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  * Default maximum supported logical ashift.
122  *
123  * The current 8k allocation block size limit is due to the 8k
124  * aligned/sized operations performed by vdev_probe() on
125  * vdev_label->vl_pad2.  Using another "safe region" for these tests
126  * would allow the limit to be raised to 16k, at the expense of
127  * only having 8 available uberblocks in the label area.
128  */
129 #define   SPA_MAXASHIFT                 13
130 
131 /*
132  * Default minimum supported logical ashift.
133  */
134 #define SPA_MINASHIFT                   SPA_MINBLOCKSHIFT
135 
136 /*
137  * Size of block to hold the configuration data (a packed nvlist)
138  */
139 #define   SPA_CONFIG_BLOCKSIZE          (1ULL << 14)
140 
141 /*
142  * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
143  * The ASIZE encoding should be at least 64 times larger (6 more bits)
144  * to support up to 4-way RAID-Z mirror mode with worst-case gang block
145  * overhead, three DVAs per bp, plus one more bit in case we do anything
146  * else that expands the ASIZE.
147  */
148 #define   SPA_LSIZEBITS                 16        /* LSIZE up to 32M (2^16 * 512)         */
149 #define   SPA_PSIZEBITS                 16        /* PSIZE up to 32M (2^16 * 512)         */
150 #define   SPA_ASIZEBITS                 24        /* ASIZE up to 64 times larger          */
151 
152 #define   SPA_COMPRESSBITS    7
153 
154 /*
155  * All SPA data is represented by 128-bit data virtual addresses (DVAs).
156  * The members of the dva_t should be considered opaque outside the SPA.
157  */
158 typedef struct dva {
159           uint64_t  dva_word[2];
160 } dva_t;
161 
162 /*
163  * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
164  */
165 typedef struct zio_cksum {
166           uint64_t  zc_word[4];
167 } zio_cksum_t;
168 
169 /*
170  * Some checksums/hashes need a 256-bit initialization salt. This salt is kept
171  * secret and is suitable for use in MAC algorithms as the key.
172  */
173 typedef struct zio_cksum_salt {
174           uint8_t             zcs_bytes[32];
175 } zio_cksum_salt_t;
176 
177 /*
178  * Each block is described by its DVAs, time of birth, checksum, etc.
179  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
180  *
181  *        64        56        48        40        32        24        16        8         0
182  *        +-------+-------+-------+-------+-------+-------+-------+-------+
183  * 0      |                   vdev1               | GRID  |   ASIZE             |
184  *        +-------+-------+-------+-------+-------+-------+-------+-------+
185  * 1      |G|                            offset1                                |
186  *        +-------+-------+-------+-------+-------+-------+-------+-------+
187  * 2      |                   vdev2               | GRID  |   ASIZE             |
188  *        +-------+-------+-------+-------+-------+-------+-------+-------+
189  * 3      |G|                            offset2                                |
190  *        +-------+-------+-------+-------+-------+-------+-------+-------+
191  * 4      |                   vdev3               | GRID  |   ASIZE             |
192  *        +-------+-------+-------+-------+-------+-------+-------+-------+
193  * 5      |G|                            offset3                                |
194  *        +-------+-------+-------+-------+-------+-------+-------+-------+
195  * 6      |BDX|lvl| type      | cksum |E| comp|    PSIZE    |     LSIZE         |
196  *        +-------+-------+-------+-------+-------+-------+-------+-------+
197  * 7      |                             padding                                           |
198  *        +-------+-------+-------+-------+-------+-------+-------+-------+
199  * 8      |                             padding                                           |
200  *        +-------+-------+-------+-------+-------+-------+-------+-------+
201  * 9      |                             physical birth txg                      |
202  *        +-------+-------+-------+-------+-------+-------+-------+-------+
203  * a      |                             logical birth txg                       |
204  *        +-------+-------+-------+-------+-------+-------+-------+-------+
205  * b      |                             fill count                                        |
206  *        +-------+-------+-------+-------+-------+-------+-------+-------+
207  * c      |                             checksum[0]                                       |
208  *        +-------+-------+-------+-------+-------+-------+-------+-------+
209  * d      |                             checksum[1]                                       |
210  *        +-------+-------+-------+-------+-------+-------+-------+-------+
211  * e      |                             checksum[2]                                       |
212  *        +-------+-------+-------+-------+-------+-------+-------+-------+
213  * f      |                             checksum[3]                                       |
214  *        +-------+-------+-------+-------+-------+-------+-------+-------+
215  *
216  * Legend:
217  *
218  * vdev             virtual device ID
219  * offset offset into virtual device
220  * LSIZE  logical size
221  * PSIZE  physical size (after compression)
222  * ASIZE  allocated size (including RAID-Z parity and gang block headers)
223  * GRID             RAID-Z layout information (reserved for future use)
224  * cksum  checksum function
225  * comp             compression function
226  * G                gang block indicator
227  * B                byteorder (endianness)
228  * D                dedup
229  * X                encryption (on version 30, which is not supported)
230  * E                blkptr_t contains embedded data (see below)
231  * lvl              level of indirection
232  * type             DMU object type
233  * phys birth       txg of block allocation; zero if same as logical birth txg
234  * log. birth       transaction group in which the block was logically born
235  * fill count       number of non-zero blocks under this bp
236  * checksum[4]      256-bit checksum of the data this bp describes
237  */
238 
239 /*
240  * "Embedded" blkptr_t's don't actually point to a block, instead they
241  * have a data payload embedded in the blkptr_t itself.  See the comment
242  * in blkptr.c for more details.
