xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/spa.h (revision 4b5c8e93cab28d3c65ba9d407fd8f46e3be1db1c)
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  * Copyright (c) 2014 Integros [integros.com]
28  */
29 
30 #ifndef _SYS_SPA_H
31 #define	_SYS_SPA_H
32 
33 #include <sys/avl.h>
34 #include <sys/zfs_context.h>
35 #include <sys/nvpair.h>
36 #include <sys/sysmacros.h>
37 #include <sys/types.h>
38 #include <sys/fs/zfs.h>
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 /*
45  * Forward references that lots of things need.
46  */
47 typedef struct spa spa_t;
48 typedef struct vdev vdev_t;
49 typedef struct metaslab metaslab_t;
50 typedef struct metaslab_group metaslab_group_t;
51 typedef struct metaslab_class metaslab_class_t;
52 typedef struct zio zio_t;
53 typedef struct zilog zilog_t;
54 typedef struct spa_aux_vdev spa_aux_vdev_t;
55 typedef struct ddt ddt_t;
56 typedef struct ddt_entry ddt_entry_t;
57 struct dsl_pool;
58 struct dsl_dataset;
59 
60 /*
61  * General-purpose 32-bit and 64-bit bitfield encodings.
62  */
63 #define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))
64 #define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))
65 #define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))
66 #define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))
67 
68 #define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)
69 #define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)
70 
71 #define	BF32_SET(x, low, len, val) do { \
72 	ASSERT3U(val, <, 1U << (len)); \
73 	ASSERT3U(low + len, <=, 32); \
74 	(x) ^= BF32_ENCODE((x >> low) ^ (val), low, len); \
75 _NOTE(CONSTCOND) } while (0)
76 
77 #define	BF64_SET(x, low, len, val) do { \
78 	ASSERT3U(val, <, 1ULL << (len)); \
79 	ASSERT3U(low + len, <=, 64); \
80 	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len)); \
81 _NOTE(CONSTCOND) } while (0)
82 
83 #define	BF32_GET_SB(x, low, len, shift, bias)	\
84 	((BF32_GET(x, low, len) + (bias)) << (shift))
85 #define	BF64_GET_SB(x, low, len, shift, bias)	\
86 	((BF64_GET(x, low, len) + (bias)) << (shift))
87 
88 #define	BF32_SET_SB(x, low, len, shift, bias, val) do { \
89 	ASSERT(IS_P2ALIGNED(val, 1U << shift)); \
90 	ASSERT3S((val) >> (shift), >=, bias); \
91 	BF32_SET(x, low, len, ((val) >> (shift)) - (bias)); \
92 _NOTE(CONSTCOND) } while (0)
93 #define	BF64_SET_SB(x, low, len, shift, bias, val) do { \
94 	ASSERT(IS_P2ALIGNED(val, 1ULL << shift)); \
95 	ASSERT3S((val) >> (shift), >=, bias); \
96 	BF64_SET(x, low, len, ((val) >> (shift)) - (bias)); \
97 _NOTE(CONSTCOND) } while (0)
98 
99 /*
100  * We currently support block sizes from 512 bytes to 16MB.
101  * The benefits of larger blocks, and thus larger IO, need to be weighed
102  * against the cost of COWing a giant block to modify one byte, and the
103  * large latency of reading or writing a large block.
104  *
105  * Note that although blocks up to 16MB are supported, the recordsize
106  * property can not be set larger than zfs_max_recordsize (default 1MB).
107  * See the comment near zfs_max_recordsize in dsl_dataset.c for details.
108  *
109  * Note that although the LSIZE field of the blkptr_t can store sizes up
110  * to 32MB, the dnode's dn_datablkszsec can only store sizes up to
111  * 32MB - 512 bytes.  Therefore, we limit SPA_MAXBLOCKSIZE to 16MB.
112  */
113 #define	SPA_MINBLOCKSHIFT	9
114 #define	SPA_OLD_MAXBLOCKSHIFT	17
115 #define	SPA_MAXBLOCKSHIFT	24
116 #define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)
117 #define	SPA_OLD_MAXBLOCKSIZE	(1ULL << SPA_OLD_MAXBLOCKSHIFT)
118 #define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)
119 
120 /*
121  * Size of block to hold the configuration data (a packed nvlist)
122  */
123 #define	SPA_CONFIG_BLOCKSIZE	(1ULL << 14)
124 
125 /*
126  * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
127  * The ASIZE encoding should be at least 64 times larger (6 more bits)
128  * to support up to 4-way RAID-Z mirror mode with worst-case gang block
129  * overhead, three DVAs per bp, plus one more bit in case we do anything
130  * else that expands the ASIZE.
131  */
132 #define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/
133 #define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/
134 #define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/
135 
136 #define	SPA_COMPRESSBITS	7
137 
138 /*
139  * All SPA data is represented by 128-bit data virtual addresses (DVAs).
140  * The members of the dva_t should be considered opaque outside the SPA.
141  */
142 typedef struct dva {
143 	uint64_t	dva_word[2];
144 } dva_t;
145 
146 /*
147  * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
148  */
149 typedef struct zio_cksum {
150 	uint64_t	zc_word[4];
151 } zio_cksum_t;
152 
153 /*
154  * Some checksums/hashes need a 256-bit initialization salt. This salt is kept
155  * secret and is suitable for use in MAC algorithms as the key.
