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 https://opensource.org/licenses/CDDL-1.0. 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) 2018 Intel Corporation. 23 * Copyright (c) 2020 by Lawrence Livermore National Security, LLC. 24 */ 25 26#include <sys/zfs_context.h> 27#include <sys/spa.h> 28#include <sys/spa_impl.h> 29#include <sys/vdev_impl.h> 30#include <sys/vdev_draid.h> 31#include <sys/vdev_raidz.h> 32#include <sys/vdev_rebuild.h> 33#include <sys/abd.h> 34#include <sys/zio.h> 35#include <sys/nvpair.h> 36#include <sys/zio_checksum.h> 37#include <sys/fs/zfs.h> 38#include <sys/fm/fs/zfs.h> 39#include <zfs_fletcher.h> 40 41#ifdef ZFS_DEBUG 42#include <sys/vdev.h> /* For vdev_xlate() in vdev_draid_io_verify() */ 43#endif 44 45/* 46 * dRAID is a distributed spare implementation for ZFS. A dRAID vdev is 47 * comprised of multiple raidz redundancy groups which are spread over the 48 * dRAID children. To ensure an even distribution, and avoid hot spots, a 49 * permutation mapping is applied to the order of the dRAID children. 50 * This mixing effectively distributes the parity columns evenly over all 51 * of the disks in the dRAID. 52 * 53 * This is beneficial because it means when resilvering all of the disks 54 * can participate thereby increasing the available IOPs and bandwidth. 55 * Furthermore, by reserving a small fraction of each child's total capacity 56 * virtual distributed spare disks can be created. These spares similarly 57 * benefit from the performance gains of spanning all of the children. The 58 * consequence of which is that resilvering to a distributed spare can 59 * substantially reduce the time required to restore full parity to pool 60 * with a failed disks. 61 * 62 * === dRAID group layout === 63 * 64 * First, let's define a "row" in the configuration to be a 16M chunk from 65 * each physical drive at the same offset. This is the minimum allowable 66 * size since it must be possible to store a full 16M block when there is 67 * only a single data column. Next, we define a "group" to be a set of 68 * sequential disks containing both the parity and data columns. We allow 69 * groups to span multiple rows in order to align any group size to any 70 * number of physical drives. Finally, a "slice" is comprised of the rows 71 * which contain the target number of groups. The permutation mappings 72 * are applied in a round robin fashion to each slice. 73 * 74 * Given D+P drives in a group (including parity drives) and C-S physical 75 * drives (not including the spare drives), we can distribute the groups 76 * across R rows without remainder by selecting the least common multiple 77 * of D+P and C-S as the number of groups; i.e. ngroups = LCM(D+P, C-S). 78 * 79 * In the example below, there are C=14 physical drives in the configuration 80 * with S=2 drives worth of spare capacity. Each group has a width of 9 81 * which includes D=8 data and P=1 parity drive. There are 4 groups and 82 * 3 rows per slice. Each group has a size of 144M (16M * 9) and a slice 83 * size is 576M (144M * 4). When allocating from a dRAID each group is 84 * filled before moving on to the next as show in slice0 below. 85 * 86 * data disks (8 data + 1 parity) spares (2) 87 * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ 88 * ^ | 2 | 6 | 1 | 11| 4 | 0 | 7 | 10| 8 | 9 | 13| 5 | 12| 3 | device map 0 89 * | +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ 90 * | | group 0 | group 1..| | 91 * | +-----------------------------------+-----------+-------| 92 * | | 0 1 2 3 4 5 6 7 8 | 36 37 38| | r 93 * | | 9 10 11 12 13 14 15 16 17| 45 46 47| | o 94 * | | 18 19 20 21 22 23 24 25 26| 54 55 56| | w 95 * | 27 28 29 30 31 32 33 34 35| 63 64 65| | 0 96 * s +-----------------------+-----------------------+-------+ 97 * l | ..group 1 | group 2.. | | 98 * i +-----------------------+-----------------------+-------+ 99 * c | 39 40 41 42 43 44| 72 73 74 75 76 77| | r 100 * e | 48 49 50 51 52 53| 81 82 83 84 85 86| | o 101 * 0 | 57 58 59 60 61 62| 90 91 92 93 94 95| | w 102 * | 66 67 68 69 70 71| 99 100 101 102 103 104| | 1 103 * | +-----------+-----------+-----------------------+-------+ 104 * | |..group 2 | group 3 | | 105 * | +-----------+-----------+-----------------------+-------+ 106 * | | 78 79 80|108 109 110 111 112 113 114 115 116| | r 107 * | | 87 88 89|117 118 119 120 121 122 123 124 125| | o 108 * | | 96 97 98|126 127 128 129 130 131 132 133 134| | w 109 * v |105 106 107|135 136 137 138 139 140 141 142 143| | 2 110 * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ 111 * | 9 | 11| 12| 2 | 4 | 1 | 3 | 0 | 10| 13| 8 | 5 | 6 | 7 | device map 1 112 * s +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ 113 * l | group 4 | group 5..| | row 3 114 * i +-----------------------+-----------+-----------+-------| 115 * c | ..group 5 | group 6.. | | row 4 116 * e +-----------+-----------+-----------------------+-------+ 117 * 1 |..group 6 | group 7 | | row 5 118 * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ 119 * | 3 | 5 | 10| 8 | 6 | 11| 12| 0 | 2 | 4 | 7 | 1 | 9 | 13| device map 2 120 * s +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ 121 * l | group 8 | group 9..| | row 6 122 * i +-----------------------------------------------+-------| 123 * c | ..group 9 | group 10.. | | row 7 124 * e +-----------------------+-----------------------+-------+ 125 * 2 |..group 10 | group 11 | | row 8 126 * +-----------+-----------------------------------+-------+ 127 * 128 * This layout has several advantages over requiring that each row contain 129 * a whole number of groups. 130 * 131 * 1. The group count is not a relevant parameter when defining a dRAID 132 * layout. Only the group width is needed, and *all* groups will have 133 * the desired size. 134 * 135 * 2. All possible group widths (<= physical disk count) can be supported. 136 * 137 * 3. The logic within vdev_draid.c is simplified when the group width is 138 * the same for all groups (although some of the logic around computing 139 * permutation numbers and drive offsets is more complicated). 140 * 141 * N.B. The following array describes all valid dRAID permutation maps. 142 * Each row is used to generate a permutation map for a different number 143 * of children from a unique seed. The seeds were generated and carefully 144 * evaluated by the 'draid' utility in order to provide balanced mappings. 145 * In addition to the seed a checksum of the in-memory mapping is stored 146 * for verification. 147 * 148 * The imbalance ratio of a given failure (e.g. 5 disks wide, child 3 failed, 149 * with a given permutation map) is the ratio of the amounts of I/O that will 150 * be sent to the least and most busy disks when resilvering. The average 151 * imbalance ratio (of a given number of disks and permutation map) is the 152 * average of the ratios of all possible single and double disk failures. 153 * 154 * In order to achieve a low imbalance ratio the number of permutations in 155 * the mapping must be significantly larger than the number of children. 156 * For dRAID the number of permutations has been limited to 512 to minimize 157 * the map size. This does result in a gradually increasing imbalance ratio 158 * as seen in the table below. Increasing the number of permutations for 159 * larger child counts would reduce the imbalance ratio. However, in practice 160 * when there are a large number of children each child is responsible for 161 * fewer total IOs so it's less of a concern. 162 * 163 * Note these values are hard coded and must never be changed. Existing 164 * pools depend on the same mapping always being generated in order to 165 * read and write from the correct locations. Any change would make 166 * existing pools completely inaccessible. 167 */ 168static const draid_map_t draid_maps[VDEV_DRAID_MAX_MAPS] = { 169 { 2, 256, 0x89ef3dabbcc7de37, 0x00000000433d433d }, /* 1.000 */ 170 { 3, 256, 0x89a57f3de98121b4, 0x00000000bcd8b7b5 }, /* 1.000 */ 171 { 4, 256, 0xc9ea9ec82340c885, 0x00000001819d7c69 }, /* 1.000 */ 172 { 5, 256, 0xf46733b7f4d47dfd, 0x00000002a1648d74 }, /* 1.010 */ 173 { 6, 256, 0x88c3c62d8585b362, 0x00000003d3b0c2c4 }, /* 1.031 */ 174 { 7, 256, 0x3a65d809b4d1b9d5, 0x000000055c4183ee }, /* 1.043 */ 175 { 8, 256, 0xe98930e3c5d2e90a, 0x00000006edfb0329 }, /* 1.059 */ 176 { 9, 256, 0x5a5430036b982ccb, 0x00000008ceaf6934 }, /* 1.056 */ 177 { 10, 256, 0x92bf389e9eadac74, 0x0000000b26668c09 }, /* 1.072 */ 178 { 11, 256, 0x74ccebf1dcf3ae80, 0x0000000dd691358c }, /* 1.083 */ 179 { 12, 256, 0x8847e41a1a9f5671, 0x00000010a0c63c8e }, /* 1.097 */ 180 { 13, 256, 0x7481b56debf0e637, 0x0000001424121fe4 }, /* 1.100 */ 181 { 14, 256, 0x559b8c44065f8967, 0x00000016ab2ff079 }, /* 1.121 */ 182 { 15, 256, 0x34c49545a2ee7f01, 0x0000001a6028efd6 }, /* 1.103 */ 183 { 16, 256, 0xb85f4fa81a7698f7, 0x0000001e95ff5e66 }, /* 1.111 */ 184 { 17, 256, 0x6353e47b7e47aba0, 0x00000021a81fa0fe }, /* 1.133 */ 185 { 18, 256, 0xaa549746b1cbb81c, 0x00000026f02494c9 }, /* 1.131 */ 186 { 19, 256, 0x892e343f2f31d690, 0x00000029eb392835 }, /* 1.130 */ 187 { 20, 256, 0x76914824db98cc3f, 0x0000003004f31a7c }, /* 1.141 */ 188 { 21, 256, 0x4b3cbabf9cfb1d0f, 0x00000036363a2408 }, /* 1.139 */ 189 { 22, 256, 0xf45c77abb4f035d4, 0x00000038dd0f3e84 }, /* 1.150 */ 190 { 23, 256, 0x5e18bd7f3fd4baf4, 0x0000003f0660391f }, /* 1.174 */ 191 { 24, 256, 0xa7b3a4d285d6503b, 0x000000443dfc9ff6 }, /* 1.168 */ 192 { 25, 256, 0x56ac7dd967521f5a, 0x0000004b03a87eb7 }, /* 1.180 */ 193 { 26, 256, 0x3a42dfda4eb880f7, 0x000000522c719bba }, /* 1.226 */ 194 { 27, 256, 0xd200d2fc6b54bf60, 0x0000005760b4fdf5 }, /* 1.228 */ 195 { 28, 256, 0xc52605bbd486c546, 0x0000005e00d8f74c }, /* 1.217 */ 196 { 29, 256, 0xc761779e63cd762f, 0x00000067be3cd85c }, /* 1.239 */ 197 { 30, 256, 0xca577b1e07f85ca5, 0x0000006f5517f3e4 }, /* 1.238 */ 198 { 31, 256, 0xfd50a593c518b3d4, 0x0000007370e7778f }, /* 1.273 */ 199 { 32, 512, 0xc6c87ba5b042650b, 0x000000f7eb08a156 }, /* 1.191 */ 200 { 33, 512, 0xc3880d0c9d458304, 0x0000010734b5d160 }, /* 1.199 */ 201 { 34, 512, 0xe920927e4d8b2c97, 0x00000118c1edbce0 }, /* 1.195 */ 202 { 35, 512, 0x8da7fcda87bde316, 0x0000012a3e9f9110 }, /* 1.201 */ 203 { 36, 512, 0xcf09937491514a29, 0x0000013bd6a24bef }, /* 1.194 */ 204 { 37, 512, 0x9b5abbf345cbd7cc, 0x0000014b9d90fac3 }, /* 1.237 */ 205 { 38, 512, 0x506312a44668d6a9, 0x0000015e1b5f6148 }, /* 1.242 */ 206 { 39, 512, 0x71659ede62b4755f, 0x00000173ef029bcd }, /* 1.231 */ 207 { 40, 512, 0xa7fde73fb74cf2d7, 0x000001866fb72748 }, /* 1.233 */ 208 { 41, 512, 0x19e8b461a1dea1d3, 0x000001a046f76b23 }, /* 1.271 */ 209 { 42, 512, 0x031c9b868cc3e976, 0x000001afa64c49d3 }, /* 1.263 */ 210 { 43, 512, 0xbaa5125faa781854, 0x000001c76789e278 }, /* 1.270 */ 211 { 44, 512, 0x4ed55052550d721b, 0x000001d800ccd8eb }, /* 1.281 */ 212 { 45, 512, 0x0fd63ddbdff90677, 0x000001f08ad59ed2 }, /* 1.282 */ 213 { 46, 512, 0x36d66546de7fdd6f, 0x000002016f09574b }, /* 1.286 */ 214 { 47, 512, 0x99f997e7eafb69d7, 0x0000021e42e47cb6 }, /* 1.329 */ 215 { 48, 512, 0xbecd9c2571312c5d, 0x000002320fe2872b }, /* 1.286 */ 216 { 49, 512, 0xd97371329e488a32, 0x0000024cd73f2ca7 }, /* 1.322 */ 217 { 50, 512, 0x30e9b136670749ee, 0x000002681c83b0e0 }, /* 1.335 */ 218 { 51, 512, 0x11ad6bc8f47aaeb4, 0x0000027e9261b5d5 }, /* 1.305 */ 219 { 52, 512, 0x68e445300af432c1, 0x0000029aa0eb7dbf }, /* 1.330 */ 220 { 53, 512, 0x910fb561657ea98c, 0x000002b3dca04853 }, /* 1.365 */ 221 { 54, 512, 0xd619693d8ce5e7a5, 0x000002cc280e9c97 }, /* 1.334 */ 222 { 55, 512, 0x24e281f564dbb60a, 0x000002e9fa842713 }, /* 1.364 */ 223 { 56, 512, 0x947a7d3bdaab44c5, 0x000003046680f72e }, /* 1.374 */ 224 { 57, 512, 0x2d44fec9c093e0de, 0x00000324198ba810 }, /* 1.363 */ 225 { 58, 512, 0x87743c272d29bb4c, 0x0000033ec48c9ac9 }, /* 1.401 */ 226 { 59, 512, 0x96aa3b6f67f5d923, 0x0000034faead902c }, /* 1.392 */ 227 { 60, 512, 0x94a4f1faf520b0d3, 0x0000037d713ab005 }, /* 1.360 */ 228 { 61, 512, 0xb13ed3a272f711a2, 0x00000397368f3cbd }, /* 1.396 */ 229 { 62, 512, 0x3b1b11805fa4a64a, 0x000003b8a5e2840c }, /* 1.453 */ 230 { 63, 512, 0x4c74caad9172ba71, 0x000003d4be280290 }, /* 1.437 */ 231 { 64, 512, 0x035ff643923dd29e, 0x000003fad6c355e1 }, /* 1.402 */ 232 { 65, 512, 0x768e9171b11abd3c, 0x0000040eb07fed20 }, /* 1.459 */ 233 { 66, 512, 0x75880e6f78a13ddd, 0x000004433d6acf14 }, /* 1.423 */ 234 { 67, 512, 0x910b9714f698a877, 0x00000451ea65d5db }, /* 1.447 */ 235 { 68, 512, 0x87f5db6f9fdcf5c7, 0x000004732169e3f7 }, /* 1.450 */ 236 { 69, 512, 0x836d4968fbaa3706, 0x000004954068a380 }, /* 1.455 */ 237 { 70, 512, 0xc567d73a036421ab, 0x000004bd7cb7bd3d }, /* 1.463 */ 238 { 71, 512, 0x619df40f240b8fed, 0x000004e376c2e972 }, /* 1.463 */ 239 { 72, 512, 0x42763a680d5bed8e, 0x000005084275c680 }, /* 1.452 */ 240 { 73, 512, 0x5866f064b3230431, 0x0000052906f2c9ab }, /* 1.498 */ 241 { 74, 512, 0x9fa08548b1621a44, 0x0000054708019247 }, /* 1.526 */ 242 { 75, 512, 0xb6053078ce0fc303, 0x00000572cc5c72b0 }, /* 1.491 */ 243 { 76, 512, 0x4a7aad7bf3890923, 0x0000058e987bc8e9 }, /* 1.470 */ 244 { 77, 512, 0xe165613fd75b5a53, 0x000005c20473a211 }, /* 1.527 */ 245 { 78, 512, 0x3ff154ac878163a6, 0x000005d659194bf3 }, /* 1.509 */ 246 { 79, 512, 0x24b93ade0aa8a532, 0x0000060a201c4f8e }, /* 1.569 */ 247 { 80, 512, 0xc18e2d14cd9bb554, 0x0000062c55cfe48c }, /* 1.555 */ 248 { 81, 512, 0x98cc78302feb58b6, 0x0000066656a07194 }, /* 1.509 */ 249 { 82, 512, 0xc6c5fd5a2abc0543, 0x0000067cff94fbf8 }, /* 1.596 */ 250 { 83, 512, 0xa7962f514acbba21, 0x000006ab7b5afa2e }, /* 1.568 */ 251 { 84, 512, 0xba02545069ddc6dc, 0x000006d19861364f }, /* 1.541 */ 252 { 85, 512, 0x447c73192c35073e, 0x000006fce315ce35 }, /* 1.623 */ 253 { 86, 512, 0x48beef9e2d42b0c2, 0x00000720a8e38b6b }, /* 1.620 */ 254 { 87, 512, 0x4874cf98541a35e0, 0x00000758382a2273 }, /* 1.597 */ 255 { 88, 512, 0xad4cf8333a31127a, 0x00000781e1651b1b }, /* 1.575 */ 256 { 89, 512, 0x47ae4859d57888c1, 0x000007b27edbe5bc }, /* 1.627 */ 257 { 90, 512, 0x06f7723cfe5d1891, 0x000007dc2a96d8eb }, /* 1.596 */ 258 { 91, 512, 0xd4e44218d660576d, 0x0000080ac46f02d5 }, /* 1.622 */ 259 { 92, 512, 0x7066702b0d5be1f2, 0x00000832c96d154e }, /* 1.695 */ 260 { 93, 512, 0x011209b4f9e11fb9, 0x0000085eefda104c }, /* 1.605 */ 261 { 94, 512, 0x47ffba30a0b35708, 0x00000899badc32dc }, /* 1.625 */ 262 { 95, 512, 0x1a95a6ac4538aaa8, 0x000008b6b69a42b2 }, /* 1.687 */ 263 { 96, 512, 0xbda2b239bb2008eb, 0x000008f22d2de38a }, /* 1.621 */ 264 { 97, 512, 0x7ffa0bea90355c6c, 0x0000092e5b23b816 }, /* 1.699 */ 265 { 98, 512, 0x1d56ba34be426795, 0x0000094f482e5d1b }, /* 1.688 */ 266 { 99, 512, 0x0aa89d45c502e93d, 0x00000977d94a98ce }, /* 1.642 */ 267 { 100, 512, 0x54369449f6857774, 0x000009c06c9b34cc }, /* 1.683 */ 268 { 101, 512, 0xf7d4dd8445b46765, 0x000009e5dc542259 }, /* 1.755 */ 269 { 102, 512, 0xfa8866312f169469, 0x00000a16b54eae93 }, /* 1.692 */ 270 { 103, 512, 0xd8a5aea08aef3ff9, 0x00000a381d2cbfe7 }, /* 1.747 */ 271 { 104, 512, 0x66bcd2c3d5f9ef0e, 0x00000a8191817be7 }, /* 1.751 */ 272 { 105, 512, 0x3fb13a47a012ec81, 0x00000ab562b9a254 }, /* 1.751 */ 273 { 106, 512, 0x43100f01c9e5e3ca, 0x00000aeee84c185f }, /* 1.726 */ 274 { 107, 512, 0xca09c50ccee2d054, 0x00000b1c359c047d }, /* 1.788 */ 275 { 108, 512, 0xd7176732ac503f9b, 0x00000b578bc52a73 }, /* 1.740 */ 276 { 109, 512, 0xed206e51f8d9422d, 0x00000b8083e0d960 }, /* 1.780 */ 277 { 110, 512, 0x17ead5dc6ba0dcd6, 0x00000bcfb1a32ca8 }, /* 1.836 */ 278 { 111, 512, 0x5f1dc21e38a969eb, 0x00000c0171becdd6 }, /* 1.778 */ 279 { 112, 512, 0xddaa973de33ec528, 0x00000c3edaba4b95 }, /* 1.831 */ 280 { 113, 512, 0x2a5eccd7735a3630, 0x00000c630664e7df }, /* 1.825 */ 281 { 114, 512, 0xafcccee5c0b71446, 0x00000cb65392f6e4 }, /* 1.826 */ 282 { 115, 512, 0x8fa30c5e7b147e27, 0x00000cd4db391e55 }, /* 1.843 */ 283 { 116, 512, 0x5afe0711fdfafd82, 0x00000d08cb4ec35d }, /* 1.826 */ 284 { 117, 512, 0x533a6090238afd4c, 0x00000d336f115d1b }, /* 1.803 */ 285 { 118, 512, 0x90cf11b595e39a84, 0x00000d8e041c2048 }, /* 1.857 */ 286 { 119, 512, 0x0d61a3b809444009, 0x00000dcb798afe35 }, /* 1.877 */ 287 { 120, 512, 0x7f34da0f54b0d114, 0x00000df3922664e1 }, /* 1.849 */ 288 { 121, 512, 0xa52258d5b72f6551, 0x00000e4d37a9872d }, /* 1.867 */ 289 { 122, 512, 0xc1de54d7672878db, 0x00000e6583a94cf6 }, /* 1.978 */ 290 { 123, 512, 0x1d03354316a414ab, 0x00000ebffc50308d }, /* 1.947 */ 291 { 124, 512, 0xcebdcc377665412c, 0x00000edee1997cea }, /* 1.865 */ 292 { 125, 512, 0x4ddd4c04b1a12344, 0x00000f21d64b373f }, /* 1.881 */ 293 { 126, 512, 0x64fc8f94e3973658, 0x00000f8f87a8896b }, /* 1.882 */ 294 { 127, 512, 0x68765f78034a334e, 0x00000fb8fe62197e }, /* 1.867 */ 295 { 128, 512, 0xaf36b871a303e816, 0x00000fec6f3afb1e }, /* 1.972 */ 296 { 129, 512, 0x2a4cbf73866c3a28, 0x00001027febfe4e5 }, /* 1.896 */ 297 { 130, 512, 0x9cb128aacdcd3b2f, 0x0000106aa8ac569d }, /* 1.965 */ 298 { 131, 512, 0x5511d41c55869124, 0x000010bbd755ddf1 }, /* 1.963 */ 299 { 132, 512, 0x42f92461937f284a, 0x000010fb8bceb3b5 }, /* 1.925 */ 300 { 133, 512, 0xe2d89a1cf6f1f287, 0x0000114cf5331e34 }, /* 1.862 */ 301 { 134, 512, 0xdc631a038956200e, 0x0000116428d2adc5 }, /* 2.042 */ 302 { 135, 512, 0xb2e5ac222cd236be, 0x000011ca88e4d4d2 }, /* 1.935 */ 303 { 136, 512, 0xbc7d8236655d88e7, 0x000011e39cb94e66 }, /* 2.005 */ 304 { 137, 512, 0x073e02d88d2d8e75, 0x0000123136c7933c }, /* 2.041 */ 305 { 138, 512, 0x3ddb9c3873166be0, 0x00001280e4ec6d52 }, /* 1.997 */ 306 { 139, 512, 0x7d3b1a845420e1b5, 0x000012c2e7cd6a44 }, /* 1.996 */ 307 { 140, 512, 0x60102308aa7b2a6c, 0x000012fc490e6c7d }, /* 2.053 */ 308 { 141, 512, 0xdb22bb2f9eb894aa, 0x00001343f5a85a1a }, /* 1.971 */ 309 { 142, 512, 0xd853f879a13b1606, 0x000013bb7d5f9048 }, /* 2.018 */ 310 { 143, 512, 0x001620a03f804b1d, 0x000013e74cc794fd }, /* 1.961 */ 311 { 144, 512, 0xfdb52dda76fbf667, 0x00001442d2f22480 }, /* 2.046 */ 312 { 145, 512, 0xa9160110f66e24ff, 0x0000144b899f9dbb }, /* 1.968 */ 313 { 146, 512, 0x77306a30379ae03b, 0x000014cb98eb1f81 }, /* 2.143 */ 314 { 147, 512, 0x14f5985d2752319d, 0x000014feab821fc9 }, /* 2.064 */ 315 { 148, 512, 0xa4b8ff11de7863f8, 0x0000154a0e60b9c9 }, /* 2.023 */ 316 { 149, 512, 0x44b345426455c1b3, 0x000015999c3c569c }, /* 2.136 */ 317 { 150, 512, 0x272677826049b46c, 0x000015c9697f4b92 }, /* 2.063 */ 318 { 151, 512, 0x2f9216e2cd74fe40, 0x0000162b1f7bbd39 }, /* 1.974 */ 319 { 152, 512, 0x706ae3e763ad8771, 0x00001661371c55e1 }, /* 2.210 */ 320 { 153, 512, 0xf7fd345307c2480e, 0x000016e251f28b6a }, /* 2.006 */ 321 { 154, 512, 0x6e94e3d26b3139eb, 0x000016f2429bb8c6 }, /* 2.193 */ 322 { 155, 512, 0x5458bbfbb781fcba, 0x0000173efdeca1b9 }, /* 2.163 */ 323 { 156, 512, 0xa80e2afeccd93b33, 0x000017bfdcb78adc }, /* 2.046 */ 324 { 157, 512, 0x1e4ccbb22796cf9d, 0x00001826fdcc39c9 }, /* 2.084 */ 325 { 158, 512, 0x8fba4b676aaa3663, 0x00001841a1379480 }, /* 2.264 */ 326 { 159, 512, 0xf82b843814b315fa, 0x000018886e19b8a3 }, /* 2.074 */ 327 { 160, 512, 0x7f21e920ecf753a3, 0x0000191812ca0ea7 }, /* 2.282 */ 328 { 161, 512, 0x48bb8ea2c4caa620, 0x0000192f310faccf }, /* 2.148 */ 329 { 162, 512, 0x5cdb652b4952c91b, 0x0000199e1d7437c7 }, /* 2.355 */ 330 { 163, 512, 0x6ac1ba6f78c06cd4, 0x000019cd11f82c70 }, /* 2.164 */ 331 { 164, 512, 0x9faf5f9ca2669a56, 0x00001a18d5431f6a }, /* 2.393 */ 332 { 165, 512, 0xaa57e9383eb01194, 0x00001a9e7d253d85 }, /* 2.178 */ 333 { 166, 512, 0x896967bf495c34d2, 0x00001afb8319b9fc }, /* 2.334 */ 334 { 167, 512, 0xdfad5f05de225f1b, 0x00001b3a59c3093b }, /* 2.266 */ 335 { 168, 512, 0xfd299a99f9f2abdd, 0x00001bb6f1a10799 }, /* 2.304 */ 336 { 169, 512, 0xdda239e798fe9fd4, 0x00001bfae0c9692d }, /* 2.218 */ 337 { 170, 512, 0x5fca670414a32c3e, 0x00001c22129dbcff }, /* 2.377 */ 338 { 171, 512, 0x1bb8934314b087de, 0x00001c955db36cd0 }, /* 2.155 */ 339 { 172, 512, 0xd96394b4b082200d, 0x00001cfc8619b7e6 }, /* 2.404 */ 340 { 173, 512, 0xb612a7735b1c8cbc, 0x00001d303acdd585 }, /* 2.205 */ 341 { 174, 512, 0x28e7430fe5875fe1, 0x00001d7ed5b3697d }, /* 2.359 */ 342 { 175, 512, 0x5038e89efdd981b9, 0x00001dc40ec35c59 }, /* 2.158 */ 343 { 176, 512, 0x075fd78f1d14db7c, 0x00001e31c83b4a2b }, /* 2.614 */ 344 { 177, 512, 0xc50fafdb5021be15, 0x00001e7cdac82fbc }, /* 2.239 */ 345 { 178, 512, 0xe6dc7572ce7b91c7, 0x00001edd8bb454fc }, /* 2.493 */ 346 { 179, 512, 0x21f7843e7beda537, 0x00001f3a8e019d6c }, /* 2.327 */ 347 { 180, 512, 0xc83385e20b43ec82, 0x00001f70735ec137 }, /* 2.231 */ 348 { 181, 512, 0xca818217dddb21fd, 0x0000201ca44c5a3c }, /* 2.237 */ 349 { 182, 512, 0xe6035defea48f933, 0x00002038e3346658 }, /* 2.691 */ 350 { 183, 512, 0x47262a4f953dac5a, 0x000020c2e554314e }, /* 2.170 */ 351 { 184, 512, 0xe24c7246260873ea, 0x000021197e618d64 }, /* 2.600 */ 352 { 185, 512, 0xeef6b57c9b58e9e1, 0x0000217ea48ecddc }, /* 2.391 */ 353 { 186, 512, 0x2becd3346e386142, 0x000021c496d4a5f9 }, /* 2.677 */ 354 { 187, 512, 0x63c6207bdf3b40a3, 0x0000220e0f2eec0c }, /* 2.410 */ 355 { 188, 512, 0x3056ce8989767d4b, 0x0000228eb76cd137 }, /* 2.776 */ 356 { 189, 512, 0x91af61c307cee780, 0x000022e17e2ea501 }, /* 2.266 */ 357 { 190, 512, 0xda359da225f6d54f, 0x00002358a2debc19 }, /* 2.717 */ 358 { 191, 512, 0x0a5f7a2a55607ba0, 0x0000238a79dac18c }, /* 2.474 */ 359 { 192, 512, 0x27bb75bf5224638a, 0x00002403a58e2351 }, /* 2.673 */ 360 { 193, 512, 0x1ebfdb94630f5d0f, 0x00002492a10cb339 }, /* 2.420 */ 361 { 194, 512, 0x6eae5e51d9c5f6fb, 0x000024ce4bf98715 }, /* 2.898 */ 362 { 195, 512, 0x08d903b4daedc2e0, 0x0000250d1e15886c }, /* 2.363 */ 363 { 196, 512, 0xc722a2f7fa7cd686, 0x0000258a99ed0c9e }, /* 2.747 */ 364 { 197, 512, 0x8f71faf0e54e361d, 0x000025dee11976f5 }, /* 2.531 */ 365 { 198, 512, 0x87f64695c91a54e7, 0x0000264e00a43da0 }, /* 2.707 */ 366 { 199, 512, 0xc719cbac2c336b92, 0x000026d327277ac1 }, /* 2.315 */ 367 { 200, 512, 0xe7e647afaf771ade, 0x000027523a5c44bf }, /* 3.012 */ 368 { 201, 512, 0x12d4b5c38ce8c946, 0x0000273898432545 }, /* 2.378 */ 369 { 202, 512, 0xf2e0cd4067bdc94a, 0x000027e47bb2c935 }, /* 2.969 */ 370 { 203, 512, 0x21b79f14d6d947d3, 0x0000281e64977f0d }, /* 2.594 */ 371 { 204, 512, 0x515093f952f18cd6, 0x0000289691a473fd }, /* 2.763 */ 372 { 205, 512, 0xd47b160a1b1022c8, 0x00002903e8b52411 }, /* 2.457 */ 373 { 206, 512, 0xc02fc96684715a16, 0x0000297515608601 }, /* 3.057 */ 374 { 207, 512, 0xef51e68efba72ed0, 0x000029ef73604804 }, /* 2.590 */ 375 { 208, 512, 0x9e3be6e5448b4f33, 0x00002a2846ed074b }, /* 3.047 */ 376 { 209, 512, 0x81d446c6d5fec063, 0x00002a92ca693455 }, /* 2.676 */ 377 { 210, 512, 0xff215de8224e57d5, 0x00002b2271fe3729 }, /* 2.993 */ 378 { 211, 512, 0xe2524d9ba8f69796, 0x00002b64b99c3ba2 }, /* 2.457 */ 379 { 212, 512, 0xf6b28e26097b7e4b, 0x00002bd768b6e068 }, /* 3.182 */ 380 { 213, 512, 0x893a487f30ce1644, 0x00002c67f722b4b2 }, /* 2.563 */ 381 { 214, 512, 0x386566c3fc9871df, 0x00002cc1cf8b4037 }, /* 3.025 */ 382 { 215, 512, 0x1e0ed78edf1f558a, 0x00002d3948d36c7f }, /* 2.730 */ 383 { 216, 512, 0xe3bc20c31e61f113, 0x00002d6d6b12e025 }, /* 3.036 */ 384 { 217, 512, 0xd6c3ad2e23021882, 0x00002deff7572241 }, /* 2.722 */ 385 { 218, 512, 0xb4a9f95cf0f69c5a, 0x00002e67d537aa36 }, /* 3.356 */ 386 { 219, 512, 0x6e98ed6f6c38e82f, 0x00002e9720626789 }, /* 2.697 */ 387 { 220, 512, 0x2e01edba33fddac7, 0x00002f407c6b0198 }, /* 2.979 */ 388 { 221, 512, 0x559d02e1f5f57ccc, 0x00002fb6a5ab4f24 }, /* 2.858 */ 389 { 222, 512, 0xac18f5a916adcd8e, 0x0000304ae1c5c57e }, /* 3.258 */ 390 { 223, 512, 0x15789fbaddb86f4b, 0x0000306f6e019c78 }, /* 2.693 */ 391 { 224, 512, 0xf4a9c36d5bc4c408, 0x000030da40434213 }, /* 3.259 */ 392 { 225, 512, 0xf640f90fd2727f44, 0x00003189ed37b90c }, /* 2.733 */ 393 { 226, 512, 0xb5313d390d61884a, 0x000031e152616b37 }, /* 3.235 */ 394 { 227, 512, 0x4bae6b3ce9160939, 0x0000321f40aeac42 }, /* 2.983 */ 395 { 228, 512, 0x838c34480f1a66a1, 0x000032f389c0f78e }, /* 3.308 */ 396 { 229, 512, 0xb1c4a52c8e3d6060, 0x0000330062a40284 }, /* 2.715 */ 397 { 230, 512, 0xe0f1110c6d0ed822, 0x0000338be435644f }, /* 3.540 */ 398 { 231, 512, 0x9f1a8ccdcea68d4b, 0x000034045a4e97e1 }, /* 2.779 */ 399 { 232, 512, 0x3261ed62223f3099, 0x000034702cfc401c }, /* 3.084 */ 400 { 233, 512, 0xf2191e2311022d65, 0x00003509dd19c9fc }, /* 2.987 */ 401 { 234, 512, 0xf102a395c2033abc, 0x000035654dc96fae }, /* 3.341 */ 402 { 235, 512, 0x11fe378f027906b6, 0x000035b5193b0264 }, /* 2.793 */ 403 { 236, 512, 0xf777f2c026b337aa, 0x000036704f5d9297 }, /* 3.518 */ 404 { 237, 512, 0x1b04e9c2ee143f32, 0x000036dfbb7af218 }, /* 2.962 */ 405 { 238, 512, 0x2fcec95266f9352c, 0x00003785c8df24a9 }, /* 3.196 */ 406 { 239, 512, 0xfe2b0e47e427dd85, 0x000037cbdf5da729 }, /* 2.914 */ 407 { 240, 512, 0x72b49bf2225f6c6d, 0x0000382227c15855 }, /* 3.408 */ 408 { 241, 512, 0x50486b43df7df9c7, 0x0000389b88be6453 }, /* 2.903 */ 409 { 242, 512, 0x5192a3e53181c8ab, 0x000038ddf3d67263 }, /* 3.778 */ 410 { 243, 512, 0xe9f5d8365296fd5e, 0x0000399f1c6c9e9c }, /* 3.026 */ 411 { 244, 512, 0xc740263f0301efa8, 0x00003a147146512d }, /* 3.347 */ 412 { 245, 512, 0x23cd0f2b5671e67d, 0x00003ab10bcc0d9d }, /* 3.212 */ 413 { 246, 512, 0x002ccc7e5cd41390, 0x00003ad6cd14a6c0 }, /* 3.482 */ 414 { 247, 512, 0x9aafb3c02544b31b, 0x00003b8cb8779fb0 }, /* 3.146 */ 415 { 248, 512, 0x72ba07a78b121999, 0x00003c24142a5a3f }, /* 3.626 */ 416 { 249, 512, 0x3d784aa58edfc7b4, 0x00003cd084817d99 }, /* 2.952 */ 417 { 250, 512, 0xaab750424d8004af, 0x00003d506a8e098e }, /* 3.463 */ 418 { 251, 512, 0x84403fcf8e6b5ca2, 0x00003d4c54c2aec4 }, /* 3.131 */ 419 { 252, 512, 0x71eb7455ec98e207, 0x00003e655715cf2c }, /* 3.538 */ 420 { 253, 512, 0xd752b4f19301595b, 0x00003ecd7b2ca5ac }, /* 2.974 */ 421 { 254, 512, 0xc4674129750499de, 0x00003e99e86d3e95 }, /* 3.843 */ 422 { 255, 512, 0x9772baff5cd12ef5, 0x00003f895c019841 }, /* 3.088 */ 423}; 424 425/* 426 * Verify the map is valid. Each device index must appear exactly 427 * once in every row, and the permutation array checksum must match. 