243  *
244  * The blkptr_t is laid out as follows:
245  *
246  *        64        56        48        40        32        24        16        8         0
247  *        +-------+-------+-------+-------+-------+-------+-------+-------+
248  * 0      |      payload                                                  |
249  * 1      |      payload                                                  |
250  * 2      |      payload                                                  |
251  * 3      |      payload                                                  |
252  * 4      |      payload                                                  |
253  * 5      |      payload                                                  |
254  *        +-------+-------+-------+-------+-------+-------+-------+-------+
255  * 6      |BDX|lvl| type      | etype |E| comp| PSIZE|              LSIZE       |
256  *        +-------+-------+-------+-------+-------+-------+-------+-------+
257  * 7      |      payload                                                  |
258  * 8      |      payload                                                  |
259  * 9      |      payload                                                  |
260  *        +-------+-------+-------+-------+-------+-------+-------+-------+
261  * a      |                             logical birth txg                       |
262  *        +-------+-------+-------+-------+-------+-------+-------+-------+
263  * b      |      payload                                                  |
264  * c      |      payload                                                  |
265  * d      |      payload                                                  |
266  * e      |      payload                                                  |
267  * f      |      payload                                                  |
268  *        +-------+-------+-------+-------+-------+-------+-------+-------+
269  *
270  * Legend:
271  *
272  * payload                    contains the embedded data
273  * B (byteorder)    byteorder (endianness)
274  * D (dedup)                  padding (set to zero)
275  * X                          encryption (set to zero; see above)
276  * E (embedded)               set to one
277  * lvl                        indirection level
278  * type                       DMU object type
279  * etype            how to interpret embedded data (BP_EMBEDDED_TYPE_*)
280  * comp                       compression function of payload
281  * PSIZE            size of payload after compression, in bytes
282  * LSIZE            logical size of payload, in bytes
283  *                            note that 25 bits is enough to store the largest
284  *                            "normal" BP's LSIZE (2^16 * 2^9) in bytes
285  * log. birth                 transaction group in which the block was logically born
286  *
287  * Note that LSIZE and PSIZE are stored in bytes, whereas for non-embedded
288  * bp's they are stored in units of SPA_MINBLOCKSHIFT.
289  * Generally, the generic BP_GET_*() macros can be used on embedded BP's.
290  * The B, D, X, lvl, type, and comp fields are stored the same as with normal
291  * BP's so the BP_SET_* macros can be used with them.  etype, PSIZE, LSIZE must
292  * be set with the BPE_SET_* macros.  BP_SET_EMBEDDED() should be called before
293  * other macros, as they assert that they are only used on BP's of the correct
294  * "embedded-ness".
295  */
296 
297 #define   BPE_GET_ETYPE(bp)   \
298           (ASSERT(BP_IS_EMBEDDED(bp)), \
299           BF64_GET((bp)->blk_prop, 40, 8))
300 #define   BPE_SET_ETYPE(bp, t)          do { \
301           ASSERT(BP_IS_EMBEDDED(bp)); \
302           BF64_SET((bp)->blk_prop, 40, 8, t); \
303 _NOTE(CONSTCOND) } while (0)
304 
305 #define   BPE_GET_LSIZE(bp)   \
306           (ASSERT(BP_IS_EMBEDDED(bp)), \
307           BF64_GET_SB((bp)->blk_prop, 0, 25, 0, 1))
308 #define   BPE_SET_LSIZE(bp, x)          do { \
309           ASSERT(BP_IS_EMBEDDED(bp)); \
310           BF64_SET_SB((bp)->blk_prop, 0, 25, 0, 1, x); \
311 _NOTE(CONSTCOND) } while (0)
312 
313 #define   BPE_GET_PSIZE(bp)   \
314           (ASSERT(BP_IS_EMBEDDED(bp)), \
315           BF64_GET_SB((bp)->blk_prop, 25, 7, 0, 1))
316 #define   BPE_SET_PSIZE(bp, x)          do { \
317           ASSERT(BP_IS_EMBEDDED(bp)); \
318           BF64_SET_SB((bp)->blk_prop, 25, 7, 0, 1, x); \
319 _NOTE(CONSTCOND) } while (0)
320 
321 typedef enum bp_embedded_type {
322           BP_EMBEDDED_TYPE_DATA,
323           BP_EMBEDDED_TYPE_RESERVED, /* Reserved for an unintegrated feature. */
324           NUM_BP_EMBEDDED_TYPES = BP_EMBEDDED_TYPE_RESERVED
325 } bp_embedded_type_t;
326 
327 #define   BPE_NUM_WORDS 14
328 #define   BPE_PAYLOAD_SIZE (BPE_NUM_WORDS * sizeof (uint64_t))
329 #define   BPE_IS_PAYLOADWORD(bp, wp) \
330           ((wp) != &(bp)->blk_prop && (wp) != &(bp)->blk_birth)
331 
332 #define   SPA_BLKPTRSHIFT     7                   /* blkptr_t is 128 bytes      */
333 #define   SPA_DVAS_PER_BP     3                   /* Number of DVAs in a bp     */
334 
335 /*
336  * A block is a hole when it has either 1) never been written to, or
337  * 2) is zero-filled. In both cases, ZFS can return all zeroes for all reads
338  * without physically allocating disk space. Holes are represented in the
339  * blkptr_t structure by zeroed blk_dva. Correct checking for holes is
340  * done through the BP_IS_HOLE macro. For holes, the logical size, level,
341  * DMU object type, and birth times are all also stored for holes that
342  * were written to at some point (i.e. were punched after having been filled).
