xref: /titanic_50/usr/src/uts/common/fs/zfs/sys/spa.h (revision 385cc6b4ad1792caef3f84eb61eed3f27085801f)
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  * Copyright 2013 Saso Kiselkov. All rights reserved.
28  * Copyright (c) 2014 Integros [integros.com]
29  */
30 
31 #ifndef _SYS_SPA_H
32 #define	_SYS_SPA_H
33 
34 #include <sys/avl.h>
35 #include <sys/zfs_context.h>
36 #include <sys/nvpair.h>
37 #include <sys/sysmacros.h>
38 #include <sys/types.h>
39 #include <sys/fs/zfs.h>
40 
41 #ifdef	__cplusplus
42 extern "C" {
43 #endif
44 
45 /*
46  * Forward references that lots of things need.
47  */
48 typedef struct spa spa_t;
49 typedef struct vdev vdev_t;
50 typedef struct metaslab metaslab_t;
51 typedef struct metaslab_group metaslab_group_t;
52 typedef struct metaslab_class metaslab_class_t;
53 typedef struct zio zio_t;
54 typedef struct zilog zilog_t;
55 typedef struct spa_aux_vdev spa_aux_vdev_t;
56 typedef struct ddt ddt_t;
57 typedef struct ddt_entry ddt_entry_t;
58 struct dsl_pool;
59 struct dsl_dataset;
60 
61 /*
62  * General-purpose 32-bit and 64-bit bitfield encodings.
63  */
64 #define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))
65 #define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))
66 #define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))
67 #define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))
68 
69 #define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)
70 #define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)
71 
72 #define	BF32_SET(x, low, len, val) do { \
73 	ASSERT3U(val, <, 1U << (len)); \
74 	ASSERT3U(low + len, <=, 32); \
75 	(x) ^= BF32_ENCODE((x >> low) ^ (val), low, len); \
76 _NOTE(CONSTCOND) } while (0)
77 
78 #define	BF64_SET(x, low, len, val) do { \
79 	ASSERT3U(val, <, 1ULL << (len)); \
80 	ASSERT3U(low + len, <=, 64); \
81 	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len)); \
82 _NOTE(CONSTCOND) } while (0)
83 
84 #define	BF32_GET_SB(x, low, len, shift, bias)	\
85 	((BF32_GET(x, low, len) + (bias)) << (shift))
86 #define	BF64_GET_SB(x, low, len, shift, bias)	\
87 	((BF64_GET(x, low, len) + (bias)) << (shift))
88 
89 #define	BF32_SET_SB(x, low, len, shift, bias, val) do { \
90 	ASSERT(IS_P2ALIGNED(val, 1U << shift)); \
91 	ASSERT3S((val) >> (shift), >=, bias); \
92 	BF32_SET(x, low, len, ((val) >> (shift)) - (bias)); \
93 _NOTE(CONSTCOND) } while (0)
94 #define	BF64_SET_SB(x, low, len, shift, bias, val) do { \
95 	ASSERT(IS_P2ALIGNED(val, 1ULL << shift)); \
96 	ASSERT3S((val) >> (shift), >=, bias); \
97 	BF64_SET(x, low, len, ((val) >> (shift)) - (bias)); \
98 _NOTE(CONSTCOND) } while (0)
99 
100 /*
101  * We currently support block sizes from 512 bytes to 16MB.
102  * The benefits of larger blocks, and thus larger IO, need to be weighed
103  * against the cost of COWing a giant block to modify one byte, and the
104  * large latency of reading or writing a large block.
105  *
106  * Note that although blocks up to 16MB are supported, the recordsize
107  * property can not be set larger than zfs_max_recordsize (default 1MB).
108  * See the comment near zfs_max_recordsize in dsl_dataset.c for details.
109  *
110  * Note that although the LSIZE field of the blkptr_t can store sizes up
111  * to 32MB, the dnode's dn_datablkszsec can only store sizes up to
112  * 32MB - 512 bytes.  Therefore, we limit SPA_MAXBLOCKSIZE to 16MB.