156  */
157 typedef struct zio_cksum_salt {
158 	uint8_t		zcs_bytes[32];
159 } zio_cksum_salt_t;
160 
161 /*
162  * Each block is described by its DVAs, time of birth, checksum, etc.
163  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
164  *
165  *	64	56	48	40	32	24	16	8	0
166  *	+-------+-------+-------+-------+-------+-------+-------+-------+
167  * 0	|		vdev1		| GRID  |	  ASIZE		|
168  *	+-------+-------+-------+-------+-------+-------+-------+-------+
169  * 1	|G|			 offset1				|
170  *	+-------+-------+-------+-------+-------+-------+-------+-------+
171  * 2	|		vdev2		| GRID  |	  ASIZE		|
172  *	+-------+-------+-------+-------+-------+-------+-------+-------+
173  * 3	|G|			 offset2				|
174  *	+-------+-------+-------+-------+-------+-------+-------+-------+
175  * 4	|		vdev3		| GRID  |	  ASIZE		|
176  *	+-------+-------+-------+-------+-------+-------+-------+-------+
177  * 5	|G|			 offset3				|
178  *	+-------+-------+-------+-------+-------+-------+-------+-------+
179  * 6	|BDX|lvl| type	| cksum |E| comp|    PSIZE	|     LSIZE	|
180  *	+-------+-------+-------+-------+-------+-------+-------+-------+
181  * 7	|			padding					|
182  *	+-------+-------+-------+-------+-------+-------+-------+-------+
183  * 8	|			padding					|
184  *	+-------+-------+-------+-------+-------+-------+-------+-------+
185  * 9	|			physical birth txg			|
186  *	+-------+-------+-------+-------+-------+-------+-------+-------+
187  * a	|			logical birth txg			|
188  *	+-------+-------+-------+-------+-------+-------+-------+-------+
189  * b	|			fill count				|
190  *	+-------+-------+-------+-------+-------+-------+-------+-------+
191  * c	|			checksum[0]				|
192  *	+-------+-------+-------+-------+-------+-------+-------+-------+
193  * d	|			checksum[1]				|
194  *	+-------+-------+-------+-------+-------+-------+-------+-------+
195  * e	|			checksum[2]				|
196  *	+-------+-------+-------+-------+-------+-------+-------+-------+
197  * f	|			checksum[3]				|
198  *	+-------+-------+-------+-------+-------+-------+-------+-------+
199  *
200  * Legend:
201  *
202  * vdev		virtual device ID
203  * offset	offset into virtual device
204  * LSIZE	logical size
205  * PSIZE	physical size (after compression)
206  * ASIZE	allocated size (including RAID-Z parity and gang block headers)
207  * GRID		RAID-Z layout information (reserved for future use)
208  * cksum	checksum function
209  * comp		compression function
210  * G		gang block indicator
211  * B		byteorder (endianness)
212  * D		dedup
213  * X		encryption (on version 30, which is not supported)
214  * E		blkptr_t contains embedded data (see below)
215  * lvl		level of indirection
216  * type		DMU object type
217  * phys birth	txg of block allocation; zero if same as logical birth txg
218  * log. birth	transaction group in which the block was logically born
219  * fill count	number of non-zero blocks under this bp
220  * checksum[4]	256-bit checksum of the data this bp describes
221  */
222 
223 /*
224  * "Embedded" blkptr_t's don't actually point to a block, instead they
225  * have a data payload embedded in the blkptr_t itself.  See the comment
226  * in blkptr.c for more details.
227  *
228  * The blkptr_t is laid out as follows:
229  *
230  *	64	56	48	40	32	24	16	8	0
231  *	+-------+-------+-------+-------+-------+-------+-------+-------+
232  * 0	|      payload                                                  |
233  * 1	|      payload                                                  |
234  * 2	|      payload                                                  |
235  * 3	|      payload                                                  |
236  * 4	|      payload                                                  |
237  * 5	|      payload                                                  |
238  *	+-------+-------+-------+-------+-------+-------+-------+-------+
239  * 6	|BDX|lvl| type	| etype |E| comp| PSIZE|              LSIZE	|
240  *	+-------+-------+-------+-------+-------+-------+-------+-------+
241  * 7	|      payload                                                  |
242  * 8	|      payload                                                  |
243  * 9	|      payload                                                  |
244  *	+-------+-------+-------+-------+-------+-------+-------+-------+
245  * a	|			logical birth txg			|
246  *	+-------+-------+-------+-------+-------+-------+-------+-------+
247  * b	|      payload                                                  |
248  * c	|      payload                                                  |
249  * d	|      payload                                                  |
250  * e	|      payload                                                  |
251  * f	|      payload                                                  |
252  *	+-------+-------+-------+-------+-------+-------+-------+-------+
253  *
254  * Legend:
255  *
256  * payload		contains the embedded data
257  * B (byteorder)	byteorder (endianness)
258  * D (dedup)		padding (set to zero)
259  * X			encryption (set to zero; see above)
260  * E (embedded)		set to one
261  * lvl			indirection level
262  * type			DMU object type
263  * etype		how to interpret embedded data (BP_EMBEDDED_TYPE_*)
264  * comp			compression function of payload
265  * PSIZE		size of payload after compression, in bytes
266  * LSIZE		logical size of payload, in bytes
267  *			note that 25 bits is enough to store the largest
268  *			"normal" BP's LSIZE (2^16 * 2^9) in bytes
269  * log. birth		transaction group in which the block was logically born
270  *
271  * Note that LSIZE and PSIZE are stored in bytes, whereas for non-embedded
272  * bp's they are stored in units of SPA_MINBLOCKSHIFT.
