xref: /titanic_50/usr/src/uts/common/fs/zfs/sys/spa.h (revision 45818ee124adeaaf947698996b4f4c722afc6d1f)
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 (c) 2011, 2014 by Delphix. All rights reserved.
24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
26  * Copyright 2013 Saso Kiselkov. 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  * Some checksums/hashes need a 256-bit initialization salt. This salt is kept
152  * secret and is suitable for use in MAC algorithms as the key.
153  */
154 typedef struct zio_cksum_salt {
155 	uint8_t		zcs_bytes[32];
156 } zio_cksum_salt_t;
157 
158 /*
159  * Each block is described by its DVAs, time of birth, checksum, etc.
160  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
161  *
162  *	64	56	48	40	32	24	16	8	0
163  *	+-------+-------+-------+-------+-------+-------+-------+-------+
164  * 0	|		vdev1		| GRID  |	  ASIZE		|
165  *	+-------+-------+-------+-------+-------+-------+-------+-------+
166  * 1	|G|			 offset1				|
167  *	+-------+-------+-------+-------+-------+-------+-------+-------+
168  * 2	|		vdev2		| GRID  |	  ASIZE		|
169  *	+-------+-------+-------+-------+-------+-------+-------+-------+
170  * 3	|G|			 offset2				|
171  *	+-------+-------+-------+-------+-------+-------+-------+-------+
172  * 4	|		vdev3		| GRID  |	  ASIZE		|
173  *	+-------+-------+-------+-------+-------+-------+-------+-------+
174  * 5	|G|			 offset3				|
175  *	+-------+-------+-------+-------+-------+-------+-------+-------+
176  * 6	|BDX|lvl| type	| cksum |E| comp|    PSIZE	|     LSIZE	|
177  *	+-------+-------+-------+-------+-------+-------+-------+-------+
178  * 7	|			padding					|
179  *	+-------+-------+-------+-------+-------+-------+-------+-------+
180  * 8	|			padding					|
181  *	+-------+-------+-------+-------+-------+-------+-------+-------+
182  * 9	|			physical birth txg			|
183  *	+-------+-------+-------+-------+-------+-------+-------+-------+
184  * a	|			logical birth txg			|
185  *	+-------+-------+-------+-------+-------+-------+-------+-------+
186  * b	|			fill count				|
187  *	+-------+-------+-------+-------+-------+-------+-------+-------+
188  * c	|			checksum[0]				|
189  *	+-------+-------+-------+-------+-------+-------+-------+-------+
190  * d	|			checksum[1]				|
191  *	+-------+-------+-------+-------+-------+-------+-------+-------+
192  * e	|			checksum[2]				|
193  *	+-------+-------+-------+-------+-------+-------+-------+-------+
194  * f	|			checksum[3]				|
195  *	+-------+-------+-------+-------+-------+-------+-------+-------+
196  *
197  * Legend:
198  *
199  * vdev		virtual device ID
200  * offset	offset into virtual device
201  * LSIZE	logical size
202  * PSIZE	physical size (after compression)
203  * ASIZE	allocated size (including RAID-Z parity and gang block headers)
204  * GRID		RAID-Z layout information (reserved for future use)
205  * cksum	checksum function
206  * comp		compression function
207  * G		gang block indicator
208  * B		byteorder (endianness)
209  * D		dedup
210  * X		encryption (on version 30, which is not supported)
211  * E		blkptr_t contains embedded data (see below)
212  * lvl		level of indirection
213  * type		DMU object type
214  * phys birth	txg of block allocation; zero if same as logical birth txg
215  * log. birth	transaction group in which the block was logically born
216  * fill count	number of non-zero blocks under this bp
217  * checksum[4]	256-bit checksum of the data this bp describes
218  */
219 
220 /*
221  * "Embedded" blkptr_t's don't actually point to a block, instead they
222  * have a data payload embedded in the blkptr_t itself.  See the comment
223  * in blkptr.c for more details.