428 */ 429static int 430verify_perms(uint8_t *perms, uint64_t children, uint64_t nperms, 431 uint64_t checksum) 432{ 433 int countssz = sizeof (uint16_t) * children; 434 uint16_t *counts = kmem_zalloc(countssz, KM_SLEEP); 435 436 for (int i = 0; i < nperms; i++) { 437 for (int j = 0; j < children; j++) { 438 uint8_t val = perms[(i * children) + j]; 439 440 if (val >= children || counts[val] != i) { 441 kmem_free(counts, countssz); 442 return (EINVAL); 443 } 444 445 counts[val]++; 446 } 447 } 448 449 if (checksum != 0) { 450 int permssz = sizeof (uint8_t) * children * nperms; 451 zio_cksum_t cksum; 452 453 fletcher_4_native_varsize(perms, permssz, &cksum); 454 455 if (checksum != cksum.zc_word[0]) { 456 kmem_free(counts, countssz); 457 return (ECKSUM); 458 } 459 } 460 461 kmem_free(counts, countssz); 462 463 return (0); 464} 465 466/* 467 * Generate the permutation array for the draid_map_t. These maps control 468 * the placement of all data in a dRAID. Therefore it's critical that the 469 * seed always generates the same mapping. We provide our own pseudo-random 470 * number generator for this purpose. 471 */ 472int 473vdev_draid_generate_perms(const draid_map_t *map, uint8_t **permsp) 474{ 475 VERIFY3U(map->dm_children, >=, VDEV_DRAID_MIN_CHILDREN); 476 VERIFY3U(map->dm_children, <=, VDEV_DRAID_MAX_CHILDREN); 477 VERIFY3U(map->dm_seed, !=, 0); 478 VERIFY3U(map->dm_nperms, !=, 0); 479 VERIFY3P(map->dm_perms, ==, NULL); 480 481#ifdef _KERNEL 482 /* 483 * The kernel code always provides both a map_seed and checksum. 484 * Only the tests/zfs-tests/cmd/draid/draid.c utility will provide 485 * a zero checksum when generating new candidate maps. 486 */ 487 VERIFY3U(map->dm_checksum, !=, 0); 488#endif 489 uint64_t children = map->dm_children; 490 uint64_t nperms = map->dm_nperms; 491 int rowsz = sizeof (uint8_t) * children; 492 int permssz = rowsz * nperms; 493 uint8_t *perms; 494 495 /* Allocate the permutation array */ 496 perms = vmem_alloc(permssz, KM_SLEEP); 497 498 /* Setup an initial row with a known pattern */ 499 uint8_t *initial_row = kmem_alloc(rowsz, KM_SLEEP); 500 for (int i = 0; i < children; i++) 501 initial_row[i] = i; 502 503 uint64_t draid_seed[2] = { VDEV_DRAID_SEED, map->dm_seed }; 504 uint8_t *current_row, *previous_row = initial_row; 505 506 /* 507 * Perform a Fisher-Yates shuffle of each row using the previous 508 * row as the starting point. An initial_row with known pattern 509 * is used as the input for the first row. 510 */ 511 for (int i = 0; i < nperms; i++) { 512 current_row = &perms[i * children]; 513 memcpy(current_row, previous_row, rowsz); 514 515 for (int j = children - 1; j > 0; j--) { 516 uint64_t k = vdev_draid_rand(draid_seed) % (j + 1); 517 uint8_t val = current_row[j]; 518 current_row[j] = current_row[k]; 519 current_row[k] = val; 520 } 521 522 previous_row = current_row; 523 } 524 525 kmem_free(initial_row, rowsz); 526 527 int error = verify_perms(perms, children, nperms, map->dm_checksum); 528 if (error) { 529 vmem_free(perms, permssz); 530 return (error); 531 } 532 533 *permsp = perms; 534 535 return (0); 536} 537 538/* 539 * Lookup the fixed draid_map_t for the requested number of children. 540 */ 541int 542vdev_draid_lookup_map(uint64_t children, const draid_map_t **mapp) 543{ 544 for (int i = 0; i < VDEV_DRAID_MAX_MAPS; i++) { 545 if (draid_maps[i].dm_children == children) { 546 *mapp = &draid_maps[i]; 547 return (0); 548 } 549 } 550 551 return (ENOENT); 552} 553 554/* 555 * Lookup the permutation array and iteration id for the provided offset. 556 */ 557static void 558vdev_draid_get_perm(vdev_draid_config_t *vdc, uint64_t pindex, 559 uint8_t **base, uint64_t *iter) 560{ 561 uint64_t ncols = vdc->vdc_children; 562 uint64_t poff = pindex % (vdc->vdc_nperms * ncols); 563 564 *base = vdc->vdc_perms + (poff / ncols) * ncols; 565 *iter = poff % ncols; 566} 567 568static inline uint64_t 569vdev_draid_permute_id(vdev_draid_config_t *vdc, 570 uint8_t *base, uint64_t iter, uint64_t index) 571{ 572 return ((base[index] + iter) % vdc->vdc_children); 573} 574 575/* 576 * Return the asize which is the psize rounded up to a full group width. 577 * i.e. vdev_draid_psize_to_asize(). 578 */ 579static uint64_t 580vdev_draid_asize(vdev_t *vd, uint64_t psize, uint64_t txg) 581{ 582 (void) txg; 583 vdev_draid_config_t *vdc = vd->vdev_tsd; 584 uint64_t ashift = vd->vdev_ashift; 585 586 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 587 588 uint64_t rows = ((psize - 1) / (vdc->vdc_ndata << ashift)) + 1; 589 uint64_t asize = (rows * vdc->vdc_groupwidth) << ashift; 590 591 ASSERT3U(asize, !=, 0); 592 ASSERT3U(asize % (vdc->vdc_groupwidth), ==, 0); 593 594 return (asize); 595} 596 597/* 598 * Deflate the asize to the psize, this includes stripping parity. 599 */ 600uint64_t 601vdev_draid_asize_to_psize(vdev_t *vd, uint64_t asize) 602{ 603 vdev_draid_config_t *vdc = vd->vdev_tsd; 604 605 ASSERT0(asize % vdc->vdc_groupwidth); 606 607 return ((asize / vdc->vdc_groupwidth) * vdc->vdc_ndata); 608} 609 610/* 611 * Convert a logical offset to the corresponding group number. 612 */ 613static uint64_t 614vdev_draid_offset_to_group(vdev_t *vd, uint64_t offset) 615{ 616 vdev_draid_config_t *vdc = vd->vdev_tsd; 617 618 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 619 620 return (offset / vdc->vdc_groupsz); 621} 622 623/* 624 * Convert a group number to the logical starting offset for that group. 625 */ 626static uint64_t 627vdev_draid_group_to_offset(vdev_t *vd, uint64_t group) 628{ 629 vdev_draid_config_t *vdc = vd->vdev_tsd; 630 631 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 632 633 return (group * vdc->vdc_groupsz); 634} 635 636/* 637 * Full stripe writes. When writing, all columns (D+P) are required. Parity 638 * is calculated over all the columns, including empty zero filled sectors, 639 * and each is written to disk. While only the data columns are needed for 640 * a normal read, all of the columns are required for reconstruction when 641 * performing a sequential resilver. 642 * 643 * For "big columns" it's sufficient to map the correct range of the zio ABD. 644 * Partial columns require allocating a gang ABD in order to zero fill the 645 * empty sectors. When the column is empty a zero filled sector must be 646 * mapped. In all cases the data ABDs must be the same size as the parity 647 * ABDs (e.g. rc->rc_size == parity_size). 648 */ 649static void 650vdev_draid_map_alloc_write(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) 651{ 652 uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; 653 uint64_t parity_size = rr->rr_col[0].rc_size; 654 uint64_t abd_off = abd_offset; 655 656 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 657 ASSERT3U(parity_size, ==, abd_get_size(rr->rr_col[0].rc_abd)); 658 659 for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { 660 raidz_col_t *rc = &rr->rr_col[c]; 661 662 if (rc->rc_size == 0) { 663 /* empty data column (small write), add a skip sector */ 664 ASSERT3U(skip_size, ==, parity_size); 665 rc->rc_abd = abd_get_zeros(skip_size); 666 } else if (rc->rc_size == parity_size) { 667 /* this is a "big column" */ 668 rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct, 669 zio->io_abd, abd_off, rc->rc_size); 670 } else { 671 /* short data column, add a skip sector */ 672 ASSERT3U(rc->rc_size + skip_size, ==, parity_size); 673 rc->rc_abd = abd_alloc_gang(); 674 abd_gang_add(rc->rc_abd, abd_get_offset_size( 675 zio->io_abd, abd_off, rc->rc_size), B_TRUE); 676 abd_gang_add(rc->rc_abd, abd_get_zeros(skip_size), 677 B_TRUE); 678 } 679 680 ASSERT3U(abd_get_size(rc->rc_abd), ==, parity_size); 681 682 abd_off += rc->rc_size; 683 rc->rc_size = parity_size; 684 } 685 686 IMPLY(abd_offset != 0, abd_off == zio->io_size); 687} 688 689/* 690 * Scrub/resilver reads. In order to store the contents of the skip sectors 691 * an additional ABD is allocated. The columns are handled in the same way 692 * as a full stripe write except instead of using the zero ABD the newly 693 * allocated skip ABD is used to back the skip sectors. In all cases the 694 * data ABD must be the same size as the parity ABDs. 695 */ 696static void 697vdev_draid_map_alloc_scrub(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) 698{ 699 uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; 700 uint64_t parity_size = rr->rr_col[0].rc_size; 701 uint64_t abd_off = abd_offset; 702 uint64_t skip_off = 0; 703 704 ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); 705 ASSERT3P(rr->rr_abd_empty, ==, NULL); 706 707 if (rr->rr_nempty > 0) { 708 rr->rr_abd_empty = abd_alloc_linear(rr->rr_nempty * skip_size, 709 B_FALSE); 710 } 711 712 for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { 713 raidz_col_t *rc = &rr->rr_col[c]; 714 715 if (rc->rc_size == 0) { 716 /* empty data column (small read), add a skip sector */ 717 ASSERT3U(skip_size, ==, parity_size); 718 ASSERT3U(rr->rr_nempty, !=, 0); 719 rc->rc_abd = abd_get_offset_size(rr->rr_abd_empty, 720 skip_off, skip_size); 721 skip_off += skip_size; 722 } else if (rc->rc_size == parity_size) { 723 /* this is a "big column" */ 724 rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct, 725 zio->io_abd, abd_off, rc->rc_size); 726 } else { 727 /* short data column, add a skip sector */ 728 ASSERT3U(rc->rc_size + skip_size, ==, parity_size); 729 ASSERT3U(rr->rr_nempty, !=, 0); 730 rc->rc_abd = abd_alloc_gang(); 731 abd_gang_add(rc->rc_abd, abd_get_offset_size( 732 zio->io_abd, abd_off, rc->rc_size), B_TRUE); 733 abd_gang_add(rc->rc_abd, abd_get_offset_size( 734 rr->rr_abd_empty, skip_off, skip_size), B_TRUE); 735 skip_off += skip_size; 736 } 737 738 uint64_t abd_size = abd_get_size(rc->rc_abd); 739 ASSERT3U(abd_size, ==, abd_get_size(rr->rr_col[0].rc_abd)); 740 741 /* 742 * Increase rc_size so the skip ABD is included in subsequent 743 * parity calculations. 744 */ 745 abd_off += rc->rc_size; 746 rc->rc_size = abd_size; 747 } 748 749 IMPLY(abd_offset != 0, abd_off == zio->io_size); 750 ASSERT3U(skip_off, ==, rr->rr_nempty * skip_size); 751} 752 753/* 754 * Normal reads. In this common case only the columns containing data 755 * are read in to the zio ABDs. Neither the parity columns or empty skip 756 * sectors are read unless the checksum fails verification. In which case 757 * vdev_raidz_read_all() will call vdev_draid_map_alloc_empty() to expand 758 * the raid map in order to allow reconstruction using the parity data and 759 * skip sectors. 760 */ 761static void 762vdev_draid_map_alloc_read(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) 763{ 764 uint64_t abd_off = abd_offset; 765 766 ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); 767 768 for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { 769 raidz_col_t *rc = &rr->rr_col[c]; 770 771 if (rc->rc_size > 0) { 772 rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct, 773 zio->io_abd, abd_off, rc->rc_size); 774 abd_off += rc->rc_size; 775 } 776 } 777 778 IMPLY(abd_offset != 0, abd_off == zio->io_size); 779} 780 781/* 782 * Converts a normal "read" raidz_row_t to a "scrub" raidz_row_t. The key 783 * difference is that an ABD is allocated to back skip sectors so they may 784 * be read in to memory, verified, and repaired if needed. 785 */ 786void 787vdev_draid_map_alloc_empty(zio_t *zio, raidz_row_t *rr) 788{ 789 uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; 790 uint64_t parity_size = rr->rr_col[0].rc_size; 791 uint64_t skip_off = 0; 792 793 ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); 794 ASSERT3P(rr->rr_abd_empty, ==, NULL); 795 796 if (rr->rr_nempty > 0) { 797 rr->rr_abd_empty = abd_alloc_linear(rr->rr_nempty * skip_size, 798 B_FALSE); 799 } 800 801 for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { 802 raidz_col_t *rc = &rr->rr_col[c]; 803 804 if (rc->rc_size == 0) { 805 /* empty data column (small read), add a skip sector */ 806 ASSERT3U(skip_size, ==, parity_size); 807 ASSERT3U(rr->rr_nempty, !=, 0); 808 ASSERT3P(rc->rc_abd, ==, NULL); 809 rc->rc_abd = abd_get_offset_size(rr->rr_abd_empty, 810 skip_off, skip_size); 811 skip_off += skip_size; 812 } else if (rc->rc_size == parity_size) { 813 /* this is a "big column", nothing to add */ 814 ASSERT3P(rc->rc_abd, !=, NULL); 815 } else { 816 /* 817 * short data column, add a skip sector and clear 818 * rc_tried to force the entire column to be re-read 819 * thereby including the missing skip sector data 820 * which is needed for reconstruction. 821 */ 822 ASSERT3U(rc->rc_size + skip_size, ==, parity_size); 823 ASSERT3U(rr->rr_nempty, !=, 0); 824 ASSERT3P(rc->rc_abd, !=, NULL); 825 ASSERT(!abd_is_gang(rc->rc_abd)); 826 abd_t *read_abd = rc->rc_abd; 827 rc->rc_abd = abd_alloc_gang(); 828 abd_gang_add(rc->rc_abd, read_abd, B_TRUE); 829 abd_gang_add(rc->rc_abd, abd_get_offset_size( 830 rr->rr_abd_empty, skip_off, skip_size), B_TRUE); 831 skip_off += skip_size; 832 rc->rc_tried = 0; 833 } 834 835 /* 836 * Increase rc_size so the empty ABD is included in subsequent 837 * parity calculations. 