273  * Generally, the generic BP_GET_*() macros can be used on embedded BP's.
274  * The B, D, X, lvl, type, and comp fields are stored the same as with normal
275  * BP's so the BP_SET_* macros can be used with them.  etype, PSIZE, LSIZE must
276  * be set with the BPE_SET_* macros.  BP_SET_EMBEDDED() should be called before
277  * other macros, as they assert that they are only used on BP's of the correct
278  * "embedded-ness".
279  */
280 
281 #define	BPE_GET_ETYPE(bp)	\
282 	(ASSERT(BP_IS_EMBEDDED(bp)), \
283 	BF64_GET((bp)->blk_prop, 40, 8))
284 #define	BPE_SET_ETYPE(bp, t)	do { \
285 	ASSERT(BP_IS_EMBEDDED(bp)); \
286 	BF64_SET((bp)->blk_prop, 40, 8, t); \
287 _NOTE(CONSTCOND) } while (0)
288 
289 #define	BPE_GET_LSIZE(bp)	\
290 	(ASSERT(BP_IS_EMBEDDED(bp)), \
291 	BF64_GET_SB((bp)->blk_prop, 0, 25, 0, 1))
292 #define	BPE_SET_LSIZE(bp, x)	do { \
293 	ASSERT(BP_IS_EMBEDDED(bp)); \
294 	BF64_SET_SB((bp)->blk_prop, 0, 25, 0, 1, x); \
295 _NOTE(CONSTCOND) } while (0)
296 
297 #define	BPE_GET_PSIZE(bp)	\
298 	(ASSERT(BP_IS_EMBEDDED(bp)), \
299 	BF64_GET_SB((bp)->blk_prop, 25, 7, 0, 1))
300 #define	BPE_SET_PSIZE(bp, x)	do { \
301 	ASSERT(BP_IS_EMBEDDED(bp)); \
302 	BF64_SET_SB((bp)->blk_prop, 25, 7, 0, 1, x); \
303 _NOTE(CONSTCOND) } while (0)
304 
305 typedef enum bp_embedded_type {
306 	BP_EMBEDDED_TYPE_DATA,
307 	BP_EMBEDDED_TYPE_RESERVED, /* Reserved for an unintegrated feature. */
308 	NUM_BP_EMBEDDED_TYPES = BP_EMBEDDED_TYPE_RESERVED
309 } bp_embedded_type_t;
310 
311 #define	BPE_NUM_WORDS 14
312 #define	BPE_PAYLOAD_SIZE (BPE_NUM_WORDS * sizeof (uint64_t))
313 #define	BPE_IS_PAYLOADWORD(bp, wp) \
314 	((wp) != &(bp)->blk_prop && (wp) != &(bp)->blk_birth)
315 
316 #define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
317 #define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
318 
319 /*
320  * A block is a hole when it has either 1) never been written to, or
321  * 2) is zero-filled. In both cases, ZFS can return all zeroes for all reads
322  * without physically allocating disk space. Holes are represented in the
323  * blkptr_t structure by zeroed blk_dva. Correct checking for holes is
324  * done through the BP_IS_HOLE macro. For holes, the logical size, level,
325  * DMU object type, and birth times are all also stored for holes that
326  * were written to at some point (i.e. were punched after having been filled).
327  */
328 typedef struct blkptr {
329 	dva_t		blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
330 	uint64_t	blk_prop;	/* size, compression, type, etc	    */
331 	uint64_t	blk_pad[2];	/* Extra space for the future	    */
332 	uint64_t	blk_phys_birth;	/* txg when block was allocated	    */
333 	uint64_t	blk_birth;	/* transaction group at birth	    */
334 	uint64_t	blk_fill;	/* fill count			    */
335 	zio_cksum_t	blk_cksum;	/* 256-bit checksum		    */
336 } blkptr_t;
337 
338 /*
339  * Macros to get and set fields in a bp or DVA.
