1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  *  GRUB  --  GRand Unified Bootloader
4  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
5  */
6 /*
7  * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
8  */
9 
10 #ifndef ZFS_SPA_HEADER
11 #define	ZFS_SPA_HEADER 1
12 
13 
14 /*
15  * General-purpose 32-bit and 64-bit bitfield encodings.
16  */
17 #define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))
18 #define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))
19 #define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))
20 #define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))
21 
22 #define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)
23 #define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)
24 
25 #define	BF32_SET(x, low, len, val)						\
26 	((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len))
27 #define	BF64_SET(x, low, len, val)						\
28 	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len))
29 
30 #define	BF32_GET_SB(x, low, len, shift, bias)		\
31 	((BF32_GET(x, low, len) + (bias)) << (shift))
32 #define	BF64_GET_SB(x, low, len, shift, bias)		\
33 	((BF64_GET(x, low, len) + (bias)) << (shift))
34 
35 #define	BF32_SET_SB(x, low, len, shift, bias, val)		\
36 	BF32_SET(x, low, len, ((val) >> (shift)) - (bias))
37 #define	BF64_SET_SB(x, low, len, shift, bias, val)		\
38 	BF64_SET(x, low, len, ((val) >> (shift)) - (bias))
39 
40 /*
41  * We currently support nine block sizes, from 512 bytes to 128K.
42  * We could go higher, but the benefits are near-zero and the cost
43  * of COWing a giant block to modify one byte would become excessive.
44  */
45 #define	SPA_MINBLOCKSHIFT	9
46 #define	SPA_MAXBLOCKSHIFT	17
47 #define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)
48 #define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)
49 
50 #define	SPA_BLOCKSIZES		(SPA_MAXBLOCKSHIFT - SPA_MINBLOCKSHIFT + 1)
51 
52 /*
53  * Size of block to hold the configuration data (a packed nvlist)
54  */
55 #define	SPA_CONFIG_BLOCKSIZE	(1 << 14)
56 
57 /*
58  * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
59  * The ASIZE encoding should be at least 64 times larger (6 more bits)
60  * to support up to 4-way RAID-Z mirror mode with worst-case gang block
61  * overhead, three DVAs per bp, plus one more bit in case we do anything
62  * else that expands the ASIZE.
63  */
64 #define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/
65 #define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/
66 #define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/
67 
68 /*
69  * All SPA data is represented by 128-bit data virtual addresses (DVAs).
70  * The members of the dva_t should be considered opaque outside the SPA.
71  */
72 typedef struct dva {
73 	uint64_t	dva_word[2];
74 } dva_t;
75 
76 /*
77  * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
78  */
79 typedef struct zio_cksum {
80 	uint64_t	zc_word[4];
81 } zio_cksum_t;
82 
83 /*
84  * Each block is described by its DVAs, time of birth, checksum, etc.
85  * The word-by-word, bit-by-bit layout of the blkptr is as follows:
86  *
87  *	64	56	48	40	32	24	16	8	0
88  *	+-------+-------+-------+-------+-------+-------+-------+-------+
89  * 0	|		vdev1		| GRID	|	  ASIZE		|
90  *	+-------+-------+-------+-------+-------+-------+-------+-------+
91  * 1	|G|			 offset1				|
92  *	+-------+-------+-------+-------+-------+-------+-------+-------+
93  * 2	|		vdev2		| GRID	|	  ASIZE		|
94  *	+-------+-------+-------+-------+-------+-------+-------+-------+
95  * 3	|G|			 offset2				|
96  *	+-------+-------+-------+-------+-------+-------+-------+-------+
97  * 4	|		vdev3		| GRID	|	  ASIZE		|
98  *	+-------+-------+-------+-------+-------+-------+-------+-------+
99  * 5	|G|			 offset3				|
