diff options
Diffstat (limited to 'module/zfs/vdev_draid.c')
| -rw-r--r-- | module/zfs/vdev_draid.c | 2984 |
1 files changed, 2984 insertions, 0 deletions
diff --git a/module/zfs/vdev_draid.c b/module/zfs/vdev_draid.c new file mode 100644 index 000000000000..6b7ad7021a50 --- /dev/null +++ b/module/zfs/vdev_draid.c @@ -0,0 +1,2984 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright (c) 2018 Intel Corporation. + * Copyright (c) 2020 by Lawrence Livermore National Security, LLC. + */ + +#include <sys/zfs_context.h> +#include <sys/spa.h> +#include <sys/spa_impl.h> +#include <sys/vdev_impl.h> +#include <sys/vdev_draid.h> +#include <sys/vdev_raidz.h> +#include <sys/vdev_rebuild.h> +#include <sys/abd.h> +#include <sys/zio.h> +#include <sys/nvpair.h> +#include <sys/zio_checksum.h> +#include <sys/fs/zfs.h> +#include <sys/fm/fs/zfs.h> +#include <zfs_fletcher.h> + +#ifdef ZFS_DEBUG +#include <sys/vdev.h> /* For vdev_xlate() in vdev_draid_io_verify() */ +#endif + +/* + * dRAID is a distributed spare implementation for ZFS. A dRAID vdev is + * comprised of multiple raidz redundancy groups which are spread over the + * dRAID children. To ensure an even distribution, and avoid hot spots, a + * permutation mapping is applied to the order of the dRAID children. + * This mixing effectively distributes the parity columns evenly over all + * of the disks in the dRAID. + * + * This is beneficial because it means when resilvering all of the disks + * can participate thereby increasing the available IOPs and bandwidth. + * Furthermore, by reserving a small fraction of each child's total capacity + * virtual distributed spare disks can be created. These spares similarly + * benefit from the performance gains of spanning all of the children. The + * consequence of which is that resilvering to a distributed spare can + * substantially reduce the time required to restore full parity to pool + * with a failed disks. + * + * === dRAID group layout === + * + * First, let's define a "row" in the configuration to be a 16M chunk from + * each physical drive at the same offset. This is the minimum allowable + * size since it must be possible to store a full 16M block when there is + * only a single data column. Next, we define a "group" to be a set of + * sequential disks containing both the parity and data columns. We allow + * groups to span multiple rows in order to align any group size to any + * number of physical drives. Finally, a "slice" is comprised of the rows + * which contain the target number of groups. The permutation mappings + * are applied in a round robin fashion to each slice. + * + * Given D+P drives in a group (including parity drives) and C-S physical + * drives (not including the spare drives), we can distribute the groups + * across R rows without remainder by selecting the least common multiple + * of D+P and C-S as the number of groups; i.e. ngroups = LCM(D+P, C-S). + * + * In the example below, there are C=14 physical drives in the configuration + * with S=2 drives worth of spare capacity. Each group has a width of 9 + * which includes D=8 data and P=1 parity drive. There are 4 groups and + * 3 rows per slice. Each group has a size of 144M (16M * 9) and a slice + * size is 576M (144M * 4). When allocating from a dRAID each group is + * filled before moving on to the next as show in slice0 below. + * + * data disks (8 data + 1 parity) spares (2) + * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ + * ^ | 2 | 6 | 1 | 11| 4 | 0 | 7 | 10| 8 | 9 | 13| 5 | 12| 3 | device map 0 + * | +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ + * | | group 0 | group 1..| | + * | +-----------------------------------+-----------+-------| + * | | 0 1 2 3 4 5 6 7 8 | 36 37 38| | r + * | | 9 10 11 12 13 14 15 16 17| 45 46 47| | o + * | | 18 19 20 21 22 23 24 25 26| 54 55 56| | w + * | 27 28 29 30 31 32 33 34 35| 63 64 65| | 0 + * s +-----------------------+-----------------------+-------+ + * l | ..group 1 | group 2.. | | + * i +-----------------------+-----------------------+-------+ + * c | 39 40 41 42 43 44| 72 73 74 75 76 77| | r + * e | 48 49 50 51 52 53| 81 82 83 84 85 86| | o + * 0 | 57 58 59 60 61 62| 90 91 92 93 94 95| | w + * | 66 67 68 69 70 71| 99 100 101 102 103 104| | 1 + * | +-----------+-----------+-----------------------+-------+ + * | |..group 2 | group 3 | | + * | +-----------+-----------+-----------------------+-------+ + * | | 78 79 80|108 109 110 111 112 113 114 115 116| | r + * | | 87 88 89|117 118 119 120 121 122 123 124 125| | o + * | | 96 97 98|126 127 128 129 130 131 132 133 134| | w + * v |105 106 107|135 136 137 138 139 140 141 142 143| | 2 + * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ + * | 9 | 11| 12| 2 | 4 | 1 | 3 | 0 | 10| 13| 8 | 5 | 6 | 7 | device map 1 + * s +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ + * l | group 4 | group 5..| | row 3 + * i +-----------------------+-----------+-----------+-------| + * c | ..group 5 | group 6.. | | row 4 + * e +-----------+-----------+-----------------------+-------+ + * 1 |..group 6 | group 7 | | row 5 + * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ + * | 3 | 5 | 10| 8 | 6 | 11| 12| 0 | 2 | 4 | 7 | 1 | 9 | 13| device map 2 + * s +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ + * l | group 8 | group 9..| | row 6 + * i +-----------------------------------------------+-------| + * c | ..group 9 | group 10.. | | row 7 + * e +-----------------------+-----------------------+-------+ + * 2 |..group 10 | group 11 | | row 8 + * +-----------+-----------------------------------+-------+ + * + * This layout has several advantages over requiring that each row contain + * a whole number of groups. + * + * 1. The group count is not a relevant parameter when defining a dRAID + * layout. Only the group width is needed, and *all* groups will have + * the desired size. + * + * 2. All possible group widths (<= physical disk count) can be supported. + * + * 3. The logic within vdev_draid.c is simplified when the group width is + * the same for all groups (although some of the logic around computing + * permutation numbers and drive offsets is more complicated). + * + * N.B. The following array describes all valid dRAID permutation maps. + * Each row is used to generate a permutation map for a different number + * of children from a unique seed. The seeds were generated and carefully + * evaluated by the 'draid' utility in order to provide balanced mappings. + * In addition to the seed a checksum of the in-memory mapping is stored + * for verification. + * + * The imbalance ratio of a given failure (e.g. 5 disks wide, child 3 failed, + * with a given permutation map) is the ratio of the amounts of I/O that will + * be sent to the least and most busy disks when resilvering. The average + * imbalance ratio (of a given number of disks and permutation map) is the + * average of the ratios of all possible single and double disk failures. + * + * In order to achieve a low imbalance ratio the number of permutations in + * the mapping must be significantly larger than the number of children. + * For dRAID the number of permutations has been limited to 512 to minimize + * the map size. This does result in a gradually increasing imbalance ratio + * as seen in the table below. Increasing the number of permutations for + * larger child counts would reduce the imbalance ratio. However, in practice + * when there are a large number of children each child is responsible for + * fewer total IOs so it's less of a concern. + * + * Note these values are hard coded and must never be changed. Existing + * pools depend on the same mapping always being generated in order to + * read and write from the correct locations. Any change would make + * existing pools completely inaccessible. + */ +static const draid_map_t draid_maps[VDEV_DRAID_MAX_MAPS] = { + { 2, 256, 0x89ef3dabbcc7de37, 0x00000000433d433d }, /* 1.000 */ + { 3, 256, 0x89a57f3de98121b4, 0x00000000bcd8b7b5 }, /* 1.000 */ + { 4, 256, 0xc9ea9ec82340c885, 0x00000001819d7c69 }, /* 1.000 */ + { 5, 256, 0xf46733b7f4d47dfd, 0x00000002a1648d74 }, /* 1.010 */ + { 6, 256, 0x88c3c62d8585b362, 0x00000003d3b0c2c4 }, /* 1.031 */ + { 7, 256, 0x3a65d809b4d1b9d5, 0x000000055c4183ee }, /* 1.043 */ + { 8, 256, 0xe98930e3c5d2e90a, 0x00000006edfb0329 }, /* 1.059 */ + { 9, 256, 0x5a5430036b982ccb, 0x00000008ceaf6934 }, /* 1.056 */ + { 10, 256, 0x92bf389e9eadac74, 0x0000000b26668c09 }, /* 1.072 */ + { 11, 256, 0x74ccebf1dcf3ae80, 0x0000000dd691358c }, /* 1.083 */ + { 12, 256, 0x8847e41a1a9f5671, 0x00000010a0c63c8e }, /* 1.097 */ + { 13, 256, 0x7481b56debf0e637, 0x0000001424121fe4 }, /* 1.100 */ + { 14, 256, 0x559b8c44065f8967, 0x00000016ab2ff079 }, /* 1.121 */ + { 15, 256, 0x34c49545a2ee7f01, 0x0000001a6028efd6 }, /* 1.103 */ + { 16, 256, 0xb85f4fa81a7698f7, 0x0000001e95ff5e66 }, /* 1.111 */ + { 17, 256, 0x6353e47b7e47aba0, 0x00000021a81fa0fe }, /* 1.133 */ + { 18, 256, 0xaa549746b1cbb81c, 0x00000026f02494c9 }, /* 1.131 */ + { 19, 256, 0x892e343f2f31d690, 0x00000029eb392835 }, /* 1.130 */ + { 20, 256, 0x76914824db98cc3f, 0x0000003004f31a7c }, /* 1.141 */ + { 21, 256, 0x4b3cbabf9cfb1d0f, 0x00000036363a2408 }, /* 1.139 */ + { 22, 256, 0xf45c77abb4f035d4, 0x00000038dd0f3e84 }, /* 1.150 */ + { 23, 256, 0x5e18bd7f3fd4baf4, 0x0000003f0660391f }, /* 1.174 */ + { 24, 256, 0xa7b3a4d285d6503b, 0x000000443dfc9ff6 }, /* 1.168 */ + { 25, 256, 0x56ac7dd967521f5a, 0x0000004b03a87eb7 }, /* 1.180 */ + { 26, 256, 0x3a42dfda4eb880f7, 0x000000522c719bba }, /* 1.226 */ + { 27, 256, 0xd200d2fc6b54bf60, 0x0000005760b4fdf5 }, /* 1.228 */ + { 28, 256, 0xc52605bbd486c546, 0x0000005e00d8f74c }, /* 1.217 */ + { 29, 256, 0xc761779e63cd762f, 0x00000067be3cd85c }, /* 1.239 */ + { 30, 256, 0xca577b1e07f85ca5, 0x0000006f5517f3e4 }, /* 1.238 */ + { 31, 256, 0xfd50a593c518b3d4, 0x0000007370e7778f }, /* 1.273 */ + { 32, 512, 0xc6c87ba5b042650b, 0x000000f7eb08a156 }, /* 1.191 */ + { 33, 512, 0xc3880d0c9d458304, 0x0000010734b5d160 }, /* 1.199 */ + { 34, 512, 0xe920927e4d8b2c97, 0x00000118c1edbce0 }, /* 1.195 */ + { 35, 512, 0x8da7fcda87bde316, 0x0000012a3e9f9110 }, /* 1.201 */ + { 36, 512, 0xcf09937491514a29, 0x0000013bd6a24bef }, /* 1.194 */ + { 37, 512, 0x9b5abbf345cbd7cc, 0x0000014b9d90fac3 }, /* 1.237 */ + { 38, 512, 0x506312a44668d6a9, 0x0000015e1b5f6148 }, /* 1.242 */ + { 39, 512, 0x71659ede62b4755f, 0x00000173ef029bcd }, /* 1.231 */ + { 40, 512, 0xa7fde73fb74cf2d7, 0x000001866fb72748 }, /* 1.233 */ + { 41, 512, 0x19e8b461a1dea1d3, 0x000001a046f76b23 }, /* 1.271 */ + { 42, 512, 0x031c9b868cc3e976, 0x000001afa64c49d3 }, /* 1.263 */ + { 43, 512, 0xbaa5125faa781854, 0x000001c76789e278 }, /* 1.270 */ + { 44, 512, 0x4ed55052550d721b, 0x000001d800ccd8eb }, /* 1.281 */ + { 45, 512, 0x0fd63ddbdff90677, 0x000001f08ad59ed2 }, /* 1.282 */ + { 46, 512, 0x36d66546de7fdd6f, 0x000002016f09574b }, /* 1.286 */ + { 47, 512, 0x99f997e7eafb69d7, 0x0000021e42e47cb6 }, /* 1.329 */ + { 48, 512, 0xbecd9c2571312c5d, 0x000002320fe2872b }, /* 1.286 */ + { 49, 512, 0xd97371329e488a32, 0x0000024cd73f2ca7 }, /* 1.322 */ + { 50, 512, 0x30e9b136670749ee, 0x000002681c83b0e0 }, /* 1.335 */ + { 51, 512, 0x11ad6bc8f47aaeb4, 0x0000027e9261b5d5 }, /* 1.305 */ + { 52, 512, 0x68e445300af432c1, 0x0000029aa0eb7dbf }, /* 1.330 */ + { 53, 512, 0x910fb561657ea98c, 0x000002b3dca04853 }, /* 1.365 */ + { 54, 512, 0xd619693d8ce5e7a5, 0x000002cc280e9c97 }, /* 1.334 */ + { 55, 512, 0x24e281f564dbb60a, 0x000002e9fa842713 }, /* 1.364 */ + { 56, 512, 0x947a7d3bdaab44c5, 0x000003046680f72e }, /* 1.374 */ + { 57, 512, 0x2d44fec9c093e0de, 0x00000324198ba810 }, /* 1.363 */ + { 58, 512, 0x87743c272d29bb4c, 0x0000033ec48c9ac9 }, /* 1.401 */ + { 59, 512, 0x96aa3b6f67f5d923, 0x0000034faead902c }, /* 1.392 */ + { 60, 512, 0x94a4f1faf520b0d3, 0x0000037d713ab005 }, /* 1.360 */ + { 61, 512, 0xb13ed3a272f711a2, 0x00000397368f3cbd }, /* 1.396 */ + { 62, 512, 0x3b1b11805fa4a64a, 0x000003b8a5e2840c }, /* 1.453 */ + { 63, 512, 0x4c74caad9172ba71, 0x000003d4be280290 }, /* 1.437 */ + { 64, 512, 0x035ff643923dd29e, 0x000003fad6c355e1 }, /* 1.402 */ + { 65, 512, 0x768e9171b11abd3c, 0x0000040eb07fed20 }, /* 1.459 */ + { 66, 512, 0x75880e6f78a13ddd, 0x000004433d6acf14 }, /* 1.423 */ + { 67, 512, 0x910b9714f698a877, 0x00000451ea65d5db }, /* 1.447 */ + { 68, 512, 0x87f5db6f9fdcf5c7, 0x000004732169e3f7 }, /* 1.450 */ + { 69, 512, 