQUAL(bp1, bp2)	\
435 	(BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&	\
436 	(bp1)->blk_birth == (bp2)->blk_birth &&			\
437 	DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&	\
438 	DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&	\
439 	DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
440 
441 #define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \
442 	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
443 	((zc1).zc_word[1] - (zc2).zc_word[1]) | \
444 	((zc1).zc_word[2] - (zc2).zc_word[2]) | \
445 	((zc1).zc_word[3] - (zc2).zc_word[3])))
446 
447 #define	ZIO_CHECKSUM_IS_ZERO(zc) \
448 	(0 == ((zc)->zc_word[0] | (zc)->zc_word[1] | \
449 	(zc)->zc_word[2] | (zc)->zc_word[3]))
450 
451 #define	ZIO_CHECKSUM_BSWAP(_zc) \
452 	do { \
453 		zio_cksum_t *zc = (_zc); \
454 		zc->zc_word[0] = BSWAP_64(zc->zc_word[0]); \
455 		zc->zc_word[1] = BSWAP_64(zc->zc_word[1]); \
456 		zc->zc_word[2] = BSWAP_64(zc->zc_word[2]); \
457 		zc->zc_word[3] = BSWAP_64(zc->zc_word[3]); \
458 		_NOTE(NOTREACHED) \
459 		_NOTE(CONSTCOND) \
460 	} while (0)
461 
462 #define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
463 
464 #define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
465 {						\
466 	(zcp)->zc_word[0] = w0;			\
467 	(zcp)->zc_word[1] = w1;			\
468 	(zcp)->zc_word[2] = w2;			\
469 	(zcp)->zc_word[3] = w3;			\
470 }
471 
472 #define	BP_IDENTITY(bp)		(ASSERT(!BP_IS_EMBEDDED(bp)), &(bp)->blk_dva[0])
473 #define	BP_IS_GANG(bp)		\
474 	(BP_IS_EMBEDDED(bp) ? B_FALSE : DVA_GET_GANG(BP_IDENTITY(bp)))
475 #define	DVA_IS_EMPTY(dva)	((dva)->dva_word[0] == 0ULL &&	\
476 				(dva)->dva_word[1] == 0ULL)
477 #define	BP_IS_HOLE(bp) \
478 	(!BP_IS_EMBEDDED(bp) && DVA_IS_EMPTY(BP_IDENTITY(bp)))
479 
480 /* BP_IS_RAIDZ(bp) assumes no block compression */
481 #define	BP_IS_RAIDZ(bp)		(DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
482 				BP_GET_PSIZE(bp))
483 
484 #define	BP_ZERO(bp)				\
485 {						\
486 	(bp)->blk_dva[0].dva_word[0] = 0;	\
487 	(bp)->blk_dva[0].dva_word[1] = 0;	\
488 	(bp)->blk_dva[1].dva_word[0] = 0;	\
489 	(bp)->blk_dva[1].dva_word[1] = 0;	\
490 	(bp)->blk_dva[2].dva_word[0] = 0;	\
491 	(bp)->blk_dva[2].dva_word[1] = 0;	\
492 	(bp)->blk_prop = 0;			\
493 	(bp)->blk_pad[0] = 0;			\
494 	(bp)->blk_pad[1] = 0;			\
495 	(bp)->blk_phys_birth = 0;		\
496 	(bp)->blk_birth = 0;			\
497 	(bp)->blk_fill = 0;			\
498 	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
499 }
500 
501 #ifdef _BIG_ENDIAN
502 #define	ZFS_HOST_BYTEORDER	(0ULL)
503 #else
504 #define	ZFS_HOST_BYTEORDER	(1ULL)
505 #endif
506 
507 #define	BP_SHOULD_BYTESWAP(bp)	(BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)
508 
509 #define	BP_SPRINTF_LEN	320
510 
511 /*
512  * This macro allows code sharing between zfs, libzpool, and mdb.
513  * 'func' is either snprintf() or mdb_snprintf().