224  *
225  * The blkptr_t is laid out as follows:
226  *
227  *	64	56	48	40	32	24	16	8	0
228  *	+-------+-------+-------+-------+-------+-------+-------+-------+
229  * 0	|      payload                                                  |
230  * 1	|      payload                                                  |
231  * 2	|      payload                                                  |
232  * 3	|      payload                                                  |
233  * 4	|      payload                                                  |
234  * 5	|      payload                                                  |
235  *	+-------+-------+-------+-------+-------+-------+-------+-------+
236  * 6	|BDX|lvl| type	| etype |E| comp| PSIZE|              LSIZE	|
237  *	+-------+-------+-------+-------+-------+-------+-------+-------+
238  * 7	|      payload                                                  |
239  * 8	|      payload                                                  |
240  * 9	|      payload                                                  |
241  *	+-------+-------+-------+-------+-------+-------+-------+-------+
242  * a	|			logical birth txg			|
243  *	+-------+-------+-------+-------+-------+-------+-------+-------+
244  * b	|      payload                                                  |
245  * c	|      payload                                                  |
246  * d	|      payload                                                  |
247  * e	|      payload                                                  |
248  * f	|      payload                                                  |
249  *	+-------+-------+-------+-------+-------+-------+-------+-------+
250  *
251  * Legend:
252  *
253  * payload		contains the embedded data
254  * B (byteorder)	byteorder (endianness)
255  * D (dedup)		padding (set to zero)
256  * X			encryption (set to zero; see above)
257  * E (embedded)		set to one
258  * lvl			indirection level
259  * type			DMU object type
260  * etype		how to interpret embedded data (BP_EMBEDDED_TYPE_*)
261  * comp			compression function of payload
262  * PSIZE		size of payload after compression, in bytes
263  * LSIZE		logical size of payload, in bytes
264  *			note that 25 bits is enough to store the largest
265  *			"normal" BP's LSIZE (2^16 * 2^9) in bytes
266  * log. birth		transaction group in which the block was logically born
267  *
268  * Note that LSIZE and PSIZE are stored in bytes, whereas for non-embedded
269  * bp's they are stored in units of SPA_MINBLOCKSHIFT.
270  * Generally, the generic BP_GET_*() macros can be used on embedded BP's.
271  * The B, D, X, lvl, type, and comp fields are stored the same as with normal
272  * BP's so the BP_SET_* macros can be used with them.  etype, PSIZE, LSIZE must
273  * be set with the BPE_SET_* macros.  BP_SET_EMBEDDED() should be called before
274  * other macros, as they assert that they are only used on BP's of the correct
275  * "embedded-ness".
276  */
277 
278 #define	BPE_GET_ETYPE(bp)	\
279 	(ASSERT(BP_IS_EMBEDDED(bp)), \
280 	BF64_GET((bp)->blk_prop, 40, 8))
281 #define	BPE_SET_ETYPE(bp, t)	do { \
282 	ASSERT(BP_IS_EMBEDDED(bp)); \
283 	BF64_SET((bp)->blk_prop, 40, 8, t); \
284 _NOTE(CONSTCOND) } while (0)
285 
286 #define	BPE_GET_LSIZE(bp)	\
287 	(ASSERT(BP_IS_EMBEDDED(bp)), \
288 	BF64_GET_SB((bp)->blk_prop, 0, 25, 0, 1))
289 #define	BPE_SET_LSIZE(bp, x)	do { \
290 	ASSERT(BP_IS_EMBEDDED(bp)); \
291 	BF64_SET_SB((bp)->blk_prop, 0, 25, 0, 1, x); \
292 _NOTE(CONSTCOND) } while (0)
293 
294 #define	BPE_GET_PSIZE(bp)	\
295 	(ASSERT(BP_IS_EMBEDDED(bp)), \
296 	BF64_GET_SB((bp)->blk_prop, 25, 7, 0, 1))
297 #define	BPE_SET_PSIZE(bp, x)	do { \
298 	ASSERT(BP_IS_EMBEDDED(bp)); \
299 	BF64_SET_SB((bp)->blk_prop, 25, 7, 0, 1, x); \
300 _NOTE(CONSTCOND) } while (0)
301 
302 typedef enum bp_embedded_type {
303 	BP_EMBEDDED_TYPE_DATA,
304 	BP_EMBEDDED_TYPE_RESERVED, /* Reserved for an unintegrated feature. */
305 	NUM_BP_EMBEDDED_TYPES = BP_EMBEDDED_TYPE_RESERVED
306 } bp_embedded_type_t;
307 
308 #define	BPE_NUM_WORDS 14
309 #define	BPE_PAYLOAD_SIZE (BPE_NUM_WORDS * sizeof (uint64_t))
310 #define	BPE_IS_PAYLOADWORD(bp, wp) \
311 	((wp) != &(bp)->blk_prop && (wp) != &(bp)->blk_birth)
312 
313 #define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
314 #define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
315 
316 /*
317  * A block is a hole when it has either 1) never been written to, or
318  * 2) is zero-filled. In both cases, ZFS can return all zeroes for all reads
319  * without physically allocating disk space. Holes are represented in the
320  * blkptr_t structure by zeroed blk_dva. Correct checking for holes is
321  * done through the BP_IS_HOLE macro. For holes, the logical size, level,
322  * DMU object type, and birth times are all also stored for holes that
323  * were written to at some point (i.e. were punched after having been filled).
324  */
325 typedef struct blkptr {
326 	dva_t		blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
327 	uint64_t	blk_prop;	/* size, compression, type, etc	    */
328 	uint64_t	blk_pad[2];	/* Extra space for the future	    */
329 	uint64_t	blk_phys_birth;	/* txg when block was allocated	    */
330 	uint64_t	blk_birth;	/* transaction group at birth	    */
331 	uint64_t	blk_fill;	/* fill count			    */
332 	zio_cksum_t	blk_cksum;	/* 256-bit checksum		    */
333 } blkptr_t;
334 
335 /*
336  * Macros to get and set fields in a bp or DVA.
