xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/spa.h (revision bc1009abdd0a493796645bd983c1601396c09a5f)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef _SYS_SPA_H
27 #define	_SYS_SPA_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/avl.h>
32 #include <sys/zfs_context.h>
33 #include <sys/nvpair.h>
34 #include <sys/sysmacros.h>
35 #include <sys/types.h>
36 #include <sys/fs/zfs.h>
37 
38 #ifdef	__cplusplus
39 extern "C" {
40 #endif
41 
42 /*
43  * Forward references that lots of things need.
44  */
45 typedef struct spa spa_t;
46 typedef struct vdev vdev_t;
47 typedef struct metaslab metaslab_t;
48 typedef struct zilog zilog_t;
49 typedef struct traverse_handle traverse_handle_t;
50 struct dsl_pool;
51 
52 /*
53  * General-purpose 32-bit and 64-bit bitfield encodings.
54  */
55 #define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))
56 #define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))
57 #define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))
58 #define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))
59 
60 #define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)
61 #define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)
62 
63 #define	BF32_SET(x, low, len, val)	\
64 	((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len))
65 #define	BF64_SET(x, low, len, val)	\
66 	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len))
67 
68 #define	BF32_GET_SB(x, low, len, shift, bias)	\
69 	((BF32_GET(x, low, len) + (bias)) << (shift))
70 #define	BF64_GET_SB(x, low, len, shift, bias)	\
71 	((BF64_GET(x, low, len) + (bias)) << (shift))
72 
73 #define	BF32_SET_SB(x, low, len, shift, bias, val)	\
74 	BF32_SET(x, low, len, ((val) >> (shift)) - (bias))
75 #define	BF64_SET_SB(x, low, len, shift, bias, val)	\
76 	BF64_SET(x, low, len, ((val) >> (shift)) - (bias))
77 
78 /*
79  * We currently support nine block sizes, from 512 bytes to 128K.
80  * We could go higher, but the benefits are near-zero and the cost
81  * of COWing a giant block to modify one byte would become excessive.
82  */
83 #define	SPA_MINBLOCKSHIFT	9
84 #define	SPA_MAXBLOCKSHIFT	17
85 #define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)
86 #define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)
87 
88 #define	SPA_BLOCKSIZES		(SPA_MAXBLOCKSHIFT - SPA_MINBLOCKSHIFT + 1)
89 
90 /*
91  * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
92  * The ASIZE encoding should be at least 64 times larger (6 more bits)
93  * to support up to 4-way RAID-Z mirror mode with worst-case gang block
94  * overhead, three DVAs per bp, plus one more bit in case we do anything
95  * else that expands the ASIZE.
96  */
97 #define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/
98 #define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/
99 #define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/
100 
101 /*
102  * All SPA data is represented by 128-bit data virtual addresses (DVAs).
103  * The members of the dva_t should be considered opaque outside the SPA.
104  */
105 typedef struct dva {
106 	uint64_t	dva_word[2];
107 } dva_t;
108 
109 /*
110  * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
111  */
112 typedef struct zio_cksum {
113 	uint64_t	zc_word[4];
114 } zio_cksum_t;
115 
116 /*
117  * Each block is described by its DVAs, time of birth, checksum, etc.