514  * 'ws' (whitespace) can be ' ' for single-line format, '\n' for multi-line.
515  */
516 #define	SNPRINTF_BLKPTR(func, ws, buf, size, bp, type, checksum, compress) \
517 {									\
518 	static const char *copyname[] =					\
519 	    { "zero", "single", "double", "triple" };			\
520 	int len = 0;							\
521 	int copies = 0;							\
522 									\
523 	if (bp == NULL) {						\
524 		len += func(buf + len, size - len, "<NULL>");		\
525 	} else if (BP_IS_HOLE(bp)) {					\
526 		len += func(buf + len, size - len,			\
527 		    "HOLE [L%llu %s] "					\
528 		    "size=%llxL birth=%lluL",				\
529 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
530 		    type,						\
531 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
532 		    (u_longlong_t)bp->blk_birth);			\
533 	} else if (BP_IS_EMBEDDED(bp)) {				\
534 		len = func(buf + len, size - len,			\
535 		    "EMBEDDED [L%llu %s] et=%u %s "			\
536 		    "size=%llxL/%llxP birth=%lluL",			\
537 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
538 		    type,						\
539 		    (int)BPE_GET_ETYPE(bp),				\
540 		    compress,						\
541 		    (u_longlong_t)BPE_GET_LSIZE(bp),			\
542 		    (u_longlong_t)BPE_GET_PSIZE(bp),			\
543 		    (u_longlong_t)bp->blk_birth);			\
544 	} else {							\
545 		for (int d = 0; d < BP_GET_NDVAS(bp); d++) {		\
546 			const dva_t *dva = &bp->blk_dva[d];		\
547 			if (DVA_IS_VALID(dva))				\
548 				copies++;				\
549 			len += func(buf + len, size - len,		\
550 			    "DVA[%d]=<%llu:%llx:%llx>%c", d,		\
551 			    (u_longlong_t)DVA_GET_VDEV(dva),		\
552 			    (u_longlong_t)DVA_GET_OFFSET(dva),		\
553 			    (u_longlong_t)DVA_GET_ASIZE(dva),		\
554 			    ws);					\
555 		}							\
556 		if (BP_IS_GANG(bp) &&					\
557 		    DVA_GET_ASIZE(&bp->blk_dva[2]) <=			\
558 		    DVA_GET_ASIZE(&bp->blk_dva[1]) / 2)			\
559 			copies--;					\
560 		len += func(buf + len, size - len,			\
561 		    "[L%llu %s] %s %s %s %s %s %s%c"			\
562 		    "size=%llxL/%llxP birth=%lluL/%lluP fill=%llu%c"	\
563 		    "cksum=%llx:%llx:%llx:%llx",			\
564 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
565 		    type,						\
566 		    checksum,						\
567 		    compress,						\
568 		    BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",		\
569 		    BP_IS_GANG(bp) ? "gang" : "contiguous",		\
570 		    BP_GET_DEDUP(bp) ? "dedup" : "unique",		\
571 		    copyname[copies],					\
572 		    ws,							\
573 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
574 		    (u_longlong_t)BP_GET_PSIZE(bp),			\
575 		    (u_longlong_t)bp->blk_birth,			\
576 		    (u_longlong_t)BP_PHYSICAL_BIRTH(bp),		\
577 		    (u_longlong_t)BP_GET_FILL(bp),			\
578 		    ws,							\
579 		    (u_longlong_t)bp->blk_cksum.zc_word[0],		\
580 		    (u_longlong_t)bp->blk_cksum.zc_word[1],		\
581 		    (u_longlong_t)bp->blk_cksum.zc_word[2],		\
582 		    (u_longlong_t)bp->blk_cksum.zc_word[3]);		\
583 	}								\
584 	ASSERT(len < size);						\
585 }
586 
587 #include <sys/dmu.h>
588 
589 #define	BP_GET_BUFC_TYPE(bp)						\
590 	(((BP_GET_LEVEL(bp) > 0) || (DMU_OT_IS_METADATA(BP_GET_TYPE(bp)))) ? \
591 	ARC_BUFC_METADATA : ARC_BUFC_DATA)
592 
593 typedef enum spa_import_type {
594 	SPA_IMPORT_EXISTING,
595 	SPA_IMPORT_ASSEMBLE