337  */
338 #define	DVA_GET_ASIZE(dva)	\
339 	BF64_GET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, SPA_MINBLOCKSHIFT, 0)
340 #define	DVA_SET_ASIZE(dva, x)	\
341 	BF64_SET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, \
342 	SPA_MINBLOCKSHIFT, 0, x)
343 
344 #define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
345 #define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
346 
347 #define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
348 #define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
349 
350 #define	DVA_GET_OFFSET(dva)	\
351 	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
352 #define	DVA_SET_OFFSET(dva, x)	\
353 	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
354 
355 #define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
356 #define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
357 
358 #define	BP_GET_LSIZE(bp)	\
359 	(BP_IS_EMBEDDED(bp) ?	\
360 	(BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA ? BPE_GET_LSIZE(bp) : 0): \
361 	BF64_GET_SB((bp)->blk_prop, 0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1))
362 #define	BP_SET_LSIZE(bp, x)	do { \
363 	ASSERT(!BP_IS_EMBEDDED(bp)); \
364 	BF64_SET_SB((bp)->blk_prop, \
365 	    0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
366 _NOTE(CONSTCOND) } while (0)
367 
368 #define	BP_GET_PSIZE(bp)	\
369 	(BP_IS_EMBEDDED(bp) ? 0 : \
370 	BF64_GET_SB((bp)->blk_prop, 16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1))
371 #define	BP_SET_PSIZE(bp, x)	do { \
372 	ASSERT(!BP_IS_EMBEDDED(bp)); \
373 	BF64_SET_SB((bp)->blk_prop, \
374 	    16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
375 _NOTE(CONSTCOND) } while (0)
376 
377 #define	BP_GET_COMPRESS(bp)		BF64_GET((bp)->blk_prop, 32, 7)
378 #define	BP_SET_COMPRESS(bp, x)		BF64_SET((bp)->blk_prop, 32, 7, x)
379 
380 #define	BP_IS_EMBEDDED(bp)		BF64_GET((bp)->blk_prop, 39, 1)
381 #define	BP_SET_EMBEDDED(bp, x)		BF64_SET((bp)->blk_prop, 39, 1, x)
382 
383 #define	BP_GET_CHECKSUM(bp)		\
384 	(BP_IS_EMBEDDED(bp) ? ZIO_CHECKSUM_OFF : \
385 	BF64_GET((bp)->blk_prop, 40, 8))
386 #define	BP_SET_CHECKSUM(bp, x)		do { \
387 	ASSERT(!BP_IS_EMBEDDED(bp)); \
388 	BF64_SET((bp)->blk_prop, 40, 8, x); \
389 _NOTE(CONSTCOND) } while (0)
390 
391 #define	BP_GET_TYPE(bp)			BF64_GET((bp)->blk_prop, 48, 8)
392 #define	BP_SET_TYPE(bp, x)		BF64_SET((bp)->blk_prop, 48, 8, x)
393 
394 #define	BP_GET_LEVEL(bp)		BF64_GET((bp)->blk_prop, 56, 5)
395 #define	BP_SET_LEVEL(bp, x)		BF64_SET((bp)->blk_prop, 56, 5, x)
396 
397 #define	BP_GET_DEDUP(bp)		BF64_GET((bp)->blk_prop, 62, 1)
398 #define	BP_SET_DEDUP(bp, x)		BF64_SET((bp)->blk_prop, 62, 1, x)
399 
400 #define	BP_GET_BYTEORDER(bp)		BF64_GET((bp)->blk_prop, 63, 1)
401 #define	BP_SET_BYTEORDER(bp, x)		BF64_SET((bp)->blk_prop, 63, 1, x)
402 
403 #define	BP_PHYSICAL_BIRTH(bp)		\
404 	(BP_IS_EMBEDDED(bp) ? 0 : \
405 	(bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
406 
407 #define	BP_SET_BIRTH(bp, logical, physical)	\
408 {						\
409 	ASSERT(!BP_IS_EMBEDDED(bp));		\
410 	(bp)->blk_birth = (logical);		\
411 	(bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
412 }
413 
414 #define	BP_GET_FILL(bp) (BP_IS_EMBEDDED(bp) ? 1 : (bp)->blk_fill)
415 
416 #define	BP_GET_ASIZE(bp)	\
417 	(BP_IS_EMBEDDED(bp) ? 0 : \
418 	DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
419 	DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
420 	DVA_GET_ASIZE(&(bp)->blk_dva[2]))
421 
422 #define	BP_GET_UCSIZE(bp) \
423 	((BP_GET_LEVEL(bp) > 0 || DMU_OT_IS_METADATA(BP_GET_TYPE(bp))) ? \
