c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2024-11-18 02:20:59 +03:00
Code Issues Packages Projects Releases Wiki Activity
e783fa0925
mirror_zfs/module/zfs/vdev_draid.c
Matthew Ahrens 330c6c0523
Clean up RAIDZ/DRAID ereport code 
The RAIDZ and DRAID code is responsible for reporting checksum errors on
their child vdevs.  Checksum errors represent events where a disk
returned data or parity that should have been correct, but was not.  In
other words, these are instances of silent data corruption.  The
checksum errors show up in the vdev stats (and thus `zpool status`'s
CKSUM column), and in the event log (`zpool events`).

Note, this is in contrast with the more common "noisy" errors where a
disk goes offline, in which case ZFS knows that the disk is bad and
doesn't try to read it, or the device returns an error on the requested
read or write operation.

RAIDZ/DRAID generate checksum errors via three code paths:

1. When RAIDZ/DRAID reconstructs a damaged block, checksum errors are
reported on any children whose data was not used during the
reconstruction.  This is handled in `raidz_reconstruct()`.  This is the
most common type of RAIDZ/DRAID checksum error.

2. When RAIDZ/DRAID is not able to reconstruct a damaged block, that
means that the data has been lost.  The zio fails and an error is
returned to the consumer (e.g. the read(2) system call).  This would
happen if, for example, three different disks in a RAIDZ2 group are
silently damaged.  Since the damage is silent, it isn't possible to know
which three disks are damaged, so a checksum error is reported against
every child that returned data or parity for this read.  (For DRAID,
typically only one "group" of children is involved in each io.)  This
case is handled in `vdev_raidz_cksum_finish()`. This is the next most
common type of RAIDZ/DRAID checksum error.

3. If RAIDZ/DRAID is not able to reconstruct a damaged block (like in
case 2), but there happens to be additional copies of this block due to
"ditto blocks" (i.e. multiple DVA's in this blkptr_t), and one of those
copies is good, then RAIDZ/DRAID compares each sector of the data or
parity that it retrieved with the good data from the other DVA, and if
they differ then it reports a checksum error on this child.  This
differs from case 2 in that the checksum error is reported on only the
subset of children that actually have bad data or parity.  This case
happens very rarely, since normally only metadata has ditto blocks.  If
the silent damage is extensive, there will be many instances of case 2,
and the pool will likely be unrecoverable.

The code for handling case 3 is considerably more complicated than the
other cases, for two reasons:

1. It needs to run after the main raidz read logic has completed.  The
data RAIDZ read needs to be preserved until after the alternate DVA has
been read, which necessitates refcounts and callbacks managed by the
non-raidz-specific zio layer.

2. It's nontrivial to map the sections of data read by RAIDZ to the
correct data.  For example, the correct data does not include the parity
information, so the parity must be recalculated based on the correct
data, and then compared to the parity that was read from the RAIDZ
children.

Due to the complexity of case 3, the rareness of hitting it, and the
minimal benefit it provides above case 2, this commit removes the code
for case 3.  These types of errors will now be handled the same as case
2, i.e. the checksum error will be reported against all children that
returned data or parity.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11735
2021-03-19 16:22:10 -07:00

2743 lines
91 KiB
C
Raw Blame History

/*
* 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);
}
/*
* 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_struct(&rc->rc_abdstruct,
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_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_struct(&rc->rc_abdstruct,
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_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_struct(&rc->rc_abdstruct,
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_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_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_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];
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;
ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops);
ASSERT3U(zio->io_offset, ==, vdev_draid_get_astart(vd, zio->io_offset));
raidz_map_t *rm = vdev_draid_map_alloc(zio);
zio->io_vsd = rm;
zio->io_vsd_ops = &vdev_raidz_vsd_ops;
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,
};
Reference in New Issue View Git Blame Copy Permalink