118  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
119  *
120  *	64	56	48	40	32	24	16	8	0
121  *	+-------+-------+-------+-------+-------+-------+-------+-------+
122  * 0	|		vdev1		| GRID  |	  ASIZE		|
123  *	+-------+-------+-------+-------+-------+-------+-------+-------+
124  * 1	|G|			 offset1				|
125  *	+-------+-------+-------+-------+-------+-------+-------+-------+
126  * 2	|		vdev2		| GRID  |	  ASIZE		|
127  *	+-------+-------+-------+-------+-------+-------+-------+-------+
128  * 3	|G|			 offset2				|
129  *	+-------+-------+-------+-------+-------+-------+-------+-------+
130  * 4	|		vdev3		| GRID  |	  ASIZE		|
131  *	+-------+-------+-------+-------+-------+-------+-------+-------+
132  * 5	|G|			 offset3				|
133  *	+-------+-------+-------+-------+-------+-------+-------+-------+
134  * 6	|E| lvl | type	| cksum | comp	|     PSIZE	|     LSIZE	|
135  *	+-------+-------+-------+-------+-------+-------+-------+-------+
136  * 7	|			padding					|
137  *	+-------+-------+-------+-------+-------+-------+-------+-------+
138  * 8	|			padding					|
139  *	+-------+-------+-------+-------+-------+-------+-------+-------+
140  * 9	|			padding					|
141  *	+-------+-------+-------+-------+-------+-------+-------+-------+
142  * a	|			birth txg				|
143  *	+-------+-------+-------+-------+-------+-------+-------+-------+
144  * b	|			fill count				|
145  *	+-------+-------+-------+-------+-------+-------+-------+-------+
146  * c	|			checksum[0]				|
147  *	+-------+-------+-------+-------+-------+-------+-------+-------+
148  * d	|			checksum[1]				|
149  *	+-------+-------+-------+-------+-------+-------+-------+-------+
150  * e	|			checksum[2]				|
151  *	+-------+-------+-------+-------+-------+-------+-------+-------+
152  * f	|			checksum[3]				|
153  *	+-------+-------+-------+-------+-------+-------+-------+-------+
154  *
155  * Legend:
156  *
157  * vdev		virtual device ID
158  * offset	offset into virtual device
159  * LSIZE	logical size
160  * PSIZE	physical size (after compression)
161  * ASIZE	allocated size (including RAID-Z parity and gang block headers)
162  * GRID		RAID-Z layout information (reserved for future use)
163  * cksum	checksum function
164  * comp		compression function
165  * G		gang block indicator
166  * E		endianness
167  * type		DMU object type
168  * lvl		level of indirection
169  * birth txg	transaction group in which the block was born
170  * fill count	number of non-zero blocks under this bp
171  * checksum[4]	256-bit checksum of the data this bp describes
172  */
173 typedef struct blkptr {
174 	dva_t		blk_dva[3];	/* 128-bit Data Virtual Address	*/
175 	uint64_t	blk_prop;	/* size, compression, type, etc	*/
176 	uint64_t	blk_pad[3];	/* Extra space for the future	*/
177 	uint64_t	blk_birth;	/* transaction group at birth	*/
178 	uint64_t	blk_fill;	/* fill count			*/
179 	zio_cksum_t	blk_cksum;	/* 256-bit checksum		*/
180 } blkptr_t;
181 
182 #define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
183 #define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
184 
185 /*
186  * Macros to get and set fields in a bp or DVA.
187  */
188 #define	DVA_GET_ASIZE(dva)	\
189 	BF64_GET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0)
190 #define	DVA_SET_ASIZE(dva, x)	\
191 	BF64_SET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0, x)
192 
193 #define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
194 #define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
195 
196 #define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
197 #define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
198 
199 #define	DVA_GET_OFFSET(dva)	\