424 	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp))
425 
426 #define	BP_GET_NDVAS(bp)	\
427 	(BP_IS_EMBEDDED(bp) ? 0 : \
428 	!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
429 	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
430 	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
431 
432 #define	BP_COUNT_GANG(bp)	\
433 	(BP_IS_EMBEDDED(bp) ? 0 : \
434 	(DVA_GET_GANG(&(bp)->blk_dva[0]) + \
435 	DVA_GET_GANG(&(bp)->blk_dva[1]) + \
436 	DVA_GET_GANG(&(bp)->blk_dva[2])))
437 
438 #define	DVA_EQUAL(dva1, dva2)	\
439 	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
440 	(dva1)->dva_word[0] == (dva2)->dva_word[0])
441 
442 #define	BP_EQUAL(bp1, bp2)	\
443 	(BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&	\
444 	(bp1)->blk_birth == (bp2)->blk_birth &&			\
445 	DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&	\
446 	DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&	\
447 	DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
448 
449 #define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \
450 	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
451 	((zc1).zc_word[1] - (zc2).zc_word[1]) | \
452 	((zc1).zc_word[2] - (zc2).zc_word[2]) | \
453 	((zc1).zc_word[3] - (zc2).zc_word[3])))
454 
455 #define	ZIO_CHECKSUM_IS_ZERO(zc) \
456 	(0 == ((zc)->zc_word[0] | (zc)->zc_word[1] | \
457 	(zc)->zc_word[2] | (zc)->zc_word[3]))
458 
459 #define	ZIO_CHECKSUM_BSWAP(zcp)					\
460 {								\
461 	(zcp)->zc_word[0] = BSWAP_64((zcp)->zc_word[0]);	\
462 	(zcp)->zc_word[1] = BSWAP_64((zcp)->zc_word[1]);	\
463 	(zcp)->zc_word[2] = BSWAP_64((zcp)->zc_word[2]);	\
464 	(zcp)->zc_word[3] = BSWAP_64((zcp)->zc_word[3]);	\
465 }
466 
467 
468 #define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
469 
470 #define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
471 {						\
472 	(zcp)->zc_word[0] = w0;			\
473 	(zcp)->zc_word[1] = w1;			\
474 	(zcp)->zc_word[2] = w2;			\
475 	(zcp)->zc_word[3] = w3;			\
476 }
477 
478 #define	BP_IDENTITY(bp)		(ASSERT(!BP_IS_EMBEDDED(bp)), &(bp)->blk_dva[0])
479 #define	BP_IS_GANG(bp)		\
480 	(BP_IS_EMBEDDED(bp) ? B_FALSE : DVA_GET_GANG(BP_IDENTITY(bp)))
481 #define	DVA_IS_EMPTY(dva)	((dva)->dva_word[0] == 0ULL &&	\
482 				(dva)->dva_word[1] == 0ULL)
483 #define	BP_IS_HOLE(bp) \
484 	(!BP_IS_EMBEDDED(bp) && DVA_IS_EMPTY(BP_IDENTITY(bp)))
485 
486 /* BP_IS_RAIDZ(bp) assumes no block compression */
487 #define	BP_IS_RAIDZ(bp)		(DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
488 				BP_GET_PSIZE(bp))
489 
490 #define	BP_ZERO(bp)				\
491 {						\
492 	(bp)->blk_dva[0].dva_word[0] = 0;	\
493 	(bp)->blk_dva[0].dva_word[1] = 0;	\
494 	(bp)->blk_dva[1].dva_word[0] = 0;	\
495 	(bp)->blk_dva[1].dva_word[1] = 0;	\
496 	(bp)->blk_dva[2].dva_word[0] = 0;	\
497 	(bp)->blk_dva[2].dva_word[1] = 0;	\
498 	(bp)->blk_prop = 0;			\
499 	(bp)->blk_pad[0] = 0;			\
500 	(bp)->blk_pad[1] = 0;			\
501 	(bp)->blk_phys_birth = 0;		\
502 	(bp)->blk_birth = 0;			\
503 	(bp)->blk_fill = 0;			\
504 	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
505 }
506 
507 #ifdef _BIG_ENDIAN
508 #define	ZFS_HOST_BYTEORDER	(0ULL)
509 #else
510 #define	ZFS_HOST_BYTEORDER	(1ULL)
511 #endif
512 
513 #define	BP_SHOULD_BYTESWAP(bp)	(BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)
514 
515 #define	BP_SPRINTF_LEN	320
516 
517 /*
518  * This macro allows code sharing between zfs, libzpool, and mdb.
519  * 'func' is either snprintf() or mdb_snprintf().
520  * 'ws' (whitespace) can be ' ' for single-line format, '\n' for multi-line.