596 } spa_import_type_t;
597 
598 /* state manipulation functions */
599 extern int spa_open(const char *pool, spa_t **, void *tag);
600 extern int spa_open_rewind(const char *pool, spa_t **, void *tag,
601     nvlist_t *policy, nvlist_t **config);
602 extern int spa_get_stats(const char *pool, nvlist_t **config, char *altroot,
603     size_t buflen);
604 extern int spa_create(const char *pool, nvlist_t *config, nvlist_t *props,
605     nvlist_t *zplprops);
606 extern int spa_import_rootpool(char *devpath, char *devid);
607 extern int spa_import(const char *pool, nvlist_t *config, nvlist_t *props,
608     uint64_t flags);
609 extern nvlist_t *spa_tryimport(nvlist_t *tryconfig);
610 extern int spa_destroy(char *pool);
611 extern int spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
612     boolean_t hardforce);
613 extern int spa_reset(char *pool);
614 extern void spa_async_request(spa_t *spa, int flag);
615 extern void spa_async_unrequest(spa_t *spa, int flag);
616 extern void spa_async_suspend(spa_t *spa);
617 extern void spa_async_resume(spa_t *spa);
618 extern spa_t *spa_inject_addref(char *pool);
619 extern void spa_inject_delref(spa_t *spa);
620 extern void spa_scan_stat_init(spa_t *spa);
621 extern int spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps);
622 
623 #define	SPA_ASYNC_CONFIG_UPDATE		0x01
624 #define	SPA_ASYNC_REMOVE		0x02
625 #define	SPA_ASYNC_PROBE			0x04
626 #define	SPA_ASYNC_RESILVER_DONE		0x08
627 #define	SPA_ASYNC_RESILVER		0x10
628 #define	SPA_ASYNC_AUTOEXPAND		0x20
629 #define	SPA_ASYNC_REMOVE_DONE		0x40
630 #define	SPA_ASYNC_REMOVE_STOP		0x80
631 #define	SPA_ASYNC_L2CACHE_REBUILD	0x100
632 
633 /*
634  * Controls the behavior of spa_vdev_remove().
635  */
636 #define	SPA_REMOVE_UNSPARE	0x01
637 #define	SPA_REMOVE_DONE		0x02
638 
639 /* device manipulation */
640 extern int spa_vdev_add(spa_t *spa, nvlist_t *nvroot);
641 extern int spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot,
642     int replacing);
643 extern int spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid,
644     int replace_done);
645 extern int spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare);
646 extern boolean_t spa_vdev_remove_active(spa_t *spa);
647 extern int spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath);
648 extern int spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru);
649 extern int spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
650     nvlist_t *props, boolean_t exp);
651 
652 /* spare state (which is global across all pools) */
653 extern void spa_spare_add(vdev_t *vd);
654 extern void spa_spare_remove(vdev_t *vd);
655 extern boolean_t spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt);
656 extern void spa_spare_activate(vdev_t *vd);
657 
658 /* L2ARC state (which is global across all pools) */
659 extern void spa_l2cache_add(vdev_t *vd);
660 extern void spa_l2cache_remove(vdev_t *vd);
661 extern boolean_t spa_l2cache_exists(uint64_t guid, uint64_t *pool);
662 extern void spa_l2cache_activate(vdev_t *vd);
663 extern void spa_l2cache_drop(spa_t *spa);
664 
665 /* scanning */
666 extern int spa_scan(spa_t *spa, pool_scan_func_t func);
667 extern int spa_scan_stop(spa_t *spa);
668 