200 	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
201 #define	DVA_SET_OFFSET(dva, x)	\
202 	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
203 
204 #define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
205 #define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
206 
207 #define	BP_GET_LSIZE(bp)	\
208 	(BP_IS_HOLE(bp) ? 0 : \
209 	BF64_GET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1))
210 #define	BP_SET_LSIZE(bp, x)	\
211 	BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x)
212 
213 #define	BP_GET_PSIZE(bp)	\
214 	BF64_GET_SB((bp)->blk_prop, 16, 16, SPA_MINBLOCKSHIFT, 1)
215 #define	BP_SET_PSIZE(bp, x)	\
216 	BF64_SET_SB((bp)->blk_prop, 16, 16, SPA_MINBLOCKSHIFT, 1, x)
217 
218 #define	BP_GET_COMPRESS(bp)	BF64_GET((bp)->blk_prop, 32, 8)
219 #define	BP_SET_COMPRESS(bp, x)	BF64_SET((bp)->blk_prop, 32, 8, x)
220 
221 #define	BP_GET_CHECKSUM(bp)	BF64_GET((bp)->blk_prop, 40, 8)
222 #define	BP_SET_CHECKSUM(bp, x)	BF64_SET((bp)->blk_prop, 40, 8, x)
223 
224 #define	BP_GET_TYPE(bp)		BF64_GET((bp)->blk_prop, 48, 8)
225 #define	BP_SET_TYPE(bp, x)	BF64_SET((bp)->blk_prop, 48, 8, x)
226 
227 #define	BP_GET_LEVEL(bp)	BF64_GET((bp)->blk_prop, 56, 5)
228 #define	BP_SET_LEVEL(bp, x)	BF64_SET((bp)->blk_prop, 56, 5, x)
229 
230 #define	BP_GET_BYTEORDER(bp)	(0 - BF64_GET((bp)->blk_prop, 63, 1))
231 #define	BP_SET_BYTEORDER(bp, x)	BF64_SET((bp)->blk_prop, 63, 1, x)
232 
233 #define	BP_GET_ASIZE(bp)	\
234 	(DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
235 		DVA_GET_ASIZE(&(bp)->blk_dva[2]))
236 
237 #define	BP_GET_UCSIZE(bp) \
238 	((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ? \
239 	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp));
240 
241 #define	BP_GET_NDVAS(bp)	\
242 	(!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
243 	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
244 	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
245 
246 #define	BP_COUNT_GANG(bp)	\
247 	(DVA_GET_GANG(&(bp)->blk_dva[0]) + \
248 	DVA_GET_GANG(&(bp)->blk_dva[1]) + \
249 	DVA_GET_GANG(&(bp)->blk_dva[2]))
250 
251 #define	DVA_EQUAL(dva1, dva2)	\
252 	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
253 	(dva1)->dva_word[0] == (dva2)->dva_word[0])
254 
255 #define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \
256 	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
257 	((zc1).zc_word[1] - (zc2).zc_word[1]) | \
258 	((zc1).zc_word[2] - (zc2).zc_word[2]) | \
259 	((zc1).zc_word[3] - (zc2).zc_word[3])))
260 
261 
262 #define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
263 
264 #define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
265 {						\
266 	(zcp)->zc_word[0] = w0;			\
267 	(zcp)->zc_word[1] = w1;			\
268 	(zcp)->zc_word[2] = w2;			\
269 	(zcp)->zc_word[3] = w3;			\
270 }
271 
272 #define	BP_IDENTITY(bp)		(&(bp)->blk_dva[0])
273 #define	BP_IS_GANG(bp)		DVA_GET_GANG(BP_IDENTITY(bp))
274 #define	BP_IS_HOLE(bp)		((bp)->blk_birth == 0)
275 
276 #define	BP_ZERO(bp)				\
277 {						\
278 	(bp)->blk_dva[0].dva_word[0] = 0;	\
279 	(bp)->blk_dva[0].dva_word[1] = 0;	\
280 	(bp)->blk_dva[1].dva_word[0] = 0;	\
281 	(bp)->blk_dva[1].dva_word[1] = 0;	\
282 	(bp)->blk_dva[2].dva_word[0] = 0;	\
283 	(bp)->blk_dva[2].dva_word[1] = 0;	\
284 	(bp)->blk_prop = 0;			\
285 	(bp)->blk_pad[0] = 0;			\
286 	(bp)->blk_pad[1] = 0;			\
287 	(bp)->blk_pad[2] = 0;			\
288 	(bp)->blk_birth = 0;			\
289 	(bp)->blk_fill = 0;			\
290 	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
291 }
292 
293 /*
294  * Note: the byteorder is either 0 or -1, both of which are palindromes.
295  * This simplifies the endianness handling a bit.