838 */ 839 rc->rc_size = parity_size; 840 } 841 842 ASSERT3U(skip_off, ==, rr->rr_nempty * skip_size); 843} 844 845/* 846 * Verify that all empty sectors are zero filled before using them to 847 * calculate parity. Otherwise, silent corruption in an empty sector will 848 * result in bad parity being generated. That bad parity will then be 849 * considered authoritative and overwrite the good parity on disk. This 850 * is possible because the checksum is only calculated over the data, 851 * thus it cannot be used to detect damage in empty sectors. 852 */ 853int 854vdev_draid_map_verify_empty(zio_t *zio, raidz_row_t *rr) 855{ 856 uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; 857 uint64_t parity_size = rr->rr_col[0].rc_size; 858 uint64_t skip_off = parity_size - skip_size; 859 uint64_t empty_off = 0; 860 int ret = 0; 861 862 ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); 863 ASSERT3P(rr->rr_abd_empty, !=, NULL); 864 ASSERT3U(rr->rr_bigcols, >, 0); 865 866 void *zero_buf = kmem_zalloc(skip_size, KM_SLEEP); 867 868 for (int c = rr->rr_bigcols; c < rr->rr_cols; c++) { 869 raidz_col_t *rc = &rr->rr_col[c]; 870 871 ASSERT3P(rc->rc_abd, !=, NULL); 872 ASSERT3U(rc->rc_size, ==, parity_size); 873 874 if (abd_cmp_buf_off(rc->rc_abd, zero_buf, skip_off, 875 skip_size) != 0) { 876 vdev_raidz_checksum_error(zio, rc, rc->rc_abd); 877 abd_zero_off(rc->rc_abd, skip_off, skip_size); 878 rc->rc_error = SET_ERROR(ECKSUM); 879 ret++; 880 } 881 882 empty_off += skip_size; 883 } 884 885 ASSERT3U(empty_off, ==, abd_get_size(rr->rr_abd_empty)); 886 887 kmem_free(zero_buf, skip_size); 888 889 return (ret); 890} 891 892/* 893 * Given a logical address within a dRAID configuration, return the physical 894 * address on the first drive in the group that this address maps to 895 * (at position 'start' in permutation number 'perm'). 896 */ 897static uint64_t 898vdev_draid_logical_to_physical(vdev_t *vd, uint64_t logical_offset, 899 uint64_t *perm, uint64_t *start) 900{ 901 vdev_draid_config_t *vdc = vd->vdev_tsd; 902 903 /* b is the dRAID (parent) sector offset. */ 904 uint64_t ashift = vd->vdev_top->vdev_ashift; 905 uint64_t b_offset = logical_offset >> ashift; 906 907 /* 908 * The height of a row in units of the vdev's minimum sector size. 909 * This is the amount of data written to each disk of each group 910 * in a given permutation. 911 */ 912 uint64_t rowheight_sectors = VDEV_DRAID_ROWHEIGHT >> ashift; 913 914 /* 915 * We cycle through a disk permutation every groupsz * ngroups chunk 916 * of address space. Note that ngroups * groupsz must be a multiple 917 * of the number of data drives (ndisks) in order to guarantee 918 * alignment. So, for example, if our row height is 16MB, our group 919 * size is 10, and there are 13 data drives in the draid, then ngroups 920 * will be 13, we will change permutation every 2.08GB and each 921 * disk will have 160MB of data per chunk. 922 */ 923 uint64_t groupwidth = vdc->vdc_groupwidth; 924 uint64_t ngroups = vdc->vdc_ngroups; 925 uint64_t ndisks = vdc->vdc_ndisks; 926 927 /* 928 * groupstart is where the group this IO will land in "starts" in 929 * the permutation array. 930 */ 931 uint64_t group = logical_offset / vdc->vdc_groupsz; 932 uint64_t groupstart = (group * groupwidth) % ndisks; 933 ASSERT3U(groupstart + groupwidth, <=, ndisks + groupstart); 934 *start = groupstart; 935 936 /* b_offset is the sector offset within a group chunk */ 937 b_offset = b_offset % (rowheight_sectors * groupwidth); 938 ASSERT0(b_offset % groupwidth); 939 940 /* 941 * Find the starting byte offset on each child vdev: 942 * - within a permutation there are ngroups groups spread over the 943 * rows, where each row covers a slice portion of the disk 944 * - each permutation has (groupwidth * ngroups) / ndisks rows 945 * - so each permutation covers rows * slice portion of the disk 946 * - so we need to find the row where this IO group target begins 947 */ 948 *perm = group / ngroups; 949 uint64_t row = (*perm * ((groupwidth * ngroups) / ndisks)) + 950 (((group % ngroups) * groupwidth) / ndisks); 951 952 return (((rowheight_sectors * row) + 953 (b_offset / groupwidth)) << ashift); 954} 955 956static uint64_t 957vdev_draid_map_alloc_row(zio_t *zio, raidz_row_t **rrp, uint64_t io_offset, 958 uint64_t abd_offset, uint64_t abd_size) 959{ 960 vdev_t *vd = zio->io_vd; 961 vdev_draid_config_t *vdc = vd->vdev_tsd; 962 uint64_t ashift = vd->vdev_top->vdev_ashift; 963 uint64_t io_size = abd_size; 964 uint64_t io_asize = vdev_draid_asize(vd, io_size, 0); 965 uint64_t group = vdev_draid_offset_to_group(vd, io_offset); 966 uint64_t start_offset = vdev_draid_group_to_offset(vd, group + 1); 967 968 /* 969 * Limit the io_size to the space remaining in the group. A second 970 * row in the raidz_map_t is created for the remainder. 971 */ 972 if (io_offset + io_asize > start_offset) { 973 io_size = vdev_draid_asize_to_psize(vd, 974 start_offset - io_offset); 975 } 976 977 /* 978 * At most a block may span the logical end of one group and the start 979 * of the next group. Therefore, at the end of a group the io_size must 980 * span the group width evenly and the remainder must be aligned to the 981 * start of the next group. 982 */ 983 IMPLY(abd_offset == 0 && io_size < zio->io_size, 984 (io_asize >> ashift) % vdc->vdc_groupwidth == 0); 985 IMPLY(abd_offset != 0, 986 vdev_draid_group_to_offset(vd, group) == io_offset); 987 988 /* Lookup starting byte offset on each child vdev */ 989 uint64_t groupstart, perm; 990 uint64_t physical_offset = vdev_draid_logical_to_physical(vd, 991 io_offset, &perm, &groupstart); 992 993 /* 994 * If there is less than groupwidth drives available after the group 995 * start, the group is going to wrap onto the next row. 'wrap' is the 996 * group disk number that starts on the next row. 997 */ 998 uint64_t ndisks = vdc->vdc_ndisks; 999 uint64_t groupwidth = vdc->vdc_groupwidth; 1000 uint64_t wrap = groupwidth; 1001 1002 if (groupstart + groupwidth > ndisks) 1003 wrap = ndisks - groupstart; 1004 1005 /* The io size in units of the vdev's minimum sector size. */ 1006 const uint64_t psize = io_size >> ashift; 1007 1008 /* 1009 * "Quotient": The number of data sectors for this stripe on all but 1010 * the "big column" child vdevs that also contain "remainder" data. 1011 */ 1012 uint64_t q = psize / vdc->vdc_ndata; 1013 1014 /* 1015 * "Remainder": The number of partial stripe data sectors in this I/O. 1016 * This will add a sector to some, but not all, child vdevs. 1017 */ 1018 uint64_t r = psize - q * vdc->vdc_ndata; 1019 1020 /* The number of "big columns" - those which contain remainder data. */ 1021 uint64_t bc = (r == 0 ? 0 : r + vdc->vdc_nparity); 1022 ASSERT3U(bc, <, groupwidth); 1023 1024 /* The total number of data and parity sectors for this I/O. */ 1025 uint64_t tot = psize + (vdc->vdc_nparity * (q + (r == 0 ? 0 : 1))); 1026 1027 ASSERT3U(vdc->vdc_nparity, >, 0); 1028 1029 raidz_row_t *rr = vdev_raidz_row_alloc(groupwidth); 1030 rr->rr_bigcols = bc; 1031 rr->rr_firstdatacol = vdc->vdc_nparity; 1032#ifdef ZFS_DEBUG 1033 rr->rr_offset = io_offset; 1034 rr->rr_size = io_size; 1035#endif 1036 *rrp = rr; 1037 1038 uint8_t *base; 1039 uint64_t iter, asize = 0; 1040 vdev_draid_get_perm(vdc, perm, &base, &iter); 1041 for (uint64_t i = 0; i < groupwidth; i++) { 1042 raidz_col_t *rc = &rr->rr_col[i]; 1043 uint64_t c = (groupstart + i) % ndisks; 1044 1045 /* increment the offset if we wrap to the next row */ 1046 if (i == wrap) 1047 physical_offset += VDEV_DRAID_ROWHEIGHT; 1048 1049 rc->rc_devidx = vdev_draid_permute_id(vdc, base, iter, c); 1050 rc->rc_offset = physical_offset; 1051 1052 if (q == 0 && i >= bc) 1053 rc->rc_size = 0; 1054 else if (i < bc) 1055 rc->rc_size = (q + 1) << ashift; 1056 else 1057 rc->rc_size = q << ashift; 1058 1059 asize += rc->rc_size; 1060 } 1061 1062 ASSERT3U(asize, ==, tot << ashift); 1063 rr->rr_nempty = roundup(tot, groupwidth) - tot; 1064 IMPLY(bc > 0, rr->rr_nempty == groupwidth - bc); 1065 1066 /* Allocate buffers for the parity columns */ 1067 for (uint64_t c = 0; c < rr->rr_firstdatacol; c++) { 1068 raidz_col_t *rc = &rr->rr_col[c]; 1069 rc->rc_abd = abd_alloc_linear(rc->rc_size, B_FALSE); 1070 } 1071 1072 /* 1073 * Map buffers for data columns and allocate/map buffers for skip 1074 * sectors. There are three distinct cases for dRAID which are 1075 * required to support sequential rebuild. 1076 */ 1077 if (zio->io_type == ZIO_TYPE_WRITE) { 1078 vdev_draid_map_alloc_write(zio, abd_offset, rr); 1079 } else if ((rr->rr_nempty > 0) && 1080 (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { 1081 vdev_draid_map_alloc_scrub(zio, abd_offset, rr); 1082 } else { 1083 ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); 1084 vdev_draid_map_alloc_read(zio, abd_offset, rr); 1085 } 1086 1087 return (io_size); 1088} 1089 1090/* 1091 * Allocate the raidz mapping to be applied to the dRAID I/O. The parity 1092 * calculations for dRAID are identical to raidz however there are a few 1093 * differences in the layout. 1094 * 1095 * - dRAID always allocates a full stripe width. Any extra sectors due 1096 * this padding are zero filled and written to disk. They will be read 1097 * back during a scrub or repair operation since they are included in 1098 * the parity calculation. This property enables sequential resilvering. 1099 * 1100 * - When the block at the logical offset spans redundancy groups then two 1101 * rows are allocated in the raidz_map_t. One row resides at the end of 1102 * the first group and the other at the start of the following group. 1103 */ 1104static raidz_map_t * 1105vdev_draid_map_alloc(zio_t *zio) 1106{ 1107 raidz_row_t *rr[2]; 1108 uint64_t abd_offset = 0; 1109 uint64_t abd_size = zio->io_size; 1110 uint64_t io_offset = zio->io_offset; 1111 uint64_t size; 1112 int nrows = 1; 1113 1114 size = vdev_draid_map_alloc_row(zio, &rr[0], io_offset, 1115 abd_offset, abd_size); 1116 if (size < abd_size) { 1117 vdev_t *vd = zio->io_vd; 1118 1119 io_offset += vdev_draid_asize(vd, size, 0); 1120 abd_offset += size; 1121 abd_size -= size; 1122 nrows++; 1123 1124 ASSERT3U(io_offset, ==, vdev_draid_group_to_offset( 1125 vd, vdev_draid_offset_to_group(vd, io_offset))); 1126 ASSERT3U(abd_offset, <, zio->io_size); 1127 ASSERT3U(abd_size, !=, 0); 1128 1129 size = vdev_draid_map_alloc_row(zio, &rr[1], 1130 io_offset, abd_offset, abd_size); 1131 VERIFY3U(size, ==, abd_size); 1132 } 1133 1134 raidz_map_t *rm; 1135 rm = kmem_zalloc(offsetof(raidz_map_t, rm_row[nrows]), KM_SLEEP); 1136 rm->rm_ops = vdev_raidz_math_get_ops(); 1137 rm->rm_nrows = nrows; 1138 rm->rm_row[0] = rr[0]; 1139 if (nrows == 2) 1140 rm->rm_row[1] = rr[1]; 1141 return (rm); 1142} 1143 1144/* 1145 * Given an offset into a dRAID return the next group width aligned offset 1146 * which can be used to start an allocation. 1147 */ 1148static uint64_t 1149vdev_draid_get_astart(vdev_t *vd, const uint64_t start) 1150{ 1151 vdev_draid_config_t *vdc = vd->vdev_tsd; 1152 1153 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1154 1155 return (roundup(start, vdc->vdc_groupwidth << vd->vdev_ashift)); 1156} 1157 1158/* 1159 * Allocatable space for dRAID is (children - nspares) * sizeof(smallest child) 1160 * rounded down to the last full slice. So each child must provide at least 1161 * 1 / (children - nspares) of its asize. 1162 */ 1163static uint64_t 1164vdev_draid_min_asize(vdev_t *vd) 1165{ 1166 vdev_draid_config_t *vdc = vd->vdev_tsd; 1167 1168 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1169 1170 return (VDEV_DRAID_REFLOW_RESERVE + 1171 (vd->vdev_min_asize + vdc->vdc_ndisks - 1) / (vdc->vdc_ndisks)); 1172} 1173 1174/* 1175 * When using dRAID the minimum allocation size is determined by the number 1176 * of data disks in the redundancy group. Full stripes are always used. 1177 */ 1178static uint64_t 1179vdev_draid_min_alloc(vdev_t *vd) 1180{ 1181 vdev_draid_config_t *vdc = vd->vdev_tsd; 1182 1183 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1184 1185 return (vdc->vdc_ndata << vd->vdev_ashift); 1186} 1187 1188/* 1189 * Returns true if the txg range does not exist on any leaf vdev. 1190 * 1191 * A dRAID spare does not fit into the DTL model. While it has child vdevs 1192 * there is no redundancy among them, and the effective child vdev is 1193 * determined by offset. Essentially we do a vdev_dtl_reassess() on the 1194 * fly by replacing a dRAID spare with the child vdev under the offset. 1195 * Note that it is a recursive process because the child vdev can be 1196 * another dRAID spare and so on. 1197 */ 1198boolean_t 1199vdev_draid_missing(vdev_t *vd, uint64_t physical_offset, uint64_t txg, 1200 uint64_t size) 1201{ 1202 if (vd->vdev_ops == &vdev_spare_ops || 1203 vd->vdev_ops == &vdev_replacing_ops) { 1204 /* 1205 * Check all of the readable children, if any child 1206 * contains the txg range the data it is not missing. 