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.
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.
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]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
27 #include <sys/zfs_context.h>
30 #include <sys/zio_checksum.h>
32 #include <zfs_fletcher.h>
37 * In the SPA, everything is checksummed. We support checksum vectors
38 * for three distinct reasons:
40 * 1. Different kinds of data need different levels of protection.
41 * For SPA metadata, we always want a very strong checksum.
42 * For user data, we let users make the trade-off between speed
43 * and checksum strength.
45 * 2. Cryptographic hash and MAC algorithms are an area of active research.
46 * It is likely that in future hash functions will be at least as strong
47 * as current best-of-breed, and may be substantially faster as well.
48 * We want the ability to take advantage of these new hashes as soon as
49 * they become available.
51 * 3. If someone develops hardware that can compute a strong hash quickly,
52 * we want the ability to take advantage of that hardware.
54 * Of course, we don't want a checksum upgrade to invalidate existing
55 * data, so we store the checksum *function* in eight bits of the bp.
56 * This gives us room for up to 256 different checksum functions.
58 * When writing a block, we always checksum it with the latest-and-greatest
59 * checksum function of the appropriate strength. When reading a block,
60 * we compare the expected checksum against the actual checksum, which we
61 * compute via the checksum function specified by BP_GET_CHECKSUM(bp).
66 zio_checksum_off(const void *buf
, uint64_t size
, zio_cksum_t
*zcp
)
68 ZIO_SET_CHECKSUM(zcp
, 0, 0, 0, 0);
71 zio_checksum_info_t zio_checksum_table
[ZIO_CHECKSUM_FUNCTIONS
] = {
72 {{NULL
, NULL
}, 0, 0, 0, "inherit"},
73 {{NULL
, NULL
}, 0, 0, 0, "on"},
74 {{zio_checksum_off
, zio_checksum_off
}, 0, 0, 0, "off"},
75 {{zio_checksum_SHA256
, zio_checksum_SHA256
}, 1, 1, 0, "label"},
76 {{zio_checksum_SHA256
, zio_checksum_SHA256
}, 1, 1, 0, "gang_header"},
77 {{fletcher_2_native
, fletcher_2_byteswap
}, 0, 1, 0, "zilog"},
78 {{fletcher_2_native
, fletcher_2_byteswap
}, 0, 0, 0, "fletcher2"},
79 {{fletcher_4_native
, fletcher_4_byteswap
}, 1, 0, 0, "fletcher4"},
80 {{zio_checksum_SHA256
, zio_checksum_SHA256
}, 1, 0, 1, "sha256"},
81 {{fletcher_4_native
, fletcher_4_byteswap
}, 0, 1, 0, "zilog2"},
82 {{zio_checksum_off
, zio_checksum_off
}, 0, 0, 0, "noparity"},
86 zio_checksum_select(enum zio_checksum child
, enum zio_checksum parent
)
88 ASSERT(child
< ZIO_CHECKSUM_FUNCTIONS
);
89 ASSERT(parent
< ZIO_CHECKSUM_FUNCTIONS
);
90 ASSERT(parent
!= ZIO_CHECKSUM_INHERIT
&& parent
!= ZIO_CHECKSUM_ON
);
92 if (child
== ZIO_CHECKSUM_INHERIT
)
95 if (child
== ZIO_CHECKSUM_ON
)
96 return (ZIO_CHECKSUM_ON_VALUE
);
102 zio_checksum_dedup_select(spa_t
*spa
, enum zio_checksum child
,
103 enum zio_checksum parent
)
105 ASSERT((child
& ZIO_CHECKSUM_MASK
) < ZIO_CHECKSUM_FUNCTIONS
);
106 ASSERT((parent
& ZIO_CHECKSUM_MASK
) < ZIO_CHECKSUM_FUNCTIONS
);
107 ASSERT(parent
!= ZIO_CHECKSUM_INHERIT
&& parent
!= ZIO_CHECKSUM_ON
);
109 if (child
== ZIO_CHECKSUM_INHERIT
)
112 if (child
== ZIO_CHECKSUM_ON
)
113 return (spa_dedup_checksum(spa
));
115 if (child
== (ZIO_CHECKSUM_ON
| ZIO_CHECKSUM_VERIFY
))
116 return (spa_dedup_checksum(spa
) | ZIO_CHECKSUM_VERIFY
);
118 ASSERT(zio_checksum_table
[child
& ZIO_CHECKSUM_MASK
].ci_dedup
||
119 (child
& ZIO_CHECKSUM_VERIFY
) || child
== ZIO_CHECKSUM_OFF
);
125 * Set the external verifier for a gang block based on <vdev, offset, txg>,
126 * a tuple which is guaranteed to be unique for the life of the pool.
129 zio_checksum_gang_verifier(zio_cksum_t
*zcp
, blkptr_t
*bp
)
131 dva_t
*dva
= BP_IDENTITY(bp
);
132 uint64_t txg
= BP_PHYSICAL_BIRTH(bp
);
134 ASSERT(BP_IS_GANG(bp
));
136 ZIO_SET_CHECKSUM(zcp
, DVA_GET_VDEV(dva
), DVA_GET_OFFSET(dva
), txg
, 0);
140 * Set the external verifier for a label block based on its offset.
141 * The vdev is implicit, and the txg is unknowable at pool open time --
142 * hence the logic in vdev_uberblock_load() to find the most recent copy.