343  */
344 typedef struct blkptr {
345           dva_t               blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
346           uint64_t  blk_prop; /* size, compression, type, etc             */
347           uint64_t  blk_pad[2];         /* Extra space for the future     */
348           uint64_t  blk_phys_birth;     /* txg when block was allocated             */
349           uint64_t  blk_birth;          /* transaction group at birth     */
350           uint64_t  blk_fill; /* fill count                               */
351           zio_cksum_t         blk_cksum;          /* 256-bit checksum               */
352 } blkptr_t;
353 
354 /*
355  * Macros to get and set fields in a bp or DVA.
356  */
357 #define   DVA_GET_ASIZE(dva)  \
358           BF64_GET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, SPA_MINBLOCKSHIFT, 0)
359 #define   DVA_SET_ASIZE(dva, x)         \
360           BF64_SET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, \
361           SPA_MINBLOCKSHIFT, 0, x)
362 
363 #define   DVA_GET_GRID(dva)   BF64_GET((dva)->dva_word[0], 24, 8)
364 #define   DVA_SET_GRID(dva, x)          BF64_SET((dva)->dva_word[0], 24, 8, x)
365 
366 #define   DVA_GET_VDEV(dva)   BF64_GET((dva)->dva_word[0], 32, 32)
367 #define   DVA_SET_VDEV(dva, x)          BF64_SET((dva)->dva_word[0], 32, 32, x)
368 
369 #define   DVA_GET_OFFSET(dva) \
370           BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
371 #define   DVA_SET_OFFSET(dva, x)        \
372           BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
373 
374 #define   DVA_GET_GANG(dva)   BF64_GET((dva)->dva_word[1], 63, 1)
375 #define   DVA_SET_GANG(dva, x)          BF64_SET((dva)->dva_word[1], 63, 1, x)
376 
377 #define   BP_GET_LSIZE(bp)    \
378           (BP_IS_EMBEDDED(bp) ?         \
379           (BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA ? BPE_GET_LSIZE(bp) : 0): \
380           BF64_GET_SB((bp)->blk_prop, 0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1))
381 #define   BP_SET_LSIZE(bp, x) do { \
382           ASSERT(!BP_IS_EMBEDDED(bp)); \
383           BF64_SET_SB((bp)->blk_prop, \
384               0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
385 _NOTE(CONSTCOND) } while (0)
386 
387 #define   BP_GET_PSIZE(bp)    \
388           (BP_IS_EMBEDDED(bp) ? 0 : \
389           BF64_GET_SB((bp)->blk_prop, 16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1))
390 #define   BP_SET_PSIZE(bp, x) do { \
391           ASSERT(!BP_IS_EMBEDDED(bp)); \
392           BF64_SET_SB((bp)->blk_prop, \
393               16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1, x); \
394 _NOTE(CONSTCOND) } while (0)
395 
396 #define   BP_GET_COMPRESS(bp)           \
397           BF64_GET((bp)->blk_prop, 32, SPA_COMPRESSBITS)
398 #define   BP_SET_COMPRESS(bp, x)                  \
399           BF64_SET((bp)->blk_prop, 32, SPA_COMPRESSBITS, x)
400 
401 #define   BP_IS_EMBEDDED(bp)            BF64_GET((bp)->blk_prop, 39, 1)
402 #define   BP_SET_EMBEDDED(bp, x)                  BF64_SET((bp)->blk_prop, 39, 1, x)
403 
404 #define   BP_GET_CHECKSUM(bp)           \
405           (BP_IS_EMBEDDED(bp) ? ZIO_CHECKSUM_OFF : \
406           BF64_GET((bp)->blk_prop, 40, 8))
407 #define   BP_SET_CHECKSUM(bp, x)                  do { \
408           ASSERT(!BP_IS_EMBEDDED(bp)); \
409           BF64_SET((bp)->blk_prop, 40, 8, x); \
410 _NOTE(CONSTCOND) } while (0)
411 
412 #define   BP_GET_TYPE(bp)                         BF64_GET((bp)->blk_prop, 48, 8)
413 #define   BP_SET_TYPE(bp, x)            BF64_SET((bp)->blk_prop, 48, 8, x)
414 
415 #define   BP_GET_LEVEL(bp)              BF64_GET((bp)->blk_prop, 56, 5)
416 #define   BP_SET_LEVEL(bp, x)           BF64_SET((bp)->blk_prop, 56, 5, x)
417 
418 #define   BP_GET_DEDUP(bp)              BF64_GET((bp)->blk_prop, 62, 1)
419 #define   BP_SET_DEDUP(bp, x)           BF64_SET((bp)->blk_prop, 62, 1, x)
420 
421 #define   BP_GET_BYTEORDER(bp)                    BF64_GET((bp)->blk_prop, 63, 1)
422 #define   BP_SET_BYTEORDER(bp, x)                 BF64_SET((bp)->blk_prop, 63, 1, x)
423 
424 #define   BP_PHYSICAL_BIRTH(bp)                   \
425           (BP_IS_EMBEDDED(bp) ? 0 : \
426           (bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
427 
428 #define   BP_SET_BIRTH(bp, logical, physical)     \
429 {                                                           \
430           ASSERT(!BP_IS_EMBEDDED(bp));            \
431           (bp)->blk_birth = (logical);            \
432           (bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
433 }
434 
435 #define   BP_GET_FILL(bp) (BP_IS_EMBEDDED(bp) ? 1 : (bp)->blk_fill)
436 
437 #define   BP_GET_ASIZE(bp)    \
438           (BP_IS_EMBEDDED(bp) ? 0 : \
439           DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