521  */
522 #define	SNPRINTF_BLKPTR(func, ws, buf, size, bp, type, checksum, compress) \
523 {									\
524 	static const char *copyname[] =					\
525 	    { "zero", "single", "double", "triple" };			\
526 	int len = 0;							\
527 	int copies = 0;							\
528 									\
529 	if (bp == NULL) {						\
530 		len += func(buf + len, size - len, "<NULL>");		\
531 	} else if (BP_IS_HOLE(bp)) {					\
532 		len += func(buf + len, size - len,			\
533 		    "HOLE [L%llu %s] "					\
534 		    "size=%llxL birth=%lluL",				\
535 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
536 		    type,						\
537 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
538 		    (u_longlong_t)bp->blk_birth);			\
539 	} else if (BP_IS_EMBEDDED(bp)) {				\
540 		len = func(buf + len, size - len,			\
541 		    "EMBEDDED [L%llu %s] et=%u %s "			\
542 		    "size=%llxL/%llxP birth=%lluL",			\
543 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
544 		    type,						\
545 		    (int)BPE_GET_ETYPE(bp),				\
546 		    compress,						\
547 		    (u_longlong_t)BPE_GET_LSIZE(bp),			\
548 		    (u_longlong_t)BPE_GET_PSIZE(bp),			\
549 		    (u_longlong_t)bp->blk_birth);			\
550 	} else {							\
551 		for (int d = 0; d < BP_GET_NDVAS(bp); d++) {		\
552 			const dva_t *dva = &bp->blk_dva[d];		\
553 			if (DVA_IS_VALID(dva))				\
554 				copies++;				\
555 			len += func(buf + len, size - len,		\
556 			    "DVA[%d]=<%llu:%llx:%llx>%c", d,		\
557 			    (u_longlong_t)DVA_GET_VDEV(dva),		\
558 			    (u_longlong_t)DVA_GET_OFFSET(dva),		\
559 			    (u_longlong_t)DVA_GET_ASIZE(dva),		\
560 			    ws);					\
561 		}							\
562 		if (BP_IS_GANG(bp) &&					\
563 		    DVA_GET_ASIZE(&bp->blk_dva[2]) <=			\
564 		    DVA_GET_ASIZE(&bp->blk_dva[1]) / 2)			\
565 			copies--;					\
566 		len += func(buf + len, size - len,			\
567 		    "[L%llu %s] %s %s %s %s %s %s%c"			\
568 		    "size=%llxL/%llxP birth=%lluL/%lluP fill=%llu%c"	\
569 		    "cksum=%llx:%llx:%llx:%llx",			\
570 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
571 		    type,						\
572 		    checksum,						\
573 		    compress,						\
574 		    BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",		\
575 		    BP_IS_GANG(bp) ? "gang" : "contiguous",		\
576 		    BP_GET_DEDUP(bp) ? "dedup" : "unique",		\
577 		    copyname[copies],					\
578 		    ws,							\
579 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
580 		    (u_longlong_t)BP_GET_PSIZE(bp),			\
581 		    (u_longlong_t)bp->blk_birth,			\
582 		    (u_longlong_t)BP_PHYSICAL_BIRTH(bp),		\
583 		    (u_longlong_t)BP_GET_FILL(bp),			\
584 		    ws,							\
585 		    (u_longlong_t)bp->blk_cksum.zc_word[0],		\
586 		    (u_longlong_t)bp->blk_cksum.zc_word[1],		\
587 		    (u_longlong_t)bp->blk_cksum.zc_word[2],		\
588 		    (u_longlong_t)bp->blk_cksum.zc_word[3]);		\
589 	}								\
590 	ASSERT(len < size);						\
591 }
592 
593 #include <sys/dmu.h>
594 
595 #define	BP_GET_BUFC_TYPE(bp)						\
596 	(((BP_GET_LEVEL(bp) > 0) || (DMU_OT_IS_METADATA(BP_GET_TYPE(bp)))) ? \
597 	ARC_BUFC_METADATA : ARC_BUFC_DATA)
598 
599 typedef enum spa_import_type {
600 	SPA_IMPORT_EXISTING,
601 	SPA_IMPORT_ASSEMBLE
602 } spa_import_type_t;
603 
604 /* state manipulation functions */
605 extern int spa_open(const char *pool, spa_t **, void *tag);
606 extern int spa_open_rewind(const char *pool, spa_t **, void *tag,
607     nvlist_t *policy, nvlist_t **config);
608 extern int spa_get_stats(const char *pool, nvlist_t **config, char *altroot,
609     size_t buflen);
610 extern int spa_create(const char *pool, nvlist_t *config, nvlist_t *props,
611     nvlist_t *zplprops);
612 extern int spa_import_rootpool(char *devpath, char *devid);
613 extern int spa_import(const char *pool, nvlist_t *config, nvlist_t *props,
614     uint64_t flags);
615 extern nvlist_t *spa_tryimport(nvlist_t *tryconfig);
616 extern int spa_destroy(char *pool);
617 extern int spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
618     boolean_t hardforce);
619 extern int spa_reset(char *pool);
620 extern void spa_async_request(spa_t *spa, int flag);
621 extern void spa_async_unrequest(spa_t *spa, int flag);
622 extern void spa_async_suspend(spa_t *spa);
623 extern void spa_async_resume(spa_t *spa);
624 extern spa_t *spa_inject_addref(char *pool);
625 extern void spa_inject_delref(spa_t *spa);
626 extern void spa_scan_stat_init(spa_t *spa);
627 extern int spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps);
628 
629 #define	SPA_ASYNC_CONFIG_UPDATE	0x01
630 #define	SPA_ASYNC_REMOVE	0x02
631 #define	SPA_ASYNC_PROBE		0x04
632 #define	SPA_ASYNC_RESILVER_DONE	0x08
633 #define	SPA_ASYNC_RESILVER	0x10
634 #define	SPA_ASYNC_AUTOEXPAND	0x20
635 #define	SPA_ASYNC_REMOVE_DONE	0x40
636 #define	SPA_ASYNC_REMOVE_STOP	0x80
637 
638 /*
639  * Controls the behavior of spa_vdev_remove().