0x836d4968fbaa3706, 0x000004954068a380 }, /* 1.455 */ + { 70, 512, 0xc567d73a036421ab, 0x000004bd7cb7bd3d }, /* 1.463 */ + { 71, 512, 0x619df40f240b8fed, 0x000004e376c2e972 }, /* 1.463 */ + { 72, 512, 0x42763a680d5bed8e, 0x000005084275c680 }, /* 1.452 */ + { 73, 512, 0x5866f064b3230431, 0x0000052906f2c9ab }, /* 1.498 */ + { 74, 512, 0x9fa08548b1621a44, 0x0000054708019247 }, /* 1.526 */ + { 75, 512, 0xb6053078ce0fc303, 0x00000572cc5c72b0 }, /* 1.491 */ + { 76, 512, 0x4a7aad7bf3890923, 0x0000058e987bc8e9 }, /* 1.470 */ + { 77, 512, 0xe165613fd75b5a53, 0x000005c20473a211 }, /* 1.527 */ + { 78, 512, 0x3ff154ac878163a6, 0x000005d659194bf3 }, /* 1.509 */ + { 79, 512, 0x24b93ade0aa8a532, 0x0000060a201c4f8e }, /* 1.569 */ + { 80, 512, 0xc18e2d14cd9bb554, 0x0000062c55cfe48c }, /* 1.555 */ + { 81, 512, 0x98cc78302feb58b6, 0x0000066656a07194 }, /* 1.509 */ + { 82, 512, 0xc6c5fd5a2abc0543, 0x0000067cff94fbf8 }, /* 1.596 */ + { 83, 512, 0xa7962f514acbba21, 0x000006ab7b5afa2e }, /* 1.568 */ + { 84, 512, 0xba02545069ddc6dc, 0x000006d19861364f }, /* 1.541 */ + { 85, 512, 0x447c73192c35073e, 0x000006fce315ce35 }, /* 1.623 */ + { 86, 512, 0x48beef9e2d42b0c2, 0x00000720a8e38b6b }, /* 1.620 */ + { 87, 512, 0x4874cf98541a35e0, 0x00000758382a2273 }, /* 1.597 */ + { 88, 512, 0xad4cf8333a31127a, 0x00000781e1651b1b }, /* 1.575 */ + { 89, 512, 0x47ae4859d57888c1, 0x000007b27edbe5bc }, /* 1.627 */ + { 90, 512, 0x06f7723cfe5d1891, 0x000007dc2a96d8eb }, /* 1.596 */ + { 91, 512, 0xd4e44218d660576d, 0x0000080ac46f02d5 }, /* 1.622 */ + { 92, 512, 0x7066702b0d5be1f2, 0x00000832c96d154e }, /* 1.695 */ + { 93, 512, 0x011209b4f9e11fb9, 0x0000085eefda104c }, /* 1.605 */ + { 94, 512, 0x47ffba30a0b35708, 0x00000899badc32dc }, /* 1.625 */ + { 95, 512, 0x1a95a6ac4538aaa8, 0x000008b6b69a42b2 }, /* 1.687 */ + { 96, 512, 0xbda2b239bb2008eb, 0x000008f22d2de38a }, /* 1.621 */ + { 97, 512, 0x7ffa0bea90355c6c, 0x0000092e5b23b816 }, /* 1.699 */ + { 98, 512, 0x1d56ba34be426795, 0x0000094f482e5d1b }, /* 1.688 */ + { 99, 512, 0x0aa89d45c502e93d, 0x00000977d94a98ce }, /* 1.642 */ + { 100, 512, 0x54369449f6857774, 0x000009c06c9b34cc }, /* 1.683 */ + { 101, 512, 0xf7d4dd8445b46765, 0x000009e5dc542259 }, /* 1.755 */ + { 102, 512, 0xfa8866312f169469, 0x00000a16b54eae93 }, /* 1.692 */ + { 103, 512, 0xd8a5aea08aef3ff9, 0x00000a381d2cbfe7 }, /* 1.747 */ + { 104, 512, 0x66bcd2c3d5f9ef0e, 0x00000a8191817be7 }, /* 1.751 */ + { 105, 512, 0x3fb13a47a012ec81, 0x00000ab562b9a254 }, /* 1.751 */ + { 106, 512, 0x43100f01c9e5e3ca, 0x00000aeee84c185f }, /* 1.726 */ + { 107, 512, 0xca09c50ccee2d054, 0x00000b1c359c047d }, /* 1.788 */ + { 108, 512, 0xd7176732ac503f9b, 0x00000b578bc52a73 }, /* 1.740 */ + { 109, 512, 0xed206e51f8d9422d, 0x00000b8083e0d960 }, /* 1.780 */ + { 110, 512, 0x17ead5dc6ba0dcd6, 0x00000bcfb1a32ca8 }, /* 1.836 */ + { 111, 512, 0x5f1dc21e38a969eb, 0x00000c0171becdd6 }, /* 1.778 */ + { 112, 512, 0xddaa973de33ec528, 0x00000c3edaba4b95 }, /* 1.831 */ + { 113, 512, 0x2a5eccd7735a3630, 0x00000c630664e7df }, /* 1.825 */ + { 114, 512, 0xafcccee5c0b71446, 0x00000cb65392f6e4 }, /* 1.826 */ + { 115, 512, 0x8fa30c5e7b147e27, 0x00000cd4db391e55 }, /* 1.843 */ + { 116, 512, 0x5afe0711fdfafd82, 0x00000d08cb4ec35d }, /* 1.826 */ + { 117, 512, 0x533a6090238afd4c, 0x00000d336f115d1b }, /* 1.803 */ + { 118, 512, 0x90cf11b595e39a84, 0x00000d8e041c2048 }, /* 1.857 */ + { 119, 512, 0x0d61a3b809444009, 0x00000dcb798afe35 }, /* 1.877 */ + { 120, 512, 0x7f34da0f54b0d114, 0x00000df3922664e1 }, /* 1.849 */ + { 121, 512, 0xa52258d5b72f6551, 0x00000e4d37a9872d }, /* 1.867 */ + { 122, 512, 0xc1de54d7672878db, 0x00000e6583a94cf6 }, /* 1.978 */ + { 123, 512, 0x1d03354316a414ab, 0x00000ebffc50308d }, /* 1.947 */ + { 124, 512, 0xcebdcc377665412c, 0x00000edee1997cea }, /* 1.865 */ + { 125, 512, 0x4ddd4c04b1a12344, 0x00000f21d64b373f }, /* 1.881 */ + { 126, 512, 0x64fc8f94e3973658, 0x00000f8f87a8896b }, /* 1.882 */ + { 127, 512, 0x68765f78034a334e, 0x00000fb8fe62197e }, /* 1.867 */ + { 128, 512, 0xaf36b871a303e816, 0x00000fec6f3afb1e }, /* 1.972 */ + { 129, 512, 0x2a4cbf73866c3a28, 0x00001027febfe4e5 }, /* 1.896 */ + { 130, 512, 0x9cb128aacdcd3b2f, 0x0000106aa8ac569d }, /* 1.965 */ + { 131, 512, 0x5511d41c55869124, 0x000010bbd755ddf1 }, /* 1.963 */ + { 132, 512, 0x42f92461937f284a, 0x000010fb8bceb3b5 }, /* 1.925 */ + { 133, 512, 0xe2d89a1cf6f1f287, 0x0000114cf5331e34 }, /* 1.862 */ + { 134, 512, 0xdc631a038956200e, 0x0000116428d2adc5 }, /* 2.042 */ + { 135, 512, 0xb2e5ac222cd236be, 0x000011ca88e4d4d2 }, /* 1.935 */ + { 136, 512, 0xbc7d8236655d88e7, 0x000011e39cb94e66 }, /* 2.005 */ + { 137, 512, 0x073e02d88d2d8e75, 0x0000123136c7933c }, /* 2.041 */ + { 138, 512, 0x3ddb9c3873166be0, 0x00001280e4ec6d52 }, /* 1.997 */ + { 139, 512, 0x7d3b1a845420e1b5, 0x000012c2e7cd6a44 }, /* 1.996 */ + { 140, 512, 0x60102308aa7b2a6c, 0x000012fc490e6c7d }, /* 2.053 */ + { 141, 512, 0xdb22bb2f9eb894aa, 0x00001343f5a85a1a }, /* 1.971 */ + { 142, 512, 0xd853f879a13b1606, 0x000013bb7d5f9048 }, /* 2.018 */ + { 143, 512, 0x001620a03f804b1d, 0x000013e74cc794fd }, /* 1.961 */ + { 144, 512, 0xfdb52dda76fbf667, 0x00001442d2f22480 }, /* 2.046 */ + { 145, 512, 0xa9160110f66e24ff, 0x0000144b899f9dbb }, /* 1.968 */ + { 146, 512, 0x77306a30379ae03b, 0x000014cb98eb1f81 }, /* 2.143 */ + { 147, 512, 0x14f5985d2752319d, 0x000014feab821fc9 }, /* 2.064 */ + { 148, 512, 0xa4b8ff11de7863f8, 0x0000154a0e60b9c9 }, /* 2.023 */ + { 149, 512, 0x44b345426455c1b3, 0x000015999c3c569c }, /* 2.136 */ + { 150, 512, 0x272677826049b46c, 0x000015c9697f4b92 }, /* 2.063 */ + { 151, 512, 0x2f9216e2cd74fe40, 0x0000162b1f7bbd39 }, /* 1.974 */ + { 152, 512, 0x706ae3e763ad8771, 0x00001661371c55e1 }, /* 2.210 */ + { 153, 512, 0xf7fd345307c2480e, 0x000016e251f28b6a }, /* 2.006 */ + { 154, 512, 0x6e94e3d26b3139eb, 0x000016f2429bb8c6 }, /* 2.193 */ + { 155, 512, 0x5458bbfbb781fcba, 0x0000173efdeca1b9 }, /* 2.163 */ + { 156, 512, 0xa80e2afeccd93b33, 0x000017bfdcb78adc }, /* 2.046 */ + { 157, 512, 0x1e4ccbb22796cf9d, 0x00001826fdcc39c9 }, /* 2.084 */ + { 158, 512, 0x8fba4b676aaa3663, 0x00001841a1379480 }, /* 2.264 */ + { 159, 512, 0xf82b843814b315fa, 0x000018886e19b8a3 }, /* 2.074 */ + { 160, 512, 0x7f21e920ecf753a3, 0x0000191812ca0ea7 }, /* 2.282 */ + { 161, 512, 0x48bb8ea2c4caa620, 0x0000192f310faccf }, /* 2.148 */ + { 162, 512, 0x5cdb652b4952c91b, 0x0000199e1d7437c7 }, /* 2.355 */ + { 163, 512, 0x6ac1ba6f78c06cd4, 0x000019cd11f82c70 }, /* 2.164 */ + { 164, 512, 0x9faf5f9ca2669a56, 0x00001a18d5431f6a }, /* 2.393 */ + { 165, 512, 0xaa57e9383eb01194, 0x00001a9e7d253d85 }, /* 2.178 */ + { 166, 512, 0x896967bf495c34d2, 0x00001afb8319b9fc }, /* 2.334 */ + { 167, 512, 0xdfad5f05de225f1b, 0x00001b3a59c3093b }, /* 2.266 */ + { 168, 512, 0xfd299a99f9f2abdd, 0x00001bb6f1a10799 }, /* 2.304 */ + { 169, 512, 0xdda239e798fe9fd4, 0x00001bfae0c9692d }, /* 2.218 */ + { 170, 512, 0x5fca670414a32c3e, 0x00001c22129dbcff }, /* 2.377 */ + { 171, 512, 0x1bb8934314b087de, 0x00001c955db36cd0 }, /* 2.155 */ + { 172, 512, 0xd96394b4b082200d, 0x00001cfc8619b7e6 }, /* 2.404 */ + { 173, 512, 0xb612a7735b1c8cbc, 0x00001d303acdd585 }, /* 2.205 */ + { 174, 512, 0x28e7430fe5875fe1, 0x00001d7ed5b3697d }, /* 2.359 */ + { 175, 512, 0x5038e89efdd981b9, 0x00001dc40ec35c59 }, /* 2.158 */ + { 176, 512, 0x075fd78f1d14db7c, 0x00001e31c83b4a2b }, /* 2.614 */ + { 177, 512, 0xc50fafdb5021be15, 0x00001e7cdac82fbc }, /* 2.239 */ + { 178, 512, 0xe6dc7572ce7b91c7, 0x00001edd8bb454fc }, /* 2.493 */ + { 179, 512, 0x21f7843e7beda537, 0x00001f3a8e019d6c }, /* 2.327 */ + { 180, 512, 0xc83385e20b43ec82, 0x00001f70735ec137 }, /* 2.231 */ + { 181, 512, 0xca818217dddb21fd, 0x0000201ca44c5a3c }, /* 2.237 */ + { 182, 512, 0xe6035defea48f933, 0x00002038e3346658 }, /* 2.691 */ + { 183, 512, 0x47262a4f953dac5a, 0x000020c2e554314e }, /* 2.170 */ + { 184, 512, 0xe24c7246260873ea, 0x000021197e618d64 }, /* 2.600 */ + { 185, 512, 0xeef6b57c9b58e9e1, 0x0000217ea48ecddc }, /* 2.391 */ + { 186, 512, 0x2becd3346e386142, 0x000021c496d4a5f9 }, /* 2.677 */ + { 187, 512, 0x63c6207bdf3b40a3, 0x0000220e0f2eec0c }, /* 2.410 */ + { 188, 512, 0x3056ce8989767d4b, 0x0000228eb76cd137 }, /* 2.776 */ + { 189, 512, 0x91af61c307cee780, 0x000022e17e2ea501 }, /* 2.266 */ + { 190, 512, 0xda359da225f6d54f, 0x00002358a2debc19 }, /* 2.717 */ + { 191, 512, 0x0a5f7a2a55607ba0, 0x0000238a79dac18c }, /* 2.474 */ + { 192, 512, 0x27bb75bf5224638a, 0x00002403a58e2351 }, /* 2.673 */ + { 193, 512, 0x1ebfdb94630f5d0f, 0x00002492a10cb339 }, /* 2.420 */ + { 194, 512, 0x6eae5e51d9c5f6fb, 0x000024ce4bf98715 }, /* 2.898 */ + { 195, 512, 0x08d903b4daedc2e0, 0x0000250d1e15886c }, /* 2.363 */ + { 196, 512, 0xc722a2f7fa7cd686, 0x0000258a99ed0c9e }, /* 2.747 */ + { 197, 512, 0x8f71faf0e54e361d, 0x000025dee11976f5 }, /* 2.531 */ + { 198, 512, 0x87f64695c91a54e7, 0x0000264e00a43da0 }, /* 2.707 */ + { 199, 512, 0xc719cbac2c336b92, 0x000026d327277ac1 }, /* 2.315 */ + { 200, 512, 0xe7e647afaf771ade, 0x000027523a5c44bf }, /* 3.012 */ + { 201, 512, 0x12d4b5c38ce8c946, 0x0000273898432545 }, /* 2.378 */ + { 202, 512, 0xf2e0cd4067bdc94a, 0x000027e47bb2c935 }, /* 2.969 */ + { 203, 512, 0x21b79f14d6d947d3, 0x0000281e64977f0d }, /* 2.594 */ + { 204, 512, 0x515093f952f18cd6, 0x0000289691a473fd }, /* 2.763 */ + { 205, 512, 0xd47b160a1b1022c8, 0x00002903e8b52411 }, /* 2.457 */ + { 206, 512, 0xc02fc96684715a16, 0x0000297515608601 }, /* 3.057 */ + { 207, 512, 0xef51e68efba72ed0, 0x000029ef73604804 }, /* 2.590 */ + { 208, 512, 0x9e3be6e5448b4f33, 0x00002a2846ed074b }, /* 3.047 */ + { 209, 512, 0x81d446c6d5fec063, 0x00002a92ca693455 }, /* 2.676 */ + { 210, 512, 0xff215de8224e57d5, 0x00002b2271fe3729 }, /* 2.993 */ + { 211, 512, 0xe2524d9ba8f69796, 0x00002b64b99c3ba2 }, /* 2.457 */ + { 212, 512, 0xf6b28e26097b7e4b, 0x00002bd768b6e068 }, /* 3.182 */ + { 213, 512, 0x893a487f30ce1644, 0x00002c67f722b4b2 }, /* 2.563 */ + { 214, 512, 0x386566c3fc9871df, 0x00002cc1cf8b4037 }, /* 3.025 */ + { 215, 512, 0x1e0ed78edf1f558a, 0x00002d3948d36c7f }, /* 2.730 */ + { 216, 512, 0xe3bc20c31e61f113, 0x00002d6d6b12e025 }, /* 3.036 */ + { 217, 512, 0xd6c3ad2e23021882, 0x00002deff7572241 }, /* 2.722 */ + { 218, 512, 0xb4a9f95cf0f69c5a, 0x00002e67d537aa36 }, /* 3.356 */ + { 219, 512, 0x6e98ed6f6c38e82f, 0x00002e9720626789 }, /* 2.697 */ + { 220, 512, 0x2e01edba33fddac7, 0x00002f407c6b0198 }, /* 2.979 */ + { 221, 512, 0x559d02e1f5f57ccc, 0x00002fb6a5ab4f24 }, /* 2.858 */ + { 222, 512, 0xac18f5a916adcd8e, 0x0000304ae1c5c57e }, /* 3.258 */ + { 223, 512, 0x15789fbaddb86f4b, 0x0000306f6e019c78 }, /* 2.693 */ + { 224, 512, 0xf4a9c36d5bc4c408, 0x000030da40434213 }, /* 3.259 */ + { 225, 512, 0xf640f90fd2727f44, 0x00003189ed37b90c }, /* 2.733 */ + { 226, 512, 0xb5313d390d61884a, 0x000031e152616b37 }, /* 3.235 */ + { 227, 512, 0x4bae6b3ce9160939, 0x0000321f40aeac42 }, /* 2.983 */ + { 228, 512, 0x838c34480f1a66a1, 0x000032f389c0f78e }, /* 3.308 */ + { 229, 512, 0xb1c4a52c8e3d6060, 0x0000330062a40284 }, /* 2.715 */ + { 230, 512, 0xe0f1110c6d0ed822, 0x0000338be435644f }, /* 3.540 */ + { 231, 512, 0x9f1a8ccdcea68d4b, 0x000034045a4e97e1 }, /* 2.779 */ + { 232, 512, 0x3261ed62223f3099, 0x000034702cfc401c }, /* 3.084 */ + { 233, 512, 0xf2191e2311022d65, 0x00003509dd19c9fc }, /* 2.987 */ + { 234, 512, 0xf102a395c2033abc, 0x000035654dc96fae }, /* 3.341 */ + { 235, 512, 0x11fe378f027906b6, 0x000035b5193b0264 }, /* 2.793 */ + { 236, 512, 0xf777f2c026b337aa, 0x000036704f5d9297 }, /* 3.518 */ + { 237, 512, 0x1b04e9c2ee143f32, 0x000036dfbb7af218 }, /* 2.962 */ + { 238, 512, 0x2fcec95266f9352c, 0x00003785c8df24a9 }, /* 3.196 */ + { 239, 512, 0xfe2b0e47e427dd85, 0x000037cbdf5da729 }, /* 2.914 */ + { 240, 512, 0x72b49bf2225f6c6d, 0x0000382227c15855 }, /* 3.408 */ + { 241, 512, 0x50486b43df7df9c7, 0x0000389b88be6453 }, /* 2.903 */ + { 242, 512, 0x5192a3e53181c8ab, 0x000038ddf3d67263 }, /* 3.778 */ + { 243, 512, 0xe9f5d8365296fd5e, 0x0000399f1c6c9e9c }, /* 3.026 */ + { 244, 512, 0xc740263f0301efa8, 0x00003a147146512d }, /* 3.347 */ + { 245, 512, 0x23cd0f2b5671e67d, 0x00003ab10bcc0d9d }, /* 3.212 */ + { 246, 512, 0x002ccc7e5cd41390, 0x00003ad6cd14a6c0 }, /* 3.482 */ + { 247, 512, 0x9aafb3c02544b31b, 0x00003b8cb8779fb0 }, /* 3.146 */ + { 248, 512, 0x72ba07a78b121999, 0x00003c24142a5a3f }, /* 3.626 */ + { 249, 512, 0x3d784aa58edfc7b4, 0x00003cd084817d99 }, /* 2.952 */ + { 250, 512, 0xaab750424d8004af, 0x00003d506a8e098e }, /* 3.463 */ + { 251, 512, 0x84403fcf8e6b5ca2, 0x00003d4c54c2aec4 }, /* 3.131 */ + { 252, 512, 0x71eb7455ec98e207, 0x00003e655715cf2c }, /* 3.538 */ + { 253, 512, 0xd752b4f19301595b, 0x00003ecd7b2ca5ac }, /* 2.974 */ + { 254, 512, 0xc4674129750499de, 0x00003e99e86d3e95 }, /* 3.843 */ + { 255, 512, 0x9772baff5cd12ef5, 0x00003f895c019841 }, /* 3.088 */ +}; + +/* + * Verify the map is valid. Each device index must appear exactly + * once in every row, and the permutation array checksum must match. + */ +static int +verify_perms(uint8_t *perms, uint64_t children, uint64_t nperms, + uint64_t checksum) +{ + int countssz = sizeof (uint16_t) * children; + uint16_t *counts = kmem_zalloc(countssz, KM_SLEEP); + + for (int i = 0; i < nperms; i++) { + for (int j = 0; j < children; j++) { + uint8_t val = perms[(i * children) + j]; + + if (val >= children || counts[val] != i) { + kmem_free(counts, countssz); + return (EINVAL); + } + + counts[val]++; + } + } + + if (checksum != 0) { + int permssz = sizeof (uint8_t) * children * nperms; + zio_cksum_t cksum; + + fletcher_4_native_varsize(perms, permssz, &cksum); + + if (checksum != cksum.zc_word[0]) { + kmem_free(counts, countssz); + return (ECKSUM); + } + } + + kmem_free(counts, countssz); + + return (0); +} + +/* + * Generate the permutation array for the draid_map_t. These maps control + * the placement of all data in a dRAID. Therefore it's critical that the + * seed always generates the same mapping. We provide our own pseudo-random + * number generator for this purpose. + */ +int +vdev_draid_generate_perms(const draid_map_t *map, uint8_t **permsp) +{ + VERIFY3U(map->dm_children, >=, VDEV_DRAID_MIN_CHILDREN); + VERIFY3U(map->dm_children, <=, VDEV_DRAID_MAX_CHILDREN); + VERIFY3U(map->dm_seed, !