340  */
341 #define	DVA_GET_ASIZE(dva)	\
342 	BF64_GET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, SPA_MINBLOCKSHIFT, 0)
343 #define	DVA_SET_ASIZE(dva, x)	\
344 	BF64_SET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, \
345 	SPA_MINBLOCKSHIFT, 0, x)
346 
347 #define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
348 #define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
349 
350 #define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
351 #define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
352 
353 #define	DVA_GET_OFFSET(dva)	\
354 	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
355 #define	DVA_SET_OFFSET(dva, x)	\
356 	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
357 
358 #define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
359 #define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
360 
361 #define	BP_GET_LSIZE(bp)	\
362 	(BP_IS_EMBEDDED(bp) ?	\
363 	(BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA ? BPE_GET_LSIZE(bp) : 0): \
364 	BF64_GET_SB((bp)->blk_prop, 0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1))
365 #define	BP_SET_LSIZE(bp, x)	do { \
366 	ASSERT(!BP_IS_EMBEDDED(bp)); \
367 	BF64_SET_SB((bp)->blk_prop, \
368 	    0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
369 _NOTE(CONSTCOND) } while (0)
370 
371 #define	BP_GET_PSIZE(bp)	\
372 	(BP_IS_EMBEDDED(bp) ? 0 : \
373 	BF64_GET_SB((bp)->blk_prop, 16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1))
374 #define	BP_SET_PSIZE(bp, x)	do { \
375 	ASSERT(!BP_IS_EMBEDDED(bp)); \
376 	BF64_SET_SB((bp)->blk_prop, \
377 	    16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
378 _NOTE(CONSTCOND) } while (0)
379 
380 #define	BP_GET_COMPRESS(bp)		\
381 	BF64_GET((bp)->blk_prop, 32, SPA_COMPRESSBITS)
382 #define	BP_SET_COMPRESS(bp, x)		\
383 	BF64_SET((bp)->blk_prop, 32, SPA_COMPRESSBITS, x)
384 
385 #define	BP_IS_EMBEDDED(bp)		BF64_GET((bp)->blk_prop, 39, 1)
386 #define	BP_SET_EMBEDDED(bp, x)		BF64_SET((bp)->blk_prop, 39, 1, x)
387 
388 #define	BP_GET_CHECKSUM(bp)		\
389 	(BP_IS_EMBEDDED(bp) ? ZIO_CHECKSUM_OFF : \
390 	BF64_GET((bp)->blk_prop, 40, 8))
391 #define	BP_SET_CHECKSUM(bp, x)		do { \
392 	ASSERT(!BP_IS_EMBEDDED(bp)); \
393 	BF64_SET((bp)->blk_prop, 40, 8, x); \
394 _NOTE(CONSTCOND) } while (0)
395 
396 #define	BP_GET_TYPE(bp)			BF64_GET((bp)->blk_prop, 48, 8)
397 #define	BP_SET_TYPE(bp, x)		BF64_SET((bp)->blk_prop, 48, 8, x)
398 
399 #define	BP_GET_LEVEL(bp)		BF64_GET((bp)->blk_prop, 56, 5)
400 #define	BP_SET_LEVEL(bp, x)		BF64_SET((bp)->blk_prop, 56, 5, x)
401 
402 #define	BP_GET_DEDUP(bp)		BF64_GET((bp)->blk_prop, 62, 1)
403 #define	BP_SET_DEDUP(bp, x)		BF64_SET((bp)->blk_prop, 62, 1, x)
404 
405 #define	BP_GET_BYTEORDER(bp)		BF64_GET((bp)->blk_prop, 63, 1)
406 #define	BP_SET_BYTEORDER(bp, x)		BF64_SET((bp)->blk_prop, 63, 1, x)
407 
408 #define	BP_PHYSICAL_BIRTH(bp)		\
409 	(BP_IS_EMBEDDED(bp) ? 0 : \
410 	(bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
411 
412 #define	BP_SET_BIRTH(bp, logical, physical)	\
413 {						\
414 	ASSERT(!BP_IS_EMBEDDED(bp));		\
415 	(bp)->blk_birth = (logical);		\
416 	(bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
417 }
418 
419 #define	BP_GET_FILL(bp) (BP_IS_EMBEDDED(bp) ? 1 : (bp)->blk_fill)
420 
421 #define	BP_GET_ASIZE(bp)	\
422 	(BP_IS_EMBEDDED(bp) ? 0 : \
423 	DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
424 	DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
425 	DVA_GET_ASIZE(&(bp)->blk_dva[2]))
426 
427 #define	BP_GET_UCSIZE(bp) \
428 	((BP_GET_LEVEL(bp) > 0 || DMU_OT_IS_METADATA(BP_GET_TYPE(bp))) ? \
429 	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp))
430 
431 #define	BP_GET_NDVAS(bp)	\
432 	(BP_IS_EMBEDDED(bp) ? 0 : \
433 	!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
434 	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
435 	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
436 
437 #define	BP_COUNT_GANG(bp)	\
438 	(BP_IS_EMBEDDED(bp) ? 0 : \
439 	(DVA_GET_GANG(&(bp)->blk_dva[0]) + \
440 	DVA_GET_GANG(&(bp)->blk_dva[1]) + \
441 	DVA_GET_GANG(&(bp)->blk_dva[2])))
442 
443 #define	DVA_EQUAL(dva1, dva2)	\
444 	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
445 	(dva1)->dva_word[0] == (dva2)->dva_word[0])
446 
447 #define	BP_EQUAL(bp1, bp2)	\
448 	(BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&	\
449 	(bp1)->blk_birth == (bp2)->blk_birth &&			\
450 	DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&	\
451 	DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&	\
452 	DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
453 
454 #define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \
455 	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
456 	((zc1).zc_word[1] - (zc2).zc_word[1]) | \
457 	((zc1).zc_word[2] - (zc2).zc_word[2]) | \
458 	((zc1).zc_word[3] - (zc2).zc_word[3])))
459 
460 #define	ZIO_CHECKSUM_IS_ZERO(zc) \
461 	(0 == ((zc)->zc_word[0] | (zc)->zc_word[1] | \
462 	(zc)->zc_word[2] | (zc)->zc_word[3]))
463 
464 #define	ZIO_CHECKSUM_BSWAP(zcp)					\
465 {								\
466 	(zcp)->zc_word[0] = BSWAP_64((zcp)->zc_word[0]);	\
467 	(zcp)->zc_word[1] = BSWAP_64((zcp)->zc_word[1]);	\
468 	(zcp)->zc_word[2] = BSWAP_64((zcp)->zc_word[2]);	\
469 	(zcp)->zc_word[3] = BSWAP_64((zcp)->zc_word[3]);	\
470 }
471 
472 
473 #define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
474 
475 #define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
476 {						\
477 	(zcp)->zc_word[0] = w0;			\
478 	(zcp)->zc_word[1] = w1;			\
479 	(zcp)->zc_word[2] = w2;			\
480 	(zcp)->zc_word[3] = w3;			\
481 }
482 
483 #define	BP_IDENTITY(bp)		(ASSERT(!BP_IS_EMBEDDED(bp)), &(bp)->blk_dva[0])
484 #define	BP_IS_GANG(bp)		\
485 	(BP_IS_EMBEDDED(bp) ? B_FALSE : DVA_GET_GANG(BP_IDENTITY(bp)))
486 #define	DVA_IS_EMPTY(dva)	((dva)->dva_word[0] == 0ULL &&	\
487 				(dva)->dva_word[1] == 0ULL)
488 #define	BP_IS_HOLE(bp) \
489 	(!BP_IS_EMBEDDED(bp) && DVA_IS_EMPTY(BP_IDENTITY(bp)))
490 
491 /* BP_IS_RAIDZ(bp) assumes no block compression */
492 #define	BP_IS_RAIDZ(bp)		(DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
493 				BP_GET_PSIZE(bp))
494 
495 #define	BP_ZERO(bp)				\
496 {						\
497 	(bp)->blk_dva[0].dva_word[0] = 0;	\
498 	(bp)->blk_dva[0].dva_word[1] = 0;	\
499 	(bp)->blk_dva[1].dva_word[0] = 0;	\
500 	(bp)->blk_dva[1].dva_word[1] = 0;	\
501 	(bp)->blk_dva[2].dva_word[0] = 0;	\
502 	(bp)->blk_dva[2].dva_word[1] = 0;	\
503 	(bp)->blk_prop = 0;			\
504 	(bp)->blk_pad[0] = 0;			\
505 	(bp)->blk_pad[1] = 0;			\
506 	(bp)->blk_phys_birth = 0;		\
507 	(bp)->blk_birth = 0;			\
508 	(bp)->blk_fill = 0;			\
509 	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
510 }
511 
512 #ifdef _BIG_ENDIAN
513 #define	ZFS_HOST_BYTEORDER	(0ULL)
514 #else
515 #define	ZFS_HOST_BYTEORDER	(1ULL)
516 #endif
517 
518 #define	BP_SHOULD_BYTESWAP(bp)	(BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)
519 
520 #define	BP_SPRINTF_LEN	320
521 
522 /*
523  * This macro allows code sharing between zfs, libzpool, and mdb.
524  * 'func' is either snprintf() or mdb_snprintf().
525  * 'ws' (whitespace) can be ' ' for single-line format, '\n' for multi-line.
526  */
527 #define	SNPRINTF_BLKPTR(func, ws, buf, size, bp, type, checksum, compress) \
528 {									\
529 	static const char *copyname[] =					\
530 	    { "zero", "single", "double", "triple" };			\
531 	int len = 0;							\
532 	int copies = 0;							\
533 									\
534 	if (bp == NULL) {						\
535 		len += func(buf + len, size - len, "<NULL>");		\
536 	} else if (BP_IS_HOLE(bp)) {					\
537 		len += func(buf + len, size - len,			\
538 		    "HOLE [L%llu %s] "					\
539 		    "size=%llxL birth=%lluL",				\
540 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
541 		    type,						\
542 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
543 		    (u_longlong_t)bp->blk_birth);			\
544 	} else if (BP_IS_EMBEDDED(bp)) {				\
545 		len = func(buf + len, size - len,			\
546 		    "EMBEDDED [L%llu %s] et=%u %s "			\
547 		    "size=%llxL/%llxP birth=%lluL",			\
548 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
549 		    type,						\
550 		    (int)BPE_GET_ETYPE(bp),				\
551 		    compress,						\
552 		    (u_longlong_t)BPE_GET_LSIZE(bp),			\
553 		    (u_longlong_t)BPE_GET_PSIZE(bp),			\
554 		    (u_longlong_t)bp->blk_birth);			\
555 	} else {							\
556 		for (int d = 0; d < BP_GET_NDVAS(bp); d++) {		\
557 			const dva_t *dva = &bp->blk_dva[d];		\
558 			if (DVA_IS_VALID(dva))				\
559 				copies++;				\
560 			len += func(buf + len, size - len,		\
561 			    "DVA[%d]=<%llu:%llx:%llx>%c", d,		\
562 			    (u_longlong_t)DVA_GET_VDEV(dva),		\
563 			    (u_longlong_t)DVA_GET_OFFSET(dva),		\
564 			    (u_longlong_t)DVA_GET_ASIZE(dva),		\
565 			    ws);					\
566 		}							\
567 		if (BP_IS_GANG(bp) &&					\
568 		    DVA_GET_ASIZE(&bp->blk_dva[2]) <=			\
569 		    DVA_GET_ASIZE(&bp->blk_dva[1]) / 2)			\
570 			copies--;					\
571 		len += func(buf + len, size - len,			\
572 		    "[L%llu %s] %s %s %s %s %s %s%c"			\
573 		    "size=%llxL/%llxP birth=%lluL/%lluP fill=%llu%c"	\
574 		    "cksum=%llx:%llx:%llx:%llx",			\
575 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
576 		    type,						\
577 		    checksum,						\
578 		    compress,						\
