1 /*
2  *  GRUB  --  GRand Unified Bootloader
3  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, write to the Free Software
17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18  */
19 
20 /*
21  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
22  * Use is subject to license terms.
23  */
24 
25 /*
26  * Copyright (c) 2013, 2015 by Delphix. All rights reserved.
27  * Copyright (c) 2014 Integros [integros.com]
28  */
29 
30 #ifndef _SYS_SPA_H
31 #define	_SYS_SPA_H
32 
33 /*
34  * General-purpose 32-bit and 64-bit bitfield encodings.
35  */
36 #define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))
37 #define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))
38 #define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))
39 #define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))
40 
41 #define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)
42 #define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)
43 
44 #define	BF32_SET(x, low, len, val)	\
45 	((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len))
46 #define	BF64_SET(x, low, len, val)	\
47 	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len))
48 
49 #define	BF32_GET_SB(x, low, len, shift, bias)	\
50 	((BF32_GET(x, low, len) + (bias)) << (shift))
51 #define	BF64_GET_SB(x, low, len, shift, bias)	\
52 	((BF64_GET(x, low, len) + (bias)) << (shift))
53 
54 #define	BF32_SET_SB(x, low, len, shift, bias, val)	\
55 	BF32_SET(x, low, len, ((val) >> (shift)) - (bias))
56 #define	BF64_SET_SB(x, low, len, shift, bias, val)	\
57 	BF64_SET(x, low, len, ((val) >> (shift)) - (bias))
58 
59 /*
60  * Note: GRUB can't actually read blocks larger than 128KB, due to lack
61  * of memory.  Therefore its SPA_MAXBLOCKSIZE is still 128KB.
62  */
63 #define	SPA_MINBLOCKSHIFT	9
64 #define	SPA_MAXBLOCKSHIFT	17
65 #define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)
66 #define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)
67 
68 /*
69  * Size of block to hold the configuration data (a packed nvlist)
70  */
71 #define	SPA_CONFIG_BLOCKSIZE	(1ULL << 14)
72 
73 /*
74  * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
75  * The ASIZE encoding should be at least 64 times larger (6 more bits)
76  * to support up to 4-way RAID-Z mirror mode with worst-case gang block
77  * overhead, three DVAs per bp, plus one more bit in case we do anything
78  * else that expands the ASIZE.
79  */
80 #define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/
81 #define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/
82 #define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/
83 
84 #define	SPA_COMPRESSBITS	7
85 
86 /*
87  * All SPA data is represented by 128-bit data virtual addresses (DVAs).
88  * The members of the dva_t should be considered opaque outside the SPA.
89  */
90 typedef struct dva {
91 	uint64_t	dva_word[2];
92 } dva_t;
93 
94 /*
95  * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
96  */
97 typedef struct zio_cksum {
98 	uint64_t	zc_word[4];
99 } zio_cksum_t;
100 
101 /*
102  * Each block is described by its DVAs, time of birth, checksum, etc.
103  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
104  *
105  *	64	56	48	40	32	24	16	8	0
106  *	+-------+-------+-------+-------+-------+-------+-------+-------+
107  * 0	|		vdev1		| GRID  |	  ASIZE		|
108  *	+-------+-------+-------+-------+-------+-------+-------+-------+
109  * 1	|G|			 offset1				|
110  *	+-------+-------+-------+-------+-------+-------+-------+-------+
111  * 2	|		vdev2		| GRID  |	  ASIZE		|
112  *	+-------+-------+-------+-------+-------+-------+-------+-------+
113  * 3	|G|			 offset2				|
114  *	+-------+-------+-------+-------+-------+-------+-------+-------+
115  * 4	|		vdev3		| GRID  |	  ASIZE		|
116  *	+-------+-------+-------+-------+-------+-------+-------+-------+
117  * 5	|G|			 offset3				|
118  *	+-------+-------+-------+-------+-------+-------+-------+-------+
119  * 6	|BDX|lvl| type	| cksum |E| comp|    PSIZE	|     LSIZE	|
120  *	+-------+-------+-------+-------+-------+-------+-------+-------+
121  * 7	|			padding					|
122  *	+-------+-------+-------+-------+-------+-------+-------+-------+