640  */
641 #define	SPA_REMOVE_UNSPARE	0x01
642 #define	SPA_REMOVE_DONE		0x02
643 
644 /* device manipulation */
645 extern int spa_vdev_add(spa_t *spa, nvlist_t *nvroot);
646 extern int spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot,
647     int replacing);
648 extern int spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid,
649     int replace_done);
650 extern int spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare);
651 extern boolean_t spa_vdev_remove_active(spa_t *spa);
652 extern int spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath);
653 extern int spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru);
654 extern int spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
655     nvlist_t *props, boolean_t exp);
656 
657 /* spare state (which is global across all pools) */
658 extern void spa_spare_add(vdev_t *vd);
659 extern void spa_spare_remove(vdev_t *vd);
660 extern boolean_t spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt);
661 extern void spa_spare_activate(vdev_t *vd);
662 
663 /* L2ARC state (which is global across all pools) */
664 extern void spa_l2cache_add(vdev_t *vd);
665 extern void spa_l2cache_remove(vdev_t *vd);
666 extern boolean_t spa_l2cache_exists(uint64_t guid, uint64_t *pool);
667 extern void spa_l2cache_activate(vdev_t *vd);
668 extern void spa_l2cache_drop(spa_t *spa);
669 
670 /* scanning */
671 extern int spa_scan(spa_t *spa, pool_scan_func_t func);
672 extern int spa_scan_stop(spa_t *spa);
673 
674 /* spa syncing */
675 extern void spa_sync(spa_t *spa, uint64_t txg); /* only for DMU use */
676 extern void spa_sync_allpools(void);
677 
678 /* spa namespace global mutex */
679 extern kmutex_t spa_namespace_lock;
680 
681 /*
682  * SPA configuration functions in spa_config.c
683  */
684 
685 #define	SPA_CONFIG_UPDATE_POOL	0
686 #define	SPA_CONFIG_UPDATE_VDEVS	1
687 
688 extern void spa_config_sync(spa_t *, boolean_t, boolean_t);
689 extern void spa_config_load(void);
690 extern nvlist_t *spa_all_configs(uint64_t *);
691 extern void spa_config_set(spa_t *spa, nvlist_t *config);
692 extern nvlist_t *spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg,
693     int getstats);
694 extern void spa_config_update(spa_t *spa, int what);
695 
696 /*
697  * Miscellaneous SPA routines in spa_misc.c
698  */
699 
700 /* Namespace manipulation */
701 extern spa_t *spa_lookup(const char *name);
702 extern spa_t *spa_add(const char *name, nvlist_t *config, const char *altroot);
703 extern void spa_remove(spa_t *spa);
704 extern spa_t *spa_next(spa_t *prev);
705 
706 /* Refcount functions */
707 extern void spa_open_ref(spa_t *spa, void *tag);
708 extern void spa_close(spa_t *spa, void *tag);
709 extern void spa_async_close(spa_t *spa, void *tag);
710 extern boolean_t spa_refcount_zero(spa_t *spa);
711 
712 #define	SCL_NONE	0x00
713 #define	SCL_CONFIG	0x01
714 #define	SCL_STATE	0x02
715 #define	SCL_L2ARC	0x04		/* hack until L2ARC 2.0 */
716 #define	SCL_ALLOC	0x08
717 #define	SCL_ZIO		0x10
718 #define	SCL_FREE	0x20
719 #define	SCL_VDEV	0x40
720 #define	SCL_LOCKS	7
721 #define	SCL_ALL		((1 << SCL_LOCKS) - 1)
722 #define	SCL_STATE_ALL	(SCL_STATE | SCL_L2ARC | SCL_ZIO)
723 
724 /* Pool configuration locks */
725 extern int spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw);
726 extern void spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw);
727 extern void spa_config_exit(spa_t *spa, int locks, void *tag);
728 extern int spa_config_held(spa_t *spa, int locks, krw_t rw);
729 
730 /* Pool vdev add/remove lock */
731 extern uint64_t spa_vdev_enter(spa_t *spa);
732 extern uint64_t spa_vdev_config_enter(spa_t *spa);
733 extern void spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg,