1207 */ 1208 for (int c = 0; c < vd->vdev_children; c++) { 1209 vdev_t *cvd = vd->vdev_child[c]; 1210 1211 if (!vdev_readable(cvd)) 1212 continue; 1213 1214 if (!vdev_draid_missing(cvd, physical_offset, 1215 txg, size)) 1216 return (B_FALSE); 1217 } 1218 1219 return (B_TRUE); 1220 } 1221 1222 if (vd->vdev_ops == &vdev_draid_spare_ops) { 1223 /* 1224 * When sequentially resilvering we don't have a proper 1225 * txg range so instead we must presume all txgs are 1226 * missing on this vdev until the resilver completes. 1227 */ 1228 if (vd->vdev_rebuild_txg != 0) 1229 return (B_TRUE); 1230 1231 /* 1232 * DTL_MISSING is set for all prior txgs when a resilver 1233 * is started in spa_vdev_attach(). 1234 */ 1235 if (vdev_dtl_contains(vd, DTL_MISSING, txg, size)) 1236 return (B_TRUE); 1237 1238 /* 1239 * Consult the DTL on the relevant vdev. Either a vdev 1240 * leaf or spare/replace mirror child may be returned so 1241 * we must recursively call vdev_draid_missing_impl(). 1242 */ 1243 vd = vdev_draid_spare_get_child(vd, physical_offset); 1244 if (vd == NULL) 1245 return (B_TRUE); 1246 1247 return (vdev_draid_missing(vd, physical_offset, 1248 txg, size)); 1249 } 1250 1251 return (vdev_dtl_contains(vd, DTL_MISSING, txg, size)); 1252} 1253 1254/* 1255 * Returns true if the txg is only partially replicated on the leaf vdevs. 1256 */ 1257static boolean_t 1258vdev_draid_partial(vdev_t *vd, uint64_t physical_offset, uint64_t txg, 1259 uint64_t size) 1260{ 1261 if (vd->vdev_ops == &vdev_spare_ops || 1262 vd->vdev_ops == &vdev_replacing_ops) { 1263 /* 1264 * Check all of the readable children, if any child is 1265 * missing the txg range then it is partially replicated. 1266 */ 1267 for (int c = 0; c < vd->vdev_children; c++) { 1268 vdev_t *cvd = vd->vdev_child[c]; 1269 1270 if (!vdev_readable(cvd)) 1271 continue; 1272 1273 if (vdev_draid_partial(cvd, physical_offset, txg, size)) 1274 return (B_TRUE); 1275 } 1276 1277 return (B_FALSE); 1278 } 1279 1280 if (vd->vdev_ops == &vdev_draid_spare_ops) { 1281 /* 1282 * When sequentially resilvering we don't have a proper 1283 * txg range so instead we must presume all txgs are 1284 * missing on this vdev until the resilver completes. 1285 */ 1286 if (vd->vdev_rebuild_txg != 0) 1287 return (B_TRUE); 1288 1289 /* 1290 * DTL_MISSING is set for all prior txgs when a resilver 1291 * is started in spa_vdev_attach(). 1292 */ 1293 if (vdev_dtl_contains(vd, DTL_MISSING, txg, size)) 1294 return (B_TRUE); 1295 1296 /* 1297 * Consult the DTL on the relevant vdev. Either a vdev 1298 * leaf or spare/replace mirror child may be returned so 1299 * we must recursively call vdev_draid_missing_impl(). 1300 */ 1301 vd = vdev_draid_spare_get_child(vd, physical_offset); 1302 if (vd == NULL) 1303 return (B_TRUE); 1304 1305 return (vdev_draid_partial(vd, physical_offset, txg, size)); 1306 } 1307 1308 return (vdev_dtl_contains(vd, DTL_MISSING, txg, size)); 1309} 1310 1311/* 1312 * Determine if the vdev is readable at the given offset. 1313 */ 1314boolean_t 1315vdev_draid_readable(vdev_t *vd, uint64_t physical_offset) 1316{ 1317 if (vd->vdev_ops == &vdev_draid_spare_ops) { 1318 vd = vdev_draid_spare_get_child(vd, physical_offset); 1319 if (vd == NULL) 1320 return (B_FALSE); 1321 } 1322 1323 if (vd->vdev_ops == &vdev_spare_ops || 1324 vd->vdev_ops == &vdev_replacing_ops) { 1325 1326 for (int c = 0; c < vd->vdev_children; c++) { 1327 vdev_t *cvd = vd->vdev_child[c]; 1328 1329 if (!vdev_readable(cvd)) 1330 continue; 1331 1332 if (vdev_draid_readable(cvd, physical_offset)) 1333 return (B_TRUE); 1334 } 1335 1336 return (B_FALSE); 1337 } 1338 1339 return (vdev_readable(vd)); 1340} 1341 1342/* 1343 * Returns the first distributed spare found under the provided vdev tree. 1344 */ 1345static vdev_t * 1346vdev_draid_find_spare(vdev_t *vd) 1347{ 1348 if (vd->vdev_ops == &vdev_draid_spare_ops) 1349 return (vd); 1350 1351 for (int c = 0; c < vd->vdev_children; c++) { 1352 vdev_t *svd = vdev_draid_find_spare(vd->vdev_child[c]); 1353 if (svd != NULL) 1354 return (svd); 1355 } 1356 1357 return (NULL); 1358} 1359 1360/* 1361 * Returns B_TRUE if the passed in vdev is currently "faulted". 1362 * Faulted, in this context, means that the vdev represents a 1363 * replacing or sparing vdev tree. 1364 */ 1365static boolean_t 1366vdev_draid_faulted(vdev_t *vd, uint64_t physical_offset) 1367{ 1368 if (vd->vdev_ops == &vdev_draid_spare_ops) { 1369 vd = vdev_draid_spare_get_child(vd, physical_offset); 1370 if (vd == NULL) 1371 return (B_FALSE); 1372 1373 /* 1374 * After resolving the distributed spare to a leaf vdev 1375 * check the parent to determine if it's "faulted". 1376 */ 1377 vd = vd->vdev_parent; 1378 } 1379 1380 return (vd->vdev_ops == &vdev_replacing_ops || 1381 vd->vdev_ops == &vdev_spare_ops); 1382} 1383 1384/* 1385 * Determine if the dRAID block at the logical offset is degraded. 1386 * Used by sequential resilver. 1387 */ 1388static boolean_t 1389vdev_draid_group_degraded(vdev_t *vd, uint64_t offset) 1390{ 1391 vdev_draid_config_t *vdc = vd->vdev_tsd; 1392 1393 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1394 ASSERT3U(vdev_draid_get_astart(vd, offset), ==, offset); 1395 1396 uint64_t groupstart, perm; 1397 uint64_t physical_offset = vdev_draid_logical_to_physical(vd, 1398 offset, &perm, &groupstart); 1399 1400 uint8_t *base; 1401 uint64_t iter; 1402 vdev_draid_get_perm(vdc, perm, &base, &iter); 1403 1404 for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { 1405 uint64_t c = (groupstart + i) % vdc->vdc_ndisks; 1406 uint64_t cid = vdev_draid_permute_id(vdc, base, iter, c); 1407 vdev_t *cvd = vd->vdev_child[cid]; 1408 1409 /* Group contains a faulted vdev. */ 1410 if (vdev_draid_faulted(cvd, physical_offset)) 1411 return (B_TRUE); 1412 1413 /* 1414 * Always check groups with active distributed spares 1415 * because any vdev failure in the pool will affect them. 1416 */ 1417 if (vdev_draid_find_spare(cvd) != NULL) 1418 return (B_TRUE); 1419 } 1420 1421 return (B_FALSE); 1422} 1423 1424/* 1425 * Determine if the txg is missing. Used by healing resilver. 1426 */ 1427static boolean_t 1428vdev_draid_group_missing(vdev_t *vd, uint64_t offset, uint64_t txg, 1429 uint64_t size) 1430{ 1431 vdev_draid_config_t *vdc = vd->vdev_tsd; 1432 1433 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1434 ASSERT3U(vdev_draid_get_astart(vd, offset), ==, offset); 1435 1436 uint64_t groupstart, perm; 1437 uint64_t physical_offset = vdev_draid_logical_to_physical(vd, 1438 offset, &perm, &groupstart); 1439 1440 uint8_t *base; 1441 uint64_t iter; 1442 vdev_draid_get_perm(vdc, perm, &base, &iter); 1443 1444 for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { 1445 uint64_t c = (groupstart + i) % vdc->vdc_ndisks; 1446 uint64_t cid = vdev_draid_permute_id(vdc, base, iter, c); 1447 vdev_t *cvd = vd->vdev_child[cid]; 1448 1449 /* Transaction group is known to be partially replicated. */ 1450 if (vdev_draid_partial(cvd, physical_offset, txg, size)) 1451 return (B_TRUE); 1452 1453 /* 1454 * Always check groups with active distributed spares 1455 * because any vdev failure in the pool will affect them. 1456 */ 1457 if (vdev_draid_find_spare(cvd) != NULL) 1458 return (B_TRUE); 1459 } 1460 1461 return (B_FALSE); 1462} 1463 1464/* 1465 * Find the smallest child asize and largest sector size to calculate the 1466 * available capacity. Distributed spares are ignored since their capacity 1467 * is also based of the minimum child size in the top-level dRAID. 1468 */ 1469static void 1470vdev_draid_calculate_asize(vdev_t *vd, uint64_t *asizep, uint64_t *max_asizep, 1471 uint64_t *logical_ashiftp, uint64_t *physical_ashiftp) 1472{ 1473 uint64_t logical_ashift = 0, physical_ashift = 0; 1474 uint64_t asize = 0, max_asize = 0; 1475 1476 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1477 1478 for (int c = 0; c < vd->vdev_children; c++) { 1479 vdev_t *cvd = vd->vdev_child[c]; 1480 1481 if (cvd->vdev_ops == &vdev_draid_spare_ops) 1482 continue; 1483 1484 asize = MIN(asize - 1, cvd->vdev_asize - 1) + 1; 1485 max_asize = MIN(max_asize - 1, cvd->vdev_max_asize - 1) + 1; 1486 logical_ashift = MAX(logical_ashift, cvd->vdev_ashift); 1487 } 1488 for (int c = 0; c < vd->vdev_children; c++) { 1489 vdev_t *cvd = vd->vdev_child[c]; 1490 1491 if (cvd->vdev_ops == &vdev_draid_spare_ops) 1492 continue; 1493 physical_ashift = vdev_best_ashift(logical_ashift, 1494 physical_ashift, cvd->vdev_physical_ashift); 1495 } 1496 1497 *asizep = asize; 1498 *max_asizep = max_asize; 1499 *logical_ashiftp = logical_ashift; 1500 *physical_ashiftp = physical_ashift; 1501} 1502 1503/* 1504 * Open spare vdevs. 1505 */ 1506static boolean_t 1507vdev_draid_open_spares(vdev_t *vd) 1508{ 1509 return (vd->vdev_ops == &vdev_draid_spare_ops || 1510 vd->vdev_ops == &vdev_replacing_ops || 1511 vd->vdev_ops == &vdev_spare_ops); 1512} 1513 1514/* 1515 * Open all children, excluding spares. 1516 */ 1517static boolean_t 1518vdev_draid_open_children(vdev_t *vd) 1519{ 1520 return (!vdev_draid_open_spares(vd)); 1521} 1522 1523/* 1524 * Open a top-level dRAID vdev. 1525 */ 1526static int 1527vdev_draid_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize, 1528 uint64_t *logical_ashift, uint64_t *physical_ashift) 1529{ 1530 vdev_draid_config_t *vdc = vd->vdev_tsd; 1531 uint64_t nparity = vdc->vdc_nparity; 1532 int open_errors = 0; 1533 1534 if (nparity > VDEV_DRAID_MAXPARITY || 1535 vd->vdev_children < nparity + 1) { 1536 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; 1537 return (SET_ERROR(EINVAL)); 1538 } 1539 1540 /* 1541 * First open the normal children then the distributed spares. This 1542 * ordering is important to ensure the distributed spares calculate 1543 * the correct psize in the event that the dRAID vdevs were expanded. 1544 */ 1545 vdev_open_children_subset(vd, vdev_draid_open_children); 1546 vdev_open_children_subset(vd, vdev_draid_open_spares); 1547 1548 /* Verify enough of the children are available to continue. */ 1549 for (int c = 0; c < vd->vdev_children; c++) { 1550 if (vd->vdev_child[c]->vdev_open_error != 0) { 1551 if ((++open_errors) > nparity) { 1552 vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; 1553 return (SET_ERROR(ENXIO)); 1554 } 1555 } 1556 } 1557 1558 /* 1559 * Allocatable capacity is the sum of the space on all children less 1560 * the number of distributed spares rounded down to last full row 1561 * and then to the last full group. An additional 32MB of scratch 1562 * space is reserved at the end of each child for use by the dRAID 1563 * expansion feature. 1564 */ 1565 uint64_t child_asize, child_max_asize; 1566 vdev_draid_calculate_asize(vd, &child_asize, &child_max_asize, 1567 logical_ashift, physical_ashift); 1568 1569 /* 1570 * Should be unreachable since the minimum child size is 64MB, but 1571 * we want to make sure an underflow absolutely cannot occur here. 1572 */ 1573 if (child_asize < VDEV_DRAID_REFLOW_RESERVE || 1574 child_max_asize < VDEV_DRAID_REFLOW_RESERVE) { 1575 return (SET_ERROR(ENXIO)); 1576 } 1577 1578 child_asize = ((child_asize - VDEV_DRAID_REFLOW_RESERVE) / 1579 VDEV_DRAID_ROWHEIGHT) * VDEV_DRAID_ROWHEIGHT; 1580 child_max_asize = ((child_max_asize - VDEV_DRAID_REFLOW_RESERVE) / 1581 VDEV_DRAID_ROWHEIGHT) * VDEV_DRAID_ROWHEIGHT; 1582 1583 *asize = (((child_asize * vdc->vdc_ndisks) / vdc->vdc_groupsz) * 1584 vdc->vdc_groupsz); 1585 *max_asize = (((child_max_asize * vdc->vdc_ndisks) / vdc->vdc_groupsz) * 1586 vdc->vdc_groupsz); 1587 1588 return (0); 1589} 1590 1591/* 1592 * Close a top-level dRAID vdev. 1593 */ 1594static void 1595vdev_draid_close(vdev_t *vd) 1596{ 1597 for (int c = 0; c < vd->vdev_children; c++) { 1598 if (vd->vdev_child[c] != NULL) 1599 vdev_close(vd->vdev_child[c]); 1600 } 1601} 1602 1603/* 1604 * Return the maximum asize for a rebuild zio in the provided range 1605 * given the following constraints. A dRAID chunks may not: 1606 * 1607 * - Exceed the maximum allowed block size (SPA_MAXBLOCKSIZE), or 1608 * - Span dRAID redundancy groups. 