100  *	+-------+-------+-------+-------+-------+-------+-------+-------+
101  * 6	|BDX|lvl| type	| cksum | comp	|	  PSIZE	|	  LSIZE	|
102  *	+-------+-------+-------+-------+-------+-------+-------+-------+
103  * 7	|			padding					|
104  *	+-------+-------+-------+-------+-------+-------+-------+-------+
105  * 8	|			padding					|
106  *	+-------+-------+-------+-------+-------+-------+-------+-------+
107  * 9	|			physical birth txg			|
108  *	+-------+-------+-------+-------+-------+-------+-------+-------+
109  * a	|			logical birth txg			|
110  *	+-------+-------+-------+-------+-------+-------+-------+-------+
111  * b	|			fill count				|
112  *	+-------+-------+-------+-------+-------+-------+-------+-------+
113  * c	|			checksum[0]				|
114  *	+-------+-------+-------+-------+-------+-------+-------+-------+
115  * d	|			checksum[1]				|
116  *	+-------+-------+-------+-------+-------+-------+-------+-------+
117  * e	|			checksum[2]				|
118  *	+-------+-------+-------+-------+-------+-------+-------+-------+
119  * f	|			checksum[3]				|
120  *	+-------+-------+-------+-------+-------+-------+-------+-------+
121  *
122  * Legend:
123  *
124  * vdev		virtual device ID
125  * offset	offset into virtual device
126  * LSIZE	logical size
127  * PSIZE	physical size (after compression)
128  * ASIZE	allocated size (including RAID-Z parity and gang block headers)
129  * GRID		RAID-Z layout information (reserved for future use)
130  * cksum	checksum function
131  * comp		compression function
132  * G		gang block indicator
133  * B		byteorder (endianness)
134  * D		dedup
135  * X		unused
136  * lvl		level of indirection
137  * type		DMU object type
138  * phys birth	txg of block allocation; zero if same as logical birth txg
139  * log. birth	transaction group in which the block was logically born
140  * fill count	number of non-zero blocks under this bp
141  * checksum[4]	256-bit checksum of the data this bp describes
142  */
143 #define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
144 #define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
145 
146 typedef struct blkptr {
147 	dva_t		blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
148 	uint64_t	blk_prop;	/* size, compression, type, etc		*/
149 	uint64_t	blk_pad[2];	/* Extra space for the future		*/
150 	uint64_t	blk_phys_birth;	/* txg when block was allocated		*/
151 	uint64_t	blk_birth;	/* transaction group at birth		*/
152 	uint64_t	blk_fill;	/* fill count				*/
153 	zio_cksum_t	blk_cksum;	/* 256-bit checksum			*/
154 } blkptr_t;
155 
156 /*
157  * Macros to get and set fields in a bp or DVA.
158  */
159 #define	DVA_GET_ASIZE(dva)											\
160 	BF64_GET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0)
161 #define	DVA_SET_ASIZE(dva, x)										\
162 	BF64_SET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0, x)
163 
164 #define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
165 #define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
166 
167 #define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
168 #define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
169 
170 #define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
171 #define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
172 
173 #define	BP_GET_LSIZE(bp)										\
174 	BF64_GET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1)
175 #define	BP_SET_LSIZE(bp, x)										\
176 	BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x)
177 
178 #define	BP_GET_COMPRESS(bp)		BF64_GET((bp)->blk_prop, 32, 8)
179 #define	BP_SET_COMPRESS(bp, x)		BF64_SET((bp)->blk_prop, 32, 8, x)
180 
181 #define	BP_GET_CHECKSUM(bp)		BF64_GET((bp)->blk_prop, 40, 8)
182 #define	BP_SET_CHECKSUM(bp, x)		BF64_SET((bp)->blk_prop, 40, 8, x)
183 