669 /* spa syncing */
670 extern void spa_sync(spa_t *spa, uint64_t txg); /* only for DMU use */
671 extern void spa_sync_allpools(void);
672 
673 /* spa namespace global mutex */
674 extern kmutex_t spa_namespace_lock;
675 
676 /*
677  * SPA configuration functions in spa_config.c
678  */
679 
680 #define	SPA_CONFIG_UPDATE_POOL	0
681 #define	SPA_CONFIG_UPDATE_VDEVS	1
682 
683 extern void spa_config_sync(spa_t *, boolean_t, boolean_t);
684 extern void spa_config_load(void);
685 extern nvlist_t *spa_all_configs(uint64_t *);
686 extern void spa_config_set(spa_t *spa, nvlist_t *config);
687 extern nvlist_t *spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg,
688     int getstats);
689 extern void spa_config_update(spa_t *spa, int what);
690 
691 /*
692  * Miscellaneous SPA routines in spa_misc.c
693  */
694 
695 /* Namespace manipulation */
696 extern spa_t *spa_lookup(const char *name);
697 extern spa_t *spa_add(const char *name, nvlist_t *config, const char *altroot);
698 extern void spa_remove(spa_t *spa);
699 extern spa_t *spa_next(spa_t *prev);
700 
701 /* Refcount functions */
702 extern void spa_open_ref(spa_t *spa, void *tag);
703 extern void spa_close(spa_t *spa, void *tag);
704 extern void spa_async_close(spa_t *spa, void *tag);
705 extern boolean_t spa_refcount_zero(spa_t *spa);
706 
707 #define	SCL_NONE	0x00
708 #define	SCL_CONFIG	0x01
709 #define	SCL_STATE	0x02
710 #define	SCL_L2ARC	0x04		/* hack until L2ARC 2.0 */
711 #define	SCL_ALLOC	0x08
712 #define	SCL_ZIO		0x10
713 #define	SCL_FREE	0x20
714 #define	SCL_VDEV	0x40
715 #define	SCL_LOCKS	7
716 #define	SCL_ALL		((1 << SCL_LOCKS) - 1)
717 #define	SCL_STATE_ALL	(SCL_STATE | SCL_L2ARC | SCL_ZIO)
718 
719 /* Pool configuration locks */
720 extern int spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw);
721 extern void spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw);
722 extern void spa_config_exit(spa_t *spa, int locks, void *tag);
723 extern int spa_config_held(spa_t *spa, int locks, krw_t rw);
724 
725 /* Pool vdev add/remove lock */
726 extern uint64_t spa_vdev_enter(spa_t *spa);
727 extern uint64_t spa_vdev_config_enter(spa_t *spa);
728 extern void spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg,
729     int error, char *tag);
730 extern int spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error);
731 
732 /* Pool vdev state change lock */
733 extern void spa_vdev_state_enter(spa_t *spa, int oplock);
734 extern int spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error);
735 
736 /* Log state */
737 typedef enum spa_log_state {
738 	SPA_LOG_UNKNOWN = 0,	/* unknown log state */
739 	SPA_LOG_MISSING,	/* missing log(s) */
740 	SPA_LOG_CLEAR,		/* clear the log(s) */
741 	SPA_LOG_GOOD,		/* log(s) are good */
742 } spa_log_state_t;
743 
744 extern spa_log_state_t spa_get_log_state(spa_t *spa);
745 extern void spa_set_log_state(spa_t *spa, spa_log_state_t state);
746 extern int spa_offline_log(spa_t *spa);
747 
748 /* Log claim callback */
749 extern void spa_claim_notify(zio_t *zio);
750 
751 /* Accessor functions */
752 extern boolean_t spa_shutting_down(spa_t *spa);
753 extern struct dsl_pool *spa_get_dsl(spa_t *spa);
754 extern boolean_t spa_is_initializing(spa_t *spa);