440           DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
441           DVA_GET_ASIZE(&(bp)->blk_dva[2]))
442 
443 #define   BP_GET_UCSIZE(bp) \
444           ((BP_GET_LEVEL(bp) > 0 || DMU_OT_IS_METADATA(BP_GET_TYPE(bp))) ? \
445           BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp))
446 
447 #define   BP_GET_NDVAS(bp)    \
448           (BP_IS_EMBEDDED(bp) ? 0 : \
449           !!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
450           !!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
451           !!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
452 
453 #define   BP_COUNT_GANG(bp)   \
454           (BP_IS_EMBEDDED(bp) ? 0 : \
455           (DVA_GET_GANG(&(bp)->blk_dva[0]) + \
456           DVA_GET_GANG(&(bp)->blk_dva[1]) + \
457           DVA_GET_GANG(&(bp)->blk_dva[2])))
458 
459 #define   DVA_EQUAL(dva1, dva2)         \
460           ((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
461           (dva1)->dva_word[0] == (dva2)->dva_word[0])
462 
463 #define   BP_EQUAL(bp1, bp2)  \
464           (BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&        \
465           (bp1)->blk_birth == (bp2)->blk_birth &&                     \
466           DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&        \
467           DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&        \
468           DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
469 
470 #define   ZIO_CHECKSUM_EQUAL(zc1, zc2) \
471           (0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
472           ((zc1).zc_word[1] - (zc2).zc_word[1]) | \
473           ((zc1).zc_word[2] - (zc2).zc_word[2]) | \
474           ((zc1).zc_word[3] - (zc2).zc_word[3])))
475 
476 #define   ZIO_CHECKSUM_IS_ZERO(zc) \
477           (0 == ((zc)->zc_word[0] | (zc)->zc_word[1] | \
478           (zc)->zc_word[2] | (zc)->zc_word[3]))
479 
480 #define   ZIO_CHECKSUM_BSWAP(zcp)                                               \
481 {                                                                               \
482           (zcp)->zc_word[0] = BSWAP_64((zcp)->zc_word[0]);  \
483           (zcp)->zc_word[1] = BSWAP_64((zcp)->zc_word[1]);  \
484           (zcp)->zc_word[2] = BSWAP_64((zcp)->zc_word[2]);  \
485           (zcp)->zc_word[3] = BSWAP_64((zcp)->zc_word[3]);  \
486 }
487 
488 
489 #define   DVA_IS_VALID(dva)   (DVA_GET_ASIZE(dva) != 0)
490 
491 #define   ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)   \
492 {                                                           \
493           (zcp)->zc_word[0] = w0;                           \
494           (zcp)->zc_word[1] = w1;                           \
495           (zcp)->zc_word[2] = w2;                           \
496           (zcp)->zc_word[3] = w3;                           \
497 }
498 
499 #define   BP_IDENTITY(bp)               (ASSERT(!BP_IS_EMBEDDED(bp)), &(bp)->blk_dva[0])
500 #define   BP_IS_GANG(bp)                \
501           (BP_IS_EMBEDDED(bp) ? B_FALSE : DVA_GET_GANG(BP_IDENTITY(bp)))
502 #define   DVA_IS_EMPTY(dva)   ((dva)->dva_word[0] == 0ULL &&          \
503                                         (dva)->dva_word[1] == 0ULL)
504 #define   BP_IS_HOLE(bp) \
505           (!BP_IS_EMBEDDED(bp) && DVA_IS_EMPTY(BP_IDENTITY(bp)))
506 
507 /* BP_IS_RAIDZ(bp) assumes no block compression */
508 #define   BP_IS_RAIDZ(bp)               (DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
509                                         BP_GET_PSIZE(bp))
510 
511 #define   BP_ZERO(bp)                                       \
512 {                                                           \
513           (bp)->blk_dva[0].dva_word[0] = 0;       \
514           (bp)->blk_dva[0].dva_word[1] = 0;       \
515           (bp)->blk_dva[1].dva_word[0] = 0;       \
516           (bp)->blk_dva[1].dva_word[1] = 0;       \
517           (bp)->blk_dva[2].dva_word[0] = 0;       \
518           (bp)->blk_dva[2].dva_word[1] = 0;       \
519           (bp)->blk_prop = 0;                     \
520           (bp)->blk_pad[0] = 0;                             \
521           (bp)->blk_pad[1] = 0;                             \
522           (bp)->blk_phys_birth = 0;               \
523           (bp)->blk_birth = 0;                              \
524           (bp)->blk_fill = 0;                     \
525           ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);   \
526 }
527 
528 #if BYTE_ORDER == _BIG_ENDIAN
529 #define   ZFS_HOST_BYTEORDER  (0ULL)
530 #else
531 #define   ZFS_HOST_BYTEORDER  (1ULL)
532 #endif
533 
534 #define   BP_SHOULD_BYTESWAP(bp)        (BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)
535 
536 #define   BP_SPRINTF_LEN      320
537 
538 /*
539  * This macro allows code sharing between zfs, libzpool, and mdb.