113  */
114 #define	SPA_MINBLOCKSHIFT	9
115 #define	SPA_OLD_MAXBLOCKSHIFT	17
116 #define	SPA_MAXBLOCKSHIFT	24
117 #define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)
118 #define	SPA_OLD_MAXBLOCKSIZE	(1ULL << SPA_OLD_MAXBLOCKSHIFT)
119 #define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)
120 
121 /*
122  * Size of block to hold the configuration data (a packed nvlist)
123  */
124 #define	SPA_CONFIG_BLOCKSIZE	(1ULL << 14)
125 
126 /*
127  * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
128  * The ASIZE encoding should be at least 64 times larger (6 more bits)
129  * to support up to 4-way RAID-Z mirror mode with worst-case gang block
130  * overhead, three DVAs per bp, plus one more bit in case we do anything
131  * else that expands the ASIZE.
132  */
133 #define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/
134 #define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/
135 #define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/
136 
137 /*
138  * All SPA data is represented by 128-bit data virtual addresses (DVAs).
139  * The members of the dva_t should be considered opaque outside the SPA.
140  */
141 typedef struct dva {
142 	uint64_t	dva_word[2];
143 } dva_t;
144 
145 /*
146  * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
147  */
148 typedef struct zio_cksum {
149 	uint64_t	zc_word[4];
150 } zio_cksum_t;
151 
152 /*
153  * Some checksums/hashes need a 256-bit initialization salt. This salt is kept
154  * secret and is suitable for use in MAC algorithms as the key.
155  */
156 typedef struct zio_cksum_salt {
157 	uint8_t		zcs_bytes[32];
158 } zio_cksum_salt_t;
159 
160 /*
161  * Each block is described by its DVAs, time of birth, checksum, etc.
162  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
163  *
164  *	64	56	48	40	32	24	16	8	0
165  *	+-------+-------+-------+-------+-------+-------+-------+-------+
166  * 0	|		vdev1		| GRID  |	  ASIZE		|
167  *	+-------+-------+-------+-------+-------+-------+-------+-------+
168  * 1	|G|			 offset1				|
169  *	+-------+-------+-------+-------+-------+-------+-------+-------+
170  * 2	|		vdev2		| GRID  |	  ASIZE		|
171  *	+-------+-------+-------+-------+-------+-------+-------+-------+
172  * 3	|G|			 offset2				|
173  *	+-------+-------+-------+-------+-------+-------+-------+-------+
174  * 4	|		vdev3		| GRID  |	  ASIZE		|
175  *	+-------+-------+-------+-------+-------+-------+-------+-------+
176  * 5	|G|			 offset3				|
177  *	+-------+-------+-------+-------+-------+-------+-------+-------+
178  * 6	|BDX|lvl| type	| cksum |E| comp|    PSIZE	|     LSIZE	|
179  *	+-------+-------+-------+-------+-------+-------+-------+-------+
180  * 7	|			padding					|
181  *	+-------+-------+-------+-------+-------+-------+-------+-------+
182  * 8	|			padding					|
183  *	+-------+-------+-------+-------+-------+-------+-------+-------+
184  * 9	|			physical birth txg			|
185  *	+-------+-------+-------+-------+-------+-------+-------+-------+
186  * a	|			logical birth txg			|
187  *	+-------+-------+-------+-------+-------+-------+-------+-------+
188  * b	|			fill count				|
189  *	+-------+-------+-------+-------+-------+-------+-------+-------+
190  * c	|			checksum[0]				|
191  *	+-------+-------+-------+-------+-------+-------+-------+-------+
192  * d	|			checksum[1]				|
193  *	+-------+-------+-------+-------+-------+-------+-------+-------+
194  * e	|			checksum[2]				|
195  *	+-------+-------+-------+-------+-------+-------+-------+-------+
196  * f	|			checksum[3]				|
197  *	+-------+-------+-------+-------+-------+-------+-------+-------+
198  *
199  * Legend:
200  *
201  * vdev		virtual device ID
202  * offset	offset into virtual device
203  * LSIZE	logical size
204  * PSIZE	physical size (after compression)
205  * ASIZE	allocated size (including RAID-Z parity and gang block headers)
206  * GRID		RAID-Z layout information (reserved for future use)
207  * cksum	checksum function
208  * comp		compression function
209  * G		gang block indicator
210  * B		byteorder (endianness)
211  * D		dedup
212  * X		encryption (on version 30, which is not supported)
213  * E		blkptr_t contains embedded data (see below)
214  * lvl		level of indirection
215  * type		DMU object type
216  * phys birth	txg of block allocation; zero if same as logical birth txg
217  * log. birth	transaction group in which the block was logically born
218  * fill count	number of non-zero blocks under this bp
219  * checksum[4]	256-bit checksum of the data this bp describes
220  */
221 
222 /*
223  * "Embedded" blkptr_t's don't actually point to a block, instead they
224  * have a data payload embedded in the blkptr_t itself.  See the comment
225  * in blkptr.c for more details.