123  * 8	|			padding					|
124  *	+-------+-------+-------+-------+-------+-------+-------+-------+
125  * 9	|			physical birth txg			|
126  *	+-------+-------+-------+-------+-------+-------+-------+-------+
127  * a	|			logical birth txg			|
128  *	+-------+-------+-------+-------+-------+-------+-------+-------+
129  * b	|			fill count				|
130  *	+-------+-------+-------+-------+-------+-------+-------+-------+
131  * c	|			checksum[0]				|
132  *	+-------+-------+-------+-------+-------+-------+-------+-------+
133  * d	|			checksum[1]				|
134  *	+-------+-------+-------+-------+-------+-------+-------+-------+
135  * e	|			checksum[2]				|
136  *	+-------+-------+-------+-------+-------+-------+-------+-------+
137  * f	|			checksum[3]				|
138  *	+-------+-------+-------+-------+-------+-------+-------+-------+
139  *
140  * Legend:
141  *
142  * vdev		virtual device ID
143  * offset	offset into virtual device
144  * LSIZE	logical size
145  * PSIZE	physical size (after compression)
146  * ASIZE	allocated size (including RAID-Z parity and gang block headers)
147  * GRID		RAID-Z layout information (reserved for future use)
148  * cksum	checksum function
149  * comp		compression function
150  * G		gang block indicator
151  * B		byteorder (endianness)
152  * D		dedup
153  * X		encryption (on version 30, which is not supported)
154  * E		blkptr_t contains embedded data
155  * lvl		level of indirection
156  * type		DMU object type
157  * phys birth	txg of block allocation; zero if same as logical birth txg
158  * log. birth	transaction group in which the block was logically born
159  * fill count	number of non-zero blocks under this bp
160  * checksum[4]	256-bit checksum of the data this bp describes
161  */
162 #define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
163 #define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
164 
165 typedef struct blkptr {
166 	dva_t		blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
167 	uint64_t	blk_prop;	/* size, compression, type, etc	    */
168 	uint64_t	blk_pad[2];	/* Extra space for the future	    */
169 	uint64_t	blk_phys_birth;	/* txg when block was allocated	    */
170 	uint64_t	blk_birth;	/* transaction group at birth	    */
171 	uint64_t	blk_fill;	/* fill count			    */
172 	zio_cksum_t	blk_cksum;	/* 256-bit checksum		    */
173 } blkptr_t;
174 
175 /*
176  * Macros to get and set fields in a bp or DVA.
177  */
178 #define	DVA_GET_ASIZE(dva)	\
179 	BF64_GET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, SPA_MINBLOCKSHIFT, 0)
180 #define	DVA_SET_ASIZE(dva, x)	\
181 	BF64_SET_SB((dva)->dva_word[0], 0, SPA_ASIZEBITS, \
182 	SPA_MINBLOCKSHIFT, 0, x)
183 
184 #define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
185 #define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
186 
187 #define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
188 #define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
189 
190 #define	DVA_GET_OFFSET(dva)	\
191 	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
192 #define	DVA_SET_OFFSET(dva, x)	\
193 	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
194 
195 #define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
196 #define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
197 
198 #define	BP_GET_LSIZE(bp)	\
199 	BF64_GET_SB((bp)->blk_prop, 0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1)
200 #define	BP_SET_LSIZE(bp, x)	\
201 	BF64_SET_SB((bp)->blk_prop, 0, SPA_LSIZEBITS, SPA_MINBLOCKSHIFT, 1, x)
202 
203 #define	BP_GET_PSIZE(bp)	\
204 	BF64_GET_SB((bp)->blk_prop, 16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1)
205 #define	BP_SET_PSIZE(bp, x)	\
206 	BF64_SET_SB((bp)->blk_prop, 16, SPA_PSIZEBITS, SPA_MINBLOCKSHIFT, 1, x)
207 
208 #define	BP_GET_COMPRESS(bp)		\
209 	BF64_GET((bp)->blk_prop, 32, SPA_COMPRESSBITS)
210 #define	BP_SET_COMPRESS(bp, x)		\
211 	BF64_SET((bp)->blk_prop, 32, SPA_COMPRESSBITS, x)
212 
213 #define	BP_GET_CHECKSUM(bp)		BF64_GET((bp)->blk_prop, 40, 8)
214 #define	BP_SET_CHECKSUM(bp, x)		BF64_SET((bp)->blk_prop, 40, 8, x)
215 
216 #define	BP_GET_TYPE(bp)			BF64_GET((bp)->blk_prop, 48, 8)