1609 */ 1610static uint64_t 1611vdev_draid_rebuild_asize(vdev_t *vd, uint64_t start, uint64_t asize, 1612 uint64_t max_segment) 1613{ 1614 vdev_draid_config_t *vdc = vd->vdev_tsd; 1615 1616 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1617 1618 uint64_t ashift = vd->vdev_ashift; 1619 uint64_t ndata = vdc->vdc_ndata; 1620 uint64_t psize = MIN(P2ROUNDUP(max_segment * ndata, 1 << ashift), 1621 SPA_MAXBLOCKSIZE); 1622 1623 ASSERT3U(vdev_draid_get_astart(vd, start), ==, start); 1624 ASSERT3U(asize % (vdc->vdc_groupwidth << ashift), ==, 0); 1625 1626 /* Chunks must evenly span all data columns in the group. */ 1627 psize = (((psize >> ashift) / ndata) * ndata) << ashift; 1628 uint64_t chunk_size = MIN(asize, vdev_psize_to_asize(vd, psize)); 1629 1630 /* Reduce the chunk size to the group space remaining. */ 1631 uint64_t group = vdev_draid_offset_to_group(vd, start); 1632 uint64_t left = vdev_draid_group_to_offset(vd, group + 1) - start; 1633 chunk_size = MIN(chunk_size, left); 1634 1635 ASSERT3U(chunk_size % (vdc->vdc_groupwidth << ashift), ==, 0); 1636 ASSERT3U(vdev_draid_offset_to_group(vd, start), ==, 1637 vdev_draid_offset_to_group(vd, start + chunk_size - 1)); 1638 1639 return (chunk_size); 1640} 1641 1642/* 1643 * Align the start of the metaslab to the group width and slightly reduce 1644 * its size to a multiple of the group width. Since full stripe writes are 1645 * required by dRAID this space is unallocable. Furthermore, aligning the 1646 * metaslab start is important for vdev initialize and TRIM which both operate 1647 * on metaslab boundaries which vdev_xlate() expects to be aligned. 1648 */ 1649static void 1650vdev_draid_metaslab_init(vdev_t *vd, uint64_t *ms_start, uint64_t *ms_size) 1651{ 1652 vdev_draid_config_t *vdc = vd->vdev_tsd; 1653 1654 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 1655 1656 uint64_t sz = vdc->vdc_groupwidth << vd->vdev_ashift; 1657 uint64_t astart = vdev_draid_get_astart(vd, *ms_start); 1658 uint64_t asize = ((*ms_size - (astart - *ms_start)) / sz) * sz; 1659 1660 *ms_start = astart; 1661 *ms_size = asize; 1662 1663 ASSERT0(*ms_start % sz); 1664 ASSERT0(*ms_size % sz); 1665} 1666 1667/* 1668 * Add virtual dRAID spares to the list of valid spares. In order to accomplish 1669 * this the existing array must be freed and reallocated with the additional 1670 * entries. 1671 */ 1672int 1673vdev_draid_spare_create(nvlist_t *nvroot, vdev_t *vd, uint64_t *ndraidp, 1674 uint64_t next_vdev_id) 1675{ 1676 uint64_t draid_nspares = 0; 1677 uint64_t ndraid = 0; 1678 int error; 1679 1680 for (uint64_t i = 0; i < vd->vdev_children; i++) { 1681 vdev_t *cvd = vd->vdev_child[i]; 1682 1683 if (cvd->vdev_ops == &vdev_draid_ops) { 1684 vdev_draid_config_t *vdc = cvd->vdev_tsd; 1685 draid_nspares += vdc->vdc_nspares; 1686 ndraid++; 1687 } 1688 } 1689 1690 if (draid_nspares == 0) { 1691 *ndraidp = ndraid; 1692 return (0); 1693 } 1694 1695 nvlist_t **old_spares, **new_spares; 1696 uint_t old_nspares; 1697 error = nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, 1698 &old_spares, &old_nspares); 1699 if (error) 1700 old_nspares = 0; 1701 1702 /* Allocate memory and copy of the existing spares. */ 1703 new_spares = kmem_alloc(sizeof (nvlist_t *) * 1704 (draid_nspares + old_nspares), KM_SLEEP); 1705 for (uint_t i = 0; i < old_nspares; i++) 1706 new_spares[i] = fnvlist_dup(old_spares[i]); 1707 1708 /* Add new distributed spares to ZPOOL_CONFIG_SPARES. */ 1709 uint64_t n = old_nspares; 1710 for (uint64_t vdev_id = 0; vdev_id < vd->vdev_children; vdev_id++) { 1711 vdev_t *cvd = vd->vdev_child[vdev_id]; 1712 char path[64]; 1713 1714 if (cvd->vdev_ops != &vdev_draid_ops) 1715 continue; 1716 1717 vdev_draid_config_t *vdc = cvd->vdev_tsd; 1718 uint64_t nspares = vdc->vdc_nspares; 1719 uint64_t nparity = vdc->vdc_nparity; 1720 1721 for (uint64_t spare_id = 0; spare_id < nspares; spare_id++) { 1722 memset(path, 0, sizeof (path)); 1723 (void) snprintf(path, sizeof (path) - 1, 1724 "%s%llu-%llu-%llu", VDEV_TYPE_DRAID, 1725 (u_longlong_t)nparity, 1726 (u_longlong_t)next_vdev_id + vdev_id, 1727 (u_longlong_t)spare_id); 1728 1729 nvlist_t *spare = fnvlist_alloc(); 1730 fnvlist_add_string(spare, ZPOOL_CONFIG_PATH, path); 1731 fnvlist_add_string(spare, ZPOOL_CONFIG_TYPE, 1732 VDEV_TYPE_DRAID_SPARE); 1733 fnvlist_add_uint64(spare, ZPOOL_CONFIG_TOP_GUID, 1734 cvd->vdev_guid); 1735 fnvlist_add_uint64(spare, ZPOOL_CONFIG_SPARE_ID, 1736 spare_id); 1737 fnvlist_add_uint64(spare, ZPOOL_CONFIG_IS_LOG, 0); 1738 fnvlist_add_uint64(spare, ZPOOL_CONFIG_IS_SPARE, 1); 1739 fnvlist_add_uint64(spare, ZPOOL_CONFIG_WHOLE_DISK, 1); 1740 fnvlist_add_uint64(spare, ZPOOL_CONFIG_ASHIFT, 1741 cvd->vdev_ashift); 1742 1743 new_spares[n] = spare; 1744 n++; 1745 } 1746 } 1747 1748 if (n > 0) { 1749 (void) nvlist_remove_all(nvroot, ZPOOL_CONFIG_SPARES); 1750 fnvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, 1751 (const nvlist_t **)new_spares, n); 1752 } 1753 1754 for (int i = 0; i < n; i++) 1755 nvlist_free(new_spares[i]); 1756 1757 kmem_free(new_spares, sizeof (*new_spares) * n); 1758 *ndraidp = ndraid; 1759 1760 return (0); 1761} 1762 1763/* 1764 * Determine if any portion of the provided block resides on a child vdev 1765 * with a dirty DTL and therefore needs to be resilvered. 1766 */ 1767static boolean_t 1768vdev_draid_need_resilver(vdev_t *vd, const dva_t *dva, size_t psize, 1769 uint64_t phys_birth) 1770{ 1771 uint64_t offset = DVA_GET_OFFSET(dva); 1772 uint64_t asize = vdev_draid_asize(vd, psize, 0); 1773 1774 if (phys_birth == TXG_UNKNOWN) { 1775 /* 1776 * Sequential resilver. There is no meaningful phys_birth 1777 * for this block, we can only determine if block resides 1778 * in a degraded group in which case it must be resilvered. 1779 */ 1780 ASSERT3U(vdev_draid_offset_to_group(vd, offset), ==, 1781 vdev_draid_offset_to_group(vd, offset + asize - 1)); 1782 1783 return (vdev_draid_group_degraded(vd, offset)); 1784 } else { 1785 /* 1786 * Healing resilver. TXGs not in DTL_PARTIAL are intact, 1787 * as are blocks in non-degraded groups. 1788 */ 1789 if (!vdev_dtl_contains(vd, DTL_PARTIAL, phys_birth, 1)) 1790 return (B_FALSE); 1791 1792 if (vdev_draid_group_missing(vd, offset, phys_birth, 1)) 1793 return (B_TRUE); 1794 1795 /* The block may span groups in which case check both. */ 1796 if (vdev_draid_offset_to_group(vd, offset) != 1797 vdev_draid_offset_to_group(vd, offset + asize - 1)) { 1798 if (vdev_draid_group_missing(vd, 1799 offset + asize, phys_birth, 1)) 1800 return (B_TRUE); 1801 } 1802 1803 return (B_FALSE); 1804 } 1805} 1806 1807static boolean_t 1808vdev_draid_rebuilding(vdev_t *vd) 1809{ 1810 if (vd->vdev_ops->vdev_op_leaf && vd->vdev_rebuild_txg) 1811 return (B_TRUE); 1812 1813 for (int i = 0; i < vd->vdev_children; i++) { 1814 if (vdev_draid_rebuilding(vd->vdev_child[i])) { 1815 return (B_TRUE); 1816 } 1817 } 1818 1819 return (B_FALSE); 1820} 1821 1822static void 1823vdev_draid_io_verify(vdev_t *vd, raidz_row_t *rr, int col) 1824{ 1825#ifdef ZFS_DEBUG 1826 range_seg64_t logical_rs, physical_rs, remain_rs; 1827 logical_rs.rs_start = rr->rr_offset; 1828 logical_rs.rs_end = logical_rs.rs_start + 1829 vdev_draid_asize(vd, rr->rr_size, 0); 1830 1831 raidz_col_t *rc = &rr->rr_col[col]; 1832 vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; 1833 1834 vdev_xlate(cvd, &logical_rs, &physical_rs, &remain_rs); 1835 ASSERT(vdev_xlate_is_empty(&remain_rs)); 1836 ASSERT3U(rc->rc_offset, ==, physical_rs.rs_start); 1837 ASSERT3U(rc->rc_offset, <, physical_rs.rs_end); 1838 ASSERT3U(rc->rc_offset + rc->rc_size, ==, physical_rs.rs_end); 1839#endif 1840} 1841 1842/* 1843 * For write operations: 1844 * 1. Generate the parity data 1845 * 2. Create child zio write operations to each column's vdev, for both 1846 * data and parity. A gang ABD is allocated by vdev_draid_map_alloc() 1847 * if a skip sector needs to be added to a column. 1848 */ 1849static void 1850vdev_draid_io_start_write(zio_t *zio, raidz_row_t *rr) 1851{ 1852 vdev_t *vd = zio->io_vd; 1853 raidz_map_t *rm = zio->io_vsd; 1854 1855 vdev_raidz_generate_parity_row(rm, rr); 1856 1857 for (int c = 0; c < rr->rr_cols; c++) { 1858 raidz_col_t *rc = &rr->rr_col[c]; 1859 1860 /* 1861 * Empty columns are zero filled and included in the parity 1862 * calculation and therefore must be written. 1863 */ 1864 ASSERT3U(rc->rc_size, !=, 0); 1865 1866 /* Verify physical to logical translation */ 1867 vdev_draid_io_verify(vd, rr, c); 1868 1869 zio_nowait(zio_vdev_child_io(zio, NULL, 1870 vd->vdev_child[rc->rc_devidx], rc->rc_offset, 1871 rc->rc_abd, rc->rc_size, zio->io_type, zio->io_priority, 1872 0, vdev_raidz_child_done, rc)); 1873 } 1874} 1875 1876/* 1877 * For read operations: 1878 * 1. The vdev_draid_map_alloc() function will create a minimal raidz 1879 * mapping for the read based on the zio->io_flags. There are two 1880 * possible mappings either 1) a normal read, or 2) a scrub/resilver. 1881 * 2. Create the zio read operations. This will include all parity 1882 * columns and skip sectors for a scrub/resilver. 1883 */ 1884static void 1885vdev_draid_io_start_read(zio_t *zio, raidz_row_t *rr) 1886{ 1887 vdev_t *vd = zio->io_vd; 1888 1889 /* Sequential rebuild must do IO at redundancy group boundary. */ 1890 IMPLY(zio->io_priority == ZIO_PRIORITY_REBUILD, rr->rr_nempty == 0); 1891 1892 /* 1893 * Iterate over the columns in reverse order so that we hit the parity 1894 * last. Any errors along the way will force us to read the parity. 1895 * For scrub/resilver IOs which verify skip sectors, a gang ABD will 1896 * have been allocated to store them and rc->rc_size is increased. 1897 */ 1898 for (int c = rr->rr_cols - 1; c >= 0; c--) { 1899 raidz_col_t *rc = &rr->rr_col[c]; 1900 vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; 1901 1902 if (!vdev_draid_readable(cvd, rc->rc_offset)) { 1903 if (c >= rr->rr_firstdatacol) 1904 rr->rr_missingdata++; 1905 else 1906 rr->rr_missingparity++; 1907 rc->rc_error = SET_ERROR(ENXIO); 1908 rc->rc_tried = 1; 1909 rc->rc_skipped = 1; 1910 continue; 1911 } 1912 1913 if (vdev_draid_missing(cvd, rc->rc_offset, zio->io_txg, 1)) { 1914 if (c >= rr->rr_firstdatacol) 1915 rr->rr_missingdata++; 1916 else 1917 rr->rr_missingparity++; 1918 rc->rc_error = SET_ERROR(ESTALE); 1919 rc->rc_skipped = 1; 1920 continue; 1921 } 1922 1923 /* 1924 * Empty columns may be read during vdev_draid_io_done(). 1925 * Only skip them after the readable and missing checks 1926 * verify they are available. 1927 */ 1928 if (rc->rc_size == 0) { 1929 rc->rc_skipped = 1; 1930 continue; 1931 } 1932 1933 if (zio->io_flags & ZIO_FLAG_RESILVER) { 1934 vdev_t *svd; 1935 1936 /* 1937 * Sequential rebuilds need to always consider the data 1938 * on the child being rebuilt to be stale. This is 1939 * important when all columns are available to aid 1940 * known reconstruction in identifing which columns 1941 * contain incorrect data. 1942 * 1943 * Furthermore, all repairs need to be constrained to 1944 * the devices being rebuilt because without a checksum 1945 * we cannot verify the data is actually correct and 1946 * performing an incorrect repair could result in 1947 * locking in damage and making the data unrecoverable. 1948 */ 1949 if (zio->io_priority == ZIO_PRIORITY_REBUILD) { 1950 if (vdev_draid_rebuilding(cvd)) { 1951 if (c >= rr->rr_firstdatacol) 1952 rr->rr_missingdata++; 1953 else 1954 rr->rr_missingparity++; 1955 rc->rc_error = SET_ERROR(ESTALE); 1956 rc->rc_skipped = 1; 1957 rc->rc_allow_repair = 1; 1958 continue; 1959 } else { 1960 rc->rc_allow_repair = 0; 1961 } 1962 } else { 1963 rc->rc_allow_repair = 1; 1964 } 1965 1966 /* 1967 * If this child is a distributed spare then the 1968 * offset might reside on the vdev being replaced. 1969 * In which case this data must be written to the 1970 * new device. Failure to do so would result in 1971 * checksum errors when the old device is detached 1972 * and the pool is scrubbed. 1973 */ 1974 if ((svd = vdev_draid_find_spare(cvd)) != NULL) { 1975 svd = vdev_draid_spare_get_child(svd, 1976 rc->rc_offset); 1977 if (svd && (svd->vdev_ops == &vdev_spare_ops || 1978 svd->vdev_ops == &vdev_replacing_ops)) { 1979 rc->rc_force_repair = 1; 1980 1981 if (vdev_draid_rebuilding(svd)) 1982 rc->rc_allow_repair = 1; 1983 } 1984 } 1985 1986 /* 1987 * Always issue a repair IO to this child when its 1988 * a spare or replacing vdev with an active rebuild. 1989 */ 1990 if ((cvd->vdev_ops == &vdev_spare_ops || 1991 cvd->vdev_ops == &vdev_replacing_ops) && 1992 vdev_draid_rebuilding(cvd)) { 1993 rc->rc_force_repair = 1; 1994 rc->rc_allow_repair = 1; 1995 } 1996 } 1997 } 1998 1999 /* 2000 * Either a parity or data column is missing this means a repair 2001 * may be attempted by vdev_draid_io_done(). Expand the raid map 2002 * to read in empty columns which are needed along with the parity 2003 * during reconstruction. 