226  *
227  * The blkptr_t is laid out as follows:
228  *
229  *	64	56	48	40	32	24	16	8	0
230  *	+-------+-------+-------+-------+-------+-------+-------+-------+
231  * 0	|      payload                                                  |
232  * 1	|      payload                                                  |
233  * 2	|      payload                                                  |
234  * 3	|      payload                                                  |
235  * 4	|      payload                                                  |
236  * 5	|      payload                                                  |
237  *	+-------+-------+-------+-------+-------+-------+-------+-------+
238  * 6	|BDX|lvl| type	| etype |E| comp| PSIZE|              LSIZE	|
239  *	+-------+-------+-------+-------+-------+-------+-------+-------+
240  * 7	|      payload                                                  |
241  * 8	|      payload                                                  |
242  * 9	|      payload                                                  |
243  *	+-------+-------+-------+-------+-------+-------+-------+-------+
244  * a	|			logical birth txg			|
245  *	+-------+-------+-------+-------+-------+-------+-------+-------+
246  * b	|      payload                                                  |
247  * c	|      payload                                                  |
248  * d	|      payload                                                  |
249  * e	|      payload                                                  |
250  * f	|      payload                                                  |
251  *	+-------+-------+-------+-------+-------+-------+-------+-------+
252  *
253  * Legend:
254  *
255  * payload		contains the embedded data
256  * B (byteorder)	byteorder (endianness)
257  * D (dedup)		padding (set to zero)
258  * X			encryption (set to zero; see above)
259  * E (embedded)		set to one
260  * lvl			indirection level
261  * type			DMU object type
262  * etype		how to interpret embedded data (BP_EMBEDDED_TYPE_*)
263  * comp			compression function of payload
264  * PSIZE		size of payload after compression, in bytes
265  * LSIZE		logical size of payload, in bytes
266  *			note that 25 bits is enough to store the largest
267  *			"normal" BP's LSIZE (2^16 * 2^9) in bytes
268  * log. birth		transaction group in which the block was logically born
269  *
270  * Note that LSIZE and PSIZE are stored in bytes, whereas for non-embedded
271  * bp's they are stored in units of SPA_MINBLOCKSHIFT.
272  * Generally, the generic BP_GET_*() macros can be used on embedded BP's.
273  * The B, D, X, lvl, type, and comp fields are stored the same as with normal
274  * BP's so the BP_SET_* macros can be used with them.  etype, PSIZE, LSIZE must
275  * be set with the BPE_SET_* macros.  BP_SET_EMBEDDED() should be called before
276  * other macros, as they assert that they are only used on BP's of the correct
277  * "embedded-ness".
278  */
279 
280 #define	BPE_GET_ETYPE(bp)	\
281 	(ASSERT(BP_IS_EMBEDDED(bp)), \
282 	BF64_GET((bp)->blk_prop, 40, 8))
283 #define	BPE_SET_ETYPE(bp, t)	do { \
284 	ASSERT(BP_IS_EMBEDDED(bp)); \
285 	BF64_SET((bp)->blk_prop, 40, 8, t); \
286 _NOTE(CONSTCOND) } while (0)
287 
288 #define	BPE_GET_LSIZE(bp)	\
289 	(ASSERT(BP_IS_EMBEDDED(bp)), \
290 	BF64_GET_SB((bp)->blk_prop, 0, 25, 0, 1))
291 #define	BPE_SET_LSIZE(bp, x)	do { \
292 	ASSERT(BP_IS_EMBEDDED(bp)); \
293 	BF64_SET_SB((bp)->blk_prop, 0, 25, 0, 1, x); \
294 _NOTE(CONSTCOND) } while (0)
295 
296 #define	BPE_GET_PSIZE(bp)	\
297 	(ASSERT(BP_IS_EMBEDDED(bp)), \
298 	BF64_GET_SB((bp)->blk_prop, 25, 7, 0, 1))
299 #define	BPE_SET_PSIZE(bp, x)	do { \
300 	ASSERT(BP_IS_EMBEDDED(bp)); \
301 	BF64_SET_SB((bp)->blk_prop, 25, 7, 0, 1, x); \
302 _NOTE(CONSTCOND) } while (0)
303 
304 typedef enum bp_embedded_type {
305 	BP_EMBEDDED_TYPE_DATA,
306 	BP_EMBEDDED_TYPE_RESERVED, /* Reserved for an unintegrated feature. */
307 	NUM_BP_EMBEDDED_TYPES = BP_EMBEDDED_TYPE_RESERVED
308 } bp_embedded_type_t;
309 
310 #define	BPE_NUM_WORDS 14
311 #define	BPE_PAYLOAD_SIZE (BPE_NUM_WORDS * sizeof (uint64_t))
312 #define	BPE_IS_PAYLOADWORD(bp, wp) \
313 	((wp) != &(bp)->blk_prop && (wp) != &(bp)->blk_birth)
314 
315 #define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
316 #define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
317 
318 /*
319  * A block is a hole when it has either 1) never been written to, or
320  * 2) is zero-filled. In both cases, ZFS can return all zeroes for all reads
321  * without physically allocating disk space. Holes are represented in the
322  * blkptr_t structure by zeroed blk_dva. Correct checking for holes is
323  * done through the BP_IS_HOLE macro. For holes, the logical size, level,
324  * DMU object type, and birth times are all also stored for holes that
325  * were written to at some point (i.e. were punched after having been filled).