734     int error, char *tag);
735 extern int spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error);
736 
737 /* Pool vdev state change lock */
738 extern void spa_vdev_state_enter(spa_t *spa, int oplock);
739 extern int spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error);
740 
741 /* Log state */
742 typedef enum spa_log_state {
743 	SPA_LOG_UNKNOWN = 0,	/* unknown log state */
744 	SPA_LOG_MISSING,	/* missing log(s) */
745 	SPA_LOG_CLEAR,		/* clear the log(s) */
746 	SPA_LOG_GOOD,		/* log(s) are good */
747 } spa_log_state_t;
748 
749 extern spa_log_state_t spa_get_log_state(spa_t *spa);
750 extern void spa_set_log_state(spa_t *spa, spa_log_state_t state);
751 extern int spa_offline_log(spa_t *spa);
752 
753 /* Log claim callback */
754 extern void spa_claim_notify(zio_t *zio);
755 
756 /* Accessor functions */
757 extern boolean_t spa_shutting_down(spa_t *spa);
758 extern struct dsl_pool *spa_get_dsl(spa_t *spa);
759 extern boolean_t spa_is_initializing(spa_t *spa);
760 extern blkptr_t *spa_get_rootblkptr(spa_t *spa);
761 extern void spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp);
762 extern void spa_altroot(spa_t *, char *, size_t);
763 extern int spa_sync_pass(spa_t *spa);
764 extern char *spa_name(spa_t *spa);
765 extern uint64_t spa_guid(spa_t *spa);
766 extern uint64_t spa_load_guid(spa_t *spa);
767 extern uint64_t spa_last_synced_txg(spa_t *spa);
768 extern uint64_t spa_first_txg(spa_t *spa);
769 extern uint64_t spa_syncing_txg(spa_t *spa);
770 extern uint64_t spa_version(spa_t *spa);
771 extern pool_state_t spa_state(spa_t *spa);
772 extern spa_load_state_t spa_load_state(spa_t *spa);
773 extern uint64_t spa_freeze_txg(spa_t *spa);
774 extern uint64_t spa_get_asize(spa_t *spa, uint64_t lsize);
775 extern uint64_t spa_get_dspace(spa_t *spa);
776 extern uint64_t spa_get_slop_space(spa_t *spa);
777 extern void spa_update_dspace(spa_t *spa);
778 extern uint64_t spa_version(spa_t *spa);
779 extern boolean_t spa_deflate(spa_t *spa);
780 extern metaslab_class_t *spa_normal_class(spa_t *spa);
781 extern metaslab_class_t *spa_log_class(spa_t *spa);
782 extern void spa_evicting_os_register(spa_t *, objset_t *os);
783 extern void spa_evicting_os_deregister(spa_t *, objset_t *os);
784 extern void spa_evicting_os_wait(spa_t *spa);
785 extern int spa_max_replication(spa_t *spa);
786 extern int spa_prev_software_version(spa_t *spa);
787 extern int spa_busy(void);
788 extern uint8_t spa_get_failmode(spa_t *spa);
789 extern boolean_t spa_suspended(spa_t *spa);
790 extern uint64_t spa_bootfs(spa_t *spa);
791 extern uint64_t spa_delegation(spa_t *spa);
792 extern objset_t *spa_meta_objset(spa_t *spa);
793 extern uint64_t spa_deadman_synctime(spa_t *spa);
794 
795 /* Miscellaneous support routines */
796 extern void spa_activate_mos_feature(spa_t *spa, const char *feature,
797     dmu_tx_t *tx);
798 extern void spa_deactivate_mos_feature(spa_t *spa, const char *feature);
799 extern int spa_rename(const char *oldname, const char *newname);
800 extern spa_t *spa_by_guid(uint64_t pool_guid, uint64_t device_guid);
801 extern boolean_t spa_guid_exists(uint64_t pool_guid, uint64_t device_guid);
802 extern char *spa_strdup(const char *);
803 extern void spa_strfree(char *);
804 extern uint64_t spa_get_random(uint64_t range);
805 extern uint64_t spa_generate_guid(spa_t *spa);
806 extern void snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp);
807 extern void spa_freeze(spa_t *spa);
808 extern int spa_change_guid(spa_t *spa);
809 extern void spa_upgrade(spa_t *spa, uint64_t version);
810 extern void spa_evict_all(void);
811 extern vdev_t *spa_lookup_by_guid(spa_t *spa, uint64_t guid,
812     boolean_t l2cache);