=, 0); + VERIFY3U(map->dm_nperms, !=, 0); + VERIFY3P(map->dm_perms, ==, NULL); + +#ifdef _KERNEL + /* + * The kernel code always provides both a map_seed and checksum. + * Only the tests/zfs-tests/cmd/draid/draid.c utility will provide + * a zero checksum when generating new candidate maps. + */ + VERIFY3U(map->dm_checksum, !=, 0); +#endif + uint64_t children = map->dm_children; + uint64_t nperms = map->dm_nperms; + int rowsz = sizeof (uint8_t) * children; + int permssz = rowsz * nperms; + uint8_t *perms; + + /* Allocate the permutation array */ + perms = vmem_alloc(permssz, KM_SLEEP); + + /* Setup an initial row with a known pattern */ + uint8_t *initial_row = kmem_alloc(rowsz, KM_SLEEP); + for (int i = 0; i < children; i++) + initial_row[i] = i; + + uint64_t draid_seed[2] = { VDEV_DRAID_SEED, map->dm_seed }; + uint8_t *current_row, *previous_row = initial_row; + + /* + * Perform a Fisher-Yates shuffle of each row using the previous + * row as the starting point. An initial_row with known pattern + * is used as the input for the first row. + */ + for (int i = 0; i < nperms; i++) { + current_row = &perms[i * children]; + memcpy(current_row, previous_row, rowsz); + + for (int j = children - 1; j > 0; j--) { + uint64_t k = vdev_draid_rand(draid_seed) % (j + 1); + uint8_t val = current_row[j]; + current_row[j] = current_row[k]; + current_row[k] = val; + } + + previous_row = current_row; + } + + kmem_free(initial_row, rowsz); + + int error = verify_perms(perms, children, nperms, map->dm_checksum); + if (error) { + vmem_free(perms, permssz); + return (error); + } + + *permsp = perms; + + return (0); +} + +/* + * Lookup the fixed draid_map_t for the requested number of children. + */ +int +vdev_draid_lookup_map(uint64_t children, const draid_map_t **mapp) +{ + for (int i = 0; i <= VDEV_DRAID_MAX_MAPS; i++) { + if (draid_maps[i].dm_children == children) { + *mapp = &draid_maps[i]; + return (0); + } + } + + return (ENOENT); +} + +/* + * Lookup the permutation array and iteration id for the provided offset. + */ +static void +vdev_draid_get_perm(vdev_draid_config_t *vdc, uint64_t pindex, + uint8_t **base, uint64_t *iter) +{ + uint64_t ncols = vdc->vdc_children; + uint64_t poff = pindex % (vdc->vdc_nperms * ncols); + + *base = vdc->vdc_perms + (poff / ncols) * ncols; + *iter = poff % ncols; +} + +static inline uint64_t +vdev_draid_permute_id(vdev_draid_config_t *vdc, + uint8_t *base, uint64_t iter, uint64_t index) +{ + return ((base[index] + iter) % vdc->vdc_children); +} + +/* + * Return the asize which is the psize rounded up to a full group width. + * i.e. vdev_draid_psize_to_asize(). + */ +static uint64_t +vdev_draid_asize(vdev_t *vd, uint64_t psize) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + uint64_t ashift = vd->vdev_ashift; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + uint64_t rows = ((psize - 1) / (vdc->vdc_ndata << ashift)) + 1; + uint64_t asize = (rows * vdc->vdc_groupwidth) << ashift; + + ASSERT3U(asize, !=, 0); + ASSERT3U(asize % (vdc->vdc_groupwidth), ==, 0); + + return (asize); +} + +/* + * Deflate the asize to the psize, this includes stripping parity. + */ +uint64_t +vdev_draid_asize_to_psize(vdev_t *vd, uint64_t asize) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT0(asize % vdc->vdc_groupwidth); + + return ((asize / vdc->vdc_groupwidth) * vdc->vdc_ndata); +} + +/* + * Convert a logical offset to the corresponding group number. + */ +static uint64_t +vdev_draid_offset_to_group(vdev_t *vd, uint64_t offset) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + return (offset / vdc->vdc_groupsz); +} + +/* + * Convert a group number to the logical starting offset for that group. + */ +static uint64_t +vdev_draid_group_to_offset(vdev_t *vd, uint64_t group) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + return (group * vdc->vdc_groupsz); +} + + +static void +vdev_draid_map_free_vsd(zio_t *zio) +{ + raidz_map_t *rm = zio->io_vsd; + + ASSERT0(rm->rm_freed); + rm->rm_freed = B_TRUE; + + if (rm->rm_reports == 0) { + vdev_raidz_map_free(rm); + } +} + +/*ARGSUSED*/ +static void +vdev_draid_cksum_free(void *arg, size_t ignored) +{ + raidz_map_t *rm = arg; + + ASSERT3U(rm->rm_reports, >, 0); + + if (--rm->rm_reports == 0 && rm->rm_freed) + vdev_raidz_map_free(rm); +} + +static void +vdev_draid_cksum_finish(zio_cksum_report_t *zcr, const abd_t *good_data) +{ + raidz_map_t *rm = zcr->zcr_cbdata; + const size_t c = zcr->zcr_cbinfo; + uint64_t skip_size = zcr->zcr_sector; + uint64_t parity_size; + size_t x, offset, size; + + if (good_data == NULL) { + zfs_ereport_finish_checksum(zcr, NULL, NULL, B_FALSE); + return; + } + + /* + * Detailed cksum reporting is currently only supported for single + * row draid mappings, this covers the vast majority of zios. Only + * a dRAID zio which spans groups will have multiple rows. + */ + if (rm->rm_nrows != 1) { + zfs_ereport_finish_checksum(zcr, NULL, NULL, B_FALSE); + return; + } + + raidz_row_t *rr = rm->rm_row[0]; + const abd_t *good = NULL; + const abd_t *bad = rr->rr_col[c].rc_abd; + + if (c < rr->rr_firstdatacol) { + /* + * The first time through, calculate the parity blocks for + * the good data (this relies on the fact that the good + * data never changes for a given logical zio) + */ + if (rr->rr_col[0].rc_gdata == NULL) { + abd_t *bad_parity[VDEV_DRAID_MAXPARITY]; + + /* + * Set up the rr_col[]s to generate the parity for + * good_data, first saving the parity bufs and + * replacing them with buffers to hold the result. + */ + for (x = 0; x < rr->rr_firstdatacol; x++) { + bad_parity[x] = rr->rr_col[x].rc_abd; + rr->rr_col[x].rc_abd = rr->rr_col[x].rc_gdata = + abd_alloc_sametype(rr->rr_col[x].rc_abd, + rr->rr_col[x].rc_size); + } + + /* + * Fill in the data columns from good_data being + * careful to pad short columns and empty columns + * with a skip sector. + */ + uint64_t good_size = abd_get_size((abd_t *)good_data); + + offset = 0; + for (; x < rr->rr_cols; x++) { + abd_put(rr->rr_col[x].rc_abd); + + if (offset == good_size) { + /* empty data column (small write) */ + rr->rr_col[x].rc_abd = + abd_get_zeros(skip_size); + } else if (x < rr->rr_bigcols) { + /* this is a "big column" */ + size = rr->rr_col[x].rc_size; + rr->rr_col[x].rc_abd = + abd_get_offset_size( + (abd_t *)good_data, offset, size); + offset += size; + } else { + /* short data column, add skip sector */ + size = rr->rr_col[x].rc_size -skip_size; + rr->rr_col[x].rc_abd = abd_alloc( + rr->rr_col[x].rc_size, B_TRUE); + abd_copy_off(rr->rr_col[x].rc_abd, + (abd_t *)good_data, 0, offset, + size); + abd_zero_off(rr->rr_col[x].rc_abd, + size, skip_size); + offset += size; + } + } + + /* + * Construct the parity from the good data. + */ + vdev_raidz_generate_parity_row(rm, rr); + + /* restore everything back to its original state */ + for (x = 0; x < rr->rr_firstdatacol; x++) + rr->rr_col[x].rc_abd = bad_parity[x]; + + offset = 0; + for (x = rr->rr_firstdatacol; x < rr->rr_cols; x++) { + if (offset == good_size || x < rr->rr_bigcols) + abd_put(rr->rr_col[x].rc_abd); + else + abd_free(rr->rr_col[x].rc_abd); + + rr->rr_col[x].rc_abd = abd_get_offset_size( + rr->rr_abd_copy, offset, + rr->rr_col[x].rc_size); + offset += rr->rr_col[x].rc_size; + } + } + + ASSERT3P(rr->rr_col[c].rc_gdata, !=, NULL); + good = abd_get_offset_size(rr->rr_col[c].rc_gdata, 0, + rr->rr_col[c].rc_size); + } else { + /* adjust good_data to point at the start of our column */ + parity_size = size = rr->rr_col[0].rc_size; + if (c >= rr->rr_bigcols) { + size -= skip_size; + zcr->zcr_length = size; + } + + /* empty column */ + if (size == 0) { + zfs_ereport_finish_checksum(zcr, NULL, NULL, B_TRUE); + return; + } + + offset = 0; + for (x = rr->rr_firstdatacol; x < c; x++) { + if (x < rr->rr_bigcols) { + offset += parity_size; + } else { + offset += parity_size - skip_size; + } + } + + good = abd_get_offset_size((abd_t *)good_data, offset, size); + } + + /* we drop the ereport if it ends up that the data was good */ + zfs_ereport_finish_checksum(zcr, good, bad, B_TRUE); + abd_put((abd_t *)good); +} + +/* + * Invoked indirectly by zfs_ereport_start_checksum(), called + * below when our read operation fails completely. The main point + * is to keep a copy of everything we read from disk, so that at + * vdev_draid_cksum_finish() time we can compare it with the good data. + */ +static void +vdev_draid_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *arg) +{ + size_t c = (size_t)(uintptr_t)arg; + raidz_map_t *rm = zio->io_vsd; + + /* set up the report and bump the refcount */ + zcr->zcr_cbdata = rm; + zcr->zcr_cbinfo = c; + zcr->zcr_finish = vdev_draid_cksum_finish; + zcr->zcr_free = vdev_draid_cksum_free; + + rm->rm_reports++; + ASSERT3U(rm->rm_reports, >, 0); + + if (rm->rm_row[0]->rr_abd_copy != NULL) + return; + + /* + * It's the first time we're called for this raidz_map_t, so we need + * to copy the data aside; there's no guarantee that our zio's buffer + * won't be re-used for something else. + * + * Our parity data is already in separate buffers, so there's no need + * to copy them. Furthermore, all columns should have been expanded + * by vdev_draid_map_alloc_empty() when attempting reconstruction. + */ + for (int i = 0; i < rm->rm_nrows; i++) { + raidz_row_t *rr = rm->rm_row[i]; + size_t offset = 0; + size_t size = 0; + + for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { + ASSERT3U(rr->rr_col[c].rc_size, ==, + rr->rr_col[0].rc_size); + size += rr->rr_col[c].rc_size; + } + + rr->rr_abd_copy = abd_alloc_for_io(size, B_FALSE); + + for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { + raidz_col_t *col = &rr->rr_col[c]; + abd_t *tmp = abd_get_offset_size(rr->rr_abd_copy, + offset, col->rc_size); + + abd_copy(tmp, col->rc_abd, col->rc_size); + + if (abd_is_gang(col->rc_abd)) + abd_free(col->rc_abd); + else + abd_put(col->rc_abd); + + col->rc_abd = tmp; + offset += col->rc_size; + } + ASSERT3U(offset, ==, size); + } +} + +const zio_vsd_ops_t vdev_draid_vsd_ops = { + .vsd_free = vdev_draid_map_free_vsd, + .vsd_cksum_report = vdev_draid_cksum_report +}; + +/* + * Full stripe writes. When writing, all columns (D+P) are required. Parity + * is calculated over all the columns, including empty zero filled sectors, + * and each is written to disk. While only the data columns are needed for + * a normal read, all of the columns are required for reconstruction when + * performing a sequential resilver. + * + * For "big columns" it's sufficient to map the correct range of the zio ABD. + * Partial columns require allocating a gang ABD in order to zero fill the + * empty sectors. When the column is empty a zero filled sector