540  * 'func' is either snprintf() or mdb_snprintf().
541  * 'ws' (whitespace) can be ' ' for single-line format, '\n' for multi-line.
542  */
543 #define   SNPRINTF_BLKPTR(func, ws, buf, size, bp, type, checksum, compress) \
544 {                                                                                         \
545           static const char *copyname[] =                                                 \
546               { "zero", "single", "double", "triple" };                         \
547           int len = 0;                                                                    \
548           int copies = 0;                                                                 \
549                                                                                           \
550           if (bp == NULL) {                                                     \
551                     len += func(buf + len, size - len, "<NULL>");               \
552           } else if (BP_IS_HOLE(bp)) {                                          \
553                     len += func(buf + len, size - len,                          \
554                         "HOLE [L%llu %s] "                                                \
555                         "size=%llxL birth=%lluL",                               \
556                         (u_longlong_t)BP_GET_LEVEL(bp),                         \
557                         type,                                                   \
558                         (u_longlong_t)BP_GET_LSIZE(bp),                         \
559                         (u_longlong_t)bp->blk_birth);                           \
560           } else if (BP_IS_EMBEDDED(bp)) {                                      \
561                     len = func(buf + len, size - len,                           \
562                         "EMBEDDED [L%llu %s] et=%u %s "                         \
563                         "size=%llxL/%llxP birth=%lluL",                         \
564                         (u_longlong_t)BP_GET_LEVEL(bp),                         \
565                         type,                                                   \
566                         (int)BPE_GET_ETYPE(bp),                                 \
567                         compress,                                                         \
568                         (u_longlong_t)BPE_GET_LSIZE(bp),                        \
569                         (u_longlong_t)BPE_GET_PSIZE(bp),                        \
570                         (u_longlong_t)bp->blk_birth);                           \
571           } else {                                                              \
572                     for (int d = 0; d < BP_GET_NDVAS(bp); d++) {                \
573                               const dva_t *dva = &bp->blk_dva[d];               \
574                               if (DVA_IS_VALID(dva))                                      \
575                                         copies++;                               \
576                               len += func(buf + len, size - len,                \
577                                   "DVA[%d]=<%llu:%llx:%llx>%c", d,              \
578                                   (u_longlong_t)DVA_GET_VDEV(dva),              \
579                                   (u_longlong_t)DVA_GET_OFFSET(dva),            \
580                                   (u_longlong_t)DVA_GET_ASIZE(dva),             \
581                                   ws);                                          \
582                     }                                                                     \
583                     if (BP_IS_GANG(bp) &&                                                 \
584                         DVA_GET_ASIZE(&bp->blk_dva[2]) <=                       \
585                         DVA_GET_ASIZE(&bp->blk_dva[1]) / 2)                     \
586                               copies--;                                         \
587                     len += func(buf + len, size - len,                          \
588                         "[L%llu %s] %s %s %s %s %s %s%c"                        \
589                         "size=%llxL/%llxP birth=%lluL/%lluP fill=%llu%c"        \
590                         "cksum=%llx:%llx:%llx:%llx",                            \
591                         (u_longlong_t)BP_GET_LEVEL(bp),                         \
592                         type,                                                   \
593                         checksum,                                                         \
594                         compress,                                                         \
595                         BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",                \
596                         BP_IS_GANG(bp) ? "gang" : "contiguous",                 \
597                         BP_GET_DEDUP(bp) ? "dedup" : "unique",                  \