296  */
297 #ifdef _BIG_ENDIAN
298 #define	ZFS_HOST_BYTEORDER	(0ULL)
299 #else
300 #define	ZFS_HOST_BYTEORDER	(-1ULL)
301 #endif
302 
303 #define	BP_SHOULD_BYTESWAP(bp)	(BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)
304 
305 #define	BP_SPRINTF_LEN	320
306 
307 #include <sys/dmu.h>
308 
309 /*
310  * Routines found in spa.c
311  */
312 
313 /* state manipulation functions */
314 extern int spa_open(const char *pool, spa_t **, void *tag);
315 extern int spa_get_stats(const char *pool, nvlist_t **config,
316     char *altroot, size_t buflen);
317 extern int spa_create(const char *pool, nvlist_t *config, const char *altroot);
318 extern int spa_import(const char *pool, nvlist_t *config, const char *altroot);
319 extern nvlist_t *spa_tryimport(nvlist_t *tryconfig);
320 extern int spa_destroy(char *pool);
321 extern int spa_export(char *pool, nvlist_t **oldconfig);
322 extern int spa_reset(char *pool);
323 extern void spa_async_request(spa_t *spa, int flag);
324 extern void spa_async_suspend(spa_t *spa);
325 extern void spa_async_resume(spa_t *spa);
326 extern spa_t *spa_inject_addref(char *pool);
327 extern void spa_inject_delref(spa_t *spa);
328 
329 #define	SPA_ASYNC_REOPEN	0x01
330 #define	SPA_ASYNC_REPLACE_DONE	0x02
331 #define	SPA_ASYNC_SCRUB		0x04
332 #define	SPA_ASYNC_RESILVER	0x08
333 #define	SPA_ASYNC_CONFIG_UPDATE	0x10
334 
335 /* device manipulation */
336 extern int spa_vdev_add(spa_t *spa, nvlist_t *nvroot);
337 extern int spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot,
338     int replacing);
339 extern int spa_vdev_detach(spa_t *spa, uint64_t guid, int replace_done);
340 extern int spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare);
341 extern int spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath);
342 
343 /* spare state (which is global across all pools) */
344 extern void spa_spare_add(uint64_t guid);
345 extern void spa_spare_remove(uint64_t guid);
346 extern boolean_t spa_spare_inuse(uint64_t guid);
347 
348 /* scrubbing */
349 extern int spa_scrub(spa_t *spa, pool_scrub_type_t type, boolean_t force);
350 extern void spa_scrub_suspend(spa_t *spa);
351 extern void spa_scrub_resume(spa_t *spa);
352 extern void spa_scrub_restart(spa_t *spa, uint64_t txg);
353 extern void spa_scrub_throttle(spa_t *spa, int direction);
354 
355 /* spa syncing */
356 extern void spa_sync(spa_t *spa, uint64_t txg); /* only for DMU use */
357 extern void spa_sync_allpools(void);
358 
359 /*
360  * SPA configuration functions in spa_config.c
361  */
362 
363 #define	SPA_CONFIG_UPDATE_POOL	0
364 #define	SPA_CONFIG_UPDATE_VDEVS	1
365 
366 extern void spa_config_sync(void);
367 extern void spa_config_load(void);
368 extern nvlist_t *spa_all_configs(uint64_t *);
369 extern void spa_config_set(spa_t *spa, nvlist_t *config);
370 extern nvlist_t *spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg,
371     int getstats);
372 extern void spa_config_update(spa_t *spa, int what);
373 
374 /*
375  * Miscellaneous SPA routines in spa_misc.c
376  */
377 
378 /* Namespace manipulation */
379 extern spa_t *spa_lookup(const char *name);
380 extern spa_t *spa_add(const char *name, const char *altroot);
381 extern void spa_remove(spa_t *spa);
382 extern spa_t *spa_next(spa_t *prev);
383 
384 /* Refcount functions */
385 extern void spa_open_ref(spa_t *spa, void *tag);
386 extern void spa_close(spa_t *spa, void *tag);
387 extern boolean_t spa_refcount_zero(spa_t *spa);
388 
389 /* Pool configuration lock */
390 extern void spa_config_enter(spa_t *spa, krw_t rw, void *tag);
391 extern void spa_config_exit(spa_t *spa, void *tag);
392 extern boolean_t spa_config_held(spa_t *spa, krw_t rw);
393 
394 /* Pool vdev add/remove lock */