326  */
327 typedef struct blkptr {
328 	dva_t		blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
329 	uint64_t	blk_prop;	/* size, compression, type, etc	    */
330 	uint64_t	blk_pad[2];	/* Extra space for the future	    */
331 	uint64_t	blk_phys_birth;	/* txg when block was allocated	    */
332 	uint64_t	blk_birth;	/* transaction group at birth	    */
333 	uint64_t	blk_fill;	/* fill count			    */
334 	zio_cksum_t	blk_cksum;	/* 256-bit checksum		    */
335 } blkptr_t;
336 
337 /*
338  * Macros to get and set fields in a bp or DVA.
339  */
340 #define	DVA_GET_ASIZE(dva)	\
341 	BF64_GET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, SPA_MINBLOCKSHIFT, 0)
342 #define	DVA_SET_ASIZE(dva, x)	\
343 	BF64_SET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, \
344 	SPA_MINBLOCKSHIFT, 0, x)
345 
346 #define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
347 #define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
348 
349 #define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
350 #define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
351 
352 #define	DVA_GET_OFFSET(dva)	\
353 	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
354 #define	DVA_SET_OFFSET(dva, x)	\
355 	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
356 
357 #define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
358 #define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
359 
360 #define	BP_GET_LSIZE(bp)	\
361 	(BP_IS_EMBEDDED(bp) ?	\
362 	(BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA ? BPE_GET_LSIZE(bp) : 0): \
363 	BF64_GET_SB((bp)->blk_prop, 0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1))
364 #define	BP_SET_LSIZE(bp, x)	do { \
365 	ASSERT(!BP_IS_EMBEDDED(bp)); \
366 	BF64_SET_SB((bp)->blk_prop, \
367 	    0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
368 _NOTE(CONSTCOND) } while (0)
369 
370 #define	BP_GET_PSIZE(bp)	\
371 	(BP_IS_EMBEDDED(bp) ? 0 : \
372 	BF64_GET_SB((bp)->blk_prop, 16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1))
373 #define	BP_SET_PSIZE(bp, x)	do { \
374 	ASSERT(!BP_IS_EMBEDDED(bp)); \
375 	BF64_SET_SB((bp)->blk_prop, \
376 	    16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
377 _NOTE(CONSTCOND) } while (0)
378 
379 #define	BP_GET_COMPRESS(bp)		BF64_GET((bp)->blk_prop, 32, 7)
380 #define	BP_SET_COMPRESS(bp, x)		BF64_SET((bp)->blk_prop, 32, 7, x)
381 
382 #define	BP_IS_EMBEDDED(bp)		BF64_GET((bp)->blk_prop, 39, 1)
383 #define	BP_SET_EMBEDDED(bp, x)		BF64_SET((bp)->blk_prop, 39, 1, x)
384 
385 #define	BP_GET_CHECKSUM(bp)		\
386 	(BP_IS_EMBEDDED(bp) ? ZIO_CHECKSUM_OFF : \
387 	BF64_GET((bp)->blk_prop, 40, 8))
388 #define	BP_SET_CHECKSUM(bp, x)		do { \
389 	ASSERT(!BP_IS_EMBEDDED(bp)); \
390 	BF64_SET((bp)->blk_prop, 40, 8, x); \
391 _NOTE(CONSTCOND) } while (0)
392 
393 #define	BP_GET_TYPE(bp)			BF64_GET((bp)->blk_prop, 48, 8)
394 #define	BP_SET_TYPE(bp, x)		BF64_SET((bp)->blk_prop, 48, 8, x)
395 
396 #define	BP_GET_LEVEL(bp)		BF64_GET((bp)->blk_prop, 56, 5)
397 #define	BP_SET_LEVEL(bp, x)		BF64_SET((bp)->blk_prop, 56, 5, x)
398 