598                         copyname[copies],                                                 \
599                         ws,                                                               \
600                         (u_longlong_t)BP_GET_LSIZE(bp),                         \
601                         (u_longlong_t)BP_GET_PSIZE(bp),                         \
602                         (u_longlong_t)bp->blk_birth,                            \
603                         (u_longlong_t)BP_PHYSICAL_BIRTH(bp),                    \
604                         (u_longlong_t)BP_GET_FILL(bp),                          \
605                         ws,                                                               \
606                         (u_longlong_t)bp->blk_cksum.zc_word[0],                 \
607                         (u_longlong_t)bp->blk_cksum.zc_word[1],                 \
608                         (u_longlong_t)bp->blk_cksum.zc_word[2],                 \
609                         (u_longlong_t)bp->blk_cksum.zc_word[3]);                \
610           }                                                                               \
611           ASSERT(len < size);                                                   \
612 }
613 
614 #include <sys/dmu.h>
615 
616 #define   BP_GET_BUFC_TYPE(bp)                                                            \
617           (((BP_GET_LEVEL(bp) > 0) || (DMU_OT_IS_METADATA(BP_GET_TYPE(bp)))) ? \
618           ARC_BUFC_METADATA : ARC_BUFC_DATA)
619 
620 typedef enum spa_import_type {
621           SPA_IMPORT_EXISTING,
622           SPA_IMPORT_ASSEMBLE
623 } spa_import_type_t;
624 
625 /* state manipulation functions */
626 extern int spa_open(const char *pool, spa_t **, void *tag);
627 extern int spa_open_rewind(const char *pool, spa_t **, void *tag,
628     nvlist_t *policy, nvlist_t **config);
629 extern int spa_get_stats(const char *pool, nvlist_t **config, char *altroot,
630     size_t buflen);
631 extern int spa_create(const char *pool, nvlist_t *config, nvlist_t *props,
632     nvlist_t *zplprops);
633 #ifdef illumos
634 extern int spa_import_rootpool(char *devpath, char *devid);
635 #else
636 extern int spa_import_rootpool(const char *name);
637 #endif
638 extern int spa_import(const char *pool, nvlist_t *config, nvlist_t *props,
639     uint64_t flags);
640 extern nvlist_t *spa_tryimport(nvlist_t *tryconfig);
641 extern int spa_destroy(char *pool);
642 extern int spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
643     boolean_t hardforce);
644 extern int spa_reset(char *pool);
645 extern void spa_async_request(spa_t *spa, int flag);
646 extern void spa_async_unrequest(spa_t *spa, int flag);
647 extern void spa_async_suspend(spa_t *spa);
648 extern void spa_async_resume(spa_t *spa);
649 extern spa_t *spa_inject_addref(char *pool);
650 extern void spa_inject_delref(spa_t *spa);
651 extern void spa_scan_stat_init(spa_t *spa);
652 extern int spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps);
653 
654 #define   SPA_ASYNC_CONFIG_UPDATE       0x01
655 #define   SPA_ASYNC_REMOVE    0x02
656 #define   SPA_ASYNC_PROBE               0x04
657 #define   SPA_ASYNC_RESILVER_DONE       0x08
658 #define   SPA_ASYNC_RESILVER  0x10
659 #define   SPA_ASYNC_AUTOEXPAND          0x20
660 #define   SPA_ASYNC_REMOVE_DONE         0x40
661 #define   SPA_ASYNC_REMOVE_STOP         0x80
662 
663 /*
664  * Controls the behavior of spa_vdev_remove().
665  */
666 #define   SPA_REMOVE_UNSPARE  0x01
667 #define   SPA_REMOVE_DONE               0x02
668 
669 /* device manipulation */
670 extern int spa_vdev_add(spa_t *spa, nvlist_t *nvroot);
671 extern int spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot,
672     int replacing);
673 extern int spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid,
674     int replace_done);
675 extern int spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare);
676 extern boolean_t spa_vdev_remove_active(spa_t *spa);
677 extern int spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath);
678 extern int spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru);
679 extern int spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
680     nvlist_t *props, boolean_t exp);
681 
682 /* spare state (which is global across all pools) */
683 extern void spa_spare_add(vdev_t *vd);
684 extern void spa_spare_remove(vdev_t *vd);
685 extern boolean_t spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt);
686 extern void spa_spare_activate(vdev_t *vd);
687 
688 /* L2ARC state (which is global across all pools) */
689 extern void spa_l2cache_add(vdev_t *vd);
690 extern void spa_l2cache_remove(vdev_t *vd);
691 extern boolean_t spa_l2cache_exists(uint64_t guid, uint64_t *pool);
692 extern void spa_l2cache_activate(vdev_t *vd);
693 extern void spa_l2cache_drop(spa_t *spa);
694 
695 /* scanning */
696 extern int spa_scan(spa_t *spa, pool_scan_func_t func);
697 extern int spa_scan_stop(spa_t *spa);
698 
699 /* spa syncing */
700 extern void spa_sync(spa_t *spa, uint64_t txg); /* only for DMU use */