145 zio_checksum_label_verifier(zio_cksum_t
*zcp
, uint64_t offset
)
147 ZIO_SET_CHECKSUM(zcp
, offset
, 0, 0, 0);
151 * Generate the checksum.
154 zio_checksum_compute(zio_t
*zio
, enum zio_checksum checksum
,
155 void *data
, uint64_t size
)
157 blkptr_t
*bp
= zio
->io_bp
;
158 uint64_t offset
= zio
->io_offset
;
159 zio_checksum_info_t
*ci
= &zio_checksum_table
[checksum
];
162 ASSERT((uint_t
)checksum
< ZIO_CHECKSUM_FUNCTIONS
);
163 ASSERT(ci
->ci_func
[0] != NULL
);
168 if (checksum
== ZIO_CHECKSUM_ZILOG2
) {
169 zil_chain_t
*zilc
= data
;
171 size
= P2ROUNDUP_TYPED(zilc
->zc_nused
, ZIL_MIN_BLKSZ
,
175 eck
= (zio_eck_t
*)((char *)data
+ size
) - 1;
177 if (checksum
== ZIO_CHECKSUM_GANG_HEADER
)
178 zio_checksum_gang_verifier(&eck
->zec_cksum
, bp
);
179 else if (checksum
== ZIO_CHECKSUM_LABEL
)
180 zio_checksum_label_verifier(&eck
->zec_cksum
, offset
);
182 bp
->blk_cksum
= eck
->zec_cksum
;
183 eck
->zec_magic
= ZEC_MAGIC
;
184 ci
->ci_func
[0](data
, size
, &cksum
);
185 eck
->zec_cksum
= cksum
;
187 ci
->ci_func
[0](data
, size
, &bp
->blk_cksum
);
192 zio_checksum_error(zio_t
*zio
, zio_bad_cksum_t
*info
)
194 blkptr_t
*bp
= zio
->io_bp
;
195 uint_t checksum
= (bp
== NULL
? zio
->io_prop
.zp_checksum
:
196 (BP_IS_GANG(bp
) ? ZIO_CHECKSUM_GANG_HEADER
: BP_GET_CHECKSUM(bp
)));
199 uint64_t size
= (bp
== NULL
? zio
->io_size
:
200 (BP_IS_GANG(bp
) ? SPA_GANGBLOCKSIZE
: BP_GET_PSIZE(bp
)));
201 uint64_t offset
= zio
->io_offset
;
202 void *data
= zio
->io_data
;
203 zio_checksum_info_t
*ci
= &zio_checksum_table
[checksum
];
204 zio_cksum_t actual_cksum
, expected_cksum
, verifier
;
206 if (checksum
>= ZIO_CHECKSUM_FUNCTIONS
|| ci
->ci_func
[0] == NULL
)
207 return (SET_ERROR(EINVAL
));
212 if (checksum
== ZIO_CHECKSUM_ZILOG2
) {
213 zil_chain_t
*zilc
= data
;
217 if (eck
->zec_magic
== ZEC_MAGIC
)
218 nused
= zilc
->zc_nused
;
219 else if (eck
->zec_magic
== BSWAP_64(ZEC_MAGIC
))
220 nused
= BSWAP_64(zilc
->zc_nused
);
222 return (SET_ERROR(ECKSUM
));
225 return (SET_ERROR(ECKSUM
));
227 size
= P2ROUNDUP_TYPED(nused
, ZIL_MIN_BLKSZ
, uint64_t);
229 eck
= (zio_eck_t
*)((char *)data
+ size
) - 1;
232 if (checksum
== ZIO_CHECKSUM_GANG_HEADER
)
233 zio_checksum_gang_verifier(&verifier
, bp
);
234 else if (checksum
== ZIO_CHECKSUM_LABEL
)
235 zio_checksum_label_verifier(&verifier
, offset
);
237 verifier
= bp
->blk_cksum
;
239 byteswap
= (eck
->zec_magic
== BSWAP_64(ZEC_MAGIC
));
242 byteswap_uint64_array(&verifier
, sizeof (zio_cksum_t
));
244 expected_cksum
= eck
->zec_cksum
;
245 eck
->zec_cksum
= verifier
;
246 ci
->ci_func
[byteswap
](data
, size
, &actual_cksum
);
247 eck
->zec_cksum
= expected_cksum
;
250 byteswap_uint64_array(&expected_cksum
,
251 sizeof (zio_cksum_t
));
253 ASSERT(!BP_IS_GANG(bp
));
254 byteswap
= BP_SHOULD_BYTESWAP(bp
);
255 expected_cksum
= bp
->blk_cksum
;
256 ci
->ci_func
[byteswap
](data
, size
, &actual_cksum
);
259 info
->zbc_expected
= expected_cksum
;
260 info
->zbc_actual
= actual_cksum
;
261 info
->zbc_checksum_name
= ci
->ci_name
;
262 info
->zbc_byteswapped
= byteswap
;
263 info
->zbc_injected
= 0;
264 info
->zbc_has_cksum
= 1;
266 if (!ZIO_CHECKSUM_EQUAL(actual_cksum
, expected_cksum
))
267 return (SET_ERROR(ECKSUM
));
269 if (zio_injection_enabled
&& !zio
->io_error
&&
270 (error
= zio_handle_fault_injection(zio
, ECKSUM
)) != 0) {
272 info
->zbc_injected
= 1;