184 #define	BP_GET_TYPE(bp)			BF64_GET((bp)->blk_prop, 48, 8)
185 #define	BP_SET_TYPE(bp, x)		BF64_SET((bp)->blk_prop, 48, 8, x)
186 
187 #define	BP_GET_LEVEL(bp)		BF64_GET((bp)->blk_prop, 56, 5)
188 #define	BP_SET_LEVEL(bp, x)		BF64_SET((bp)->blk_prop, 56, 5, x)
189 
190 #define	BP_GET_PROP_BIT_61(bp)		BF64_GET((bp)->blk_prop, 61, 1)
191 #define	BP_SET_PROP_BIT_61(bp, x)	BF64_SET((bp)->blk_prop, 61, 1, x)
192 
193 #define	BP_GET_DEDUP(bp)		BF64_GET((bp)->blk_prop, 62, 1)
194 #define	BP_SET_DEDUP(bp, x)		BF64_SET((bp)->blk_prop, 62, 1, x)
195 
196 #define	BP_GET_BYTEORDER(bp)		(0 - BF64_GET((bp)->blk_prop, 63, 1))
197 #define	BP_SET_BYTEORDER(bp, x)		BF64_SET((bp)->blk_prop, 63, 1, x)
198 
199 #define	BP_PHYSICAL_BIRTH(bp)										\
200 	((bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
201 
202 #define	BP_SET_BIRTH(bp, logical, physical)								\
203 	{																	\
204 		(bp)->blk_birth = (logical);									\
205 		(bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
206 	}
207 
208 #define	BP_GET_ASIZE(bp)												\
209 	(DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
210 	 DVA_GET_ASIZE(&(bp)->blk_dva[2]))
211 
212 #define	BP_GET_UCSIZE(bp)												\
213 	((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ?	\
214 	 BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp));
215 
216 #define	BP_GET_NDVAS(bp)						\
217 	(!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) +		\
218 	 !!DVA_GET_ASIZE(&(bp)->blk_dva[1]) +		\
219 	 !!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
220 
221 #define	BP_COUNT_GANG(bp)						\
222 	(DVA_GET_GANG(&(bp)->blk_dva[0]) +			\
223 	 DVA_GET_GANG(&(bp)->blk_dva[1]) +			\
224 	 DVA_GET_GANG(&(bp)->blk_dva[2]))
225 
226 #define	DVA_EQUAL(dva1, dva2)						\
227 	((dva1)->dva_word[1] == (dva2)->dva_word[1] &&	\
228 	 (dva1)->dva_word[0] == (dva2)->dva_word[0])
229 
230 #define	BP_EQUAL(bp1, bp2)									\
231 	(BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&	\
232 	 DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&	\
233 	 DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&	\
234 	 DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
235 
236 #define	ZIO_CHECKSUM_EQUAL(zc1, zc2)				\
237 	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) |	\
238 		   ((zc1).zc_word[1] - (zc2).zc_word[1]) |	\
239 		   ((zc1).zc_word[2] - (zc2).zc_word[2]) |	\
240 		   ((zc1).zc_word[3] - (zc2).zc_word[3])))
241 
242 #define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
243 
244 #define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
245 	{											\
246 		(zcp)->zc_word[0] = w0;					\
247 		(zcp)->zc_word[1] = w1;					\
248 		(zcp)->zc_word[2] = w2;					\
249 		(zcp)->zc_word[3] = w3;					\
250 	}
251 
252 #define	BP_IDENTITY(bp)		(&(bp)->blk_dva[0])
253 #define	BP_IS_GANG(bp)		DVA_GET_GANG(BP_IDENTITY(bp))
254 #define	BP_IS_HOLE(bp)		((bp)->blk_birth == 0)
255 
256 /* BP_IS_RAIDZ(bp) assumes no block compression */
257 #define	BP_IS_RAIDZ(bp)		(DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
258 							 BP_GET_PSIZE(bp))
259 
260 #define	BP_ZERO(bp)										\
261 	{													\
262 		(bp)->blk_dva[0].dva_word[0] = 0;				\
263 		(bp)->blk_dva[0].dva_word[1] = 0;				\
264 		(bp)->blk_dva[1].dva_word[0] = 0;				\
265 		(bp)->blk_dva[1].dva_word[1] = 0;				\
266 		(bp)->blk_dva[2].dva_word[0] = 0;				\
267 		(bp)->blk_dva[2].dva_word[1] = 0;				\
268 		(bp)->blk_prop = 0;								\
269 		(bp)->blk_pad[0] = 0;							\
270 		(bp)->blk_pad[1] = 0;							\
271 		(bp)->blk_phys_birth = 0;						\
272 		(bp)->blk_birth = 0;							\
273 		(bp)->blk_fill = 0;								\
274 		ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
275 	}
276 
277 #define	BP_SPRINTF_LEN	320
278 
279 #endif	/* ! ZFS_SPA_HEADER */
280