must be + * mapped. In all cases the data ABDs must be the same size as the parity + * ABDs (e.g. rc->rc_size == parity_size). + */ +static void +vdev_draid_map_alloc_write(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) +{ + uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; + uint64_t parity_size = rr->rr_col[0].rc_size; + uint64_t abd_off = abd_offset; + + ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); + ASSERT3U(parity_size, ==, abd_get_size(rr->rr_col[0].rc_abd)); + + for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { + raidz_col_t *rc = &rr->rr_col[c]; + + if (rc->rc_size == 0) { + /* empty data column (small write), add a skip sector */ + ASSERT3U(skip_size, ==, parity_size); + rc->rc_abd = abd_get_zeros(skip_size); + } else if (rc->rc_size == parity_size) { + /* this is a "big column" */ + rc->rc_abd = abd_get_offset_size(zio->io_abd, + abd_off, rc->rc_size); + } else { + /* short data column, add a skip sector */ + ASSERT3U(rc->rc_size + skip_size, ==, parity_size); + rc->rc_abd = abd_alloc_gang_abd(); + abd_gang_add(rc->rc_abd, abd_get_offset_size( + zio->io_abd, abd_off, rc->rc_size), B_TRUE); + abd_gang_add(rc->rc_abd, abd_get_zeros(skip_size), + B_TRUE); + } + + ASSERT3U(abd_get_size(rc->rc_abd), ==, parity_size); + + abd_off += rc->rc_size; + rc->rc_size = parity_size; + } + + IMPLY(abd_offset != 0, abd_off == zio->io_size); +} + +/* + * Scrub/resilver reads. In order to store the contents of the skip sectors + * an additional ABD is allocated. The columns are handled in the same way + * as a full stripe write except instead of using the zero ABD the newly + * allocated skip ABD is used to back the skip sectors. In all cases the + * data ABD must be the same size as the parity ABDs. + */ +static void +vdev_draid_map_alloc_scrub(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) +{ + uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; + uint64_t parity_size = rr->rr_col[0].rc_size; + uint64_t abd_off = abd_offset; + uint64_t skip_off = 0; + + ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); + ASSERT3P(rr->rr_abd_empty, ==, NULL); + + if (rr->rr_nempty > 0) { + rr->rr_abd_empty = abd_alloc_linear(rr->rr_nempty * skip_size, + B_FALSE); + } + + for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { + raidz_col_t *rc = &rr->rr_col[c]; + + if (rc->rc_size == 0) { + /* empty data column (small read), add a skip sector */ + ASSERT3U(skip_size, ==, parity_size); + ASSERT3U(rr->rr_nempty, !=, 0); + rc->rc_abd = abd_get_offset_size(rr->rr_abd_empty, + skip_off, skip_size); + skip_off += skip_size; + } else if (rc->rc_size == parity_size) { + /* this is a "big column" */ + rc->rc_abd = abd_get_offset_size(zio->io_abd, + abd_off, rc->rc_size); + } else { + /* short data column, add a skip sector */ + ASSERT3U(rc->rc_size + skip_size, ==, parity_size); + ASSERT3U(rr->rr_nempty, !=, 0); + rc->rc_abd = abd_alloc_gang_abd(); + abd_gang_add(rc->rc_abd, abd_get_offset_size( + zio->io_abd, abd_off, rc->rc_size), B_TRUE); + abd_gang_add(rc->rc_abd, abd_get_offset_size( + rr->rr_abd_empty, skip_off, skip_size), B_TRUE); + skip_off += skip_size; + } + + uint64_t abd_size = abd_get_size(rc->rc_abd); + ASSERT3U(abd_size, ==, abd_get_size(rr->rr_col[0].rc_abd)); + + /* + * Increase rc_size so the skip ABD is included in subsequent + * parity calculations. + */ + abd_off += rc->rc_size; + rc->rc_size = abd_size; + } + + IMPLY(abd_offset != 0, abd_off == zio->io_size); + ASSERT3U(skip_off, ==, rr->rr_nempty * skip_size); +} + +/* + * Normal reads. In this common case only the columns containing data + * are read in to the zio ABDs. Neither the parity columns or empty skip + * sectors are read unless the checksum fails verification. In which case + * vdev_raidz_read_all() will call vdev_draid_map_alloc_empty() to expand + * the raid map in order to allow reconstruction using the parity data and + * skip sectors. + */ +static void +vdev_draid_map_alloc_read(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) +{ + uint64_t abd_off = abd_offset; + + ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); + + for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { + raidz_col_t *rc = &rr->rr_col[c]; + + if (rc->rc_size > 0) { + rc->rc_abd = abd_get_offset_size(zio->io_abd, + abd_off, rc->rc_size); + abd_off += rc->rc_size; + } + } + + IMPLY(abd_offset != 0, abd_off == zio->io_size); +} + +/* + * Converts a normal "read" raidz_row_t to a "scrub" raidz_row_t. The key + * difference is that an ABD is allocated to back skip sectors so they may + * be read in to memory, verified, and repaired if needed. + */ +void +vdev_draid_map_alloc_empty(zio_t *zio, raidz_row_t *rr) +{ + uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; + uint64_t parity_size = rr->rr_col[0].rc_size; + uint64_t skip_off = 0; + + ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); + ASSERT3P(rr->rr_abd_empty, ==, NULL); + + if (rr->rr_nempty > 0) { + rr->rr_abd_empty = abd_alloc_linear(rr->rr_nempty * skip_size, + B_FALSE); + } + + for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { + raidz_col_t *rc = &rr->rr_col[c]; + + if (rc->rc_size == 0) { + /* empty data column (small read), add a skip sector */ + ASSERT3U(skip_size, ==, parity_size); + ASSERT3U(rr->rr_nempty, !=, 0); + ASSERT3P(rc->rc_abd, ==, NULL); + rc->rc_abd = abd_get_offset_size(rr->rr_abd_empty, + skip_off, skip_size); + skip_off += skip_size; + } else if (rc->rc_size == parity_size) { + /* this is a "big column", nothing to add */ + ASSERT3P(rc->rc_abd, !=, NULL); + } else { + /* short data column, add a skip sector */ + ASSERT3U(rc->rc_size + skip_size, ==, parity_size); + ASSERT3U(rr->rr_nempty, !=, 0); + ASSERT3P(rc->rc_abd, !=, NULL); + ASSERT(!abd_is_gang(rc->rc_abd)); + abd_t *read_abd = rc->rc_abd; + rc->rc_abd = abd_alloc_gang_abd(); + abd_gang_add(rc->rc_abd, read_abd, B_TRUE); + abd_gang_add(rc->rc_abd, abd_get_offset_size( + rr->rr_abd_empty, skip_off, skip_size), B_TRUE); + skip_off += skip_size; + } + + /* + * Increase rc_size so the empty ABD is included in subsequent + * parity calculations. + */ + rc->rc_size = parity_size; + } + + ASSERT3U(skip_off, ==, rr->rr_nempty * skip_size); +} + +/* + * Given a logical address within a dRAID configuration, return the physical + * address on the first drive in the group that this address maps to + * (at position 'start' in permutation number 'perm'). + */ +static uint64_t +vdev_draid_logical_to_physical(vdev_t *vd, uint64_t logical_offset, + uint64_t *perm, uint64_t *start) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + /* b is the dRAID (parent) sector offset. */ + uint64_t ashift = vd->vdev_top->vdev_ashift; + uint64_t b_offset = logical_offset >> ashift; + + /* + * The height of a row in units of the vdev's minimum sector size. + * This is the amount of data written to each disk of each group + * in a given permutation. + */ + uint64_t rowheight_sectors = VDEV_DRAID_ROWHEIGHT >> ashift; + + /* + * We cycle through a disk permutation every groupsz * ngroups chunk + * of address space. Note that ngroups * groupsz must be a multiple + * of the number of data drives (ndisks) in order to guarantee + * alignment. So, for example, if our row height is 16MB, our group + * size is 10, and there are 13 data drives in the draid, then ngroups + * will be 13, we will change permutation every 2.08GB and each + * disk will have 160MB of data per chunk. + */ + uint64_t groupwidth = vdc->vdc_groupwidth; + uint64_t ngroups = vdc->vdc_ngroups; + uint64_t ndisks = vdc->vdc_ndisks; + + /* + * groupstart is where the group this IO will land in "starts" in + * the permutation array. + */ + uint64_t group = logical_offset / vdc->vdc_groupsz; + uint64_t groupstart = (group * groupwidth) % ndisks; + ASSERT3U(groupstart + groupwidth, <=, ndisks + groupstart); + *start = groupstart; + + /* b_offset is the sector offset within a group chunk */ + b_offset = b_offset % (rowheight_sectors * groupwidth); + ASSERT0(b_offset % groupwidth); + + /* + * Find the starting byte offset on each child vdev: + * - within a permutation there are ngroups groups spread over the + * rows, where each row covers a slice portion of the disk + * - each permutation has (groupwidth * ngroups) / ndisks rows + * - so each permutation covers rows * slice portion of the disk + * - so we need to find the row where this IO group target begins + */ + *perm = group / ngroups; + uint64_t row = (*perm * ((groupwidth * ngroups) / ndisks)) + + (((group % ngroups) * groupwidth) / ndisks); + + return (((rowheight_sectors * row) + + (b_offset / groupwidth)) << ashift); +} + +static uint64_t +vdev_draid_map_alloc_row(zio_t *zio, raidz_row_t **rrp, uint64_t io_offset, + uint64_t abd_offset, uint64_t abd_size) +{ + vdev_t *vd = zio->io_vd; + vdev_draid_config_t *vdc = vd->vdev_tsd; + uint64_t ashift = vd->vdev_top->vdev_ashift; + uint64_t io_size = abd_size; + uint64_t io_asize = vdev_draid_asize(vd, io_size); + uint64_t group = vdev_draid_offset_to_group(vd, io_offset); + uint64_t start_offset = vdev_draid_group_to_offset(vd, group + 1); + + /* + * Limit the io_size to the space remaining in the group. A second + * row in the raidz_map_t is created for the remainder. + */ + if (io_offset + io_asize > start_offset) { + io_size = vdev_draid_asize_to_psize(vd, + start_offset - io_offset); + } + + /* + * At most a block may span the logical end of one group and the start + * of the next group. Therefore, at the end of a group the io_size must + * span the group width evenly and the remainder must be aligned to the + * start of the next group. + */ + IMPLY(abd_offset == 0 && io_size < zio->io_size, + (io_asize >> ashift) % vdc->vdc_groupwidth == 0); + IMPLY(abd_offset != 0, + vdev_draid_group_to_offset(vd, group) == io_offset); + + /* Lookup starting byte offset on each child vdev */ + uint64_t groupstart, perm; + uint64_t physical_offset = vdev_draid_logical_to_physical(vd, + io_offset, &perm, &groupstart); + + /* + * If there is less than groupwidth drives available after the group + * start, the group is going to wrap onto the next row. 'wrap' is the + * group disk number that starts on the next row. + */ + uint64_t ndisks = vdc->vdc_ndisks; + uint64_t groupwidth = vdc->vdc_groupwidth; + uint64_t wrap = groupwidth; + + if (groupstart + groupwidth > ndisks) + wrap = ndisks - groupstart; + + /* The io size in units of the vdev's minimum sector size. */ + const uint64_t psize = io_size >> ashift; + + /* + * "Quotient": The number of data sectors for this stripe on all but + * the "big column" child vdevs that also contain "remainder" data. + */ + uint64_t q = psize / vdc->vdc_ndata; + + /* + * "Remainder": The number of partial stripe data sectors in this I/O. + * This will add a sector to some, but not all, child vdevs. + */ + uint64_t r = psize - q * vdc->vdc_ndata; + + /* The number of "big columns" - those which contain remainder data. */ + uint64_t bc = (r == 0 ? 0 : r + vdc->vdc_nparity); + ASSERT3U(bc, <, groupwidth); + + /* The total number of data and parity sectors for this I/O. */ + uint64_t tot = psize + (vdc->vdc_nparity * (q + (r == 0 ? 