701 extern void spa_sync_allpools(void);
702 
703 /* spa namespace global mutex */
704 extern kmutex_t spa_namespace_lock;
705 
706 /*
707  * SPA configuration functions in spa_config.c
708  */
709 
710 #define   SPA_CONFIG_UPDATE_POOL        0
711 #define   SPA_CONFIG_UPDATE_VDEVS       1
712 
713 extern void spa_config_sync(spa_t *, boolean_t, boolean_t);
714 extern void spa_config_load(void);
715 extern nvlist_t *spa_all_configs(uint64_t *);
716 extern void spa_config_set(spa_t *spa, nvlist_t *config);
717 extern nvlist_t *spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg,
718     int getstats);
719 extern void spa_config_update(spa_t *spa, int what);
720 
721 /*
722  * Miscellaneous SPA routines in spa_misc.c
723  */
724 
725 /* Namespace manipulation */
726 extern spa_t *spa_lookup(const char *name);
727 extern spa_t *spa_add(const char *name, nvlist_t *config, const char *altroot);
728 extern void spa_remove(spa_t *spa);
729 extern spa_t *spa_next(spa_t *prev);
730 
731 /* Refcount functions */
732 extern void spa_open_ref(spa_t *spa, void *tag);
733 extern void spa_close(spa_t *spa, void *tag);
734 extern void spa_async_close(spa_t *spa, void *tag);
735 extern boolean_t spa_refcount_zero(spa_t *spa);
736 
737 #define   SCL_NONE  0x00
738 #define   SCL_CONFIG          0x01
739 #define   SCL_STATE 0x02
740 #define   SCL_L2ARC 0x04                /* hack until L2ARC 2.0 */
741 #define   SCL_ALLOC 0x08
742 #define   SCL_ZIO             0x10
743 #define   SCL_FREE  0x20
744 #define   SCL_VDEV  0x40
745 #define   SCL_LOCKS 7
746 #define   SCL_ALL             ((1 << SCL_LOCKS) - 1)
747 #define   SCL_STATE_ALL       (SCL_STATE | SCL_L2ARC | SCL_ZIO)
748 
749 /* Pool configuration locks */
750 extern int spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw);
751 extern void spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw);
752 extern void spa_config_exit(spa_t *spa, int locks, void *tag);
753 extern int spa_config_held(spa_t *spa, int locks, krw_t rw);
754 
755 /* Pool vdev add/remove lock */
756 extern uint64_t spa_vdev_enter(spa_t *spa);
757 extern uint64_t spa_vdev_config_enter(spa_t *spa);
758 extern void spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg,
759     int error, char *tag);
760 extern int spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error);
761 
762 /* Pool vdev state change lock */
763 extern void spa_vdev_state_enter(spa_t *spa, int oplock);
764 extern int spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error);
765 
766 /* Log state */
767 typedef enum spa_log_state {
768           SPA_LOG_UNKNOWN = 0,          /* unknown log state */
769           SPA_LOG_MISSING,    /* missing log(s) */
770           SPA_LOG_CLEAR,                /* clear the log(s) */
771           SPA_LOG_GOOD,                 /* log(s) are good */
772 } spa_log_state_t;
773 
774 extern spa_log_state_t spa_get_log_state(spa_t *spa);
775 extern void spa_set_log_state(spa_t *spa, spa_log_state_t state);
776 extern int spa_offline_log(spa_t *spa);
777 
778 /* Log claim callback */
779 extern void spa_claim_notify(zio_t *zio);
780 
781 /* Accessor functions */
782 extern boolean_t spa_shutting_down(spa_t *spa);
783 extern struct dsl_pool *spa_get_dsl(spa_t *spa);
784 extern boolean_t spa_is_initializing(spa_t *spa);
785 extern blkptr_t *spa_get_rootblkptr(spa_t *spa);
786 extern void spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp);
787 extern void spa_altroot(spa_t *, char *, size_t);
788 extern int spa_sync_pass(spa_t *spa);
789 extern char *spa_name(spa_t *spa);
790 extern uint64_t spa_guid(spa_t *spa);
791 extern uint64_t spa_load_guid(spa_t *spa);
792 extern uint64_t spa_last_synced_txg(spa_t *spa);
793 extern uint64_t spa_first_txg(spa_t *spa);
794 extern uint64_t spa_syncing_txg(spa_t *spa);
795 extern uint64_t spa_version(spa_t *spa);
796 extern pool_state_t spa_state(spa_t *spa);
797 extern spa_load_state_t spa_load_state(spa_t *spa);
798 extern uint64_t spa_freeze_txg(spa_t *spa);
799 extern uint64_t spa_get_asize(spa_t *spa, uint64_t lsize);
800 extern uint64_t spa_get_dspace(spa_t *spa);
801 extern uint64_t spa_get_slop_space(spa_t *spa);
802 extern void spa_update_dspace(spa_t *spa);
803 extern uint64_t spa_version(spa_t *spa);
804 extern boolean_t spa_deflate(spa_t *spa);
805 extern metaslab_class_t *spa_normal_class(spa_t *spa);
806 extern metaslab_class_t *spa_log_class(spa_t *spa);
807 extern void spa_evicting_os_register(spa_t *, objset_t *os);
808 extern void spa_evicting_os_deregister(spa_t *, objset_t *os);
809 extern void spa_evicting_os_wait(spa_t *spa);
810 extern int spa_max_replication(spa_t *spa);
811 extern int spa_prev_software_version(spa_t *spa);
812 extern int spa_busy(void);
813 extern uint8_t spa_get_failmode(spa_t *spa);
814 extern boolean_t spa_suspended(spa_t *spa);
815 extern uint64_t spa_bootfs(spa_t *spa);
816 extern uint64_t spa_delegation(spa_t *spa);
817 extern objset_t *spa_meta_objset(spa_t *spa);
818 extern uint64_t spa_deadman_synctime(spa_t *spa);
819 
820 /* Miscellaneous support routines */