579 		    BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",		\
580 		    BP_IS_GANG(bp) ? "gang" : "contiguous",		\
581 		    BP_GET_DEDUP(bp) ? "dedup" : "unique",		\
582 		    copyname[copies],					\
583 		    ws,							\
584 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
585 		    (u_longlong_t)BP_GET_PSIZE(bp),			\
586 		    (u_longlong_t)bp->blk_birth,			\
587 		    (u_longlong_t)BP_PHYSICAL_BIRTH(bp),		\
588 		    (u_longlong_t)BP_GET_FILL(bp),			\
589 		    ws,							\
590 		    (u_longlong_t)bp->blk_cksum.zc_word[0],		\
591 		    (u_longlong_t)bp->blk_cksum.zc_word[1],		\
592 		    (u_longlong_t)bp->blk_cksum.zc_word[2],		\
593 		    (u_longlong_t)bp->blk_cksum.zc_word[3]);		\
594 	}								\
595 	ASSERT(len < size);						\
596 }
597 
598 #include <sys/dmu.h>
599 
600 #define	BP_GET_BUFC_TYPE(bp)						\
601 	(((BP_GET_LEVEL(bp) > 0) || (DMU_OT_IS_METADATA(BP_GET_TYPE(bp)))) ? \
602 	ARC_BUFC_METADATA : ARC_BUFC_DATA)
603 
604 typedef enum spa_import_type {
605 	SPA_IMPORT_EXISTING,
606 	SPA_IMPORT_ASSEMBLE
607 } spa_import_type_t;
608 
609 /* state manipulation functions */
610 extern int spa_open(const char *pool, spa_t **, void *tag);
611 extern int spa_open_rewind(const char *pool, spa_t **, void *tag,
612     nvlist_t *policy, nvlist_t **config);
613 extern int spa_get_stats(const char *pool, nvlist_t **config, char *altroot,
614     size_t buflen);
615 extern int spa_create(const char *pool, nvlist_t *config, nvlist_t *props,
616     nvlist_t *zplprops);
617 extern int spa_import_rootpool(char *devpath, char *devid);
618 extern int spa_import(const char *pool, nvlist_t *config, nvlist_t *props,
619     uint64_t flags);
620 extern nvlist_t *spa_tryimport(nvlist_t *tryconfig);
621 extern int spa_destroy(char *pool);
622 extern int spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
623     boolean_t hardforce);
624 extern int spa_reset(char *pool);
625 extern void spa_async_request(spa_t *spa, int flag);
626 extern void spa_async_unrequest(spa_t *spa, int flag);
627 extern void spa_async_suspend(spa_t *spa);
628 extern void spa_async_resume(spa_t *spa);
629 extern spa_t *spa_inject_addref(char *pool);
630 extern void spa_inject_delref(spa_t *spa);
631 extern void spa_scan_stat_init(spa_t *spa);
632 extern int spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps);
633 
634 #define	SPA_ASYNC_CONFIG_UPDATE	0x01
635 #define	SPA_ASYNC_REMOVE	0x02
636 #define	SPA_ASYNC_PROBE		0x04
637 #define	SPA_ASYNC_RESILVER_DONE	0x08
638 #define	SPA_ASYNC_RESILVER	0x10
639 #define	SPA_ASYNC_AUTOEXPAND	0x20
640 #define	SPA_ASYNC_REMOVE_DONE	0x40
641 #define	SPA_ASYNC_REMOVE_STOP	0x80
642 
643 /*
644  * Controls the behavior of spa_vdev_remove().
645  */
646 #define	SPA_REMOVE_UNSPARE	0x01
647 #define	SPA_REMOVE_DONE		0x02
648 
649 /* device manipulation */
650 extern int spa_vdev_add(spa_t *spa, nvlist_t *nvroot);
651 extern int spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot,
652     int replacing);
653 extern int spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid,
654     int replace_done);
655 extern int spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare);
656 extern boolean_t spa_vdev_remove_active(spa_t *spa);
657 extern int spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath);
658 extern int spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru);
659 extern int spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
660     nvlist_t *props, boolean_t exp);
661 
662 /* spare state (which is global across all pools) */
663 extern void spa_spare_add(vdev_t *vd);
664 extern void spa_spare_remove(vdev_t *vd);
665 extern boolean_t spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt);
666 extern void spa_spare_activate(vdev_t *vd);
667 
668 /* L2ARC state (which is global across all pools) */
669 extern void spa_l2cache_add(vdev_t *vd);
670 extern void spa_l2cache_remove(vdev_t *vd);
671 extern boolean_t spa_l2cache_exists(uint64_t guid, uint64_t *pool);
672 extern void spa_l2cache_activate(vdev_t *vd);
673 extern void spa_l2cache_drop(spa_t *spa);
674 
675 /* scanning */
676 extern int spa_scan(spa_t *spa, pool_scan_func_t func);
677 extern int spa_scan_stop(spa_t *spa);
678 
679 /* spa syncing */
680 extern void spa_sync(spa_t *spa, uint64_t txg); /* only for DMU use */
681 extern void spa_sync_allpools(void);
682 
683 /* spa namespace global mutex */
684 extern kmutex_t spa_namespace_lock;
685 
686 /*
687  * SPA configuration functions in spa_config.c
688  */
689 
690 #define	SPA_CONFIG_UPDATE_POOL	0
691 #define	SPA_CONFIG_UPDATE_VDEVS	1
692 
693 extern void spa_config_sync(spa_t *, boolean_t, boolean_t);