2004 */ 2005 if ((rr->rr_missingdata > 0 || rr->rr_missingparity > 0) && 2006 rr->rr_nempty > 0 && rr->rr_abd_empty == NULL) { 2007 vdev_draid_map_alloc_empty(zio, rr); 2008 } 2009 2010 for (int c = rr->rr_cols - 1; c >= 0; c--) { 2011 raidz_col_t *rc = &rr->rr_col[c]; 2012 vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; 2013 2014 if (rc->rc_error || rc->rc_size == 0) 2015 continue; 2016 2017 if (c >= rr->rr_firstdatacol || rr->rr_missingdata > 0 || 2018 (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { 2019 zio_nowait(zio_vdev_child_io(zio, NULL, cvd, 2020 rc->rc_offset, rc->rc_abd, rc->rc_size, 2021 zio->io_type, zio->io_priority, 0, 2022 vdev_raidz_child_done, rc)); 2023 } 2024 } 2025} 2026 2027/* 2028 * Start an IO operation to a dRAID vdev. 2029 */ 2030static void 2031vdev_draid_io_start(zio_t *zio) 2032{ 2033 vdev_t *vd __maybe_unused = zio->io_vd; 2034 2035 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 2036 ASSERT3U(zio->io_offset, ==, vdev_draid_get_astart(vd, zio->io_offset)); 2037 2038 raidz_map_t *rm = vdev_draid_map_alloc(zio); 2039 zio->io_vsd = rm; 2040 zio->io_vsd_ops = &vdev_raidz_vsd_ops; 2041 2042 if (zio->io_type == ZIO_TYPE_WRITE) { 2043 for (int i = 0; i < rm->rm_nrows; i++) { 2044 vdev_draid_io_start_write(zio, rm->rm_row[i]); 2045 } 2046 } else { 2047 ASSERT(zio->io_type == ZIO_TYPE_READ); 2048 2049 for (int i = 0; i < rm->rm_nrows; i++) { 2050 vdev_draid_io_start_read(zio, rm->rm_row[i]); 2051 } 2052 } 2053 2054 zio_execute(zio); 2055} 2056 2057/* 2058 * Complete an IO operation on a dRAID vdev. The raidz logic can be applied 2059 * to dRAID since the layout is fully described by the raidz_map_t. 2060 */ 2061static void 2062vdev_draid_io_done(zio_t *zio) 2063{ 2064 vdev_raidz_io_done(zio); 2065} 2066 2067static void 2068vdev_draid_state_change(vdev_t *vd, int faulted, int degraded) 2069{ 2070 vdev_draid_config_t *vdc = vd->vdev_tsd; 2071 ASSERT(vd->vdev_ops == &vdev_draid_ops); 2072 2073 if (faulted > vdc->vdc_nparity) 2074 vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, 2075 VDEV_AUX_NO_REPLICAS); 2076 else if (degraded + faulted != 0) 2077 vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); 2078 else 2079 vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); 2080} 2081 2082static void 2083vdev_draid_xlate(vdev_t *cvd, const range_seg64_t *logical_rs, 2084 range_seg64_t *physical_rs, range_seg64_t *remain_rs) 2085{ 2086 vdev_t *raidvd = cvd->vdev_parent; 2087 ASSERT(raidvd->vdev_ops == &vdev_draid_ops); 2088 2089 vdev_draid_config_t *vdc = raidvd->vdev_tsd; 2090 uint64_t ashift = raidvd->vdev_top->vdev_ashift; 2091 2092 /* Make sure the offsets are block-aligned */ 2093 ASSERT0(logical_rs->rs_start % (1 << ashift)); 2094 ASSERT0(logical_rs->rs_end % (1 << ashift)); 2095 2096 uint64_t logical_start = logical_rs->rs_start; 2097 uint64_t logical_end = logical_rs->rs_end; 2098 2099 /* 2100 * Unaligned ranges must be skipped. All metaslabs are correctly 2101 * aligned so this should not happen, but this case is handled in 2102 * case it's needed by future callers. 2103 */ 2104 uint64_t astart = vdev_draid_get_astart(raidvd, logical_start); 2105 if (astart != logical_start) { 2106 physical_rs->rs_start = logical_start; 2107 physical_rs->rs_end = logical_start; 2108 remain_rs->rs_start = MIN(astart, logical_end); 2109 remain_rs->rs_end = logical_end; 2110 return; 2111 } 2112 2113 /* 2114 * Unlike with mirrors and raidz a dRAID logical range can map 2115 * to multiple non-contiguous physical ranges. This is handled by 2116 * limiting the size of the logical range to a single group and 2117 * setting the remain argument such that it describes the remaining 2118 * unmapped logical range. This is stricter than absolutely 2119 * necessary but helps simplify the logic below. 2120 */ 2121 uint64_t group = vdev_draid_offset_to_group(raidvd, logical_start); 2122 uint64_t nextstart = vdev_draid_group_to_offset(raidvd, group + 1); 2123 if (logical_end > nextstart) 2124 logical_end = nextstart; 2125 2126 /* Find the starting offset for each vdev in the group */ 2127 uint64_t perm, groupstart; 2128 uint64_t start = vdev_draid_logical_to_physical(raidvd, 2129 logical_start, &perm, &groupstart); 2130 uint64_t end = start; 2131 2132 uint8_t *base; 2133 uint64_t iter, id; 2134 vdev_draid_get_perm(vdc, perm, &base, &iter); 2135 2136 /* 2137 * Check if the passed child falls within the group. If it does 2138 * update the start and end to reflect the physical range. 2139 * Otherwise, leave them unmodified which will result in an empty 2140 * (zero-length) physical range being returned. 2141 */ 2142 for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { 2143 uint64_t c = (groupstart + i) % vdc->vdc_ndisks; 2144 2145 if (c == 0 && i != 0) { 2146 /* the group wrapped, increment the start */ 2147 start += VDEV_DRAID_ROWHEIGHT; 2148 end = start; 2149 } 2150 2151 id = vdev_draid_permute_id(vdc, base, iter, c); 2152 if (id == cvd->vdev_id) { 2153 uint64_t b_size = (logical_end >> ashift) - 2154 (logical_start >> ashift); 2155 ASSERT3U(b_size, >, 0); 2156 end = start + ((((b_size - 1) / 2157 vdc->vdc_groupwidth) + 1) << ashift); 2158 break; 2159 } 2160 } 2161 physical_rs->rs_start = start; 2162 physical_rs->rs_end = end; 2163 2164 /* 2165 * Only top-level vdevs are allowed to set remain_rs because 2166 * when .vdev_op_xlate() is called for their children the full 2167 * logical range is not provided by vdev_xlate(). 2168 */ 2169 remain_rs->rs_start = logical_end; 2170 remain_rs->rs_end = logical_rs->rs_end; 2171 2172 ASSERT3U(physical_rs->rs_start, <=, logical_start); 2173 ASSERT3U(physical_rs->rs_end - physical_rs->rs_start, <=, 2174 logical_end - logical_start); 2175} 2176 2177/* 2178 * Add dRAID specific fields to the config nvlist. 2179 */ 2180static void 2181vdev_draid_config_generate(vdev_t *vd, nvlist_t *nv) 2182{ 2183 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); 2184 vdev_draid_config_t *vdc = vd->vdev_tsd; 2185 2186 fnvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, vdc->vdc_nparity); 2187 fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NDATA, vdc->vdc_ndata); 2188 fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NSPARES, vdc->vdc_nspares); 2189 fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NGROUPS, vdc->vdc_ngroups); 2190} 2191 2192/* 2193 * Initialize private dRAID specific fields from the nvlist. 2194 */ 2195static int 2196vdev_draid_init(spa_t *spa, nvlist_t *nv, void **tsd) 2197{ 2198 (void) spa; 2199 uint64_t ndata, nparity, nspares, ngroups; 2200 int error; 2201 2202 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NDATA, &ndata)) 2203 return (SET_ERROR(EINVAL)); 2204 2205 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY, &nparity) || 2206 nparity == 0 || nparity > VDEV_DRAID_MAXPARITY) { 2207 return (SET_ERROR(EINVAL)); 2208 } 2209 2210 uint_t children; 2211 nvlist_t **child; 2212 if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, 2213 &child, &children) != 0 || children == 0 || 2214 children > VDEV_DRAID_MAX_CHILDREN) { 2215 return (SET_ERROR(EINVAL)); 2216 } 2217 2218 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NSPARES, &nspares) || 2219 nspares > 100 || nspares > (children - (ndata + nparity))) { 2220 return (SET_ERROR(EINVAL)); 2221 } 2222 2223 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NGROUPS, &ngroups) || 2224 ngroups == 0 || ngroups > VDEV_DRAID_MAX_CHILDREN) { 2225 return (SET_ERROR(EINVAL)); 2226 } 2227 2228 /* 2229 * Validate the minimum number of children exist per group for the 2230 * specified parity level (draid1 >= 2, draid2 >= 3, draid3 >= 4). 2231 */ 2232 if (children < (ndata + nparity + nspares)) 2233 return (SET_ERROR(EINVAL)); 2234 2235 /* 2236 * Create the dRAID configuration using the pool nvlist configuration 2237 * and the fixed mapping for the correct number of children. 2238 */ 2239 vdev_draid_config_t *vdc; 2240 const draid_map_t *map; 2241 2242 error = vdev_draid_lookup_map(children, &map); 2243 if (error) 2244 return (SET_ERROR(EINVAL)); 2245 2246 vdc = kmem_zalloc(sizeof (*vdc), KM_SLEEP); 2247 vdc->vdc_ndata = ndata; 2248 vdc->vdc_nparity = nparity; 2249 vdc->vdc_nspares = nspares; 2250 vdc->vdc_children = children; 2251 vdc->vdc_ngroups = ngroups; 2252 vdc->vdc_nperms = map->dm_nperms; 2253 2254 error = vdev_draid_generate_perms(map, &vdc->vdc_perms); 2255 if (error) { 2256 kmem_free(vdc, sizeof (*vdc)); 2257 return (SET_ERROR(EINVAL)); 2258 } 2259 2260 /* 2261 * Derived constants. 2262 */ 2263 vdc->vdc_groupwidth = vdc->vdc_ndata + vdc->vdc_nparity; 2264 vdc->vdc_ndisks = vdc->vdc_children - vdc->vdc_nspares; 2265 vdc->vdc_groupsz = vdc->vdc_groupwidth * VDEV_DRAID_ROWHEIGHT; 2266 vdc->vdc_devslicesz = (vdc->vdc_groupsz * vdc->vdc_ngroups) / 2267 vdc->vdc_ndisks; 2268 2269 ASSERT3U(vdc->vdc_groupwidth, >=, 2); 2270 ASSERT3U(vdc->vdc_groupwidth, <=, vdc->vdc_ndisks); 2271 ASSERT3U(vdc->vdc_groupsz, >=, 2 * VDEV_DRAID_ROWHEIGHT); 2272 ASSERT3U(vdc->vdc_devslicesz, >=, VDEV_DRAID_ROWHEIGHT); 2273 ASSERT3U(vdc->vdc_devslicesz % VDEV_DRAID_ROWHEIGHT, ==, 0); 2274 ASSERT3U((vdc->vdc_groupwidth * vdc->vdc_ngroups) % 2275 vdc->vdc_ndisks, ==, 0); 2276 2277 *tsd = vdc; 2278 2279 return (0); 2280} 2281 2282static void 2283vdev_draid_fini(vdev_t *vd) 2284{ 2285 vdev_draid_config_t *vdc = vd->vdev_tsd; 2286 2287 vmem_free(vdc->vdc_perms, sizeof (uint8_t) * 2288 vdc->vdc_children * vdc->vdc_nperms); 2289 kmem_free(vdc, sizeof (*vdc)); 2290} 2291 2292static uint64_t 2293vdev_draid_nparity(vdev_t *vd) 2294{ 2295 vdev_draid_config_t *vdc = vd->vdev_tsd; 2296 2297 return (vdc->vdc_nparity); 2298} 2299 2300static uint64_t 2301vdev_draid_ndisks(vdev_t *vd) 2302{ 2303 vdev_draid_config_t *vdc = vd->vdev_tsd; 2304 2305 return (vdc->vdc_ndisks); 2306} 2307 2308vdev_ops_t vdev_draid_ops = { 2309 .vdev_op_init = vdev_draid_init, 2310 .vdev_op_fini = vdev_draid_fini, 2311 .vdev_op_open = vdev_draid_open, 2312 .vdev_op_close = vdev_draid_close, 2313 .vdev_op_asize = vdev_draid_asize, 2314 .vdev_op_min_asize = vdev_draid_min_asize, 2315 .vdev_op_min_alloc = vdev_draid_min_alloc, 2316 .vdev_op_io_start = vdev_draid_io_start, 2317 .vdev_op_io_done = vdev_draid_io_done, 2318 .vdev_op_state_change = vdev_draid_state_change, 2319 .vdev_op_need_resilver = vdev_draid_need_resilver, 2320 .vdev_op_hold = NULL, 2321 .vdev_op_rele = NULL, 2322 .vdev_op_remap = NULL, 2323 .vdev_op_xlate = vdev_draid_xlate, 2324 .vdev_op_rebuild_asize = vdev_draid_rebuild_asize, 2325 .vdev_op_metaslab_init = vdev_draid_metaslab_init, 2326 .vdev_op_config_generate = vdev_draid_config_generate, 2327 .vdev_op_nparity = vdev_draid_nparity, 2328 .vdev_op_ndisks = vdev_draid_ndisks, 2329 .vdev_op_type = VDEV_TYPE_DRAID, 2330 .vdev_op_leaf = B_FALSE, 2331}; 2332 2333 2334/* 2335 * A dRAID distributed spare is a virtual leaf vdev which is included in the 2336 * parent dRAID configuration. The last N columns of the dRAID permutation 2337 * table are used to determine on which dRAID children a specific offset 2338 * should be written. These spare leaf vdevs can only be used to replace 2339 * faulted children in the same dRAID configuration. 2340 */ 2341 2342/* 2343 * Distributed spare state. All fields are set when the distributed spare is 2344 * first opened and are immutable. 2345 */ 2346typedef struct { 2347 vdev_t *vds_draid_vdev; /* top-level parent dRAID vdev */ 2348 uint64_t vds_top_guid; /* top-level parent dRAID guid */ 2349 uint64_t vds_spare_id; /* spare id (0 - vdc->vdc_nspares-1) */ 2350} vdev_draid_spare_t; 2351 2352/* 2353 * Returns the parent dRAID vdev to which the distributed spare belongs. 2354 * This may be safely called even when the vdev is not open. 2355 */ 2356vdev_t * 2357vdev_draid_spare_get_parent(vdev_t *vd) 2358{ 2359 vdev_draid_spare_t *vds = vd->vdev_tsd; 2360 2361 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); 2362 2363 if (vds->vds_draid_vdev != NULL) 2364 return (vds->vds_draid_vdev); 2365 2366 return (vdev_lookup_by_guid(vd->vdev_spa->spa_root_vdev, 2367 vds->vds_top_guid)); 2368} 2369 2370/* 2371 * A dRAID space is active when it's the child of a vdev using the 2372 * vdev_spare_ops, vdev_replacing_ops or vdev_draid_ops. 2373 */ 2374static boolean_t 2375vdev_draid_spare_is_active(vdev_t *vd) 2376{ 2377 vdev_t *pvd = vd->vdev_parent; 2378 2379 if (pvd != NULL && (pvd->vdev_ops == &vdev_spare_ops || 2380 pvd->vdev_ops == &vdev_replacing_ops || 2381 pvd->vdev_ops == &vdev_draid_ops)) { 2382 return (B_TRUE); 2383 } else { 2384 return (B_FALSE); 2385 } 2386} 2387 2388/* 2389 * Given a dRAID distribute spare vdev, returns the physical child vdev 2390 * on which the provided offset resides. This may involve recursing through 2391 * multiple layers of distributed spares. Note that offset is relative to 2392 * this vdev. 2393 */ 2394vdev_t * 2395vdev_draid_spare_get_child(vdev_t *vd, uint64_t physical_offset) 2396{ 2397 vdev_draid_spare_t *vds = vd->vdev_tsd; 2398 2399 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); 2400 2401 /* The vdev is closed */ 2402 if (vds->vds_draid_vdev == NULL) 2403 return (NULL); 2404 2405 vdev_t *tvd = vds->vds_draid_vdev; 2406 vdev_draid_config_t *vdc = tvd->vdev_tsd; 2407 2408 ASSERT3P(tvd->vdev_ops, ==, &vdev_draid_ops); 2409 ASSERT3U(vds->vds_spare_id, <, vdc->vdc_nspares); 2410 2411 uint8_t *base; 2412 uint64_t iter; 2413 uint64_t perm = physical_offset / vdc->vdc_devslicesz; 2414 2415 vdev_draid_get_perm(vdc, perm, &base, &iter); 2416 2417 uint64_t cid = vdev_draid_permute_id(vdc, base, iter, 2418 (tvd->vdev_children - 1) - vds->vds_spare_id); 2419 vdev_t *cvd = tvd->vdev_child[cid]; 2420 2421 if (cvd->vdev_ops == &vdev_draid_spare_ops) 2422 return (vdev_draid_spare_get_child(cvd, physical_offset)); 2423 2424 return (cvd); 2425} 2426 2427static void 2428vdev_draid_spare_close(vdev_t *vd) 2429{ 2430 vdev_draid_spare_t *vds = vd->vdev_tsd; 2431 vds->vds_draid_vdev = NULL; 2432} 2433 2434/* 2435 * Opening a dRAID spare device is done by looking up the associated dRAID 2436 * top-level vdev guid from the spare configuration. 