813 extern boolean_t spa_has_spare(spa_t *, uint64_t guid);
814 extern uint64_t dva_get_dsize_sync(spa_t *spa, const dva_t *dva);
815 extern uint64_t bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp);
816 extern uint64_t bp_get_dsize(spa_t *spa, const blkptr_t *bp);
817 extern boolean_t spa_has_slogs(spa_t *spa);
818 extern boolean_t spa_is_root(spa_t *spa);
819 extern boolean_t spa_writeable(spa_t *spa);
820 extern boolean_t spa_has_pending_synctask(spa_t *spa);
821 extern int spa_maxblocksize(spa_t *spa);
822 extern void zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp);
823 
824 extern int spa_mode(spa_t *spa);
825 extern uint64_t strtonum(const char *str, char **nptr);
826 
827 extern char *spa_his_ievent_table[];
828 
829 extern void spa_history_create_obj(spa_t *spa, dmu_tx_t *tx);
830 extern int spa_history_get(spa_t *spa, uint64_t *offset, uint64_t *len_read,
831     char *his_buf);
832 extern int spa_history_log(spa_t *spa, const char *his_buf);
833 extern int spa_history_log_nvl(spa_t *spa, nvlist_t *nvl);
834 extern void spa_history_log_version(spa_t *spa, const char *operation);
835 extern void spa_history_log_internal(spa_t *spa, const char *operation,
836     dmu_tx_t *tx, const char *fmt, ...);
837 extern void spa_history_log_internal_ds(struct dsl_dataset *ds, const char *op,
838     dmu_tx_t *tx, const char *fmt, ...);
839 extern void spa_history_log_internal_dd(dsl_dir_t *dd, const char *operation,
840     dmu_tx_t *tx, const char *fmt, ...);
841 
842 /* error handling */
843 struct zbookmark_phys;
844 extern void spa_log_error(spa_t *spa, zio_t *zio);
845 extern void zfs_ereport_post(const char *class, spa_t *spa, vdev_t *vd,
846     zio_t *zio, uint64_t stateoroffset, uint64_t length);
847 extern void zfs_post_remove(spa_t *spa, vdev_t *vd);
848 extern void zfs_post_state_change(spa_t *spa, vdev_t *vd);
849 extern void zfs_post_autoreplace(spa_t *spa, vdev_t *vd);
850 extern uint64_t spa_get_errlog_size(spa_t *spa);
851 extern int spa_get_errlog(spa_t *spa, void *uaddr, size_t *count);
852 extern void spa_errlog_rotate(spa_t *spa);
853 extern void spa_errlog_drain(spa_t *spa);
854 extern void spa_errlog_sync(spa_t *spa, uint64_t txg);
855 extern void spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub);
856 
857 /* vdev cache */
858 extern void vdev_cache_stat_init(void);
859 extern void vdev_cache_stat_fini(void);
860 
861 /* Initialization and termination */
862 extern void spa_init(int flags);
863 extern void spa_fini(void);
864 extern void spa_boot_init();
865 
866 /* properties */
867 extern int spa_prop_set(spa_t *spa, nvlist_t *nvp);
868 extern int spa_prop_get(spa_t *spa, nvlist_t **nvp);
869 extern void spa_prop_clear_bootfs(spa_t *spa, uint64_t obj, dmu_tx_t *tx);
870 extern void spa_configfile_set(spa_t *, nvlist_t *, boolean_t);
871 
872 /* asynchronous event notification */
873 extern void spa_event_notify(spa_t *spa, vdev_t *vdev, const char *name);
874 
875 #ifdef ZFS_DEBUG
876 #define	dprintf_bp(bp, fmt, ...) do {				\
877 	if (zfs_flags & ZFS_DEBUG_DPRINTF) {			\
878 	char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP);	\
879 	snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, (bp));	\
880 	dprintf(fmt " %s\n", __VA_ARGS__, __blkbuf);		\
881 	kmem_free(__blkbuf, BP_SPRINTF_LEN);			\
882 	} \
883 _NOTE(CONSTCOND) } while (0)
884 #else
885 #define	dprintf_bp(bp, fmt, ...)
886 #endif
887 
888 extern boolean_t spa_debug_enabled(spa_t *spa);
889 #define	spa_dbgmsg(spa, ...)			\
890 {						\
891 	if (spa_debug_enabled(spa))		\
892 		zfs_dbgmsg(__VA_ARGS__);	\
893 }
894 
895 extern int spa_mode_global;			/* mode, e.g. FREAD | FWRITE */
896 
897 #ifdef	__cplusplus
898 }
899 #endif
900 
901 #endif	/* _SYS_SPA_H */
902