0 : 1))); + + raidz_row_t *rr; + rr = kmem_alloc(offsetof(raidz_row_t, rr_col[groupwidth]), KM_SLEEP); + rr->rr_cols = groupwidth; + rr->rr_scols = groupwidth; + rr->rr_bigcols = bc; + rr->rr_missingdata = 0; + rr->rr_missingparity = 0; + rr->rr_firstdatacol = vdc->vdc_nparity; + rr->rr_abd_copy = NULL; + rr->rr_abd_empty = NULL; +#ifdef ZFS_DEBUG + rr->rr_offset = io_offset; + rr->rr_size = io_size; +#endif + *rrp = rr; + + uint8_t *base; + uint64_t iter, asize = 0; + vdev_draid_get_perm(vdc, perm, &base, &iter); + for (uint64_t i = 0; i < groupwidth; i++) { + raidz_col_t *rc = &rr->rr_col[i]; + uint64_t c = (groupstart + i) % ndisks; + + /* increment the offset if we wrap to the next row */ + if (i == wrap) + physical_offset += VDEV_DRAID_ROWHEIGHT; + + rc->rc_devidx = vdev_draid_permute_id(vdc, base, iter, c); + rc->rc_offset = physical_offset; + rc->rc_abd = NULL; + rc->rc_gdata = NULL; + rc->rc_orig_data = NULL; + rc->rc_error = 0; + rc->rc_tried = 0; + rc->rc_skipped = 0; + rc->rc_repair = 0; + rc->rc_need_orig_restore = B_FALSE; + + if (q == 0 && i >= bc) + rc->rc_size = 0; + else if (i < bc) + rc->rc_size = (q + 1) << ashift; + else + rc->rc_size = q << ashift; + + asize += rc->rc_size; + } + + ASSERT3U(asize, ==, tot << ashift); + rr->rr_nempty = roundup(tot, groupwidth) - tot; + IMPLY(bc > 0, rr->rr_nempty == groupwidth - bc); + + /* Allocate buffers for the parity columns */ + for (uint64_t c = 0; c < rr->rr_firstdatacol; c++) { + raidz_col_t *rc = &rr->rr_col[c]; + rc->rc_abd = abd_alloc_linear(rc->rc_size, B_FALSE); + } + + /* + * Map buffers for data columns and allocate/map buffers for skip + * sectors. There are three distinct cases for dRAID which are + * required to support sequential rebuild. + */ + if (zio->io_type == ZIO_TYPE_WRITE) { + vdev_draid_map_alloc_write(zio, abd_offset, rr); + } else if ((rr->rr_nempty > 0) && + (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { + vdev_draid_map_alloc_scrub(zio, abd_offset, rr); + } else { + ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); + vdev_draid_map_alloc_read(zio, abd_offset, rr); + } + + return (io_size); +} + +/* + * Allocate the raidz mapping to be applied to the dRAID I/O. The parity + * calculations for dRAID are identical to raidz however there are a few + * differences in the layout. + * + * - dRAID always allocates a full stripe width. Any extra sectors due + * this padding are zero filled and written to disk. They will be read + * back during a scrub or repair operation since they are included in + * the parity calculation. This property enables sequential resilvering. + * + * - When the block at the logical offset spans redundancy groups then two + * rows are allocated in the raidz_map_t. One row resides at the end of + * the first group and the other at the start of the following group. + */ +static raidz_map_t * +vdev_draid_map_alloc(zio_t *zio) +{ + raidz_row_t *rr[2]; + uint64_t abd_offset = 0; + uint64_t abd_size = zio->io_size; + uint64_t io_offset = zio->io_offset; + uint64_t size; + int nrows = 1; + + size = vdev_draid_map_alloc_row(zio, &rr[0], io_offset, + abd_offset, abd_size); + if (size < abd_size) { + vdev_t *vd = zio->io_vd; + + io_offset += vdev_draid_asize(vd, size); + abd_offset += size; + abd_size -= size; + nrows++; + + ASSERT3U(io_offset, ==, vdev_draid_group_to_offset( + vd, vdev_draid_offset_to_group(vd, io_offset))); + ASSERT3U(abd_offset, <, zio->io_size); + ASSERT3U(abd_size, !=, 0); + + size = vdev_draid_map_alloc_row(zio, &rr[1], + io_offset, abd_offset, abd_size); + VERIFY3U(size, ==, abd_size); + } + + raidz_map_t *rm; + rm = kmem_zalloc(offsetof(raidz_map_t, rm_row[nrows]), KM_SLEEP); + rm->rm_ops = vdev_raidz_math_get_ops(); + rm->rm_nrows = nrows; + rm->rm_row[0] = rr[0]; + if (nrows == 2) + rm->rm_row[1] = rr[1]; + + zio->io_vsd = rm; + zio->io_vsd_ops = &vdev_draid_vsd_ops; + + return (rm); +} + +/* + * Given an offset into a dRAID return the next group width aligned offset + * which can be used to start an allocation. + */ +static uint64_t +vdev_draid_get_astart(vdev_t *vd, const uint64_t start) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + return (roundup(start, vdc->vdc_groupwidth << vd->vdev_ashift)); +} + +/* + * Allocatable space for dRAID is (children - nspares) * sizeof(smallest child) + * rounded down to the last full slice. So each child must provide at least + * 1 / (children - nspares) of its asize. + */ +static uint64_t +vdev_draid_min_asize(vdev_t *vd) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + return ((vd->vdev_min_asize + vdc->vdc_ndisks - 1) / (vdc->vdc_ndisks)); +} + +/* + * When using dRAID the minimum allocation size is determined by the number + * of data disks in the redundancy group. Full stripes are always used. + */ +static uint64_t +vdev_draid_min_alloc(vdev_t *vd) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + return (vdc->vdc_ndata << vd->vdev_ashift); +} + +/* + * Returns true if the txg range does not exist on any leaf vdev. + * + * A dRAID spare does not fit into the DTL model. While it has child vdevs + * there is no redundancy among them, and the effective child vdev is + * determined by offset. Essentially we do a vdev_dtl_reassess() on the + * fly by replacing a dRAID spare with the child vdev under the offset. + * Note that it is a recursive process because the child vdev can be + * another dRAID spare and so on. + */ +boolean_t +vdev_draid_missing(vdev_t *vd, uint64_t physical_offset, uint64_t txg, + uint64_t size) +{ + if (vd->vdev_ops == &vdev_spare_ops || + vd->vdev_ops == &vdev_replacing_ops) { + /* + * Check all of the readable children, if any child + * contains the txg range the data it is not missing. + */ + for (int c = 0; c < vd->vdev_children; c++) { + vdev_t *cvd = vd->vdev_child[c]; + + if (!vdev_readable(cvd)) + continue; + + if (!vdev_draid_missing(cvd, physical_offset, + txg, size)) + return (B_FALSE); + } + + return (B_TRUE); + } + + if (vd->vdev_ops == &vdev_draid_spare_ops) { + /* + * When sequentially resilvering we don't have a proper + * txg range so instead we must presume all txgs are + * missing on this vdev until the resilver completes. + */ + if (vd->vdev_rebuild_txg != 0) + return (B_TRUE); + + /* + * DTL_MISSING is set for all prior txgs when a resilver + * is started in spa_vdev_attach(). + */ + if (vdev_dtl_contains(vd, DTL_MISSING, txg, size)) + return (B_TRUE); + + /* + * Consult the DTL on the relevant vdev. Either a vdev + * leaf or spare/replace mirror child may be returned so + * we must recursively call vdev_draid_missing_impl(). + */ + vd = vdev_draid_spare_get_child(vd, physical_offset); + if (vd == NULL) + return (B_TRUE); + + return (vdev_draid_missing(vd, physical_offset, + txg, size)); + } + + return (vdev_dtl_contains(vd, DTL_MISSING, txg, size)); +} + +/* + * Returns true if the txg is only partially replicated on the leaf vdevs. + */ +static boolean_t +vdev_draid_partial(vdev_t *vd, uint64_t physical_offset, uint64_t txg, + uint64_t size) +{ + if (vd->vdev_ops == &vdev_spare_ops || + vd->vdev_ops == &vdev_replacing_ops) { + /* + * Check all of the readable children, if any child is + * missing the txg range then it is partially replicated. + */ + for (int c = 0; c < vd->vdev_children; c++) { + vdev_t *cvd = vd->vdev_child[c]; + + if (!vdev_readable(cvd)) + continue; + + if (vdev_draid_partial(cvd, physical_offset, txg, size)) + return (B_TRUE); + } + + return (B_FALSE); + } + + if (vd->vdev_ops == &vdev_draid_spare_ops) { + /* + * When sequentially resilvering we don't have a proper + * txg range so instead we must presume all txgs are + * missing on this vdev until the resilver completes. + */ + if (vd->vdev_rebuild_txg != 0) + return (B_TRUE); + + /* + * DTL_MISSING is set for all prior txgs when a resilver + * is started in spa_vdev_attach(). + */ + if (vdev_dtl_contains(vd, DTL_MISSING, txg, size)) + return (B_TRUE); + + /* + * Consult the DTL on the relevant vdev. Either a vdev + * leaf or spare/replace mirror child may be returned so + * we must recursively call vdev_draid_missing_impl(). + */ + vd = vdev_draid_spare_get_child(vd, physical_offset); + if (vd == NULL) + return (B_TRUE); + + return (vdev_draid_partial(vd, physical_offset, txg, size)); + } + + return (vdev_dtl_contains(vd, DTL_MISSING, txg, size)); +} + +/* + * Determine if the vdev is readable at the given offset. + */ +boolean_t +vdev_draid_readable(vdev_t *vd, uint64_t physical_offset) +{ + if (vd->vdev_ops == &vdev_draid_spare_ops) { + vd = vdev_draid_spare_get_child(vd, physical_offset); + if (vd == NULL) + return (B_FALSE); + } + + if (vd->vdev_ops == &vdev_spare_ops || + vd->vdev_ops == &vdev_replacing_ops) { + + for (int c = 0; c < vd->vdev_children; c++) { + vdev_t *cvd = vd->vdev_child[c]; + + if (!vdev_readable(cvd)) + continue; + + if (vdev_draid_readable(cvd, physical_offset)) + return (B_TRUE); + } + + return (B_FALSE); + } + + return (vdev_readable(vd)); +} + +/* + * Returns the first distributed spare found under the provided vdev tree. + */ +static vdev_t * +vdev_draid_find_spare(vdev_t *vd) +{ + if (vd->vdev_ops == &vdev_draid_spare_ops) + return (vd); + + for (int c = 0; c < vd->vdev_children; c++) { + vdev_t *svd = vdev_draid_find_spare(vd->vdev_child[c]); + if (svd != NULL) + return (svd); + } + + return (NULL); +} + +/* + * Returns B_TRUE if the passed in vdev is currently "faulted". + * Faulted, in this context, means that the vdev represents a + * replacing or sparing vdev tree. + */ +static boolean_t +vdev_draid_faulted(vdev_t *vd, uint64_t physical_offset) +{ + if (vd->vdev_ops == &vdev_draid_spare_ops) { + vd = vdev_draid_spare_get_child(vd, physical_offset); + if (vd == NULL) + return (B_FALSE); + + /* + * After resolving the distributed spare to a leaf vdev + * check the parent to determine if it's "faulted". + */ + vd = vd->vdev_parent; + } + + return (vd->vdev_ops == &vdev_replacing_ops || + vd->vdev_ops == &vdev_spare_ops); +} + +/* + * Determine if the dRAID block at the logical offset is degraded. + * Used by sequential resilver. + */ +static boolean_t +vdev_draid_group_degraded(vdev_t *vd, uint64_t offset) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + ASSERT3U(vdev_draid_get_astart(vd, offset), ==, offset); + + uint64_t groupstart, perm; + uint64_t physical_offset = vdev_draid_logical_to_physical(vd, + offset, &perm, &groupstart); + + uint8_t *base; + uint64_t iter; + vdev_draid_get_perm(vdc, perm, &base, &iter); + + for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { + uint64_t c = (groupstart + i) % vdc->vdc_ndisks; + uint64_t cid = vdev_draid_permute_id(vdc, base, iter, c); + vdev_t *cvd = vd->vdev_child[cid]; + + /* Group contains a faulted vdev. */ + if (vdev_draid_faulted(cvd, physical_offset)) + return (B_TRUE); + + /* + * Always check groups with active distributed spares + * because any vdev failure in the pool will affect them. + */ + if (vdev_draid_find_spare(cvd) != NULL) + return (B_TRUE); + } + + return (B_FALSE); +} + +/* + * Determine if the txg is missing. Used by healing resilver. + */ +static boolean_t +vdev_draid_group_missing(vdev_t *vd, uint64_t offset, uint64_t txg, + uint64_t size) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + ASSERT3U(vdev_draid_get_astart(vd, offset), ==, offset); + + uint64_t groupstart, perm; + uint64_t physical_offset = vdev_draid_logical_to_physical(vd, + offset, &perm, &groupstart); + + uint8_t *base; + uint64_t iter; + vdev_draid_get_perm(vdc, perm, &base, &iter); + + for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { + uint64_t c = (groupstart + i) % vdc->vdc_ndisks; + uint64_t cid = vdev_draid_permute_id(vdc, base, iter, c); + vdev_t *cvd = vd->vdev_child[cid]; + + /* Transaction group is known to be partially replicated. */ + if (vdev_draid_partial(cvd, physical_offset, txg, size)) + return (B_TRUE); + + /* + * Always check groups with active distributed spares + * because any vdev failure in the pool will affect them. + */ + if (vdev_draid_find_spare(cvd) != NULL) + return (B_TRUE); + } + + return (B_FALSE); +} + +/* + * Find the smallest child asize and largest sector size to calculate the + * available capacity. Distributed spares are ignored since their capacity + * is also based of the minimum child size in the top-level dRAID. + */ +static void +vdev_draid_calculate_asize(vdev_t *vd, uint64_t *asizep, uint64_t *max_asizep, + uint64_t *logical_ashiftp, uint64_t *physical_ashiftp) +{ + uint64_t logical_ashift = 0, physical_ashift = 0; + uint64_t asize = 0, max_asize = 0; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + for (int c = 0; c < vd->vdev_children; c++) { + vdev_t *cvd = vd->vdev_child[c]; + + if (cvd->vdev_ops == &vdev_draid_spare_ops) + continue; + + asize = MIN(asize - 1, cvd->vdev_asize - 1) + 1; + max_asize = MIN(max_asize - 1, cvd->vdev_max_asize - 1) + 1; + logical_ashift = MAX(logical_ashift, cvd->vdev_ashift); + physical_ashift = MAX(physical_ashift, + cvd->vdev_physical_ashift); + } + + *asizep = asize; + *max_asizep = max_asize; + *logical_ashiftp = logical_ashift; + *physical_ashiftp = physical_ashift; +} + +/* + * Open spare vdevs. + */ +static boolean_t +vdev_draid_open_spares(vdev_t *vd) +{ + return (vd->vdev_ops == &vdev_draid_spare_ops || + vd->vdev_ops == &vdev_replacing_ops || + vd->vdev_ops == &vdev_spare_ops); +} + +/* + * Open all children, excluding spares. + */ +static boolean_t +vdev_draid_open_children(vdev_t *vd) +{ + return (!vdev_draid_open_spares(vd)); +} + +/* + * Open a top-level dRAID vdev. + */ +static int +vdev_draid_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize, + uint64_t *logical_ashift, uint64_t *physical_ashift) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + uint64_t nparity = vdc->vdc_nparity; + int open_errors = 0; + + if (nparity > VDEV_DRAID_MAXPARITY || + vd->vdev_children < nparity + 1) { + vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; + return (SET_ERROR(EINVAL)); + } + + /* + * First open the normal children then the distributed spares. This + * ordering is important to ensure the distributed spares calculate + * the correct psize in the event that the dRAID vdevs were expanded. + */ + vdev_open_children_subset(vd, vdev_draid_open_children); + vdev_open_children_subset(vd, vdev_draid_open_spares); + + /* Verify enough of the children are available to continue. */ + for (int c = 0; c < vd->vdev_children; c++) { + if (vd->vdev_child[c]->vdev_open_error != 0) { + if ((++open_errors) > nparity) { + vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; + return (SET_ERROR(ENXIO)); + } + } + } + + /* + * Allocatable capacity is the sum of the space on all children less + * the number of distributed spares rounded down to last full row + * and then to the last full group. An additional 32MB of scratch + * space is reserved at the end of each child for use by the dRAID + * expansion feature. + */ + uint64_t child_asize, child_max_asize; + vdev_draid_calculate_asize(vd, &child_asize, &child_max_asize, + logical_ashift, physical_ashift); + + /* + * Should be unreachable since the minimum child size is 64MB, but + * we want to make sure an underflow absolutely cannot occur here. + */ + if (child_asize < VDEV_DRAID_REFLOW_RESERVE || + child_max_asize < VDEV_DRAID_REFLOW_RESERVE) { + return (SET_ERROR(ENXIO)); + } + + child_asize = ((child_asize - VDEV_DRAID_REFLOW_RESERVE) / + VDEV_DRAID_ROWHEIGHT) * VDEV_DRAID_ROWHEIGHT; + child_max_asize = ((child_max_asize - VDEV_DRAID_REFLOW_RESERVE) / + VDEV_DRAID_ROWHEIGHT) * VDEV_DRAID_ROWHEIGHT; + + *asize = (((child_asize * vdc->vdc_ndisks) / vdc->vdc_groupsz) * + vdc->vdc_groupsz); + *max_asize = (((child_max_asize * vdc->vdc_ndisks) / vdc->vdc_groupsz) * + vdc->vdc_groupsz); + + return (0); +} + +/* + * Close a top-level dRAID vdev. + */ +static void +vdev_draid_close(vdev_t *vd) +{ + for (int c = 0; c < vd->vdev_children; c++) { + if (vd->vdev_child[c] != NULL) + vdev_close(vd->vdev_child[c]); + } +} + +/* + * Return the maximum asize for a rebuild zio in the provided range + * given the following constraints. A dRAID chunks may not: + * + * - Exceed the maximum allowed block size (SPA_MAXBLOCKSIZE), or + * - Span dRAID redundancy groups. + */ +static uint64_t +vdev_draid_rebuild_asize(vdev_t *vd, uint64_t start, uint64_t asize, + uint64_t max_segment) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + uint64_t ashift = vd->vdev_ashift; + uint64_t ndata = vdc->vdc_ndata; + uint64_t psize = MIN(P2ROUNDUP(max_segment * ndata, 1 << ashift), + SPA_MAXBLOCKSIZE); + + ASSERT3U(vdev_draid_get_astart(vd, start), ==, start); + ASSERT3U(asize % (vdc->vdc_groupwidth << ashift), ==, 0); + + /* Chunks must evenly span all data columns in the group. */ + psize = (((psize >> ashift) / ndata) * ndata) << ashift; + uint64_t chunk_size = MIN(asize, vdev_psize_to_asize(vd, psize)); + + /* Reduce the chunk size to the group space remaining. */ + uint64_t group = vdev_draid_offset_to_group(vd, start); + uint64_t left = vdev_draid_group_to_offset(vd, group + 1) - start; + chunk_size = MIN(chunk_size, left); + + ASSERT3U(chunk_size % (vdc->vdc_groupwidth << ashift), ==, 0); + ASSERT3U(vdev_draid_offset_to_group(vd, start), ==, + vdev_draid_offset_to_group(vd, start + chunk_size - 1)); + + return (chunk_size); +} + +/* + * Align the start of the metaslab to the group width and slightly reduce + * its size to a multiple of the group width. Since full stripe writes are + * required by dRAID this space is unallocable. Furthermore, aligning the + * metaslab start is important for vdev initialize and TRIM which both operate + * on metaslab boundaries which vdev_xlate() expects to be aligned. + */ +static void +vdev_draid_metaslab_init(vdev_t *vd, uint64_t *ms_start, uint64_t *ms_size) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + + uint64_t sz = vdc->vdc_groupwidth << vd->vdev_ashift; + uint64_t astart = vdev_draid_get_astart(vd, *ms_start); + uint64_t asize = ((*ms_size - (astart - *ms_start)) / sz) * sz; + + *ms_start = astart; + *ms_size = asize; + + ASSERT0(*ms_start % sz); + ASSERT0(*ms_size % sz); +} + +/* + * Add virtual dRAID spares to the list of valid spares. In order to accomplish + * this the existing array must be freed and reallocated with the additional + * entries. + */ +int +vdev_draid_spare_create(nvlist_t *nvroot, vdev_t *vd, uint64_t *ndraidp, + uint64_t next_vdev_id) +{ + uint64_t draid_nspares = 0; + uint64_t ndraid = 0; + int error; + + for (uint64_t i = 0; i < vd->vdev_children; i++) { + vdev_t *cvd = vd->vdev_child[i]; + + if (cvd->vdev_ops == &vdev_draid_ops) { + vdev_draid_config_t *vdc = cvd->vdev_tsd; + draid_nspares += vdc->vdc_nspares; + ndraid++; + } + } + + if (draid_nspares == 0) { + *ndraidp = ndraid; + return (0); + } + + nvlist_t **old_spares, **new_spares; + uint_t old_nspares; + error = nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, + &old_spares, &old_nspares); + if (error) + old_nspares = 0; + + /* Allocate memory and copy of the existing spares. */ + new_spares = kmem_alloc(sizeof (nvlist_t *) * + (draid_nspares + old_nspares), KM_SLEEP); + for (uint_t i = 0; i < old_nspares; i++) + new_spares[i] = fnvlist_dup(old_spares[i]); + + /* Add new distributed spares to ZPOOL_CONFIG_SPARES. */ + uint64_t n = old_nspares; + for (uint64_t vdev_id = 0; vdev_id < vd->vdev_children; vdev_id++) { + vdev_t *cvd = vd->vdev_child[vdev_id]; + char path[64]; + + if (cvd->vdev_ops != &vdev_draid_ops) + continue; + + vdev_draid_config_t *vdc = cvd->vdev_tsd; + uint64_t nspares = vdc->vdc_nspares; + uint64_t nparity = vdc->vdc_nparity; + + for (uint64_t spare_id = 0; spare_id < nspares; spare_id++) { + bzero(path, sizeof (path)); + (void) snprintf(path, sizeof (path) - 1, + "%s%llu-%llu-%llu", VDEV_TYPE_DRAID, + (u_longlong_t)nparity, + (u_longlong_t)next_vdev_id + vdev_id, + (u_longlong_t)spare_id); + + nvlist_t *spare = fnvlist_alloc(); + fnvlist_add_string(spare, ZPOOL_CONFIG_PATH, path); + fnvlist_add_string(spare, ZPOOL_CONFIG_TYPE, + VDEV_TYPE_DRAID_SPARE); + fnvlist_add_uint64(spare, ZPOOL_CONFIG_TOP_GUID, + cvd->vdev_guid); + fnvlist_add_uint64(spare, ZPOOL_CONFIG_SPARE_ID, + spare_id); + fnvlist_add_uint64(spare, ZPOOL_CONFIG_IS_LOG, 0); + fnvlist_add_uint64(spare, ZPOOL_CONFIG_IS_SPARE, 1); + fnvlist_add_uint64(spare, ZPOOL_CONFIG_WHOLE_DISK, 1); + fnvlist_add_uint64(spare, ZPOOL_CONFIG_ASHIFT, + cvd->vdev_ashift); + + new_spares[n] = spare; + n++; + } + } + + if (n > 0) { + (void) nvlist_remove_all(nvroot, ZPOOL_CONFIG_SPARES); + fnvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, + new_spares, n); + } + + for (int i = 0; i < n; i++) + nvlist_free(new_spares[i]); + + kmem_free(new_spares, sizeof (*new_spares) * n); + *ndraidp = ndraid; + + return (0); +} + +/* + * Determine if any portion of the provided block resides on a child vdev + * with a dirty DTL and therefore needs to be resilvered. + */ +static boolean_t +vdev_draid_need_resilver(vdev_t *vd, const dva_t *dva, size_t psize, + uint64_t phys_birth) +{ + uint64_t offset = DVA_GET_OFFSET(dva); + uint64_t asize = vdev_draid_asize(vd, psize); + + if (phys_birth == TXG_UNKNOWN) { + /* + * Sequential resilver. There is no meaningful phys_birth + * for this block, we can only determine if block resides + * in a degraded group in which case it must be resilvered. + */ + ASSERT3U(vdev_draid_offset_to_group(vd, offset), ==, + vdev_draid_offset_to_group(vd, offset + asize - 1)); + + return (vdev_draid_group_degraded(vd, offset)); + } else { + /* + * Healing resilver. TXGs not in DTL_PARTIAL are intact, + * as are blocks in non-degraded groups. + */ + if (!vdev_dtl_contains(vd, DTL_PARTIAL, phys_birth, 1)) + return (B_FALSE); + + if (vdev_draid_group_missing(vd, offset, phys_birth, 1)) + return (B_TRUE); + + /* The block may span groups in which case check both. */ + if (vdev_draid_offset_to_group(vd, offset) != + vdev_draid_offset_to_group(vd, offset + asize - 1)) { + if (vdev_draid_group_missing(vd, + offset + asize, phys_birth, 1)) + return (B_TRUE); + } + + return (B_FALSE); + } +} + +static boolean_t +vdev_draid_rebuilding(vdev_t *vd) +{ + if (vd->vdev_ops->vdev_op_leaf && vd->vdev_rebuild_txg) + return (B_TRUE); + + for (int i = 0; i < vd->vdev_children; i++) { + if (vdev_draid_rebuilding(vd->vdev_child[i])) { + return (B_TRUE); + } + } + + return (B_FALSE); +} + +static void +vdev_draid_io_verify(vdev_t *vd, raidz_row_t *rr, int col) +{ +#ifdef ZFS_DEBUG + range_seg64_t logical_rs, physical_rs, remain_rs; + logical_rs.rs_start = rr->rr_offset; + logical_rs.rs_end = logical_rs.rs_start + + vdev_draid_asize(vd, rr->rr_size); + + raidz_col_t *rc = &rr->rr_col[col]; + vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; + + vdev_xlate(cvd, &logical_rs, &physical_rs, &remain_rs); + ASSERT(vdev_xlate_is_empty(&remain_rs)); + ASSERT3U(rc->rc_offset, ==, physical_rs.rs_start); + ASSERT3U(rc->rc_offset, <, physical_rs.rs_end); + ASSERT3U(rc->rc_offset + rc->rc_size, ==, physical_rs.rs_end); +#endif +} + +/* + * For write operations: + * 1. Generate the parity data + * 2. Create child zio write operations to each column's vdev, for both + * data and parity. A gang ABD is allocated by vdev_draid_map_alloc() + * if a skip sector needs to be added to a column. + */ +static void +vdev_draid_io_start_write(zio_t *zio, raidz_row_t *rr) +{ + vdev_t *vd = zio->io_vd; + raidz_map_t *rm = zio->io_vsd; + + vdev_raidz_generate_parity_row(rm, rr); + + for (int c = 0; c < rr->rr_cols; c++) { + raidz_col_t *rc = &rr->rr_col[c]; + + /* + * Empty columns are zero filled and included in the parity + * calculation and therefore must be written. + */ + ASSERT3U(rc->rc_size, !=, 0); + + /* Verify physical to logical translation */ + vdev_draid_io_verify(vd, rr, c); + + zio_nowait(zio_vdev_child_io(zio, NULL, + vd->vdev_child[rc->rc_devidx], rc->rc_offset, + rc->rc_abd, rc->rc_size, zio->io_type, zio->io_priority, + 0, vdev_raidz_child_done, rc)); + } +} + +/* + * For read operations: + * 1. The vdev_draid_map_alloc() function will create a minimal raidz + * mapping for the read based on the zio->io_flags. There are two + * possible mappings either 1) a normal read, or 2) a scrub/resilver. + * 2. Create the zio read operations. This will include all parity + * columns and skip sectors for a scrub/resilver. + */ +static void +vdev_draid_io_start_read(zio_t *zio, raidz_row_t *rr) +{ + vdev_t *vd = zio->io_vd; + + /* Sequential rebuild must do IO at redundancy group boundary. */ + IMPLY(zio->io_priority == ZIO_PRIORITY_REBUILD, rr->rr_nempty == 0); + + /* + * Iterate over the columns in reverse order so that we hit the parity + * last. Any errors along the way will force us to read the parity. + * For scrub/resilver IOs which verify skip sectors, a gang ABD will + * have been allocated to store them and rc->rc_size is increased. + */ + for (int c = rr->rr_cols - 1; c >= 0; c--) { + raidz_col_t *rc = &rr->rr_col[c]; + vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; + + if (!vdev_draid_readable(cvd, rc->rc_offset)) { + if (c >= rr->rr_firstdatacol) + rr->rr_missingdata++; + else + rr->rr_missingparity++; + rc->rc_error = SET_ERROR(ENXIO); + rc->rc_tried = 1; + rc->rc_skipped = 1; + continue; + } + + if (vdev_draid_missing(cvd, rc->rc_offset, zio->io_txg, 1)) { + if (c >= rr->rr_firstdatacol) + rr->rr_missingdata++; + else + rr->rr_missingparity++; + rc->rc_error = SET_ERROR(ESTALE); + rc->rc_skipped = 1; + continue; + } + + /* + * Empty columns may be read during vdev_draid_io_done(). + * Only skip them after the readable and missing checks + * verify they are available. + */ + if (rc->rc_size == 0) { + rc->rc_skipped = 1; + continue; + } + + if (zio->io_flags & ZIO_FLAG_RESILVER) { + vdev_t *svd; + + /* + * If this child is a distributed spare then the + * offset might reside on the vdev being replaced. + * In which case this data must be written to the + * new device. Failure to do so would result in + * checksum