755 extern blkptr_t *spa_get_rootblkptr(spa_t *spa);
756 extern void spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp);
757 extern void spa_altroot(spa_t *, char *, size_t);
758 extern int spa_sync_pass(spa_t *spa);
759 extern char *spa_name(spa_t *spa);
760 extern uint64_t spa_guid(spa_t *spa);
761 extern uint64_t spa_load_guid(spa_t *spa);
762 extern uint64_t spa_last_synced_txg(spa_t *spa);
763 extern uint64_t spa_first_txg(spa_t *spa);
764 extern uint64_t spa_syncing_txg(spa_t *spa);
765 extern uint64_t spa_version(spa_t *spa);
766 extern pool_state_t spa_state(spa_t *spa);
767 extern spa_load_state_t spa_load_state(spa_t *spa);
768 extern uint64_t spa_freeze_txg(spa_t *spa);
769 extern uint64_t spa_get_asize(spa_t *spa, uint64_t lsize);
770 extern uint64_t spa_get_dspace(spa_t *spa);
771 extern uint64_t spa_get_slop_space(spa_t *spa);
772 extern void spa_update_dspace(spa_t *spa);
773 extern uint64_t spa_version(spa_t *spa);
774 extern boolean_t spa_deflate(spa_t *spa);
775 extern metaslab_class_t *spa_normal_class(spa_t *spa);
776 extern metaslab_class_t *spa_log_class(spa_t *spa);
777 extern void spa_evicting_os_register(spa_t *, objset_t *os);
778 extern void spa_evicting_os_deregister(spa_t *, objset_t *os);
779 extern void spa_evicting_os_wait(spa_t *spa);
780 extern int spa_max_replication(spa_t *spa);
781 extern int spa_prev_software_version(spa_t *spa);
782 extern int spa_busy(void);
783 extern uint8_t spa_get_failmode(spa_t *spa);
784 extern boolean_t spa_suspended(spa_t *spa);
785 extern uint64_t spa_bootfs(spa_t *spa);
786 extern uint64_t spa_delegation(spa_t *spa);
787 extern objset_t *spa_meta_objset(spa_t *spa);
788 extern uint64_t spa_deadman_synctime(spa_t *spa);
789 
790 /* Miscellaneous support routines */
791 extern void spa_activate_mos_feature(spa_t *spa, const char *feature,
792     dmu_tx_t *tx);
793 extern void spa_deactivate_mos_feature(spa_t *spa, const char *feature);
794 extern int spa_rename(const char *oldname, const char *newname);
795 extern spa_t *spa_by_guid(uint64_t pool_guid, uint64_t device_guid);
796 extern boolean_t spa_guid_exists(uint64_t pool_guid, uint64_t device_guid);
797 extern char *spa_strdup(const char *);
798 extern void spa_strfree(char *);
799 extern uint64_t spa_get_random(uint64_t range);
800 extern uint64_t spa_generate_guid(spa_t *spa);
801 extern void snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp);
802 extern void spa_freeze(spa_t *spa);
803 extern int spa_change_guid(spa_t *spa);
804 extern void spa_upgrade(spa_t *spa, uint64_t version);
805 extern void spa_evict_all(void);
806 extern vdev_t *spa_lookup_by_guid(spa_t *spa, uint64_t guid,
807     boolean_t l2cache);
808 extern boolean_t spa_has_spare(spa_t *, uint64_t guid);
809 extern uint64_t dva_get_dsize_sync(spa_t *spa, const dva_t *dva);
810 extern uint64_t bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp);
811 extern uint64_t bp_get_dsize(spa_t *spa, const blkptr_t *bp);
812 extern boolean_t spa_has_slogs(spa_t *spa);
813 extern boolean_t spa_is_root(spa_t *spa);
814 extern boolean_t spa_writeable(spa_t *spa);
815 extern boolean_t spa_has_pending_synctask(spa_t *spa);
816 extern int spa_maxblocksize(spa_t *spa);