2437 */ 2438static int 2439vdev_draid_spare_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize, 2440 uint64_t *logical_ashift, uint64_t *physical_ashift) 2441{ 2442 vdev_draid_spare_t *vds = vd->vdev_tsd; 2443 vdev_t *rvd = vd->vdev_spa->spa_root_vdev; 2444 uint64_t asize, max_asize; 2445 2446 vdev_t *tvd = vdev_lookup_by_guid(rvd, vds->vds_top_guid); 2447 if (tvd == NULL) { 2448 /* 2449 * When spa_vdev_add() is labeling new spares the 2450 * associated dRAID is not attached to the root vdev 2451 * nor does this spare have a parent. Simulate a valid 2452 * device in order to allow the label to be initialized 2453 * and the distributed spare added to the configuration. 2454 */ 2455 if (vd->vdev_parent == NULL) { 2456 *psize = *max_psize = SPA_MINDEVSIZE; 2457 *logical_ashift = *physical_ashift = ASHIFT_MIN; 2458 return (0); 2459 } 2460 2461 return (SET_ERROR(EINVAL)); 2462 } 2463 2464 vdev_draid_config_t *vdc = tvd->vdev_tsd; 2465 if (tvd->vdev_ops != &vdev_draid_ops || vdc == NULL) 2466 return (SET_ERROR(EINVAL)); 2467 2468 if (vds->vds_spare_id >= vdc->vdc_nspares) 2469 return (SET_ERROR(EINVAL)); 2470 2471 /* 2472 * Neither tvd->vdev_asize or tvd->vdev_max_asize can be used here 2473 * because the caller may be vdev_draid_open() in which case the 2474 * values are stale as they haven't yet been updated by vdev_open(). 2475 * To avoid this always recalculate the dRAID asize and max_asize. 2476 */ 2477 vdev_draid_calculate_asize(tvd, &asize, &max_asize, 2478 logical_ashift, physical_ashift); 2479 2480 *psize = asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE; 2481 *max_psize = max_asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE; 2482 2483 vds->vds_draid_vdev = tvd; 2484 2485 return (0); 2486} 2487 2488/* 2489 * Completed distributed spare IO. Store the result in the parent zio 2490 * as if it had performed the operation itself. Only the first error is 2491 * preserved if there are multiple errors. 2492 */ 2493static void 2494vdev_draid_spare_child_done(zio_t *zio) 2495{ 2496 zio_t *pio = zio->io_private; 2497 2498 /* 2499 * IOs are issued to non-writable vdevs in order to keep their 2500 * DTLs accurate. However, we don't want to propagate the 2501 * error in to the distributed spare's DTL. When resilvering 2502 * vdev_draid_need_resilver() will consult the relevant DTL 2503 * to determine if the data is missing and must be repaired. 2504 */ 2505 if (!vdev_writeable(zio->io_vd)) 2506 return; 2507 2508 if (pio->io_error == 0) 2509 pio->io_error = zio->io_error; 2510} 2511 2512/* 2513 * Returns a valid label nvlist for the distributed spare vdev. This is 2514 * used to bypass the IO pipeline to avoid the complexity of constructing 2515 * a complete label with valid checksum to return when read. 2516 */ 2517nvlist_t * 2518vdev_draid_read_config_spare(vdev_t *vd) 2519{ 2520 spa_t *spa = vd->vdev_spa; 2521 spa_aux_vdev_t *sav = &spa->spa_spares; 2522 uint64_t guid = vd->vdev_guid; 2523 2524 nvlist_t *nv = fnvlist_alloc(); 2525 fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1); 2526 fnvlist_add_uint64(nv, ZPOOL_CONFIG_CREATE_TXG, vd->vdev_crtxg); 2527 fnvlist_add_uint64(nv, ZPOOL_CONFIG_VERSION, spa_version(spa)); 2528 fnvlist_add_string(nv, ZPOOL_CONFIG_POOL_NAME, spa_name(spa)); 2529 fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); 2530 fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_TXG, spa->spa_config_txg); 2531 fnvlist_add_uint64(nv, ZPOOL_CONFIG_TOP_GUID, vd->vdev_top->vdev_guid); 2532 fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_STATE, 2533 vdev_draid_spare_is_active(vd) ? 2534 POOL_STATE_ACTIVE : POOL_STATE_SPARE); 2535 2536 /* Set the vdev guid based on the vdev list in sav_count. */ 2537 for (int i = 0; i < sav->sav_count; i++) { 2538 if (sav->sav_vdevs[i]->vdev_ops == &vdev_draid_spare_ops && 2539 strcmp(sav->sav_vdevs[i]->vdev_path, vd->vdev_path) == 0) { 2540 guid = sav->sav_vdevs[i]->vdev_guid; 2541 break; 2542 } 2543 } 2544 2545 fnvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, guid); 2546 2547 return (nv); 2548} 2549 2550/* 2551 * Handle any flush requested of the distributed spare. All children must be 2552 * flushed. 2553 */ 2554static int 2555vdev_draid_spare_flush(zio_t *zio) 2556{ 2557 vdev_t *vd = zio->io_vd; 2558 int error = 0; 2559 2560 for (int c = 0; c < vd->vdev_children; c++) { 2561 zio_nowait(zio_vdev_child_io(zio, NULL, 2562 vd->vdev_child[c], zio->io_offset, zio->io_abd, 2563 zio->io_size, zio->io_type, zio->io_priority, 0, 2564 vdev_draid_spare_child_done, zio)); 2565 } 2566 2567 return (error); 2568} 2569 2570/* 2571 * Initiate an IO to the distributed spare. For normal IOs this entails using 2572 * the zio->io_offset and permutation table to calculate which child dRAID vdev 2573 * is responsible for the data. Then passing along the zio to that child to 2574 * perform the actual IO. The label ranges are not stored on disk and require 2575 * some special handling which is described below. 2576 */ 2577static void 2578vdev_draid_spare_io_start(zio_t *zio) 2579{ 2580 vdev_t *cvd = NULL, *vd = zio->io_vd; 2581 vdev_draid_spare_t *vds = vd->vdev_tsd; 2582 uint64_t offset = zio->io_offset - VDEV_LABEL_START_SIZE; 2583 2584 /* 2585 * If the vdev is closed, it's likely in the REMOVED or FAULTED state. 2586 * Nothing to be done here but return failure. 2587 */ 2588 if (vds == NULL) { 2589 zio->io_error = ENXIO; 2590 zio_interrupt(zio); 2591 return; 2592 } 2593 2594 switch (zio->io_type) { 2595 case ZIO_TYPE_FLUSH: 2596 zio->io_error = vdev_draid_spare_flush(zio); 2597 break; 2598 2599 case ZIO_TYPE_WRITE: 2600 if (VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)) { 2601 /* 2602 * Accept probe IOs and config writers to simulate the 2603 * existence of an on disk label. vdev_label_sync(), 2604 * vdev_uberblock_sync() and vdev_copy_uberblocks() 2605 * skip the distributed spares. This only leaves 2606 * vdev_label_init() which is allowed to succeed to 2607 * avoid adding special cases the function. 2608 */ 2609 if (zio->io_flags & ZIO_FLAG_PROBE || 2610 zio->io_flags & ZIO_FLAG_CONFIG_WRITER) { 2611 zio->io_error = 0; 2612 } else { 2613 zio->io_error = SET_ERROR(EIO); 2614 } 2615 } else { 2616 cvd = vdev_draid_spare_get_child(vd, offset); 2617 2618 if (cvd == NULL) { 2619 zio->io_error = SET_ERROR(ENXIO); 2620 } else { 2621 zio_nowait(zio_vdev_child_io(zio, NULL, cvd, 2622 offset, zio->io_abd, zio->io_size, 2623 zio->io_type, zio->io_priority, 0, 2624 vdev_draid_spare_child_done, zio)); 2625 } 2626 } 2627 break; 2628 2629 case ZIO_TYPE_READ: 2630 if (VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)) { 2631 /* 2632 * Accept probe IOs to simulate the existence of a 2633 * label. vdev_label_read_config() bypasses the 2634 * pipeline to read the label configuration and 2635 * vdev_uberblock_load() skips distributed spares 2636 * when attempting to locate the best uberblock. 2637 */ 2638 if (zio->io_flags & ZIO_FLAG_PROBE) { 2639 zio->io_error = 0; 2640 } else { 2641 zio->io_error = SET_ERROR(EIO); 2642 } 2643 } else { 2644 cvd = vdev_draid_spare_get_child(vd, offset); 2645 2646 if (cvd == NULL || !vdev_readable(cvd)) { 2647 zio->io_error = SET_ERROR(ENXIO); 2648 } else { 2649 zio_nowait(zio_vdev_child_io(zio, NULL, cvd, 2650 offset, zio->io_abd, zio->io_size, 2651 zio->io_type, zio->io_priority, 0, 2652 vdev_draid_spare_child_done, zio)); 2653 } 2654 } 2655 break; 2656 2657 case ZIO_TYPE_TRIM: 2658 /* The vdev label ranges are never trimmed */ 2659 ASSERT0(VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)); 2660 2661 cvd = vdev_draid_spare_get_child(vd, offset); 2662 2663 if (cvd == NULL || !cvd->vdev_has_trim) { 2664 zio->io_error = SET_ERROR(ENXIO); 2665 } else { 2666 zio_nowait(zio_vdev_child_io(zio, NULL, cvd, 2667 offset, zio->io_abd, zio->io_size, 2668 zio->io_type, zio->io_priority, 0, 2669 vdev_draid_spare_child_done, zio)); 2670 } 2671 break; 2672 2673 default: 2674 zio->io_error = SET_ERROR(ENOTSUP); 2675 break; 2676 } 2677 2678 zio_execute(zio); 2679} 2680 2681static void 2682vdev_draid_spare_io_done(zio_t *zio) 2683{ 2684 (void) zio; 2685} 2686 2687/* 2688 * Lookup the full spare config in spa->spa_spares.sav_config and 2689 * return the top_guid and spare_id for the named spare. 2690 */ 2691static int 2692vdev_draid_spare_lookup(spa_t *spa, nvlist_t *nv, uint64_t *top_guidp, 2693 uint64_t *spare_idp) 2694{ 2695 nvlist_t **spares; 2696 uint_t nspares; 2697 int error; 2698 2699 if ((spa->spa_spares.sav_config == NULL) || 2700 (nvlist_lookup_nvlist_array(spa->spa_spares.sav_config, 2701 ZPOOL_CONFIG_SPARES, &spares, &nspares) != 0)) { 2702 return (SET_ERROR(ENOENT)); 2703 } 2704 2705 const char *spare_name; 2706 error = nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &spare_name); 2707 if (error != 0) 2708 return (SET_ERROR(EINVAL)); 2709 2710 for (int i = 0; i < nspares; i++) { 2711 nvlist_t *spare = spares[i]; 2712 uint64_t top_guid, spare_id; 2713 const char *type, *path; 2714 2715 /* Skip non-distributed spares */ 2716 error = nvlist_lookup_string(spare, ZPOOL_CONFIG_TYPE, &type); 2717 if (error != 0 || strcmp(type, VDEV_TYPE_DRAID_SPARE) != 0) 2718 continue; 2719 2720 /* Skip spares with the wrong name */ 2721 error = nvlist_lookup_string(spare, ZPOOL_CONFIG_PATH, &path); 2722 if (error != 0 || strcmp(path, spare_name) != 0) 2723 continue; 2724 2725 /* Found the matching spare */ 2726 error = nvlist_lookup_uint64(spare, 2727 ZPOOL_CONFIG_TOP_GUID, &top_guid); 2728 if (error == 0) { 2729 error = nvlist_lookup_uint64(spare, 2730 ZPOOL_CONFIG_SPARE_ID, &spare_id); 2731 } 2732 2733 if (error != 0) { 2734 return (SET_ERROR(EINVAL)); 2735 } else { 2736 *top_guidp = top_guid; 2737 *spare_idp = spare_id; 2738 return (0); 2739 } 2740 } 2741 2742 return (SET_ERROR(ENOENT)); 2743} 2744 2745/* 2746 * Initialize private dRAID spare specific fields from the nvlist. 2747 */ 2748static int 2749vdev_draid_spare_init(spa_t *spa, nvlist_t *nv, void **tsd) 2750{ 2751 vdev_draid_spare_t *vds; 2752 uint64_t top_guid = 0; 2753 uint64_t spare_id; 2754 2755 /* 2756 * In the normal case check the list of spares stored in the spa 2757 * to lookup the top_guid and spare_id for provided spare config. 2758 * When creating a new pool or adding vdevs the spare list is not 2759 * yet populated and the values are provided in the passed config. 2760 */ 2761 if (vdev_draid_spare_lookup(spa, nv, &top_guid, &spare_id) != 0) { 2762 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_TOP_GUID, 2763 &top_guid) != 0) 2764 return (SET_ERROR(EINVAL)); 2765 2766 if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_SPARE_ID, 2767 &spare_id) != 0) 2768 return (SET_ERROR(EINVAL)); 2769 } 2770 2771 vds = kmem_alloc(sizeof (vdev_draid_spare_t), KM_SLEEP); 2772 vds->vds_draid_vdev = NULL; 2773 vds->vds_top_guid = top_guid; 2774 vds->vds_spare_id = spare_id; 2775 2776 *tsd = vds; 2777 2778 return (0); 2779} 2780 2781static void 2782vdev_draid_spare_fini(vdev_t *vd) 2783{ 2784 kmem_free(vd->vdev_tsd, sizeof (vdev_draid_spare_t)); 2785} 2786 2787static void 2788vdev_draid_spare_config_generate(vdev_t *vd, nvlist_t *nv) 2789{ 2790 vdev_draid_spare_t *vds = vd->vdev_tsd; 2791 2792 ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); 2793 2794 fnvlist_add_uint64(nv, ZPOOL_CONFIG_TOP_GUID, vds->vds_top_guid); 2795 fnvlist_add_uint64(nv, ZPOOL_CONFIG_SPARE_ID, vds->vds_spare_id); 2796} 2797 2798vdev_ops_t vdev_draid_spare_ops = { 2799 .vdev_op_init = vdev_draid_spare_init, 2800 .vdev_op_fini = vdev_draid_spare_fini, 2801 .vdev_op_open = vdev_draid_spare_open, 2802 .vdev_op_close = vdev_draid_spare_close, 2803 .vdev_op_asize = vdev_default_asize, 2804 .vdev_op_min_asize = vdev_default_min_asize, 2805 .vdev_op_min_alloc = NULL, 2806 .vdev_op_io_start = vdev_draid_spare_io_start, 2807 .vdev_op_io_done = vdev_draid_spare_io_done, 2808 .vdev_op_state_change = NULL, 2809 .vdev_op_need_resilver = NULL, 2810 .vdev_op_hold = NULL, 2811 .vdev_op_rele = NULL, 2812 .vdev_op_remap = NULL, 2813 .vdev_op_xlate = vdev_default_xlate, 2814 .vdev_op_rebuild_asize = NULL, 2815 .vdev_op_metaslab_init = NULL, 2816 .vdev_op_config_generate = vdev_draid_spare_config_generate, 2817 .vdev_op_nparity = NULL, 2818 .vdev_op_ndisks = NULL, 2819 .vdev_op_type = VDEV_TYPE_DRAID_SPARE, 2820 .vdev_op_leaf = B_TRUE, 2821}; 2822