217 #define	BP_SET_TYPE(bp, x)		BF64_SET((bp)->blk_prop, 48, 8, x)
218 
219 #define	BP_GET_LEVEL(bp)		BF64_GET((bp)->blk_prop, 56, 5)
220 #define	BP_SET_LEVEL(bp, x)		BF64_SET((bp)->blk_prop, 56, 5, x)
221 
222 #define	BP_IS_EMBEDDED(bp)		BF64_GET((bp)->blk_prop, 39, 1)
223 
224 #define	BP_GET_DEDUP(bp)		BF64_GET((bp)->blk_prop, 62, 1)
225 #define	BP_SET_DEDUP(bp, x)		BF64_SET((bp)->blk_prop, 62, 1, x)
226 
227 #define	BP_GET_BYTEORDER(bp)		BF64_GET((bp)->blk_prop, 63, 1)
228 #define	BP_SET_BYTEORDER(bp, x)		BF64_SET((bp)->blk_prop, 63, 1, x)
229 
230 #define	BP_PHYSICAL_BIRTH(bp)		\
231 	((bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
232 
233 #define	BP_SET_BIRTH(bp, logical, physical)	\
234 {						\
235 	(bp)->blk_birth = (logical);		\
236 	(bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
237 }
238 
239 #define	BP_GET_ASIZE(bp)	\
240 	(DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
241 		DVA_GET_ASIZE(&(bp)->blk_dva[2]))
242 
243 #define	BP_GET_UCSIZE(bp) \
244 	((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ? \
245 	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp));
246 
247 #define	BP_GET_NDVAS(bp)	\
248 	(!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
249 	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
250 	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
251 
252 #define	DVA_EQUAL(dva1, dva2)	\
253 	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
254 	(dva1)->dva_word[0] == (dva2)->dva_word[0])
255 
256 #define	BP_EQUAL(bp1, bp2)	\
257 	(BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&	\
258 	DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&	\
259 	DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&	\
260 	DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
261 
262 #define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \
263 	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
264 	((zc1).zc_word[1] - (zc2).zc_word[1]) | \
265 	((zc1).zc_word[2] - (zc2).zc_word[2]) | \
266 	((zc1).zc_word[3] - (zc2).zc_word[3])))
267 
268 #define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
269 
270 #define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
271 {						\
272 	(zcp)->zc_word[0] = w0;			\
273 	(zcp)->zc_word[1] = w1;			\
274 	(zcp)->zc_word[2] = w2;			\
275 	(zcp)->zc_word[3] = w3;			\
276 }
277 
278 #define	BP_IDENTITY(bp)		(&(bp)->blk_dva[0])
279 #define	BP_IS_GANG(bp)		DVA_GET_GANG(BP_IDENTITY(bp))
280 #define	DVA_IS_EMPTY(dva)	((dva)->dva_word[0] == 0ULL &&	\
281 				(dva)->dva_word[1] == 0ULL)
282 #define	BP_IS_HOLE(bp)		DVA_IS_EMPTY(BP_IDENTITY(bp))
283 
284 /* BP_IS_RAIDZ(bp) assumes no block compression */
285 #define	BP_IS_RAIDZ(bp)		(DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
286 				BP_GET_PSIZE(bp))
287 
288 #define	BP_ZERO(bp)				\
289 {						\
290 	(bp)->blk_dva[0].dva_word[0] = 0;	\
291 	(bp)->blk_dva[0].dva_word[1] = 0;	\
292 	(bp)->blk_dva[1].dva_word[0] = 0;	\
293 	(bp)->blk_dva[1].dva_word[1] = 0;	\
294 	(bp)->blk_dva[2].dva_word[0] = 0;	\
295 	(bp)->blk_dva[2].dva_word[1] = 0;	\
296 	(bp)->blk_prop = 0;			\
297 	(bp)->blk_pad[0] = 0;			\
298 	(bp)->blk_pad[1] = 0;			\
299 	(bp)->blk_phys_birth = 0;		\
300 	(bp)->blk_birth = 0;			\
301 	(bp)->blk_fill = 0;			\
302 	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
303 }
304 
305 #define	BPE_GET_ETYPE(bp)	BP_GET_CHECKSUM(bp)
306 #define	BPE_GET_LSIZE(bp)	\
307 	BF64_GET_SB((bp)->blk_prop, 0, 25, 0, 1)
308 #define	BPE_GET_PSIZE(bp)	\
309 	BF64_GET_SB((bp)->blk_prop, 25, 7, 0, 1)
310 
311 typedef enum bp_embedded_type {
312 	BP_EMBEDDED_TYPE_DATA,
313 	NUM_BP_EMBEDDED_TYPES
314 } bp_embedded_type_t;
315 
316 #define	BPE_NUM_WORDS 14
317 #define	BPE_PAYLOAD_SIZE (BPE_NUM_WORDS * sizeof (uint64_t))
318 #define	BPE_IS_PAYLOADWORD(bp, wp) \
319 	((wp) != &(bp)->blk_prop && (wp) != &(bp)->blk_birth)
320 
321 #ifdef _BIG_ENDIAN
322 #define	ZFS_HOST_BYTEORDER	(0ULL)
323 #else
324 #define	ZFS_HOST_BYTEORDER	(1ULL)
325 #endif
326 
327 #define	BP_SHOULD_BYTESWAP(bp)	(BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)
328 
329 #define	BP_SPRINTF_LEN	320
330 
331 #endif	/* _SYS_SPA_H */
332