694 extern void spa_config_load(void);
695 extern nvlist_t *spa_all_configs(uint64_t *);
696 extern void spa_config_set(spa_t *spa, nvlist_t *config);
697 extern nvlist_t *spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg,
698     int getstats);
699 extern void spa_config_update(spa_t *spa, int what);
700 
701 /*
702  * Miscellaneous SPA routines in spa_misc.c
703  */
704 
705 /* Namespace manipulation */
706 extern spa_t *spa_lookup(const char *name);
707 extern spa_t *spa_add(const char *name, nvlist_t *config, const char *altroot);
708 extern void spa_remove(spa_t *spa);
709 extern spa_t *spa_next(spa_t *prev);
710 
711 /* Refcount functions */
712 extern void spa_open_ref(spa_t *spa, void *tag);
713 extern void spa_close(spa_t *spa, void *tag);
714 extern void spa_async_close(spa_t *spa, void *tag);
715 extern boolean_t spa_refcount_zero(spa_t *spa);
716 
717 #define	SCL_NONE	0x00
718 #define	SCL_CONFIG	0x01
719 #define	SCL_STATE	0x02
720 #define	SCL_L2ARC	0x04		/* hack until L2ARC 2.0 */
721 #define	SCL_ALLOC	0x08
722 #define	SCL_ZIO		0x10
723 #define	SCL_FREE	0x20
724 #define	SCL_VDEV	0x40
725 #define	SCL_LOCKS	7
726 #define	SCL_ALL		((1 << SCL_LOCKS) - 1)
727 #define	SCL_STATE_ALL	(SCL_STATE | SCL_L2ARC | SCL_ZIO)
728 
729 /* Pool configuration locks */
730 extern int spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw);
731 extern void spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw);
732 extern void spa_config_exit(spa_t *spa, int locks, void *tag);
733 extern int spa_config_held(spa_t *spa, int locks, krw_t rw);
734 
735 /* Pool vdev add/remove lock */
736 extern uint64_t spa_vdev_enter(spa_t *spa);
737 extern uint64_t spa_vdev_config_enter(spa_t *spa);
738 extern void spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg,
739     int error, char *tag);
740 extern int spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error);
741 
742 /* Pool vdev state change lock */
743 extern void spa_vdev_state_enter(spa_t *spa, int oplock);
744 extern int spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error);
745 
746 /* Log state */
747 typedef enum spa_log_state {
748 	SPA_LOG_UNKNOWN = 0,	/* unknown log state */
749 	SPA_LOG_MISSING,	/* missing log(s) */
750 	SPA_LOG_CLEAR,		/* clear the log(s) */
751 	SPA_LOG_GOOD,		/* log(s) are good */
752 } spa_log_state_t;
753 
754 extern spa_log_state_t spa_get_log_state(spa_t *spa);
755 extern void spa_set_log_state(spa_t *spa, spa_log_state_t state);
756 extern int spa_offline_log(spa_t *spa);
757 
758 /* Log claim callback */
759 extern void spa_claim_notify(zio_t *zio);
760 
761 /* Accessor functions */
762 extern boolean_t spa_shutting_down(spa_t *spa);
763 extern struct dsl_pool *spa_get_dsl(spa_t *spa);
764 extern boolean_t spa_is_initializing(spa_t *spa);
765 extern blkptr_t *spa_get_rootblkptr(spa_t *spa);
766 extern void spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp);
767 extern void spa_altroot(spa_t *, char *, size_t);
768 extern int spa_sync_pass(spa_t *spa);
769 extern char *spa_name(spa_t *spa);
770 extern uint64_t spa_guid(spa_t *spa);
771 extern uint64_t spa_load_guid(spa_t *spa);
772 extern uint64_t spa_last_synced_txg(spa_t *spa);
773 extern uint64_t spa_first_txg(spa_t *spa);
774 extern uint64_t spa_syncing_txg(spa_t *spa);
775 extern uint64_t spa_version(spa_t *spa);
776 extern pool_state_t spa_state(spa_t *spa);
777 extern spa_load_state_t spa_load_state(spa_t *spa);
778 extern uint64_t spa_freeze_txg(spa_t *spa);
779 extern uint64_t spa_get_asize(spa_t *spa, uint64_t lsize);
780 extern uint64_t spa_get_dspace(spa_t *spa);
781 extern uint64_t spa_get_slop_space(spa_t *spa);
782 extern void spa_update_dspace(spa_t *spa);
783 extern uint64_t spa_version(spa_t *spa);
784 extern boolean_t spa_deflate(spa_t *spa);
785 extern metaslab_class_t *spa_normal_class(spa_t *spa);
786 extern metaslab_class_t *spa_log_class(spa_t *spa);
787 extern void spa_evicting_os_register(spa_t *, objset_t *os);
788 extern void spa_evicting_os_deregister(spa_t *, objset_t *os);
789 extern void spa_evicting_os_wait(spa_t *spa);
790 extern int spa_max_replication(spa_t *spa);
791 extern int spa_prev_software_version(spa_t *spa);
792 extern int spa_busy(void);
793 extern uint8_t spa_get_failmode(spa_t *spa);
794 extern boolean_t spa_suspended(spa_t *spa);
795 extern uint64_t spa_bootfs(spa_t *spa);
796 extern uint64_t spa_delegation(spa_t *spa);
797 extern objset_t *spa_meta_objset(spa_t *spa);
798 extern uint64_t spa_deadman_synctime(spa_t *spa);
799 
800 /* Miscellaneous support routines */
801 extern void spa_activate_mos_feature(spa_t *spa, const char *feature,