395 extern uint64_t spa_vdev_enter(spa_t *spa);
396 extern int spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error);
397 
398 /* Accessor functions */
399 extern krwlock_t *spa_traverse_rwlock(spa_t *spa);
400 extern int spa_traverse_wanted(spa_t *spa);
401 extern struct dsl_pool *spa_get_dsl(spa_t *spa);
402 extern blkptr_t *spa_get_rootblkptr(spa_t *spa);
403 extern void spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp);
404 extern void spa_altroot(spa_t *, char *, size_t);
405 extern int spa_sync_pass(spa_t *spa);
406 extern char *spa_name(spa_t *spa);
407 extern uint64_t spa_guid(spa_t *spa);
408 extern uint64_t spa_last_synced_txg(spa_t *spa);
409 extern uint64_t spa_first_txg(spa_t *spa);
410 extern uint64_t spa_version(spa_t *spa);
411 extern int spa_state(spa_t *spa);
412 extern uint64_t spa_freeze_txg(spa_t *spa);
413 struct metaslab_class;
414 extern struct metaslab_class *spa_metaslab_class_select(spa_t *spa);
415 extern uint64_t spa_get_alloc(spa_t *spa);
416 extern uint64_t spa_get_space(spa_t *spa);
417 extern uint64_t spa_get_dspace(spa_t *spa);
418 extern uint64_t spa_get_asize(spa_t *spa, uint64_t lsize);
419 extern uint64_t spa_version(spa_t *spa);
420 extern int spa_max_replication(spa_t *spa);
421 extern int spa_busy(void);
422 
423 /* Miscellaneous support routines */
424 extern int spa_rename(const char *oldname, const char *newname);
425 extern boolean_t spa_guid_exists(uint64_t pool_guid, uint64_t device_guid);
426 extern char *spa_strdup(const char *);
427 extern void spa_strfree(char *);
428 extern uint64_t spa_get_random(uint64_t range);
429 extern void sprintf_blkptr(char *buf, int len, const blkptr_t *bp);
430 extern void spa_freeze(spa_t *spa);
431 extern void spa_upgrade(spa_t *spa);
432 extern void spa_evict_all(void);
433 extern vdev_t *spa_lookup_by_guid(spa_t *spa, uint64_t guid);
434 extern boolean_t spa_has_spare(spa_t *, uint64_t guid);
435 extern uint64_t bp_get_dasize(spa_t *spa, const blkptr_t *bp);
436 
437 /* history logging */
438 extern void spa_history_create_obj(spa_t *spa, dmu_tx_t *tx);
439 extern int spa_history_get(spa_t *spa, uint64_t *offset, uint64_t *len_read,
440     char *his_buf);
441 extern int spa_history_log(spa_t *spa, const char *his_buf,
442     uint64_t pool_create);
443 
444 /* error handling */
445 struct zbookmark;
446 struct zio;
447 extern void spa_log_error(spa_t *spa, struct zio *zio);
448 extern void zfs_ereport_post(const char *class, spa_t *spa, vdev_t *vd,
449     struct zio *zio, uint64_t stateoroffset, uint64_t length);
450 extern void zfs_post_ok(spa_t *spa, vdev_t *vd);
451 extern uint64_t spa_get_errlog_size(spa_t *spa);
452 extern int spa_get_errlog(spa_t *spa, void *uaddr, size_t *count);
453 extern void spa_errlog_rotate(spa_t *spa);
454 extern void spa_errlog_drain(spa_t *spa);
455 extern void spa_errlog_sync(spa_t *spa, uint64_t txg);
456 extern int spa_bookmark_name(spa_t *spa, struct zbookmark *zb,
457     nvlist_t *nvl);
458 extern void spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub);
459 
460 /* Initialization and termination */
461 extern void spa_init(int flags);
462 extern void spa_fini(void);
463 
464 #ifdef ZFS_DEBUG
465 #define	dprintf_bp(bp, fmt, ...) do {			\
466 	if (zfs_flags & ZFS_DEBUG_DPRINTF) { 		\
467 	char __blkbuf[BP_SPRINTF_LEN];			\
468 	sprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, (bp));	\
469 	dprintf(fmt " %s\n", __VA_ARGS__, __blkbuf);	\
470 	} \
471 _NOTE(CONSTCOND) } while (0)
472 #else
473 #define	dprintf_bp(bp, fmt, ...)
474 #endif
475 
476 extern int spa_mode;			/* mode, e.g. FREAD | FWRITE */
477 
478 #ifdef	__cplusplus
479 }
480 #endif
481 
482 #endif	/* _SYS_SPA_H */
483