errors when the old device is detached + * and the pool is scrubbed. + */ + if ((svd = vdev_draid_find_spare(cvd)) != NULL) { + svd = vdev_draid_spare_get_child(svd, + rc->rc_offset); + if (svd && (svd->vdev_ops == &vdev_spare_ops || + svd->vdev_ops == &vdev_replacing_ops)) { + rc->rc_repair = 1; + } + } + + /* + * Always issue a repair IO to this child when its + * a spare or replacing vdev with an active rebuild. + */ + if ((cvd->vdev_ops == &vdev_spare_ops || + cvd->vdev_ops == &vdev_replacing_ops) && + vdev_draid_rebuilding(cvd)) { + rc->rc_repair = 1; + } + } + } + + /* + * Either a parity or data column is missing this means a repair + * may be attempted by vdev_draid_io_done(). Expand the raid map + * to read in empty columns which are needed along with the parity + * during reconstruction. + */ + if ((rr->rr_missingdata > 0 || rr->rr_missingparity > 0) && + rr->rr_nempty > 0 && rr->rr_abd_empty == NULL) { + vdev_draid_map_alloc_empty(zio, rr); + } + + for (int c = rr->rr_cols - 1; c >= 0; c--) { + raidz_col_t *rc = &rr->rr_col[c]; + vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; + + if (rc->rc_error || rc->rc_size == 0) + continue; + + if (c >= rr->rr_firstdatacol || rr->rr_missingdata > 0 || + (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { + zio_nowait(zio_vdev_child_io(zio, NULL, cvd, + rc->rc_offset, rc->rc_abd, rc->rc_size, + zio->io_type, zio->io_priority, 0, + vdev_raidz_child_done, rc)); + } + } +} + +/* + * Start an IO operation to a dRAID vdev. + */ +static void +vdev_draid_io_start(zio_t *zio) +{ + vdev_t *vd __maybe_unused = zio->io_vd; + raidz_map_t *rm; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + ASSERT3U(zio->io_offset, ==, vdev_draid_get_astart(vd, zio->io_offset)); + + rm = vdev_draid_map_alloc(zio); + + if (zio->io_type == ZIO_TYPE_WRITE) { + for (int i = 0; i < rm->rm_nrows; i++) { + vdev_draid_io_start_write(zio, rm->rm_row[i]); + } + } else { + ASSERT(zio->io_type == ZIO_TYPE_READ); + + for (int i = 0; i < rm->rm_nrows; i++) { + vdev_draid_io_start_read(zio, rm->rm_row[i]); + } + } + + zio_execute(zio); +} + +/* + * Complete an IO operation on a dRAID vdev. The raidz logic can be applied + * to dRAID since the layout is fully described by the raidz_map_t. + */ +static void +vdev_draid_io_done(zio_t *zio) +{ + vdev_raidz_io_done(zio); +} + +static void +vdev_draid_state_change(vdev_t *vd, int faulted, int degraded) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + ASSERT(vd->vdev_ops == &vdev_draid_ops); + + if (faulted > vdc->vdc_nparity) + vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, + VDEV_AUX_NO_REPLICAS); + else if (degraded + faulted != 0) + vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); + else + vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); +} + +static void +vdev_draid_xlate(vdev_t *cvd, const range_seg64_t *logical_rs, + range_seg64_t *physical_rs, range_seg64_t *remain_rs) +{ + vdev_t *raidvd = cvd->vdev_parent; + ASSERT(raidvd->vdev_ops == &vdev_draid_ops); + + vdev_draid_config_t *vdc = raidvd->vdev_tsd; + uint64_t ashift = raidvd->vdev_top->vdev_ashift; + + /* Make sure the offsets are block-aligned */ + ASSERT0(logical_rs->rs_start % (1 << ashift)); + ASSERT0(logical_rs->rs_end % (1 << ashift)); + + uint64_t logical_start = logical_rs->rs_start; + uint64_t logical_end = logical_rs->rs_end; + + /* + * Unaligned ranges must be skipped. All metaslabs are correctly + * aligned so this should not happen, but this case is handled in + * case it's needed by future callers. + */ + uint64_t astart = vdev_draid_get_astart(raidvd, logical_start); + if (astart != logical_start) { + physical_rs->rs_start = logical_start; + physical_rs->rs_end = logical_start; + remain_rs->rs_start = MIN(astart, logical_end); + remain_rs->rs_end = logical_end; + return; + } + + /* + * Unlike with mirrors and raidz a dRAID logical range can map + * to multiple non-contiguous physical ranges. This is handled by + * limiting the size of the logical range to a single group and + * setting the remain argument such that it describes the remaining + * unmapped logical range. This is stricter than absolutely + * necessary but helps simplify the logic below. + */ + uint64_t group = vdev_draid_offset_to_group(raidvd, logical_start); + uint64_t nextstart = vdev_draid_group_to_offset(raidvd, group + 1); + if (logical_end > nextstart) + logical_end = nextstart; + + /* Find the starting offset for each vdev in the group */ + uint64_t perm, groupstart; + uint64_t start = vdev_draid_logical_to_physical(raidvd, + logical_start, &perm, &groupstart); + uint64_t end = start; + + uint8_t *base; + uint64_t iter, id; + vdev_draid_get_perm(vdc, perm, &base, &iter); + + /* + * Check if the passed child falls within the group. If it does + * update the start and end to reflect the physical range. + * Otherwise, leave them unmodified which will result in an empty + * (zero-length) physical range being returned. + */ + for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { + uint64_t c = (groupstart + i) % vdc->vdc_ndisks; + + if (c == 0 && i != 0) { + /* the group wrapped, increment the start */ + start += VDEV_DRAID_ROWHEIGHT; + end = start; + } + + id = vdev_draid_permute_id(vdc, base, iter, c); + if (id == cvd->vdev_id) { + uint64_t b_size = (logical_end >> ashift) - + (logical_start >> ashift); + ASSERT3U(b_size, >, 0); + end = start + ((((b_size - 1) / + vdc->vdc_groupwidth) + 1) << ashift); + break; + } + } + physical_rs->rs_start = start; + physical_rs->rs_end = end; + + /* + * Only top-level vdevs are allowed to set remain_rs because + * when .vdev_op_xlate() is called for their children the full + * logical range is not provided by vdev_xlate(). + */ + remain_rs->rs_start = logical_end; + remain_rs->rs_end = logical_rs->rs_end; + + ASSERT3U(physical_rs->rs_start, <=, logical_start); + ASSERT3U(physical_rs->rs_end - physical_rs->rs_start, <=, + logical_end - logical_start); +} + +/* + * Add dRAID specific fields to the config nvlist. + */ +static void +vdev_draid_config_generate(vdev_t *vd, nvlist_t *nv) +{ + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); + vdev_draid_config_t *vdc = vd->vdev_tsd; + + fnvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, vdc->vdc_nparity); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NDATA, vdc->vdc_ndata); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NSPARES, vdc->vdc_nspares); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NGROUPS, vdc->vdc_ngroups); +} + +/* + * Initialize private dRAID specific fields from the nvlist. + */ +static int +vdev_draid_init(spa_t *spa, nvlist_t *nv, void **tsd) +{ + uint64_t ndata, nparity, nspares, ngroups; + int error; + + if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NDATA, &ndata)) + return (SET_ERROR(EINVAL)); + + if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY, &nparity) || + nparity == 0 || nparity > VDEV_DRAID_MAXPARITY) { + return (SET_ERROR(EINVAL)); + } + + uint_t children; + nvlist_t **child; + if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, + &child, &children) != 0 || children == 0 || + children > VDEV_DRAID_MAX_CHILDREN) { + return (SET_ERROR(EINVAL)); + } + + if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NSPARES, &nspares) || + nspares > 100 || nspares > (children - (ndata + nparity))) { + return (SET_ERROR(EINVAL)); + } + + if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NGROUPS, &ngroups) || + ngroups == 0 || ngroups > VDEV_DRAID_MAX_CHILDREN) { + return (SET_ERROR(EINVAL)); + } + + /* + * Validate the minimum number of children exist per group for the + * specified parity level (draid1 >= 2, draid2 >= 3, draid3 >= 4). + */ + if (children < (ndata + nparity + nspares)) + return (SET_ERROR(EINVAL)); + + /* + * Create the dRAID configuration using the pool nvlist configuration + * and the fixed mapping for the correct number of children. + */ + vdev_draid_config_t *vdc; + const draid_map_t *map; + + error = vdev_draid_lookup_map(children, &map); + if (error) + return (SET_ERROR(EINVAL)); + + vdc = kmem_zalloc(sizeof (*vdc), KM_SLEEP); + vdc->vdc_ndata = ndata; + vdc->vdc_nparity = nparity; + vdc->vdc_nspares = nspares; + vdc->vdc_children = children; + vdc->vdc_ngroups = ngroups; + vdc->vdc_nperms = map->dm_nperms; + + error = vdev_draid_generate_perms(map, &vdc->vdc_perms); + if (error) { + kmem_free(vdc, sizeof (*vdc)); + return (SET_ERROR(EINVAL)); + } + + /* + * Derived constants. + */ + vdc->vdc_groupwidth = vdc->vdc_ndata + vdc->vdc_nparity; + vdc->vdc_ndisks = vdc->vdc_children - vdc->vdc_nspares; + vdc->vdc_groupsz = vdc->vdc_groupwidth * VDEV_DRAID_ROWHEIGHT; + vdc->vdc_devslicesz = (vdc->vdc_groupsz * vdc->vdc_ngroups) / + vdc->vdc_ndisks; + + ASSERT3U(vdc->vdc_groupwidth, >=, 2); + ASSERT3U(vdc->vdc_groupwidth, <=, vdc->vdc_ndisks); + ASSERT3U(vdc->vdc_groupsz, >=, 2 * VDEV_DRAID_ROWHEIGHT); + ASSERT3U(vdc->vdc_devslicesz, >=, VDEV_DRAID_ROWHEIGHT); + ASSERT3U(vdc->vdc_devslicesz % VDEV_DRAID_ROWHEIGHT, ==, 0); + ASSERT3U((vdc->vdc_groupwidth * vdc->vdc_ngroups) % + vdc->vdc_ndisks, ==, 0); + + *tsd = vdc; + + return (0); +} + +static void +vdev_draid_fini(vdev_t *vd) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + vmem_free(vdc->vdc_perms, sizeof (uint8_t) * + vdc->vdc_children * vdc->vdc_nperms); + kmem_free(vdc, sizeof (*vdc)); +} + +static uint64_t +vdev_draid_nparity(vdev_t *vd) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + return (vdc->vdc_nparity); +} + +static uint64_t +vdev_draid_ndisks(vdev_t *vd) +{ + vdev_draid_config_t *vdc = vd->vdev_tsd; + + return (vdc->vdc_ndisks); +} + +vdev_ops_t vdev_draid_ops = { + .vdev_op_init = vdev_draid_init, + .vdev_op_fini = vdev_draid_fini, + .vdev_op_open = vdev_draid_open, + .vdev_op_close = vdev_draid_close, + .vdev_op_asize = vdev_draid_asize, + .vdev_op_min_asize = vdev_draid_min_asize, + .vdev_op_min_alloc = vdev_draid_min_alloc, + .vdev_op_io_start = vdev_draid_io_start, + .vdev_op_io_done = vdev_draid_io_done, + .vdev_op_state_change = vdev_draid_state_change, + .vdev_op_need_resilver = vdev_draid_need_resilver, + .vdev_op_hold = NULL, + .vdev_op_rele = NULL, + .vdev_op_remap = NULL, + .vdev_op_xlate = vdev_draid_xlate, + .vdev_op_rebuild_asize = vdev_draid_rebuild_asize, + .vdev_op_metaslab_init = vdev_draid_metaslab_init, + .vdev_op_config_generate = vdev_draid_config_generate, + .vdev_op_nparity = vdev_draid_nparity, + .vdev_op_ndisks = vdev_draid_ndisks, + .vdev_op_type = VDEV_TYPE_DRAID, + .vdev_op_leaf = B_FALSE, +}; + + +/* + * A dRAID distributed spare is a virtual leaf vdev which is included in the + * parent dRAID configuration. The last N columns of the dRAID permutation + * table are used to determine on which dRAID children a specific offset + * should be written. These spare leaf vdevs can only be used to replace + * faulted children in the same dRAID configuration. + */ + +/* + * Distributed spare state. All fields are set when the distributed spare is + * first opened and are immutable. + */ +typedef struct { + vdev_t *vds_draid_vdev; /* top-level parent dRAID vdev */ + uint64_t vds_top_guid; /* top-level parent dRAID guid */ + uint64_t vds_spare_id; /* spare id (0 - vdc->vdc_nspares-1) */ +} vdev_draid_spare_t; + +/* + * Returns the parent dRAID vdev to which the distributed spare belongs. + * This may be safely called even when the vdev is not open. + */ +vdev_t * +vdev_draid_spare_get_parent(vdev_t *vd) +{ + vdev_draid_spare_t *vds = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); + + if (vds->vds_draid_vdev != NULL) + return (vds->vds_draid_vdev); + + return (vdev_lookup_by_guid(vd->vdev_spa->spa_root_vdev, + vds->vds_top_guid)); +} + +/* + * A dRAID space is active when it's the child of a vdev using the + * vdev_spare_ops, vdev_replacing_ops or vdev_draid_ops. + */ +static boolean_t +vdev_draid_spare_is_active(vdev_t *vd) +{ + vdev_t *pvd = vd->vdev_parent; + + if (pvd != NULL && (pvd->vdev_ops == &vdev_spare_ops || + pvd->vdev_ops == &vdev_replacing_ops || + pvd->vdev_ops == &vdev_draid_ops)) { + return (B_TRUE); + } else { + return (B_FALSE); + } +} + +/* + * Given a dRAID distribute spare vdev, returns the physical child vdev + * on which the provided offset resides. This may involve recursing through + * multiple layers of distributed spares. Note that offset is relative to + * this vdev. + */ +vdev_t * +vdev_draid_spare_get_child(vdev_t *vd, uint64_t physical_offset) +{ + vdev_draid_spare_t *vds = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); + + /* The vdev is closed */ + if (vds->vds_draid_vdev == NULL) + return (NULL); + + vdev_t *tvd = vds->vds_draid_vdev; + vdev_draid_config_t *vdc = tvd->vdev_tsd; + + ASSERT3P(tvd->vdev_ops, ==, &vdev_draid_ops); + ASSERT3U(vds->vds_spare_id, <, vdc->vdc_nspares); + + uint8_t *base; + uint64_t iter; + uint64_t perm = physical_offset / vdc->vdc_devslicesz; + + vdev_draid_get_perm(vdc, perm, &base, &iter); + + uint64_t cid = vdev_draid_permute_id(vdc, base, iter, + (tvd->vdev_children - 1) - vds->vds_spare_id); + vdev_t *cvd = tvd->vdev_child[cid]; + + if (cvd->vdev_ops == &vdev_draid_spare_ops) + return (vdev_draid_spare_get_child(cvd, physical_offset)); + + return (cvd); +} + +/* ARGSUSED */ +static void +vdev_draid_spare_close(vdev_t *vd) +{ + vdev_draid_spare_t *vds = vd->vdev_tsd; + vds->vds_draid_vdev = NULL; +} + +/* + * Opening a dRAID spare device is done by looking up the associated dRAID + * top-level vdev guid from the spare configuration. + */ +static int +vdev_draid_spare_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize, + uint64_t *logical_ashift, uint64_t *physical_ashift) +{ + vdev_draid_spare_t *vds = vd->vdev_tsd; + vdev_t *rvd = vd->vdev_spa->spa_root_vdev; + uint64_t asize, max_asize; + + vdev_t *tvd = vdev_lookup_by_guid(rvd, vds->vds_top_guid); + if (tvd == NULL) { + /* + * When spa_vdev_add() is labeling new spares the + * associated dRAID is not attached to the root vdev + * nor does this spare have a parent. Simulate a valid + * device in order to allow the label to be initialized + * and the distributed spare added to the configuration. + */ + if (vd->vdev_parent == NULL) { + *psize = *max_psize = SPA_MINDEVSIZE; + *logical_ashift = *physical_ashift = ASHIFT_MIN; + return (0); + } + + return (SET_ERROR(EINVAL)); + } + + vdev_draid_config_t *vdc = tvd->vdev_tsd; + if (tvd->vdev_ops != &vdev_draid_ops || vdc == NULL) + return (SET_ERROR(EINVAL)); + + if (vds->vds_spare_id >= vdc->vdc_nspares) + return (SET_ERROR(EINVAL)); + + /* + * Neither tvd->vdev_asize or tvd->vdev_max_asize can be used here + * because the caller may be vdev_draid_open() in which case the + * values are stale as they haven't yet been updated by vdev_open(). + * To avoid this always recalculate the dRAID asize and max_asize. + */ + vdev_draid_calculate_asize(tvd, &asize, &max_asize, + logical_ashift, physical_ashift); + + *psize = asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE; + *max_psize = max_asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE; + + vds->vds_draid_vdev = tvd; + + return (0); +} + +/* + * Completed distributed spare IO. Store the result in the parent zio + * as if it had performed the operation itself. Only the first error is + * preserved if there are multiple errors. + */ +static void +vdev_draid_spare_child_done(zio_t *zio) +{ + zio_t *pio = zio->io_private; + + /* + * IOs are issued to non-writable vdevs in order to keep their + * DTLs accurate. However, we don't want to propagate the + * error in to the distributed spare's DTL. When resilvering + * vdev_draid_need_resilver() will consult the relevant DTL + * to determine if the data is missing and must be repaired. + */ + if (!vdev_writeable(zio->io_vd)) + return; + + if (pio->io_error == 0) + pio->io_error = zio->io_error; +} + +/* + * Returns a valid label nvlist for the distributed spare vdev. This is + * used to bypass the IO pipeline to avoid the complexity of constructing + * a complete label with valid checksum to return when read. + */ +nvlist_t * +vdev_draid_read_config_spare(vdev_t *vd) +{ + spa_t *spa = vd->vdev_spa; + spa_aux_vdev_t *sav = &spa->spa_spares; + uint64_t guid = vd->vdev_guid; + + nvlist_t *nv = fnvlist_alloc(); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_CREATE_TXG, vd->vdev_crtxg); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_VERSION, spa_version(spa)); + fnvlist_add_string(nv, ZPOOL_CONFIG_POOL_NAME, spa_name(spa)); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_TXG, spa->spa_config_txg); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_TOP_GUID, vd->vdev_top->vdev_guid); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_STATE, + vdev_draid_spare_is_active(vd) ? + POOL_STATE_ACTIVE : POOL_STATE_SPARE); + + /* Set the vdev guid based on the vdev list in sav_count. */ + for (int i = 0; i < sav->sav_count; i++) { + if (sav->sav_vdevs[i]->vdev_ops == &vdev_draid_spare_ops && + strcmp(sav->sav_vdevs[i]->vdev_path, vd->vdev_path) == 0) { + guid = sav->sav_vdevs[i]->vdev_guid; + break; + } + } + + fnvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, guid); + + return (nv); +} + +/* + * Handle any ioctl requested of the distributed spare. Only flushes + * are supported in which case all children must be flushed. + */ +static int +vdev_draid_spare_ioctl(zio_t *zio) +{ + vdev_t *vd = zio->io_vd; + int error = 0; + + if (zio->io_cmd == DKIOCFLUSHWRITECACHE) { + for (int c = 0; c < vd->vdev_children; c++) { + zio_nowait(zio_vdev_child_io(zio, NULL, + vd->vdev_child[c], zio->io_offset, zio->io_abd, + zio->io_size, zio->io_type, zio->io_priority, 0, + vdev_draid_spare_child_done, zio)); + } + } else { + error = SET_ERROR(ENOTSUP); + } + + return (error); +} + +/* + * Initiate an IO to the distributed spare. For normal IOs this entails using + * the zio->io_offset and permutation table to calculate which child dRAID vdev + * is responsible for the data. Then passing along the zio to that child to + * perform the actual IO. The label ranges are not stored on disk and require + * some special handling which is described below. + */ +static void +vdev_draid_spare_io_start(zio_t *zio) +{ + vdev_t *cvd = NULL, *vd = zio->io_vd; + vdev_draid_spare_t *vds = vd->vdev_tsd; + uint64_t offset = zio->io_offset - VDEV_LABEL_START_SIZE; + + /* + * If the vdev is closed, it's likely in the REMOVED or FAULTED state. + * Nothing to be done here but return failure. + */ + if (vds == NULL) { + zio->io_error = ENXIO; + zio_interrupt(zio); + return; + } + + switch (zio->io_type) { + case ZIO_TYPE_IOCTL: + zio->io_error = vdev_draid_spare_ioctl(zio); + break; + + case ZIO_TYPE_WRITE: + if (VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)) { + /* + * Accept probe IOs and config writers to simulate the + * existence of an on disk label. vdev_label_sync(), + * vdev_uberblock_sync() and vdev_copy_uberblocks() + * skip the distributed spares. This only leaves + * vdev_label_init() which is allowed to succeed to + * avoid adding special cases the function. + */ + if (zio->io_flags & ZIO_FLAG_PROBE || + zio->io_flags & ZIO_FLAG_CONFIG_WRITER) { + zio->io_error = 0; + } else { + zio->io_error = SET_ERROR(EIO); + } + } else { + cvd = vdev_draid_spare_get_child(vd, offset); + + if (cvd == NULL) { + zio->io_error = SET_ERROR(ENXIO); + } else { + zio_nowait(zio_vdev_child_io(zio, NULL, cvd, + offset, zio->io_abd, zio->io_size, + zio->io_type, zio->io_priority, 0, + vdev_draid_spare_child_done, zio)); + } + } + break; + + case ZIO_TYPE_READ: + if (VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)) { + /* + * Accept probe IOs to simulate the existence of a + * label. vdev_label_read_config() bypasses the + * pipeline to read the label configuration and + * vdev_uberblock_load() skips distributed spares + * when attempting to locate the best uberblock. + */ + if (zio->io_flags & ZIO_FLAG_PROBE) { + zio->io_error = 0; + } else { + zio->io_error = SET_ERROR(EIO); + } + } else { + cvd = vdev_draid_spare_get_child(vd, offset); + + if (cvd == NULL || !vdev_readable(cvd)) { + zio->io_error = SET_ERROR(ENXIO); + } else { + zio_nowait(zio_vdev_child_io(zio, NULL, cvd, + offset, zio->io_abd, zio->io_size, + zio->io_type, zio->io_priority, 0, + vdev_draid_spare_child_done, zio)); + } + } + break; + + case ZIO_TYPE_TRIM: + /* The vdev label ranges are never trimmed */ + ASSERT0(VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)); + + cvd = vdev_draid_spare_get_child(vd, offset); + + if (cvd == NULL || !cvd->vdev_has_trim) { + zio->io_error = SET_ERROR(ENXIO); + } else { + zio_nowait(zio_vdev_child_io(zio, NULL, cvd, + offset, zio->io_abd, zio->io_size, + zio->io_type, zio->io_priority, 0, + vdev_draid_spare_child_done, zio)); + } + break; + + default: + zio->io_error = SET_ERROR(ENOTSUP); + break; + } + + zio_execute(zio); +} + +/* ARGSUSED */ +static void +vdev_draid_spare_io_done(zio_t *zio) +{ +} + +/* + * Lookup the full spare config in spa->spa_spares.sav_config and + * return the top_guid and spare_id for the named spare. + */ +static int +vdev_draid_spare_lookup(spa_t *spa, nvlist_t *nv, uint64_t *top_guidp, + uint64_t *spare_idp) +{ + nvlist_t **spares; + uint_t nspares; + int error; + + if ((spa->spa_spares.sav_config == NULL) || + (nvlist_lookup_nvlist_array(spa->spa_spares.sav_config, + ZPOOL_CONFIG_SPARES, &spares, &nspares) != 0)) { + return (SET_ERROR(ENOENT)); + } + + char *spare_name; + error = nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &spare_name); + if (error != 0) + return (SET_ERROR(EINVAL)); + + for (int i = 0; i < nspares; i++) { + nvlist_t *spare = spares[i]; + uint64_t top_guid, spare_id; + char *type, *path; + + /* Skip non-distributed spares */ + error = nvlist_lookup_string(spare, ZPOOL_CONFIG_TYPE, &type); + if (error != 0 || strcmp(type, VDEV_TYPE_DRAID_SPARE) != 0) + continue; + + /* Skip spares with the wrong name */ + error = nvlist_lookup_string(spare, ZPOOL_CONFIG_PATH, &path); + if (error != 0 || strcmp(path, spare_name) != 0) + continue; + + /* Found the matching spare */ + error = nvlist_lookup_uint64(spare, + ZPOOL_CONFIG_TOP_GUID, &top_guid); + if (error == 0) { + error = nvlist_lookup_uint64(spare, + ZPOOL_CONFIG_SPARE_ID, &spare_id); + } + + if (error != 0) { + return (SET_ERROR(EINVAL)); + } else { + *top_guidp = top_guid; + *spare_idp = spare_id; + return (0); + } + } + + return (SET_ERROR(ENOENT)); +} + +/* + * Initialize private dRAID spare specific fields from the nvlist. + */ +static int +vdev_draid_spare_init(spa_t *spa, nvlist_t *nv, void **tsd) +{ + vdev_draid_spare_t *vds; + uint64_t top_guid = 0; + uint64_t spare_id; + + /* + * In the normal case check the list of spares stored in the spa + * to lookup the top_guid and spare_id for provided spare config. + * When creating a new pool or adding vdevs the spare list is not + * yet populated and the values are provided in the passed config. + */ + if (vdev_draid_spare_lookup(spa, nv, &top_guid, &spare_id) != 0) { + if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_TOP_GUID, + &top_guid) != 0) + return (SET_ERROR(EINVAL)); + + if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_SPARE_ID, + &spare_id) != 0) + return (SET_ERROR(EINVAL)); + } + + vds = kmem_alloc(sizeof (vdev_draid_spare_t), KM_SLEEP); + vds->vds_draid_vdev = NULL; + vds->vds_top_guid = top_guid; + vds->vds_spare_id = spare_id; + + *tsd = vds; + + return (0); +} + +static void +vdev_draid_spare_fini(vdev_t *vd) +{ + kmem_free(vd->vdev_tsd, sizeof (vdev_draid_spare_t)); +} + +static void +vdev_draid_spare_config_generate(vdev_t *vd, nvlist_t *nv) +{ + vdev_draid_spare_t *vds = vd->vdev_tsd; + + ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); + + fnvlist_add_uint64(nv, ZPOOL_CONFIG_TOP_GUID, vds->vds_top_guid); + fnvlist_add_uint64(nv, ZPOOL_CONFIG_SPARE_ID, vds->vds_spare_id); +} + +vdev_ops_t vdev_draid_spare_ops = { + .vdev_op_init = vdev_draid_spare_init, + .vdev_op_fini = vdev_draid_spare_fini, + .vdev_op_open = vdev_draid_spare_open, + .vdev_op_close = vdev_draid_spare_close, + .vdev_op_asize = vdev_default_asize, + .vdev_op_min_asize = vdev_default_min_asize, + .vdev_op_min_alloc = NULL, + .vdev_op_io_start = vdev_draid_spare_io_start, + .vdev_op_io_done = vdev_draid_spare_io_done, + .vdev_op_state_change = NULL, + .vdev_op_need_resilver = NULL, + .vdev_op_hold = NULL, + .vdev_op_rele = NULL, + .vdev_op_remap = NULL, + .vdev_op_xlate = vdev_default_xlate, + .vdev_op_rebuild_asize = NULL, + .vdev_op_metaslab_init = NULL, + .vdev_op_config_generate = vdev_draid_spare_config_generate, + .vdev_op_nparity = NULL, + .vdev_op_ndisks = NULL, + .vdev_op_type = VDEV_TYPE_DRAID_SPARE, + .vdev_op_leaf = B_TRUE, +}; 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