821 extern void spa_activate_mos_feature(spa_t *spa, const char *feature,
822     dmu_tx_t *tx);
823 extern void spa_deactivate_mos_feature(spa_t *spa, const char *feature);
824 extern int spa_rename(const char *oldname, const char *newname);
825 extern spa_t *spa_by_guid(uint64_t pool_guid, uint64_t device_guid);
826 extern boolean_t spa_guid_exists(uint64_t pool_guid, uint64_t device_guid);
827 extern char *spa_strdup(const char *);
828 extern void spa_strfree(char *);
829 extern uint64_t spa_get_random(uint64_t range);
830 extern uint64_t spa_generate_guid(spa_t *spa);
831 extern void snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp);
832 extern void spa_freeze(spa_t *spa);
833 extern int spa_change_guid(spa_t *spa);
834 extern void spa_upgrade(spa_t *spa, uint64_t version);
835 extern void spa_evict_all(void);
836 extern vdev_t *spa_lookup_by_guid(spa_t *spa, uint64_t guid,
837     boolean_t l2cache);
838 extern boolean_t spa_has_spare(spa_t *, uint64_t guid);
839 extern uint64_t dva_get_dsize_sync(spa_t *spa, const dva_t *dva);
840 extern uint64_t bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp);
841 extern uint64_t bp_get_dsize(spa_t *spa, const blkptr_t *bp);
842 extern boolean_t spa_has_slogs(spa_t *spa);
843 extern boolean_t spa_is_root(spa_t *spa);
844 extern boolean_t spa_writeable(spa_t *spa);
845 extern boolean_t spa_has_pending_synctask(spa_t *spa);
846 extern int spa_maxblocksize(spa_t *spa);
847 extern void zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp);
848 
849 extern int spa_mode(spa_t *spa);
850 extern uint64_t zfs_strtonum(const char *str, char **nptr);
851 #define   strtonum(str, nptr) zfs_strtonum((str), (nptr))
852 
853 extern char *spa_his_ievent_table[];
854 
855 extern void spa_history_create_obj(spa_t *spa, dmu_tx_t *tx);
856 extern int spa_history_get(spa_t *spa, uint64_t *offset, uint64_t *len_read,
857     char *his_buf);
858 extern int spa_history_log(spa_t *spa, const char *his_buf);
859 extern int spa_history_log_nvl(spa_t *spa, nvlist_t *nvl);
860 extern void spa_history_log_version(spa_t *spa, const char *operation);
861 extern void spa_history_log_internal(spa_t *spa, const char *operation,
862     dmu_tx_t *tx, const char *fmt, ...);
863 extern void spa_history_log_internal_ds(struct dsl_dataset *ds, const char *op,
864     dmu_tx_t *tx, const char *fmt, ...);
865 extern void spa_history_log_internal_dd(dsl_dir_t *dd, const char *operation,
866     dmu_tx_t *tx, const char *fmt, ...);
867 
868 /* error handling */
869 struct zbookmark_phys;
870 extern void spa_log_error(spa_t *spa, zio_t *zio);
871 extern void zfs_ereport_post(const char *cls, spa_t *spa, vdev_t *vd,
872     zio_t *zio, uint64_t stateoroffset, uint64_t length);
873 extern void zfs_post_remove(spa_t *spa, vdev_t *vd);
874 extern void zfs_post_state_change(spa_t *spa, vdev_t *vd);
875 extern void zfs_post_autoreplace(spa_t *spa, vdev_t *vd);
876 extern uint64_t spa_get_errlog_size(spa_t *spa);
877 extern int spa_get_errlog(spa_t *spa, void *uaddr, size_t *count);
878 extern void spa_errlog_rotate(spa_t *spa);
879 extern void spa_errlog_drain(spa_t *spa);
880 extern void spa_errlog_sync(spa_t *spa, uint64_t txg);
881 extern void spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub);
882 
883 /* vdev cache */
884 extern void vdev_cache_stat_init(void);
885 extern void vdev_cache_stat_fini(void);
886 
887 /* Initialization and termination */
888 extern void spa_init(int flags);
889 extern void spa_fini(void);
890 extern void spa_boot_init();
891 
892 /* properties */
893 extern int spa_prop_set(spa_t *spa, nvlist_t *nvp);
894 extern int spa_prop_get(spa_t *spa, nvlist_t **nvp);
895 extern void spa_prop_clear_bootfs(spa_t *spa, uint64_t obj, dmu_tx_t *tx);
896 extern void spa_configfile_set(spa_t *, nvlist_t *, boolean_t);
897 
898 /* asynchronous event notification */
899 extern void spa_event_notify(spa_t *spa, vdev_t *vdev, const char *name);
900 
901 #ifdef ZFS_DEBUG
902 #define   dprintf_bp(bp, fmt, ...) do {                               \
903           if (zfs_flags & ZFS_DEBUG_DPRINTF) {                        \
904           char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP);      \
905           snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, (bp));  \
906           dprintf(fmt " %s\n", __VA_ARGS__, __blkbuf);                \
907           kmem_free(__blkbuf, BP_SPRINTF_LEN);                        \
908           } \
909 _NOTE(CONSTCOND) } while (0)
910 #else
911 #define   dprintf_bp(bp, fmt, ...)
912 #endif
913 
914 extern boolean_t spa_debug_enabled(spa_t *spa);
915 #define   spa_dbgmsg(spa, ...)                              \
916 {                                                           \
917           if (spa_debug_enabled(spa))             \
918                     zfs_dbgmsg(__VA_ARGS__);      \
919 }
920 
921 extern int spa_mode_global;                       /* mode, e.g. FREAD | FWRITE */
922 
923 #ifdef    __cplusplus
924 }
925 #endif
926 
927 #endif    /* _SYS_SPA_H */
928