399 #define	BP_GET_DEDUP(bp)		BF64_GET((bp)->blk_prop, 62, 1)
400 #define	BP_SET_DEDUP(bp, x)		BF64_SET((bp)->blk_prop, 62, 1, x)
401 
402 #define	BP_GET_BYTEORDER(bp)		BF64_GET((bp)->blk_prop, 63, 1)
403 #define	BP_SET_BYTEORDER(bp, x)		BF64_SET((bp)->blk_prop, 63, 1, x)
404 
405 #define	BP_PHYSICAL_BIRTH(bp)		\
406 	(BP_IS_EMBEDDED(bp) ? 0 : \
407 	(bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
408 
409 #define	BP_SET_BIRTH(bp, logical, physical)	\
410 {						\
411 	ASSERT(!BP_IS_EMBEDDED(bp));		\
412 	(bp)->blk_birth = (logical);		\
413 	(bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
414 }
415 
416 #define	BP_GET_FILL(bp) (BP_IS_EMBEDDED(bp) ? 1 : (bp)->blk_fill)
417 
418 #define	BP_GET_ASIZE(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_GET_UCSIZE(bp) \
425 	((BP_GET_LEVEL(bp) > 0 || DMU_OT_IS_METADATA(BP_GET_TYPE(bp))) ? \
426 	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp))
427 
428 #define	BP_GET_NDVAS(bp)	\
429 	(BP_IS_EMBEDDED(bp) ? 0 : \
430 	!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
431 	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
432 	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
433 
434 #define	BP_COUNT_GANG(bp)	\
435 	(BP_IS_EMBEDDED(bp) ? 0 : \
436 	(DVA_GET_GANG(&(bp)->blk_dva[0]) + \
437 	DVA_GET_GANG(&(bp)->blk_dva[1]) + \
438 	DVA_GET_GANG(&(bp)->blk_dva[2])))
439 
440 #define	DVA_EQUAL(dva1, dva2)	\
441 	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
442 	(dva1)->dva_word[0] == (dva2)->dva_word[0])
443 
444 #define	BP_EQUAL(bp1, bp2)	\
445 	(BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&	\
446 	(bp1)->blk_birth == (bp2)->blk_birth &&			\
447 	DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&	\
448 	DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&	\
449 	DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
450 
451 #define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \
452 	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
453 	((zc1).zc_word[1] - (zc2).zc_word[1]) | \
454 	((zc1).zc_word[2] - (zc2).zc_word[2]) | \
455 	((zc1).zc_word[3] - (zc2).zc_word[3])))
456 
457 #define	ZIO_CHECKSUM_IS_ZERO(zc) \
458 	(0 == ((zc)->zc_word[0] | (zc)->zc_word[1] | \
459 	(zc)->zc_word[2] | (zc)->zc_word[3]))
460 
461 #define	ZIO_CHECKSUM_BSWAP(_zc) \
462 	do { \
463 		zio_cksum_t *zc = (_zc); \
464 		zc->zc_word[0] = BSWAP_64(zc->zc_word[0]); \
465 		zc->zc_word[1] = BSWAP_64(zc->zc_word[1]); \
466 		zc->zc_word[2] = BSWAP_64(zc->zc_word[2]); \
467 		zc->zc_word[3] = BSWAP_64(zc->zc_word[3]); \
468 		_NOTE(NOTREACHED) \
469 		_NOTE(CONSTCOND) \
470 	} while (0)
471 
472 #define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
473 
474 #define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
475 {						\
476 	(zcp)->zc_word[0] = w0;			\
477 	(zcp)->zc_word[1] = w1;			\
478 	(zcp)->zc_word[2] = w2;			\
479 	(zcp)->zc_word[3] = w3;			\
480 }
481 
482 #define	BP_IDENTITY(bp)		(ASSERT(!BP_IS_EMBEDDED(bp)), &(bp)->blk_dva[0])
483 #define	BP_IS_GANG(bp)		\
484 	(BP_IS_EMBEDDED(bp) ? B_FALSE : DVA_GET_GANG(BP_IDENTITY(bp)))