817 extern void zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp);
818 
819 extern int spa_mode(spa_t *spa);
820 extern uint64_t strtonum(const char *str, char **nptr);
821 
822 extern char *spa_his_ievent_table[];
823 
824 extern void spa_history_create_obj(spa_t *spa, dmu_tx_t *tx);
825 extern int spa_history_get(spa_t *spa, uint64_t *offset, uint64_t *len_read,
826     char *his_buf);
827 extern int spa_history_log(spa_t *spa, const char *his_buf);
828 extern int spa_history_log_nvl(spa_t *spa, nvlist_t *nvl);
829 extern void spa_history_log_version(spa_t *spa, const char *operation);
830 extern void spa_history_log_internal(spa_t *spa, const char *operation,
831     dmu_tx_t *tx, const char *fmt, ...);
832 extern void spa_history_log_internal_ds(struct dsl_dataset *ds, const char *op,
833     dmu_tx_t *tx, const char *fmt, ...);
834 extern void spa_history_log_internal_dd(dsl_dir_t *dd, const char *operation,
835     dmu_tx_t *tx, const char *fmt, ...);
836 
837 /* error handling */
838 struct zbookmark_phys;
839 extern void spa_log_error(spa_t *spa, zio_t *zio);
840 extern void zfs_ereport_post(const char *class, spa_t *spa, vdev_t *vd,
841     zio_t *zio, uint64_t stateoroffset, uint64_t length);
842 extern void zfs_post_remove(spa_t *spa, vdev_t *vd);
843 extern void zfs_post_state_change(spa_t *spa, vdev_t *vd);
844 extern void zfs_post_autoreplace(spa_t *spa, vdev_t *vd);
845 extern uint64_t spa_get_errlog_size(spa_t *spa);
846 extern int spa_get_errlog(spa_t *spa, void *uaddr, size_t *count);
847 extern void spa_errlog_rotate(spa_t *spa);
848 extern void spa_errlog_drain(spa_t *spa);
849 extern void spa_errlog_sync(spa_t *spa, uint64_t txg);
850 extern void spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub);
851 
852 /* vdev cache */
853 extern void vdev_cache_stat_init(void);
854 extern void vdev_cache_stat_fini(void);
855 
856 /* Initialization and termination */
857 extern void spa_init(int flags);
858 extern void spa_fini(void);
859 extern void spa_boot_init();
860 
861 /* properties */
862 extern int spa_prop_set(spa_t *spa, nvlist_t *nvp);
863 extern int spa_prop_get(spa_t *spa, nvlist_t **nvp);
864 extern void spa_prop_clear_bootfs(spa_t *spa, uint64_t obj, dmu_tx_t *tx);
865 extern void spa_configfile_set(spa_t *, nvlist_t *, boolean_t);
866 
867 /* asynchronous event notification */
868 extern void spa_event_notify(spa_t *spa, vdev_t *vdev, const char *name);
869 
870 #ifdef ZFS_DEBUG
871 #define	dprintf_bp(bp, fmt, ...) do {				\
872 	if (zfs_flags & ZFS_DEBUG_DPRINTF) {			\
873 	char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP);	\
874 	snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, (bp));	\
875 	dprintf(fmt " %s\n", __VA_ARGS__, __blkbuf);		\
876 	kmem_free(__blkbuf, BP_SPRINTF_LEN);			\
877 	} \
878 _NOTE(CONSTCOND) } while (0)
879 #else
880 #define	dprintf_bp(bp, fmt, ...)
881 #endif
882 
883 extern boolean_t spa_debug_enabled(spa_t *spa);
884 #define	spa_dbgmsg(spa, ...)			\
885 {						\
886 	if (spa_debug_enabled(spa))		\
887 		zfs_dbgmsg(__VA_ARGS__);	\
888 }
889 
890 extern int spa_mode_global;			/* mode, e.g. FREAD | FWRITE */
891 
892 #ifdef	__cplusplus
893 }
894 #endif
895 
896 #endif	/* _SYS_SPA_H */
897