802     dmu_tx_t *tx);
803 extern void spa_deactivate_mos_feature(spa_t *spa, const char *feature);
804 extern int spa_rename(const char *oldname, const char *newname);
805 extern spa_t *spa_by_guid(uint64_t pool_guid, uint64_t device_guid);
806 extern boolean_t spa_guid_exists(uint64_t pool_guid, uint64_t device_guid);
807 extern char *spa_strdup(const char *);
808 extern void spa_strfree(char *);
809 extern uint64_t spa_get_random(uint64_t range);
810 extern uint64_t spa_generate_guid(spa_t *spa);
811 extern void snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp);
812 extern void spa_freeze(spa_t *spa);
813 extern int spa_change_guid(spa_t *spa);
814 extern void spa_upgrade(spa_t *spa, uint64_t version);
815 extern void spa_evict_all(void);
816 extern vdev_t *spa_lookup_by_guid(spa_t *spa, uint64_t guid,
817     boolean_t l2cache);
818 extern boolean_t spa_has_spare(spa_t *, uint64_t guid);
819 extern uint64_t dva_get_dsize_sync(spa_t *spa, const dva_t *dva);
820 extern uint64_t bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp);
821 extern uint64_t bp_get_dsize(spa_t *spa, const blkptr_t *bp);
822 extern boolean_t spa_has_slogs(spa_t *spa);
823 extern boolean_t spa_is_root(spa_t *spa);
824 extern boolean_t spa_writeable(spa_t *spa);
825 extern boolean_t spa_has_pending_synctask(spa_t *spa);
826 extern int spa_maxblocksize(spa_t *spa);
827 extern void zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp);
828 
829 extern int spa_mode(spa_t *spa);
830 extern uint64_t strtonum(const char *str, char **nptr);
831 
832 extern char *spa_his_ievent_table[];
833 
834 extern void spa_history_create_obj(spa_t *spa, dmu_tx_t *tx);
835 extern int spa_history_get(spa_t *spa, uint64_t *offset, uint64_t *len_read,
836     char *his_buf);
837 extern int spa_history_log(spa_t *spa, const char *his_buf);
838 extern int spa_history_log_nvl(spa_t *spa, nvlist_t *nvl);
839 extern void spa_history_log_version(spa_t *spa, const char *operation);
840 extern void spa_history_log_internal(spa_t *spa, const char *operation,
841     dmu_tx_t *tx, const char *fmt, ...);
842 extern void spa_history_log_internal_ds(struct dsl_dataset *ds, const char *op,
843     dmu_tx_t *tx, const char *fmt, ...);
844 extern void spa_history_log_internal_dd(dsl_dir_t *dd, const char *operation,
845     dmu_tx_t *tx, const char *fmt, ...);
846 
847 /* error handling */
848 struct zbookmark_phys;
849 extern void spa_log_error(spa_t *spa, zio_t *zio);
850 extern void zfs_ereport_post(const char *class, spa_t *spa, vdev_t *vd,
851     zio_t *zio, uint64_t stateoroffset, uint64_t length);
852 extern void zfs_post_remove(spa_t *spa, vdev_t *vd);
853 extern void zfs_post_state_change(spa_t *spa, vdev_t *vd);
854 extern void zfs_post_autoreplace(spa_t *spa, vdev_t *vd);
855 extern uint64_t spa_get_errlog_size(spa_t *spa);
856 extern int spa_get_errlog(spa_t *spa, void *uaddr, size_t *count);
857 extern void spa_errlog_rotate(spa_t *spa);
858 extern void spa_errlog_drain(spa_t *spa);
859 extern void spa_errlog_sync(spa_t *spa, uint64_t txg);
860 extern void spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub);
861 
862 /* vdev cache */
863 extern void vdev_cache_stat_init(void);
864 extern void vdev_cache_stat_fini(void);
865 
866 /* Initialization and termination */
867 extern void spa_init(int flags);
868 extern void spa_fini(void);
869 extern void spa_boot_init();
870 
871 /* properties */
872 extern int spa_prop_set(spa_t *spa, nvlist_t *nvp);
873 extern int spa_prop_get(spa_t *spa, nvlist_t **nvp);
874 extern void spa_prop_clear_bootfs(spa_t *spa, uint64_t obj, dmu_tx_t *tx);
875 extern void spa_configfile_set(spa_t *, nvlist_t *, boolean_t);
876 
877 /* asynchronous event notification */
878 extern void spa_event_notify(spa_t *spa, vdev_t *vdev, const char *name);
879 
880 #ifdef ZFS_DEBUG
881 #define	dprintf_bp(bp, fmt, ...) do {				\
882 	if (zfs_flags & ZFS_DEBUG_DPRINTF) {			\
883 	char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP);	\
884 	snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, (bp));	\
885 	dprintf(fmt " %s\n", __VA_ARGS__, __blkbuf);		\
886 	kmem_free(__blkbuf, BP_SPRINTF_LEN);			\
887 	} \
888 _NOTE(CONSTCOND) } while (0)
889 #else
890 #define	dprintf_bp(bp, fmt, ...)
891 #endif
892 
893 extern boolean_t spa_debug_enabled(spa_t *spa);
894 #define	spa_dbgmsg(spa, ...)			\
895 {						\
896 	if (spa_debug_enabled(spa))		\
897 		zfs_dbgmsg(__VA_ARGS__);	\
898 }
899 
900 extern int spa_mode_global;			/* mode, e.g. FREAD | FWRITE */
901 
902 #ifdef	__cplusplus
903 }
904 #endif
905 
906 #endif	/* _SYS_SPA_H */
907