485 #define	DVA_IS_EMPTY(dva)	((dva)->dva_word[0] == 0ULL &&	\
486 				(dva)->dva_word[1] == 0ULL)
487 #define	BP_IS_HOLE(bp) \
488 	(!BP_IS_EMBEDDED(bp) && DVA_IS_EMPTY(BP_IDENTITY(bp)))
489 
490 /* BP_IS_RAIDZ(bp) assumes no block compression */
491 #define	BP_IS_RAIDZ(bp)		(DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
492 				BP_GET_PSIZE(bp))
493 
494 #define	BP_ZERO(bp)				\
495 {						\
496 	(bp)->blk_dva[0].dva_word[0] = 0;	\
497 	(bp)->blk_dva[0].dva_word[1] = 0;	\
498 	(bp)->blk_dva[1].dva_word[0] = 0;	\
499 	(bp)->blk_dva[1].dva_word[1] = 0;	\
500 	(bp)->blk_dva[2].dva_word[0] = 0;	\
501 	(bp)->blk_dva[2].dva_word[1] = 0;	\
502 	(bp)->blk_prop = 0;			\
503 	(bp)->blk_pad[0] = 0;			\
504 	(bp)->blk_pad[1] = 0;			\
505 	(bp)->blk_phys_birth = 0;		\
506 	(bp)->blk_birth = 0;			\
507 	(bp)->blk_fill = 0;			\
508 	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
509 }
510 
511 #ifdef _BIG_ENDIAN
512 #define	ZFS_HOST_BYTEORDER	(0ULL)
513 #else
514 #define	ZFS_HOST_BYTEORDER	(1ULL)
515 #endif
516 
517 #define	BP_SHOULD_BYTESWAP(bp)	(BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)
518 
519 #define	BP_SPRINTF_LEN	320
520 
521 /*
522  * This macro allows code sharing between zfs, libzpool, and mdb.
523  * 'func' is either snprintf() or mdb_snprintf().
524  * 'ws' (whitespace) can be ' ' for single-line format, '\n' for multi-line.
525  */
526 #define	SNPRINTF_BLKPTR(func, ws, buf, size, bp, type, checksum, compress) \
527 {									\
528 	static const char *copyname[] =					\
529 	    { "zero", "single", "double", "triple" };			\
530 	int len = 0;							\
531 	int copies = 0;							\
532 									\
533 	if (bp == NULL) {						\
534 		len += func(buf + len, size - len, "<NULL>");		\
535 	} else if (BP_IS_HOLE(bp)) {					\
536 		len += func(buf + len, size - len,			\
537 		    "HOLE [L%llu %s] "					\
538 		    "size=%llxL birth=%lluL",				\
539 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
540 		    type,						\
541 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
542 		    (u_longlong_t)bp->blk_birth);			\
543 	} else if (BP_IS_EMBEDDED(bp)) {				\
544 		len = func(buf + len, size - len,			\
545 		    "EMBEDDED [L%llu %s] et=%u %s "			\
546 		    "size=%llxL/%llxP birth=%lluL",			\
547 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
548 		    type,						\
549 		    (int)BPE_GET_ETYPE(bp),				\
550 		    compress,						\
551 		    (u_longlong_t)BPE_GET_LSIZE(bp),			\
552 		    (u_longlong_t)BPE_GET_PSIZE(bp),			\
553 		    (u_longlong_t)bp->blk_birth);			\
554 	} else {							\
555 		for (int d = 0; d < BP_GET_NDVAS(bp); d++) {		\
556 			const dva_t *dva = &bp->blk_dva[d];		\
557 			if (DVA_IS_VALID(dva))				\
558 				copies++;				\
559 			len += func(buf + len, size - len,		\
560 			    "DVA[%d]=<%llu:%llx:%llx>%c", d,		\
561 			    (u_longlong_t)DVA_GET_VDEV(dva),		\
562 			    (u_longlong_t)DVA_GET_OFFSET(dva),		\
563 			    (u_longlong_t)DVA_GET_ASIZE(dva),		\
564 			    ws);					\
565 		}							\
566 		if (BP_IS_GANG(bp) &&					\
567 		    DVA_GET_ASIZE(&bp->blk_dva[2]) <=			\
568 		    DVA_GET_ASIZE(&bp->blk_dva[1]) / 2)			\
569 			copies--;					\
570 		len += func(buf + len, size - len,			\
571 		    "[L%llu %s] %s %s %s %s %s %s%c"			\
572 		    "size=%llxL/%llxP birth=%lluL/%lluP fill=%llu%c"	\
573 		    "cksum=%llx:%llx:%llx:%llx",			\
574 		    (u_longlong_t)BP_GET_LEVEL(bp),			\
575 		    type,						\
576 		    checksum,						\
577 		    compress,						\
578 		    BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",		\
579 		    BP_IS_GANG(bp) ? "gang" : "contiguous",		\
580 		    BP_GET_DEDUP(bp) ? "dedup" : "unique",		\
581 		    copyname[copies],					\
582 		    ws,							\
583 		    (u_longlong_t)BP_GET_LSIZE(bp),			\
584 		    (u_longlong_t)BP_GET_PSIZE(bp),			\
585 		    (u_longlong_t)bp->blk_birth,			\
586 		    (u_longlong_t)BP_PHYSICAL_BIRTH(bp),		\
587 		    (u_longlong_t)BP_GET_FILL(bp),			\
588 		    ws,							\
589 		    (u_longlong_t)bp->blk_cksum.zc_word[0],		\
590 		    (u_longlong_t)bp->blk_cksum.zc_word[1],		\
591 		    (u_longlong_t)bp->blk_cksum.zc_word[2],		\
592 		    (u_longlong_t)bp->blk_cksum.zc_word[3]);		\
593 	}								\
594 	ASSERT(len < size);						\
595 }
596 
597 #include <sys/dmu.h>
598 
599 #define	BP_GET_BUFC_TYPE(bp)						\
600 	(((BP_GET_LEVEL(bp) > 0) || (DMU_OT_IS_METADATA(BP_GET_TYPE(bp)))) ? \
601 	ARC_BUFC_METADATA : ARC_BUFC_DATA)
602 
603 typedef enum spa_import_type {
604 	SPA_IMPORT_EXISTING,
605 	SPA_IMPORT_ASSEMBLE
606 } spa_import_type_t;
607 
608 /* state manipulation functions */
609 extern int spa_open(const char *pool, spa_t **, void *tag);
610 extern int spa_open_rewind(const char *pool, spa_t **, void *tag,
611     nvlist_t *policy, nvlist_t **config);
612 extern int spa_get_stats(const char *pool, nvlist_t **config, char *altroot,
613     size_t buflen);
614 extern int spa_create(const char *pool, nvlist_t *config, nvlist_t *props,
615     nvlist_t *zplprops);
616 extern int spa_import_rootpool(char *devpath, char *devid);
617 extern int spa_import(const char *pool, nvlist_t *config, nvlist_t *props,
618     uint64_t flags);
619 extern nvlist_t *spa_tryimport(nvlist_t *tryconfig);
620 extern int spa_destroy(char *pool);
621 extern int spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
622     boolean_t hardforce);
623 extern int spa_reset(char *pool);
624 extern void spa_async_request(spa_t *spa, int flag);
625 extern void spa_async_unrequest(spa_t *spa, int flag);
626 extern void spa_async_suspend(spa_t *spa);
627 extern void spa_async_resume(spa_t *spa);
628 extern spa_t *spa_inject_addref(char *pool);
629 extern void spa_inject_delref(spa_t *spa);
630 extern void spa_scan_stat_init(spa_t *spa);
631 extern int spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps);
632 
633 #define	SPA_ASYNC_CONFIG_UPDATE		0x01
634 #define	SPA_ASYNC_REMOVE		0x02
635 #define	SPA_ASYNC_PROBE			0x04
636 #define	SPA_ASYNC_RESILVER_DONE		0x08
637 #define	SPA_ASYNC_RESILVER		0x10
638 #define	SPA_ASYNC_AUTOEXPAND		0x20
639 #define	SPA_ASYNC_REMOVE_DONE		0x40
640 #define	SPA_ASYNC_REMOVE_STOP		0x80
641 #define	SPA_ASYNC_L2CACHE_REBUILD	0x100
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